Rotary valve and a method of assembling the rotary valve

Abstract

During the assembly steps of a rotary valve, after an input shaft is attached onto a torsion bar, the input shaft is rotated clockwise and counterclockwise concentrically with the torsion bar. A central position is thus detected and determined such that a hydraulic pressure, which is generated when the input shaft is rotated by some angle clockwise from the central position relative to an output shaft, is symmetrical with a hydraulic pressure generated when the input shaft is rotated by the same angle counterclockwise from the central position. While the determined central position of the input shaft in a peripheral direction relative to the torsion bar is maintained, the input shaft is axially secured. By pulling the torsion bar further into the input shaft, an engaging portion of the torsion bar engages in a securing bore of the input shaft. When a notch of the torsion bar is aligned flush with an end face of the input shaft and the torsion bar is completely press-fitted into the input shaft, a chuck portion is removed from the end of the torsion bar. Since the input shaft and the torsion bar require no through bores or O rings for interconnection, the rotary valve can be easily assembled through simple steps. At the same time, since the input shaft and the torsion bar do not have any positional deviation, the symmetry of the hydraulic pressure characteristics is improved.

Dependencies are inferred from the claim text.