The terms ‘clutch release bearing’ and ‘throwout bearing’ refer to the same component in a manual transmission vehicle. This bearing is a key component of the clutch system and serves to disconnect the engine from the transmission when the clutch pedal is depressed.

The clutch release bearing (also known as a throwout bearing) is located between the pressure plate and the input shaft of the transmission. When the clutch pedal is depressed, it activates the clutch master cylinder, which in turn pushes the clutch slave cylinder. The slave cylinder then pushes the throwout bearing against the pressure plate, which releases pressure on the clutch disc, thereby disengaging the engine from the transmission and allowing the driver to shift gears. This type of bearing takes advantage of the benefits of hydraulics, such as smooth force transmission, lower noise and longer service life, to optimise clutch handling.

In short, ‘clutch release bearings’ and ‘throwout bearings’ are interchangeable terms used for the same component that facilitates clutch release in manual transmissions.

How clutch release bearings work.

The operating principle of the clutch release bearing relates to the control mechanism of the clutch in a manual transmission vehicle. It is located between the clutch and the transmission, specifically, it is mounted on the extension tube of the first shaft of the transmission and is kept in the standby position by means of a return spring. The following is its detailed work flow:

1. Engaged state: During normal driving, a certain clearance is maintained between the release bearing and the pressure plate, at which time the clutch engages and the engine speed is transferred to the driven disc through the flywheel and then to the transmission for power transmission.

2. Disengagement process: When the driver depresses the clutch pedal, a series of levers or a hydraulic system (depending on the vehicle design) act on the release fork, which in turn pushes the release bearing forward. This action overcomes the force of the return spring and causes the release bearing to press against the release lever (or release lever acting directly on the pressure plate).

3. Power interruption: As the release bearing advances, it pushes the pressure disc backwards, reducing the pressure of the pressure disc on the follower disc, thus permitting the friction between the follower disc and the flywheel to decrease until complete separation is achieved. This interrupts the transfer of power from the engine to the transmission, providing the conditions for shifting gears.

4. Precise control: The movement of the release bearing ensures precise clutch disengagement, allowing the driver to shift smoothly without causing sudden power changes, ensuring a smooth ride.

5. Return and Protection: When the clutch pedal is released, the release bearing is returned to its original position by means of a return spring, which maintains clearance with the release lever and prepares it for the next operation, while avoiding unnecessary wear.

Through this mechanism, the clutch release bearing plays a key role in every gear shift, ensuring that the clutch can be effectively disengaged and engaged, resulting in smooth gear shifts and power transmission control of the vehicle.

Function of the clutch release bearing:

Clutch release bearing, also known as clutch release bearing or thrust bearing, its core function is to achieve the clutch release action to interrupt the power transmission between the engine and the transmission system. Specifically, its functions include:

1. Power interruption: when the driver depresses the clutch pedal, the release bearing pushes the pressure plate away from the flywheel through a series of mechanical connections (e.g., the release fork or the hydraulic system), thus separating the clutch disc from the flywheel and interrupting the transmission of engine speed to the transmission.

2. Smooth Gear Shift: Ensures smoothness during gear shift by precisely controlling the clutch release, avoiding hard collisions between gears and protecting the gearbox from shock loads.

3. Reduced wear and tear: Ensure the clutch is disengaged at the right time, reducing unnecessary friction and thus prolonging the service life of the clutch friction disc and other related parts.

4. Dynamic adjustment: During operation, it allows small movements and adjustments in the clutch system, ensuring that the effective disengagement function is maintained even in the presence of wear.

5. Support and guidance: in some designs, it also serves to support the transmission input shaft and acts as a guiding element in the power transmission path.

6. Protection mechanism: through its work, it indirectly protects the clutch system from excessive pressure and maintains the stable operation of the whole transmission system.

To sum up, the clutch release bearing (also known as throwout bearing) is vital in a manual gearbox, which controls the separation and engagement of the clutch, interrupts the power transmission between the engine and the transmission, and achieves smooth gear shifting. It reduces wear and prolongs component life by precisely controlling the clearance between the pressure plate and flywheel. At the same time, it supports the input shaft and protects the clutch system, ensuring efficient power shifts and a smooth ride.