The motorcycle's transmission system consists of primary deceleration, clutch, gearbox, and secondary deceleration.
The primary deceleration consists mainly of the drive sprocket (drive gear) mounted on the crankshaft end, the sleeve roller chain and the driven sprocket (driven gear) on the clutch as a deceleration and transmits the engine power to the clutch.
Motorcycle clutches have the following types of construction:
(1) The wet multi-plate friction clutch clutch assembly is immersed in the oil to be divided into three parts: active, driven and separated. The power of the engine is driven by a sprocket-type gear drive, and the periphery of the cover is grooved. Five friction plates (active sheets) embedded with rubber cork friction material are placed, and the outer edge of the bump is placed in the groove of the active cover. Rotate as one of the active parts of the clutch. The four steel driven pieces are connected to the driven piece fixing basin through the internal teeth to form a driven portion. The main and driven pieces are staggered, and the fixed basin is connected to the gearbox main shaft by internal splines. The four clutch springs on the gland press the friction plate and the driven piece to transmit the power to the gearbox. The clutch is normally engaged. When the clutch lever is tightened by the cable to rotate the screw sleeve in the left cover, the adjusting screw in the screw sleeve moves to the right, pushing the separation push rod and the gland, the spring pressure disappears, the friction sign and the follower piece Separation.
(2) Automatic centrifugal clutch This structure is used on mopeds such as Yamaha CY80 and Suzuki FR50 to automatically control the separation and engagement of the clutch according to the engine speed. The clutch consists of an active, driven and disengaged engagement mechanism. The active part is composed of a clutch cover, a thrust piece, a clutch plate and the like. The driven part is composed of a friction plate, a center sleeve and the like. When the engine is running, as the rotation speed increases, the centrifugal force generated by the steel ball also increases, and the axial component force overcomes the tension of the separation spring to move outward along the groove in the clutch housing, and the compression thrust piece is tightly pressed. Pressing the clutch plate and friction causes the clutch to be engaged, and the power is output. When the engine speed is reduced to 怠 or flameout, the centrifugal force of the steel ball is reduced or not. The tension of the separation spring overcomes the centrifugal force of the steel ball to return the steel ball to the original position along the groove, and the clutch is separated.