JP6496229B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine.

A rotating electrical machine such as an electric motor or a generator mounted on a vehicle includes a rotor, a stator core having a plurality of slots, a stator coil wound around each slot, and a terminal portion of each stator coil. And a stator having a connection ring to be joined. For example, in a three-phase AC type rotating electrical machine, each connection ring is provided in an annular shape along the circumferential direction of the stator core as a phase winding of U phase, V phase, W phase, etc., and a plurality of phase windings are provided. They are arranged in the radial direction of the stator core.
Each connection ring is formed with joint portions at predetermined intervals along the circumferential direction, and the terminal portions of the stator coils are joined at the joint portions by welding such as TIG welding (for example, Patent Document 1). reference).

Patent No. 5016969

  Although not described in the above-mentioned patent document, in order to prevent the generation of voids in the joining of the connection ring and the stator coil and to ensure the reliability of joining, the connection ring and the stator coil are usually both Oxygen-free copper and high-purity copper (6N, purity 99.9999%) are used. In order to produce such oxygen-free copper and high-purity copper, many processes are required to reduce the oxygen content, resulting in high costs, which contributes to the cost increase of the rotating electrical machine. ing.

According to one aspect of the present invention, a rotating electrical machine includes a rotor, a stator core having a teeth portion, and a terminal wire wound around the teeth portion and protruding from an end surface in the axial direction of the stator core. A stator coil, and a stator having a connection ring having a terminal portion to which the terminal wire of the stator coil is joined, and the stator coil is insulated from a winding portion wound around the teeth portion. The connection ring and the stator coil are covered with a film, and the connection ring and the stator coil are made of copper , and the connection ring is a diluted copper alloy containing oxygen and titanium and having a purity of 4N (99.99%) or less, and the stator coil Is copper with a purity of 4N (99.99%) or less that does not contain titanium .

  According to the present invention, the cost of the rotating electrical machine can be reduced.

It is a perspective view of an important section section showing composition of a rotary electric machine by one embodiment of the present invention. FIG. 2 is a cross-sectional perspective view illustrating a state in which the connection ring and the stator coil are assembled to the stator in the rotating electric machine illustrated in FIG. 1. It is a disassembled perspective view which shows the structure of the connection ring of the rotary electric machine shown in FIG. FIG. 3 is a perspective view illustrating a state in which a stator coil is wound in the stator illustrated in FIG. 2. FIG. 3 is a cross-sectional perspective view illustrating a configuration of a terminal portion of a connection ring in the stator illustrated in FIG. 2. It is a schematic diagram which shows the state of the junction part of a connection ring and a stator coil, (A) shows the joining state by one embodiment of this invention, (B) shows the joining state by the method of a comparative example, ( C) shows a joining state when oxygen-free copper (6N) is used for the connection ring and the stator coil.

Hereinafter, an embodiment of a rotating electrical machine of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view of an essential part cross section showing a configuration of a rotating electrical machine according to an embodiment of the present invention.
The rotating electrical machine 1 is mounted on, for example, a hybrid electric vehicle. In the following description, “axial direction” refers to the direction along the rotational axis of the rotating electrical machine 1, and “circumferential direction” refers to the direction along the rotational direction of the rotating electrical machine 1. The “radial direction” refers to a radial direction (radial direction) when the rotation axis of the rotating electrical machine 1 is the center.

  The illustrated rotating electrical machine 1 is thin and is disposed between the engine and the transmission. A rotor 6 of the rotating electrical machine 1 is fitted to a shaft 7 and connected to an engine crankshaft and a transmission via a switching device such as a clutch. The stator 4 is fixed to the housing 3. The housing 3 is fixed to the engine or the transmission case. The rotor 6 is rotatable with respect to the stator 4.

   The rotating electrical machine 1 is supplied with electric power and assists the engine, or drives the vehicle with the rotating electrical machine 1 alone via the transmission. Further, the rotating electrical machine 1 can regenerate a part of the kinetic energy of the vehicle into electric power when the vehicle is decelerated.

  In the present embodiment, the rotating electrical machine 1 is a three-phase four-wire AC type, and a plurality of stator coils 5 provided on the stator 4 correspond to the U phase, V phase, W phase, and neutral phase. Are connected by a power distribution component 10. The power distribution component 10 is provided with a power supply terminal unit 11 corresponding to each phase. In the power supply terminal unit 11, power of each phase is supplied from the battery to the terminal unit 11 of each phase via an inverter. Is done.

FIG. 2 is a cross-sectional perspective view showing a state where the connection ring and the stator coil are assembled to the stator in the rotating electrical machine shown in FIG. 1.
The stator 4 includes a plurality of stator cores 8 arranged along the circumferential direction. The stator core 8 is formed with a tooth portion 12 (see also FIG. 4) that protrudes radially inward. A conductive wire (enameled wire) covered with an insulating coating 5a (see FIG. 4) formed by plating is wound around the tooth portion 12 through a bobbin 9 of an insulating material to form one stator coil 5. Is done. A plurality of stator coils 5 are arranged in the circumferential direction. The stator core 8 arranged in the circumferential direction forms a circular stator 4 by being press-fitted or shrink-fitted into the housing 3. The rotor 6 is illustrated as a permanent magnet type.

  The ends of the stator coil 5 are entangled with the flange portion of the bobbin 9 and then are raised and arranged in the axial direction of the rotating electrical machine 1. Here, the insulating film 5a of the coil terminal portion is peeled off at the start and end of winding of the coil. A power distribution component 10 is provided on the upper surface of the winding portion of the stator coil 5 located on the axial end surface of the stator so as to cover the winding portion. The connection rings 13U, 13V, 13W provided in the power distribution component 10 and the terminal wire 20a on the winding start side of the stator coil 5 are connected for each phase, and the power supply terminal portions 11U, 11V, 11W (see FIG. 3). ), The U-phase, V-phase, and W-phase excitation currents are supplied to the stator coil 5. Further, the terminal wire 20b on the winding end side of the stator coil 5 is connected to the neutral phase connection ring 13N over the entire circumference to constitute a neutral phase of star connection. The power distribution component 10 includes connection rings 13U, 13V, and 13W corresponding to each phase, a connection ring 13N that forms a neutral phase of star connection, and an insulating member 15 that houses these connection rings. In addition, the stator coil 5 and the connection rings 13U, 13V, 13W, and 13N are illustrated as a structure using a round wire.

FIG. 3 is an exploded perspective view showing the configuration of the connection ring of the rotating electrical machine shown in FIG.
The connection rings 13U, 13V, and 13W are annular, and have a plurality of terminal portions 16 protruding in the axial direction of the rotating electrical machine (in this example, eight locations on each connection ring), and three-phase formed on the radially outer side. It has power supply terminal portions 11U, 11V, and 11W. The neutral phase connection ring 13N is also annular, but the connection ring 13N has 24 terminal portions 16 formed therein.
The connection rings 13U, 13V, 13W, and 13N are formed of a copper single wire conductor. For the connection rings 13U, 13V, 13W, 13N, bare copper wires without an insulating film are used. The materials constituting the connection rings 13U, 13V, 13W, 13N will be described later.

  As illustrated in FIG. 2, the connection rings 13U, 13V, 13W, and 13N are disposed on the donut-shaped insulating member 15 in a concentric plane. In the insulating member 15, grooves 18 corresponding to the connection rings 13U, 13V, 13W, and 13N are formed. The connection rings 13U, 13V, 13W, 13N are installed in the groove 18 in the order of the connection rings 13N, 13W, 13V, 13U from the inner diameter side of the stator 4, and are integrated as the power distribution component 10. Further, the terminal portions 16 of the connection rings 13U, 13V, 13W, and 13N are arranged so as to be shifted in the circumferential direction so as not to be adjacent to each other.

FIG. 4 is a perspective view illustrating a state where the stator coil is wound in the stator illustrated in FIG. 2.
An insulating film 5 a such as an enamel plating film is formed on the surface of the stator coil 5. The terminal wires 20a and 20b on the winding start side and winding end side of the stator coil 5 have the insulating coating 5a at the tip thereof peeled off. The terminal wires 20 a and 20 b are entangled with the flange portion of the bobbin 9, then bent and formed up in the axial direction of the stator 4.

  The terminal wire 20b on one winding end side rises as a neutral phase immediately below the terminal portion 16 of the connection ring 13N (see FIGS. 2 and 3), and the terminal wire 20a on the other winding start side has U, The connection rings 13U, 13V, and 13W (see FIGS. 2 and 3) that are connected to the V and W phases are provided immediately below the terminal portions 16 of the connection rings.

Reference is again made to FIG.
In the power distribution component 10, the insulating member 15 is provided with holes 17 into which the terminal wires 20 a and 20 b of the stator coil 5 are inserted. The terminal wires 20a and 20b of the stator coil 5 are inserted into the holes 17 of the insulating member 15, and further connected to the terminal portions 16 of the connection rings 13U, 13V, and 13W. A protrusion 21 is formed on the terminal portion 16. The terminal wires 20a and 20b of the stator coil 5 are joined to the corresponding connection rings 13U, 13V, 13W, and 13N by welding such as TIG welding at the protruding portion 21. Details of the bonding structure will be described later.

In this embodiment, the insulating member 15 is provided with 24 holes for the connection ring 13N and 8 holes for each of the connection rings 13U, 13V, and 13W.
Further, the groove portion 18 of the insulating member 15 is provided with a relief 19 at a portion corresponding to the terminal portion 16 of the connection ring for avoiding a thermal effect when the terminal portion 16 is joined.

FIG. 5 is a cross-sectional perspective view showing the configuration of the terminal portion of the connection ring in the stator shown in FIG.
With reference to FIG. 5, the connection structure of each terminal part 16 of the connection rings 13U, 13V, and 13W and the terminal wire 20a of the stator coil 5, and the connection ring 13N and the terminal wire 20b of the stator coil 5 will be described.
The connection structures of the terminal portions 16 of the connection rings 13U, 13V, and 13W and the terminal wire 20a of the stator coil 5 and the connection ring 13N and the terminal wire 20b of the stator coil 5 are the same. Therefore, in the following description, the connection rings 13U, 13V, 13W, and 13N are represented as connection rings 13 and the terminal lines 20a and 20b are represented as terminal lines 20 as appropriate.
The terminal portion 16 of the connection ring 13 includes a protruding portion 21, a groove 22, and a through hole 23. The protruding portion 21 is formed to protrude in a cylindrical shape on one surface of the rotating ring 1, that is, the connection ring 13 in the axial direction of the stator 4. The groove 22 is provided on the side opposite to the one surface on which the projection 21 of the connection ring 13 is provided. The through hole 23 is formed through the connection ring 13 from the bottom surface of the groove 22 to the end surface 21 a of the protrusion 21. The terminal wire 20 is inserted into the through-hole 23 from the groove 22 side of the connection ring 13, and the end surface 26 is disposed at a position that is substantially flush with the end surface 21 a of the protrusion 21.
In this state, the projection 21 of the connection ring 13 and the terminal wire 20 of the stator coil 5 are joined by welding such as TIG welding, and the end wire 21 on the projection 21 of the connection ring 13 and the terminal wire of the stator coil 5 are connected. The joining portion 24 is formed on the end face 26 of the 20.

  The terminal portion 16 of the connection ring 13 is formed by plastic working. That is, the protrusion 21 is formed simultaneously with the formation of the groove 22, and the through hole 23 for inserting the terminal wire 20 of the stator coil 5 is formed substantially at the center of the protrusion 21. By forming the protrusion 21 simultaneously with the groove 22 by plastic working, the space of the groove 22 and the volume of the protrusion 21 can be made substantially equal, and the protrusion 21 can be easily formed. Further, by forming the protrusion 21 simultaneously with the groove 22 by plastic working, the volume excluding the space of the through hole 23 of the protrusion 21 is the tip of the terminal wire 20 of the stator coil inserted into the through hole 23. The volume can be substantially equal to. For this reason, the joining by welding, such as TIG welding, is stabilized by the heat balance at the time of melting.

  After the terminal wire 20 of the stator coil 5 is inserted into the through hole 23, the terminal wire 20 of the connection ring 13 is fixed to the protrusion 21 of the connection ring 13 by caulking the protrusion 21 of the connection ring 13 from the outer periphery. .

  After joining the connection ring 13 and the stator coil 5, the connection ring 13 including the joint portion 24 between the terminal portion 16 of the connection ring 13 and the terminal wire 20 of the stator coil 5 and disposed on the insulating member 15 is provided. Cover with insulating resin. Thereby, the insulation quality between each connection ring further improves.

  In the present embodiment, the insulating member 15 is formed with a groove portion 18 in which the connection rings 13U, 13V, 13W, and 13N are disposed, and a creeping distance to the connection rings 13U, 13V, 13W, and 13N is ensured. For this reason, a bare copper wire without an insulating film can be used as the connection rings 13U, 13V, 13W, 13N.

  As described above, the terminal portion 16 of the connection ring 13 and the terminal wire 20 of the stator coil 5 are joined by welding such as TIG welding. The connection ring 13 and the stator coil 5 are made of copper. In order to suppress the occurrence of voids and the like in the joint 24 and ensure the reliability of the joint 24, the connection ring 13 and the stator coil 5 are both made of oxygen-free copper having a purity level of 6N (99.9999%), high It is necessary to use pure copper. In order to obtain oxygen-free copper and high-purity copper having a purity level of 6N, a large number of steps are required to reduce impurities such as oxygen, resulting in high costs. Therefore, the use of the connection ring 13 and the stator coil 5 made of oxygen-free copper having a purity level of 6N and high-purity copper and the stator coil 5 are factors that increase the cost of the rotating electrical machine 1.

  Therefore, in the present embodiment, a dilute copper alloy having a purity of 5N (99.999%) or less, preferably 4N (99.99%) or less containing titanium is used for the connection ring 13, and a purity of 5N or less is used for the stator coil 5. Desirably, ordinary copper having a purity of 4N or less was used. As an example, the dilute copper alloy of the connection ring 13 includes 2 to 12 mass ppm of sulfur, 2 to 30 mass ppm of oxygen, and 4 to 55 mass ppm of titanium, with the balance being made of copper. This diluted copper alloy has a copper purity of 4N or 5N, but has a high bonding reliability and is cheaper than oxygen-free copper and high-purity copper.

  FIGS. 6A to 6C are schematic views showing a joined state between the terminal portion 16 of the connection ring 13 and the terminal wire 20 of the stator coil 5. FIG. 6A shows an embodiment of the present invention, that is, the connection ring 13 is made of 4N copper containing titanium, and the stator coil 5, that is, the terminal wire 20 is made of normal 4N copper. It is a thing. FIG. 6B is a comparative example in which the connection ring 13 and the stator coil 5 are both made of ordinary copper having a purity of 4N. FIG. 6C shows a conventional product in which the connection ring 13 and the stator coil 5 are both made of high-purity copper having a purity of 6N. The black spots shown in each figure are voids.

  In the embodiment of the present invention shown in FIG. 6 (A), 1 to 2 voids are observed, but the quantity, size, and width of the generation region are all shown in FIG. 6 (B). Compared to a comparative example in which copper having a purity of 4N is bonded to each other, it is much smaller. In the comparative example shown in FIG. 6B, since copper with a purity of 4N contains oxygen, oxygen O2 is precipitated by welding, and a large number of large voids are generated over a wide range. On the other hand, in the Example of this invention, since the connection ring 13 contains titanium, it contains the same amount of oxygen as in the comparative example. However, even if welding is performed, titanium oxide (Ti-O ), Titanium dioxide (Ti-O2) is generated, and the generation of voids is suppressed. It was confirmed that the effect of suppressing the generation of voids due to the inclusion of titanium was obtained even when titanium was contained only in the connection ring 13 and not contained in the stator coil 5.

  In the joining of the high purity copper (6N) shown in FIG. 6C, almost no voids are observed. Compared to this, the suppression of void generation in the embodiment of the present invention is slightly less. However, it was confirmed that the reliability of the bonding was not affected.

The stator coil 5 may be formed of the same material as the connection ring 13, that is, a diluted copper alloy containing titanium. However, the stator coil 5 needs to be insulated by applying an insulating film 5a such as an enamel plating film except for the terminal wire 20, but the diluted copper alloy containing titanium forms a strong passive film. It is difficult to form the insulating film 5a such as enamel by plating. Although there is a method of plating by preventing the regeneration of the passive film by pretreatment, the cost is increased.
For this reason, it decided to form with the copper of the normal purity 4N which does not contain titanium substantially. The production of copper having a normal purity of 4N has an advantage that the production cost is lower than that in the case of producing a dilute copper alloy containing a predetermined amount of titanium.

According to the embodiment of the present invention, the following effects can be obtained.
(1) In the stator 4 in which the terminal portion 16 of the connection ring 13 and the terminal wire 20 of the stator coil 5 are joined by welding, the connection ring 13 is made of copper containing more titanium than the stator coil 5. The stator coil 5 was formed of copper having a purity of 5N (99.999%) or less. Thereby, cost reduction of the connection ring 13 and the stator coil 5 can be achieved, and the reliability of joining can be ensured.

(2) The stator coil 5 was formed of copper having a normal purity of 4N and covered with an enamel plating film. For this reason, the stator coil 5 can be efficiently manufactured, and reliability at the time of joining can be ensured even by welding with the connection ring 13 formed of copper containing titanium.

(3) By making the purity of the copper of the stator coil 5 4N (99.99%) or less, the cost can be further reduced.

  In addition, in the said embodiment, it illustrated as a structure using the bare copper wire without an insulating film as the connection rings 13U, 13V, 13W, and 13N. However, plated copper wiring may be used as the connection rings 13U, 13V, 13W, and 13N.

  In the said embodiment, it illustrated as the rotary electric machine 1 of a three-phase 4 wire type star connection type. However, the present invention does not have a neutral phase, but can be applied to a three-phase AC type rotating electrical machine of delta connection type. Further, the present invention can be applied to a three-phase six-wire rotary electric machine. Furthermore, the present invention can be applied to a larger number of phases (for example, six phases) than three phases.

  Although the connection ring 13 and the stator coil 5 are exemplified as round lines, both may be square lines or a combination of round lines and square lines. Moreover, you may make it mix a round wire and a square wire in the one connection ring 13 by deform | transforming a copper wire. Similarly, a round wire or a square wire may be mixed in one stator coil 5. The round line need not be a perfect circle and may be an ellipse. The square line need not be a square, and may be a polygon other than a square.

  In the above embodiment, the rotor 6 is exemplified as the permanent magnet type rotating electrical machine 1. However, the present invention can be applied not only to the permanent magnet type but also to the induction type, synchronous reluctance, claw magnetic pole type, and the like. Further, although the explanation is made with the inner rotation type, the present invention can also be applied to an outer rotation type, a linear motor, and an axial gap type.

  Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other embodiments conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 4 Stator 5 Stator coil 6 Rotor 8 Stator core 11, 11U, 11V, 11W Power supply terminal part 12 Teeth part 13, 13U, 13V, 13W, 13N Connection ring 16 Terminal part 20, 20a, 20b Terminal line 21 Protrusion 21a End face 22 Groove 23 Through-hole

Claims (5)

A rotor,
A stator core having a tooth portion, a stator coil wound around the tooth portion and having a terminal wire protruding from an end surface in the axial direction of the stator core, and the terminal wire of the stator coil are joined. And a stator having a connection ring having a terminal portion,
The stator coil has a winding portion wound around the teeth portion covered with an insulating film,
The connection ring and the stator coil are made of copper,
The connection ring is a dilute copper alloy having a purity of 4N (99.99%) or less containing oxygen and titanium, and the stator coil is a copper having a purity of 4N (99.99%) or less not containing the titanium. Rotating electric machine. In the rotating electrical machine according to claim 1,
The rotary electric machine, wherein the insulating film covering the stator coil is an enamel plating film. In the rotating electrical machine according to claim 1,
The said connection ring is a rotary electric machine which contains 2-12 mass ppm sulfur, 2-30 mass ppm oxygen, 4-55 mass ppm titanium, and the remainder consists of copper. In the rotary electric machine as described in any one of Claims 1-3 ,
The terminal portion of the connection ring includes a protrusion protruding on one surface in the axial direction of the stator in the connection ring, a groove provided on the opposite side of the protrusion of the connection ring, and the groove from the groove Having a through-hole penetrating to the end face of the protrusion,
The rotating electrical machine in which the terminal wire of the stator coil is disposed in the through hole of the terminal portion of the connection ring and joined to the protruding portion. In the rotating electrical machine according to claim 4 ,
The rotating electrical machine in which the terminal wire of the stator coil and the terminal portion of the connection ring are joined by welding.

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