| 摘要 |
<p>PURPOSE:To decrease fluctuation in velocity in a low-speed area by shutting off the connection between a pump and a hydraulic motor in a stationary state, while by communicating them with each other when a spool is transferred to a side where an oil chamber in an exit side is compressed. CONSTITUTION:When an output pressure P2 of a hydraulic motor 2 is lowered due to the generation or increase of a friction torque in a low-speed area of the motor 2, a spool axis directional force As X P2 that works on a surface 18 of a land 14 becomes smaller than a spool axis directional force As X Ps/2 that works on a rising surface 21 (area: As) from an end surface 20 (area: 2As) of a cylindrical part 17 of the spool 12 of a three way guide valve 9, as well as from a land 16. Since the spool 12 is moved to a side (left side) where an exit side oil chamber 19 is compressed, a connection port 27 closed by a land 15 is opened, and a working oil from a pump 28 is supplied to an entrance side of the motor 2, through an oiling port 29, an oiling chamber 24, and the connection port 27. At the time of spool movement, viscosity resistance proportional to the velocity of movement works on the spool 12 through throttling mechanisms 35-38, whereby flow discharge from the motor 2 is kept stable along with a valve 7.</p> |
