VARIATEUR DE VITESSE, NOTAMMENT POUR DISPOSITIF DE DISTRIBUTION DE DESSILEUSE DISTRIBUTRICE D'ENSILAGE

摘要

The speed changer is mounted on an extension (21) of the drive shaft (22) and has a semi-circular fixed cam (34) and a semi-circular pivoting cam (36) which is spring loaded to remain in the closed position. The driving pinion (12) carries a ratchet pawl (24) with two faces. The pawl engages with a mating toothed gear (20) on the drive shaft (22). During its travel around the fixed cam the pinion (12) drives the shaft (22). When the roller (32) of the pawl engages with the mobile cam (36) it will drive the chain shaft only if the load is light. As the load on the chain increases the stiffness of the spring (44) is overcome and the cam (36) pivots to allow the ratchet to slip, until the next revolution.