Patent ID: 6257084
Filing Date: 2001-07-10
Classification: F16H,Y10T

Abstract:
A transmission comprising a casing and a plurality of rotatable shafts supported by the casing, the plurality of the rotatable shafts including at least an input shaft operatively coupled to a power source and an output shaft for outputting the drive power transmitted from the input shaft, and the change speed operation of the transmission being conducted between a pair of drive and driven shafts among the rotatable shafts, the pair of drive and driven shafts being disposed adjacent and substantially in parallel to each other,wherein the transmission comprises a plurality of gear type change speed devices each of which comprises a rotatable gear supported on one of the drive and driven shafts; a synchromesh device supported on the one of said drive and driven shafts so as to be axially slidable but non-rotatable relative thereto, said synchromesh device being designed to be synchronizedly connected with the corresponding rotatable gear by a friction face and thereafter a meshing portion provided on the rotatable gear, and a fixed gear supported on the other shaft of the drive and driven shafts in a non-rotatable manner and operatively coupled to the corresponding rotatable gear,wherein the synchromesh device of selected one of the plurality of gear type change speed devices is moved to mesh with the corresponding rotatable gear such that the rotatable gear is synchronized with said one of the shafts and rotates the driven shaft at a desired speed via the corresponding fixed gear operatively coupled to the rotatable gear,wherein i) at least the rotatable gear operatively coupled to the corresponding fixed gear having the smallest pitch circle among the plurality of fixed gears and ii) the synchromesh device corresponding to said rotatable gear operatively coupled to said fixed gear with the smallest pitch circle are mounted on the driven shaft,wherein the casing has an opening at its front end, wherein an operating device is provided in the casing to operate the gear type change speed devices, said operating device comprising:a plurality of shift forks to engage the sychromesh devices of the gear type change speed devices;a plurality of fork shafts supporting each of the shift forks in a longitudinally slidable manner;a control member having an arm to engage a selected one of the receiving portions formed in the shift forks; anda shift shaft supporting the control member in axially slidable but non-rotatable manner relative to the shift shaft,said fork shafts being supported by a rear wall of the transmission casing and a closure wall closing the front opening of the transmission casing; andsaid shift shaft being supported by opposing side walls of the transmission casing rotatable relative thereto,wherein both ends of the shift shaft are extended outwardly beyond the opposing side walls of the transmission casing, and the extended portions of the shift shaft are capable of being provided with a shift lever which is non-rotatable relative to the shift shaft.