WO2021095343A1

WO2021095343A1 - Motor

Info

Publication number: WO2021095343A1
Application number: PCT/JP2020/034409
Authority: WO
Inventors: 菱田　光起; 元輝近藤; 祐一吉川
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2019-11-12
Filing date: 2020-09-11
Publication date: 2021-05-20
Also published as: JPWO2021095343A1

Abstract

This motor includes: a stator core including a configuration of a laminated body obtained by laminating a plurality of stator core sheets; a stator including stator coils in which teeth provided to the stator core are portions of magnetic cores; and a rotor that is rotatably supported while having gaps formed between the rotor and the tips of the teeth of the stator core. A portion of a coil end part where the stator coils project relative to an end surface of the stator core in a direction in which the stator core sheets are laminated in the stator core, has cutout structure parts each provided so as to form a cutout in a groove shape from a side facing an outer diameter direction of the stator core to a side facing a direction in which the rotor is located.

Description

motor

The present invention relates to a motor. The present invention particularly relates to the configuration of the stator coil of the motor.

In recent years, the demand for motors has been increasing for industrial and in-vehicle applications. Among them, improvement of motor efficiency and cost reduction are required.

It is known to improve the space factor of the stator coil arranged in the slot of the stator as one method of improving the efficiency of the motor. By improving the space factor of the stator coil, it is possible to suppress the loss caused by the current flowing through the stator coil when the motor is driven.

As a method for improving the space factor of the stator coil, a configuration such as arranging a cast coil using a copper material in a slot is shown (see, for example, Patent Document 1).

One of the factors that lower the motor efficiency is the temperature rise due to heat generation such as copper loss in the stator coil and iron loss in the stator core. It is known that a refrigerant is circulated inside the motor to dissipate heat and suppress a temperature rise (see, for example, Patent Document 2).

When the space factor of the stator coil is improved, the dead space in the slot becomes smaller. However, the dead space constitutes a part of the flow path of the refrigerant, and reducing the dead space in the slot is equivalent to narrowing the flow path of the refrigerant, and reduces the flow rate of the refrigerant. As a result, the cooling effect of the refrigerant does not work effectively. The temperature rise due to the heat generated by the stator coil or the stator core becomes excessive, which leads to a decrease in the efficiency of the motor.

The efficiency of the motor is the ratio of the mechanical output from the motor to the input power to the motor expressed as a percentage (percentage, unit symbol [%]). The space factor is the ratio of the conductor portion such as the conducting wire to the accommodating cross-sectional area of the winding accommodating portion such as a slot or an insulator. If the cross section of the conducting wire or the like is circular, a dead space is generated between the adjacent circular circles, so that there is a limit to increasing the space factor. In addition, the thickness of the insulating coating of the conducting wire is also a factor that lowers the space factor. Incidentally, when the thickness of the insulating coating of the conducting wire is constant, the smaller the diameter of the conducting wire, the higher the thickness of the insulating coating or the ratio of the area occupied by the insulating coating.

On the other hand, as the space factor of the stator coil arranged in the slot of the stator is improved, the loss due to the eddy current generated in the stator coil may remarkably appear. Therefore, as a method for reducing the eddy current of the coil, a configuration is shown in which a conductor having a cross section composed of a plurality of regions in the collective conductor is used for the stator coil (see, for example, Patent Document 3).

The stator coil is excited by receiving an alternating current supplied from the outside. Naturally, the magnetic flux generated in the stator including the stator coil is an alternating magnetic flux. The alternating magnetic flux mainly uses the stator core and the rotor core as magnetic paths. However, a part of the alternating magnetic flux becomes a leakage magnetic flux and interlinks parts other than the stator core and the rotor core. It has been conventionally known that one of the places where the leakage magnetic flux is large is the tooth tip side of the stator core. When the conductor cross section is a circular conductor, the conductor area where the leakage magnetic flux is linked is limited. Therefore, the eddy current generated in the conducting wire is not remarkable.

On the other hand, in order to increase the space factor of the stator coil, a spiral laminated coil having a spiral surface is formed by a conductor having an elongated cross-sectional shape in which the width dimension in the conductor cross section is larger than the thickness dimension in the conductor cross section. To do. In this case, the area of the conductor where the leakage magnetic flux is interlinked is several times wider than that of the conductor having a circular cross section. As a result, the generation of eddy current becomes remarkable.

The stator coil is excited by receiving an alternating current supplied from the outside. Naturally, the magnetic flux generated in the stator including the stator coil is an alternating magnetic flux. The main magnetic path of the alternating magnetic flux is the stator core and the rotor core, but a part of the alternating magnetic flux becomes a leakage magnetic flux and interlinks a part other than the stator core and the rotor core. It has been conventionally known that one of the places where the leakage magnetic flux is large is the tooth tip side of the stator core. When the conductor cross section is a circular conductor, the eddy current generated in the conductor is not remarkable because the conductor area where the leakage magnetic flux is interlinked is limited.

On the other hand, in order to increase the space factor of the stator coil, a spiral laminated coil having a spiral surface is formed by a conductor having an elongated cross-sectional shape in which the width dimension in the conductor cross section is larger than the thickness dimension in the conductor cross section. To do. In this case, the area of the conductor where the leakage magnetic flux is interlinked is several times wider than that of the conductor having a circular cross section, and the generation of eddy current is remarkable. For example, depending on the size of the stator coil, the resistivity of the material, or the driving conditions of the motor, the heat generation becomes large, and their loss cannot be ignored. As a result, problems such as a decrease in efficiency as a motor have been considered.

As a conventional example, FIGS. 4A, 4B and 4C are illustrated. FIG. 4A is a front view of the stator coil 5 illustrated as a conventional example. FIG. 4B is a perspective view showing a stator coil 5 illustrated as a conventional example. FIG. 4C is a side view of the stator coil 5 illustrated as a conventional example. In the stator coil 5, an eddy current 45 as shown by a dotted line and an arrow A virtually represented in FIG. 4A is generated in the coil line portion 5q of each turn. The eddy current 45 generates Joule heat, which causes a loss and reduces the efficiency of the motor. Furthermore, the self-temperature rise of the motor itself due to the eddy current causes an increase in copper loss of the motor itself.

German Patent Application Publication No. 10202012212637 JP-A-2015-109733 JP-A-2009-199749

The present invention provides a stator coil having improved heat dissipation against heat generated by an eddy current even when the space factor of the stator coil is increased. An object of the present invention is to improve the characteristics of the stator coil and the motor as compared with the conventional case.

In order to solve the problem, the first invention comprises a stator core including a laminate in which a plurality of stator core sheets are laminated, a stator including a stator coil having a tooth provided in the stator core as a part of a magnetic core, and a tooth of the stator core. In a motor including a tip and a rotor rotatably supported through a gap, the stator coil has a conductor portion of the stator coil and a conductor portion including an insulating coating covering the conductor portion and a cross section of the conductor portion. A substantially rectangular shape, a coil with a predetermined number of turns, and a substantially continuous spiral from the first turn of the stator coil turns to the last turn of the number of turns. A part of the coil end portion that includes a surface, includes two opposing sides of the four sides of a rectangular cross-sectional shape in the spiral surface, is in the direction in which the stator cores are laminated, and is a portion where the stator coil protrudes from the end surface of the stator core. In addition, the motor includes an absent structure portion that is absent from the side facing the outer diameter direction of the stator core to the side facing the direction in which the rotor is located.

Further, in the second invention, the absent structure portion is a groove portion which is formed in a part of the coil end portion in a groove shape from the side facing the outer diameter direction of the stator core to the side facing the direction where the rotor is located. This is the motor of the first invention.

Further, in the third invention, the missing structure portion is a hole formed in a part of the coil end portion from the side facing the outer diameter direction of the stator core to the side facing the direction in which the rotor is located. It is a motor of the first invention which is a part.

According to the present invention, even when the space factor of the stator coil is increased, a stator coil having improved heat dissipation against heat generated by eddy current is found, and the motor has improved characteristics of the stator coil as compared with the conventional case. Can be provided.

Top view showing the motor according to the first embodiment Side view showing the motor according to the first embodiment Sectional view taken along the line 1C-1C in FIG. 1B Front view of the stator coil according to the first embodiment Front view of the stator coil according to the second embodiment Front view of the stator coil illustrated as a conventional example Perspective view of the stator coil illustrated as a conventional example Side view of the stator coil illustrated as a conventional example

Hereinafter, the motor of the present invention will be described with reference to the drawings as appropriate. It should be noted that each of the embodiments described below is merely an example, and is not intended to limit the present invention, its application, or its use.

(Embodiment 1)
[About the structure of the motor]
FIG. 1A is a top view showing a motor according to the first embodiment. FIG. 1B is a side view showing the motor according to the first embodiment. FIG. 1C is a cross-sectional view taken along the line 1C-1C in FIG. 1B. However, in any case, the cover case, insulators and other insulating materials are not shown. The motor 1 has a shaft 2, a rotor 3, a stator 4, an insulator (not shown), and stator coils U11, U22, U32, U41, and V12 inside a cover case (not shown). It includes V21, V31, V42, W11, W22, W32, W41 and

bus bars

51, 52, 53, 54.

Here, the longitudinal direction of the shaft 2 (direction perpendicular to the paper surface of FIG. 1A) is referred to as the Z-axis direction, and the direction orthogonal to this (direction parallel to the paper surface of FIG. 1A) is the X-axis direction and the Y-axis. Called direction.

In addition, "integration" or "integration" means that a plurality of parts are not only mechanically connected by bolting or caulking, but also by material bonding such as covalent bond, ionic bond, and metal bond. , The state of one object in which parts are electrically connected, or the state of one object in which the entire parts are material-bonded by melting or the like and electrically connected.

A refrigerant (not shown) circulates inside the motor 1, and the heat generated by the motor is cooled by the refrigerant. The refrigerant flows from the upstream portion to the downstream side where the refrigerant is circulated through the gaps provided in each of the stator core, the stator coil, and the periphery of the rotor, and then returns to the upstream portion to circulate. A part of the flow path of the refrigerant is provided with a heat radiating portion for cooling the refrigerant. The circulation of the refrigerant may be provided with a device for forcibly circulating the refrigerant. By providing such a configuration, the rotor 3 and the stator 4 are cooled.

The rotor 3 is provided in contact with the outer periphery of the shaft 2. The rotor 3 includes magnets 31 in which north poles and south poles are alternately arranged along the outer peripheral direction of the shaft 2 so as to face the stator 4. A neodymium magnet is used as the magnet 31 used in the rotor 3, but the material, shape, or material thereof can be appropriately changed according to the output of the motor and the like.

The stator 4 has a substantially annular stator core 41, a plurality of teeth 42 provided at equal intervals along the inner circumference thereof, and slots 43 provided between the teeth 42, respectively. The stator 4 is arranged outside the rotor 3 at regular intervals from the rotor 3 when viewed from the Z-axis direction.

The stator core 41 is configured as an aggregate of a plurality of core segments. The core segment is composed of a yoke 44 and a plurality of teeth 42. As the configuration of the core segment, a suitable configuration may be appropriately selected in addition to the configuration illustrated in the present embodiment. For example, the yoke 44 has an annular shape. However, the yoke 44 may form a plurality of fan-shaped core segments, and the fan-shaped core segments may be arranged in an annular shape. The stator core 41 and each core segment are laminated bodies formed by laminating and integrating a plurality of core sheets (stator core sheet 41a) obtained by punching an electromagnetic steel sheet containing, for example, silicon into a predetermined shape.

In the present embodiment, the number of magnetic poles of the rotor 3 is 5 N poles facing the stator 4 and 5 S poles, for a total of 10 poles. The number of slots 43 is twelve. However, the number of magnetic poles of the rotor 3 and the number of slots 43 are not particularly limited to this. Other combinations of the number of magnetic poles and the number of slots are also applicable.

The stator 4 has 12 stator coils U11, U22, U32, U41, V12. It has V21, V31, V42, W11, W22, W32, W41. The stator coil is attached to each tooth 42. The stator coils are arranged in each slot 43 when viewed from the Z-axis direction. That is, the stator coils U11, U22, U32, U41, V12. V21, V31, V42, W11, W22, W32, and W41 are concentrated windings with respect to the teeth 42. Further, the stator coils U11, U22, U32, and U41 are arranged integrally with the bus bar 51, the stator coils V12 to V42 are arranged together with the bus bar 52, and the stator coils W11 to W41 are arranged integrally with the bus bar 53. Here, the bus bar may or may not be configured, and may be connected by a connection board, lead wires, or the like.

Here, among the symbols UXY, VXY, and WXY representing the stator coil, the first character represents each phase of the motor 1 (in the case of this embodiment, the U phase, the V phase, and the W phase). The second letter indicates the arrangement order of the stator coils in the same phase. The third character represents the circumferential direction of the spiral coil, which is the stator coil. In this embodiment, 1 is a clockwise direction and 2 is a counterclockwise direction. Therefore, the stator coil U11 indicates that the U-phase arrangement order is the first stator coil and the circumferential direction is the clockwise direction. The stator coil V42 indicates that the V-phase arrangement order is the fourth stator coil, and the circumferential direction is the counterclockwise direction. Note that clockwise means clockwise when viewed from the center of motor 1, and "counterclockwise" means counterclockwise when viewed from the center of motor 1.

Strictly speaking, the stator coils U11 and U41 are U-phase stator coils, and the stator coils U22 and U32 are U-bar phase stator coils (the direction of the magnetic field generated is opposite to that of the U-phase stator coil). However, in the following description, unless otherwise specified, they are collectively referred to as U-phase stator coils. Similarly, the stator coils V12 to V42 and the stator coils W11 to W41 are collectively referred to as a V-phase stator coil and a W-phase stator coil, respectively.

[About the structure of the stator coil]
FIG. 2 is a front view of the stator coil according to the first embodiment. Further, the stator coil 5 according to the present embodiment having the configuration shown in FIG. 2 has the stator coils U11, U22, U32, U41 and V12 mounted on the teeth 42 of the motor 1 shown in FIG. 1C. It is applied to V21, V31, V42, W11, W22, W32, W41. The stator coil 5 has a spiral structure including an annular body 5 m having a predetermined number of turns. As shown in FIG. 2, the configuration of each turn of the annular body 5 m is substantially rectangular in a plan view. In FIG. 2, of a part of the short shape of the annular body 5 m in a plan view, the long side side is located on each side of the surface where the laminated surface of the stator core sheet 41a appears in the teeth, and is referred to as a coil line portion 5q. .. Of the part of the short shape in the plan view of the annular body 5 m, the short side side is located between the end sides of the pair of long side sides of the coil line portion 5q in the same direction, and this is called the coil end portion 5r. To do. The coil end portion 5r is a portion in the direction in which a plurality of stator core sheets 41a in the stator core 41 are laminated, and is also a position where the stator coil 5 protrudes from the end surface of the stator core 41.

The portion where one side of the coil line portion 5q shifts to one side of the coil end portion 5r is referred to as a coil corner portion 5s.

The stator coil 5, which is a spiral coil, includes a conductor portion 5a, an insulating coating 5b provided on the surface of the conductor portion 5a, and a drawer portion 5c from the first turn 5t and the tenth turn 5u of the stator coil 5, respectively. It has a drawer portion 5d. Further, the annular body 5m which is the second turn to the tenth turn 5u of the stator coil 5 is a substantially rectangular annular body in a plan view. The annular body 5 m has two short sides, two long sides, and four coil corner portions 5s. In addition, in FIG. 2, each annular body 5m from the first turn 5t to the ninth turn is configured to make one round in an annular shape. On the other hand, in the 10th turn 5u, the shape of the ring is less than one round, and the short side of the ring 5m is not enough by one. To express this configuration in another expression, in the 10th turn 5u, the shape of the ring is less than about a quarter lap, which is substantially 3/4 laps (3/4 laps). Is. The reason why the 10th turn 5u is less than about a quarter of a lap is due to the arrangement of the drawer portion 5c and the drawer portion 5d. Depending on the positions of the drawer portion 5c and the drawer portion 5d, it may be considered that the tenth turn 5u fills one lap or laps slightly more than one lap. Similarly, it may be considered that the first turn 5t may be less than one lap or slightly more than one lap.

The conductor portion 5a has a conductor having a rectangular cross section and an insulating coating 5b that covers the conductor. The conducting wire portion 5a is a structure in which an annular structure is spirally laminated. The spirally laminated structure is a structure in which the motor is laminated in the inner and outer directions in the radial direction. The spirally laminated configuration includes a predetermined number of turns of the annular body 5 m. For example, the predetermined number of turns consists of the first turn 5t to the nth turn (n is an integer of 2 or more). The first turn 5t to the nth turn is referred to as a turn train.

The conducting wire portion 5a is a wire rod made of a conductive member having a substantially rectangular cross section. An annular body 5 m is formed of this wire rod, and the annular body 5 m is spirally laminated for 10 turns to form a single-layer structure, whereby the conductor portion 5a constitutes a spiral coil. The conducting wire portion 5a is formed of, for example, copper, aluminum, zinc, magnesium, brass, iron, SUS (Steel Use Stainless) or the like. These are described in a single layer. However, it can be applied not only to a single layer coil but also to a multi-layer coil.

In the following description, the portion wound from the tip of the drawer portion 5c to the lower part of the position where the drawer portion 5d is provided is referred to as the first turn 5t. Subsequent turns, which are wound one lap at a time, are sequentially counted as the second turn, the third turn, and the tenth turn 5u. How to take the starting point of each turn can be decided arbitrarily. The side of the stator coil 5 provided with the first turn 5t is referred to as "outside", and the side provided with the tenth turn 5u is referred to as "inside". This is because the outside of the motor is "outside" and the center side of the motor is "inside" with respect to the radial direction of the motor structure.

The insulating coating 5b is provided on the entire surface of the conducting wire portion 5a so as to insulate the stator coil 5 and an external member (not shown). For example, in the motor 1 shown in FIGS. 1A, 1B and 1C, the stator coil 5 is insulated from the stator core 41 and the teeth 42 by an insulating coating 5b and an insulating member (not shown) such as insulating paper. The adjacent turns of the stator coil 5 are insulated by an insulating coating 5b. The insulating coating 5b is formed of, for example, polyimide, nylon, PEEK (Poly Ether Ether Ketone, polyetheretherketone), acrylic, amideimide, esterimide, enamel, heat-resistant resin, or the like. The thickness of the insulating coating 5b is about several tens of μm, for example, between 5 μm and 50 μm.

Both the drawer portion 5c and the drawer portion 5d are a part of the conductor portion 5a. The drawer portion 5c and the drawer portion 5d are outside the side surface of the stator coil 5, in other words, the plane intersecting the turn row of the conductor portion 5a in order to receive a current supply from the outside or to supply a current to the outside. It extends to. In order to connect to an external member, for example, the bus bar 51, the bus bar 52, the bus bar 53, or the bus bar 54 shown in FIGS. 1A, 1B, and 1C, the insulating coating 5b is removed from the drawer portion 5c and the drawer portion 5d. Has been done. The insulating coating 5b does not have to be removed in the entire region of the drawer portion 5c and the drawer portion 5d. For example, the insulating coating 5b may be removed only from the portion necessary for connection with the bus bar 51, the bus bar 52, the bus bar 53, and the bus bar 54.

Here, the characteristics of the shape of the stator coil 5 according to the present embodiment will be described in detail. The stator coil 5 has a conducting wire portion 5a including a conducting wire portion 5g and an insulating coating 5b that covers the conducting wire portion 5g. The stator coil 5 has a structure in which the cross-sectional shape of the conducting wire portion 5g is substantially rectangular, a coil having a predetermined number of turns, and is substantially continuous from the first turn to the last turn of this coil. The helicoid surface 5i includes two opposing sides of the four sides of the rectangle having the above-mentioned cross-sectional shape. The stator coil 5 faces a part of the coil end portion 5r, which is a direction in which the stator core sheet 41a of the stator core 41 is laminated and a portion where the stator coil 5 protrudes from the end surface of the stator core 41, in the outer diameter direction of the stator core 41. It is an absent structure portion that is absent from the side to the side facing the direction in which the rotor 3 is located. This absent structure portion is, for example, a structure such as a groove portion 5e that is notched in a groove shape.

As will be described later, the above-mentioned missing structure portion is bored in a part of the coil end portion 5r from the side facing the outer diameter direction of the stator core 41 to the side facing the direction in which the rotor 3 is located. The hole portion 5f (see FIG. 3) may be used.

The shape of the groove portion 5e seen from the side facing the outer diameter direction of the stator core 41 to the side facing the direction in which the rotor 3 is located is as shown in FIG. , It looks like a V-shaped valley-shaped notch. The shape of the groove 5e is not limited to the V-shaped valley shape, but may be a U-shaped valley shape or other shape, and further, a sharp angle shape may be formed on a part of the V-shaped valley shape, the U-shaped valley shape, or the other shape. It may include an arc shape, an obscure shape, a curved shape, a straight line, or the like, and does not specify the shape.

For example, the structure and shape of the groove 5e are preferably such that the rigidity of the stator coil 5 is not impaired. When the cross-sectional shape of the conducting wire portion 5g is substantially rectangular, it is considered that the ratio of the groove portion 5e to the width dimension in the cross-sectional shape of the conducting wire portion 5g is preferably about 1/3. The groove bottom portion (valley bottom portion) of the groove portion 5e may have a valley-shaped groove structure having a curved surface, a U-shaped valley-shaped groove structure, or a groove structure having a flat surface.

Further, in order to improve the film formation of the insulating coating 5b, the cross-sectional shape of the conducting wire portion 5g including the portion where the groove portion 5e is arranged and the cross-sectional shape of the conducting wire portion 5g where the groove portion 5e is not arranged are substantially. Is rectangular. However, it is not preferable to form an acute-angled ridgeline at the corners of the four corners in the cross-sectional shape of the rectangular lead wire portion 5g, and the tip of the ridgeline is a curved surface (so-called R chamfer) or C chamfer. It is preferable that the configuration is as follows.

In FIG. 2, the groove portion 5e is arranged only on the side of the coil end portion 5r that does not face the teeth and on the outer peripheral side of the annular body 5m, but is not limited to this. For example, the groove portion 5e may be arranged on the side of the coil end portion 5r facing the teeth and on the inner peripheral side of the annular body 5m. Further, the groove portion 5e may be arranged on both the inner peripheral side and the outer peripheral side of the annular body 5 m.

When the cross-sectional shape of the conductor portion 5g is substantially rectangular, the ratio of the groove portion 5e to the width dimension in the cross-sectional shape of the conductor portion 5g is not limited to about 1/3. Considering that the rigidity of the stator coil 5 and the heat generated by Joule heat (temperature rise due to self-heating) due to the increase in the electrical resistance value of the stator coil 5 are in a trade-off relationship with each other, and in light of the motor specifications, The ratio of the groove portion 5e to the width dimension in the cross-sectional shape of the conductor portion 5g is appropriately selected.

The number of locations where the grooves 5e are arranged is not particularly limited, and the rigidity of the stator coil 5 and the heat generated by Joule heat (temperature rise due to self-heating) due to the increase in the electric resistance value of the stator coil 5 are mutually exclusive. Select as appropriate in consideration of the trade-off relationship and in light of the motor specifications.

In the present embodiment, the number of turns of the stator coil 5 is substantially 10. However, the value is not particularly limited to this, and other values may be used. As described above, the number of turns of the stator coil 5 in the present embodiment is about 9.75, which is slightly less than 10, but it is often interpreted as substantially 10.

As described above, the motor 1 of the present embodiment includes a stator core 41 including a laminated body in which a plurality of stator core sheets 41a are laminated, and a stator including a stator coil 5 having a tooth 42 provided in the stator core 41 as a part of a magnetic core. In the motor 1 including the fourth and the rotor 3 rotatably supported through the gap between the tip of the teeth 42 of the stator core 41, the stator coil 5 is an insulator that covers the conductor portion 5 g and the conductor portion 5 g of the stator coil 5. The coil has a conducting wire portion 5a including a sexual coating, the cross-sectional shape of the conductor portion 5g is substantially rectangular, the coil has a predetermined number of turns, and the number of turns of the stator coil 5 is from the first turn. This is the direction in which the stator cores 41 are laminated, including substantially continuous spiral surfaces up to the last turn of the number of turns, including two opposing sides of the four sides of the rectangular cross-sectional shape in the spiral surface. Further, it is absent from the side facing the outer diameter direction of the stator core 41 to the side facing the position of the rotor 3 in a part of the coil end portion 5r where the stator coil 5 protrudes from the end surface of the stator core 41. Includes absent structural parts.

As a result, even when the space factor of the stator coil 5 is increased, the stator coil 5 with improved heat dissipation against heat generated by the eddy current is found, and the motor has improved characteristics of the stator coil 5 as compared with the conventional case. Can be provided.

Further, the missing structure portion is a groove portion 5e that is missing in a part of the coil end portion 5r in a groove shape from the side facing the outer diameter direction of the stator core 41 to the side facing the direction in which the rotor 3 is located. You may.

(Embodiment 2)
FIG. 3 is a front view of the stator coil 5 according to the second embodiment. The configuration of the motor in the present embodiment has the same contents as those in the first embodiment, and the description of the overlapping contents will be omitted.

The missing structure portion in the present embodiment is a hole formed in a part of the coil end portion 5r from the side facing the outer diameter direction of the stator core 41 to the side facing the direction in which the rotor 3 is located. Part 5f (see FIG. 3).

Further, the above-mentioned missing structure portion has the shape of the hole portion 5f as viewed from the side facing the outer diameter direction of the stator core 41 to the side facing the direction in which the rotor 3 is located. As shown in 3, it looks like a round hole drilled in a substantially circular shape. The shape of the hole portion 5f is not limited to a circular round hole, and may be an elliptical elliptical hole, a square square hole, a triangular triangular hole, a polygonal polygonal hole, or another shape. Further, a part of the hole shape may include an acute-angled shape, an arc shape, an obtuse-angled shape, a curved line, a straight line, or the like. It does not specify the shape of the hole 5f.

The structure and shape of the hole 5f are preferably such that the rigidity of the stator coil 5 is not impaired. When the cross-sectional shape of the conducting wire portion 5g is substantially rectangular, it is considered that the ratio of the hole portion 5f to the width dimension in the cross-sectional shape of the conducting wire portion 5g is preferably about 1/3.

In order to improve the film formation of the insulating coating 5b, the cross-sectional shape of the conducting wire portion 5g including the portion where the hole portion 5f is arranged and the cross-sectional shape of the conducting wire portion 5g where the hole portion 5f is not arranged are substantially. Is rectangular. However, it is not preferable to form an acute-angled ridgeline at the corners of the four corners in the cross-sectional shape of the rectangular lead wire portion 5g, and the tip of the ridgeline is curved surface (so-called R chamfer) or C chamfered. It is preferable that the configuration is different.

In FIG. 3, the holes 5f are arranged in a line at substantially the center of the coil end 5r. However, it is not limited to this. For example, the holes 5f may be arranged in a staggered pattern instead of in a single row.

When the cross-sectional shape of the conductor portion 5g is substantially rectangular, the ratio of the hole portion 5f to the width dimension in the cross-sectional shape of the conductor portion 5g is not limited to about 1/3. Considering that the rigidity of the stator coil 5 and the heat generated by Joule heat (temperature rise due to self-heating) due to the increase in the electrical resistance value of the stator coil 5 are in a trade-off relationship with each other, and in light of the motor specifications, The ratio of the hole portion 5f to the width dimension in the cross-sectional shape of the conducting wire portion 5g should be appropriately selected.

Further, the number of locations where the groove 5e is arranged is not particularly limited. Regarding the number of locations where the grooves 5e are arranged, consideration is given to the fact that the rigidity of the stator coil 5 and the heat generated by Joule heat (temperature rise due to self-heating) due to the increase in the electric resistance value of the stator coil 5 are in a trade-off relationship with each other. However, it is selected appropriately in light of the specifications of the motor.

The stator coil 5 in the present invention can be formed by casting. According to this method, a spiral stator coil can be easily formed from a conductor having a large cross-sectional area. In addition to the above casting, it may be formed by another method. For example, it may be formed from a solid material such as copper, aluminum, zinc, magnesium, iron, SUS, and brass by cutting or the like. Individually molded parts may be formed by integrating members by welding or joining.

As described above, in the motor 1 of the present embodiment, the missing structure portion is formed on a part of the coil end portion 5r from the side facing the outer diameter direction of the stator core 41 to the side facing the direction in which the rotor 3 is located. It is a hole portion 5f that is notched in a hole shape over the entire surface.

According to the present invention, even when the space factor of the stator coil is increased, the configuration of the stator coil with improved heat dissipation against heat generated by the eddy current is found, and the characteristics of the stator coil are improved as compared with the conventional case. It is possible to provide a motor. Therefore, it has great industrial value.

1 Motor 3 Rotor 4 Stator 5 Stator coil 5a Conductor 5b Insulating coating 5c Drawer 5d Drawer 5e Groove 5f Hole 5g Conductor

5i Spiral surface 5m Annulus

5q Coil line 5r Coil end 5s Coil 1 turn 5u 10th turn 41 Stator core 41a Stator core sheet 42 Teeth 43 Slot 44 Yoke 45

Eddy current

51, 52, 53, 54 Bus bar A Arrow U11, U22, U32, U41, V12. V21, V31, V42, W11, W22, W32, W41 stator coil

Claims

A stator core including a laminate in which a plurality of stator core sheets are laminated, a stator including a stator coil having a tooth provided in the stator core as a part of a magnetic core, and a stator rotatably supported via a gap between the tip of the tooth of the stator core and a gap. In the motor including the rotor
The stator coil is
It has a conductor portion including a conductor portion of the stator coil and an insulating coating that covers the conductor portion, and the cross-sectional shape of the conductor portion is substantially rectangular.
A coil having a predetermined number of turns and comprising a substantially continuous spiral surface from the first turn of the number of turns of the stator coil to the last turn of the number of turns.
The helicoid surface includes two opposite sides of the four sides of the rectangle having the cross-sectional shape.
In the direction in which the rotor is located from the side facing the outer diameter direction of the stator core to a part of the coil end portion where the stator coil protrudes from the end surface of the stator core in the stacking direction of the stator core. A motor that includes an absent structural part that is absent over the facing side.
The missing structure portion is a groove portion that is formed in a groove shape from a side facing the outer diameter direction of the stator core to a side facing the direction in which the rotor is located in a part of the coil end portion. The described motor.
The missing structure portion is a hole portion that is bored in a part of the coil end portion from the side facing the outer diameter direction of the stator core to the side facing the direction in which the rotor is located. 1. The motor according to 1.