Profile design and displacement analysis of the low pulsating gear pump

Aiming at the problems of the general involute external gear pump, a gear pump with double circular arc helical gear as motion pair is proposed. Based on the comparison and analysis of their meshing characteristics, the advantages of contact strength, bending strength, and transmission stability are significant with the double circular arc helical gear as motion pair. Taking the sine curve as the transition curve and on the basis of the conjugate principle of gear meshing, the surface tooth profile equation of double circular arc helical gear is given out by coordinate transformation. The equal area method is used to deduce the displacement of double circular arc gear pump, then the maximum and the minimum instantaneous displacement of the double helical gear pump are solved, thus the theoretical pulsation tends to 0. Using Fluent three-dimensional dynamic mesh technique, by comparing and simulating the flow pulsation of double circular arc helical gear pump and ordinary involute helical gear pump of the same gear parameters, it is concluded that the flow pulsation of the double circular helical gear pump is much smaller than that of the involute helical gear pump. In summary, this article provides reference for design of high-performance gear pump.