JP2024055350A - Fastening structure for motor windings and motor - Google Patents

Abstract

[Problem] To provide a fastening structure for motor windings that is easy to fasten to a winding and a bus bar. [Solution] The fastening structure for motor windings is a fastening structure for motor windings that connects a winding 4 to a bus bar 10, and the winding 4 is connected to the bus bar 10 via a conductive press-fit part 20, and the press-fit part 20 is press-fitted into a press-fit hole 13 of the bus bar 10 while gripping the winding 4. [Selected Figure] Figure 1

Description

The present invention relates to a motor winding fastening structure and a motor.

Patent Document 1 and other publications disclose motors in which windings and bus bars are connected. Methods for fastening the conductors at the winding terminals to the bus bars include soldering, crimping, and welding. Of these methods, soldering ensures continuity by wrapping the conductors around the bus bars and bringing them into close contact, and then soldering them. Soldering is also widely used because it does not require special tools or equipment compared to other fastening methods.

JP 2021-57986 A

With conventional methods, as the diameter of the conductor increases, the rigidity of the conductor increases, making bending and connecting to the bus bar difficult. In particular, as the motor output increases, the diameter of the conductor increases, resulting in a problem of reduced efficiency in wiring work for large-capacity motors.

The present invention aims to provide a motor winding fastening structure that makes it easy to fasten the windings and bus bars, and a motor that uses the same.

According to one aspect of the present invention,
A fastening structure for a motor winding that connects a conductor to a bus bar,
the conductor is connected to the bus bar via a conductive press-fit part,
The press-fit part is press-fitted into the press-fit hole of the bus bar while gripping the conductor, thereby providing a fastening structure for a motor winding.

According to one aspect of the present invention,
In a motor having a stator or a rotor around which the winding is wound,
A motor is provided having the above-described fastening structure for motor windings.

The present invention provides a motor winding fastening structure that is easy to fasten to a conductor and a bus bar, and a motor using the same.

1 is a diagram showing a stator (an example of a stator) of a motor according to an embodiment of the present invention; FIG. 2 is an enlarged view of the bus bar and the insulator. 4 is an enlarged view showing a tip portion of a second portion of the bus bar. FIG. FIG. 6 is a diagram showing the dimensional relationship between the outer diameter of a sleeve and a press-fit hole of a bus bar. FIG. 6 is a diagram showing the dimensional relationship between the outer diameter of a sleeve and a press-fit hole of a bus bar. FIG. 6 is a diagram showing the dimensional relationship between the outer diameter of a sleeve and a press-fit hole of a bus bar. FIG. 6 is a diagram showing the dimensional relationship between the outer diameter of a sleeve and a press-fit hole of a bus bar. FIG. 13A and 13B are diagrams showing modified examples of press-fit parts in the fastening structure for motor windings of the present invention. 13A and 13B are diagrams showing modified examples of press-fit parts in the fastening structure for motor windings of the present invention. 13A and 13B are diagrams showing modified examples of press-fit parts in the fastening structure for motor windings of the present invention. 13A and 13B are diagrams showing modified examples of press-fit parts in the fastening structure for motor windings of the present invention.

The following describes an embodiment of the present invention with reference to the drawings. For the sake of convenience, the description of components having the same reference numbers as components already described in the description of the embodiment will be omitted. Also, for the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

Fig. 1 is a diagram showing a stator 2 (an example of a stator) of a motor 1 according to an embodiment of the present invention. As shown in Fig. 1, the stator 2 has a stator core 3, a winding 4 wound around the stator core 3, a bus bar 10, an insulator 5 (see Fig. 2), and a conductive sleeve 20 (an example of a press-fit part).
A plurality of stator cores 3 are combined to form a cylindrical shape. A bus bar 10 is disposed outside the insulator 6 at the end of the stator core 3 in the axial direction A. The sleeve 20 is press-fitted onto the bus bar 10 while gripping the end 41 of the winding 4, thereby fastening the winding 4 and the bus bar 10. In the following description, the direction in which the axis of rotation of the motor 1 extends is referred to as the axial direction A, and the radial direction R and the circumferential direction C are defined and used based on this axial direction A in the description.
Although not shown, a motor can be formed by the stator 2 and a rotor shown in FIG.

Figure 2 is an enlarged view of the busbar 10 and the insulator 5. As shown in Figure 2, the busbar 10 is formed by punching and bending a conductive plate-like member such as a metal plate. The busbar 10 has a curved first portion 11 and a plurality of second portions 12 extending inward in the radial direction R from the first portion 11. The first portion 11 is a portion that extends along the axial direction A and the circumferential direction C. The second portions 12 are portions that extend inward in the radial direction R from the end of the first portion 11 in the axial direction A.

In the example shown in FIG. 2, four bus bars 10 are arranged so as to overlap in the radial direction R. Between each bus bar 10, a strip-shaped insulator 5 is provided to prevent the bus bars 10 from being electrically connected to each other. The first bus bar 10A from the inside in the radial direction R is connected to a winding 4 that carries, for example, a U-phase current. The second bus bar 10B from the inside in the radial direction R is connected to a winding 4 that carries, for example, a V-phase current. The third bus bar 10C from the inside in the radial direction R is connected to a winding 4 that carries, for example, a W-phase current. The fourth bus bar 10D from the inside in the radial direction R is, for example, a neutral point in a Y-connection, and is connected to the windings 4 of each phase. The number of bus bars 10 is not limited to four. The number of bus bars 10 is provided according to the number of phases of the motor 1 and the arrangement of the windings 4.

Figure 3 is an enlarged view showing the tip portion of the second portion 12 of the busbar 10. As shown in Figure 3, the second portion 12 of the busbar 10 has a press-fit hole 13 that penetrates the busbar 10 in the thickness direction. A sleeve 20 is press-fitted into this press-fit hole 13. A busbar side tapered portion 14 is provided on the side of the press-fit hole 13 where the sleeve 20 is inserted. The inner diameter of the busbar side tapered portion 14 increases toward the sleeve 20. This makes it easier to insert the sleeve 20 into the press-fit hole 13.

Fig. 4 is a perspective view showing the sleeve 20. As shown in Fig. 4, the sleeve 20 includes a cylindrical main body portion 21 and a flange portion 22 (an example of a fixing portion). The sleeve 20 is press-fitted into the press-fit hole 13 of the busbar 10 while gripping the end portion 41 of the winding 4. The sleeve 20 is provided with a slit 23 penetrating in the axial direction A and the radial direction R. This allows the sleeve 20 to be inserted into the press-fit hole 13 by elastically deforming, and prevents the sleeve 20 from coming off after being pressed in.
The flange portion 22 is provided at an end of the main body portion 21 in the axial direction A. The outer diameter of the flange portion 22 is larger than the outer diameter of the main body portion 21. The flange portion 22 has an outer peripheral surface 221 extending in the axial direction A and the circumferential direction C, a step surface 222, and a bottom surface 223. The step surface 222 is a surface that connects the outer peripheral surface 211 and the main body portion 21, and extends in the radial direction R. The bottom surface 223 is provided on the opposite side of the outer peripheral surface 211 to the step surface 222 in the axial direction A, and extends in the radial direction R.

The inner circumferential surface of the main body 21 is provided with a gripping hole 24 for gripping the end 41 of the winding 4. The inner diameter of the gripping hole 24 is approximately the same as or larger than the outer diameter of the conductor when no external force is applied to the sleeve 20 (hereinafter referred to as the no-load state). When the sleeve 20 is press-fitted into the busbar 10 (hereinafter referred to as the press-fit state), the inner circumferential surface of the gripping hole 24 is pressed firmly against the end 41 of the winding 4.

The sleeve 20 has a sleeve-side tapered portion 25 at the tip end in the press-fitting direction, the outer diameter of which decreases toward the tip end. Specifically, the sleeve-side tapered portion 25 is provided at the end of the main body portion 21 in the axial direction A opposite the flange portion 22. The outer diameter of the tip of the sleeve-side tapered portion 25 decreases toward the press-fitting hole 13. This makes it easier to insert the sleeve 20 into the press-fitting hole 13.

Figures 5 to 8 are diagrams showing the dimensional relationship between the outer diameter of the sleeve 20 and the press-fit hole 13 of the busbar 10. Figures 5 and 6 are diagrams showing the dimensional relationship between the outer diameter of the sleeve 20 and the press-fit hole 13 of the busbar 10 when the main body 21 is not pressed into the press-fit hole 13 (unloaded state). Figure 5 is a diagram seen from the axial direction A, and Figure 6 is a cross-sectional view taken along the axial direction A. Figures 7 and 8 are diagrams showing the dimensional relationship between the outer diameter of the sleeve 20 and the press-fit hole 13 of the busbar 10 when the main body 21 is pressed into the press-fit hole 13 (press-fit state). Figure 7 is a diagram seen from the axial direction A, and Figure 8 is a cross-sectional view taken along the axial direction A.

As shown in Figures 6 and 8, whether in an unloaded state or in a pressed-in state, the outer diameter (r1) of the end of the sleeve-side tapered portion 25 in the press-fit direction is smaller than the inner diameter (R) of the press-fit hole 13.
In addition, as shown in Figures 5 and 6, the outer diameter (r2) of the main body portion 21 of the press-fit part is larger than the inner diameter (R) of the press-fit hole 13 in an unloaded state, and as shown in Figures 7 and 8, when the main body portion 21 is press-fitted into the press-fit hole 13, the outer diameter (r2) is the same as or smaller than the inner diameter (R) of the press-fit hole 13.
Furthermore, as shown in Figures 6 and 8, whether the main body portion 21 is in an unloaded state or in a press-fit state in the bus bar 10, the outer diameter (r3) of the flange portion 22 is larger than the inner diameter (R) of the press-fit hole 13.

As shown in FIG. 8, when the sleeve 20 is fully inserted into the press-fit hole 13, the step surface 222 of the flange portion 22 comes into contact with the busbar 10, preventing the sleeve 20 from being inserted further into the press-fit hole 13. This restricts the insertion length of the sleeve 20 into the press-fit hole 13.

<Method of connecting winding 4 to busbar 10 using sleeve 20>
Next, a method of connecting the winding 4 to the bus bar 10 using the sleeve 20 will be described.
1 , the end 41 of the winding 4 is set to extend along the axial direction A of the motor 1. Next, while passing the end 41 of the winding 4 through the press-fit hole 13 of the bus bar 10, the bus bar 10 is moved toward the stator core 3, and the bus bar 10 is attached to the outside of the insulator 6.

Next, the end 41 inserted into the busbar 10 is passed through the gripping hole 24 of the sleeve 20, and the sleeve 20 is moved along the end 41 to the busbar 10 while the end 41 is still passing through the gripping hole 24. In this state, no external force is acting on the sleeve 20, and it is in an unloaded state. Therefore, the inner diameter of the inner circumferential surface of the sleeve 20 is larger than the outer diameter of the end 41, and the sleeve 20 can move freely along the conductor of the end 41.

The sleeve 20 is then moved along the end 41, and the bottom surface 223 of the sleeve 20 is pressed to press the sleeve 20 into the press-fit hole 13 of the busbar 10 in order to insert the sleeve 20 into the press-fit hole 13 of the busbar 10. When the step surface 222 of the flange portion 22 of the sleeve 20 comes into contact with the busbar 10, the sleeve 20 abuts and does not move any further. The sleeve 20 is in a press-fit state, and the gripping hole 24 of the sleeve 20 firmly grips the end 41. As a result, the winding 4 is fastened to the busbar 10 via the conductive sleeve 20.

According to the fastening structure of the motor winding disclosed herein, the winding 4 is connected to the bus bar 10 via a conductive press-fit part (sleeve 20), and the press-fit part (sleeve 20) is pressed into the press-fit hole 13 of the bus bar 10 while gripping the end 41.
Therefore, compared to connecting the windings 4 to the busbar 10 by means of soldering, welding, or the like, no special equipment such as a soldering iron, welding rod, or welding torch is required, and the windings 4 can be fastened to the busbar 10 by the simple task of pressing press-fit parts into the press-fit holes 13. In addition, since there is no need to bend the conductor wires, a decrease in efficiency of the wiring work for large-capacity motors can be suppressed even if the conductor wires become thicker and their rigidity increases. In addition, since the work is completed in a single process of inserting the press-fit parts through which the conductor wires have passed into the press-fit holes 13 and pressing them in, the fastening work can be completed quickly.

Furthermore, in the fastening structure of the present disclosure, the press-fit part is provided with at least one slit 23 extending along the press-fitting direction (axial direction A).
Therefore, the press-fit part can be elastically deformed in a direction perpendicular to the press-fit direction (circumferential direction C in this disclosure) so that the gap of the slit 23 expands and contracts. The press-fit part is inserted into the press-fit hole 13 while elastically deforming during press-fitting, making the press-fitting operation easy. In addition, since an elastic restoring force acts on the press-fit part in the pressed-in state, the press-fit part is unlikely to fall out of the press-fit hole, making it easy to maintain the fastened state.

In addition, in the fastening structure of the present disclosure, a tapered portion (sleeve-side tapered portion 25) is provided on the tip side in the press-fitting direction of the press-fit part (sleeve 20).
Since the press-fit part is guided into the press-fit hole 13 by the tapered portion, the press-fit part can be easily inserted into the press-fit hole 13.

In addition, in the fastening structure of the present disclosure,
The press-fit part (sleeve 20) has a main body portion 21 extending from a tapered portion (sleeve-side tapered portion 25) in a direction opposite to the press-fitting direction,
Whether the main body 21 is in an unloaded state or in a pressed-in state in the press-fit hole 13, the outer diameter (r1) of the end of the tapered portion (sleeve-side tapered portion 25) in the press-fit direction is smaller than the inner diameter (R) of the press-fit hole 13.
The outer diameter (r2) of the main body 21 of the press-fit part is
When the main body 21 is not press-fitted into the press-fit hole 13, the main body 21 has a diameter larger than the inner diameter (R) of the press-fit hole 13.
When the main body portion 21 is press-fitted into the press-fit hole 13 , the inner diameter (R) of the press-fit hole 13 is equal to or smaller than the inner diameter (R) of the press-fit hole 13 .
By setting the outer diameter of the main body portion 21 in this manner, it is easy to insert the press-fit part into the bus bar 10 and also easy to maintain the fastened state.

In addition, in the fastening structure of the present disclosure, a fixing portion (flange portion 22) is provided on the tip side of the press-fit part in the direction opposite to the press-fitting direction.
In addition, in the fastening structure of the present disclosure, the outer diameter (r3) of the fixing portion is larger than the inner diameter (R) of the press-fit hole 13.
Therefore, when the press-fit part is press-fitted into the bus bar 10 by a predetermined length, the step surface 222 comes into contact with the bus bar 10, preventing the press-fit part from being pressed in any further. This makes it possible to easily manage the press-fit length of the press-fit part.

<Modification>
In the fastening structure for a motor winding of the present invention, there is no particular limitation on the shapes of the press-fit parts and the bus bar 10. Modified examples of the press-fit parts in the fastening structure for a motor winding of the present invention will be described with reference to Figs. 9 to 12 .
FIG. 9 is a cross-sectional perspective view of a modified example of a press-fit part in a fastening structure for a motor winding according to the modified example 1 of the present disclosure. As shown in FIG. 9, an inner uneven portion 241 may be provided on the inner circumferential surface of the gripping hole 24 of the press-fit part. The illustrated inner uneven portion 241 has a plurality of convex shapes extending in the axial direction A. When the press-fit part is press-fitted into the busbar 10, the inner uneven portion 241 bites into the outer circumferential surface of the winding 4, and can firmly grip the end portion 41. Note that, although the convex shape extends in the axial direction A in FIG. 9, the inner uneven portion 241a may be provided as a plurality of convex shapes extending in the circumferential direction C as shown in FIG. 10. Even with such a configuration, when the press-fit part is press-fitted into the busbar 10, the inner uneven portion 241a bites into the outer circumferential surface of the end portion 41, and can firmly grip the end portion 41.
In addition, when the inner unevenness 241, 241a is provided on the inner surface of the gripping hole 24 in this manner, it is preferable that the inner diameter of the recess is larger than the outer diameter of the end 41 in the unloaded state, and that the inner diameter of the recess is the same as or smaller than the outer diameter of the end 41 in the pressed-in state.

As shown in Figures 9 and 10, it is preferable that an opening 242 having a larger diameter than the inner diameter of the recess in the inner peripheral surface of the gripping hole 24 is provided at the end of the press-fit part opposite the press-fit direction of the gripping hole 24 (the side farther from the busbar 10). Such an opening 242 reduces the volume of the flange portion 22 and lowers the rigidity of the flange portion 22, making it easier for the flange portion 22 to deform during press-fitting and improving press-fitting workability. After press-fitting, the opening 242 has a larger diameter than the gripping hole 24 at the end 41 of the winding 4, making it less likely to come out and improving the retention performance of the conductor after press-fitting.

Also, FIG. 11 is a perspective view of a modified example of a press-fit part in a fastening structure for a motor winding according to modified example 2 of the present disclosure. As shown in FIG. 11, an outer uneven portion 212 may be provided on the outer peripheral surface 211 of the main body portion 21. The outer uneven portion 212 increases the contact area with the busbar 10, improving the stability of electrical conduction. Note that while the outer uneven portion 212 in FIG. 11 has multiple convex shapes extending in the axial direction A, it may also be configured with multiple convex shapes extending in the circumferential direction C.

Furthermore, FIG. 12 is a perspective view of a modified example of a press-fit part in a fastening structure for a motor winding according to modified example 3 of the present disclosure. As shown in FIG. 12, one or more notches 224 may be provided on the outer periphery of the flange portion 22. The notches 224 are formed by cutting out a part of the outer periphery of the flange portion 22 in the circumferential direction C inward in the radial direction R. Such notches 224 reduce the rigidity of the flange portion 22, making it easier to deform when pressed in, improving the ease of the press-fitting work.

Although an embodiment of the present invention has been described above, it goes without saying that the technical scope of the present invention should not be interpreted as being limited by the description of this embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications of the embodiment are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and its equivalents.

In the above embodiment, the press-fit part is cylindrical, but the press-fit part may be polygonal prism-shaped. Similarly, the press-fit hole is not limited to being circular, but may be polygonal.
In addition, although an example in which a slit extending over the entire press-fit part has been described, the slit may be provided only in the main body part and the sleeve side tapered part, and not in the flange part. In this way, when the slit is provided in a part of the axial direction A, a plurality of slits may be provided.
Furthermore, although an example has been described in which the present invention is applied to a fastening structure for fastening the stator windings to the busbar, the present invention may also be applied to a fastening structure for fastening the rotor windings to the busbar.

REFERENCE SIGNS LIST 1 Motor 2 Stator 3 Stator core 4 Winding 5 Insulator 6 Insulator 10, 10A, 10B, 10C, 10D Busbar 11 First part 12 Second part 13 Press-fit hole 14 Busbar side tapered part 20 Sleeve (press-fit part)
21 Main body portion 22 Flange portion 23 Slit 24 Grip hole 25 Sleeve side tapered portion 212 Outer uneven portion 211, 221 Outer peripheral surface 222 Step surface 223 Bottom surface 224 Notch 241 Inner uneven portion

Claims (10)

A fastening structure for a motor winding that connects a winding to a bus bar, comprising:
the winding is connected to the bus bar via a conductive press-fit part;
13. A motor winding fastening structure, comprising: a press-fit part that is press-fitted into a press-fit hole of the bus bar while gripping the winding. The motor winding fastening structure according to claim 1, wherein the press-fit part has at least one slit extending along the press-fit direction. The motor winding fastening structure according to claim 1, in which a tapered portion is provided on the tip side of the press-fitting part in the press-fitting direction. The press-fit component has a main body portion extending from the tapered portion in a direction opposite to a press-fitting direction,
Whether the main body portion is not press-fitted into the press-fit hole or the main body portion is press-fitted into the press-fit hole, the outer diameter (r1) of the end portion of the tapered portion in the press-fit direction is smaller than the inner diameter (R) of the press-fit hole,
The outer diameter (r2) of the main body of the press-fit part is
When the main body portion is not press-fitted into the press-fit hole, the main body portion has a larger inner diameter (R) than the inner diameter (R) of the press-fit hole,
4. The motor winding fastening structure according to claim 3, wherein when the main body is press-fitted into the press-fit hole, the main body has an inner diameter (R) equal to or smaller than the inner diameter (R) of the press-fit hole. The motor winding fastening structure according to claim 1, in which a fixing portion is provided on the tip side of the press-fit part in the direction opposite to the press-fit direction. The motor winding fastening structure according to claim 5, wherein the outer diameter (r3) of the fixed portion is greater than the inner diameter (R) of the press-fit hole. the press-fitting part has a press-fitting hole for gripping the winding,
The fastening structure for a motor winding according to claim 1 , wherein an inner circumferential surface of the press-fit hole is provided with an uneven portion. The motor winding fastening structure according to claim 4, wherein an outer circumferential surface of the main body is provided with an outer uneven portion. The motor winding fastening structure according to claim 5, wherein at least one notch is provided on the outer periphery of the fixed portion. In a motor having a stator or a rotor around which the winding is wound,
A motor having the fastening structure for a motor winding according to any one of claims 1 to 9.

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