| 摘要 |
PURPOSE:To inhibit the generation of cavitation by forming the base width of a rotor rotating direction edge of at least either an inlet port or a discharge port of an internal gear-type pump moderately decreased toward the edge. CONSTITUTION:An inlet port 10 of an internal gear-type pump is formed having the cross-sectional area of the inlet port 10 decreased from the central part 10c toward both edges 10a and 10b. Furthermore, as the width of a base 18 of the inlet port becomes narrower so that the inlet port 10 can be formed tapered, the flow passage cross-sectional area does not change remarkably, thereby the inflow of lubricating oil that flows into a pump space 26 from the inlet port 10 does not change suddenly either rear both edges 10a, 10b of the inlet port. Lubricating oil flows smoothly into the pump space and the generation of cavitation is thus inhibited. The same is applied as to a discharge port 11. |
