A method of engaging a drive system with a rotating wheel of an aircraft landing gear is disclosed. A motor is operated to apply torque to a pinion so the pinion rotates. An engagement command is issued to an actuator at an engagement time, and the actuator operates the actuator in response to the engagement command to move the pinion from a neutral position to a contact position in which it contacts a rotating driven gear at an initial contact time, the rotating driven gear being mounted to a rotating wheel of an aircraft landing gear; then after the initial contact time operating the actuator to move the pinion further to a meshing position where the pinion meshes with the driven gear. A centre-to-centre distance between the pinion and the driven gear reduces as the pinion moves to the contact position and to the meshing position.

A method of engaging a drive system with a rotating wheel of an aircraft landing gear is disclosed. A motor is operated to apply torque to a pinion so the pinion rotates. An engagement command is issued to an actuator at an engagement time, and the actuator operates the actuator in response to the engagement command to move the pinion from a neutral position to a contact position in which it contacts a rotating driven gear at an initial contact time, the rotating driven gear being mounted to a rotating wheel of an aircraft landing gear; then after the initial contact time operating the actuator to move the pinion further to a meshing position where the pinion meshes with the driven gear. A centre-to-centre distance between the pinion and the driven gear reduces as the pinion moves to the contact position and to the meshing position.

A rotary drive device includes a pair of drive force transmissions, a pair of decelerators, a pair of carriers, and at least one coupler. Driving rollers are included in the pair of drive force transmissions. Driving rollers transmit drive force to a main wheel. The main wheel includes driven rollers. The pair of drive force transmissions are rotatable about a rotation axis. The pair of carriers accommodate at least a portion of the decelerators. The pair of carriers oppose each other in an axial direction along the rotation axis. The pair of carriers include a first carrier and a second carrier that are directly or indirectly coupled by the at least one coupler.

A vehicle power steering assembly includes a housing, a ball nut configured to be operatively disposed in the housing and including an extension portion provided with a convex bearing surface, an insert supported on the housing and provided with a concave bearing surface. The concave bearing surface is complementary to the convex bearing surface. The convex and concave bearing surfaces are a plain bearing configured to provide sliding movement relative to each other. The sliding movement provides relative rotation between the convex and concave bearing surfaces in a first direction on the ball nut axis and a second direction on a rotation axis that is transverse to the ball nut axis.

A multiband antenna transmission, including: a driving gear, a shifter, and a plurality of screw assemblies. The position and the driving gear are coaxially and rotatably arranged, and the shifter comprises a plate and a boss protruding from a side of the plate. The plurality of screw assemblies are arranged in a circumferential direction of the driving gear. Each of the plurality of screw assemblies includes: a lead screw, a driven gear selectively connected with or separated from the lead screw, and a first elastic member arranged between the lead screw and the driven gear. The boss is configured to sequentially push the driven gear of the respective screw assembly during rotation of the shifter, such that the driven gear is connected with the corresponding lead screw and whereby the driven gear is in mesh with the driving gear for transmission.

A drive wheel in which the rotational axial center of a wheel along the vertical direction intersecting the axial center of the axle is arranged shifted in the horizontal direction orthogonal to the axial center of the axle with respect to the axial center of the pivot shaft. When a radius R1 of the wheel, center distance R2 between the rotational axial center and the axial center of the pivot shaft, rotational frequency n1 of the wheel, rotational frequency n2 of the pivot shaft, rotational speed V1 of the wheel, and steering rotational speed V2 of the wheel rolling on a floor surface while turning the pivot shaft satisfy V1=V2, relations of V1=2R1n1, V2=2R2n2, and n1=n2 (R2/R1) are satisfied.

A drive wheel in which the rotational axial center of a wheel along the vertical direction intersecting the axial center of the axle is arranged shifted in the horizontal direction orthogonal to the axial center of the axle with respect to the axial center of the pivot shaft. When a radius R1 of the wheel, center distance R2 between the rotational axial center and the axial center of the pivot shaft, rotational frequency n1 of the wheel, rotational frequency n2 of the pivot shaft, rotational speed V1 of the wheel, and steering rotational speed V2 of the wheel rolling on a floor surface while turning the pivot shaft satisfy V1=V2, relations of V1=2R1n1, V2=2R2n2, and n1=n2 (R2/R1) are satisfied.

A method of engaging a drive system with a rotating wheel of an aircraft landing gear is disclosed. A motor is operated to apply torque to a pinion so the pinion rotates and moved from a neutral position to a contact position in which it contacts a rotating driven gear at an initial contact time, the rotating driven gear being mounted to a rotating wheel of an aircraft landing gear. After the initial contact time the pinion is moved further to a meshing position where the pinion meshes with the driven gear. A centre-to-centre distance between the pinion and the driven gear reduces as the pinion moves to the contact position and to the meshing position. The driven gear contacts the pinion in a series of impacts as the pinion moves from the contact position to the meshing position, each impact induces a spike in electromotive force or angular velocity at the motor.

A method of engaging a drive system with a rotating wheel of an aircraft landing gear is disclosed. A motor is operated to apply torque to a pinion so the pinion rotates and moved from a neutral position to a contact position in which it contacts a rotating driven gear at an initial contact time, the rotating driven gear being mounted to a rotating wheel of an aircraft landing gear. After the initial contact time the pinion is moved further to a meshing position where the pinion meshes with the driven gear. A centre-to-centre distance between the pinion and the driven gear reduces as the pinion moves to the contact position and to the meshing position. The driven gear contacts the pinion in a series of impacts as the pinion moves from the contact position to the meshing position, each impact induces a spike in electromotive force or angular velocity at the motor.

A gearbox assembly includes a housing, a first shaft assembly having a worm gear and supported relative to the housing by a first bearing assembly, and a second shaft assembly including a wheel gear which is also supported relative to the housing by a second bearing assembly, the wheel gear engaging with the worm of the worm gear to permit the transfer of torque between the two shaft assemblies, wherein the first shaft assembly includes an elongate shaft carrying the worm gear, and a separate dog drive mechanism secured to one end of the elongate shaft by the first bearing such that in use torque is transferred between the elongate shaft and the dog drive mechanism.