摘要 |
A power transmission system comprises a synchronous main toothed clutch 20 and a subsidiary toothed clutch 21 arranged in parallel in main and subsidiary power paths 6, 7 respectively between an input shaft 1 and an output shaft 2. When the main clutch 20 is engaged this causes engagement of the subsidiary clutch 21. The main power path 6 has a torsional stiffness which is substantially less than that of the subsidiary power path 7 over at least an initial part of the range of torque loading between zero and full power, such that at full power or at a pre-determined proportion of full power the main power path 6 and the subsidiary power path 7 transmit substantially the same load. |