Design and Analysis of New Type of Piston Pump

To improve the pulsating performance of a swashplate piston pump, a new type of double-acting piston pump is designed based on the meshing theory and the related knowledge of geometry. The pump is driven by the double curve-face gear and its pistons drain oil uninterruptedly. By using the transmission principle of the curve-face gear pair, the engagement coordinates of the double curve-face gear and piston motion analysis coordinates were established. The piston structure was designed according to the working characteristics of the piston pump, and the piston distribution of a new type piston pump is discussed. The equations of piston displacement, velocity, and instantaneous flow were deduced based on the working principle of the proposed double-acting piston pump, and the factors affecting the flow pulsation rate, such as the number of plungers, eccentricity, and the order of curve-face gear, were analysed. The analysis results show that compared with the existing swashplate piston pump, the variation in the flow pulsation rate of the proposed double-acting piston pump is more stable, and the flow pulsation rate decreases with increase in the number of plungers, decrease in the eccentricity, and increase in the order of the curve-face gear. The test-bed was used to test the plunger velocity, and the maximum error value is 4.79 mm/s.were in good agreement with the theoretical values; the error was less than 5%, which is within the allowable range of error.