Vibration and noise proofing system for a hydrostatic stepless transmission attached to a transmission case

摘要

A vibration and sound proofing system for a working vehicle such as a tractor or a lawn mower having a hydrostatic stepless transmission (HST) included in a propelling transmission system for transmitting engine output to wheels. The HST is mounted in a case secured to intermediate mounting plates attached to a gear transmission case through vibration and sound absorbers. Output shafts of the HST are connected to input shafts of a gear transmission through vibration absorbing shaft couplings. Each of the vibration absorbers includes a metallic outer tube, a metallic inner tube disposed concentrically with the outer tube, and a rubber element filled tight in an annular space defined between the outer and inner tubes. The intermediate mounting plates are connected to the transmission case with the outer tubes inserted into bores defined in the intermediate mounting plates, by tightening bolts extending through the inner tubes and through spacers interposed between the inner tubes and the transmission case, respectively.