Nidec Corporation

Ntn Corporation

Shigeharu Sumi

Takeshi Ohiro

Masaharu Hori

Yoshito Oku

Hironori Ando

Tatsuya Yoshida

Toshikazu Himeno

Hongbing Du

Kazuya Enokizono

Junichi Hashimoto

Hiromasa Fujii

Shigeru Maeda

Jyoichi Hiroshi

Shozo Ibara

A winding machine includes a winding core around which a winding is wound, a first winding jig and a second winding jig positioned with the winding core interposed therebetween in an axial direction of a central axis of the winding core, and a first gripper and a second gripper that are located on an outer side of the winding core in a radial direction around the central axis. An outer edge portion of the first winding jig in the radial direction and an outer edge portion of the second winding jig in the radial direction are located on an outer side, in the radial direction, from the winding core. Each of the first gripper and the second gripper includes a pair of rollers to interpose and grip the winding. At least one of the first gripper or the second gripper is rotatable about the central axis.

Winding machine and method of manufacturing coil

A coil attachable to a tooth extending to one radial side of the tooth from an annular core back surrounding a central axis of a motor includes a first winding body including a first wound flat wire, and a second winding body including a second wound flat wire, that is located on a radial side of the first winding body, and that is connected to the first winding body. When N is a freely-selected integer of 1 or more, and M is a freely-selected integer larger than N, the first winding body is an N-layer winding body aligned and wound in two rows aligned in a radial direction, and the second winding body is an M-layer winding body aligned and wound in two rows aligned in the radial direction.

Coil with contour shape, stator, and motor having same

A manufacturing method for a coil includes: a step of winding a wire (conductive wire) in multiple layers and multiple rows and forming a coil having a trapezoidal cross-sectional shape; a step of arranging the coil in a molding space surrounded by a plurality of split dies; and a step of moving the slit die in a direction of narrowing the molding space to mold the cross-sectional shape of the coil. In the step of molding the cross-sectional shape, at least one of the plurality of split dies is moved to mold the cross-sectional shape into a fan shape by surfaces formed in the split dies.

Coil manufacturing method, coil manufacturing device, coil, and motor

Provided is a manufacturing method of a wire rod for forming a coil, the manufacturing method including the steps of: placing an element wire in a forming space surrounded by a plurality of split dies; and pressure-forming the element wire by moving the plurality of split dies in a direction of narrowing the forming space. In the step of pressure-forming the element wire, at least one of the plurality of split dies is moved, and the plurality of split dies each having a surface that changes in shape in a longitudinal direction of an element wire to pressure-form the element wire into the wire rod having a plurality of different cross-sectional shapes in the longitudinal direction.

Manufacturing method of wire rod, manufacturing apparatus of wire rod, wire rod, and motor

A method of manufacturing a coil includes forming a wound body by winding a coil wire in multiple layers, and forming a coil by pressing the wound body using a die surrounding the wound body and compressively deforming the wound body. The wound body has a contour of a rectangular or substantially rectangular shape in cross section, and includes coil wire portions located in the cross section of the coil wire, the coil wire portions being aligned along each side of the rectangular or substantially rectangular shape. The coil has a contour of a fan shape or approximate fan shape in the cross section, where the coil wire portions are aligned in a direction along an arc and a radial direction of the fan shape or approximate fan shape.

Method of manufacturing coil and method of manufacturing motor

A stator configured to rotate of a rotor about a central axis includes a first member having a plurality of first concavity portions located in a circumferential direction at a preset interval, each of first concavity portions having a pair of first inner side face and second inner side face whose a circumferential-directional distance therebetween with respect to the central axis becomes narrow from one radial-directional side towards the other radial-directional side with respect to the central axis; and a plurality of second members, each of which having a first protrusion extending along the first inner side face, a second protrusion extending along the second inner side face, and a teeth portion protruding from the first protrusion and the second protrusion to the other radial-direction side, wherein the plurality of second members are formed to corresponding to the plurality of concavity portions, respectively.

Stator and motor

A motor armature includes a core including a stack of electromagnetic steel sheets, a tooth portion extending in a radial direction of the motor, and a conductive wire that is wound around the tooth portion in a circumferential direction. First recessed portions extending in the radial direction are located in a surface of the tooth portion of each of the electromagnetic steel sheets of the core.

Motor armature and motor

A spindle motor includes a flat stator, a rotor magnet arranged above the stator, and a magnetic portion made of a ferromagnetic material. The magnetic portion is positioned lower than the stator and the magnetic portion are axially overlapped with coils. A magnetic attraction force is generated between the magnetic portion and the rotor magnet. Since the magnetic portion is positioned lower than the stator, it is possible to cause magnetic fluxes to efficiently flow between the rotor magnet and the stator. Further, the stator includes a protrusion protruded radially outward beyond an outer circumferential portion of a rotor hub. Accordingly, in a plan view, the stator is positioned radially outward of the rotor hub.

Spindle motor and disk drive apparatus

A protrusion () directed axially downwards is provided at a bottom portion () of a housing (), and an outer peripheral surface () of the protrusion () is fixed to an inner peripheral surface () of a bracket (). When a thrust load is applied to the bottom portion () of the housing (), a part of the load is supported by the bracket () via the protrusion (). Thus, a strength of a boundary portion (P) between a side portion () and the bottom portion () of the housing () increases, making it possible to prevent rupture of the boundary portion (P) due to an excessive thrust load. On the other hand, a wall thickness of the bottom portion () can be made invariable, so it is possible to suppress deformation through molding shrinkage of a thrust bearing surface formed on an inner end surface () of the bottom portion ().

Fluid dynamic bearing device

A fluid dynamic bearing includes a shaft, a stationary portion supporting the shaft in a rotatable manner, a lubricating oil arranged in a radial gap defined between an outer circumferential surface of the shaft and a surface of the stationary portion, opposing each other. The fluid dynamic bearing includes a first seal portion arranged radially outside of the radial gap, and a second seal portion arranged at an axially upper end of the radial gap. The axial length of the first seal portion is greater than that of the second seal portion.

Fluid dynamic pressure bearing and spindle motor

Spindle motor capable of positively fixing and securing conduction between a housing and a bracket, and a recording disk driving apparatus using the spindle motor. The bracket has a circular through hole, and the housing is fixedly inserted in the circular through hole. A protrusion is formed on at least one of the bracket and the housing. A conductive member is between and in contact with a flange and the bracket or the housing in the direction of the rotary axis to electrically connect the flange and the bracket or the housing. The conductive member is in contact with the flange and the bracket or the housing under an elastic stress.

Spindle motor and recording disk driving apparatus having the spindle motor

Fluid-dynamic-pressure bearing manufacturing method for more efficient and fail-safe degassing of bearing oil. Method makes it possible to prevent the generation of air bubbles in the course of an oil-charging operation that amounts to a step following degassing, and to single out the causative source of air bubbles when their generation has been detected. At the same time oil that is under a reduced-pressure environment within an oil-storing vacuum chamber is vacuum-degassed, immersed within the oil a stirrer for agitating and degassing the oil is rotated by indirect drive means, and the oil after having been degassed is supplied to a vacuum chamber where a fluid-dynamic-pressure bearing unit is retained&#x2014;which has been pumped down to a pressure below the pressure within the oil-storing vacuum chamber&#x2014;and is charged into the bearing clearances by raising the internal pressure of the bearing-retaining vacuum chamber.

Technique for filling bearing clearance of fluid-dynamic-pressure bearing unit with oil

A fluid dynamic pressure bearing having a tapered seal part provided between a sleeve and a housing, from which lubricating liquid is injected and functions as a buffer of the lubricating liquid. An end part of a radial gap between the sleeve and a shaft body is a labyrinth filled with lubricating liquid. An opening periphery is covered with an oil repellent film to prevent outflow of the lubricating liquid. These features can make the size of the tapered seal part small in the axial direction. It enables a larger radial dynamic pressure bearing mechanism to be formed and, in particular, bearing rigidity in the radial direction can be increased.

According to the invention, a shaft as a component of a shaft member of a hydrodynamic bearing and a disc member such as a thrust plate are joined to each other by welding by a simple method with high precision. A shaft having a cylindrical outer circumferential surface, in joint surfaces which are joined to each other of the shaft and a disc member having a flat surface facing an end surface of the shaft, a circumferential projection having a diameter smaller than the outside diameter of the shaft and projected in the axial direction and a recess at least of which outer periphery has a diameter smaller than the outside diameter of the shaft and larger than the diameter of the projection and has a circular shape are provided.

Hydrodynamic bearing, method of manufacturing the same, method of manufacturing shaft member for hydrodynamic bearing, spindle motor, and recording disk driving apparatus

A fluid seal is disposed in a radial gap between a shaft of a motor and a hub rotatably held about the shaft, for preventing contaminates such as oil dusts and the like within the motor from leaking to the outside of the motor. The fluid seal has an annular body disposed about the axis of the motor shaft that is fixed to the hub directly or with a fluid seal holder. The annular sealing surface of the annular body is spaced from the outer sealing surface of the shaft by a minute gap, and a sealing portion is formed in the gap. The gap is filled with a fluid having a sufficient barrier pressure to prevent contaminates from flowing out of the motor. The fluid seal may have an approximately concave shape facing the axis of the shaft when the shaft is cut away by a plane passing through the axis of the shaft. This structure prevents the fluid from being scattered due to centrifugal force arising during operation of the motor. The fluid seal also may have an angled seal structure to keep the fluid in against external shocks. A fluid seal built-into a ball bearing is also disclosed.

Growing community of inventors

Kyoto, Japan

Shigeharu Sumi