JP2008312402A - Axial air-gap type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial air-gap type motor which suppresses vibration of rotors and outputs rotational driving force of the rotors with a main shaft. <P>SOLUTION: The first rotor 31 is coaxially fixed to an output shaft, while the other second rotor 32 is not connected to the output shaft 4, and is fixed to the first rotor 31 through an outer peripheral face of a stator 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an axial air gap type electric motor in which a pair of rotors are opposed to each other with a predetermined gap along the axial direction of the output shaft across a stator, and more specifically, connecting each rotor, The present invention relates to an axial air gap type electric motor that reduces the vibration of a rotor.

  For example, as shown in Patent Document 1, an axial air gap type motor is composed of a pair of rotors facing each other with a predetermined gap in the axial direction of the output shaft across a stator, compared to a general radial gap type motor. The axial length can be shortened.

  Each rotor has a disk-shaped rotor back yoke, and an output shaft is coaxially attached to the center thereof. In the rotor back yoke, a plurality of fan-shaped rotor magnets are annularly arranged around the output shaft.

  In this axial air gap type electric motor, the rotor magnet vibrates because the attraction and repulsion are repeated when the rotor magnet moves over between the magnetic poles of the stator. The vibration of the rotor is preferably suppressed as much as possible because it may cause problems such as vibration noise and a problem of contact of the stator with the rotor.

  Therefore, conventionally, vibration prevention measures have been taken, such as increasing the gap distance between the rotor and the stator or increasing the rigidity by increasing the thickness of the back yoke. Further, as another method, as shown in Patent Document 2, an outer peripheral edge of each rotor is connected by a cylindrical rotor ring so that vibration of the rotor can be restrained.

JP 2004-282899 A JP 2006-31688 A

  In the axial air gap type motor described in Patent Document 2, since the stator is completely covered with each rotor and the rotor ring, a power cable for supplying power to the stator is drawn out through the main shaft. ing.

  However, according to this, since the main shaft cannot be rotated, the rotational driving force cannot be extracted using the main shaft as an output shaft as in the prior art, and the rotational driving force generated by the rotor must be extracted by a member different from the main shaft. I must.

  Accordingly, in order to solve the above-described problems, an object of the present invention is to provide an axial air gap type electric motor that can suppress the vibration of the rotor and can output the rotational driving force of the rotor via the main shaft.

  In order to achieve the above-described object, the present invention has several features described below. The invention according to claim 1 is an axial air gap type electric motor in which the first and second rotors are arranged opposite to each other on the side surface of the stator with a predetermined gap along the axial direction of the output shaft. The one first rotor is coaxially fixed to the output shaft, and the other second rotor has an inner peripheral edge that is not connected to the output shaft, and an outer peripheral edge that has a predetermined connecting means. The first rotor is connected to the first rotor.

  According to a second aspect of the present invention, in the first aspect, the connecting means includes a side plate that is integrally provided upright from an outer peripheral end of a back yoke of the first rotor or the second rotor. When standing from the first rotor, the second rotor is connected, and when the side plate is standing from the second rotor, the first rotor is connected. .

  According to a third aspect of the present invention, in the first or second aspect, the inner peripheral edge side of the second rotor that is not connected to the output shaft is supported by a bearing provided between the stator and the stator. The axial air gap type electric motor according to claim 1, wherein the axial air gap type electric motor is provided.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, at the center of the second rotor, various cables connected to the stator are drawn out to the side surface of the second rotor. It is characterized in that an extraction hole is provided.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the side surface of the stator facing the second rotor is provided with a convex portion that is led out to the side surface of the second rotor through the extraction hole. It is characterized by being.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, a step surface on which a control board for controlling the stator is placed is provided on a part of the convex portion. A terminal pin of the stator is protruded.

  According to a seventh aspect of the present invention, in the fifth or sixth aspect, the rotor and the stator are accommodated in a bracket, a lid cover is attached to the open end of the bracket, and the bracket or the A fixing means for fixing the lid cover is provided.

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the output shaft is provided with a fixing member for fixing the first rotor to the output shaft. It is a feature.

  According to the first aspect of the present invention, the first rotor is fixed to the output shaft, the second rotor is not connected to the output shaft on the inner peripheral side, and the outer peripheral end is fixed to a part of the first rotor. Thus, not only can the vibration of the rotor be efficiently suppressed, but also the rotational driving force of the rotor can be taken out via the output shaft.

  According to the second aspect of the present invention, the connecting means includes a side plate that is erected integrally from the outer peripheral end of the back yoke of the first rotor or the second rotor along the side peripheral surface of the stator, By connecting the second rotor to the side plate, the rotors can be combined with each other without using a plurality of parts, and the vibration isolation characteristics are improved.

  According to the third aspect of the present invention, the other end of the second rotor is supported by the thrust ball bearing provided between the second rotor and the second rotor. Vibration can be suppressed more reliably.

  According to the fourth aspect of the present invention, a lead-out hole for drawing out various cables connected to the stator to the side surface of the second rotor is provided in the center of the second rotor, so that the gap between the rotors is provided. The cable can be easily pulled out from the sandwiched stator.

  According to the fifth aspect of the present invention, since the convex portion that is drawn out to the side surface of the second rotor is provided on the side surface of the stator that faces the second rotor, a part of the convex portion is interposed via the extraction hole. The cable can be easily pulled out by protruding the side surface of the second rotor.

  According to the invention described in claim 6, a step surface on which a control board for controlling the stator is placed is provided on a part of the convex portion, and the terminal pin of the stator is projected on the step surface. Positioning of the control board and electrical connection with the stator can be performed simultaneously, the control board can be stored without difficulty, and the rotor magnet position can be sensed by an on-board sensor on the control board adjacent to the second rotor. it can.

  According to the seventh aspect of the present invention, by providing the fixing means for fixing the bracket or the lid cover to a part of the convex portion, the stator can be firmly stored in the bracket.

  According to the invention described in claim 8, by providing the output shaft with the fixing member for firmly fixing the first rotor to the output shaft, the connection between the first rotor and the output shaft can be further strengthened. Thus, slippage between the output shaft and the output shaft can be prevented.

  Next, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. FIG. 1a is an exploded perspective view of an axial air gap type motor according to an embodiment of the present invention, and FIG. 1b is a cross-sectional view of the axial air gap type motor.

  As shown in FIG. 1a and FIG. 1b, this axial air gap type motor 1 is opposed to a stator 2 formed in a disc shape, with a predetermined gap (gap) between both sides of the stator 2 sandwiched between the stator 2 and the stator 2. The stator 2 and the rotor 3 are housed in a bracket 6.

  The stator 2 includes a plurality (9 in this example) of pole members 21 that are annularly arranged at equal intervals along a circumferential direction around the rotation axis of the output shaft 4. Each pole member 21 has the same configuration, and a coil 23 is wound around a core member having tooth surfaces 22a and 22b at both left and right ends.

  The core material is formed by laminating a plurality of electromagnetic steel plates formed in an H shape along the radial direction. The core material may be a magnetic powder formed by powder molding. In addition, when the skew for the cogging torque reduction is formed in the adjacent surface (slot surface) of each pole member 21, a vibration is reduced more.

  After each pole member 21 is connected in an annular shape by the connecting means, it is integrally molded with resin by insert molding together with the bearing portion 24. The bearing portion 24 is made of a metal sleeve fitting, and the outer ring of a pair of radial ball bearings 241 and 242 is held at the center, and the output shaft 4 is press-fitted into the inner ring.

  A spacer 243 that positions the distance between the first rotor 31 and the tooth surface 22a is provided between the first rotor 31 and the radial ball bearing 241. One end side of the output shaft 4 is drawn from the side surface (left side surface in FIG. 1 b) of the stator 2 to the outside of the bracket 6, and the other end is housed in the stator 2.

  Next, the rotor 3 has a first rotor 31 disposed opposite to one side surface (left side surface in FIG. 1b) of the stator 2 with a predetermined gap, and a predetermined surface on the other side surface (right side surface in FIG. 1b). And a second rotor 32 arranged opposite to each other.

  The first rotor 31 includes a disc-shaped back yoke 311 disposed substantially parallel to a plane including one tooth surface 22 a of the stator 2, and a circumferential surface of the stator 2 from the outer peripheral end of the back yoke 311. The back yoke 311 is provided with a plurality of, preferably fan-shaped, rotor magnets 33 in an annular shape so as to face the tooth surface 22a. ing.

  A flange 313 for receiving the second rotor 32 is provided at the other end of the side plate 312, and the second rotor 32 abuts along the flange portion 313. A shaft fixing hole 314 to which the output shaft 4 is attached is provided at the center of the back yoke 311, and the output shaft 4 is press-fitted into the shaft fixing hole 314.

  The second rotor 32 has a disk-shaped back yoke 321 disposed so as to be substantially parallel to the other tooth surface 22b of the stator 2, and the back yoke 311 includes a plurality of, preferably fan-shaped, yokes. The rotor magnet 33 is formed in an annular shape so as to face the tooth surface 22b.

  In the center of the second rotor 32, a lead-out hole 322 for pulling out the convex portion 26 of the stator 2 to the lid cover 62 side (right side surface in FIG. 1b) of the bracket 6 is coaxial with the axis of the output shaft 4 as the center. Is provided. The lead-out hole 322 has a size that allows at least the convex portion 26 to be pulled out, and is coaxially arranged at a predetermined interval from the outer surface of the convex portion 26. Therefore, the second rotor 32 is not connected to the output shaft 4.

  On one side surface (right side surface in FIG. 1 b) of the stator 2, a convex portion 26 is provided for pulling out a part of the stator 2 to the other side surface of the second rotor 32 whose one side surface faces the stator 2. . The convex portion 26 has a cylindrical shape integrally formed with a synthetic resin during the above-described insert molding, and protrudes coaxially with the axis of the output shaft 4.

  A step surface 261 on which the control board 5 for controlling the rotation of the stator 2 is placed is formed on a part of the convex portion 26. A terminal pin 262 connected to the coil 23 protrudes from the stepped surface 261. By inserting the terminal pin 262 into a through hole (not shown) provided in the control board 5, the terminal pin 262 becomes a guide. Thus, the control board 5 is attached to the step surface 261.

  A top portion 263 of the convex portion 261 is in contact with a lid cover 62 of the bracket 6 described later, and the top portion 263 is provided with a screw hole (not shown) for fixing the lid cover 62. In this example, the top portion 263 is provided with a screw hole as a fixing means, but a bolt screw or the like may be embedded. In addition, it may be fixed by welding.

  The control board 5 has a disk shape arranged to face the side surface of the second rotor 32, and an electronic component is mounted thereon. The control board 5 may be provided with a sensor (not shown) for sensing the position of the second rotor 32. In this case, the sensor is mounted so as to face the position detection magnet 34 provided opposite to the rotor magnet 33 with the back yoke 321 interposed therebetween.

  In this example, the second rotor 32 is supported by the first rotor 31 and is not connected to the output shaft 4, but as shown in FIG. 2, the side surface of the stator 2 and the second rotor 32 A thrust ball bearing 243 may be provided therebetween to support the inner peripheral side of the second rotor 32, and such an aspect is also included in the present invention. In FIG. 2, the same reference numerals are assigned to portions that are considered the same or the same.

  The second rotor 32 is fixed to the flange 313 of the first rotor 31 by projection welding, screwing, or the like. As a more preferable aspect, as shown in FIGS. It is preferable that positioning means for positioning the two rotors 32 on the first rotor 31 is provided.

  The positioning means shown in FIG. 3A is provided with a half-cut portion 341 made of unevenness on the opposed surfaces of the flange 313 and the second rotor 32. By matching these with each other, the first rotor 31 and the second rotor The rotor 32 is positioned. After positioning, the first rotor 31 and the second rotor 32 are bonded by welding such as projection welding.

  As another method for fixing the first rotor 31 and the second rotor 32, as shown in FIG. 3B, screw holes 342 are formed on the opposing surfaces of the flange 313 and the second rotor 32, and each screw The hole 342 may be screwed with a screw 343. A rivet or the like may be used in addition to the screw.

  In this case, as shown in FIG. 3C, the positioning means presses a part of the second rotor 32 to form the guide convex portion 344, and follows the inner diameter of the side plate 312 of the first rotor 31. The guide protrusions 344 may be matched with each other.

  Further, as another positioning means, as shown in FIG. 3D, a step surface 345 is provided on the surface of the second rotor 32 facing the first rotor 31, and the first rotor 31 is moved along the step surface 345. The flange 313 may be fitted.

  In this example, the output shaft 4 is fixed to the first rotor 31 by press fitting, but the first rotor 31 is preferably fixed more firmly in order to support the second rotor 32. An example thereof is illustrated in FIGS.

  As shown in FIG. 4A, a fixing member 7 for fixing the first rotor 31 more firmly is coaxially attached to the output shaft 4. The fixing member 7 has a cylindrical shape that is press-fitted along the output shaft 4 at the center, and a flange 71 that receives the back yoke 311 of the first rotor 31 is formed on the outer peripheral surface.

  The flange 71 is provided with a screw hole (not shown). After the back yoke 311 is brought into contact with the flange 71, the first rotor 31 is output by being fixed to the flange 71 with a screw 72. It can be attached to the shaft 4. In this example, the fixing member 7 is integrally provided with a spacer 711 for positioning between the flange 71 and the radial ball bearing 241.

  As another method, as shown in FIG. 4 (b), a thread is formed on a support shaft 73 into which the back yoke 311 of the fixing member 7 is inserted, and a nut 74 is attached thereto to attach the first rotor. 31 may be fixed.

  Further, in place of the fixing member 7, as shown in FIG. 4C, a part of the mounting hole 314 may be formed into a cylindrical shape by burring, and the output shaft 4 may be press-fitted therein, Also by this, since the contact area with respect to the output shaft 4 increases, it can fix more firmly.

  The bracket 6 includes a cup-shaped bracket body 61 having a depth that covers the stator 2 and the rotor 3, and a lid cover 62 that closes the open end of the bracket body 61. In the center of the bracket main body 61, a shaft extraction hole 611 for extracting the output shaft 4 is provided.

  The lid cover 62 has a disk shape that closes the opening of the bracket body 61, and is fixed to the top 263 of the convex portion 26 of the stator 2 by screws as described above. In the present invention, the configuration of the bracket 6 is an arbitrary matter.

  Next, an example of the assembly procedure of the axial air gap type electric motor 1 will be described with reference to FIGS. In the following description, it is assumed that the stator 2 and the rotor 3 are assembled in advance.

  First, the output shaft 4 drawn out from the stator 2 is press-fitted into the bearing hole 314 of the first rotor 31 and is pushed in until the spacer 243 contacts the radial ball bearing 241. Thereby, the space | interval of the 1st rotor 31 and the teeth surface 22a is positioned. Next, the second rotor 32 is attached along the flange 313 of the first rotor 31.

  At this time, the 1st rotor 31 and the 2nd rotor 32 are positioned in the mutually symmetrical position via the positioning means shown to Fig.3 (a)-(d). Thereafter, the flange 313 of the first rotor 31 and the second rotor 32 are integrally fixed by projection welding.

  Thereby, the convex part 26 of the stator 2 protrudes from the extraction hole 322 of the second rotor 32. Next, the control substrate 5 is mounted along the step surface 261 by attaching the control substrate 5 to the step surface 261 of the convex portion 26 using the terminal pin 262 as a guide.

  Finally, after the cord 51 pulled out from the control board 5 is pulled out from the bracket main body 61, the lid cover 62 is put on the opening of the bracket main body 61, and the top portion 261 of the convex portion 26 and the lid cover 62 are fixed integrally. To do. As described above, the stator 2 and the rotor 3 are integrally assembled in the bracket 61 by a series of operations.

  In this example, the first rotor 31 and the second rotor 32 are connected by a side plate 312 formed integrally with the first rotor 31, but the side plate 312 may be molded as a ring-shaped separate body. Alternatively, the side plates may be formed integrally with each of the first rotor 31 and the second rotor 32.

1 is an exploded perspective view of an axial air gap type electric motor according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of a main part of the axial air gap type electric motor according to the embodiment. The principal part sectional drawing of the state which applied the thrust ball bearing to the said axial air gap type electric motor. (A)-(d) The fragmentary sectional view explaining the alignment means of a 1st rotor and a 2nd rotor. (A)-(c) Explanatory drawing explaining the attachment aspect of a 1st rotor and an output shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Axial air gap type motor 2 Stator 21 Pole member 22 Teeth surface 23 Coil 24 Bearing part 26 Convex part 3 Rotor 31 1st rotor 311 Back yoke 312 Side plate 313 Flange 32 2nd rotor 321 Rotor 322 Pull-out hole 33 Rotor magnet 4 Output shaft 5 Control board 6 Bracket

Claims (8)

In the axial air gap type electric motor in which the first and second two rotors are arranged opposite to each other with a predetermined gap along the axial direction of the output shaft on the side surface of the stator,
The one first rotor is coaxially fixed to the output shaft, and the other second rotor has an inner peripheral edge that is not connected to the output shaft, and an outer peripheral edge that has a predetermined connecting means. And an axial air gap type electric motor connected to the first rotor via the first air rotor.   The connecting means includes a side plate that is integrally provided upright from an outer peripheral end of a back yoke of the first rotor or the second rotor, and when the side plate is provided upright from the first rotor, the second plate The axial air gap type electric motor according to claim 1, wherein when the rotor is connected and the side plate is erected from the second rotor, the first rotor is connected.   3. The axial air gap according to claim 1, wherein an inner peripheral edge side of the second rotor that is not connected to the output shaft is supported by a bearing provided between the stator and the stator. Type electric motor.   4. The lead hole for drawing various cables connected to the stator to the side surface of the second rotor is provided at the center of the second rotor. 5. An axial air gap type electric motor described in 1.   5. The axial air gap according to claim 4, wherein the side surface of the stator facing the second rotor is provided with a convex portion that is led out to the side surface of the second rotor through the extraction hole. Type electric motor.   A step surface on which a control board for controlling the stator is placed is provided at a part of the convex portion, and a terminal pin of the stator is projected from the step surface. The axial air gap type electric motor according to claim 5.   The rotor and the stator are housed in a bracket, a lid cover is attached to an open end of the bracket, and a fixing means for fixing the bracket or the lid cover is provided on the convex portion. An axial air gap type electric motor according to claim 5 or 6.   8. The axial air gap type electric motor according to claim 1, wherein the output shaft is provided with a fixing member for fixing the first rotor to the output shaft. 9.

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