Proper disassembly and assembly of the Kamaz 5320 steering hydraulic pump.
1. Introduction............................................... .....................….......................…………one
2. Maintenance and repair of steering KAMAZ5320. Equipment and tools. Organization of the workplace.…...........................................…………2
3. Safety .......................................................................... ......................…………….five
4. Conclusion ............................................... .......................................…………….6
5. List of references .............................................................. ....…………....7
6. Notes ............................................................... ................................................. .........8
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Steering is used to change and maintain the selected direction of movement of the car. The main way to change the direction of movement is to turn the front guide wheels in the horizontal plane relative to the rear wheels.
On a KamAZ - 5320 car, it is used steering mechanical type with hydraulic booster. The steering mechanism with an angular gear reducer is equipped with a steering gear with working pairs such as a screw - a nut with circulating balls and a rack - a gear sector. The steering gear ratio is 20:1.
The hydraulic booster facilitates driving and increases the safety of its movement. Hydraulic booster, using engine power to steer and hold the wheels, reduces driver fatigue, improves the vehicle's agility and steerability in difficult conditions such as sudden tire failure.
Maintenance and repair of steering KAMAZ 5320. Equipment and tools. Workplace organization.
Car maintenance is divided into the following types:
Designed to monitor the state of the steering drive.
- include checking the oil level in the reservoir of the power steering pump, if necessary, add oil to the norm;
Lubricate the steering rod joints with a grease fitting until fresh grease appears in the gaps.
– check of backlashes in hinges of steering draughts and cardan shaft;
- Check and, if necessary, restore the free wheeling of the steering wheel within acceptable limits;
– remove and wash the pump filter.
- Unbend lock washer 4 (Fig. 1) and unscrew nut 5.Remove the bipod of the Kamaz-5320 steering gear with a puller.
Remove the magnetic plug from the steering box and drain the oil. Screw in the plug with a torque of 29-39 Nm (3-4 kg/cm).
Disconnect the pipelines of high 8 (see Fig. 1) and low 9 pressure from the steering mechanism and drain the oil remaining in the pipelines.
Unscrew the nut of the bolt securing the lower propeller shaft fork, knock out the bolt and disconnect the shaft from the steering mechanism by lifting the fork up.
Remove the four bolts securing the steering box to the front spring bracket and remove the steering box.
Drain the remaining oil by turning the Kamaz-5320 steering mechanism with the valve down and turning the drive gear shaft of the angular gearbox 2-3 times from one extreme position to another.
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GUR KamAZ is an integral component of the truck, but for its correct operation, periodic maintenance is required with the replacement of parts if necessary. Let's look at what a KamAZ power steering is for, what device it has, characteristics and main malfunctions, as well as the subtleties of repair and adjustment of the mechanism.
purpose
The main function of the mechanism is to reduce the effort required to turn the steering wheel while the truck is moving. That is, the node provides comfortable control and cornering. With a faulty system, even at low speeds, significant efforts have to be made, and at high speeds, especially when performing maneuvers, control may be impossible at all (up to the steering wheel jamming).
Tasks that the GUR solves
The main task of any power steering is to simplify the steering. Without it, even with minor turns of the steering wheel, significant physical effort would be required.
Another task of the KamAZ power steering is to guarantee the normal controllability of the vehicle. In other words, it is an element necessary to ensure a sufficient level of safety in the operation of the machine.
Device
The KamAZ power steering includes the following components:
- distribution mechanism. It is used to direct the flow of working media, including hydraulic oil, to the units and compartments of the power steering system.
- Hydraulic cylinder. Used as a converter hydraulic pressure into mechanical impulses necessary for the movement of pistons and rods.
- hydraulic fluid. This is the working medium that transmits the force from the pumping unit to the hydraulic cylinder. The liquid performs lubrication of the contacting elements and assemblies.
- Power steering pump KAMAZ. Maintains the pressure required for the correct operation of the system. Also, the KamAZ power steering pump circulates the working fluid.
- Elements for connecting nodes or highways. Necessary to combine all parts of the system into a single mechanism.
- filtering mechanism.
- Control device or electronic module. Used for guiding and adjusting work.
The KamAZ power steering device for different models of the Kama Automobile Plant may differ slightly.
Power steering characteristic
Structural parameters:
- Steering gear - has a hydraulic booster installed in the same crankcase as the steering gear. The device provides for the presence of a screw with a nut on the rotating shafts and a piston that is in contact with the toothed part of the bipod shaft.
- Gear ratio - 20
- Control valve - spool valve, made with safety and bypass valves.
- The pump is a rotary mechanism with blades and a gear drive, gear ratio 1.25.
- The drive of the steering wheel and hydraulic booster is a cardan shaft connected by a sliding spline, the angular gear is equipped with conical gears.
- The radiator is an aluminum structure with fins installed in front of the radiator of the cooling system.
- Steering wheel drive - has two rods (transverse and longitudinal types) with skew joints without the possibility of adjustment.
You can see the general scheme of the power steering KamAZ in the picture at the beginning of the section.
Power steering repair
Repair of power steering KamAZ should be carried out by specialists with the necessary skills. It is best to order a service in specialized car services where they service KamAZ vehicles or trucks.
Common faults
In general, repair of the hydraulic power steering on KamAZ trucks is required very often, since this is a fairly reliable system. Especially if the rules for using the node are observed and its scheduled maintenance is performed.
Usually, interruptions in the operation of the power steering occur at negative air temperatures, in winter, with temperature changes. All breakdowns of the KamAZ power steering can be divided into two categories: mechanical and hydraulic (both types of faults can occur in any part of the assembly).
The main problem is related to the pump at the KamAZ power steering: the viscosity of lubricants increases, which contributes to the extrusion of oil seals and oil leakage. Such a malfunction occurs especially often on machines that are operated incorrectly, for example, left in a parking lot with the wheels unscrewed. When starting the motor, the pressure increases only on one side, and the oil seal is squeezed out.
At positive temperatures, interruptions in the operation of the mechanism occur due to dirt and dust that are blown into the system. This leads to depressurization of individual elements, which increases the wear of bushings and rods. On the latter, rust forms quite quickly, which also contributes to the rapid abrasion of the bushings. When using a truck after 200-300 km of run, a play appears between these parts, this causes a knock on the steering rack. It is also often necessary to adjust the gearing.
Important: restoration and repair of KamAZ power steering should be carried out only by professionals, using specialized equipment.
How to remove an airlock from the system
When refueling with lubricants or after repair, it is required to remove air from the system (pump the power steering on KamAZ).
The sequence of actions is as follows:
- Hanging the front axle so that the wheels do not touch the ground. The truck is lifted with a jack and the trestles are placed under the beam on both sides.
The pumping of the power steering KamAZ cannot be started if the wheels are on the ground. Alternatively, you can disconnect the longitudinal link from the hydraulic booster.
- Removing the cap of the tank neck through which oil is poured.
- Dismantling the rubber lining from the bypass valve and fixing the elastic hose on the spherical head. The other end is located in a glass vessel with a volume of 0.5 liters, half filled with oil.
- Loosen the bypass valve halfway - three-quarters of a turn.
- Turning the steering wheel all the way to the left.
- Filling the lubricant into the pump tank to a level where it will not drop.
- Starting the engine and adding oil while rotating crankshaft at low speeds. It is necessary that the oil level does not decrease until the formation of air bubbles at the outlet of the hose located on the bypass valve stops.
- Next, you need to turn off the bypass valve.
- Turning the steering wheel to the right until it stops and back, to the left until it stops. The steering wheel is held in this position, and the bypass valve is turned off half - three-quarters of a turn. Here you also need to control the release of air bubbles. After the air has escaped, the bypass valve is closed.
- Repeat step 9 several times. It is important to ensure that, as a result, clean oil (without air impurities) comes out of the valve.
- Stopping the motor.
- Dismantling the hose and fixing the protective cap on the valve head. The level of lubricant in the pump tank is then checked. If the tie rod was disconnected, you need to reinstall it.
Better if this work will be performed by specialists who know how to pump the power steering on KamAZ correctly so that there is definitely no air left in the system.
Replacement of parts during the repair of the power steering
Starting the repair of the hydraulic booster, the power steering pump housing and other elements of the system, you need to understand that parts that have exhausted their resources cannot be restored, they can only be replaced with new ones. The production of spare parts with high precision and smooth surfaces is possible only in factories that specialize in the creation of such parts. That is why it is necessary to buy components for KamAZ from reliable companies that supply from official manufacturers.
Steering gear adjustment
It is possible to check and adjust the steering mechanism only in the position when the engine is turned off and the tie rod is disconnected.
Before starting work, you need to check the wheel balance, pressure level, the presence of oil in the steering and on the hubs, the settings of the wheel bearings and rods, the functioning of the shock absorbers, the quality of the front wheels, the oil level in the pump.
To check the force of the steering column, a dynamometer mounted on the wheel rim is used. The effort is checked at different positions of the steering wheel: when turning 2 or more turns from the initial position, when turning three-quarters of a turn, when the wheel passes the initial position.
Forces that do not correspond to the specified values in the desired positions must be adjusted. This may require the dismantling of the assembly, its partial or complete disassembly:
- First, adjustment is carried out at the third position, adjustment is carried out by means of the bipod shaft screw;
- Then the first position is debugged - it is necessary to tighten or loosen the place of attachment of the thrust bearings (partial disassembly of the mechanism is required);
- Adjustment in the second position is carried out when the hydraulic booster is completely disassembled.
VEHICLE CONTROL SYSTEMS
STEERING
On the modernized KAMAZ vehicles, enhanced steering (power steering model 4310) is installed.
The steering of the car (Fig. 270) is equipped with a hydraulic booster 7, combined in one unit with a steering mechanism, a hydraulic booster control valve 5 and an angular gearbox 6. In addition to the mentioned nodes, it includes:
Column 2 steering with steering wheel 1;
Cardan shaft 3 steering;
The pump 12 of the power steering assembly with the reservoir 13 of the hydraulic system;
Radiator 4;
Pipelines of high 11 and low 10 pressure;
Steering linkages.
Rice. 270. Steering: 1 - steering wheel; 2 - column; 3 - cardan shaft; 4 - radiator; 5 - hydraulic booster control valve; 6 - angular reducer; 7 - hydraulic booster with steering gear; 8 - longitudinal thrust; 9 - bipod; 10 - low pressure pipeline; 11 - high pressure pipeline; 12 - power steering pump; 13 - hydraulic reservoir
Power steering Reduces the amount of force required to turn the front wheels on the steering wheel, cushions shock from bumps in the road, and improves driving safety by allowing you to maintain control of your vehicle's direction of travel in the event of a front tire blowout.
On the upgraded KAMAZ vehicles, the steering arm mount has been changed, see fig. 271. Instead of coupling bolts, nuts and cotter pins, a nut with a lock washer is used for fastening.
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| combined with a hydraulic booster. Working pairs: a screw with a nut on circulating balls and a piston-rack that engages with the gear sector of the bipod shaft | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Steering gear ratio | 20 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Drive from the shaft of the steering column with the steering wheel to the steering gear | via cardan shaft and bevel gear | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Angular gear ratio | 1 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Power steering pump | lamellar, double acting, left hand rotation | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Power steering pump drive | gear, from the engine crankshaft | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Pump drive gear ratio | 1,25 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Time, min | Oil pressure, kPa (kgf / cm 2) | Pump shaft speed, min -1 |
| 1 | 147,1 (1,5) | 845 |
| 2 | 490 (5) | 845 |
| 3 | 980,7 (10) | 1270 |
| 5 | 1961,4 (20) | 1680 |
| 3 | 2942,1 (30) | 2600 |
In this case, the oil temperature should be 45 ... 50 ° C. A short-term increase in temperature at the end of running-in up to 55°C is allowed.
After the pump has run in, check:
The flow rate at a pump shaft speed of 600 min -1 and 2000 min -1 and a pressure of 5394 kPa (55 kgf / cm 2) must be at least 9 1 / min and 13 ... 17 1 / min, respectively (checking time is not more than 30 from);
The pressure in the discharge cavities of the pump at a speed of 600 min -1 and a blocked outlet should be 8334 ... 8826 kPa (85 ... 90 kgf / cm 2) (test time no more than 15 s);
- the presence of vibration, sharp noise, foam in the tank is not allowed;
- oil leakage through the joints and the cuff of the pump shaft is not allowed.
After the test, drain the oil and wash the pump filter.
The failure-free operation of the steering control is determined both by the serviceability of its constituent elements and by the correct operation of other vehicle assembly units, therefore, when determining the causes of a malfunction in the steering system, it should be borne in mind that the reasons for the deterioration of the vehicle’s driving stability (the car “holds the road” poorly) can to be:
- incorrect wheel balancing;
- Insufficient or different tire pressure;
- backlash in the hub bearings and improper tightening of the nuts securing the wheels to the hubs;
- malfunctions of shock absorbers;
- incorrect installation of the steered wheels (installation angles and convergence do not correspond to the recommended ones).
The reasons for the deterioration of the self-return of the steered wheels to the neutral position (the driver is forced to return them to the middle position all the time) can be:
- lack of lubrication and high friction in the knuckle joints;
- Insufficient tire pressure.
The reasons for the increase in effort on the steering wheel can be:
- insufficient tire pressure;
Lack of lubrication in the pivot assemblies of the steering knuckles (especially in the thrust bearings), in the wheel hubs and in the steering rod joints;
- a banner of bearings of naves of forward wheels;
- Steering column bearings.
If you find any defect in the steering system, do not rush to disassemble its mechanism. Try to first establish the possible cause of the malfunction or failure. Remember that unnecessarily dismantling the steering gear or pump can lead to leaks and more serious problems. Disassembly and assembly of the steering gear and pump must be carried out only by a qualified mechanic in conditions of complete cleanliness.
TABLE 43
POSSIBLE FAULTS OF THE STEERING SYSTEM AND WAYS TO ELIMINATE THEM
| Cause of malfunction | Elimination method |
| Unsteady movement of the vehicle on the road (regular additional operation of the steering wheel is required to maintain this direction of movement) | |
| Increased steering wheel play | Adjust steering wheel free play |
| Worn parts of the steering gear screw pair | Replace Ball Screw Kit |
| Adjust nut tightening | |
| Steering gear inner seals damaged | Replace defective seal parts |
| Insufficient or uneven operation of the hydraulic booster | |
| The presence of air in the system (foam in the tank, cloudy oil) | Remove air. If the air cannot be removed, check the tightness of all connections, remove and rinse the filter, check the integrity of the filter elements and gaskets under the manifold, as well as the pump reservoir. Make sure that the collector bearing surface is flat and that the mating flanges of the cover and the pump housing are in the correct relative position (for the installation of the pump reservoir) * . Check the tightness of the four manifold mounting bolts and, if all of the above is correct, fill in the oil and bleed the system again Adjust the steering |
| Excessive tightness in the gearing of the steering gear | Adjust the steering mechanism with the adjusting screw, bring the force on the steering wheel rim to the norm |
| The pump does not develop the required flow due to clogging of the filter or wear of the parts of the pumping unit | Wash the filter and disassemble the pump to check its parts. Replace pump if necessary |
| Increased internal oil leakage in the steering gear due to wear or damage to the internal seals | Disassemble mechanism, replace O-rings or other damaged seals |
| Bypass valve stuck intermittently due to contamination |
Disassemble the pump, clean the bypass valve and the hole in the pump cover with acetone, cleaning their working surfaces from burrs and foreign particles |
| Steering check valve leak | Repair leaking check valve |
| Steering screw thrust bearing nut loose | Adjust nut tightening |
| Steering relief valve spring misadjusted or valve leaking due to dirt or nicks | Adjust valve, repair leak |
| Complete lack of gain at various engine speeds | |
| The seat of the pump relief valve is loosened or the valve spring is broken | Dismantle pump, screw seat or replace valve spring |
| Bypass valve sticking or steering check valve malfunction | Dismantle the pump and flush the valve, repair the leakage of the non-return valve |
| Breakage of a spring of the safety valve of the steering mechanism | Replace spring and adjust valve |
| The force on the steering wheel is not the same when turning right and left | |
| Damaged inner seals of propeller and steering piston | Replace defective screw and piston seal parts |
| Steering gear sticks when turning | |
| Stuck spool or jet plungers in power steering valve body | Eliminate the jam, wash the parts |
| Wear of the parts of the connection of the adjusting screw with the shaft of the bipod or gearing of the steering mechanism | Adjust the axial clearance in the connection by selecting an adjusting washer. If the gearing or connection of the adjusting screw with the bipod shaft is worn above the permissible value, replace the steering gear |
| Knocking in the steering mechanism or in the cardan shaft of the steering column | |
| Increased backlash in the gearing of the steering gear | Adjust the gap with the adjusting screw |
| The nuts of the bolts of the steering arm connection are not tightened | Tighten nuts |
| The nuts of the wedges for fastening the propeller shaft forks are not tightened or the spline connection is worn out | Tighten nuts. Replace worn parts |
| Increased noise during pump operation | |
| Insufficient oil level in the pump reservoir | Bring the oil level in the pump reservoir to normal |
| Wash or replace the filter | |
| The presence of air in the hydraulic system (foam in the tank, cloudy oil) | Remove the air |
| Repair bent or replace gasket | |
| Ejection of oil through the safety valve of the pump reservoir cap | |
| Excessively high oil level in the pump reservoir | Bring the oil level up to normal |
| Clogged or damaged pump filter | Wash or replace the filter |
| Bent manifold or broken gasket | Repair bent or replace gasket, bleed system |
| Constant drop in oil level in the pump reservoir | |
| Oil leakage into the engine due to damage to the cuff of the pump shaft | Remove the pump from the engine and replace the cuff |
| Breakage of the front cover of the steering mechanism (in the cold season) | |
| The steering hydraulic system is filled with oil not recommended by the lubrication chart | Replace cover. Fill with oil according to the lubrication chart |
| Replacement oil has not been changed during seasonal maintenance | Replace cover. Change the oil for the season |
| There was (or got into during operation) water in the oil, and during a long stop in the cold with the engine turned off, ice plugs formed | Replace the cap, replace the existing oil in the system with an oil checked for the absence of water, bleed the air from the system. The type of oil must match the season! |
The steering of a KamAZ vehicle consists of a column with a steering wheel shaft, a cardan shaft, an angular gearbox, a power steering gear, a steering gear, a power steering pump, a radiator and high and low pressure pipelines.
Rice. 85. Scheme of the steering KAMAZ:
The steering system is a set of mechanisms whose purpose is to orient the front wheels so that the driver can effortlessly steer the vehicle. Basically, the steering system consists of a number of elements that work as follows: the driver controls the road of the car through the steering wheel, which will drive the steering rod, which is responsible for attaching it to the steering box.
Tasks that the GUR solves
It owes its name when it consists of a rigid part, but to be precise, today it is a few small pieces that can be put together in case of an accident. When the steering receives motion, it transmits it to the wheels with the help of gears.
a - schematic diagram; b - when turning right; c - when turning left;
1 - steering wheel; 2 - steering column, 3 - cardan shaft; 4 - angular reducer; 5 - steering gear housing; 6 - screw; 7 - ball nut; 8 - bipod shaft with a gear sector; 9 - piston-rail; 10 - bypass valve; 11 - spool; 12 - control valve; 13 - thrust bearing; 14 - safety valve; 15 - oil cooler; 16 - low pressure oil pipeline; 17 - high pressure oil line; 18 - hydraulic booster pump.
How does the pump work?
The box can be, as we shall see later, of various types, such as struts or recirculating balls, although if it is a rudder of this type, at the end we will find a connecting rod that will attach the box to the central rod. In other assumptions, the rod is directly attached to the steering box to send movement to the steering terminals: a series of articulated joints that are attached to the steering wheels and which absorb the firm's bumps, thanks to which we spread.
Steering system characteristics
The steering system of the vehicle is included in the vehicle safety element group due to the importance of its operation, so it must always meet the following requirements. Safety: This will depend both on the quality of the materials, on the reliability of the mechanism, and on its good use. Saavidad: A lot depends on the pleasantness of driving, as a very hard steering system is uncomfortable and tiring. Accuracy: Due to malfunction between different controls, uneven tire wear and wear, and deformed axle or chassis, we may lose track accuracy. The ideal is to prevent excess hardness, as we mentioned in the previous point, but not too soft, which does not allow us to feel the direction. Irreversible: When the rudder or steering wheel is giving the system rotation, incident vibrations or uneven terrain must not be transmitted back to the steering wheel so that they do not affect the change in trajectory.
Classes of control systems
To avoid this, it must be well lubricated and neatly assembled. . Now that we know about the mechanisms that do this and the characteristics that it must have, we will discover the types of steering systems that we can find in a vehicle.Power steering reduces the amount of force required to turn the front wheels, softens the impact of bumps in the road, and improves driving safety by helping you maintain your vehicle's direction in the event of a front tire blowout.
Steering column KAMAZ
Steering KAMAZ
Ball recycling system: We usually find it in heavy vehicles, buses and trucks. It gets this name because it is made up of spheres responsible for facilitating movement by softening it. It has a storage tank that dispenses a special oil that is activated by a pump. Electro-hydraulic steering system: In this case, the difference with the hydraulic system is that the force that moves the pump comes from the independent electric motor of the vehicle's own engine, thus it does not reduce engine power, so it is ideal for cars with low operating volume. It also allows the hardness of the steering system to be electronically adjusted. To learn more about this system or other components in your vehicle, continue browsing the mechanics section.
The steering column at the top is attached to a bracket fixed to the cab interior panel; at the bottom - to the flange installed on the cabin floor.
Shaft 1 of the steering column rotates in two special ball bearings 2. Spontaneous unscrewing of the nut prevents the eye of the lock washer bent into the groove of the nut.
We decided to participate in this edition of the event for two main reasons. And, secondly, we are going to bring our latest offer closer to potential customers, including deeply modernized vehicles, specially prepared for the needs of the Western European market. Equipped with modern and environmentally friendly sources of movement.
About the most characteristic breakdowns that are inherent in GUR
In addition, we have a wide range of varieties that can be found in the domestic building sector. These are both chassis and tractors, with short cabs - day or long and one, two or three drive axles, including all with single tires. Both of these vehicles are the latest generation of products from the Russian manufacturer, derived from their own family truck, which has made over 300 significant modifications. Assembly of a power package with key components from well-known Western suppliers and the introduction of components from such suppliers.
Rice. 86. Steering column:
1 - column shaft; 2 - ball bearing with seal; 3 - thrust ring; 4 - expanding ring; 5 - column pipe; 6 - clip with seal; 7 - lock washer; 8 - bearing adjustment nut.
Power steering pump KAMAZ
The KamAZ power steering pump with a reservoir is installed in the collapse of the cylinder block. The pump drive is gear, from the block of distribution gears. Gear 1 is fixed on pump shaft 5 with key 6 and nut 2 with cotter pin 3.
In the braking system, the completed examples feature significantly improved performance, including reduced fuel consumption, reduced inspection requirements, and improved ride comfort. Moreover, the origin of these cars is important. This two-stage production process allows you to combine high quality products with an attractive price.
Both cab types are upgraded, plastic front fascia, panoramic windshield, external sun visor and standard parking heater, radio, adjustable steering column, sunroof and the comfort of a pneumatically suspended driver's seat. They also have a more ergonomic design, more in line with modern European standards in this area.
Vane-type pump, double-acting, i.e. for one revolution of the shaft, two complete suction and two discharge cycles are performed. In the rotor 38 of the pump there are grooves in which the blades 33 move. The rotor is mounted inside the stator on the shaft 5 of the pump on splines; the landing of the rotor on the splines is free.
The position of the stator 35 relative to the pump housing 37 is fixed, i.e. the direction of the arrow on the stator coincides with the direction of rotation of the pump shaft.
These trucks are also characterized by the typical design of this category of vehicles. It has a steel chest with a steel floor and steel side sills opening in the lower and upper axles with power. In addition, the hydrogen system does not need to be filled with hydrogen, since it itself produces hydrogen from water and therefore does not need to be stored. As a result, it takes up little space and does not require a pressurized container.
The differences also extend to the allowable total masses of the set. The new designed cabin - the so-called. A stateroom with new decorations, characterized by rounded shapes and equipped with an adjustable seat. As a standard, the warranty period for the entire vehicle is 12 months with no limit to the number of kilometers driven. On the territory of Poland, more than 20 operating authorized service points, reviews, warranty and post-warranty repairs are responsible for its safety. In the case of engines, a mobile service has been launched in cooperation with the engine manufacturer, which, in the event of a failure, performs an inspection or repair directly at the customer or at another location specified by the customer, without visiting the service center.
When the pump shaft rotates, the blades are pressed against the curved surface of the stator under the action of centrifugal force and oil pressure flowing through the channels in the distribution disk 32 under the pump blades. Between the blades, cavities of variable volume are formed, which are filled with oil coming from the suction cavities of the distribution disk. In the suction cavity, oil enters from the cavity of the pump housing 37 through the channels in the stator 35. With a decrease in the interblade volume, the oil is displaced into the discharge cavity through the channels in the distribution disk 32.
Signs of typical element malfunctions
We now offer a wide range of vehicles that can be found in the construction sector. The extremely low total cost of living is also important as more and more customers pay attention. These low total cost of living are the result of both competitive pricing and more extreme competitive operating costs. We also offer chassis without built-in and finished vehicles, including built-in, including built-in chassis. In this regard, we can offer many varieties that are delivered to the customer in full - together with the buildings, or we can transfer the car itself to the subsequent development, carried out without our participation or with our support.
The end surfaces of the body and the distribution disc are carefully polished. The presence of nicks, burrs, etc. on them, as well as on the rotor, stator and blades, is unacceptable.
The pump has a tank 22 for oil, closed with a lid 20, which is fixed with a bolt 16. A washer 15 and a rubber ring 17 are installed under it, which, together with the rubber gasket 21, seals the internal cavity of the tank. A safety valve 19 is screwed into the lid of the tank, which limits the pressure inside the tank. All oil returning from the hydraulic booster to the pump passes through a strainer 23 located inside the tank.
The customer decides everything, and we maintain the necessary flexibility. If we need to provide the chassis, if the chassis is required with the specified chassis, national or imported. The choice is made by the client - ends the director Wojciech Traczuk. The user wins on several levels. First, it takes a ready-to-use ready-to-use product. Secondly, it is extremely important that both the carrier and the chassis are ideally matched to the masses, pressures and dimensions. Nothing here matches or changes. As a result, the equipment we sell on a prefabricated chassis fulfills all administrative requirements in terms of weight, dimensions and pressure.
The pump has a combination valve located in the cover 30 of the pump. This valve consists of two valves - safety and bypass. The first, placed inside the second, limits the oil pressure in the system (75-80 kgf / cm2), and the second - the amount of incoming oil supplied by the pump to the hydraulic booster with an increase in the engine crankshaft speed.
Thanks to this, without problems and special permits, you can move on public roads. This eliminates many potential bumps and bugs that could lead to unplanned downtime. And finally, thirdly, such integrated transport solutions are available at extremely attractive prices, lower than if the chassis and specialized equipment are ordered separately. It is a classic high performance chassis and very high tactical mobility.
Thus, it is characterized by super-average field prowess, so that it can work without difficulty in difficult road conditions. The drive axles are equipped with differentials supplemented with locks. In addition, the chassis frame features a traditional ladder system with chassis members and lintels. The fully mechanical front and rear suspension is based on leaf springs and front also on shock absorbers.
Rice. 91. KamAZ power steering pump:
1 - drive gear; 2 - gear nut; 3 - cotter pin; 4, 15 and 27 - washers; 5 - pump shaft; 6 - segment key; 7 - thrust ring; 8 - ball bearings; 9 - oil ring; 10 - thrust ring; 11 - stuffing box; 12 - needle bearing; 13 - filler cap; 14 - inlet filter; 16 - bolt; 17, 34 and 36 - o-rings; 18 - filter rack; 19 - safety valve; 20 - tank cover with a spring; 21 - cover gasket; 22 - pump tank 23 - segment filter; 24 - pump manifold; 25 - tank tube; 26 - fitting; 28 - manifold gasket; 29 - sealing gasket; 30 - pump cover; 31 - bypass valve assembly with safety valve; 32 - distribution disk; 33 - pump blade; 35 - pump stator; 37 - pump housing; 38 - pump rotor; 39 - ball; K - calibrated hole.
The cab, due to relatively low average daily mileage, is short. It was upgraded to a frontal plastic boat, a panoramic windshield, an external sun visor and standard air conditioning, an independent parking heater, a radio, an adjustable steering column, a sunroof and a pneumatically suspended driver's seat. It is also a more ergonomic design and a more carefully designed interior, more in line with modern European standards in this area.
There are three sections that make it easy to customize the output to suit your current needs. The device is controlled manually from the operator's desktop using two joysticks. The operator has developed a new cab. It has rounded shapes and is equipped with a corner protection tube, along with a handrail and an adjustable chair. It is important to note that the crane can be tilted upside down during operation to provide better control over loading operations, thus increasing the comfort and safety of the tasks being performed.
The bypass valve works as follows.
With an increase in the oil supply to the hydraulic booster system (as a result of an increase in the engine crankshaft speed), the pressure difference in the pump discharge cavity and the hydraulic booster discharge line increases due to the resistance of hole K, and consequently, the pressure difference at the ends of the bypass valve also increases. At a certain pressure difference, the force tending to move the valve increases so much that the spring is compressed, and the valve, moving to the right, communicates the discharge cavity with the tank. Thus, a further increase in the flow of oil into the system almost stops.
In some cases, they are even better than similar designs offered by reputable competitors. It's related, by the way. with modern building technology. Its shapes are optimized for functionality, durability and weight reduction while still maintaining sufficient strength and ability to perform specific tasks. Among others, the production of the sleeve is based on the latest technologies and materials - high-strength steel, which results in a low weight. Vehicle in transport position - length 950 mm, width 500 mm and height 910 mm - compact, compact.
To prevent noise during operation and reduce wear of pump parts at high engine speeds, the oil that is bypassed by valve 31 is forcibly directed back into the cavity of the pump housing and the suction channels. For this purpose, the collector 24 serves, in which the internal channel, which communicates with the cavity of the bypass valve, has a small flow area, which further expands. This leads to a sharp increase in the flow rate of oil bypassed into the suction cavity of the housing, and creates some increase in suction pressure.
The radiator designed to cool the oil in the power steering system is an aluminum finned tube installed in front of the oil cooler of the engine lubrication system.
Oil from the steering gear to the radiator and from the radiator to the pump is supplied through rubber hoses.
Steering gear KAMAZ
The KamAZ steering mechanism has two working pairs: a screw 37 with a nut 38 on circulating balls 40 and a piston-rack 34 meshing with the toothed sector 63 of the bipod shaft. The steering gear ratio is 20:1. The steering mechanism is attached to the left bracket of the front spring and is connected to the shaft of the steering column by a propeller shaft having two hinges.
The crankcase 33 of the steering mechanism is also a hydraulic booster cylinder in which the piston-rack 34 moves.
The teeth of the rack and sector of the bipod shaft have a thickness variable along the length, which makes it possible to adjust the gap in engagement by means of axial movement of the bipod shaft, the shaft itself rotates in a bronze bushing 64 pressed into the crankcase. The axial position of the bipod shaft is set by adjusting screw 55, the head of which enters the hole in the bipod shaft and rests on washer 62. The axial movement of the adjusting screw after assembly should be within 0.02-0.08 mm, it is limited by adjusting washer 61 and retaining ring 60 .
Rice. 89. Steering gear KAMAZ:
1 - front cover; 2 - jet plunger; 3 - control valve; 4 - spring of reactive plungers; 5, 7, 21, 24, 26, 31, 41, 48, 52, 58 and 59 - o-rings; 6 - shims; 8, 15, 22, 45, 60 and 66 - thrust rings; 9, 17, 62 and 68 - thrust washers; 10 and 20 - ball bearings; 11, 43, 54 and 56 - nuts; 12 - shaft with drive gear; 13 - needle bearing; 14, 65 to 67 - oil seals; 16 - protective cover; 18 - housing of the drive gear; 19 - driven gear; 23 and 64 - bushings; 25 and 27 - spacer rings; 28 - set screw; 29 - bypass valve; 30 - cap; 32 - back cover; 33 - steering gear housing; 34 - piston-rail; 35 - magnetic plug; 36 - plug gasket; 37 - screw; 38 - ball nut; 39 - gutter; 40 - balls; 42 - thrust cover; 44 - lock washer; 46 - gearbox housing; 47 - thrust bearing; 49 - safety valve; 50 - spring; 51 - spool; 53 - spring washer; 55 - adjusting screw; 57 - side cover; 61 - adjusting washer; 63 - toothed sector of the bipod shaft.
A ball nut 38 is inserted into the piston rail, which is fixed with set screws 28, which are punched after assembly. Two stamped grooves 39 are inserted into the groove of the ball nut, connected by two holes to its helical groove. end of the nut, return along the grooves to its other end.
The screw 37 of the steering gear has splines in the middle part, on which the driven gear 19 of the angular gearbox sits freely, rotating in two ball bearings.
To the housing 46 of the angular gearbox is attached to the studs the housing of the control valve 3. The valve spool 51 and thrust roller bearings 47 are fixed on the steering gear screw with a nut 54, the thinned edge of which is pressed into the groove of the screw. A conical spring washer 53 is placed under the nut, which ensures uniform compression of the thrust bearings. The concave side of the washer is directed towards the bearing. The large roller bearing rings face the spool.
Spool 51 and screw 37 can move in the axial direction by 1.1 mm in each direction from the middle position, since the length of the spool is greater than the length of the hole for it in the valve body. They return to the middle position under the action of springs 4 and reactive plungers 2, which are pressed by oil coming from the high pressure line.
High and low pressure (drain) hoses are connected to the control valve body from the hydraulic booster pump. According to the first, the oil leaves the pump, and according to the second, it returns.
When the screw 37 rotates in one direction or another, due to the resistance that occurs when the wheels turn, a force is created that tends to move the screw in the axial direction in the corresponding direction. If this force exceeds the precompression force of the springs 4, then the screw moves and displaces the spool 51. At the same time, the pressure increases in one of the cavities of the control valve and the hydraulic booster.
The oil coming from the pump into the cylinder puts pressure on the piston rack, creating additional force on the steering bipod sector, and thereby helping to turn the wheels.
The pressure in the working cavity of the cylinder increases with increasing resistance to turning the track. At the same time, the pressure under the reactive plungers 2 increases. The screw and spool, under the action of springs 4 and reactive plungers 2, tend to return to the middle position.
The greater the resistance to turning the wheels and the higher the pressure in the working cavity of the cylinder, the greater the force with which the spool seeks to return to the middle position, as well as the force on the steering wheel. If the force on the steering wheel increases with increasing resistance to turning the wheels, the driver gets a "sense of the road".
When the steering wheel stops turning, and hence the piston movement, the oil entering the cylinder acts on the piston rail with the screw and shifts the spool to the middle position, which lowers the pressure in the cylinder to the value necessary to keep the wheels in the turned position.
In the control valve body there is a ball check valve 6, which connects the high pressure and drain lines when the pump is not running. In this case, the steering mechanism works like a normal steering mechanism without hydraulic booster. In addition, the valve body has a safety ball valve 8, which connects the high and low pressure lines at a pressure of 65-70 kgf / cm2 and thereby protects the pump from overheating during hydraulic booster operation at this pressure.
The cavities of the control valve and the angular gearbox are connected to the drain and sealed at the ends with rubber rings 48 and 41 of circular cross section. All fixed connections of the hydraulic booster are sealed with similar rings.
The bipod shaft is sealed with an oil seal 65 with a thrust ring 66, which prevents the cuff from turning out at high pressure. The outer seal 67 protects the bipod shaft from dust and dirt.
The piston in the cylinder is sealed with a fluoroplastic ring 26 in combination with a spacer ring 27. The screw 37 of the steering gear is sealed in the bevel gear housing with a spacer 25 and rubber 24 rings. The adjusting screw 55 of the bipod shaft is sealed with a rubber O-ring 59.
The seal of the drive shaft 12 with the gear of the bevel gear is combined, it consists of two seals 14, which are fixed from axial movement by a split thrust ring 15.
In the crankcase of the steering mechanism there is a plug 35 with a magnet that traps steel and cast iron particles from the oil.
Angle gearbox KAMAZ
The KAMAZ angular gearbox transmits rotation from the cardan shaft to the steering gear screw. The gearbox consists of a driving 7 and a driven 11 bevel gears, and the drive gear is made as one piece with the shaft 1 and is installed in the housing 4 on the needle 3 and ball 5 bearings. The ball bearing is fixed on the shaft 1 with a nut 16, its thinned edge (to prevent spontaneous unscrewing) is pressed into the groove. The driven gear rotates in two ball bearings 10, fixed on the shank of the gear with a nut 14 with a lock washer 15. In the axial position, the driven gear 11 is fixed with a retaining ring 9 and a thrust cover 12.
The engagement of the bevel gears is regulated by gaskets 6 installed between the drive gear housing 4 and the gearbox housing 13.
Rice. 88. Angle gearbox KAMAZ:
1 - shaft of the leading bevel gear; 2 - stuffing box; 3 - needle bearing; 4 - housing of the drive gear; 5 and 10 - ball bearings; 6 - shims; 7 - leading bevel gear; 8 - sealing ring; 9 - retaining ring; 11 - driven bevel gear; 12 - persistent cover; 13 - gearbox housing; 14 - bearing fastening nut; 15 - lock washer; 16 - bearing fastening nut.
TO category:
Cars Kamaz Ural
The device and operation of the steering of cars KAMAZ-5320, KAMAZ-4310
The steering system consists of a steering wheel, a steering column, a driveline, an angular gearbox, a steering gear, a hydraulic booster (including a control valve, a radiator, a pump with a reservoir and a steering gear.
Rice. 6.2. steering column
1 - shaft; 2 - retaining ring; 3 - bearing; 4-pipe; 5 - bracket; 6-sleeve; 7 - lock washer; 8 - nut
The steering column (Fig. 6.2) consists of a shaft 1, a pipe 4 and is attached to top panel cabin with a bracket, in the lower part. - to a pipe fixed to its floor.
The shaft is mounted in a pipe on two ball bearings. The upper bearing is locked with a thrust and expansion rings, the lower one with a lock washer and nut. The axial clearance in the bearings is also regulated by a nut. The bearings are sealed. The bearings are greased during assembly.
A steering wheel is attached to the upper end of the shaft. The lower end of the shaft is provided with a groove for attaching the cardan fork.
The cardan transmission transmits forces from the steering column shaft to the drive gear of the angular gearbox and consists of a shaft (Fig. 6.3), a bushing and two cardan joints.
Each joint consists of forks and a cross with four needle bearings installed in the glasses. The bearings are equipped with sealing rings; during assembly, 1-1.2 g of lubricant is put into each of them. Before assembling the driveline, 2.8 ... 3.3 g of lubricant is also put into the sleeve and the splines of the rod and sleeve are covered with it.
When assembling the driveline, the splines of the shaft and bushings are connected so that the forks of the hinges are in the same plane. This ensures uniform rotation of the shafts.
The hinge fork, connected to the sleeve, is mounted on the steering column shaft; the shaft yoke is connected to the drive gear shaft of the angular gearbox. The forks are fixed with wedge screws entering the holes, locked with nuts and cotter pins.
Rice. 6.3. Cardan gear:
1, 9 - forks; 2 - needle bearing; 3 - glass; 4 - cross; 6 - shaft; 7 - seal; 8 sleeve; 10 fixing hole
Rice. 6.4. Steering gear:
a - steering gear assembly with an angular gearbox: 1 - cover; 2 - reactive plunger; 3 - control valve body; 4 - spring; 5-adjusting gasket; 6 - bearing; 7- drive shaft with gear; 8- needle bearing; 9 - sealing device; 10 - body; 11 - driven gear; 12 - bearing; 13 - retaining ring; 14- cover; 15 - thrust ring; 16 - ring; 17 - screw; 18 - bypass valve; 19 - cap; 20 - cover; 21 - crankcase; 22 - piston-rail; 23 - cork; 24 - screw; 25 - nut; 26 - gutter; 27 - ball; 28 - sector; 29 - nut; 30 - locking pin; 31 - ring; 32 - body; 33 - thrust bearing; 34 - plunger; 35 - spring; 36 - spool; 37 - washer; 38 - nut; 39 - adjusting screw; 40 - nut; 41 - baby; 42 - seal; 43 - ring; 44 - adjusting washer; 45 - thrust ring; 46 - bipod shaft
b - angular gearbox: 1 - drive shaft with gear; 2 - sealing device; 3 - housing cover; 4 - housing of the drive gear; 5,7, 10 - ball bearings; 6 - adjusting gasket; 8, 15 - sealing rings; 9 - retaining ring; I - driven gear; 12 - persistent cover; 13 - gearbox housing; 14 - spacer sleeve
The gear reducer transmits the force from the driveline to the steering gear screw. It is attached to its crankcase with studs. The gear ratio of the gearbox is 1:1.
The shaft (Fig. 6.4) with the drive gear is mounted in a housing on ball and needle bearings. On the shaft, the ball bearing is fixed with a nut, the thin edge of which is pressed into the groove of the shaft. The needle bearing is fixed with a circlip. In the angular gearbox of the steering mechanism of the KamAZ-4310 car, the drive shaft with the gear is mounted on two ball bearings in the housing. The bearings are held on the shaft by a nut. In connection with these design changes, the shape of the body and the cover of the body have been changed accordingly. The driven gear is mounted in the gearbox housing on two ball bearings secured with a nut with a lock washer. Axial forces are absorbed by the cover and thrust ring. The driven gear is connected to the screw with slots, which makes it possible to move relative to the gear. In this case, the hydraulic booster spool mounted on the shaft can move relative to the housing. Gear engagement is controlled by changing the thickness of the spacers.
The steering mechanism is arranged together with an angular gear, a control valve and a hydraulic booster cylinder. Attaches with bolts to the left spring bracket.
In the crankcase of the steering mechanism (Fig. 6.4) there are: a screw with a nut, an amplifier piston with a gear rack and a gear sector with a bipod shaft. The steering gear housing is also a hydraulic booster cylinder.
The nut is connected to the piston with set screws. The screws are screwed after assembly.
To reduce friction forces in the steering mechanism, the screw rotates in the nut on balls placed in the grooves of the screw and nut. Two grooves of circular cross section are installed in the hole and groove of the nut, forming a tube. When the screw is turned in the nut, the balls, rolling along the helical groove, fall into the tube, consisting of grooves, and again into the helical groove, i.e., continuous circulation of the balls is ensured.
The toothed sector with the bipod shaft is mounted on a bronze bushing in the crankcase of the steering mechanism and in the hole of the side cover attached to the crankcase. To adjust the gap in the engagement of the rail with the sector, their teeth have a variable thickness along the length.
Adjustment of engagement and fixation of the toothed sector with the bipod shaft in the axial direction is provided by a screw screwed into the side cover. The head of the adjusting screw enters the hole in the bipod shaft and rests against the thrust ring. The axial movement of the bipod shaft relative to the screw head should not exceed 0.02 ... 0.08 mm. It is regulated by the selection of the thickness of the shim. The screw after adjusting the gap of the gearing is locked with a nut. A bypass valve is screwed into the crankcase, which ensures the release of air from the hydraulic booster. The valve is closed with a rubber cap. A bipod is installed on the splines of the shaft and locked with bolts. A drain plug is screwed into the bottom of the crankcase (see Fig. 6.4)
The hydraulic booster consists of a spool-type control valve (switchgear), a hydraulic crankcase, a pump with a reservoir, a radiator, pipelines and hoses.
The control valve housing (Fig. 6.4) is studded to the bevel gear housing. The control valve spool is mounted at the front end of the steering mechanism on thrust bearings. The inner rings of large diameter bearings are pressed with a nut to the reactive plungers located in three holes in the housing together with the centering springs. Thrust bearings with a spool are fixed on the screw with a shoulder and a nut. The conical washer is installed under the nut with the concave side facing the bearing. Grooves are made in the valve body on both sides. Therefore, thrust bearings, a spool with a screw can move in both directions from the middle position by 1.1 mm (spool stroke), while shifting the plungers and compressing the springs.
Bypass and safety valves and plungers with springs are also installed in the openings of the control valve body (Fig. 6.5). The safety valve connects the high and low oil pressure lines at a pressure of 6500…7000 kPa (65…70 kgf/cm2). The bypass valve connects the cavities of the cylinder when the pump is not working, reducing the resistance of the amplifier when the wheels are turned.
The hydraulic booster cylinder is located in the steering gear housing. The piston of the cylinder is equipped with a sealing ring and oil grooves.
The hydraulic booster pump is installed between the engine blocks. The pump shaft is driven by the high pressure fuel pump gear.
Vane-type pump, double-acting, i.e. for one revolution of the shaft, two suction and discharge cycles occur. The pump (Fig. 6.6) consists of a cover, a housing, a rotor with a shaft, a stator and a distribution disk. The shaft, on the splines of which the rotor is installed, rotates on ball 4 and needle bearings. The drive gear is locked on the shaft with a key and fastened with a nut. Blades are installed in the radial grooves of the rotor.
The stator is mounted in the housing on pins and pressed against the distribution disk by bolts.
The rotor with blades is installed inside the stator, the working surface of which has an oval shape. When the rotor rotates, its blades are pressed against the working surfaces under the action of centrifugal forces and oil pressure in the central cavity of the rotor.
Rice. 6.5. Hydraulic booster control valve:
1, 10 - plungers; 2, 4.7, 8 - springs; 3, 6, 12 - valves; 5 - cap; 9 - body; 11- spool; 13 - gasket
stator, distribution disk and housing, forming chambers of variable volume.
With an increase in their volume, a vacuum is created and the oil from the tank enters the chambers. In the future, the blades, sliding along the surface of the stator, are displaced along the grooves to the center of the rotor, the volume of the chambers decreases and the oil pressure in them increases. When the chambers coincide with the holes in the distribution disk, the oil enters the pump discharge cavity. The working surfaces of the housing, rotor, stator and distribution disc are carefully ground, which reduces oil leakage.
A bypass valve with a spring is installed in the housing cover. Inside the bypass valve there is a safety ball valve with a spring, which limits the pressure in the pump to 7500…8000 kPa (75…80 kgf/cm2).
The pump safety valve is adjusted to an opening pressure of 500 kPa (5 kgf/cm2) higher than the opening pressure of the safety valve (Fig. 6.5) located in the steering gear.
Rice. 6.6. Hydraulic booster pump:
1 - gear; 2 - shaft; 3 - key; 4 - bearing; 5 - ring; b - seal; 7- needle bearing; 8 - cover; 9- oil level indicator; 10 - bolt; 11 - gasket; 12- filter rack; 13 - safety valve; 14 - cover; 15 - gasket; 16 - tank; 17 - mesh filter; 18 - collector; 19 - tube; 20 - gasket; 21 - cover; 22 - safety valve; 23 - bypass valve; 24 - distribution disk; 25 - blade; 26 - stator; 27 - body; 28-rotor
With regard to the hydraulic system of the power steering of the KamAZ-4310 vehicle, the opening pressure of the safety valve in the control valve body is set to 7500 ... 8000 kPa (75 ... 80 kgf / cm2), and the opening pressure of the safety valve in the pump is 8500 ... 9000 kPa (85 ... cm2).
The bypass valve and a calibrated hole connecting the pump discharge cavity with the outlet line limit the amount of oil circulating in the amplifier when the pump rotor speed increases.
A collector is attached to the pump housing (see Fig. 6.6) through a gasket, which ensures the creation of excess pressure in the suction channel, which improves the operating conditions of the pump, reducing noise and wear of its parts.
Rice. 6.7. Steering drive:
1 - cover: 2 - gasket; 3, 16 - springs; 4, 6, 14, 15 - liners; 5, 13 - fingers; 7 - oiler; 8 - thrust tip; 9, 12, 20 - sealing pads; 10 - transverse thrust; 11 - longitudinal thrust; 17 - gasket; 18 - screw cap; 19- washer
The tank with filler cap and filter is screwed to the pump housing. The tank cover is bolted to the filter stand. The joints of the cover with the bolt and the body are sealed with gaskets. A safety valve is installed in the lid, limiting the pressure inside the tank. The oil circulating in the booster's hydraulic system is cleaned in a strainer. An oil level indicator is fixed in the filler cap.
The radiator is designed to cool the oil circulating in the hydraulic booster. The radiator in the form of a double-bent finned tube made of aluminum alloy is attached in front of the radiator of the engine lubrication system with strips and screws.
The hydraulic booster units are interconnected by high and low pressure hoses and pipelines. High pressure hoses have a double inner braid; the ends of the hoses close up in tips.
The steering drive consists of a bipod, longitudinal and transverse steering rods and levers.
The levers of the rotary knuckles are pivotally connected to the transverse link, forming a steering trapezoid that ensures the rotation of the steered wheels at the appropriate angles. The levers are inserted into the conical holes of the knuckles and are fastened with dowels and nuts.
Tips are screwed onto the threaded ends of the transverse rod (Fig. 6.7), which are the heads of the hinges. The rotation of the tips regulates the toe-in of the wheels in front, compensating for their possible discrepancy in operation due to wear of parts, which increases tire wear and makes driving harder. The tie rod ends are fixed with bolts. The thrust joint consists of a pin with a spherical head, liners pressed against the head by a spring, fastening and sealing parts. The spring provides a backlash-free connection and compensates for wear on the surfaces of the parts.
The longitudinal rod is forged together with the hinge heads. The hinges are closed with screw caps and sealing plates. The hinges are lubricated through grease fittings. Rotary axles-pins of the wheels are installed with lateral inclinations in the transverse plane by 8°. Therefore, when turning the wheels, the front of the car rises slightly, which creates stabilization of the steered wheels (the desire of the steered wheels to return to the middle position after the turn).
The inclination of the pivots in the longitudinal plane back by 3° creates the stabilization of the steered wheels due to the centrifugal forces that arise when turning.
When the steering wheel is released after a turn, the normal load on the steered wheels and centrifugal forces creates stabilizing moments that automatically return the steered wheels to the center position. This makes driving much easier. The axes of rotation of the wheels are inclined with their outer ends down by 1°, forming a camber, which makes it difficult for the reverse camber of the wheels to appear in operation due to wear of the bearings. Reverse camber driving increases tire wear and makes driving harder.
In the steering drive of the KamAZ-4310 vehicle, the transverse steering rod has a U-shape due to the presence of the main gear housing of the front drive axle.
Steering operation. During rectilinear movement, the spool (Fig. 6.8) of the control valve is held by springs in the middle position. The oil supplied by the pump passes through the annular slots of the control valve, fills the cavities of the cylinder and drains through the radiator into the tank. With an increase in the rotor speed, the intensity of circulation and oil heating in the hydraulic booster increase. The bypass valve restricts oil circulation. With an increase in oil consumption, a pressure drop is created on the end surfaces of the valve due to an increase in the resistance of the calibrated hole. When the force from the pressure difference on the valve exceeds the force of the spring, it will move and connect the discharge cavity of the pump with the tank. In this case, most of the oil will circulate along the pump-tank-pump circuit.
When the steering wheel is turned, the force through the cardan gear, the angular gearbox is transmitted to the steering gear screw.
If significant efforts are required to turn the wheels, then the screw, screwing into the nut (or unscrewing from it), will displace the thrust bearing and spool, while shifting the plunger and compressing the centering springs. The displacement of the spool in the housing changes the cross section of the annular slots associated with the cylinder cavities. A decrease in the cross section of the drain slot with a simultaneous increase in the amount of oil due to an increase in the cross section of the discharge slot leads to an increase in pressure in one of the cylinder cavities. In the other cavity of the cylinder, where the change in the cross sections of the slots is opposite, the oil pressure does not increase. If the difference in oil pressure on the piston creates a force, a greater resistance force, then it begins to move. The movement of the piston through the gear rack causes the rotation of the sector and further, through the steering gear, the rotation of the steered wheels.
The continuous rotation of the steering wheel maintains the displacement of the spool in the housing, the difference in oil pressure in the cylinder cavities, the movement of the piston and the rotation of the steered wheels.
Stopping the steering wheel will stop the piston and the steered wheels at the moment when the piston, continuing to move under the action of the oil pressure difference, displaces the screw with the spool in the axial direction to the middle position. Changing the cross sections of the slots in the control valve will lead to a decrease in pressure in the working cavity of the cylinder, the piston and steered wheels will stop. This ensures the "tracking" action of the amplifier on the angle of rotation of the steering wheel.
The discharge line of the pump supplies oil between the plungers. The greater the force of resistance to the rotation of the wheels, the higher the oil pressure in the line and at the ends of the plungers, and, consequently, the force of resistance to their movement when the spool is displaced. This is how a “following” action is created by the force of resistance to turning the wheels, i.e., the “feeling” of the road.
At the oil pressure limit of 7500…8000 kPa (75…80 kgf/cm2), the valves open, protecting the booster hydraulic system from damage.
To quickly exit the turn, release the steering wheel. By the combined action of the reactive plungers and springs, the spool is displaced and held in the middle position. The steered wheels, under the action of stabilizing moments, turn to the middle position, displace the piston and push the liquid into the drain line. As you approach the middle position, the stabilizing moments decrease and the wheels stop.
Spontaneous turning of the wheels under the influence of impacts on uneven roads is possible only when the piston moves, i.e., pushing a portion of oil from the cylinder into the tank. Thus, the amplifier works as a shock absorber, reducing shock loads and reducing spontaneous steering wheel turns.
In the event of a sudden stop of the engine, pump or loss of oil, the ability to control the efforts of the driver remains. The driver, turning the steering wheel, shifts the plungers with the spool until it stops in the control valve body, and then the rotation is provided only by the mechanical connection of the steering parts. The effort on the steering wheel thus increases. To reduce the resistance force when the piston moves, the bypass valve located in the plunger ensures the flow of oil from the cylinder cavities.
TO Category: - Cars Kamaz Ural