Optimal Design Of The Tooth Profile Of Elliptical Cycloid Rotor Oil Pump With Lower Noise

The tooth profile of rotor decides the overall performance especially the continuity and smoothness of movement directly when the inner rotor is meshing with the outer rotor. Therefore, it is significant to study the effect of tooth profile on the meshing and noise of rotor oil pump. This paper is based on the project of Noise Control Mechanism of Rotor Oil Pump Based on Sound-Vibration Coupling(12JJ9015) funded by Hunan Natural Science Funds. A type of elliptical cycloid rotor oil pump is studied in this paper, the calculation method of tooth profile of the inner rotor is provided first. Considering the meshing characteristic and noise, the optimal design is proposed for the tooth profile. Then the verification of sound field simulation and noise test is carried out for both the protpotype pump and elliptical-circle cycloid rotor oil pump. The main findings of this paper are as follows:(1) The theoretical tooth profiles of internal and external rotors are obtained according to the conjugation characteristic and the double enveloping of tooth profile of the elliptical cycloid rotor oil pump. It showes that there is meshing boundary point on the tooth profile, considering the meshing characteristic and sliding rate of tooth profile, the tooth profile the protpotype pump is optimal designed as elliptical-circle cycloid.(2) A section of circle meshing profile is added in the tooth profile of the outer rotor behind the meshing boundary point of the elliptical cycloid rotor oil pump. Therefore,the maximum value point of sliding rate of tooth profile is also avoided, and the meshing impact of the prototype pump is improved, the meshing of the prototype pump is changing from multi-tooth meshing to single-tooth meshing. As a result, the optimal design will help to reduce the noise of rotor oil pump.(3) Dynamics simulation is accomplished with software ADAMS to obtain the load the rotor oil pump, then the load is imported into the sound field simulation software Virtual.lab as exciting force. The Modal-ATV solution of acoustic BEM and experiments are carried to simulate and verification the performance of noise of the protpotype pump and pump with rotor tooth profile correction. The optimal design achieves the target.