| 摘要 |
PURPOSE:To enable reduction of pulsation of discharge oil and the occurrence of a fluctuation in a pressure, by a method wherein a space, formed between contact parts of inner and outer rotors, is communicated with a groove formed in and open to the end surface of the inner rotor between tooth grooves having ends adjoining to each other. CONSTITUTION:A groove 3, circumferentially extended, is formed in the tooth foot part of the end surface of an outer rotor 2, and the ends of the groove 3 are respectively open to tooth grooves 2a located on both sides of the groove 3. Thus, pressure oil, present in a space S formed between contact parts of teeth 1a and 2A of the inner and outer rotors 1 and 2, is moved in other space S through the groove 3. In which case, the sectional area of the groove 3 is decided in consideration of a reduction in pulsation and a fluctuation in a pressure and lowering of pump efficiency. This constitution enables relieve of momentary high and low pressures, prevents the occurrence of pulsation and a fluctuation in a pressure of discharge oil, and permits sharp decrease of the generation of noise and vibration. |
