Rotary Displacement Pump With a Sinusoidal Working Chamber and Oscillating Pistons

This article critically analyzes the structural design of a rotary positive displacement pump described in two patent applications. The general description of the pump in the patent applications is the main reason why the examined solution has not found practical applications to date. The shape of the inner contour of the pump's housing has been described in detail in the proposed solution. The analysis demonstrated that an odd number of pendulum blocks is required and that the number of blocks is determined by the division module of the inner contour of the pump's housing (number of depressions in the wavy surface). The diameter of the cylindrical cross section of a pendulum block and the guiding radius between the axis of the pendulum block and the rotor's axis of rotation were optimized based on the proposed pump geometry. The goal of the optimization process was to minimize clearance as a measure of the pump's internal leak tightness. The estimated optimal values were used to simulate the pump's full operating cycle, depending on the nominal diameter, division module, and the shape factor of pump housing. The results of the simulation indicate that the described solution could have many practical applications. However, the described geometric relationships have to be maintained, and the number of pendulum blocks, the guiding radius, and piston diameter have to be optimized for the needs of specific applications.