| 摘要 |
PURPOSE:To make the proper amount of lubricating oil maintainable all the time as well as to prevent a vane or the like from a breakdown accident, by installing an oil separator which recovers a discharged outflow portion of the lubricating oil from a vacuum pump, while setting the separator to ''OFF'' in time of nonpressure at the suction side and to ''ON'' or a state of interconnection at atmospheric pressure, respectively. CONSTITUTION:At the point midway in a discharge side circuit A of a vane type vacuum pump 12, an oil separator 35 is installed in a level higher than that of the pump 12. A sliding part spot of the vane outer end edge and a bearing part spot 45 are of the part required for lubrication. A part of lubricating oil is taken away from a discharge part 21 whereby the separator 35 collects the lubricating oil separated by a cyclone into an oil sump part 46. A siphon release valve 48 sets an interval between a suction side circuit B and a return circuit 47 to ''OFF'' when the suction side circuit B comes to the specified suction pressure and makes oil flow back as in an arrow R with a pressure difference between the lubrication required part and the oil sump part 46. When rotation in the pump 12 stops and therefore the suction side circuit B comes close to atmospheric pressure, an interval between the circuit B and the return circuit 47 is set to ''ON'' or a state of interconnection, thus the flow-down of lubricating oil from the return circuit 47 is prevented by the siphon. |
