摘要 |
PURPOSE:To aim at enhancing the volumetric efficiency of a pump, by forming hollow chambers in vanes and the projected part of a vane shaft and as well by charging, in the hollow chambers, coolant which changes its phase between liquid and gas in dependence upon temperature variations. CONSTITUTION:Air in a casing 1 is repeatedly compressed on the outlet side of a pump under operation, and therefore a large amount of heat is generated so that the temperature of vanes 5 in the vicinity of the outer peripheries thereof becomes relatively high. As a result, coolant in the vicinity of the outer peripheries of the hollow chambers of the vanes 5 absorbs heat from the vanes 5 and is therefore evaporated. Next, the coolant is liquefied in the projected part 4a of a vane shaft 4 and therefore, the absorbed heat thereof is released. Such actions are repeated. Accordingly, sufficient cooling effect may be obtained, thereby the volumentric efficiency of the pump becomes high. |