Minebea Mitsumi Inc.

Samsung Electro-mechanics Japan Advanced Technology Co., Ltd.

Alphana Technology Co., Ltd.

Minebea Company, Limited

Yuji Omura

Mitsuo Kodama

Hiroyuki Kaidu

Takuji Yamada

Masato Aoki

Tomoyuki Suzuki

Tetsuo Kitamura

Aikra Suzuki

Takahiro Sakaguchi

Hiroyuki Kato

Tomoyuki Tashiro

Takahiro Suzuki

Kenji Nishihara

Toshikazu Koshiba

Tomoaki Nakano

Shinichi Uchikawa

Yuma Ohno

Masaaki Nishizawa

Kouji Kebukawa

Tomoyuki Tsukada

Mitsuhiko Takahashi

To provide an axial fan motor increasing the mounting area of a circuit board and further improving heat dissipation as compared with the axial fan motor in the related art. A fan device as an axial fan motor includes: a casing having a hollow tubular shape and provided with an intake opening at one end in an axial direction and an exhaust opening at another end in the axial direction; an impeller including a plurality of blades and accommodated in the casing; a motor accommodated in the casing and configured to rotate the impeller; and a plurality of circuit boards arranged along the axial direction at a side close to exhaust opening in the casing.

Axial fan motor

A motor drive control device has a control circuit that generates a drive control signal for controlling a rotational speed of a motor based on a speed command signal indicating a target rotational speed of the motor, and a motor driving unit that drives the motor based on the drive control signal. The control circuit performs speed feedback control for generating the drive control signal so that the rotational speed of the motor coincides with the target rotational speed when the target rotational speed is lower than a rotational speed threshold value, and generates the drive control signal based on a relationship between current flowing through the motor and a reference current value when the target rotational speed is higher than the rotational speed threshold value.

Motor drive control device using feedback speed control and motor current control

A fan deviceincludes a second housingand a hub. The hubincludes a hub body partand a hub outer peripheral wall part. The hub body partis a surface extending in the radial direction orthogonal to the direction of the axis x, and the hub body partcovers the motorfrom the upper side 'a' in the direction of an axis c. The hub outer peripheral wall partextends from the end portion of the hub body parttoward the lower side 'b' from the upper side &#x201c;a&#x201d; in the direction of the axis x. Assuming that the outer diameter of the outer peripheral surface of the hub outer peripheral wall partis &#x201c;a1&#x201d;, and the outer diameter of the outer peripheral surface of the base outer peripheral wall partis &#x201c;b1&#x201d;, 1.05&#x3c;b1/a1&#x3c;1.13 is established.

Fan device

A motor drive control device capable of reducing the occurrence of vibration in a simple circuit configuration is provided. The motor drive control device () includes a motor drive unit () that selectively energizes coils with a plurality of phases (Lu, Lv and Lw) of a motor () and a control circuit () that outputs a drive control signal (Sd) which is a PWM signal to the motor drive unit () and thereby controls driving of the motor () while switching energization phases of the coils with the plurality of phases (Lu, Lv and Lw) energized by the motor drive unit () in predetermined order. The control circuit () executes reduction control to temporarily reduce a duty ratio of the drive control signal (Sd) every time a period of 1/m (m is an integer of 2 or more) of a switching cycle of the energization phases elapses after switching the energization phases.

Motor drive control device and motor drive control method

A motor drive control device drives a motor including a plurality of phase coils and a rotor rotatably supported with respect to the plurality of phase coils, and the motor drive control device includes a controller, which generates a drive control signal; a motor driver, which outputs a drive signal to each of the phase coils of the motor, based on the drive control signal; and a back-electromotive-voltage detector, which is connected to each of the phase coils and includes resistive voltage dividing circuits having respectively different voltage-dividing ratios, wherein the back-electromotive-voltage detector detects a rotational position of a rotor for sensorless driving by using the resistive voltage dividing circuits.

Motor drive control device

A motor drive controller includes: a motor driver that applies a voltage to each phase of a motor to rotate; a rotational position detector that detects rotational position of the motor and generates rotational position information indicating the rotational position; and a controller that outputs, to the motor driver, driving control signals for repeatedly adjusting an advance angle and a lag angle at energization switching of the each phase of the motor in a prescribed pattern based on the rotational position information generated by the rotational position detector.

Motor drive controller

A single-phase brushless motor has both superior start-up stability and low cogging torque. In the outer-rotor-type single-phase brushless motor, when a gap width between the rotor and one edge of the salient pole surface is defined as d, a gap width between the rotor and the other edge of the salient pole surface is defined as d, and a minimum gap width between the rotor and the salient pole surface is defined as d, the formula d&#x3c;d&#x3c;dis satisfied, and the gap width is dat a position shifted toward the one edge of the salient pole surface from the center of the arc shape which forms the salient pole surface.

Single phase brushless motor

A disk driving apparatus includes a base member, a hub member, and a fluid bearing unit. The base member has a head movement region on which a head unit is to be mounted such that a head portion of the head unit can be moved along the radial direction of a recording face in a reciprocating manner while facing the recording face of a recording disk to be mounted on the hub member, and a recessed housing portion housing the fluid bearing unit such that it surrounds at least a part of a rotor unit supported by the fluid bearing unit. Furthermore, the base member has an inhibiting wall at a boundary between the head movement region and the recessed housing portion so as to prevent a lubricant fluid from migrating toward the recording disk side.

Disk driving apparatus having improved quality

A sleeve supports a shaft. A housing member is arranged so as to surround the sleeve and make the end of the sleeve protrude. A base member holds the housing member and fixes a stator core so as to surround the housing member. A hub drives a recording disk by being rotated integrally with the shaft, with a magnet being fixed to an annular portion concentric with the shaft so as to face the stator core fixed to the base member. A thrust member is rotated integrally with the hub, and a descender portion and a ring portion.

Disk drive device provided with fluid dynamic bearing

A method of manufacturing a disk drive device including: assembling a subassembly by fixing at least a bearing unit, a drive unit and a hub to a base member in a first clean room; cleaning the subassembly in a second clean room; and sealing the subassembly by a sealing member. The first clean room and the second clean room are communicated with each other by a communicating opening for transferring the subassembly, and an atmospheric pressure in the second clean room is equal to or higher than that in the first clean room.

Method of manufacturing a disk drive having a base member, bearing unit, drive unit and hub

A bearing unit includes a shaft and a hub as a conductive rotating body that supports a recording disk. Also, the bearing unit includes a conductive resin housing configured to surround at least part of the shaft to support the shaft and to be able to conduct electricity to the recording disk via the shaft. The conductive resin housing includes a conductive adhesive to be applied to secure conduction with the base housing. The conductive resin housing has an exposed portion where the inner layer of the conductive resin housing is exposed, at a position to which the conductive adhesive is applied.

Disk drive device having function of discharging static electricity

A motor adopting an improved mechanism is composed of a stator having a shaft and a rotor provided with a sleeve and a hub, wherein the shaft is inserted into the hub and the hub is fixed on an outer circumferential surface of the sleeve. The outer circumferential surface of the sleeve is provided with a first outer circumferential surface, a second outer circumferential surface and a receiving surface that links between the first and second outer circumferential surfaces. The hub is provided with a base section, a through hole and a first protruded section protruding downward from the base section. A tip end portion of the first protruded section is provided with a hitting surface that contacts with the receiving surface of the sleeve and a second protruded section that links to the contacting surface and protrudes downward from the contacting surface.

Growing community of inventors

Shizuoka, Japan

Yuji Omura