electric motor

Abstract

The electric motor (100) comprises a field (1) and an armature (2). The armature (2) comprises a stator core (21) having a core back (21a) and a plurality of teeth (21b), a plurality of insulators (22), and a plurality of coils (23). Each tooth (21b) has a winding portion (21c) and a tip portion (21d). A core back side groove (22d) is formed at one end of the first insulator portion (22a). A field side groove (22e) is formed at one end of the third insulator portion (22c). The winding start point (24a) of the conductive wire (24) is in the portion of the winding portion (21c) adjacent to the core back (21a). The winding end point (24b) of the conductive wire (24) is in the portion of the winding portion (21c) adjacent to the tip portion (21d). The crossover wire (24c) is positioned along the field groove (22e), and then extends from the field groove (22e) to the core back groove (22d) and is positioned along the core back groove (22d).

Description

Technical Field

[0001] The present disclosure relates to an electric motor including a field magnet and an armature.

Background Art

[0002] Conventionally, an electric motor including a field magnet and an armature is known. The armature is disposed opposite the field magnet through an air gap and is movable relative to the field magnet. The armature includes a stator core having a core back and a plurality of teeth, and a plurality of coils wound around each tooth through an insulator. Each coil is formed by winding a conductive wire around each tooth through an insulator. Each tooth has a winding portion around which the coil is wound and a tip portion continuous with a portion of the winding portion facing the field magnet.

[0003] In general, winding of a conductive wire around a tooth in an electric motor often starts from a portion adjacent to the core back of the tooth and ends at a portion adjacent to the core back. For this reason, in the final turn, the conductive wire is folded back at the tip portion of the tooth and wound around the tooth toward the core back, and there is a constraint that the number of layers of the coil (the number of layers of the conductive wire) must be an even number.

[0004] Therefore, Patent Document 1 discloses a technique for winding an odd number of layers of a coil, in which a U-shaped notch is cut out in the portion between the winding portion and the tip portion to provide a locking piece connected only to the winding portion, and the portion between the winding portion and the tip portion excluding the locking piece is bent in the height direction to form a bent portion that is offset in the height direction from the locking piece. In this technique, when the conductive wire is finished winding in the portion of the winding portion closest to the tip portion, the conductive wire is placed in the space between the locking piece and the bent portion, hooked onto the locking piece, and folded back toward the core back, extending toward the core back so as not to be wound into the coil. For example, by extending the conductive wire folded back by the locking piece toward the core back so as to pass through a position that does not overlap with the coil in a plan view, it becomes possible to wind an odd number of layers of a coil even when the winding start point is in the portion of the teeth adjacent to the core back. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2009-060694 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, in the technology disclosed in Patent Document 1, a part of the tooth is cut out to form a locking piece, and a part of the tooth is bent to form a bent portion, resulting in a complex shape for the tooth. This also leads to a complex shape for the mold used to manufacture the tooth, increasing the design cost of the mold and shortening the mold's lifespan, which in turn increases the operating cost (running cost) of the mold.

[0007] Furthermore, the technology disclosed in Patent Document 1 has the problem of increased manufacturing costs because it requires extra complex manufacturing processes such as cutting out or bending parts of the teeth.

[0008] This disclosure is made in view of the above and aims to provide an electric motor that can reduce the costs associated with the manufacture of teeth by simplifying the shape of the teeth and the production process of the teeth. [Means for solving the problem]

[0009] To solve the above-mentioned problems and achieve the objective, the electric motor according to this disclosure comprises a field and an armature positioned opposite the field with an air gap between them in a first direction and movable relative to the field in a second direction perpendicular to the first direction. The armature comprises a stator core having a core back and a plurality of teeth extending from the core back toward the field in a first direction, a plurality of insulators provided on the stator core, and a plurality of coils wound around each tooth via each insulator. Each tooth has a winding portion continuous with the portion of the core back facing the field and around which the coil is wound, and a tip portion continuous with the portion of the winding portion facing the field. Each insulator has a first insulating portion provided on the core back, a second insulating portion provided on the winding portion, and a third insulating portion provided on the tip portion. A core back side groove is formed at one end of the first insulating portion in the third direction perpendicular to the first and second directions. A field groove is formed at one end of the third insulator in the third direction. Each coil is formed by winding conductive wire around the winding portion of each tooth via each insulator. The starting point of the conductive wire winding is in the portion of the winding portion adjacent to the core back or adjacent to the tip. The ending point of the conductive wire winding is in the portion of the winding portion adjacent to the tip. A connecting wire extending from the end point of the conductive wire winding is positioned along the field groove, and then extends from the field groove to the core back groove and is positioned along the core back groove. [Effects of the Invention]

[0010] The electric motor described herein has the effect of reducing the costs associated with the manufacture of teeth through the simplification of the tooth shape and the tooth production process. [Brief explanation of the drawing]

[0011] [Figure 1] Side view showing an example of the configuration of an electric motor according to Embodiment 1. [Figure 2] A perspective view showing an example of the armature configuration of an electric motor according to Embodiment 1. [Figure 3] Side view showing an example of the configuration of the stator core of an electric motor according to Embodiment 1. [Figure 4] View of the armature of the electric motor according to Embodiment 1, as seen from the direction of arrow A in Figure 2. [Figure 5] View of the armature of the electric motor according to Embodiment 1, as seen from the direction of arrow B in Figure 4. [Figure 6] A partially enlarged perspective view of the conductive wires and field grooves and their surroundings of the armature of the electric motor according to Embodiment 1. [Figure 7] Cross-sectional view along line VII-VII in Figure 6 [Figure 8] View of the armature of the electric motor according to Embodiment 1, as seen from the direction of arrow C in Figure 1. [Figure 9] This diagram shows the armature of the electric motor in the comparative example, and corresponds to the view from the direction of arrow C in Figure 1. [Modes for carrying out the invention]

[0012] The electric motor according to the embodiment will be described in detail below with reference to the drawings.

[0013] Embodiment 1. Figure 1 is a side view showing an example of the configuration of an electric motor 100 according to Embodiment 1. As shown in Figure 1, the electric motor 100 comprises a field 1 and an armature 2. In this embodiment, the electric motor 100 is exemplified as a linear motor with a concentrated winding structure in which coils 23 corresponding to each phase are wound around separate teeth 21b, driven by three-phase alternating current, but this is not intended to limit the configuration of the electric motor 100 of this disclosure. By supplying a three-phase alternating current to the electric motor 100, a moving magnetic field is formed, and as a result, an electromagnetic force is generated in the direction in which the multiple armature modules 2A are arranged, causing linear motion of the armature 2. Hereinafter, when describing the direction of each component of the electric motor 100, the direction in which the electromagnetic force is generated is defined as the X-axis direction, the direction in which the armature 2 and the field 1 face each other (the direction in which the armature 2 and the field 1 are arranged at a constant interval in the air gap 3) is defined as the Z-axis direction, and the direction perpendicular to the X-axis direction and the Z-axis direction is defined as the Y-axis direction. For each axis, the direction indicated by the arrow is considered one direction, and the direction opposite to the arrow is considered the other. In this embodiment, we will describe the case where the Z-axis direction corresponds to the first direction, the X-axis direction corresponds to the second direction, and the Y-axis direction corresponds to the third direction.

[0014] The field magnet 1 comprises a plurality of magnetized permanent magnets 1a and a field yoke 1b to which each permanent magnet 1a is fixed. Each permanent magnet 1a has the function of generating magnetic flux. S-pole permanent magnets 1a and N-pole permanent magnets 1a are arranged alternately in the X-axis direction. In Figure 1, dot hatching is applied only to the S-pole permanent magnets 1a to distinguish them from the N-pole permanent magnets 1a. The S-pole permanent magnets 1a shown in Figures 2 and later also have the same dot hatching as the S-pole permanent magnets 1a in Figure 1. Each permanent magnet 1a is arranged with an air gap 3 between it and the armature 2 in the Z-axis direction. The field yoke 1b has the function of efficiently guiding the magnetic flux generated by each permanent magnet 1a. The shape of the field yoke 1b is plate-like, extending in the X-axis direction and the Z-axis direction. The field yoke 1b is arranged on the opposite side of the armature 2 from each permanent magnet 1a in the Z-axis direction.

[0015] The armature 2 is arranged facing the field magnet 1 in the Z-axis direction through the air gap 3 and is movable relative to the field magnet 1 in the X-axis direction. The armature 2 includes a plurality of armature modules 2A arranged in the X-axis direction. Each armature module 2A has the same configuration. Adjacent armature modules 2A are connected to each other.

[0016] The armature module 2A includes a stator core 21, a plurality of insulators 22, and a plurality of coils 23. In FIG. 1 and the like, in order to clarify the regions of the stator core 21, the insulators 22, and the coils 23, the stator core 21 and the coils 23 are given dot hatching. The stator core 21 illustrated in the figures after FIG. 2 is also given the same dot hatching as the stator core 21 in FIG. 1. The coils 23 illustrated in the figures after FIG. 2 are also given the same dot hatching as the coils 23 in FIG. 1.

[0017] FIG. 2 is a perspective view showing a configuration example of the armature 2 of the motor 100 according to Embodiment 1. FIG. 3 is a side view showing a configuration example of the stator core 21 of the motor 100 according to Embodiment 1. As shown in FIG. 2, the stator core 21 is, for example, a laminate of a plurality of electromagnetic steel sheets laminated in the Y-axis direction. Each of the plurality of electromagnetic steel sheets is fixed to each other by caulking, welding, adhesion, or the like. As shown in FIG. 3, the stator core 21 has a core back 21a and a plurality of teeth 21b (only one is shown in FIG. 3). As shown in FIG. 1, the core back 21a extends in the X-axis direction. The core back 21a is divided into a plurality in the X-axis direction. Note that the core back 21a may not be divided into a plurality in the X-axis direction and may have a single configuration.

[0018] The plurality of teeth 21b are arranged at equal intervals in the X-axis direction. Each tooth 21b extends in the Z-axis direction from the core back 21a toward the field magnet 1. Each tooth 21b is provided on each of the divided pieces of the divided core back 21a. As shown in FIG. 3, each tooth 21b has a winding portion 21c and a tip portion 21d. The winding portion 21c is continuous with the portion of the core back 21a facing the field magnet 1 and is the portion around which the coil 23 is wound. The tip portion 21d is a portion continuous with the portion of the winding portion 21c facing the field magnet 1. Each tooth 21b has a tip surface 21e facing the field magnet 1. The tip surface 21e is a part of the tip portion 21d.

[0019] As shown in FIG. 1, each insulator 22 is provided on the stator core 21 and has a function of electrically insulating the stator core 21 and the coil 23. Each insulator 22 is integrally formed of a resinous insulating material on each of the core back 21a and the teeth 21b. The insulating material of each insulator 22 is a material having excellent electrical insulation performance, such as polyimide, polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), liquid crystal polymer (LCP), etc. As shown in FIG. 2, each insulator 22 has a first insulating portion 22a, a second insulating portion 22b, and a third insulating portion 22c.

[0020] The first insulating portion 22a is a portion provided on the core back 21a. The first insulating portion 22a covers a part of the core back 21a. The second insulating portion 22b is a portion provided on the winding portion 21c. The second insulating portion 22b covers all of the winding portion 21c. The third insulating portion 22c is a portion provided on the tip portion 21d. The third insulating portion 22c covers a part of the tip portion 21d. The tip surface 21e is not covered by the third insulating portion 22c and is exposed.

[0021] Cylindrical pins 25 and 26 are attached to one end of the first insulating portion 22a in the Y-axis direction. Pin 25 is the neutral point at the beginning of winding the conductive wire 24. Pin 26 is the neutral point at the end of winding the conductive wire 24. The two pins 25 and 26 are located at the same position in the Z-axis direction. The two pins 25 and 26 are separated from each other in the X-axis direction.

[0022] A core back groove 22d is formed at one end of the first insulating portion 22a in the Y-axis direction. The core back groove 22d is a groove that extends in the Z-axis direction and opens toward the other end in the X-axis direction. The core back groove 22d is located closer to pin 26 than to pin 25. The core back groove 22d is located closer to coil 23 than to pin 26 in the Z-axis direction. The core back groove 22d is located at the portion of one end of the first insulating portion 22a in the Y-axis direction that is adjacent to coil 23. The core back groove 22d is located at the other end in the X-axis direction that is closer to the center of the first insulating portion 22a in the X-axis direction. The core back groove 22d is located at the boundary between one end of the first insulating portion 22a in the Y-axis direction and the other end of the first insulating portion 22a in the X-axis direction. A field groove 22e is formed at one end of the third insulating portion 22c in the Y-axis direction. Details of the field groove 22e will be described later.

[0023] As shown in Figure 1, each coil 23 is wound around each tooth 21b via each insulator 22. Each coil 23 is formed by winding a conductive wire 24 around the winding portion 21c of each tooth 21b via each insulator 22. The conductive wire 24 is a conductor made of copper, aluminum, or the like, covered with an insulating coating. In this embodiment, the conductive wire 24 is a round wire, but it may also be a flat wire or the like. When viewing the coil 23 from the field 1 along the Z-axis direction, the winding direction of the conductive wire 24 is counterclockwise in this embodiment, but it may also be clockwise.

[0024] As shown in Figure 2, the starting point 24a of the conductive wire 24, where the conductive wire 24 begins to be wound around the winding section 21c, is located in the winding section 21c adjacent to the core back 21a (the second insulating section 22b adjacent to the first insulating section 22a). The ending point 24b of the conductive wire 24, where the conductive wire 24 is finished being wound around the winding section 21c, is located in the winding section 21c adjacent to the tip 21d (the second insulating section 22b adjacent to the third insulating section 22c). The ending point 24b is where the conductive wire 24, which has been extending from one side in the Y-axis direction to the other, is bent towards the field 1 in the Z-axis direction.

[0025] The connecting wire 24c of the conductive wire 24, extending from the winding end point 24b, extends in one direction in the Z-axis direction and is positioned on one end of the third insulating portion 22c in the Y-axis direction, then bent in one direction in the X-axis direction and extends toward the field groove 22e. After being positioned along the field groove 22e, the connecting wire 24c extends from the field groove 22e to the core back groove 22d and is positioned along the core back groove 22d. After being positioned along the core back groove 22d, the connecting wire 24c extends in the other direction in the Z-axis direction toward the pin 26 and is wrapped around the pin 26. In this specification, the connecting wire 24c refers to the portion of the conductive wire 24 from the winding end point 24b to the pin 26.

[0026] Figure 4 is a view of the armature 2 of the electric motor 100 according to Embodiment 1, as seen from the direction of arrow A in Figure 2. One end of the third insulating portion 22c in the Y-axis direction includes a covering portion 22f that covers one end of the tip portion 21d in the Y-axis direction, and a resin portion 22g that extends from one end of the covering portion 22f in the Y-axis direction in one direction in the Y-axis direction. A field groove 22e for arranging a jumper wire 24c is formed at the boundary between the resin portion 22g and the covering portion 22f. The field groove 22e is a groove that extends in the X-axis direction and opens in one direction in the Z-axis direction toward the field 1. The field groove 22e is formed along the entire length of the resin portion 22g in the X-axis direction.

[0027] The resin portion 22g has the function of supporting the conductive wire 24 under tension. The length of the resin portion 22g in the X-axis direction is shorter than the length of the covering portion 22f in the X-axis direction. A first space portion 22h is formed in the portion adjacent to the other end of the resin portion 22g in the X-axis direction (the other end of the field groove 22e in the X-axis direction), communicating with the field groove 22e. The first space portion 22h is a space for guiding the connecting wire 24c from the winding end point 24b to the field groove 22e.

[0028] An inclined portion 22m is formed at the other end of the resin portion 22g adjacent to the first space portion 22h in the X-axis direction. The inclined portion 22m is adjacent to the side surface 22p of the field groove 22e, which will be described later, in the Y-axis direction. The inclined portion 22m is inclined so as it moves from one side to the other in the Y-axis direction, it moves away from the first space portion 22h. The inclined portion 22m is an inclined surface that facilitates the guidance of the connecting wire 24c from the winding end point 24b to the field groove 22e.

[0029] A second space 22i is formed in the portion adjacent to one end of the resin portion 22g in the X-axis direction (one end of the field groove 22e in the X-axis direction), communicating with the field groove 22e. The second space 22i is a space for guiding the connecting wire 24c, which extends from the winding end point 24b to the field groove 22e, back to the other side in the Z-axis direction and towards the core back groove 22d. The length of the first space 22h in the X-axis direction is longer than the length of the second space 22i in the X-axis direction. Therefore, when viewing the third insulating portion 22c from the field 1 along the Z-axis direction, the shapes of the portions adjacent to both ends of the field groove 22e in the X-axis direction are different from each other.

[0030] Here, we will explain the relationship between the dimensions and effects of the resin portion 22g, the first space portion 22h, and the second space portion 22i. If the conductive wire 24 becomes loose, the winding of the coil 23 will become disordered and the dimensions of the coil 23 will increase more than necessary. Therefore, in the manufacturing process of the coil 23 of the electric motor 100, the conductive wire 24 is often wound around the winding portion 21c while a certain tension is applied to it. For this reason, even when wiring the conductive wire 24 to locations other than the winding portion 21c (such as the field side groove 22e and the core back side groove 22d), a tension sufficient to prevent loosening is applied to the conductive wire 24. The larger the dimensions of the resin portion 22g in the X-axis direction, the greater the force that the resin portion 22g can bear in terms of tension during wiring, thereby reducing the rate of defects such as deformation and damage to the resin portion 22g. On the other hand, the larger the dimensions of the first space portion 22h in the X-axis direction, the wider the working space during wiring, which makes it easier to create the operation program for the manufacturing equipment used when manufacturing the coil 23.

[0031] The dimensions of the second space 22i in the X-axis direction contribute to the electrical insulation performance and structural strength of the electric motor 100. Specifically, the shorter the dimensions of the second space 22i in the X-axis direction, the shorter the distance in the X-axis direction between the jumper wire 24c near the exit portion 22t of one adjacent armature module 2A shown in Figure 1 and the winding end portion 24b of the other adjacent armature module 2A. This may make it impossible to secure the necessary spatial insulation distance between the conductive wires 24 of adjacent armature modules 2A. On the other hand, the shorter the dimensions of the second space 22i in the X-axis direction shown in Figure 4, the larger the dimensions of the resin portion 22g in the X-axis direction. This reduces stress concentration on the resin portion 22g due to the tension applied to the conductive wire 24 at the timing when the jumper wire 24c is folded back toward the core back 21a, allowing the stress to be distributed and absorbed by the entire resin portion 22g. On the other hand, the longer the dimension of the second space 22i in the X-axis direction, the greater the spatial insulation distance, thereby improving the electrical insulation performance between the conductive wires 24 of adjacent armature modules 2A. Conversely, the longer the dimension of the second space 22i in the X-axis direction, the smaller the dimension of the resin part 22g that receives the stress in the X-axis direction becomes, making it easier for stress concentration to occur on the resin part 22g, which may cause deformation or damage to the resin part 22g toward the core back 21a. In the example shown in Figure 4, the dimension of the second space 22i in the X-axis direction is set to a dimension that ensures sufficient electrical insulation performance and structural strength of the motor 100 in relation to other components. Within a range that does not impair the electrical insulation performance and structural strength of the motor 100, the dimension of the second space 22i in the X-axis direction may be changed as appropriate, or the second space 22i itself may be omitted. There are constraints on the dimensions of the entire resin part 22g, including the resin part 22g, the first space 22h, and the second space 22i, in the X-axis direction. On the other hand, the effects of the resin part 22g, the first space 22h, and the second space 22i partially compete with each other in terms of dimensions in the X-axis direction. Therefore, the dimensions of the resin part 22g, the first space 22h, and the second space 22i in the X-axis direction should be set appropriately, taking into account the degree of influence of each effect.

[0032] Figure 5 is a view of the armature 2 of the electric motor 100 according to Embodiment 1, as seen from the direction of arrow B in Figure 4. In Figure 5, the field 1 is shown for convenience of explanation. As shown in Figure 5, a projection 22n is formed in the portion of the armature 22 that is adjacent to the field groove 22e in the Y-axis direction and is farther from the teeth 21b. The projection 22n protrudes in one direction in the Z-axis direction toward the field 1 from the bottom surface 22o of the field groove 22e, which will be described later. The projection 22n is located on the opposite side of the covering portion 22f from the field groove 22e in the Y-axis direction. The projection 22n has the function of preventing the connecting wire 24c, which is located in the field groove 22e, from exiting the field groove 22e in one direction in the Y-axis direction. As shown in Figure 4, the inclined portion 22m is formed at the other end of the projection 22n in the X-axis direction, adjacent to the first space portion 22h.

[0033] Figure 6 is a partially enlarged perspective view of the conductive wire 24 and field groove 22e and its surroundings in the armature 2 of the electric motor 100 according to Embodiment 1. Figure 7 is a cross-sectional view along line VII-VII in Figure 6. As shown in Figure 7, the inner surface of the field groove 22e includes a bottom surface 22o, two side surfaces 22p and 22q, and two corners 22r and 22s. In Figure 7, for the sake of explanation, the regions of each corner 22r and 22s and half of the outer surface of the conductive wire 24 are clearly indicated by thick lines. The bottom surface 22o is a surface that extends in the X-axis direction and the Y-axis direction. Each side surface 22p and 22q is a surface that extends in the X-axis direction and the Z-axis direction. One side surface 22p extends in one direction in the Z-axis direction from one end of the bottom surface 22o in the Y-axis direction toward the field 1. The other side surface 22q extends in one direction in the Z-axis direction toward the field 1 from the other end of the bottom surface 22o in the Y-axis direction. One corner 22r is a corner formed by the bottom surface 22o and one side surface 22p. The other corner 22s is a corner formed by the bottom surface 22o and the other side surface 22q. Each corner 22r, 22s is a portion that can make point contact or line contact with the conductive wire 24. In Figure 7, for the sake of explanation, the state in which each corner 22r, 22s and the conductive wire 24 are not in contact is illustrated.

[0034] When the radius of the round conductive wire 24 is R1, and the radii of each corner 22r, 22s on the inner surface of the field groove 22e that the conductive wire 24 can contact are R2, the conductive wire 24 and the field groove 22e are formed such that the relationship R1 ≤ R2 holds. The outer shape of the conductive wire 24 is a circle with radius R1 centered at the first center O1. The shape of each corner 22r, 22s is an arc shape with radius R2 centered at the second center O2. The radii R2 of each corner 22r, 22s are set appropriately according to the radius R1 of the conductive wire 24 so that the relationship R1 ≤ R2 holds. It is preferable that the relationship R1 ≤ R2 holds between the radius R1 of the conductive wire 24 and the radii R2 of each corner 22r, 22s, but the relationship R1 > R2 may also hold.

[0035] Figure 8 is a view of the armature 2 of the electric motor 100 according to Embodiment 1, as seen from the direction of arrow C in Figure 1. Although pin 25 is hidden by pin 26 and not visible in Figure 8, pin 25 will also be explained. In addition to the field 1 and armature 2, the electric motor 100 further includes, for example, internal structural components 4 and 5. Internal structural component 4 and internal structural component 5 are arranged side by side in the Z-axis direction at the position shown in Figure 8.

[0036] Internal structural component 4 is positioned on one side of the third insulating part 22c, jumper wire 24c, coil 23, and first insulating part 22a in the Y-axis direction, with a gap between it and the third insulating part 22c, jumper wire 24c, coil 23, and first insulating part 22a. The internal structural component 4 and pins 25, 26 are in the same position in the X-axis direction, but their positions are misaligned in the Z-axis direction. The internal structural component 4 and pins 25, 26 are positioned so that they do not overlap when viewed along the Y-axis direction. Internal structural component 5 is positioned on one side of the first insulating part 22a in the Y-axis direction, with a gap between it and the first insulating part 22a. The internal structural component 5 and pins 25, 26 are in the same position in the X-axis and Z-axis directions. The internal structural component 5 and pins 25, 26 are positioned so that they overlap when viewed along the Y-axis direction. Pins 25, 26 are provided penetrating the internal structural component 5 in the Y-axis direction.

[0037] The core back groove 22d and the field groove 22e are located at the same position in the Y-axis direction. Therefore, the portion of the connecting wire 24c from the field groove 22e to the core back groove 22d passes through the gap between the coil 23 and the internal structural component 4 while maintaining a constant position in the Y-axis direction. The portion of the connecting wire 24c from the field groove 22e to the core back groove 22d is positioned with a gap between it and the coil 23 on one side in the Y-axis direction, and is positioned on the other side in the Y-axis direction from the gap between the first insulating part 22a and the internal structural component 4. The portion of the connecting wire 24c from the field groove 22e to the core back groove 22d is positioned so as not to interfere with the coil 23, and so as not to protrude into the gap between the first insulating part 22a and the internal structural component 4. The pins 25 and 26 protrude to one side in the Y-axis direction from the first insulating part 22a. The jumper wire 24c is wrapped around the portion of the pin 26 that is located on one side in the Y-axis direction relative to the first insulating portion 22a.

[0038] As shown in Figures 1 and 2, the exit portion 22t of the field groove 22e where the connecting wire 24c exits the field groove 22e and the entrance portion 22u of the core back groove 22d where the connecting wire 24c enters the core back groove 22d are offset from each other in the X-axis direction. The connecting wire 24c extends from the field groove 22e to the core back groove 22d at an oblique angle in the Z-axis direction. The connecting wire 24c extends diagonally from one end to the other of the stator core 21 in the X-axis direction.

[0039] Next, the effects of the electric motor 100 according to Embodiment 1 will be described.

[0040] In typical electric motors, the winding of conductive wire onto the teeth often begins and ends at the portion of the tooth adjacent to the core back. Therefore, the final turn involves folding the conductive wire back onto the tip of the tooth and winding it towards the core back, resulting in a constraint that the number of coil layers in both the X and Y axes must always be even.

[0041] In this embodiment, as shown in Figure 2, the starting point 24a of the conductive wire 24 winding is located in the portion of the winding section 21c adjacent to the core back 21a, and the ending point 24b of the conductive wire 24 winding is located in the portion of the winding section 21c adjacent to the tip 21d. With this configuration, the winding of the conductive wire 24 onto the teeth 21b can be started from the portion of the winding section 21c adjacent to the core back 21a and ended in the portion of the winding section 21c adjacent to the tip 21d. As a result, the number of coil layers 23 in both the X-axis and Y-axis directions becomes odd, thus overcoming the limitations of the prior art. On the other hand, in this embodiment, the motor 100 has a jumper wire 24c extending from the winding ending point 24b of the conductive wire 24, making it possible to have an even number of coil layers in both the X-axis and Y-axis directions. For example, winding the conductive wire 24 onto the teeth 21b is started from the portion of the winding section 21c adjacent to the tip 21d and ends at the same portion of the winding section 21c adjacent to the tip 21d. Then, the connecting wire 24c is passed from the field groove 22e to the core back groove 22d and connected at the core back 21a. By adopting this structure, it is also possible to have an even number of coil layers in both the X-axis and Y-axis directions. Alternatively, for example, winding the conductive wire 24 onto the teeth 21b is started from the portion of the winding section 21c adjacent to the core back 21a and ends at the portion of the winding section 21c adjacent to the tip 21d, and then the connecting wire 24c is passed from the field groove 22e to the core back groove 22d and temporarily connected at the core back 21a. Then, the winding of the conductive wire 24 onto the teeth 21b is restarted from the portion of the winding section 21c adjacent to the core back 21a, and ends at the portion of the winding section 21c adjacent to the tip 21d. After that, the connecting wire 24c is again passed from the field groove 22e to the core back groove 22d and connected at the core back 21a. By adopting this structure, it is possible to make the number of coil layers in both the X-axis and Y-axis directions an even number. Therefore, it is possible to expand the degree of freedom in product design and manufacture an electric motor 100 having a winding structure with an optimized number of coil layers 23.The starting point 24a of the conductive wire 24 may be located in the portion of the winding section 21c adjacent to the core back 21a or in the portion of the winding section 21c adjacent to the tip 21d. The ending point 24b of the conductive wire 24 may be located in the portion of the winding section 21c adjacent to the tip 21d.

[0042] In conventional electric motors, even if calculations show that an odd number of coil layers would suffice to meet the required performance, the aforementioned constraints necessitate that the coils be constructed with an even number of layers. As a result, the winding area becomes unnecessarily large, increasing the external dimensions of the electric motor, and consequently, the external dimensions of the equipment using the electric motor also have to be increased.

[0043] In this respect, this embodiment can overcome the limitations of the prior art and allows for the manufacture of an electric motor 100 having the number of coil layers 23 required by calculation. As a result, it becomes possible to reduce the external dimensions of the electric motor 100 compared to conventional electric motors, and consequently, the external dimensions of the equipment that uses the electric motor 100 can also be reduced. The equipment that uses the electric motor 100 includes chip mounting machines (mounters), semiconductor manufacturing equipment, and NC (Numerical Control) machine tools.

[0044] In the technology disclosed in Patent Document 1, a part of the tooth is cut out to form a locking piece, and a part of the tooth is bent to form a bent portion, resulting in a complex tooth shape. This also leads to a complex shape for the mold used to manufacture the teeth, increasing the design cost of the mold and shortening the mold's lifespan, thus increasing the operating cost of the mold. Furthermore, the complex manufacturing process of cutting out and bending parts of the tooth is required, which also increases manufacturing costs.

[0045] In this embodiment, as shown in Figure 1, the electric motor 100 is provided with a plurality of insulators 22 on the stator core 21. Each insulator 22 has a first insulating portion 22a provided on the core back 21a, a second insulating portion 22b provided on the winding portion 21c, and a third insulating portion 22c provided on the tip portion 21d. As shown in Figure 2, a core back side groove 22d is formed at one end of the first insulating portion 22a in the Y-axis direction. A field side groove 22e is formed at one end of the third insulating portion 22c in the Y-axis direction. The winding start point 24a of the conductive wire 24 is located in the winding portion 21c adjacent to the core back 21a or in the winding portion 21c adjacent to the tip portion 21d, and the winding end point 24b of the conductive wire 24 is located in the winding portion 21c adjacent to the tip portion 21d. The connecting wire 24c of the conductive wire 24, which extends from the winding end point 24b, is positioned along the field groove 22e, then extends from the field groove 22e to the core back groove 22d, and is positioned along the core back groove 22d. With this configuration, the connecting wire 24c extended from the winding end point 24b can be passed through the field groove 22e of the third insulating part 22c, then folded back towards the core back 21a, and extended to the core back groove 22d of the first insulating part 22a so as not to be wound around the coil 23. In this embodiment, the field groove 22e for folding the connecting wire 24c back towards the core back 21a is provided in the insulator 22 rather than the teeth 21b, and there is no need to provide a locking piece and a bending part on the teeth 21b as in Patent Document 1, so the shape of the teeth 21b can be simplified. This simplifies the shape of the mold used to manufacture the teeth 21b, reducing mold design costs and extending mold life, thereby lowering mold operating costs. Furthermore, complex manufacturing processes such as cutting out or bending parts of the teeth 21b are eliminated, further reducing manufacturing costs. As described above, this embodiment eliminates costs associated with the manufacture of the teeth 21b through the simplification of the shape of the teeth 21b and the production process for the teeth 21b.

[0046] In conventional technology, connections are often made on the core back side to electrically connect adjacent armature modules and form a circuit. Specifically, two pins, a winding start point, and a winding end point are provided on the core back side. At the start of winding, a portion of the conductive wire with the insulation coating removed is wrapped around one pin and then extended to the winding start point. At the end of winding, the conductive wire is extended from the winding end point to the other pin, and a portion of the conductive wire with the insulation coating removed is wrapped around the other pin, thus completing the connection on the core back side. For this reason, many conventional motor manufacturing facilities are based on the premise of connecting on the core back side. Consequently, for motors that are connected on the teeth side, existing motor manufacturing facilities cannot be used, and new motor manufacturing facilities must be prepared, resulting in increased capital investment costs.

[0047] In this embodiment, as shown in Figure 2, two pins 25 and 26 and a winding start point 24a are provided on the core back 21a. In this embodiment, the connecting wire 24c extended from the winding end point 24b can be passed through the field groove 22e of the third insulating part 22c, then folded back towards the core back 21a, and extended to the core back groove 22d of the first insulating part 22a so as not to be wound around the coil 23. The connecting wire 24c can then be passed through the core back groove 22d and extended to the pin 26, and finally wrapped around the pin 26. Therefore, at the start of winding, a portion of the conductive wire 24 with the insulating coating removed can be wrapped around the pin 25 and then extended to the winding start point 24a, and at the end of winding, the conductive wire 24 can be extended from the winding end point 24b to the pin 26 via the field groove 22e and the core back groove 22d. This allows the conductive wire 24 to be connected at the core back 21a even when the winding end point 24b of the conductive wire 24 is adjacent to the tip 21d of the winding portion 21c by wrapping a portion of the conductive wire 24, from which the insulating coating has been stripped, around the pin 26. Therefore, existing motor manufacturing equipment can be used, and there is no need to prepare new motor manufacturing equipment, thus reducing equipment investment costs.

[0048] In the technology disclosed in Patent Document 1, when a part of the teeth is bent, the radius of the corner of the bent portion is smaller than the radius of the conductive wire. As a result, when the conductive wire under tension comes into contact with the corner, stress concentration occurs on the conductive wire. This causes damage to the insulating coating of the conductive wire, leading to a deterioration in the electrical insulation performance of the insulating coating.

[0049] In this embodiment, as shown in Figure 7, when the radius of the conductive wire 24 is R1 and the radii of the corners 22r and 22s on the inner surface of the field groove 22e that the conductive wire 24 can contact are R2, the conductive wire 24 and the field groove 22e are formed such that the relationship R1 ≤ R2 holds. With this configuration, when the conductive wire 24 under tension comes into contact with each corner 22r and 22s, stress concentration on the conductive wire 24 can be mitigated. Therefore, damage to the insulating coating of the conductive wire 24 can be suppressed, and deterioration of the electrical insulation performance of the insulating coating can be suppressed.

[0050] In this embodiment, as shown in Figure 4, the field groove 22e is a groove that extends in the X-axis direction and opens toward the field 1 in the Z-axis direction. When viewing the third insulating portion 22c along the Z-axis direction from the field 1, the shapes of the portions adjacent to both ends of the field groove 22e in the X-axis direction are different. The portion adjacent to the other end of the field groove 22e in the X-axis direction (first space portion 22h) is the portion before the jumper wire 24c, extended from the winding end portion 24b, enters the field groove 22e. The larger the dimension of this portion in the X-axis direction, the wider the working space during wiring, making it easier to create the operation program for the manufacturing equipment used when manufacturing the coil 23. On the other hand, the portion adjacent to one end of the field groove 22e in the X-axis direction (second space portion 22i) is the portion where the jumper wire 24c that has come out of the field groove 22e is folded back toward the core back groove 22d. By changing the dimensions of this part in the X-axis direction, the electrical insulation performance and structural strength of the electric motor 100 can be altered. Furthermore, the larger the dimensions of the resin part 22g, including the field groove 22e, in the X-axis direction, the greater the force that the resin part 22g can bear in terms of tension during wiring, thereby reducing the rate of defects such as deformation and damage to the resin part 22g. By adjusting the dimensions of the resin part 22g, the first space 22h, and the second space 22i in the X-axis direction, it becomes possible to design the electric motor 100 while taking into account the influence of each effect.

[0051] In this embodiment, as shown in Figure 5, a projection 22n is formed in the portion adjacent to the field groove 22e in the Y-axis direction, but farther from the teeth 21b, projecting in the Z-axis direction toward the field 1 from the bottom surface 22o of the field groove 22e. This configuration makes it possible to suppress manufacturing defects in which the connecting wire 24c comes out of the field groove 22e in one direction in the Y-axis direction, even when tension is applied to the connecting wire 24c arranged along the field groove 22e during wiring.

[0052] In this embodiment, as shown in Figure 2, the exit portion 22t of the field groove 22e where the connecting wire 24c exits the field groove 22e and the entrance portion 22u of the core back groove 22d where the connecting wire 24c enters the core back groove 22d are offset from each other in the X-axis direction. Furthermore, the connecting wire 24c extends from the field groove 22e to the core back groove 22d at an oblique angle in the Z-axis direction. With these configurations, the tension applied to the connecting wire 24c and the portion of the conductive wire 24 wound around the winding portion 21c as the coil 23 does not decrease, thus suppressing loosening of the connecting wire 24c and the coil 23. Therefore, it is possible to suppress an unnecessary increase in the dimensions of the coil 23 and to suppress deterioration of electrical insulation performance due to the insulation distance between the teeth 21b and the conductive wire 24 becoming shorter than expected.

[0053] The shape and arrangement of internal structural components 4 and 5 shown in Figure 8 vary depending on the structure of the armature 2. However, generally, by reducing the external dimensions of the motor 100 while maintaining its functionality, the external dimensions of the device using the motor 100 are also reduced. Therefore, miniaturization of the external dimensions is required while maintaining the functionality of the motor 100. One method for miniaturizing the external dimensions of the motor 100 is to arrange the components inside the motor 100 as densely as possible. The following explains how to miniaturize the external dimensions of the motor 100, including comparative examples.

[0054] Figure 9 shows the armature 2 of the motor 100A according to the comparative example, and corresponds to the view from the direction of arrow C in Figure 1. When wrapping the jumper wire 24c, which extends from the field groove 22e, around the pin 26, due to the constraints of the manufacturing equipment that winds the conductive wire 24 around the winding section 21c, it is not possible to start wrapping from near the joint between the first insulating section 22a and the pin 26 (the base of the pin 26). As a result, the jumper wire 24c is wrapped around the portion of the pin 26 that is located on one side in the Y-axis direction relative to the core back groove 22d. For this reason, as in the comparative example, if the jumper wire 24c is extended from the field groove 22e to the pin 26 without going through the core back groove 22d and wrapped around the pin 26, the portion of the jumper wire 24c from the field groove 22e to the pin 26 will pass through the gap between the coil 23 and the internal structural component 4 in a state where it is inclined so that it is located on one side in the Y-axis direction as it approaches the pin 26 from the field groove 22e. Therefore, the gap between the jumper wire 24c and the coil 23 is not constant and becomes larger in some areas, making it difficult to bring the entire jumper wire 24c close to the coil 23. In addition, the portion of the jumper wire 24c from the field groove 22e to the pin 26 passes through the gap between the first insulating part 22a and the internal structural component 4. Therefore, if an attempt is made to arrange the armature 2 and the internal structural component 4 as closely together as possible inside the motor 100A, the jumper wire 24c and the internal structural component 4 will interfere with each other as shown in the figure, making it difficult to bring the armature 2 and the internal structural component 4 close to each other. Consequently, it is not easy to reduce the external dimensions of the motor 100A.

[0055] In this embodiment, as shown in Figure 8, the core back groove 22d and the field groove 22e are located at the same position in the Y-axis direction. With this configuration, the portion of the connecting wire 24c from the field groove 22e to the core back groove 22d passes through the gap between the coil 23 and the internal structural component 4 while maintaining a constant position in the Y-axis direction. As a result, the width of the gap between the connecting wire 24c and the coil 23 remains constant, allowing the entire connecting wire 24c to be brought closer to the coil 23. Furthermore, in this embodiment, the core back groove 22d and the field groove 22e are located on the other side in the Y-axis direction from the portion of the pin 26 to which the connecting wire 24c is wrapped and from the gap between the first insulating part 22a and the internal structural component 4. With this configuration, the portion of the connecting wire 24c from the field groove 22e to the core back groove 22d does not pass through the gap between the first insulating part 22a and the internal structural component 4. Therefore, interference between the jumper wire 24c and the internal structural component 4 can be avoided, and the armature 2 and the internal structural component 4 can be brought closer to each other, making it possible to arrange the armature 2 and the internal structural component 4 as closely together as possible inside the motor 100. Thus, the external dimensions of the motor 100 can be reduced while maintaining the functionality of the motor 100. Furthermore, after passing through the core back groove 22d, the jumper wire 24c extends in one direction in the Y-axis direction toward the pin 26 at a position where it does not interfere with the internal structural component 4, and therefore does not hinder bringing the armature 2 and the internal structural component 4 closer to each other.

[0056] Next, a modified example of Embodiment 1 will be described.

[0057] In this embodiment, as shown in Figure 1, the field 1 was a permanent magnet field having a permanent magnet 1a and a field yoke 1b, but it may also be an electromagnetic field that generates a magnetic field by passing an electric current through the coil 23.

[0058] In this embodiment, as shown in Figure 1, for simplicity, we have illustrated a case where there are three armature modules 2A and four permanent magnets 1a. However, the number of armature modules 2A and permanent magnets 1a are not limited to the illustrated example and may be changed as appropriate.

[0059] In this embodiment, as shown in Figure 1, the motor 100 is exemplified as a motor that drives linearly, but the motor 100 may also be a motor that drives rotationally, a motor that drives a multi-degree-of-freedom system, and the like.

[0060] The configurations shown in the above embodiments are merely examples, and can be combined with other known technologies. It is also possible to omit or modify parts of the configuration without departing from the gist of the invention. [Explanation of symbols]

[0061] 1 Field, 1a Permanent magnet, 1b Field yoke, 2 Armature, 2A Armature module, 3 Air gap, 4,5 Internal structural components, 21 Stator core, 21a Core back, 21b Teeth, 21c Winding section, 21d Tip section, 21e Tip surface, 22 Insulator, 22a First insulating section, 22b Second insulating section, 22c Third insulating section, 22d Core back side groove, 22e Field side groove, 22f Covering section, 22g Resin section, 22h First space, 22i Second space, 22m Inclined section, 22n Protrusion, 22o Bottom surface, 22p, 22q Sides, 22r, 22s Corners, 22t Outlet section, 22u Inlet section, 23 Coil, 24 Conductive wire, 24a Winding start point, 24b; Winding end point, 24c; Crossover wires, 25, 26; Pins, 100, 100A; Motor.

Claims

1. The magnetic field and, An armature is positioned facing the field with an air gap between them in a first direction and is movable relative to the field in a second direction perpendicular to the first direction, Equipped with, The aforementioned armature is A stator core having a core back and a plurality of teeth extending in the first direction from the core back toward the field, Multiple insulators provided on the stator core, A plurality of coils wound around each of the teeth via each of the insulators, Equipped with, Each of the aforementioned teeth is The core back includes a winding section that is continuous with the portion facing the field and around which the coil is wound, The tip portion of the winding portion that is continuous with the portion facing the field, It has, Each of the above insulators is The first insulating portion provided on the core back, The second insulating portion provided in the winding portion, The third insulating portion provided at the tip, It has, A core back groove is formed at one end of the first insulating portion in a third direction perpendicular to the first and second directions. A field groove is formed at one end of the third insulating portion in the third direction. Each of the coils is formed by winding a conductive wire around the winding portion of each of the teeth via each of the insulators. The starting point of the winding of the conductive wire is located in the portion of the winding section adjacent to the core back or in the portion of the winding section adjacent to the tip, and the ending point of the winding of the conductive wire is located in the portion of the winding section adjacent to the tip. An electric motor characterized in that, among the conductive wires, the jumper wires extending from the winding end point are arranged along the field groove, and then extend from the field groove to the core back groove and are arranged along the core back groove.

2. The electric motor according to claim 1, characterized in that the conductive wire and the field groove are formed such that the relationship R1 ≤ R2 holds, where R1 is the radius of the conductive wire and R2 is the radius of the corner of the inner surface of the field groove that the conductive wire can contact.

3. The field side groove is a groove that extends in the second direction and opens toward the field in the first direction. The electric motor according to claim 1, characterized in that when the third insulating portion is viewed from the field along the first direction, the shapes of the portions adjacent to both ends of the field side groove in the second direction are different from each other.

4. The electric motor according to claim 1, characterized in that, in the portion adjacent to the field groove in the third direction, the portion furthest from the teeth, a projection is formed that protrudes in the first direction toward the field from the bottom surface of the field groove.

5. The exit portion of the field side groove where the connecting wire exits the field side groove and the entrance portion of the core back side groove where the connecting wire enters the core back side groove are offset from each other in the second direction. The electric motor according to any one of claims 1 to 4, characterized in that the crossover wire extends from the field side groove to the core back side groove in a state that is oblique to the first direction.

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