JP2005020887A - Magnet fixing structure and magnet fixing method of rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnet fixing structure of a rotating electric machine to which a magnet can be fixed without using an adhesive. <P>SOLUTION: A magnet holder 19 is attached to the external periphery of a rotor core 16 fixed to a rotor shaft 2. The magnet holder 19 comprises spacer arms 32 having wing pieces 35 and formed into almost a V-shape at its cross section. The spacer arms 32 axially extend, and a rotor magnet 17 is accommodated between the spacer arms. A magnet cover 21 is attached to the outside of the magnet holder 19. The rotor magnet 17 is fixed to the external periphery of the rotor core 16 together with the magnet holder 19 by the bondage force of the magnet holder 19 without using the adhesive. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnet fixing structure in a rotating electric machine such as a motor or a generator, and more particularly to a magnet fixing structure in a rotating electric machine that can fix a magnet without using an adhesive.
[0002]
[Prior art]
Conventionally, many small motors and generators use a permanent magnet field, and in that case, the magnet is often fixed to the rotor or stator by an adhesive. In many cases, a magnet cover is attached to the outer side of the magnet after the magnet is bonded to the rotor. For example, in a motor for an electric power steering device (hereinafter abbreviated as EPS), a magnet cover is attached to the outside of the rotor magnet to prevent the motor from being locked when the magnet is detached or cracked. There is something.
[0003]
[Patent Document 1] Japanese Utility Model Laid-Open No. 60-24149
[Patent Document 2] Japanese Utility Model Publication No. 61-195663
[Patent Document 3] JP-A-5-153745
[Patent Document 4] JP-A-9-19091
[0004]
[Problems to be solved by the invention]
However, in the case of a configuration in which the magnet is fixed to the rotor or the like using an adhesive, there is a problem that a waiting time until the adhesive process or the adhesive is cured is required, and the man-hour is increased accordingly. In addition, there are uneasy factors such as non-uniform adhesion due to uneven adhesion and the possibility of magnet peeling off due to deterioration of the adhesive under severe use environment.
[0005]
The objective of this invention is providing the magnet fixing structure of the rotary electric machine which can fix a magnet without using an adhesive agent.
[0006]
[Means for Solving the Problems]
A magnet fixing structure for a rotating electrical machine according to the present invention is the magnet fixing structure for a rotating electrical machine having a rotor formed by attaching a plurality of magnets along the circumferential direction to the outer periphery of a rotor core fixed to a rotating shaft, A spacer member disposed between the magnets, and a magnet that is formed in a cylindrical shape and is attached to the outside of the magnet, and the spacer member and the magnet are held between the inner peripheral surface and the outer peripheral surface of the rotor core. And a cover.
[0007]
In the present invention, the magnet can be fixed to the rotor core together with the spacer member by the binding force of the magnet cover attached to the outer periphery of the rotor core. For this reason, a magnet can be fixed to a rotor core without using an adhesive agent, and an adhesive application operation and an adhesive curing time during the manufacturing process become unnecessary, and the number of man-hours can be reduced. Further, the number of parts is reduced by the amount of the adhesive, and the manufacturing cost can be reduced.
[0008]
In the magnet fixing structure of the rotating electrical machine, the spacer member may be formed so as to protrude in the axial direction from a base portion fixed to the rotating shaft adjacent to one end side of the rotor core.
[0009]
In the magnet fixing structure of the rotating electrical machine, an elastic piece for sandwiching the magnet from the circumferential direction may be provided on the spacer member, and the magnet is held by the spacer member in a state where movement in the circumferential direction is restricted by the elastic piece. Is done. The spacer member may further be provided with an engagement piece that engages with the outer peripheral surface of the magnet, and the engagement piece further restricts the movement of the magnet in the radial direction.
[0010]
In the magnet fixing structure of the rotating electrical machine, the spacer member may be formed of an elastic member that bulges and deforms in the circumferential direction by a radial pressing force and contacts the magnet. When the spacer member bulges and deforms in the circumferential direction of the rotor core and contacts the magnet, the magnet is held by the spacer member in a state where movement in the circumferential direction is restricted.
[0011]
In the magnet fixing structure of the rotating electrical machine, a fitting portion that fits with a positioning portion formed on the outer periphery of the rotor core may be provided in the magnet holder. Moreover, you may provide the positioning groove which fits the said magnet in the outer periphery of the said rotor core. Thereby, the magnet is positioned with respect to the rotor core. For example, when the fixing structure is applied to a brushless motor, the positioning between the sensor magnet and the magnet of the rotor can be easily performed.
[0012]
In the magnet fixing structure, slits may be provided on an outer peripheral surface and an inner peripheral surface of the spacer member, and the spacer member may be formed so as to be bent around the slit. Due to the slit, when the magnet cover is mounted, the spacer member bends in a direction in which the magnet is pressed against the outer periphery of the rotor core, and the magnet is fixed to the rotor core. In this case, the spacer member is formed in a substantially convex cross section including a base portion disposed on the outer peripheral side and a protrusion portion protruding from the base portion and disposed on the inner peripheral side, and the outer peripheral surface of the base portion and the protrusion You may form the said slit in the internal peripheral surface of a part.
[0013]
In the magnet fixing structure of the rotating electrical machine, the spacer member may be formed in a hollow ring shape in cross section. The spacer member formed in the hollow ring shape bulges and deforms in the circumferential direction of the rotor core by a pressing force in the radial direction and contacts the magnet. Thus, the magnet is held by the spacer member in a state where movement in the circumferential direction is restricted.
[0014]
In the magnet fixing structure of the rotating electrical machine, an inner diameter of the magnet cover may be formed smaller than an outer diameter of the spacer member, and the magnet cover may be press-fitted outside the spacer member. In the magnet fixing structure of the rotating electrical machine, the magnet and the spacer member may be fixed to the outer periphery of the rotor core by a binding force of the magnet cover.
[0015]
Another magnet fixing structure of a rotating electric machine according to the present invention is the magnet fixing structure of a rotating electric machine having a stator formed by attaching a plurality of magnets along the circumferential direction to the inner periphery of a yoke formed in a cylindrical shape. A spacer member mounted on the inner side of the yoke and disposed between the magnets, and formed in a cylindrical shape on the inner peripheral side of the magnet, between the outer peripheral surface and the inner peripheral surface of the yoke And a magnet cover on which the spacer member and the magnet are held.
[0016]
In the present invention, the magnet can be fixed together with the spacer member on the inner peripheral surface of the yoke by the binding force of the magnet cover. For this reason, the magnet can be fixed to the yoke without using an adhesive, and the time for applying the adhesive and the time for curing the adhesive during the manufacturing process become unnecessary, and the number of steps can be reduced. Further, the number of parts is reduced by the amount of the adhesive, and the manufacturing cost can be reduced.
[0017]
In the magnet fixing structure of the rotating electrical machine, an elastic piece is formed on the spacer member so as to be able to bend in the radial direction, and abuts on the outer peripheral surface of the magnet cover to press the magnet in the outer radial direction. Thus, the magnet may be pressed against the inner peripheral surface of the yoke. In the magnet fixing structure of the rotating electrical machine, the magnet and the spacer member may be fixed inside the yoke by a binding force of the magnet cover.
[0018]
On the other hand, in the magnet fixing method for a rotating electrical machine according to the present invention, a plurality of magnets are arranged along the circumferential direction on the outer periphery of the rotor core fixed to the rotating shaft, and a spacer member is arranged between the magnets to form a cylindrical shape. A magnet cover formed on the outside of the magnet, and the spacer member and the magnet are fixed between the inner peripheral surface of the magnet cover and the outer peripheral surface of the rotor core by a binding force of the magnet cover. It is characterized by.
[0019]
According to another magnet fixing method for a rotating electric machine of the present invention, a plurality of magnets are arranged along a circumferential direction on an inner periphery of a cylindrical yoke, and a spacer member is arranged between the magnets. A magnet cover formed in a cylindrical shape is attached to the inside of the magnet, and the spacer member and the magnet are placed between the outer peripheral surface of the magnet cover and the inner peripheral surface of the yoke by the binding force of the magnet cover. It is fixed.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a cross-sectional view showing a configuration of a brushless motor using a magnet fixing structure and a fixing method according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view of the brushless motor of FIG.
[0021]
The brushless motor 1 shown in FIGS. 1 and 2 (hereinafter abbreviated as “motor 1”) is used as an EPS drive source. When the driver operates the steering wheel, the steering assist force is supplied according to the steering angle, the vehicle traveling speed, and the like. . A rotor shaft (rotating shaft) 2 of the motor 1 is connected to an input shaft of a gear box (not shown) via a joint 3. The rotation of the motor 1 is appropriately decelerated in the gear box and then transmitted to the steering column, and the steering force is assisted by the rotational force of the motor 1.
[0022]
The motor 1 is roughly composed of a motor unit 4 and a sensor unit 5. The motor unit 4 includes a stator 6 and a rotor 7, and a hall element (magnetic detection element) 8 is disposed in the sensor unit 5. The rotor 7 is rotatably arranged inside the stator 6, and the motor 1 is a so-called inner rotor type brushless motor.
[0023]
The stator 6 includes a stator core 12 around which a drive coil 11 is wound, and a metal yoke 13 that houses the stator core 12. The stator core 12 is formed by laminating metal plates made of a magnetic material, and the drive coil 11 is wound around a salient pole projecting on the inner peripheral side to form a winding. The yoke 13 is formed in a cylindrical shape with a bottom by a magnetic body, and a bracket 14 made of aluminum die casting (or synthetic resin) is attached to the opening end side thereof.
[0024]
The rotor 7 is provided with a rotor shaft 2. The rotor shaft 2 is rotatably supported by bearings 15a and 15b attached to the yoke 13 and the bracket 14, respectively. A rotor core 16 formed by laminating metal plates made of a magnetic material is fixed to the rotor shaft 2. Six segmented rotor magnets 17 are attached to the outer periphery of the rotor core 16. A side plate 18 is attached to the axial end of the rotor core 16.
[0025]
Further, a synthetic resin magnet holder 19 is fixed to the rotor shaft 2. 3 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 4 is a half-sectional side view of the magnet holder 19, and FIG. 5 is a side view of the magnet holder 19 in FIG. is there. As shown in FIG. 4, the magnet holder 19 is provided with a base portion 31 fixed to the rotor shaft 2 and a spacer arm (spacer member) 32 that protrudes from the base portion 31 in the axial direction. A sensor magnet attachment portion 33 to which the sensor magnet 20 is attached is notched at the end of the base portion 31.
[0026]
The spacer arm 32 has a cantilever structure extending in the axial direction from the base portion 31, and itself can be bent in the circumferential direction as indicated by an arrow Y in FIG. The inner peripheral portion 34 of the spacer arm 32 contacts the outer peripheral surface 16 a of the rotor core 16 when the base portion 31 is attached to the rotor shaft 2. As shown in FIGS. 3 and 5, the spacer arm 32 has a substantially V-shaped cross section including a pair of blade pieces (elastic pieces) 35. The wing piece 35 is connected to the inner peripheral portion 34 on one end side. The free end side of the blade piece 35 is formed so as to be able to bend in a substantially circumferential direction as indicated by an arrow Z in FIG. 5 except for the base portion (near the base portion 31) of the spacer arm 32. That is, the blade piece 35 has an elastic structure capable of opening and closing the V-shaped central angle θ.
[0027]
A segmented rotor magnet 17 is accommodated between the spacer arms 32. The rotor magnet 17 is mounted on the outer periphery of the rotor core 16 along the axial direction from the free end side (right end side in FIG. 4) of the spacer arm 32 and is accommodated between the opposed blade pieces 35 of the adjacent spacer arm 32. . The rotor magnet 17 is sandwiched between the spacer arms 32 by the elastic force of the spacer arm 32 itself and the elastic force of the blade piece 35. Thereby, the rotor magnet 17 is held on the outer periphery of the rotor core 16 while being restricted from moving in the circumferential direction.
[0028]
The ring-shaped sensor magnet 20 is attached to the sensor magnet attachment portion 33. The sensor magnet mounting portion 33 is notched in a step shape on the outer periphery of the tip (left end in FIG. 4) of the base portion 31, and the sensor magnet 20 is externally inserted there. The magnetic poles of the sensor magnet 20 are magnetized to have the same number of poles as the rotor magnets 17 and are arranged at the same positions in the circumferential direction as the magnetic poles of the rotor magnet 17. In the motor 1, the rotor magnet 17 has a 6-pole configuration, and the sensor magnet 20 is also magnetized to 6 poles in the circumferential direction accordingly.
[0029]
A magnet cover 21 is externally provided on the outside of the magnet holder 19. The magnet cover 21 is formed by deep drawing using a nonmagnetic material such as stainless steel or aluminum. The magnet cover 21 is provided with a small-diameter portion 21 a that covers the sensor magnet 20 and a large-diameter portion 21 b that covers the rotor magnet 17. A tapered portion 21c is formed between the small diameter portion 21a and the large diameter portion 21b.
[0030]
The magnet cover 21 is attached from the base portion 31 side to the magnet holder 19 in which the rotor magnet 17 is accommodated and the sensor magnet 20 is attached. The inner diameter of the magnet cover 21 is slightly smaller than the outer diameter of the spacer arm 32, and the magnet cover 21 is attached to the outside of the magnet holder 19 in a press-fit manner. The magnet cover 21 is covered with the rotor magnet 17 in a state where movement in the circumferential direction is restricted by the magnet holder 19, thereby restricting movement of the rotor magnet 17 in the radial direction. That is, the rotor magnet 17 is fixed to the outer periphery of the rotor core 16 by the binding force of the magnet cover 21. A magnet cover 21 is also externally mounted on the sensor magnet 20 and is fixed to the magnet holder 19 by its binding force.
[0031]
Thus, in the motor 1, the rotor magnet 17 is fixed together with the spacer arm 32 of the magnet holder 19 to the outer periphery of the rotor core 16 by the binding force of the magnet cover 21 without using an adhesive. The sensor magnet 20 is also fixed to the magnet holder 19 at the same time by the binding force of the magnet cover 21. This eliminates the need for adhesive application work and adhesive curing time during the manufacturing process, thereby reducing the number of steps. Further, since no adhesive is required, the number of parts is reduced, and the manufacturing cost can be reduced.
[0032]
On the sensor unit 5 side, a hall element 8 is disposed on the radially outer side of the sensor magnet 20. The hall element 8 is provided with a total of three U, V, and W phases, and is opposed to the sensor magnet 20 with a predetermined gap. The magnetic poles of the sensor magnet 20 are magnetized to have the same number of poles corresponding to the rotor magnet 17, arranged at the same circumferential position as the magnetic poles of the rotor magnet 17, and fixed by the magnet cover 21. In the motor 1, the rotor magnet 17 has a 6-pole configuration, and the sensor magnet 20 is also magnetized to 6 poles in the circumferential direction accordingly. The Hall element 8 sends a signal along with the magnetic pole change of the sensor magnet 20, thereby detecting the rotational position of the rotor 7.
[0033]
The hall element 8 is arranged side by side in the circumferential direction at the tip of the sensor holder 22 attached to the bracket 14. A printed circuit board 23 is attached to the outside of the sensor holder 22, and the sensor holder 22 and the printed circuit board 23 are fixed to the bracket 14 with screws 24. An end cap 25 is attached to the outer end portion of the bracket 14 to cover components housed in the bracket 14 such as the printed circuit board 23 from the outside air. A power line 26 for supplying power to the drive coil 11 is also connected to the bracket 14. The power line 26 is drawn out of the motor through a rubber grommet 27 attached to the side of the bracket 14.
[0034]
(Embodiment 2)
Next, a magnet fixing structure according to the second embodiment of the present invention will be described. FIG. 6 is a cross-sectional view showing the configuration. In the following embodiment, the same reference numerals are used for the same parts and members as in the first embodiment, and the description thereof is omitted.
[0035]
In the magnet fixing structure of the second embodiment, the shapes of the magnet holder 36 and the rotor magnet 37 are different from those of the magnet holder 19 and the rotor magnet 17 of the first embodiment. As shown in FIG. 6, in the magnet holder 36, the dimension of the inner peripheral portion 34 of the spacer arm 38 is longer than that in the first embodiment, and the cross-sectional shape of the spacer arm 38 is substantially trapezoidal. An engagement piece 39 extending in the circumferential direction is bent at the free end side of the wing piece 35. The blade piece 35 is formed to be bendable in the circumferential direction, and the free end side distance L between the opposed blade pieces 35 is slightly smaller than the width W of the rotor magnet 37 in the free state (L <W). The distance on the inner peripheral portion 34 side between the blade pieces 35 is substantially the same as the width W of the rotor magnet 37.
[0036]
Also in this case, the rotor magnet 37 is mounted on the outer periphery of the rotor core 16 along the axial direction from the free end side of the spacer arm 38 and is accommodated between the opposed blade pieces 35 of the adjacent spacer arm 38. At this time, since L <W as described above, the rotor magnet 37 is mounted between the blade pieces 35 while being slightly opened. As a result, the rotor magnet 37 is elastically held between the blade pieces 35 and the movement in the circumferential direction is restricted.
[0037]
On the other hand, an engagement piece 39 at the tip of the blade piece 35 is engaged with the outer peripheral portion of the rotor magnet 37. As a result, the rotor magnet 37 is also restricted from moving in the radial direction and is held without dropping from the magnet holder 36. The magnet cover 21 is externally mounted on the outside of the magnet holder 36, and the rotor magnet 37 is fixed to the outer periphery of the rotor core 16 without using an adhesive by the binding force of the magnet cover 21.
[0038]
(Embodiment 3)
FIG. 7 is a cross-sectional view showing the configuration of the magnet fixing structure according to the third embodiment of the present invention. As described above, the brushless motor requires positioning of the sensor magnet 20 and the rotor magnet 37. In the motor, since the sensor magnet is attached to the magnet holder together with the rotor magnet, the positioning between the two magnets is facilitated by first positioning the rotor magnet.
[0039]
Therefore, in the magnet fixing structure of the third embodiment, as shown in FIG. 7, a positioning protrusion (fitting portion) 42 is formed on the magnet holder 41. On the other hand, a plurality of positioning grooves (positioning portions) 43 are provided on the rotor core 16 side with respect to the positioning protrusions 42. The positioning projection 42 is adapted to fit into the positioning groove 43, whereby the magnet holder 41 is positioned at a predetermined position with respect to the rotor core 16. Therefore, the rotor magnet 37 accommodated in the magnet holder 41 is also positioned at a predetermined position, and positioning with the sensor magnet 20 is facilitated.
[0040]
In the structure of FIG. 7, the projection is provided on the magnet holder 41 side and is positioned by fitting the projection with the recess formed on the rotor core 16 side. good. That is, it is good also as a structure which provides a recessed part in the magnet holder 41 side, and positions this by making it fit with the convex part formed in the rotor core 16 side. Further, the positioning groove 43 may be formed larger than that in FIG. 7 so that the entire inner peripheral portion 34 is fitted.
[0041]
In the case of the structure of FIG. 7, the q-axis side inductance in the figure is reduced as compared with the d-axis side. For this reason, the response characteristic of a motor improves and the reaction of EPS is improved. However, reluctance torque is generated due to the difference in dq axis inductance, and problems such as cogging and torque ripple may occur. However, the difference in inductance is extremely small, and cogging is not a problem in practice. Rather, it is possible to improve the output of the motor by using this reluctance torque together.
[0042]
(Embodiment 4)
FIG. 8 is a cross-sectional view showing the configuration of the magnet fixing structure according to the fourth embodiment of the present invention. Here, the positioning structure of the rotor magnet 37 is different from that of the third embodiment, and a plurality of positioning grooves 44 are formed in the outer periphery of the rotor core 16. The inner circumferential side of the rotor magnet 37 is fitted into the positioning groove 44, whereby the rotor magnet 37 is positioned. As the magnet holder, the same magnet holder as that of the second embodiment is used.
[0043]
(Embodiment 5)
9A is a cross-sectional view showing a configuration of a magnet fixing structure according to a fifth embodiment of the present invention, and FIG. 9B is an explanatory diagram showing a state before the magnet cover 21 is mounted in the magnet fixing structure of FIG. 9A. . Here, a magnet holder 45 in which the cross section of the spacer arm 32 is formed in a hollow ring shape is used. As shown in FIG. 9B, the spacer arm 32 is disposed between the rotor magnets 37. The outer diameter Ds of the spacer arm 32 is formed larger than the thickness t of the rotor magnet 37 (Ds> t). Therefore, when the spacer arm 32 is disposed between the rotor magnets 37, the upper end of the spacer arm 32 slightly protrudes from the outer periphery of the rotor magnet 37 as shown in FIG. 9B.
[0044]
The magnet cover 21 is attached from the state shown in FIG. The inner diameter Dmc of the magnet cover 21 is smaller than the dimension obtained by adding the spacer arm 32 to the rotor core 16 (Dmc <Ds). Therefore, when the magnet cover 21 is attached with the spacer arm 32 attached, the ring-shaped spacer arm 32 is crushed in the radial direction, and as shown in FIG. Deform. The spacer arm 32 deformed into an elliptical shape is in contact with the end surface of the rotor magnet 37. Thereby, the movement of the rotor magnet 37 in the radial direction is restricted, and the rotor magnet 37 is fixed to the outer periphery of the rotor core 16 by using the binding force of the magnet cover 21 without using an adhesive.
[0045]
(Embodiment 6)
FIG. 10A is a cross-sectional view showing a configuration of a magnet fixing structure according to Embodiment 6 of the present invention, and FIG. 10B is an explanatory view showing a state before the magnet cover 21 is mounted in the magnet fixing structure of FIG. . Here, a magnet holder 46 in which the spacer arm 32 is formed of an elastic member such as rubber or foamed rubber is used. Although the cross section of the spacer arm 32 is formed in a substantially rectangular shape, a positioning protrusion (fitting portion) 42 is formed on the inner peripheral surface side in a protruding manner, similarly to the magnet fixing structure in FIG. 7 (Embodiment 3). ing.
[0046]
The spacer arm 32 is also disposed between the rotor magnets 37 as shown in FIG. The outer diameter Ds of the spacer arm 32 is formed larger than the thickness t of the rotor magnet 37 (Ds> t). Therefore, when the magnet cover 21 is mounted with the spacer arm 32 attached, the spacer arm 32 made of an elastic member is crushed in the radial direction and bulged and deformed in the circumferential direction as shown in FIG. Thereby, the movement of the rotor magnet 37 in the radial direction is restricted, and the rotor magnet 37 is fixed to the outer periphery of the rotor core 16 by using the binding force of the magnet cover 21 without using an adhesive.
[0047]
(Embodiment 7)
FIG. 11 is a cross-sectional view showing the configuration of the magnet fixing structure according to the seventh embodiment of the present invention. In this embodiment, a magnet holder 47 is used in which the cross-sectional shape of the spacer arm 32 is different from that described above. As shown in FIG. 11, the spacer arm 32 of the magnet holder 47 is formed in a substantially convex cross section having a base 48 and a protrusion 49. The base 48 is disposed on the outer peripheral side, and the protrusion 49 is disposed on the inner peripheral side (rotor core 16 side). Slits 51 and 52 are formed in the center of the base 48 and the protrusion 49, respectively.
[0048]
Here, the same rotor magnet 17 as in the first embodiment is used, and the rotor magnet 17 is mounted between the spacer arms 32. At this time, the rotor magnet 17 is accommodated in a stepped portion 53 formed by the base portion 48 and the protruding portion 49. In a state where the rotor magnet 17 is accommodated in the magnet holder 47, the magnet cover 21 is externally provided on the outside thereof. The magnet cover 21 is attached in a press-fit manner so as to press the spacer arm 32 from the outer peripheral side.
[0049]
When mounting the magnet cover 21, the spacer arm 32 is pressed against the magnet cover 21 from the outer peripheral side, and the rotor magnet 17 is pressed against the outer peripheral surface of the rotor core 16 by the stepped portion 53. Further, since the slit 51 is provided on the outer peripheral side of the spacer arm 32 and the slit 52 is provided on the inner peripheral side, when the magnet cover 21 is attached, the spacer arm 32 is centered on the slits 51 and 52 in the direction indicated by the arrow S. Bend to. That is, when the slit 51 is opened and the slit 52 is closed, the entire spacer arm 32 is bent inward. As the spacer arm 32 is deformed, the rotor magnet 17 inserted into the stepped portion 53 is further pressed against the outer peripheral surface of the rotor core 16 by the inner peripheral surface 48 a of the base portion 48. Thereby, the rotor magnet 17 is fixed to the outer periphery of the rotor core 16 by using the binding force of the magnet cover 21 without using an adhesive.
[0050]
(Embodiment 8)
FIG. 12 is a sectional view showing a configuration of a magnet fixing structure according to the eighth embodiment of the present invention. In the above-described embodiment, the sensor magnet 20 is attached to the base portion of the magnet holder. However, the sensor magnet can be provided separately from the rotor.
[0051]
Here, as shown in FIG. 12, the rotor core 16 and the sensor magnet 54 are separately attached to the rotor shaft 2. The sensor magnet 54 is formed in a ring shape and is directly attached to the rotor shaft 2. A rotor magnet 55 is disposed on the outer periphery of the rotor core 16, and spacers (spacer members) 56 are attached between the rotor magnets 17. A side plate 18 is attached to the end of the rotor core 16 in the axial direction, and a magnet cover 21 is externally mounted on the outer periphery of the rotor magnet 17 and the spacer 56.
[0052]
For example, the spacer 56 is formed in the same manner as the spacer arm 32 of FIG. The magnet cover 21 is attached in a press-fit manner so as to press the spacer 56 from the outer peripheral side. When the magnet cover 21 is attached, the spacer 56 abuts against the rotor magnet 55 and restricts movement in the circumferential direction. Accordingly, the movement of the rotor magnet 55 in the radial direction is restricted, and the rotor magnet 55 is fixed to the outer periphery of the rotor core 16 without using an adhesive by the binding force of the magnet cover 21. The spacer 56 may take a form other than that shown in FIG.
[0053]
(Embodiment 9)
FIG. 13: is sectional drawing which shows the structure of the magnet fixing structure which is Embodiment 9 of this invention. In the above-described embodiment, the case where the magnet is fixed to the rotor side has been described. However, this embodiment is applied to the case where the fixing structure of the present invention is fixed to the stator side.
[0054]
The motor to which the fixing structure of FIG. 13 is applied is an electric motor with a brush, unlike the motor 1 of FIG. In FIG. 13, the outermost shell portion is a metal yoke 57, and a magnet 58 is attached to the inner peripheral surface 57a, and a bearing 59 is attached to the bottom surface 57b. The magnet 58 is held by a magnet holder 61. The magnet holder 61 is made of synthetic resin and is attached to the inner peripheral surface 57 a of the yoke 57. A spacer arm 32 protrudes from the magnet holder 61 in the axial direction. The spacer arm 32 is provided with a first arm 62 on the outer peripheral side and a second arm 63 on the inner peripheral side. The first and second arms 62 and 63 are formed so as to be able to bend in the radial direction.
[0055]
A magnet cover 64 is attached to the inner peripheral side of the magnet 58. The outer diameter of the magnet cover 64 is slightly larger than the inner diameter of the second arm 63. When the magnet cover 64 is attached to the inner peripheral side of the magnet 58, the second arm 63 is pushed outward by the magnet cover 64 and bends toward the first arm 62 side. The second arm 63 is provided with an engaging surface 63 a, and the engaging surface 63 a is engaged with the end inclined surface 58 a of the magnet 58. The first arm 62 is also provided with an engagement surface 62a and is engaged with the end inclined surface 58a of the magnet 58.
[0056]
In this state, when the second arm 63 bends to the outer diameter side, the magnet 58 is pressed by the second arm 63 and pressed against the inner peripheral surface 57 a of the yoke 57. That is, the magnet 58 is fixed to the inner peripheral surface 57 a of the yoke 57 without using an adhesive by the binding force of the magnet cover 64. As described above, the structure of the present invention in which the magnet is fixed by the binding force of the magnet cover 64 is effective when the magnet is fixed not only on the rotor side but also on the stator side.
[0057]
It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, an example in which the fixing structure of the present invention is applied to an inner rotor type brushless motor or a motor with a brush has been shown. However, the fixing structure of the present invention can also be applied to an outer rotor type brushless motor. It is. In the case of an outer rotor type brushless motor, a magnet is fixed to the outer rotor with the same configuration as in the sixth embodiment. Moreover, it is also possible to apply the said structure not only to a motor but to a generator.
[0058]
Furthermore, in the above-described embodiment, the sensor magnet 20 is fixed together with the rotor magnets 17 and 37 by the magnet cover 21, but the sensor magnet 20 is not necessarily fixed integrally by the magnet cover 21. That is, a structure in which the sensor magnet 20 is not covered with the cover 22 or a structure in which the sensor magnet 20 itself is separated from the rotor core 16 as in the eighth embodiment (FIG. 12) can be employed. In addition, in the above-described embodiment, a mode in which the magnet cover 21 is press-fitted to the outside of the magnet holder 19 has been shown. You may wear it.
[0059]
According to the structure of the present invention, it is possible to fix the rotor magnets 17 and 37 to the rotor core 16 without using an adhesive, but after temporarily fixing the rotor magnets 17 and 37 with a small amount of adhesive. It is also possible to attach the magnet cover 21. Alternatively, the magnet cover 21 may be mounted after the sensor magnet 20 is temporarily fixed to the magnet holder 19 or the like with a small amount of adhesive. In this case, an adhesive is used during the manufacturing process, but since the amount of the adhesive used can be reduced as compared with the case where the adhesive is used for fixing, the curing time is greatly shortened.
[0060]
【The invention's effect】
According to the magnet fixing structure of the rotating electrical machine of the present invention, the magnet is disposed on the outer periphery of the rotor core, and the magnet cover is attached to the outer side of the magnet member with the spacer member disposed between the magnets. Since the spacer member and the magnet are held between the outer peripheral surface of the rotor core and the outer periphery of the rotor core, the magnet can be fixed together with the spacer member on the outer periphery of the rotor core by the binding force of the magnet cover. For this reason, a magnet can be fixed to a rotor core without using an adhesive agent, and an adhesive application operation and an adhesive curing time during the manufacturing process become unnecessary, and the number of man-hours can be reduced. Further, the number of parts is reduced by the amount of the adhesive, and the manufacturing cost can be reduced.
[0061]
Further, according to another magnet fixing structure of a rotating electric machine of the present invention, a magnet is arranged on the inner periphery of the yoke, and a magnet cover is mounted on the inner side with a spacer member arranged between these magnets. Since the spacer member and the magnet are held between the outer peripheral surface of the magnet cover and the inner peripheral surface of the yoke, the magnet can be fixed together with the spacer member on the inner periphery of the yoke by the binding force of the magnet cover. For this reason, the magnet can be fixed to the yoke without using an adhesive, and the time for applying the adhesive and the time for curing the adhesive during the manufacturing process become unnecessary, and the number of steps can be reduced. Further, the number of parts is reduced by the amount of the adhesive, and the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a brushless motor using a magnet fixing structure according to a first embodiment of the present invention.
2 is an exploded perspective view of the brushless motor of FIG. 1. FIG.
3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a half sectional side view of a magnet holder.
5 is a side view of the magnet holder of FIG. 4 when viewed from the direction indicated by the arrow X. FIG.
FIG. 6 is a sectional view showing a configuration of a magnet fixing structure according to a second embodiment of the present invention.
FIG. 7 is a cross-sectional view showing a configuration of a magnet fixing structure according to a third embodiment of the present invention.
FIG. 8 is a cross-sectional view showing a configuration of a magnet fixing structure according to a fourth embodiment of the present invention.
9A is a cross-sectional view showing a configuration of a magnet fixing structure according to a fifth embodiment of the present invention, and FIG. 9B is an explanatory diagram showing a state before the magnet cover is mounted in the magnet fixing structure of FIG. 9A. is there.
10A is a cross-sectional view showing a configuration of a magnet fixing structure according to a sixth embodiment of the present invention, and FIG. 10B is an explanatory view showing a state before the magnet cover is mounted in the magnet fixing structure of FIG. 10A. is there.
FIG. 11 is a sectional view showing a configuration of a magnet fixing structure according to a seventh embodiment of the present invention.
FIG. 12 is a sectional view showing a configuration of a magnet fixing structure according to an eighth embodiment of the present invention.
FIG. 13 is a sectional view showing a configuration of a magnet fixing structure according to a ninth embodiment of the present invention.
[Explanation of symbols]
1 Brushless motor
2 Rotor shaft (rotating shaft)
3 Joint
4 Motor part
5 Sensor part
6 Stator
7 Rotor
8 Hall element
11 Drive coil
12 Stator core
13 York
14 Bracket
15a, 15b Bearing
16 Rotor core
16a outer peripheral surface
17 Rotor magnet
18 Side plate
19 Magnet holder
20 Sensor magnet
21 Magnet cover
21a Small diameter part
21b Large diameter part
21c Taper part
22 Sensor holder
23 Printed circuit board
24 screws
25 End cap
26 Power line
27 Rubber Grommet
31 Shaft mounting
32 Spacer arm (spacer member)
33 Sensor magnet mounting part
34 Inner circumference
35 Wings (elastic pieces)
36 Magnet holder
37 Rotor Magnet
38 Spacer arm (spacer member)
39 Engagement piece
41 Magnet holder
42 Positioning protrusion (fitting part)
43 Positioning groove (positioning part)
44 Positioning groove
45 Magnet holder
46 Magnet holder
47 Magnet holder
48 base
48a Inner peripheral surface
49 Projection
51 slit
52 slit
53 steps
54 Sensor magnet
55 Rotor Magnet
56 Spacer (Spacer member)
57 York
57a Inner peripheral surface
57b Bottom
58 Magnet
58a End slope
59 Bearing
61 Magnet holder
62 First arm
62a engagement surface
63 Second arm
63a engagement surface
64 Magnet cover

Claims (17)

A structure for fixing the magnet of a rotating electrical machine having a rotor formed by attaching a plurality of magnets along the circumferential direction to the outer periphery of a rotor core fixed to a rotating shaft,
A spacer member disposed between the magnets;
A rotating electric machine comprising a magnet cover that is formed in a cylindrical shape and is attached to the outside of the magnet, and the spacer member and the magnet are held between an inner peripheral surface of the magnet and an outer peripheral surface of the rotor core. Magnet fixing structure. 2. The magnet fixing structure for a rotating electrical machine according to claim 1, wherein the spacer member is formed so as to protrude along the axial direction from a base portion fixed to the rotating shaft adjacent to one end side of the rotor core. Magnet fixing structure for rotating electrical machines. 3. The magnet fixing structure for a rotating electrical machine according to claim 1, wherein the spacer member includes an elastic piece for sandwiching the magnet from the circumferential direction. The magnet fixing structure for a rotating electrical machine according to any one of claims 1 to 3, wherein the spacer member has an engagement piece that engages with an outer peripheral surface of the magnet. Construction. 3. The magnet fixing structure for a rotating electrical machine according to claim 1, wherein the spacer member is formed of an elastic member that bulges and deforms in the circumferential direction by a radial pressing force and contacts the magnet. The magnet fixing structure of the rotating electrical machine. The magnet fixing structure for a rotating electrical machine according to any one of claims 1 to 5, wherein the spacer member has a fitting portion that fits with a positioning portion formed on an outer periphery of the rotor core. Magnet fixing structure for rotating electrical machines. The magnet fixing structure for a rotating electrical machine according to any one of claims 1 to 6, wherein a positioning groove for fitting with the magnet is provided on an outer periphery of the rotor core. 3. The magnet fixing structure for a rotating electrical machine according to claim 1, wherein the spacer member has slits on an outer peripheral surface and an inner peripheral surface, and is formed so as to be bent around the slit. Magnet fixing structure for rotating electrical machines. 9. The magnet fixing structure for a rotating electrical machine according to claim 8, wherein the spacer member is formed in a substantially convex cross section having a base portion disposed on the outer peripheral side and a protrusion portion protruding from the base portion and disposed on the inner peripheral side. And the slit is formed in the outer peripheral surface of the base and the inner peripheral surface of the protrusion. 3. The magnet fixing structure for a rotating electric machine according to claim 1, wherein the spacer member is formed in a hollow ring shape in cross section. The magnet fixing structure for a rotating electrical machine according to any one of claims 1 to 10, wherein an inner diameter of the magnet cover is formed smaller than an outer diameter of the spacer member, and the magnet cover is press-fitted outside the spacer member. A magnet fixing structure for a rotating electrical machine. 12. The rotating machine according to claim 1, wherein the magnet and the spacer member are fixed to an outer periphery of the rotor core by a binding force of the magnet cover. Electric magnet fixing structure. The magnet fixing structure of a rotating electrical machine having a stator formed by attaching a plurality of magnets along the circumferential direction to the inner periphery of a yoke formed in a cylindrical shape,
A spacer member mounted inside the yoke and disposed between the magnets;
It is formed in a cylindrical shape and is attached to the inner peripheral side of the magnet, and has a magnet cover for holding the spacer member and the magnet between the outer peripheral surface and the inner peripheral surface of the yoke. Magnet fixing structure for rotating electrical machines. 14. The magnet fixing structure for a rotating electrical machine according to claim 13, wherein the spacer member has an elastic piece formed so as to be able to bend in a radial direction, and the elastic piece is in contact with an outer peripheral surface of the magnet cover. A magnet fixing structure for a rotating electrical machine, wherein the magnet is pressed against the inner peripheral surface of the yoke. 15. The magnet fixing structure for a rotating electrical machine according to claim 13, wherein the magnet and the spacer member are fixed inside the yoke by a binding force of the magnet cover. A plurality of magnets are arranged along the circumferential direction on the outer periphery of the rotor core fixed to the rotating shaft, and a spacer member is arranged between the magnets,
A magnet cover formed in a cylindrical shape is attached to the outside of the magnet, and the spacer member and the magnet are fixed between the inner peripheral surface of the magnet cover and the outer peripheral surface of the rotor core by the binding force of the magnet cover. A magnet fixing method for a rotating electrical machine, characterized by: A plurality of magnets are disposed along the circumferential direction on the inner periphery of the yoke formed in a cylindrical shape, and a spacer member is disposed between the magnets.
A magnet cover formed in a cylindrical shape is attached to the inside of the magnet, and the spacer member and the magnet are fixed between the outer peripheral surface of the magnet cover and the inner peripheral surface of the yoke by the binding force of the magnet cover. A magnet fixing method for a rotating electrical machine, characterized by:

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