A spindle drive comprising a threaded spindle with an external thread, a spindle nut with an internal thread that is in engagement with the external thread of the threaded spindle, characterized in that the external thread of the threaded spindle has multiple threaded areas that are separated from each other by first flattenings on their circumference extending in the longitudinal direction, and the first flattenings have guide areas that abut the core diameter of the internal thread of the spindle nut.

A worm (40) according to an embodiment is a worm made of resin and formed by injection molding. The worm includes a gear portion (40a), a cavity (40c) having an axis being a longitudinal axis (40d) of the worm being formed at the gear portion, and a top portion (40b) formed at a first end portion of the gear portion in a direction of the longitudinal axis. A plurality of recesses (40e) including a hole portion communicating with the cavity are formed at the top portion in a radial direction, and are located on an outer peripheral portion side of the gear portion with respect to the cavity.

A mechanical actuator for vehicles includes a ball nut having a hardened inner part defining a ball track, a malleable outer part comprising a riveting area with a riveting edge, and a bearing riveted with the riveting edge to the riveting area of the outer part of the ball nut.

Lead screw nuts having a body having a threaded opening having a thread region formed from a plurality of different materials having different properties, e.g., a thread region formed from a first material, such as a relatively low friction material, and a second material, such as a relatively high strength material (having thread portions formed from the first material and thread portions formed from the second material).

An electric power steering apparatus includes: a ball nut, which is coupled to a rack bar therein, slides the rack bar, and has a first coupling portion formed to protrude in radial directions from one side of an external circumferential surface such that a fastening member is coupled to the first coupling portion; a nut pulley having a second coupling portion, which is formed to protrude in radial directions from an internal circumferential surface having a hollow therein and which comes in contact with the first coupling portion and to which the fastening member is coupled, and having an external circumferential surface to which the belt is connected and rotates the ball nut; and a deformation preventing member coupled to an opposite end of a portion of the nut pulley in which the second coupling portion is formed.

Provided is a steering function equipped hub unit (1) including: a hub unit body (2); a unit support member (3) configured to be provided to a knuckle (6) and to support the hub unit body (2) such that the hub unit body is rotatable about a turning axis (A) extending in a vertical direction; and a steering actuator (5) configured to rotate the hub unit body (2) about the turning axis (A), wherein the steering actuator (5) includes a motor (26) and a linear motion mechanism (25) configured to convert a rotary output from the motor (26) into a linear motion, the linear motion mechanism (25) includes a feed screw mechanism (33) of a sliding screw type including a nut part (36) and a threaded shaft (36), and a surface hardening layer is provided on at least a threaded surface of one or both of the nut part (35) and the threaded shaft (36).

A threaded shaft for a ball screw comprising: a shaft of fibre-reinforced polymer material; and a helical ridge formed on an outer surface of said shaft, said helical ridge being formed from a fibre-reinforced polymer material comprising a plurality of helical fibres wound around the shaft in the same sense and grouped together to form the ridge. The helical ridge formed from grouped helical fibres all wound with the same sense provides excellent axial load carrying capability as the fibres run continuously from end to end of the shaft and can thus transmit load from end to end. This adds much greater strength than a shaft formed from plastics only. The load carrying capability of the fibre wound helical ridge can indeed approach that of existing metal threads while still being much lighter in weight.

An actuator includes: a cylinder, formed of carbon fiber reinforced polymer (CFRP), that extends along an actuator axis between a cylinder first end and a cylinder second end, and defines a cylinder inner diameter surface; a screw shaft that extends along the actuator axis between a screw shaft first end and a screw shaft second end, that is at least partially within the cylinder, and that is operationally connected, intermediate of the screw shaft first and second ends, to the cylinder second end; a screw shaft head affixed to the screw shaft first end, that in operation rotates relative to the cylinder, and that defines a screw shaft head outer diameter surface that faces the cylinder inner diameter surface with a slip fit therebetween; and a bearing ring affixed to the screw shaft head outer diameter surface, that is formed of polyether ether ketone (PEEK).

A threaded shaft for a ball screw comprising: a shaft of fibre-reinforced polymer material; and a helical ridge formed on an outer surface of said shaft, said helical ridge being formed from a fibre-reinforced polymer material comprising a plurality of helical fibres wound around the shaft in the same sense and grouped together to form the ridge. The helical ridge formed from grouped helical fibres all wound with the same sense provides excellent axial load carrying capability as the fibres run continuously from end to end of the shaft and can thus transmit load from end to end. This adds much greater strength than a shaft formed from plastics only. The load carrying capability of the fibre wound helical ridge can indeed approach that of existing metal threads while still being much lighter in weight.

The present disclosure relates to a hollow-type BLDC motor of a power sliding device of a vehicle seat, and a nut coupled to a lead screw is injection-molded with a plastic and installed only on a longitudinal partial section of the inner diameter of a rotor, a magnet of the rotor is produced in an integrated cylindrical shape having no gap between magnetic poles, and a skew angle is given on a boundary line between the magnetic poles, thereby reducing noise and vibration.