JP6834285B2 - Rotating machine stator - Google Patents

Description

The present disclosure relates to a rotary electric machine stator.

The stator of a rotary electric machine is configured to include a stator core, which is a laminated body of thin magnetic sheets, and a coil winding wound around the stator core, as well as many members. These members have different coefficients of thermal expansion depending on the material. Therefore, the stator may be deformed due to a temperature change.

In Patent Document 1, in the structure of an electric motor in which an annular stator core made of silicon steel plate is shrink-fitted into a housing made of aluminum, the degree of tightening at a low temperature is due to the difference in the coefficient of thermal expansion between the silicon steel plate and aluminum. He points out that he will be too strong. Therefore, it is disclosed that the peripheral wall of the stator core is provided with the same number of gaps extending in the axial direction as the teeth to absorb the shrinkage difference at low temperature.

Japanese Unexamined Patent Publication No. 2004-112988

In the stator of a rotary electric machine, the space between the stator core and the coil winding is fixed with a winding fixing material. In that case, since the coefficient of thermal expansion between the stator core and the winding fixing material is different, deformation occurs on the end face side in the axial direction of the stator core due to the temperature change. In order to prevent this, if a notch extending in the axial direction is provided on the peripheral wall of the stator core, the torque of the rotary electric machine may decrease. Therefore, there is a demand for a rotary electric machine stator that can suppress deformation of the axial end face of the stator core caused by the difference in the coefficient of thermal expansion between the winding fixing material and the stator core while maintaining the characteristics of the rotary electric machine.

The rotary electric stator according to the present disclosure includes an annular back yoke and a stator core of a laminated body in which a predetermined number of magnetic thin plates having a plurality of teeth protruding from the back yoke to the inner peripheral side are stacked in the axial direction, and the coil is wound around the teeth. The coil winding and the portion where the coil winding protrudes from the axial end surface of the stator core and is wound as the coil end are the outermost ends of the coil end side of the laminated body in the axial direction and the other end in the axial direction. is disposed between the teeth on the coil winding end Men磁material elements thin, and winding fixed material of the insulating resin adhesive having a larger thermal expansion coefficient than the thermal expansion coefficient of the thin magnetic plate, the Including, the stator core includes an outermost end surface magnetic thin plate having a plurality of notches on the outer peripheral surface at a position corresponding to the teeth, an outermost end surface magnetic thin plate at one end in the axial direction, and an outermost end surface magnetic material at the other end in the axial direction. It has a core main body between the thin plates, and the magnetic thin plate constituting the core main body is not provided with a notch .

According to the above configuration, the notch provided on the outermost end surface can relieve the stress in the stator core caused by the difference in the coefficient of thermal expansion between the winding fixing material and the stator.

According to the rotary electric machine stator according to the present disclosure, the stress caused by the difference in the coefficient of thermal expansion between the winding fixing material and the stator core can be relaxed while maintaining the characteristics of the rotary electric machine, so that the deformation of the axial end face of the stator core can be prevented. Can be suppressed.

It is a block diagram of the rotary electric machine stator which concerns on this embodiment. FIG. 1A is a top view and FIG. 1B is a side view. FIG. 2A is a cross-sectional view taken along the line AA of FIG. (B) is an enlarged view of part B of (a). It is a perspective view of the insulator used for the rotary electric machine stator which concerns on this embodiment. It is a partial decomposition view of the rotary electric machine stator which concerns on this embodiment. As a comparative example, it is a stress generation diagram in a stator core composed of a magnetic thin plate having no notch.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the following, a stator used for a rotary electric machine mounted on a vehicle will be described, but this is an example for explanation, and any rotary electric machine stator may be used for purposes other than mounting on a vehicle. In the following, the coil winding will be described as a centralized winding, but this is an example for explanation, and a distributed winding may be used as long as a winding fixing material is used. In the following, the coil winding will be described as a round wire having a circular cross section, but this is also an example for explanation and may be a coil winding other than the circular cross section. For example, a flat wire having a rectangular cross section, a winding having an elliptical cross section, or the like may be used.

The shapes, dimensions, number of teeth, number of turns, materials, etc. described below are examples for explanation and can be appropriately changed according to the specifications of the rotary electric machine stator. In the following, similar elements are designated by the same reference numerals in all drawings, and duplicate description will be omitted.

FIG. 1 is a diagram showing a configuration of a rotary electric machine stator 10 used for a rotary electric machine mounted on a vehicle. Hereinafter, the rotary electric machine stator 10 will be referred to as a stator 10 unless otherwise specified. The rotary electric machine in which the stator 10 is used is a motor generator that functions as an electric motor when the vehicle is power running and as a generator when the vehicle is braking by controlling the drive circuit. It is a three-phase synchronous rotary electric machine. is there. The rotary electric machine is composed of a stator 10 which is a stator shown in FIG. 1 and a rotor which is an annular rotor which is arranged on the inner peripheral side of the stator 10 with a predetermined gap. In FIG. 1, the rotor is not shown.

FIG. 1A is a top view of the stator 10 as viewed from the axial direction, and FIG. 1B is a side view. FIG. 1B shows the axial direction of the stator 10. Both ends in the axial direction are distinguished and are called one end side and the other end side.

The stator 10 includes a stator core 12, a coil winding 14, an insulator 16 arranged between the stator core 12 and the coil winding 14, and a winding fixing member 20 arranged on an axial end surface of the stator core 12. Including. The winding fixing member 20 is arranged at one end in the axial direction of the stator core 12 and the other end, respectively.

The stator core 12 is an annular magnetic component, and includes an annular back yoke 22 and a plurality of teeth 24 protruding inward from the back yoke 22. The space between the adjacent teeth 24 is a slot. In the example of FIG. 1, the number of teeth 24 is six.

The stator core 12 is a laminated body including a back yoke 22 and teeth 24, and a predetermined number of annular magnetic thin plates 26 formed into a predetermined shape so as to form a slot are stacked in the axial direction. Both sides of the magnetic sheet 26 are electrically insulated. As the material of the magnetic thin plate 26, an electromagnetic steel plate, which is a kind of silicon steel plate, can be used. The coefficient of thermal expansion of the silicon steel sheet is (12 to 15) × 10 ^-6 (° C.).

As shown in FIG. 1B, the stator core 12 includes a magnetic thin plate 32 on the outermost end surface at one end in the axial direction, a magnetic thin plate 34 on the outermost end surface at the other end, and a core main body 30 between them. Are laminated. The magnetic thin plates 32 and 34 are provided with notches 40, and the magnetic thin plates 26 of the core main body 30 are not provided with notches. Since FIG. 1A is a top view, the magnetic thin plate 32 and the notch 40 are shown, and the core main body 30 that appears through the notch 40 is shown. The contents of the notch 40 and its action and effect will be described later.

The coil winding 14 is a centralized winding coil in which a lead wire having an insulating film is wound around one tooth 24 by a predetermined number of turns to form one phase winding. The portion where the coil winding 14 projects from the axial end surface of the stator core 12 and is wound is the coil end. FIG. 1 shows a coil end 28 at one end in the axial direction and a coil end 29 at the other end. As the wire of the lead wire with the insulating film of the coil winding 14, a copper wire, a copper-tin alloy wire, a silver-plated copper-tin alloy wire, or the like can be used. As the strand, a round wire having a circular cross-sectional shape is used. As the insulating film, a polyamide-imide enamel film is used. Instead of this, polyesterimide, polyimide, polyester, formal and the like can be used.

The insulator 16 is an insulator having a tubular shape held between the inner peripheral side surface of the coil winding 14 and the outer peripheral side surface of the teeth 24 facing the inner peripheral side surface of the coil winding 14. The insulator 16 is fixed to the stator core 12 by a fixing means such as adhesion. As the insulator 16, a sheet having an electrically insulating property formed into a predetermined shape can be used. As the sheet having electrical insulation, a plastic film can be used in addition to paper. The configuration of the insulator 16 will be described later.

The winding fixing material 20 is an insulating resin adhesive that is arranged on the magnetic thin plates 32 and 34 on the outermost end faces of the laminate in the axial direction, which is the stator core 12, and fixes the coil winding 14 to the stator core 12. The end face in the axial direction has one end and the other end, and the winding fixing member 20 is arranged on the magnetic thin plates 32 and 34 of the outermost end faces of the one end and the other end, respectively. An epoxy resin is used as the insulating resin adhesive used as the winding fixing material 20. The coefficient of thermal expansion of the epoxy resin is 62 × 10 ^-6 (° C.). Varnish may be used instead of the epoxy resin. The coefficient of thermal expansion of the varnish is (18-21) × 10 ^-6 (° C). The coefficient of thermal expansion of the epoxy resin and the coefficient of thermal expansion of the varnish are both larger than the coefficient of thermal expansion of the silicon steel plate.

FIG. 2 shows the arrangement relationship of the stator core 12, the coil winding 14, and the winding fixing material 20.
FIG. 2A is a cross-sectional view taken along the line AA of FIG. (B) is an enlarged view of part B of (a). (B) is an enlarged view of one end in the axial direction, but since the contents at the other end are the same, the arrangement relationship at one end will be described. As shown in (b), the winding fixing material 20 is arranged on the end surface of one end of the stator core 12 which is a laminated body, and the coil winding 14 is wound on the winding fixing material 20.

When an epoxy resin is used as the winding fixing material 20, the epoxy resin in a liquid state or a semi-solidified state is applied to the upper surface of the magnetic thin plate 32 on the outermost end surface at one end in the axial direction of the stator core 12. Then, the coil winding 14 is wound around the winding fixing material 20 and treated under appropriate heat curing conditions to solidify. As a result, the coil winding 14 is fixed to the stator core 12 via the solidified winding fixing member 20.

Since the winding fixing material 20 is an insulating resin adhesive, it becomes an insulator after being solidified. The insulator 16 is also an insulator arranged between the stator core 12 and the coil winding 14. Since the winding fixing member 20 is arranged at one end and the other end in the axial direction of the stator core 12, the arrangement of the insulator 16 can be omitted at that position. FIG. 3 is a perspective view showing the configuration of the insulator 16.

The insulator 16 includes a first seat portion 50 arranged between the back yoke 22 and the coil winding 14, a second seat portion 52 arranged on the tip end side of the teeth 24, and a tubular seat portion 54 connecting between them. It is a member having a tubular shape including and. The first sheet portion 50 is provided with a first opening 56 through which the root portion of the teeth 24 on the back yoke 22 side is passed, and the second sheet portion 52 is provided with a second opening 58 through which the tip portion of the teeth 24 is passed. It is provided. The tubular sheet portion 54 is a tubular portion through which the teeth 24 are passed, and the inner wall thereof faces the outer peripheral surface of the teeth 24.

The tubular sheet portion 54 of the insulator 16 is provided with a third opening 60 at a portion on one end side in the axial direction and a fourth opening 62 at a portion on the other end side. The winding fixing material 20 is arranged in the third opening 60 and the fourth opening 62, and is directly applied to the outer peripheral surface on one end side in the axial direction and the outer peripheral surface on the other end side in the teeth 24. Placed in. In other words, the insulator 16 is provided with two openings, a third opening 60 and a fourth opening 62, at a position where the winding fixing member 20 is arranged.

The contents and effects of the notch 40 described in FIG. 1 will be described with reference to FIGS. 4 and 5. When the coil winding 14 is wound on the winding fixing material 20, the winding fixing material 20 is solidified under appropriate heat curing conditions, and then the temperature is returned to room temperature, the space between the winding fixing material 20 and the stator core 12 is reached. Due to the difference in the coefficient of thermal expansion, stress that deforms the stator core 12 can be generated. The notch 40 described in FIG. 1 has an action of alleviating the generation of stress.

FIG. 4 is a partial decomposition view of the laminated body of the stator core 12. The partial exploded view shows the magnetic thin plate 32 on the outermost end surface at one end in the axial direction and the outermost end surface at the other end, instead of disassembling the plurality of magnetic thin plates 26 constituting the laminated body one by one. It is a figure which is disassembled into the magnetic material thin plate 34 and the core main body part 30 between them.

The magnetic thin plate 32 and the magnetic thin plate 34 have a plurality of notches 40 on the outer peripheral surface. The notch 40 is provided at a position corresponding to the arrangement position of each tooth 24 on the outer peripheral surface of the back yoke 22 in consideration of the fact that the generation of stress described in FIG. 5 is repeated for each tooth 24. In the example of FIG. 4, since there are six teeth 24, six notches 40 are provided for each of the magnetic thin plate 32 and the magnetic thin plate 34. The notch 40 is not provided in each magnetic thin plate 26 constituting the core main body 30. In some cases, not one but two or three magnetic thin plates may be provided with notches 40 similar to the magnetic thin plate 32 on the outermost end surface at one end and the other end in the axial direction. The shape of the notch 40 is substantially triangular. This is an example, and may be a semicircular notch, a square notch, or the like.

In order to explain the effect of the notch 40, as a comparative example, FIG. 5 shows a stress generation diagram in the stator core 13 made of a magnetic thin plate 26 having no notch. FIG. 5A is a top view and FIG. 5B is a side view. Here, the coil winding 14 is indicated by a chain double-dashed line.

In the stator core 13 composed of only the magnetic thin plate 26 having no notch, the stress that deforms the stator core 13 in the direction indicated by the arrow due to the difference in the coefficient of thermal expansion between the winding fixing material 20 and the stator core 12. 70, 72, 74 occur. The stress 70 is generated in the direction in which the stator core 13 is contracted toward the position where the winding fixing member 20 is arranged. Due to the generation of the stress 70, stresses 72 and 74 that contract the stator core 13 from the outer peripheral surface side of the back yoke 22 toward the winding fixing member 20 are generated. Since the outer peripheral length of the magnetic thin plate 26 is constant, the entire magnetic thin plate 26 is eventually distorted and deformed. FIG. 5B shows an outline of deformation of both end faces in the axial direction of the stator core 12 by a chain double-dashed line.

When the stator core 13 is deformed as shown in FIG. 5B, when the stator 10 is bolted to the motor case or the like, the force for flattening the deformation becomes the reaction force of the bolt axial force, and the tightening force is increased. Need to raise. On the other hand, in the stator 10 having the configuration shown in FIG. 1, since a plurality of notches 40 are provided on the outer peripheral surfaces of the magnetic thin plates 32 and 34 on the outermost end surface in the axial direction of the stator core 12, the stresses 70 and 72 in FIG. Stress relaxation and stress release occur as the 74 heads towards the notch 40. As a result, it is possible to suppress the occurrence of deformation on the axial end surface of the stator core 12.

The rotary electric machine stator 10 according to the present embodiment is a stator core of a laminated body in which a predetermined number of thin magnetic materials having an annular back yoke 22 and a plurality of teeth 24 protruding from the back yoke 22 to the inner peripheral side are stacked in the axial direction. Has twelve. It also has a coil winding 14 wound around the teeth 24. Further, the portion where the coil winding 14 protrudes from the axial end surface of the stator core 12 and is wound is used as the coil end, and is arranged on the magnetic thin plates 32 and 34 on the outermost end surface of the laminated body on the coil end side. A winding fixing material 20 made of a material having a coefficient of thermal expansion larger than that of a thin plate is included. The magnetic thin plates 32 and 34 on the outermost end surface of the laminated body on the coil end side have a plurality of notches on the outer peripheral surface at positions corresponding to the teeth 24.

According to the rotary electric machine stator 10 according to the present embodiment, the notch 40 is provided in the magnetic thin plates 32 and 34 on the outermost end faces in the axial direction of the laminated body, but is not provided in all the magnetic thin plates. , It is possible to suppress the decrease in torque due to the notch and maintain the characteristics of the rotating electric machine. Further, since the stress generated by the difference in the coefficient of thermal expansion between the winding fixing member 20 and the stator core 12 can be relaxed by the notch 40, the deformation of the axial end surface of the stator core 12 can be suppressed. Further, since the axial end surface of the stator core 12 which is a reaction force of the bolt axial force is not deformed, the reliability of the fastening between the stator 10 and the motor case or the like is improved.

10 (Rotary machine) stator, 12, 13 stator core (laminated body), 14 coil winding, 16 insulator, 20 winding fixing material, 22 back yoke, 24 teeth, 26 magnetic sheet, 28, 29 coil end, 30 core Main body, 32, 34 Magnetic sheet (on the outermost surface in the axial direction), 40 notches, 50 1st sheet, 52 2nd sheet, 54 Cylinder sheet, 56 1st opening, 58 2nd opening , 60 3rd opening, 62 4th opening, 70,72,74 stress.

Claims (1)

An annular back yoke and a stator core made of a laminated body in which a predetermined number of magnetic thin plates having a plurality of teeth protruding from the back yoke to the inner peripheral side are stacked in the axial direction.
With the coil winding wound around the teeth,
The portion in which the coil winding is wound protrude from the axial end surface of the stator core as a coil end, each Saisototan Men磁 of one axial end and the other axial end of the coil end side of the laminate wherein the on the teeth of the body sheet is disposed between the coil winding, and the winding fixing material of the insulating resin adhesive having a larger thermal expansion coefficient than the thermal expansion coefficient of the thin magnetic plate,
Including
The stator core
The outermost magnetic material thin plate having a plurality of notches on the outer peripheral surface at a position corresponding to the teeth, and
It has a core main body portion between the outermost magnetic material thin plate at one end in the axial direction and the outermost magnetic material thin plate at the other end in the axial direction.
A rotary electric machine stator in which the notch is not provided in the magnetic thin plate constituting the core main body.

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