Structurally, the clutch consists of a clutch cover with a pressure plate (1, fig. 7.1), slave drive (2) and a clutch release mechanism that includes a release bearing (3), release bearing lever (5), ball pin (6) and spring clip (7). driven disc (2) located between pressure plate (1) and flywheel.
The hallmarks of clutch type «SAC» is the presence of three sockets with stops for adjusting rings (see fig. 7.12).
Clutch cover with pressure plate, referred to as «basket», installed on the end (rear) flywheel surfaces on bolts that are cross-tightened in several steps, the final force depends on the engine model:
- M8 bolts (8.8) torque 25 Nm (2.5 kgf·m);
- M8 bolts (10.9) torque 34 Nm (3.4 kgf·m).
The driven clutch disc with an elastic hub has a splined connection with the primary (input) manual gearbox shaft (RKPP) and slide freely over it. Friction linings are installed on the surfaces of the disc with the help of rivets, the minimum thickness of the disc lining is 7.5 mm. In this case, the residual thickness of the lining between its surface and the head of the rivet must be at least 1.0 mm. The brand of friction lining material is Textar T50 SM7. The disc hub has damping springs that dampen the shock of the transmission during engine start and stop, when the clutch is abruptly engaged, as well as the engine vibrations themselves, which guarantees a smooth drive (move) car. The clutch disc is centered with the gearbox input shaft.
The clutch release lever is installed in the clutch housing. It is linked to a maintenance-free, self-centering release bearing.
As the lining of the driven disk wears out, the pressure disk moves towards the flywheel, and the sectors of the diaphragm spring straighten. Hydraulic clutch (pic. 7.2), does not require adjustment, since the amount of hydraulic fluid in the system automatically compensates for wear after each pressing the clutch pedal.
The design of the hydraulic clutch release actuator is shown in Figure 7.2 and includes the main components - the master cylinder (1), pipelines (8, 12), hose (7) brake fluid reservoir, working (executive) clutch actuator cylinder (14), clutch switch module (20). On cars «x5» engine flywheels are dual-mass (pic. 7.3.). One part (1) connected to the crankshaft flange, its other part is connected to the clutch basket and is the working surface of the clutch mechanism. The rubbing surface has the ability to move, because. an elastic element is located between the parts of the flywheel (2) spring type, which plays the role of a torsional vibration damper, in addition to which a friction torque limiter is used.
The maximum allowable end runout of the working surface of the driven disk is not more than 0.5 mm. For the pressure plate, warping should be no more than 0.3 mm, end runout relative to the diaphragm spring - no more than 0.6 mm, non-flatness (warpage) flywheel surface under the driven disk in operation - no more than 0.2 mm.