JP3999358B2 - Cylindrical radial gap type rotating electrical machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a small cylindrical radial gap type rotating electrical machine having a permanent magnet in a rotor. In particular, in a rotating electrical machine having a magnetic circuit configuration in which an armature is composed of a stator ring portion and a plurality of salient pole portions, the salient pole shape and the stator ring shape are devised to ensure their mechanical / magnetic coupling while rotating. The present invention relates to a salient pole structure of a DC brushless motor with improved heat dissipation of the electric machine itself.
[0002]
[Prior art]
A configuration of a rotating electrical machine in which a plurality of salient poles wound with a stator coil are radially arranged as viewed from the rotation axis, and the length of the salient poles in the axial direction is substantially the same as the length of the opposing rotor magnet is patented. Application No. 306115 in 1997.
[0003]
[Problems to be solved by the invention]
With this method, it is possible to sufficiently secure the cross-sectional area of the salient pole, so that the magnetic saturation can be improved. However, since the armature is composed of the stator ring part and the plurality of salient pole parts, There is a drawback that the efficiency of the rotating electrical machine (motor) deteriorates depending on the mechanical / magnetic coupling. In addition, since each salient pole is not exposed at all from the outer peripheral surface of the stator ring, the heat inside the motor (particularly generated by the salient pole and the coil wound around it) cannot be effectively released outside the motor. There were drawbacks.
[0004]
The present invention aims to remedy the above-mentioned conventional drawbacks, and its purpose is to provide a core-shaped radial gap small cylindrical rotating electrical machine having a permanent magnet in a rotor and having a core of the same shape. To provide a structure of a rotating electrical machine that is easy to assemble and has good heat dissipation characteristics, without using a so-called conventional lamination structure laminated in the axial direction, and an armature having a structure of a stator ring and a plurality of salient poles. It is in. In particular, according to the present invention, the shape of the joint portion between the stator ring and the salient pole is devised to sufficiently stabilize the mechanical coupling force, and at the same time, a part of the salient pole is actively moved outward from the stator ring surface. The object is to provide a motor structure that protrudes and has good heat dissipation.
[0005]
[Means for Solving the Problems]
According to one aspect of the present invention, a cylindrical stator ring constituting the yoke of the stator;
A rotating shaft that holds the rotor magnet and is rotatably supported on both end faces of the stator ring;
A plurality of salient poles disposed on the inner side of the stator ring and provided with stator windings to face the magnetic poles of the rotor magnet;
In a cylindrical radial gap type rotating electrical machine having
The salient pole has a substantially T-shaped axial cross-section, the I-shaped cross-section perpendicular to the rotation axis, and the pole teeth that are the upper end surface of the T-shape are opposed to the outer peripheral surface of the rotor magnet. Is disposed and mechanically fitted and fixed to a penetrating portion provided in the stator ring at the lower end of the salient pole, and at least a part of the lower end of the salient pole is protruded from the outer peripheral surface of the stator ring,
The salient pole lower end has a first slit,
The penetrating portion provided in the stator ring is configured by a second slit that extends in the axial direction from one end of the stator ring toward the other end and is fitted to the first slit. A cylindrical radial gap type rotating electrical machine is provided.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side sectional view in the axial direction of an inner rotor type DC brushless motor according to the present invention, and FIG. 2 is a half sectional front view. As can be seen from these drawings, the inner rotor type DC brushless motor according to the present invention has a cylindrical stator ring 1 on the outer periphery. The stator ring 1 serves as a yoke for the stator. Flange 2 and 2 are attached to both ends of the stator ring 1. Bearings 3 and 4 are fixed to the flanges 2 and 2, and a rotary shaft 5 is rotatably supported by these bearings 3 and 4.
[0007]
As shown in FIG. 1, a cylindrical sleeve 6 is fitted to the rotary shaft 5, and a rotor magnet 7 as a field magnetic pole made of a rare earth synthetic resin permanent magnet is fitted on the outer periphery of the sleeve 6. It is. On the outer surface of the rotor magnet 7, N poles and S poles that are long in the direction of the rotation axis are alternately magnetized 12 poles along the circumference. A rotor magnet position detection magnet 8 for detecting the rotational position of the rotor magnet 7 is attached to the right end edge of the rotor magnet 7 separately from the rotor magnet 7, and the rotor magnet position detection magnet 8 includes Many N poles and S poles are alternately magnetized. A spacer 9 is loosely fitted between the sleeve 6 and the bearing 4, and the rotor magnet 7, the sleeve 6, and the spacer 9 constitute a rotor portion 10. A thrust washer 11 is interposed on the rotary shaft 5 between the spacer 9 and the bearing 4, and a thrust washer 12 is also interposed between the rotor magnet 7 and the bearing 3 to absorb play in the thrust direction of the rotor unit 10. At the same time, the number of inserted sheets is adjusted so that the axial positional relationship of the rotor is appropriate. The rotor magnet 7 may be an alloy or a sintered permanent magnet.
[0008]
Nine salient poles 14 are provided on the inner side of the stator ring 1 so as to face the rotor magnet 7 through the gap 13. The salient pole 14 is composed of a laminated body (FIG. 4) in which a plurality of T-shaped silicon steel plates 14 ′ shown in FIG. 3 are stacked, and a slit 16 is formed in the root portion 15. Further, as shown in FIG. 5, the stator ring 1 is also formed with a slit 17, and the salient pole 14 inserted into the slit 17 of the stator ring 1 from the left in FIG. Thus, the salient pole 14 is fixed in close contact with the inner surface of the stator ring 1. A stator winding 20 is wound around the salient pole 14 via a bobbin 19. The bobbin 19 and the stator winding 20 constitute a fixed magnetic pole 21 together with the salient pole 14. A plate-like printed wiring board 22 is attached to the side end of the bobbin 19. On the printed wiring board 22, an electronic component 23 for a motor drive circuit is placed, and necessary electrical wiring is provided, and the rotor is opposed to a plurality of magnets formed on the rotor magnet position detection magnet 8. Three Hall elements 24 for detecting the position of are mounted. A lead wire 25 such as an FPC that connects to an external electric circuit is attached to the end of the printed wiring board 22, and the motor rotates when a necessary power source and signal are applied thereto.
[0009]
FIG. 6 is a perspective view showing one fixed magnetic pole 21. As can be seen from FIG. 6, the bobbin 19 has a straight or tapered square hole 26 at the center so that the root 15 of the T-shaped salient pole 14 can be inserted. Further, the lower end portion of the T-shaped salient pole 14 is contacted / fixed to the stator ring 1. The bobbin 19 is integrally formed of synthetic resin, and a terminal 27 is inserted into the lower end portion of the flange portion 19a, and the leading end 29 of the lead wire 28 of the stator winding 20 is pulled up here. The terminal 27 is inserted into the printed wiring board 22 and soldered thereto . As shown in FIG. 7, a pole for converging magnetic flux having a long quadrilateral shape with an insertion hole 31 through which the tip of the pole tooth 30 is inserted at the center is formed around the pole tooth 30 provided at the tip of the salient pole 14. A tooth plate 32 is fitted. In the present invention, a fixed magnetic pole 21 composed of a plurality of salient poles 14 around which a stator winding 20 is wound is fixed to the inside of the stator ring 1 to constitute a stator portion. The flange portion of the bobbin 19 on the salient pole lower end portion 14 ″ side has a curvature corresponding to the inner peripheral surface of the stator ring 1.
[0010]
Here, the detailed structure of the stator ring 1 will be described with reference to FIG. FIG. 5 is an enlarged perspective view of the stator ring 1. Since the stator ring 1 forms a part of the magnetic circuit, it needs to be a soft magnetic material. In the embodiment of the present invention, pure iron is used as the material. The stator ring 1 is provided with slits 17, 17... Equal to the number of salient poles along the axial direction, and a slit 16 provided at the salient pole lower end portion 14 "is inserted into the slit 17. As a result, the stator ring 1 and the salient pole 14 can be mechanically and magnetically connected to each other, and the salient pole lower end portion 14 ″ protrudes from the outer periphery of the stator ring 1 as shown in FIGS. As a result, the heat radiating surface area on the outer periphery of the motor is increased, and the heat dissipating property is remarkably increased in that one end closest to the heat generating portion is directly projected on the outer periphery of the motor.
[0011]
The groove width of the slit 16 of the salient pole 14 is equal to or smaller than the thickness of the stator ring 1, and the groove width of the slit 17 of the stator ring 1 is equal to the circumferential width of the salient pole 14 or By making it narrower than this and assembling while press-fitting each, the magnetic coupling is high and the mechanical rigidity can be increased.
[0012]
FIG. 6 is a perspective view showing a state in which the salient pole 14 is inserted into the square hole 26 of the bobbin 19 after the stator winding 20 is wound around the bobbin 19 as described above. Needless to say, the assembly in this state is assembled to the stator ring 1 in the required number and in a radial manner. Further, a pole tooth plate 32 for converging the magnetic flux is provided around the tip of the pole tooth 30. By attaching the pole tooth plate 32 for converging the magnetic flux, the magnetic flux from the rotor magnet 7 is provided. Is effectively linked to the salient poles 14, and at the same time, the curvature of the pole tooth plate 32 makes the air gap width seen in the circumferential direction unequal, and the cogging / torque The ripple can be improved. Further, the pole teeth 30 are fitted with the pole teeth plate 32 for converging the magnetic flux, and as a result, vibration due to the excitation of the salient poles is reduced and the noise is reduced.
[0013]
Next, a second embodiment of the present invention will be described with reference to FIGS. In the description of the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals in the drawings, and the description of the parts that need not be described is omitted. The feature of the second embodiment is an example in which the slit 17 is not provided in the stator ring 1 but the elongated square hole 33 is provided in the stator ring 1 for pole coupling of the stator ring 1 and the salient pole 14. is there. In addition, the lower end portion 14 ″ of the salient pole 14 protrudes from the inner side direction of the stator ring 1 to the outer peripheral direction from the square hole 33, and both ends of the lower end portion 14 ″ are mechanically bent on the outer periphery of the stator ring 1, thereby Connect and fix.
[0014]
FIG. 9 is a perspective view of the salient pole 14 used in the second embodiment. The salient pole 14 has an approximately T-shaped axial cross-sectional shape, and is composed of four parts, similar to those shown in FIGS. 3 and 4. That is, a portion of the pole teeth 30 facing the rotor magnet 7, a root portion 15 for housing the bobbin-wound stator winding 20, a portion protruding from the outer periphery of the stator ring 1 at the lower end portion 14 ″, and a pair of slits 16'16 ". The shape of the slits 16 'and 16 "in the figure is tapered so that the strength can be increased when the lower end 14" of the salient pole 14 is bent after the salient pole 14 is inserted into the stator ring 1. The relationship between the dimensions L1, L2, and L3 in the figure is
L2 <L1 <L3
Is preferable. As a result, the salient poles 14 can be fixed to the outer peripheral surface of the stator ring 12 having a curvature with high strength. However, L1 is the thickness of the stator ring 1, L2 is the minimum value of the slits 16 ′ and 16 ″ from the reference surface, and L3 is also the maximum value of these from the reference surface.
FIG. 10 is a perspective view showing a state in which the salient poles 14 are inserted and fixed to the stator ring 1. A part of the lower end portion 14 ″ of the salient pole 14 is bent and fixed as shown in the figure. Further, since the lower end portion 14 ″ of the salient pole 14 protrudes from the outer periphery of the stator ring 1, the heat radiation effect is the first embodiment. As high as. In order to further increase the heat dissipation efficiency of the motor, the cooling efficiency can be improved by adding a cooling fan to the motor rotating shaft 5 and forcibly cooling it.
[0015]
Although the present invention has been described above by the above embodiment, the present invention is not limited to the three-phase DC brushless motor having the number of rotor magnetic poles (12 poles) and the number of salient poles (9) as in the above embodiment. In addition, the number of phases, the number of rotor magnetic poles, and the number of salient poles are not limited thereto. Also, various modifications and applications are possible within the scope of the present invention, such as being applicable not only to DC brushless motors but also to permanent magnet type synchronous motors and permanent magnet type generators. Applications are not excluded from the scope of the present invention.
[0016]
【The invention's effect】
As described above in detail, according to the present invention, the shape of the salient pole is substantially T-shaped in the axial cross-section, and the cross-sectional shape perpendicular to the rotation axis is I-shaped, which is the upper end surface of the T-shape. The pole teeth are opposed to the axial direction of the rotor magnet, and are mechanically fitted and fixed to the penetrating portion provided in the stator ring at the lower end of the salient pole, and at least a part of the lower end of the salient pole is separated from the stator ring surface. Since it has a structure to project, the heat radiation surface area increases, and at the same time, the heat generated in the salient pole part is efficiently released to the outside of the rotating electrical machine, and the heat dissipation is remarkably improved. For this reason, a large output can be taken out when the temperature rise is allowed to be the same.
In particular, because the salient poles are constructed by laminating magnetic steel sheets in the circumferential direction, there is an advantage that iron loss generated in the salient poles is remarkably reduced, and combined with the heat dissipation efficiency, the thermal resistance can be improved. . In particular, when the number of rotor magnetic poles is large and the rotation speed is high, the iron loss at the salient poles 10 is remarkably increased. Therefore, a configuration in which electromagnetic steel sheets are laminated is preferable.
In the invention according to claim 8, the magnetic flux from the rotor magnet is effectively linked with the salient poles, and at the same time, the pole tooth plate is given a curvature so that The seen air gap width can be made non-uniform so that cogging / torque ripple can be improved. Further, the pole teeth are fitted with the pole teeth plate for converging the magnetic flux, and as a result, the vibration due to the excitation of the salient poles is reduced and the noise is reduced. The inner rotor type DC brushless motor is particularly effective.
[Brief description of the drawings]
FIG. 1 is a cross-sectional side view in the axial direction of a cylindrical radial gap type rotating electrical machine according to the present invention.
FIG. 2 is a half-sectional front view in the axial direction of a cylindrical radial gap type rotating electrical machine according to the present invention.
FIG. 3 is a perspective view of one salient pole.
FIG. 4 is a perspective view of stacked salient poles.
FIG. 5 is a perspective view of a stator ring.
FIG. 6 is a perspective view of a fixed magnetic pole.
FIG. 7 is a perspective view of a pole tooth plate for flux convergence.
FIG. 8 is a cross-sectional side view in the axial direction of a second embodiment of the cylindrical radial gap type rotating electrical machine according to the present invention.
FIG. 9 is a perspective view of a salient pole according to a second embodiment.
FIG. 10 is a perspective view showing a stator ring of a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Stator ring 2 ... Flange 3 ... Bearing 4 ... Bearing 5 ... Rotating shaft 6 ... Sleeve 7 ... Rotor magnet 8 ... Rotor magnet position detection magnet 9 ... Spacer 10 ... Rotor 11 ... Thrust washer 12 ... Thrust washer 13 ...・ Gap 14... Salient pole 14 ′... T-shaped silicon steel plate 14 ”.・ Slit 16 ”... Slit 17... Slit 18 .. Fixed portion 19... Bobbin 19a. ..... Fixed magnetic pole 22 ... Printed wiring board 23 ... Electronic component 24 ... Hall element 25 ... Leader wire 26 ... Square hole 27 ... Terminal 28 ... Leader wire 29 ... Tip 30 ... Polar tooth 31 ... Insertion Hole 32 ... pole tooth plate 33 for converging magnetic flux ... square hole

Claims (5)

A cylindrical stator ring constituting a stator yoke ;
A rotating shaft that holds the rotor magnet and is rotatably supported at both end faces of the stator ring;
A plurality of salient poles disposed on the inner side of the stator ring and provided with stator windings to face the magnetic poles of the rotor magnet;
In a cylindrical radial gap type rotating electrical machine having
The shape of the salient pole in the axial direction sectional shape is substantially T-shaped, cross-sectional shape perpendicular to the rotation axis is I-shaped, pole teeth which is the upper end surface of the T-shape is opposed to the outer peripheral surface of the rotor magnet Is disposed and mechanically fitted and fixed to a penetrating portion provided in the stator ring at the lower end portion of the salient pole, and at least a part of the lower end portion of the salient pole is projected from the outer peripheral surface of the stator ring,
The salient pole lower end has a first slit,
The through portion provided in the stator ring is configured by a second slit that extends in the axial direction from one end of the stator ring toward the other end and is fitted to the first slit. Cylindrical radial gap type rotating electrical machine. The cylindrical radial gap type rotating electrical machine according to claim 1, wherein the salient poles are formed by laminating electromagnetic steel plates in a circumferential direction. 2. The cylindrical radial gap type rotating electrical machine according to claim 1, wherein the stator ring has flanges at both ends, and a bearing for rotatably supporting the rotating shaft is mounted on each of the flanges. . The cylindrical radial gap type rotating electric machine according to any one of claims 1 to 3, wherein the rotating electric machine is a DC brushless motor. The cylindrical radial gap type rotating electrical machine according to any one of claims 1 to 4, wherein a pole tooth plate for converging magnetic flux is provided around a tip of a pole tooth provided on the salient pole.

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