- Definition: Hydraulic Throwout Bearing (Hydraulic Throwout Bearing), also known as the hydraulic clutch release bearing, is a component of the clutch system in the automobile manual transmission.
- Function: When the clutch pedal is pressed down, the hydraulic throwout bearing separates the clutch pressure plate from the clutch disc (also known as the clutch plate), thus interrupting the power transmission between the engine and the transmission.
- The driver depresses the clutch pedal, which is connected to the master cylinder by a linkage or cable.
- The piston in the master cylinder moves to pressurise the hydraulic oil.
- The pressurised hydraulic fluid is transferred to the slave cylinder through the hydraulic line.
- The piston in the slave cylinder pushes the hydraulic throw-out bearing outwards.
- The hydraulic throwout bearing contacts the release lever of the clutch disc and pushes the disc away from the clutch disc, thus breaking the power transmission.
- Unlike traditional mechanical throwout bearings, hydraulic throwout bearings do not require periodic adjustment because they rely on a hydraulic system to maintain the correct clearance.
- The hydraulic system reduces the amount of effort required by the driver to depress the clutch pedal, making driving easier.
- The hydraulic system provides a smoother and more linear clutch engagement feel, improving the driving experience.
- Hydraulic throwout bearings are typically more durable than conventional bearings due to reduced mechanical wear.
Hydraulic throwout bearings can be damaged due to the following reasons:
- After prolonged use, due to frequent contact with the clutch pressure plate, the bearing surface will gradually wear out, resulting in poor operation.
- Lack of proper lubrication is a common cause of premature bearing damage. If the grease runs out or the seals fail, the bearing will be damaged by dry friction.
- Frequent fast shifting or heavy driving can increase the load on the bearings, leading to overheating and wear.
- For example, prolonged semi-clutching (especially when climbing or starting) can cause the bearings to be subjected to constant high loads and accelerate wear.
- Improper operation during installation, such as over-tightening or over-loosening, may affect the normal operation of the bearings and lead to early damage.
- External contaminants such as dust, mud, etc. enter into the internal bearing, which will aggravate the wear.
- The heat generated by continuous high load work may lead to bearing material performance decline, and thus damage.
- Manufacturing defects or material problems in the bearing itself may also lead to its premature failure.
- Misalignment of the clutch assembly or bending of the shaft may increase non-uniform loading on the bearing, resulting in damage.
- A dirty or leaking hydraulic fluid in the hydraulic clutch system may cause damage to the throwout bearing.
- According to the equipment load, speed, working environment and other conditions, select the appropriate type and specifications of the bearing.
- Select bearings of well-known brands and reliable quality, and ensure the manufacturing precision and material quality of the bearings.
- Use professional mounting tools, such as impact rings, sockets, wrenches, etc. Avoid using hammers to directly strike the bearings.
- Before mounting, make sure the bearings and the mounting environment are clean to avoid contaminants entering the bearings.
- Apply appropriate amount of grease or lubricant to ensure the lubrication effect of the bearings.
- Adjust the bearing clearance to ensure that the inner and outer rings are in the same centre of rotation, avoiding the phenomenon of different centres.
- According to the working conditions of the bearings and the requirements of the equipment, choose the appropriate type and specification of lubricant.
- Ensure that the quality of lubricant is reliable, avoid using expired or deteriorated lubricant.
- Follow the correct lubrication method and filling cycle, and fill the lubricant for the bearings regularly.
- Pay attention to the amount of lubricant to avoid too much or too little lubricant, which may lead to increased wear of the bearings.
- Regularly clean the dirt and impurities on the bearing surface to keep the bearings clean.
- Use special cleaning agents or solvents, avoid the use of corrosive cleaning agents.
- Ensure that the bearing sealing device is intact, to prevent sand, dust, metal shavings and other pollutants into the bearing.
- Regularly check the condition of the sealing device and replace damaged seals in time.
- Regularly check the wear of bearings, changes in clearance, lubrication effect, etc., to find and deal with potential problems in time.
- Use professional testing instruments, such as vernier calipers, micrometers, etc., to measure the size and clearance of the bearings.
- Replace the bearings with new ones as soon as you find signs of damage, such as cracks, corrosion and wear.
- Avoid continuing to use damaged bearings, which may lead to equipment failure or increased damage.
- Monitor the working temperature of the bearings to ensure that they operate within the appropriate range.
- Avoid keeping the bearings in a high or low temperature environment for a long time, so as not to lead to material deformation or reduced lubrication effect.
- Optimise the design of equipment to reduce the impact of mechanical vibration on bearings.
- Regularly check the operating status of the equipment, timely adjust and maintain the equipment to ensure smooth operation.
Summary
The hydraulic throwout bearing is a key component of the clutch system in automotive manual transmissions, and its design simplifies maintenance of the clutch system and improves driving comfort. However, the hydraulic system may require regular inspections and maintenance, such as checking hydraulic fluid levels and replacing seals, to keep it performing at its best. Understanding the working principle, characteristics, causes of damage and preventive measures of hydraulic throwout bearings can help vehicle owners and repairers better maintain this important component and ensure the proper operation of the vehicle's clutch system.