A drive unit includes a drive stem having first friction surfaces and a load coupling, wherein the load coupling is a threaded coupling. The drive unit also includes a transmission unit having second friction surfaces parallel to the first friction surfaces; and shoulders proximate a bottom of the transmission unit. The drive unit further includes a transmission selector movable to an on position or an off position, wherein the drive stem moves synchronously with the transmission unit when the transmission selector is in the on position.

A hub unit has a brake disc and a hub body disposed to rotate with a rim on which a tire is mounted. An internal space is formed in the hub body, wherein the brake disc is fixed in the internal space. A fixed shaft is disposed and fixed along a rotation center shaft of the hub body. A brake shoe is coupled to the fixed shaft. A brake pad is disposed to contact the brake disc. A braking force applier supplies a braking force to the hub body wherein the brake pad and the brake disc are in contact with each other.

A hub unit has a brake disc and a hub body disposed to rotate with a rim on which a tire is mounted. An internal space is formed in the hub body, wherein the brake disc is fixed in the internal space. A fixed shaft is disposed and fixed along a rotation center shaft of the hub body. A brake shoe is coupled to the fixed shaft. A brake pad is disposed to contact the brake disc. A braking force applier supplies a braking force to the hub body wherein the brake pad and the brake disc are in contact with each other.

A transmission includes a case, a torque sensor, and a two-piece output shaft. The torque sensor is attached to the case and defines an inner diameter. The two-piece output shaft assembly is partially disposed within the case and includes a planet carrier operably coupled to a shaft extending through the inner diameter. The carrier and the shaft are separate components that are directly connected together and the carrier defines a park gear.

A transmission includes a case, a torque sensor, and a two-piece output shaft. The torque sensor is attached to the case and defines an inner diameter. The two-piece output shaft assembly is partially disposed within the case and includes a planet carrier operably coupled to a shaft extending through the inner diameter. The carrier and the shaft are separate components that are directly connected together and the carrier defines a park gear.

A shaft, especially a motor shaft, is inserted into an accommodation area of a hub, especially an adapter shaft, and is connected with force locking, especially being clamped. The hub, at least in one axial area, has three flattenings evenly spaced from one another in the circumferential direction. A first threaded part, particularly a first, preferably radially-acting setscrew, is screwed into a clamping ring and presses on one area of the hub in order to bring about the force-locking connection, especially by bracing the clamping ring against the hub, in particular, the area covering an angle-at-circumference area which is smaller than the angular distance in the circumferential direction between two flattenings immediately adjacent in the circumferential direction.

A shaft, especially a motor shaft, is inserted into an accommodation area of a hub, especially an adapter shaft, and is connected with force locking, especially being clamped. The hub, at least in one axial area, has three flattenings evenly spaced from one another in the circumferential direction. A first threaded part, particularly a first, preferably radially-acting setscrew, is screwed into a clamping ring and presses on one area of the hub in order to bring about the force-locking connection, especially by bracing the clamping ring against the hub, in particular, the area covering an angle-at-circumference area which is smaller than the angular distance in the circumferential direction between two flattenings immediately adjacent in the circumferential direction.

A shaft-and-gear arrangement includes a shaft having a longitudinal axis of rotation, a first portion having an outer diameter, a second portion, and a third portion axially between the first portion and second portions. A first gear is formed either integrally with the second portion of the shaft or has a circumferential inner surface secured to an outer surface of the second portion of the shaft. The first gear has a first subportion having a maximum outer diameter of the first gear and a second subportion having a radially outer surface having a maximum outer diameter less than the maximum outer diameter of the first gear, and the second subportion includes a first axially facing abutment surface. The second gear also has a first subportion and a second subportion with a second axially facing abutment surface in contact with the first axially facing abutment surface.

A composite shaft with an end fitting mounted on an interface region on at least one end of said shaft, and a preload structure arranged to provide a biasing force to bias the composite shaft against the end fitting; wherein the preload structure is in an interference fit with the composite shaft. The preload structure is applied to the composite shaft in a subsequent operation to the mounting of the end fitting to the shaft.

A composite shaft with an end fitting mounted on an interface region on at least one end of said shaft, and a preload structure arranged to provide a biasing force to bias the composite shaft against the end fitting; wherein the preload structure is in an interference fit with the composite shaft. The preload structure is applied to the composite shaft in a subsequent operation to the mounting of the end fitting to the shaft.