electric motor

Abstract

To provide an electric motor configured so that a winding wire can be suppressed from being damaged and a step of twisting a pull-out part around a locking part from being complicated.SOLUTION: A stator 13 has: a stator core 30 having a yoke 31 and a plurality of teeth 32; coils 41 formed of winding wires 40 wound around the plurality of teeth 32 respectively; and a first bobbin 50a for insulation arranged on a first end face 30a of the stator core 30 and provided between the teeth 32 and the coils 41. The first bobbin 50a has an annular part 51 covering the yoke 31, on the first end face 30a. The annular part 51 is provided with locking parts 54 that lock the wiring wires 40 to the first bobbin 50a by twisting pull-put parts 42 of the winding wires 40 pulled out from the coils 41 to the locking parts. Protective members 60 are provided between the locking parts 54 and the winding wires 40. The protective members 60 are mounted on the locking parts 54 to cover outer peripheral surfaces of the locking parts 54.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric motor. [Background technology]

[0002] Patent Document 1 discloses an electric motor including a rotor fixed to a rotating shaft and rotating integrally with the rotating shaft, and a stator disposed on the outside of the rotor. The stator has a stator core, a coil, and a bobbin. The stator core has a cylindrical yoke extending in the axial direction of the rotating shaft and a plurality of teeth extending from the inner peripheral surface of the yoke toward the rotor. The coil is formed by winding a wire around each of the plurality of teeth. The bobbin is disposed on the axial end face of the stator core. The bobbin is an insulating bobbin provided between the teeth and the coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-21824 Summary of the Invention [Problem to be solved by the invention]

[0004] In such electric motors, the lead-out portions, which are the portions of the windings that are drawn out from the coils, can become loose. To prevent the lead-out portions from loosening, for example, the lead-out portions are hooked onto locking portions provided on the bobbin. By hooking the lead-out portions onto the locking portions, the windings are locked onto the bobbin, preventing the lead-out portions from loosening. However, vibrations of the electric motor can damage the windings where the lead-out portions and the locking portions come into contact.

[0005] One possible method for preventing such damage to the windings is to insert the lead-out portions into a cylindrical protective member and then hook them around the locking portion. However, this method requires cutting the windings to insert the lead-out portions into the protective member. Cutting the windings loosens them, making it difficult to maintain the necessary tension when hooking the lead-out portions around the locking portion. Furthermore, when hooking the lead-out portions around the locking portion, it is necessary to adjust the position of the protective member relative to the lead-out portions so that the protective member is positioned between the locking portion and the lead-out portions. When preventing damage to the windings by attaching a protective member to the lead-out portions in this way, the process of hooking the lead-out portions around the locking portion becomes complicated. [Means for solving the problem]

[0006] An electric motor for solving the above problems includes: a rotor fixed to a rotating shaft and rotating integrally with the rotating shaft; and a stator arranged on the outside of the rotor, wherein the stator has a stator core having a cylindrical yoke extending in the axial direction of the rotating shaft and a plurality of teeth extending from the inner surface of the yoke toward the rotor; a coil formed by winding a winding around each of the plurality of teeth; and an insulating bobbin arranged on an axial end face of the stator core and provided between the teeth and the coil, wherein the bobbin has an annular portion that covers the yoke at the end face, and a locking portion is provided on the annular portion that locks the winding to the bobbin by entangling a lead-out portion, which is a portion of the winding that is led out from the coil, and a protective member is provided between the locking portion and the lead-out portion, and the protective member is attached to the locking portion so as to cover the outer peripheral surface of the locking portion.

[0007] A protective member is provided between the locking portion and the lead-out portion, which prevents damage to the windings due to vibrations of the motor. Furthermore, when the protective member is attached to the locking portion, cutting the windings and adjusting the position of the protective member relative to the lead-out portion, which were previously required when attaching the protective member to the lead-out portion, are no longer necessary. This prevents the process of entangling the lead-out portion with the locking portion from becoming too complicated.

[0008] In the electric motor, the protective member may be a cylindrical elastic resin member attached to the engaging portion. Because the protective member is cylindrical, it can be easily attached to the locking portion by, for example, placing the protective member above the locking portion and then dropping the protective member, thereby automating the process of attaching the locking portion to the protective member.

[0009] For example, if the protective member is attached to the locking portion by being applied to the outer peripheral surface of the locking portion, the drawer portion may not be entangled until the protective member has dried after being applied to the outer peripheral surface of the locking portion. In contrast, if the protective member is a cylindrical, elastic resin, the drawer portion can be entangled with the locking portion immediately after the protective member is attached to the locking portion.

[0010] In the electric motor, the protective member may be made of a resilient resin that is applied to and attached to the outer circumferential surface of the engaging portion. Compared to when the protective member is a cylindrical elastic resin member, it is easier to deal with changes in the dimensions of the engaging portion.

[0011] In the electric motor, the protective member may protrude beyond the engaging portion in the axial direction. Even if the drawn-out portion moves in the axial direction of the stator core relative to the locking portion, damage to the winding can be suppressed. [Effects of the Invention]

[0012] According to the present invention, damage to the winding can be suppressed, and the process of entangling the lead-out portion with the locking portion can be prevented from becoming complicated. [Brief explanation of the drawings]

[0013] [Figure 1] (a) is a plan view of the motor, and (b) is an enlarged view of a portion of (a). [Figure 2] FIG. [Figure 3]FIG. [Figure 4] FIG. 10 is a plan view of a protective member according to a modified example. [Figure 5] FIG. 10 is a plan view of a protective member according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the electric motor will be described below with reference to FIGS. As shown in FIG. 1(a), an electric motor 10 includes a rotating shaft 11, a rotor 12, and a stator 13. The stator 13 is disposed outside the rotor 12. The rotor 12 has a cylindrical shape. The rotating shaft 11 is inserted inside the rotor 12. The rotor 12 is fixed to the rotating shaft 11. The rotor 12 rotates integrally with the rotating shaft 11. The stator 13 includes a stator core 30, U-phase, V-phase, and W-phase windings 40, a first bobbin 50a and a second bobbin 50b as bobbins, three protective members 60, and three tube members 70.

[0015] <Stator core> As shown in FIGS. 1(a) and 2, the stator core 30 has a cylindrical yoke 31 extending in the axial direction of the rotating shaft 11 and a plurality of teeth 32 extending from the inner peripheral surface of the yoke 31 toward the rotor 12. Hereinafter, the axial, radial, and circumferential directions of the yoke 31 will be referred to as the axial, radial, and circumferential directions of the stator core 30, respectively. The plurality of teeth 32 are arranged at equal intervals in the circumferential direction of the stator core 30. The stator core 30 has a first core end face 30a and a second core end face 30b. The first core end face 30a and the second core end face 30b are each end faces of the stator core 30 in the axial direction. The second core end face 30b is located opposite the first core end face 30a in the axial direction of the stator core 30.

[0016] <Winding> The winding 40 is wound around each of the multiple teeth 32 to form a coil 41. The winding 40 is wound around the teeth 32 in a concentrated winding manner. A portion of the winding 40 is not wound around the teeth 32 but is pulled out from the coil 41. The portion of the winding 40 pulled out from the coil 41 is called a pull-out portion 42. The pull-out portion 42 is pulled out from the end of the coil 41. In this embodiment, the winding 40 is wound around the teeth 32 radially outward of the stator core 30. Therefore, the pull-out portion 42 is pulled out from one end of the coil 41 in the radial direction of the stator core 30 that is closer to the yoke 31. Although not shown, the winding 40 is composed of a conductor and an insulating coating that covers the conductor. The end of the pull-out portion 42 is connected to a connection terminal, not shown.

[0017] <Bobbin> 2, the first bobbin 50a is disposed on the first core end face 30a of the stator core 30. The second bobbin 50b is disposed on the second core end face 30b of the stator core 30. Therefore, the stator core 30 is sandwiched between the first bobbin 50a and the second bobbin 50b. The first bobbin 50a and the second bobbin 50b are each formed from an insulating material.

[0018] Each bobbin 50a, 50b has a cylindrical annular portion 51 extending in the axial direction of the stator core 30 and a plurality of extension portions 52 extending from the inner circumferential surface of the annular portion 51 toward the rotor 12. The annular portion 51 has a first bobbin end face 51a and a second bobbin end face 51b. The first bobbin end face 51a and the second bobbin end face 51b are each end faces of the annular portion 51 in the axial direction of the stator core 30. The second bobbin end face 51b is located opposite the first bobbin end face 51a in the axial direction of the stator core 30. The plurality of extension portions 52 are arranged at equal intervals in the circumferential direction of the stator core 30. The number of extension portions 52 included in one bobbin 50a, 50b is the same as the number of teeth 32.

[0019] The annular portion 51 of the first bobbin 50a covers the yoke 31 at the first core end face 30a of the stator core 30. Specifically, the first bobbin end face 51a of the annular portion 51 of the first bobbin 50a abuts against the yoke 31 at the first core end face 30a of the stator core 30. The annular portion 51 of the second bobbin 50b covers the yoke 31 at the second core end face 30b of the stator core 30. Specifically, the first bobbin end face 51a of the annular portion 51 of the second bobbin 50b abuts against the yoke 31 at the second core end face 30b of the stator core 30.

[0020] The extending portions 52 of the first bobbin 50a cover the teeth 32 at the first core end face 30a of the stator core 30. The extending portions 52 of the second bobbin 50b cover the teeth 32 at the second core end face 30b of the stator core 30. The windings 40 are wound around the teeth 32 that are covered by the extending portions 52 of the first bobbin 50a and the second bobbin 50b. Therefore, the extending portions 52 are provided between the teeth 32 and the coils 41. The extending portions 52 insulate the teeth 32 from the coils 41. Each of the bobbins 50a, 50b is an insulating bobbin that insulates the teeth 32 from the coils 41.

[0021] The annular portion 51 of the first bobbin 50a has six recesses 53 recessed from the second bobbin end face 51b. The six recesses 53 are arranged two at a time in the circumferential direction of the stator core 30. The recesses 53 are open on the inner and outer circumferential surfaces of the annular portion 51.

[0022] The annular portion 51 of the first bobbin 50a has three locking portions 54. As will be described later, the locking portions 54 are portions around which the lead-out portion 42 is wound, thereby locking the winding 40 to the first bobbin 50a.

[0023] As shown in Fig. 1(b), the locking portion 54 in this embodiment is a portion located between two recesses 53 in the circumferential direction of the stator core 30. The locking portion 54 has four corners. Of the four corners, two corners located on the outer side in the radial direction of the stator core 30 are chamfered.

[0024] 3, the locking portions 54 in this embodiment extend linearly along the axial direction of the stator core 30. The width of the locking portions 54 in the circumferential direction of the stator core 30 is constant. The thickness of the locking portions 54 in the radial direction of the stator core 30 is also constant.

[0025] <Protective materials> As shown in Figures 1(a), 1(b), and 2, the protective member 60 is cylindrical. The protective member 60 of this embodiment is formed from a resilient resin. The protective member 60 is attached to the locking portion 54 by inserting the locking portion 54 into the inside of the protective member 60. The protective member 60 is attached to the locking portion 54 so as to cover the outer peripheral surface of the locking portion 54.

[0026] 3, the axial dimension of the protective member 60 of this embodiment is longer than the dimension of the locking portion 54 in the axial direction of the stator core 30. Therefore, the protective member 60 of this embodiment protrudes beyond the locking portion 54 in the axial direction of the stator core 30.

[0027] In this embodiment, after the locking portion 54 is inserted into the annular protective member 60, the protective member 60 is thermally shrunk so that the inner peripheral surface of the protective member 60 is tightly attached to the outer peripheral surface of the locking portion 54. The protective member 60 shown in Fig. 2 is in a state before being thermally shrunk. The protective member 60 shown in Figs. 1(a) and 1(b) is in a state after being thermally shrunk.

[0028] The lead-out portions 42 of the windings 40 of each phase are wound around the respective locking portions 54 to which protective members 60 are attached. In this embodiment, the lead-out portions 42 are wound around the outer circumferential surfaces of the locking portions 54 covered by the protective members 60. This locks the windings 40 to the first bobbin 50a, preventing loosening of the lead-out portions 42. The protective members 60 are provided between the locking portions 54 and the lead-out portions 42.

[0029] The lead-out portion 42 has a portion that is inserted into the tube member 70. The portion of the winding 40 that is wound around the locking portion 54 is located between the portion that forms the coil 41 and the portion that is inserted into the tube member 70.

[0030] [Operation of this embodiment] The operation of this embodiment will be described. Protective member 60 is attached to locking portion 54 so as to cover the outer peripheral surface of locking portion 54. Pull-out portion 42 is entangled with locking portion 54 to which protective member 60 is attached. Therefore, protective member 60 is provided between locking portion 54 and pull-out portion 42. Damage to winding 40 due to vibration of motor 10 is therefore suppressed.

[0031] As a method for preventing damage to the lead-out portion 42, for example, the lead-out portion 42 may be inserted into a cylindrical protective member and hooked around the locking portion 54. In this case, the protective member is provided between the locking portion 54 and the lead-out portion 42, thereby preventing damage to the windings 40. However, when the above method is adopted, the process of hooking the lead-out portion 42 around the locking portion 54 becomes complicated. The reason for this will be explained below.

[0032] When manufacturing stator 13 using the above method, first, coil 41 is formed by winding winding 40 around teeth 32. Next, winding 40 is pulled out from coil 41 and cut to form lead-out portion 42. Next, lead-out portion 42 is inserted into a protective member. Then, lead-out portion 42 inserted into the protective member is hooked around locking portion 54.

[0033] In the process of winding the winding 40 around the teeth 32 and in the process of winding the lead-out portion 42 around the locking portion 54, tension must be applied to the winding 40 to prevent it from loosening. However, with the above method, the winding 40 must be cut to insert the winding 40 into the protective member, which loosens the winding 40 when the winding 40 is cut. This makes it difficult to maintain tension on the winding 40. Furthermore, in the process of inserting the lead-out portion 42 into the protective member, the position of the protective member relative to the lead-out portion 42 is not fixed. Therefore, in the process of winding the lead-out portion 42 around the locking portion 54, the position of the protective member relative to the lead-out portion 42 must be adjusted so that the protective member is located between the locking portion 54 and the lead-out portion 42. For these reasons, when a protective member is attached to the lead-out portion 42, the process of winding the lead-out portion 42 around the locking portion 54 becomes complicated.

[0034] In contrast, in this embodiment, the protective member 60 is attached to the locking portion 54. Note that the protective member 60 can be easily attached to the locking portion 54 by, for example, placing the protective member 60 above the locking portion 54 and then dropping the protective member 60. In this embodiment, the cutting of the winding 40, which was previously required to insert the lead-out portion 42 into the protective member, is not necessary. Therefore, the lead-out portion 42 can be entangled with the locking portion 54 while maintaining the tension of the winding 40. Furthermore, simply entanglement of the lead-out portion 42 with the locking portion 54 to which the protective member 60 is attached positions the protective member 60 between the locking portion 54 and the lead-out portion 42, eliminating the need to adjust the position of the protective member 60 relative to the lead-out portion 42. This prevents the process of entanglement of the lead-out portion 42 with the locking portion 54 from becoming complicated.

[0035] [Effects of this embodiment] The effects of this embodiment will be described. (1) The protective member 60 is attached to the locking portion 54 so as to cover the outer peripheral surface of the locking portion 54. The lead-out portion 42 of the winding 40 is entangled with the locking portion 54 to which the protective member 60 is attached. Therefore, the protective member 60 is provided between the locking portion 54 and the lead-out portion 42. This makes it possible to prevent damage to the winding 40 due to vibration of the electric motor 10. Furthermore, because the protective member 60 is attached to the locking portion 54, it is not necessary to cut the winding 40 or adjust the position of the protective member relative to the lead-out portion 42, which would be necessary if the protective member were attached to the lead-out portion 42. This makes it possible to prevent the process of entanglement of the lead-out portion 42 with the locking portion 54 from becoming complicated.

[0036] (2) The protective member 60 is cylindrical. Therefore, the protective member 60 can be easily attached to the locking portion 54 by, for example, placing the protective member 60 above the locking portion 54 and then dropping the protective member 60. This makes it possible to automate the process of attaching the locking portion 54 to the protective member 60. Therefore, the process from winding the winding 40 around the tooth 32 to entangling the lead-out portion 42 with the locking portion 54 can be automated.

[0037] (3) As will be described later, for example, the protective member 60 may be attached to the locking portion 54 by being applied to the outer peripheral surface of the locking portion 54. In this case, after the protective member 60 is applied to the outer peripheral surface of the locking portion 54, it may not be possible to fasten the draw-out portion 42 to the locking portion 54 until the protective member 60 dries. In contrast, the protective member 60 of this embodiment is a cylindrical, elastic resin. Therefore, the draw-out portion 42 can be fastened to the locking portion 54 immediately after the protective member 60 is attached to the locking portion 54.

[0038] (4) Protective member 60 protrudes beyond locking portion 54 in the axial direction of stator core 30. Therefore, even if lead-out portion 42 moves in the axial direction of stator core 30 relative to locking portion 54, damage to windings 40 can be suppressed.

[0039] (5) Of the four corners of the locking portion 54, the two corners located on the outer side in the radial direction of the stator core 30 are chamfered. Therefore, compared to when the corners of the locking portion 54 are not chamfered, the load applied to the lead-out portion 42 entangled with the locking portion 54 can be reduced.

[0040] (6) The protective member 60 is heat-shrunk. Therefore, after the protective member 60 is attached to the locking portion 54, the protective member 60 can be heat-shrunk to adhere closely to the locking portion 54. Therefore, the protective member 60 is less likely to come off the locking portion 54.

[0041] (7) When attaching the protective member to the lead-out portion 42, the length of the protective member is often set to be sufficiently longer than the circumferential length of the locking portion 54 so that the protective member can be easily positioned between the locking portion 54 and the lead-out portion 42. For this reason, the protective member has many portions that are not disposed between the locking portion 54 and the lead-out portion 42, i.e., that do not contribute to preventing damage to the windings 40. In contrast, in this embodiment, the protective member 60 is attached to the locking portion 54, and therefore the length of the protective member 60 only needs to be approximately the same as the length of the locking portion 54. Therefore, the length of the protective member 60 can be shorter than when the protective member is attached to the lead-out portion 42. This allows for a reduction in the amount of material used for the protective member 60.

[0042] [Example of change] The above-described embodiments can be modified as follows: The above-described embodiments and the following modifications can be combined with each other within the scope of technical compatibility.

[0043] 4, the protective member 60 may be made of a flexible resin and attached to the locking portion 54 by being applied to the outer circumferential surface of the locking portion 54. In this case, it is easier to deal with changes in the dimensions of the locking portion 54 than in the above embodiment, where the protective member 60 is made of a cylindrical flexible resin.

[0044] 5, the protective member 60 may be made of elastic resin and attached to the locking portion 54 by being stuck to the outer circumferential surface of the locking portion 54. In this case, the shape of the protective member 60 does not have to be cylindrical. Note that the task of attaching the protective member 60 to the locking portion 54 by sticking it to the outer circumferential surface of the locking portion 54 may be performed manually by an operator.

[0045] The material of the protective member 60 may be changed as appropriate as long as it is less likely to damage the winding 40 than the material of the first bobbin 50a. The axial dimension of the protective member 60 may be the same as the dimension of the locking portion 54 in the axial direction of the stator core 30, or may be shorter than the dimension of the locking portion 54 in the axial direction of the stator core 30. In other words, the protective member 60 does not need to protrude beyond the locking portion 54 in the axial direction of the stator core 30.

[0046] The protective member 60 may cover not only the outer circumferential surface of the locking portion 54 but also the tip surface of the locking portion 54. That is, the protective member 60 may be a cylindrical member with a cap made of elastic resin. The locking portion 54 may be a protrusion that protrudes from the second bobbin end surface 51 b of the annular portion 51 .

[0047] The corners of the locking portion 54 do not have to be rounded. Of the four corners of the locking portion 54, two corners located on the inner side in the radial direction of the stator core 30 may be chamfered.

[0048] The locking portion 54 may have a tapered shape such that the width in the circumferential direction of the stator core 30 gradually decreases from the bottom surface of the recess 53 toward the tip end. The locking portion 54 may have a tapered shape such that the thickness in the radial direction of the stator core 30 gradually decreases from the bottom surface of the recess 53 toward the tip end. [Explanation of symbols]

[0049] 10...electric motor, 11...rotating shaft, 12...rotor, 13...stator, 30...stator core, 30a...first core end face as end face, 31...yoke, 32...teeth, 40...winding, 41...coil, 42...draw-out portion, 50a...first bobbin as bobbin, 51...annular portion, 54...locking portion, 60...protective member.

Claims

1. a rotor fixed to a rotating shaft and rotating integrally with the rotating shaft, and a stator disposed outside the rotor, The stator includes: a stator core having a cylindrical yoke extending in the axial direction of the rotary shaft and a plurality of teeth extending from an inner peripheral surface of the yoke toward the rotor; a coil formed by winding a wire around each of the plurality of teeth; an insulating bobbin disposed on an axial end surface of the stator core and provided between the teeth and the coil, the bobbin has an annular portion that covers the yoke at the end surface, the annular portion is provided with a locking portion that locks the winding to the bobbin by winding a lead-out portion, which is a portion of the winding that is led out from the coil, a protective member is provided between the locking portion and the drawer portion; the protective member is cylindrical and attached to the locking portion so as to cover an outer peripheral surface of the locking portion, an axial dimension of the protective member in the stator core is formed to be longer than an axial dimension of the locking portion in the stator core, and the protective member protrudes beyond the locking portion in the axial direction of the stator core, The electric motor is characterized in that the drawn-out portion is wound around the outer circumferential surface of the engaging portion covered by the protective member.

2. 2. The electric motor according to claim 1, wherein the protective member is made of a resilient resin and attached to the engaging portion.

3. 2. The electric motor according to claim 1, wherein the protective member is made of a resilient resin that is applied to and attached to the outer circumferential surface of the engaging portion.

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