Clutch Pressure Plate and Throw Out Bearing Introduction

Clutch Pressure Plate and Throw Out Bearing are two key components in the clutch system of automobile manual transmission, they work together to ensure the smooth transmission and interruption of engine power. The following is a detailed introduction of these two components and their roles and differences in the clutch system.

 I. Clutch Pressure Plate

1. Clutch Pressure Plate Definition and Function

- Definition: Clutch Pressure Plate is a key component in the clutch assembly, located between the clutch plate and flywheel. Its main function is to apply pressure to the clutch plate by means of a spring or other pressure device to ensure close contact between the clutch plate and the flywheel, thus transmitting the torque generated by the engine.

- Clutch Pressure Plate Function:

  - Engaging: When the driver releases the clutch pedal, the pressure plate moves forward under the force of the spring, pressing the clutch plate tightly against the flywheel, so that the engine power is transmitted to the transmission through friction.

  - Separation: When the driver depresses the clutch pedal, the release bearing pushes the pressure plate backward, reducing the pressure on the clutch plate and separating the clutch plate from the flywheel, interrupting the transmission of power and permitting shifting or stopping.

2. Clutch Pressure Plate Structure and Material

- Structure: The clutch pressure plate usually consists of a metal disk containing a set of strong springs (usually diaphragm springs or coil springs) to provide the necessary compression force. The surface of the pressure plate is designed with tabs or spring seats that act directly on the clutch disc.

- Material: The pressure plate is usually made of high strength steel or alloy steel to withstand high temperatures and repetitive mechanical stresses. Its surface may be coated with rust and wear resistant coatings to increase durability and minimize wear.

3. Clutch Pressure Plate Working Principle

- Engaged state: When the clutch pedal is not pressed down, the pressure plate is pressed tightly against the clutch disc under the action of spring force, keeping the clutch disc in close contact with the flywheel to ensure power transmission.

- Separation state: When the driver depresses the clutch pedal, the release bearing pushes the pressure plate backward, reducing the pressure on the clutch plate, separating the clutch plate from the flywheel, and interrupting the power transmission. This allows the driver to shift gears or stop smoothly.

4. Clutch Pressure Plate Use and Maintenance

- Wear and Replacement: The pressure plate may fail due to wear or deformation during long-term use. It is important to check the pressure plate regularly for wear and deformation. If abnormalities are found, such as uneven surface of the platen or insufficient spring force, the platen should be replaced with a new one.

- Design influence: The design and material of the pressure plate directly affects the clutch engagement and disengagement feeling. The design of the pressure plate may vary from model to model. Choosing the right pressure plate is essential to ensure the proper functioning of the clutch.

Clutch Release Bearing (Throw Out Bearing)

1. Clutch Throw Out Bearing Definition and Function

- Definition: The release bearing, also known as the “thrust bearing”, is another important part of the clutch assembly. It is located between the clutch pressure plate and the transmission, and its main function is to push the pressure plate backward during the clutch disengagement process, so that the clutch plate and the flywheel can be separated, thus interrupting the power transmission.

- Clutch Throw Out Bearing Function:

  - Disengagement: When the driver depresses the clutch pedal, the release bearing is pushed through the mechanical linkage or hydraulic system, moves forward along the transmission input shaft and pushes the pressure plate backward to separate the clutch plate from the flywheel.

  - Return: When the driver releases the clutch pedal, the release bearing moves backward under the action of the return spring and returns to the initial position, and the pressure plate resumes tightening the clutch plate to resume power transmission.

2. Clutch Throw Out Bearing Structure and Material

- Structure: The release bearing is usually a needle roller bearing or ball bearing designed to rotate rapidly and to withstand certain axial loads. It consists of components such as rolling bodies (e.g. steel balls, cylindrical rollers, etc.), inner and outer rings and cages, and is capable of withstanding high speed rotation and axial loads.

- Material: Separate bearings are usually made of high-quality steel and high-quality alloy steel, and the surface may be coated with anti-rust and lubricating coatings. The interior is filled with grease to minimize friction and wear.

3. Clutch Throw Out Bearing Working Principle

- Separation process: When the driver depresses the clutch pedal, the release bearing moves forward along the input shaft of the transmission and pushes the release arm of the pressure plate, which moves the pressure plate backward and reduces the pressure on the clutch disc, realizing the separation of the clutch disc from the flywheel.

- Supporting and guiding: The release bearing not only pushes the pressure plate, but also supports and guides it to ensure that the pressure plate can move smoothly and avoid deflection or stalling.

4. Clutch Throw Out Bearing Use and Maintenance

- Lubrication and Cleaning: The lubrication and cleaning of the release bearing is vital to the performance of the clutch. Most modern release bearings are of sealed design and do not require additional lubrication, but it is still necessary to check periodically that the seals are intact. For non-sealed bearings, lubrication should be carried out in accordance with the manufacturer's recommendations. Keeping the clutch system clean and avoiding contaminants from entering the release bearing will prolong its life.

- Fault Detection: The release bearing may fail due to wear, poor lubrication or overheating during use. Common failures are indicated by strange noise, jamming or incomplete separation. Regularly checking the working condition of the release bearing and replacing the damaged bearing in time can prevent the clutch system from having bigger problems.

Difference between clutch pressure plate and release bearing 

Characteristics Clutch pressure plate Release bearing

Position Between clutch disc and flywheel Between clutch pressure plate and transmission

Function Applies pressure to the clutch disc by means of a spring to ensure power transmission Eliminates friction and pushes the pressure plate to separate the clutch disc from the flywheel.

Structure Metal disk with strong spring inside Needle roller bearing or ball bearing with rolling elements, inner and outer rings and cage

Material High-strength steel or alloy steel with rust- and wear-resistant coating High-quality steel and high-quality alloy steel, grease-filled inside

Principle of operation The clutch disc is pressed against the flywheel by spring force. The pressure plate is pushed by a mechanical linkage or hydraulic system to achieve separation.

Maintenance requirements Regularly check for wear and deformation, replace if necessary Regularly check for lubrication and working condition, replace if necessary

Summarizing

The clutch pressure plate and release bearing are the two core components in the clutch system of a manual transmission, and they work together to ensure the smooth transmission and interruption of engine power. The clutch pressure plate exerts pressure on the clutch disc through the spring to ensure power transmission; while the release bearing is responsible for pushing the pressure plate to realize the separation of the clutch disc and flywheel, interrupting the power transmission. These two parts are different in material, structure and function, but both are indispensable parts of the clutch system.

During use, it is important to regularly check the wear and working condition of the clutch pressure plate and release bearing. Timely replacement of damaged parts can ensure the normal operation of the clutch system, extend its service life, and ensure the safety and reliability of the vehicle. In addition, proper driving habits (e.g. smooth operation of the clutch pedal) will also help to minimize the wear of these parts and extend their service life.