JPH0690543A - Sealed type motor - Google Patents

Abstract

PURPOSE:To abolish a circular cylindrical can interposed between a stator and a rotor and obtain a highly efficient and large-capacity sealed motor by a method wherein spaces between iron sheets of a lamination type stator core are retained in airtight with a resistance to pressure through insulative resin coating agent or sealing agent. CONSTITUTION:In a diagram, A shows a load or a screw compressor and B shows a sealed type motor. The motor is provided with a rotor 41, fixed to a rotary shaft 36, and a stator 42, surrounding the rotor 41, while the stator 42 is constituted of a stator core 43 and a winding 45. The stator core 143 is sealed so as to be airtight by applying insulative resin coating agent or another bonding agent 46 on the laminating surfaces of a multitude of field core sheets 43a or laminated sheets are solidiified integrally by hot pessing through an insulating film 46 having thermal fusibility to retain in airtight with a resistance to pressure. The stator core 43 is provided with cirular cylindrical shape substantially and both axial ends thereof are bonded to the flange of an outer frame housing 148, fixed to a bearing housing 35 of the compressor A so as to be airtight, and the flange of a free end side 28 so as to be airtight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed electric motor which is directly connected to a rotary fluid machine that can function as a compressor, an expander, or a fluid pump, and is particularly designed to improve pressure resistance, touch resistance and efficiency. Sealed electric motor.

[0002]

2. Description of the Related Art In a refrigerator using a screw type rotary fluid machine that can function as a conventional compressor or expander or a fluid pump, a freon-based system is used while directly connecting a sealed electric motor in order to save space. When using a refrigerant,
When adopting a hermetic or semi-hermetic electric motor in which the rotor and the stator are directly housed in an airtight motor frame, paying attention to the chemical stability and electrical insulation of CFCs. There are many. However, in recent years, the release of CFCs into the atmosphere has caused destruction of the global environment, especially the ozone layer. Therefore, the prohibition of its use has been called for. Therefore, the use of ammonia gas as a substitute refrigerant gas has been considered especially in large refrigerators. ing. However, when using an ammonia refrigerant, the stator together with the rotor are placed in the same space of the hermetically sealed frame as in the hermetic and semi-hermetic types against the strong corrosive and conductive properties of ammonia and the odorous toxicity. In the existing configuration, ammonia refrigerant penetrates into the electric motor from the shaft part of the rotating fluid machine and causes a corrosive action on both the rotor and the stator. Therefore, the manufacturing cost is significantly increased. Therefore, in the hermetically-sealed electric motor that is directly connected to the fluid machine using the ammonia refrigerant, a cylindrical cylinder-shaped can is fitted and fixed between the stator and the rotor, and the ammonia refrigerant reaches the stator located on the outer peripheral side of the can. The adoption of a can-type motor with a structure that does not leak is being considered.

However, the can has a high-density alternating magnetic flux interlinking with it, which increases the magnetic resistance in the air gap including the eddy current loss and the can, and a large amount of heat is generated due to the excitation loss and the like. Since the efficiency is remarkably reduced, it is difficult to design and manufacture a large capacity machine. Therefore, in recent years, a can using a soft magnetic metal plate with a high electric resistance value in which the magnetic resistance loss is reduced has been developed, and the excitation loss and the eddy current loss are reduced thereby to improve the efficiency of the motor. There is a limit to the size of resistance. Further, since the wall thickness of the high-pressure container, that is, the can becomes large due to the large horsepower and the magnet distance becomes large, the motor efficiency is deteriorated. At present, the eddy current loss still accounts for a large proportion of the loss.

Therefore, the applicant of the present invention is, for example, the actual Kaihei 1-162.
In 755, a cylindrical aggregate in which soft magnetic fine wires having high magnetic permeability are wound in a non-contact manner with each other and a can formed by enclosing the aggregate with an airtight non-metallic material to form a hollow cylinder are proposed. In addition, we have tried to prevent the occurrence of eddy current loss while reducing the magnetic resistance loss.

[0005]

However, even in the above-mentioned conventional technique, although the magnetic resistance and the electromagnetic loss due to the eddy current are suppressed, the thickness is reduced in order to suppress the magnetic resistance because of the mechanical structure. As described above, since the high-pressure fluid pressurized by the compressor connected to the canned motor enters the can through the bearing portion, the can itself has sufficient pressure resistance, no leakage, and a machine for easy hermetic assembly work. It is necessary to satisfy the requirements of the physical structure, and as a result, it is difficult to design and manufacture a large capacity machine.

Further, in the above-mentioned prior art, the cylindrical aggregate wound with the soft magnetic fine wire has the strength in the radial direction, but the strength in the axial direction is the same as the strength of the non-metal material covering the above-mentioned aggregate. It is not satisfactory to rely on, and as the diameter of the can increases, the defects in the mechanical structure further increase, making it difficult to design and manufacture a large-capacity machine.

The present invention has been made in view of the above-mentioned drawbacks of the prior art.
(EN) Provided is a hermetically-sealed electric motor capable of manufacturing a large-capacity sealed-type fluid machine with high efficiency by increasing pressure resistance, touch resistance, and airtightness while maintaining airtightness between a rotor and a stator without using a can. To aim for things.

[0008]

In order to achieve the above technical objects, the present invention provides a hermetically sealed electric motor which is directly connected to a rotary fluid machine capable of functioning as a compressor, an expander or a fluid pump. While surrounding the stator iron core through a predetermined gap without interposing a can around the
The stator core is configured as a pressure-proof sealed structure container. In this case, in order to configure the stator core as a pressure-tight sealed structure container, for example, in a hermetic motor in which a plurality of field core plates are laminated to form a stator core, a sealant is applied on the laminated surface. It suffices that the iron core plates are interposed and the airtightness is maintained between the iron core plates through a sealant such as an insulating resin coating agent or an insulating film. More preferably, the pressure-resistant sealing structure is further improved by press-bonding a nonmagnetic thin plate or a resin thin film on the inner peripheral surface side of the stator core to form a coating. Now, by adopting the above structure, it is possible to obtain a pressure resistant structure of the stator core, but the winding wire housed in the open groove on the inner peripheral side of the stator core must be located in the pressure resistant container of the stator core. Therefore, when the working fluid of the rotary fluid machine is ammonia gas, the winding may be corroded. In this case,
It is preferable that a seal member is disposed on the inner peripheral surface of the stator core facing the rotor in the groove after the winding is inserted, and the seal can be hermetically sealed. Further, it is preferable that the seal member is formed of a resin bind filled in the groove or a seal plate having both sides tapered so as to be fitted into the opening end of the groove.

[0009]

According to this technical means, the stator core itself functions as a pressure vessel, so that the can is unnecessary, and the stator core is formed of a thick field core, which is sufficient. It can be made into a container having pressure resistance, which can sufficiently cope with the increase in diameter and capacity of the electric motor. Further, in the configuration using the can, the rotor and the stator cannot be brought close to each other because of the presence of the can, but according to the present invention,
Since the can can be omitted, the air gap between the rotor and the stator can be minimized, and as a result, eddy current loss, excitation loss, etc. can be reduced.
Design and manufacture of large capacity machines are facilitated. Furthermore, a resin binding layer or a wedge-shaped member is also abutted on the opening surface of the open groove for embedding the winding in the stator core to provide a strong pressure resistance in the circumferential direction and axial direction of the can and airtightness. In addition, the corrosion resistance is obtained and the ammonia resistance strength is also increased.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the drawings. The dimensions and shapes of the components, means and the like described in these embodiments, and their relative arrangement are described. Unless otherwise noted, the scope of the present invention is not intended to be limited thereto and is merely an example of description.

FIG. 1 and FIG. 2 show the structure of a refrigerator in which a screw compressor is directly connected to a hermetically sealed electric motor according to an embodiment of the present invention, and a hermetically sealed compressor is obtained by directly connecting the electric motor and the screw compressor. First, the configuration of the main body of the machine will be described, and first, the configuration on the side of the screw compressor A will be described. A discharge port for discharging the compressed refrigerant gas to the condenser side, 33 a rotor housing enclosing the compressed refrigerant gas, 34A a bearing fitted in a disk-shaped bearing housing 35, and a rotating shaft 36 on the electric motor B side.
The rotor shaft 37a fitted with the sprocket shaft is supported. The rotor shaft 37b on the other side is supported by the bearing 34B. In this case, an incompletely sealed state is formed between the rotor shaft 37a and the bearing 34A so that the working fluid composition can be introduced from the compressor A side to the electric motor B side. A return hole 39 for the working fluid that has flowed to the electric motor B side is provided below the disk-shaped bearing housing 35 to equalize the pressure in the rotor 41 space on the compressor A side and the electric motor side. On the other hand, the electric motor B side includes a rotor 41 fixed to the rotary shaft 36, a stator 42 surrounding the rotor 41, and the stator 4
As shown in FIG. 5, reference numeral 2 denotes a stator core 43 formed by laminating a large number of field core plates 43a, and a cross-section extending in the axial direction on the inner peripheral surface side of the stator core 43. U-shaped open groove 4
The winding 45 accommodated in the coil 4 and the coils 45a located on both axial sides of the stator core 43 are portions where the coil of the winding is extended. The stator core 43 is coated with an insulating resin coating agent or other adhesive 46 on the laminated surface of a large number of field core plates 43a to hermetically seal or a heat-meltable insulating film 46. The two are solidified integrally by thermocompression with the interposition of, and airtightly maintained in a pressure resistant manner.
Further, a non-magnetic thin plate 47 is formed on the inner peripheral surface side of the stator core 43.
Alternatively, the resin thin film 47 is pressure-bonded to form a coating to further improve the airtightness. The stator core 43 has a substantially cylindrical shape, and both ends of the stator core 43 in the axial direction are hermetically fixed to the bearing housing 35 on the side of the compressor A and the flange 48a of the outer frame housing 48 and the free end side of the rotary shaft 36. The flange portion 28a of the end plate-shaped housing 28 integrated with the bearing 29 is brought into contact with and integrally and airtightly fixed.

According to this structure, the stator core 43
Because both ends thereof are integrally fixed to the outer frame housing 48 that is airtightly fixed to the compressor A side as described above and the end plate-shaped housing 28 located on the free end side of the rotating shaft 36. In addition, it can function as a pressure-resistant container by cooperating with these members, so that the compression of the refrigerant gas is 20 Kg /
Sufficient pressure resistance can be ensured even for refrigerators reaching m ² .

On the other hand, since the winding 45 housed in the open groove 44 of the stator core 43 is located in the same space as the rotor 41, the rotor shaft of the compressor A in the incompletely sealed state. Since the working fluid composition containing the corrosive ammonia refrigerant enters the electric motor B between the portion 37a and the bearing 34,
Although it is necessary to perform the corrosion-resistant insulation treatment on the winding 45 together with the rotor 41, the ammonia-resistant insulation treatment on the winding is quite difficult. Therefore, as shown in FIG. 2 (B), the open groove 44 is filled with the binding resin 49 and the inner peripheral side thereof is covered with the insulating resin thin film 47 ′ so as to be hermetically sealed. As shown in FIG. 2 (A), the open groove 44 is filled with the binding resin, and the open groove 4 is formed.
4 is fitted to the opening end of the seal plate 27 having tapered side portions, a back pressure is applied from the back side of the seal plate 27 by the refrigerant gas pressure in the container, and the opening end of the open groove 44 is formed. It is possible to fit and seal hermetically. As a result, the stator winding 44 is fixed in the open groove 12, and at the same time, the opening surface thereof is closed, so that tough mechanical strength, touch resistance and airtightness can be simultaneously maintained.

[0014]

As described above, according to the present invention, since the stator itself functions as a pressure resistant container, the pressure resistance strength can be maintained while maintaining the airtightness between the rotor and the stator without using a can. In addition, it is possible to manufacture a high-capacity sealed fluid machine with improved contact resistance and airtightness and high efficiency. Further, according to the present invention, since the can can be omitted, the gap between the rotor and the stator can be minimized, and as a result, eddy current loss, excitation loss, etc. can be reduced. In addition to having various remarkable effects, it is extremely suitable as a sealed electric motor used for a refrigerator using ammonia in particular.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a hermetically sealed compressor of a hermetically sealed electric motor direct connection type according to an embodiment of the present invention.

FIG. 2A is an enlarged view of a main part showing a cross-sectional structure of the stator shown in FIG. 1, and FIG. 2B shows a modification of the open groove portion.

[Explanation of symbols]

 A electric motor B compressor 41 rotor 43 stator iron core 43a field iron core plate 46 sealant 27, 47 'non-magnetic thin plate or resin thin film 47 seal member

Claims (7)

[Claims] 1. A hermetically sealed electric motor which is directly connected to a rotary fluid machine capable of functioning as a compressor, an expander, or a fluid pump, wherein a stator core is surrounded by a predetermined gap around the rotor, and Sealed electric motor characterized in that the stator core is configured as a pressure-resistant sealed structure container. 2. A hermetically sealed electric motor in which a plurality of field iron core plates are laminated to form a stator core, wherein a sealing agent is provided on the laminated surface, and the iron core plates are interposed via the sealing agent. The hermetically sealed electric motor according to claim 1, wherein the hermetically-sealed electric motor is pressure-tightly maintained. 3. The sealed electric motor according to claim 2, wherein the sealing agent is an insulating resin coating agent or an insulating film. 4. The sealed electric motor according to claim 1, wherein a non-magnetic thin plate or a resin thin film is pressure-bonded to the inner peripheral surface side of the stator core to form a coating. 5. A seal member is disposed on the inner peripheral surface side of the open groove after inserting the winding of the stator core, which faces the rotor, and the inside of the open groove can be hermetically sealed via the seal member. The sealed electric motor according to claim 1, which is configured. 6. The sealed electric motor according to claim 5, wherein the working fluid of the rotary fluid machine is ammonia gas. 7. The seal member according to claim 4, which is a resin plate filled in the opening groove or a sealing plate having both side portions formed in a tapered shape so as to be fitted into an opening end of the opening groove. The sealed electric motor according to claim 1.