According to the embodiments, it is possible to mitigate noise by compensating for the clearance inside the bearing supporting the rotation of the ball nut and the clearance between the ball nut and the ball screw and prevent excessive friction between the ball nut and the ball screw and inside the bearing to thereby allow the driver a better steering feel.

A ball screw device includes a screw shaft, a plurality of balls, a nut, a pair of guide members, and a transmission member. The nut has a pair of large-diameter portions and a small-diameter part between the two large-diameter portions. The two guide members are attachable to and detachable from an outer circumferential surface of the small-diameter portion in a radial direction and are located with a certain gap in the outer circumferential direction of the small-diameter portion. A fitting portion of the transmission member fits over the two large-diameter portions such that the fitting portion covers the two guide members while restricting radially outward displacements thereof. The fitting portion works with the small-diameter portion and the two guide members to define a circulation passage through which the balls are circulated. The transmission member is coupled to the nut.

A ball screw device includes a screw shaft, a plurality of balls, a nut, a pair of guide members, and a transmission member. The nut has a pair of large-diameter portions and a small-diameter part between the two large-diameter portions. The two guide members are attachable to and detachable from an outer circumferential surface of the small-diameter portion in a radial direction and are located with a certain gap in the outer circumferential direction of the small-diameter portion. A fitting portion of the transmission member fits over the two large-diameter portions such that the fitting portion covers the two guide members while restricting radially outward displacements thereof. The fitting portion works with the small-diameter portion and the two guide members to define a circulation passage through which the balls are circulated. The transmission member is coupled to the nut.

A steering device includes: a first steering mechanism including a first ball nut steering, and a first motor actuator, the first ball nut steering including a first output shaft, a first ball screw, and a first transmitting mechanism, the first motor actuator arranged to provide a rotation force to the first output shaft, a second steering mechanism including a second ball nut steering, and a second motor actuator, the second ball nut steering including a second output shaft, a second ball screw, and a second transmitting mechanism, the second motor actuator arranged to provide a rotation force to the second output shaft, a connection member arranged to connect the first transmitting mechanism and the second transmitting mechanism so as to interlock a movement of the first transmitting mechanism and a movement of the second transmitting mechanism.

A steering device includes: a first steering mechanism including a first ball nut steering, and a first motor actuator, the first ball nut steering including a first output shaft, a first ball screw, and a first transmitting mechanism, the first motor actuator arranged to provide a rotation force to the first output shaft, a second steering mechanism including a second ball nut steering, and a second motor actuator, the second ball nut steering including a second output shaft, a second ball screw, and a second transmitting mechanism, the second motor actuator arranged to provide a rotation force to the second output shaft, a connection member arranged to connect the first transmitting mechanism and the second transmitting mechanism so as to interlock a movement of the first transmitting mechanism and a movement of the second transmitting mechanism.

In a power steering system employing an end of travel system including valve actuating rings disposed about a Pitman arm shaft, a device is provided for setting the positions of the rings on the shaft. The device includes a fixed member positioned about, and fixed against movement along, a longitudinal axis perpendicular to the shaft's rotational axis and a movable member that moves along the longitudinal axis relative to the fixed member. The movable member defines a pin at one end configured for engagement with the circumferential ends of the actuating rings. A positioning force applied to one of the members causes the movable member to move between set and reset positions in which the pin engages corresponding ends of the actuating rings during rotation of the shaft and a running position in which the pin remains disengaged from the ends of the actuating ring during rotation of the shaft.

In a power steering system employing an end of travel system including valve actuating rings disposed about a Pitman arm shaft, a device is provided for setting the positions of the rings on the shaft. The device includes a fixed member positioned about, and fixed against movement along, a longitudinal axis perpendicular to the shaft's rotational axis and a movable member that moves along the longitudinal axis relative to the fixed member. The movable member defines a pin at one end configured for engagement with the circumferential ends of the actuating rings. A positioning force applied to one of the members causes the movable member to move between set and reset positions in which the pin engages corresponding ends of the actuating rings during rotation of the shaft and a running position in which the pin remains disengaged from the ends of the actuating ring during rotation of the shaft.

An electric powered recirculating ball assembly includes a steering rack. The electric powered recirculating ball assembly also includes a steering gear housing. The electric powered recirculating ball assembly further includes a plurality of rolling elements operatively coupled to the steering rack and in contact with mating geometry of a component operatively coupled to, or integrally formed with, the steering gear housing.

An electronic power steering apparatus, according to one embodiment of the present invention, comprises: an output shaft rotated by means of a reduction gear connected to a driving motor; a ball screw having an upper end coupled to a lower end of the output shaft, and having outer circumferential screw grooves formed on an outer circumferential surface thereof to rotate in conjunction with the output shaft; a ball nut having gear teeth formed on an outer circumferential surface thereof and inner circumferential screw grooves corresponding to the outer circumferential screw grooves formed on an inner circumferential surface thereof, the ball nut being coupled to the ball screw via a ball and sliding in an axial direction; and a sector shaft, coupled to the gear teeth of the ball nut, for operating a pitman arm while rotating during the axial sliding of the ball nut.

A modular power steering apparatus includes a rotatable shaft, which is selectively rotatable to effect turning movement of at least one vehicle wheel. A housing supports the rotatable shaft for rotation relative thereto, about a shaft axis. A first rotational input assembly is provided for transmitting a steering command from a steering member to the rotatable shaft. A second rotational input assembly is operatively connected with the rotatable shaft. The second rotational input assembly is configured to apply a rotational force to the rotatable shaft. The apparatus includes a plurality of drive stations. Each drive station is configured to selectively accept both of the first and second rotational input assemblies for operating connection to the rotatable shaft at different times.