JP6938933B2 - Rotating machine stator - Google Patents

Description

The present disclosure relates to a rotary electric machine stator, and more particularly to a rotary electric machine stator including an insulating paper, a stator winding, and a varnish in a slot of a stator core.

In the stator of a rotary electric machine, an insulating paper is arranged between the stator core and the stator winding in the slot of the stator core in order to ensure the electrical insulation between the stator core and the stator winding. Then, in order to fix the stator winding, the slot including the stator winding and the insulating paper is impregnated with varnish.

Patent Document 1 discloses a technique in which an insulating paper provided with a plurality of small holes or a large number of elongated openings in an oblique direction is mounted in a slot of a stator core to wind a stator winding. The insulating paper is formed with folds that cover the opening edge of the slot, and the small holes and elongated openings are only in the part facing the inner wall surface of the slot inside so as not to cover the opening edge of the slot. It is formed.

In Patent Document 2, a plurality of insulating papers having a plurality of small holes are used, and varnish is dropped from the coil end portion of the stator to fill the space between the insulating paper in the slot and the stator windings. It is disclosed that the varnish is also supplied to the gap between the insulating paper and the stator core through the small holes.

Patent Document 3 points out that the tensile strength for adhesion between the varnish and the insulating paper on a flat surface is only half of the tensile strength for adhesion between the varnish and the stator winding. Here, regarding the structure in which the two stator windings are arranged so as to be surrounded by one insulating paper, and the area other than the stator winding and the insulating paper is filled with varnish in the slot, on both the front and back surfaces of the insulating paper. Unevenness is provided on both the front and back sides to increase the adhesion area to the varnish.

Japanese Unexamined Patent Publication No. 2000-012067 JP-A-2007-166731 Japanese Unexamined Patent Publication No. 2013-009493

In a structure in which one insulating paper is arranged along the inner wall surface of the slot of the stator and the stator winding is wound through the insulating paper, when varnish is dropped on the stator winding, the inner wall surface of the stator and the insulating paper are inevitably formed. The varnish is hard to turn between. Therefore, if a through hole is made in the insulating paper, the varnish can easily go around the inner wall surface of the stator core, but the through hole may reduce the insulation between the stator core and the stator winding, and the insulating paper The rigidity is lowered and the assembling property to the slot is lowered. Therefore, a rotary electric machine using insulating paper that secures electrical insulation between the stator core and the stator windings, secures rigidity that affects assembling property, and allows varnish to easily rotate between the inner wall surface of the slot. Stator is required.

The stator of the rotary electric machine according to the present disclosure includes an annular back yoke, a plurality of teeth protruding inward from the back yoke, a stator core including a plurality of slots which are spaces between adjacent teeth, and the teeth of the stator core. A plurality of grooves, which are arranged between the wound stator winding and the inner wall surface of the slot and the stator winding, and which are oblique from one end face side in the axial direction of the stator core to the other end face side, are formed in the slot. The insulating paper provided only on the surface facing the inner wall surface and the varnish impregnated between the stator core, the insulating paper, and the stator windings are provided, and the plurality of grooves have a groove depth and the thickness of the insulating paper. It is set in the range of 0.3 to 0.5 times, and the groove width is less than (1/2) of the pitch of the plurality of grooves measured along the longitudinal direction when the insulating paper is unfolded. , At least one groove is set in a range including (1/3) of the groove pitch, and at least one groove is in contact with the stator winding through the insulating paper, and one winding of the stator winding. At least one groove is in contact with each other, the varnish is housed in at least a part of the groove, the inner surface of each slot is covered with only one insulating paper, and the plurality of grooves are the diameters of the slots in the insulating paper. A plurality of grooves are provided other than the radial inner end of the insulating paper, including a groove passing through a portion covering the outer end face of the direction, and one end of the insulating paper in the axial direction and the other. The insulating paper contains two or more grooves that open at both ends, and the thickness of the grooved portion is thinner than the thickness of the non-grooved portion .

According to the stator of the rotary electric machine having the above configuration, the groove is provided only on the surface of the insulating paper facing the inner wall surface of the slot. As a result, the electrical insulation between the stator core and the stator winding can be ensured, the rigidity that affects the assembling property can be secured, and the varnish can easily rotate between the inner wall surface of the slot.

It is a figure which shows the stator of the rotary electric machine which concerns on embodiment. It is a figure which took out and developed the insulating paper in FIG. FIG. 3A is a partially enlarged view of FIG. 2, and FIG. 3B is a cross-sectional view taken along the line BB in FIG. 3A.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the following, the rotary electric machine will be described for being mounted on a vehicle, but this is an example for explanation and may be used for purposes other than mounting on a vehicle. The shapes, dimensions, the number of teeth and slots, the number of turns of the stator windings, the material, and the like described below are examples for explanation, and can be appropriately changed according to the specifications of the stator of the rotary electric machine. In the following, similar elements will be 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 stator 10 of a rotary electric machine. Hereinafter, unless otherwise specified, the stator 10 of the rotary electric machine is referred to as a stator 10. The rotary electric machine in which the stator 10 is used is a rotary electric machine mounted on a vehicle. A rotary electric machine 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, and is a three-phase synchronous type rotary electric machine. The rotary electric machine includes a stator 10 shown in FIG. 1 and a rotor (not shown) arranged on the inner peripheral side of the stator 10 at a predetermined interval.

FIG. 1 shows the axial direction, the radial direction, and the circumferential direction. The axial direction is the direction along the central axis CL of the annular center hole of the stator 10. When distinguishing between both axial directions, they are called one side and the other side. In FIG. 1, the upward direction of the paper is one side, and the downward direction is the other side. The radial direction is a radial direction passing through the central axis CL in a plane perpendicular to the axial direction, the direction toward the central axis CL side is the inner peripheral side, and the opposite side is the outer peripheral side. The circumferential direction is a direction along the circumferential direction with the central axis CL as the center.

The stator 10 includes a stator core 12 and a stator winding 20. The stator core 12 is a magnetic component having an annular center hole in which a rotor is arranged, and includes an annular back yoke 14 and a plurality of teeth 16 protruding inward from the back yoke 14. The space between adjacent teeth 16 is slot 18. In FIG. 1, the number of teeth 16 and the number of slots 18 are the same, and the number is 48, which is a multiple of 3, but a part of them is shown.

The stator core 12 is a laminated body including a back yoke 14 and teeth 16 and in which a predetermined number of annular magnetic thin plates formed into a predetermined shape so as to form a slot 18 are stacked in the axial direction. Both sides of the magnetic thin plate are electrically insulated. As the material of the magnetic thin plate, an electromagnetic steel plate, which is a kind of silicon steel plate, can be used. Instead of the laminated body of the magnetic thin plates, the stator core 12 may be formed by integrally molding the magnetic powder. The dimension between the end face 11 on one side and the end face 13 on the other side along the axial direction is the height H in the axial direction of the stator core 12.

The stator winding 20 is a three-phase distributed winding coil, and one phase winding is formed by winding around a tooth 16 across a plurality of slots 18. In FIG. 1, U1, U2, V1, V2, W1, W2 attached to the slot 18 indicate the phase of the three-phase winding inserted into the slot 18. Since each phase winding is distributed and wound in two turns, each circumference is distinguished by U1 and U2 in the case of U-phase winding, V1 and V2 in the case of V-phase winding, and W-phase winding. In the case of a line, it is W1 and W2. In a three-phase winding of this configuration, the same phase winding is wound across different slots 18 at intervals of 6 slots. In FIG. 1, the portion connecting between the different slots 18 is omitted, and the portion arranged in the slot 18 is shown as the stator winding 20.

In the stator winding 20, conductor wires of the same phase are wound in a plurality of turns along the radial direction. In the example of FIG. 1, the number of turns = 8. This is an example for explanation, and the number of turns may be other than eight. The stator winding 20 is a conductor wire with an insulating film in which a flat wire having a rectangular cross section is used as a conductor wire and an insulating film is coated around the conductor wire. In the rectangular shape of the flat line, the length of the short side is a and the length of the long side is b, and in the slot 18, the long side is arranged along the circumferential direction and the short side side is arranged along the radial direction. .. The flat wire straddles between different slots 18 by edgewise bending that bends the short side, and a predetermined stator winding 20 is formed. As the conductor strand of the conductor wire with an insulating film, a copper wire, a copper-tin alloy wire, a silver-plated copper-tin alloy wire, or the like is used. As the insulating film, a polyamide-imide enamel film is used.

The insulating paper 30 is an insulator that electrically insulates between the stator core 12 and the stator winding 20. The insulating paper 30 is formed by bending one insulating sheet having the same width as the axial height H of the stator core 12 or slightly longer along the inner wall surface of the slot 18. Both end faces in the longitudinal direction of one insulating sheet are joined together with a slight opening on the inner peripheral side of the slot 18. A plastic sheet is used as the insulating sheet for forming the insulating paper 30. As the material of the plastic sheet, polyethylene terephthalate (PET) film, polyimide film, heat-resistant amylad paper and the like can be used.

The varnish 40 is an insulating resin impregnated between the stator core 12, the insulating paper 30, and the stator winding 20. The varnish 40 is a liquid having low viscosity at room temperature, and has a gap between adjacent conductor wires of the stator winding 20, a gap between the outer peripheral surface of the stator winding 20 and the insulating paper 30, and a gap between the insulating paper 30 and the slot 18. Each penetrates into the gap between the inner wall surface and then solidifies. As a result, the inner wall surface of the slot 18, the insulating paper 30, and the stator winding 20 are fixed to each other. As the varnish 40, a resin such as an epoxy resin-based resin, a heat-resistant alkyd resin-based resin, or an unsaturated polyester resin-based resin is used.

As a method of impregnating the varnish 40 between the inner wall surface of the slot 18, the insulating paper 30, and the stator winding 20, the coil end is in a state where the stator winding 20 is wound around the stator core 12 via the insulating paper 30. The varnish 40 is dropped from the side. The coil end is a portion protruding from one end surface 11 on one side and the other end surface 13 in the axial direction of the stator core 12 when the stator winding 20 is wound across different slots 18 of the stator core 12, respectively. (The illustration is omitted in FIG. 1).

The insulating paper 30 is provided with a diagonal groove 50 on the surface 42 facing the inner wall surface of the slot 18. The groove 50 is provided so that the varnish 40 can be easily impregnated between the inner wall surface of the slot 18 and the insulating paper 30. The details of the groove 50 provided in the insulating paper 30 will be described with reference to FIGS. 2 and 3.

FIG. 2 is a diagram showing a state in which one insulating paper 30 arranged in one slot 18 is extracted and unfolded. FIG. 2A is a diagram showing the insulating paper 30 seen from the end surface 11 side on one side of the stator core 12 shown in the perspective view of FIG. The stator winding 20 is indicated by a chain double-dashed line. (B) is a view of the insulating paper 30 in the state of (a) developed so that the surface 42 facing the inner wall surface of the slot 18 can be visually recognized as the front side of the paper surface. The development relationship between (a) and (b) is shown by a chain double-dashed line. In (b), the surface of the insulating paper 30 on the other side of the paper surface is the surface facing the stator winding 20.

In the unfolded insulating paper 30 shown in FIG. 2B, the width direction is the direction along the axial direction of the stator 10, the longitudinal direction is the unfolded direction, and the direction is perpendicular to the width direction. In the state where the insulating paper 30 is arranged in the slot 18, the side 31 on one side of the insulating paper 30 in the width direction corresponds to the end surface 11 on one side of the stator core 12, and the side 33 on the other side in the width direction of the insulating paper 30. Corresponds to the other end face 13 of the stator core 12, respectively.

The groove 50 is a concave groove that is oblique between the side 31 on one side in the width direction and the side 33 on the other side in the insulating paper 30 and opens on at least one side. In other words, assuming that the length of the insulating paper 30 in the width direction is the same as the height H of the stator core 12, when the insulating paper 30 is arranged in the slot 18, the groove 50 is one end surface of the stator core 12 in the axial direction. It is a concave groove that is oblique between the 11 side and the end surface 13 side on the other side. The groove 50 is provided only on the surface 42 of the insulating paper 30 facing the inner wall surface of the slot 18 of the stator core 12, and is not provided on the surface facing the stator winding 20 which is the opposite surface of the surface 42. As a result, the rigidity of the insulating paper 30 is increased as compared with the case where the grooves 50 are provided on both sides of the insulating paper 30, and the workability of arranging the insulating paper 30 in the slot 18 of the stator core 12 and winding the stator winding 20 is improved. Assemblability is improved.

FIG. 3 is a diagram showing details of the oblique state of the groove 50. FIG. 3A is an enlarged view of a portion shown as a length (6a) in FIG. 2B. FIG. 3B is a cross-sectional view taken along the line BB of FIG. 3A. The BB line is a line that passes through the midpoint of the length H in the width direction of the insulating paper 30 and is parallel to the width direction of the insulating paper 30.

Using FIG. 3, the diagonal angle θ of the groove 50, the groove depth t _{1 with respect to the thickness t 0} of the insulating paper 30, the pitch c of the groove 50 along the longitudinal direction of the insulating paper 30, and the groove width d are set. explain. These are set in consideration of the rigidity of the insulating paper 30 and the impregnation property of the varnish 40 with respect to the groove 50.

If the groove depth t ₁ is too shallow, the varnish 40 will not penetrate sufficiently between one side 31 side and the other side 33 side of the insulating paper 30, and if it is too deep, the rigidity of the insulating paper 30 will be insufficient. Decreases. Set (t ₁ / t ₀ ) with that balance. As an example _{, (t 1} / t ₀ ) is set in the range of about 0.3 to 0.5, _{assuming that t 0} = about 0.1 mm.

The oblique angle θ of the groove 50 is the inclination angle of the groove 50 with respect to the BB line. The skew angle θ is set by the number N of the stator windings 20 in which the varnish 40 impregnated in one groove 50 is in contact with the insulating paper 30. Referring to FIG. 3A, when tan ^-1 θ = (H / a), 1 ≦ N ≦ 2, and when tan ^-1 θ = (H / 2a), 2 ≦ N ≦ 3. , Tan ^-1 θ = (H / 3a), it can be seen that 3 ≦ N ≦ 4. Since it is preferable that one groove 50 is in contact with a plurality of stator windings 20 via the insulating paper 30, it is preferable that N ≧ 2. 2 and 3 show an example of N = 2.

The pitch c of the grooves 50 defines the number M of the grooves 50 per winding of the stator winding 20. Referring to FIG. 3A, 1 ≦ M ≦ 2 when c = a, 0.5 ≦ M ≦ 1 when c = 2a, and 2 ≦ when c = 0.5a. It can be seen that M ≦ 4. Since it is preferable that at least one groove 50 corresponds to one roll, c ≦ a is preferable. 2 and 3 show the case of c = a.

_{Similar to the groove depth t 1} , if the groove width d is too narrow, the varnish 40 will not penetrate sufficiently between the side 31 on one side and the side 33 on the other side, and if it is too wide, the insulating paper The rigidity of 30 is reduced. Set (d / c) with that balance. As an example, let (d / c) <(1/2). 2 and 3 show an example of (d / c) = (1/3).

The above numerical values and the like are examples for explaining the setting guideline, and _{can be appropriately changed depending on the material of the insulating paper 30, the thickness t 0} , the height H of the stator core 12, the viscosity of the varnish 40, and the like.

In the above, the stator winding 20 is a distributed winding, but this is an example for explanation and may be a centralized winding. When performing edgewise winding of a flat wire in concentrated winding, the length a of the short side of the flat wire in concentrated winding can be considered in the same manner as in FIG. 3a. In the above, the conductor wire is a flat wire, but in some cases, a conductor wire having an elliptical cross section or a circular cross section may be used. In the case of a conductor wire having an elliptical cross section, the length of the minor axis can be considered in the same manner as in FIG. 3a. In the case of a conductor wire having a circular cross section, the diameter of the circle can be considered in the same manner as in FIG. 3a.

The stator 10 of the rotary electric machine according to the present embodiment has an annular back yoke 14, a plurality of teeth 16 protruding inward from the back yoke 14, and a plurality of slots 18 which are spaces between adjacent teeth 16. A stator core 12 including the stator core 12 is provided. Further, a stator winding 20 wound around the teeth 16 of the stator core 12 is provided. Further, a groove 50, which is arranged between the inner wall surface of the slot 18 and the stator winding 20 and is oblique from the end surface 11 side on one side in the axial direction of the stator core 12 to the end surface 13 side on the other side, is an inner wall surface of the slot 18. The insulating paper 30 provided only on the surface 42 facing the surface 42 is provided. Then, the varnish 40 impregnated between the stator core 12, the insulating paper 30, and the stator winding 20 is provided.

According to the stator 10 of the transfer electric machine having the above configuration, since the groove 50 is provided only on the surface 42 of the insulating paper 30 facing the inner wall surface of the slot 18 of the stator core 12, the insulation between the stator core 12 and the stator winding 20 is improved. Can be secured. Further, the rigidity that affects the assembling property can be secured, and the varnish 40 can easily rotate between the slot 18 and the inner wall surface.

10 (Rotary machine) stator, 11 one end face, 12 stator core, 13 other end face, 14 back yoke, 16 teeth, 18 slots, 20 stator windings, 30 insulating paper, 31 one side, 33 other Sides, 40 varnishes, 42 faces (opposing the inner wall of the slot), 50 grooves.

Claims (1)

An annular back yoke, a plurality of teeth protruding inward from the back yoke, and a stator core including a plurality of slots that are spaces between the adjacent teeth.
A stator winding wound around the teeth of the stator core, and
A plurality of grooves, which are arranged between the inner wall surface of the slot and the stator winding and are oblique from one end face side in the axial direction of the stator core to the other end face side, face the inner wall surface of the slot. Insulating paper provided only on the surface and
With the varnish impregnated between the stator core, the insulating paper, and the stator windings,
With
The plurality of said grooves
The groove depth is set in the range of 0.3 to 0.5 times the thickness of the insulating paper.
The groove width is less than (1/2) of the pitch of the plurality of grooves measured along the longitudinal direction of the insulating paper when unfolded, and includes at least a length of (1/3) of the pitch of the grooves. It is set in the range and
Through the insulating paper
At least one of the grooves is in contact with the stator winding, and at least one of the grooves is in contact with each winding of the stator winding .
The varnish is contained in at least a part of the groove.
The inner surface of each of the slots is covered with only one insulating paper.
The plurality of grooves include a groove that passes through a portion of the insulating paper that covers the radial outer end face of the slot.
The plurality of grooves include two or more grooves provided at other than the radial inner end of the insulating paper and opened at both one end and the other end of the insulating paper in the axial direction.
The insulating paper is a stator of a rotary electric machine in which the thickness of the portion where the groove is formed is thinner than the thickness of the portion where the groove is not formed.

Images