JP2014150695A - Permanent magnet motor, sealed compressor and refrigeration cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet motor in which the total length of permanent magnets housed in the magnet housing hole of a rotor is increased, and a portion hard to be magnetized can be reduced, and to provide a sealed compressor and a refrigeration cycle device.SOLUTION: A permanent magnet motor includes a stator having a stator winding, and a rotor 11 housing permanent magnets, respectively, in a plurality of magnet housing holes 14 provided in a rotor core 12. The magnet housing hole 14 has an arcuate housing part 14a where the convex side faces the center O side of the rotor core 12 in the plan view, and linear housing parts 14b, 14c formed on both end sides of the arcuate housing part 14a. An arcuate permanent magnet 16 is housed in the arcuate housing part 14a, and planar permanent magnets 17a, 17b are housed, respectively, in the linear housing parts 14b, 14c.

Description

  Embodiments described herein relate generally to a permanent magnet motor, a hermetic compressor, and a refrigeration cycle apparatus.

  Conventionally, in a refrigeration cycle apparatus, it is known to use a permanent magnet motor as a drive source for the hermetic compressor.

  In general, this type of permanent magnet motor includes a stator having a fixed winding and a rotor in which permanent magnets are housed in a plurality of magnet housing holes provided in the rotor core.

  As shown in FIG. 9, as an example of a rotor 1 of a conventional permanent magnet electric motor, a planar rotor core 2 around a center O of a shaft hole 3 into which a rotation shaft (not shown) is inserted is substantially planar. A plurality of V-shaped magnet housing holes 4, 4,... Are formed in the axial direction. In each of the magnet housing holes 4, two flat permanent magnets 5 and 6 having a parallel magnetic field orientation 7 shown in FIG.

  In another conventional permanent magnet motor, the magnet housing hole formed in the rotor core is formed in a trapezoidal shape in plan view with the convex side facing the center side of the rotor core. There is known a rotor that houses flat plate-like permanent magnets on the sides (see, for example, Patent Document 1).

JP 2001-178045 A

  However, in the conventional rotor shown in FIG. 9, the two flat permanent magnets 5 and 6 are accommodated in each V-shaped magnet accommodating hole 4, so that the center O side of the shaft hole 3 is located. There is a problem that a space portion 4a in which the permanent magnets 5 and 6 do not exist is formed on the V-shaped pointed end side of the facing magnet housing hole 4.

  That is, the plate-like permanent magnets 5 and 6 respectively accommodated in the V-shaped magnet housing hole 4 are in contact with each other at the V-shaped pointed ends of the magnet housing holes 4 at the inner ends in the width direction. Since it cannot be inserted further to the center O side, a substantially triangular space 4a is formed.

  For this reason, since the total length of the two permanent magnets 5 and 6 accommodated in each magnet accommodation hole 4 is shortened, the amount of magnetic flux of the rotor 1 is reduced accordingly, and the permanent magnet motor Incurs performance degradation.

  Moreover, in each magnet accommodation hole 4, the raw material before magnetizing as the permanent magnets 5 and 6, for example, flat materials, such as a ferrite, are accommodated, From the outer peripheral side of the rotor 1, it is the structure substantially the same as a stator. When a magnetic field is applied by a magnetizer, the space portions 4a themselves of the magnet housing holes 4, 4,... Are not magnetized, and the periphery of the space portion 4a is the center O of the shaft hole 3. Since it is located in the deep part near the side and is far from the magnetizer, there is a problem that it is difficult to magnetize.

  For this reason, since the magnetic flux amount of the rotor 1 is reduced, the performance of the permanent magnet motor is deteriorated.

  Further, the rotor described in Patent Document 1 also accommodates a plate-like permanent magnet in one of the trapezoidal magnet accommodation holes at three locations, that is, the top side of the trapezoid and the oblique sides on both sides thereof. Therefore, a gap is easily generated between these three permanent magnets.

  For this reason, it has the subject similar to the prior art example which has the said V-shaped magnet accommodation hole.

  The problem to be solved by the present invention is to increase the total length of the permanent magnets accommodated in the magnet accommodation holes of the rotor, and to reduce the number of parts that are difficult to be magnetized, and to seal An object of the present invention is to provide a mold compressor and a refrigeration cycle apparatus.

  The permanent magnet motor according to the embodiment includes a stator having a stator winding, and a rotor that houses permanent magnets in a plurality of magnet housing holes provided in the rotor core.

  The magnet housing hole has an arcuate housing portion whose convex side faces the center side of the rotor core in a plan view, and linear housing portions formed on both ends of the arcuate housing portion. An arc-shaped permanent magnet is accommodated in the portion, and a plate-shaped permanent magnet is accommodated in the linear accommodating portion.

The top view of the rotor of the permanent magnet electric motor of an embodiment. (A) is a figure which shows the radial magnetic field orientation of the arc-shaped permanent magnet accommodated in the arc-shaped accommodation part of the magnet accommodation hole of the rotor shown in FIG. 1, (B) is the linear accommodation of the magnet accommodation hole. The figure which shows the parallel magnetic field orientation of the flat permanent magnet accommodated in each part. (A) is the analysis figure of the magnetic flux which flows at the time of magnetization of the rotor which concerns on embodiment shown in FIG. 1, (B) is a graph which shows the magnetic flux density of an arc-shaped permanent magnet and its peripheral part. (A) is an analysis figure of the magnetic flux which flows at the time of the magnetization of the conventional rotor shown in FIG. 9, (B) is a graph which shows the magnetic flux density of a V-shaped point part and its periphery part. (A) is a figure which shows the total length of the permanent magnet each accommodated in each magnet accommodation hole of the rotor which concerns on embodiment shown in FIG. 1 etc., (B) is a figure of the conventional rotor shown in FIG. The figure which shows the total length of the permanent magnet accommodated in each V-shaped magnet accommodation hole, respectively. In the case where the number of magnetic poles of the permanent magnet motor is 6, the outer diameter of the rotor is φ65, and the inner diameter is φ16, the total length of the magnets accommodated in each magnet accommodation hole is as shown in FIG. 10 is a graph showing a comparison with the conventional example shown in FIG. 9. When the number of magnetic poles of the permanent magnet motor is 4, the outer diameter of the rotor is φ65, and the inner diameter is φ16, the total length of the magnets accommodated in each magnet accommodation hole is as shown in FIG. 10 is a graph showing a comparison with the conventional example shown in FIG. 9. The figure which shows the whole structure of the refrigerating-cycle apparatus provided with this sealed compressor while showing a part of sealed compressor which comprised the permanent magnet electric motor which concerns on embodiment shown in FIG. The top view of the rotor of the conventional permanent magnet electric motor. The figure which shows the parallel magnetic field orientation of the permanent magnet accommodated in the V-shaped magnet accommodation hole shown in FIG.

  Hereinafter, the present embodiment will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent part in several drawing.

(First embodiment)
The permanent magnet motor according to the first embodiment includes a rotor 11 shown in FIG. 1 and a stator 24a shown in FIG. 8 and described later.

  As shown in FIG. 1, the rotor 11 is formed around the center of a shaft hole 13 in which a rotation shaft (not shown) of a cylindrical rotor core 12 is inserted and fixed by press-fitting or the like, that is, around the center O of the rotor 11. A plurality of magnet housing holes 14, 14,.

  The rotor core 12 is formed in a cylindrical shape by laminating a plurality of thin circular plates made of electromagnetic steel plates or the like in the axial direction, and a plurality of rivet insertion holes 15 through which rivets (not shown) are inserted are formed around the center O. doing.

  Each magnet housing hole 14 has a required large arcuate housing part 14a facing the convex side on the center O side of the rotor core 12, and a pair of required large formed on both ends of the arcuate housing part 14a. It has the linear accommodating parts 14b and 14c, and these 14a-14c is formed over the axial direction substantially full length of the rotor core 12. As shown in FIG.

  The arcuate accommodating portion 14a extends its convex arc-shaped inner peripheral surface deeply to the vicinity of the outer periphery of the rotor center O. The central angle of the arcuate housing portion 14a is appropriately formed according to the number of magnetic poles of the permanent magnet motor.

  The pair of linear accommodating portions 14 b and 14 c extend substantially linearly outward from the both ends of the arcuate accommodating portion 14 a in the radial direction of the rotor core 12, and terminate before the outer peripheral wall of the rotor core 12. ing.

  And in each arcuate accommodation part 14a, an arcuate permanent magnet 16 made of ferrite or the like formed so as to be able to be fitted in substantially the same shape as the plan view of the arcuate accommodation part 14a is the axis of the arcuate accommodation part 14a. It is accommodated over almost the entire length of the direction.

  Further, in the pair of linear accommodating portions 14b and 14c, flat permanent magnets 17a and 17b made of ferrite or the like are formed so as to be fitted in substantially the same shape as the plan view of the linear accommodating portions 14b and 14c. The linear accommodating portions 14b and 14c are accommodated over substantially the entire length in the axial direction. The abutting end surfaces of the plate-like permanent magnets 17a and 17b and the arc-shaped permanent magnet 16 are formed so as to adhere as much as possible. Therefore, it is possible to reduce the gap between the arc-shaped permanent magnet 16 accommodated in each magnet accommodating hole 14 and the pair of plate-shaped permanent magnets 17a, 17b, and the arc-shaped, plate-shaped The total length of the permanent magnets 16, 17a, 17b can be increased.

  As shown in FIG. 2 (A), each arc-shaped permanent magnet 16 is formed in a radial magnetic field orientation as shown by reference numeral 16c, and each flat permanent magnet 17a, 17b shown in FIG. As shown by 17c, it is formed in a parallel magnetic field orientation. That is, permanent magnets 16, 17 a and 17 b having different magnetic field orientations are accommodated in one magnet accommodation hole 14.

  FIG. 3 shows the flow of a part of the magnetic flux around the center O of the rotor core 12 when the rotor 11 is magnetized. That is, a magnetic body such as ferrite before the arc-shaped permanent magnet 16 and the pair of plate-shaped permanent magnets 17a and 17b are magnetized as permanent magnets is accommodated in the magnet accommodation hole 14, Magnetization is performed by applying a magnetic field from the outer peripheral side of the rotor 11 by a magnetizer (not shown) that is substantially the same as the stator of the rotor 11.

  As shown in FIG. 3A, the arc-shaped permanent magnet 16 is close to the center O of the rotor core 12 and far from the magnetizer, and accordingly, the plate-shaped permanent magnets 17a and 17b It is lower than the magnetic flux density.

  Further, in FIG. 3A, the magnetic flux density at the outer peripheral portion of the arc-shaped permanent magnet 16 indicated by the arc arrow is the lowest at the intermediate portion in the circumferential direction, as shown in FIG. Distributed in a U-shape that rises. For example, the magnetic flux density in the circumferential intermediate portion having the lowest magnetic flux density is about 0.8T.

  On the other hand, in the plate-like permanent magnets 5 and 6 in the conventional V-shaped magnet housing hole 4 shown in FIG. 9 and the like, as shown in FIG. A substantially triangular space 4a is formed.

  For this purpose, as shown by a thick and short straight arrow in FIG. 4B, the magnetic flux in the plate thickness direction at one end face of the flat permanent magnet 6 on the side in contact with the oblique side on the right side of the substantially triangular space 4a. The density gradually decreases from the apex side of the space 4a toward the opposite side (that is, the outer surface side), and the lowest magnetic flux density is, for example, about 0.39 T, which is about half that of the present embodiment. It is as follows.

  FIG. 5 shows the total length in the width direction of the arc-shaped permanent magnet 16 and the pair of plate-shaped permanent magnets 17a and 17b accommodated in one magnet accommodation hole 14 according to the present embodiment shown in FIG. And the total length of the plate-like permanent magnets 5 and 6 accommodated in one conventional V-shaped magnet accommodation hole 4 shown in FIG. The total length of these permanent magnets 5, 6, 16, 17a and 17b is measured by the length on the central axis in the plate thickness direction. In the present embodiment and the conventional example, the rotor cores 2 and 12 have the same outer diameter and inner diameter (shaft hole), and the tip of the magnet housing holes 4 and 14 on the rotor center O side and the shaft. The distance a between the holes 3 and 13 and the inner peripheral surface is equal.

  FIGS. 6 and 7 compare the total lengths of the permanent magnets 5, 6, 16, 17 a, and 17 b when the length of a shown in FIGS. 5A and 5B is used as a parameter. In the figure, the solid line α indicates the length of the present embodiment, and the broken line β indicates the length of the conventional example (V-shaped).

  FIG. 6 shows permanent magnets 5, 6, 16 and 17 a in the case of a permanent magnet motor having 6 magnetic poles, rotors 1 and 11 having an outer diameter of φ65 (mm) and an inner diameter of φ16 (mm). 7 shows the total length of each of 17b, and FIG. 7 is the same as the case of FIG. 6 in which the inner and outer diameters of the rotors 1 and 11 are the same, but the permanent magnets 5 and 6, 16 and 17a and 17b when the number of magnetic poles is four. The total length of each is shown.

  That is, regardless of whether the number of magnetic poles is 4 or 6, the total length of the permanent magnets 16, 17a, 17b according to the U-shaped arrangement according to the embodiment indicated by the solid line α is indicated by the broken line β. It is longer than that of the conventional example of the V-shaped arrangement.

  Thereby, the permanent magnet electric motor provided with the rotor 11 according to the present embodiment has a larger amount of magnetic flux and can improve the capacity as an electric motor. Further, according to the present embodiment, an inexpensive ferrite magnet can be used as the material (magnetic material) of the arc-shaped and flat-plate-shaped permanent magnets 16, 17a, 17b, so that the cost of the permanent magnet motor can be reduced. be able to.

(Second and third embodiments)
FIG. 8 shows a configuration of a hermetic compressor 20 in which the permanent magnet motor is assembled and a refrigeration cycle apparatus 40 including the hermetic compressor 20.

  As shown in FIG. 8, the hermetic compressor 20 has a hermetic container 21, a compression mechanism 23 is provided in the lower part of the hermetic container 21, and the permanent magnet according to the first embodiment is disposed in the upper part. An electric motor 24 is provided. The compression mechanism unit 23 and the permanent magnet motor 24 are connected by a rotating shaft 25.

  The permanent magnet motor 24 is fixed to the inner peripheral surface of the hermetic container 21 by press-fitting or shrink fitting, and is provided with a cylindrical stator 24a on which windings are mounted, and rotatably provided inside the stator 24a. The rotor 11 includes the permanent magnet according to the first embodiment.

  The compression mechanism section 23 includes a first cylinder 26A on the upper surface portion of the intermediate partition plate 22 via the intermediate partition plate 22, and a second cylinder 26B on the lower surface portion. Further, a main bearing 27 is attached and fixed to the upper surface of the first cylinder 26A, and a sub-bearing 28 is attached and fixed to the lower surface of the second cylinder 26B.

  The main bearing 27 supports the main shaft portion 25 a of the rotating shaft 25, and the auxiliary bearing 28 supports the auxiliary shaft portion 25 b of the rotating shaft 25. The rotary shaft 25 penetrates through the insides of the first and second cylinders 26A and 26B, and integrally includes a first eccentric portion a and a second eccentric portion b formed with a phase difference of about 180 °. Yes.

  The first and second eccentric parts a and b have the same diameter as each other and are assembled so as to be positioned at the inner diameter parts of the first and second cylinders 26A and 26B. A first eccentric roller 29a is fitted to the peripheral surface of the first eccentric portion a, and a second eccentric roller 29b is fitted to the peripheral surface of the second eccentric portion b.

  The inner diameter portion of the first cylinder 26A is surrounded by the main bearing 27 and the intermediate partition plate 22 to form a first cylinder chamber Sa. An inner diameter portion of the second cylinder 26B is surrounded by the auxiliary bearing 28 and the intermediate partition plate 22, and a second cylinder chamber Sb is formed.

  The cylinder chambers Sa and Sb are formed to have the same diameter and height, and a part of the peripheral wall of the eccentric rollers 29a and 29b is accommodated so as to be eccentrically rotatable while being in line contact with a part of the peripheral wall of the cylinder chambers Sa and Sb. The

  Although not particularly illustrated, the first cylinder 26A is provided with a vane chamber communicating with the first cylinder chamber Sa, and the vane is movably accommodated therein. The second cylinder 26B is provided with a vane chamber communicating with the second cylinder chamber Sb, and the vane is movably accommodated therein.

  The tip of each vane is formed in a semicircular shape in plan view, protrudes into the opposing cylinder chambers Sa and Sb, and circularly in the plan view in the first and second eccentric rollers 29a and 29b. Line contact is possible regardless of this rotation angle.

  A lateral hole that communicates the vane chamber of the first cylinder 26A and the outer peripheral surface of the cylinder 26A is provided, and a spring member that is a compression spring is accommodated. This spring member is interposed between the rear end side end face of the vane and the inner peripheral wall of the sealed container 21, and applies an elastic force (back pressure) to the vane.

  A horizontal hole that communicates the vane chamber of the second cylinder 26B and the outer peripheral surface of the cylinder 26B is provided, and a spring member that is a compression spring is accommodated. This spring member is interposed between the rear end side end face of the vane and the inner peripheral wall of the sealed container 21, and applies an elastic force (back pressure) to the vane.

  In the refrigeration cycle apparatus 40, a refrigerant pipe P is connected to the upper end portion of the sealed container 21, and an accumulator (not shown) is connected to the refrigerant pipe P via a condenser 31, an expansion device 32, and an evaporator 33. Is connected.

  Furthermore, from the accumulator, the first suction refrigerant pipe Pa passing through the sealed container 21 of the hermetic compressor 20 and the side of the first cylinder 26A and directly communicating with the first cylinder chamber Sa; And a second suction refrigerant pipe Pb that penetrates the side of the second cylinder 26B and communicates directly with the second cylinder chamber Sb.

  Since the permanent magnet motor 24 uses the rotor 11 having a large amount of magnetic flux shown in FIG. 1 or the like as the rotor 24b, the capacity as the motor, that is, the power can be increased. Therefore, according to the hermetic compressor 20 including the compression mechanism unit 23 driven by the permanent magnet motor 24, the refrigerant compression capability of the compression mechanism unit 23 can be improved.

  Therefore, according to the refrigeration cycle apparatus 40, since the compression mechanism section 23 having a high refrigerant compression capability is provided, the refrigeration capability can be improved accordingly.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of this invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the present invention. These embodiments and modifications thereof are included in the scope and gist of the present invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 11 ... Rotor, 12 ... Rotor core, 13 ... Shaft hole, 14 ... Magnet accommodation hole, 14a ... Arc-shaped accommodation part, 14b, 14c ... Linear accommodation part, 16 ... Arc-shaped permanent magnet, 17a, 17b ... A pair of plate-like permanent magnets, 20 ... hermetic compressor, 21 ... hermetic container, 23 ... compression mechanism, 24 ... permanent magnet motor, 24a ... stator, 24b ... rotor, 25 ... rotating shaft, 40 ... freezing Cycle device, O ... Center of the rotor core.

Claims (3)

A stator having a stator winding;
A rotor containing permanent magnets in a plurality of magnet housing holes provided in the rotor core;
In the permanent magnet motor equipped with
The magnet housing hole has an arcuate housing portion with a convex side facing the center side of the rotor core in a plan view, and linear housing portions formed on both ends of the arcuate housing portion. An arc-shaped permanent magnet is accommodated in the arc-shaped accommodating portion, and a flat permanent magnet is accommodated in each of the linear accommodating portions. A hermetic compressor in which the permanent magnet motor according to claim 1 and a compression mechanism connected to a rotating shaft of the permanent magnet motor are housed in a hermetic container. A refrigeration cycle apparatus comprising the hermetic compressor according to claim 2, a condenser, an expansion device, and an evaporator.

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