JP2005168153A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive motor with small cogging torque without the need for forming a groove to a stator core. <P>SOLUTION: Magnetic characteristics are deteriorated by pressurizing one-side tip 14a of a tooth 13 of the stator core 11 laminated to the thickness of about a half of the lamination thickness as a stator. The other tip 14b of the stator core 11 similarly laminated to the thickness of about a half of the lamination thickness is pressurized. The two stator cores 13 whose tips 14 are pressurized are laminated so that the tip 14a and the tip 14b become point-symmetry. Consequently, the deteriorated part of the magnetic characteristic becomes point symmetry. An effect similar to skew can be obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a stator structure for a motor used as a power source in a wide range of fields.

  Conventionally, as a motor using a magnet for a rotor, the one shown in FIG. 3 is generally known. 31 is a stator core, 32 is a coil, 33 is a rotor core, and 34 is a magnet. When a predetermined current is passed through the coil 32, magnetic flux is generated and acts on the magnetic flux from the magnet 34, so that the rotor portion composed of the rotor core 33 and the magnet 34 rotates.

  The number of teeth of the stator core 31 of this motor and the number of magnetic poles of the magnet 34 cause a cogging torque of an intrinsic order, which causes deterioration in positioning accuracy, vibration, and noise.

On the other hand, it is known that a groove is provided in the axial direction on each peripheral surface of the teeth facing the peripheral surface of the rotor magnet and the groove is skewed. (For example, refer to Patent Document 1.)
JP 2001-218392 A

  The problem to be solved is that the groove portion provided in the teeth portion is skewed to reduce the cogging torque, and it is necessary to turn the mold for forming the groove little by little according to the stacking position. This is a complicated point of pressing and lamination.

  An object of the present invention is to provide a motor having a small cogging torque at low cost without providing a groove in the stator core.

  In order to solve the above-described problems, the present invention includes a stator having a stator core with a winding, and a magnet rotor that is rotatably supported with a radial gap with respect to the stator core. The magnetic characteristics are deteriorated by applying stress to a part of the tip of the tooth portion protruding in the radial direction from the yoke portion.

  Further, the portions having deteriorated magnetic characteristics are arranged so as to be shifted from each other with respect to the circumferential direction.

  According to the motor of the present invention, stress is applied to a part of the tip of the tooth portion to deteriorate the magnetic characteristics, and the portions that have deteriorated the magnetic characteristics are arranged so as to be shifted from each other in the circumferential direction. can get.

  Moreover, since it pressurizes after dividing | segmenting into a unit of teeth, it can implement | achieve easily.

  As described above, a motor with a small cogging torque can be provided by disposing the portions where the magnetic characteristics of the teeth portion are deteriorated to be point-symmetric with respect to the circumferential direction.

  A stator having a stator core with a winding and a magnet rotor rotatably supported with a radial gap with respect to the stator core. The stator core is divided in units of teeth in the circumferential direction, and the radius from the yoke portion. Stress is applied to a part of the tip of the tooth portion protruding in the direction, and the portion where the magnetic properties are deteriorated is arranged symmetrically in the circumferential direction, and concentrated winding is applied to each tooth.

  The feature of the present invention is the magnetic characteristics of the stator core, which will be described below with reference to the drawings. In FIG. 1, a stator core 11 made of an electromagnetic steel plate is composed of a yoke portion 12 that forms the outer periphery and a tooth portion 13 that protrudes radially from the yoke portion 12, and the adjacent tooth portions 13 are open slots in the circumferential direction. Are arranged at equal intervals and are sequentially stacked.

  First, the one end portion 14a of the teeth portion 13 of the stator core 11 laminated to about ½ of the laminated thickness of the stator is pressed to deteriorate the magnetic characteristics. Similarly, the other end portion 14b of the stator core 11 laminated about 1/2 is pressurized. The two stator cores 13 that pressurize the tip portion 14 are stacked so that the tip portion 14a and the tip portion 14b are point-symmetric. At this time, the stator core 13 having the same pressing portion may be overlapped so that the pressing direction is reversed, and point symmetry may be obtained, and the deteriorated portion of the magnetic characteristics becomes point symmetrical so that the same effect as skew can be obtained.

  Thereafter, a coil is wound around a tooth portion 13 that has been subjected to insulation treatment in the same manner as in the prior art to form a stator, which has a radial gap with respect to the inner peripheral surface of the stator. A motor is obtained.

  In the second embodiment, the stator core is equally divided for each tooth unit in the circumferential direction, and a skew effect is provided by making the deterioration of the magnetic characteristics due to pressurization stepwise.

  In FIG. 2, a stator core 21 made of electromagnetic steel sheets that are equally divided for each tooth unit is composed of a yoke part 22 that forms the outer periphery and a tooth part 23 that protrudes in the radial direction.

  The one end portion 24a of the tooth portion 23 of the stator core 21 laminated to about 1/3 of the laminated thickness of the stator is pressed to deteriorate the magnetic characteristics. Similarly, both end portions 24b of the teeth portion 23 of the stator core 21 laminated about 1/3 are pressurized. The pressurization width of both the tip portions 24b is about half of the previous pressurization width. Further, the opposite end portion 24c of the teeth portion 23 of the stator core 21 laminated about 1/3 is pressurized.

  When the three stator cores 21 that pressurize these tip portions 24 are stacked so that the pressurizing portions are point-symmetric, the yoke portion 23 becomes a stator whose magnetic characteristics are deteriorated in a staircase shape, and a skew effect is obtained as compared with the first embodiment. It is done.

  The stator core 21 having a stepped magnetic characteristic at the tip 24 of the yoke portion 23 is joined with the yoke portion in an annular shape after the coil is wound after the insulation process. A motor having a radial gap with respect to the inner peripheral surface of the stator and having a small cogging torque can be obtained when a magnet rotor is rotatably mounted.

  In Example 2, since the divided stator core can be annularly joined after winding to form a stator, even if the gap between adjacent teeth is made as small as possible, the stator has a magnetic property that deteriorates stepwise, and the cogging torque is reduced. A small motor is obtained. Further, even if the tip of the teeth approaches, the magnetic characteristics are deteriorated, so that the magnetic leakage is small and the magnetic flux can be used effectively.

  In addition, Example 1 and Example 2 are examples which actualized this invention, and do not limit the technical scope of this invention.

  The motor of the present invention is useful for reducing the cogging torque without changing the press die for forming the stator core.

The principal part perspective view of the stator core in Example 1 of this invention The perspective view of the divided stator core in Example 2 of this invention Cross section of the main part of a conventional motor

Explanation of symbols

11, 21 Stator core 12, 22 Yoke part 13, 23 Teeth part 14, 24 Tip part

Claims (3)

A stator having a stator core with a winding; and a magnet rotor rotatably supported with a radial gap with respect to the stator core, the stator having a tooth portion tip projecting radially from a yoke portion of the stator core A motor characterized by applying a stress to a part of the motor to deteriorate the magnetic characteristics. The motor according to claim 1, wherein the portions having deteriorated magnetic characteristics are arranged so as to be shifted from each other in the circumferential direction. The motor according to claim 1, wherein the stator core is divided in units of teeth in the circumferential direction.