JP2009159706A - Rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a rotating electric machine which suppresses leakage of magnetic flux to a balancer side from a permanent magnet installed in a rotor. <P>SOLUTION: A recess 40 separated from the rotor is formed on the magnet opposite surface 36 of a balancer 34 via a boundary step 38. The depth of the recess 40 is made to be not smaller than 2 mm. Thus, by forming the recess which is recessed in a direction where the recess is separated from the permanent magnet on the magnet opposing surface 36 of the balancer 34, the leakage of the magnetic flux to the balancer 34 side from the permanent magnet installed in the rotor is suppressed compared with the case where the recess 40 is not formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine including a balancer that suppresses rotational fluctuation.

  In a rotating electrical machine used for a compressor or the like, a balancer may be provided on a rotating shaft member of the rotating electrical machine in order to cancel the rotational fluctuation of the compressor.

In Patent Document 1, a balancer and a rotor that suppress rotational fluctuation are disposed adjacent to each other in the direction of the rotation axis. As described above, the balancer and the rotor are disposed adjacent to each other in the direction of the rotation axis so that an increase in the size of the apparatus main body can be suppressed.
JP 2004-336831 A

  However, if the balancer and the rotor are arranged adjacent to each other, the magnetic flux leaks from the permanent magnet provided on the rotor to the balancer side, and the rotational characteristics of the rotating electrical machine may be deteriorated.

  An object of the present invention is to suppress the leakage of magnetic flux from the permanent magnet provided on the rotor to the balancer side in consideration of the above fact.

  A rotating electrical machine according to a first aspect of the present invention includes a rotating shaft member that is rotatably supported, and a plurality of receiving holes that are fixed to the rotating shaft member and penetrate in the axial direction of the rotating shaft member. A rotor core, an embedded magnet housed in the housing hole of the rotor core, and fixed to the rotary shaft member side by side in the axial direction of the rotor core and the rotary shaft member, A balancer that includes a magnet facing surface facing the embedded magnet and that suppresses rotational fluctuations of the rotating shaft member, and the magnet facing surface of the balancer is recessed in a direction away from the rotor. The area where the exposed surface of the embedded magnet faces the concave portion is equal to or larger than the area where the exposed surface of the embedded magnet faces the magnet facing surface.

  According to the above configuration, the rotor core fixed to the rotating shaft member is formed with a plurality of receiving holes penetrating in the axial direction in the circumferential direction. An embedded magnet is accommodated in the accommodation hole.

  Furthermore, a balancer that suppresses rotational fluctuation of the rotating shaft member is fixedly supported by the rotating shaft member side by side in the axial direction of the rotor core and the rotating shaft member. Further, the balancer is provided with a magnet facing surface that faces the embedded magnet of the rotor, and the magnet facing surface is provided with a recess that is recessed in a direction away from the rotor.

  Here, the area where the exposed surface of the embedded magnet faces the recess is equal to or larger than the area where the exposed surface of the embedded magnet faces the magnet facing surface.

  In this way, a recess is provided on the surface of the balancer facing the magnet away from the embedded magnet, and the area where the exposed surface of the embedded magnet faces the recess is increased, compared to the case where no recess is provided. And it can suppress that magnetic flux leaks from the embedded magnet provided in the rotor to the balancer side.

  The rotating electrical machine according to claim 2 of the present invention is the rotating electrical machine according to claim 1, wherein the shape of the storage hole provided in the rotor core is rectangular, the embedded magnet is plate-shaped, and the adjacent storage holes Are arranged in a V-shape that is convex inward in the radial direction.

  According to the said structure, the shape of the accommodation hole provided in the rotor core is made into the rectangle, and the embedded magnet is made into plate shape. Further, the adjacent storage holes are arranged in a V shape that is convex inward in the radial direction. That is, the adjacent plate-shaped embedded magnets are also arranged in a V-shape that protrudes radially inward.

  As described above, even when the embedded magnet is arranged in a V shape, it is possible to prevent the magnetic flux from leaking from the embedded magnet provided on the rotor to the balancer side by providing a recess on the magnet facing surface of the balancer. it can.

  The rotating electrical machine according to claim 3 of the present invention is characterized in that, in claim 2, the boundary step portion between the magnet facing surface and the concave portion forms a V shape and passes through the center line of the embedded magnet. To do.

  According to the above configuration, the boundary step portion between the magnet facing surface and the concave portion has a V shape and is provided so as to pass through the center line of the embedded magnet.

  Thus, by providing the boundary step portion so as to pass through the center line of the embedded magnet, the magnet facing surface can support the embedded magnet in a well-balanced manner.

  A rotating electrical machine according to a fourth aspect of the present invention is the rotary electric machine according to the second aspect, wherein a boundary step portion between the magnet facing surface and the concave portion forms a V shape, and the embedded magnet is formed from a center line of the embedded magnet. The exposed surface is provided in a direction in which the area facing the concave portion increases.

  According to the above configuration, the boundary step between the magnet facing surface and the recess is V-shaped, and the exposed surface of the embedded magnet is provided in a direction in which the area facing the recess is larger than the center line of the embedded magnet. Yes.

  As described above, by providing the boundary step in the direction in which the exposed surface of the embedded magnet increases the area facing the recess, it is possible to effectively suppress the leakage of magnetic flux from the embedded magnet of the rotor to the balancer side. .

  The rotating electrical machine according to claim 5 of the present invention is characterized in that, in any one of claims 1 to 4, the outer peripheral surface side of the balancer in the recess is open.

  According to the said structure, the outer peripheral surface side of the balancer in a recessed part is open | released.

  Thus, by releasing the outer peripheral surface side of the balancer in the recess, it is possible to effectively suppress the leakage of magnetic flux from the outer side in the radial direction of the rotor to the balancer side.

  A rotary electric machine according to a sixth aspect of the present invention is the rotary electric machine according to any one of the first to fifth aspects, wherein the depth of the concave portion is 2 mm or more.

  According to the above configuration, since the depth of the concave portion is 2 mm or more, it is possible to suppress the leakage of magnetic flux from the embedded magnet provided in the rotor to the balancer side as compared with the case where the depth is shallower than 2 mm. it can.

A motor 10 as a rotating electrical machine according to the first embodiment will be described with reference to FIGS.
(overall structure)
As shown in FIG. 9, the motor 10 includes a stator 12 and a rotor 14.

  The stator 12 is formed in a substantially cylindrical shape as a whole, and has a plurality of teeth 18 formed so as to extend from the inner peripheral surface of the cylindrical portion 16 forming the outer shape toward the axial center at equal circumferential intervals. A stator core 20 is provided. Further, a winding 22 is wound around the tooth 18 via an insulator (not shown). In the present embodiment, twelve teeth 18 are formed.

  On the other hand, the rotor 14 fixed to the rotating shaft 24 includes a rotor core 26, a plurality of permanent magnets 28 as embedded magnets arranged in a V shape, a first end plate 30 and a second end as receiving members. A plate 32 (see FIG. 10) is included.

  In the present embodiment, eight sets of permanent magnets 28 are provided in a V shape. Further, the rotating shaft 24 of the present embodiment is connected to a load that fluctuates periodically, for example, via a cam. The rotor core 26 is formed in a substantially cylindrical shape by laminating plate materials in the axial direction, and the rotating shaft 24 is fixed to the center hole thereof.

  Specifically, the rotor core 26 that is rotatably supported inside the stator 12 has a rectangular accommodation hole 26 </ b> A that penetrates in the axial direction and is arranged in a substantially V shape protruding radially inward in the circumferential direction. Eight pairs are formed side by side. All of the accommodation holes 26A of the present embodiment have the same shape and are formed at equiangular intervals in the circumferential direction.

  A plate-like permanent magnet 28 is accommodated and held in each accommodation hole 26A. The permanent magnet 28 is arranged in a substantially V-shape (see FIG. 9) convex radially inward by inserting and holding the permanent magnets 28 having the same shape in all rectangular parallelepipeds into the receiving holes 26A. It has become.

  Note that the permanent magnets 28 arranged in a V-shape projecting radially inward are of the same polarity, and are arranged so that their magnetic poles (directions thereof) are alternated (reverse) in the circumferential direction. ing.

  Further, as shown in FIG. 10, a first end plate 30 and a second end plate 32 for preventing the axial movement of the permanent magnet 28 are provided at both ends in the axial direction of the accommodation hole 26A (see FIG. 9). Is held.

Specifically, the first end plate 30 and the second end plate 32 of the present embodiment are made of stainless steel and have the same circular shape.
(Main part configuration)
As shown in FIG. 10, a balancer 34 that suppresses rotation fluctuations of the rotation shaft 24 is fixed to the rotation shaft 24 (integrated molding in the present embodiment), and is arranged side by side in the axial direction of the rotor core 26 and the rotation shaft 24. Has been.

  As shown in FIG. 1, the cross section of the balancer 34 orthogonal to the axial direction of the rotating shaft 24 is semicircular, and the central portion of the balancer 34 is fixed to the rotating shaft 24. Further, the balancer 34 is provided with a magnet facing surface 36 that faces the permanent magnet 28 of the rotor 14 with the first end plate 30 (see FIG. 10) interposed therebetween. In the present embodiment, the radius of the balancer 34 is slightly smaller than the radius of the rotor core 26.

  As shown in FIGS. 1, 3, and 4, the magnet facing surface 36 is provided with a recess 40 that is recessed in a direction away from the rotor 14 via a boundary stepped portion 38. Furthermore, the depth of the recess 40 is set to 2 mm or more.

  As shown in FIG. 2, the boundary step portion 38 has a V-shape that is convex toward the rotation shaft 24 when viewed from the axial direction of the rotation shaft 24, and further, the center line of the permanent magnet 28 It is provided to pass. Furthermore, the V-shaped end portion drawn by the boundary stepped portion 38 reaches the outer peripheral surface of the balancer 34. That is, the outer peripheral surface side of the balancer 34 in the recess 40 is configured to be opened.

In FIG. 2, the rotor core 26 and the like are omitted in order to easily understand the positional relationship between the boundary stepped portion 38 and the permanent magnet 28.
(Action / Effect)
Here, the inventor of the present application analyzed the magnetic flux density distribution of the motor 10 by FEM.

  In FIG. 7, the magnetic flux density of the motor using the conventional balancer having no recess is represented by a vector, and in FIG. 6, the magnetic flux density of the motor 10 using the balancer 34 having the recess 40 is represented by the vector. It is represented. The longer and thicker the vector, the higher the magnetic flux density.

  As shown in FIG. 7, when a conventional balancer having no recess is used, it can be seen that a large amount of magnetic flux leaks from the rotor to the balancer side. Further, it can be seen that the leaked magnetic flux makes a U-turn in the balancer and is incident from the balancer side to the rotor side in the vicinity of the outer periphery of the balancer. Thus, it can be seen that there are many magnetic fluxes in the vicinity of the outer periphery of the balancer.

  On the other hand, as shown in FIG. 6, when the balancer 34 having the recess 40 is used, it can be seen that the leakage of magnetic flux is reduced. And it turns out that a magnetic field is small because leakage becomes small.

  Furthermore, this inventor investigated about the relationship between the depth of the recessed part 40, and a leakage magnetic flux.

  The vertical axis of the graph shown in FIG. 8 indicates the leakage magnetic flux, and the horizontal axis indicates the depth of the recess 40. Moreover, the solid line of a graph shows the relationship between the depth of the recessed part 40 and leakage magnetic flux, and a dotted line shows the leakage magnetic flux of the motor which is not provided with a balancer. That is, even if the balancer 34 is removed from the motor 10, it can be seen that leakage magnetic flux is generated. As shown in FIG. 8, it can be seen that the leakage flux decreases as the depth of the recess 40 increases. However, when the depth is 2 mm or more, the leakage flux is constant even if the depth of the recess 40 changes. I understand.

  Thus, as can be understood from the analysis of the inventors of the present application, the permanent magnet provided in the rotor 14 is provided by providing the concave portion 40 on the magnet facing surface 36 of the balancer 34 as compared with the configuration in which the concave portion 40 is not provided. It is possible to prevent the magnetic flux from leaking from 28 to the balancer 34 side.

  Moreover, it can suppress that the rotational characteristic of the motor 10 falls by suppressing that a magnetic flux leaks from the permanent magnet 28 to the balancer 34 side.

  Further, even when the permanent magnet 28 is arranged in a V shape, it is possible to prevent the magnetic flux from leaking from the permanent magnet 28 to the balancer 34 side by providing the recess 40 on the magnet facing surface 36 of the balancer 34.

  Further, by providing the boundary stepped portion 38 so as to pass through the center line of the permanent magnet 28, the magnet facing surface 36 can support the permanent magnet 28 with a good balance.

  Further, by opening the outer peripheral surface side of the balancer 34 in the recess 40, magnetic flux leaks from the radially outer side of the rotor 14 to the balancer 34 side, or magnetic flux enters the rotor 14 from the radially outer side of the balancer 34. Can be effectively suppressed.

  Further, by setting the depth of the recess 40 to 2 mm or more, it is possible to suppress the leakage of magnetic flux from the permanent magnet 28 provided on the rotor 14 to the balancer 34 side as compared to the case where the depth is shallower than 2 mm. it can.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. For example, in the above-described embodiment, the permanent magnets 28 are arranged in a V shape. However, the permanent magnets 28 may not be particularly V-shaped, and other arrangement forms may be used.

  Next, a second embodiment of the motor 50 of the present invention will be described with reference to FIG.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 11, in this embodiment, unlike the first embodiment, the boundary step portion 60 between the magnet facing surface 36 and the recess 40 has a recessed surface where the exposed surface of the permanent magnet 28 is recessed from the center line of the permanent magnet 28. It is provided in a direction in which the area facing 40 is increased. That is, the boundary stepped portions 60 that face each other with the concave portion 40 interposed therebetween are provided in directions away from each other with respect to the first embodiment.

    In FIG. 11, in order to easily understand the positional relationship between the boundary stepped portion 60 and the permanent magnet 28, the rotor core 26 and the like are omitted.

  Thus, by providing the boundary stepped portion 60 in the direction in which the opposed area of the exposed surface of the permanent magnet 28 and the recess 40 increases, it is possible to effectively suppress the leakage of magnetic flux from the permanent magnet 28 to the balancer 34 side. Can do.

It is the perspective view which showed the balancer etc. which were employ | adopted as the motor which concerns on 1st Embodiment of this invention. It is the front view which showed the permanent magnet etc. which were provided in the magnet opposing surface of the balancer employ | adopted as the motor which concerns on 1st Embodiment of this invention, and a rotor core. It is the side view which showed the balancer, the rotor, etc. which were employ | adopted as the motor which concerns on 1st Embodiment of this invention. It is FF sectional drawing in FIG. 3 which showed the balancer, rotor, etc. which were employ | adopted as the motor which concerns on 1st Embodiment of this invention. It is the perspective view which showed the permanent magnet provided in the rotor employ | adopted for the motor which concerns on 1st Embodiment of this invention, and the rotor. In the motor which concerns on 1st Embodiment of this invention, it is drawing which showed the magnetic flux density between a rotor and a balancer by the vector. It is drawing which showed the magnetic flux density between a rotor and the conventional balancer by the vector as a comparison of the magnetic flux density between the rotor and balancer of the motor which concerns on 1st Embodiment of this invention. In the motor which concerns on 1st Embodiment of this invention, it is drawing which showed the relationship between the depth of a recessed part, and leakage magnetic flux. It is the front view which showed the rotor, the stator, etc. which were employ | adopted as the motor which concerns on 1st Embodiment of this invention. It is the side view which showed the rotor, the stator, etc. which were employ | adopted as the motor which concerns on 1st Embodiment of this invention. It is the front view which showed the permanent magnet etc. which were provided in the magnet opposing surface of the balancer employ | adopted as the motor which concerns on 1st Embodiment of this invention, and a rotor core.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Motor (rotary electric machine), 14 ... Rotor, 24 ... Rotating shaft (Rotating shaft member), 26 ... Rotor core, 26A ... Housing hole, 28 ... Permanent magnet (Embedded) Magnet), 34 ... balancer, 36 ... magnet facing surface, 38 ... boundary step, 40 ... recess, 50 ... motor (rotary electric machine), 60 ... boundary step

Claims (6)

A rotating shaft member rotatably supported;
A rotor comprising: a rotor core fixed to the rotary shaft member and having a plurality of receiving holes formed in a circumferential direction penetrating in the axial direction of the rotary shaft member; and an embedded magnet received in the receiving hole of the rotor core. When,
A balancer that is fixed to the rotary shaft member side by side in the axial direction of the rotor core and the rotary shaft member, includes a magnet facing surface that faces the embedded magnet of the rotor, and suppresses rotational fluctuations of the rotary shaft member; ,
With
The magnet facing surface of the balancer is provided with a recess recessed in a direction away from the rotor,
The rotating electric machine characterized in that an area where the exposed surface of the embedded magnet faces the concave portion is equal to or larger than an area where the exposed surface of the embedded magnet faces the magnet facing surface.   The shape of the storage hole provided in the rotor core is rectangular, the embedded magnet is plate-shaped, and the adjacent storage holes are arranged in a V shape projecting radially inward. The rotating electrical machine according to claim 1.   The rotating electrical machine according to claim 2, wherein a boundary step portion between the magnet facing surface and the concave portion has a V shape and passes through a center line of the embedded magnet.   The boundary step between the magnet facing surface and the recess has a V shape, and the exposed surface of the embedded magnet is provided in a direction in which the area facing the recess is larger than the center line of the embedded magnet. The rotating electrical machine according to claim 2, wherein   5. The rotating electrical machine according to claim 1, wherein an outer peripheral surface side of the balancer in the recess is open.   The rotary electric machine according to any one of claims 1 to 5, wherein a depth of the concave portion is 2 mm or more.

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