In this paper, a newly designed rotary disk type distribution valve was reported for the radial piston type water hydraulic motors. Radial piston motors require a distribution valve to supply and discharge fluid to the cylinders arranged radially around the output shaft. The number of cylinders is usually five or seven to reduce fluctuations in output torque and angular velocity. The distribution valve rotates in sync with the output shaft, switching the flow at the top and bottom dead centers of the piston. In this study, a rotary disk type distribution valve was developed with a structure suitable for radial piston type water hydraulic motors . Packing is not used to reduce friction loss, and pressure compensation pockets are used to reduce leakage flow. The pressure compensation pockets have the effect of suppressing the increase of the clearance between the sliding parts, which is caused by the deformation of parts due to pressure acting inside the distributing valve. The developed distribution valve was incorporated into a radial piston type water hydraulic motor using a cam mechanism, and the results of a performance test under load were reported.
Kenji SUZUKI (Wed,) studied this question.