Armature Structure of Three-Phase Motor

Abstract

The present invention provides an armature structure for a three-phase motor, which includes: 6N slits, 1N coils for each phase, 3N main magnetic poles and 3N auxiliary magnetic poles, where N is a natural number. Coils are wound around the main magnetic poles, and the coils are wound around a winding frame inserted into the slits. No coils are wound around the auxiliary magnetic poles. The main magnetic poles and the auxiliary magnetic poles are alternately arranged. The winding frame includes a main body portion and a jaw portion. The main body portion abuts against the circumferential side surface of the main magnetic pole within the slit, and the jaw portion stands up from the main body portion along the bottom of the first outer peripheral side of the slit within the slit. Within the slit, the circumferential side surface of the auxiliary magnetic pole, the outer peripheral surface of the coil, and the bottom of the second outer peripheral side of the slit define a gap region not filled with the coil. The bottom of the second outer peripheral side is continuous with the bottom of the first outer peripheral side and extends in a direction intersecting with the bottom of the first outer peripheral side.

Description

[0001] Cross-reference to related patents

[0002] This application is based on Japanese Patent Application No. 2018-240710 filed with the Japan Patent Office on December 25, 2018, the entire contents of which are incorporated herein by reference. Technical field

[0003] The present invention relates to an armature structure of a three-phase motor. Background art

[0004] Currently, in a three-phase synchronous motor having permanent magnets, for example, as shown in Japanese Patent Laid-Open Publication No. Hei 11-234990 (Patent Document 1), a three-phase motor structure having 6N slits (N: natural number) and 3N coils per phase is disclosed.

[0005] In addition, in Japanese Patent Publication No. 5253789 (Patent Document 2), an uncoiled auxiliary magnetic pole is inclined parallel to the main magnetic pole midway, and a shoulder is provided to ensure a space for a hole.

[0006] According to the structure described in Patent Document 1, the shape of the coil is wound in a manner along the bottom of the arc-shaped slit. That is, the winding is not formed until the auxiliary magnetic pole becomes parallel to the winding.

[0007] Therefore, since the winding space is not effectively utilized, the winding space occupancy rate is reduced. This results in fewer windings beneficial to improving the motor performance.

[0008] In addition, according to Patent Document 2, the winding is filled in the slit without gaps. Therefore, although the winding space occupancy rate is high, a flow path for resin molding cannot be ensured. As a result, the resin filling performance cannot be improved. In addition, if a winding capable of filling the gap amount is wound, torque improvement cannot be achieved. Furthermore, since the winding bulges in the axial direction, there is a problem of increasing the overall length of the motor. Summary of the invention

[0009] An object of the present invention is to solve the above problems.

[0010] The present invention provides an armature structure for a three-phase motor, which includes 6N slits, 1N coils for each phase, 3N main magnetic poles and 3N auxiliary magnetic poles, where N is a natural number. Coils are wound around the main magnetic poles, and the coils are wound on a winding frame inserted into the slits. No coils are wound around the auxiliary magnetic poles. The main magnetic poles and the auxiliary magnetic poles are alternately arranged. The winding frame includes a main body portion and a jaw portion. The main body portion abuts against the circumferential side surface of the main magnetic pole within the slit, and the jaw portion erects from the main body portion along the bottom of the first outer peripheral side of the slit within the slit. Within the slit, the circumferential side surface of the auxiliary magnetic pole, the outer peripheral surface of the coil, and the bottom of the second outer peripheral side of the slit define a gap region not filled with the coil. The bottom of the second outer peripheral side is continuous with the bottom of the first outer peripheral side and extends in a direction intersecting with the bottom of the first outer peripheral side.

[0011] According to the above-mentioned armature structure of the three-phase motor, in the case of molding by resin casting, the gap formed between the coil and the auxiliary magnetic pole forms a flow path for the casting resin to pass through. The resin can reach the coil end on the opposite side through this flow path. Therefore, the resin filling property can be improved.

[0012] At the inner peripheral side ends of the core plates of the main magnetic poles and the auxiliary magnetic poles, it is preferable that at least the core plates located at the axial ends have connecting portions.

[0013] Preferably, the arc length of the front end of the magnetic pole on the inner peripheral surface of the main magnetic pole and the auxiliary magnetic pole is formed into a shape that is a part of an arc of a concentric circle having a circumferential length that constitutes a specified ratio with respect to the circumferential length of the outer peripheral circle of the iron core, and one of the front ends of the main magnetic pole or the auxiliary magnetic pole has a jaw-shaped portion extending on both sides in the circumferential direction. The arc length of the front end of the other of the main magnetic pole or the auxiliary magnetic pole is formed to correspond to the arc length of the jaw-shaped portion of one of the main magnetic pole end or the auxiliary magnetic pole end, and its arc length is smaller than the circumferential direction width of the portion other than the front end of the other of the main magnetic pole or the auxiliary magnetic pole, forming a front-end tapered shape.

[0014] In the case of distinguishing the main magnetic pole and the auxiliary magnetic pole where the magnetomotive force of the coil is concentrated, by making at least one of the front ends of the main magnetic pole and the auxiliary magnetic pole narrower than the magnetic pole, the leakage magnetic flux can be effectively suppressed.

[0015] According to the present invention, in a three-phase motor, the space occupancy rate of the winding can be increased. In addition, the temperature rise of the winding can be suppressed.

[0016] In addition, the ensured gap can limit the axial bulge of the winding to the minimum and can shorten the overall length of the motor.

[0017] In addition, the coil ends are not useful for the torque of the motor. Therefore, the uncoiled winding in the gap does not have an adverse effect on the torque. That is, an increase in torque and a reduction in cogging torque can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A and 1B is a cross-sectional view showing the armature structure of a three-phase synchronous motor according to an embodiment of the present invention. Figure 1A is a cross-sectional view showing the core cross-sectional structure and the coil as viewed axially. Figure 1B is along Figure 1A the cross-sectional view of the Ia-Ib line of

[0019] Figure 1C is showing Figure 1A a modified example of

[0020] Figure 2 is a cross-sectional view showing the first embodiment of the front-end asymmetric structure and corresponding to Figure 1C

[0021] Figure 3 is a cross-sectional view showing the second embodiment of the front-end asymmetric structure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In the following detailed description, for the purpose of explanation, in order to provide a thorough understanding of the disclosed embodiments, many specific details are set forth. However, it is apparent that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.

[0023] In the present specification, a bobbin means a cylinder around which a wire for forming a coil is wound. The bobbin can be made of an insulating material. In addition, an empty bobbin means a bobbin around which no wire is wound.

[0024] In addition, the circumference closer to the rotation axis C in the radial direction with respect to the rotation axis C is called the inner circumference. The circumference farther from the rotation axis C is called the outer circumference. The direction along the rotation axis is called the rotation axis direction. The direction radially extending with the rotation axis as the center is called the radial direction. In addition, the direction of rotation around the rotation axis is called the circumferential direction. The side closer to the rotation axis with the rotation axis as the center is called the inner circumference side. The side farther from the rotation axis is called the outer circumference side. The inner diameter side circumference is called the inner circumference. The outer diameter side circumference is called the outer circumference. Hereinafter, the positional relationship is described based on the rotation axis C of the motor.

[0025] Hereinafter, with reference to the drawings, the armature structure of a three-phase synchronous motor including a permanent magnet according to an embodiment of the present invention will be described in detail.

[0026] ​In a rotating machine, improving the winding space occupancy rate and the winding casting such as die casting or injection molding using resin are related to reducing the armature temperature and increasing the output. Therefore, thermal design becomes a very important point.

[0027] (First Embodiment)

[0028] Figure 1A And 1B is a cross-sectional view showing the armature structure X of a three-phase synchronous motor according to the present embodiment. Figure 1A is a cross-sectional view of the core cross-sectional structure and the coil as viewed axially. Figure 1B is a cross-sectional view showing the core radial cross-sectional structure along the Ia-Ib line. The armature of the motor is, for example, a cylindrical armature in which a rotating rotor (rotor) is arranged on its inner peripheral side.

[0029] As Figure 1A shown, in the armature structure X of a three-phase motor, the core 1 has 6N (N is a natural number) slits. On the other hand, the armature structure X has 3N coils. The number of coils is half the number of slits. The coils and the slits are, for example, alternately arranged.

[0030] The core 1 is divided into a main magnetic pole 1a and an auxiliary magnetic pole 1b. The main magnetic pole 1a is wound with the coil 3. That is, the coil 3 is wound around a winding bobbin (winding frame) 2 inserted into the slit S adjacent to the main magnetic pole 1a. In contrast, the auxiliary magnetic pole 1b is not wound with the coil 3. The outer peripheral shape (bottom) of the bottom of the slit S is determined by dividing using the roots (outer diameter side ends) A of the main magnetic pole 1a and the auxiliary magnetic pole 1b, a line C1 (first imaginary line) perpendicular to the side surface B1 of the main magnetic pole 1a (imaginary line, the same below), and a line C2 (second imaginary line) perpendicular to the auxiliary magnetic pole 1b. Figure 1A shows a structure including the inner peripheral side front end portions of adjacent magnetic poles along the circumferential direction of the rotation axis that are interconnected.

[0031] More specifically, the winding bobbin 2 includes: a main body portion 2a that abuts against the main magnetic pole 1a in the slit S; an inner peripheral side flange portion 2b that stands up from the main body portion 2a along the first outer peripheral side bottom (bottom surface along C1) of the slit S in the slit S; and an outer peripheral side flange portion 2c. The main body portion 2a is arranged along the line B1. The outer peripheral side flange portion 2c is arranged along the line C1. That is, in the shape of the winding bobbin 2 in the slit S, the outer peripheral side flange portion 2c stands upright in the circumferential direction and is substantially perpendicular to the main body portion 2a.

[0032] Furthermore, a second outer peripheral side bottom (bottom surface along C2) continuous with the first outer peripheral side bottom of the slit S is formed in the slit S. The second outer peripheral side bottom extends along a direction intersecting the first outer peripheral side bottom.

[0033] In addition, a gap region 4 in which the coil 3 is not filled is formed within the slit S. The gap region 4 is demarcated and defined by the circumferential side surface of the auxiliary magnetic pole 1b (the side surface along line B2), the outer circumferential side surface of the coil 3 wound around the bobbin 2 (the side surface along line D1), and the second outer circumferential side bottom surface (the bottom surface along C2).

[0034] Taking the sectional structure of the above structure as an example, an explanation will be given. According to the structure of the bobbin 2 described above, in the region surrounded by the lines D1, B2, and C2 that are parallel to line B1 and along the outer circumference of the coil, the lines D1, B2, and C2 have angles that intersect each other. Therefore, a gap region 4 is formed between the coil 3 and the auxiliary magnetic pole 1b. Figure 1A In addition, it is preferable that electrical insulation is provided between the auxiliary magnetic pole 1b and the outer circumferential surface of the coil 3 facing it. For example, an insulator may also be inserted between the auxiliary magnetic pole 1b and the outer circumferential surface of the coil 3 facing it. Alternatively, the auxiliary magnetic pole 1b and the outer circumferential surface of the coil 3 may simply be spatially separated. In addition, a second bobbin (an empty bobbin without windings) inserted into the slit S adjacent to the auxiliary magnetic pole 1b may also be provided.

[0035] Moreover, after the winding is assembled, the gap region 4 of the armature structure of the present embodiment serves as a flow path for the casting resin to flow during casting operations such as casting or injection molding using varnish or resin. For example, during the casting operation, when resin is filled from the gate, which is set as the inlet for the resin to flow into the molded product, in the direction of arrow 6, the resin can pass through the appropriate gap region 4 formed between the coil 3 and the auxiliary magnetic pole 1b of the present embodiment and reach the coil end on the opposite side. Thereby, the filling property of the resin can be improved. Generally, holes may also be formed during the filling process. However, the armature structure of the present embodiment is different from the normal filling process in that the resin directly contacts the winding. Therefore, it has the advantage of being able to more effectively dissipate the heat of the winding.

[0036] In addition, as shown, by restricting the length of the coil end, the length of the overall length 5 of the motor can be restricted to be shorter. Figure 1B Furthermore, the guaranteed gap region 4 can limit the axial bulging of the coil 3 to the minimum. Therefore, the overall length of the motor can be made shorter. That is to say, its structure is not particularly limited. According to the armature structure of the synchronous motor of the present embodiment, compared with the structure in which the coil 3 is wound up to the part of the gap region 4, the number of layers of the coil wound around the main magnetic pole 1a is fewer. Therefore, by restricting the length of the coil, the overall length 5 of the motor can be shortened.

[0037] In addition, as Figure 1B shown, by restricting the length of the coil end, the length of the overall length 5 of the motor can be restricted to be shorter.

[0038] Furthermore, the guaranteed gap region 4 can limit the axial bulging of the coil 3 to the minimum. Therefore, the overall length of the motor can be made shorter. That is to say, its structure is not particularly limited. According to the armature structure of the synchronous motor of the present embodiment, compared with the structure in which the coil 3 is wound up to the part of the gap region 4, the number of layers of the coil wound around the main magnetic pole 1a is fewer. Therefore, by restricting the length of the coil, the overall length 5 of the motor can be shortened.

[0039] In addition, the coil ends are not useful for the torque of the motor. Therefore, not winding the winding at the gap will not have an adverse effect on the torque. That is to say, according to this embodiment, the torque can be increased and the cogging torque can be reduced.

[0040] The iron core 1 is formed of laminated core plates, for example.

[0041] That is to say, the laminated core plates may also have a connecting portion 1c (structure 1) that connects the inner peripheral side front end portions of the magnetic poles adjacent in the circumferential direction along the rotation axis. In addition, there may also be a non-connecting portion 1d (structure 2) that separates the inner peripheral side front end portions of the magnetic poles adjacent in the circumferential direction along the rotation axis.

[0042] Alternatively, the iron core may be formed by laminating the core plates of structure 1 and the core plates of structure 2 that are aligned in such a way that the connecting portion 1c and the non-connecting portion 1d overlap (structure 3).

[0043] Preferably, at least the core plates located at the axial ends in the core plates of the main magnetic poles 1a and the auxiliary magnetic poles 1b have connecting portions.

[0044] Figure 1C It represents Figure 1A a modified example diagram of Figure 1C Compared with Figure 1A the difference is that: relative to Figure 1A where the main magnetic poles 1a and the auxiliary magnetic poles 1b are connected on the inner peripheral side of the iron core 1, Figure 1C in Figure 1C the main magnetic poles 1a and the auxiliary magnetic poles 1b are not connected but separated on the inner peripheral side of the iron core 1. That is to say,

[0045] shows a structure including the inner peripheral side front end portions of the magnetic poles adjacent in the circumferential direction along the rotation axis that are separated from each other.

[0046] According to this embodiment, the space occupancy rate of the winding can be increased in a three-phase motor. In addition, the temperature rise of the winding can be restricted.

[0047] In addition, the ensured gap can limit the axial bulge of the winding to the minimum, and can make the overall length of the motor shorter.

[0048] Furthermore, the coil ends are not useful for the torque of the motor. Therefore, not winding the winding in the gap will not have an adverse effect on the torque. That is to say, an increase in torque and a reduction in cogging torque can be achieved.

[0049] (Second Embodiment)

[0050] In the second embodiment of the present invention, not only the shape of the root (outer diameter side end) of the magnetic pole of the three-phase motor armature structure of the first embodiment is improved, but also the shape of the front end (inner diameter side end) is improved. As a result, it is possible to simultaneously achieve an increase in torque and a reduction in cogging torque.

[0051] Hereinafter, an example will be described with the Figure 1C structure. However, of course Figure 1A the structure can also be applied to the second embodiment. That is, any one of the above structures 1 to 3 can be used. That is, the second embodiment does not depend on whether or not there is a connection at the inner peripheral side front end of the iron core 1.

[0052] Figure 2 is a cross-sectional view showing a first embodiment having a front-end asymmetric structure. Figure 2 is a diagram corresponding to Figure 1C . As Figure 2 shown, the armature structure X includes: a main magnetic pole 1a around which a coil 3 is wound, and the coil 3 is wound around an inserted winding frame 2; an auxiliary magnetic pole 1b around which no coil is wound. Moreover, the inner peripheral side front end portions of the main magnetic pole 1a and the auxiliary magnetic pole 1b are formed in an arc shape, and this arc shape constitutes a part of the circumference of a concentric circle having a circumferential length having a specified ratio with respect to the circumferential length of the outer peripheral circle of the iron core. And, the inner peripheral side front end portion of the auxiliary magnetic pole 1b has a jaw-shaped portion 21 extending to both sides on this concentric circumference.

[0053] The inner peripheral side front end portion of the main magnetic pole 1a is formed in a tapered portion 23 that is thin at the front end. That is, corresponding to the arc length of the jaw-shaped portion 21 of the auxiliary magnetic pole 1b, the arc length of the inner peripheral side front end portion of the main magnetic pole 1a is smaller than the circumferential direction width of the portion other than the inner peripheral side front end portion of the auxiliary magnetic pole 1b. For example, the circumferential width Δd2 of the jaw-shaped portion 21 may be the same as the circumferential width Δd1 of the tapered portion 23.

[0054] In a motor, usually by expanding the front end of the magnetic pole with respect to the width of the magnetic pole, the rotor can transfer magnetic flux more effectively. As a result, a large torque can be derived. However, due to the design of the iron core cross-section, the distance from the adjacent magnetic poles becomes closer. Therefore, sometimes "leakage flux" occurs where the magnetic flux of the armature short-circuits between the magnetic poles, and thus the expansion of the front end of the magnetic pole is useless for torque.

[0055] In this case, a design that narrows the expansion of the front end of the magnetic pole sometimes helps to increase the torque. Especially in the case where, as in the present embodiment, the main magnetic pole 1a where the magnetomotive force of the coil is concentrated and the auxiliary magnetic pole 1b are separated, by making the inner peripheral side front end portion of the main magnetic pole 1a narrower than other parts of the magnetic pole, it is possible to effectively suppress the leakage flux.

[0056] In addition, the spreading angle of the front end portion on the inner peripheral side of adjacent magnetic poles determines the cogging torque. Therefore, by providing the same conical shape as described above, the cogging torque can also be suppressed.

[0057] From this, it can be understood that the effect of suppressing the cogging torque generated by the conical magnetic poles can be well exhibited when the size ratio of the outer periphery to the inner periphery of the iron core is inner periphery / outer periphery ≤ 0.55.

[0058] Figure 3 It is a diagram showing a second embodiment having a front end asymmetric structure. As Figure 3 shown, contrary to the structure of Figure 2 , the armature structure X includes: a main magnetic pole 1a around which a coil 3 is wound, and this coil 3 is wound around an inserted winding frame 2; an auxiliary magnetic pole 1b around which no coil is wound. The front end portion on the inner peripheral side of the main magnetic pole 1a is formed in a jaw-shaped portion 31. The front end portion on the inner peripheral side of the auxiliary magnetic pole 1b may also be formed in a conical shape portion 33 in such a way that the width thereof is made narrower than other portions of the magnetic pole.

[0059] In such a structure, the same effect as that of the Figure 2 structure can also be obtained.

[0060] As described above, according to the present embodiment, by making the armature slot shape of the synchronous motor having a permanent magnet asymmetric, the space occupancy rate of the winding can be increased. At the same time, the set potting resin can achieve a reduction in the temperature of the winding. In addition, by making the shape of the front end portion on the inner peripheral side of the magnetic pole asymmetric, the torque can be increased and the cogging torque can be reduced.

[0061] The above-described embodiment is not limited to the structures shown in the drawings and the like. The structure can be appropriately changed within the range where the effects of the present embodiment can be achieved. In addition, as long as it does not deviate from the scope of the purpose of the present embodiment, an embodiment with an appropriately changed structure can also be applied.

[0062] In addition, each structural element of the present embodiment can be arbitrarily selected. An embodiment having the selected structure is also included in the present embodiment.

[0063] The present invention can be used for the armature structure of a synchronous motor.

[0064] The armature structure of the three-phase motor according to the embodiment of the present invention can be the armature structures of the following first to third three-phase motors.

[0065] The armature structure of the first three-phase motor described above is a three-phase motor in which the number of slots in the motor armature is 6N (N is a natural number), and the number of coils per phase is 1N. In this three-phase motor armature structure, the main magnetic poles with winding frames wound with 3N coils inserted alternately and the auxiliary magnetic poles without coils wound are arranged. In this three-phase motor armature structure, the winding frame includes: a main body portion that abuts against the circumferential side surface of the main magnetic pole within the slot; and an outer peripheral jaw portion that protrudes from the main body portion along the bottom of the first outer peripheral side of the slot within the slot. And a gap region without coils filled is provided within the slot, and this gap region is demarcated by the circumferential side surface of the auxiliary magnetic pole, the outer peripheral surface of the coil wound around the winding frame, and a second outer peripheral side bottom that is continuous with the first outer peripheral side bottom of the slot and extends in a direction intersecting the first outer peripheral side bottom.

[0066] The armature structure of the second three-phase motor described above is based on the armature structure of the first three-phase motor. At the inner peripheral side end of the core plates of the main magnetic poles and the auxiliary magnetic poles, at least the core plates located at the axial ends have connecting portions.

[0067] The armature structure of the third three-phase motor described above is based on the armature structure of the first or second three-phase motor. The arc length of the front end portion of the magnetic pole located on the inner peripheral surface of the main magnetic pole and the auxiliary magnetic pole is formed into a shape that is a part of an arc of a concentric circle having a circumferential length that constitutes a specified ratio to the circumferential length of the outer peripheral circle of the iron core. And one of the front end portions of the main magnetic pole or the auxiliary magnetic pole has a jaw-shaped portion that extends on both sides in the circumferential direction. The arc length of the front end portion of the other of the main magnetic pole or the auxiliary magnetic pole is formed to correspond to the arc length of the jaw-shaped portion of one of the main magnetic pole end or the auxiliary magnetic pole end, and its arc length is smaller than the circumferential direction width of the portion other than the front end portion of the other of the main magnetic pole or the auxiliary magnetic pole, and is a tapered portion with a thinner front end.

[0068] The detailed description has been given for purposes of illustration and explanation. Many variations and changes are possible in light of the above teachings. The detailed description is not without omissions or intended to limit the subject matter described herein. Although the subject matter has been described in words with specific structural features and / or method processes, it should be understood that the subject matter defined in the claims is not necessarily limited to the specific features or specific processes described. Rather, the specific features and specific processes have been described as examples for implementing the claims.

Claims

1. An armature structure of a three-phase motor, characterized in that it includes 6N slots, 1N coils for each phase, 3N main magnetic poles and 3N auxiliary magnetic poles, where N is a natural number, coils are wound around the main magnetic poles, and the coils are wound on a winding frame inserted into the slots, no coils are wound around the auxiliary magnetic poles, the main magnetic poles and the auxiliary magnetic poles are alternately arranged, the winding frame includes a main body portion and a jaw portion, the main body portion abuts against the circumferential side surface of the main magnetic pole within the slot, the jaw portion stands up from the main body portion along the bottom of the first outer peripheral side of the slot within the slot, within the slot, the circumferential side surface of the auxiliary magnetic pole, the outer peripheral surface of the coil, and the bottom of the second outer peripheral side of the slot define a gap region not filled with the coil, the gap region has a triangular cross-sectional shape with a width narrowing towards the central axis, the bottom of the second outer peripheral side is continuous with the bottom of the first outer peripheral side and extends in a direction intersecting the bottom of the first outer peripheral side, the gap region is a flow path through which the molded resin passes and is filled with resin.

2. The armature structure of a three-phase motor according to claim 1, characterized in that connection portions are provided at the front end portions of the magnetic poles on the inner peripheral surface of the main magnetic poles and the auxiliary magnetic poles included in at least the core plate located at the axial end in the core plate including the main magnetic poles and the auxiliary magnetic poles.

3. The armature structure of a three-phase motor according to claim 1 or 2, characterized in that the front end portions of the magnetic poles on the inner peripheral surface of the main magnetic poles and the auxiliary magnetic poles are formed in an arc shape, and this arc shape is a part of the circumference of a concentric circle having a circumferential length with a specified ratio to the circumferential length of the outer peripheral circle of the iron core, one of the main magnetic poles and the auxiliary magnetic poles has a jaw-shaped portion extending to both sides on the concentric circumference at the front end portion of the magnetic pole, the arc length of the front end portion of the other of the main magnetic poles and the auxiliary magnetic poles corresponds to the arc length of the jaw-shaped portion and is smaller than the circumferential direction width of the portion other than the front end portion of the other magnetic pole.

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