Patent ID: 9027430
Filing Date: 2015-05-12
Classification: F16H,Y10T

Abstract:
1. A shift drum structure for a drum-type transmission, comprising: a shift drum including a cylindrical drum main body and drum spindles projecting outward from drum end walls on a respective two sides of the drum main body, and a guide groove formed in an outer peripheral surface of the drum main body in a circumferential direction, a work groove formed in the shift drum in the outer peripheral surface of the drum main body from one end surface to an opposite end surface of the drum main body, or to the guide groove near the opposite end surface, the work groove oriented in the axial direction orthogonal to the guide groove, wherein the two sides of the drum body include a front end side and a rear end side, a flower-shaped cam portion is arranged in the front end side of the drum body, a shift drum input gear is arranged in the rear end side of the drum body, the shift drum input gear is open without closing the front end side opening of the work groove, and a shift fork moving on a shift fork shaft in an axial direction while guided by the guide groove in response to a turn of the shift drum is configured to change speeds by sliding a shifter member on a transmission driving shaft pivotally supporting a transmission gear.