Clutch device

The transmission of the car consists of a clutch, a gearbox combined with a main gear and a differential, and a front wheel drive.

The engine assembly with the gearbox constitutes the power unit. The power unit is located across the car and has a three-point attachment to the subframe brackets through rubber elements. Torque is transmitted directly from the power unit to the drive wheels through transmission units, which are compactly located in a single crankcase. It is assembled with wheel drives and a downpipe of the exhaust system mounted on a subframe along with the front suspension, front wheel brakes and steering gear.


To reduce the complexity in the repair of the gearbox and the convenience of its removal, the left side member 7 (see ch. 23) the subframe has a bolted connection with the front cross member 13 of the subframe and the steering gear support. To remove the gearbox, it is enough to remove the left side member of the subframe to free up space for removing and lowering the gearbox.

Clutch

The clutch is single-disk, dry with a central diaphragm pressure spring of a permanently closed type, with a cable drive. This type of clutch is distinguished by its simplicity, compactness and reliability of design and is widely used in passenger cars. The clutch has a low maintenance complexity and is consistent with other transmission mechanisms in terms of service life.

Using the clutch, the driver briefly disconnects the engine from the transmission when shifting gears and braking, and smoothly connects them when starting the car. The clutch also protects transmission parts from dynamic loads due to partial disc slip and damper operation (vibration damper) slave disk.

The clutch is attached to the flywheel 2 with a casing 5 with six bolts and is centered on the flywheel with three dowel pins. The clutch is closed with an aluminum crankcase 29. A cast holder 1 of the rear oil seal of the crankshaft of the engine is clamped between the engine block and the clutch housing. From below, the cavity of the clutch housing is closed with a stamped cover. There is a hatch in the upper part of the clutch housing. and on the stuffing box holder - scale 3, for checking and setting the ignition timing according to the marks on the flywheel and on the scale.


Two cylindrical roller bearings are pressed into the sockets of the clutch housing, one for the primary, the second for the secondary shafts of the box and a differential tapered roller bearing. To the inner end of the bearing seat 28 of the input shaft 22, the guide sleeve 20 of the clutch 13 of the clutch release bearing is attached with its flange. One of the mounting bolts of the guide sleeve has a ball head, which is a support 16 for the fork 14 of the clutch. The fork passes through the crankcase window to the outside and is sealed with a rubber boot 17 at the exit. The clutch housing also has sockets for the gear selection rod, for the starter support sleeve and for the axis of the reverse intermediate gear. Breather pipe 11 is pressed into the clutch housing from above, through which the cavity of the gearbox housing communicates with the atmosphere. A rubber cap 10 is installed on the breather tube. To prevent oil from being ejected through the breather, the cavity of the breather tube on the side of the gearbox is closed with a plate 18. Outside, in the socket of the clutch housing, the case 50 is mounted on a stud with a nut (see ch. 19) speedometer drive.

The gearbox housing is attached to the rear plane of the clutch housing.

Leading part

The leading part of the clutch is made of a one-piece assembly, which includes a casing 5, a pressure plate 6, a pressure spring 7 and elastic plates 27 connecting the clutch casing to the pressure plate. This part of the clutch is directly attached to the flywheel and, through the friction linings 23, transmits the engine torque to the driven part of the clutch, and through it to the input shaft of the gearbox.


The clutch cover is stamped from sheet steel. In the cavity of the casing, the support ring 8 of the pressure spring is welded by relief welding in three places. The other ring is sandwiched between the heads of six rivets 9 connecting the pressure spring to the clutch cover. Thus, support rings are located on both sides of the pressure spring, relative to which its deflection occurs. Three pairs of elastic plates 27 are riveted to the clutch casing at one end, and at the other end they are riveted to the pressure plate, elastically connecting both parts.

The pressure plate 6 is cast iron, has three lugs for attaching elastic plates. The working surface of the pressure plate is polished. On the side of the pressure spring, the disk has an annular protrusion, on which the working edge of the pressure spring presses, moving the disk towards the flywheel. There are windows in the collar for better ventilation of the clutch.

The pressure spring 7 is made of spring steel and has the shape of a conical diaphragm. Radial slots form 12 petals on the spring. The slots end with holes, through six of which rivets pass to connect the spring to the clutch covers. The pressure spring is supported by two wire rings 8, one on each side of the spring. To the petals of the pressure spring is constantly pressed with a force of 30... 70 N (3.3...7.1 kgf) self-aligning bearing 12 clutch release.

Driven part

The driven part of the clutch consists of a driven disc 4 and a damper (vibration damper). The surface of the driven disk is divided into six sectors by curly cuts, the outer contour of which is made along the circumference in the form of a wavy curve. Figured cutouts are also made on the surface of the driven disk, due to which the elasticity of each sector is improved. To preserve the wave-like shape of the disc sectors, the friction linings are riveted to the sectors with steel rivets independently of each other. The heads of the rivets are recessed in the holes of the overlays, and their rods are riveted from the side of the disk. Holes are made in the opposite lining to access the rivets


The convex part of the sectors creates an uneven specific pressure on the surface of the linings and the surfaces of the flywheel and pressure plate in contact with them: it is greater under the convex part of the sector, and less in the intervals between them, and only after the driven disk is completely compressed, the specific pressure on these surfaces is equalized, which ensures smooth engagement of the clutch. In this case, the initially driven disk slips relative to the surfaces of the flywheel and pressure plate, and the transmitted torque increases gradually. This protects the transmission parts from overloads and contributes to smooth starting of the car.

The driven disk is connected to the hub 24 through the parts of the torsional vibration damper, which creates an elastic connection between them. The need for a vibration damper is caused by the following. With a sharp change in vehicle speed, hitting bumps in the road, abrupt engagement of the clutch, and also due to uneven torque during the four-stroke cycle of the engine, dynamic loads occur in the transmission, causing twisting (unwinding) vehicle transmission shafts. Uneven engine torque can cause significant overloads in the transmission due to the occurrence of torsional vibrations and resonance when the oscillation frequencies of the transmitted loads coincide with the natural frequencies of the transmission. These elastic vibrations of the transmission can lead to failure of the transmission parts when the vibration amplitudes reach a large value. The torsional vibration energy is absorbed by the vibration damper (damper).

It includes: 34 front and 26 rear damper plates, 25 springs, 31 friction ring, 33 support ring and 32 spring washer. damper plates 34 and 26, which are interconnected by thrust fingers 30 (rivets). These fingers pass freely through the three horseshoe cutouts of the hub flange and limit the angle of rotation of the driven disk (together with damper plates) regarding the hub. The friction ring 31 is pressed against the hub flange by a conical spring washer 32 with a force that ensures the movement of the driven disk relative to the hub (to the fingertips) at a torque of over 7 kgf·m. At the same time, resistance to rotation of disk 4 relative to the hub is created by three pairs of springs 25 of different elasticity and coloring (coatings), placed in rectangular windows of hub 24, disk 4 and damper plates.

Springs of the same color are located opposite each other. From falling out of the windows of the hub and disk, the springs are fixed by flanging holes in both damper plates.

The driven disk assembly is mounted on the pins of the input shaft 22 of the gearbox and can move along the shaft.

The clutch is released using a cable drive, the force from which is transmitted through the fork 14 to the clutch release bearing 12.

The clutch 13, complete with bearing, is located on the guide sleeve 20, which is attached to the clutch housing with three bolts with its flange. One of the fastening bolts has a ball head 16, which is a support for the fork 14. The fork is fixed on the ball bearing with a spring 15. The exit point of the fork from the clutch housing is sealed with a protective cover 17.