The clutch release bearing is a relatively important part of the car. If it fails due to poor maintenance, it will not only cause economic losses, but also take a lot of trouble to disassemble and assemble once. Therefore, it is of great significance to find out the cause of the failure of the clutch release bearing and to maintain and maintain it reasonably during use, which is of great significance to prolong the life of the release bearing, improve labor productivity, and obtain better economic benefits.
The clutch release bearing is installed between the clutch and the transmission. The release bearing seat is loosely fitted on the tubular extension of the first shaft bearing cover of the transmission. The shoulder of the release bearing always touches the release fork through the return spring and retreats to the final position. , keep a gap of about 3~4mm with the end of the separation lever (separation finger). Since the clutch pressure plate, release lever and engine crankshaft operate synchronously, and the release fork can only move axially along the output shaft of the clutch, it is obviously not possible to directly use the release fork to move the release lever. The release lever can be rotated for one side through the clutch release bearing. The output shaft of the edge clutch moves axially, thus ensuring the smooth engagement of the clutch, soft disengagement, reducing wear and prolonging the service life of the clutch and the entire transmission system.
The automotive clutch release bearings should move flexibly without sharp noise or stagnation, its axial clearance should not exceed 0.60mm, and the wear of the inner race should not exceed 0.30mm. If the clutch release bearing fails to meet the above requirements, it is considered to be faulty. After a fault occurs, it is first necessary to determine which phenomenon belongs to the damage of the release bearing. After starting the engine, step on the clutch pedal lightly. When the free travel just disappears, there will be a "rustling" or "squeaking" sound. Continue to step on the clutch pedal. If the sound disappears, it is not a problem with the release bearing. If there is still a sound, it is the release bearing.
The release bearing (i.e. chevrolet cruze clutch release bearing) is affected by axial load, impact load, and radial centrifugal force during high-speed rotation during use. In addition, because the thrust of the shift fork and the reaction force of the release lever are not on the same straight line, a torsional moment is also formed. The clutch release bearing has poor working conditions, intermittent high-speed rotation and high-speed friction, high temperature, poor lubrication conditions, and no cooling conditions.
The damage to the hydraulic clutch bearing has a lot to do with the driver's operation, maintenance and adjustment. The reasons for the damage are roughly as follows:
1. The working temperature is too high to produce overheating
Many drivers often half step on the clutch when turning or decelerating, and some drivers still put their feet on the clutch pedal after shifting into gear; Due to dry friction, a large amount of heat is transferred to the release bearing. When the bearing is heated to a certain temperature, the butter melts or dilutes and flows, which further increases the temperature of the release bearing. When the temperature reaches a certain level, it will burn out.
2. Lack of lubricating oil and wear
The clutch release bearing is lubricated with butter. There are two ways to add butter. For the release bearing, the back cover of the bearing should be opened and filled with grease during maintenance or when the transmission is removed, and then the back cover should be reassembled That's it; for the release bearing, it can be removed and soaked in melted grease, and then taken out after cooling to achieve the purpose of lubrication. In actual work, drivers tend to ignore this point, resulting in lack of oil in the clutch release bearing. In the case of no lubrication or less lubrication, the wear amount of the release bearing is often several to dozens of times that of the lubricated wear amount. As wear increases, the temperature will also increase greatly, making it more susceptible to damage.
3. The free stroke is too small or the number of loads is too much
According to the requirements, generally the gap between the clutch release bearing and the release lever is 2.5mm, which is more suitable, and the free travel reflected on the clutch pedal is 30-40mm. If the free travel is too small or there is no free travel at all, the release lever and the release lever will Bearings are in constant engagement. According to the principle of fatigue damage, the longer the working time of the bearing, the more serious the damage will be; the more times the bearing is loaded, the more likely the separation bearing will be fatigue damage. Moreover, the longer the working time, the higher the temperature of the bearing, the easier it is to burn out, and the service life of the clutch release bearing is reduced.