JP2016096670A - Rotor, and motor and compressor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor, a motor, and a compressor capable of maintaining a yield at a manufacturing step.SOLUTION: A rotor 10 comprises a rotor core 20 and an end plate 30. The rotor core 20 is in a columnar shape having an upper surface, a lower surface, and a central axis C. The end plate 30 covers the upper surface or the lower surface of the rotor core 20. The rotor core 20 is formed with a shaft holding hole 21 and a fluid passage 22. The shaft holding hole 21 has a circular cross section using a point on the central axis C of the rotor core 20 as the center, and extending in a direction in which the central axis C extends. The fluid passage 22 extends in parallel to the central axis C of the rotor core 20. An opening formed on the end plate 30 includes a shaft passing opening and a recessed part. The shaft passing opening is communicated with the shaft holding hole 21. The recessed part is communicated with the fluid passage 22, and extends radially outward from the shaft passing opening.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotor, and a motor and a compressor using the rotor.

  Some motors have a rotor with embedded permanent magnets. Such a magnet-embedded rotor constitutes a motor together with a stator including an exciting coil that generates a magnetic flux by passing a current. Such a motor is mounted on, for example, a compressor of an outdoor unit of an air conditioner.

  Japanese Patent Laid-Open No. 6-269140 discloses an example of a magnet embedded rotor. This rotor has a rotor core and two end plates attached to the upper and lower surfaces of the rotor core. The rotor core is formed with a shaft holding hole for holding a shaft that functions as a rotating shaft of the rotor. Each of the two end plates is formed with a shaft passage opening for allowing the shaft to pass therethrough.

  The manufacturing process of such a rotor usually includes a shrink fitting process for fixing the shaft to the rotor. This shrink fitting process is performed by the following procedure. First, the end plate is attached to the rotor core. Next, the vicinity of the shaft holding hole of the rotor core is heated. By this heating, the rotor core expands and the shaft holding hole slightly expands. Next, the shaft is inserted into the shaft holding hole in which the rotor core is widened and the shaft passage opening of the end plate. Finally, the shaft holding hole is narrowed by the temperature drop of the rotor, and the shaft is firmly held by the contracted rotor core.

  In the shrink fitting process, not only the rotor core is heated, but also the temperature of the end plate is increased. Particularly, the vicinity of the shaft passage opening of the end plate becomes high temperature. This excessive local temperature rise can cause problems such as warping and deformation of the end plate. In particular, when another hole is provided for some purpose in the vicinity of the shaft passage opening portion of the end plate, the portion of the end plate existing between the shaft passage opening portion and the hole is provided. Due to factors such as the concentration of heat, the occurrence of defects becomes more prominent, and the yield of rotor manufacture can deteriorate. If the heating target temperature is set low in order to avoid this problem, a defect in the fixed state between the shaft and the rotor occurs, and the yield of rotor production is deteriorated.

  The subject of this invention is providing the rotor which can maintain a yield in a manufacturing process. The further subject of this invention is providing the motor and compressor which can maintain a yield in a manufacturing process.

  A rotor according to a first aspect of the present invention includes a rotor core and an end plate. The rotor core has a cylindrical shape having an upper surface, a lower surface, and a central axis. The end plate covers the upper surface or the lower surface of the rotor core. The rotor core is formed with a first through hole and at least one second through hole. The first through hole has a circular cross section centered on a point on the central axis of the rotor core, and extends in a direction in which the central axis extends. At least one second through hole extends in parallel with the central axis of the rotor core. An opening is formed in the end plate. The opening includes a shaft passing opening and at least one recess. The shaft passage opening communicates with the first through hole. The at least one recess communicates with the second through hole and extends outward in the radial direction from the shaft passage opening.

  According to this configuration, it is possible to suppress heat from being excessively accumulated in the end plate. As a result, the yield can be maintained in the rotor manufacturing process.

  A rotor according to a second aspect of the present invention is the rotor according to the first aspect, wherein a plurality of second through holes are formed in the rotor core. The opening formed in the end plate includes a plurality of recesses.

  According to this configuration, even in a rotor manufacturing process that requires a plurality of second through holes, the yield can be maintained by the plurality of recesses.

  The rotor which concerns on the 3rd viewpoint of this invention is a rotor which concerns on a 2nd viewpoint, and an end plate is a disk shape.

  According to this configuration, the shape of the end plate substantially matches the shape of the rotor. As a result, since the exposed area of the rotor core decreases, it is possible to suppress the rotor core from being affected by some external factor.

  A rotor according to a fourth aspect of the present invention is the rotor according to the second aspect, wherein the end plate has a polygonal shape or a regular polygonal shape.

  According to this structure, the outline of an end plate consists of a linear side. As a result, the manufacture or processing of the end plate can be made easier.

  A rotor according to a fifth aspect of the present invention is the rotor according to the third aspect, wherein the end plate includes an annular portion and a plurality of convex portions. The plurality of convex portions extend from the annular portion toward the inside in the radial direction to the shaft passing opening. Each of the plurality of concave portions is located between two adjacent ones of the plurality of convex portions. The opening is gear-shaped.

  According to this configuration, it is possible to further suppress local heat concentration from occurring at any part of the end plate.

  A rotor according to a sixth aspect of the present invention is the rotor according to any one of the first to fifth aspects, wherein the rotor core has a plurality of stacked steel plates. The end plate is a nonmagnetic material.

  According to this configuration, the magnetic flux generated from the rotor can be directed in an appropriate direction. As a result, energy efficiency is increased.

  A rotor according to a seventh aspect of the present invention is the rotor according to any one of the first to sixth aspects, further comprising a permanent magnet and a fastener. The fastener is for fixing the rotor core and the end plate. The rotor core is further formed with a third through hole and a fourth through hole. The third through hole extends in parallel with the central axis and accommodates a permanent magnet. The fourth through hole extends in parallel with the central axis and allows the fastener to pass therethrough. A fastener passage hole is further formed in the end plate. The fastener passage hole communicates with the fourth through hole.

  According to this configuration, the rotor can perform magnetic interaction with the outside. In addition, the rotor core and the end plate can be fixed to each other.

  A rotor according to an eighth aspect of the present invention is the rotor according to any one of the first to seventh aspects, wherein the second through-hole extends in the circumferential direction of the rotor core, or a circular shape. Having a cross section.

  This configuration includes a plurality of specific design examples for the second through hole. From these, according to various conditions such as the cross-sectional area of the second through-hole to be secured and the area of the end plate to be secured, the designer, manufacturer, or similar person should select the optimum configuration. Can do.

  A motor according to a ninth aspect of the present invention includes the rotor according to any one of the first to eighth aspects, a shaft, and a coil. The shaft is shrink fitted into the first through hole. The coil can rotate the rotor and shaft by passing an electric current.

  According to this configuration, the yield can be maintained in the motor manufacturing process.

  A compressor according to a tenth aspect of the present invention includes the motor according to the ninth aspect and a compression mechanism. The compression mechanism compresses the fluid by the rotation of the shaft.

  According to this configuration, the yield can be maintained in the compressor manufacturing process.

  According to the rotor according to the first aspect or the second aspect of the present invention, the yield can be maintained in the manufacturing process.

  According to the rotor according to the third aspect of the present invention, it is possible to suppress the rotor core from being affected by some external factor.

  According to the rotor according to the fourth aspect of the present invention, it is possible to more easily manufacture or process the end plate.

  According to the rotor according to the fifth aspect of the present invention, it is possible to further suppress the local concentration of heat in any part of the end plate.

  The rotor according to the sixth aspect of the present invention increases the energy efficiency of the motor.

  According to the rotor according to the seventh aspect of the present invention, magnetic interaction with the outside can be realized. In addition, the rotor core and the end plate can be fixed to each other.

  According to the rotor according to the eighth aspect of the present invention, those skilled in the art can use a more specific design concept.

  According to the motor of the ninth aspect of the present invention, the yield can be maintained in the manufacturing process of the motor.

  According to the compressor concerning the 10th viewpoint of the present invention, a yield can be maintained in a manufacturing process of a compressor.

The top view of the rotor which concerns on 1st Embodiment of this invention. The top view of the end plate which comprises the rotor which concerns on 1st Embodiment of this invention. Sectional drawing along the III-III line of FIG. Sectional drawing along the IV-IV line of FIG. 1 is a schematic view of a motor using a rotor according to a first embodiment of the present invention. The schematic block diagram of the compressor using the motor shown in FIG. The top view of the end plate which comprises the rotor which concerns on the modification 1A of 1st Embodiment of this invention. The top view of the end plate which comprises the rotor which concerns on the modification 1B of 1st Embodiment of this invention. The top view of the rotor which concerns on 2nd Embodiment of this invention. The top view of the end plate which comprises the rotor which concerns on 2nd Embodiment of this invention. The top view of the rotor which concerns on 3rd Embodiment of this invention. The top view of the rotor which concerns on 4th Embodiment of this invention.

<First Embodiment>
Hereinafter, a first embodiment of a rotor, a motor, and a compressor according to the present invention will be described with reference to FIGS.

(1) Configuration of Rotor 10 FIGS. 1, 3, and 4 show the rotor 10 according to the first embodiment of the present invention. The rotor 10 includes a rotor core 20, an end plate 30, a permanent magnet 40, and a fastener 50. However, the fastener 50 is omitted in FIG. The rotor 10 is formed with a shaft attachment hole 11 for attaching a shaft 60 (see FIG. 5).

(1-1) Rotor core 20
The rotor core 20 is formed of a plurality of stacked steel plates and has a cylindrical shape having a central axis C as a whole. As shown in FIG. 1, the rotor core 20 accommodates a shaft holding hole 21 for holding a shaft 60 (see FIG. 5), a fluid passage 22 for allowing a fluid such as a refrigerant gas to pass therethrough, and a permanent magnet 40. The magnet accommodation hole 23 and the fastener accommodation hole 24 for accommodating the fastener 50 (refer FIG. 4) are formed.

  The shaft holding hole 21, the fluid passage 22, the magnet accommodation hole 23, and the fastener accommodation hole 24 are all through holes that penetrate the rotor core 20 in the direction of the central axis C.

  The cross-sectional shape of the shaft holding hole 21 is a circle, and the center of the circle is on the central axis C of the rotor core 20.

  Six fluid passages 22 are formed. The cross section of each fluid passage 22 has a shape extending in the circumferential direction of the rotor core 20. The fluid passages 22 are evenly spaced along the same virtual circumference. That is, as apparent from FIG. 1, the interval between adjacent fluid passages corresponds to a central angle of 60 °.

(1-2) End plate 30
The end plate 30 is for preventing the permanent magnet 40 from going out of the magnet housing hole 23. As shown in FIGS. 3 and 4, end plates 30 are attached to the upper surface 25 and the lower surface 26 of the rotor core 20, respectively. The end plate 30 is made of stainless steel which is a nonmagnetic material.

  FIG. 2 shows only one end plate 30. The end plate 30 has a disk shape, and the end plate 30 has a circular outline. The end plate 30 has an annular portion 37 and six convex portions 38 that protrude from the annular portion 37 inward in the radial direction.

  An opening 31 is formed in the end plate 30. The opening 31 includes a shaft passing opening 311 and six recesses 39 extending outward from the shaft passing opening 311 in the radial direction. Therefore, the opening 31 has a shape like a gear as a whole. Each recess 39 is located between two adjacent protrusions 38. Two opposing sides of the concave portion 39 located across one fluid passage 22 extend in parallel.

  Further, the end plate 30 is formed with a fastener passage hole 34 for allowing the fastener 50 (see FIG. 4) to pass therethrough.

  The annular portion 37 occupies a region between the outer periphery 35 and the virtual circle 312. The convex portion 38 extends from a virtual circle 312 that is an edge of the annular portion 37 to the shaft passing opening 311.

  The six convex portions 38 are evenly spaced along the virtual circle 312. Similarly, the six recesses 39 are equally spaced along the virtual circle 312.

  As shown in FIG. 1, when the end plate 30 is attached to the rotor core 20, the fluid passage 22 of the rotor core 20 and the concave portion 39 of the end plate 30 overlap each other. Furthermore, the shaft mounting hole 11 of the rotor 10 is formed by overlapping the shaft holding hole 21 of the rotor core 20 and the opening 31 of the end plate 30.

(1-3) Permanent magnet 40
The permanent magnet 40 is for giving a magnetic pole to the rotor 10. As shown in FIG. 1, six permanent magnets 40 are attached to the rotor 10. As shown in FIG. 3, each permanent magnet 40 is accommodated in the magnet accommodation hole 23.

(1-4) Fastener 50
The fastener 50 shown in FIG. 4 is for fixing the rotor core 20 and the two end plates 30 to each other. The fastener 50 is, for example, a rivet, a bolt and a nut, or the like. The fastener 50 includes a fastener passage hole 34 formed in the end plate 30 on the upper surface 25 side, a fastener receiving hole 24 formed in the rotor core 20, and a fastener passage hole 34 formed in the end plate 30 on the lower surface 26 side. , Arranged to pass through. Thereafter, the rotor core 20 and the end plate 30 are fixed to each other by a method such as caulking the lower end of the fastener 50.

(1-5) Supplement In the first embodiment described above, the number of the fluid passages 22, the convex portions 38, the concave portions 39, and the permanent magnets 40 is all six. Various changes can be made according to the usage conditions.

(2) Configuration of Motor 80 FIG. 5 is a schematic diagram of a motor 80 configured using the rotor 10 described above. The motor 80 has a casing 81 and the rotor 10 and the stator 70 installed therein.

  A shaft 60 is fixed to the shaft mounting hole 11 of the rotor 10 by shrink fitting.

  The stator 70 is provided with a plurality of exciting coils 71. The plurality of exciting coils 71 are sequentially excited according to a predetermined sequence, whereby the rotor 10 rotates together with the shaft 60.

(3) Configuration of Compressor 90 FIG. 6 is a schematic block diagram of a compressor 90 configured using the motor 80 described above. The compressor 90 is mounted on, for example, an outdoor unit of an air conditioner.

  The compressor 90 has a compression mechanism 91. The compression mechanism 91 is for compressing the fluid refrigerant. The refrigerant compression operation of the compression mechanism 91 is executed by the power supplied by the rotating shaft 60.

(4) Shrink Fit Process The manufacturing process of the motor 80 includes a shrink fit process in which the shaft 60 is fixed to the shaft mounting hole 11 by heating the rotor 10. In this shrink fitting process, a technique called “high frequency induction heating” is often used. This technique is performed in the following procedure.

  First, the rotor 10 is prepared by combining the rotor core 20, the end plate 30, the permanent magnet 40, and the fastener 50.

  Next, a heating coil is disposed in the shaft attachment hole 11 of the rotor 10, and a high-frequency alternating current is passed through the heating coil. This alternating current generates an alternating magnetic field. Furthermore, this alternating magnetic field generates an eddy current on the inner surface of the shaft mounting hole 11. This eddy current generates Joule heat due to the electrical resistance of the laminated steel sheet and raises the temperature in the vicinity of the shaft mounting hole 11. As a result, the rotor core 20 expands, and the inner diameter of the shaft holding hole 21 of the rotor core 20 slightly increases.

  Thereafter, the flow of alternating current through the heating coil is stopped, and the heating coil is removed from the shaft mounting hole 11. Immediately thereafter, the shaft is inserted into the shaft mounting hole 11.

  Finally, if the temperature of the rotor 10 decreases, the inner diameter of the shaft holding hole 21 becomes smaller again, and the shaft is held firmly.

  The shrink fitting process may be performed by a technique other than “high frequency induction heating”. Moreover, the location to be heated is not limited to the vicinity of the shaft holding hole 21 of the rotor 10. For example, the entire rotor 10 may be heated. One possible shrink fit method is to heat the rotor 10 in a furnace.

(5) Features (5-1) Formation of Recess 39 As described above, the recess 39 is formed in the end plate 30. As shown in FIG. 1, the rotor core 20 has a relatively thin partition wall portion 27 located between the shaft holding hole 21 and the fluid passage 22. In a state where the end plate 30 is attached to the rotor core 20, the end plate 30 does not completely cover the partition wall portion 27.

(5-2) Action of Recess 39 In the shrink fitting process for fixing the shaft 60 to the rotor 10, not only the rotor core 20 but also the end plate 30 is heated, so that the vicinity of the shaft passage opening 311 of the end plate 30 is It becomes hot.

  If the end plate 30 has a narrow portion that completely covers the partition wall portion 27 of the rotor core 20, the heat transferred to the narrow portion cannot escape to the outside in the radial direction by conduction, and the narrow portion The heat would have accumulated. Thus, the narrow portion would have experienced an excessive temperature rise and would induce inconveniences such as end plate 30 deformation and warping.

  The end plate 30 constituting the rotor 10 according to the present embodiment does not have such a narrow portion due to the formation of the recess 39. Therefore, the occurrence of defects in the shrink-fitting process is suppressed, and the manufacturing yield of the rotor 10 is expected to be maintained or improved. Also, due to this, the production yield of the motor 80 and the compressor 90 is expected to be maintained or improved.

(6) Modification Examples of the present embodiment are shown below. It should be noted that a plurality of modified examples may be appropriately combined within a range that is consistent with each other.

(6-1) Modification 1A
FIG. 7 shows a modification 1A of the above embodiment. The end plate 30 according to the modified example 1A is the same as the first embodiment except that the shape of the recess 39 is different. In the concave portion 39 of the modified example 1A, the two opposing sides located across the one fluid passage 22 are not parallel but extend radially.

  Such an end plate 30 also does not have a narrow portion that completely covers the partition wall portion 27 of the rotor core 20, and therefore can contribute to maintaining or improving the manufacturing yield of the rotor 10, the motor 80, and the compressor 90.

(6-2) Modification 1B
FIG. 8 shows a modification 1B of the above embodiment. The end plate 30 according to the modified example 1B is the same as the first embodiment except that the shape of the recess 39 is different. In the concave portion 39 of the modified example 1B, two opposing sides that are located across the one fluid passage 22 are curved.

  Such an end plate 30 also does not have a narrow portion that completely covers the partition wall portion 27 of the rotor core 20, and therefore can contribute to maintaining or improving the manufacturing yield of the rotor 10, the motor 80, and the compressor 90.

Second Embodiment
Next, a second embodiment of the rotor, motor, and compressor according to the present invention will be described with reference to FIGS.

  As shown in FIGS. 9 and 10, the rotor, the motor, and the compressor according to the second embodiment have the shapes of the fluid passage 22 ′ of the rotor core 20 and the convex portions 38 ′ and the concave portions 39 ′ of the end plate 30. This embodiment is different from the first embodiment, and is otherwise the same as the first embodiment.

  In the rotor core 20 according to the second embodiment, a fluid passage 22 ′ having a circular cross section is formed instead of the fluid passage 22 having a cross section extending in the circumferential direction of the rotor core 20.

  Further, the end plate 30 according to the second embodiment is provided with a convex portion 38 ′ and a concave portion 39 ′ shaped so as to fit the circular fluid passage 22 ′.

  The end plate 30 according to the second embodiment also has no narrow portion due to the formation of the recess 39 '. Therefore, the occurrence of problems in the shrink-fitting process is suppressed, and the manufacturing yield of the rotor 10, the motor 80, and the compressor 90 is expected to be maintained or improved.

<Third Embodiment>
Next, a third embodiment of the rotor, motor, and compressor according to the present invention will be described with reference to FIG.

  As shown in FIG. 11, the rotor, the motor, and the compressor according to the third embodiment are different from the first embodiment in that the end plate 30 has a dodecagonal outline, and in other points. Is the same as in the first embodiment.

  In this way, by adopting a contour composed of straight sides, the end plate 30 can be manufactured or processed more easily.

<Fourth embodiment>
Next, a fourth embodiment of the rotor, motor, and compressor according to the present invention will be described with reference to FIG.

  As shown in FIG. 12, the rotor, the motor, and the compressor according to the fourth embodiment are different from the first embodiment in that the end plate 30 has a regular hexagonal outline, and in other points. The same as in the first embodiment.

  In this way, by adopting a contour composed of straight sides, the end plate 30 can be manufactured or processed more easily.

<Other modifications>
Specific configurations of the rotor, the motor, and the compressor according to the present invention are not limited to the above-described embodiments and modifications. For example, the number of permanent magnets 40, the number of exciting coils 71, the number and shape of the fluid passages 22 of the rotor core 20, the number and shape of the concave portions 39 of the end plate 30, or other elements do not depart from the spirit of the invention. The range can be changed as appropriate. For example, the rotor core 20
The plurality of fluid passages 22 or the plurality of convex portions 38 and the plurality of concave portions 39 in the end plate 30 may not be evenly spaced. Further, the contour of the end plate is not limited to the disk shape or the polygonal shape, but may be an elliptical shape or a shape having a curved side and a straight side.

  INDUSTRIAL APPLICABILITY The present invention can be used for motors and compressors mounted on products in all technical fields including outdoor units for air conditioners.

C Central axis 10 Rotor 11 Shaft mounting hole 20 Rotor core 21 Shaft holding hole 22 Fluid passage 22 'Fluid passage 23 Magnet housing hole 24 Fastener housing hole 25 Upper surface 26 Lower surface 27 Partition portion 30 End plate 31 Opening 311 Shaft passage opening 312 Virtual circle 34 Fastener passing hole 35 Outer periphery 37 Annular part 38 Convex part 38 'Convex part 39 Concave part 39' Concave part 40 Permanent magnet 50 Fastener 60 Shaft 70 Stator 71 Excitation coil 80 Motor 81 Casing 90 Compressor 91 Compression mechanism

JP-A-6-269140

Claims (10)

A cylindrical rotor core (20) having an upper surface (25), a lower surface (26), and a central axis (C);
An end plate (30) covering the upper surface or the lower surface;
With
In the rotor core,
A first through hole (21) having a circular cross section centered on a point on the central axis and extending in a direction in which the central axis extends;
At least one second through hole (22, 22 ') extending parallel to the central axis;
Is formed,
In the end plate,
A shaft passage opening (311) communicating with the first through hole;
At least one recess (39, 39 ′) communicating with the second through hole and extending radially outward from the shaft passage opening;
An opening (31) containing is formed,
Rotor (10). A plurality of the second through holes are formed in the rotor core,
In the end plate, the opening including a plurality of the recesses is formed.
The rotor according to claim 1. The end plate has a disk shape,
The rotor according to claim 2. The end plate has a polygonal shape or a regular polygonal shape.
The rotor according to claim 2. The end plate is
An annulus (37);
A plurality of convex portions (38, 38 ') extending from the annular portion toward the shaft passing opening toward the inside in the radial direction;
Including
Each of the plurality of concave portions is located between two adjacent ones of the plurality of convex portions,
The opening is gear-shaped,
The rotor according to claim 3. The rotor core has a plurality of laminated steel plates,
The end plate is a non-magnetic material.
The rotor according to any one of claims 1 to 5. A permanent magnet (40);
A fastener (50) for fixing the rotor core and the end plate;
Further comprising
In the rotor core,
A third through hole (23) for accommodating the permanent magnet, extending parallel to the central axis;
A fourth through hole (24) for passing the fastener, extending parallel to the central axis;
Is further formed,
In the end plate,
A fastener passage hole (34) communicating with the fourth through hole,
Is further formed,
The rotor according to any one of claims 1 to 6. The second through hole has a cross section (22) or a circular cross section (22 ′) extending in the circumferential direction of the rotor core,
The rotor according to any one of claims 1 to 7. A rotor according to any one of claims 1 to 8,
A shaft (60) shrink-fitted into the first through hole;
A coil (71) capable of rotating the rotor and the shaft by passing an electric current;
A motor (80) comprising: A motor according to claim 9;
A compression mechanism (91) for compressing fluid by rotation of the shaft;
A compressor (90).

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