A refrigerator comprising a door rotatable about a hinge shaft. A door opening and closing apparatus comprises a drive motor, a first gear configured to receive power from the drive motor, a second gear, spaced apart from the first gear, configured to transmit a rotational force to the hinge shaft, a clutch gear configured to be rotatable around a rotation axis of the first gear, and configured to transmit power of the first gear to the second gear based on a position of the clutch gear around the rotation axis of the first gear, and a position detection sensor configured to detect the position of the clutch gear so that while the clutch gear is at the position, the clutch gear transmits the power received from the first gear to the second gear which transmits the rotational force to the hinge shaft to open and close the door.

A planetary gear mechanism includes a sun gear rotatable about an axis, a first shaft that is fixed to the sun gear and is rotatable integrally with the sun gear, a plurality of planetary gears that mesh with the sun gear and are rotatable about a center line thereof parallel to the axis, an internal gear that includes internal teeth facing inside in a radial direction to mesh with the planetary gears and is rotatable about the axis, a second shaft that extends in the axial direction to be connected to the internal gear and rotates about the axis together with the internal gear, and a reinforcing member that is fixed to an outer peripheral surface of the internal gear and is formed in an annular shape of a material having a higher specific strength than that of a material forming the internal gear.

A pressure supply unit for a brake system including a booster body that defines an axially extending cylinder. A piston is slideable within the cylinder. The piston defines a bore that receives a spindle. The spindle is rotationally fixed and axially moveable for providing the axial movement of the piston. A motor is positioned about the spindle and is configured to axially translate the spindle and piston. A ball and socket joint connects the piston and spindle while accommodating pivoting movement of the spindle. The ball and socket joint includes a ball at a front end of the spindle and a socket in the bore of the piston which receives the ball.

A foldable screen and a shower room are provided. The foldable screen includes a transmission gear mechanism and a plurality of panel bodies arranged in sequence. End portions of two adjacent sides of two adjacent panel bodies enclose to form a mounting opening into which the transmission gear mechanism is installed for realizing folding and unfolding of the plurality of panel bodies. The transmission gear mechanism includes a housing having a receiving cavity therein, the housing being installed in the mounting opening; a first gear located in the receiving cavity and installed on one of the two adjacent panel bodies; and a second gear meshed with the first gear, the second gear being located in the receiving cavity and installed on the other of the two adjacent panel bodies.

A foldable screen and a shower room are provided. The foldable screen includes a transmission gear mechanism and a plurality of panel bodies arranged in sequence. End portions of two adjacent sides of two adjacent panel bodies enclose to form a mounting opening into which the transmission gear mechanism is installed for realizing folding and unfolding of the plurality of panel bodies. The transmission gear mechanism includes a housing having a receiving cavity therein, the housing being installed in the mounting opening; a first gear located in the receiving cavity and installed on one of the two adjacent panel bodies; and a second gear meshed with the first gear, the second gear being located in the receiving cavity and installed on the other of the two adjacent panel bodies.

Disclosed is a device for moving a brake pedal. The device for moving a brake pedal according to the present embodiment comprises: a lead screw fixed to an input rod of the brake pedal and having a first screw thread formed on the outer circumferential surface thereof; a first anti-rotation unit that prevents rotation of the lead screw; an actuator that provides power; a rotator rotated by the actuator; and a nut that rotates together with the rotator and is provided to be slidably movable with respect to the rotator, and that has a second screw thread formed on the inner circumferential surface thereof for meshing with the first screw thread.

Disclosed is a device for moving a brake pedal. The device for moving a brake pedal according to the present embodiment comprises: a lead screw fixed to an input rod of the brake pedal and having a first screw thread formed on the outer circumferential surface thereof; a first anti-rotation unit that prevents rotation of the lead screw; an actuator that provides power; a rotator rotated by the actuator; and a nut that rotates together with the rotator and is provided to be slidably movable with respect to the rotator, and that has a second screw thread formed on the inner circumferential surface thereof for meshing with the first screw thread.

A work of incorporating a speed reduction mechanism including a scissors gear into a gear case is facilitated. In a state where the angular positions of gear teeth of a first gear and the angular positions of gear teeth of a scissors gear are made to coincide with each other against the elastic force of a torsion spring (19), these angular positions are fixed by a fixing member (position fixing step). The first gear, the scissors gear, and a second gear are housed in a gear case, and the gear teeth of the second gear are made to engage with the gear teeth of the first gear and the gear teeth of the scissors gear (gear incorporating step). The fixing of the angular position of the first gear and the angular position of the scissors gear by the fixing member is released through an opening formed in the gear case.

A work of incorporating a speed reduction mechanism including a scissors gear into a gear case is facilitated. In a state where the angular positions of gear teeth of a first gear and the angular positions of gear teeth of a scissors gear are made to coincide with each other against the elastic force of a torsion spring (19), these angular positions are fixed by a fixing member (position fixing step). The first gear, the scissors gear, and a second gear are housed in a gear case, and the gear teeth of the second gear are made to engage with the gear teeth of the first gear and the gear teeth of the scissors gear (gear incorporating step). The fixing of the angular position of the first gear and the angular position of the scissors gear by the fixing member is released through an opening formed in the gear case.

A power transmission device according to one aspect of the disclosure includes a first gear, a base member, a second gear, a support block, a position adjusting unit, and a fixing unit. The base member rotatably supports the first gear. The second gear engages with the first gear so as to be able to transmit power. The support block rotatably supports the second gear. The position adjusting unit adjusts relative positions of the support block and the base member in a direction in which an engagement depth between the second gear and the first gear varies. The fixing unit fixes the relative positions of the support block and the base member.