JP2021019388A - Electric motor, power device for vehicle, power generator, vehicle wheel bearing with power generator, and manufacturing method of electric motor - Google Patents

Abstract

To provide an electric motor, a power device for a vehicle, a power generator, a vehicle wheel bearing with a power generator, and a manufacturing method of the electric motor, where a fractional slot structure is provided, reduction in manufacturing man-hours can be achieved, and a coil wire connection space can be reduced.SOLUTION: An electric motor 1 comprises: a stator 2 that has a stator core 4 and a stator coil 5 including a plurality of coils 5a that are wound on each tooth 4a; and a rotor 3 that is positioned facing the stator 2 in a radial direction. In this electric motor 1, when N is the number of pairs of poles of the rotor 3 and P is the number of teeth 4a per one phase in the stator 2, P/3N is not an integer. The stator core 4 is an assembled structure where at least a plurality of tooth components 6 that are divided at each tooth are assembled in a circular ring shape. Among each of the coils 5a, coils 5a of the same phase form a serial circuit, and among the coils of the same phase, coils 5a that are neighboring in the circumferential direction comprise one strand and are structured with opposite polarities with regard to one another.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing an electric motor, a power unit for a vehicle, a generator, a bearing for wheels with a generator, and an electric motor, and relates to a technique capable of simplifying a connection process of a fractional groove motor and facilitating the manufacture.

A three-phase synchronous motor (hereinafter referred to as a motor) having a general radial structure has a structure in which teeth are evenly arranged on an annular member as a stator core structure. A coil is wound around the tooth, and the coil is configured by connecting three-phase power lines (for example, Patent Documents 1 and 2).

In a motor, a motor in which the number of slots per phase divided by the total number of poles is a fraction is referred to as a fractional groove motor (for example, Patent Documents 3 and 4). In a three-phase synchronous motor, when the number of pole pairs of the rotor is N and the number of slots per phase (= number of teeth) is P, P / 3N is a fraction. The fractional groove motor has low vibration and low torque ripple because the torque generation position during driving is dispersed over the entire circumference of the motor. Further, since the position where the tip of the stator teeth and the magnet are closest to each other is dispersed over the entire circumference of the motor, the attractive force of the magnet is dispersed and the cogging torque is low.

However, it is difficult to manufacture a coil circuit because the coil circuit configuration has a large periodicity. The ratio of 5: 4 with the number of pole pairs N = 5 of the rotor and the number of slots P = 4 per phase in the configuration of the fractional groove motor, that is, the total number of poles 2N for a three-phase motor: the total number of slots 3P = In the case of a motor having a ratio of 10:12, the position of the phase and the direction of the winding in each tooth are as shown in FIG. 19 (b). This is because the polarities of the adjacent teeth 50 in the same phase are opposite to each other, and when forming a series circuit with the adjacent teeth 50 and 50, if the windings are made in the same direction, the winding start and winding of the coils 51 of each other are performed. The ends must be connected, and a wiring step is required to connect the adjacent coils.

In the general integer groove motor shown in FIG. 19A, the winding directions of the adjacent coils 51 are constant and their polarities are also the same. Therefore, for example, the neutral point is connected to a uniform coil end. However, it can be installed and is easier to manufacture than a fractional groove motor.
In FIGS. 19A and 19B, the alphabets shown in the teeth 50 represent the phase of the current flowing during driving, and the +-symbols indicate the winding directions at the time of circuit configuration. The in-phase coils 51 are connected in series or in parallel, and in-phase alternating current flows in the direction of the +-symbol in the opposite direction.

FIG. 20 shows the direction of the winding. According to the right-handed screw rule, the sign of the direction in which the magnetic flux flows toward the tip of the tooth is +. Further, the case where the current direction is toward the back of the paper surface with respect to the coil cross section is indicated by a cross, and the case where the current direction is toward the front of the paper surface is indicated by a circle. These show the relationship between the coil connection directions of each tooth, and since the current used for operating the motor in the present invention is an alternating current, the directions of the current and the magnetic flux during operation are changed at any time. Another schematic diagram of the stator is shown in FIG. The coils of each phase are all in series, all in parallel, or a combination of both, depending on the purpose.

Japanese Patent No. 5847543 Japanese Patent No. 6139723 Japanese Patent No. 6095267 Japanese Patent No. 6430570

As shown in FIG. 19B, in a three-phase AC motor, a fractional groove motor having a total number of poles: total number of slots of 10:12 has 12 teeth and has coil circuit periodicity, and adjacent teeth are used. The direction of the current is opposite or the phase is different. On the other hand, in the case of an integer groove, the period is three teeth, and in most cases, the polarity of the teeth is also constant. Therefore, it is difficult to manufacture a coil winding and a coil circuit in a fractional groove motor as compared with an integer groove motor. If you have a fractional groove motor with a ratio of 5: 4 slots per phase and have a series connection to the coil connection circuit, you need to connect the winding start and winding end of adjacent coils in the same phase. A process and connection space for coil connection are required.

An object of the present invention is for electric motors, vehicle power units, generators, wheels with generators, which can provide a fractional groove configuration, reduce manufacturing manpower, and reduce coil connection space. It is to provide a method of manufacturing a bearing and an electric motor.

The electric motor of the present invention includes a stator core, a stator having a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and a rotor located so as to face the stator in the radial direction. When the number of pole pairs of the rotor is N and the number of teeth per phase in the stator is P, P / 3N is not an integer.
The stator core has an assembly structure in which a plurality of tooth parts divided at least for each of the teeth are assembled in an annular shape, and the in-phase coils of the respective coils form a series circuit, and the in-phase coils are formed. The coils adjacent to each other in the circumferential direction are composed of one wire and are configured to have opposite polarities.

According to this configuration, in an electric motor having a fractional groove configuration, coils having the same phase adjacent to each other in the circumferential direction are composed of one wire and are configured to have opposite polarities to each other, so that they are adjacent to each other in the circumferential direction. The portion where the in-phase coils are connected in series can be omitted. Therefore, the manufacturing man-hours can be reduced. Further, since the stator core has an assembly structure in which a plurality of tooth parts divided for each tooth are assembled in an annular shape, it is possible to easily wind a coil around each tooth in a state where each tooth is divided. .. After winding this coil, a plurality of tooth parts can be assembled in an annular shape. As a result, the coil connection space can be reduced even in an electric motor having a fractional groove configuration.

Each tooth component has the tooth and a connecting portion extending in the circumferential direction from the root portion of the tooth, and the stator core may have a plurality of the connecting portions assembled in an annular shape. In this case, a plurality of tooth parts can be combined to form an annular portion of the stator core. In this case, the ring portion of the stator core may be formed by combining tooth parts having the same shape. According to this configuration, it is possible to reduce the types of molds at the time of manufacturing the stator, and it is possible to reduce the manufacturing cost.

The stator core may include an annular portion and a plurality of teeth in which the root portion of each of the teeth is fixed to the inner circumference or the outer circumference of the annular portion. In this case, since the shape error of the annular portion is smaller than that of the divided structure on the circumference, the assembling property when assembling the annular portion of the stator to other parts can be improved. Further, as compared with the split structure on the circumference, the magnetic path is not interrupted at the annular portion of the stator core, so that the loss of the stator can be reduced, that is, the magnetic flux density can be increased. In addition, since the shape of the teeth can be made linear as compared with the split structure on the circumference, it is easy to hold the teeth by the winding machine and there is no part that interferes with the winding part. Winding becomes easy, and the space factor of the coil can be improved.

The electric motor may be an inner rotor type in which the rotor is located inward in the radial direction of the stator. In this case, since the moment of inertia of the rotor is lower than that of the outer rotor type motor of the same size, the motor can be used for high-speed rotation.

The electric motor may be an outer rotor type in which the rotor is located outward in the radial direction of the stator. In this case, the area where the rotor and the stator face each other can be increased as compared with the inner rotor type electric motor of the same size. This makes it possible to maximize the output torque in a limited space.

The tooth has a shape with a protruding portion provided at the tip of the tooth with protruding portions protruding in an arc shape on both sides in the circumferential direction, or a shape in which the protruding portion is not provided at the tip. It may have a protruding shape. When a bobbin, which is an insulating member, is interposed between the coil and the stator core, if a non-protruding tooth having a shape in which the protruding portion is not provided at the tip portion is applied, the bobbin is pushed from the tip side of the tooth. Since the bobbin can be inserted and the bobbin does not need to be divided, the electric motor can be manufactured at low cost. By applying a tooth with a protruding portion, the flow of magnetic flux can be optimized, the output of the electric motor can be improved, and the cogging torque can be reduced.

The electric motor may be a fractional groove motor having a ratio of N: P = 5: 4, where N is the number of pole pairs of the rotor and P is the number of teeth per phase in the stator. By applying the electric motor to such a fractional groove motor, it is possible to reduce the cogging torque and improve the torque density. Since the torque density can be improved, the motor output can be increased.

The vehicle power device of the present invention has a fixed wheel and a hub flange, and has a rotating wheel that is rotatably supported by the fixed wheel via a rolling element and to which a vehicle wheel and a brake rotor are attached to the hub flange. A wheel bearing and an electric motor according to any one of the above inventions attached to the wheel bearing are provided, the stator is attached to the fixed wheel, and the rotor is attached to the rotating wheel.

According to this configuration, it is possible to omit a portion in which coils of the same phase adjacent to each other in the circumferential direction are connected in series, so that the dimensions in the stator axial direction required for the connection can be shortened. Therefore, the axial dimension of the electric motor can be increased within the limited dimensions, and the output of the electric motor can be improved.

The generator of the present invention includes a stator core and a stator having a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and a rotor located radially opposed to the stator. When the number of pole pairs of the rotor is N and the number of teeth per phase in the stator is P, P / 3N is not an integer.
The stator core has an assembly structure in which a plurality of tooth parts divided at least for each of the teeth are assembled in an annular shape, and the in-phase coils of the respective coils form a series circuit, and the in-phase coils are formed. The coils adjacent to each other in the circumferential direction are composed of one wire and are configured to have opposite polarities.

According to this configuration, in a generator having a fractional groove configuration, coils having the same phase adjacent to each other in the circumferential direction are composed of one strand and are configured to have opposite polarities to each other, so that they are adjacent to each other in the circumferential direction. The portion for connecting the matching in-phase coils in series can be omitted. Therefore, the manufacturing man-hours can be reduced. Further, since the stator core has an assembly structure in which a plurality of tooth parts divided for each tooth are assembled in an annular shape, it is possible to easily wind a coil around each tooth in a state where each tooth is divided. .. After winding this coil, a plurality of tooth parts can be assembled in an annular shape. As a result, the coil connection space can be reduced even in a generator having a fractional groove configuration.

The bearing for wheels with a generator of the present invention has a fixed wheel and a hub flange, and is rotatably supported by the fixed wheel via a rolling element, and a vehicle wheel and a brake rotor are attached to the hub flange. The wheel bearing and the generator according to the invention described above are attached to the wheel bearing, the stator is attached to the fixed wheel, and the rotor is attached to the rotating wheel.

According to this configuration, it is possible to omit a portion in which coils of the same phase adjacent to each other in the circumferential direction are connected in series, so that the dimensions in the stator axial direction required for the connection can be shortened. Therefore, the axial dimension of the generator can be increased within the limited dimensions, and the output of the generator can be improved.

The method for manufacturing an electric motor of the present invention is located at a stator having a stator core and a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and facing the stator in the radial direction. A method for manufacturing an electric motor in which a rotor is provided, the number of pole pairs of the rotor is N, and the number of teeth per phase in the stator is P, P / 3N is not an integer.
The stator core has at least a plurality of tooth parts divided for each tooth.
Of the coils, two tooth parts around which a coil of the same phase forming a series circuit is wound are arranged so that their tips face each other, and the two teeth parts are wound around the two tooth parts. The coil winding preparation process to fix a part of one wire that will be the coil,
After this coil winding preparation process, a coil winding process in which the strands are relatively wound so that the polarities of the two opposed tooth parts are opposite to each other,
After this coil winding process, there is an assembly process in which the two tooth parts are opened at a desired angle and assembled in an annular shape.

In the coil winding preparation process, the two tooth parts are arranged so that their tips face each other, and a part of one wire is fixed. In the coil winding process, the strands are wound relative to each of the teeth of the two facing tooth parts so as to have polarities opposite to each other. Then, in the assembly process, the two tooth parts are opened at a desired angle and assembled in an annular shape. Before assembling the plurality of tooth parts in an annular shape in this way, the wires are wound relative to each of the teeth of the two opposed tooth parts so as to have opposite polarities. It is possible to easily wind the coil around each tooth rather than winding the undivided annular stator core. Further, since one wire is relatively wound around each tooth so that the polarities are opposite to each other, it is possible to omit the portion in which the coils of the same phase adjacent to each other in the circumferential direction are connected in series. it can.

After the coil winding process and before the assembly process, there may be a pressing process of pressing the coil wound around each tooth with a mold. In this case, the space factor of the coils can be improved, and the adhesion between the coils and between the coils and the stator core can be improved. By improving the space factor of the coil, it can be expected that the output of the electric motor will be improved. By improving the adhesion of the coil, the heat generated by the current of the coil can be efficiently transmitted to the stator core, and the amount of current that can be passed through the coil can be improved.

The electric motor of the present invention includes a stator core, a stator having a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and a rotor located so as to face the stator in the radial direction. When the number of pole pairs of the rotor is N and the number of teeth per phase in the stator is P, the motor is an electric motor in which P / 3N is not an integer, and the stator core is divided at least for each of the teeth. It is an assembly structure in which a plurality of tooth parts are assembled in an annular shape. Of the coils, the coils of the same phase form a series circuit, and the coils of the coils of the same phase adjacent to each other in the circumferential direction are one element. It is composed of lines and has opposite polarities. Therefore, the structure of the fractional groove can be provided, the manufacturing man-hours can be reduced, and the coil connection space can be reduced.

The vehicle power device of the present invention has a fixed wheel and a hub flange, and has a rotating wheel that is rotatably supported by the fixed wheel via a rolling element and to which a vehicle wheel and a brake rotor are attached to the hub flange. A wheel bearing and the electric motor of the invention according to any one of the above, which are attached to the wheel bearing, are provided, and the stator is attached to the fixed wheel and the rotor is attached to the rotating wheel. In addition to having a fractional groove configuration, it is possible to reduce the number of manufacturing steps and the coil connection space.

The generator of the present invention includes a stator core and a stator having a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and a rotor located radially opposed to the stator. When the number of pole pairs of the rotor is N and the number of teeth per phase in the stator is P, P / 3N is not an integer, and the stator core is divided at least for each tooth. This is an assembly structure in which a plurality of the teeth parts are assembled in an annular shape. Of the coils, the in-phase coils form a series circuit, and one of the in-phase coils adjacent to each other in the circumferential direction. It is composed of the wires of the above and has polarities opposite to each other. Therefore, the structure of the fractional groove can be provided, the manufacturing man-hours can be reduced, and the coil connection space can be reduced.

The bearing for wheels with a generator of the present invention has a fixed wheel and a hub flange, and is rotatably supported by the fixed wheel via a rolling element, and a vehicle wheel and a brake rotor are attached to the hub flange. The bearing for wheels and the generator of the invention described above attached to the bearing for wheels are provided, the stator is attached to the fixed wheel, and the rotor is attached to the rotating wheel. In addition to having a fractional groove configuration, it is possible to reduce the number of manufacturing steps and the coil connection space.

The method for manufacturing an electric motor of the present invention is located at a stator having a stator core and a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and facing the stator in the radial direction. A method for manufacturing an electric motor in which a rotor is provided, the number of pole pairs of the rotor is N, and the number of teeth per phase in the stator is P, P / 3N is not an integer, and the stator core is at least said. Two tooth parts having a plurality of tooth parts divided for each tooth and wound with coils of the same phase forming a series circuit among the coils are arranged so that their tip portions face each other. A coil winding preparation process for fixing a part of one wire that is wound around the two tooth parts to form the two coils, and after the coil winding preparation process, the two opposed pieces are opposed to each other. A coil winding process in which the wire is relatively wound so that the respective teeth have polarities opposite to each other, and after this coil winding process, the two tooth parts are installed. It has an assembly process that opens at a desired angle and assembles in an annular shape. Therefore, the structure of the fractional groove can be provided, the manufacturing man-hours can be reduced, and the coil connection space can be reduced.

It is sectional drawing of the electric motor which concerns on embodiment of this invention. It is a figure which shows the teeth of the inner rotor type electric motor in an enlarged manner. It is a figure explaining the step up of the coil of the electric motor. It is a figure which shows the shape example of the tip of the tooth. It is a figure which shows the manufacturing method of the electric motor step by step. It is a figure which shows the state which assembled a plurality of teeth in an annular shape by the same manufacturing method. It is a figure which shows the other manufacturing method of the electric motor step by step. It is a figure which shows the state which assembled a plurality of teeth in an annular shape by the same manufacturing method. It is a figure which shows the other manufacturing method of the electric motor. It is sectional drawing of the electric motor which concerns on other embodiment of this invention. It is a figure which enlarges and shows the teeth of the outer rotor type electric motor which concerns on still another Embodiment of this invention. It is a figure explaining the step up of the coil of the electric motor. It is a figure which shows the example of how to wind the coil of the electric motor. It is a perspective view of the assembly of the electric motor. It is a front view of the assembly of the electric motor. It is a partially enlarged view of FIG. It is a partially enlarged sectional view of the assembly of the electric motor. It is sectional drawing of the power unit for a vehicle provided with the outer rotor type electric motor. It is a figure which shows the winding distribution example of a three-phase synchronous motor. It is a figure which shows the example of the winding direction of a coil. It is a figure which shows the stator schematically.

[First Embodiment]
The electric motor according to the embodiment of the present invention will be described with reference to FIGS. 1 to 9.
As shown in FIG. 1, the electric motor 1 according to this embodiment is an inner rotor type including an annular stator 2 having a split core structure described later and a rotor 3 located inward in the radial direction with respect to the stator 2. Surface magnet type permanent magnet motor. However, the electric motor 1 can also be applied to the outer rotor type described later. The stator 2 has a stator core 4 and a stator coil 5 including a plurality of coils 5a wound around each tooth 4a arranged in the circumferential direction of the stator core 4.

<Fraction groove configuration example>
The electric motor 1 is a so-called fractional groove motor in which the number of teeth 4a per phase in the stator 2 divided by the total number of poles of the rotor 3 is a fraction. As an example, when the number of pole pairs of the rotor 3 is N and the number of teeth 4a per phase of the stator 2 is P, it is suitable for an electric motor which is a multiple of N: P = 5: 4. That is, in the case of a three-phase synchronous motor, it can be applied to a motor having 2N: 3P = 10:12, 20:24, 30:36, ... Other fractional groove motors can also be applied to a configuration in which windings of in-phase teeth 4a adjacent to each other in the circumferential direction are reversely wound.

If the electric motor has one or more series circuits in the connection circuit of the coil 5a, the series circuit portion of the coil 5a in which the teeth 4a adjacent to each other in the circumferential direction have the same phase and opposite polarities can be easily manufactured. That is, the coil winding manufactured by the present embodiment is characterized in that it is composed of a continuous coil 5a composed of one wire in order to omit the connection step of the coils 5a that are in phase and adjacent to each other in the circumferential direction. To do. Therefore, the manufacturing man-hours can be reduced and the connection space can be omitted. The continuous coil 5a does not include a coil in which the ends of the coils are connected to each other by welding or a connector or the like, and a coil 5a made of one wire is used with a required coil length.

As another example of a fractional groove configuration, an electric motor having a ratio of 2N: 3P = 14:12 and 14:15 can be easily applied because the windings of the in-phase teeth adjacent to each other in the circumferential direction are reversely wound. It can also be applied to fractional groove motors. In this embodiment, a three-phase motor is taken as an example, but it can be applied to any number of phases. For example, in the case of a five-phase motor, the total number of poles and the total number of slots are suitable for 2N: 5P = 10:20, 20:40, and so on.

<Example of split configuration of stator core 4>
The stator core 4 has an assembly structure in which a plurality of tooth parts 6 divided at least for each tooth 4a are assembled in an annular shape. Each tooth component 6 has a tooth 4a and a connecting portion 7 extending from the root portion of the tooth 4a to both sides in the circumferential direction, and the stator core 4 is formed by assembling a plurality of connecting portions 7 in an annular shape. .. In other words, the stator core 4 is configured to be divided in the circumferential direction by the annular portion 8.

As each tooth component 6, for example, a plurality of thin plate-shaped electromagnetic steel plates are laminated and fixed in the axial direction. The connecting portions 7 on both sides in the circumferential direction of each tooth component 6 are provided with fitting portions 7a to be fitted with the adjacent connecting portions 7. The fitting portion 7a has a concavo-convex portion in which the contact surfaces of the tooth components 6 adjacent to each other in the circumferential direction have an uneven shape, and the concavo-convex portions adjacent in the circumferential direction are fitted to each other to form the annular portion 8. Configure. The tooth component 6 is, for example, one electromagnetic steel plate that is asymmetrical left and right and laminated by reversing the front and back.

The electromagnetic steel sheet of this example is asymmetrical when viewed from the front, because one connecting portion 7 in the circumferential direction forming a part of the annular portion 8 is formed shorter than the other connecting portion 7 with the teeth 4a as the center. Consists of the electromagnetic steel sheet of. For each of the tooth parts 6, the uneven portion is formed by sequentially laminating one piece of left-right asymmetrical electromagnetic steel plate with the front and back reversed at a constant product thickness. The magnetic steel sheets laminated to the desired product thickness are joined to each other by crimping or bonding. Each tooth component 6 may be integrally formed of a dust core or the like.

<About step-up of coil 5a>
As shown in FIGS. 2 and 3, in the case of the inner rotor type electric motor 1, since the space between the coil 5a and the adjacent coil 5a is wider on the tooth root side than on the tooth tip side, the coil 5a is stepped up on the tooth root side ( It is desirable that the part to be wound in layers) is constructed. By winding the coil 5a as in the winding construction example described later, the step-up of the coil 5a on the root side of the teeth becomes easy. Further, by rotating the tooth component 6 with the coil 5a fixed, a similar winding can be formed.

<Example of tooth tip shape>
As shown in FIG. 4A, the teeth 4a may have a straight shape, that is, a non-protruding shape extending linearly from the root portion 4aa of the teeth 4a to the tip portion 4ab, or as shown in FIG. 4B. As described above, the tip portion 4ab may have a shape with a protruding portion having protruding portions 4ac protruding in an arc shape on both sides in the circumferential direction. When a bobbin 9 (FIG. 3), which is an insulating member, is interposed between the coil and the stator core, when the straight-shaped tooth 4a shown in FIG. 4 (a) is applied, the bobbin is inserted from the tip side of the tooth 4a. This can be done, and the bobbin does not need to be divided, so that the electric motor can be manufactured at low cost. As shown in FIG. 4B, when the protruding portions 4ac protruding in an arc shape from the tip of the teeth 4a on both sides in the circumferential direction are provided, the flow of magnetic flux is optimized and the output of the electric motor can be improved. Moreover, the cogging torque can be reduced.

<Example of winding construction>
FIG. 5 is a diagram showing a stepwise manufacturing method of this electric motor, and FIG. 6 is a diagram showing a state in which a plurality of teeth 4a are assembled in an annular shape by the manufacturing method. The manufacturing method of this electric motor sequentially includes a coil winding preparation process, a coil winding process, and an assembly process. In the coil winding preparation process, as shown in FIG. 5A, the tips of the two tooth parts 6 and 6 around which the in-phase coils forming the series circuit of each coil are wound are spaced apart from each other at predetermined intervals. Arrange them so as to face each other with a gap, and prepare one wire S with the coil length required for the winding of these teeth. The central portion Sa of the coil wire S in the longitudinal direction is fixed to a workbench or the like (not shown), and one end Sb of the coil wire S in the longitudinal direction is fixed to the root of the teeth 4a on one side (right side in FIG. 5A). To do.

Next, in the coil winding process, as shown in FIG. 5B, the coil elements have polarities opposite to each other with respect to each of the teeth 4a of the two facing tooth parts 6 and 6. The wire S is wound relatively. Specifically, the other end Sc of the coil wire S in the longitudinal direction is moved to the axial root side of the tooth 4a while rotating relative to the tooth 4a on the other side (left side in FIG. 5A). Let me. Further, while the central portion Sa of the coil wire S in the longitudinal direction is fixed, the tooth 4a of the one end portion Sb of the coil wire S in the longitudinal direction is fixed (on the right side in FIG. 5 (a)) of the tooth 4a. By rotating in the axial direction, windings in the same direction are formed on the teeth 4a and 4a on both sides.

After that, in the assembly process, as shown in FIGS. 5C and 6, the two tooth parts 6 and 6 are opened at a desired angle, assembled and fixed in an annular shape, and the coil end portion that is not connected is desired. The stator 2 is completed by connecting to the circuit of. After that, the motor 1 is completed by combining the rotor 3 (FIG. 1) and the stator 2.

The electric motor may be manufactured as shown in FIGS. 7 and 8.
In the coil winding preparation process shown in FIG. 7A, two tooth parts 6 and 6 around which coils of the same phase are wound are arranged so that their tip portions face each other with a predetermined interval. Prepare one wire S with the coil length required for winding the teeth of. The central portion Sa of the coil wire S in the longitudinal direction is fixed to a workbench or the like (not shown).

Next, in the coil winding process, as shown in FIG. 7B, both ends Sb and Sc of the coil wire S in the longitudinal direction are rotated relative to the teeth 4a and 4a, and the coil wire S is While rotating the other end Sc of the coil strand S in the longitudinal direction with respect to one end Sb in the longitudinal direction, the other end Sc of the coil wire S is moved toward the root side in the axial direction of each tooth 4a to form a winding.

After that, in the assembly process, as shown in FIGS. 7 (c) and 8, the two tooth parts 6 and 6 are opened at a desired angle, assembled and fixed in an annular shape, and the coil end portion that is not connected is desired. The stator 2 is completed by connecting to the circuit of. After that, the motor 1 is completed by combining the rotor 3 (FIG. 1) and the stator 2.

In a general motor winding process, a winding machine that ejects a coil wire with a nozzle (not shown) is used, but in the embodiment of the present invention, it is not necessary to use the nozzle, and the coil wire diameter is used in the coil winding process. And there is no effect of nozzle diameter. When winding on a conventional undivided annular stator, the coil is passed through a gap between adjacent coils in the circumferential direction. Therefore, there is a risk of damaging adjacent coils, and it is difficult to maximize the space factor of the coils.
In the present embodiment, since the stator is assembled in the assembly process after the coil winding process, winding can be performed up to the upper limit of the range not in contact with the adjacent coils. Further, since the nozzle is not used, a coil having an arbitrary cross-sectional shape can be freely wound.

As shown in FIG. 9, after the coil winding process and before the assembly process, there may be a pressing process of pressing the coil 5a wound around each tooth 4a with the mold 10. In the winding according to the present embodiment, it is easy to press the teeth 4a and the coil 5a with the mold 10 after the coil winding. By pressing in this way, the space factor of the coil 5a can be improved, and the adhesion between the coils and the coil 5a and the stator core can be improved. By improving the space factor of the coil 5a, it can be expected that the output of the electric motor will be improved. By improving the adhesion of the coil 5a, the heat generated by the current of the coil 5a can be efficiently transmitted to the stator core, and the amount of current that can be passed through the coil 5a can be improved.

<Effect>
According to the electric motor 1 and its manufacturing method described above, in the electric motor having the configuration of the fractional groove, the coils 5a having the same phase adjacent to each other in the circumferential direction are composed of one wire S and are configured to have opposite polarities. Therefore, it is possible to omit the portion in which the coils 5a having the same phase adjacent to each other in the circumferential direction are connected in series. Therefore, the manufacturing man-hours can be reduced. Further, since the stator core 4 has an assembly structure in which a plurality of tooth parts 6 divided for each tooth 4a are assembled in an annular shape, the coil 5a can be easily wound around each tooth 4a in a state where each tooth 4a is divided. It becomes possible to do. After winding this coil, a plurality of tooth parts 6 can be assembled in an annular shape. As a result, the connection space of the coil 5a can be reduced even in an electric motor having a fractional groove configuration.

When a plurality of tooth parts 6 are combined to form the annular portion 8 of the stator core 4, the tooth parts 6 having the same shape can be combined to form the annular portion 8 of the stator core 4. In this case, the ring portion 8 of the stator core 4 can be formed by combining the tooth parts 6 having the same shape. According to this configuration, it is possible to reduce the types of molds at the time of manufacturing the stator, and it is possible to reduce the manufacturing cost.
Since the rotor 3 is an inner rotor type motor in which the rotor 3 is located inward in the radial direction of the stator 2, the electric motor 1 has a lower moment of inertia of the rotor 3 than an outer rotor type motor of the same size, and is suitable for high-speed rotation. Can be done.

<About other embodiments>
In the following description, the same reference numerals will be given to the parts corresponding to the matters described in advance in each embodiment, and duplicate description will be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described above unless otherwise specified. It has the same effect from the same configuration. In addition to the combination of the parts specifically described in each embodiment, it is also possible to partially combine the embodiments as long as the combination does not cause any trouble.

As shown in FIG. 10, the stator core 4 has a structure including a plurality of teeth 4a and an annular portion 8 for fixing the root portions of the plurality of teeth 4a to the inner circumference, in other words, only the teeth portion is divided. It may be a structure. A plurality of engaged portions 8a are provided on the inner circumference of the annular portion 8 at regular intervals in the circumferential direction, and the root portion of the teeth 4a can be engaged with each of the engaged portions 8a.

In this case, since the shape error of the annular portion 8 is smaller than that of the divided structure on the circumference, the assembling property when assembling the annular portion 8 of the stator 2 to other parts can be improved. Further, since the magnetic path is not interrupted at the annular portion 8 of the stator core 4 as compared with the divided structure on the circumference, the loss of the stator 2 can be reduced, that is, the magnetic flux density can be increased. Further, since the shape of the teeth 4a can be made linear as compared with the split structure on the circumference, the teeth 4a can be easily held by the winding machine and there is no portion that interferes with the winding portion. Winding around 4a becomes easy, and the space factor of coil 5a can be improved.

As shown in FIGS. 11 and 12, the electric motor 1 may be an outer rotor type in which the rotor 3 is located outside the stator 2 in the radial direction. In the case of the outer rotor type electric motor 1, since the space between the coil 5a and the adjacent coil 5a is wider on the tooth tip side than on the tooth root side, it is desirable that the coil 5a is stepped up on the tooth tip side.

Therefore, as shown in FIG. 13, one coil wire S is prepared with the coil length required for winding the two teeth. By fixing both ends of the coil wire S in the longitudinal direction to the roots of the two teeth 4a and 4a and winding the central portion Sa of the coil wire S in the longitudinal direction around the two teeth 4a and 4a at the same time, the teeth The step-up of the coil 5a on the tip side can be easily constructed. Further, the same winding can be formed by rotating the tooth component 6 in the axial direction of the tooth 4a while fixing the coil wire S. In this case, by setting the winding start of the coil wire S to either the central portion Sa in the longitudinal direction of the coil strand S or both ends in the longitudinal direction of the coil strand S, the step-up position of the coil 5a can be arbitrarily set. It can be used for both inner rotor type and outer rotor type.

The stator in each embodiment can be manufactured by using various manufacturing methods regardless of the manufacturing method such as press working and wire cutting. The rotor combined with the stator is applicable regardless of its type such as IPM, SPM, SR.

14 to 16 show an assembly of the electric motor 1 connected in this embodiment. The electric motor 1 is an outer rotor type electric motor. There are bus bars 11, 12, 13 and neutral point bus bars 14 of each phase on the inner diameter side of the stator core 4, and teeth adjacent to each other in the circumferential direction of the same phase are wound by a continuous coil 5a composed of one strand. There is. In the figure, the power lines of each phase are omitted.
According to the electric motor 1, by providing the bus bars 11 to 14 on the inner diameter side of the stator core 4, the stator width can be reduced and the accommodation space of the electric motor 1 can be secured. Although not shown, the bus bar may be provided on the coil end instead of on the inner diameter side of the stator core 4. In this case, it becomes easy to fix the stator with the annular portion of the electric motor.

FIG. 17 shows a partially enlarged cross-sectional view of the assembly of the electric motor 1. As an insulating member between the stator 2 and the coil 5a, for example, a resin bobbin 9 can be applied. In addition, as the insulating member, insulating paper or insulating coating on a stator can also be applied. By making the coil 5a a round wire cross section shown in this figure, the coil 5a can be twisted during the coil winding process, so that the productivity of the electric motor 1 is improved. The coil may have a rectangular cross section (not shown). In this case, the contact area between the coils is larger than that of the coil having a round cross section, and the thermal conductivity of the coil is improved.

<Vehicle power unit>
The electric motor of any of the embodiments may be mounted on the vehicle power unit.
In the vehicle power unit of FIG. 18, the outer rotor type electric motor 1 is attached to the wheel bearing 15. The vehicle power unit includes a wheel bearing 15 and an electric motor 1 attached to the wheel bearing 15.

The wheel bearing 15 has an outer ring 16 which is a fixed ring, a rolling element 17 in a double row, and an inner ring 18 which is a rotating wheel. The inner ring 18 is rotatably supported by the outer ring 16 via a double-row rolling element 17. Grease is sealed in the bearing space between the inner and outer rings 18 and 16. The inner ring 18 has a hub flange 18a at a position protruding toward the outboard side in the axial direction from the outer ring 16. The outer ring 16 is bolted to a suspension frame component 19 such as a knuckle at an end on the inboard side. In this specification, the side that is closer to the outside in the vehicle width direction of the vehicle when the power unit for the vehicle is mounted on the vehicle is called the outboard side, and the side that is closer to the center in the vehicle width direction is called the inboard. Called the side.

A brake rotor 20 and a wheel 21a of a wheel 21 which is a driving wheel are attached to a side surface of the hub flange 18a on the outboard side by a hub bolt 22 in a state where they overlap in the axial direction. The tire 21b of the wheel 21 is attached to the outer circumference of the wheel 21a. The entire wheel bearing 15 is contained within the axial width of the wheel 21a.

The stator 2 of the electric motor 1 is attached to the outer peripheral surface of the outer ring 16, and the rotor 3 is arranged on the outer peripheral side of the stator 2. The rotor 3 includes a rotating case 23, a magnetic body 24 provided on the inner circumference of the rotating case 23, and a permanent magnet provided on the magnetic body 24, and the rotating case 23 is attached to a hub flange 18a. The inner peripheral surface of the rotating case 23 on the outboard side is fixed to the outer peripheral surface of the hub flange 18a by, for example, fitting, welding, or adhesion. In the electric motor 1 of this example, the wheels 21 can be rotationally driven by generating electricity by rotating the wheels 21 and supplying power.

The entire electric motor 1 has a smaller diameter than the outer peripheral portion of the brake rotor 20. Further, the entire motor 1 except for the attachment portion to the hub flange 18a is located in the axial range between the vehicle body attachment surface on the inboard side of the wheel bearing 15 and the hub flange 18a. Therefore, when the electric motor 1 is supported by the wheel bearing 15, it is not necessary to change the structure of the damping device or the like around the wheel 21. Further, as for the wheel bearing 15, existing products can be used for the components such as the inner ring 18 other than the outer ring. According to this vehicle power unit, it is possible to omit a portion in which coils of the same phase adjacent to each other in the circumferential direction are connected in series, so that the stator axial dimension required for the connection can be shortened. Therefore, the axial dimension of the electric motor 1 can be increased within the limited dimensions, and the output of the electric motor 1 can be improved.

<Bearings for wheels with generator>
The vehicle may be equipped with bearings for wheels with a generator, which have a function of generating electricity but do not drive rotationally by power supply. The wheel bearing with a generator includes a generator 1A that does not also serve as a motor, and a wheel bearing 15. The wheel bearing with a generator has the same configuration as the above-mentioned vehicle power unit except for the electric motor 1 capable of generating electricity and rotationally driving. According to a vehicle equipped with a wheel bearing with a generator, for example, a braking force can be generated by using the regenerative power generated by the generator 1A.

The electric motor can also be applied to household motors, industrial motors, and the like. The generator is applicable to wind power generators or hydroelectric generators.

Although the embodiments for carrying out the present invention have been described above based on the embodiments, the embodiments disclosed this time are exemplary in all respects and are not limiting. The scope of the present invention is shown not by the above description but by the scope of claims, and it is intended that all modifications within the meaning and scope equivalent to the scope of claims are included.

1 ... electric motor, 1A ... generator, 2 ... stator, 3 ... rotor, 4 ... stator core, 4a ... teeth, 4ac ... protruding part, 5 ... stator coil, 5a ... coil, 6 ... teeth parts, 7 ... connecting part, 8 ... Annulus, 15 ... Wheel bearing, 16 ... Outer ring (fixed wheel), 17 ... Rolling element, 18 ... Inner ring (rotary wheel), 18a ... Hub flange, 20 ... Brake rotor, S ... Coil wire (wire) )

Claims (12)

A stator having a stator core and a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and a rotor located radially opposite to the stator, the poles of the rotor. When the logarithm is N and the number of teeth per phase in the stator is P, P / 3N is a non-integer electric motor.
The stator core has an assembly structure in which a plurality of tooth parts divided at least for each of the teeth are assembled in an annular shape, and the in-phase coils of the respective coils form a series circuit, and the in-phase coils are formed. An electric motor in which coils adjacent to each other in the circumferential direction are composed of a single wire and have opposite polarities. In the electric motor according to claim 1, each of the teeth parts has the teeth and a connecting portion extending in the circumferential direction from the root portion of the teeth, and the stator core has a plurality of the connecting portions in an annular shape. The electric motor that is being assembled. In the electric motor according to claim 1, the stator core is an electric motor including an annular portion and a plurality of teeth in which a root portion of each of the teeth is fixed to the inner circumference or the outer circumference of the annular portion. The electric motor according to any one of claims 1 to 3, wherein the electric motor is an inner rotor type electric motor in which the rotor is located inward in the radial direction of the stator. The electric motor according to any one of claims 1 to 3, wherein the electric motor is an outer rotor type electric motor in which the rotor is located outside the radial direction of the stator. In the electric motor according to any one of claims 1 to 5, the tooth has a shape with a protruding portion in which projecting portions projecting in an arc shape on both sides in the circumferential direction are provided at the tip of the tooth. Or, a non-protruding electric motor having a shape in which the protruding portion is not provided at the tip portion. In the electric motor according to any one of claims 1 to 6, when the number of pole pairs of the rotor is N and the number of teeth per phase in the stator is P, N: P. An electric motor that is a fractional groove motor with a ratio of = 5: 4. A wheel bearing having a fixed wheel and a rotating wheel having a hub flange and being rotatably supported by the fixed wheel via a rolling element to attach a vehicle wheel and a brake rotor to the hub flange, and a bearing for the wheel. A vehicle power unit comprising the electric motor according to any one of claims 1 to 7 attached to the fixed wheel, the stator attached to the fixed wheel, and the rotor attached to the rotating wheel. A stator having a stator core and a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and a rotor located radially opposed to the stator, the poles of the rotor. When the logarithm is N and the number of teeth per phase in the stator is P, P / 3N is a non-integer generator.
The stator core has an assembly structure in which a plurality of tooth parts divided at least for each of the teeth are assembled in an annular shape, and the in-phase coils of the respective coils form a series circuit, and the in-phase coils are formed. A generator in which coils adjacent to each other in the circumferential direction are composed of one wire and have opposite polarities. A wheel bearing having a fixed wheel and a hub flange and having a rotating wheel rotatably supported by the fixed wheel via a rolling element and to which a vehicle wheel and a brake rotor are attached to the hub flange, and a bearing for the wheel. A bearing for a wheel with a generator, comprising the generator according to claim 9, wherein the stator is attached to the fixed wheel, and the rotor is attached to the rotating wheel. A stator having a stator core and a stator coil including a plurality of coils wound around each tooth arranged in the circumferential direction of the stator core, and a rotor located radially opposite to the stator, the poles of the rotor. When the logarithm is N and the number of teeth per phase in the stator is P, it is a method for manufacturing an electric motor in which P / 3N is not an integer.
The stator core has at least a plurality of tooth parts divided for each tooth.
Of the coils, two tooth parts around which a coil of the same phase forming a series circuit is wound are arranged so that their tips face each other, and the two teeth parts are wound around the two tooth parts. The coil winding preparation process to fix a part of one wire that will be the coil,
After this coil winding preparation process, a coil winding process in which the strands are relatively wound so that the polarities of the two opposed tooth parts are opposite to each other,
A method for manufacturing an electric motor, comprising: after this coil winding process, an assembly process in which the two tooth parts are opened at a desired angle and assembled in an annular shape. The method for manufacturing an electric motor according to claim 11, wherein the method for manufacturing an electric motor includes a pressing process of pressing the coil wound around each tooth with a mold after the coil winding process and before the assembly process. ..

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