What is a clutch release bearing

The clutch release bearing is a key component in a clutch. Its main function is to disengage the clutch by pushing on the release fingers of the clutch pressure plate when the driver depresses the clutch pedal. In this way, engine power is not transmitted to the transmission, allowing the driver to shift gears or stop the vehicle without stalling.

The clutch release bearing is usually mounted in the clutch housing and is connected to the clutch pedal by some mechanism, such as a cable or hydraulic piston. When the driver depresses the clutch pedal, this mechanism pushes the clutch release bearing so that it makes contact with the release fingers of the clutch pressure disc and pushes them, thereby separating the clutch pressure disc from the clutch disc (clutch disc).

The clutch release bearing is pushed by a cable or a hydraulic piston, depending on the specific design of the clutch system.

What pushes on the clutch release bearing?

When the driver depresses the clutch pedal.

In a cable-operated system, a cable is connected to the clutch pedal and to the clutch release bearing. Pulling on the cable causes the bearing to push against the fingers of the pressure plate and disengage the clutch.

In the hydraulic system, depressing the clutch pedal compresses the piston in the master cylinder, thereby increasing the pressure of the hydraulic fluid. This pressurised fluid is then sent to a slave cylinder where it pushes a piston that moves the clutch release bearing.

In both cases, the movement of the clutch release bearing moves the pressure plate away from the clutch disc, reducing or eliminating friction between them and disconnecting the engine from the transmission.

The clutch release bearing is pushed by the clutch fork or, in hydraulic systems, directly from the slave cylinder. Here's a detailed explanation.

The interaction between the clutch pedal and the clutch release bearing is transmitted through a series of mechanical or hydraulic components that ensure a smooth separation and combination of engine and transmission power transmission during driving.

1. Clutch pedal operation:

When the driver depresses the clutch pedal, a chain reaction begins. The movement of the pedal is transmitted via a mechanical linkage (for mechanical clutches) or via a hydraulic system (for hydraulic clutches).

2. Transmission in mechanical clutches:

   - In a mechanical system, the movement of the pedal pushes the release fork directly or indirectly via a push rod or cable.

   - The release fork in turn pushes the release bearing, which is located between the clutch pressure plate and the flywheel. 

3. Hydraulic clutch transmission:

   - The downward pressure of the pedal compresses the hydraulic oil in the master cylinder and transfers the pressure to the hydraulic lines.

   - The hydraulic pressure reaches the slave cylinder (or slave cylinder) located near the clutch.

   - The piston in the slave cylinder moves outward under pressure, and this action pushes the release bearing either directly or through a mechanical connection (e.g., the release fork). 

4. Action of the release bearing:

   - The release bearing is pushed towards the centre of the pressure plate. This action overcomes the pressure of the pressure plate on the clutch disc.

   - As the pressure disc recedes, the pressure between it and the flywheel is reduced, thus separating the clutch disc from the flywheel and interrupting the power transmission.

5. Release and engagement:

   - When the driver releases the clutch pedal, either in a mechanical or hydraulic system, the release bearing retracts by the opposite mechanism, allowing the pressure disc to tighten on the clutch disc again, re-establishing power transmission from the engine to the gearbox.

6. Free Travel: 

The clutch pedal is usually designed with free travel to ensure that even when the clutch disc wears out, there is still some clearance between the release lever and the release bearing to ensure that the clutch can fully engage and avoid slippage.

Through such a mechanism, each operation of the clutch pedal precisely controls the clutch release and engagement, enabling smooth starting and gear shifting of the vehicle.

In these two systems, the clutch release bearing serves as a critical interface, transmitting the necessary force to disengage the clutch and facilitate smooth gear shifting.

The working condition of the clutch release bearing is critical to the performance and longevity of the clutch. If the bearing is worn or damaged, it may result in incomplete clutch disengagement, which in turn affects the smoothness of the gearshift and the driving performance of the vehicle. Therefore, regular inspection and maintenance of the clutch release bearing is an important step in ensuring proper clutch operation.