The steering consists of a steering wheel 1, a column 2, the shaft of which is connected to the steering mechanism 7 through a cardan gear 3, and a steering gear.

The steering gear is a system of rods and levers that, together with the steering mechanism, turns the car.

Through the steering mechanism, the longitudinal link 8 moves forward or backward, causing one wheel to turn left or right, and the steering link transmits the turning moment to the other wheel.

The trapezoid includes a beam 5 (Fig. 2.) of the front axle, levers 3 and 6 of the steering knuckles and a tie rod 4.

When you turn one wheel through levers 3 and 6 and rod 4, the other wheel also turns.

In this case, due to a change in the position of the transverse link 4 relative to the front axle, the inner wheel towards the center of rotation turns through an angle greater than the angle of rotation of the outer wheel.


Fig.1. Steering: 1 - steering wheel, 2 - column, 3 - cardan shaft, 4 - radiator, 5 - hydraulic booster control valve, 6 - angular gearbox, 7 - steering gear, 8 - longitudinal thrust, 9 - bipod, 10 - low pipe pressure, 11 - high pressure pipeline, 12 - power steering pump, 13 - hydraulic reservoir

Steering trapezoid

The steering gear of KamAZ vehicles includes an angular gear reducer, a screw-nut transmission with circulating balls and a pair of rack-toothed sector.

The steering gear housing is also the hydraulic booster housing, with which the steering gear is combined.

The gear ratio of the angular gearbox is 1:1, the steering gear of cars with a wheel arrangement of 6X4-20: 1, off-road vehicles is 21.7: 1.

Power steering

Fig.3. Steering gear with built-in hydraulic booster: 1 - front cover, 2 - hydraulic booster control valve, 3, 29 - thrust rings, 4 - floating sleeve, 5, 7 - sealing rings, 6.8 - spacer rings, 9 - set screw, 10 - bipod shaft, 11 - bypass valve, 12 - protective cap, 13 - back cover, 14 - steering gear housing, 15 - piston rack, 16 - magnetic plug, 17 - screw, 18 - ball nut, 19 - groove, 20 - ball, 21 bevel gear, 22 thrust roller bearing, 23 spring washer, 24 nut, 25 thrust washer, 26 shim, 27 adjusting screw, 28 adjusting screw lock nut, 30 side cover

The steering mechanism consists of a crankcase 14 (Fig. 3.), in which the piston-rack 15 moves, engaging with the toothed sector of the bipod shaft 10.

A ball nut 18 is fixed in the piston-rail with setscrews 9.

The screws are locked by punching them in the groove of the piston-rack.

The ball nut 18 and the screw 17 have helical grooves.

On the outer surface of the ball nut, an oblique groove is made, connected by two holes to its helical groove.

Two grooves 19 are inserted into this groove, forming together a tube, which is, as it were, a continuation of the helical groove.

The screw channel formed by the grooves of the screw and nut and the grooves contains balls 20.

When the screw is rotated, the balls roll out from one side of the nut, pass through the grooves, as if through a bypass channel, and return to the screw channel, but on the other side of the nut.

In total, 31 balls circulate in the closed channel, 8 of them are in the bypass channel.

The thickness of the teeth of the sector of the bipod shaft and the piston-rack is variable in length, which allows you to change the gap in engagement by axial movement of the adjusting screw 27, screwed into the side cover 30.

The free axial movement of the bipod shaft after assembling the steering mechanism should be 0.02 ... 0.08 mm, which is ensured by changing the thickness of the adjusting washer 26.

On the part of the steering gear screw located in the cavity of the angular gear housing 21, there are splines that connect the screw to the gear wheel of the angular gear.