The present invention relates to a speed reducer for a vehicle. The speed reducer includes: a gear housing configured to enclose a worm wheel and a worm shaft and including one of a first magnetic member and a second magnetic member, which generate attractive force or repulsive force therebetween as current is applied to a position facing the worm shaft in an axial direction; a first bearing coupled to an end of the worm shaft at an opposite side to a motor shaft-coupling portion; and a moving member coupled, at one side thereof, to an outer race of the first bearing and including, at a remaining side thereof, a remaining one of the first and second magnetic members, so that the moving member is axially moved according to the attractive force or the repulsive force.

A control device for a vehicle is provided with: two drive devices; a first speed reducer that transmits the torque of one drive device to an output shaft; and a second speed reducer that transmits the torque of the other drive device to the output shaft. The control device is provided with a torque control unit that controls, according to a target torque, the torque output by the two drive devices. The torque control unit includes a restriction unit that controls the torque output by the two drive devices when the sign of the target torque is changed from a first sign to a second sign. While outputting torque that reduces the backlash of the first speed reducer or the second speed reducer to one of the drive devices, the restriction unit outputs torque according to the target torque to the other drive device.

A method for controlling a separation between rotational axes of a pair of meshing gears is disclosed. A parameter indicative of a transmission error through the gears is measured and the separation is controlled, aiming to minimise variations in the measured signal. This acts to reduce variations in transmission error and the related vibrations created in the drive system and in the surrounding components. A related drive system and aircraft landing gear are described.

Magnetically-assisted mechanical gear systems and other power transmission systems, and related methods of operation and assembly, are disclosed herein. In an example embodiment, such a system includes a driving gear, a driven gear, and a first magnetomotive force (MMF) source that generates a magnetic flux. A first portion of the flux is communicated between at least one driving gear teeth and at least one driven gear teeth so that one or more magnetic forces are exerted between the gears. When the first rotational movement of the driving gear alternates from being in the first rotational direction to being in a third rotational direction opposite the first rotational direction, then the driven gear is driven by the one or more magnetic forces so that the second rotational movement also alternates, and a first amount of backlash movement between the driving and driven gears is avoided or reduced.

A pitch assembly for a wind turbine includes a pitch bearing comprising an inner race, an outer race, and a plurality of gear teeth arranged on one of the inner race or the outer race. The pitch assembly further includes a pitch drive mechanism having a pitch drive motor and a primary pitch drive pinion. The primary pitch drive pinion is configured to rotate one of the inner race or the outer race of the pitch bearing about a pitch axis by engaging with a first set of the plurality of gear teeth. The pitch assembly also includes a secondary pinion engaging a second set of the plurality of gear teeth. The secondary pinion is constructed of a deformable material such that backlash is eliminated between the secondary pinion and the plurality of gear teeth, thereby minimizing micro-pitching of the pitch assembly.

A method of controlling torque of a drive system of an electric vehicle includes determining, by a controller, required torque according to a vehicle driving state while the vehicle is driven, and determining a total torque command based on the determined required torque, and performing, by the controller, a front wheel and rear wheel torque distribution process on the total torque command, so that a front wheel torque command and a rear wheel torque command following the total torque command are determined.

A system having an anti-backlash mechanism, a method for removing backlash, and an anti-backlash mechanism for a gear assembly is provided. The gear assembly having a pinion and an output gear. The anti-backlash mechanism includes a frame and a first idler gear operably disposed between the pinion and the output gear. A first flexure device is coupled between the first idler gear and the frame, the first flexure device applying a pre-load to the first idler gear to move the first idler gear into engagement with the pinion and output gear. A second idler gear is operably disposed between the pinion and the output gear. A second flexure device is coupled between the second idler gear and the frame, the second flexure device applying a pre-load to the second idler gear to move the second idler gear into engagement with the pinion and output gear.