| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent hunting (a rotational fluctuation) and looseness of a hydraulic motor by arranging a spool in a driving hydraulic circuit of the hydraulic motor. SOLUTION: When a spool moves toward a neutral position N from a first position A, the communicating area of a left side chamber 28 with a first pump side part 22 becomes large in the initial stage of a stroke, becomes small in the middle stage of a stroke, and becomes medium in the last stage of a stroke. When the spool moves toward the neutral position N from a second position B, the communicating area of a right side chamber 29 with a second pump side port 23 becomes large in the initial stage of a stroke, becomes small in the middle stage of a stroke, and becomes medium in the last stage of a stroke. In this way, when the spool moves toward the neutral position from the first position A and the second position B, a moving speed of the spool becomes high in the initial stage of a stroke, becomes low in the middle state, and becomes medium in the last stage, and while preventing cavitation, the spool can be moved to the neutral position in a short time. Therefore, by arranging the spool in a driving hydraulic circuit of a hydraulic motor 5, the speed is reduced without a shock while preventing cavitation, and the hydraulic motor 5 can be stopped in a short time.</p> |
