| 摘要 |
PURPOSE:To enable a delivery amount to be easily changed, and reduce cost related to a design change by introducing differential pressure across a variable throttle to a flow control valve, and discharging a part of delivered hydraulic fluid via a change in the opening area of a drain passage. CONSTITUTION:Hydraulic fluid sent to a support hole 16 via a pumping effect is delivered to a delivery port 26 via passages 25a and 25b. In this case, a solenoid valve 27 sets the area of the passages 25a and 25b at the predetermined value by means of the valve plate 27a thereof. Also, a part of the hydraulic fluid is introduced to the front and rear sides of the spool of a flow control valve 51 via introduction passages 36 and 37. In this case, however, differential pressure across the spool does not reach the predetermined value before the speed of a rotary shaft 5 increases to a certain extent, and the delivery amount of the fluid increases with a rise in the speed of the shaft 5, while the spool closing a drain port 38. When the speed of the shaft 5 rises from that state and the differential pressure reaches the predetermined value, the spool opens the drain port 38, thereby discharging a part of the hydraulic fluid. According to this construction, the delivery amount of the hydraulic fluid can be freely varied by changing the flow passage area with a signal sent from a controller 50 to the solenoid valve 27. |
