The power unit, depending on the model and equipment, can be equipped with a clutch of several models
Clutch intended for:
- smooth starting off of the vehicle by providing a gradual increase in pressure on the clutch friction surface when the driver releases the clutch pedal;
- reliable transmission of engine torque to the transmission (without slipping) with the clutch fully engaged;
- momentary disconnection of the engine from the transmission at the moment of gear shifting and in other necessary cases.
The main condition for the reliable operation of the clutch on a vehicle is knowledge of the features of the clutch device and its drive, as well as strict adherence to the instructions for their operation and maintenance.
Pay special attention to the following when operating the vehicle:
- avoid operating with a defective clutch and clutch release actuator;
- Do not open the clutch housing hatches while the engine is running;
- when installing a pressure plate with a casing on the engine flywheel, ensure that the bolts securing the casing to the flywheel are securely tightened;
- Observe other clutch operation rules.
Design and operation of the clutch
The diaphragm clutch (Fig. 1) consists of driving and driven parts, as well as parts of the clutch release mechanism installed in the clutch housing.
The leading part of the clutch is a pressure plate 2 with a casing, which is mounted on the engine flywheel and fastened with M10 bolts (12 pcs.) with a diameter of 450 mm.
Centering is carried out on a cylindrical groove with a diameter of 475 mm on the flywheel and clutch cover.
The pressure plate is connected to the casing with 4 packs of plates that provide centering, axial movement and transmission of torque from the casing to the pressure plate.
To prevent rotation of the diaphragm spring relative to the casing and pressure plate, 6 pairs of bushings with special brackets are installed on the latter.
The use of these brackets allows you to maintain constant contact between the pressure plate and the spring and ensure that the first one leaves when the clutch is released.
Driven part - driven disc 1 is installed between the flywheel and the pressure plate and is centered on the splines of the gearbox input shaft.
In clutches of this type, a driven disk with a spring-friction type damper with elastic fastening of one of the friction linings is used.
Thanks to this, the clutch reduces the dynamic loads on the transmission during sudden starts (starting off, shifting gears), and also eliminates resonance phenomena and reduces the maximum "peak" torque values u200bu200bwhen the vehicle is in steady motion.
The fastening of the friction linings is shown in fig. 2.
The clutch release mechanism consists of a clutch 4 (Fig. 1) with a bearing, a fork 6 and a roller 8. The clutch is connected through a thrust ring 3 to a diaphragm spring using a locking device.
Retract spring 7 (Fig. 1) prevents rotation and axial movement of the sleeve 7 relative to the thrust ring 1 (Fig. 3).
As the friction linings wear out, the clutch release clutch 4 moves along with the spring towards the flywheel, while the design of the clutch release drive of a car or other vehicle ensures that the fork 6 (Fig. 1) turns clockwise after selecting the gap between the fork legs and clutch due to periodic adjustment of the drive or gradual rotation due to the design of the hydraulic drive.
The design of the locking device is shown in fig. 3.
It includes a thrust ring 1, a clutch bearing bush 7 with a shaped groove, an O-ring 2, and a locking ring 5.
The thrust ring 1 is installed on the diaphragm spring when assembling the pressure plate with the casing and is held by the spring washer 3 and the retaining ring 4. In the figure, the clutch is locked (connected) to the thrust ring.
Inside the clutch bearing sleeve 7, a safety ring 6 is installed, which has a protruding mustache on the outside, preventing accidental disconnection of the clutch release clutch and thrust ring 1.
The clutch is disengaged by turning the shaft clockwise. Valid for the direction of moving the clutch and turning the shaft to disengage the clutch is shown in fig. 1 arrows.
Moving the coupling and turning the shaft in the opposite direction is not allowed.
Features of clutch operation
The durability and reliability of the clutch during vehicle operation depends on the loads acting on the clutch parts, which in turn are determined by the specific use of the clutch during operation.
To reduce the work of friction (slip) and heating of the clutch parts, follow these requirements:
- when starting off, use 1st gear in the gearbox;
- release the clutch pedal at the lowest possible crankshaft speed;
- choose the optimal pace (speed) of releasing the clutch pedal in such a way that the starting time is as short as possible, and the vehicle starts to move off without "jerks" and "twitches";
- when maneuvering a vehicle (driving through bottlenecks, entering inspection pits, overpasses, into boxes, etc.), do not allow speed control by slipping the clutch (the clutch pedal is partially depressed);
- Complete the clutch maintenance requirements on time and in full;
- Do not allow operation with a faulty clutch release drive, with the clutch slipping when the pedal is fully released, as well as with "driving".
Operation with slippage leads to increased wear of the friction linings, the appearance of cracks on the flywheel and pressure plate from increased heat.
Driving operation leads to difficult shifting and wear of gearbox synchronizer parts.
One of the features of the operation of the clutch is that its malfunctions (slip, steering, delayed engagement, etc.) are often associated with a malfunction of the clutch release mechanism, so it must be periodically checked and timely maintenance carried out.
Model - YaMZ-183
Clutch type - dry, friction, single disc, with diaphragm exhaust spring and asbestos-free lining
Engine torque, N m (kgf m):
- - minimum 1100 (112);
- - maximum 1400 (143)
Clutch driven disc with damper, spring-friction type, with elastic fastening of one of the friction linings
Dimensions of friction linings, mm:
- - outer diameter 430;
- - inner diameter 240;
- - thickness 4.3
Diameter of the pressure plate belt Dн - 320 mm
The thickness of the pressure spring T is 5 mm
Drive hub splines:
- - number of slots 10
- - inner diameter 34 mm
- - outer diameter 42 mm
- - cavity width 6 mm
Clutch release stroke required for disengagement, mm:
- -minimum 11
- - max 13
Departure of the pressure plate when turning off, at least 2.3 mm
Clutch release bearing - ball radial 70-117 GOST 8338-75
Force on the clutch release clutch, kgf no more than 560
Torque on the shaft of the clutch release fork, Nm no more than 600
Lubrication of clutch bearings and release fork shaft supports SHRUS - 4M TU 38401-58-128-95, SHRUS-4 TU 0254-001-05766076-98.
Types and frequency of maintenance of the clutch correspond to the types and frequency of maintenance of the engine.
Clutch maintenance includes a daily check of the operation of the clutch on the vehicle, as well as, after one TO-1 (after 500 hours) and at each TO-2, lubricate the clutch release clutch with the bearing and the clutch release fork roller.
Daily inspection of vehicle clutch operation includes checking for slippage, "driving" and extraneous noises and knocks.
Clutch slip is detected during gear shifting, when the vehicle speed does not increase after releasing the clutch pedal and a sharp increase in engine speed.
Clutch engagement (incomplete disengagement) has several characteristic features:
- Enabling synchronized transmissions is difficult;
- the inclusion of unsynchronized gears occurs with a characteristic rattle in the gearbox;
- Vehicle in low gear and clutch pedal depressed.
Grease is supplied to the coupling through the hose lubricator until grease appears in the gap between the bearing sleeve and the deflector.
The clutch release fork roller is lubricated through two grease fittings, making two strokes with a syringe.
To ensure the normal operation of the clutch, the lane Periodically check the correct adjustment of the clutch drive.
The frequency and procedure for monitoring and adjusting the clutch actuator is determined by the vehicle operating manual.
Mounting the clutch on the engine
The clutch is installed on the engine in the following order:
- Using a special mandrel, install the driven disk on the flywheel, while the friction lining riveted to the spring plate should be located to the pressure plate, and the elongated part of the hub should be outward (away from the engine).
- Install the pressure plate with casing assembly, making sure the mounting holes of the clutch casing and the flywheel are aligned.
- Tighten the clutch mounting bolts by hand to a depth of at least 4 mm.
- Tighten the clutch mounting bolts with Mcr 60...70 Nm in several steps, evenly pulling the pressure plate with the casing to the flywheel, avoiding significant distortions of the pressure (diaphragm) spring.
- Using a special mandrel, center ring 3 (Fig. 3) relative to the axis of the engine crankshaft.
The design of the locking device of the clutch release mechanism requires special rules for installing the gearbox on the engine.
The main positions of the locking device are shown in fig. 4.
The gearbox is installed and the clutch release clutch is engaged with the diaphragm spring thrust ring in the following order (the lever is located on the left side of the engine):
- Turn the locking ring 5 on the coupling so that its protrusions do not coincide with the grooves of the coupling bearing bush ("a" position).
- Make sure that the clutch release clutch is retracted all the way into the bearing cover of the input shaft of the gearbox with the spring 7 fig. 1.
- Install the gearbox and secure with two bolts.
Attention! When installing the gearbox, do not allow the clutch release clutch to move towards the flywheel after it has been connected to the compression spring.
- Move the clutch release clutch to the thrust ring until it stops, for which, using the technological lever, turn the shaft of the clutch release fork counterclockwise.
The spring ring then falls into the shaped groove of the thrust ring (position "b", fig. 4).
- Turning the release fork shaft clockwise, move the clutch away from the engine ("В" position fig. 4).
- Make sure the clutch release clutch is engaged with the thrust collar by applying additional force to the clutch away from the engine.
- Finally fix the gearbox.
Checking the quality of the clutch installation (lack of "leading", control of the torque on the fork shaft) is carried out with the engine off.
To do this, it is necessary to turn the fork shaft by an angle of 9º30...11º clockwise, which corresponds to the displacement of the coupling by 11...13 mm from the engine.
In this case, the output shaft of the gearbox, with the gear engaged, must rotate when a torque of not more than 5 Nm (0.5 kgf m) is applied.
Clockwise rotation of the clutch release fork shaft is shown in fig. 1.
Removing the clutch from the engine
Remove the clutch from the engine with the gearbox installed in the following order:
- Remove the nut securing the lubrication hose.
- Push the lubricant hose into the cavity of the clutch housing.
- Remove the gearbox, leaving the clutch release on the diaphragm spring stop ring.
- Align the semicircular groove on the clutch release clutch in its front part with the protruding mustache of the safety ring 6 (Fig. 3) and, having sunk it with some object, hold it in a recessed position through the central hole of the clutch release clutch.
- Turn the locking ring 5 (Fig. 4) relative to the sleeve 6 so that the protrusions of the ring coincide with the grooves of the sleeve ("г" position).
- Push the clutch towards the flywheel until it stops, while the spring ring 4 will come out of the shaped groove of the thrust ring and stand in a rectangular position ("д").
- Disconnect the clutch by moving it in the opposite direction (away from the flywheel), while the spring ring remains in the rectangular groove of the thrust ring (position "e"), and then removed from it.</ li>
- Remove the pressure plate with the casing, for which unscrew the clutch mounting bolts, gradually in several steps, avoiding significant distortions of the pressure spring.
Fault - Remedy
Worn disc friction linings - Replace linings or driven disc assembly
Oil entering the friction surfaces of the clutch through the seals of the engine or gearbox - Remove oil from the friction surfaces, eliminate the oil leak
Faulty pressure spring - Replace pressure spring or pressure plate with casing and spring assembly
Clutch partially disengaged due to failure of the release drive - Repair the failure of the clutch release drive according to the vehicle manual.
Clutch release drive does not provide the required release clutch travel - Check the operation of the clutch release drive and troubleshoot
Pressure plate warped - Replace pressure plate with casing assembly
Using a driven plate after repair with unacceptable runout and curvature - Replace the driven plate
Destruction of the lining of the driven disk - Replace the linings or the driven disk
Emerging noise at the location of the clutch
Lack of lubrication in the release clutch bearing or its wear - Lubricate the clutch release clutch through an oiler, if the noise is not eliminated - replace the clutch with bearing