Patent ID: 8635927
Filing Date: 2014-01-28
Classification: F16H,Y10T

Abstract:
1. A speed change device for shifting a gear of a transmission, comprising: a plurality of speed-changing sleeves in said transmission, said plurality of speed-changing sleeves moving in an axial direction to shift the gear; a plurality of forks for moving said speed-changing sleeves, said plurality of forks comprising a plurality of fork operation members coupled thereto; a cylindrical drum that is installed so as to be reciprocally movable in the axial direction and being rotatably supported, the cylindrical surface of said cylindrical drum forming a plurality of drum grooves into which said fork operation members are fitted, a rotary drum sleeve that is arranged inside of said cylindrical drum; a threaded shaft that is arranged penetrating through said rotary drum sleeve in concentric with said rotary drum sleeve; a nut body that is located in said cylindrical drum at a portion apart from said rotary drum sleeve in an axial direction of said threaded shaft, a select actuator and a shift actuator mounted on a casing of said transmission, each actuator operating independently, wherein said select actuator rotates said rotary drum sleeve around said threaded shaft accompanying the rotation of said cylindrical drum, and wherein said shift actuator rotates said threaded shaft accompanying the reciprocally movement of said cylindrical drum in the axial direction of said cylindrical drum.