JP5846081B2 - Stator coil structure of rotating electrical machine - Google Patents

Description

  The present invention relates to a stator coil structure of a rotating electrical machine comprising a unit coil configured by winding a winding between specific slot sets, and a crossover between other slots so as to connect the two unit coils. About.

  A stator coil of a rotating electrical machine usually has a plurality of unit coils and a connecting wire connecting the unit coils. Each unit coil is wound between two specific slots, specifically, between two adjacent slots in the case of concentrated winding, or between two slots separated by at least three slots in the case of distributed winding. Configured by turning. Patent Documents 1 and 2 disclose a stator coil structure of a rotating electrical machine constituted by distributed winding.

  Of the unit coil and the connecting wire, a portion protruding from the end of the stator core is a so-called coil end. In this coil end portion, the unit coil and the jumper wire protrude from the end of the slot and extend in the stator axial direction, and then in the stator circumferential direction (more precisely, the oblique direction that advances in the stator axial direction as it advances in the stator circumferential direction) ) To the other slot.

JP 2000-350425 A JP 2012-016195 A

  However, the jumper wire is once bent in the radial direction after protruding from the end of the slot, and then bent in the oblique direction. Therefore, the crossover is bent in an oblique direction at a higher position than the unit coil.

  Here, conventionally, the bending angle in the oblique direction is often the same between the crossover and the unit coil. On the other hand, the crossover position is higher at the position of bending in the oblique direction. For this reason, when the wire travels in the circumferential direction after bending in an oblique direction, the crossover wire is higher than the unit coil. As a result, the height of the entire coil end is uneven. Such uneven coil end height makes it difficult to adjust the shape of the coil end in the stator coil manufacturing process, or prevents the smooth flow of refrigerant supplied to the stator coil when the rotating electrical machine is driven. It was.

  In order to avoid such a problem, after projecting the unit coil from the end of the slot, the distance traveled in the stator axial direction is lengthened, and the stator axial direction position when bending in the oblique direction is determined by the crossover and the unit coil. The same thing can be considered. In this case, since the height of the bending position and the bending angle are the same also in the connecting wire and the unit coil, the height of the connecting wire and the unit coil can be made uniform. However, in this case, an extra winding is required as much as the distance of the unit coil in the axial direction of the stator is increased, leading to an increase in material costs.

  Therefore, an object of the present invention is to provide a stator coil structure of a rotating electrical machine that can make the coil end height uniform while suppressing an increase in the amount of winding used.

  A stator coil structure of a rotating electrical machine according to the present invention includes a unit coil configured by winding a winding between specific slots, and a crossover that crosses between other slots to connect two unit coils. In the stator coil structure of a rotating electrical machine, the unit coil is bent at a first angle so as to go from the end of the slot toward the top of the unit coil at a position away from the stator axial direction and the circumferential direction. The connecting wire extends from the end of the slot in the axial direction of the stator, and is at a position apart from the axial direction of the stator and in the circumferential direction and at the same height as the top of the unit coil. It is bent at a second angle to be directed, and the first angle is larger than the second angle.

  In a preferred aspect, the crossover wire also bends in the stator radial direction after extending in the stator axial direction until it is bent toward the top. In another preferred aspect, the stator axial position where the unit coil bends toward the top is lower than the stator axial position where the connecting wire bends toward the top.

  In this invention, since the top part of the unit coil is made the same height as the top part of the connecting wire, the height of the coil end can be made uniform. In addition, since the unit coil is bent toward the top at an angle larger than the crossover wire, the unit coil is the same as the top of the crossover wire without increasing the distance extending in the axial direction after protruding from the slot end. Can reach the top of the height. As a result, according to the present invention, the coil end height can be made uniform while suppressing an increase in the amount of winding used.

It is a schematic perspective view of the stator which is embodiment of this invention. It is a figure which shows the structure of one unit coil. It is an image figure of the unit coil in this embodiment, and a crossover. It is an image figure of the unit coil in a prior art, and a crossover. It is an image figure of the unit coil in another prior art, and a crossover. It is an image figure of the unit coil in another prior art, and a crossover. It is a figure which shows the coil end shape in the stator coil structure shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view of a stator 10 of a rotating electrical machine that is an embodiment of the present invention. As is well known, the stator 10 includes a stator core 12 and a stator coil 20 wound around the stator core 12. In the case of a three-phase motor, the stator coil 20 is provided with three phases of the U phase, the V phase, and the W phase. However, in FIG. 1, only the stator coil 20 for one phase is shown for ease of viewing. .

  A plurality of slots 14 are arranged in the circumferential direction on the inner periphery of the stator core 12, and a stator coil 20 is wound between the pair of slots 14. The stator coil 20 is configured by connecting a plurality of unit coils that are displaced in the circumferential direction of the stator by windings called crossover wires. Each unit coil is configured by winding a winding between a specific set of slots. At this time, the winding is wound between two adjacent slots, and concentrated winding, and the winding is wound between two slots separated by three slots or more. In this embodiment, distributed winding is employed. In the present embodiment, a rectangular wire coil having a substantially rectangular cross section, such as a conductor segment, is used as the winding for improving the occupation ratio. However, as a matter of course, a round wire coil having a circular cross section may be used instead of the flat wire coil.

  FIG. 2 is a diagram illustrating a configuration of one unit coil 22, and is a schematic diagram when the stator 10 is viewed from the stator axial direction. In FIG. 2, the thick solid line indicates a winding that crosses between the slots 14 on one end face of the stator core 12, and the alternate long and short dash line indicates a winding that crosses between the slots 14 on the other end face of the stator core 12. Further, in the following description, a winding portion that proceeds in the slot 14 among the windings constituting the unit coil 22 is referred to as an “in-slot winding portion”, and the alphabet W includes R or L indicating left and right, and a diameter. The code | symbol which provided the number which shows a direction position is used. Further, a winding portion that traverses between the slots 14 is referred to as a “transverse winding portion”, and a symbol in which a number indicating the winding order is added to the alphabet W is used.

  The windings constituting the unit coil 22 repeat the flow of proceeding in the axial direction in one of the left and right slots 14 and projecting from the end face of the stator core 12 and then proceeding in the circumferential direction and entering the other slot 14. At this time, the radial position in the slot 14 shifts to the inner peripheral side as the winding proceeds.

  For example, in the example of FIG. 2, at the outermost peripheral position of the right slot (hereinafter referred to as “right slot 14R”), the winding advances from the front side of the drawing to the back side to form the in-slot winding portion WR1. And protrudes from the other end surface of the stator core 12. The winding projecting to the other end surface then proceeds to the left in the circumferential direction, forms a transverse winding W1, and reaches the outermost peripheral position of the slot on the left side of the drawing (hereinafter referred to as “left slot 14L”). The winding advances in the left slot 14 </ b> L from the back side to the front side at the outermost peripheral position, forms the in-slot winding portion WL <b> 1, and projects from one end surface of the stator core 12. Thereafter, the winding advances to the right side in the circumferential direction and radially inward to form the transverse winding portion W2, and is located on the inner peripheral side of the slot inner winding portion WR1 located on the outermost periphery of the right slot 14R. Reach position. The winding that has reached the right slot 14R proceeds in the right slot 14R from the front side to the back side in the drawing to form the in-slot winding portion WR2. In the following, the transverse winding portion that advances from the right to the left, the winding portion in the slot that advances in the left slot 14L, the transverse winding portion that advances from the left to the right, and the winding portion in the slot that advances in the right slot 14R are repeated. The winding is wound so as to be configured. Finally, when the winding is wound until it protrudes from one end face of the left slot 14L, the unit coil 22 is completed.

  The winding constituting the unit coil 22 may be constituted by a single continuous winding, or a plurality of conductors (for example, a conductor segment formed to have a length corresponding to one turn). You may be comprised so that it may connect with a book.

  One stator coil 20 is configured by connecting a plurality of unit coils 22 that are shifted in the circumferential direction with windings called crossover wires 24. The crossover 24 is connected to the winding start or winding end, which is the outermost or innermost end of the unit coil 22, and crosses between the slots 14. The connecting wire 24 connected to the outermost peripheral end of the unit coil 22 is connected to the outermost peripheral end of the other unit coil 22, and the connecting wire 24 connected to the innermost peripheral end of the unit coil 22 is connected to the other unit coil 22. 22 is connected to the innermost peripheral end. In other words, the connecting wire 24 is configured such that the position in the stator radial direction does not shift between the start point and the end point. For this reason, if the crossover line 24 has a linear shape connecting the start point and the end point thereof, interference with other crossover lines 24 occurs.

  In order to avoid such interference, a part of the crossover wire 24 is offset in the stator radial direction. For example, the connecting wire 24 located at the outermost periphery protrudes from the end of the slot 14 and proceeds in the stator axial direction, and then bends toward the outer periphery. The connecting wire 24 bent to the outer peripheral side is then bent in the circumferential direction, advanced a certain distance in the circumferential direction, and then bent toward the inner peripheral side. Due to the bending toward the inner peripheral side, the crossover 24 returns to the original radial position. Then, the crossover wire 24 again proceeds in the circumferential direction and is connected to another unit coil 22.

  On the other hand, as described above, the winding constituting the unit coil 22 is displaced in the radial direction as it is wound. For this reason, in the transverse winding portion that traverses between the slots in the unit coil 22, there is no need for a temporary offset in the radial direction, and consequently, a bending in the radial direction. In other words, the crossover wire 24 and the unit coil 22 (transverse winding portion) are different in the number of bends when crossing between the slots.

  Conventionally, the height of the coil end has become uneven due to the difference in the number of bendings. This will be described with reference to FIGS. FIG. 6 is an image view of the unit coil 22 and the connecting wire 24 in the prior art, and is a schematic view when the stator 10 is viewed from the inner peripheral surface side. FIG. 7 is a view showing the shape of the coil end 50, and is a schematic view of a radial cross section of the stator 10. When the stator 10 is viewed from the inner periphery, a larger number of windings should be visible than in the state illustrated in FIG. 6, but here, the connecting wire 24 protruding from one slot 14 and the other wires Only two windings constituting the unit coil 22 protruding from the slot 14 are shown.

  The crossover wire 24 and the unit coil 22 both project from the end of the slot 14 and then proceed in the stator axial direction. Then, it is bent toward the top portions 26 and 28 at the bending positions 30 and 32, respectively. The top portions 26 and 28 are portions where the height in the stator axial direction is the highest among the windings crossing between the slots 14, and are positions shifted in the stator axial direction and the circumferential direction as viewed from the protruding position from the slot 14. It is in. Therefore, the crossover wire 24 and the unit coil 22 are bent in the circumferential direction and in the stator axial direction (in the oblique upward direction in the figure) so as to go to the top portions 26 and 28 after proceeding in the stator axial direction.

  However, as described above, in order to avoid interference with other windings, the crossover wire 24 extends in the radial direction after protruding from the end of the slot 14 in the stator axial direction and then bending toward the top. Also bends. Since it is difficult to bend the connecting wire 24 made of a winding having a certain thickness at a right angle, the bending in the radial direction is performed at a certain angle. As a result, the connecting wire 24 also advances in the stator axial direction from the start of bending in the radial direction to the end of bending. In FIG. 6, a range indicated by a symbol T indicates a range in which bending in the radial direction is performed.

  As described above, the connecting wire 24 travels further in the stator axial direction by at least the distance T required for bending in the radial direction, and then bends toward the top portion 28 at the bending position 32. Therefore, the crossover 24 is bent toward the top portion 28 at a bending position 32 that is higher than the bending position 30 of the unit coil 22 by a distance T or more. Here, hereinafter, the angle when the unit coil 22 is bent toward the top portion 26 is referred to as “first angle α”, and the angle when the crossover 24 is bent toward the top portion 28 is referred to as “second angle β. " The first and second bending angles α and β are conventionally the same (α = β). For this reason, even if the circumferential distance traveled after bending is the same, the position in the stator axial direction is higher in the connecting wire 24 than in the unit coil 22. And as a result, when it sees in the coil end 50 whole, as shown in FIG. 7, it became the shape with the unevenness | corrugation from which only the innermost periphery and the outermost periphery become high.

  Here, in the manufacturing process of the stator coil 20, the coil end 50 is adjusted to a desired shape by applying pressure using a jig made according to the desired shape. As shown in FIG. 7, in the case of the uneven stator coil 20, there is a problem that the shape of the jig becomes complicated or the work for adjusting the shape becomes difficult. Further, when driving the rotating electrical machine, the refrigerant is normally discharged toward the coil end 50 for heat dissipation. If the height of the coil end 50 is not uniform, the refrigerant smoothly flows to the entire coil end 50. There was also a risk that the cooling efficiency would decrease without flowing.

  Therefore, in order to solve such a problem, as shown in FIG. 4, in the unit coil 22, the distance of traveling in the stator axial direction may be increased, and the heights of the top portions 26 and 28 may be made uniform by the crossover 24 and the unit coil 22. Conceivable. However, in this case, there arises a new problem that the number of windings (copper) increases by the amount that the unit coil 22 is extended in the axial direction.

  As another method, as shown in FIG. 5, after the unit coil 22 is bent toward the top portion 26, the height of the unit coil 22 reaches the same height as the top portion 28 of the connecting wire 24. Until then, it may be possible to continue extending the unit coil 22 obliquely upward. According to such a form, the heights of the top portions 26 and 28 can be made uniform while suppressing an increase in the winding amount. However, in this case, since the circumferential distance traveled until reaching the top portion 26 becomes long, the configuration is often not applicable in relation to the inter-slot distance traversed by the unit coil 22.

  Therefore, in the present embodiment, as shown in FIG. 3, the bending angles α and β toward the top portions 26 and 28 are changed between the crossover wire 24 and the unit coil 22 (α ≠ β), and the top portions 26 and 28. Aligned the height. In other words, in this embodiment, the unit coil 22 protrudes from the end of the slot 14 and slightly advances in the stator axial direction, and then bends toward the top 26 at the bending position 30. At this time, the bending angle of the unit coil 22, that is, the first angle α is set to be larger than the bending angle β of the connecting wire 24, that is, the second angle β (α> β). In other words, the unit coil 22 heads from the bent position to the top at a steeper angle than the connecting wire 24. Therefore, even if the distance traveled in the circumferential direction is the same for the unit coil 22 and the connecting wire 24, the distance traveling in the axial direction is longer for the unit coil 22 than for the connecting wire 24. As a result, even when the bending position 32 of the connecting wire 24 is higher than the bending position 30 of the unit coil 22, the heights of the top portions 26 and 28 that finally reach the unit coil 22 and the connecting wire 24 are made uniform. Can do. As a result, the height of the coil ends can be made uniform, the manufacturing process of the stator coil 20 can be simplified, and the cooling efficiency can be improved.

  Further, in the present embodiment, the unit coil advances in a straight line in an oblique direction from the bending position 30 at the same low position as the conventional one (form of FIG. 6) to the top portion 26. Therefore, the present embodiment also reduces the amount of winding to be used, as compared with the conventional configuration of FIG. 4 that proceeds in the axial direction from the bent position 30 (the configuration of FIG. 6) and then proceeds obliquely toward the top portion 26. it can. As a result, the manufacturing cost of the stator coil 20 can also be reduced.

  In the present embodiment, the distributed winding in which the winding is wound between two slots 14 separated by 3 slots or more has been described as an example. However, the technique of the present embodiment is performed between two adjacent slots 14. You may apply to the concentrated winding which winds a coil | winding.

  10 stators, 12 stator cores, 14 slots, 20 stator coils, 22 unit coils, 24 crossovers, 26, 28 tops, 30, 32 bent positions, 50 coil ends.

Claims (3)

A stator coil structure of a rotating electrical machine comprising a unit coil configured by winding a winding between specific slots, and a jumper crossing between other slots to connect the two unit coils,
The unit coil is bent at a first angle so as to go from the end of the slot toward the top of the unit coil at a position apart in the stator axial direction and the circumferential direction,
The crossover wire extends from the end of the slot in the stator axial direction, and is located at a position apart from the stator axial direction and the circumferential direction and at the same height as the top of the unit coil. Bend at a second angle,
The first angle is greater than the second angle;
A stator coil structure for a rotating electrical machine. A stator coil structure for a rotating electrical machine according to claim 1,
The crossover wire is also bent in the stator radial direction after extending in the stator axial direction until it is bent toward the top portion. A stator coil structure for a rotating electrical machine according to claim 1 or 2,
A stator coil structure for a rotating electrical machine, wherein a position in the stator axial direction where the unit coil is bent toward the top is lower than a position in the stator axial direction where the connecting wire is bent toward the top.

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