Abstract: An actuator includes a motor including a first rotor rotatable in a circumferential direction about a center axis extending in a vertical direction, a second rotor including a sensor magnet and rotatable in the circumferential direction about the center axis, and a speed reducer that reduces rotation of the first rotor and transmits a torque to the second rotor. The motor includes a stationary portion including a stator facing the first rotor and a first bearing rotatably supporting the first rotor with respect to the stationary portion. The stationary portion includes a sensor which faces a portion of a trajectory of the sensor magnet rotating in the circumferential direction and detects a rotation position of the sensor magnet.

Abstract: An actuator includes a motor including a first rotor rotatable in a circumferential direction about a center axis extending in a vertical direction, a second rotor including a sensor magnet and rotatable in the circumferential direction about the center axis, and a speed reducer that reduces rotation of the first rotor and transmits a torque to the second rotor. The motor includes a stationary portion including a stator facing the first rotor and a first bearing rotatably supporting the first rotor with respect to the stationary portion. The stationary portion includes a sensor which faces a portion of a trajectory of the sensor magnet rotating in the circumferential direction and detects a rotation position of the sensor magnet.

Abstract: An actuator includes a motor including a first rotor rotatable in a circumferential direction, and a stator to drive the first rotor; a second rotor rotatable in the circumferential direction; and a speed reducer that reduces rotation of the first rotor and transmits a torque to the second rotor via a bearing. The first and second rotors include first and second tube portions extending in an axial direction, respectively. The second tube portion is radially outward of the first tube portion. A lubricant is filled in a filling space including at least a portion of a space between an outer surface of the first tube portion and an inner surface of the second tube portion. The actuator includes a width reducing portion that reduces a width of the filling space in a radial direction in at least a portion of the filling space in the axial direction.

Abstract: A transmission includes a first shaft rotatable in a circumferential direction about a central axis extending in one direction, a second shaft rotatable in the circumferential direction and in series with the first shaft in an axial direction in which the central axis extends, an internal gear including an internal tooth portion, a housing that houses the internal gear therein, an annular external gear connected to the second shaft and including an external tooth portion that partially meshes with the internal tooth portion, a cam that is rotatable together with the first shaft, and includes a connection hole that houses a portion of the first shaft, and a bearing between an inner circumferential surface of the external gear and an outer circumferential surface of the cam. The cam includes an inner circumferential surface defining the connection hole and a recessed portion recessed in radial directions centered on the central axis.

Abstract: A transmission includes a first shaft rotatable in a circumferential direction about a central axis extending in one direction, a second shaft rotatable in the circumferential direction and in series with the first shaft in an axial direction in which the central axis extends, an internal gear including an internal tooth portion, a housing that houses the internal gear therein, an annular external gear connected to the second shaft and including an external tooth portion that partially meshes with the internal tooth portion, a cam that rotates together with the first shaft, and including a connection hole that houses a portion of the first shaft, and a bearing located between an inner circumferential surface of the external gear and an outer circumferential surface of the cam. An outer circumferential surface of the portion of the first shaft housed in the connection hole includes a recessed portion recessed in radial directions centered on the central axis.

Abstract: A dynamic pressure bearing apparatus includes a bearing portion, a shaft, a radial dynamic pressure bearing portion, and a seal gap. An annular member arranged in an annular shape, fixed to the shaft axially between the seal portion and the attachment surface, and arranged to extend radially outward beyond an opening of the seal gap. A minute horizontal gap extending radially is defined between an upper surface of the bearing portion and a lower surface of the annular member. The seal gap is arranged to be in communication with an exterior space through the horizontal gap.

Abstract: A dynamic pressure bearing apparatus includes a bearing portion, a shaft, a radial dynamic pressure bearing portion, and a seal gap. An annular member arranged in an annular shape, fixed to the shaft axially between the seal portion and the attachment surface, and arranged to extend radially outward beyond an opening of the seal gap. A minute horizontal gap extending radially is defined between an upper surface of the bearing portion and a lower surface of the annular member. The seal gap is arranged to be in communication with an exterior space through the horizontal gap.

Abstract: A fan includes a motor and an impeller. The motor includes a stationary portion and a rotating portion rotatably supported by the stationary portion. The stationary portion includes a stator and a bearing portion arranged inside of the stator. The rotating portion includes a rotor magnet arranged radially outside the stator; a shaft inserted in the bearing portion, and having an upper portion fixed to the impeller directly or through one or more members; and a thrust portion arranged axially opposite the bearing portion, and including an annular surface arranged around the shaft.

Abstract: A dynamic pressure bearing apparatus includes a bearing portion; a shaft; a substantially annular bushing; a radial dynamic pressure bearing portion; and a seal gap. A minute horizontal gap extending radially is defined between an upper surface of the bearing portion and a lower surface of the bushing. The seal gap is arranged to be in communication with an exterior space through the horizontal gap.

Abstract: A fan includes a motor and an impeller. The motor includes a stationary portion and a rotating portion rotatably supported by the stationary portion. The stationary portion includes a stator and a bearing portion arranged inside of the stator. The rotating portion includes a rotor magnet arranged radially outside the stator; a shaft inserted in the bearing portion, and having an upper portion fixed to the impeller directly or through one or more members; and a thrust portion arranged axially opposite the bearing portion, and including an annular surface arranged around the shaft.

Abstract: A first seal portion having a surface of a lubricating oil defined therein is defined between a sleeve portion and a bearing housing. A side communicating channel arranged to bring a first seal gap and a thrust gap into communication with each other is defined either between a sleeve portion and a bearing housing or in an outer circumferential portion of a sleeve portion. A second seal portion having another surface of a lubricating oil defined therein is defined in a gap constituted by a side minute gap between a thrust plate and a bearing housing and a lower minute gap between a thrust plate and a cap member.

Abstract: A bearing apparatus includes a first cup portion defining a portion of a stationary portion of a bearing apparatus includes a first circular plate portion and a first cylindrical portion projecting downward from an outer edge portion of the first circular plate portion. A rotating portion of the bearing apparatus includes an annular recessed portion arranged to accommodate at least a lower end portion of the first cylindrical portion. The stationary portion includes a second cup portion including a second circular plate portion arranged to extend radially outward from an outer circumferential surface of a stationary shaft below the first cup portion and a second cylindrical portion arranged to project upward from an outer edge portion of the second circular plate portion. One of the first and second cup portions is integral with the stationary shaft defining a single monolithic member, and the other is fixed to the stationary shaft.

Abstract: A dynamic pressure bearing apparatus includes a bearing portion; a shaft; a substantially annular bushing; a radial dynamic pressure bearing portion; and a seal gap. A minute horizontal gap extending radially is defined between an upper surface of the bearing portion and a lower surface of the bushing. The seal gap is arranged to be in communication with an exterior space through the horizontal gap.

Abstract: A bearing apparatus includes a stationary shaft, a first annular member, and a rotating member. The rotating member includes a first inner circumferential surface arranged opposite to the outer circumferential surface of the stationary shaft, and a second inner circumferential surface arranged opposite to an outer circumferential surface of the first annular member. A lubricating oil is arranged in a gap between a surface of a stationary member and the rotating member. On an upper side of an upper surface of the lubricating oil, the first annular member and the rotating member are arranged radially opposite to each other with a slight gap defined therebetween, so that a labyrinth seal is defined. The labyrinth seal and a fixing range over which the stationary shaft and the first annular member are fixed to each other are arranged to overlap with each other in a radial direction.

Abstract: A dynamic pressure bearing has a reduced axial dimension and is constructed to ensure smooth feeding of a lubricating oil. The dynamic pressure bearing includes a communicating hole and at least one tapered seal, and is constructed such that an opening angle of one of the at least one tapered seal through which oil feeding is possible is in a range of about 30 degrees inclusive to about 180 degrees exclusive, a tapered seal wall surface depth W1 of the tapered seal is about 0.3 mm or more, and a sum of distances over which the lubricating oil travels from both sides of an end portion of the communicating hole in a cross-section beyond a wall surface of the communicating hole along a wall surface opposite the end portion of the communicating hole exceeds an inside diameter of the communicating hole.

Abstract: A bearing apparatus includes a first cup portion defining a portion of a stationary portion of a bearing apparatus includes a first circular plate portion and a first cylindrical portion projecting downward from an outer edge portion of the first circular plate portion. A rotating portion of the bearing apparatus includes an annular recessed portion arranged to accommodate at least a lower end portion of the first cylindrical portion. The stationary portion includes a second cup portion including a second circular plate portion arranged to extend radially outward from an outer circumferential surface of a stationary shaft below the first cup portion and a second cylindrical portion arranged to project upward from an outer edge portion of the second circular plate portion. One of the first and second cup portions is integral with the stationary shaft defining a single monolithic member, and the other is fixed to the stationary shaft.

Abstract: In a bearing apparatus, a first cup portion defining a portion of a stationary portion of a bearing apparatus includes a circular plate portion and a cylindrical portion projecting downward from an outer edge portion of the circular plate portion. A rotating portion of the bearing apparatus includes an annular recessed portion arranged to accommodate at least a lower end portion of the cylindrical portion. Accordingly, it is possible to limit the axial dimension of the bearing apparatus while also enabling a radial dynamic pressure groove array. Additionally, one end of a through hole defined in the rotating portion is arranged to open into the annular recessed portion.

Abstract: A bearing apparatus includes stationary and rotating portions. The stationary portion includes a stationary shaft and a first cup portion. The rotating portion includes an annular recessed portion and first and second inner circumferential surfaces. Lubricating oil is arranged in a gap between the stationary and rotating portions. An upper surface of the lubricating oil is located between the second inner circumferential surface and an outer circumferential surface of the first cup portion. A lower surface of the lubricating oil is located between the rotating and stationary portions. The rotating portion further includes a through hole filled with the lubricating oil. One of the first cup portion and the rotating portion includes a pumping groove array arranged thereon to cause the lubricating oil to flow toward one end of the through hole during rotation of the rotating portion.

Abstract: A first seal portion having a surface of a lubricating oil defined therein is defined between a sleeve portion and a bearing housing. A side communicating channel arranged to bring a first seal gap and a thrust gap into communication with each other is defined either between a sleeve portion and a bearing housing or in an outer circumferential portion of a sleeve portion. A second seal portion having another surface of a lubricating oil defined therein is defined in a gap constituted by a side minute gap between a thrust plate and a bearing housing and a lower minute gap between a thrust plate and a cap member.

Abstract: A fan includes a motor and an impeller. The motor includes a stationary portion and a rotating portion. The stationary portion includes a stator and a bearing portion. The bearing portion includes a sleeve and a bearing housing. The rotating portion includes a rotor magnet, a shaft, and a thrust plate. A radial gap includes a radial dynamic pressure bearing portion arranged to generate a fluid dynamic pressure acting axially downward on a lubricating oil, while a thrust gap includes a thrust dynamic pressure bearing portion arranged to generate a fluid dynamic pressure acting radially inward on the lubricating oil. A circulation hole extending in an axial direction is defined between the bearing housing and the sleeve. The radial gap is arranged to have a radial width in a range of about 5 ?m to about 20 ?m.