JPH0617354U - Fully sealed electric motor for driving ammonia compressor - Google Patents

Abstract

(57) [Abstract] [Purpose] A highly corrosive ammonia refrigerant compressor driving electric motor is used in a space containing at least the axial direction in the electric motor frame, regardless of the conventional can type hermetically sealed structure, in the ammonia refrigerant gas phase region. By installing and isolating and separating from the refrigerant liquid phase region at the lower end of the frame, the stator winding arranged in the gas phase region, its connecting portion, and the lead-out terminal can maintain corrosion resistance and electrical insulation, thus achieving high efficiency. To obtain the economical fully sealed electric motor for driving ammonia compressor. [Structure] In a gas phase region 9 of an ammonia refrigerant provided in an electric motor frame 5, a stator winding 7 subjected to an ammonia resistant insulation treatment is provided.
And the winding connecting portion 12 and the sealed terminal 8 made of an insulating material against ammonia are always located in the upper gas phase region in the frame, and the refrigerant and the melted lubricating oil and the like intruding from the rotating shaft 4 and the frame are arranged. An insulating distance that does not cause bridging with the portion is provided, and the refrigerant liquid is discharged from the liquid reservoir 10 or the liquid reservoir 11 at the lower end of the frame to the outside of the machine.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a driving motor for a compressor that uses ammonia as a refrigerant, and relates to a simple all-sealed structure that should be provided in an ammonia-resistant motor when it is integrally configured with the compressor.

[0002]

[Prior art]

 Conventionally, two types of refrigerants for compressors, which are suitable for refrigerating equipment, have been put into practical use, including fluorocarbons and ammonia, but recently, due to conservation of the global environment, ammonia, which has been used for many years, will be reviewed. Became.

However, ammonia itself has a physicochemical property such that it is highly corrosive, gives off a bad odor, and is electrically conductive because it has hygroscopicity. To the extent that the iron core and these windings are simply insulation-coated or surface-treated with a conventional material, the corrosion of ammonia causes the insulation coating material of the wire conductor, especially the resin, to melt or peel off, resulting in a core wire. Since it also has a serious adverse effect such as eroding even the normal copper wire that is a conductor, if the insulation resistance of the winding of the above-mentioned motor is extremely lowered, if the operation is continued as it is, the winding will be short-circuited and burned out. It will cause troubles such as disconnection.

On the other hand, in a hermetically sealed electric motor directly connected to a compressor using a chlorofluorocarbon refrigerant, the refrigerant attributes are chemically stable, non-combustible, non-explosive, non-corrosive, and suitable for cooling and insulation. However, since the electric motor can be advantageously handled for electrical insulation, cooling, and airtight structure, a hermetic or semi-hermetic motor frame structure is adopted.

On the other hand, when the ammonia is used as the refrigerant, both the stator and the rotor of the electric motor are required to have corrosion resistance and insulation properties. Therefore, a can is fitted into and fixed to the inner periphery of the stator to fix the can. The applicant has made some proposals to make the rotor part have a sealed structure as a canned motor in which a small gap is maintained between the rotor and the child. However, in the above-mentioned canned motor, since this can is linked to a high-density alternating magnetic flux, heat is generated due to eddy current loss and excitation loss due to an increase in magnetic resistance in the air gap including the can. As a result, the efficiency of the electric motor will be reduced, making it particularly difficult to design a large capacity machine.

Further, even when a polyethylene-coated insulated wire is used to make the stator windings resistant to ammonia, the terminals of the stator windings to be phase-connected, the connecting portions of the lead wires, or the motor frame are not connected. Since there is a connection in the penetrating sealed terminal part, it is difficult to treat them with ammonia resistant insulation so as to maintain a perfect airtight state. It cannot be done.

[0007]

[Problems to be solved by the device]

 Thus, in view of the above-mentioned conventional technical problems, the present invention, despite the fact that corrosion by the ammonia refrigerant occurs at the portion immersed in the liquid of ammonia and does not exhibit conductivity in the gas phase atmosphere, Originally, it was forbidden to expose an insulated winding that uses a copper-based metal conductor, which has poor corrosion resistance, as a core wire to the vapor phase of ammonia, and the structure of the conventional canned motor. In consideration of the coming efficiency, cooling, and design and production problems, the structure of the electric motor having excellent ammonia resistance is provided by carefully considering the properties of the refrigerant without making the structure complicated.

[0008]

[Means for Solving the Problems]

 Therefore, according to the present invention, in the axial space in the motor frame, the stator winding wound with the ammonia resistant insulated wire is always arranged in the vapor phase portion which is not immersed in the liquid phase of the ammonia refrigerant. By arranging the motor components in the frame so that they are isolated from the liquefied refrigerant that accumulates at the lower end of the frame, the corrosion resistance and electrical insulation of the ammonia refrigerant can be maintained.

[0009]

[Action]

 With the above configuration and arrangement, all the surfaces of the stator windings, which are insulated against ammonia, the winding interconnections, and the sealed terminals are all contained in the vapor phase region of the ammonia refrigerant in the space inside the motor frame. Is placed, and is kept in an isolated state so as not to be immersed in the liquid phase of the ammonia refrigerant, and can be operated as an electric motor having a sealed structure excellent in insulation, efficiency, and economy. In addition, the stator winding and the winding connection portion that connects each end are located above the ammonia vapor phase region in the frame and at a position separated from the components including the frame by the minimum insulation distance. By being provided, the corrosion resistance and the electrical insulation can be sufficiently maintained. Furthermore, by installing a liquid reservoir or reservoir at the lower end of the frame, separated from the lower edge of the stator winding, the continuously accumulated ammonia refrigerant is returned to the compressor side, and there is a fluctuation in the flow rate. Even so, the buffering effect can be achieved, whereby the above-mentioned effect can be achieved smoothly. Furthermore, by arranging the lead-out portion for connecting and connecting each phase of the stator winding above the ammonia vapor phase region in the frame, and by piercing the frame with corrosion-resistant and insulating sealed terminals, It is possible to maintain sufficient corrosion resistance and insulation and facilitate wiring outside the machine.

[0010]

【Example】

 Hereinafter, preferred embodiments of the present invention will be illustratively described in detail with reference to the drawings. The dimensions and shapes of the components, means, etc. described in these embodiments, and their relative arrangement are described in particular. Unless specifically stated, the scope of the present invention is not limited thereto, and is merely an explanation.

FIG. 1 is a partially cutaway side view of an ammonia compressor driving fully sealed electric motor of the present invention, wherein 1 is an ammonia compressor and 2 is a totally sealed electric motor for driving the same. Since the bearing portion 3 of the compressor 1 and the rotary shaft 4 of the rotor 13 are simply rotatably supported, the ammonia refrigerant compressed by the compressor 1 passes through the bearing portion and the frame of the electric motor. It leaches into 5 and eventually becomes gaseous, filling the axial space and forming a gaseous phase region 9 of ammonia. 6 is a stator core fixed to the inner wall of the outer shell frame 5 of the electric motor 2, 7 is ammonia resistant insulation wound around the stator core, for example, stator winding insulation-coated with polyethylene, 8 is the above This is a sealed terminal made of ammonia resistant insulation material that leads the lead wire from the end of the stator winding to the outside of the machine.

FIG. 2 is a vertical cross-sectional view of the electric motor cut along the line YY of FIG. 1, showing a state diagram (A) of the liquid reservoir 10 of the liquid refrigerant and an attachment state diagram (B) of the liquid reservoir 11. Is. As can be seen from the above two figures, the ammonia insulating insulation stator winding 7 is arranged in the vapor phase region 9 of the ammonia refrigerant as described above, and has an arrangement structure that is separated and isolated from the refrigerant liquid. By adopting this, by providing a liquid reservoir 10 or a liquid reservoir 11 leading to the compressor at the lowermost portion of the electric motor frame, the refrigerant liquid is always returned to the compressor side.

Further, as will be described with reference to FIG. 3 showing an example of interconnection or drawing out from the middle of the stator winding or from the end, it is communicated with a space in the axial direction of the rotating shaft 4 in the frame 5. A vapor phase region 9 of the ammonia refrigerant also extends to the space around the outer periphery of the stator core 6. The lead-out connecting portion 12 of the stator winding is subjected to ammonia-proof insulation treatment to prevent the pinholes completely from disappearing. It is placed in the vapor phase region above the frame where there is no danger of being immersed in the frame, and is also caused by the lubricating oil or refrigerant liquid in which the refrigerant has been eluted, especially between the structural members such as the frame members below the frame. It is designed to maintain a distance that does not cause a bridge. In the present embodiment, the connecting portion between the lead wire for leading out from each of the stator windings 7 to the outside of the frame 5 and the sealing terminal 8 is arranged in the refrigerant gas phase region 9 above the frame. However, the connecting portion 12 and the sealing terminal 8 between the stator windings 7 represent a connection example of one phase of the stator winding 7, and the same connection mode is applied to other phases. Therefore, the description is omitted.

[0014]

[Effect of device]

 Thus, according to the present invention, in the frame of the electric motor integrated with the ammonia compressor, a gas phase region by the ammonia refrigerant invading from the compressor side through the rotary bearing is provided, and the stator winding insulated from ammonia is wound. Since wires, these connection parts, and each connection part of the lead wire are provided, there is no risk of being immersed in ammonia refrigerant liquid, no conductivity is given, and corrosion resistance and insulation are maintained. In addition, the winding connection part located in the ammonia gas phase region in the upper part of the frame is made to lead out all the sealed terminals made of the ammonia resistant insulation material drilled in the frame, so that the corrosion resistance is improved. External wiring can be performed while maintaining insulation. Furthermore, the ammonia refrigerant liquid that accumulates at the lower end of the frame is provided with a liquid reservoir or a reservoir so that it can be continuously returned to the compressor, so that sufficient corrosion resistance and insulation distance can be obtained for the components inside the frame including the frame. It became possible to secure. Therefore, the bearing does not have a special sealing mechanism, and even though the structure is the same as that of an ordinary electric motor in which a sealing can is not fitted in the air gap like the canned motor, the inside of the frame has an ammonia gas phase. It is possible to separate the liquid phase region from the liquid phase region, and to arrange each member in the frame at an insulation distance that does not cause bridging with the ammonia refrigerant liquid or the lubricating oil etc. eluted from this, designing a large machine. It is possible to obtain a fully sealed electric motor for driving an ammonia compressor which is highly efficient and economical.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a totally sealed electric motor for driving an ammonia compressor according to the present invention.

FIG. 2 is a vertical cross-sectional view of the electric motor taken along line YY of FIG. 1, in which (A) is a liquid reservoir of an ammonia refrigerant liquid, and (B) is a layout view of liquid reservoirs.

FIG. 3 is a layout view of a stator winding, a connecting portion thereof, and a sealed terminal in an ammonia refrigerant gas phase region in an electric motor frame.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ammonia compressor, 2 Fully sealed electric motor 3 Bearing part, 4 Rotating shaft 5 Frame, 6 Stator core 7 Stator winding, 8 Sealing terminal 9 Ammonia refrigerant gas phase region, 10 Liquid reservoir 11 Liquid reservoir, 12 Connection

Claims (4)

[Scope of utility model registration request] 1. A driving electric motor integrally connected to an ammonia compressor to form a totally sealed structure, wherein a gas phase of the ammonia refrigerant from the compressor is provided in a space including at least both axial ends of the electric motor frame. Is provided so that the stator winding wound around the stator core is located in the refrigerant gas phase region, and the frame is separated and separated into an ammonia refrigerant gas phase region and a liquid phase region. A fully sealed electric motor for driving an ammonia compressor, which is characterized in that 2. A winding connecting portion for connecting the stator winding and each terminal thereof is arranged at a position above an ammonia refrigerant vapor phase region in the frame and at a position separated from a constituent member including the frame by a minimum insulation distance. Is installed,
The fully sealed electric motor for driving an ammonia compressor according to claim 1. 3. A liquid reservoir or a liquid reservoir for returning the liquefied refrigerant liquid separated in the frame to the compressor side from the lower end of the frame separated from the lower edge of the stator winding. The fully sealed electric motor for driving an ammonia compressor according to claim 1, characterized by being provided. 4. A lead-out portion, which is connected and connected for each phase of the stator winding, is arranged above the refrigerant vapor phase region in the frame, and a corrosion-resistant insulating sealed terminal penetrating outside the machine is provided in the frame. The fully sealed electric motor for driving an ammonia compressor according to claim 1, wherein the totally enclosed electric motor is provided.