What type of release bearing is used in the clutch release system?

The main types of release bearings used in the clutch release system are the traditional push-pull release bearings, self-aligning release bearings, and hydraulic release bearings.

 Push-pull release bearings

This is the most traditional type and is directly affected by the driver's pedal force through a mechanical linkage, lever or cable system. When the clutch pedal is depressed, the bearing is pushed, which in turn disengages the clutch and permits shift operation.

 Self-aligning Release Bearing

This design improves on the performance of conventional bearings by automatically adjusting its centring position to the release lever, reducing wear and vibration. It uses angular contact ball bearings and may have a fully sealed structure with high-temperature lithium grease for harsh operating environments. Its design allows the bearing to remain stable when not in operation, while applying uniform forces during operation, increasing service life.

Hydraulic Release Bearings

The hydraulic release bearing is an innovative component used in automotive clutch systems, especially in manual transmission vehicles. It controls the clutch release and engagement process through a hydraulic system, replacing the traditional mechanical release mechanism. Specifically, the hydraulic release bearing utilises hydraulic pressure to actuate the release mechanism, typically by transmitting pressure to this bearing via the clutch master cylinder, which in turn separates the clutch pressure plate from the slave plate, allowing for a gearshift operation.

Advantages of this design include:

- Smoother operation: As the hydraulic system provides a more linear force transfer, it allows the clutch to engage and disengage more smoothly, improving driving comfort.

- Integrated design: Hydraulic release bearings often incorporate the functions of several components, such as clutch split pumps and mechanical forks, simplifying the mechanical structure and saving space.

- Improved reliability and longevity: Hydraulic systems typically have a longer service life and higher reliability due to fewer mechanical wear points.

- Precise control: Hydraulic systems can more precisely control the degree of clutch disengagement, which is conducive to improving vehicle handling.

 Clutch release bearing working principle:

The clutch release bearing is installed between the clutch and the transmission, and maintains proper clearance with the release fork through the return spring. When it is necessary to disengage the clutch, the driver depresses the pedal, and the mechanical or hydraulic system transmits the force to the release bearing, which pushes it forward and compresses the diaphragm spring, separating the clutch disc from the engine flywheel and interrupting the power transmission. During the separation process, the bearing contacts the release lever (release finger) and controls the degree of clutch separation.

 Clutch release bearing characteristics:

- Self-aligning: Ensures that the bearing is centred on the release mechanism and reduces wear.

- Lubrication improvement: special grease and sealing designs are used to increase resistance to high temperatures and wear.

- Structural optimisation: Some designs alter the rotating parts, e.g. the inner ring rotates and the outer ring is fixed, to improve lubrication and life.

- Hydraulic operation: In some modern vehicles, hydraulic systems are used instead of mechanical connections to provide smoother operation.

 Summarising

The clutch release bearing is a key component in the clutch release system, which ensures smooth gear shifting in a vehicle, and is characterised by high load carrying capacity, resistance to wear and flexible movement. Its working principle is to use the return spring and the push effect of the release fork to make the release lever rotate and move axially along the clutch output shaft, so as to realise the separation and engagement of the clutch. The performance of the clutch release bearing directly affects the service life of the clutch and the driving performance of the whole vehicle, so it needs to pay attention to the maintenance and repair in the process of use, and be inspected and replaced regularly.

From conventional push-pull to self-aligning to hydraulically operated, each type is designed to reduce wear, improve responsiveness and extend service life by optimising the operating principle. The introduction of self-aligning and hydraulic clutch release bearings significantly improves the overall performance of the clutch system and the driving experience.