WO2018180345A1

WO2018180345A1 - Electric motor stator and electric motor

Info

Publication number: WO2018180345A1
Application number: PCT/JP2018/009036
Authority: WO
Inventors: 俊輔村上; 英博芳賀; 智哉上田
Original assignee: 日本電産株式会社
Priority date: 2017-03-31
Filing date: 2018-03-08
Publication date: 2018-10-04
Also published as: CN110462978A; JPWO2018180345A1

Abstract

This stator (200) for an electric motor (100) comprises: a laminated body (210) having a plurality of annular core sheets (230) laminated therein and a plurality of laminated teeth (212); and a plurality of windings (220) attached to the plurality of laminated teeth (212). Each of the plurality of annular core sheets (230) comprises: an annular core back (231); a plurality of teeth (232) arranged at even intervals on the inner circumference of the core back (231) and protruding towards the center of the core back (231); and a coupling section (233) that couples the tips of two adjacent teeth (232) and includes a joint (234).

Description

Stator for electric motor and electric motor

The present disclosure relates to an electric motor stator and an electric motor.

In recent years, there is an increasing demand for vibration reduction for electric motors (hereinafter simply referred to as “motors”). In particular, a motor for an electric power steering apparatus is further required to reduce vibrations in order to improve steering feeling. As such an approach, for example, a technique is known that attempts to reduce the vibration of the motor by increasing the rigidity of the stator.

For example, Patent Document 1 discloses an annular stator including a tooth iron core in which a plurality of iron core members are stacked, and an annular yoke iron core fitted to the outer periphery of the tooth iron core. Each iron core member has a plurality of tooth portions and a bridging portion that connects the tips of two adjacent tooth portions of the plurality of tooth portions. As a stator manufacturing method, a plurality of iron core members are formed by punching a steel plate. A tooth core is obtained by rotating and laminating a plurality of iron core members by a certain angle for each sheet. After the winding is attached from the outer peripheral side of the tooth core, the stator is obtained by press-fitting the tooth core into the inner peripheral portion of the yoke core. According to the stator structure, magnetic flux leakage is reduced while the mechanical strength of the stator is improved by the bridge portion.

Japanese Patent Laid-Open No. 3-169235

： Further improvement is required for motor vibration reduction.

The embodiment of the present disclosure provides a stator capable of reducing motor vibration.

An exemplary stator for a motor of the present disclosure includes a laminated body in which a plurality of annular core sheets are laminated, a plurality of laminated teeth, and a plurality of windings attached to the plurality of laminated teeth. Each of the core sheets is connected to an annular core back, a plurality of teeth arranged at equal intervals on the inner periphery of the core back, and protruding toward the center of the core back, and the tips of two adjacent teeth. And a connecting portion including a joint.

According to an embodiment of the present disclosure, a stator capable of reducing motor vibration is provided.

FIG. 1 is a cross-sectional view along the central axis 500 showing an exemplary structure of the motor 100. FIG. 2 is a perspective view of the laminate 210. FIG. 3 is a plan view of the stator 200 in a state where the windings 220 are attached to the multilayer body 210 as viewed from the stacking direction of the multilayer body 210. FIG. 4 is a plan view of the annular core sheet 230 constituting the stacked body 210 as viewed from the stacking direction of the stacked body 210. FIG. 5A is a schematic diagram showing a pair of adjacent two laminated teeth 212 in an enlarged manner. FIG. 5B is an enlarged schematic view showing one of a plurality of connecting portions 233 between a pair of adjacent two stacked teeth 212. FIG. 6 is a development view of the laminated body 210 obtained by cutting the laminated core back 211 located between a pair of laminated teeth 212 in the y direction and developing the laminated body 210 in the x direction. FIG. 7 is a flowchart showing a flow of a method for manufacturing the motor 100 and the stator 200. FIG. 8A is a schematic view showing a state where a plurality of annular core sheets 230 are formed by punching the electromagnetic steel sheet 700 in an annular shape using a mold 800. FIG. 8B is a schematic diagram showing a plurality of annular core sheets 230 formed by stamping. FIG. 9 is a schematic diagram showing a state in which the connecting portion 233 is cut using the cutting blade 710. FIG. 10 is a schematic view showing a state in which a plurality of annular core sheets 230 are stacked by rotating each of the annular core sheets 230 by a predetermined angle in the circumferential direction. FIG. 11A is a schematic diagram showing how the laminated annular core 210 is divided into 12 divided cores 250. FIG. 11B is a schematic diagram showing how the jig 900 is inserted into the slot 214 to divide the laminated annular core 210. FIG. 11C is a plan view of the twelve divided cores 250 as seen from the stacking direction of the stacked annular cores 210. FIG. 12A is a plan view of the split core 250 to which the winding 220 is attached. FIG. 12B is a perspective view of the split core 250 in which the winding 220 is attached to the laminated tooth 212. FIG. 13 is a schematic diagram showing a state in which the laminated annular core 210 divided into a plurality of divided cores 250 is returned to an annular shape using a jig. FIG. 14 is a schematic diagram showing how the cut surfaces of the connecting portion 233 are brought into contact with each other during reassembly. FIG. 15 is a plan view illustrating an example of the stator 200 and the rotor 300 included in the motor 100. FIG. 16 is a plan view showing an example of the stator 200. FIG. 17 is a diagram illustrating a position where the connecting portion 233 in the stator 200 is disposed. FIG. 18 is a diagram illustrating another example of a position where the connecting portion 233 in the stator 200 is disposed. FIG. 19 is a diagram showing still another example of a position where the connecting portion 233 in the stator 200 is arranged. FIG. 20 is a diagram illustrating still another example of the position where the coupling portion 233 in the stator 200 is disposed. FIG. 21 is a diagram showing a simulation result of the operation of the motor 100 having the stator structure shown in FIGS.

Hereinafter, embodiments of a motor stator and a motor according to the present disclosure will be described in detail with reference to the accompanying drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

(Embodiment)
FIG. 1 is a cross-sectional view along the central axis 500 showing an exemplary structure of the motor 100.

The motor 100 according to the present embodiment is a so-called inner rotor type motor. The motor 100 is mounted on, for example, an automobile and is suitably used as a motor for an electric power steering device. In that case, the motor 100 generates the driving force of the electric power steering apparatus.

The motor 100 includes a stator 200, a rotor 300, a housing 400, a lid 420, a lower bearing 430, and an upper bearing 440. The stator 200 is also referred to as an armature.

The housing 400 is a substantially cylindrical casing having a bottom, and houses the stator 200, the lower bearing 430, and the rotor 300 therein. A recess 410 that holds the lower bearing 430 is in the center of the bottom of the housing 400. The lid 420 is a plate-like member that closes the opening at the top of the housing 400. A circular hole 421 that holds the upper bearing 440 is in the center of the lid portion 420.

The stator 200 is annular and has a laminated body (sometimes referred to as a “laminated annular core”) 210 and a winding (sometimes referred to as a “coil”) 220. The stator 200 generates a magnetic flux according to the drive current. The laminated body 210 is composed of a laminated steel plate in which a plurality of steel plates are laminated in a direction along the central axis 500 (y direction in FIG. 1), and includes an annular laminated core back 211 and a plurality of laminated teeth (teeth) 212. The laminated core back 211 is fixed to the inner wall of the housing 400. The structure of the stator 200 will be described in detail later. The central axis 500 is a rotation axis of the rotor 300.

The winding 220 is constituted by a conductive wire (generally a copper wire), and is typically attached to each of the plurality of laminated teeth 212 of the laminated body 210.

The lower bearing 430 and the upper bearing 440 are mechanisms that rotatably support the shaft 340 of the rotor 300. For example, as the lower bearing 430 and the upper bearing 440, ball bearings that relatively rotate an outer ring and an inner ring via a sphere can be used. FIG. 1 shows a ball bearing.

The outer ring 431 of the lower bearing 430 is fixed to the recess 410 of the housing 400. The outer ring 441 of the upper bearing 440 is fixed to the edge of the circular hole 421 of the lid part 420. The

inner rings

432 and 442 of the lower bearing 430 and the upper bearing 440 are fixed to the shaft 340. For this reason, the shaft 340 is rotatably supported with respect to the housing 400 and the lid 420.

The rotor 300 includes

rotor units

310 and 320, a shaft 340, and a cover 350. The shaft 340 is a substantially cylindrical member that extends in the vertical direction along the central axis 500. The shaft 340 is rotatably supported by the lower bearing 430 and the upper bearing 440 and can rotate about the central axis 500. The shaft 340 has a head 341 at the tip on the lid 420 side. The head 341 is connected to a power transmission mechanism such as a gear that transmits a driving force to an electric power steering device of an automobile, for example.

The

rotor units

310 and 320 and the cover 350 rotate together with the shaft 340 in the internal space in the radial direction of the stator 200. Each of the

rotor units

310 and 320 includes a rotor core 331, a magnet holder 332, and a plurality of magnets 333. The

rotor units

310 and 320 are arranged along the central axis 500 in a state where the upper and lower sides are reversed. The plurality of magnets 333 are arranged at substantially equal intervals along the circumferential direction of the rotor 300.

The cover 350 is a substantially cylindrical member that holds the

rotor units

310 and 320. The cover 350 covers the outer peripheral surfaces of the

rotor units

310 and 320 and part of the upper and lower end surfaces. As a result, the

rotor units

310 and 320 are held in a state of being close to or in contact with each other.

In the motor 100, when a drive current is passed through the winding 220 of the stator 200, radial magnetic flux is generated in the plurality of laminated teeth 212 of the laminated body 210. Torque is generated in the circumferential direction by the action of magnetic flux between the plurality of laminated teeth 212 and the magnet 333, and the rotor 300 rotates about the central axis 500 with respect to the stator 200. When the rotor 300 rotates, for example, a driving force is generated in the electric power steering device.

Next, the structure of the stator 200 according to the present embodiment will be described in detail with reference to FIGS.

The stator 200 according to the embodiment of the present disclosure may have M (M is an integer of 2 or more) teeth (in other words, M slots). Hereinafter, as a specific example, the structure of the stator 200 having 12 teeth (12 slots) will be described.

FIG. 2 is a perspective view of the laminate 210. FIG. 3 is a plan view of the stator 200 in a state where the windings 220 are attached to the multilayer body 210 as viewed from the stacking direction of the multilayer body 210. FIG. 4 is a plan view of the annular core sheet 230 constituting the stacked body 210 as viewed from the stacking direction of the stacked body 210.

The stator 200 includes a laminate 210 and a winding 220. The laminated body 210 has 12 laminated teeth 212 and a laminated core back 211. The twelve laminated teeth 212 protrude toward the center of the annular laminated core back 211. There is a slot 214 between two adjacent stacked teeth 212.

A winding 220 is attached to each laminated tooth 212. However, the winding 220 may be attached to at least one of the twelve laminated teeth 212. For example, the winding may be attached to nine or six of the twelve laminated teeth 212.

In the laminate 210, a plurality of annular core sheets 230 are laminated. The laminate 210 according to the present embodiment includes 60 annular core sheets 230. However, the number of stacked layers is not limited to this, and is appropriately determined according to, for example, necessary characteristics required for the motor. For example, the number of stacked layers may be the same as the number of slots or may be larger than the number of slots. Of course, the number of stacked layers may be smaller than the number of slots.

The annular core sheet 230 has an annular core back 231 and twelve teeth 232 that are arranged at equal intervals on the inner periphery of the core back 231 and project toward the center of the core back 231. In the present specification, the term “equal intervals” is not limited to being strictly equal intervals, and includes cases where the intervals are substantially equal. The tips of the twelve teeth 232 are arranged in an annular shape and form the inner periphery of the annular core sheet 230. The plurality of annular core sheets 230 are laminated in the laminate 210 so that the positions of the twelve teeth 232 are aligned between the plurality of annular core sheets 230. As shown in FIG. 4, the annular core sheet 230 has one connecting portion 233 that connects the tips of two adjacent teeth 232 and includes a joint. However, the present disclosure is not limited to this, and each annular core sheet 230 may have a plurality of connecting portions 233. Also, for example, one annular core sheet 230 has twelve connecting portions 233 as many as the number of teeth 232, and the other has two continuous annular core sheets 230 not having connecting portions 233 in the laminate 210. May be laminated. In the present disclosure, at least one of the plurality of annular core sheets 230 may have at least one connecting portion 233. In other words, the stacked body 210 only needs to have at least one connecting portion 233.

FIG. 5A shows a pair of adjacent two laminated teeth 212 in an enlarged manner. FIG. 5B shows an enlarged view of one of the plurality of connecting portions 233 between a pair of adjacent two stacked teeth 212. FIG. 6 is a development view of the laminated body 210 obtained by cutting the laminated core back 211 located between a pair of laminated teeth 212 in the y direction and developing the laminated body 210 in the x direction.

The plurality of connecting portions 233 exist between the tips of a pair of adjacent two laminated teeth 212. In the present embodiment, the connecting portion 233 exists between the 60 annular core sheets 230 for every 12 annular core sheets 230. Five connecting portions 233 exist between the tips of a pair of two adjacent laminated teeth 212. This is merely an example, and the connecting portions 233 can be arranged in various patterns. For example, there are five connecting portions 233 between the tips of a pair of adjacent two stacked teeth 212, and four connecting portions between the tips of another pair of adjacent stacked teeth 212. 233 may be present. Further, there are five or more connecting portions 233 between the tips of two adjacent adjacent laminated teeth 212, and the connecting portion 233 is provided between the tips of another pair of adjacent adjacent two stacked teeth 212. It does not have to exist. According to the present disclosure, it is sufficient that at least one connecting portion 233 is present in the stacked body 210. For example, the same number of connecting portions 233 as the teeth 232 exist in a certain annular core sheet 230, and the connecting portions 233 may not exist at all in a certain annular core sheet.

As shown in FIG. 5B, the connecting portion 233 has a joint 234. The joint 234 appears to be connected apparently. However, as shown in FIG. 9, which will be described in detail later, the joint 234 has two cut

surfaces

235A and 235B that are mechanically cut. Specifically, the first cutting surface 235A on one side of the two adjacent teeth 212 of the connecting portion 233 and the second cutting surface 235B on the other side of the connecting portion 233 are in contact with each other at the joint 234. Yes. An adhesive or the like may be interposed between the two

cut surfaces

235A and 235B, or the two

cut surfaces

235A and 235B may be coated with a nonmagnetic material.

As described above, according to the stator structure of Patent Document 1, a pair of adjacent two tooth portions are still connected by a continuous bridge portion that is not mechanically cut. Magnetic flux leakage occurs through. On the other hand, although the connection part 233 by this indication is cut | disconnected mechanically and is not continuous, the cut surfaces of the connection part 233 are contacting. Therefore, when a force that reduces the distance between two adjacent teeth 232 acts on the stator 200 by the magnetic force generated in the radial direction of the stator 200 during the rotation of the motor, the action is suppressed by the connecting portion 233. Can do. Thus, the rigidity of the stator (specifically, the strength of the inner peripheral portion of the laminate 210) can be increased by the connecting portion 233. Moreover, the magnetic flux leakage through the connection part 233 can be suppressed by the cut surface cut mechanically. Suppression of magnetic flux leakage leads to improvement of cogging torque, for example.

The laminated body 210 has a plurality of connecting portions 233 that are periodically arranged in the circumferential direction of the core back 231 (in other words, the ring formed by the tips of the plurality of teeth 232) between the plurality of annular core sheets 230. You may do it. As shown in FIG. 6, when attention is paid to 12 consecutive annular core sheets 230 out of 60 annular core sheets 230 in the laminate 210, the 12 connecting portions 233 are located between adjacent annular core sheets 230. Can be arranged to exist in two adjacent slots 214. In other words, the twelve connecting portions 233 may exist spirally in the circumferential direction between the plurality of annular core sheets 230. By adopting the spiral structure, the strength of the inner peripheral portion of the stacked body 210 can be ensured even if the number of connecting portions 233 is small.

A specific example of the manufacturing method of the motor 100 and the stator 200 will be described with reference to FIGS.

FIG. 7 shows an exemplary flow of a method for manufacturing the motor 100 and the stator 200. The manufacturing method of the stator 200 according to the present embodiment includes a step of preparing a plurality of annular core sheets 230 (S600), a step of cutting the connecting portion 233 (S610), and a step of obtaining a laminated annular core (laminated body) 210 ( S620), a step of dividing the laminated annular core 210 into a plurality of divided cores 250 (S630), a step of attaching the windings 220 to the divided cores 250 (S640), and reassembling the plurality of divided cores 250 to form the stator 200. (S650). In addition to these steps, the method for manufacturing the motor 100 further includes a step of housing the stator 200 and the rotor 300 in the housing 400 (S660).

First, in step S600, a plurality of annular core sheets 230 shown in FIG. 4 are prepared. For example, twelve or more annular core sheets 230 having the same number as the teeth 232 are prepared. As described above, the number of sheets to be prepared is not limited to this, and is appropriately determined according to, for example, necessary characteristics required for the motor 100. In order to obtain the laminated body 210 shown in FIG. 2, for example, 60 annular core sheets 230 are prepared. Each annular core sheet 230 includes a core back 231, twelve teeth 232, and a connecting portion 233 that connects the tips of two adjacent teeth 232. In step 600, the connecting portion 233 does not yet have the joint 234. Further, at least one of the plurality of annular core sheets 230 only needs to include at least one connecting portion 233, and only a necessary number of the annular core sheets 230 may be prepared.

FIG. 8A schematically shows a state in which a plurality of core sheets 230 are formed by punching the electromagnetic steel sheet 700 into a ring shape using a mold 800. FIG. 8B schematically shows a plurality of annular core sheets 230 formed by stamping. As a method for preparing a plurality of annular core sheets 230, a plurality of annular cores are formed by placing an electromagnetic steel sheet 700 on a die 810 and punching the electromagnetic steel sheet 700 into a ring shape using a mold (punch) 800 as shown in the figure. The sheet 230 may be formed. In addition to press working, for example, wire electric discharge machining or laser machining can also be used. Alternatively, for example, a plurality of annular core sheets 230 may be supplied as parts from a supplier. In the present embodiment, the electromagnetic steel sheet 700 is punched in an annular shape using a mold 800 to form 60 annular core sheets 230.

Next, in step S610, the connecting portion 233 is cut.

FIG. 9 schematically shows how the connecting portion 233 is cut using the cutting blade 710. For example, the joint 234 is formed by mechanically cutting the approximate center of the connecting portion 233 using the cutting blade 710. Thereby, the first cut surface 235 </ b> A is formed on one side of the two adjacent teeth 232 of the connecting portion 233, and the second cut surface 235 </ b> B is formed on the other side of the connecting portion 233. The connecting portion 233 is mechanically cut for each annular core sheet 230 to form joints 234 in all the connecting portions 233 included in the plurality of annular core sheets 230. Further, in order to divide the laminated annular core 210 in step S630, which will be described later, as shown in FIG. 9, it is preferable to make a cut 237 in the approximate center of the core back 231 between the two adjacent teeth 232. .

Next, in step S620, a plurality of annular core sheets 230 are laminated to obtain a laminated annular core 210 having 12 laminated teeth 212. In the present embodiment, after the 60 annular core sheets 230 are stacked, the plurality of annular core sheets 230 are fixed by caulking, adhesion, or laser welding, for example. As a result, a laminated annular core 210 having 12 laminated teeth 212 is obtained. The laminated annular core 210 corresponds to the laminated body 210 described above.

FIG. 10 schematically shows a state in which a plurality of annular core sheets 230 are stacked by rotating in a circumferential direction by a predetermined angle for each sheet. In FIG. 10, two of the 60 annular core sheets 230 are shown. It is preferable that the plurality of annular core sheets 230 be laminated by rotating in a circumferential direction by a predetermined angle for each sheet. Such a stack is generally referred to as “rolling”. Since the connecting portion 233 is spirally arranged by rolling, the strength of the inner peripheral portion of the laminated annular core 210 can be ensured.

The predetermined angle is N times (360 / M) (N is an integer of 1 or more). As described above, M indicates the number of teeth (or slots). When M = 12, the predetermined angle is an integral multiple of 30 °. In this embodiment, as shown in FIG. 10, 60 annular core sheets are laminated by rotating each sheet clockwise by 30 °. Thereby, an arrangement pattern (that is, a spiral structure) of the connecting portions 233 as shown in FIG. 6 is obtained in the laminated annular core 210. 10 is a direction parallel to the central axis of the laminated annular core 210. The y direction shown in FIG. The 60 annular core sheets 230 are laminated along the y direction so that 12 teeth 232 are aligned.

Next, in step S630, the laminated annular core 210 is divided into 12 or less divided cores 250.

FIG. 11A schematically shows a state in which the laminated annular core 210 is divided into 12 divided cores 250. FIG. 11B schematically shows a state where the jig 900 is inserted into the slot 214 and the laminated annular core 210 is divided. FIG. 11C is a plan view of the twelve divided cores 250 as seen from the stacking direction of the stacked annular cores 210. FIG. 11B shows an enlarged part of the laminated annular core 210. For example, the jig 900 is inserted into the slot 214 in the direction of the arrow shown in FIG. 11A. Specifically, as shown in FIG. 11B, by inserting a jig 900 into the slot 214 and applying a force in the circumferential direction of the laminated annular core 210, each laminated annular core 210 has one laminated tooth. It is divided into 12 divided cores 250 having 212. In step S610, the cuts 237 are formed in advance in the core back 231 of each annular core sheet 230, so that the laminated annular core 210 can be easily divided. Of the plurality of slots 214, the jig 900 may be inserted and divided one by one, or the jig 900 may be simultaneously inserted and divided at a plurality of positions.

In the case of concentrated winding, in principle, the laminated annular core 210 is divided so that each divided core 250 has one laminated tooth 212.

Next, in step S640, the winding 220 is attached to at least one of the twelve divided cores 250.

FIG. 12A is a plan view of the split core 250 to which the winding 220 is attached. FIG. 12B is a perspective view of the split core 250 in which the winding 220 is attached to the laminated tooth 212. In this embodiment, the insulating member 260 is attached to each of the laminated teeth 212 of the twelve divided cores 250, and the winding 220 is attached thereon (so-called concentrated winding). As a method of winding the conducting wire around the split core 250, for example, spindle winding and nozzle winding can be used. It is not necessary to attach the windings 220 to all the split cores 250 (laminated teeth 212), and the windings 220 may be attached to the required number of split cores 250 according to the design specifications. In other words, the winding 220 may be attached to at least one laminated tooth 212 of the twelve divided cores 250. For example, the winding 220 may be attached to the nine laminated teeth 212 of the twelve divided cores 250.

Next, in step S650, the plurality of split cores 250 each having the winding 220 attached thereto are reassembled to obtain the annular stator 200.

FIG. 13 schematically shows a state in which the laminated annular core 210 divided into a plurality of divided cores 250 is returned to an annular shape using a jig (not shown). FIG. 14 schematically shows how the cut surfaces of the connecting portion 233 are brought into contact with each other during reassembly. “Reassembly” means that the plurality of split cores 250 are fixed to each other and returned to the shape before splitting (that is, annular). More specifically, after the winding 220 is attached, the 12 divided cores 250 are reassembled to generate the annular stator 200. Each cut surface of the split core 250 has an uneven shape. When the cut surfaces of two adjacent divided cores 250 are brought into contact with each other, the shapes of the two cut surfaces are matched, and the divided cores 250 can be returned to the positional relationship before cutting. At the time of the reassembly, the cut surfaces of the connecting portion 233 cut in step S610 are brought into contact with each other. By returning the divided cores 250 to the positional relationship before cutting, the cut surfaces of the connecting portion 233 can also be matched. In the present embodiment, 12 divided cores 250 are reassembled using a jig. At that time, as shown in FIG. 14, the respective cut surfaces (first and second cut surfaces 235 </ b> A, 235 </ b> B) of the 60 connecting portions 233 mechanically cut are brought into contact with each other.

The plurality of divided cores 250 are fixed by, for example, adhesion or laser welding. This fixing is performed in consideration of (1) circumferential variation and (2) axial height variation of the laminated annular core 210 among the plurality of laminated teeth 212. In addition, after cut | disconnecting the connection part 233, before making a cut surface contact, you may coat each cut surface with a nonmagnetic material. Further, the cut surfaces may be brought into contact with each other through an adhesive.

Suppose that a tooth iron core (corresponding to the ring core sheet 230 excluding the core back 231) and a yoke iron core (corresponding to the core back 231) are prepared as independent members as in Patent Document 1. In that case, for example, a punching variation (error) due to a mold may occur between the plurality of teeth 232, and therefore, at the time of assembly (particularly after the tooth core is press-fitted into the yoke core), Misalignment occurs and it is difficult to bring the tips of two adjacent teeth into contact with each other. On the other hand, according to the present embodiment, the annular core sheet 230 including the core back 231 and the coupling part 233 is punched in an annular shape, and then the coupling part 233 is cut. Since the core back 231 and the plurality of teeth 232 are integrated, the cut surfaces can be kept in contact with each other even after the connecting portion 233 is cut. In addition, since the plurality of laminated annular core sheets 230 are laminated in this state, the cut surfaces can be kept in contact with each other until the laminated annular core 210 is divided (until just before the division). In addition, since the press-fitting operation does not occur, the positional deviation of the tip of the tooth 232 that occurs during press-fitting does not occur. Therefore, when the split cores 250 are reassembled, the cut surfaces of the cut connecting portions 233 can be brought into contact with each other.

In the method for manufacturing the motor 100, the stator 200 and the rotor 300 are housed in the housing 400 in step S660.

An example of a method for manufacturing the rotor 300 will be briefly described. The rotor core 331 and the magnet holder 332 are integrated by insert molding. More specifically, resin is injected around the rotor core 331 inserted into the mold to integrate the rotor core 331 and the resin. When the resin is cooled and solidified, the magnet holder 332 is formed. Next, the magnet 333 is inserted into the integrated rotor core 331 and magnet holder 332. Thereby, the magnet 333 is fixed to the side surface of the rotor core 331 while being supported by the magnet holder 332.

A lower bearing 430 (for example, a ball bearing) is disposed in the recess 410 of the housing 400. Next, after housing the stator 200 in the housing 400, the shaft 340 is inserted into the lower bearing 430, and the rotor 300 integrated with the shaft 340 is disposed in the internal space of the stator 200. Finally, an upper bearing 440 (for example, a ball bearing) is disposed in the circular hole 421 of the lid portion 420, and the opening at the top of the housing 400 is closed by the lid portion 420.

In addition, a part of manufacturing process mentioned above can be replaced by a well-known manufacturing method (for example, the method disclosed in Patent Document 1).

According to the method for manufacturing the motor 100 and the stator 200 according to the present embodiment, the laminated annular core 210 is divided by forming the joint 234 in the coupling portion 233, so that the plurality of laminated teeth are not affected by the coupling portion 233. The winding 220 can be easily attached to 212, and the press-fitting work into the laminated core back 211 as in Patent Document 1, for example, becomes unnecessary. As a result, not only the assembly of the stator 200 is facilitated, but also the harmful effects of contamination during press-fitting can be prevented. Furthermore, since there is no state in which only the connecting portion 233 is connected in the assembling process, deformation of the connecting portion 233 can be prevented.

As described above, according to the present embodiment, the rigidity of the stator 200 can be increased by the connecting portion 233 and the vibration of the motor 100 can be reduced. Moreover, since the connection part 233 has the cut surface cut | disconnected mechanically, the magnetic flux leakage through the connection part 233 can be reduced.

Next, in the motor 100 including the connecting portion 233, a structure for more effectively reducing the vibration of the motor 100 will be described. Here, in the motor 100 in which the stator 200 includes twelve laminated teeth 212 and the rotor includes ten magnets 333, how to dispose the connecting portion 233 that reduces vibration more effectively will be described.

FIG. 15 is a plan view showing an example of the stator 200 and the rotor 300 included in the motor 100. FIG. 16 is a plan view showing an example of the stator 200. For ease of understanding, the winding 220 is not shown in FIGS. 15 and 16. In this example, the stator 200 includes twelve laminated teeth 212. The rotor 300 includes ten magnets 333. A structure including such a number of laminated teeth 212 and magnets 333 may be referred to as 12S10P (12 slots 10 poles).

In this example, the motor 100 is a three-phase motor having three-phase (U-phase, V-phase, W-phase) windings. As shown in FIG. 16, the twelve laminated teeth 212 include U, U, V, V, W, W, U, U, V, V, W, W in order of U phase, V phase, W phase. Is assigned. Each of the plurality of annular core sheets 230 included in the stator 200 includes 12 teeth 232. The U-phase, V-phase, and W-phase are assigned to the 12 teeth 232 of the annular core sheet 230 in the order shown in FIG.

FIG. 17 is a view showing a position where the connecting portion 233 in the stator 200 is arranged. Twelve laminated teeth 212 to which a U phase, a V phase, and a W phase are assigned are arranged along the horizontal direction of FIG. Numerical values of 0, 30, 60,..., 330 arranged in the horizontal direction indicate angles along the circumferential direction of the stator 200. Since the number of the laminated teeth 212 is 12, the laminated teeth 212 are arranged on the stator 200 at intervals of 30 degrees. In this example, the stator 200 includes 12 annular core sheets 230. The

numbers

1, 2, 3,..., 12 arranged in the vertical direction in FIG. 17 indicate the 12 annular core sheets 230 stacked. The laminated body 210 of the stator 200 has a structure in which twelve annular core sheets 230 are laminated by rotating in the circumferential direction by 30 degrees for each sheet. That is, the transversion angle is 30 degrees. In this example, the number of the annular core sheets 230 is twelve, but this number is an example, and the number is appropriately determined according to necessary characteristics required for the motor. For example, as described above, 60 annular core sheets 230 may be stacked.

In the structure of the stator 200 shown in FIG. 17, each of the twelve annular core sheets 230 includes one connecting portion 233. A black square portion in FIG. 17 represents the connecting portion 233.

Of the twelve annular core sheets 230, one connecting portion 233 provided in the uppermost annular core sheet 230 includes teeth 232 to which the W phase is assigned and teeth 232 to which the U phase is assigned. It is connected. Similarly, one connecting portion 233 included in the seventh annular core sheet 230 from the top connects the tooth 232 to which the W phase is assigned and the tooth 232 to which the U phase is assigned.

Of the twelve annular core sheets 230, one connecting portion 233 provided in the second annular core sheet 230 from the top includes a tooth 232 to which the U phase is assigned and a tooth 232 to which the U phase is assigned. Are connected. That is, adjacent teeth 232 to which the same U phase is assigned are connected to each other. Similarly, one connecting portion 233 included in the eighth annular core sheet 230 from the top connects the tooth 232 to which the U phase is assigned and the tooth 232 to which the U phase is assigned.

Of the twelve annular core sheets 230, one connecting portion 233 provided in the third annular core sheet 230 from the top includes teeth 232 to which the U phase is assigned and teeth 232 to which the V phase is assigned. Are connected. Similarly, one connecting part 233 provided in the ninth annular core sheet 230 from the top connects the teeth 232 to which the U phase is assigned and the teeth 232 to which the V phase is assigned.

Of the twelve annular core sheets 230, one connecting portion 233 provided in the fourth annular core sheet 230 from the top includes a tooth 232 to which the V phase is assigned and a tooth 232 to which the V phase is assigned. Are connected. That is, adjacent teeth 232 to which the same V phase is assigned are connected to each other. Similarly, one connecting portion 233 included in the tenth annular core sheet 230 from the top connects the tooth 232 to which the V phase is assigned and the tooth 232 to which the V phase is assigned.

Of the twelve annular core sheets 230, one connecting portion 233 provided in the fifth annular core sheet 230 from the top includes teeth 232 to which the V phase is assigned and teeth 232 to which the W phase is assigned. Are connected. Similarly, one connecting portion 233 included in the eleventh annular core sheet 230 from the top connects the tooth 232 to which the V phase is assigned and the tooth 232 to which the W phase is assigned.

Of the twelve annular core sheets 230, one connecting portion 233 provided in the sixth annular core sheet 230 from the top includes a tooth 232 to which the W phase is assigned and a tooth 232 to which the W phase is assigned. Are connected. That is, adjacent teeth 232 to which the same W phase is assigned are connected to each other. Similarly, one connecting portion 233 provided in the twelfth annular core sheet 230 from the top connects the tooth 232 to which the W phase is assigned and the tooth 232 to which the W phase is assigned.

The inventor of the present application performed a simulation on the operation of the motor 100 having the stator structure shown in FIG. 17 and examined the result. Details of the operation of the motor 100 will be described later with reference to FIG.

FIG. 18 is a diagram illustrating another example of a position where the connecting portion 233 in the stator 200 is disposed. Twelve laminated teeth 212 to which a U phase, a V phase, and a W phase are assigned are arranged along the horizontal direction of FIG. Numerical values of 0, 30, 60,..., 330 arranged in the horizontal direction indicate angles along the circumferential direction of the stator 200. In this example, the stator 200 includes 12 annular core sheets 230. The

numbers

1, 2, 3,..., 12 arranged in the vertical direction in FIG. 18 indicate the 12 annular core sheets 230 stacked. The laminated body 210 of the stator 200 has a structure in which twelve annular core sheets 230 are laminated by rotating in the circumferential direction by 30 degrees for each sheet.

In the structure of the stator 200 shown in FIG. 18, each of the 12 annular core sheets 230 includes two connecting portions 233. A black square portion in FIG. 18 represents the connecting portion 233.

Of the twelve annular core sheets 230, each of the two connecting portions 233 included in the annular core sheet 230 positioned at the top has a tooth 232 to which the W phase is assigned and a tooth 232 to which the U phase is assigned. Are linked. Similarly, the two connecting portions 233 included in the seventh annular core sheet 230 from the top connect the tooth 232 to which the W phase is assigned and the tooth 232 to which the U phase is assigned.

Of the twelve annular core sheets 230, each of the two connecting portions 233 included in the annular core sheet 230 located second from the top includes a tooth 232 to which the U phase is assigned and a tooth to which the U phase is assigned. 232 is connected. That is, adjacent teeth 232 to which the same U phase is assigned are connected to each other. Similarly, the two connecting portions 233 included in the eighth annular core sheet 230 from the top connect the teeth 232 to which the U phase is assigned and the teeth 232 to which the U phase is assigned.

Of the twelve annular core sheets 230, each of the two connecting portions 233 included in the third annular core sheet 230 from the top includes a tooth 232 to which the U phase is assigned and a tooth to which the V phase is assigned. 232 is connected. Similarly, the two connecting portions 233 included in the ninth annular core sheet 230 from the top connect the teeth 232 to which the U phase is assigned and the teeth 232 to which the V phase is assigned.

Of the twelve annular core sheets 230, each of the two connecting portions 233 provided in the fourth annular core sheet 230 from the top includes a tooth 232 to which the V phase is assigned and a tooth to which the V phase is assigned. 232 is connected. That is, adjacent teeth 232 to which the same V phase is assigned are connected to each other. Similarly, the two connecting portions 233 included in the tenth annular core sheet 230 from the top connect the teeth 232 to which the V phase is assigned and the teeth 232 to which the V phase is assigned.

Of the twelve annular core sheets 230, the two connecting portions 233 provided in the fifth annular core sheet 230 from the top are teeth 232 to which the V phase is assigned and teeth 232 to which the W phase is assigned. Are connected. Similarly, the two connecting portions 233 included in the eleventh annular core sheet 230 from the top connect the teeth 232 to which the V phase is assigned and the teeth 232 to which the W phase is assigned.

Of the twelve annular core sheets 230, each of the two connecting portions 233 included in the sixth annular core sheet 230 from the top includes a tooth 232 to which the W phase is assigned and a tooth to which the W phase is assigned. 232 is connected. That is, adjacent teeth 232 to which the same W phase is assigned are connected to each other. Similarly, the two connecting portions 233 included in the twelfth annular core sheet 230 from the top connect the tooth 232 to which the W phase is assigned and the tooth 232 to which the W phase is assigned.

The inventor of the present application performed a simulation on the operation of the motor 100 having the stator structure shown in FIG. 18 and examined the result. Details of the operation of the motor 100 will be described later with reference to FIG.

FIG. 19 is a diagram showing still another example of the position where the connecting portion 233 in the stator 200 is arranged. Twelve laminated teeth 212 to which a U phase, a V phase, and a W phase are assigned are arranged along the horizontal direction of FIG. Numerical values of 0, 30, 60,..., 330 arranged in the horizontal direction indicate angles along the circumferential direction of the stator 200. In this example, the stator 200 includes 12 annular core sheets 230. The

numbers

1, 2, 3,..., 12 arranged in the vertical direction in FIG. 19 indicate the 12 annular core sheets 230 stacked. The laminated body 210 of the stator 200 has a structure in which twelve annular core sheets 230 are laminated by rotating in the circumferential direction by 30 degrees for each sheet.

In the structure of the stator 200 shown in FIG. 19, each of the twelve annular core sheets 230 includes three connecting portions 233. In FIG. 19, a black square portion represents the connecting portion 233.

Of the twelve annular core sheets 230, one of the three connecting portions 233 provided in the uppermost annular core sheet 230 is assigned the teeth 232 to which the W phase is assigned and the U phase. The teeth 232 are connected. Another one of the three connecting portions 233 connects the tooth 232 to which the V phase is assigned and the tooth 232 to which the W phase is assigned. Still another one of the three connecting portions 233 connects the tooth 232 to which the U phase is assigned and the tooth 232 to which the V phase is assigned. The three connecting portions 233 included in each of the third, fifth, seventh, ninth, and eleventh annular core sheets 230 from the top also have the same connection pattern as the first annular core sheet 230 from the top.

Of the twelve annular core sheets 230, one of the three connecting portions 233 included in the second annular core sheet 230 from the top is assigned to the teeth 232 to which the U phase is assigned and the U phase is assigned. The connected teeth 232 are connected. Another one of the three connecting portions 233 connects the tooth 232 to which the W phase is assigned and the tooth 232 to which the W phase is assigned. Yet another one of the three connecting portions 233 connects the tooth 232 to which the V phase is assigned and the tooth 232 to which the V phase is assigned. The three connecting portions 233 included in the fourth, sixth, eighth, tenth, and twelfth annular core sheets 230 from the top also have the same connection pattern as the second annular core sheet 230 from the top.

The inventor of the present application performed a simulation on the operation of the motor 100 having the stator structure shown in FIG. 19 and examined the result. Details of the operation of the motor 100 will be described later with reference to FIG.

FIG. 20 is a diagram showing still another example of a position where the connecting portion 233 in the stator 200 is arranged. Twelve laminated teeth 212 to which a U phase, a V phase, and a W phase are assigned are arranged along the horizontal direction of FIG. Numerical values of 0, 30, 60,..., 330 arranged in the horizontal direction indicate angles along the circumferential direction of the stator 200. In this example, the stator 200 includes 12 annular core sheets 230. The

numbers

1, 2, 3,..., 12 arranged in the vertical direction in FIG. 20 indicate the 12 annular core sheets 230 stacked. The laminated body 210 of the stator 200 has a structure in which twelve annular core sheets 230 are laminated by rotating in the circumferential direction by 30 degrees for each sheet.

In the structure of the stator 200 shown in FIG. 20, each of the twelve annular core sheets 230 includes four connecting portions 233. A black square portion in FIG. 20 represents the connecting portion 233.

Of the twelve annular core sheets 230, two of the four connecting portions 233 included in the uppermost annular core sheet 230 are assigned the teeth 232 to which the W phase is assigned and the U phase. The teeth 232 are connected. Another two of the four connecting portions 233 connect the tooth 232 to which the V phase is assigned and the tooth 232 to which the V phase is assigned. The four connecting portions 233 included in the fourth, seventh, and tenth annular core sheets 230 from the top also have the same connection pattern as the first annular core sheet 230 from the top.

Of the twelve annular core sheets 230, two of the four connecting portions 233 included in the annular core sheet 230 located second from the top are assigned to the teeth 232 to which the U phase is assigned and the U phase is assigned. The connected teeth 232 are connected. Another two of the four connecting portions 233 connect the tooth 232 to which the V phase is assigned and the tooth 232 to which the W phase is assigned. The four connecting portions 233 included in the fifth, eighth, and eleventh annular core sheets 230 from the top also have the same connection pattern as the second annular core sheet 230 from the top.

Of the twelve annular core sheets 230, two of the four connecting portions 233 included in the annular core sheet 230 located third from the top are assigned the teeth 232 to which the U phase is assigned and the V phase. The connected teeth 232 are connected. Another two of the four connecting portions 233 connect the tooth 232 to which the W phase is assigned and the tooth 232 to which the W phase is assigned. The four connecting portions 233 included in the sixth, ninth, and twelfth annular core sheets 230 from the top also have the same connection pattern as the third annular core sheet 230 from the top.

FIG. 21 is a diagram showing simulation results of the operation of the motor 100 having the stator structure shown in FIGS. The vertical axis in FIG. 21 represents acceleration, and the horizontal axis represents angle.

A solid line 301 indicates the acceleration of the rotor 300 of the motor 100 having the stator structure shown in FIG. In the stator structure shown in FIG. 17, each of the twelve annular core sheets 230 includes one connecting portion 233.

A solid line 302 indicates the acceleration of the rotor 300 of the motor 100 having the stator structure shown in FIG. In the stator structure shown in FIG. 18, each of the twelve annular core sheets 230 includes two connecting portions 233.

A solid line 303 indicates the acceleration of the rotor 300 of the motor 100 having the stator structure shown in FIG. In the stator structure shown in FIG. 19, each of the twelve annular core sheets 230 includes three connecting portions 233.

A solid line 304 indicates the acceleration of the rotor 300 of the motor 100 having the stator structure shown in FIG. In the stator structure shown in FIG. 20, each of the twelve annular core sheets 230 includes four connecting portions 233. A solid line 30N indicates the acceleration of the rotor 300 of the motor 100 that does not include the connecting portion 233.

As shown by the solid line 303, in the motor 100 in which each of the annular core sheets 230 includes the three connecting portions 233, the fluctuation range of the acceleration during one rotation of the rotor 300 is large. When the fluctuation range of the acceleration during one rotation of the rotor 300 is large, the vibration of the motor 100 increases. Although not shown, in this structure, the torque ripple that is the fluctuation range of the torque becomes large.

On the other hand, as shown by the solid line 301, in the motor 100 in which each of the annular core sheets 230 includes one connecting portion 233, the fluctuation range of the acceleration during one rotation of the rotor 300 is small. Further, as indicated by the solid line 302, even in the motor 100 in which each of the annular core sheets 230 includes the two connecting portions 233, the fluctuation range of the acceleration during one rotation of the rotor 300 is small. Further, as indicated by the solid line 304, in the motor 100 including each of the annular core sheets 230 including the four connecting portions 233, the fluctuation range of the acceleration during one rotation of the rotor 300 is small. For this reason, in the structure shown in FIGS. 17, 18 and 20, it can be seen that the vibration of the motor 100 can be reduced. Although not shown, the torque ripple can be reduced by the structure shown in FIGS. 17, 18, and 20.

Thus, by providing the motor 100 with the stator structure shown in FIGS. 17, 18 and 20, the vibration of the motor 100 can be more effectively reduced.

The embodiments of the present disclosure can be widely used in various motors used in vacuum cleaners, dryers, ceiling fans, washing machines, refrigerators, electric power steering devices, and the like.

100: motor, 200: stator, 210: laminated body (laminated annular core), 211: laminated core back, 212: laminated teeth, 214: slot, 220: winding, 230: annular core sheet, 231: core back, 232 : Teeth, 233: connecting portion, 234: joint, 235A: first cut surface, 235B: second cut surface, 237: cut, 250: split core, 260: insulating member, 300: rotor, 400: housing

Claims

A laminated body in which a plurality of annular core sheets are laminated and have a plurality of laminated teeth;
A plurality of windings attached to a plurality of laminated teeth;
With
Each of the plurality of annular core sheets is
An annular core back,
A plurality of teeth arranged at equal intervals on the inner periphery of the core back and protruding toward the center of the core back;
Connecting the tips of two adjacent teeth and including a joint;
A stator for an electric motor.
The stator according to claim 1, wherein the connecting portion has a cut surface mechanically cut at the joint.
The said connection part WHEREIN: The 1st cutting surface of the one side of the said two adjacent teeth and the 2nd cutting surface of the other side of the said connection part are contacting with the said joint. Stator.
The stator according to any one of claims 1 to 3, wherein each of the plurality of annular core sheets has a plurality of the connecting portions.
The plurality of windings include three-phase windings;
The three phases include a first phase, a second phase, and a third phase;
The plurality of teeth of each of the plurality of annular core sheets is assigned the first phase, the second phase, and the third phase;
The plurality of annular core sheets include a first annular core sheet;
5. The stator according to claim 4, wherein each of the plurality of connecting portions of the first annular core sheet connects a tooth to which a first phase is assigned and a tooth to which a second phase is assigned.
The plurality of annular core sheets include a second annular core sheet;
6. The stator according to claim 5, wherein each of the plurality of connecting portions of the second annular core sheet connects a tooth to which a second phase is assigned and a tooth to which a second phase is assigned.
The plurality of annular core sheets include a third annular core sheet;
Each of the said some connection part which the said 3rd cyclic | annular core sheet has connects the tooth | gear to which the 2nd phase was allocated, and the tooth | gear to which the 3rd phase was allocated. Stator.
The plurality of windings include three-phase windings;
The three phases include a first phase, a second phase, and a third phase;
The plurality of teeth of each of the plurality of annular core sheets is assigned the first phase, the second phase, and the third phase;
The plurality of annular core sheets include a first annular core sheet;
One of the plurality of connecting portions of the first annular core sheet connects the teeth to which the first phase is assigned and the teeth to which the second phase is assigned,
5. The another one of the plurality of connecting portions of the first annular core sheet connects a tooth to which a third phase is assigned and a tooth to which a third phase is assigned. The stator described in 1.
The plurality of annular core sheets include a second annular core sheet;
One of the plurality of connecting portions of the second annular core sheet connects a tooth to which a second phase is assigned and a tooth to which a second phase is assigned,
The other one of the plurality of connecting portions of the second annular core sheet connects a tooth to which the third phase is assigned and a tooth to which the first phase is assigned. The stator described in 1.
The plurality of annular core sheets include a third annular core sheet;
One of the plurality of connecting portions of the third annular core sheet connects a tooth to which a second phase is assigned and a tooth to which a third phase is assigned,
The other one of the plurality of connecting portions of the third annular core sheet connects a tooth assigned with the first phase and a tooth assigned with the first phase. Or the stator according to 9.
The stator according to any one of claims 1 to 10, wherein the number of the laminated teeth is twelve.
Each of the 12 teeth of the plurality of annular core sheets has the first phase, the second phase, and the third phase,
First phase, first phase, second phase, second phase, third phase, third phase, first phase, first phase, second phase, second phase, The stator according to claim 11, which is assigned in the order of the third phase and the third phase.
The stator according to any one of claims 1 to 3, wherein each of the plurality of annular core sheets has one connecting portion.
The plurality of windings include three-phase windings;
The three phases include a first phase, a second phase, and a third phase;
The plurality of teeth of each of the plurality of annular core sheets is assigned the first phase, the second phase, and the third phase;
The plurality of annular core sheets include a first annular core sheet;
The stator according to claim 13, wherein the connecting portion of the first annular core sheet connects a tooth to which the first phase is assigned and a tooth to which the second phase is assigned.
The plurality of annular core sheets include a second annular core sheet;
The stator according to claim 14, wherein the connecting portion of the second annular core sheet connects a tooth to which a second phase is assigned and a tooth to which a second phase is assigned.
The plurality of annular core sheets include a third annular core sheet;
The stator according to claim 14 or 15, wherein the connecting portion of the third annular core sheet connects a tooth to which the second phase is assigned and a tooth to which the third phase is assigned.
The stator according to any one of claims 3 to 16, wherein the number of the laminated teeth is twelve.
Each of the 12 teeth of the plurality of annular core sheets has the first phase, the second phase, and the third phase,
First phase, first phase, second phase, second phase, third phase, third phase, first phase, first phase, second phase, second phase, The stator according to claim 17 assigned in the order of the third phase and the third phase.
The stator according to any one of claims 1 to 18, wherein the laminated body has a structure in which the plurality of annular core sheets are laminated in a circumferential direction by a predetermined angle for each sheet.
The stator according to any one of claims 1 to 19, wherein the laminated body has a structure in which the plurality of annular core sheets are laminated in a circumferential direction by 30 degrees for each sheet.
The stator according to any one of claims 1 to 20,
A rotor that rotates relative to the stator;
A housing for housing the stator and the rotor;
An electric motor.
The stator includes twelve laminated teeth,
The electric motor according to claim 21, wherein the rotor includes ten magnets.
The electric motor according to claim 22, wherein the laminated body has a structure in which the plurality of annular core sheets are laminated by rotating each of the annular core sheets 30 degrees in the circumferential direction.