| 摘要 |
PCT No. PCT/EP95/03440 Sec. 371 Date Feb. 21, 1997 Sec. 102(e) Date Feb. 21, 1997 PCT Filed Sep. 1, 1995 PCT Pub. No. WO96/07840 PCT Pub. Date Mar. 14, 1996The vehicle drive system for mobile hydraulics has a hydrostatic power transmission and a multi-speed selector gear. When the gears are shifted, the speed of the hydrostatic variable displacement motor is controlled in such a way that synchronous engine speeds are set on the engaging elements. Thus, during upshifting, a directional valve is shifted into a neutral position and afterward shifted back into the basic position. For downshifting there is a synchronizing valve that replaces a control pressure, which is dependent on the speed of a primary drive motor with a constant maximum charge pressure. As a result, the engine speed of the hydrostatic variable displacement motor reaches, in the shortest time possible, the engine speed that matches the ratio range in the transmission. Following synchronization the gearshift system runs without detectable engagement jerks.
|
