Abstract: A method of position estimation including: a signal detection step in which N (where N is an integer of 3 or more) sensors each detect a magnetic field which is in accordance with a position of a mover and output a detection signal as an electrical signal, the detection signals being displaced in phase by an angle obtained by dividing 360 degrees by N; a crossing detection step in which a crossing detection section sequentially detects a crossing at which each detection signal having been output through the signal detection step crosses another; a subdivision detection step in which a subdivision detection section detects a portion of the detection signal that connects from a crossing to another crossing which is adjacent to that crossing, as one or more subdivision signals; and a line segment joining step in which a line segment joining section sequentially joins the subdivision signals and estimates the position of the mover based on the plural subdivision signals having been joined, to generate an estimate
Abstract: A motor includes a rotor, a stator, and a circuit board below the stator. The stator includes an insulator to cover at least a portion of each of an upper surface, a lower surface, and circumferential side surfaces of each of teeth of the stator, coils each of which is defined by a conducting wire wound around a separate one of the teeth with the insulator therebetween, and a drawn-out wire drawn out from the coils and electrically connected to the circuit board. A lower portion of the insulator includes a guide radially outward of the coils and including a wall extending downward from a lower surface of the insulator and a bend extending radially outward from a lower end of the wall. At least a portion of the drawn-out wire extends in a circumferential direction along a radially outer surface of the wall.
Abstract: A stator assembly includes a stator that drives a rotor rotatable about a central axis extending in a vertical direction, a cover that accommodates the stator, a filling portion that fills a space between the cover and the stator. The cover includes a tubular portion that extends in an axial direction and covers a radially side portion of the stator opposing the rotor in a radial direction, a lid portion that covers an axially upper end portion of the stator, and a cover stepped portion that is provided on a first radial side with respect to the tubular portion. The cover stepped portion comes in contact with the axially upper end portion of the stator and is positioned on an axially lower side with respect to an axially upper end portion of the tubular portion.
Abstract: A motor includes a shaft centered on a center axis oriented in a vertical direction, a bearing rotatably supporting the shaft, an armature disposed radially outward of the bearing, a bracket to which the bearing and the armature are fixed, and a covered cylindrical rotor connected to the shaft. The rotor includes a disk-shaped rotor lid portion connected to the shaft, and a rotor side wall portion extending downward from an outer edge of the rotor lid portion. The shaft is made of metal. The rotor lid portion and the rotor side wall portion are made of resin. The rotor lid portion and the shaft are an integrally molded article.
Abstract: A centrifugal fan includes a motor, a support body, a rotating body, and a housing. The motor includes a rotor hub that rotates around a central axis extending up and down. The support body is fixed to the rotor hub and rotates together with the rotor hub. The rotating body is different from the support body in material. The rotating body is a continuous porous body. The housing accommodates the rotating body, the support body, and the motor. The housing includes an air inlet open in an axial direction and at least one air outlet open in a radial direction. A radially inner surface of the rotating body opposes a radially outer surface of the rotor hub with a gap interposed therebetween.
Abstract: A gas dynamic pressure bearing includes a shaft centered on a central axis extending in an up-down direction, and a sleeve that faces at least a portion of the shaft in a radial direction. The portion in which the sleeve and the shaft face each other in the radial direction includes a first dynamic pressure portion at each of both ends in the axial direction, and a second dynamic pressure portion between the first dynamic pressure portions. In the first dynamic pressure portion, one of the sleeve and the shaft includes dynamic pressure grooves arranged in a circumferential direction. A sum of center angles of groove widths of the dynamic pressure grooves in a cross-section cut along a plane orthogonal to the central axis is about 144° or more and about 216° or less.
Abstract: A motor includes a magnet rotating together with a rotor about a central axis, a substrate on which a sensor to detect a position of the magnet is installed, a housing to hold a stator to drive the rotor, a bearing assembly including a bearing holder, and a conductor assembly between the housing and the bearing assembly. The conductor assembly includes a conductor including a first conductor electrically connected to the sensor through the substrate and a conductor holder covering the conductor. The substrate is fixed to the conductor holder. In the radial direction, a gap is located between an outer side surface of the bearing holder and an inner side surface of the conductor holder, and at least a portion of the magnet is located in the gap.
Abstract: In a drive device, a housing includes an outer lid that covers one side in an axial direction of a motor shaft. A pump includes an external gear fixed to an end on one side in the axial direction of the motor shaft, an internal gear surrounding a radial outside of the external gear and meshing with the external gear, a pump room recessed from a surface on the other side in the axial direction of an outer lid toward one side in the axial direction, the pump room accommodating the internal gear and the external gear, a suction port through which the oil is to be sucked into the pump room, and a discharge port through which the oil is to be discharged from the pump room. The motor shaft includes a motor shaft body to which a rotor core is fixed and a closer fixed to the motor shaft body to overlap the internal gear and close at least a portion of the opening on the other side in the axial direction of the pump room.
Abstract: A sensor magnet assembly has a cylindrical shape extending in an axial direction and includes a fixing member fixed to a one side end of a shaft in the axial direction and a sensor magnet fixed to an outer circumferential surface of the fixing member. The fixing member includes a first groove recessed inward from the outer circumferential surface in a radial direction and has an annular shape extending in a circumferential direction and first recesses recessed inward from the outer circumferential surface in the radial direction and spaced apart along the circumferential direction. The first recesses are disposed at positions different from the first groove in the axial direction. The first groove and the first recesses are disposed in a portion of the outer circumferential surface of the fixing member, to which the sensor magnet is fixed.
Abstract: A transmission includes a first shaft that is rotatable in a circumferential direction about a central axis extending in one direction, a second shaft that is rotatable in the circumferential direction and in series with the first shaft in an axial direction in which the central axis extends, a tubular housing, an internal gear including an internal tooth portion, and held by an inner surface of the housing, an annular external gear connected to the second shaft, and including an external tooth portion that partially meshes with the internal tooth portion, and a wave generator connected to the first shaft to deform the external gear such that meshing positions between the internal tooth portion and the external tooth portion shift in the circumferential direction. The internal gear and the housing are defined by separate members.
September 6, 2018
Date of Patent:
March 23, 2021
Takunori Shinao, Wataru Yamauchi, Akihiro Toda
Abstract: A cooling device is provided with a cooling unit that includes a cold plate extending in a first direction; a pump and a tank disposed on one side in a second direction perpendicular to the first direction of the cold plate; and a partition member extending in the first direction and covering the cold plate on one side in the second direction. The cold plate includes a first refrigerant flow path through which a refrigerant flows in the first direction. The pump includes a pump chamber where a rotating body is accommodated. The tank includes a tank chamber storing the refrigerant and a first tank hole part communicating with the pump chamber. The partition member, including a first hole part that communicates the first flow path and the tank chamber, is provided on one side in the first direction with respect to the first hole part.
Abstract: A motor includes a shaft that extends in an axial direction, a rotor including a field magnet, a stator, a resolver positioned farther toward one side of the motor in the axial direction than the rotor and the stator, and a shield including at least a portion is between the rotor and the resolver in the axial direction. The shield includes a bottom portion of which at least a portion is between the rotor and the resolver in the axial direction and which includes a through-hole through which the shaft passes, and a convex portion that extends from the bottom portion toward the other side in the axial direction. A front end portion of the convex portion is positioned farther toward an inner side of the motor in a radial direction than an outer circumferential portion of the field magnet when viewed in the axial direction.
Abstract: A base plate is a portion of a housing of a hard disk drive, and includes a cast base body. The base body includes an inner surface including an inside machined surface that is machined and an inside non-machined surface that is not machined. The base body includes an outer surface including an outside machined surface that is machined and an outside non-machined surface that is not machined. The outside machined surface and the inside non-machined surface overlap in an axial direction that is a direction parallel or substantially parallel to a rotation axis of a disk of the hard disk drive.
Abstract: A slot array antenna includes: a first conductive member having a first conductive surface and a plurality of slots therein, the slots being arrayed in a first direction and in a second direction which intersects the first direction; a second conductive member having a second conductive surface which opposes the first conductive surface; a plurality of waveguide members arrayed between the first and second conductive members along a direction which intersects the first direction, each waveguide member having an conductive waveguide face which extends along the first direction so as to oppose at least one of the slots; and an artificial magnetic conductor in a subregion which is within a region between the first and second conductive members but outside of a subregion containing the waveguide members. Neither an electric wall nor an artificial magnetic conductor exists in a space between two adjacent waveguide faces among the waveguide members.
Abstract: A motor includes a heat sink including an inner region, and an outer region located radially outward from the inner region. An axial thickness of the inner region is larger than an axial thickness of the outer region, the bottom surface of the outer region is located axially above the bottom surface of the inner region, and the inner region and the electronic component at least partially overlap in an axial direction. A bus bar holder is located axially below the outer region and overlaps the inner region in a radial direction.
Abstract: A motor includes a rotor with a shaft that extends axially, a stator that surrounds a radial outer side of the rotor, a heat sink that is axially above the stator and provided with cavities that pass conductors therethrough and extend axially, and a substrate that is axially above the heat sink and includes an electronic component mounted thereon, wherein the heat sink includes a contact surface that contacts the substrate or electronic component directly or via a heat dissipating member and an exposed surface that does not come into contact with other members, wherein the exposed surface is located closer to an outer edge than the cavities.
Abstract: A motor includes a rotor, a stator, a housing, a substrate, a connector, and a cover. The cover includes a covering wall that extends axially downward from a radial outer rim and covers at least a portion of the radial outer rim of the connector, and a cover recess that is radially inward from the covering wall and is depressed axially. The connector includes a connector projection that is provided in a radial outer edge area and extends axially, and the connector projection and the cover recess are fitted together through a gap.
Abstract: A motor includes a rotor, a stator, a housing, and a flange. The housing includes a first cylindrical portion, a contact portion extending radially inward from an axial lower end of the first cylindrical portion, a second cylindrical portion that extends axially downward from a radial inner edge of the contact portion and has a smaller outer diameter than the first cylindrical portion, and a bottom portion extending radially inward from an axial lower end of the second cylindrical portion. The flange includes a flange cylindrical portion, and a flange flat portion extending radially outward from an axial lower end of the flange cylindrical portion. The flange cylindrical portion is fixed to an outer surface of the second cylindrical portion and an upper end of the flange cylindrical portion contacts with an outside lower surface of the contact portion.
Abstract: A drive apparatus includes a motor that includes a motor shaft disposed along a first central axis that extends in one direction, a housing that includes a first housing portion housing the motor and that is capable of storing oil, and a liquid cooling portion disposed in thermal contact with an inverter electrically coupled to the motor, the liquid cooling portion including a refrigerant liquid flowing therein. The housing includes a contact portion with which the liquid cooling portion is in thermal contact. At least a portion of the contact portion is disposed below an oil surface of the oil stored in the housing.
Abstract: A drive device includes a rotor, a stator, a housing including an accommodation portion to store oil, and a pump driven through a motor shaft. The pump includes an external gear fixed to an end on one side in an axial direction of the motor shaft, an internal gear surrounding a radial outside of the external gear and meshing with the external gear, a pump room accommodating the internal gear and the external gear, a suction port through which the oil is to be sucked into the pump room, and a discharge port through which the oil is to be discharged from the pump room. The housing includes an outer lid in which the pump room is provided.