Industrial Technology Research Institute

Sunonwealth Electric Machine Industry Co., Ltd.

Shyh-Jier Wang

Der-Ray Huang

Li-Te Kuo

Tzuan-Ren Jeng

Chi-Shen Chang

Min-Der Wu

Shir-Kuan Lin

Hsing-Cheng Yu

Jieh-Yee Huang

Tai-Fa Ying

Yin-Rong Hong

Jau-Jiu Ju

Yu-Hsiu Chang

Alex Hong

Chau-Yuan Ke

Chun-Te Wu

Ming-Tsan Peng

Yeong-Der Yao

Hung-Kuang Hsu

Chien-Chang Wang

Tzung-Yuan Lee

Chia-Ming Lee

King Yin Wang

Kwen-Jin Lee

Chin-Po Liao

Chi-Mou Zhao

Chin Po Liao

Ying Tai-Fa

Lei-Ming Yang

Chiang Cheng Huang

Huang Der-Ray

Han Chung Wang

Eric-G Lean

Hai-Jo Huang

Hsing-Yu Lin

Meng-Hsun Hsieh

Yann-Guang Pan

Chi Mou Zhao

A vibration absorber provided on an optical disk drive module of a disk drive for suppressing vibration produced by the optical disk drive module at various speeds. The vibration absorber at least has a body, dampers, elastic members, an actuator and a controller. The body is secured on the optical disk drive module. The dampers elastically and vertically shift on the body. The elastic members are provided on the body for providing elasticity in shifting of the damper. The actuator is provided on the body and coupled to the damper for providing a driving force for the vertical shifting of the damper. The controller controls the driving force outputted by the actuator based on the change in rotational speed of the optical disk drive module, so as to change the elasticity in vertical shifting of the damper to reduce the shifting and corresponding vibration of the optical disk drive module.

Vibration absorber

An optical pickup head and an electromagnetic actuating device thereof are provided. The electromagnetic actuating device is used to move an objective lens carrier having an objective lens assembly to form an optical pickup head. The electromagnetic actuating device includes at least a magnet, at least a coil, and at least a yoke. The magnet is spaced apart from the objective lens carrier by a distance, and the coil is disposed at the objective lens carrier, for generating an electromagnetic force to interact with the magnet. The yoke is spaced apart from the objective lens carrier by a distance, in which the yoke has a protruding part that extends towards the objective lens carrier and is used to attract magnetic flux lines produced by the magnet, and thus making the magnetic flux that passes through the coil be distributed evenly.

Optical pickup head and electromagnetic actuating device thereof

A sensorless driving method for a brushless DC motor is provided. The time for the motor to rotate an electrical angle 60&#xb0; is obtained by alternatively counting the occurrences of zero crossings with two counters and comparing the counted values, and the motor is delayed an electrical angle of 30&#xb0;, by which a precise commutating time is obtained. The driving method provides a mask-based phase shift digital detection mechanism for effectively detecting true zero-crossing points. The driving method further provides an inhabitation mechanism with the function of soft-switch for inhibiting noise caused by transistor switching. By using these two counters, the time for the motor to rotate two electrical angles 30&#xb0;&#x2212;&#x394;&#x3b8; and 30&#xb0;+&#x394;&#x3b8; are obtained and stored in two registers. The time period before and after the commutating point is added into a pulse width modulation (PWM) signal to reduce the noise and vibration.

Sensorless driving method for brushless DC motor

A method and an apparatus for estimating the position of a moving part of a linear actuator are provided. The method comprises the following steps. Move the moving part towards a target position. Receive magnetic signals generated by the magneto-resistive sensor of the linear actuator, which include a sine signal and a cosine signal. Then, generate a first square wave, a second square wave, and a regional square wave based on the sine signal and the cosine signal. Generate a saw-tooth wave based on the sine signal, the cosine signal, the second square wave, and the regional square wave. Next, calculate the number of regions which the moving part is across from the origin point based on the first square wave, the second square wave, and the regional square wave. Finally, estimate the current position of the moving part based on the saw-tooth wave and the number of regions.

Method and apparatus for estimating the position of a moving part of a linear actuator

A method for measuring the electromotive force of motors is provided. The method enables the motor to rotate in single phase mode, and thereby measures the electromotive force constant of the motor. According to the principles and the method, motors do not have to work in close-loop. Neither encoders for detecting angle displacement or angle velocity are needed for motors, nor the motor impedance or current have to obtain in advance. Compared with the prior art, the disclosed method is more efficiency and economic.

Method for measuring the electromotive force constant of motors

A magnetic bearing includes a base, a spindle rotatably mounted onto the base and a magnetic portion mounted between the base and the spindle to provide a magnetic repulsion that suspends the spindle. The magnetic portion further includes an inner magnetic portion and an outer magnetic portion that repulse against each other. The outer magnetic portion is located around the inner magnetic portion so that the inner magnetic portion and the spindle are suspended. Therefore, mechanical friction in the magnetic bearing is minimized.

Magnetic bearing

The invention pertains to a method for determining whether a rotor is good in magnetic induction by measuring the electromotive force (emf) of a motor. A standard stator of the motor is prepared as the standard of measurement. A set of induction coil is wound upon the standard stator so that when the rotor is combined with the standard stator and is subject to running by a driver, the induction coil can detect the back-emf signal generated by the rotor, by which the rotor quality can be determined. Since the measuring method disclosed in the invention is performed within the closed system composed of the rotor and the stator, the result is not only close to a real motor in rotation, the detection is simple and free from the problem of axis alignment. Thus, this method can increase the production efficiency of the product line.

Method for determining whether a rotor is good in magnetic induction by measuring the EMF of a motor

The present invention is a starting method for brushless DC motor and a device for the same, especially adapted to provide the starting method for a single-phase DC brushless motor in an open circuit and the device for the same. According to the art as disclosed in the present invention, there are two successive steps in starting a motor. An oscillator signal is transmitted to the driver at first, which causes the motor to oscillate in both clockwise and counter-clockwise direction. An operating signal is then sent to cause the motor to rotate normally in one direction once the motor is out of the dead initiating position. By that the rotor can be triggered out of the dead initiating position when the motor is going to start and the motor can be smoothly operated under the low cogging torque.

Starting method for brushless DC motor and device for the same

A method for designing an optimal bi-axial type of magnetic gear system that uses magnetic coupling for transmitting torque in order to be free from the defects caused by using a conventional mechanical gear system. A non-coaxial rather than a conventional coaxial type of magnetic gear design is considered for this invention. For the non-coaxial magnetic gear system, the size of torque will depend on the number of poles magnetized out of the strong magnetic material around the magnetic gear. Therefore, the optimum number of magnetized poles must be carefully selected for a set of specified conditions such that the largest torque can be obtained. An optimal magnetic gear system can be produced by the method in this invention.

Method of designing optimal bi-axial magnetic gears and system of the

A spindle motor for a disc drive, such as a CD-ROM drive, is provided. This spindle motor is a brushless motor of a single-phase axial-winding and radial-gap type including a stator, a rotor coupled to said stator, and a driving circuit for supplying a driving signal to the stator to rotate the rotor. The stator includes a pair of upper and bottom salient-pole pieces formed with a plurality of tooth-like portions serving as salient-poles. The peak surface of each tooth-like portion is formed into a symmetrical convex shape, which minimizes the cogging torque of the motor. Further, the use of a phase-adjuster in the driving circuit allows the motor to produce large output torque at high speeds. The output characteristics of this spindle motor meet the requirements of high speed CD-ROM drives.

Spindle motor for optical disc drives

A brushless motor stator for an axially wound brushless motor with a diametrical air-gap having a plate structure with at least one plate, the profile of the plate comprising: a central circular hole; a number of salient poles surrounding the central circular hole; and a slot opening between every two adjacent said salient poles. The salient poles and those slot openings have the following characteristics: (1) the outer rim of the salient pole is in the form of a circular arc segment whose arc radius R.sub.S satisfies the following inequality relation: .pi./P.times.R.sub.M &lt;R.sub.S &lt;0.95R.sub.M ; (2) the neck width W.sub.S of the salient pole satisfies the following inequality relation: .pi./2P.times.R.sub.M &lt;W.sub.S &lt;2.pi./P.times.R.sub.M -g; (3) the depth D.sub.S of the slot opening satisfies the following inequality relation: .pi./P.times.R.sub.M &lt;D.sub.S &lt;2.5.pi./P.times.R.sub.M ; where R.sub.M reprents the radius from the center to the outer rim of the brushless motor stator; P reprents the number of poles of permanent magnets used in the brushless motor; and g reprents air-gap width between the salient poles and the permanent magnets. The three aforementioned characteristics can be used either individually or in various combinational groups for designing the profile of a stator.

Brushless motor stator design

A stator for a single-phase axially wound brushless motor with a diametrical air-gap has a plate structure with at least one plate whose profile comprises: a central circular hole; a plurality of salient poles surrounding the central hole with each salient pole having a symmetrical profile; and a groove opening for every two adjacent salient poles. The ratio of the included angle of the two sides of a groove opening divided by the pitch angle of salient poles is between 0.55 to 0.68.

Optimum groove/pole ratio for brushless motor stator profile

Growing community of inventors

Hsinchu, Taiwan

Shyh-Jier Wang