Concentric clutch release bearings

 I. Concentric clutch release bearings definition and function

Concentric clutch release bearings definition:

Concentric clutch release bearings are specially designed bearings to eliminate the heat and resistance generated by the direct friction between the clutch pressure plate and the fork. It is installed between the clutch and the transmission to ensure smooth operation and reduce wear and noise during clutch operation even if there is some misalignment.

Concentric clutch release bearing function:

- Separation and engagement: When the clutch pedal is depressed, the release bearing pushes the pressure disc to separate it from the friction disc, thus cutting off the power output from the crankshaft. When the clutch pedal is released, the spring pressure inside the pressure disc pushes the pressure disc forward and presses it against the clutch disc, so that the clutch disc and flywheel re-engage and power transmission is resumed.

- Reduced friction: By reducing the friction between the pressure disc lever and the release fork, it makes the clutch operation smoother and more precise.

 Second, concentric clutch release bearing working principle

1. Return spring action:

   - The release bearing is kept in the position of the main release fork by means of the return spring and is able to retreat to the final position, keeping a certain distance from the end (usually 3~4mm).

2. Pedal Conducted Force:

   - The force of the clutch pedal is transmitted to the clutch release bearing, causing it to move towards the centre of the clutch pressure plate, which pushes the pressure plate away and separates the clutch disc from the flywheel.

3. spring pressure recovery:

   - When the clutch pedal is released, the spring pressure inside the pressure plate will push the pressure plate forward and press it towards the clutch disc, so that the clutch disc and the clutch bearing will be separated, completing a working cycle.

 Concentric clutch release bearing characteristics and requirements

1. High concentricity:

   - The inner and outer rings have high concentricity to ensure the stability and reliability of the bearing in the running process.

2. Flexible movement:

   - The release bearing should move flexibly, without sharp noise or stalling phenomenon.

3. axial clearance:

   - The axial clearance shall not exceed the specified value (usually within 0.60mm) to ensure normal operation of the clutch.

4. Inner ring wear:

   - The inner seat ring shall not be worn beyond the specified value (usually within 0.30mm), otherwise it should be replaced with a new one.

 IV. Design details

1. Shape of the bearing end face:

   - The shape of the end of the concentric freewheel release bearing closely matches the shape of the tip of the release finger. According to the shape of the finger tip part (flat or curved surface), the corresponding bearing end face shape (spherical or flat concave curved) is selected to ensure the stability and reliability of the fit.

2. Radial clearance:

   - Radial clearances are provided between the outer ring of the bearing and the outer flange of the separating sleeve and the outer housing, as well as between the inner ring of the bearing and the inner flange of the separating sleeve. These clearances allow the separation bearing to have a radial range of movement of approximately 1mm relative to the separation sleeve to suit different operating conditions.

3. Wave springs:

   - A wave spring is fitted between the outer ring and the end face of the sleeve, which holds the outer ring firmly against the end face of the flange of the separating sleeve and ensures that the bearing does not wobble at rest. This design improves the stability and service life of the bearing.

 V. Concentric clutch release bearing fault detection and prevention

1. Troubleshooting:

   - Strange noise: abnormal sound when operating the clutch, may be the release bearing is worn or poorly lubricated.

   - Heat: The clutch area is hot, probably the release bearing is overheated.

   - Increased wear: Severe wear of the release bearing may result in poor clutch operation.

2. Preventive Measures:

   - Regular lubrication: Ensure that there is sufficient lubricant inside the bearing by regularly filling it with grease or engine oil.

   - Avoid prolonged semi-clutching: Reduce the frequency of clutch use and shock load.

   - Adjust the free travel: Ensure that the free travel of the clutch pedal is within the appropriate range (usually 30~40mm) to prevent the free travel from being too large or too small resulting in increased wear of the bearing.

   - Levelling the clutch release lever: Make sure the spring force of the return spring meets the requirements to keep the bearing running normally.

 VI. Other Precautions

1. Bearing replacement:

   - When the clutch release bearing is seriously worn or malfunctions, it should be replaced with a new one in time. In the process of replacement, it should be ensured that the model, specification and fit clearance of the new bearing are the same as the original bearing, so as to ensure that the replaced bearing can work normally.

2. Bearing installation:

   - When installing the clutch release bearing, attention should be paid to the installation direction and position of the bearing to ensure that the bearing can be correctly installed between the clutch and transmission. At the same time, it should be ensured that the bearing is fixed and lubricated in accordance with the design requirements.

Summary

Concentric clutch release bearing is an indispensable part of the clutch system, and its performance directly affects the normal operation of the clutch and the service life of the vehicle. By understanding its structure, function and maintenance points, the role of this important automotive part can be better understood. Regular inspection and maintenance can effectively prevent failures and ensure the stability and reliability of the clutch release bearing.