| 摘要 |
The present invention comprises a pair of gears 20 whose tooth portions mesh with each other, a housing having a hydraulic chamber in which the pair of gears 20 are contained in a meshing state, and bushes contained in the hydraulic chamber of the housing in a state of being contact with both end surfaces of the gears, and, on edges of the end surfaces of gears, chamfering M is performed on at least intermediate parts between the tooth tips and the tooth bottoms, and the roundness or inclination of the intermediate parts is larger than those of the tooth tips and the tooth bottoms. This makes it possible to prevent damage of the edges due to contact force when the pair of gears mesh with each other and prevent leakage of an operation fluid through between the gears and support members. Accordingly, an original performance of being quiet and having high output efficiency can be maintained for a long time and high reliability can be obtained. |
