JP2007306686A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor, having a stator and a rotor of different height and a sensor magnet for detecting rotor position where torque is increased, by utilizing the flux of the sensor magnet effectively while realizing miniaturization. <P>SOLUTION: Axial height of a rotor magnet and a stator is made to coincide, by forming the stator tooth end portion of freely formable magnetic powder, and the stator tooth end portion is formed, in matching with the axial height of the rotor magnet, without having to change the positional relation of the stator and the magnet. Consequently, the flux of the rotor magnet can be utilized effectively for increasing the torque, and a motor in which vibration and noise are suppressed in the thrust direction is realized, by matching the magnetic center of the stator and the rotor magnet. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor having a sensor magnet.

  FIG. 2 is a sectional view of a conventional motor using a sensor magnet.

Conventionally, a motor using a sensor magnet has a sensor magnet for position detection, or a magnet having both functions for driving and position detection. In the motor having the above conventional structure, in order to detect the position of the rotor by the magnetic flux from the sensor magnet, the axial length of the magnet facing the stator is set to the side having the position detection function rather than the thickness of the stator. Sometimes it had a longer structure.
JP 2004-364402 A

  The problem to be solved is that in the case of a motor using a sensor magnet or a motor that has been downsized, the axial height of the magnet is longer than the thickness of the stator toward the side having the function of detecting the rotor position. As a result, the magnetic flux of the magnet could not be fully utilized, preventing the motor torque from being increased. In addition, since the axial lengths of the magnet and the stator are different, the magnetic center of the stator and the rotor is shifted, which has problems such as generation of vibration and noise in the thrust direction.

  In the above case, there is a method of extending the magnet opposite to the side having the position detection function in order to make the magnetic center of the magnet and the stator coincide with each other. In addition, it was a factor that hindered miniaturization of the motor.

  In order to solve the above-described problems, the present invention provides a stator in which a coil is wound around a tooth on a yoke outer periphery, a rotor core that is opposed to the stator via a slight gap and is rotatably held around a shaft, In a motor comprising a rotor having a permanent magnet mounted on the surface of the rotor core so as to face the stator, the axial direction of the magnet can be achieved by molding the stator tooth end with magnetic powder without changing the position of the current stator and magnet. A stator tooth end having a length corresponding to the height is formed.

  According to claim 1 of the present application, the tooth end portion of the stator is formed according to the axial height of the rotor magnet using magnetic powder, so that it has a function of detecting the position in the axial direction rather than the thickness of the stator. It is possible to efficiently take in the magnetic flux from the protruding magnet. Thereby, the effective magnetic flux can be improved without changing the positional relationship between the stator and the magnet.

  Furthermore, with the above configuration, the magnetic center of the stator and the magnet can be matched, the effective magnetic flux can be increased, vibration and noise in the thrust direction can be suppressed, and the motor torque can be increased.

In the invention according to claim 2, by integrally forming the stator core and the housing with magnetic powder, it is possible to reduce the number of parts and to improve the contact strength between the stator core and the housing portion.

  In the invention according to claim 3, by forming the stator winding contact portion with a groove or R, it is possible to reduce the end of the winding and to effectively use the space factor. Downsizing can be realized.

  In the invention according to claim 4, by forming the stator tooth end portion according to the winding height and wrapping the winding with the stator, the magnetic flux flowing in from the axial direction of the magnet is simultaneously protected while protecting the winding. It is possible to capture more and increase torque.

  As described above, in the present invention, by utilizing the feature that magnetic powder can be formed freely, the axial height of the stator tooth end is formed in accordance with the height of the magnet axial direction. Increase (torque up) can be achieved. Further, by forming the stator winding portion with R and grooves, it is possible to make the winding easy to wind, and the winding end portion becomes small, so that the motor can be miniaturized.

  A stator in which a coil is wound around teeth on the inner periphery of the yoke, a substantially annular rotor core that is opposed to the stator via a slight gap and is rotatably held around a shaft, and the stator on the surface of the rotor core In a motor composed of a rotor mounted with a permanent magnet opposite to the magnet, compression molding is performed by using freely-formable magnetic powder so that the axial height of the stator tooth end matches the axial height of the magnet.

  FIG. 1 shows a cross-sectional view of the motor of the present invention. In the present invention, freely formable magnetic powder is used, and compression molding is performed so that the axial height of the stator tooth end matches the axial height of the magnet, thereby forming a stator having thick tooth ends. With the above configuration, it is possible to effectively use the magnetic flux of a magnet that has been extended in the axial direction so as to be used as a sensor magnet in order to increase torque.

  In addition, with the above-described configuration, it is possible to match the magnetic center of the magnet and the stator, thereby obtaining a motor that increases the effective magnetic flux and suppresses vibration and noise in the thrust direction.

  In the motor shown in FIG. 1, the stator and the housing are press-fitted at six points. By integrally molding the stator and the housing with magnetic powder, it is possible to reduce the number of parts, improve the working efficiency, and obtain a motor with increased strength of the stator and the housing. Further, by integrating the stator and the housing, vibration and noise reduction effects can be expected by changing the housing shape.

  One factor that determines the height of the rotor frame is the size of the winding end. In order to reduce the size of the motor, the winding end portion of the winding can be reduced by attaching a curve or a guide to the teeth width portion around which the winding is wound when the stator is molded with magnetic powder. As a result, the winding end can be reduced without changing the number of turns of the winding, and the motor can be miniaturized.

  The use environment where the winding needs to be protected by using the magnetic powder to form the winding embedded in the stator by matching the axial height of the stator tooth end with the height of the winding end. In addition, it is possible to protect the winding in the application, and at the same time, it is possible to more effectively take in the magnetic flux that circulates from the axial direction of the magnet, thereby realizing an increase in the torque of the motor.

  The motor of the present invention is optimal for downsizing and efficiency, and is useful for applications that dislike noise and vibration.

Sectional drawing of the motor in Example 1 of this invention Conventional sectional view

Explanation of symbols

1 Shaft 2 Bearing 3 Stator 4 Stator Using Magnetic Powder 5 Magnet 6 Winding 7 Rotor Frame

Claims (4)

A stator in which a coil is wound around teeth on the outer periphery of the yoke, a rotor core that is opposed to the stator through a slight gap and is rotatably supported around a shaft, and a surface of the rotor core that faces the stator A motor composed of a rotor equipped with a magnet and having a stator and a rotor having different axial heights, and using magnetic powder to match the height of the stator tooth end to the axial height of the magnet. The motor according to claim 1, wherein the stator core and the housing are integrally formed. The motor according to claim 1, wherein the winding contact portion of the stator is formed with a groove or R. The motor according to claim 1, wherein the stator tooth end is formed in accordance with the height of the winding end and the winding is wrapped by the stator.