Abstract: A method of manufacturing a rack guide base body wherein a cavity (40) is formed which has a pair of semicylindrical convex surfaces (44a and 44b) and a pair of flat surfaces (45) each located between the semicylindrical convex surfaces (44a and 44b), and has a recessed surface (41) located on one axial end portion side inwardly of the semicylindrical convex surfaces (44a and 44b) and the flat surfaces (45) and a cylindrical surface (42) located on the other axial end portion side inwardly of the semicylindrical convex surfaces (44a and 44b) and the flat surfaces (45); a hollow portion (9c) is formed for allowing the cavity (40) to communicate with a hollow portion (10c) at one flat surface (45) and with a hollow portion (8c) at the other flat surface (45); a rack guide base body (50) is die cast by forcing molten metal of aluminum from the hollow portion (10c) into the cavity (40); and runners (56) integrally joined to flat surfaces (55) of the rack guide base body (50) formed by the respective flat surfaces

Abstract: Prior to engaging a male screw formed on the outer circumference of a second member with a female screw formed on the inner circumference of a hole in a first member, protruding parts which protrude outward in the radial direction and are positioned at one end side of the male screw in the axial direction are formed in a plurality of regions which are separated from each other in the circumferential direction on the outer circumference of the second member on which the male screw is formed. The male screw is then engaged with the female screw from the other end side of the male screw in the axial direction. The torque required to rotate the male screw engaged with the female screw in the loosening direction is set so as to be greater in a state where the protruding parts are interposed between the male screw and the female screw than in a state where the protruding parts are not so interposed.

Abstract: A method of manufacturing a rack guide base body wherein a cavity (40) is formed which has a pair of semicylindrical convex surfaces (44a and 44b) and a pair of flat surfaces (45) each located between the semicylindrical convex surfaces (44a and 44b), and has a recessed surface (41) located on one axial end portion side inwardly of the semicylindrical convex surfaces (44a and 44b) and the flat surfaces (45) and a cylindrical surface (42) located on the other axial end portion side inwardly of the semicylindrical convex surfaces (44a and 44b) and the flat surfaces (45); a hollow portion (9c) is formed for allowing the cavity (40) to communicate with a hollow portion (10c) at one flat surface (45) and with a hollow portion (8c) at the other flat surface (45); a rack guide base body (50) is die cast by forcing molten metal of aluminum from the hollow portion (10c) into the cavity (40); and runners (56) integrally joined to flat surfaces (55) of the rack guide base body (50) formed by the respective flat surfaces

Abstract: A rack guide includes a rack guide base body which has on its outer peripheral surface a pair of semicylindrical surfaces and a pair of planar surfaces each located between the pair of semicylindrical surfaces, has a concavely recessed surface located on one axial end portion side inwardly of the pair of semicylindrical surfaces and the planar surfaces, and has a cylindrical surface located on the other axial end portion side inwardly of the pair of semicylindrical surfaces and the planar surfaces; and a slider secured to the rack guide base body.

Abstract: A rack guide includes a rack guide base body which has on its outer peripheral surface a pair of semicylindrical surfaces and a pair of planar surfaces each located between the pair of semicylindrical surfaces, has a concavely recessed surface located on one axial end portion side inwardly of the pair of semicylindrical surfaces and the planar surfaces, and has a cylindrical surface located on the other axial end portion side inwardly of the pair of semicylindrical surfaces and the planar surfaces; and a slider secured to the rack guide base body.

Abstract: An electric power steering system is provided, which comprises a steering assist electric motor, and a reduction gear mechanism for reducing a rotation speed of a rotatable shaft of the electric motor. The reduction gear mechanism comprises a worm shaft driven by the rotatable shaft, and a worm wheel driven by the warm shaft. The electric power steering system further comprises a joint for coupling the rotatable shaft to the worm shaft for transmission of a driving force. Longitudinally biasing means is provided in association with the joint for longitudinally biasing the worm shaft.

Abstract: An electric power steering system is provided, which comprises a steering assist electric motor, and a reduction gear mechanism for reducing a rotation speed of a rotatable shaft of the electric motor. The reduction gear mechanism comprises a worm shaft driven by the rotatable shaft, and a worm wheel driven by the warm shaft. The electric power steering system further comprises a joint for coupling the rotatable shaft to the worm shaft for transmission of a driving force. Longitudinally biasing means is provided in association with the joint for longitudinally biasing the worm shaft.

Abstract: A hydraulic power steering device responsive to the speed of a vehicle and comprising a housing, an output shaft disposed in the housing, an input shaft disposed in the housing and coaxial with the output shaft, a torsion bar provided between the output shaft and the input shaft, a control valve provided around the input shaft for controlling the amount of pressure oil to be supplied from a hydraulic pump to a power cylinder in accordance with the torsion of the torsion bar, and plungers each slidably fitted in a hole formed in the output shaft, each of the plungers being adapted to be pressed at its forward end against the input shaft by oil pressure in accordance with the vehicle speed to obtain a reaction. At least one of the portion of the plunger slidable in contact with the inner peripheral surface of the output shaft defining the hole and the portion of the plunger to be pressed into contact with the input shaft is made of a synthetic resin.