JP7563571B2 - Stator of rotating electrical machine - Google Patents

Description

The present invention relates to a stator for a rotating electric machine.

JP2017-208924A discloses a stator for a rotating electric machine that includes a stator core having multiple slots and a coil attached to the stator core. The coil has multiple slot coils inserted into the slots and a connection coil that connects the slot coils axially outward of the axial end face of the stator core. The slot coil is a flat conductor covered with an insulating material, and is fixed in the slot by a protrusion provided on the outer periphery of the insulating material engaging with the inner peripheral surface of the slot.

The stator in the above document has a manufacturing problem in that when inserting the slot coil into the slot, a force greater than the frictional force generated between the protrusions of the insulating material and the inner surface of the slot is required.

Therefore, the present invention aims to provide a stator that requires less force to insert a slot coil into a slot and ensures that the slot coil is securely fixed in the slot.

According to one aspect of the present invention, a stator for a rotating electric machine is provided that includes a stator core having a plurality of slots, a plurality of slot coils inserted into the slots, and separate coil ends connected to portions of the slot coils that pass through the slots and protrude from the stator core. The stator for the rotating electric machine includes a load application mechanism that applies a circumferential load, which is a load in the circumferential direction of the stator core, to the slot coils.

FIG. 1 is an exploded perspective view of a stator according to an embodiment. FIG. 2 is a diagram showing the shape of the connection member. FIG. 3 is a schematic diagram of a separate coil end. FIG. 4 is a plan view showing a connected state of one connection member. FIG. 5 is a perspective view of the same portion as FIG. FIG. 6 is an enlarged view of a connection portion between the separate coil end and the slot coil. FIG. 7A is a diagram showing an example of a configuration for applying a radial load to a slot coil. FIG. 7B is a diagram showing the overall configuration of a stator having the configuration of FIG. 7A. FIG. 8 is an enlarged view of a connection portion between a separate coil end and a slot coil in the first modified example. FIG. 9 is an enlarged view of a connection portion between a separate coil end and a slot coil in the second modified example.

Below, an embodiment of the present invention is described with reference to the drawings.

Figure 1 is an exploded perspective view of a stator 1 according to this embodiment. The stator 1 includes a stator core 2, slot coils 3, and separate coil ends 4.

In the following description, radial, axial, and circumferential directions refer to the radial, axial, and circumferential directions of the stator core 2, respectively.

The stator core 2 is made of multiple plate-shaped electromagnetic steel sheets stacked in the thickness direction, and has multiple teeth 2A protruding radially inward and slots formed between adjacent teeth 2A.

The slot coil 3 is an assembly of multiple roughly U-shaped coil elements 3A, and has an overall cylindrical shape. The coil elements 3A are composed of multiple rectangular wires. The rectangular wires are composed of conductive materials such as copper and aluminum. Each rectangular wire is coated with an insulator such as enamel, except for both ends to which the connecting members 6 described below are connected. The slot coil 3 is inserted into the slots 5 from one end side of the stator core 2. Note that insulating paper is inserted into each slot 5, which electrically insulates the slot coil 3 from the teeth 2A.

The separate coil ends 4 are an assembly of connecting members 6 that electrically connect specific ends of the slot coils 3 that pass through the slots 5 and protrude from the stator core 2, and have an overall ring shape. Here, the connecting members 6 and the separate coil ends 4 will be described with reference to Figures 2 and 3.

Figure 2 shows the shape of the connecting member 6, and Figure 3 is a schematic diagram of the separate coil end 4.

The connection member 6 is made of a conductive material and has a leg 6A and connection parts 6B provided on both ends of the leg 6A. The leg 6A has a leaf spring shape bent at the middle as shown in FIG. 2, for example. The distance from one connection part 6B to the other connection part 6B is longer than the distance between the ends of the slot coil 3 to which each connection member 6 is connected. In other words, the connection member 6 is connected to the slot coil 3 in a state where the two connection parts 6B are elastically deformed in the direction of approaching each other. In other words, the connection member 6 applies an elastic force to the ends of the slot coil 3 to which it is connected.

The shape of the leg 6A is not limited to this, and may be any shape that is elastically deformable. Also, in FIG. 2, the connection portion 6B is bent into a curved shape, but this is not limited to this.

The separate coil end 4 is made up of multiple connection members 6 arranged in a circular ring shape. The separate coil end 4 is assembled to the slot coil 3 after multiple connection members 6 are temporarily assembled in a circular ring shape using a jig. For simplicity, Fig. 3 shows a separate coil end 4 in which the coil element 3A is composed of a single rectangular wire. In the case of multiple rectangular wires, as shown in Fig. 6 described below, each connection member 6 in Fig. 3 is stacked in the same number as the number of rectangular wires.

Next, the connection state between the separate coil end 4 and the slot coil 3 will be explained with reference to Figures 4 to 6.

Figure 4 is a plan view showing the connection state of one connecting member 6, and Figure 5 is a perspective view of the same part as Figure 4. Here, the connecting member 6 that connects the coil element 3AA inserted into the slot 5A and the coil element 3AB inserted into the slot 5B is shown. Figure 6 is an enlarged view of the connection part between the separate coil end 4 and the slot coil 3.

In this embodiment, the coil element 3A is configured with three rectangular wires that protrude relatively large from the end of the stator core 2 and three rectangular wires that protrude relatively small, arranged alternately. The second radially inner end of the coil element 3AA in the slot 5A is connected to the radially innermost end of the coil element 3AB in the slot 5B by a connecting member 6. The coil element 3A and the connection portion 6B of the connecting member 6 are electrically connected by a method such as welding, soldering, contact connection, solid-state bonding, or bonding with a conductive adhesive.

The elastic force applied to coil element 3A from the above-mentioned connecting member 6 acts on coil element 3AA and coil element 3AB in a direction away from each other (i.e., approximately in the circumferential direction). As a result, coil element 3AA and coil element 3AB are pressed against slot 5, respectively, and the resulting frictional force fixes slot coil 3 to slot 5.

The same is true for the other ends, with the fourth end from the radial inside of coil element 3AA in slot 5A being connected to the third end from the radial inside of coil element 3AB in slot 5B. Also, the radially outermost end of coil element 3AA in slot 5A is connected to the fifth end from the radial inside of coil element 3AB in slot 5B.

The other slots 5 are then connected in the same manner. As a result, the connection state shown in Figure 6 is obtained. Note that the shape of the connection member 6 near the connection portion 6B has been appropriately modified to avoid interference with other connection members 6.

Once the separate coil end 4 and the slot coil 3 are connected, the end of the slot coil 3 protruding from the stator core 2 and the separate coil end 4 are covered with a cover made of an insulator.

As described above, in the stator 1 of this embodiment, the slot coil 3 is fixed in the slot 5 by the elastic force of the separate coil end 4. Therefore, the frictional resistance between the slot coil 3 and the inner surface of the slot 5 when inserting the slot coil 3 into the slot 5 can be significantly reduced. Furthermore, if the shapes of the slot coil 3 and the slot 5 are as designed, no frictional force is generated between the slot coil 3 and the inner surface of the slot 5. In other words, with the above-mentioned configuration, the force required to insert the slot coil 3 into the slot 5 is reduced, so that it can be inserted using a simple device.

In addition, with the above-mentioned configuration, the slot coil 3 can be fixed to the slot 5 without providing any protrusions or other shapes to the insulator covering the slot coil 3. This makes it possible to use inexpensive insulating materials manufactured as roll materials. In addition, there is no need to use varnish, adhesives, etc. to fix the slot coil 3. This makes it possible to reduce manufacturing costs and simplify the manufacturing process.

Furthermore, since the load direction due to the elastic force of the separate coil end 4 is the circumferential direction, the load is balanced between the separate coil end 4, the slot coil 3, and the stator core 2. This eliminates the need for additional parts to support the load required to fix the slot coil 3.

Here, the case where the load direction is radial will be described with reference to Figures 7A and 7B. As shown in Figure 7A, even if the load direction from the connection part 6B of the connection member 6 to the coil element 3A is radially outward, the slot coil 3 can be pressed against the inner peripheral surface of the slot 5 and fixed. However, in this case, the load is not balanced between the separate coil end 4, the slot coil 3, and the stator core 2, so a configuration for supporting the load is required. For example, as shown in Figure 7B, an outer peripheral ring part 10, an inner peripheral ring part 11, and multiple elastic members 12 that connect these ring parts 10, 11 and the insulating cover 7 are required. For this reason, the structure is more complex than the configuration of this embodiment.

In the present embodiment, the elastic force generated by the connection member 6 is used as the load for fixing the slot coil 3 to the inner peripheral surface of the slot 5. However, the load may be generated by other configurations, as in the modified examples described below. Both the first and second modified examples described below are included in the technical scope of the present invention, just like the present embodiment.

[First Modification]
8 is an enlarged view of the connection portion between the coil element 3A and the connection member 6 in the configuration according to the first modified example. As in the above embodiment, the three connection members 6 are connected to the second, fourth, and sixth coil elements 3A from the radially inner side, respectively. However, the connection member 6 in this modified example does not generate elastic force when connected to the coil element 3A. Instead, the insulating cover 7 is provided with elastic deformation portions 7A, 7B, and 7C, which elastically deform when the insulating cover 7 is attached. The elastic force generated by the elastic deformation portions 7A, 7B, and 7C acts on the connection portion between the coil element 3A and the connection member 6 in the circumferential direction.

[Second Modification]
9 is an enlarged view of the connection portion between the coil element 3A and the connection member 6 in the configuration according to the second modified example. In the first modified example, parts of the insulating cover 7 are formed as elastic deformation portions 7A, 7B, and 7C, whereas in this modified example, elastic members 8A, 8B, and 8C such as springs are used that are separate from the insulating cover 7. These elastic members 8A, 8B, and 8C elastically deform in the compression direction when the insulating cover 7 is attached. Then, an elastic force generated by this elastic deformation acts in the circumferential direction on the connection portion between the coil element 3A and the connection member 6.

[Summary of effects]
As described above, according to the present embodiment and the modified example, there is provided a stator 1 for a rotating electric machine, which includes a stator core 2 having a plurality of slots 5, a plurality of slot coils 3 inserted into the slots 5, and separate coil ends 4 connected to portions of the slot coils 3 that pass through the slots 5 and protrude from the stator core 2. This stator 1 includes a load application mechanism that applies a circumferential load, which is a load in the circumferential direction of the stator core 2, to the slot coils 3. As a result, the slot coils 3 are pressed and fixed against the slots 5 by the circumferential load. Furthermore, since there is no need to provide protrusions or the like on the slot coils 3, it is possible to reduce the force required to insert the slot coils into the slots.

In this embodiment, the load application mechanism is a leg (deformation portion) 6A provided on the separate coil end 4, which elastically deforms when the separate coil end 4 is connected to the slot coil 3, and applies the elastic force generated by the elastic deformation as a circumferential load to the slot coil 3. In this way, no circumferential load is applied at the stage of inserting the slot coil 3 into the slot 5, so that the slot coil 3 can be inserted into the slot 5 with a smaller force.

In the first modified embodiment of this embodiment, an insulating cover 7 is further provided which covers the portion of the slot coil 3 protruding from the stator core 2 and the separate coil end 4, and the load application mechanism is elastic deformation parts 7A-7C provided on the insulating cover 7, which elastically deform when the insulating cover 7 is attached, and apply the elastic force generated by the elastic deformation to the slot coil 3 as a circumferential load. This provides the same effect as the present embodiment described above. In addition, since the connecting member 6 does not deform when combining the provisionally assembled separate coil end 4 and slot coil 3, the process of combining is made easier.

In the second modified example of this embodiment, the load application mechanism is elastic members 8A-8C interposed between the insulating cover 7 and the slot coil 3, and the elastic members 8A-8C elastically deform when the insulating cover 7 is attached, and apply the elastic force generated by the elastic deformation to the slot coil 3 as the circumferential load. This provides the same effect as the first modified example. In addition, since the shape of the insulating cover 7 is simpler than in the first modified example, molding of the insulating cover 7 becomes easier. It is formed in a shape that allows elastic deformation.

The above describes embodiments of the present invention, but the above embodiments merely illustrate some of the application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Claims (4)

A stator core having a plurality of slots;
A plurality of slot coils inserted into the slots;
a separate coil end connected to a portion of the slot coil that passes through the slot and protrudes from the stator core;
In a stator of a rotating electric machine comprising:
a load application mechanism that applies a circumferential load, which is a load in a circumferential direction of the stator core, to a portion of the slot coil that protrudes from the stator core,
A stator for a rotating electric machine, in which the slot coil is pressed against the slot by a circumferential load applied by the load application mechanism, and is fixed to the slot by the frictional force generated thereby. 2. The stator of a rotating electric machine according to claim 1,
the load application mechanism is a deformation portion provided in the separate coil end,
The deformation portion elastically deforms when the separate coil end is connected to the slot coil, and applies an elastic force generated by the elastic deformation to the slot coil as the circumferential load. 2. The stator of a rotating electric machine according to claim 1,
The coil end of the slot coil is provided with an insulating cover that covers the portion of the slot coil protruding from the stator core and the separate coil end.
the load application mechanism is an elastic deformation portion provided on the insulating cover,
The elastic deformation portion elastically deforms when the insulating cover is attached, and applies an elastic force generated by the elastic deformation to the slot coil as the circumferential load. 2. The stator of a rotating electric machine according to claim 1,
The coil end of the slot coil is provided with an insulating cover that covers the portion of the slot coil protruding from the stator core and the separate coil end.
the load application mechanism is an elastic member interposed between the insulating cover and the slot coil,
The elastic member elastically deforms when the insulating cover is attached, and applies an elastic force generated by the elastic deformation to the slot coil as the circumferential load.

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