Input torque detector for vehicle power steering - has input shaft and output shaft coupled to each other through a torsion bar, with a sleeve provided on the outer peripheries of the input shaft and the output shaft to couple with input shaft through helical splines

摘要

In a power steering system, an input torque detector detects the torque by converting the relative rotation between the input shaft and the output shaft into the movement in the axial direction. The input shaft (1) and the output shaft (3) are coupled to each other through a torsion bar (2), and a sleeve (7) is provided on the outer peripheries of the input shaft (1) and the output shaft (3) so as to couple with the input shaft (1) through helical splines (8a, 8b) extending obliquely relative to the axis and coupled with the output shaft (3) through straight splines (9a, 9b) extending axially, so that the torsion of the torsion bar (2) caused by the input torque is detected as an axial sliding amount of the sleeve (7) determined by the helical splines (8a, 8b). Thus the input shaft (1) and the output shaft (3) engage with the sleeve (7) through the splines whereby the manufacturing cost is lowered and the durability of such engaging portions is enhanced.