JP7306040B2 - motor - Google Patents

Description

The present invention relates to motors.

In recent years, the development of motors mounted on hybrid vehicles and electric vehicles has been actively carried out. Patent Literature 1 describes a construction method called a cassette method in which pre-wound coils are radially moved and attached to teeth.

WO2018/092552

An umbrella portion may be provided at the tip of the tooth portion. The umbrella section also functions to prevent the coil from being detached from the slot. From this point of view, it is desirable that the gap between the adjacent umbrella portions is narrow. On the other hand, when adopting the cassette method, if the gap between the adjacent umbrella portions is too narrow, the tact time of the coil mounting process for mounting the coil becomes long.

SUMMARY OF THE INVENTION In view of the above problems, an object of one aspect of the present invention is to provide a motor capable of shortening a coil mounting process for mounting a coil.
An object of one aspect of the present invention is to provide a motor (having a function of suppressing detachment of a coil) that suppresses lengthening of time in a coil mounting process.

One aspect of the motor of the present invention includes a rotor rotatable about a central axis, and a stator surrounding the rotor from the outside in the radial direction. The stator has an annular core-back portion about the central axis. and a stator core having a plurality of tooth portions extending radially inward from the core back portion and arranged in the circumferential direction; a coil made of a coil wire and mounted on the tooth portions; a wedge member positioned radially inward of the coil within the slot, wherein the tooth portion includes a tooth body extending along the radial direction and an umbrella portion positioned at a radially inner end of the tooth body. , wherein the gap dimension between the umbrella portions adjacent in the circumferential direction is at least twice the wire diameter of the coil wire, and the wedge member includes a body piece extending along the circumferential direction, and the body piece and a pair of side pieces extending radially outward along side surfaces of the tooth body from both circumferentially opposite ends of the tooth body, wherein the body pieces close gaps between the umbrella portions adjacent in the circumferential direction, A corner portion between the main body piece and the side piece is bent, and the umbrella portion has a protruding portion that protrudes in the circumferential direction with respect to the side surface of the tooth main body facing the circumferential direction, and the protruding dimension of the protruding portion is It is larger than half the wire diameter of the coil wire and smaller than the wire diameter of the coil wire.

According to one aspect of the present invention, a motor is provided that can shorten a coil mounting process for mounting a coil.
According to one aspect of the present invention, there is provided a motor (having a coil detachment suppressing function and suppressing lengthening of time in the coil mounting process).

FIG. 1 is a conceptual diagram of a motor unit of one embodiment. FIG. 2 is a cross-sectional view of the motor of one embodiment. FIG. 3 is a partial cross-sectional view of a stator of one embodiment. FIG. 4 is a schematic diagram showing the winding configuration of the coil of one embodiment. FIG. 5 is a schematic diagram showing one step of the stator manufacturing method according to one embodiment.

Hereinafter, motors and motor units according to embodiments of the present invention will be described with reference to the drawings. It should be noted that the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. Also, in the drawings below, in order to make each configuration easier to understand, there are cases where the actual structure and the scale and number of each structure are different.

In the following description, the vertical direction is defined based on the positional relationship when the motor unit 10 of this embodiment shown in each drawing is mounted on a vehicle positioned on a horizontal road surface. Moreover, in the drawings, the Y-axis extending in the lateral direction (vehicle width direction) of the vehicle is shown as appropriate.

FIG. 1 is a conceptual diagram of a motor unit 10 of one embodiment. A motor shaft (central shaft) J1, a counter shaft J3, and an output shaft J4, which will be described later, are virtual axes that do not actually exist.

The motor unit 10 is mounted on the vehicle and drives the vehicle by rotating wheels. The motor unit 10 is mounted, for example, on an electric vehicle (EV). The motor unit 10 may be installed in a vehicle using a motor as a power source, such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHV), or the like.

As shown in FIG. 1 , the motor unit 10 includes a motor 9 , a transmission mechanism 5 (transaxle), an inverter unit 8 and a housing 6 .

The inverter unit 8 is fixed to the outer surface of the housing 6 in the inverter case 8b. The inverter unit 8 has an inverter 8a and an inverter case 8b that accommodates the inverter 8a. Although not shown, the inverter unit 8 further has a circuit board and a capacitor.

The inverter 8a is connected to the motor 9 via a busbar (not shown). The inverter 8a supplies alternating current to the motor 9 via the busbar. Thereby, the inverter unit 8 supplies electric power to the motor 9 .

The transmission mechanism 5 transmits the power of the motor 9 and outputs it from the output shaft 55 . The transmission mechanism 5 incorporates a plurality of mechanisms responsible for power transmission between the drive source and the driven device.

The transmission mechanism 5 includes a motor drive shaft 11, a motor drive gear 21, a counter shaft 13, a counter gear (large gear portion) 23, a drive gear (small gear portion) 24, a ring gear 51, and an output shaft (axle ) 55 and a differential gear 50 .

The motor drive shaft 11 extends along the motor axis J1. Motor drive shaft 11 is rotated by motor 9 . A motor drive gear 21 is fixed to the motor drive shaft 11 . Motor drive gear 21 meshes with counter gear 23 .

The counter gear 23 extends along the counter shaft J3 and is fixed to the counter shaft 13 . A drive gear 24 is fixed to the counter shaft 13 in addition to the counter gear 23 . Drive gear 24 meshes with ring gear 51 .

Ring gear 51 is fixed to differential gear 50 . The ring gear 51 rotates around the output shaft J4. The ring gear 51 transmits the power of the motor 9 transmitted through the drive gear 24 to the differential device 50 .

The differential gear 50 is a device for transmitting the torque output from the motor 9 to the wheels of the vehicle. The differential 50 is connected to a pair of output shafts 55 . Wheels are attached to the pair of output shafts 55, respectively. The differential gear 50 has a function of transmitting the same torque to the pair of output shafts 55 while absorbing the speed difference between the left and right wheels when the vehicle is turning.

Housing 6 accommodates motor 9 and transmission mechanism 5 . The housing 6 is made of an aluminum alloy manufactured by die casting, for example. Inside the housing 6, a motor chamber A1 that houses the motor 9 and a gear chamber A2 that houses the transmission mechanism 5 are provided. Oil O accumulates inside the housing. The oil O is used for lubricating the transmission mechanism 5 and for cooling the motor 9 .

The motor 9 is a motor-generator having both a function as an electric motor and a function as a generator. The motor 9 mainly functions as an electric motor to drive the vehicle, and functions as a generator during regeneration. The motor 9 is an inner rotor type motor.

The motor 9 has a rotor 31 and a stator 32 surrounding the rotor 31 from the outside in the radial direction of the motor shaft (central axis) J1.
In the following description, the radial direction centered on the motor shaft J1 is simply referred to as the "radial direction", and the circumferential direction centered on the motor shaft J1, that is, the circumference of the motor shaft J1 is simply referred to as the "circumferential direction". call.

The rotor 31 is rotatable around a horizontally extending motor shaft J1. The rotor 31 rotates when power is supplied to the stator 32 from a battery (not shown). The rotor 31 is connected to the motor drive shaft 11 of the transmission mechanism 5 and rotates the motor drive shaft 11 . The torque of the rotor 31 is thereby transmitted to the transmission mechanism 5 .

FIG. 2 is a sectional view of the motor 9. As shown in FIG. In FIG. 2, the coil wire 34a forming the coil 34 is shown in a simplified manner.

The rotor 31 has a rotor core 31a and a rotor magnet 31b.
The rotor core 31a is configured by laminating electromagnetic steel sheets. The rotor core 31a is a cylindrical body extending along the axial direction. The rotor core 31a is provided with a holding hole 31aa into which the rotor magnet 31b is inserted and fixed.
The rotor magnet 31b faces the stator 32 in the radial direction. The rotor magnet 31b is held embedded in the rotor core 31a. In this embodiment, the rotor magnet 31b is composed of eight segment magnets 31ba. That is, the rotor magnet 31b of this embodiment has eight segment magnets 31ba. Further, the rotor magnet 31b of this embodiment has eight poles. That is, the rotor 31 of this embodiment has 8 poles. Note that the number of poles of the rotor 31 is not limited to that of this embodiment. Also, the rotor magnet 31b may be an annular ring magnet.

The stator 32 has a stator core 33 , a coil 34 made of coil wire 34 a (not shown in FIG. 2 ), a plurality of insulating papers 35 , and a plurality of wedge members 36 .

The stator core 33 is made of a plurality of magnetic steel sheets laminated along the axial direction. The stator core 33 has an annular core-back portion 33a centered on the motor shaft J1, and a plurality of tooth portions 33b extending radially inward from the core-back portion 33a.

The plurality of tooth portions 33b are arranged at regular intervals in the circumferential direction. A coil 34 is attached to the tooth portion 33b. Slots 39 are provided between tooth portions 33b adjacent in the circumferential direction. The slot 39 opens radially inward at an open end 39a. A portion of the coil 34 excluding the coil ends is accommodated in the slot 39 . A portion of the coil wire 34 a extending in the axial direction passes through the slot 39 . Also, one insulating paper 35 and one wedge member are arranged in the slot 39 .

In this embodiment, the stator core 33 has 48 teeth 33b. That is, the stator 32 of this embodiment has 48 slots. The number of slots of the stator 32 is appropriately set according to the number of poles of the rotor magnet 31b and the winding method of the coil 34. FIG.

FIG. 3 is a partial cross-sectional view of the stator 32. FIG.
The tooth portion 33b has a tooth body 33c extending in the radial direction and an umbrella portion 33d located at the radially inner end portion of the tooth body 33c.

The tooth main body 33c extends with a uniform width along the radial direction. The tooth main body 33c has a pair of side surfaces 33ca facing both sides in the circumferential direction. The umbrella portion 33d is wider in the circumferential direction than the tooth main body 33c. A radially inward facing surface of the umbrella portion 33d has an arc shape centered on the motor shaft J1 when viewed from the axial direction.

The umbrella portion 33d has a pair of projecting portions 33e positioned on both sides in the circumferential direction. The protruding portion 33e protrudes in the circumferential direction with respect to the side surface 33ca of the tooth main body 33c. The protruding portions 33e of a pair of tooth portions 33b adjacent in the circumferential direction face each other in the circumferential direction with the opening end 39a of the slot 39 interposed therebetween. Therefore, the pair of protrusions 33e adjacent in the circumferential direction narrows the opening end 39a of the slot 39. As shown in FIG.

The projecting portion 33e has a retaining surface 33ea facing radially outward. The holding surface 33ea is a surface that continues to the side surface 33ca of the tooth body 33c. Further, the holding surface 33ea is a surface for hooking and holding the wedge member 36 in the slot 39. As shown in FIG.

In this embodiment, the dimension d along the circumferential direction of the open end 39a of the slot 39 is at least twice the wire diameter p of the coil wire 34a. By setting the dimension d of the open end 39a to be at least twice the wire diameter p, it is possible to shorten the time required for the coil mounting step of mounting the coil 34 on the tooth portion 33b as will be described later. The dimension d along the circumferential direction of the open end 39a is the dimension d of the gap between the umbrella portions 33d adjacent to each other in the circumferential direction.

The insulating paper 35 is provided to ensure insulation between the coil wire 34 a and the stator core 33 . Insulating paper 35 is placed between coil 34 and stator core 33 in slot 39 . In the coil mounting step of mounting the coil 34 on the tooth portion 33 b , the insulating paper 35 is placed in the slot 39 in advance before inserting the coil 34 into the slot 39 .

The insulating paper 35 extends along the axial direction with a uniform cross-sectional shape. The insulating paper 35 has a first piece 35a extending along the circumferential direction and a pair of second pieces 35b extending radially inward from both circumferential ends of the first piece 35a. The first piece 35 a and the pair of second pieces 35 b are folded so that the insulating paper 35 is along the inner surface of the slot 39 . The first piece 35a extends in the slot 39 along the radially inwardly facing surface of the core back portion 33a. The second piece 35b extends along the side surface 33ca of the tooth body 33c inside the slot 39. As shown in FIG. The pair of second pieces 35b face each other in the circumferential direction.

Wedge member 36 is positioned radially inward of coil 34 within slot 39 . The wedge member 36 prevents the coil wire 34 a from protruding radially inward from the slot 39 . The wedge member 36 is retained in the slot 39 by hooking on the protrusion 33e. In the coil mounting step of mounting the coil 34 on the tooth portion 33b, the wedge member 36 is inserted along the axial direction after inserting the coil 34 into the slot 39. As shown in FIG.

Wedge member 36 extends axially with a uniform cross-sectional shape. The wedge member 36 has a body piece 36a extending along the circumferential direction and a pair of side pieces 36b extending radially outward from both circumferential ends of the body piece 36a.

The main body piece 36a closes the gap between the umbrella portions 33d adjacent in the circumferential direction. That is, the body piece 36a closes the open end 39a of the slot 39. As shown in FIG. Both circumferential ends of the main body piece 36a extend along the holding surface 33ea on the radially outer side of the projecting portion 33e.

The side piece 36b extends along the side surface 33ca of the tooth body 33c. The pair of side pieces 36b face each other in the circumferential direction. The side piece 36 b overlaps the second piece 35 b of the insulating paper 35 . That is, the radially inner end of the second piece 35b of the insulating paper 35 is sandwiched between the side piece 36b and the tooth main body 33c.

A corner portion 36c is provided at the boundary between the body piece 36a and the side piece 36b. That is, the wedge member 36 is provided with a pair of corner portions 36c. The corner portion 36c extends linearly along the axial direction. The corner portion 36c is located radially outside the projecting portion 33e. The corner portion 36c of this embodiment is sharply bent. The wedge member of the present embodiment is formed by a metal mold so as to have a bent shape, rather than by bending a sheet formed into a flat shape.

Next, the winding configuration of the coil 34 in this embodiment will be described based on FIG.
As shown in FIG. 4, the plurality of coils 34 are classified into those corresponding to U-phase, V-phase and W-phase. Four coils 34 for each phase are provided. Each coil 34 has an inner coil 34A and an outer coil 34B wound around the inner coil 34A. One coil 34 is composed of one coil wire 34a. That is, the inner coil 34A and the outer coil 34B are connected to each other by a single coil wire 34a.

The inner coil 34A straddles the five tooth portions 33b. That is, the inner coil 34A is distributed winding. The outer coil 34B straddles seven teeth 33b including five teeth 33b wound by the inner coil 34A. That is, the outer coil 34B is distributed winding. The slot 39 through which the outer coil 34B passes is adjacent to the slot 39 through which the inner coil 34A passes. Five teeth are arranged between the outer coils 34B of the coils 34 adjacent in the circumferential direction.

According to this embodiment, the coil 34 is double-wound with an inner coil 34A and an outer coil 34B. The inner coil 34A functions as one coil surrounding the five teeth 33b. On the other hand, the outer coil 34B functions as one plastic coil (virtual coil 34V) positioned between the two inner coils 34A. The virtual coil 34V is formed by a coil wire 34a on one side in the circumferential direction of one outer coil 34B and a coil wire 34a on the other side in the circumferential direction of another outer coil 34B positioned on one side in the circumferential direction of the outer coil 34B. Configured.
In FIG. 4, only in the U-phase configuration, the virtual coil 34V formed by two adjacent outer coils 34B is indicated by a dashed line.

In the cassette type coil mounting process, the inner coil 34A and the outer coil 34B can be inserted at the same time. Therefore, according to the present embodiment, mounting of the coil 34 is completed by inserting the coil four times in each phase.
On the other hand, if a coil corresponding to the inner coil 34A and a coil corresponding to the virtual coil 34V are provided, it is necessary to insert these coils separately. Therefore, in this case, eight coil insertions are required.
That is, according to this embodiment, the number of times the coil 34 is inserted into the slot 39 can be reduced, and the coil mounting process can be shortened.

FIG. 5 is a schematic diagram showing a coil mounting process for mounting the coils 34 on the tooth portions 33b in the method of manufacturing the stator 32 of the present embodiment. The coil mounting process of this embodiment is a construction method called a cassette method in which the pre-wound coil 34 is radially inserted from the opening end 39 a of the slot 39 . The coil mounting process of this embodiment is performed using the coil mounting device 4 .

The coil mounting device 4 is arranged radially inside the stator core 33 while holding the coil wire 34a wound in advance by the winding process. In the winding process, the coil wire 34a is wound twice around one winding frame. Therefore, the coil wires 34a are aligned in two rows in the state where the coils 34 are formed. The coils 34 are held by the coil mounting device 4 in a state in which the coil wires 34a are arranged in two rows in the circumferential direction and in a plurality of rows in the radial direction. The coil 34 is inserted into the slot 39 from the open end 39a by the coil mounting device 4 with the coil wires 34a arranged in two rows in the circumferential direction. After the coil 34 is inserted into the slot 39, the wedge member 36 is axially inserted into the slot 39. As shown in FIG.

According to this embodiment, the coil mounting device 4 inserts the coil wires 34a into the slots 39 in two rows. Therefore, it is possible to prevent the coil wires 34a from intersecting each other in the slot 39 in the coil mounting process, and to increase the space factor of the coil wires 34a in the slot 39 .

Next, based on FIG. 3, the effect of the stator 32 of this embodiment is demonstrated.
According to the present embodiment, the gap dimension d between the umbrella portions 33d adjacent in the circumferential direction is at least twice the wire diameter p of the coil wire 34a. The coil wires 34a arranged in two rows can be inserted into the slots 39 from the gaps between the umbrella portions 33d adjacent to each other in the circumferential direction, and the coil mounting process can be shortened.

According to this embodiment, the corner portion 36c of the wedge member 36 is sharply bent. A conventional wedge member is in the form of a flat sheet and is curved following the shape of the slot when it is inserted into the slot. On the other hand, since the wedge member 36 of this embodiment has the corner portion 36c in advance, the wedge member 36 is caught by the umbrella portion 33d at the corner portion 36c. Therefore, even in the case where the gap dimension d is secured large for the purpose of shortening the coil mounting process as in the present embodiment, the wedge member 36 is likely to remain in the slot 39, and the coil 34 can be displaced from the slot 39. It can be suppressed to jump out in the direction.

In the present embodiment, it is preferable that the radius of curvature R of the corner portion 36c viewed from the axial direction is 9 mm or less. By setting the curvature radius R of the corner portion 36 c to 9 mm or less, the corner portion 36 c is easily caught by the umbrella portion 33 d and the wedge member 36 is more easily retained in the slot 39 .
In this specification, the radius of curvature R of the corner portion 36c means the radius of curvature of the outer side of the corner portion 36c. That is, the curvature radius R of the corner portion 36c is the curvature radius of the portion where the surface of the main body piece 36a facing the umbrella portion 33d and the surface of the side piece 36b facing the tooth main body 33c are connected.

In this embodiment, the gap dimension d between the umbrella portions 33d adjacent in the circumferential direction is preferably three times or less the wire diameter p of the coil wire 34a. If the gap dimension d exceeds three times the wire diameter p, the open end 39a of the slot 39 becomes too wide, and the coil wire 34a is likely to protrude from the slot 39 together with the wedge member 36 . The wedge member 36 and the coil wire 34a can be easily retained in the slot 39 by setting the gap dimension d to three times or less the wire diameter p.

In this embodiment, the projection dimension h of the projecting portion 33e is preferably larger than half the wire diameter p of the coil wire 34a. By making the projecting dimension h larger than half the wire diameter p, when the coil wire 34a in the slot 39 approaches the open end 39a, the coil wire 34a and the holding surface 33ea of the projecting portion 33e move the wedge member 36. Sandwich. This retains the wedge member 36 within the slot 39 , making it easier for the wedge member 36 to stay in the slot 39 .
The projection dimension h of the projecting portion 33e means the distance dimension from the side surface 33ca to the tip position of the projecting portion 33e in the normal direction of the side surface 33ca of the tooth body 33c.

In this embodiment, the angle θ between the holding surface 33ea of the projection 33e and the side surface 33ca of the tooth body 33c is preferably 111° or less. By setting the angle θ to 111° or less, the reliability of holding the wedge member 36 on the holding surface 33ea can be enhanced.
Also, the angle θ is preferably 100° or more. By bringing the angle θ closer to 90°, it becomes easier to hold the wedge member 36 on the holding surface 33ea. However, if the angle .theta. Setting the angle θ to 100° or more facilitates manufacturing the stator core 33 .

Although the embodiment of the present invention has been described above, the combination of each configuration in the embodiment is an example, and addition, omission, replacement, and other modifications of the configuration are possible without departing from the scope of the present invention. is. Moreover, the present invention is not limited by the embodiments.

9 Motor 31 Rotor 32 Stator 33 Stator core 33a Core back portion 33b Teeth portion 33c Teeth main body 33ca Side surface 33d Umbrella portion 33e Protruding portion 34 Coil 34a... coil wire, 36... wedge member, 36a... body piece, 36b... side piece, 36c... corner portion, 39... slot, d... dimension, h... projection dimension, J1... motor shaft (central axis), p... wire Diameter, R... radius of curvature, θ... angle

Claims (4)

a rotor rotatable about a central axis;
a stator surrounding the rotor from the outside in the radial direction,
The stator is
a stator core having an annular core-back portion centered on a central axis and a plurality of tooth portions extending radially inward from the core-back portion and arranged in a circumferential direction;
a coil made of a coil wire and attached to the teeth;
a wedge member positioned radially inward of the coil in a slot between the tooth portions adjacent in the circumferential direction;
The teeth portion is
a tooth body extending along the radial direction;
an umbrella portion located at a radially inner end portion of the tooth body;
A gap dimension between the umbrella portions adjacent in the circumferential direction is at least twice the wire diameter of the coil wire,
The wedge member is
a body piece extending along the circumferential direction;
a pair of side pieces extending radially outward along side surfaces of the tooth body from circumferentially opposite side ends of the body piece,
The main body piece closes a gap between the umbrella portions adjacent in the circumferential direction,
A corner portion between the body piece and the side piece is bent ,
The umbrella portion has a protruding portion that protrudes in the circumferential direction with respect to the side surface of the tooth body facing the circumferential direction,
a projection dimension of the projecting portion is larger than half the wire diameter of the coil wire and smaller than the wire diameter of the coil wire;
motor. The corner portion has a radius of curvature of 9 mm or less when viewed from the axial direction.
A motor according to claim 1. The gap dimension between the umbrella portions adjacent in the circumferential direction is three times or less the wire diameter of the coil wire,
A motor according to claim 1 or 2. The umbrella portion has a protruding portion that protrudes in the circumferential direction with respect to the side surface of the tooth body facing the circumferential direction,
The angle formed by the radially outer surface of the protruding portion and the side surface of the tooth body is 111° or less,
A motor according to any one of claims 1 to 3 .

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