JP2011072100A - Self-starting permanent-magnet synchronous motor, and compressor and air conditioner using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-starting permanent-magnet synchronous motor of low cost with a reduced number of manufacturing man-hours. <P>SOLUTION: The self-starting permanent-magnet synchronous motor includes a cage conductor comprised of a conductor bar and end rings that couple the conductor bar at the ends thereof. The cage conductor is characterized in that the conductor bar and the end rings are electrically and mechanically coupled together by caulking. Of the end rings, an end ring that couples one end of the conductor bar may be preferably a previously integrated member. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a self-starting permanent magnet synchronous motor and a compressor using the same.

  As a method for manufacturing a rotor of a conventional self-starting permanent magnet synchronous motor, for example, as described in Patent Document 1, a plurality of slots positioned on the inner periphery of a rotor core laminated with electromagnetic steel plates are provided with bars. A method of electrically and mechanically joining an end ring that short-circuits the bar at an axial end thereof by friction stir welding is known. Since this method does not handle high-temperature molten metal in the manufacturing process unlike die casting, there is an advantage that the working environment is good.

  Generally, aluminum is used for the secondary conductor of the rotor of the self-starting permanent magnet synchronous motor. However, if copper is used, the specific resistance is as low as about 60% compared to aluminum. Thus, the diameter of the bar can be reduced to the same resistance value as that of the aluminum bar, and the permanent magnet embedded in the inner core of the bar can be arranged on the outer peripheral side to increase the surface area of the permanent magnet. The efficiency of the self-starting permanent magnet synchronous motor with high motor efficiency can be further increased.

JP 2006-333627 A

  In the conventional method for manufacturing a rotor of a self-starting permanent magnet synchronous motor, when the conductor bar and the end ring constituting the squirrel-cage secondary conductor are joined by friction stirring, the rotor core and the end ring are firmly fixed. There is a problem that it takes time for preparation work to set the fixing jig.

  Also, when joining copper bars and end rings, the melting point of the copper material is as high as 1083 ° C., so it takes a long time to locally soften by friction and stirring. It takes a lot of processing time to join these bars continuously and is not suitable for mass production in terms of cost.

  An object of the present invention is to provide a low-cost self-starting permanent magnet synchronous motor motor with reduced manufacturing steps.

The purpose of the present invention is to
In a self-starting permanent magnet synchronous motor having a squirrel-cage conductor composed of a conductor bar and an end ring that joins the conductor bar at an end,
The cage conductor is achieved by a self-starting permanent magnet synchronous motor characterized in that it is electrically and mechanically coupled by caulking the conductor bar and the end ring.

  According to the present invention, the number of manufacturing steps can be reduced.

The cross-sectional block diagram of the rotor of the self-starting permanent magnet synchronous motor which shows the form of 1st Example of this invention. Sectional drawing of the iron core and end ring of the rotor of 1st Example. FIG. 3 is a configuration external view of the rotor of the first embodiment. Configuration external view of the rotor of the second embodiment. Configuration outline drawing of rotor of 3rd example. Configuration outline drawing of rotor of 4th Example. The cross-section figure of the compressor which shows the form of 1st Example. The refrigeration cycle block diagram of the air conditioner which shows the form of 1st Example.

  Embodiments of the present invention will be described below with reference to the drawings.

  Embodiment 1 will be described with reference to FIGS. FIG. 1 is a cross-sectional configuration diagram of a rotor of a self-starting permanent magnet synchronous motor showing a form of a first embodiment of the present invention. In addition, the stator, casing, shaft and bearing are omitted. The structure of the rotor will be described below.

  The rotor includes a rotor core 1, a cylindrical conductor bar 2, a permanent magnet 3 and an end ring 4. The end rings 4 are disposed on both sides.

  As shown in FIG. 2A, the rotor core 1 is a laminate of electromagnetic steel plates. The magnetic steel sheet has an inner diameter 1d through which the shaft passes, a plurality of slots 2a for inserting a conductor bar are provided on the outer diameter side, and a magnet insertion hole 3a is provided on the inner diameter side. Therefore, the rotor core 1 is formed with a plurality of slots 2a and magnet insertion holes 3a in the cage conductor bar along the axial direction. Further, the length of the permanent magnet 3 inserted into the magnet insertion hole 3a is designed to be slightly shorter (about 0.1 to 2 mm) than the rotor core 1 (t in FIG. 1).

  The end ring 4 shown in FIG. 2B is an annular member made of aluminum material (or aluminum alloy material) formed by die casting. This annular member may be formed of a forged copper material (or copper alloy material). A through hole 4c for inserting a conductor bar is provided on the outer diameter side of the end ring 4, and a hole 4d (4d> 4c) concentric with the hole 2a is provided on one end surface to form a stepped hole. The hole 4d is a caulking hole provided on the side opposite to the magnet.

  When manufacturing the rotor, a plurality of conductor bars 2 and a plurality of permanent magnets 3 are inserted into the slots 2a and the magnet insertion holes 3a of the rotor core 1, respectively, and both ends of the conductor bar 2 are connected to both end faces of the rotor core 1. Project more evenly. The relative dimensions of the conductor bar 2 are designed such that both ends of the conductor bar 2 protrude from the end face of the end ring 4. Then, after both end portions of the conductor bar 2 are fitted into the plurality of holes 4c of the end ring 4, the conductor 5 is used with a tool 5 made of a cylindrical hard iron alloy material as shown in FIG. Apply pressure to both ends of the bar 2 to crimp. By caulking, the end metal of the cylindrical conductor bar is crushed and spreads in the direction perpendicular to the axis, is filled in the end ring stepped hole 4d, and the end ring 4 and the conductor bar 2 on both sides are electrically and mechanically connected. Combined. In this way, the rotor of the self-starting permanent magnet synchronous motor is manufactured.

  As described above, a plurality of conductor bars protruding from the rotor core are inserted into a plurality of slots positioned on the outer diameter side of the rotor core laminated with magnetic steel sheets, and the end of the bar protrudes into the portion where Fit the end ring through the hole for inserting the bar, and then press the end of the bar in the axial direction to crush the end of the bar and expand it in the radial direction of the bar. To electrically and mechanically connect the bar and end ring.

In the present embodiment, unlike the conventional friction stir welding and die casting manufacturing methods, the end rings 4 on both sides of the rotor have two roles: a role as a secondary conductor and a role for preventing the magnet from falling off.
According to the present embodiment, it is possible to omit the end plates that cover both end portions of the magnet insertion hole required in the case of the die casting method, and thus it is possible to reduce the cost.

  Further, in the self-starting permanent magnet synchronous motor, almost no current flows through the secondary cage conductor during operation. Therefore, secondary copper loss does not occur, and the efficiency of the electric motor is improved.

  Furthermore, if a copper end ring and a copper conductor bar are used, the size of the end ring and the conductor bar can be reduced, and the motor can be downsized. This is because the electrical conductivity of the copper material is higher than that of aluminum, so that the performance can be maintained even if it is reduced.

  FIG. 7 is a sectional view of the compressor. In FIG. 7, the structure of the compressor 82 will be described. The compression mechanism 83 is formed by meshing a spiral wrap 62 standing upright on the end plate 61 of the fixed scroll member 60 and a spiral wrap 65 standing upright on the end plate 64 of the orbiting scroll member 63. The revolving scroll member 63 is revolved by the crankshaft 16 to compress the refrigerant.

  Of the compression chambers 66 (66a, 66b,...) Formed by the fixed scroll member 60 and the orbiting scroll member 63, the compression chamber 66 located on the outermost diameter side has both scroll members 60 accompanying the orbiting motion. , 63, and the volume gradually decreases. When both the compression chambers 66 a and 66 b reach the vicinity of the centers of the scroll members 60 and 63, the compressed gas in both the compression chambers 66 is discharged from a discharge port 67 communicating with the compression chamber 66. The discharged compressed gas passes through a gas passage (not shown) provided in the fixed scroll member 60 and the frame 68 and reaches the pressure vessel 69 below the frame 68, and a discharge pipe provided on the side wall of the pressure vessel 69. 70 is discharged out of the compressor. Such a compressor is called a high pressure chamber type.

  A self-starting permanent magnet synchronous motor 18 composed of the stator 12 and the rotor 1 is enclosed in the pressure vessel 69, rotates at a constant speed, and performs a compression operation. An oil reservoir 71 is provided at the lower part of the electric motor 18. Oil in the oil reservoir 71 passes through an oil hole 72 provided in the crankshaft 16 due to a pressure difference caused by a rotational motion, and a sliding portion between the orbiting scroll member 63 and the crankshaft 16, a sliding bearing 73 and the like. Used for lubrication.

  If the above-mentioned self-starting permanent magnet synchronous motor is applied as the motor for driving such a compressor, the efficiency of the constant speed compressor can be increased. Moreover, since the starting torque generated excessively by the power-on phase can be reduced, it is possible to contribute to the improvement of reliability, such as the stress destruction of the bearing 73 and the orbiting scroll member 63 can be prevented.

  FIG. 8 is a configuration diagram of the refrigeration cycle of the air conditioner. In FIG. 8, 80 is an outdoor unit, 81 is an indoor unit, and 82 is a compressor. In the compressor 82, a self-starting permanent magnet synchronous motor 18 and a compression mechanism 83 are arranged. 84 is a condenser, 85 is an expansion valve, and 86 is an evaporator. The refrigeration cycle circulates the refrigerant in the direction of the arrow, and the compressor 82 compresses the refrigerant to exchange heat between the outdoor unit 80 including the condenser 84 and the expansion valve 85 and the indoor unit 81 including the evaporator 86. In the indoor unit 81, the cooling function is exhibited.

If the self-starting permanent magnet synchronous motor 18 described above is used in a compressor such as an air conditioner, refrigeration and refrigeration equipment, the input can be reduced by improving the efficiency of the self-starting permanent magnet synchronous motor 18, leading to global warming. This has the effect of reducing CO ₂ emissions. It can also contribute to the improvement of reliability.

  FIG. 4 is an external view of a rotor configuration of a self-starting permanent magnet synchronous motor showing a second embodiment of the present invention. Referring to FIG. 4, among the two end rings constituting the cage secondary conductor, the end ring 6a is formed by die casting (or forging) to form an aluminum part 6 in which a plurality of conductor bars 6b are integrated in advance. Yes. A forging method may be used instead of die casting, and the material may be a copper material or a copper alloy material instead of aluminum.

  The plurality of conductor bars 6b and the plurality of permanent magnets 3 of the integrated component 6 are respectively inserted into the plurality of slots 2a and the plurality of magnet insertion holes 3a of the rotor core 1, and the conductor bar 6b is inserted into one side of the rotor core 1. It sticks out to the end face. The plurality of holes 4 c of the end ring 4 are fitted and fixed to the conductor bar 6 b protruding from the end face of the rotor core 1. Thereafter, pressure is applied to the protruding conductor bar 6b using the cylindrical tool 5 as shown in FIG.

  That is, pressure is applied to the end portions of the plurality of conductor bars 6b in order (or simultaneously with the plurality of bars 6b), and the deformation of the end portions is used to caulk the component 6 integrated with the end ring 4. . Thus, the end metal of the conductor bar 6b is crushed, spreads in the direction perpendicular to the axis, and fills the end ring stepped hole 4d. Therefore, the end ring 4 is electrically and mechanically coupled.

  By utilizing an integrated part of the conductor bar and end ring in the rotor of the self-starting permanent magnet synchronous motor according to the present embodiment, the production process for crimping the conductor bar can be reduced and the production efficiency can be improved. Also, the cost can be reduced.

  FIG. 5 is an external view of the processing of a self-starting permanent magnet synchronous motor rotor showing a third embodiment of the present invention. Description of the same parts as in the first embodiment will be omitted to avoid duplication, and differences will be mainly described.

  The rotor 1 includes a rotor core 1, a conductor bar 2, a permanent magnet 3, end rings 4 and 7, and a balance weight 8.

  Here, the use of attaching a balance weight to the rotor will be described. For example, when an operation connected to a load via a rotating shaft of an electric motor, such as a compressor, the rotational center of gravity of the load is shifted from the center of the rotating shaft of the electric motor, and the rotational balance is lost. Then, vibration and noise of the electric motor may occur, and normal performance may not be exhibited. In such a case, by attaching a balance weight so that the total radial moment of the rotor becomes zero, the rotation balance of the electric motor can be achieved and normal operation can be performed. Generally, a brass material having a relatively large specific gravity is used for the balance weight.

  The end ring 7 shown in FIG. 5 is an annular member made of aluminum (or copper) formed by die casting or forging, and a plurality of stepped holes 7c, 7d (7d> 7c) for inserting conductor bars in the end ring 4. Is provided. In order to attach the semi-annular balance weight 8, several pins 7a are provided.

  The balance weight 8 is a non-magnetic material alloy (for example, an alloy copper material) formed by die casting (or forging). The balance weight 8 is provided with several stepped holes 8d and 8c (8d> 8c) for attachment.

  In the rotor processed by the same manufacturing procedure as in the first embodiment, the portion of the hole 8c is fitted and fixed with several pins 7a standing on the end ring 7 using the balance weight 8. By applying an appropriate pressure to the pin 7a protruding from the end face of the balance weight 8 and caulking, the pin 7a is crushed and spreads in the stepped hole 8d. As a result, the balance weight 8 is firmly fixed.

  By adding a balance weight to the rotor, including the advantages of Example 1 according to this embodiment, it can be applied to an operation in an unbalanced load state such as a compressor. As a result, the efficiency of the compressor is increased.

  FIG. 6 is an external view of rotor processing of a self-starting permanent magnet synchronous motor showing the form of the fourth embodiment of the present invention. As shown in FIG. 6, in a circular member 9 in which an end ring 9a and a balance weight 9b formed by die casting or forging are integrated, a plurality of stepped holes 9d, 9c (9d> 9c for inserting conductor bars on the outer diameter side). ) And 9f, 9e (9f> 9e). The material of the member 9 is aluminum (or copper alloy).

  The rotor is constituted by a rotor core 1, a conductor bar 2, a conductor bar 2h (2h> 2), an end ring 4, a permanent magnet 3 and a member 9 of an end ring 9a with a balance weight 9b.

  A plurality of conductor bars 2 and 2h are inserted into the slots 2a of the rotor core 1, the permanent magnets 3 are mounted in the magnet insertion holes 3a, and both end portions of the conductor bars 2 and 2h protrude from both end surfaces of the rotor core 1. Arrange. The connection between one end of the conductor bars 2 and 2h and the end ring 4 is performed in the same procedure as in the first embodiment. The procedure for joining the opposite conductor bar and the member 9 is performed as follows.

  The holes 9c and 9e of the end ring 9a with the balance weight 9b are fitted into the ends of the plurality of conductor bars 2 and 2h protruding from the end surface of the rotor core 1, and the ends of the conductor bars 2 and 2h are respectively connected to the end ring 9a and The balance weight 9b is projected from both end faces. By crimping the ends of the conductor bars 2 and 2h with pressure, the ends of the conductor bars 2 and 2h are crushed and spread in the direction perpendicular to the axis, and are filled in the end ring stepped holes 9d and 9f. Thereby, the conductor bars 2 and 2h and the member 9 are electrically and mechanically coupled.

  Including the advantages of Example 4 according to the present embodiment, by using an integrated part of the end ring and the balance weight, the production process for crimping the conductor bar can be reduced and the production efficiency can be improved.

  As described above, each embodiment has its effects by itself. Of course, even when the embodiments are combined, the respective effects can be achieved and the goodness of each can be enjoyed.

DESCRIPTION OF SYMBOLS 1 Rotor core 1a Rotor core 2, 6b Conductor bar 2a Rotor core slot 3 Permanent magnet 3a Magnet insertion hole 4, 4a, 4b, 6a, 7 End ring 4d, 4c, 7d, 7c, 8d, 8c, 9d , 9c, 9e, 9f Stepped hole 5 Crimping tool 6 Conductor bar and end ring integrated member 7 Pin end ring 7a Pin 8 Balance weight 9 Balance weight end ring 11 Stator 12 Stator core 16 Shaft 18 Self Starter-type permanent magnet synchronous motor 60 Fixed scroll members 62 and 65 Spiral wrap 63 Orbiting scroll member 66 Compression chamber 67 Discharge port 68 Frame 69 Pressure vessel 70 Discharge pipe 71 Oil reservoir 72 Oil hole 73 Sliding bearing 80 Outdoor unit 81 Indoor unit 82 Compressor 83 Compression mechanism 84 Condenser 85 Expansion valve 86 Evaporator

Claims (7)

A stator having a winding wound around a slot of a stator core, and a rotor slightly smaller than the inner diameter of the stator inside the stator, and the iron core of the rotor is formed by laminating a plurality of electromagnetic steel plates; A plurality of slots located inside the outer periphery of the laminated iron core, a conductor bar formed by fitting the bar with an end ring at the end in the axial direction, and a plurality of permanent magnets on the inner peripheral iron core of the bar In a self-starting permanent magnet synchronous motor consisting of an inserted embedded rotor,
The self-starting permanent magnet synchronous motor is characterized in that the cage conductor is electrically and mechanically coupled by caulking the conductor bar and the end ring. In claim 1,
A self-starting permanent magnet synchronous motor characterized in that, among the end rings, an end ring that joins one end of the conductor bar is a previously integrated member. In claim 1,
A self-starting permanent magnet synchronous motor characterized in that a convex portion for attaching a balance weight is provided on an end ring that joins one end of the conductor bar among the end rings. In claim 1,
A self-starting permanent magnet synchronous motor characterized in that an end ring for coupling one end of the conductor bar and a balance weight are integrated in the end ring. In claim 1,
A self-starting permanent magnet synchronous motor characterized in that a material of the conductor bar and the end ring is any one of a copper material, a copper alloy, aluminum, and an aluminum alloy. In a compressor composed of a compression mechanism section that sucks and compresses refrigerant and discharges the compressed refrigerant, and an electric motor section that drives the compression mechanism section.
A compressor using the self-starting permanent magnet synchronous motor according to claim 1 as a drive source of the compressor. In an air conditioner where the compressor is driven at a constant speed, the refrigerant is sucked in, compressed and discharged, and the drive energy is converted into other energy.
An air conditioner comprising the compressor according to claim 6.

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