The role of the clutch and the four major categories

The clutch is a device that has a function of engagement or disengagement when the main and driven parts transmit power or move on a coaxial line. The clutch is located in the flywheel housing between the engine and the transmission, and the clutch assembly is fixed to the rear surface of the flywheel with screws. The output shaft of the clutch is the input shaft of the transmission. During driving of the vehicle, the driver may depress or release the clutch pedal as required to temporarily disengage and gradually engage the engine from the transmission to cut off or transmit power input by the engine to the transmission.

Mainly includes the active part, driven part, pressing mechanism and operating mechanism. The active parts are: flywheel, clutch cover and pressure plate; driven part is driven plate; pressing mechanism is compression spring; control mechanism has separation fork, release bearing, clutch pedal and transmission components.

The role of the clutch

1, ensure that the car starts steadily

This is the primary function of the clutch. Before the car starts, it is natural to start the engine first. When the car starts, the car gradually accelerates from a completely static state. If the drive train (which is in contact with the entire car) is rigidly linked to the engine, the transmission will hang up and the car will suddenly rush forward, but it will not start. This is because the car has a great inertia when it comes to standstill and causes great resistance to the engine. Under this inertial moment of resistance, the engine speed drops sharply to the lowest stable speed (typically 300-500 RPM) during the instant. The engine is off and cannot work. Of course, the car cannot start.

Therefore, we need the help of a clutch. After the engine is started, before the car starts, the driver first depresses the clutch pedal, disengages the clutch, disengages the engine from the driveline, and then hangs up the transmission, and gradually releases the clutch pedal to gradually engage the clutch. In the process of joining, the resistance torque of the engine gradually increases, so the accelerator pedal should be gradually depressed, that is, the fuel supply to the engine is gradually increased, so that the engine speed is always maintained at the lowest stable speed without flameout. At the same time, as the tightness of the clutch is gradually increased, the torque transmitted from the engine to the drive wheels via the drive train gradually increases. When the traction force is sufficient to overcome the starting resistance, the car starts to move from rest and accelerates gradually.

2, to achieve a smooth shift

In the process of driving a car, in order to adapt to changing driving conditions, the drive train often needs to change gears in different positions. To achieve the shift of the gear type transmission, it is usually toggle gear or other gear mechanism, so that a certain gear pair of the original gear position is pushed out of the transmission, and then another gear position of the gear is put into operation. Before the gear shift, the clutch pedal must be depressed to interrupt the power transmission, which facilitates disengagement of the original gear position and simultaneously synchronizes the speed of the meshing position of the new gear meshing position. This will greatly increase the impact of meshing. Reduce, smooth shifts.

3, to prevent overloading the drive train

When the car is in emergency braking, if there is no clutch, the engine will rapidly reduce the speed due to its rigid connection with the drive train. Therefore, all of the moving parts will generate a large moment of inertia (the value may be greatly exceeded when the engine is working normally. The maximum torque) causes damage to the powertrain that exceeds its load carrying capacity. With a clutch, the relative motion that may occur between the active and driven parts of the clutch can be used to eliminate this danger. Therefore, we need clutches to limit the maximum torque that the drivetrain can withstand and ensure safety.

The clutch is divided into electromagnetic clutch and magnetic powder clutch, friction clutch, fluid coupling

The mechanical parts that can engage or disengage the drive shaft from the driven shaft at any time as required by the work. It can be used to control the start, stop, speed change and commutation of the machine drive system. There are many types of clutches. According to the nature of the work, they can be divided into: 1 operating clutches. The methods of operation are mechanical, electromagnetic, pneumatic, and hydraulic, such as embedded clutches (transmitting torque through the teeth, teeth, or keys), friction clutches (transmitting torque with friction), and air-flexible clutches. The compressed air swells and contracts to manipulate the friction member engaged or disengaged clutches, the electromagnetic slip clutch (which generates magnetic force with exciting current to transmit torque), and the magnetic powder clutch (magnetizes the magnetic powder with the exciter coil to form a magnetic powder chain to transmit torque). 2 automatic clutch. Use a simple mechanical method to automatically complete the joint or separate action, and is divided into safety clutch (When the transmission torque reaches a certain value, the drive shaft can be automatically separated to prevent overload, to avoid the damage of important parts in the machine), centrifugal clutch (when the drive shaft When the rotation speed reaches a certain value, due to the effect of centrifugal force, the transmission shaft can connect itself or exceed a certain rotation speed and can self-separate), orientation clutch (also called overrunning clutch, using the engagement of ratchet-pawl or roller and wedge). The wedge action acts unidirectionally to transmit motion or torque, and the clutch automatically separates when the drive shaft reverses or the speed is lower than the driven shaft.