| 摘要 |
A pump comprises: a pump body 10 which sucks in air from an inlet 7 and discharges the air; a hydraulic pump which pressure-feeds a lubricating oil to the pump body 10 in accordance with the driving of the pump body 10; a non-return valve 70 which is disposed in a valve accommodation portion 6 between the inlet 7 and the pump body 10 to open and close the valve accommodation portion 6; an air introduction path 19 which introduces air into a cylinder 74 of the non-return valve 70; and an air introduction valve 60 which opens the air introduction path 19 when the hydraulic pump is not operating. When the pump body 10 is stopped, the non-return valve 70 closes the inlet 7 in response to a difference in pressure between the pressure of the valve accommodation portion 6 reduced to a value equal to or less than atmospheric pressure by the operation of the pump body 10, and the pressure of the air introduced into the cylinder 74 by the opening of the air introduction valve 60 owing to the stoppage of the hydraulic pump associated with the stoppage of the pump body 10. |
