Abstract: A rack and pinion steering gear unit is achieved that is capable of preventing an increase in operating force of the steering wheel and auxiliary operating force from a motor, and improving the response performance to minute operation when traveling straight. A pressing roller 34 elastically pushes the rear surface 29 of a rack shaft 9 toward a pinion shaft 5. This pressing roller 34 is supported by way of a radial needle bearing 16a by a support shaft 33 that is supported by and fastened to a holder 30 so as to be able to rotate freely. A thrust needle bearing 35 that receives a thrust load that is applied to the pressing roller 34 is provided between both side surfaces in the axial direction of the pressing roller 34 and the inside surface of the holder 30.

Abstract: A rack and pinion steering gear unit is achieved that is capable of preventing an increase in operating force of the steering wheel and auxiliary operating force from a motor, and improving the response performance to minute operation when traveling straight. A pressing roller 34 elastically pushes the rear surface 29 of a rack shaft 9 toward a pinion shaft 5. This pressing roller 34 is supported by way of a radial needle bearing 16a by a support shaft 33 that is supported by and fastened to a holder 30 so as to be able to rotate freely. A thrust needle bearing 35 that receives a thrust load that is applied to the pressing roller 34 is provided between both side surfaces in the axial direction of the pressing roller 34 and the inside surface of the holder 30.

Abstract: Even when bending stress acts on a steering gearbox 1 about attachment holes 161 and 171 of vehicle attachment boss portions 16 and 17, deformation of the vehicle attachment boss portions 16 and 17 in both the longitudinal direction and the vertical direction of the vehicle becomes small since rigidity with respect to deformation in the vicinity of the vehicle attachment boss portions 16 and 17 in both the longitudinal direction and the vertical direction of the vehicle is large due to a first rib 61 to a fourth rib 64. Accordingly, it is possible to improve steering stability at the time a steering reaction force occurs.

Abstract: Since a rigid supporting structure for a gear box GB and a rolling type rack supporting device RSD are employed, an electric power steering apparatus having no response delay and having a high transmission efficiency can be realized. Further, a high steering performance required for a long period and a steering assist force that is increasing recently can be efficiently transmitted to wheels. Further, when the wheels collide with a shoulder of a road to receive a counter input, a torque sensor TS detects a torque and an assist steering force against the counter input is outputted to an output shaft OS. Consequently, the torque of the counter input is restrained from being transmitted to a steering shaft SS side. Thus, a kick back and a vibration are advantageously hardly transmitted to a steering wheel SW from the wheels.

Abstract: Even when bending stress acts on a steering gearbox 1 about attachment holes 161 and 171 of vehicle attachment boss portions 16 and 17, deformation of the vehicle attachment boss portions 16 and 17 in both the longitudinal direction and the vertical direction of the vehicle becomes small since rigidity with respect to deformation in the vicinity of the vehicle attachment boss portions 16 and 17 in both the longitudinal direction and the vertical direction of the vehicle is large due to a first rib 61 to a fourth rib 64. Accordingly, it is possible to improve steering stability at the time a steering reaction force occurs.

Abstract: A rack and pinion steering gear 10 including a pinion shaft 11 coupled to a steering shaft, a rack shaft 12 which meshes with the pinion 11, and a rack guide 14 having provided thereon a metallic roller 16 adapted to roll on a back side of the rack shaft 12 and adapted to support the rack shaft 12 via the metallic roller 16, wherein the metallic roller 16 has an elastic member 32 which is partially secured to a rolling contact surface 29 thereof in a circumferential direction, whereby the metallic roller 16 is brought into contact with the back side of the rack shaft 12 at a metallic portion of the rolling contact surface 29 and the elastic member 32 By this configuration, the generation of abnormal noise can be suppressed, and the increase in driving stability of the vehicle can be realized.

Abstract: Since a rigid supporting structure for a gear box GB and a rolling type rack supporting device RSD are employed, an electric power steering apparatus having no response delay and having a high transmission efficiency can be realized. Further, a high steering performance required for a long period and a steering assist force that is increasing recently can be efficiently transmitted to wheels. Further, when the wheels collide with a shoulder of a road to receive a counter input, a torque sensor TS detects a torque and an assist steering force against the counter input is outputted to an output shaft OS Consequently, the torque of the counter input is restrained from being transmitted to a steering shaft SS side. Thus, a kick back and a vibration are advantageously hardly transmitted to a steering wheel SW from the wheels.