JP5950873B2 - Three-phase motor, hermetic compressor, and refrigeration cycle apparatus - Google Patents

Description

  The present invention relates to a three-phase motor with an improved neutral point connection method, a hermetic compressor using the three-phase motor, and a refrigeration cycle apparatus using the hermetic compressor.

  Conventionally, as a method for connecting a stator of a three-phase motor driven by a three-phase AC power source used in a refrigeration cycle apparatus or the like, for example, there is a Y connection as shown in FIG. In this Y connection, it is necessary to form a neutral point 20 in which neutral wires from a pair of coils 2u, 2v, 2w of three phases (U phase, V phase, W phase) are connected together. Three neutral wires are concentrated and connected to the neutral point 20. In this case, the connection between the three neutral wires is made by means such as soldering, TIG welding, brazing welding, or connection by a crimp terminal.

  Such a connection between the neutral wires of the Y-connection requires a lot of labor for the connection work because the number of the conductive wires is very large. Therefore, a neutral point forming method is known in which a neutral point is divided into two and two of three neutral lines are connected to each other (see, for example, Patent Document 1).

JP 2000-232745 A

  However, since such a neutral point still has a large number of conductors, many conductors must be connected to each other in order to form a neutral point, and it takes a long time to connect the wires and causes poor connection. The possibility was high and there was a problem in terms of reliability. Further, when the number of neutral points is increased, it is difficult to insert the insulating member, and there is a possibility that an insulation failure occurs.

  The present invention has been made in consideration of such a problem, and the stator connection structure that forms a neutral point by connecting a smaller number of conductors than the conventional one makes the connection in the stator easy and reliable. An object is to provide a three-phase motor that is excellent in performance and low in cost. It is another object of the present invention to provide a hermetic compressor using the three-phase motor, and a refrigeration cycle apparatus using the hermetic compressor.

  In order to solve the above problems, the present invention provides a plurality of coils to which a three-phase AC power is supplied, a plurality of neutral wires connected to the coils, and a neutral point in which the plurality of neutral wires are connected to each other. And the neutral wire is a conductive wire group formed by combining a plurality of conductive wires, and at least one of the plurality of neutral wires is divided into other wires. By connecting to the neutral line, a plurality of neutral points are formed.

  According to the three-phase motor according to the present invention, by reducing the number of neutral connection points in the Y connection, it is possible to reduce the labor of the connection and prevent a connection failure and provide a highly reliable three-phase motor. Can do.

It is sectional drawing of the compressor which concerns on embodiment of this invention. It is a Y connection structure figure of stator 1 of a three phase motor concerning an embodiment of the invention. It is a connection diagram of the neutral point 20 of the three-phase motor according to Embodiment 1 of the present invention. It is a connection diagram of the neutral point 20 of the three-phase motor according to Embodiment 2 of the present invention. It is a connection diagram of the neutral point 20 of the three-phase motor according to Embodiment 3 of the present invention. It is a connection diagram of the Y connection system in the conventional three-phase motor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below. Moreover, in the following drawings, the relationship of the size of each component may be different from the actual one.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of a compressor according to an embodiment of the present invention.
FIG. 2 is a Y connection structure diagram of the stator 1 of the three-phase motor according to the embodiment of the present invention.
FIG. 3 is a connection diagram of neutral point 20 of the electric motor according to Embodiment 1 of the present invention.

First, the structure of the compressor will be described with reference to FIG.
FIG. 1 is a cross-sectional view of a general hermetic compressor 100 used in a refrigeration cycle apparatus.
The hermetic compressor 100 houses therein a compression mechanism 51, a three-phase motor 52, a crankshaft 53, and the like with a hermetic container 50 as a case.
The three-phase motor 52 is formed of a stator 1 and a rotor 5, and has a structure in which the rotor 5 rotates when a three-phase AC power is supplied to the stator 1.
A gas refrigerant in a refrigerant circuit (not shown) of the refrigeration cycle apparatus is sucked from the suction pipe 54, enters the compression mechanism 51 through the accumulator 55, is compressed, and is sent out from the discharge pipe 56 as a high-temperature and high-pressure refrigerant.

Next, a three-phase connection structure in the stator 1 of the three-phase motor 52 will be described with reference to FIG.
FIG. 2 shows a stator 1 of a general three-phase motor 52 to which the present invention is applied.
The stator 1 includes terminals U, V, and W to which a three-phase AC power is supplied, a plurality of stators 3 arranged at intervals in the circumferential direction, and a yoke that connects the outer peripheral sides of these stators 3. A stator core 10 having an iron core 4 is provided. Three-phase Y-connected coils 2u, 2v, and 2w are mounted on the stators 3 of the stator core 10, respectively.

  In the stator 1, a total of 6 poles 2 u, 2 v, 2 w, 2 poles for each phase, are arranged in series in a three-phase Y connection. The three-phase motor 52 includes a rotor 5 having a magnetic pole and disposed coaxially in the stator 1.

  For the three phases U, V, and W, a pair (two poles) of coils 2u, 2v, and 2w are provided facing each other in the radial direction of the stator 1, and a pair of coils 2u and 2v that constitute each phase. 2w are respectively connected in series.

  The neutral wire 9v from the V-phase coil 2v, the neutral wire 9u from the U-phase coil 2u, and the neutral wire 9w from the W-phase coil 2w in the stator 1 are neutral at one location. Connected at point 20. The neutral wires 9u, 9v, 9w are formed of a conductive wire group in which a plurality of conductive wires are bundled. An example of the conductive wire is a copper metal wire.

Next, the connection structure of the neutral point 20 of the three-phase motor 52 according to Embodiment 1 of the present invention will be described with reference to FIG.
The two neutral points 20 shown in FIG. 3 are formed by dividing the conductive wire of the V-phase neutral wire 9v into two and connecting it to the U-phase neutral wire 9u and the W-phase neutral wire 9w. Has been. Further, the jumper wire 30 is passed between the two formed neutral points 20 to be conductive. When connecting conducting wires, it is possible to perform connection by soldering, TIG welding, brazing welding, crimp terminals, or the like.

  By forming the neutral point 20 in this way, it becomes a configuration in which a smaller number of conductive wires are connected at the neutral point 20 than in the case of connecting the neutral wires for two phases as in the prior art, and the labor of connection is reduced. Thus, it is possible to prevent connection failure.

Embodiment 2. FIG.
A connection diagram of the neutral point 20 of the three-phase motor 52 according to the second embodiment of the present invention is shown in FIG.
The Y connection structure of the stator 1 of the three-phase motor 52 is the same as that of the first embodiment.

  The two neutral points 20 shown in FIG. 4 divide the lead wire of the neutral wire 9v of the V phase, the neutral wire 9u of the U phase and the neutral wire 9w of the W phase into two, respectively, Connect to form a neutral point 20.

  By forming the neutral point 20 in this way, it becomes a configuration in which a smaller number of conductive wires are connected at the neutral point 20 than in the case of connecting the neutral wires for two phases as in the prior art, and the labor of connection is reduced. Thus, it is possible to prevent connection failure.

Embodiment 3 FIG.
A connection diagram of the neutral point 20 of the three-phase motor 52 according to Embodiment 3 of the present invention is shown in FIG.
The Y connection structure of the stator 1 of the three-phase motor 52 is the same as that of the first embodiment.

  The neutral point 20 shown in FIG. 5 connects one end of the jumper wire 30 to the leading end of the V-phase neutral wire 9v, the U-phase neutral wire 9u, and the W-phase neutral wire 9w. The other end portions of the phase jumper wires 30 are connected to each other.

  By forming the neutral point 20 in this way, the configuration is such that only one phase of conducting wire is connected to one end of the jumper wire 30 rather than connecting two phases of neutral wires as in the prior art. It is possible to reduce the trouble of connection and prevent connection failure.

Although the connection structure of the neutral point of Y connection which concerns on Embodiment 1-3 can be employ | adopted for all three-phase electric motors, it is suitable for employ | adopting, for example as an electric motor for closed type compressors of a refrigerator or an air conditioner. is there.
In the first to third embodiments, the stator 1 of the three-phase motor 52 is provided with a 6-pole stator, but the number of poles is not particularly limited. In addition, in the stator 1, an example in which the coils 2u to 2w having a total of 6 poles, 2 poles for each phase, are connected in series to the three-phase Y connection has been shown. Of course it is also possible to do.

  1 stator, 2u coil, 2v coil, 2w coil, 3 stator, 4 yoke iron core, 5 rotor, 9u neutral wire, 9v neutral wire, 9w neutral wire, 10 stator iron core, 20 neutral point, 30 jumper wire, 50 sealed container, 51 compression mechanism, 52 three-phase electric motor, 53 crankshaft, 54 suction pipe, 55 accumulator, 56 discharge pipe, 100 hermetic compressor.

Claims (5)

A three-phase motor comprising a plurality of coils to which a three-phase AC power is supplied, a plurality of neutral wires connected to the coils, and a neutral point connecting the plurality of neutral wires. ,
The neutral wire is a conductive wire group formed by collecting a plurality of conductive wires, and by dividing at least one conductive wire group of the plurality of neutral wires and connecting to another neutral wire, A three-phase electric motor characterized by forming the neutral point.   The neutral wire conducting group of one neutral wire among the plurality of neutral wires is divided into two and connected to other neutral wires to form the two neutral points. The three-phase motor according to claim 1, wherein the three-phase motor is connected by a crossover.   All of the plurality of neutral wires are divided into two, and the two divided wires are connected so that the plurality of neutral wires are joined to form the two neutral points. The three-phase motor according to claim 1.   A hermetic compressor using the three-phase motor according to any one of claims 1 to 3.   A refrigeration cycle apparatus using the hermetic compressor according to claim 4.

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