Clutch is the main, driven part of the coaxial line in the transmission of power or movement, with splicing or separation function of the device. The clutch is located in the flywheel housing between the engine and gearbox. The clutch assembly is secured to the rear surface of the flywheel with screws, and the output shaft of the clutch is the input shaft of the transmission. During driving, the driver can depress or release the clutch pedal according to need, so that the engine and the gearbox temporary separation and gradual engagement to cut off or transmit the engine to the transmission input power.

　The invention mainly comprises an active part, a driven part, a pressing mechanism and an operating mechanism. Active part: flywheel, clutch cover and pressure plate; driven part is the driven plate; compression mechanism is the compression spring; operating mechanism separation fork, separation bearing, clutch pedal and transmission components.

　The role of the clutch

　1, to ensure a smooth start car
　This is the primary function of the clutch. In the car before the start, naturally the first to start the engine. While the car starts, the car is from a completely static state gradually accelerated. If the driveline, which links the entire car, is rigidly connected to the engine, the car will suddenly rush forward when the transmission is hoisted, but it will not start. This is because the car from standstill to forward, with great inertia, causing great resistance to the engine torque. Under this inertial moment of resistance, the engine in the instantaneous speed dropped sharply to the lowest stable speed (usually 300-500RPM) the following, the engine is flame and can not work, of course, cars can not start.
　Therefore, we need the help of the clutch. Before starting the engine, the driver depresses the clutch pedal, separates the clutch, disconnects the engine and driveline, and then upshifts the transmission, and then gradually releases the clutch pedal to gradually engage the clutch. During the joining process, the resistance torque of the engine gradually increases, so should gradually depress the accelerator pedal, that is gradually increase the fuel supply to the engine, so that the engine speed is always maintained at the minimum steady speed, without flameout. At the same time, as the degree of tightness of the clutch engagement increases, the torque transmitted by the engine to the driving wheel is gradually increased, and when the traction is sufficient to overcome the starting resistance, the vehicle starts moving from the standstill and accelerates

　2, to achieve a smooth shift
　In the car driving process, in order to adapt to changing driving conditions, the transmission system often have to change the work of different stalls. To achieve the gear-type transmission gear shift is generally toggle gear or other gear-linked institutions, so that the original gear with a gear pair of the launch drive, and then make another gear gear into the work. The clutch pedal must be depressed before the shift to interrupt the power transmission, easy to make the original gear of the vice-vice, while the new gear position of the meshing of the meshing speed gradually synchronized, so that the impact into the meshing can greatly To achieve a smooth shift.

　3, to prevent overloading the drive train
　When the vehicle is in emergency braking, without the clutch, the engine will be rigidly connected with the driveline to reduce the speed drastically, so that all the moving parts will produce large moment of inertia (the value may be much higher than when the engine is working Of the maximum torque), causing the transmission system beyond its load capacity of the load, leaving the mechanical damage. With the clutch, it is possible to rely on the relative movement that may occur between the clutch active section and the driven section to eliminate this danger. Therefore, we need a clutch to limit the transmission torque to bear the maximum torque, to ensure safety.

　Clutch is divided into electromagnetic clutch and magnetic powder clutch, friction clutch, hydraulic coupling
　Can work according to the need to always be driven shaft and driven shaft joint or separation of mechanical parts. Can be used to control the machine drive system start, stop, speed and commutation. Clutch a wide range, according to the nature of work can be divided into: ① control clutch. They are manipulated mechanically, electromagnetically, pneumatically and hydraulically, such as embedded clutches (torque transmitted through the teeth of teeth, teeth or keys), friction clutches (using friction to transmit torque), air flexible clutches Electromagnetic clutch (which generates magnetic force to transmit torque), and magnetic powder clutch (magnetizing the magnetic powder by the exciting coil to form a magnetic powder chain to transmit the torque), and the magnetic clutch is used as a magnetic clutch to drive the friction clutch to engage or separate the friction element. ② automatic clutch. (Or when the transmission torque reaches a certain value, the drive shaft can be separated automatically, so as to avoid overloading and avoid the damage of the important parts of the machine), and the centrifugal clutch (when the driving shaft is driven by the driving shaft) When the speed reaches a certain value, due to the role of centrifugal force can make the drive shaft self-connection or more than a certain speed after its own separation), directional clutch (also known as clutch, ratchet-pawl meshing or roller wedge Wedge action unidirectional transfer movement or torque, when the drive shaft reverse or speed below the driven shaft, the clutch will automatically separate).

　Electromagnetic clutch
　The engagement and disengagement of the clutch is controlled by turning on and off the coil.
Electromagnetic clutch can be divided into: dry single-chip electromagnetic clutch, dry multi-chip electromagnetic clutch, wet multi-chip electromagnetic clutch, magnetic clutch, slip-type electromagnetic clutch.
　Electromagnetic clutch work can be divided into: power combination and power combination.
　When the coil is disconnected, the armature bounces back and the clutch is in the disengaged state. When the coil is energized, the armature is in the separated state.
　Dry multi-chip wet multi-chip electromagnetic clutch: the same principle, the addition of several friction to pay the same volume of torque than dry single-chip electromagnetic clutch, wet multi-chip electromagnetic clutch work must have oil or other coolant cooling.

　2. Magnetic powder clutch
　When the magnetic powder is placed between the active and the follower, the magnetic powder is in a loose state when the power is not applied, and the magnetic powder is combined at the time of electrification, and the active piece and the driven piece rotate at the same time. Advantages: By adjusting the current to adjust the torque, allowing a large slip. Disadvantages: larger slip temperature rise, the relative high prices
Slip-type electromagnetic clutch: clutch work, the main and sub-part of the existence of a speed difference must have a torque transmission. Torque depends on the magnetic field strength and speed difference. Excitation current remains unchanged, with the torque increase and the sharp decline in torque to maintain the same, reducing the excitation current, speed is reduced more serious.
Slip-type electromagnetic clutch as the main and follower components without any mechanical connection, no wear and tear, no magnetic powder leakage, no impact, adjust the excitation current can change the speed, for continuously variable transmission, this is its advantage. The main disadvantage of this clutch is that the vortex in the rotor generates heat, which is proportional to the speed difference. Efficiency at low speed is very low, the efficiency value of the main, slave shaft speed ratio, that is, η = n2 / n1
A mechanical transmission system suitable for high frequency operation allows the driven section to be engaged or disengaged from the active section in the case of the active section operation.
　When the active part and the driven part are in the separated state, the active part rotates, the follower is stationary; the active part and the driven part are in the joint state, and the active part brings the driven part to rotate.
Widely used in machine tools, packaging, printing, textile, light industry, and office equipment.
　Electromagnetic clutch is generally used for ambient temperature -20-50%, humidity less than 85%, no explosion hazard in the medium, the coil voltage fluctuations do not exceed the rated voltage of ± 5%

　3. Friction clutch
　At present in the car is widely used in spring-loaded friction clutch (referred to as the friction clutch). Match with the manual transmission of the vast majority of dry friction clutch for the clutch, according to the number of its driven disk, is divided into single-disc, dual-disc and multi-disc, and several other. According to other standards, friction clutch is divided into wet and dry two. Wet friction clutch is generally multi-disc type, immersed in oil in order to facilitate heat dissipation. The use of a number of coil springs as a compression spring, and these springs along the pressure plate around the distribution of the clutch known as the week cloth spring clutch. The use of diaphragm spring as a compression spring clutch called the diaphragm spring clutch