CN113708535A

CN113708535A - Stator assembly and motor

Info

Publication number: CN113708535A
Application number: CN202110986418.4A
Authority: CN
Inventors: 裘华潮; 黄建成
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2021-08-26
Filing date: 2021-08-26
Publication date: 2021-11-26

Abstract

The present invention relates to a stator assembly for an electrical machine and to the electrical machine itself. The stator assembly comprises a stator winding (2) having a winding lead-out (6) and a busbar (3) having a busbar lead-out (5), wherein the winding lead-out (6) and the busbar lead-out (5) bear against one another by means of respective free end sections to form a cylinder and are welded to one another at the free end of the cylinder, wherein the busbar lead-out (5) is configured with a main body which forms a cylinder with the winding lead-out (6) and with limbs (7, 8) which project from the main body, wherein the limbs (7, 8) at least partially surround the winding lead-out (6) so as to clamp the winding lead-out (6) in a direction perpendicular to the longitudinal axis of the cylinder. The motor comprises the stator assembly.

Description

Stator assembly and motor

Technical Field

The invention relates to the technical field of motors. The invention relates in particular to a stator assembly and an electric machine.

Background

With the development of new energy automobile industry, the development of driving motors thereof also tends to develop in the direction of high-voltage, high-speed and small-sized. Therefore, a substantial increase in the power density of the motor is required. In this case, the windings of the electric machine, in particular the stator windings, can be flat copper wires in order to increase the slot fill factor. Furthermore, the axial ends of the stator winding are provided with busbars, the outgoing lines of the stator winding and the corresponding outgoing lines of the busbars abutting against one another via respective free end sections to form a cylinder and being welded at the free ends of the cylinder.

In patent application WO 2021023334 a1 an electric machine is disclosed, the stator assembly of which comprises stator windings and a busbar, wherein the lead-out wires of the stator windings and the lead-out wires of the busbar are welded to each other at free end points. In order to prevent the holding structure from being too long due to the cantilevered section of the stator winding lead-out wire, i.e. the section that projects from the stator core slot until it is welded to the busbar, the holding structure is integrated on the insulating housing of the busbar and can simultaneously clamp several stator winding lead-out wires that extend in the circumferential direction at the axial ends of the stator winding.

However, the above-described holding structure cannot directly act on the welded portions of the respective stator winding lead-out wires and bus bar lead-out wires, which may cause a dislocation when the motor is operated, particularly, when the stator winding and the bus bar are subjected to a force or vibration. In this case, the welded portion between the respective lead wires is highly susceptible to fatigue fracture.

Disclosure of Invention

It is therefore an object of the present invention to provide a stator assembly that is capable of improving fatigue characteristics at welds between stator windings and respective lead-out wires of a bus bar, and in particular, extending fatigue life at welds.

According to one aspect of the invention, the above object is achieved by a stator assembly for an electrical machine, comprising a stator winding having winding leads and a busbar having busbar leads, wherein the winding leads and the busbar leads abut against each other by means of respective free end sections to form a cylinder and are welded to each other at the free end of the cylinder, wherein the busbar leads are configured with a main body forming the cylinder with the winding leads and with arms projecting from the main body, wherein the arms at least partially surround the winding leads so as to clamp the winding leads in a direction perpendicular to the longitudinal axis of the cylinder.

The bus bar outlet comprises a main body and at least one arm extending from the main body. In this case, in the process of connecting the stator winding and the busbar, it is preferable to perform the steps of first attaching the main body of the busbar lead-out wire and the winding lead-out wire to each other to form a column; then bending the support arms to enable the support arms to at least partially surround the winding lead-out wire, and enabling one support arm to singly or at least two support arms to clamp the winding lead-out wire in a direction perpendicular to the longitudinal axis of the cylinder together; the free ends of the cylinders, i.e. the free ends of the winding lead-out wires and the free ends of the main body of the busbar lead-out wires, are then welded to one another using a welding technique.

By virtue of the clamping of the winding lead-out wire by the support arm, the main body of the bus bar lead-out wire and the winding lead-out wire can be firmly attached to each other, and the relative movement of the two in a direction perpendicular to the longitudinal axis of the cylinder is limited. Further, in the direction of the longitudinal axis of the column body, due to the clamping of the winding lead-out wire by the arm, a frictional force is generated between the arm and the winding lead-out wire and/or between the main body of the bus bar lead-out wire and the winding lead-out wire, thereby restricting a relative dislocation of the bus bar lead-out wire and the winding lead-out wire in the direction of the longitudinal axis of the column body. Thus, even when the stator winding and the bus bar are subjected to a force or vibration for a long period of time, the stator winding and the bus bar lead wire can be stably held in relative positions for a long period of time in a section near the welded portion, here, a region where the columnar body is formed, thereby improving fatigue characteristics at the welded portion, particularly, extending fatigue life at the welded portion.

In a preferred embodiment, the busbar lead-out wire is a sheet metal component. Thus, the bus bar lead-out wire with the support arm can be manufactured at lower cost.

In a preferred embodiment, the busbar lead is made of a copper material. Here, the copper material has good electric conductivity and the support arm made of the copper material is easy to bend.

In a preferred embodiment, the arm extends from the main body perpendicularly to the main body of the bus bar lead-out wire. The limb preferably partially surrounds and clamps the winding lead-out wire in a plane perpendicular to the longitudinal axis of the cylinder formed by the winding lead-out wire and the busbar lead-out wire. In this case, the winding lead-out wire can be clamped in a direction perpendicular to the longitudinal axis of the column with a smaller total arm length, i.e. the sum of the lengths of all the arms, so that material is saved and cost is reduced while the clamping performance is ensured.

In an alternative embodiment, the arm projects from the main body obliquely to the main body of the bus bar outlet. The arm can be wound substantially spirally along the longitudinal axis of the column formed by the winding lead wire and the bus bar lead wire, and can sandwich the winding lead wire. In this case, the total contact area of the bus bar lead-out wire and the winding lead-out wire can be largely achieved, so that the relative dislocation of the bus bar lead-out wire and the winding lead-out wire in the longitudinal axis direction of the column can be restricted. Meanwhile, in the case of an appropriate inclination angle, even if the support arms are configured long, the overlapping between different support arms or the overlapping of the same support arm after surrounding the winding lead-out wire for one turn in the direction perpendicular to the longitudinal axis of the column can be avoided, so that a sufficient space can be maintained between the connection structure of the plurality of corresponding winding lead-out wires and the bus bar lead-out wire of the stator assembly, that is, the column, and further, the arrangement of other parts is facilitated or accidental short circuit is prevented.

In an advantageous embodiment, the bus bar extension line is formed with two limbs, wherein the two limbs project at the same longitudinal height position of the bus bar extension line. Here, the same longitudinal height position of the bus bar lead-out wires means: substantially the same position in the direction of the longitudinal axis of the cylinder. In this case, the winding lead-out wire can be stably held in a direction perpendicular to the longitudinal axis of the column by surrounding the winding lead-out wire at least half a circumference by the bus bar lead-out wire and the arm of a short configuration in common.

In an advantageous embodiment, the bus bar extension line is formed with two limbs, wherein the two limbs project at different longitudinal height positions of the bus bar extension line. Here, the different longitudinal height positions of the busbar lead wires refer to: positions offset from each other in the direction of the longitudinal axis of the cylinder. In this case, the arm can be configured longer to increase the total contact area of the bus bar lead-out wire and the winding lead-out wire, thereby increasing the frictional force between the bus bar lead-out wire and the winding lead-out wire.

In this case, it is particularly advantageous if the winding leadout is configured as a flat wire, the two limbs each extending as far as the surface of the winding leadout facing away from the main body of the busbar leadout. In other words, in the case where the winding lead-out wire is a flat wire, it is possible to cause two arms of a hook-like configuration to extend from the main body of the bus bar lead-out wire and to be snapped to the surface of the winding lead-out wire facing away from the main body, thereby clamping the winding lead-out wire in both directions perpendicular to and parallel to the contact surface of the bus bar lead-out wire and the winding lead-out wire.

In this case, it is particularly advantageous if the winding leadout is configured as a flat wire and the bus bar leadout is configured with a limb, wherein the limb extends over a surface of the winding leadout facing away from the main body of the bus bar leadout and towards the main body of the bus bar leadout. The support arm can be realized in a simple structure and clamps the winding lead-out wire in a direction perpendicular to and parallel to the contact surface of the bus bar lead-out wire and the winding lead-out wire.

According to another aspect of the invention, the above object is achieved by an electric machine comprising a stator assembly constructed in accordance with the above embodiment.

Drawings

Features, advantages and technical effects of preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 is a schematic perspective view of a stator assembly at the end of an electric machine according to a preferred embodiment of the present invention;

figure 2 is a perspective view of a busbar lead-out wire of the stator assembly according to figure 1;

FIG. 3 is a schematic view of a step in the connection of the stator windings and the bus bars according to the stator assembly of FIG. 1;

FIG. 4 is a schematic view of a step in the connection of the stator windings and the bus bars according to the stator assembly of FIG. 1; and

fig. 5 is a schematic view of a step in the connection of the stator windings and the busbars of the stator assembly according to fig. 1.

Detailed Description

Fig. 1 shows a schematic perspective view of a stator assembly at the end of an electrical machine according to a preferred embodiment of the invention. The stator assembly can be a component of a drive motor of an electric vehicle, for example.

As shown in fig. 1, the stator assembly includes a stator core 1, stator windings 2, and bus bars 3. The stator winding 2 consists of a preferably drawn flat copper wire. The stator winding 2 is wound at the stator core 1 and has a plurality of winding lead-out wires 6. The bus bars 3 are configured in the present embodiment in the shape of an arc and are fixed at the ends of the stator winding 2. The bus bar 3 has a plurality of bus bar lead wires 5 and an insulating portion.

The plurality of winding lead-out wires 6 and the plurality of bus bar lead-out wires 5 are electrically connected to each other correspondingly according to the motor wiring scheme. In this case, the respective winding lead-out wires 6 and busbar lead-out wires 5 lie against one another via the respective free end sections and thus form a cylinder. Each cylinder extends in the axial direction of the stator assembly and is welded to each other at the free end of the cylinder by means of tungsten-arc gas welding (TIG), i.e. a weld 4 is formed. The specific structure of the column is not shown in detail in fig. 1 for the sake of clarity.

Fig. 2 shows a perspective view of a bus bar lead-out wire of the stator assembly according to fig. 1. As shown in fig. 2, the busbar lead-out wire 5 is constructed as a sheet metal component, here in particular as a thin sheet of copper. The busbar lead-out wire 5 has a main body in the shape of a strip as a whole and two

arms

7, 8 extending from the main body, wherein the two

arms

7, 8 extend from the main body at the same longitudinal height position and extend in a direction perpendicular to the longitudinal direction of the main body.

Fig. 3, 4 and 5 schematically show steps in the connection process of the stator windings and the busbars, respectively, of the stator assembly according to fig. 1.

Here, first, as shown in fig. 3, the main body of the bus bar lead-out wire 5 and the winding lead-out wire 6 are abutted against each other to form a cylinder.

Then, as shown in fig. 4, the

arms

7, 8 are bent so that the

arms

7, 8 partially surround the winding lead-out wire 6, wherein the hooks bent from the free ends of the

arms

7, 8 are engaged with the surface of the winding lead-out wire 6 facing away from the main body of the bus bar lead-out wire 5, thereby holding the winding lead-out wire 6 in a direction perpendicular to and parallel to the contact surface of the bus bar lead-out wire 5 and the winding lead-out wire 6. In this case, the main body of the bus bar lead-out wire 5 and the winding lead-out wire 6 can be firmly abutted against each other, and relative movement of the two in a direction perpendicular to the longitudinal axis of the cylinder is restricted. Furthermore, in the direction of the longitudinal axis of the column, due to the clamping of the winding lead-out wire 6 by the

arms

7, 8, a frictional force is generated between the

arms

7, 8 and the winding lead-out wire 6 and/or between the main body of the bus bar lead-out wire 5 and the winding lead-out wire 6, thereby restricting relative dislocation of the bus bar lead-out wire 5 and the winding lead-out wire 6 in the direction of the longitudinal axis of the column.

Subsequently, as shown in fig. 5, the free end portions of the cylindrical bodies, that is, the free end portions of the winding lead-out wires 6 and the free end portions of the main bodies of the bus bar lead-out wires 5 are welded to each other by a welding technique, thereby forming the welded portion 4.

By means of the arm pair winding lead-out wires 6, the lead-out

wires

5, 6 of the stator winding 2 and the bus bar 3 can be kept in relative positions very stably in a section near the welded portion 4, here, a region where a column is formed, and a sufficient fatigue life at the welded portion 4 can be ensured even when the stator winding 2 and the bus bar 3 are subjected to a force or vibration for a long period of time.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

List of reference numerals

1 stator core

2 stator winding

3 bus bar

4 welding part

5 bus bar lead-out wire

6 winding lead-out wire

7 support arm

8 support arm

Claims

1. A stator assembly for an electric machine, the stator assembly comprising:

a stator winding (2) having winding lead-out wires (6), an

A bus bar (3) having bus bar lead-out wires (5),

wherein the winding lead-out wires (6) and the busbar lead-out wires (5) are applied to each other by means of respective free end sections to form a cylinder and are welded to each other at the free end of the cylinder,

characterized in that the busbar lead-out wire (5) is configured with a main body forming the cylinder with the winding lead-out wire (6) and with arms (7, 8) projecting from the main body, wherein the arms (7, 8) at least partially surround the winding lead-out wire (6) so as to clamp the winding lead-out wire (6) in a direction perpendicular to the longitudinal axis of the cylinder.

2. The stator assembly according to claim 1, characterized in that the busbar lead-out wires (5) are sheet metal members.

3. Stator assembly according to claim 1, characterized in that the busbar lead-out wires (5) are made of copper material.

4. A stator assembly according to claim 1, characterized in that the arms (7, 8) extend from the body in a direction perpendicular to the body.

5. A stator assembly according to claim 1, characterized in that the arms (7, 8) protrude from the body in a direction oblique to the body.

6. Stator assembly according to claim 1, characterized in that the busbar lead-out wire (5) is configured with two arms (7, 8), wherein the two arms (7, 8) protrude from the main body at the same longitudinal height position.

7. Stator assembly according to claim 1, characterized in that the busbar lead-out wire (5) is configured with two arms (7, 8), wherein the two arms protrude from the main body at different longitudinal height positions.

8. The stator assembly according to claim 6 or 7, characterized in that the winding lead-out wires (6) are configured as flat wires, the two legs (7, 8) extending up to the surface of the winding lead-out wires (6) facing away from the main body, respectively.

9. The stator assembly according to claim 1, characterized in that the winding lead-out wires (6) are configured as flat wires and the busbar lead-out wires (5) are configured with a limb, wherein the limb extends over the surface of the winding lead-out wires (6) facing away from the main body and towards the main body.

10. An electrical machine, characterized in that the electrical machine comprises a stator assembly according to any of claims 1-9.