Abstract: At least one main bearing is configured to support a rotational element of the electric motor, and a sacrificial bearing. The main bearing includes at least one inner ring, at least one outer ring and at least one plurality of rolling elements. The sacrificial bearing provides an outer ring, an inner ring, and a plurality of rolling elements disposed between the outer ring and the inner ring. A value of a breakdown voltage for the sacrificial bearing is less than a value of the breakdown voltage for the at least one main bearing.

Abstract: A bearing fitted to a motor shaft for an anti-corrosion function may ensure lower material costs and weight by adopting a smaller size compared to the prior art, and also ensure a significantly-reduced rotational frictional force, and be advantageous in terms of the noise, vibration, and harshness (NVH) of a vehicle as well by having a conductive seal formed in a brush type and in contact with an end cover and a rear cover in an axis direction.

Abstract: A rotor for a high-speed electrical machine with gas bearings includes at least one rotor side radial bearing, a rotor side axial bearing, a rotor body section including the at least one rotor side radial bearing, and a rotor end section including the rotor side axial bearing. When seen along the rotor's axis of rotation, a radial bearing section is defined as a section along which a radial bearing extends. Therein, an outer rotor part extends along the rotor end section and the rotor body section. The outer rotor part is shaped to form, in the rotor body section, a hollow cylinder or bearing sleeve. At least one rotor plug is arranged inside the bearing sleeve, and the material of the at least one rotor plug has a CTE lower than 7E-6 K{circumflex over (?)}-1.

Abstract: A motor system includes: a stator connected to a case of a motor; main bearings connected to the case; a main shaft rotating on the main bearings; a rotor mounted on the main shaft and rotating relative to the stator; and at least one of a magnetic flux reducing circuit element and a conductive rolling-element device disposed inward of the main bearings and closer to the stator and the rotor than the main bearings and reducing flow of bearing current through the main bearings.

Abstract: There is provided an electric motor in which a flange portion can be miniaturized in a radial direction while securing a space for fastening a metal member to the flange portion.

Abstract: A bending meshing type gear device includes a wave generator and a wave generator bearing disposed between the wave generator and an external gear. The wave generator bearing includes a first rolling element row with first rolling elements aligned in a circumferential direction, a first holder, a second rolling element row offset in an axial direction from the first element row with second rolling elements aligned in the circumferential direction, and a second holder. The first holder includes first pockets accommodating the first rolling elements, each pocket is open toward a side of the second rolling element row in the axial direction. The second holder includes second pockets accommodating the second rolling elements, each pocket is open toward a side of the first rolling element row in the axial direction. A spacer member is disposed between the first and the second rolling element rows.

Abstract: A motor is provided that includes a shaft, a rotor coupled to the shaft, a stator disposed to correspond to the rotor, a bearing housing coupled to the shaft, and a bearing that supports the bearing housing. The rotor includes a rotor core and a magnet coupled to the rotor core. The bearing housing includes a first surface in contact with the bearing, a second surface in contact with the rotor core, and a third surface in contact with the shaft.

Abstract: A power assembly includes a power component and a shell. The shell includes an accommodating structure, a flow diversion structure, a liquid storage structure, a heat dissipation structure, and a heat exchange structure. The accommodating structure is filled with cooling liquid. The flow diversion structure is configured to guide a flow direction of the cooling liquid. The liquid storage structure is configured to store the cooling liquid that is guided by the flow diversion structure to enter the liquid storage structure, and to distribute the cooling liquid that enters the liquid storage structure. The heat dissipation structure is configured to receive the cooling liquid distributed by the liquid storage structure, and to transfer the cooling liquid to the power component to cool the power component. The heat exchange structure is configured to perform heat exchange and cooling on the cooling liquid in the accommodating structure.

Abstract: There is provided a permanent magnet electric motor that can be downsized in a rotation axis direction and can also suppress a leakage flux. The permanent magnet electric motor includes: a columnar rotor including a permanent magnet portion annularly disposed; a shaft disposed along a rotation axis of the rotor; a cylindrical stator core disposed on an outer circumferential side of the rotor; a main body including a shell integrally formed with the stator core; a bracket attached to one end side of the main body; and a bearing that rotatably supports the shaft. The bracket includes a bearing house portion that stores the bearing, and a non-magnetic portion that is connected to the bearing house portion. The bearing house portion is disposed on an inner diameter side relative to the permanent magnet portion as viewed from an axis direction of the rotation axis, and an edge portion of the bearing house portion on an outer diameter side is covered with the non-magnetic portion.

Abstract: A rotor assembly includes a rotor for an electric motor, a rotor carrier non-rotatably connected to the rotor, a rotor carrier flange, and a split spring. The rotor carrier includes a groove and a castellated portion and the split spring is disposed in the groove and arranged to clamp the rotor carrier flange against the castellated portion. The split spring may include an annular portion disposed in the groove and a tapered portion extending radially inwards from the annular portion. The split spring may also include a cut portion separating opposite circumferential ends of the annular portion.

Abstract: A canned motor for a submersible pump system and a method of manufacturing the canned motor are provided. The canned motor includes: a canned stator comprising a can disposed within a central bore of a lamination stack, wherein an inner diameter of the can comprises at least one keyway; and a rotor bearing comprising at least one key configured to engage the keyway of the can when a shaft and rotor sub-assembly is disposed within the canned stator.

Abstract: A centrifugal fan includes a first portion in a rotor, and a second portion in a fan unit and having a greater linear coefficient of expansion than that of the first portion. The first portion has a top portion having a flat surface and a first tubular portion. The second portion has a main portion located in a first axial direction with respect to the top portion, a second tubular portion having an inner tube surface facing the outer tube surface of the first tubular portion with a clearance therebetween, an annular rib portion protruding from the main portion in a second axial direction, and a plurality of auxiliary rib portions. A bonding portion of an adhesive is provided between each of an annular end surface of the annular rib portion and the end surfaces of the plurality of auxiliary rib portions facing the flat surface, and the flat surface.

Abstract: There is provided a sliding component disposed at a relative rotational location of a rotating machine to slide relative to another sliding component. The sliding component has a sliding surface provided with a fluid inlet groove communicating with at least one of a sealed fluid side space and a leakage side space and a dynamic pressure generation groove communicating with the fluid inlet groove and extending in a circumferential direction. Both side edges and a terminating end edge of the dynamic pressure generation groove are curvedly continuous with each other in a plan view.

Abstract: A bearing system for a rotatable shaft includes a bearing shaft coaxial with the rotatable shaft, a bearing coaxial with the bearing shaft, a bearing housing surrounding the bearing and having a plurality of retention channels disposed axially along the bearing housing, and a dampening assembly comprising a plurality of circumferential seal elements disposed within each of the plurality of retention channels. A first subset of the plurality of seal elements is formed from a first material and a second subset of the plurality of seal elements is formed from a second material.

Abstract: Positioning apparatus for an electric motor and bearing block, wherein the electric motor includes a rotor, a rotor shaft and a stator. The positioning apparatus is configured at least partially from an elastic material and in a substantially pot-like manner with an interior and can be positioned in a central recess of the bearing block for at least partially receiving a first end of the rotor shaft.

Abstract: A converter motor includes a braking resistor, and an electric motor with a junction box. The junction box is formed from a bottom part and a cover placed on the bottom part, and a printed circuit board of the converter is fastened to the cover. A braking resistor is thermally conductively connected to the bottom part and/or fastened on the bottom part, and a metal sheet is connected to the bottom part. The braking resistor is arranged on that side of the metal sheet which is averted from the printed circuit board.

Abstract: A device includes: a motor; a gear device disposed on one side of the motor and including a first lubricated member; an oil accumulation portion provided on the other side of the motor; a second lubricated member provided in the oil accumulation portion; and a communication passage configured to allows gear device side to communicate with the oil accumulation portion, in which the communication passage is provided above respective lowest points on a lower side in a gravity direction of lubrication target locations of the first lubricated member and the second lubricated member, the oil accumulation portion includes an enlarged portion in which an upper side in the gravity direction is thicker than a lower side in an axial direction, and the lowest point of the second lubricated member is positioned in the enlarged portion.

Abstract: The present invention may provide a motor including a housing, a stator disposed in the housing, a rotor disposed in the stator, and a shaft coupled to the rotor, wherein the housing includes a first housing, the first housing includes a main body, a flange, and a joint disposed between the flange and the main body in an axial direction, the flange includes holes, the joint includes first step parts and second step parts which protrude further outward than an outer surface of the main body in a radial direction, and the first step parts and the second step parts are symmetrically disposed with respect to a reference line passing through a center of one of the holes and a center of the first housing.

Abstract: A linear-actuated press machine comprises a press ram with a tool, a first linear actuator having a first actuator rod, a second line actuator having a second linear actuator rod, a high-speed motor coupled to the first linear actuator for providing a high-speed condition on the press ram, a first high-torque motor coupled to the first linear actuator, and a second high-torque motor coupled to the second linear actuator. The press machine (i) advances the tool toward the part by operation of the high-speed motor associated with the first linear actuator, (ii) forms the part with the tool by simultaneous operation of the first high-torque motor associated with the first linear actuator and the second high-torque motor associated with the second linear actuator, and (iii) retracts the tool from the part by operation of the high-speed motor associated with the first linear actuator.

Abstract: In some aspects, a magnetic gear system includes a flux focusing magnet arrangement having a low-pole count rotor, a pair of modulator rotors disposed on either side of the low-pole count rotor, and a pair of high-pole count outer rotors disposed outside of the pair of modulator rotors. In some aspects, a magnetic gear system includes a motor with a stator and a pair of low-pole count rotors disposed on either side of the stator. The magnetic gear system further includes a pair of modulator rotors disposed on either side of the motor, and a pair of high-pole outer rotors disposed on opposite sides of the pair of modulator rotors.

Abstract: A rotating electric machine system includes a rotor and a stator. A rotor internal oil passage is formed in the interior of the rotor. The rotor is cooled by a first cooling oil serving as a lubricating oil that flows through a rotor internal oil passage. A housing internal oil passage is formed in a rotating electric machine housing. The stator is cooled by a second cooling oil serving as a lubricating oil that flows through the housing internal oil passage. A route by which the first cooling oil is supplied to the rotor internal oil passage, and a route by which the second cooling oil is supplied to the housing internal oil passage are different from each other.

Abstract: An electric machine, in particular a motor or a generator, comprising a rotor and a stator, wherein the rotor comprises a planar, ring-shaped rotor base element and the stator comprises a planar ring-shaped stator base element, wherein the rotor base element and the stator base element are aligned along an axial axis (Z) of the electric machine, wherein a plurality of magnet elements are arranged around the circumference of the ring-shaped rotor base element forming a Halbach magnet-ring assembly, wherein the Halbach magnet-ring assembly generates a magnetic field (BR) with axial and azimuthal components, wherein a plurality of coils are arranged around the circumference (C) of the ring-shaped stator base element.

Abstract: A power tool includes a housing and a brushless motor with a rotor and a stator assembly. The motor defines a motor envelope bounded by a rear plane at a rearmost point of the stator assembly and rotor, a front plane at a frontmost point of the stator assembly and rotor, and a generally cylindrical boundary surrounding a radially outermost portion of the stator assembly and rotor. A rotor shaft is rotatably driven by the rotor. A transmission includes an input member rotatably driven by the rotor shaft and an output member. A first bearing supporting the rotor shaft is at least partially received within the motor envelope. A second bearing supporting the rotor shaft or a component of the transmission is at least partially received within the motor envelope. A support plate supporting a component of the transmission may be at least partially received within the motor envelope.

Abstract: A two-phased liquid-cooled AC rotating electrical includes a plurality of cooling circuits that recirculate and transition respective engineered liquids between liquid and vapor states around closed-loop fluid paths to cool a plurality of machine components e.g., hollow conductor rotor and stator windings and a magnetic stator core. A portion of each fluid path is either integrated with or in thermal contact with its component. The engineered liquids are evaporated within the respective portions of the fluid paths to hold the operating temperatures at or near the respective and different phase transition temperatures.

Abstract: A vehicle driving apparatus includes: an electric motor including a rotor provided movably in an axial direction relative to a rotor shaft and a stator disposed on an outside of the rotor in a radial direction; a first gear provided movably in the axial direction relative to the rotor shaft and disposed so as to face an end face of the rotor; a power transmission path including a second gear engaged with the first gear and coupling the first gear and wheels to each other; and an actuator that moves the rotor to a first position and a second position. The rotor is moved to the second position by the actuator. The first gear is urged in the axial direction due to a magnetic force applied between the rotor and the first gear. A tooth surface of the first gear is pushed against a tooth surface of the second gear.

Abstract: The motor includes a shaft, a cartridge including a plurality of bearings that support the shaft, and a sleeve that surrounds the bearings, and a housing including a bottom portion for receiving an impact from outside and an attaching portion provided in the bottom portion. The bottom portion of the housing extends in a direction intersecting with respect to a longitudinal direction of the shaft, and the cartridge is removably attached to the attaching portion.

Abstract: An e-machine system includes a housing and an e-machine. The e-machine system further includes a rotor shaft that is elongate and that extends along an axis between a first end and a second end of the rotor shaft. The e-machine is at least partly supported on the rotor shaft, and the rotor shaft is supported for rotation within the housing about the axis. The system further includes a rotor shaft axial passage that extends through the rotor shaft along the axis. The rotor shaft axial passage defines an inlet extending axially through the first end and a first outlet extending axially through the second end. The rotor shaft includes a radial aperture extending radially out of the rotor shaft. The rotor shaft axial passage is configured to receive a fluid via the inlet and to distribute out the fluid via the first outlet and the radial aperture.

Abstract: Provided are a fan capable of preventing oil-scattering without using an oil-scattering prevention washer and simultaneously preventing the escape of a rotary shaft due to a lift, and a manufacturing method therefor. The fan includes: a cylindrical fan housing; a base having a bearing housing integrally formed therewith, the bearing housing protruding from the rear surface of the fan housing to the center portion thereof; a sleeve bearing inserted in the bearing housing; a rotary shaft of which the lower portion is rotatably supported by the sleeve bearing; a rotor fixed to the upper portion of the rotary shaft; a stator which is coupled to the outer circumference of the bearing housing, and is arranged with a predetermined gap from the rotor; and an impeller which is integrally formed with the outer circumference of the rotor.

Abstract: An axial field rotary energy device can include a rotor comprising an axis of rotation and a magnet. In addition, a stator can be coaxial with the rotor. The stator can include a plurality of stator segments that are coupled together about the axis. Each stator segment can include a printed circuit board (PCB) having a PCB layer comprising a coil. Each stator segment also can include only one electrical phase. The stator itself can include one or more electrical phases.

Abstract: A stator assembly for use with a brushless geared motor assembly, including: two plastic parts located on each end of a core of the stator assembly, at least one of the plastic parts including several protruding parts configured to fit into complementary slots of the stator core, wherein the protruding parts are cut at corners in order to provide flexibility to the protruding parts.

Abstract: A device (24) for controlling a magnetic bearing (22) includes an axis with two electromagnets (26, 28) diametrically opposed. The device (24) includes two power converters per axis of the magnetic bearing. Each power converter supplies one different electromagnet. The device includes eight power devices (40, 42, 44, 46, 48, 50, 52, 54) arranged in a first line (88) and a second line (90). Each of the first and second lines includes four power devices. A first set of four power devices (40, 42, 44, 46) are connected together to form a first power converter. A second set of four power devices (48, 50, 52, 54) are connected together to form a second power converter. Each of the first and second lines (88, 90) includes two power devices (40, 42, 44, 46) of the first set and two power devices (48, 50, 52, 54) of the second set.

Abstract: The present disclosure is directed to a cooling tower including a cooling tower structure including fill material supported by the cooling tower structure and configured to receive heated process fluid and a motor mounted to the cooling tower structure. The motor includes a casing and a rotatable shaft and is sealed to prevent fluids, moisture, foreign particles and contaminants from entering the casing. A fan is connected to the rotatable shaft of the motor. Rotation of the rotatable shaft rotates the fan thereby inducing an upward moving mass flow of cool air through the fill material. A basin is attached to the cooling tower structure for collecting cooled fluid. A fluid distribution system distributes the cooled fluid in the basin.

Abstract: A magnetic disk device according to one embodiment includes a base, five or more magnetic disks in the base, a head actuator, and a spindle motor. The base has a bottom wall having a second thickness and a side wall. The spindle motor includes a sleeve with a first hole, fixed to the bottom wall, a shaft inserted in the first hole rotatably, and a hub rotatable integrally with the shaft. The hub includes a first part, a second part extending from a lowermost surface of the first part in a first direction being from the magnetic disks toward the bottom wall, and a third part having a first thickness and extending from a lowermost surface of the second part in a second direction orthogonal to the first direction. A value obtained by dividing the second thickness by the first thickness is greater than or equal to 1.89.

Abstract: The present invention may provide a motor including a shaft, a rotor coupled to the shaft, a stator disposed to correspond to the rotor, a bearing which supports the shaft, and a shaft guide which supports the bearing, wherein the shaft guide includes a first groove in which the shaft is disposed, an outer surface of the shaft guide includes a first surface and a second surface, the first surface is in contact with an inner circumferential surface of an inner ring of the bearing, the second surface is in contact with one surface of the inner ring of the bearing, and the shaft guide includes a second groove which is disposed in a bottom surface of the first groove.

Abstract: A flywheel system including a rotor forming an aperture extending through a rotation axis of the rotor and a fixture including a shaft assembly for passing through the aperture of the rotor, wherein the rotor rotates about the shaft assembly. The shaft assembly includes a bottom support, a top support, a central rod connecting the bottom support to the top support, a plurality of stacked modules, each module forming an aperture for receiving the central rod, a top pre-tensioning nut affixed to a top end of the central rod, and a bottom pretensioning nut affixed to a bottom end of the central rod. The top pre-tensioning nut and the bottom pre-tensioning nut clamp the plurality of stacked modules between the bottom support and the top support.

Abstract: In a motor device, since the bearing support member mounted to the housing and supporting, from the axial direction, the another axial side of the ball bearing (outer race) includes the annular support part (annular flat surface) which supports, from the axial direction, the entire circumference of the another axial side of the ball bearing (outer race), tilting of the ball bearing with respect to the housing can be suppressed in the case where a lateral force acts on the rotating shaft. Therefore, it is possible to improve the fixing strength of the ball bearing to the housing, and thus suppress rattling of the speed reduction mechanism.

Abstract: A snake-like robot includes a first link having a first distal end, a first proximal end, and a first longitudinal axis extending between the first distal end and the first proximal end. A second link has a second proximal end, a second distal end operatively coupled to the first proximal end, and a second longitudinal axis extending between the second proximal end and the second distal end. Rotation of the first link relative to the second link alternatively performs the following effects: elongation of the robot; pivoting of the first longitudinal axis relative to the second longitudinal axis; and rotation of the first longitudinal axis relative to the second longitudinal axis.

Abstract: Some examples of a motor bearing seal include silicone glue bonding a Teflon tube to the inboard end of a motor housing. The Teflon tube's ID is in close sliding contact with the OD of a sleeve on the motor's shaft. The motor housing's inboard end, the silicone glue and the Teflon tube are stationary, while the sleeve and the shaft rotate. In some examples, the shaft supports a stack of fan wheels held in axial compression by a nut on the end of the shaft. In some examples, another adhesive sealingly bonds the ID of the sleeve to the shaft. In some examples, a relatively thin gasket is axially compressed between the sleeve and the stack of the fan wheels. In some examples, the silicone glue contains embedded reinforcement, e.g., fibers, mesh, or protrusions extending integrally from the motor's inboard end.

Abstract: The disclosure relates to an electric machine arrangement comprising an electric axial flux machine having a stator and a rotor, further comprising a component supporting the stator, and comprising an output element that is in contact with the rotor for conjoint rotation therewith. The rotor is rotatably mounted in the electric machine arrangement via at least one bearing point. According to the disclosure, a shaft grounding element and/or a rotor position sensor is/are arranged in a space located between the rotor shaft and the stator in the radial direction and within the axial extent of the stator in the axial direction.

Abstract: A hybrid driving module includes a housing and an axial movement prevention part configured to restrict forward and rearward movements of a rotor hub relative to the housing. The axial movement prevention part provided in a bearing interposed between the housing and the rotor hub. The bearing includes a first race configured to adjoin a first peripheral surface, a second race configured to adjoin a second peripheral surface, and rolling elements interposed between the first race and the second race. The axial movement prevention part includes a bearing groove provided in a surface of the first race, a circumferential surface groove provided in a first circumferential surface, and a clearance prevention ring inserted across the circumferential surface groove and the bearing groove. A height of the clearance prevention ring is equal to or smaller than a depth of the circumferential surface groove.

Abstract: The hollow shaft motor according to the present invention comprises a motor housing 11 having a cylindrical shape; a housing cover assembly 12 coupled to an upper portion of the motor housing 11; a stator assembly 20 located in the motor housing 11 and in a lower portion of the housing cover assembly 12; a rotor assembly 30 located in the stator assembly 20 to rotate; a screw shaft 10 coupled to the rotor assembly 30 to rotate together; and a ball nut 17 coupled to the screw shaft 10 to move vertically, wherein the housing cover assembly 12 comprises a housing cover 121 having a sleeve 124 extended downwardly so as for the screw shaft 10 to be located inside, and an inner upward bending part 124B bent inwardly and heading upwardly is formed at the bottom end of the sleeve 124.

Abstract: An electric propulsion system for a vertical take-off and landing (VTOL) aircraft having a heat exchanger to cool fluids used in an electrical engine, the electric propulsion system comprising at least one electrical engine mechanically connected directly or indirectly to a fuselage of the VTOL aircraft and electrically connected to an electrical power source. The electrical engine may comprise an electrical motor having a stator and a rotor; a gearbox assembly comprising a sun gear; at least one planetary gear; a ring gear; and a planetary carrier. The electric engine may include an inverter assembly comprising a thermal plate and an inverter assembly housing; an end bell assembly that is connected to the thermal plate of the inverter assembly; and a heat exchanger comprising an array of cooling fins and tubes.

Abstract: The present disclosure describes a sealing assembly (100) for sealing a shaft (150) passage opening (141) comprising: a rotatable motor shaft (150) with at least one bearing (161) which is supported by at least one bearing support (170), a motor plate (140) with a passage opening (141) for the motor shaft (150) with the at least one bearing (161), a seal (110) having a first scaling portion (111) and a second scaling portion (112), wherein the first sealing portion (111) is arranged between at least a portion of an outer peripheral surface of the at least one bearing (161) and a portion of the bearing support (170); and the second scaling portion (112) extends radially outwardly in a direction away from the motor shaft (150) and is fixed against radial and axial displacements on the motor plate (140) by fixing means, wherein the second sealing portion (112) is spaced from an edge of the passage opening (141).

Abstract: A rotating electric machine system is equipped with a fire prevention member that covers at least one end part of a rotating electric machine housing. By the fire prevention member, a fire prevention region is formed in which the rotating electric machine housing is not positioned. A first insertion hole is formed in the fire prevention member. The first insertion hole is closed by a terminal casing in which electric terminal portions are accommodated.

Abstract: A fan with electromagnetic radiation shielding structure includes a fan impeller and a shaft seat. The fan impeller includes a metal hub, a plurality of blades circumferentially spaced on an outer surface of the metal hub, and a magnetic element provided on an inner surface of the metal hub. The shaft seat is provided at a central area with an upward projected shaft barrel, which is rotatably connected to the fan impeller and has a stator externally fitted therearound. A metal carrier is provided on the shaft seat and has a peripheral edge extended upward to form a sidewall and define an open-topped receiving space for receiving the stator therein. The metal hub and the metal carrier together define a shielding space, such that the stator is located in the shielding space and isolated from outer environment to avoid leakage of electromagnetic radiation produced by the stator.

Abstract: A bearing assembly includes a housing having an annular interior portion and a bearing cartridge disposed radially inboard of the annular interior portion. The bearing cartridge includes a bearing that includes an inner ring, an outer ring, and a plurality of rolling elements disposed radially between the inner and outer rings, a washer engaged with the bearing and having a retention tab, and a spring that is retained in engagement with the washer via the retention tab. The spring biases the washer and the bearing relative to the housing in a first axial direction.

Abstract: An electric motor includes a stator and a rotor rotatable relative to the stator. The rotor includes an axial shaft, a disc projecting radially from the shaft, and a ring magnet affixed to the disc. The shaft and the disc are integrally formed as a unitary body.

Abstract: An internal pore of a sintered metal bearing 8 is impregnated with a lubricating fluid, and a radial dynamic pressure generation portion 8a1 is formed on an inner peripheral surface 8a. An axial dimension L is 4.8 nm or less, a thickness dimension t is 0.5 mm or more and 1.5 nm or less, and a ratio L/D2 of the axial dimension L to an outer diameter dimension D2 is 0.24 or more and 0.6 or less.

Abstract: A bearing unit that supports a rotating shaft includes: a frame including a tubular body; a bearing disposed in the frame; and a pressing spring that is disposed in the frame and presses the bearing, the pressing spring including a protrusion as a positioning part that comes into contact with an inner surface of the tubular body of the frame to determine a position of the pressing spring.

Abstract: A first seal and a second seal seal an annular space between an outer ring and an inner ring by sandwiching a retainer. A stator including a coil is supported by the first seal and is opposed to a magnetic ring. A sensor, a wireless communication circuit, and a power supply circuit are supported by the second seal. A wire electrically connects the coil and the power supply circuit. The wire includes a part disposed in a groove extending in an axial direction of a bearing on an outer peripheral surface of the outer ring.