Transient Motion of Hydrostatic Lead Screws With Continuous Helical Recesses

Hydrostatic lead screws possess superior motion characteristics and often run under high speeds and variable loads. This paper presents research on the transient motion of capillary compensated hydrostatic lead screws with continuous helical recesses under high speeds and variable loads. The model is based on the Reynolds equation, the equation of motion and the Euler equation, and takes pitch errors into account. The simulation results show that: (a) the displacement curves of the nut thread calculated under lower static loads can be obtained approximately by translating the displacement curve calculated under no load, (b) under high speeds and higher static loads, the displacement curves of the nut thread present differences, (c) under step loads, the hydrostatic nut has a smooth transient process, and (d) under sinusoidal loads, the amplitude of transient response path is smaller than the displacement of the nut thread under a static load with the same magnitude, and decreases with increase in the frequency of the sinusoidal load.