JP7586872B2 - Stator manufacturing method and stator manufacturing device - Google Patents

Description

The present invention relates to a stator manufacturing method and a stator manufacturing device.

Conventionally, a stator is known in which the straight sections of multiple segment coils are inserted into the slots of a stator core so that they are arranged in multiple layers in the radial direction, and the coil end sections are formed by bending the straight sections protruding from one end face of the stator core (see, for example, Patent Document 1).

In the coil end section, the ends of a pair of radially adjacent straight sections are welded together to join them. When joining, the ends of the multiple straight sections that make up the coil end section are clamped and supported from the circumferential direction by a clamping jig, and are aligned radially in pairs. This allows the welding work to be carried out efficiently.

Patent No. 6549872

In general, the length of the slot along the radial direction of the stator core is made longer than the length when all the straight sections to be inserted into the slot are bundled and arranged in the radial direction of the stator core, in order to make it easier to insert the multiple straight sections of the segment coil. Even when all the straight sections are inserted into the slot, a small gap is formed in the slot. When the clamping jig clamps the straight sections, the clamped segment coil is pulled in the circumferential direction of the stator core, which may cause the straight sections to lose their upright position in the slot and fall in the radial direction. When the upright position of the straight sections is disturbed, the corners of the fallen straight sections may hit other straight sections, damaging the insulating coating that covers the surface of the segment coil and reducing the precision of the stator.

The present invention aims to provide a stator manufacturing method and device that can join the straight sections of multiple segment coils mounted in the slots of a stator core without disturbing their upright position, thereby improving the precision of the stator.

(1) The method of manufacturing a stator according to the present invention is a method of manufacturing a stator including a stator core (e.g., stator core 2 described later) having a stator coil (e.g., stator core 2 described later) and a coil end portion (e.g., coil end portion 300 described later) formed by straight portions (e.g., straight portions 31 described later) of a plurality of segment coils (e.g., segment coils 30 described later) that are inserted radially (e.g., in the Y direction described later) into slots (e.g., slots 22 described later) of the stator core and that protrude from one end face (e.g., end face 2b described later) of the stator core. This is a method for manufacturing a stator (e.g., stator 1 described below) that joins the ends of a pair of radially adjacent straight sections (e.g., rising section 312 described below) in the slot in the coil end section, in which the ends are joined by supporting the vicinity of the ends of the straight sections arranged in the radial direction of the stator core from the circumferential direction (e.g., X direction described below) while expanding the width between at least one of the layers of the straight sections in the coil end section in the radial direction.

(2) In the method for manufacturing a stator described in (1) above, the gap between at least one of the layers may be radially expanded by inserting an annular spacer member (e.g., spacer member 5 described below) from one end face side of the stator core between the layers.

(3) The stator manufacturing apparatus according to the present invention is for a stator (e.g., stator 1 described below) in which a coil end portion (e.g., coil end portion 300 described below) is formed by straight portions (e.g., straight portion 31 described below) of a plurality of segment coils (e.g., segment coils 30 described below) that are inserted radially (e.g., in the Y direction) into slots (e.g., slots 22 described below) of a stator core (e.g., stator core 2 described below) so as to be arranged in multiple layers (e.g., 1T layers to 8T layers described below) and protrude from one end face (e.g., end face 2b described below) of the stator core, and the stator manufacturing apparatus is for manufacturing a stator (e.g., stator 1 described below) in which a coil end portion (e.g., coil end portion 300 described below) is formed by straight portions (e.g., straight portion 31 described below) of a plurality of segment coils (e.g., segment coils 30 described below) that are inserted radially (e.g., in the Y direction) into slots (e.g., slots 22 described below) of the stator core and protrude from one end face (e.g., end face 2b described below), the end portions being a pair of straight portions that are radially adjacent in the slot in the coil end portion. This is a stator manufacturing device (e.g., stator manufacturing device 4 described later) that joins two straight portions (e.g., rising portion 312 described later) together, and includes an annular spacer member (e.g., spacer member 5 described later) that is inserted between at least one of the layers of the straight portions in the coil end portion from the one end face side of the stator core to radially expand the gap between the layers, and a clamping jig (e.g., clamping jig 6 described later) that supports the vicinity of the end of the straight portion arranged in the radial direction of the stator core in the coil end portion in a state in which the gap between the layers is radially expanded, from the circumferential direction (e.g., X direction described later).

(4) In the stator manufacturing device described in (3) above, the clamp jig has a pair of clamp bodies (e.g., clamp body 61 described later) that circumferentially sandwich the vicinity of the end of the straight portion, and the pair of clamp bodies each have a plurality of guide protrusions (e.g., guide protrusions 611, 612 described later) that circumferentially sandwich the vicinity of the end of the straight portion, thereby moving the ends of the pair of straight portions to be joined in the radial direction so that they approach each other, and the radial width of the guide protrusion (e.g., guide protrusion 612 described later) that is arranged at a portion corresponding to the gap between the layers that is widened by the spacer member may be larger than the radial width of the guide protrusion (e.g., guide protrusion 611 described later) that is arranged at another portion.

The present invention provides a stator manufacturing method and a stator manufacturing device that can join the straight sections of multiple segment coils mounted in the slots of a stator core without disturbing their upright posture, thereby improving the accuracy of the stator.

FIG. 2 is a perspective view of a stator according to the present embodiment. FIG. 2 is an exploded perspective view of the stator of the present embodiment. 1 is an oblique view showing how bundled segment coils are inserted into slots of a stator core in a stator of this embodiment. FIG. 2 is an oblique view showing a state in which all segment coils are inserted into the slots of the stator core in the stator of this embodiment. FIG. 1 is a diagram showing a state in which eight layers of straight portions are arranged within a slot in the stator of the present embodiment. FIG. 2 is an enlarged perspective view showing a part of a coil end portion on one end surface of the stator according to the embodiment. FIG. 1 is an exploded perspective view showing a schematic configuration of a stator manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a plan view of a spacer member according to the embodiment. 9 is a cross-sectional view taken along line AA in FIG. 8. 1 is a plan view showing a state in which a spacer member is inserted into a coil end portion of the stator of the embodiment to widen the space between layers. FIG. FIG. 2 is a perspective view showing one clamp body of the clamp jig of the present embodiment. FIG. 2 is a plan view of a clamp jig in which a pair of clamp bodies of the present embodiment are arranged opposite each other. A plan view showing the state before the straight portion of the segment coil is supported by the clamp jig of this embodiment. A plan view showing the state after the straight portion of the segment coil is supported by the clamp jig of this embodiment. 1A to 1C are diagrams illustrating the effects of the stator manufacturing method and the stator manufacturing apparatus of the present embodiment. 11A and 11B are diagrams illustrating a state in which a straight portion is tilted in a conventional stator manufacturing method. A plan view showing the state in which the ends of the straight portions of the segment coil supported by the clamping jig of this embodiment are joined together.

The stator manufacturing method and stator manufacturing device of this embodiment will be described in detail below with reference to the drawings. First, stator 1 will be described with reference to Figs. 1 to 5. Stator 1 is, for example, a stator for a rotating electric machine, and includes a stator core 2 and a group of segment coils 3 attached to the stator core 2.

The stator core 2 has an annular portion 21 made of a laminate of multiple thin core plates. The annular portion 21 has an axial hole 20 that passes through the center in the axial direction, and multiple slots 22 that are arranged around the axial hole 20 and pass through the stator core 2 in the axial direction. The slots 22 are arranged radially at regular intervals along the circumferential direction of the annular portion 21, and have narrow openings 22a that open toward the axial hole 20.

In the stator 1 and stator core 2, as shown by the arrows in the figure, the circumferential direction is the X direction in which the slots 22 are arranged. The radial direction is the Y direction along the radial direction. The axial direction is the Z direction that passes through the axial hole 20.

The segment coil group 3 is a collection of a plurality of segment coils 30. The segment coils 30 are formed, for example, by forming a conductor made of a rectangular wire with a cross section into an approximately U-shape. As shown in Figs. 2 and 3, each segment coil 30 has a pair of parallel straight sections 31 and a connecting section 32 that connects one end of the pair of straight sections 31. In this embodiment, as shown in Fig. 3, four segment coils 30 are stacked and bundled in the radial direction of the stator core 2. The four bundled segment coils 30 are attached to the stator core 2 by inserting one straight section 31 and the other straight section 31 into two slots 22, 22 along the axial direction, respectively. The straight sections 31, 31 of each segment coil 30 inserted into the slot 22 protrude upright from the end face (one end face) 2b opposite to the end face 2a on the insertion side of the stator core 2, as shown in Fig. 4.

In this embodiment, the straight portions 31 of four bundled segment coils 30 and the straight portions 31 of four bundled segment coils 30 are inserted into one slot 22 so as to be arranged in the radial direction of the stator core 2. As a result, eight straight portions 31 are arranged in the radial direction in each slot 22, as shown in FIG. 5. Among the eight straight portions 31 in each slot 22, multiple straight portions 31 arranged at the same radial position of the stator core 2 form one layer. Therefore, in the stator core 2 of this embodiment, a segment coil group 3 having an eight-layer structure consisting of 1T layers to 8T layers is mounted from the radial inside to the radial outside.

The length of the slot 22 along the radial direction of the stator core 2 is longer than the length when the eight straight parts 31 are bundled and arranged in the radial direction of the stator core 2. Therefore, even if the eight straight parts 31 are inserted into the slot 22 so as to be arranged in the radial direction, there is a gap in the slot 22 through which the straight parts 31 can move slightly. Note that an insulating member is inserted into each slot 22 of the stator core 2, but the insulating members are omitted in each figure.

After all the segment coils 30 are inserted into all the slots 22 of the stator core 2, the straight portions 31 protruding from the end faces 2b of the stator core 2 are bent in the circumferential direction of the stator core 2 to form the coil end portions 300, as shown in FIG. 6. Each straight portion 31 forming the coil end portion 300 has an inclined portion 311 bent diagonally in the circumferential direction of the stator core 2, and a rising portion 312 bent so that the tip side of the inclined portion 311 rises in the axial direction of the stator core 2.

The slanted portions 311 of the straight portions 31 arranged at the same radial position in each slot 22 are bent so that they are bent in the same direction, and the slanted portions 311, 311 of the straight portions 31, 31 adjacent in the radial direction are bent so that they are bent in opposite directions. The rising portions 312, 312 of the bent straight portions 31, 31 of the same phase segment coils 30 are aligned in the radial direction and welded and joined by a welding torch 42 (see Figure 7) in the stator manufacturing device 4 described later.

As shown in FIG. 6, the entire segment coil 30 is covered with a resin insulating coating 3A, but only the tip 31a of each straight portion 31 of the segment coil 30 has the insulating coating 3A completely peeled off over a predetermined length. This forms a coating peeled portion 3B at each tip 31a of the straight portion 31. The rising portion 312 is formed only by the coating peeled portion 3B.

Next, the configuration of the stator manufacturing device 4 for manufacturing the stator 1 by joining each rising portion 312 of the coil end portion 300 protruding from the end surface 2b of the stator core 2 will be described with reference to Figures 7 to 12.

As shown in FIG. 7, the stator manufacturing device 4 includes a fixing jig 41 for fixing the stator 1, a welding torch 42 for welding the pair of raised portions 312, 312 by TIG (Tungsten Inert Gas) welding or the like, a spacer member 5, and a clamping jig 6.

The spacer member 5 is formed in an annular shape from a metal material such as stainless steel, and is inserted between the layers of the coil end portion 300 protruding from the end face 2b of the stator core 2 by a lifting device (not shown) or by manual insertion by an operator. As shown in Figures 8 and 9, the spacer member 5 has a spacer body 51 and multiple ears 52.

The spacer body 51 is formed in a cylindrical shape. The axial length (Z direction) of the spacer body 51 is slightly shorter than the axial protruding height of the coil end portion 300 protruding from the end face 2b of the stator core 2. Therefore, when the spacer member 5 is inserted between the layers of the coil end portion 300 so that its tip abuts against the end face 2b of the stator core 2, each rising portion 312 of the coil end portion 300 protrudes beyond the spacer member 5, ensuring a clamping portion by the clamping jig 6 described below.

The radial thickness of the spacer body 51 is equal to or greater than the thickness of the gap left in the slot 22 with the eight straight portions 31 inserted. Therefore, when the spacer body 51 is inserted between the layers of the coil end portion 300, the two layers of the coil end portion 300 are pressed radially inward and outward, respectively, of the slot 22. As shown in FIG. 9, the lower end portion 51a of the spacer body 51 is tapered to improve the ease of insertion between the layers of the coil end portion 300.

The ears 52 are disposed at the upper end of the spacer body 51 and extend radially outward. The spacer member 5 of this embodiment has four ears 52 disposed at 90 degree angles around the spacer body 51. The ears 52 are fixed when the spacer member 5 is attached to a lifting device (not shown), or are handled by an operator. The ears 52 are each formed in a narrow rectangular plate shape. In more detail, the circumferential width of the ears 52 is wide enough to fit between the rising portions 312, 312 adjacent to each other in the circumferential direction of the coil end portion 300.

The spacer member 5 is inserted between any of the layers of the coil end portion 300 from the end face 2b side of the stator core 2. As shown in FIG. 10, in this embodiment, the spacer member 5 is inserted between the 4T layer and the 5T layer of the coil end portion 300 consisting of eight straight portions 31. However, the spacer member 5 only needs to be inserted between at least one layer of the coil end portion 300, and may be inserted between two or more layers.

Each ear 52 of the spacer member 5 inserted between the layers of the coil end portion 300 is positioned between the rising portions 312, 312 adjacent in the circumferential direction of the stator core 2. At this time, the spacer body 51 of the spacer member 5 presses the 1T to 4T layers radially inward within the slot 22, and the 5T to 8T layers radially outward within the slot 22. As a result, the eight-layer straight portion 31 of the segment coil 30 inserted into the slot 22 is divided into two layers of four layers each, and the space between the two layers is expanded in the radial direction of the stator core 2 by the spacer body 51 of the spacer member 5.

The clamp jig 6 is composed of a pair of clamp bodies 61, 61. The pair of clamp bodies 61, 61 have a symmetrical structure, so one clamp body 61 will be described with reference to Figure 11. The clamp body 61 is formed in a long rod shape along the radial direction of the stator core 2 from a metal material such as stainless steel. Mounting parts 62, 62 are integrally provided at both ends in the longitudinal direction of the clamp body 61 for mounting to a clamp drive device (not shown) with bolts 63 (see Figures 13 to 15).

The clamp body 61 has a plurality of guide protrusions 611, 612 on the surface 61a facing the other clamp body 61. More specifically, two guide protrusions 611 and one guide protrusion 612 are integrally formed on the surface 61a of the clamp body 61. One guide protrusion 612 is disposed at approximately the center in the longitudinal direction of the clamp body 61. Specifically, the guide protrusion 612 is disposed at a position corresponding to directly above the spacer body 51 of the spacer member 5 inserted into the coil end portion 300. The guide protrusions 611 are disposed on both sides of the guide protrusion 612 in the longitudinal direction of the clamp body 61 at a predetermined interval.

The guide protrusions 611, 612 each have two inclined surfaces in the radial direction of the stator core 2, and are formed in a substantially triangular or trapezoidal shape that tapers toward the other clamp body 61. As shown in FIG. 12, the width W1 of the guide protrusion 612 along the radial direction of the stator core 2 is larger than the width W2 of the two guide protrusions 611, 611. At both ends of the clamp body 61 near the mounting parts 62, 62, inclined surfaces 613, 613 facing one of the inclined surfaces of the guide protrusion 611 are formed at a predetermined interval outside the two guide protrusions 611, 611. As a result, as shown in FIG. 11, a housing groove 614 is formed between the guide protrusion 611 and the inclined surface 613 on the surface 61a of the clamp body 61 and between the guide protrusion 611 and the guide protrusion 612 on the surface 61a of the clamp body 61, which houses the pair of clamped rising parts 312, 312 while guiding them.

As shown in FIG. 13, the clamp jig 6 is attached from above the coil end portion 300 after the spacer member 5 is inserted, with the pair of clamp bodies 61, 61 positioned so that the guide protrusions 611, 612 face each other. In more detail, the pair of clamp bodies 61, 61 are positioned so that they can sandwich the vicinity of the ends of the rising portions 312 of the eight straight portions 31 arranged along the radial direction of the stator core 2 from both sides in the circumferential direction of the stator core 2. The central guide protrusions 612 of each clamp body 61, 61 are positioned approximately directly above the spacer body 51 inserted between the 4T layer and the 5T layer of the coil end portion 300.

As shown in FIG. 14, when the pair of clamp bodies 61, 61 are closed by the driving of a clamp driving device (not shown), the eight rising portions 312 sandwiched between the pair of clamp bodies 61, 61 are sandwiched two by two between the guide protrusion 611 and the inclined surface 613 and between the guide protrusion 611 and the guide protrusion 612. The two rising portions 312 are guided by the inclined surfaces and inclined surfaces 613 of the guide protrusions 611, 612, move radially toward each other, and are accommodated in the accommodation groove 614. As a result, the eight rising portions 312 are aligned in the radial direction of the stator core 2 in bundles of two.

The width W1 of the guide protrusion 612, which is positioned approximately directly above the spacer body 51, is greater than the width W2 of the guide protrusion 611, so the rising portion 312 of the straight portion 31 of the 4T layer and the rising portion 312 of the straight portion 31 of the 5T layer, which are positioned on either side of the spacer body 51, are guided by the guide protrusion 612 and smoothly widen in the same way as the straight portion 31 in the slot 22.

Because the spacer body 51 of the spacer member 5 is inserted between the 4T layer and the 8T layer of the coil end portion 300, as shown in FIG. 15A, the straight portion 31 in the slot 22 is widened in the radial direction of the stator core 2 between the 4T layer and the 5T layer, and is pressed against the inner end and the outer end of the slot 22, respectively. Therefore, when the eight radial rising portions 312 of the stator core 2 are clamped from the circumferential direction by a pair of clamp bodies 61, 61 of the clamp jig 6, even if each segment coil 30 is pulled in the circumferential direction of the stator core 2, the straight portion 31 does not shift within the slot 22, so there is no risk of the upright posture of each rising portion 312 being disturbed.

In contrast, when the spacer member 5 is not inserted into the coil end portion 300, as shown in FIG. 15B, when the eight radially extending raised portions 312 of the stator core 2 are clamped from the circumferential direction by a pair of clamp bodies 61, 61 of the clamp jig 6 and the segment coil 30 is pulled in the circumferential direction of the stator core 2, the straight portions 31 may shift within the slots 22, causing some of the straight portions 31 to fall in the radial direction of the stator core 2. At this time, the boundary portion 3C between the insulating coating 3A and the coating peeling portion 3B may come into contact with another segment coil 30 at a corner, potentially damaging the insulating coating 3A.

After the eight rising portions 312 are clamped by the clamping jig 6, the two aligned rising portions 312, 312 are welded by the welding torch 42. As a result, as shown in FIG. 16, the two rising portions 312, 312 are joined by forming a welded portion 100 at their tips. In the same manner, all the two rising portions 312, 312 arranged in the radial direction of the stator core 2 are joined together to obtain the stator 1.

The stator manufacturing method and stator manufacturing device 4 according to this embodiment provide the following advantages:

The manufacturing method of the stator according to this embodiment is a manufacturing method of the stator 1 in which the coil end portion 300 is formed by the straight portions 31 of the multiple segment coils 30 that are inserted into the slots 22 of the stator core 2 so as to be arranged in multiple layers in the radial direction and protruding from one end face 2b of the stator core 2, and in which the rising portions 312, 312 that are the ends of a pair of radially adjacent straight portions 31, 31 in the slots 22 in the coil end portion 300 are joined together, and in which the ends of the straight portions 31 arranged in the radial direction of the stator core 2 are supported from the circumferential direction in the vicinity of the ends in the state where the space between at least one of the multiple layers of straight portions 31 in the coil end portion 300 is expanded in the radial direction, and the manufacturing method of the stator 1 is such that the ends are joined together.

As a result, at least one layer of the straight section 31 in the slot 22 is widened in the radial direction of the stator core 2 and pressed against the inner and outer ends of the slot 22, respectively. Therefore, even if the vicinity of the end of the straight section 31, i.e., the vicinity of the end of the rising section 312, is pinched, the straight section 31 will not shift within the slot 22, and there is no risk of the upright position of the rising section 312 of each straight section 31 being disturbed. Therefore, the straight section 31 of the segment coil 30 can be joined in an upright position without being disturbed, and the precision of the stator 1 can be improved.

In the manufacturing method of the stator 1 according to this embodiment, an annular spacer member 5 is inserted between at least one layer from one end face 2b of the stator core 2, thereby widening the gap between the layers in the radial direction.

This allows the straight section 31 in the slot 22 to be easily widened in the radial direction of the stator core 2, reliably preventing the upright position from being disturbed.

The stator manufacturing device according to this embodiment is a stator manufacturing device 4 that joins the rising portions 312, 312, which are the ends of a pair of radially adjacent straight portions 31, 31 in the slot 22 in the coil end portion 300 in a stator 1 in which the coil end portion 300 is formed by the straight portions 31 of the multiple segment coils 30 that are inserted into the slot 22 of the stator core 2 so as to be arranged in multiple layers in the radial direction and protruding from one end face 2b of the stator core 2. The stator manufacturing device 4 includes an annular spacer member 5 that is inserted between at least one of the multiple layers of straight portions 31 in the coil end portion 300 from the one end face 2b side of the stator core 2 to radially expand the gap between the layers, and a clamping jig 6 that supports from the circumferential direction the vicinity of the end of the straight portion 31 arranged in the radial direction of the stator core 2 in the coil end portion 300 in a state in which the gap between the layers is expanded in the radial direction, i.e., the vicinity of the end of the rising portion 312.

This allows at least one layer of the straight section 31 in the slot 22 to be easily widened in the radial direction of the stator core 2, and each layer is pressed against the inner and outer ends of the slot 22. Therefore, even if the vicinity of the end of the straight section 31, i.e., the vicinity of the end of the rising section 312, is clamped by the clamp jig 6, the straight section 31 will not shift within the slot 22, and there is no risk of the upright position of the rising section 312 of each straight section 31 being disturbed. Therefore, the straight section 31 of the segment coil 30 can be joined in a state in which the disturbance of the upright position is reliably prevented, and the precision of the stator 1 can be improved.

In the stator manufacturing device 4 according to this embodiment, the clamp jig 6 has a pair of clamp bodies 61, 61 that circumferentially sandwich the vicinity of the end of the straight portion 31, i.e., the vicinity of the end of the rising portion 312, and the pair of clamp bodies 61, 61 each have a plurality of guide protrusions 611, 612 that circumferentially sandwich the vicinity of the end of the straight portion 31, i.e., the vicinity of the end of the rising portion 312, which are the ends of the pair of straight portions 31 to be joined, and move the rising portions 312, 312 radially so that they approach each other. Of the plurality of guide protrusions 611, 612, the radial width W1 of the guide protrusions 612 arranged at the portion corresponding to the gap between the layers widened by the spacer member 5 is greater than the radial width W2 of the guide protrusions 611 arranged at other portions.

As a result, the space between the rising portions 312, 312 of the straight portions 31, 31 arranged on either side of the spacer member 5 is also guided by the guide protrusions 612 and smoothly widened in the same way as the straight portions 31, 31 in the slot 22.

1 Stator 2 Stator core 2b End face (one end face)
22 slot 30 segment coil 31 straight portion 300 coil end portion 4 stator manufacturing device 5 spacer member 6 clamp jig 61 clamp body 611, 612 guide projection

Claims (1)

A stator manufacturing device for a stator in which coil end portions are formed by straight portions of a plurality of segment coils that are inserted into slots of a stator core so as to be arranged in multiple layers in the radial direction and protruding from one end face of the stator core, the device joining ends of a pair of straight portions that are adjacent to each other in the radial direction in the slot in the coil end portion,
an annular spacer member that is inserted between at least one of the linear portions of the plurality of layers in the coil end portion from the one end face side of the stator core to radially expand the gap between the layers;
a clamping jig that supports the coil end portion of the stator core by clamping the ends of the linear portions arranged in the radial direction of the stator core in the coil end portion in a state in which the interlayer space is expanded in the radial direction from both sides in the circumferential direction;
Equipped with
The clamp jig has a pair of clamp bodies that circumferentially sandwich the vicinity of the end of the straight portion,
The pair of clamp bodies each include a plurality of guide protrusions that circumferentially sandwich the vicinity of the end of the straight portion, thereby moving the ends of the pair of straight portions to be joined in a radial direction so that they approach each other,
a radial width of the guide protrusions arranged at a portion corresponding to the gap between the layers that is widened by the spacer member is larger than a radial width of the guide protrusions arranged at other portions,

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