JP2005130548A - Permanent magnet generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet generator enhancing electromotive force by minimizing an air gap between a permanent magnet of a rotor and a salient pole part of a stator while reducing manufacturing cost. <P>SOLUTION: Tapered surfaces 2a and 2b becoming higher toward an outer circumferential direction are formed on opposite end faces of a permanent magnet 2 in an axial direction. A plurality of permanent magnets 2 are arranged along an inner side face of a cylindrical section 3 of a rotor while being held by an annular bottom side spacer 7 and an opening forward end side spacer 6. An annular retaining plate 9 is arranged on an outside of the opening forward end side spacer 6. When a caulking part 3a provided at an end part of the cylindrical section 3 of a rotor is caulked inward, the opening forward end side spacer 6 is pressed to the permanent magnet 2 side through an annular retaining plate 9 and secured in place and the forward end of the salient pole part of a stator core 11 faces the inner side face of the permanent magnet 2 directly. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a magnet generator that is mounted on an engine such as a motorcycle, a buggy, or a snow vehicle, and is used for charging an on-board battery or supplying electric power to an electric device.

As shown in the sectional views of FIGS. 7 and 8, the rotor of this type of magnetic generator is generally provided with a boss portion 24 at the center of a rotor body 21 formed in a cup shape, and the outer periphery of the rotor body 21. A rotor cylindrical portion 23 is formed on the wall, and a plurality of annular permanent magnets 22 are provided along the inner periphery of the rotor cylindrical portion 23, and a cylindrical magnet protective cover is provided inside the permanent magnet 22. 25 is press-fitted (see, for example, Patent Document 1 below). Also, in this type of magnet generator, the air gap between the stator and the stator disposed inside the rotor is made as small as possible, the magnetic flux density passing through the air gap is increased, and the electromotive force of the generator is increased. I try to make it high.
Japanese Patent Laid-Open No. 2002-247821

  However, in the conventional magnetic generator of this type, since the cylindrical magnet protective cover 25 is attached to the inner side of the permanent magnet 22 disposed on the inner side of the rotor, the thickness of the magnet protective cover 25 is reduced. As a result, the gap between the permanent magnet 22 of the rotor and the salient pole part of the stator is increased, and the magnet protective cover 25 interposed therebetween reduces the magnetic flux density generated between the permanent magnet 22 and the power generating coil of the salient pole part. There was a problem that electric power decreased.

  For this reason, in recent years, rare earth magnets with higher performance tend to be used in place of the ferrite magnets generally used as the permanent magnets 22. However, although rare earth magnets have a higher magnetic force per unit volume than ferrite magnets and can improve the electromotive force of the generator, the price is high, so the use of many rare earth magnets increases the manufacturing cost of the generator. There was a problem of becoming.

  The present invention has been made in view of the above points, and can minimize the air gap between the permanent magnet of the rotor and the salient pole portion of the stator, improve the electromotive force, and can be manufactured at low cost. It is an object of the present invention to provide a possible magnet generator.

In order to achieve the above object, a magnet generator according to claim 1 of the present invention is configured such that a rotor cylindrical portion is formed on an outer peripheral wall of a rotor body formed in a cup shape by providing a boss portion at the center. A rotor in which a plurality of permanent magnets are attached along the inner surface of
A stator in which a power generation coil is wound around a plurality of salient pole portions projecting from a stator core, and a tip portion of the salient pole portion is disposed inside the rotor so as to face the permanent magnet of the rotor;
A taper surface that increases in the outer circumferential direction is formed on both end surfaces in the axial direction of the permanent magnet, and the plurality of permanent magnets are annular bottom portions along the inner surface of the rotor cylindrical portion. Between the side spacer and the opening front end spacer, an annular retainer plate is provided outside the opening front end spacer, and the caulking portion provided at the end of the rotor cylindrical portion is caulked inward. Thus, the opening tip side spacer is pressed against and fixed to the permanent magnet side via an annular holding plate, and the salient pole tip of the stator core is directly opposed to the inner surface of the permanent magnet.

  In this case, a tapered surface corresponding to the end surface of the permanent magnet can be formed on the contact surface of the bottom side spacer and the opening tip side spacer with the permanent magnet.

  According to a third aspect of the present invention, the bottom side spacer and the opening tip side spacer are provided with protruding portions that are fitted between the permanent magnets and the permanent magnets at predetermined intervals, and the protruding portion permanent magnets and A small convex portion is provided on the surface to be contacted, and the convex portion can be fitted and fixed between the permanent magnet and the permanent magnet by an interference fit.

  In this magnet generator, the rotor is driven to rotate by the engine, and as the rotor rotates, magnetic flux flows between the permanent magnet mounted on the inner side of the rotor and the stator core. By cutting, an induced electromotive force is generated in the power generation coil, and power generation is performed. At this time, magnetic flux flows between the tip of each salient pole part of the stator core and the permanent magnet of the rotor facing it, and an electromotive force is generated in the power generation coil, but the tip of the stator core salient pole part directly faces the inner surface of the permanent magnet. Therefore, the gap between the tip of the salient pole part and the permanent magnet can be made smaller than when a conventional magnet protective cover is interposed, thereby increasing the magnetic flux density between them and the same type of conventional magnet The electromotive force can be increased from the generator.

  Further, since the electromotive force increases, it is not necessary to increase the shape of the expensive rare earth magnet, or an inexpensive ferrite magnet can be used, thereby preventing an increase in manufacturing cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a cross-sectional view of a rotor 1 and a stator 10 of a magnet generator. The main body of the rotor 1 is formed in a substantially cup shape by hot forging, cutting, or the like using a magnetic metal material.

  A boss portion 4 is formed at the center of the main body of the rotor 1, and a tapered hole 4 a is formed in the boss portion 4 so as to be fitted to the crankshaft of the engine. A surface 4b is provided, and a screw 4c for screwing when the rotor 1 is pulled out is provided on the outer peripheral portion of the boss portion 4. A rotor cylindrical portion 3 is formed on the outer peripheral wall of the main body of the rotor 1, and a rotor bottom portion 5 is integrally formed between the rotor cylindrical portion 3 and the boss portion 4. A plurality of opening holes 5a are formed in the rotor bottom 5 for air cooling.

  A permanent magnet 2 made of a ferrite magnet or a rare earth magnet is attached to the inner peripheral surface of the rotor cylindrical portion 3. The permanent magnet 2 is divided into a plurality of parts, and as shown in FIG. 4, each permanent magnet 2 is arranged inside the rotor cylindrical portion 3 so as to form an annular shape with a predetermined interval therebetween. And is attached in such a manner that it is sandwiched between an opening tip side spacer 6 and a bottom side spacer 7 which will be described later.

  As shown in FIGS. 4 and 6, each permanent magnet 2 is formed in a plate shape having a curved surface along the circumference of the rotor cylindrical portion 3, and in particular, on the end surface on the opening tip side of each permanent magnet 2. As shown in FIG. 3, a tapered surface 2a is formed which is higher on the outer peripheral side and lower on the inner peripheral side. In addition, a tapered surface 2b that is higher on the outer peripheral side and lower on the inner peripheral side is also formed on the end surface on the bottom side of each permanent magnet 2 (FIG. 2). In this specification, the “opening tip side” with respect to the rotor 1 means the opening side of the rotor 1 on the left side of FIG. 2 where the caulking portion 3a of the rotor cylindrical portion 3 is located. The “bottom side” means the bottom side on the right side of FIG. 2 where the rotor bottom 5 of the rotor 1 is located. Further, “high on the outer peripheral side and lower on the inner peripheral side” means the height when the axial direction of the rotor is up and down.

  In order to attach each permanent magnet 2 to a predetermined position on the inner peripheral side of the rotor cylindrical portion 3, a cylindrical, nonmagnetic (made of synthetic resin) bottom side spacer 7 is permanently provided on the bottom side inside the rotor cylindrical portion 3. Arranged between the magnet 2 and the bottom part, an annular, non-magnetic, open tip side spacer 6 is arranged between the permanent magnet 2 and the caulking part 3a on the opening tip side of the rotor cylindrical part 3. It is installed.

  The opening front end side spacer 6 is formed in an annular shape that can be fitted to the inner peripheral surface of the rotor cylindrical portion 3 and, as shown in FIGS. 2 and 5, a tapered surface that presses the tapered surface 2 a of each permanent magnet 2. 6a is formed on the magnet side, and a convex portion 6b is formed between the tapered surface 6a and the tapered surface 6a. By inserting the convex portion 6b between the permanent magnet 2 and the permanent magnet 2, each permanent The magnets 2 can be arranged on the circumference at predetermined intervals. Further, as shown in FIGS. 5 and 6, small convex portions 6c are formed on both sides of each convex portion 6b, and when each permanent magnet 2 is press-fitted between the convex portions 6b and 6b, plastic deformation occurs. It is possible to assemble with an interference fit.

  Furthermore, the bottom side spacer 7 disposed on the rotor bottom side is formed in a cylindrical shape that can be fitted to the inner peripheral surface of the rotor circumferential part 3, and on the tip side (permanent magnet 2 side), As shown in FIG. 5, a taper surface 7a for pressing the taper surface 2b of each permanent magnet 2 is formed, and a convex portion 7b is formed between the taper surface 7a and the taper surface 7a. By inserting between the permanent magnet 2 and the permanent magnet 2, each permanent magnet 2 can be arrange | positioned on a circumference with a predetermined space | interval. Further, as shown in FIG. 5, small convex portions 7c are formed on both sides of each convex portion 7b, and when each permanent magnet 2 is press-fitted between the convex portions 7b and 7b, it is plastically deformed. It is possible to assemble with interference fit.

  An annular retainer plate 9 is inserted at the distal end portion of the rotor cylindrical portion 3, and a caulking portion 3 a for fixing the opening distal end side spacer 6 through the annular retainer plate 9 is formed with a reduced thickness. The

  When assembling the rotor 1 configured as described above, for example, a cylindrical jig is first prepared, and a plurality of permanent magnets 2 are assembled around the opening tip side spacer 6 and the bottom side spacer 7 around the jig. At this time, the bottom side spacer 7 is arranged on the upper side, and the opening tip side spacer 6 is first fitted into the outer periphery of the jig, and each permanent magnet 2 is interposed between the convex portion 6b and the convex portion 6b of the opening tip side spacer 6. Fit. Then, the bottom side spacer 7 is fitted from above the permanent magnets 2 so that the convex portions 7 b of the bottom side spacer 7 are fitted between the permanent magnets 2 and 2.

  Next, the rotor cylindrical portion 3 of the rotor 1 with the opening down is attached to the assembly of the opening tip side spacer 6, the permanent magnet 2, and the bottom side spacer 7 assembled on the outer periphery of the jig as described above. Press fit to cover the assembly.

  At this time, the assembly of the opening tip side spacer 6, the permanent magnet 2 and the bottom side spacer 7 is compressed inward by the rotor cylindrical portion 3, and the convex portions 6 b and 7 b of the opening tip side spacer 6 and the bottom side spacer 7 are compressed. Since the small convex portions 6 c and 7 c are formed on both sides, the small convex portions 6 c and 7 c are plastically deformed and brought into an interference fit state during press-fitting. Pressed against the inner peripheral surface, the opening tip side spacer 6, the bottom side spacer 7, and the permanent magnet 2 are firmly assembled.

  Then, an annular holding plate 9 is placed on the opening front end side spacer 6, and finally, the caulking portion 3 a at the front end of the rotor cylindrical portion 3 is caulked inward and fixed. Accordingly, a large number of permanent magnets 2 are assembled at predetermined positions in the rotor cylindrical portion 3 in a state where the permanent magnets 2 are sandwiched between the opening front end side spacer 6 and the bottom side spacer 7.

  As shown in FIGS. 2 and 3, the assembled state of many permanent magnets 2 on the inner peripheral surface of the rotor cylindrical portion 3 is such that the outer peripheral side is raised on the front end side surface and the bottom side surface of each permanent magnet 2. Tapered surfaces 2a and 2b are formed, and this tapered surface 2a is pressed by the tapered surface 6a of the opening end side spacer 6 and the tapered surface 2b is pressed by the tapered surface 7a of the bottom side spacer 7, thereby each permanent surface Since the magnet 2 is subjected to a force pressed against the rotor cylindrical portion 3, each permanent magnet 2 can be held at a predetermined position in the rotor cylindrical portion 3 without a conventional magnet protective cover.

  In addition, when the use environment of the generator is severe, if the permanent magnet 2 is further bonded to the rotor cylindrical portion 3 using an adhesive, the permanent magnet 2 is sufficiently prevented from falling off even in a severe environment. be able to.

  On the other hand, as shown in FIG. 1, the stator 10 is configured by winding a power generation coil 13 around a plurality of salient pole portions projecting from the outer peripheral portion of the stator core 11. A stator core 11 formed by laminating a large number of core plates formed by punching steel plates into a predetermined shape has a plurality of salient poles protruding radially at predetermined angular intervals on the outer periphery of a ring-shaped yoke portion. End plates are disposed on the outermost sides on both sides of a large number of core plates formed and stacked.

  The end plate basically has substantially the same shape as the core plate, but its tip is bent outward to form a flange shape in order to hold the wound power generation coil 13. . The laminated core plate and end plate are fixed by caulking together by inserting a rivet 14 into a hole formed in the ring-shaped yoke portion. Then, after the surface of each salient pole portion is coated with an epoxy resin, the generator coil 13 is wound by a predetermined number of turns.

  The stator 10 thus configured is fastened and fixed at a predetermined position inside an engine casing (not shown) by inserting a fixing bolt into an attachment hole of the ring-shaped yoke portion of the stator core 11. On the other hand, the rotor 1 covers the outer peripheral portion of the stator 10 at the tip of the crankshaft of the engine (not shown), and the inner peripheral surface of the permanent magnet 2 inside the rotor cylindrical portion 3 and the tip of the salient pole portion of the stator core. In a state in which a slight gap is formed between them, the fastening is fixed.

  In this way, with the stator 10 and the rotor 1 mounted at predetermined positions of the engine, the tips of the salient pole portions of the stator 10 directly face the inner surface of the permanent magnet 2 of the rotor 1 as shown in FIG. Thus, the gap between the salient pole portion and the permanent magnet 2 can be reduced to the minimum state by the amount that the conventionally used magnet protective cover is not interposed.

  In the magnet generator having such a configuration, the rotor 1 is driven to rotate by the engine, and a magnetic flux is generated between the permanent magnet 2 mounted inside the rotor 1 and the tip of the salient pole portion of the stator core 11 of the stator 10 as the rotor 1 rotates. When the power generation coil 13 of the stator 10 that flows and relatively rotates cuts the magnetic flux, an induced electromotive force is generated in the power generation coil 13 to generate power. As described above, since the gap between the stator 10 and the permanent magnet 2 of the rotor 1 is set to be narrow, the magnetic flux density generated therebetween increases, and the electromotive force can be increased. Further, by increasing the magnetic flux density, it is possible to use a smaller ferrite magnet or rare earth magnet for the permanent magnet 2, thereby preventing an increase in manufacturing cost. Furthermore, since the conventionally used cylindrical magnet protective cover is not required, a material for the magnet protective cover and a step of deep drawing it with a press or the like are not required, and the manufacturing cost can be reduced.

  In the above embodiment, the small convex portions 6c are provided on both sides of each convex portion 6b of the opening front end side spacer 6, and the small convex portions 7c are provided on both sides of each convex portion 7b of the bottom side spacer 7. Small protrusions 6c and 7c can be provided on either side, or a shape that allows an interference fit without such small protrusions 6c and 7c, or a permanent magnet in the rotor. If the spacers are formed so that they can be assembled individually, it is possible to assemble each permanent magnet 2 while holding the permanent magnets 2 between the opening tip side spacer 6 and the bottom side spacer 7.

  As described above, according to the magnet generator of the present invention, since the tip of the salient pole portion of the stator core is directly opposed to the inner surface of the permanent magnet, the projecting portion is more difficult than the case where a conventional magnet protective cover is interposed. The gap between the pole tip and the permanent magnet can be reduced, thereby increasing the magnetic flux density between them and increasing the electromotive force over a conventional magnet generator of the same type. In addition, since the electromotive force increases, it is not necessary to increase the shape of the expensive rare earth magnet, or an inexpensive ferrite magnet can be used, thereby preventing an increase in manufacturing cost.

It is sectional drawing of the rotor and stator of a magnet type generator which show one Embodiment of this invention. It is sectional drawing of the rotor of the generator. It is a partial expanded sectional view of the rotor. It is IV-IV sectional drawing of FIG. FIG. 5 is a partially enlarged arrow view of a portion indicated by an arrow V in FIG. 4. It is VI-VI expanded sectional drawing of FIG. FIG. 7 is a VII-VII cross-sectional view of a conventional rotor 21. It is VIII-VIII sectional drawing of the conventional rotor 21. FIG.

Explanation of symbols

1-rotor 2-permanent magnet 2a, 2b-tapered surface 3-rotor cylindrical portion 3a-caulking portion 4-boss portion 5-rotor bottom portion 6-opening end side spacer 7-bottom end side spacer 9-annular retainer plate 10-stator 11-stator core 13-generating coil

Claims (3)

A rotor cylindrical portion is formed on the outer peripheral wall of the rotor body formed in a cup shape by providing a boss portion at the center, and a rotor in which a plurality of permanent magnets are attached along the inner surface of the rotor cylindrical portion;
A stator in which a power generation coil is wound around the plurality of salient pole portions projecting from the stator core, and a tip portion of the salient pole portion is disposed inside the rotor so as to face the permanent magnet of the rotor;
In the magnet generator with
Tapered surfaces that increase in the outer circumferential direction are formed on both end surfaces of the permanent magnet in the axial direction, and the plurality of permanent magnets are formed along the inner side surface of the rotor cylindrical portion with an annular bottom side spacer and opening tip. An annular retainer plate is disposed on the outer side of the opening front end side spacer, and a caulking portion provided on an end of the rotor cylindrical portion is caulked on the inner side to dispose the circle. A magnet type power generation characterized in that the opening tip side spacer is pressed against and fixed to the permanent magnet side via an annular holding plate, and the salient pole tip of the stator core is directly opposed to the inner surface of the permanent magnet. Machine.   The magnet generator according to claim 1, wherein a taper surface corresponding to an end surface of the permanent magnet is formed on a contact surface of the bottom side spacer and the opening tip side spacer with the permanent magnet.   On the bottom side spacer and the opening tip side spacer, convex portions that fit between the permanent magnets protrude from the permanent magnet at a predetermined interval, and a small convex portion is formed on a surface of the convex portion that contacts the permanent magnet. The magnet type generator according to claim 1, wherein the projection is inserted and the convex portion is inserted between the permanent magnets by an interference fit.

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