| 摘要 |
PROBLEM TO BE SOLVED: To facilitate straight run and turning of a roll press machine and prevent the running speed of a roll press machine from varying large when changing-over is made from the condition out of differential lock to the differential locked condition or vice versa. SOLUTION: Pistons of radial piston motors 2 arranged symmetrically to the left and right are divided into a first piston group 13 and a second piston group 14, and independent ports 16, 17, 18 are provided. The first groups of pistons 13 of the two motors 2 are coupled parallel always with a hydraulic pump 19, and the second groups of pistons 14 are coupled through a selector valve 24. In the condition out of differential lock, the two sides of second piston groups 14 are made in series by means of changing-over of the selector valve 24 and made parallel in the differential locked condition so as to facilitate a straight run and turning, whereby the change in the rate of flow lessens and the running speed remains unchanged to any large extent because the parallel-series connections of the second groups of pistons 14 are solely changed.
|
