JP5423971B2 - Axial gap type electric motor - Google Patents

Description

  The present invention relates to a single rotor type axial gap type motor in which a rotor and a stator are arranged to face each other with a predetermined gap along an axial direction of an output shaft, and in particular, a magnetic core of a core member constituting the stator TECHNICAL FIELD The present invention relates to an axial gap type electric motor that improves material yield at the time of manufacturing and secures magnetic coupling between magnetic cores.

  As a single rotor type axial gap type electric motor, one having the configuration shown in FIG. 8 has been proposed (see Patent Document 1). In FIG. 8, 500 is a case, 600 is a stator, 700 is a rotor, and 800 is an output shaft. The case 500 includes a front case 510, a rear case 520, an outer peripheral case 530 that couples the cases 510 and 520, and bearings 540 and 550. The stator 600 includes a plurality of core members 610 arranged at equal angular pitches in the circumferential direction inside the rear case 520. The output shaft 800 is supported between the cases 510 and 520 via bearings 540 and 550. The central portion of the rotor 700 is fixed to the output shaft 800. In this rotor 700, a plurality of permanent magnets 720 are circumferentially arranged at equal angular pitches so as to face the core member 610 through a gap G on the surface facing the rear case 620 side of the disk-shaped rotor yoke 710. It is fixed. The core member 610 includes a magnetic core 611, an insulating bobbin 612 that covers the periphery of the magnetic core 611, and a coil 613 wound around the bobbin 612.

  As shown in FIG. 9, the magnetic core 611 includes a rectangular parallelepiped core front end portion 611 a whose front end face faces the gap G, and a core rear end portion 611 b which is located on the rear case 520 side and extends in the circumferential direction of the stator 600. Have Then, as shown in FIG. 10, a plurality of magnetic cores 611 are assembled in an annular shape in the circumferential direction of the stator 600, and the side end surfaces 611b1 of the core rear end portion 611b are brought into contact with each other. As described above, since the plurality of magnetic cores 611 are connected in the circumferential direction, the core front end portion 611a and the core rear end portion 611b are narrow on the inner peripheral side (left side in FIG. 9) and on the outer peripheral side (FIG. 9). Then, the right side) is formed by laminating a plurality of electromagnetic core pieces in the radial direction (arrow A direction) of the stator 600 so as to form a wide trapezoidal shape.

JP 2006-050745 A

  However, in the conventional electric motor described with reference to FIGS. 8 to 10, the magnetic core 611 has a trapezoidal shape in the stacking direction A in which the inner peripheral side is narrow and the outer peripheral side is wide. The shape of the electromagnetic core pieces are all different, and there is a problem that the material yield is reduced and the cost is deteriorated when punching and forming each shape of the electromagnetic core pieces from a roll-shaped electromagnetic steel sheet with a progressive die. . Further, when a plurality of magnetic cores 611 are joined in an annular shape, the only part that contacts each other is the side end surface 611b1 of the core rear end 611b, the contact area is small, and the adjacent magnetic cores 611 are magnetically connected to each other. May not be combined.

  An object of the present invention is to provide a magnetic core which can improve the material yield of punching by using only one type of punching die for electromagnetic steel sheets and can magnetically couple adjacent magnetic cores with each other. An axial gap type electric motor is provided.

In order to achieve the above-described object, the invention according to claim 1 is such that the stator and the rotor are arranged to face each other along the axial direction of the output shaft of the rotor, and the rotor has the axis of the output shaft. The stator has a plurality of permanent magnets arranged in the circumferential direction at the center, and the stator has a plurality of core members arranged in the circumferential direction around the axis of the output shaft, and the core members are mutually connected. In each of the axial gap type motors connected to each other at a predetermined angular pitch, each core member includes a magnetic core in which steel plates having the same shape are stacked in the radial direction of the stator, and the magnetic core is opposed to the permanent magnet. A core front end, a core rear end for magnetically connecting the core members to each other to form an annular magnetic yoke, and a connection between the core rear end and the core front end A core torso and a front At the one end portion and the other end portion in the circumferential direction at the core rear end portion, a rectangular coupling plane overlapping with the core rear end portion of another core member adjacent in the circumferential direction in the axial direction is provided. It is characterized by that.
According to a second aspect of the present invention, in the axial gap type electric motor according to the first aspect, the coupling plane provided at the one end portion in the circumferential direction of the core rear end portion has the one end portion along the axial direction. The coupling plane provided at the other end portion is formed at a position where the other end portion is recessed toward the non-rotor side along the axial direction. It is characterized by that.
According to a third aspect of the present invention, in the axial gap motor according to the second aspect, the circumferential length of the coupling plane is X, the radial length is t, and the core members are arranged. When the angular pitch is α, the circumferential length X is
X ≧ t · sinα
It is characterized by being set to.
According to a fourth aspect of the present invention, in the axial gap type electric motor according to the first, second, or third aspect, the core member further covers an outer periphery of the magnetic core, leaving at least a front end surface of the core front end portion. A bobbin having a front flange parallel to the front end surface of the front end portion and a rear flange parallel to the rear end surface of the rear end portion of the core, wherein at least the front end surface of the core front end portion extends from the front flange to the rotor in the axial direction. It protrudes to the side.
According to a fifth aspect of the present invention, in the axial gap type electric motor according to the first, second, third, or fourth aspect, a hook projects from the circumferential end of the front flange and the rear flange. A locking shaft that protrudes in the axial direction and that locks the hook of the adjacent core member is provided on the end side, and the distal end surface of the core distal end portion is further forward in the axial direction than the distal end of the locking shaft. It is characterized by protruding.

  According to the present invention, since the steel plates constituting the magnetic core by laminating a plurality of sheets are the same shape steel plates, the material yield is improved when the steel plates are stamped and manufactured with a press die. Moreover, since the core rear ends of adjacent magnetic cores overlap each other in the axial direction in the coupling plane, they can be reliably coupled magnetically.

It is principal part sectional drawing of the axial gap type motor of the Example of this invention. It is a perspective view of the core member (coil non-winding) of each direction. It is a perspective view of the magnetic core of each direction. It is a perspective view of each direction of the combined state of two core members (coil non-winding). It is explanatory drawing which couple | bonded the magnetic core in the annular | circular shape. It is explanatory drawing of the coupling | bonding of two magnetic cores. It is explanatory drawing which punches out a magnetic iron core piece from a magnetic steel plate. It is principal part sectional drawing of the conventional axial gap type motor. It is a perspective view of the magnetic core used for the electric motor of FIG. It is explanatory drawing which couple | bonded the magnetic core of FIG. 9 in the annular | circular shape.

  FIG. 1 shows a cross section of a single-rotor axial gap motor according to one embodiment of the present invention. In FIG. 1, 100 is a stator, 200 is a rotor, and 300 is an output shaft. The stator 100 includes a plurality of core members 110 arranged at equal angular pitches in the circumferential direction of the output shaft 300, bearings 120, and resin molded bodies 130 that integrally hold the core members 110 and the bearings 120. The rotor 200 includes a disk-shaped magnetic yoke 210 and a plurality of rotors 200 arranged at equiangular pitches in the circumferential direction of the output shaft 300 so as to face the front surface of the core member 110 via a predetermined gap G on the back surface of the magnetic yoke 210. The permanent magnet 220 is provided. The output shaft 300 is integrated with the center of the rotor 200 and is supported by the bearing 120 of the stator 100. The output shaft 300 may be further supported by a bearing attached to a case (not shown) that holds the stator 100 and extends forward (right side in FIG. 1) in order to extract rotational force. .

  The core member 110 includes a magnetic core 111, a bobbin 112 made of an insulating material attached to the magnetic core 111, and a coil 113 wound around the bobbin 112. FIG. 2 shows the core member 110 in each direction. However, the coil 113 is not wound here.

  FIG. 3 shows the magnetic core 111 in each direction. This magnetic core 111 is formed by laminating a plurality of steel plates (electromagnetic core pieces 401 described later) having a substantially E-shaped cross section formed by punching an electromagnetic steel plate in the direction of arrow A, which is the radial direction of the stator 100. The core front end portion 111a facing the front end surface 111a1 to the permanent magnet 220 of the rotor 200, the core rear end portion 111b on the opposite side, and the core front end portion 111a and the core rear end portion 111b are connected. It consists of a core body part 111c. The core rear end portion 111b has two end surfaces (an upper end surface 111b21 and a bottom end surface 111b11) that are substantially perpendicular to the arrow C direction that is the axial direction of the output shaft 300. Further, an outer step coupling plane 111b1 is formed which is recessed one step lower in the axial direction from the bottom end surface 111b11 at one end in the circumferential direction B of the core rear end portion 111b, and from the upper end surface 111b21 at the other end in the axial direction. An inner step coupling plane 111b2 that is recessed by one step is formed. Since the plurality of punched electromagnetic core pieces 401 have the same shape, when they are stacked, the front end surface 111b1 of the core front end portion 111a and the bottom end surface 111b11 of the core rear end portion 111b become rectangular, and the outer step coupling plane 111b1. The inner step coupling plane 111b2 has a constant width in the stacking direction (A direction: radial direction of the stator 100).

  As shown in FIG. 2, the bobbin 112 includes a front flange 112a parallel to the front end surface 111a1 of the core front end 111a, a rear flange 112b parallel to the bottom end surface 111b11 of the core rear end 111b, and both flanges 112a and 112b. It consists of the winding cylinder 112c which connects. A hook 112a1, a locking shaft 112a2, an engagement recess 112a3, and an engagement piece 112a4 are formed in the front flange 112a. The rear flange 112b is also formed with a hook 112b1, a locking shaft 112b2, an engaging recess 112b3, an engaging piece 112b4, and a terminal block 112b5. The bobbin 112 is made of a synthetic resin molded product, and is substantially divided in half along the circumferential direction of the magnetic core 111. The bobbin 112 is attached to the magnetic core 111 by fitting them from both sides of the magnetic core 111. It is supposed to be.

  In the core member 110, the core body 111c of the magnetic core 111 is disposed in the winding cylinder 112c of the bobbin 112, and the core tip 111a of the magnetic core 111 protrudes outside the front flange 112a (FIG. 2 (a)). After the bobbin 112 is integrated so that the core rear end 111b protrudes outside the rear flange 112b (FIG. 2B), the coil 113 is wound around the winding cylinder 112c (not shown in FIG. 2). ) The terminal of the coil 113 is connected to a terminal pin (not shown) attached to the terminal block 112b5. In this assembled state, the front end surface 111a1 of the core front end portion 111a protrudes forward in the axial direction from the front flange 112a, and the bottom end surface 111b11 of the core rear end portion 111b protrudes rearward in the axial direction from the rear flange 112b. Further, the front end surface 111a1 of the core front end 111a protrudes forward in the axial direction from the front end of the locking shaft 112a2. That is, the front end surface 111a1 of the core front end portion 111a is located at the most distal end and faces the permanent magnet, and the bottom end surface 111b11 of the core rear end portion 111b is located at the most rear end.

  The hooks 112a1 and the locking shafts 112a2 of the front flanges 112a of the adjacent bobbins 112 are arranged so that the core front end 111a of the magnetic core 111 faces the same surface and the core rear end 111b faces the same surface. , The hook 112b1 of the rear flange 112b and the locking shaft 112b2 are locked, the engagement recess 112a3 and the engagement piece 112a4 are engaged, and the engagement recess 112b3 and the engagement piece 112b4 are engaged. As shown in FIG. 4, the plurality of core members 110 are coupled at a predetermined angular pitch in the C direction that is the circumferential direction of the stator 100. At this time, between the adjacent magnetic cores 111, the core front end portion 111a does not contact, and the core rear end portion 111b comes into contact with the outer step coupling plane 111b1 and the inner step coupling plane 111b2 partially overlapping. By this contact, lines of magnetic force can pass between adjacent magnetic cores 111. Accordingly, the outer step coupling plane 111b1 and the inner step coupling plane 111b2 of the core rear end portion 111b serve as coupling surfaces for magnetically coupling the adjacent magnetic cores 111. When a predetermined number of core members 110 are sequentially connected, the whole becomes an endless annular shape, and the core rear end portion 111b becomes an annular magnetic yoke. FIG. 5 shows a state in which only the magnetic core 111 is coupled in an annular shape (the laminated state of the electromagnetic core pieces 401 is omitted).

  The plurality of core members 110 assembled in an annular shape as described above are attached to a dedicated insert mold (not shown) together with the bearing 120, and then a molten resin is poured into the mold so that the core tip portion 111a is attached. The whole is integrally molded as a resin molding 130.

Here, the outer step coupling plane 111b1 and the inner step coupling plane 111b2 of the core rear end portion 111b of the magnetic core 111 will be described in detail with reference to the drawings. FIG. 6 is an explanatory diagram of a D portion in FIG. In order for the outer step coupling plane 111b1 and the inner step coupling plane 111b2 that are partially in contact with each other between the adjacent magnetic cores 111 in the axial direction of the output shaft 300 to always contact each other in the radial direction, at least FIG. ) And (b) as shown in FIG. In this case, the width X of the step coupling planes 111b1 and 111b2 is t in the radial direction (corresponding to the radial thickness of the magnetic core 111), and α is the angular pitch between the adjacent magnetic cores 111. Then, the angle formed by the line segment a1 (the line segment along the direction of the thickness t of the right magnetic core 111) and the line segment a2 (the line segment along the direction of the thickness t of the left magnetic core 11) is also α So,
X = t · sinα (1)
It becomes. Therefore, the width X is X ≧ t · sin α (2)
If set to, the adjacent magnetic cores 111 can always be brought into contact with each other in the radial direction.

  In this way, by allowing the outer step coupling plane 111b1 and the inner step coupling plane 111b2 to always contact each other in the radial direction, all the electromagnetic core pieces 401 constituting the magnetic core 111 are magnetically coupled to the adjacent magnetic core. Combined. Therefore, an annular magnetic yoke having a small magnetic resistance is formed at the core rear end 111b in the core member 110 in which a plurality of magnetic cores 111 are connected.

  In addition, as described above, the magnetic core 111 of the present embodiment is formed by punching an electromagnetic steel sheet with a press die to form a plurality of electromagnetic core pieces having a substantially E-shaped cross section, and laminating them. Yes, the electromagnetic core pieces used therein have the same shape, that is, one type. Therefore, for example, when the electromagnetic iron core piece 401 is punched from the electromagnetic steel sheet 400, it can be punched as shown in FIG. 7, so that the material yield can be improved.

  The shape of the electromagnetic core piece 401 is orthogonal to the direction of lamination of the first shape portion 401a having a shape corresponding to the surface shape orthogonal to the direction of lamination of the core front end portion 111a of the magnetic core 111 and the core rear end portion 111b. A shape corresponding to the surface shape, that is, a second shape portion 401b having an outer step portion 401b1 corresponding to the outer step-coupling plane 111b1 and an inner step portion 401b2 corresponding to the inner step-coupling plane 111b2, and a core body portion 111c are stacked. It is a substantially e-shape composed of a third shape portion 401c having a shape corresponding to a surface shape orthogonal to the direction.

DESCRIPTION OF SYMBOLS 100: Stator, 110: Core member, 111: Magnetic core, 111a: Core front-end | tip part, 111a1: Front end surface, 111b: Core rear-end part, 111c: Core body part, 111b1: Outer level | step difference coupling plane, 111b2: Inner level | step difference coupling Plane, 111b11: Bottom end surface, 111b21: Upper end surface, 112: Bobbin, 112a: Front flange, 112b: Rear flange, 112c: Winding body, 112a1, 112b1: Hook, 112a2, 112b2: Locking shaft, 112a3, 112b3: Engaging recess, 112a4, 112b4: engaging piece, 112b5: terminal block 200: rotor, 210: magnetic yoke, 220: permanent magnet 300: output shaft 400: electromagnetic steel plate, 401: electromagnetic iron core piece, 401a: first shape Part, 401b: second shape part, 401b1: outside step part, 401b2: inside step part 401c: third shape portion 500: case, 510: front case, 520: rear case, 530: outer case, 540, 440: bearing 600: stator, 610: core member, 611: magnetic core, 612: bobbin, 613: Coil 700: Rotor, 710: Magnetic yoke, 720: Permanent magnet 800: Output shaft

Claims (5)

A stator and a rotor are arranged opposite to each other along the axial direction of the output shaft of the rotor, and the rotor has a plurality of permanent magnets arranged circumferentially around the axis of the output shaft. In the axial gap type electric motor, the stator has a plurality of core members arranged in a circumferential direction around the axis of the output shaft, and the core members are connected to each other at a predetermined angular pitch.
Each core member includes a magnetic core in which steel plates of the same shape are laminated in the radial direction of the stator,
The magnetic core includes a core front end facing the permanent magnet, a core rear end for magnetically connecting the core members to each other to form an annular magnetic yoke, and the core rear end A core body part that connects between the part and the core tip part,
At one end and the other end in the circumferential direction at the core rear end, a rectangular coupling plane overlapping the core rear end of another core member adjacent in the circumferential direction in the axial direction is provided. Yes,
An axial gap type electric motor characterized by that. In the axial gap type electric motor according to claim 1,
The coupling plane provided at the one end in the circumferential direction of the core rear end is formed at a position where the one end is recessed toward the rotor along the axial direction, and the other end. The coupling plane provided in the axial gap type electric motor is characterized in that the other end is formed at a position recessed in the counter-rotor side along the axial direction. In the axial gap type electric motor according to claim 2,
When the circumferential length of the coupling plane is X, the radial length is t, and the angular pitch at which the core members are arranged is α, the circumferential length X is:
X ≧ t · sinα
Axial gap type electric motor characterized by being set to. In the axial gap type electric motor according to claim 1, 2, or 3,
The core member further covers the outer periphery of the magnetic core, leaving at least the front end surface of the core front end, and a front flange parallel to the front end surface of the core front end and a rear flange parallel to the rear end surface of the core rear end An axial gap type electric motor comprising: a bobbin having at least a core end portion protruding from the front flange toward the rotor side in the axial direction. In the axial gap type electric motor according to claim 1, 2, 3, or 4,
A hook is projected from one end side in the circumferential direction of the front flange and the rear flange, and a locking shaft is provided on the other end side to protrude in the axial direction and to be locked by the hook of the adjacent core member. The axial gap type electric motor is characterized in that the front end surface of the core front end protrudes further forward in the axial direction than the front end of the locking shaft.

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