| 摘要 |
<P>PROBLEM TO BE SOLVED: To surely prevent air inflow to a pump part and to suck oil leakage from a pump chamber by a simple structure. <P>SOLUTION: A gear pump P is driven by a motor M. A high pressure seal 8 is interposed between the pump part 10 and the motor M, and a low pressure seal 9 is interposed around a rotary shaft 3. An oil seal chamber 20 is formed between both the seals 8 and 9. In the seal chamber 20, liquid oil a is filled at a degree for sinking an outer periphery of the rotary shaft 3, and an air layer 24 is formed on an upper part. By the existence of the oil a, the air inflow to the pump part 10 via the high pressure seal 8 is prevented, while the oil leakage from the pump part 10 is sucked into the oil seal chamber 20 by contraction of the air layer 24. Oil is injected from an injection port 22 to the oil seal chamber 20 via a recess chamber 21. Air discharge is performed from an upper side communication hole 23a, and oil surfaces of the recess chamber 21 and the oil seal chamber 20 are made to coincide each other by a lower side communication hole 23b. <P>COPYRIGHT: (C)2004,JPO |
