Abstract: An electric power steering apparatus includes a reduction gear mechanism (17) for reducing the rotation speed of an output shaft (16) of an electric motor (15). The reduction gear mechanism (17) comprises an inscribed gear (39) rotatable interlockingly with the output shaft (16), and a circumscribed gear (40) in which the inscribed gear (39) is inscribed. An endless belt connects a driving pulley (41) integrally rotatable with the circumscribed gear (40) and a driven pulley (42) disposed so as to surround a steerable shaft. By heightening the reduction gear ratio by the speed reduction using the inscribed gear (39) and the circumscribed gear (40), the reduction gear mechanism (17) as a whole can achieve a high reduction gear ratio without making the diameter of the driving pulley (41) very small.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other and a belt tension adjuster.

Abstract: A ball screw (26) includes a screw shaft (29) a nut (25) surrounding the screw shaft (29), and a plurality of balls (30) engageable with the screw shaft (29) and the nut (25). The ball screw (26) includes first and second raceways (S, K). The first raceway (S) is defined between the screw shaft (29) and the nut (25), and has first and second ends (S1, S2). The second raceway (K) has first and second ends (K1, K2) respectively connected to the first and second ends (S1, S2) of the first raceway (S) for circulating the balls (30) into the first raceway (S). The second raceway (K) accommodates an odd number of balls (30) at the maximum at a time.

Abstract: An electric power steering apparatus comprises a speed reduction mechanism for decelerating the rotation of an output shaft in an electric motor for steering assist. The speed reduction mechanism comprises a driving gear connected to the output shaft in the electric motor and a driven gear meshed with the driving gear. One of respective tooth sections in the driving gear and the driven gear includes a tooth section formed of a material having a relatively low hardness, and the other tooth section includes a tooth section formed of a material having a relatively high hardness. The profile of the tooth section formed of the material having a relatively low hardness is shifted in the direction in which the thickness at the root of the teeth of the tooth section is increased. The profile of the tooth section formed of the material having a relatively high hardness is shifted in the direction in which the thickness at the root of the teeth of the tooth section is decreased.

Abstract: An electric power steering apparatus includes a reduction gear mechanism (17) for reducing the rotation speed of an output shaft (16) of an electric motor (15). The reduction gear mechanism (17) comprises an inscribed gear (39) rotatable interlockingly with the output shaft (16), and a circumscribed gear (40) in which the inscribed gear (39) is inscribed. An endless belt connects a driving pulley (41) integrally rotatable with the circumscribed gear (40) and a driven pulley (42) disposed so as to surround a steerable shaft. By heightening the reduction gear ratio by the speed reduction using the inscribed gear (39) and the circumscribed gear (40), the reduction gear mechanism (17) as a whole can achieve a high reduction gear ratio without making the diameter of the driving pulley (41) very small.

Abstract: In a vehicle steering apparatus, a rotating cylinder supported by a rack housing is threadingly engaged via rolling elements with a screw shaft integrated with a rack which meshes with a pinion which rotates by steering operation. The rotating cylinder is driven by a motor. All of the rolling elements are arranged between a rack support member which supports the rack in the position where the rack is meshed with the pinion, and a support body that is arranged in the movement range of the screw shaft and is capable of supporting the outer circumference of the screw shaft. Loads acting on the rack from the road surface are received by the support body and the rack support member.

Abstract: An electric power steering apparatus comprises a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism comprises an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and means for adjusting the tension of the belt.

Abstract: An electric power steering apparatus includes a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism includes an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and a belt tension adjuster.

Abstract: An electric power steering apparatus comprises a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism comprises an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and means for adjusting the tension of the belt.

Abstract: An electric power steering apparatus comprises a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism comprises an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and means for adjusting the tension of the belt.

Abstract: An electric power steering apparatus comprises a speed reduction mechanism for decelerating the rotation of an output shaft in an electric motor for steering assist. The speed reduction mechanism comprises a driving gear connected to the output shaft in the electric motor and a driven gear meshed with the driving gear. One of respective tooth sections in the driving gear and the driven gear includes a tooth section formed of a material having a relatively low hardness, and the other tooth section includes a tooth section formed of a material having a relatively high hardness. The profile of the tooth section formed of the material having a relatively low hardness is shifted in the direction in which the thickness at the root of the teeth of the tooth section is increased. The profile of the tooth section formed of the material having a relatively high hardness is shifted in the direction in which the thickness at the root of the teeth of the tooth section is decreased.

Abstract: An electric power steering apparatus comprises a speed reducing mechanism for decelerating the rotation of a rotatable shaft in an electric motor and a converting mechanism for converting the output rotation of the speed reducing mechanism into the axial movement of a steering shaft extending toward the right and left sides of a vehicle. The speed reducing mechanism comprises an input pulley driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley to each other, and means for adjusting the tension of the belt.

Abstract: In a vehicle steering apparatus, a rotating cylinder supported by a rack housing is threadingly engaged via rolling elements with a screw shaft integrated with a rack which meshes with a pinion which rotates by steering operation. The rotating cylinder is driven by a motor. All of the rolling elements are arranged between a rack support member which supports the rack in the position where the rack is meshed with the pinion, and a support body that is arranged in the movement range of the screw shaft and is capable of supporting the outer circumference of the screw shaft. Loads acting on the rack from the road surface are received by the support body and the rack support member.