| 摘要 |
PURPOSE:To prevent the occurrence of cavitation corrosion, by increasing the mechanical strength by forming a recess at the back of respective small grooves formed at one end portion of discharge ports and increasing the sintering density by reducing the internal thickness at said portions. CONSTITUTION:Discharge ports 21 consisting of an arcuate elongated hole are formed in a side plate 13 on the side of a turning shaft (not shown) at the portions thereof corresponding to the discharge regions of a pump in the manner that they are extended from one side to the other side of the side plate 13. Further, small grooves 30 are also formed in the side plate 13 at the side where it is held in sliding contact with a rotor (not shown) to locate at one end of the discharge ports 21, and recesses 31 are formed at the back of respective small grooves 30 to extend along the extension of the discharge ports 21. Resultantly, the thickness of the side plate 13 at the portions where the small grooves 30 are formed can be decreased. Thus, since the sintering density and the strength at said portions are increased, it is enabled to increase durability against cavitation corrosion. |
