JP2006333545A - Three-phase claw pole type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To downsize a three-phase claw pole type motor while keeping the same output. <P>SOLUTION: A stator core 5 is arranged, leaving a specified air gap, inside a rotor 1 where permanent magnets 4 are arranged in its circumferential direction. For the stator core 5, upper claw magnetic poles 6 and lower claw magnetic poles 6' are arranged alternately on the circumference of its periphery, and a ring-shaped coil 7 is wound between the claw poles so as to constitute one phase (u phase). Furthermore, another phase (v phase) is arranged at a position where the elements for one phase are slid for 120° in electric angle, and further another phase (w phase) is arranged at a position where they are slid more for 120°, being piled up each in its axial direction, thereby obtaining the three-phase claw pole type motor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to the structure of a three-phase claw pole type motor used in the industrial, household, and automobile fields.

  Claw pole type motors are used in OA equipment and automobile equipment due to their inexpensive structure and simplicity of drive circuit, etc., and are usually configured as inversion type stepping motors as described in Patent Documents 1 and 2 Has been. There are single-phase, two-phase, and three-phase motor types. Among them, the three-phase motor has the advantage of good controllability and can be driven with a small number of transistors.

JP 2001-161054 A JP 2003-9500 A

  A conventional claw pole motor is an add-on type in which a rotor is disposed inside a stator core, and it is necessary to reduce the diameters of the stator and the rotor in order to reduce the size of the motor. However, since the rotational torque of the motor is proportional to the diameter of the rotor, reducing the rotor diameter causes a reduction in rotational torque. For this reason, it was difficult to reduce the size while maintaining the same output.

  In addition, in an addendum type claw pole motor, since the rotor support mechanism part which consists of a bearing and an end ring is provided at both ends in the axial direction of the stator core, the increase in the size of the motor due to the axial thickness is inevitable. It was.

  An object of the present invention is to provide a three-phase claw pole type motor that enables downsizing while maintaining the same output in view of the above-mentioned problems of the prior art.

  The present invention for achieving the above object is an abduction type three-phase claw pole type motor. That is, a plurality of upper and lower claw magnetic poles are provided on the outer peripheral portion of the stator core, and a rotor supported rotatably via a predetermined gap is provided on the outer peripheral side of the claw magnetic pole. A coil wound in a toroidal shape (ring shape) is sandwiched between the upper and lower claw magnetic poles to form one phase, and the same phase as the one phase is shifted by 120 degrees in electrical angle in the axial direction. To arrange the other two phases.

  The entire stator core or at least the claw magnetic poles are integrally formed of powder. The inner core side contact surface of the stator core is provided with a hole for taking out the terminal wire of the ring coil to the outside and a groove extending in the axial direction connected to the hole.

  In addition, a concave portion is provided at both axial end portions of the stator core, and bearings for supporting the rotor are disposed in the concave portion.

  The outer-rotation type three-phase claw pole motor according to the present invention can achieve downsizing with the same output and higher output with the same physique compared with the inner-rotation motor. Further, since the stator core is arranged on the inner peripheral side, the coil length is shortened and the electric resistance is reduced, so that the motor efficiency can be improved.

  In addition, since the stator core is integrally formed with a powder molded product, the stator core including the claw magnetic poles can be easily downsized and manufacturing variations can be reduced.

  Furthermore, by providing recesses on both ends of the stator core and disposing the bearings there, the axial length of the motor can be shortened by the axial thickness of the bearing, thereby enabling further miniaturization.

  In order to reduce the size, increase the torque, and improve the motor efficiency of the three-phase claw pole type motor, a motor structure in which the stator core is constituted by a powder molded product called a dust core is adopted. Embodiments will be described below with reference to the drawings. In addition, the same code | symbol has shown the equivalent thing through each figure.

  FIG. 4 is an example showing the structure of a conventional inward-rotating three-phase claw pole motor. In FIG. 4, 1 is a rotor, 2 is a shaft, 3 is a rotor core, 4 is a rotor magnet, 5 is a stator, 6 is a claw pole, and 7 is a winding.

  FIG. 5 shows a perspective view of a conventional claw magnetic pole for one pole. In FIG. 5, 6 is an upper claw magnetic pole and 6 'is a lower claw magnetic pole. FIG. 4A is a partial view of the stator 5 in FIG. 4 as viewed from the rotor side. The upper and lower claw magnetic poles are arranged with the ring coil 7 interposed therebetween, and the upper claw magnetic pole 6 and the lower claw magnetic pole 6 ′ are alternately arranged on the circumference. One phase (u phase) is configured in the state of being arranged. Another phase (v phase) is shifted to the position where one phase is shifted by 120 degrees in electrical angle, and another phase (w layer) is further stacked in the position shifted by 120 degrees in the axial direction to obtain a three-phase motor.

  FIG. 5B shows a cross section of each phase in FIG. The number of poles of the magnet is the same as the number of pairs of claws (same pole pair), and the model shown is an example of 12 poles. In this case, the positional relationship between the upper magnetic pole claw 6 and the lower magnetic pole claw 6 'is as shown.

  Next, the relationship between the magnetic field and the permanent magnet in such a three-phase claw pole motor will be described. FIG. 3 is an explanatory diagram showing the relationship between the magnetic field of the stator and the permanent magnet of the rotor. Assuming that the stator coil 7 is energized with the three-phase alternating current shown in (a), the relationship between the magnetic field formed in the stator at the instant of time t1 and the permanent magnet of the rotor is as shown in (b). However, the clockwise direction of the ring coil is the positive direction of the current.

  That is, a positive current flows in the U phase at time t1. At this time, the flow of magnetic flux in the U-phase is as indicated by the dotted arrow shown in the A cross section of (b). The claw magnetic pole 6u functions as the N pole and the claw magnetic pole 6u ′ functions as the S pole. A repulsive force is generated between them. Similarly, a positive current flows in the V phase at time t1. The flow of magnetic flux in the V phase is as indicated by the dotted arrow shown in the B cross section of (b), and the claw magnetic pole 6v functions as the N pole, so that an attractive force is generated between it and the rotor S pole. On the other hand, since 6v 'functions as the S pole, a repulsive force is generated between the rotor S pole and an attractive force is generated between the rotor N pole. Similarly, a negative current flows in the W phase at time t1. At this time, the flow of magnetic flux in the W phase is as indicated by the dotted arrow shown in the section C of FIG. 3B, and the claw magnetic pole 6w functions as the S pole. A suction force is generated between the N poles. On the other hand, since 6w 'functions as an N pole, an attractive force is generated between the rotor S pole and a repulsive force between the rotor N pole. Therefore, the resultant force of each phase becomes the rotational force of the rotor, and the rotor rotates counterclockwise in the figure.

  In order to reduce the size of the add-on claw pole motor, it is necessary to reduce the diameters of the stator and the rotor. However, generally, the rotational torque of the motor is proportional to the diameter of the rotor, and when the rotor diameter is reduced, the rotational torque is reduced accordingly. On the other hand, even in the case of downsizing by keeping the rotor diameter constant and reducing the outer diameter of the stator, the energizing current is reduced as the coil slot cross-sectional area is reduced, resulting in a reduction in the rotational torque. Therefore, it is difficult to reduce the size of the add-on claw pole motor while maintaining the same output.

  In order to solve this problem, the claw pole type motor of the present invention has an abduction type rotor. As a result, a smaller size and higher output can be realized as compared with a conventional add-on claw pole motor.

  FIG. 1 is a perspective view showing the entire structure of an outer rotation type three-phase claw pole motor of the present invention. In FIG. 1, 1 is a rotor, 2 is a shaft, 3 is a rotor core, 4 is a rotor magnet, and 5 is a stator. Between the upper and lower claw magnetic poles of the stator core 5, a toroidal coil is wound. The entire stator core 5 or at least the claw magnetic poles are integrally formed of a dust core.

  FIG. 2 is a perspective view of a claw magnetic pole for one pole of the present embodiment. The basic configuration of the stator core 5 is the same as that of FIG. 5, but the stator core 5 of this embodiment is disposed inside the rotor 1. That is, one phase (u phase) is provided in a state where the upper claw magnetic poles 6u and the lower claw magnetic poles 6u 'are alternately arranged on the circumference. The upper claw magnetic pole 6v and the lower claw magnetic pole 6v 'are arranged in the axial direction at a position where one phase (u phase) is shifted by 120 degrees in electrical angle, and another phase (v phase) is provided. Further, the upper claw magnetic pole 6w and the lower claw magnetic pole 6w 'are arranged in the axial direction at a position shifted by 120 degrees, and another phase (w layer) is provided to constitute a three-phase claw pole motor.

  FIG. 6 shows the difference in dimensions between the addendum and the addendum. (A) is a conventional internal rotation type, and is a rotor diameter r and an outer stator thickness a. (B) is an abduction type of this embodiment, and a stator core 5 is arranged on the inner peripheral side of the rotor 1. Therefore, it is possible to reduce the size of the stator core 5 by the amount corresponding to the radial thickness a of the stator core 5 without reducing the rotor diameter r and rotating torque.

  Further, by appropriately selecting the inner diameter of the stator core, a desired coil slot cross-sectional area (= a × length in the axial direction) can be ensured, so that there is no reduction in energization current or reduction in rotational torque. Furthermore, since the stator core is arranged on the inner peripheral side, the peripheral length of the coil is reduced and the electric resistance is reduced, so that the motor efficiency can be improved.

  Next, the drawer structure of the coil terminal of the claw pole type motor will be described. FIG. 7 shows a pull-out structure of a coil terminal of a claw pole type motor. FIG. 7A shows a conventional inner rotation type, and FIG. 7B shows an outer rotation type of this embodiment. In the case of the add-on type, since the stator is located outside, in order to draw out the coil terminal of each phase, it is only necessary to provide a hole 10 for drawing out the coil terminal wire as shown in FIG. However, in the case of the outer rotation type, since the stator is covered with the rotor, the structure is not simple, and in particular, it is difficult to process the drawing groove with a conventional silicon steel plate.

  In this embodiment, a stator as shown in FIG. 7B is configured by a three-dimensional structure using a powder molded body such as a dust core, so that the coil terminal wire of the outer claw pole motor can be easily drawn. It has become. FIG. 7B is a partial view of the stator 5 as viewed from the shaft 2 side. Each phase is provided with a hole portion 11 for pulling out a coil terminal and a pulling groove 11 connected thereto, and the stator 5 is taken out from the hole portion 10. The coil terminals of the respective phases are drawn out through the grooves 11.

  Next, the rotor support mechanism of the claw pole type motor will be described. FIG. 8 shows a rotor support mechanism of a claw pole type motor. (A) shows a sectional view of a conventional inward-rotating three-phase claw pole type motor. In the case of an internal motor, a rotor support mechanism including a bearing 8 and an end ring 9 is provided on both axial end surfaces of the stator core 5. An increase in the size of the motor due to the axial thickness of the rotor support mechanism is inevitable.

  FIG. 8B shows a cross-sectional view of an outer rotation type three-phase claw pole type motor according to this embodiment. In (b), concave portions are provided at both ends of the stator core 5, and the bearings 8 are disposed there. According to this, since the axial length of the motor can be shortened by the axial thickness of the bearing 8, further miniaturization can be realized.

1 is an overall view of an abduction type three-phase claw pole motor according to an embodiment of the present invention. Explanatory drawing which shows the stator structure of a present Example, and the cross section of each phase. Explanatory drawing which shows the relationship between the magnetic field and permanent magnet in a present Example. The exploded view which shows the rotor and stator of the conventional internal rotation type | mold 3 phase claw pole motor. Explanatory drawing which shows the cross section of the conventional stator structure and each phase. The comparison figure which showed the difference in the dimension of an internal-rotation type and an external-rotation type 3 phase claw pole motor. FIG. 3 is a structural diagram showing a coil terminal drawer structure of an adder type and an outer type. Sectional drawing which shows the rotor support mechanism of a three-phase claw pole motor of an inner rotation type and an outer rotation type.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Shaft, 3 ... Rotor (rotor core), 4 ... Rotor magnet, 5 ... Stator (stator core), 6 ... Claw magnetic pole, 6u, 6v, 6w ... Upper claw magnetic pole, 6u ', 6v', 6w ' ... lower claw magnetic pole, 7, 7u, 7v, 7w ... coil, 8 ... bearing, 9 ... end ring.

Claims (5)

  A three-phase claw characterized in that a plurality of upper and lower claw magnetic poles are provided on an outer peripheral portion of a stator core, and a rotor supported rotatably through a predetermined gap is provided on the outer peripheral side of the claw magnetic poles. Pole type motor.   The ring-shaped coil is sandwiched between the upper and lower claw magnetic poles to form one phase, and the phase having the same shape as the one phase is shifted in an electrical angle by 120 degrees and arranged in the axial direction. A three-phase claw pole type motor characterized by constituting another two phases.   In Claim 1, The hole part for taking out the terminal wire of the ring-shaped coil wound around the said stator core outside to the inner peripheral side shaft contact surface of the said stator core, and a shaft connected with this hole part A three-phase claw pole type motor having a groove extending in the direction.   2. The three-phase claw pole type motor according to claim 1, wherein the entire stator core or at least the claw magnetic poles are integrally formed.   2. The three-phase claw pole type motor according to claim 1, wherein recesses are provided at both axial ends of the stator core, and bearings for supporting the rotor are disposed in the recesses.

Images