JP2008283732A - Stator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stator for driving a motor efficiently by eliminating the phase difference of a voltage induced by offsetting the three-phase teeth in the axial direction in respect of structure. <P>SOLUTION: In the stator having three-phase teeth and applied with a meandering ring winding of two layers, the three-phase teeth are mutually offset in the axial direction and a plurality of sets of three teeth adjoining in the circumferential direction are arranged at a fixed pitch in the circumferential direction. The circumferential distance of an adjoining first pair of teeth having the largest difference in axial offset is set larger than the circumferential distance of the adjoining second and third pairs of teeth, and the circumferential distance of the surface of the three-phase teeth opposing the rotor is set based on the axial offset of the three-phase teeth. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stator structure for a motor.

  As a motor for a hybrid vehicle or a motor for an electric vehicle, a permanent magnet type AC synchronous motor or a brushless DC motor using a permanent magnet as a rotor is often used. This type of motor includes a stator in which windings (coils) are wound by concentrated winding on a stator core for each of the three phases including the U phase, the V phase, and the W phase, and the stator includes a permanent magnet. A permanent magnet type three-phase synchronous motor for driving a rotor in three phases is known from, for example, Japanese Patent Application Laid-Open No. 11-299137.

  In addition, the winding of each phase of the U phase, V phase, and W phase is wound so as to sew between adjacent teeth (claw poles) in the circumferential direction, so that the winding is wound in a wave shape. A permanent magnet type three-phase synchronous motor that includes the above-described stator and drives the rotor in the 3U phase by this stator is known, for example, in Japanese Patent Laid-Open No. 2002-165396.

  By the way, in the three-phase synchronous motor according to the above-described prior art, since windings for each of the three phases are necessary, it is difficult to suppress an increase in the number of parts required for the configuration of the stator, There arises a problem that a troublesome work is required for winding the winding for each phase.

  Moreover, in a stator in which windings are wound by wave winding, it is difficult to improve the winding space factor between adjacent teeth, and further, the height of the coil end is reduced to reduce the motor axis. There arises a problem that it is difficult to reduce the size of the direction and improve the mountability in a vehicle or the like.

In order to solve such a problem, the present applicant alternately arranges a three-phase stator ring and a two-phase annular winding so as to be sequentially stacked along a direction parallel to the axis. Japanese Patent Laid-Open Nos. 2006-280189 and 2006-280190 have proposed a stator for a motor in which a plurality of meandering portions are formed in the annular winding to increase the magnetic flux generated by the stator.
Japanese Patent Laid-Open No. 11-299137 JP 2002-165396 A JP 2006-280189 A JP 2006-280190 A

  By the way, in the above Patent Document 3, in a motor having a two-phase 120 ° short coil, three-phase teeth are arranged in a staggered manner in the axial direction in order to reduce the stator width and the coil (winding) copper loss. A stator with an offset arrangement is disclosed.

  Thus, when the rotor facing surface of the stator teeth is offset in the axial direction by 120 ° short-pitch winding, when the rotor made of permanent magnets rotates in the stator, the magnets in the axial direction with respect to the U-phase teeth and W-phase teeth. Therefore, the magnetic flux that enters the teeth from the magnet is different from the teeth that are equally aligned in the normal axial direction.

  In particular, when the magnet moves from the W-phase teeth to the U-phase teeth where the difference in the amount of axial offset is the largest, the magnetic flux of the magnet that protrudes from the teeth escapes to the adjacent teeth with low magnetic resistance. The interlinkage magnetic flux of the wire and the W-phase winding becomes narrower than the structural pitch of the teeth, and the induced voltage phase difference becomes smaller than 120 °.

  As a result, the induced voltage shifts with respect to the three-phase AC current having a phase difference of 120 ° between the U phase, the V phase, and the W phase, thereby reducing the motor output and deteriorating its controllability. Will occur.

  The present invention has been made in view of these points, and the object of the present invention is to eliminate an induced voltage phase difference caused by offsetting three-phase teeth in the axial direction in terms of structure, and to improve efficiency. It is to provide a stator that can drive a motor well.

  According to the first aspect of the present invention, the stator has three-phase teeth and has two layers of meandering annular windings, and the three-phase teeth are offset from each other in the axial direction. The phase teeth are composed of three teeth adjacent in the circumferential direction as a set, and the set is arranged at a constant pitch in a plurality of sets in the circumferential direction. The distance between the circumferential directions of the pair of teeth is set larger than the distance between the circumferential directions of the adjacent second pair and third pair of teeth, and the rotor of the three-phase teeth is opposed to the rotor. The stator is characterized in that the distance between the circumferential directions of the surfaces is set based on the axial offset amount of the three-phase teeth.

  According to a second aspect of the present invention, there is provided a stator having three-phase teeth and two layers of meandering annular windings, wherein the three-phase teeth are arranged so as to be offset from each other in the axial direction. The phase teeth are composed of three teeth adjacent in the circumferential direction as a set, and the set is arranged at a constant pitch in a plurality of sets in the circumferential direction. The distance between the circumferential directions of the pair of teeth is set larger than the distance between the circumferential directions of the adjacent second pair and third pair of teeth, and the circumferential direction of the three-phase teeth. The distance between each other is set based on the shape of the rotor facing surface of the three-phase teeth.

  According to the invention of claim 3, in the invention of claim 1 or 2, the distance between the circumferential directions of the second pair of teeth is equal to the distance between the circumferential directions of the three pairs of teeth. A stator is provided that is characterized by being set.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, each of the three-phase teeth exchanges a magnetic flux with a winding adjacent portion adjacent to the winding, and a permanent magnet of the rotor. The stator is characterized in that the distance between the circumferential directions of the three-phase teeth is based on the winding adjacent portion.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to third aspects, each of the three-phase teeth exchanges a magnetic flux with a winding adjacent portion adjacent to the winding, and a permanent magnet of the rotor. The stator is characterized in that the distance between the circumferential directions of the three-phase teeth is based on the teeth tip.

  According to the first and second aspects of the invention, the deviation of the induced voltage phase difference caused by offsetting the three-phase teeth in the axial direction can be eliminated in terms of structure, and deterioration of the controllability of the motor is prevented. In addition, the motor can be driven efficiently.

  According to the invention described in claim 3, since the distance between the circumferential direction of the second pair of teeth and the third pair of teeth is set equal, in addition to the effect of the invention described in claims 1 and 2, the stator The structure can be simplified and the productivity can be improved.

  According to the invention described in claim 4, the distance between the circumferential directions of the three-phase teeth is set based on the winding adjacent portion, and the same effect as that of the invention described in claim 1 or 2 can be achieved.

  According to the invention described in claim 5, the distance between the circumferential directions of the three-phase teeth is set with reference to the tip of the teeth, and the same effect as in the invention described in claim 1 or 2 can be achieved.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view of an annular stator according to the first embodiment of the present invention, and FIG. 2 is a perspective view of an assembled stator.

  The annular stator 2 constitutes, for example, a permanent magnet AC synchronous motor (also referred to as a brushless DC motor or a claw pole type motor) mounted on a hybrid vehicle as a vehicle drive source together with an engine. In a parallel hybrid vehicle having a structure in which a transmission and a transmission are connected in series, at least the driving force of either the engine or the claw pole type motor is transmitted to the driving wheels of the vehicle via the transmission.

  Further, when the driving force is transmitted from the driving wheel side to the claw pole type motor during deceleration of the vehicle, the claw pole type motor functions as a generator to generate a so-called regenerative braking force, and the kinetic energy of the vehicle body is converted into electric energy ( Recovered as regenerative energy). Further, when the output of the engine is transmitted to the claw pole type motor, the claw pole type motor functions as a generator and generates power generation energy.

  As shown in FIG. 1, an annular stator 2 includes a U-phase stator ring (teeth ring) 4, a V-phase stator ring (teeth ring) 6, a W-phase stator ring (teeth ring) 8, and a U-phase annular winding. 22 and a W-phase annular winding 26.

  The U-phase stator ring 4 includes an annular yoke 9 and a plurality (ten in this embodiment) of U-phase teeth (U-phase claw poles) formed integrally with the annular yoke 9 and spaced apart at equal intervals in the circumferential direction. ) 10 and a plurality of coupling portions 12 formed integrally with the annular yoke 9 and spaced apart in the circumferential direction. Each U-phase tooth 10 protrudes on one side in the axial direction (right side in FIG. 1).

  The V-phase stator ring 6 includes an annular yoke 13, a plurality (ten in this embodiment) of V-phase teeth 14 that are integrally formed with the annular yoke 13 and spaced apart at equal intervals in the circumferential direction, and the annular yoke 13. And a plurality of coupling portions 16 that are formed integrally with each other and spaced apart in the circumferential direction. Each V-phase tooth 14 protrudes on both sides in the axial direction.

  The W-phase stator ring 8 includes an annular yoke 17, a plurality (ten in this embodiment) of W-phase teeth 18 that are integrally formed with the annular yoke 17 and spaced apart at equal intervals in the circumferential direction, and the annular yoke 17. And a plurality of coupling portions 20 that are formed integrally with each other and spaced apart in the circumferential direction. Each W-phase tooth 18 protrudes to the other side in the axial direction (left side in FIG. 1). That is, the U-phase teeth 10 and the W-phase teeth 18 protrude in a direction approaching each other.

  It should be noted here that the U-phase tooth 10, the V-phase tooth 14 and the W-phase tooth 18 are connected to the U-phase stator ring 4, the V-phase stator ring 6 and the W-phase stator ring 8 at each coupling portion 12, 16 and 20. When stacked and bonded, they are arranged at positions that are relatively shifted so as not to overlap each other.

  The U-phase annular winding 22 is configured by winding a copper wire in an annular shape, and has a plurality (ten in this embodiment) of meandering portions 24 meandering in the axial direction of the stator 2. Similarly, the W-phase annular winding 26 has a plurality (ten in this embodiment) of meandering portions 28 meandering in the axial direction of the stator 2.

  The connecting portions 12, 16, and 20 of the stator rings 4, 6, and 8 are aligned, the U-phase annular winding 22 and the W-phase annular winding 26 are arranged at predetermined positions in the circumferential direction, and the stator rings 4, 6 are arranged. , 8 are bolted to complete the annular stator 2 as shown in FIG.

  As apparent from observation of FIG. 2, the U-phase teeth 10, the V-phase teeth 14, and the W-phase teeth 18 are arranged offset in the axial direction. Although not clear from FIG. 2, as will be described in detail later, between the circumferential directions of a pair of adjacent teeth (W-phase teeth 18 and U-phase teeth 10) having the largest difference in axial offset amount. The distance between the two adjacent pairs of teeth (a pair of U-phase teeth 10 and V-phase teeth 14 and a pair of V-phase teeth 14 and W-phase teeth 18) is set larger than the distance between the circumferential directions. ing.

  As apparent from observation of FIGS. 1 and 2, the teeth 10, 14, 18 are arranged in a predetermined order in the circumferential direction (U-phase teeth 10, W-phase teeth 18, V-phase teeth 14, U-phase teeth 10,...). The meandering portion 24 of the U-phase annular winding 22 is disposed between the teeth 10 and 14 adjacent in the circumferential direction, and the meandering portion 28 of the W-phase annular winding 26 is disposed between the adjacent teeth 14 and 18 in the circumferential direction. Is arranged.

  That is, one U-phase tooth 10 is disposed in the U-phase meandering portion 24, and one W-phase tooth 18 is disposed in the W-phase meandering portion 28, and the U-phase meandering portion 24 and the W-phase meandering that are adjacent in the circumferential direction. One V-phase tooth 14 is disposed between the portion 28.

  The meandering portion 24 of the U-layer annular winding 22 and the meandering portion 28 of the W-phase annular winding 26 are provided so as to protrude in different directions, and the U-phase annular winding 22 and the W-phase annular winding 26 are: They are arranged at positions that are relatively displaced in the circumferential direction so as to have a phase difference of 240 ° in electrical angle.

  As a result, the two-phase annular windings 22 and 26 arranged so as to sew between the adjacent teeth 10 and 14 or 14 and 18 in the circumferential direction form a short-pitch winding with a so-called electrical angle of 120 ° or less. It is formed as follows.

  Next, problems to be solved by the present invention will be described with reference to FIGS. 3A is a schematic plan view showing the relationship between the W-phase teeth 18 and U-phase teeth 10 that are offset in the axial direction and the magnet 30 that constitutes the rotor, and FIG. 3B is a side view thereof. It is. 4A is a plan view of the state in which the magnet 30 has moved slightly in the direction of the arrow 32, and FIG. 4B is a side view thereof.

  As shown in FIG. 3A, since the W-phase teeth 18 and the U-phase teeth 10 are offset in the axial direction, a part of the magnetic flux emitted from the protruding portion 34 of the magnet 30 is shown in FIG. As shown in FIG. 5, the U-phase teeth 10 having a magnetic resistance lower (closer) than that of the W-phase teeth 18 are entered. As a result, the U-phase induced voltage phase is advanced.

  When the magnet 30 moves (rotates) in the direction of the arrow 32 and enters the state shown in FIG. 4A, a part of the magnetic flux from the protruding portion 36 of the magnet 30 is as shown in FIG. In addition, the W-phase teeth 18 having a magnetic resistance lower (closer) than that of the U-phase teeth 10 are entered. As a result, the W-phase induced voltage phase is delayed.

  Therefore, since the U-phase induced voltage phase is advanced in the state of FIG. 3 and the W-phase induced voltage phase is delayed in the state of FIG. 4, the U-W phase induced voltage phase difference is smaller than 120 °. As a result, there is a problem that the induced voltage shifts with respect to the three-phase alternating current (120 °) current, the output of the motor is lowered, and the controllability is also deteriorated.

  The present invention has been made to solve this problem, and the present invention will be described in detail with reference to FIGS. FIG. 5 is a schematic diagram showing the positional relationship between the three-phase teeth 10, 14, 18 and the U-phase coil 22 and the W-phase coil 26, which are offset from each other in the axial direction, for explaining the principle of the present invention. It is.

  In the present invention, the U-phase teeth 10, the V-phase teeth 14 and the W-phase teeth 18 are arranged offset from each other in the motor shaft direction. The U-phase teeth 10, the V-phase teeth 14, and the W-phase teeth 18 are a set of three teeth adjacent in the circumferential direction, and a plurality of these groups are arranged at a constant pitch in the circumferential direction.

  Furthermore, the distance between the circumferential directions of adjacent W-phase teeth 18 and U-phase teeth 10 having the largest difference in the amount of axial offset is the distance between the circumferential directions of U-phase teeth 10 and V-phase teeth 14, and V It is set larger than the distance between the circumferential directions of the phase teeth 14 and the W phase teeth 18.

  That is, if the circumferential distance between the U-phase teeth 10 and the V-phase teeth 14 is A, the circumferential distance between the V-phase teeth 14 and the W-phase teeth 18 is A, and the W-phase teeth 18 and the U-phase teeth. The distance between the ten circumferential directions is set larger than A. However, the distance between the circumferential directions of the V-phase teeth 14 and the W-phase teeth 18 is not necessarily equal to A.

  Specifically, the distance between the circumferential directions of the rotor facing surfaces of the three-phase teeth 10, 14, 18 is set based on the axial offset amount of the three-phase teeth 10, 14, 18. As an alternative, the distance between the circumferential directions of the three-phase teeth 10, 14, 18 is set based on the shape of the rotor facing surface of the three-phase teeth 10, 14, 18.

  Next, the operation of the present invention will be described with reference to FIG. 6A is a plan view of a state in which the magnets 30 constituting the rotor are superimposed on the arrangement relationship shown in FIG. 5, and FIG. 6B is a side view thereof. The facing surfaces of the three-phase teeth 10, 14, 18 of the magnet 30 are alternately magnetized to N, S. The rotor rotates (moves) in the direction of arrow 38.

  For convenience of explanation, the magnet 30 shown in FIG. 6B is assumed to be 30a, 30b, 30c in order from the left. The surface of the magnet 30a facing the V-phase teeth 14 is magnetized by S, the surface of the magnet 30b facing the W-phase teeth 18 is magnetized by N, and the surface of the magnet 30c facing the V-phase teeth 14 is magnetized by S. And

  Therefore, all the magnetic fluxes emitted from the magnet 30a pass downward through the paper surface and pass through the V-phase teeth 14, and all the magnetic fluxes emitted from the magnet 30c pass downward through the paper surface and pass through the V-phase teeth 14. Further, since the circumferential interval between the W-phase teeth 18 and the U-phase teeth 10 is set wide, the magnetic flux emitted from the magnet 30b is directed upward on the paper surface and does not leak to the U-phase teeth 10, and all the W-phase teeth. Pass through 18.

  As a result, the phase difference of the induced voltage is eliminated and the phase difference of the induced voltage is aligned at about 120 °, so that the controllability of the motor can be improved and the motor can be driven efficiently.

  FIG. 7 schematically shows the stator 2 according to the first embodiment of the present invention. FIG. 7A is a schematic perspective view of the stator 2, and FIG. 7B is a plan view of the stator 2. As shown in FIG. 7A, the V-phase teeth 10 are composed of a body portion (winding adjacent portion) 10a and an ear portion (an heel portion) 10b formed integrally with the body portion 10a. The ear | edge part 10b forms a rotor opposing surface.

  Similarly, the V-phase tooth 14 is composed of a body portion 14a and an ear portion 14b, and the W-phase tooth 18 is also composed of a body portion 18a and an ear portion 18b. FIG. 8 is a cross-sectional view taken along line 8-8 of FIG.

  In the stator 2 of the present embodiment, only the circumferential interval between the body portion 18a of the W-phase teeth 18 and the body portion 10a of the U-phase teeth 10 is enlarged, and the interval between the ear portions 18b and 10b is kept at a constant pitch as before. It is a thing.

  For example, the interval between the body portion 18a of the W-phase teeth 18 and the body portion 10a of the U-phase teeth 10 is set to an electrical angle of 137 °, and the interval between the U-phase teeth 10 and the V-phase teeth 14 and the V-phase teeth 14 The distance from the W-phase teeth 18 was set to 111.5 ° in terms of electrical angle. Thereby, the shift of the phase difference of the induced voltage could be eliminated, and the phase difference of the induced voltage could be aligned to approximately 120 °.

  FIG. 9 shows a stator 2A according to a second embodiment of the present invention, FIG. 9 (A) is a schematic perspective view of the stator 2A, and FIG. 9 (B) is a plan view thereof. In the stator 2A of the present embodiment, only the ear portion 18b of the W-phase tooth 18 and the ear portion 10b of the U-phase tooth 10 are enlarged in the circumferential direction, and the interval between the body portions 18a and 10a is kept at a uniform pitch as before. It is a thing.

  As described above, even when the distance between the circumferential directions is enlarged only between the ear portions 18b and 10b of the W-phase teeth 18 and the U-phase teeth 10, the deviation of the induced voltage phase difference can be eliminated. Also in this embodiment, the U-phase teeth 10 and the V-phase teeth 14 and the V-phase teeth 14 and the W-phase teeth 18 remain at the same pitch as before.

  FIG. 10 shows a stator 2B according to a third embodiment of the present invention. FIG. 10 (A) is a schematic perspective view of the stator 2B, and FIG. 10 (B) is a plan view thereof. In the present embodiment, the circumferential interval between the body portion 18a of the W-phase teeth 18 and the body portion 10a of the U-phase teeth 10 is increased, and the circumferential interval between the ear portions 18b and 10b is also increased.

  In the present embodiment, the circumferential interval between the U-phase teeth 10 and the V-phase teeth 14 is set equal to the circumferential interval between the V-phase teeth 14 and the W-phase teeth 18. Thus, the expansion of the circumferential interval between the body portions 18a and 10a can be suppressed by widening the circumferential interval between the W-phase teeth 18 and the U-phase teeth 10 in both the body portion and the ear portion. Also in this embodiment, the same effects as those in the first and second embodiments described above can be obtained.

It is a disassembled perspective view of the stator of 1st Embodiment of this invention. It is a perspective view of the assembled stator. FIG. 3A is a plan view for explaining a problem to be solved by the present invention, and FIG. 3B is a side view thereof. 4A is a plan view for explaining the problem to be solved by the present invention, and FIG. 4B is a side view thereof. It is a figure which shows the arrangement | positioning relationship between the three-phase teeth and winding which show the principle of this invention. FIG. 6 (A) is a plan view showing the positional relationship between the three-phase teeth and the magnet rotor for explaining the principle of the present invention, and FIG. 6 (B) is a side view thereof. FIG. 7A is a schematic perspective view of the stator according to the first embodiment of the present invention, and FIG. 7B is a plan view thereof. FIG. 8B is a cross-sectional view taken along line 8-8 in FIG. FIG. 9A is a schematic perspective view of a stator according to the second embodiment of the present invention, and FIG. 9B is a plan view thereof. FIG. 10A is a schematic perspective view of a stator according to the third embodiment of the present invention, and FIG. 10B is a plan view thereof.

Explanation of symbols

2 Stator 4 U phase stator ring 6 V phase stator ring 8 W phase stator ring 10 U phase teeth (U phase claw pole)
14 V-phase teeth (V-phase claw pole)
18 W phase teeth (W phase claw pole)
22 U-phase annular windings 24, 28 meandering portion 26 W-phase annular windings 30 magnets 34, 36 Magnet protrusions

Claims (5)

A stator having three-phase teeth and two layers of meandering annular windings,
The three-phase teeth are offset from each other in the axial direction,
The three-phase teeth are a set of three teeth adjacent in the circumferential direction, and the set is arranged at a constant pitch in the circumferential direction.
The distance between the circumferential directions of the adjacent first pair of teeth having the largest difference in the axial offset amount is larger than the distance between the circumferential directions of the adjacent second pair and third pair of teeth. Is set,
The distance between the circumferential directions of the rotor facing surfaces of the three-phase teeth is set based on an axial offset amount of the three-phase teeth. A stator having three-phase teeth and two layers of meandering annular windings,
The three-phase teeth are offset from each other in the axial direction,
The three-phase teeth are a set of three teeth adjacent in the circumferential direction, and the set is arranged at a constant pitch in the circumferential direction.
The distance between the circumferential directions of the adjacent first pair of teeth having the largest difference in the axial offset amount is larger than the distance between the circumferential directions of the adjacent second pair and third pair of teeth. Is set,
The distance between the circumferential directions of the three-phase teeth is set based on the shape of the rotor facing surface of the three-phase teeth.   3. The stator according to claim 1, wherein a distance between circumferential directions of the second pair of teeth is set to be equal to a distance between circumferential directions of the three pairs of teeth. Each of the three-phase teeth is composed of a winding adjacent portion adjacent to the winding, and a tooth tip portion that exchanges magnetic flux with the permanent magnet of the rotor,
The stator according to any one of claims 1 to 3, wherein a distance between circumferential directions of the three-phase teeth is based on the winding adjacent portion. Each of the three-phase teeth is composed of a winding adjacent portion adjacent to the winding, and a tooth tip portion that exchanges magnetic flux with the permanent magnet of the rotor,
The stator according to any one of claims 1 to 3, wherein a distance between circumferential directions of the three-phase teeth is based on a tip end portion of the teeth.

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