Steering mechanism: description, types, purpose, principle of operation, device. Vehicle steering

5.3. The device and operation of the steering

Steering serves to turn the front wheels of the car during its movement and consists of a steering drive and a steering mechanism. In order for the movement of the wheels of the car on a turn to occur without side slip, the steered wheels must turn at different angles: the inner wheel at a larger angle, and the outer wheel at a smaller one.

The steering mechanism is used to convert the rotational motion of the steering wheel into linear linear motion transmitted to the wheels. For rectilinear movement, you need to convert the rotational movement of the steering wheel into a swing of the steering arm or create a reciprocating movement of the steering rack. In addition, the steering mechanism provides a reduction gear ratio, due to which the effort applied by the driver to control the wheels is reduced. This is especially important when the vehicle is stationary or moving slowly and the steering wheel is most difficult to turn.

The ratio between the steering angle and the steering angle is called the steering ratio. Gear ratios can be fixed or variable. Steering with a constant gear ratio is referred to as "linear". In linear steering, turning the steering wheel a fixed number of degrees moves the steered wheels a proportional angle dependent on the gear ratio at any steering position.

Steering with a variable gear ratio is referred to as "proportional". With proportional steering, the gear ratio changes with each turn of the steering wheel. Generally, as the steering angle increases, the rate at which the wheel angle changes increases. The gear ratio is the steering angle divided by the steering angle.

Typically, the reduction steering ratio is between 14:1 and 22:1. Ratios between 14:1 and 18:1 generally require power steering. To move the wheels between the limit positions, you need to turn steering wheel 3-4 full turns. The steering gear must be strong enough to withstand the different loads it is subjected to under different driving conditions. The driver should not feel the jolts accompanying the movement through the steering wheel.

5.3.1. Steering mechanisms

There are several different designs of steering gears, but there are two main types:

Steering mechanisms with rotational movement (Fig. 5.26);

Rice. 5.26. Steering gear with rotational movement

Steering gears with sliding motion (Fig. 5.27).

Rice. 5.27. Sliding Steering Gear

Steering mechanisms with rotational movement

Steering mechanisms with rotational movement have various designs:

Ball screw steering mechanism;

Steering gear type "screw-nut" with rings-sliders;

Worm-sector steering gear;

Worm-roller steering mechanism;

Steering gear with worm and roller pin.

On fig. 5.28 shows a ball screw steering mechanism. It uses several balls that circulate in "tracks" formed by grooves found in the steering nut and on the steering shaft. As the steering shaft rotates, the balls roll along the "tracks" and cause the steering nut to move up or down the steering shaft. The steering arm is rotated by a toothed sector that meshes with the teeth on the steering nut.

Rice. 5.28. Ball screw steering gear

The gear ratio in this steering mechanism is constant. The balls reduce friction between the moving parts, so this type of steering mechanism is practically not subject to wear. Excessive play in the steering gear can usually be eliminated by adjusting the position of the steering shaft.

On fig. 5.29 shows a steering gear with a worm and a roller pin. Its design uses a cylindrical worm with an uneven pitch. As the worm rotates, the conical pin moves axially along the worm. The steering arm is mounted on a corresponding shaft connected to a pin and can be rotated through 70°. The wear of the working elements of this mechanism is relatively low, the play in the steering shaft and between the pin and the worm is adjustable. The gear ratio of the steering mechanism with a worm and a roller pin changes proportionally due to the uneven pitch of the worm.

Rice. 5.29. Steering gear with worm and roller pin

The worm-sector steering mechanism is shown in fig. 5.30.

Rice. 5.30. Worm-sector steering gear

In this type of steering mechanism, a cylindrical worm is provided at the end of the steering shaft, which moves the gear sector. The advantage of the worm gear is that high gear ratios of up to 22:1 can be easily achieved. The gear sector is in constant engagement with the worm, any rotation of the steering shaft causes the gear sector to rotate. The steering arm is mounted on a gear sector and can be rotated 70°. The wear of this type of steering mechanism is relatively high due to the sliding friction of the operating elements. The disadvantage of the worm-sector steering mechanism is that the driver needs to apply considerable force to the steering wheel.

On fig. 5.31 shows a steering mechanism of the "screw-nut" type with slider rings.

Rice. 5.31. Steering gear type "screw-nut" with rings-sliders

By the principle of operation, this mechanism is similar to the steering mechanism with ball circulation. Slider rings located on the side of the steering nut transmit the movement of the nut to the steering fork. The steering bipod mounted on the bipod shaft, which is located on the steering fork, rotates 90 °. The wear of this type of steering mechanism due to friction is usually high. The gear ratio is constant.

Rice. 5.32 represents a worm and roller steering gear.

Rice. 5.32. Worm-roller steering gear

In this steering mechanism, a roller is used instead of a gear sector to transmit movement from the worm. The worm in this steering mechanism is reduced to a cone towards the center and takes the form resembling an hourglass (globoid). The advantage of this worm shape is that it allows the roller to turn about its center and this reduces the size of the steering gear. The steering arm is attached to the roller shaft and can be rotated 90°. The gear ratio remains constant. Increased play can be eliminated by adjusting the position of the steering shaft.

Sliding steering gear

On fig. 5.33 shows a constant pitch steering gear, the most common type of steering gear used in modern cars.

Rice. 5.33. Steering gear with constant tooth pitch

Rack and pinion steering gears use a rotating gear to create linear movement of the rack. The gear teeth are in constant mesh with the rack teeth, and any movement of the steering column shaft causes the steering rack to move laterally. The movement of the rack is directly transmitted to the steering rods installed at both ends of the rack. Ball joints located between the rack and steering rods provide the possibility of independent vertical movement steering rods. The rack is held in engagement with the pinion by a spring-loaded pressure pad that adjusts for any gap between the teeth. The sliding friction between rack and pinion provides a cushioning effect and absorbs shocks generated during movement.

Among the advantages of rack and pinion steering is direct steering. The gear ratio is constant.

On fig. 5.34 shows a steering rack with variable tooth pitch. For clarity, the housing and steering gear are not shown.

Rice. 5.34. Steering rack with variable tooth pitch

The variable pitch rack and pinion steering works in the same way as the fixed pitch rack and pinion steering described above. In the center of the rack, the tooth pitch is greater than at the edges. Variable pitch makes it possible to increase the steering ratio as the gear rotates. The teeth in the center of the rack cause the rack to move more with each turn of the gear, which requires a relatively large amount of force. The teeth at the ends of the rack allow for less rack movement, requiring relatively little driver force. To eliminate this shortcoming, power steering is installed on modern cars. In fact, in this system, the more you turn the steering wheel, the less effort. When driving in a straight line, the steering is heavier than when the steering wheel is turned to the limit position - this makes it easier to maneuver and park.

The variable pitch rack and pinion steering has a proportionally increasing gear ratio.

On fig. 5.35 (see also color insert in fig. CV 5.35) shows a typical power steering hydraulic system equipped with a fluid pump that serves to supply pressurized hydraulic fluid to the hydraulic circuit. The pump may be electrically driven and housed in the power steering reservoir, or may be mechanically driven by the engine.

Rice. 5.35. Hydraulic system power steering

Mechanical pumps are usually equipped with a separate reservoir for the working fluid. The working fluid under pressure created by the pump enters the control spool valve in the steering gear. When the steering shaft is in a straight line position, the working fluid passes through the control spool valve and returns to the reservoir. When the steering wheel is turned, the control spool valve directs hydraulic fluid to the corresponding side of the piston, which is located in the cylinder at the end of the rack and pinion steering gear. The rod attached to the piston is connected to the rack, and any fluid pressure acting on the piston helps move the rack. The working fluid from the reverse side returns to the tank through the spool valve. Turning the steering wheel in the other direction does the opposite. If the power steering fails, the mechanical action of the steering mechanism is maintained, but much more effort will be required.

5.3.2. Steering gear

The steering gear serves to transfer the driver's effort through the steering wheel to the steered wheels of the car. The steering mechanism converts the rotary motion of the steering wheel into a linear motion that pulls the steering linkages. The converted motion is transmitted from the steering gear to the steering gear. Ball joints at the ends of the longitudinal and transverse steering rods provide the possibility of any rotary and rotational movements in the drive. The layout and number of tie rods in the steering gear depends on the design of the axle and suspension.

Steering gear layout options

The simplest steering drive design is a single-section tie rod moved by a steering arm (Fig. 5.36). The steering arm pushes or pulls the longitudinal tie rod to move the lever, which is connected to the pivot joint on the steering knuckle. A tie rod connects both pivot joints on the steering knuckles of the vehicle's front wheels. Any movement of one of the swivel joints is transmitted through the tie rod to the swivel joint on the opposite steering knuckle.

Rice. 5.36. Steering gear with single-section tie rod

This type of steering gear is usually used in vehicles with a rigid axle, in which the distance between the steering knuckle arms does not change. Ball joints are used to connect the tie rod to the steering knuckle arms.

On fig. 5.37 shows a modified version of a single-section tie rod - a steering gear with a two-section tie rod moved by a steering arm. The steering arm pulls or pushes two separate tie rods that are connected to the steering knuckle arms via ball joints. Moving the tie rods rotates the pivot joints on the steering knuckles. Steering gear of this type is usually used in vehicles with independent suspension, in which the pivot joints can move one independently of the other.

Rice. 5.37. Steering gear with two-piece tie rod

The steering drive with a three-section tie rod, movable steering arm, is shown in fig. 5.38. This tie rod has a pendulum arm that transmits steering motion to the opposite side of the vehicle. This type of steering gear is used in cars with independent suspension, but this design option has a high cost.

Rice. 5.38. Steering gear with three-section tie rod

The three-section tie rod provides the highest degree of precision and maximum steering control. When driving on a rough road, shocks are transmitted through the steering gear and steering mechanism to the driver. To mitigate these shocks, a shock absorber is installed on the steering gear. Steering shock absorbers can be built into any type of steering gear (Fig. 5.39), but they are not often used in cars with rack and pinion steering. The steering damper helps counteract increased steering forces and unintentional steering wheel movement.

Rice. 5.39. Steering dampers

On fig. 5.40 shows steering gears with two-section steering rods of a movable rack. The rack and pinion steering system uses two tie rods to transmit steering input to the steering knuckles.

Rice. 5.40. Steering gears with two-section steering rods

There are also steering racks for connection with knuckles. They use steering gears of a similar design. The rectilinear movement of the steering rack is transmitted through the ball joint to the steering rods.

5.3.3. Diagnostics and maintenance of the front, rear suspension and steering

Faults and solutions

The amount of free play of the steering wheel is indicated in the vehicle's operating instructions. Increased free play is detected by shaking the steering wheel. There may be several reasons for its occurrence:

Loosening of the nuts for fastening the ball joints of the steering rods;

Increased clearance of spherical joints of steering rods;

Increased clearance of the ball joints of the front suspension arms;

Backlash as a result of wear of the front wheel bearings;

Backlash as a result of wear of the steering gear teeth;

Backlash in the elastic coupling connecting the steering gear with the steering wheel shaft;

Play in the bearings of the steering shaft of the steering wheel.

To eliminate the malfunction, it is necessary to check the tightening of all fasteners and replace worn parts.

Noise (knocking) in the steering can cause the following reasons:

Loosening of nuts of fastening of ball joints of steering rods;

Increasing the gap between the rail stop and the nut;

Loose steering gear nuts, as well as all of the above malfunctions.

Steering wheel tight:

Damage to the bearing of the upper support of the steering wheel shaft;

Lowering the air pressure in the tires of the front wheels;

Damage to parts of the telescopic rack and wheel suspension;

Violation of the power steering pump;

Ingress of foreign particles into the hydraulic steering system;

Increased oil level in the steering pump reservoir;

Wear or damage to the cuffs of the steering gear and pump;

Deterioration of hydraulic hoses.

To eliminate malfunctions, it is necessary to check the tightening of all fasteners and replace worn components and parts, as well as check the power steering fluid level and replace worn and damaged parts of the power steering. This text is an introductory piece.

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Management. What is it for? The main functions are aimed at converting the rotational movement of the steering wheel into reciprocating. This task is performed by the steering and mechanism. Various systems are installed on cars. Let's look at the device and the principle of operation of these nodes.

Purpose

In order for vehicles to be able to move in the direction chosen by the driver, it is necessary that they be equipped with mechanisms for steering. Its design determines whether the car will be safe to drive, as well as at what speed the driver will get tired and tired.

Requirements

Certain requirements are imposed on the steering and mechanism. First of all, it is the provision of high maneuverability. In addition, the mechanism must be designed in such a way that it is easy to drive the vehicle. If possible, only rolling is provided, without lateral slips of tires in a turn. The steered wheels shall automatically return to the straight-ahead state after the driver releases the steering wheel. Another requirement is the absence of reversibility. That is, in the control system there should not be even the slightest opportunity to transfer blows from the road to the steering wheel.

It is important that the system has a follow-up action. The car should immediately respond to even the smallest turns of the steering wheel.

Device

Consider the device of the steering mechanism. In general, the system is directly a mechanism, an amplifier, and also a drive. As for types, they distinguish:

rack and pinion steering;
worm mechanism;
screw.

The general device is quite simple. The design is logical and optimal. This is proved by the fact that for many years in the automotive industry, no significant changes have been made to the control mechanism.

Speaker

Without exception, all mechanisms are equipped with a steering column. Its device includes several different components and parts. This is a steering wheel, a steering shaft, as well as a casing in the form of a pipe with bearings. In addition, the column consists of various fasteners that ensure the immobility and stability of the entire structure.

This node functions very simply. Driver vehicle affects steering. The mechanism converts the driver's effort, which is transmitted along the shaft.

Rail

This is the most popular and widely used type of steering gear. Such control is often equipped with cars that have an independent suspension system on a steerable pair of wheels. It is based on a gear and a rack. The first is rigidly and permanently fixed to the steering shaft through the universal joint. It is also in constant engagement with the teeth on the rack. When the driver turns the steering wheel, under the influence of the gear, the rack moves to the left or right. On each side, rods and tips are attached to it. These are the parts of the steering gear that act on the steered wheels.

Among the advantages are the simplicity and reliability of the design, high efficiency, fewer rods in comparison with other types of steering. The steering mechanism is compact and has a low price.

There are also disadvantages - this is susceptibility and sensitivity to road irregularities. Any shocks from the front steered wheels are immediately transferred to the steering wheel. In general, the mechanism is very afraid of vibrations. The system is difficult to install on vehicles where the front wheel suspension is dependent. This limits the scope of this mechanism to only passenger cars and light commercial transport(for example, "Fiat Ducato" or "Citroen Jumper").

It is worth noting that the rack and pinion mechanism loves a neat and measured ride on smooth roads. If you drive carelessly, the part starts to knock and quickly fails. If the teeth on the rack or on the gear are damaged, then the steering wheel may bite. These are the main malfunctions of the node.

Worm

The worm gear steering is now considered obsolete. But it definitely needs to be considered, because old cars are equipped with it (for example, the “classic” from AvtoVAZ), and they are still in operation. Also, this system can be found on all-wheel drive off-road vehicles, on vehicles with a dependent type of suspension of a controlled pair of wheels. In addition, light trucks and buses are equipped with the mechanism of this design. The UAZ steering mechanism is designed and works the same way.

The worm gear is based on a toothed screw of variable diameter. It is linked to other elements. This is the roller and the steering column shaft. A special lever is installed on this shaft - a bipod. The latter is related to steering rods.

It all works in the following way. When the driver needs to change direction, he acts on the steering wheel. He turns and acts on the shaft of the column. The shaft, in turn, acts on the worm. The roller rolls along the steering shaft, which is why the bipod is also set in motion. Together with the bipod, the tie rods move, and then a pair of front steered wheels.

This type of mechanism has a low sensitivity to shock loads, unlike the rack and pinion mechanism. As for other characteristics, it is possible to allocate a greater eversion of the wheels and improved maneuverability. However, the device is more complex, and the cost of production is higher due to the large number of different connections. For effective steering operation, this type of mechanism needs frequent adjustments.

Many motorists met this system on GAZ, VAZ and others. But such a gearbox is also found on expensive comfortable luxury cars with a large mass and front independent suspension.

screw gearbox

In this mechanism, several elements work together. This is a screw mounted on the steering column shaft, a nut that moves along the screw, a gear rack and a sector connected to the rack. The latter is equipped with a shaft, and a steering arm is fixed on it. These gearboxes are found mainly on trucks - this is how the KamAZ steering mechanism works.

The peculiarity of this mechanism is a screw and a nut connected to each other by means of balls. Due to this, it was possible to achieve a reduction in friction and wear of this pair.

As for the principle of operation, this mechanism works in much the same way as a worm gear. When the steering wheel is turned, the screw that moves the nut rotates. In this case, the balls circulate. The nut moves the sector through the gear rack, and the bipod moves with it.

This mechanism is characterized by high efficiency and is able to implement significant efforts. The system is used not only on trucks, but also on light vehicles (mostly executive class). Similar controls are also found on buses. You can find a similar steering mechanism on the GAZelle. But this applies only to older models, as well as business class versions. On the new "Nexts" the rake is already used.

Faults

Steering failures are considered one of the most serious vehicle breakdowns. Since on most passenger cars a rack and pinion mechanism was installed, the number of breakdowns was significantly reduced.

Typical breakdowns include the wear of a pair of rack and pinion, a violation of the tightness of the mechanism housing, a worn bearing on the steering shaft, as well as rod joints. The latter is the most common malfunction in rack and pinion mechanisms.

In the process of active use of the car, the working areas of the bearing roller, bipod shaft, and worm naturally wear out. The adjusting screw is also erased. Due to wear, gaps appear in the steering mechanisms, which can provoke knocks when driving. Often these gaps can cause vibrations on the steered wheels, loss of stability of the car. You can determine the appearance of gaps by the increased play on the steering wheel. The gap occurs in a pair of worm-roller. Then the axial displacement of the worm grows. Gaps can be eliminated by adjustment.

Causes of the malfunction

Among the causes of typical malfunctions, several of the most basic can be distinguished. So, the first and main reason why the rails fail is the quality of the roads. Then we can note periodic violations of the rules of operation, the use of low-quality components, unskilled repair of steering mechanisms.

signs

If in the process of driving a car, a knock is clearly detected by ear, then this indicates that the swivel joint of the thrust tip is badly worn. Also, these same symptoms may indicate an excessively worn ball joint.

If a beating is felt on the steering wheel, then the hinge on the thrust tip may be worn out, the shaft bearing is destroyed. When the free play is clearly felt on the steering wheel, this also indicates worn traction or a faulty transmission pair.

Adjustment

This process is a complex of operations aimed at reducing steering backlash, increasing accuracy when driving, and the speed of the car's response to the driver's actions. To adjust, you need to correctly set the axial and lateral clearances of the sector shaft and the worm. Correct settings will provide a slight backlash.

The adjustment process consists of loosening the lock nut and tightening the adjusting screw. In this case, constantly in the process of tightening the screw, you need to check for the presence of play. After it is removed, the screw is fixed in position with a lock nut.

This adjustment most often helps to eliminate backlash, but if the gap remains, then the worm pair in the mechanism is too worn out and needs to be replaced. To do this, dismantle the gearbox and replace worn parts.

Conclusion

These are all types of steering mechanisms that exist today. We learned how they work, briefly got acquainted with their principle of operation, learned about the signs of malfunctions. This information can help in the repair process or planned Maintenance car. It is important to remember that the steering is a very important unit and you should always keep it in good condition. With it, the driver can quickly change the direction of the vehicle, which allows you to maneuver the car on any part of the road, quickly respond in case of dangerous situations.

Each node and mechanism of the car is important in its own way. Perhaps there is no such system, without which the car could function normally. One of these systems is the steering mechanism. This is probably one of the most important parts of the car. Let's look at how this node is arranged, its purpose, structural elements. And also learn how to regulate and repair this system.

The principle of operation of rack and pinion tie rod

Rack and pinion steering

The rack and pinion steering mechanism is the most common type of mechanism installed on cars. The main elements of the steering gear are the gear and the steering rack. The gear is mounted on the steering wheel shaft and is in constant engagement with the steering (gear) rack.
Scheme rack and pinion steering

1 - plain bearing; 2 - high pressure cuffs; 3 - body of spools; 4 - pump; 5 - compensation tank; 6 – steering draft; 7 - steering shaft; 8 - rail; 9 - compression seal; 10 - protective cover.
The operation of the rack and pinion steering mechanism is as follows. When the steering wheel is turned, the rack moves to the left or right. During the movement of the rack, the steering rods attached to it move and turn the steered wheels.

The rack and pinion steering mechanism is distinguished by its simple design and, as a result, high efficiency, and also has high rigidity. But this type of steering mechanism is sensitive to shock loads from road irregularities, prone to vibrations. Due to their design features rack and pinion steering used on front-wheel drive vehicles

Worm gear

Worm gear diagram

This steering mechanism is one of the "obsolete" devices. They are equipped with almost all models of domestic "classics". The mechanism is used on cars with cross-country ability with dependent suspension of steered wheels, as well as in light trucks and buses.

Structurally, the device consists of the following elements:

steering shaft
worm-roller transmission
crankcase
steering arm

A pair of "worm-roller" is in constant engagement. The globoidal worm is the lower part of the steering shaft, and the roller is mounted on the bipod shaft. When the steering wheel is rotated, the roller moves along the teeth of the worm, due to which the steering arm shaft also rotates. The result of this interaction is the transfer of translational movements to the drive and wheels.

The worm gear steering has the following advantages:

the ability to turn the wheels at a greater angle
shock absorption from road bumps
transmission of great effort
providing better machine maneuverability

The manufacture of the structure is quite complicated and expensive - this is its main disadvantage. Steering with such a mechanism consists of many connections, the periodic adjustment of which is simply necessary. Otherwise, damaged items will have to be replaced.

Steering column

Performs the transfer of rotational force that the driver creates to change direction. It consists of a steering wheel located in the passenger compartment (the driver acts on it by rotating it). It is rigidly planted on the column shaft. In the device of this part of the steering, a shaft is often used, divided into several parts, interconnected by cardan joints.

This design is not just made. Firstly, it allows you to change the angle of the steering wheel relative to the mechanism, to shift it in a certain direction, which is often necessary when arranging constituent parts auto. In addition, this design allows you to increase the comfort of the cabin - the driver can change the position of the steering wheel in terms of reach and tilt, providing the most comfortable position.

Second, the composite steering column has the ability to "break" in the event of an accident, reducing the likelihood of injury to the driver. The bottom line is this - in a frontal impact, the engine can move back and push the steering mechanism. If the column shaft were solid, changing the position of the mechanism would lead to the output of the shaft with the steering wheel into the passenger compartment. In the case of a composite column, the movement of the mechanism will be accompanied by only a change in the angle of one component of the shaft relative to the second, and the column itself remains motionless.

Screw steering gear

The screw steering mechanism integrates the following structural elements: screw on steering wheel shaft; a nut that moves along the screw; gear rack, cut into a nut; toothed sector connected to the rail; steering arm located on the sector shaft.

A feature of the screw steering mechanism is the connection of the screw and nut with the help of balls, which achieves less friction and wear of the pair.

In principle, the operation of the screw steering mechanism is similar to the operation of the worm gear. Turning the steering wheel is accompanied by the rotation of the screw, which moves the nut put on it. In this case, the circulation of the balls occurs. Nut by means of a gear rack moves the gear sector and with it the steering arm.

The screw steering mechanism, in comparison with the worm gear, has a greater efficiency and implements greater efforts. This type of steering mechanism is installed on selected luxury cars, heavy trucks and buses.

Conclusion

In general, the mechanism is a fairly reliable unit that does not require any maintenance. But at the same time, the operation of the steering of a car implies timely diagnostics to identify faults.

The design of this node consists of many elements with movable joints. And where there are such connections, over time, due to the wear of the contacting elements, backlashes appear in them, which can significantly affect the handling of the car.

The complexity of steering diagnostics depends on its design. So in the nodes with the gear-rack mechanism, there are not so many connections that need to be checked: tips, gear engagement with the rack, steering column universal joints.

But with a worm gear, due to the complex design of the drive, there are much more diagnostic points.

Concerning repair work in the event of a malfunction of the assembly, then the tips are simply replaced in case of severe wear. In the steering mechanism, at the initial stage, the backlash can be removed by adjusting the gearing, and if this does not help, by reassembling the assembly using repair kits. The cardan shafts of the column, as well as the tips, are simply replaced.

Steering

Steering is a set of devices that turn the steered wheels of the car.

Rice. 2. Steering controls for independent (a) and dependent (b) suspension of steered wheels:
1 - steering wheel; 2 - shaft; 3 - steering gear (mechanism); 4 and 12 pins;
5, 9, 11 and 14 - levers; 7- bipod; 6, 8, 10, 13 and 15 - thrust

Safety steering

In addition to the steering wheel with a recessed hub and two spokes, which significantly reduces the severity of injuries on impact, a special energy-absorbing device is installed in the steering mechanism, and the steering shaft is made composite. All this ensures a slight movement of the steering shaft inside the car body in a head-on collision with an obstacle.

a - folding steering shaft; b - bellows shaft; c - perforated shaft; 1- bracket; 2- universal joint; 3 - cylinder; 4- pipe

In safety steering cars other energy-absorbing devices are also used that connect composite steering shafts: rubber couplings of a special design, devices like a Japanese lantern, in the form of several longitudinal plates welded to the ends of the connected parts of the steering shaft. In collisions, the rubber clutch is destroyed, and the connecting plates are deformed, reducing the movement of the steering shaft into the interior of the body.

Steering gear

Steering is a mechanism that converts the rotation of the steering wheel into translational movement of the steering gear, causing the steering wheels to turn. It serves to increase the effort of the driver applied to the steering wheel and transmit it to the steering gear.

The increase in the effort applied to the steering wheel occurs due to the gear ratio of the steering mechanism. The steering gear ratio is the ratio of the angle of rotation of the steering wheel to the angle of rotation of the steering arm shaft. Depending on the type of car, it is 15...20 for cars and 20...25 for trucks and buses. Such gear ratios for 1 ... 2 full turns of the steering wheel ensure the rotation of the steered wheels of vehicles at maximum angles (35 ... 45 °).

Used on cars Various types steering mechanisms.

a - worm-roller; b - screw rack; in - rack; 1 - worm; 2, 4 and 9 - shafts; 3 - roller; 5 - screw; 6 - nut; 7 - ball; 8 - sector; 10 - gear; 11 - rail

Steering gear

The steering drive is a system of rods and levers that connects the steered wheels of the car with the steering mechanism. It serves to transmit power from the steering gear to the steered wheels and ensure their correct rotation.

Various types of steering gears are used on cars.

The main part of the steering gear is steering trapezoid

The steering linkage can be front or rear, depending on its location in front of the axle of the front steered wheels (see Fig. 2, a) or behind it (see Fig. 2, b). The use of a steering gear with a front or rear steering linkage depends on the layout of the vehicle and its steering. In this case, the steering drive can be with a continuous or split steering linkage, depending on the type of suspension.
The continuous steering trapezoid has a solid transverse steering rod connecting the steered wheels (see Fig. 2, b).
This trapezoid is used for dependent suspension front steering wheels on trucks and buses.
The split steering trapezoid has a multi-link transverse steering rod connecting the steered wheels (see Fig. 2, a).
It is used for independent suspension of steered wheels on passenger cars.

Power steering

The power steering is a mechanism that creates, under the pressure of fluid or compressed air, an additional force on the steering gear necessary to turn the steered wheels of the car.

1 - spool; 2, 3 and 11 - oil pipelines; 4- spring; 5-wheel; 6 and 9 - thrust; 7 and 8 - levers; 10 - piston; a...G- cameras; A and B - cavities; B - tank; GN - hydraulic pump; RM - steering mechanism; GR - hydraulic distributor; HZ - hydraulic cylinder

Steering structures

Left, safety, without amplifier. Safety of steering is ensured by the design of the intermediate shaft of the steering wheel and the special fastening of the steering shaft to the car body.

1 and 3 - thrust; 2 - bipod; 4 and 7 - levers; 5 - clutch; 6 - fist; 8 and 16 - brackets; 9 - bearing; 10 - pipe; 11 and 13 - shafts; 12 - crankcase; 14 - column; 15- steering wheel; 17 - finger; 18 - case; 19 - tip; 20 - insert; 21 - spring; 22 - plug

The steering gear of a VAZ cross-country car:
1 - bipod; 2 and 13 - cuffs; 3- bushing; 4 - crankcase; 5 and 12 - shafts; 6 - roller; 7- screw; 8- nut; 9- cork; 10 and 16 - covers; 11 - worm; 14 and 18 - bearings; 15- adjusting shims; 17- axis

1 - lever; 2 - hinge; 3 and 5 - thrust; 4 and 34 - nuts; 6 - finger; 7 and 13 - covers; 8 - insert; 9 and 33 - springs; 10 and 20 - bolts; 11- bracket; 12 - support; 14 and 15 - plates; 16 and 17 - bushings; 18- rail; 19- crankcase; 21 - clutch; 22 - extinguishing device, 23 - steering wheel; 24, 29 and 31 - bearings; 25 - shaft; 26 - column; 27- bracket; 28- cap; 30 - gear; 32- emphasis

Do you know what the steering wheel on a racing car is called? Steering wheel! And in our cars, all that is a steering wheel ... Do you feel the difference? But let's leave Schumacher's Schumacher and talk about what is steering, or steering gear.

The steering system is used to control the car and ensure its movement in a given direction at the command of the driver. The system includes steering gear and steering gear. To imagine the operation of steering mechanisms different generations, we will divide the explanation into three parts, that is how many there are in the automotive industry.

Worm gear

It got its name because of the steering column drive system, namely the worm gear. The steering system includes:

steering wheel (I think it is not necessary to explain?)
steering shaft with cross, is a metal rod, which on one side has slots for fixing the steering wheel, and on the other side there are internal slots for attaching to the steering column. Full fixation is made by a turnbuckle, which compresses the junction of the shaft and the “worm” of the column drive. At the bend of the shaft, it is installed, with the help of which the lateral force of rotation is transmitted.
steering column, a device assembled in one cast housing, which includes a worm drive gear and a driven one. The driven gear is rigidly connected to the steering arm.
steering rods, tips and "pendulum", the totality of these parts connected to each other by means of ball and threaded joints.

The operation of the steering mechanism is as follows: when the steering wheel is rotated, the rotational force is transmitted to the worm gear of the column, the "worm" rotates the driven gear, which in turn drives the steering arm. The bipod is connected to the middle steering rod, the second end of the rod is attached to the pendulum lever. The lever is mounted on a support and is rigidly attached to the car body. Side rods depart from the bipod and the “pendulum”, which are connected to the steering tips with the help of crimp couplings. The tips are connected to the hub. The steering arm, turning, transfers the force simultaneously to the side rod and to the middle lever. The middle lever actuates the second lateral link and the hubs turn, respectively the wheels too.

Such a system was common on old Zhiguli and BMW models.

Rack and pinion steering

The most common system at present. The main nodes are:

steering wheel (steering wheel)
steering shaft (same as in the worm gear)
the steering rack is a unit consisting of a gear rack, which is driven by steering gear. Assembled in one body, often made of light alloy, it is attached directly to the car body. At the ends of the gear rack, threaded holes are made for attaching steering rods.
Tie rods are a metal rod with a thread on one end and a threaded swivel ball device on the other.
steering tip, this is a body with a ball joint and an internal thread, for screwing in the steering rod.

When the steering wheel is rotated, the force is transferred to the gear, which drives steering rack. The rail "leaves" the body to the left or right. The force is transmitted to the steering lever with a tip. The tip is inserted into the hub, which it turns in the future.

To reduce the effort of the driver when turning the steering wheel, in the rack and pinion steering gear power steering was introduced, we will dwell on them in more detail

The power steering is an auxiliary device for turning the steering wheel. There are several types of power steering. This is hydraulic booster, hydroelectric booster, electric booster and pneumatic booster.

The hydraulic booster consists of a hydraulic pump, which drives, a high-pressure hose system, and a fluid reservoir. The rack housing is hermetically sealed, as it contains hydraulic fluid. The principle of operation of the hydraulic booster is as follows: the pump builds up pressure in the system, but if the steering wheel is in place, the pump simply circulates the fluid. As soon as the driver begins to turn the steering wheel, the circulation is blocked, and the liquid begins to put pressure on the rail, “helping” the driver. The pressure is directed in the direction in which the "steering wheel" rotates.
AT hydroelectric booster the system is exactly the same, only the pump rotates the electric motor.
AT electric booster an electric motor is also used, but it is connected directly to the rack or to the steering shaft. Controlled electronic unit management. The electric power steering is also called an adaptive power steering due to the possibility of applying different forces to the rotation of the steering wheel, depending on the speed. The famous Servotronic system.
Pneumatic booster this is a close “relative” of the hydraulic booster, only the liquid has been replaced with compressed air.

Active steering system

The most "advanced" at the present time, it includes:

steering rack with and electric motor
electronic control unit
steering rods, tips
steering wheel (well, what about without it?)

The principle of operation of the steering system reminiscent of something. When the steering wheel rotates, the planetary mechanism rotates, which drives the rack, but only the gear ratio is always different, depending on the speed of the car. The fact is that the sun gear is rotated from the outside by an electric motor, therefore, depending on the speed of rotation, the gear ratio changes. At low speed, the transmission coefficient is unity. But with greater acceleration, when the slightest movement of the steering wheel can lead to negative consequences, the electric motor turns on, rotates the sun gear, and accordingly, it is necessary to turn the steering wheel more when turning. At low vehicle speed, the electric motor rotates in reverse side, creating a more comfortable control.

The rest of the process looks like a simple rack system.

Haven't forgotten anything? Forgotten, of course! They forgot one more system - screw. True, this system is more like a worm gear. So - a screw thread is machined on the shaft, along which a kind of nut “creeps”, it is a gear rack with a thread inside. The rack teeth actuate the steering sector, in turn, it betrays the movement of the bipod, and then, as in the worm system. To reduce friction, there are balls inside the "nut" that "circulate" during rotation.

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