| 摘要 |
<p>A vane type vacuum pump 1 is provided in the vicinity of an air intake passage 11 for sucking the air into a pump chamber 2, and communicates a space A on the front side and a space B on the back side of the rotational direction of the vane at the time of the reverse rotation of the vane 6, and includes an escaping groove 21 for allowing a lubricating oil to escape into the space B on the back side from the space A on the front side. The escaping groove 21 is provided in a side plate 4, and a wall surface 21A of the escaping groove which becomes the back side of the rotational direction of the vane at the time of the reverse rotation of the vane 6 becomes an inclined surface whose opening side is further expanded than a bottom 21B of the escaping groove 21. The other wall surface 21C of the escaping groove 21 also is preferably made into the inclined surface whose opening side is further expanded than the bottom. Comparing with the case where the sectional shape of the escaping groove 21 is made into a square section, the foreign matters and friction powders 22 are allowed to smoothly escape and remove from the inside of the escaping groove 21.</p> |
