Steering KAMAZ. KAMAZ steering gear bipod: an important part of truck control

Steering of KamAZ vehicles divided, with hydraulic booster and one-piece steering linkage. Steering consists of steering wheel 1 ( rice. 124), steering column 2, driveline 6, bevel gear 9, steering mechanism 10, shaft 13, bipod 12, longitudinal tie rod 11 and steering trapezoid. The hydraulic booster consists of a distributor 8, a hydraulic cylinder located in the crankcase of the steering mechanism 10, a pump 1 with a reservoir 15, a radiator 7, pipelines and hoses.

The steering column, consisting of a pipe with placed in it on two ball bearings steering shaft, attached in the upper part of the cabin panel using bracket 3, and in the lower part - to the cabin floor using flange 4. The axial clearance in the bearings is adjusted with nut 5.

Cardan gear 6, which includes a shaft, a bushing and two cardan joints, transmits rotation from the steering shaft to the shaft of the bevel gear of the angular gearbox 9.

Rice. 124. Steering of KamAZ vehicles: 1 - steering wheel; 2 - steering column; 3 - bracket; 4 - flange; 5 - adjusting nut; in - cardan transmission; 7 - radiator; 8-distributor; nine- angle gearbox; 10 - steering mechanism; 11 - longitudinal Tie Rod; 12 - bipod; 13 - bipod shaft; 14 - pump; 15 - tank.

A bevel single-stage angular gearbox is used to transfer rotation from the cardan gear to the steering gear screw with a gear ratio equal to one. Assembled gearbox in housing 33 ( rice. 125), which is studded to the crankcase 23 of the steering mechanism. Leading conical gear made as one piece with the shaft 7 and installed in a removable housing 10 on ball 6 and needle 8 bearings. The ball bearing is secured with a nut, the needle bearing with a circlip.

Rice. 125. The steering mechanism of the KamAZ-5320 car: 1, 14, 22 and 42 - covers; 2 - jet plunger; 3 - control valve body; 4 and 36 - springs; 5 - shims; 6 and 12 - ball bearings; 7 - drive shaft with gear; 8 - needle bearing; 9 - sealing device; 10 - body; 11 - driven gear; 13, 32 and 44 - retaining rings; 15 - thrust ring; relative ring; 17 and 26 - screws; 18 - sector; 19 - bipod shaft; 20 bypass valve; 21 - cap; 23 - crankcase; 24 - piston-rail; 25 - cork; 27, 30, 39 and 41 - nuts; 28 - gutter; 29 - ball; 31 - lock washer; 33 - gearbox housing; 34- thrust bearing; 35 - plunger; 37 - spool; 38 - washer; 40 - adjusting screw; 43 - seal; 45 - adjusting washer; 46 - thrust washer.

The driven bevel gear 11 rotates in two ball bearings 12 installed in the gearbox housing 33. The ball bearings are fitted with an interference fit on the shank of the gear wheel and secured with a nut 30 with a lock washer 31. Axial movements of the gear wheel are limited by the retaining ring 32 and cover 14. The engagement of the bevel gears is regulated by changing the thickness of the spacers 5.

The driven bevel gear of the angular gearbox is splined with screw 26 and transmits rotation from the steering wheel to it; while the screw can move in the axial direction (forward and backward).

The steering mechanism is assembled in the crankcase 23, which also serves as a hydraulic booster cylinder. A double gear was used as a steering mechanism: screw 26 - nut 27 and rail (piston) 24 - sector 18.

To reduce friction forces, the screw 26 rotates in the nut 27 on balls placed in the grooves of the screw and nut with a swing tube. The nut, assembled with the screw and balls, is installed in the piston rail 24 and fixed with two set screws 17.

The piston-rack is placed in the crankcase 23, which serves as its cylinder. The piston has a sealing ring 16 and oil grooves. The rail engages with the gear sector 18 of the bipod shaft 19 and turns it in a bronze bushing pressed into the steering gear housing and in the aluminum side cover 42.

The thickness of the teeth of the sector and the piston-rack is made variable in length, which allows you to change the clearance in engagement by moving the bipod shaft with the toothed sector using the adjusting screw 40. which keeps the bipod shaft from axial movements to the left through the thrust washer 46, and to the right - through the adjusting washer 45 and the retaining ring 44. The axial displacement of the bipod shaft of 0.02 ... 0.08 mm is achieved by selecting an adjusting washer 45 of a certain thickness. Screw 40 is locked with nut 41.

On the splined end of the shaft 13 ( see fig. 124) is installed and bolted to the bipod 12, which is connected to the longitudinal rod 11 of the steering gear. The longitudinal thrust is also connected by a hinged device to top lever left rotary knuckle. The longitudinal rod is a one-piece forged part with non-adjustable hinged devices.

The steering linkage consists of a tie rod and two steering knuckle levers. The levers are mounted on a segment key in tapered holes steering knuckles and secured with slotted nuts. The tubular transverse rod has threaded ends, on which tips with hinged devices are screwed. The tips are fixed with terminal clamp bolts. The articulated device of both rods consists of a ball pin, upper and lower bushings, a spring and a cover.

KAMAZ vehicles use the traditional for trucks steering, which provides for the presence of a steering column. Read about how KAMAZ steering is generally arranged, and what role the steering column plays in it (as well as about its structure, operation and maintenance), read in this article.

The general arrangement of the steering system of KAMAZ trucks

In all relevant and early models KAMAZ trucks are used fundamentally identical in design and built on a single component base steering systems. The composition of the steering kama trucks includes:

Steering gear;
Steering gear;
Power steering;
Steering column;
Steering wheel;
cardan transmission;
Angle gearbox.

Each of the units plays a specific role in the system and has its own characteristics.

Steering gear. Built according to the traditional scheme, on cars with all wheel arrangements it is installed on the front axle (or two front axles in 8×4 and 8×8 models) with steerable wheels. The drive is a system of one longitudinal rod, which is connected to the bipod of the steering mechanism and the steering knuckle lever, and one transverse link connecting the levers of both steering knuckles of the axle. In vehicles with two controlled axles an identical set of rods is added on the second axle, as well as one more longitudinal rod and a lever for transferring the force t of the steering mechanism located in the area of the front axle to the rear axle.

Steering gear. All KAMAZ trucks use a mechanism built on two working pairs. The first pair is a screw with a nut (which simultaneously acts as a rack) on circulating balls - it converts the torque from the steering wheel into the translational movement of the rack. The second pair is a rack (with four teeth) with a sector - they convert the translational movement of the rack into a rotational movement of the sector connected to the swivel bipod. AT current models KAMAZ steering is combined with a power steering, its crankcase acts as a power steering cylinder, and the rack acts as a piston.

Today, domestic mechanisms of models 4310 and 6540 with gear ratio 21.7:1, as well as mechanisms of foreign production RBL (Germany) with a variable gear ratio from 17:1 to 20:1, or with a constant gear ratio of 21:1. RBL mechanisms have a hydraulic turn limiter that prevents deformation and fracture of the steering rods in the extreme positions of the steering wheel.

The steering mechanism is usually mounted on the left side member of the frame, next to the front axle of the vehicle, or on the left spring mounting bracket.

Power steering (GUR). As already mentioned, the power steering cylinder is combined with the steering mechanism, the power steering pump is also part of the amplifier (today, the vane pumps of the 4310 model are most often used, as well as those of ZF and RBL), a cooling radiator working fluid(it is necessary, since the hydraulic booster is under heavy loads and the liquid is subjected to serious heating), bypass valve, control valve and spool (located in a separate block on the steering gear), piping system and expansion tank. It is important to note that in vehicles with a wheel arrangement of 8×4 and 8×8, an additional power steering hydraulic cylinder is installed, which facilitates changing the position of the wheels of the second axle.

Angle gearbox. The simplest gearbox on two bevel gears, which provide a change in the direction of the flow of torque from the steering wheel to the steering mechanism. The driven gear of the reducer is made hollow, which makes it possible to pass through it the shaft going from the power steering spool mechanism to the steering gear screw. The angle gearbox is located between the steering gear and the hydraulic booster spool mechanism.

Cardan transmission. It is necessary to transmit torque from the steering shaft to the bevel gear. cardan shaft composite, it consists of a tubular shaft with a fork and a sliding fork inserted into it on the slots - this solution allows the shaft to change its length when the car moves over bumps. The forks of the shaft are connected by means of crosses with the mating forks on the steering column shaft and the drive gear shaft of the angular gearbox, they form two cardan joints. The crosspieces are installed in the forks on maintenance-free needle bearings.

Let's talk about the steering column in more detail.

Purpose, types, devices and operation of the KAMAZ steering column

The steering column, together with the steering wheel, is the main control of the vehicle's direction of travel. The steering column solves two main tasks:

Provides the most convenient for work installation of a wheel on height and an inclination;
Provides a constant position of the steering wheel while the car is moving.

KAMAZ vehicles use two types of steering columns:

The old model - without adjustments for tilt and height;
A new sample - modern speakers with adjustable height and angle of the steering wheel.

Even though the old steering columns are quite uncomfortable, they still find the widest use even on new trucks. This is due to their simple design, very high reliability and low cost. New steering columns installed on a number of KAMAZ-5460, 6520 and other models provide the ability to adjust the angle and height of the steering wheel to fit the height and anatomical features of the driver. However, as practice shows, they are less reliable and more expensive.

Set up very simply. It is based on a hollow tube, inside of which a shaft is mounted on two ball bearings. In the upper part, a steering wheel is installed on this shaft by means of a nut, with reverse side a universal joint fork is attached to the shaft. Approximately in the middle part of the dispenser, a bracket is provided for attaching it to the cabin panel, and there is a flange at the bottom of the dispenser. Through this flange, the column is mounted on a wider pipe (also called a flange) screwed to the cabin floor. This flange has a window (closed with a bolted cover) for access to the upper joint of the cardan shaft.

The new type of columns have a similar design, but they are shorter, and have a coaxial installation with a cardan shaft - this solution allows you to easily and conveniently change the angle of the steering column. And the spline connection of the halves of the shaft allows you to change the height of the steering wheel above the floor level. The column is provided with mechanisms with locks that provide the ability to change and set the desired angle and height of the steering wheel.

On the steering column, in addition to the steering wheel, controls for wipers and lighting devices are also mounted. The handles of the combined switches are mounted under the steering wheel, which makes it convenient to turn on and off the wipers and washer, direction indicators, dipped and high beam headlights In the columns of the new model, the switches themselves, all the electronics and mechanisms for changing the angle of inclination and height of the steering wheel are hidden under decorative plastic casings.

Features of maintenance and repair of the KAMAZ steering column

The steering column and steering wheel are one of the most reliable steering parts in a car, but they also require periodic maintenance and repair. Maintenance usually comes down to inspecting the reliability of fastening and assessing the condition of the parts of the steering column and steering wheel, and the steering as a whole.

If during the inspection, axial play of the shaft is detected (which indicates a poor condition of the bearings), destruction of the bearings or their excessive wear, rudder play due to wear spline connection cardan shaft or cardan joints(crosses or needle bearings), deformation of the shaft, or severe deformation of the column itself, repair or replacement of parts is necessary.

Dismantling the steering column in the general case is carried out as follows:

Set the steered wheels in a straight position and fix them;
Dismantle the steering wheel (for which you need to remove the cover and unscrew one nut);
Remove all switches from the column;
Unscrew the bolts holding the cover on the flange;
Unscrew and knock out the bolt holding the upper universal joint fork;
Unscrew the screws holding steering column on the flange and on the panel, remove the column.

The installation of the column is carried out in the reverse order, while it is necessary to ensure that the universal joint yoke bolt is tightened with a certain force, and also to install the steering wheel correctly.

Of great importance for the diagnosis of steering is play of the steering wheel. It can be caused both by wear of splines or cardan joints, and by other malfunctions - wear of parts in the steering mechanism, wear of the steering gear of the wheels, etc. Usually the backlash running engine on Idling should not exceed 25°, and in many models even less. With more play, diagnostics and repair should be carried out.

The force that has to be applied to the steering wheel to turn it in one direction or another is also important. This is an effort for different models KAMAZ is not the same, it is measured with a special device, and is set by adjusting the steering gear and power steering.

At regular maintenance and timely repair will provide accurate and reliable steering, and at the same time help in diagnosing truck steering problems.

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1. Purpose and technical characteristics of the KamAZ vehicle- 5 320

On the roads of our country, you can increasingly see powerful three-axle trucks - KamAZ. The large-scale mass production of these machines is carried out by the Kama association for the production of heavy vehicles.

Now KamAZ has reached the forefront in the global automotive industry. Over 300 thousand trucks various modifications already working on the roads of our country.

KamAZ trucks were designed for mass transportation of goods in any climatic zones. When choosing a scheme new car First of all, the circumstance was taken into account that the coverage of most of the roads in our country is designed for axial load car no more than 6 tons. And since rear axle a car with a gross weight of about 16 tons lays down almost two-thirds of this load - 11 tons - KamAZ trucks were made three-axle. However, for each of rear axles models 5320 and 5410 have a mass of about 5.5 tons. These cars belong to the so-called group B, that is, cars whose one axle creates a load on the roadbed of no more than 6 tons.

Operating data
Wheel formula
The mass of the transported cargo or mounted
Load on the fifth wheel coupling, kg
Weight of equipped vehicle, kg
Gross vehicle weight, kg
Determination of the mass of the equipped car on the road, kg
Go, for the car gross weight, kg:
Maximum travel speed (depending on gear ratio main gear), km/h
Climbing angle, % not less than
Control fuel consumption per 100 km of track when driving at full load and at a speed of 60 km/h, l:
Cruising range according to the control fuel consumption, km:
Acceleration time to 60 km / h of a car of full weight, s. not
Braking distance with full load when driving at a speed of 60 km / h to a complete stop, m, when using the service brake
braking system from a speed of 40 km/h:
Outer overall radius R of the car turning along the front buffer, m
Fuel tank capacity, l:
Disk wheels

2. Purpose of steering wheels

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 a horizontal plane relative to rear wheels. The steering control must provide the correct turning kinematics and traffic safety, small efforts on the steering wheel, and prevent the transfer of a push from the roughness of the road to the steering wheel. The steering mechanism increases the effort of the driver applied to the steering wheel, and improves the accuracy of driving. Thanks to this, it remains possible to drive the car when the amplifier is not working, for example, when the engine suddenly stops, which increases traffic safety.

The hydraulic booster facilitates driving and increases the safety of its movement. Hydraulic booster, using engine power to turn and hold the wheels, reduces driver fatigue, improves vehicle maneuverability and provides steering in difficult conditions, for example, in case of sudden tire damage. When driving on rough roads and terrain, the hydraulic booster reduces shock loads in the steering, reducing the likelihood of damage to it, increasing the comfort and safety of driving.

The steering drive transfers the efforts of the driver and the hydraulic booster to the steered wheels, ensuring their rotation at mutually different angles. This reduces slip and therefore tire wear and makes steering easier.

3. Device andSteering principle

On a KamAZ - 5320 car, steering is used 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. gear ratio steering ratio is 20:1.

The hydraulic booster is made according to the scheme with constant fluid circulation, which helps to reduce the pump load. Max pressure liquid in the system is 7500 - 8000 kPa. The hydraulic booster cylinder is integrated into the steering gear housing. The spool-type control valve is equipped with centering springs and reactive plungers that create a feeling of resistance force on the steering wheel to turn the wheels. The hydraulic booster pump is rotary-vane type, double-acting, gear-driven fuel pump engine. The radiator of the hydraulic booster, which provides cooling of the circulating fluid, is installed on the radiator of the cooling system.

Steering gear - mechanical, with articulated parts. steered wheels installed with a tilt - camber in the transverse steered wheels are inclined in the transverse direction by 8 degrees, in the longitudinal plane by 3 degrees to create stabilization of the steering wheels. The maximum turning angles of the wheels, equal to 45 degrees, provide a minimum turning radius of the car along the stool of the outer wheel of 8.5 m with a width of the occupied corridor of 4.5 m.

4. The purpose of the device and the principle of operation of the steering mechanismsth control of the car KAMAZ

The steering 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 drive.

steering column consists of a shaft, a pipe and is attached to the top panel of the 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 thrust and clamping rings, the lower one with a lock washer and nut. The axial clearance in the bearings is also regulated by the nut 8. The bearings are equipped with seals.

A steering wheel is attached to the upper end of the shaft. The lower end of the shaft is equipped with a groove for attaching the cardan fork.

The bearings are greased during assembly.

cardan gear transmits forces from the steering column shaft to the drive gear of the angular gearbox and consists of shaft 6, bushing 8 and two cardan joints.

Each joint consists of forks and a cross with four needle bearings mounted in machines. The bearings are equipped with sealed rings; during assembly, 1-1.2 g of grease is put into each of them and the splines of the rod and bushing 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 shaft.

The hinge fork, connected to the sleeve, is mounted on the steering column shaft; the yoke of the shaft is connected to the shaft of the drive gear of the angular gearbox. The forks are fixed with wedge screws entering the hole, locked with nuts and cotter pins.

Angle gear transfers 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 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. 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. The engagement of the gears is controlled by changing the thickness of the spacers.

Steering gear arranged together with an angular gearbox, a control valve and a hydraulic booster cylinder. Attaches with bolts to the left spring bracket.

In the crankcase of the steering mechanism there are: a screw with nuts, 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. ensures continuous circulation of the balls.

The toothed sector with the bipod shaft is mounted on a bronze bushing in the steering gear housing and in the hole in the side cover attached to the crater. 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 of the bipod shaft relative to the head of the screw 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. On the splines of the shaft is installed and locked with bipod bolts. A drain plug is screwed into the bottom of the crankcase.

hydraulic booster consists of a control valve (switchgear) of a spool type, a hydraulic crankcase, a pump with a reservoir, a radiator, pipelines and hoses.

The control valve housing is studded to the bevel gear housing. The control valve spool is mounted on the front end of the steering gear screw 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 centering springs 4, 35. Thrust bearings are fixed on the screw with a shoulder and a nut by a spool. 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 northern 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. The safety valve connects the high and low pressure oil at a pressure of 6500-7000 kPa. 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 provided with a sealing ring and oil channels.

Hydraulic booster pump installed between engine blocks. The pump shaft is driven by the fuel pump gear high pressure.

Vane type pump, double acting, i.e. for one rotation of the shaft, two suction and heating cycles occur. The pump 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 mounted, rotates on ball 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 under the action of centrifugal forces and the oil pressure in the central cavity of the rotor is pressed against the working surfaces of the 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 slide along the surfaces of the stator, move 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, stator rotor 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.

A 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 manifold is attached to the pump housing 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.

Tank with lid filler neck and the 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. Installed in the lid safety valve limiting the pressure inside the tank. The oils circulating in the booster's hydraulic system are cleaned in a strainer. An oil indicator is fixed in the filler cap.

Radiator 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 straps and shrouds.

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.

Steering drive consists of a bipod, longitudinal and transverse steering rods and levers.

The levers of the steering knuckles, pivotally connected to the transverse link, form steering linkage, which ensures the rotation of the steered wheels at mutually different angles. The levers are inserted into the conical holes of the knuckles and are fastened with dowels and nuts.

Tips 8 are screwed onto the threaded ends of the transverse rod, which are the heads of the hinges. The rotation of the tips is regulated by 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 heavier. 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 - wheel pivots are installed with lateral inclinations of the transverse plane by 8 degrees inward. 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 of the longitudinal plane back by 3 degrees creates the stabilization of the steered wheels due to the centrifugal forces that arise when turning.

When the steering wheel is released after turning, the weight force and centrifugal forces create stabilizing moments that automatically return the steered wheels to the middle position. The axes of rotation of the wheels are inclined with their outer ends down by 1 degree, 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.

Steering operation . During rectilinear movement, the control valve spool is held in the middle position by springs. 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 heating of the oil in the hydraulic booster increases. 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 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 to the tank. In this case, most of the oil will circulate along the pump-tank-pump circuit.

When turning the steering wheel, the force through cardan transmission, angular gear, transfers to the steering gear screw.

If significant effort is required to turn the wheel, then the screw. it is screwed into the nut (or unscrewed from it) by displacing 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 slots 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 cylinder cavity. 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 large resistance force, then it begins to move. Piston movement through gear rack causes the rotation of the sector and further, through the steering gear, the rotation of the steered wheels.

Continuous rotation of the steering wheel is supported by the mixing of the spool in the housing, the oil pressure drop 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. Thus, the “following” action of the amplifier in terms of the angle of rotation of the steering wheel is provided.

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 resistance force to their movement when the spool is displaced. This is how a “following” action is created by the force of resistance to the rotation of the wheels, i.e. "feeling of the road".

At the limit value of the oil pressure of 7500 - 8000 kPa, the valves open and, protecting hydraulic system amplifier from damage.

The steering wheel is released to quickly exit a turn. 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 rotation 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 cases of sudden stop of the engine, pump or loss of oil, the ability to control the effort 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 ensured only due to the mechanical connection of the steering parts. The force on the steering wheel when moving the piston bypass valve located in the plunger ensures the flow of oil from the cylinder cavities.

5. Faults that occur during esteering operation

repair car steering

Cause of malfunction	Solutions
Increased (more than 25 0 ) total steering wheel play
Increased gap in fastening the worm with a roller	Adjust the engagement of the worm with the roller
The appearance of a gap in the bearings of the worm	Adjust worm bearings
Wear parts of cardan joints	Replace worn parts
Wear of the fastening parts of the steering rod joints	Replace worn parts
Steering gear sticking or great effort spent when turning the steering wheel
Wear or destruction of the bipod shaft roller bearing	Replace bipod shaft
Steering, squeaking or clicking noises in steering gear
Excessive wear of the roller or worm, chipping and dents on their surface.	Replace the worm or bipod shaft as a set)
Axial movement of the worm shaft
The appearance of a gap in the worm bearing	Adjust bearings

Technological process of steering repair

Name of service	OKUN service code	Job number as part of the service	Brief description of the work performed as part of the service
Routine work (about the types of maintenance)			A set of works established by the documentation of the manufacturer or the applicant enterprise on the mileage of trucks and buses, carried out in the form of preventive measures for the relevant units and assemblies
Adjusting the angles of the steered wheels			Checking and adjusting the clearance in the bearings of the hubs of the steered wheels and the convergence of the steered wheels
			Determining and fixing the maximum angle of rotation of the steered wheels
			Determination of violations of parallelism of bridges and their displacements along the axis truck and bus, parallelism adjustment
			Determining and adjusting the offset of the axles of the articulated buses and adjusting the skid of the rear articulated part
Steering adjustment			By steering mechanism
			Checking the tightness of the steering mechanism
			Steering gear adjustment
			Checking and adjusting the operation of the power steering
			By drive

Adjusting the angles of the steered wheels 017107	Steering angles (degrees)
Steering adjustment 017113	Serviceability of a steering and conformity to the established requirements of adjusting parameters, including: Steering wheel rotation without jerking and jamming; Lack of spontaneous steering wheel turn in AMTS with power steering; Absence of movements of steering parts and assemblies not provided for by the design; Lack of parts with traces of deformation, cracks and other defects; Compliance with the requirements for the operation of the power steering pump drive; Total play in steering

6. fixtures, used in the repair of steeringeniya KAMAZ

Stand for checking and adjusting the angles of the steered wheels

Ruler for checking the convergence of steered wheels

Steering tester

Power steering tester

Installation for measuring the pressure and performance of the hydraulic booster

Drive Belt Tension Checker

Device for checking the presence of gaps in the couplings of the steering rods

Tire pressure gauge

Ruler for adjusting the connection of steering rods with the steering mechanism

Name of SI		No. of the State Register	Application
Wheel geometry check (camber)
Rulers for checking the convergence of car wheels			For checking wheel alignment during operation on vehicles. MPI - 1 year.
Devices for monitoring the convergence of the front wheels of cars			To measure and set the angles of convergence of the front wheels of cars and control the correct installation of the wheels during the operation of the car. MPI - 1 year.
Devices for controlling the geometry of the running gear of cars			To control the geometry of the chassis of various vehicles. MPI - 1 year.
Stands for checking and adjusting the geometry of wheel axles	Models 8670, 8675		To adjust the suspension, measure and set the angles of the steered and non-steered wheels of vehicles in the conditions of motor transport enterprises, service stations, automobile factories and diagnostic centers. MPI - 1 year.
steering play
Car steering play gauges			For control total backlash steering controls of vehicles, regulated by GOST 5478-91, can be used on motor transport enterprises, in bus and taxi fleets, at service stations, in cooperative and private car repair and maintenance workshops in collective garages and car inspection points, at traffic police control posts, by individual owners of vehicles. MPI - 1 year.

Maintenance of steering KAMAZ

No. of work performed	Name and content of works	Place of work	Devices, tool, fixtures, model, type	Technical requirements and instructions

	Check the cotter pin nuts of the ball pins of the steering rods		Electromechanical lift P-128	No pins are allowed
		On the left front of the car	Electromechanical lift P-128	No pins are allowed
	Check the cotter pin nuts on the steering knuckle arms	On the right front of the car	Electromechanical lift P-128	No pins are allowed
	Check the splitting of the nuts of the bolts for fastening the bipod of the steering mechanism		Electromechanical lift P-128	No pins are allowed
	Check the clearance in the tie rod joints		Probe set No. 2 GOST 882-75	The presence of increased play is not allowed
	Check the play in the lower joint of the propeller shaft of the steering	In the interior and front of the car	Probe set No. 2 GOST 882-75
	Check the clearance in the upper joint of the propeller shaft of the steering	In the interior and front of the car	Probe set No. 2 GOST 882-75	The presence of play in the hinges is not allowed
	Check the axial clearance of the pivot joint	In front of the car	Probe set No. 2 GOST 882-75
	Check the radial clearance of the pivot joint	In front of the car	Tester front axle T-1, Electromechanical lift P-128	The gap should not exceed 0.25 mm
	Hang the front wheels	In front of the car	Electromechanical lift P-128	Wheels must not touch the floor
	Check the condition of the pivot bearings	In front of the car	Steering tester K-187	Perceptible gap not allowed
		On the left front of the car
	Check wheel bearing installation	On the right front of the car		The wheels should rotate smoothly, without swings in a vertical plane.
		On the left front of the car
	Remove the hub cap, unlock and unscrew the lock nut, remove the lock and lock washer	On the right front of the car	Front wheel bearing wrench	Nuts must have clear edges
		On the left front of the car		The wheels should rotate smoothly, without swings in a vertical plane.
	Install bearings in correct position	On the right front of the car		The wheels should rotate smoothly, without swings in a vertical plane.
		On the left front of the car	Torque wrench
	Tighten hub nut, install the washer and locknut	On the right front of the car	Torque wrench	Tighten the nut with a force of 140-160N * m
	Check wheel alignment	In front of the car	Ruler for checking wheel alignment K-624
	Adjust wheel alignment by changing the position of the rod in the tip	In front of the car	Wheel alignment ruler K-624, tool kit 2446	Wheel alignment should be 0.9-1.9 mm
	Check steering wheel play	In front of the car		Free play must not exceed 25º
	Check axial movement of the steering wheel	Inside the car		Axial movement not allowed

7. Ways to restore rudder nodesth control of the car KAMAZ

To determine the degree of wear and the nature of the repair of parts, the steering mechanism is disassembled. At the same time, pullers are used to remove the steering wheel and steering bipod. The main defects of the steering mechanism parts are: wear of the worm and the bipod shaft roller, bushings, bearings and their seats; breaks and cracks on the crankcase mounting flange; wear of the hole in the crankcase for the bushing of the steering arm shaft and parts of the ball joints of the steering rods; bending of the rods and loosening of the steering wheel on the shaft.

The worm of the steering mechanism is replaced with significant wear of the working surface or delamination of the hardened layer. The bipod shaft roller is rejected if there are cracks and dents on its surface. Worm and roller are replaced at the same time.

Worn bearing journals of the bipod shaft are restored by chrome plating, followed by grinding to the nominal size. The neck can be restored by grinding to the repair size of the bronze bushings installed in the crankcase. The worn threaded end of the steering arm shaft is restored by vibro-arc surfacing. Previously, on a lathe, the old thread is cut off, then the metal is deposited, turned to the nominal size and a new thread is cut. The bipod shaft with traces of twisted splines is rejected.

Worn bearing seats in the steering gear housing are restored by setting an additional part. To do this, the hole is bored, then the bushings are pressed in and their inner diameter is machined to fit the size of the bearings.

Breaks and cracks on the crankcase mounting flange are eliminated by welding. Gas welding is used and general heating of the part is carried out. Worn hole in the crankcase, under the steering arm shaft sleeve, they are deployed to the repair size.

In the steering gear, more rapid wear is ball pins and tie rod liners, tips for less wear. In addition, there is wear on the holes at the ends of the rods, thread stripping, weakening or breakage of the springs, and bending of the rods.

Depending on the nature of wear, the suitability of the tips (assembly) of the tie rod or individual parts is determined. If necessary, the hinged tips are disassembled. To do this, unpin the screw plug, unscrew it from the hole in the thrust head, and remove the parts. Worn out. ball fingers. as well as fingers that have chips and scuffs are replaced with new ones. At the same time, new ball pin bushings are installed. Weak or broken springs are replaced with new ones. The developed holes at the ends of the steering rods are welded. The curvature of the steering rod is eliminated by editing in the cold state. Before straightening, the draft is filled with dry fine sand.

8. The composition and properties of the material from which parts and furs are madesteering nims KAMAZ

- The lever of rotary pins and steering bipods - steel 35X, 40X, ZOHGM, 40XN.

- Rail? carbon steel 45 followed by heat treatment (hardening and tempering).

- Pit arm shaft - ZOH, 40X, ZOHM steel.

- Worm, steering gear screw - steel 35X, 20XH2M or ASZOHM

- Steering gear shaft - steel 10, 20, 35.

Literature

1. GOST R 51709-2001 - Vehicles. security requirements for technical condition and verification methods.

2. V.A. Bondarenko, N.N. Yakunin, V.Ya. Klimentov - "Licensing and certification for road transport". Tutorial. 2nd edition - M; Engineering, 2004-496 p. Moscow "Engineering" 2004

3. Mashkov E.A. Maintenance and repair of KmAZ vehicles

4. Illustrated edition-Publishing house "Third Rome", 1997-88 p.

5. Osyko V.V. etc. The device and operation of the KamAZ vehicle

6. TutorialM.: Patriot, 1991. - 351 p.: ill.

7. Rogovtsev V.L. etc. The device and operation of motor vehicles

8. Tools: Driver's manual. M.: Transport, 1989. - 432 p.: ill.

9. Rumyantsev S.I. etc. Maintenance and repair of vehicles:

10. Textbook for vocational schools. M.: Mashinostroenie, 1989. - 272 p.

11. Device, maintenance and repair of vehicles. Yu.I.

12. Borovskikh, Yu.V. Buralev, K.A. Morozov, V.M. Nikiforov, A.I. Feshenko - M.: Higher School; Publishing Center "Academy", 1997.-528 p.

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The general arrangement of the steering system of KAMAZ trucks

Purpose, types, devices and operation of the KAMAZ steering column

Features of maintenance and repair of the KAMAZ steering column

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