JP2004120817A - Rotor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor along with its manufacturing method capable of easily improving precision in positioning between a sensor magnet and a rotor magnet. <P>SOLUTION: A rotor 9 comprises a shaft 2 rotatably supported through a bearing, a rotor magnet 5 which constitutes a motor, and a sensor magnet 3 which constitutes a rotational angle sensor with the rotor magnet 5 and the sensor magnet 3 fixed to the shaft 2. A sensor magnet magnetizing yoke 11 magnetizes the sensor magnet 3. A rotor magnet magnetizing yoke 12 magnetizes the rotor magnet 5. A positioning mechanism 13 keeps positional relationship between the sensor magnet magnetizing yoke 11 and the rotor magnet magnetizing yoke 12. After the sensor magnet 3 and the rotor magnet 5 are fixed to the shaft 2, the sensor magnet 3 and the rotor magnet 5 are synchronously magnetized. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in a rotor provided in a brushless motor or the like and a method of manufacturing the rotor.
[0002]
[Prior art]
Conventionally, as this kind of rotor, there is a rotor in which a rotor magnet constituting a motor and a sensor magnet constituting a rotation angle sensor are fixed to a shaft thereof, and a motor driving current of a motor driving current is determined in accordance with a detection signal of the rotation angle sensor. The phase is controlled (see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-11-356024
[Problems to be solved by the invention]
However, in such a conventional method for manufacturing a rotor, since the sensor magnet and the rotor magnet, which are magnetized in advance, are fixed to the shaft, it takes time and effort to perform positioning between the sensor magnet and the rotor magnet. There was a problem that the cost of the product was increased.
[0005]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a rotor capable of easily increasing the positioning accuracy between a sensor magnet and a rotor magnet, and a method for manufacturing the rotor.
[0006]
[Means for Solving the Problems]
A first invention includes a shaft rotatably supported via a bearing, a rotor magnet forming a motor, and a sensor magnet forming a rotation angle sensor, and the rotor magnet and the sensor magnet are fixed to the shaft. Applies to rotor manufacturing methods.
[0007]
And a sensor magnet magnetized yoke for magnetizing the sensor magnet, a rotor magnet magnetized yoke for magnetizing the rotor magnet, and a positioning mechanism for maintaining the relative positions of the sensor magnet magnetized yoke and the rotor magnet magnetized yoke are provided. After the sensor magnet and the rotor magnet are fixed to the shaft, the sensor magnet and the rotor magnet are synchronously magnetized.
[0008]
A second invention includes a shaft rotatably supported via a bearing, a rotor magnet forming a motor, and a sensor magnet forming a rotation angle sensor, and the rotor magnet and the sensor magnet are fixed to the shaft. Applies to rotor.
[0009]
And a sensor magnet magnetized yoke for magnetizing the sensor magnet, a rotor magnet magnetized yoke for magnetizing the rotor magnet, and a positioning mechanism for maintaining the relative positions of the sensor magnet magnetized yoke and the rotor magnet magnetized yoke are provided. After the sensor magnet and the rotor magnet are fixed to the shaft, the sensor magnet and the rotor magnet are synchronously magnetized.
[0010]
According to a third aspect, in the second aspect, the bearing is disposed between the sensor magnet and the rotor magnet, and the sensor magnet and the rotor magnet are synchronously magnetized after the bearing, the sensor magnet, and the rotor magnet are fixed to the shaft. The feature was adopted.
[0011]
Function and Effect of the Invention
According to the first and second aspects of the present invention, the sensor magnet and the rotor magnet are synchronously magnetized by the sensor magnet magnetized yoke and the rotor magnet magnetized yoke positioned with respect to each other while being fixed to the shaft in advance. The positioning accuracy between the sensor magnet and the rotor magnet can be easily increased. Therefore, unlike the conventional structure in which the magnetized sensor magnet and the rotor magnet are fixed to the shaft, the work of positioning between the sensor magnet and the rotor magnet does not take much time, the adjustment man-hour is reduced, and the cost of the product is reduced. Down is measured.
[0012]
According to the third aspect of the present invention, since the bearing is assembled synchronously with the shaft assembled, the positioning accuracy between the sensor magnet and the rotor magnet is impaired without removing the rotor magnet or the sensor magnet from the shaft after the magnetization. No need.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0014]
As shown in FIG. 1, a rotor 9 constituting a motor has a rotor magnet 5, a sensor magnet 3, and a bearing 6 fixed to a shaft 2. The annular rotor magnet 5 and the sensor magnet 3 are fitted and attached to the outer peripheral surface of the shaft 2, and are arranged concentrically with the shaft 2.
[0015]
The bearing 6 is fixed between the rotor magnet 5 and the sensor magnet 3. The bearing 6 and a bearing (not shown) rotatably support the shaft 2 with the rotor magnet 5 interposed therebetween.
[0016]
As shown in FIG. 3A, the motor 20 is mainly composed of the rotor magnet 5 and the stator 21. The rotor magnet 5 has three pairs of north and south poles symmetrically arranged with respect to the center of rotation. Each coil 22 constituting each of the u, v, and w phase magnetic poles is wound around the stator 21.
[0017]
A controller (not shown) controls the phase of each drive current such that the rotation angle of the rotor 9 and the timing for exciting each coil 22 are optimized according to the detection signal of the rotation angle sensor.
[0018]
As shown in FIG. 2, the rotation angle sensor 1 mainly includes a sensor magnet 3 and first and second Hall elements 7 and 8. The sensor magnet 3 has a pair of N and S poles arranged symmetrically about the center of rotation.
[0019]
The first and second Hall elements 7 and 8 provided as magnetic flux density detectors output a voltage corresponding to a magnetic flux density that changes as the sensor magnet 3 relatively rotates. The first and second Hall elements 7, 8 are fixed to the case 4.
[0020]
FIG. 3B shows how the voltages output from the first and second Hall elements 7 and 8 change according to the rotation angle. The outputs A and B of the first and second Hall elements 7 and 8 are sine waves having phases different by 90 degrees. As a signal for detecting the rotation angle, one of the outputs A and B of the first and second Hall elements 7 and 8 having a larger voltage change with respect to the rotation angle is used. For example, while the second Hall element 8 makes one rotation, the same output can be obtained at, for example, two points by the output B. However, the rotation angle is specified by monitoring the output A. That is, the first and second Hall elements 7, 8 which are used as signals for detecting the rotation angle by using the output A, B of the first and second Hall elements 7, 8 whose voltage change with respect to the rotation angle is smaller. It is configured to determine in which rotation angle area the outputs A and B are located.
[0021]
The sensor magnet 3 composed of a permanent magnet and the rotor magnet 5 are magnetized by the sensor magnet magnetized yoke 11 and the rotor magnet magnetized yoke 12.
[0022]
As a gist of the present invention, a positioning mechanism 13 for maintaining a relative position between the sensor magnet magnetized yoke 11 and the rotor magnet magnetized yoke 12 is provided, and the sensor magnet 3, the rotor magnet 5 and the bearing 9 are fixed to the shaft 2. After that, the sensor magnet 3 and the rotor magnet 5 are synchronously magnetized by the sensor magnet magnetized yoke 11 and the rotor magnet magnetized yoke 12.
[0023]
As described above, by arranging the first and second Hall elements 7 and 8 outside the rotation path of the sensor magnet 3, the degree of freedom of arrangement of the rotation angle sensor 1 can be increased. That is, when the Hall element is arranged inside the rotation path of the sensor magnet, the rotation angle sensor 1 can be arranged only at the end of the rotor shaft 2, but the Hall element is arranged outside the rotation path of the sensor magnet. Thereby, the rotation angle sensor 1 can be arranged in the middle of the shaft 2.
[0024]
The sensor magnet 3 and the rotor magnet 5 are fixed to the shaft 2 in advance, and are synchronously magnetized by the sensor magnet magnetization yoke 11 and the rotor magnet magnetization yoke 12 positioned with respect to each other. The positioning accuracy between the rotor magnets 5 can be easily increased. Therefore, unlike the conventional structure in which the sensor magnet and the rotor magnet after magnetization are fixed to the shaft, the work of positioning between the sensor magnet and the rotor magnet does not take much time, the adjustment man-hour is reduced, and the product cost is reduced. Down is measured.
[0025]
Because the bearing 6 is configured to be synchronously magnetized while being assembled to the shaft 2, the bearing 6 is assembled between the rotor magnet 5 and the sensor magnet 3 without removing the rotor magnet 5 and the sensor magnet 3 from the shaft 2 after the magnetization. This allows the positioning accuracy between the sensor magnet 3 and the rotor magnet 5 to be maintained.
[0026]
The bearing 6 is not limited to the structure provided between the sensor magnet 3 and the rotor magnet 5, but may be provided at the end of the shaft 2.
[0027]
Further, the sensor magnet 3 may have more polarities to increase the sensor output resolution.
[0028]
It is apparent that the present invention is not limited to the above-described embodiment, and that various changes can be made within the scope of the technical idea.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a rotor and a magnetized yoke of a rotor and a method of manufacturing the rotor according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of a rotation angle sensor.
3A is a configuration diagram of a motor, and FIG. 3B is a diagram showing sensor output characteristics.
[Description of Signs] Rotation angle sensor 1 Rotation angle sensor 2 Shaft 3 Sensor magnet 5 Rotor magnet 6 Bearing 7, 8 First and second Hall elements 9 Rotor 11 Sensor magnet magnetization yoke 12 Rotor magnet magnetization yoke 13 Positioning mechanism

Claims (3)

A shaft rotatably supported via a bearing, a rotor magnet constituting a motor, and a sensor magnet constituting a rotation angle sensor, a rotor magnet and a rotor manufacturing method in which the sensor magnet is fixed to the shaft,
A sensor magnet magnetized yoke for magnetizing the sensor magnet, a rotor magnet magnetized yoke for magnetizing the rotor magnet, and a positioning mechanism for maintaining the relative positions of the sensor magnet magnetized yoke and the rotor magnet magnetized yoke are provided. A method of manufacturing a rotor, comprising: fixing a sensor magnet and a rotor magnet to the shaft; and synchronously magnetizing the sensor magnet and the rotor magnet. A shaft rotatably supported via a bearing, a rotor magnet constituting a motor, and a sensor magnet constituting a rotation angle sensor, a rotor having the rotor magnet and the sensor magnet fixed to the shaft,
A sensor magnet magnetized yoke for magnetizing the sensor magnet, a rotor magnet magnetized yoke for magnetizing the rotor magnet, and a positioning mechanism for maintaining the relative positions of the sensor magnet magnetized yoke and the rotor magnet magnetized yoke are provided. A rotor wherein the sensor magnet and the rotor magnet are synchronously magnetized after the sensor magnet and the rotor magnet are fixed to the shaft. The said bearing was arrange | positioned between the said sensor magnet and the said rotor magnet, The sensor magnet and the rotor magnet were synchronously magnetized after fixing the bearing, the sensor magnet, and the rotor magnet to the said shaft, The Claim 2 characterized by the above-mentioned. Rotor.

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