摘要 |
The invention relates to a hydraulic motor with two cylinder sets of different diameters and with a slide valve for directing a pressure medium simultaneously to both cylinder sets or to either one of them. In order to achieve smooth shifting from one driving state to another, the slide valve comprises means for connecting the pressure openings of the disconnected cylinder set to a space wherein return pressure prevails, whereby the pistons of the said cylinder set passively will follow the rolling space of the cam ring of the motor. The valve structure further comprises means for connecting the pressure openings of both cylinder sets with the said space of return pressure, if the work pressure of the motor approaches the return pressure. |