This rotating shaft structure comprises a first link, a second link connected to the first link, and a plurality of speed reducers positioned between the first link and the second link. At least one of a speed-reducer-side attachment hole and a first-link-side attachment hole, which are for joining the speed reducers to the first link, is larger or longer than the other.

An actuation mechanism for a surgical instrument (100) includes a sleeve (202) configured to receive the surgical instrument and including one or more parts (208, 210, 226), with studs (250, 252) provided on each part, on some parts only, or distributed over the different parts. At least two wheels (204, 206) are mounted on the sleeve on either side of the part or parts, each wheel being equipped with at least one groove (242) and a mechanical transmission element (244). The groove of each wheel movably receives one of the studs in the groove. At least two drive shafts (212, 214), each being equipped with a first mechanical transmission element (254), cooperate with the mechanical transmission element (244) of one of the wheels.

A fail-safe drive (1) for an actuating drive is provided, which has a cam disc (8), at least one restoring element, a counter-element (5) and an output shaft (3), with the cam disc (8) and the counter-element (5) being configured for joint conversion of an axial movement of the restoring element along the output shaft (3) into a rotational movement of the output shaft (3). The cam disc (8) has a control cam (10), the profile of which is adapted to a spring characteristic curve of the restoring element such that, in the case of activation of the failsafe drive (1), a constant output movement and/or a constant output torque can be generated.

The subject matter of this specification can be embodied in, among other things, an actuator that includes a worm drive assembly having a worm shaft, and a worm wheel configured as a ring having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a coaxial radially inner perimeter comprising a second collection of gear teeth extending radially inward from the inner perimeter, and an epicyclic gear assembly having a sun gear and a planet gear engaged with the sun gear and the second collection of gear teeth.

A direct-drive double wing scooter includes a frame, an actuation assembly, a drive assembly, and a transmission assembly. The actuation assembly includes left and right swing wings each pivoted close to a front end of the frame through a pivot. The drive assembly includes a first turning shaft and a second turning shaft penetrating two sides of the frame. A distance between the first turning shaft and the pivot is defined as a first distance. A distance between a rear end of the right swing wing is defined as a second distance, or a distance between a rear end of the left swing wing is defined as a second distance. The first distance is in the range of 0.10-0.65 times the length of the second distance. The direct-drive double wing scooter provides a simple and reliable drive way and has transportation, amusement and fitness effects.

The subject matter of this specification can be embodied in, among other things, an actuator that includes a worm drive assembly having a worm shaft, and a worm wheel configured as a ring having a radially outer perimeter comprising a first collection of gear teeth extending radially outward from the radially outer perimeter and at least partly engaged with the worm shaft, and a coaxial radially inner perimeter comprising a second collection of gear teeth extending radially inward from the inner perimeter, and an epicyclic gear assembly having a sun gear and a planet gear engaged with the sun gear and the second collection of gear teeth.

The present disclosure relates to a variable valve drive for a lifting valve, in particular for a charge-exchange valve of an internal combustion engine, which is periodically movable between a closed position and an open position indirectly by way of a cam via a rocker lever. The variable valve drive includes a switchable rocker lever arrangement for the actuation of the lifting valve, having a transmission rocker lever and a valve rocker lever which are mounted pivotably on different rocker lever axles which are each parallel to the camshaft axis.

A novel deformation motion mechanism with precise motion precise motion and structural robustness is achieved. A deformation motion mechanism includes: an elastic ring member shaped symmetrically with respect to a center line, wherein one end of the elastic ring member is fixed and the other end is movable along the center line; a drive unit which is placed within the elastic ring member and is arranged to rotate a feed screw engaged with both ends of the elastic ring member along an operating line orthogonal to the center line, to press or stretch the elastic ring member along the center line; and a plurality of flexible arms which connects the drive unit to the elastic member in at least a direction of the center line.

A derailleur includes a fixed component, a movable component, a linkage component, a deceleration component and a drive component. The fixed component is for being fixed to a bicycle frame. The movable component is for being fixed to a chain guide. The linkage component includes a first linkage and a second linkage. Two ends of the first linkage pivot on the fixed component and the movable component, respectively. Two ends of the second linkage pivot on the fixed component and the movable component, respectively. The deceleration component includes a circular spline, a flex spline and a wave generator. The flex spline is disposed inside the circular spline, for rotating the first linkage and the second linkage relative to the fixed component. The wave generator is disposed inside the flex spline. The drive component is connected to the wave generator, for rotating the wave generator.

A door opening and closing apparatus for a vehicle includes a transmission gear configured to be driven to rotate by a motor, a pulley arranged coaxially with the transmission gear and configured to open and close a vehicle door by moving a rope member with a rotation of the pulley, an output member arranged coaxially with the transmission gear and configured to bring a door lock to a holding state with a rotation of the output member, a first clutch housed in the pulley in a state being coaxial with the transmission gear, the first clutch selectively permitting and prohibiting a rotation transmission between the transmission gear and the pulley, and a second clutch housed in the transmission gear in a state being coaxial with the transmission gear, the second clutch selectively permitting and prohibiting a rotation transmission between the transmission gear and the output member.