An annular power transmission element with a longitudinal axis that has a first annular part, a second annular part with torque transmission means and a third annular part. The first, second and third annular parts are integral with each other. The first annular part and the third annular part are made of a first metallic material and the second annular part is made of a second metallic material having a density greater than the density of the first metallic material. The second annular part is locked longitudinally between the first annular part and the third annular part and radially on the first annular part, the first annular part is in contact with the third annular part and welded thereto.

A planetary gear device includes: a housing cover disposed at one end portion of a housing in an axis direction, the housing being configured to house a sun gear and a planetary gear inside the housing; and a carrier cover disposed next to the housing cover in the axial direction in the inside, and configured to support a shaft of the planetary gear from one end portion side in the axial direction. One opposing part of a pair of opposing parts opposite to each other in the housing cover and the carrier cover includes a cone-shaped part whose diameter varies in the axial direction, and the other opposing part of the pair of opposing parts includes a sliding part configured to slide on a peripheral surface of the cone-shaped part with a same axis as an axis of the cone-shaped part.

To provide a disc brake having a planetary gear reduction mechanism that may be satisfactory costly and achieve improved reliability, a planetary gear reduction mechanism of a disc brake according to the present disclosure includes a sun gear having an input gear portion to which rotation from a motor is transmitted and an output gear portion extending axially from a radial central region of the input gear portion, a plurality of planetary gears configured to mesh with the output gear portion of the sun gear, and an internal gear configured to mesh with each planetary gear, and the internal gear has a cylindrical support portion configured to rotatably support the sun gear. Accordingly, at the time of assembly, the axis of the sun gear and the axis of the internal gear may be arranged substantially concentrically, which may result in improved reliability and cost satisfaction.

Rolling bearing (1) comprising an inner ring (3), an outer ring (2), at least one row of rolling elements which are arranged between raceways formed on the rings (2, 3) and a ring gear (6) that has a circumference of less than 360° and is fixed to one of the rings (2). The ring gear (6) is formed of a single gear segment (7) which has a circumference substantially equal to the circumference of the ring gear (6) and is provided on its inner or outer peripheral surface with a plurality of meshing means (7b) and fixed only to one of either the inner or outer rings (3) of the rolling bearing (1).

A geared motor includes a gear mechanism portion that meshes with a rotational shaft provided within a main motor unit. The gear mechanism portion has a multistage planetary gear reducing mechanism. The multistage planetary gear reducing mechanism includes a first stage gear formed helically and a final stage gear formed with spur teeth.

The present disclosure may relate to centerless wheel assembly that includes a centerless rim including a first center point laying in a first plane generally defined by the centerless rim. The centerless wheel assembly may also include a centerless ring gear coupled to the centerless rim such that rotation of the centerless ring gear causes a corresponding rotation of the centerless rim. The centerless ring gear may include a second center point laying in a second plane generally defined by the centerless ring gear, and the first plane may be generally parallel to the second plane. Additionally, the centerless ring gear may be shaped to interface with a drive gear that drives the centerless ring gear.

An electric brake assembly for a planetary reduction drive includes a first housing defining a brake housing compartment, first and second stators disposed within the brake housing compartment, and a rotor disposed within the brake housing compartment between the first and second stators. The rotor has a spline engaging an output shaft of a motor. The electric brake assembly also includes a brake end cap coupled to the first housing and defining a cylindrical volume, a plug movably disposed in the cylindrical volume of the brake end cap, a spring disposed within the cylindrical volume of the brake end cap and compressed by the plug to apply a spring biasing force for pressing the second stator against the rotor, and an electric brake coil positioned adjacent to the second stator to electromagnetically pull the second stator away from the rotor when energized.

A gear device includes an external gear, and an internal gear that meshes with the external gear. The external gear is formed of metal. The internal gear is formed of a carbon fiber reinforced resin.

Provided is a double-flexspline harmonic reducer, comprising a strong flexspline (3), a weak flexspline (2) and a wave generator (1). The strong flexspline (3) and the weak flexspline (2) are coaxially fixed in an axial direction and a radial direction, and teeth which can be engaged with each other and are different in the number thereof are provided on the strong flexspline (3) and the weak flexspline (2) respectively. The wave generator (1) causes the weak flexspline (2) to undergo non-circular elastic deformation and then to partially engage with the strong flexspline (3), and a contact portion of the strong flexspline (3) and the weak flexspline (2) undergoes non-circular elastic deformation under a radial pressure from the weak flexspline (2). A wall thickness of the strong flexspline (3) is greater than or equal to 2 times and less than 5 times that of the weak flexspline (2).

A gearwheel (20) for a gear step in an electric vehicle transmission (18) includes a gearwheel carrier and a toothed ring (30) having an external toothing (42). The toothed ring is rotationally fixable to the gearwheel carrier. The gearwheel carrier is formed by a first partial carrier (38) and a second partial carrier (40) that are at least partially axially spaced apart and extend from the toothed ring radially inward. An axial spacing of the two partial carriers is greater, at least partially, than an axial length of the toothed ring.