JP3348104B2 - Can type electric motor for driving ammonia refrigerant compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a can-type electric motor for driving an ammonia refrigerant compressor, and more particularly to an improvement of an insulated electric wire for ammonia-resistant winding used for a stator wire of the can-type electric motor.

[0002]

2. Description of the Related Art In recent years, there has been an increasing public interest in refrigerants used for cooling devices and the like, and technical measures meeting the above-mentioned interests have been demanded for equipment using refrigerants and their components and industrial materials. Conventionally, a chlorofluorocarbon-based material that is harmless to the human body, has excellent insulation properties, and does not easily disassemble has been frequently used in a cooling device, and a motor for driving the cooling device is also a stator wire formed of a CFC-resistant insulated wire. Hermetic motors having a simple structure capable of driving wheels in a CFC atmosphere have been widely used. Since the use and production of CFC-related equipment has been restricted since the pollution of the global environment by CFC-based substances has become a problem, ammonia refrigerant compressors have begun to be reviewed as an alternative to CFC-based cooling equipment. I have. Ammonia is a useful industrial material that does not have the disadvantages of global pollution and can widely utilize its features such as its refrigerant capacity and low cost if it can overcome the technical disadvantages of ammonia, but it is flammable and toxic. In addition, many general-purpose industrial materials having high hygroscopicity are gases exhibiting strong corrosiveness and are electrically conductive, so that careful handling of electric equipment is required.

[0003] As a device for handling ammonia, there is, for example, a cooling device which has long used ammonia as a refrigerant, and a compressor driving electric motor applied to the device has a completely hermetic structure in which the refrigerant does not leak outside the device. FIG. 4 shows a can-type motor 15 for driving the compressor, which was the most important electric device for ammonia. The structure of the can motor 15 protects the stator wire 7 composed of the insulated wire 18 inside the motor frame 13 under the atmospheric pressure so that the wire does not come into contact with the ammonia. If possible, a special internal structure is required which inserts and separates a metallic can 16 between the stator core and the rotor core between the air gaps. The insulated wire 18 is generally formed by covering the surface of a conductive wire 1 made of copper with a general-purpose enamel wire 4 having electrical resistance and non-ammonia resistance. Although the above structure allows the use of ammonia, the drawback of the electric motor 15 is that loss due to an increase in exciting current caused by an increase in the air gap and eddy current loss in the can 16 due to the presence of an alternating magnetic flux due to the stator wire ring 7. As a result, the motor efficiency is remarkably reduced, and the amount of heat generated due to the loss is large, and a special cooling device is required.

However, even in the protected stator wire 7 of the can-type motor 15, the outer section area may be exposed to the ammonia atmosphere due to leakage of the ammonia refrigerant due to the equipment or arrangement of the cooling device. For example, the stator wire 7 of the conductive material treated there is in contact with the ammonia gas, and the insulated wire 18 for the wire is damaged by ammonia because the wire for the ammonia resistant winding is not used, and the air is damaged. The copper wire 1 which inevitably permeates the moisture and ammonia therein and which is not necessarily resistant to ammonia also starts to corrode, and finally the stator wire loop 7 is disconnected.

[0005] As described above, a can-type motor used in an ammonia atmosphere is a passive technical measure for avoiding obstacles caused by ammonia by isolating devices and parts in a structure that is not exposed to ammonia. In addition, the development of ammonia-resistant can-type electric motors has hardly been actively carried out due to the influence of the above-mentioned chlorofluorocarbon-based refrigerants being frequently used for a long period of time.

[0006]

However, in the face of the requirement to restrict the use of CFC-based substances, it is difficult to develop a CFC replacement technology. With the demand for the motor, the capacity of the motor has been increasing, and it has become difficult for the conventional canned motor to cope with this.
Here, the use of ammonia is a basic technology relating to a can-type electric motor, at least first to corrosion resistance to ammonia, and second to good electrical insulation, which can be provided to industrial materials or components or parts having characteristics. If there is, the structure of the electric equipment using them can be simply or simply configured, and by solving the above-mentioned electric motor cooling measures together, socially through measures to comply with Freon regulations, Can meet the demand for increased motor capacity.

[0007] The object of the present invention, in view of the disadvantages of the prior art,
Used under an ammonia refrigerant atmosphere to form an insulated wire with at least excellent ammonia resistance, electrical insulation and durability, and used for winding of a can-type motor for driving an ammonia refrigerant compressor. It is an object of the present invention to provide a can-type electric motor for driving an ammonia refrigerant compressor having a simple structure.

[0008]

SUMMARY OF THE INVENTION The first aspect of the present invention is to provide a method for protecting a stator wire loop composed of an insulated wire, which is disposed inside a motor frame, between a stator core and a rotor core. In a can-type electric motor for driving an ammonia refrigerant compressor having a metallic can inserted therein, the insulated wire is formed by vapor-depositing an ammonia-resistant metal containing aluminum, alumite treatment, or the like on the surface of a conductive wire made of copper. Forming the intermediate coating layer by a die drawing method, forming an application layer or a baked layer of an ammonia-resistant electric insulating material on the surface of the intermediate coating layer to form an insulated wire, and reducing the diameter of the copper wire. On the other hand, the thickness t of the coating layer is set to 10.96% or less.

Secondly, the present invention provides a metal can between a stator core and a rotor core so as to protect a stator wire loop composed of insulated wires, which is disposed inside a motor frame. In the inserted can-type electric motor for driving the ammonia refrigerant compressor, the insulated wire is formed by coating an aluminum oxide metal film by anodic oxidation on a surface of a conductive wire made of aluminum to form an intermediate coating layer. And a step of forming a coating layer or a baking layer of an ammonia-resistant electric insulating material on the surface of the intermediate coating layer to form an insulated wire.

In other words, when the required corrosion resistance to ammonia cannot be ensured, or when the thickness of the coating layer exceeds the limit ratio, and the thickness t of the coating layer cannot be set to 10.96% or less, the above-mentioned thin line is used. The conductor is also made of aluminum wire instead of copper. In this case, it is preferable to improve the corrosion resistance by applying an alumite-treated layer, that is, an aluminum oxide metal film formed by anodic oxidation on the surface of the aluminum wire.

The limit ratio is a diameter D made of a metal C having a specific resistance m as shown in a calculation example described later.
And a metal A having a specific resistance n.
When there is an intermediate coating layer having a coating thickness t, a resistance value when the metal A of the intermediate coating layer is made to have a diameter D is determined, and the specific resistance between the conductive wire and the intermediate coating layer is the same according to the resistance value. The ratio of the coating thickness t of the intermediate coating layer to the outer diameter (D) including the intermediate coating layer. Therefore, when the coating thickness t exceeds the calculated limit ratio, it is better to replace the copper wire used for the conductor with aluminum, which is the metal of the intermediate coating layer, so that the conductor is also an aluminum conductor. Show good things. For example, copper for the conductor,
When the intermediate coating layer is made of aluminum, the coating thickness t can be set only to 10.96% or less of the coating layer thickness. The second invention shows that the use of an aluminum wire has a technical advantage.

The above-mentioned alumite-treated layer may be double-coated with a coating layer or a baking layer of the above-mentioned ammonia-resistant electric insulating material.

[0013]

According to this technical means, as in the prior art, when subjected to a temperature change in an ammonia atmosphere, the resin or paint coating the copper wire separates and separates from the copper wire, Is not cracked or corroded, has at least an intermediate coating layer integrally formed on the conductor, has flexibility and does not suffer from the peeling failure, and is free from ammonia gas, liquid, lubricating oil, etc. Aluminum or other metal or an alloy thereof, which is not violated by the air, is used as a metal surface, and is not corroded by air mixed into the gas or moisture contained in the air.

In the first aspect of the invention, a copper wire is used as a core wire, the surface of which is used as an intermediate coating metal layer, and a coating layer or a baking layer of an ammonia-resistant electric insulating material is formed on the surface. By forming a corrosion-resistant metal layer such as aluminum and its alloys having high electrical insulation, the conductivity of the copper wire is not hindered. In other words, an efficient design of the stator wire loop of the can type motor is to select the resistance loss of the winding to a minimum. Therefore, the material with high conductivity is copper wire in practice, but ammonia-resistant insulation Even if an organic material such as polyethylene or Teflon is used as the material, the copper wire cannot be protected from the molecular roughness of the organic material. Therefore, a vapor-depositing process, an anodizing process, or a die-drawing process of aluminum or nickel-containing ammonia-resistant metal. If the intermediate coating layer is formed by the method, the intermediate coating layer can be formed without pinholes.

However, if a copper wire is used for the core wire during such processing, the thickness of the core wire itself is limited.
It is a crucial factor for determining the core wire material and the thickness of the intermediate coating layer from both aspects of electrical characteristics and is an important factor. The first and second inventions effectively combine the limit ratio, the core wire material and the intermediate coating layer.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just

FIG. 1 shows details of an embodiment of the present invention,
(A) is a cross-sectional view of a main part of the first embodiment, (C) is a perspective view of a main part of (A), (B) is a cross-sectional view of FIG. Forming an intermediate coating layer 2 having a diameter D with a coating thickness t formed by vapor deposition, deposition or die drawing by using an ammonia-resistant metal containing iron, nickel, iron or an alloy thereof; The surface of the wire 2 is formed by applying or baking a cross-linked polyethylene or the like as an example of the ammonia-resistant electric insulating material 3 to form the insulated wire for wire 10. The coating thickness t
Is formed below the limit ratio determined by the specific resistance of the metal selected for the ammonia-resistant intermediate coating layer 2 and the metal used for the conductive wire 1.

Normally, a copper wire is used for the conductive wire 1 to form the intermediate coating layer 2 made of a metal layer made of the ammonia-resistant metal. However, when the intermediate coating layer 2 is made of aluminum, a sufficient thickness of the coating layer cannot be obtained even if the intermediate coating layer 2 has a thickness lower than the limit ratio. The coating thickness is
In the case of a thin line that must be given for a specific reason,
The conductor is also made of aluminum wire instead of copper. An alumite-treated layer, that is, an aluminum oxide metal film formed by anodic oxidation may be applied to the surface of the aluminum wire to enhance corrosion resistance.

FIG. 2 is a sectional view showing a main part of another embodiment of the present invention, in which the conductive wire 1 is a copper wire, and the intermediate coating layer 2 made of aluminum is formed on the surface of the copper wire. The surface of the intermediate coating layer 2 is coated with a film of the alumite treatment layer 2a, and the above-mentioned ammonia-resistant electric insulating material 3 is formed on the surface by coating or baking.
0.

FIG. 3 shows the electric equipment used in the embodiment of the present invention. FIG. 3 is a cutaway side view of a main part of a can-type electric motor for driving an ammonia compressor. The electric motor 5 includes a compressor or a pump for ammonia. One end is connected to the load 6 via a bearing (not shown), and the other end is mounted on a bearing 12 fitted to the outer shell of the electric motor 5, a drive shaft 11 rotatably supported on the rotor 6, and a rotor core 8. And a stator core 9 is wound inside the outer shell by an insulated wire 10 (not shown) and a stator core 9 is opposed to the rotor core 8 via an air gap. It is configured by mounting. The space between the load 6 and the internal structure of the electric motor 5 allows the ammonia gas G to freely flow through the pressure equalizing holes 14 so that the internal structure can be cooled and the outer shell has a completely sealed structure. Thus, the internal ammonia gas G does not leak to the outside.

Next, the operation of the present invention and its application will be described. Forming the intermediate coating layer 2 on the surface of the conductive wire 1 by vapor-depositing an aluminum-containing metal containing aluminum, alumite treatment or die-drawing, and applying or baking a layer of an ammonia-resistant electric insulating material; Bonding of each layer is integrated and has adhesiveness, and since the forming metals are each soft, they are flexible and sufficiently cope with bending at the time of winding formation, peeling between the respective layers, There are no cracks. Also, in an ammonia atmosphere, the first layer of the ammonia-resistant electrical insulating material comes into contact with the gas, and the second layer of the ammonia-resistant metal layer or film is formed under the first layer. It prevents penetration into the lower conducting wire 1. Also, the first layer ensures insulation,
The second layer protects the operation of the conductor 1 without inhibiting the conductivity of the conductor. The ammonia-resistant metal is selected according to the adhesiveness with the conductive wire 1, the workability, and the economical efficiency in accordance with the application.

An example in which the intermediate coating layer is used below the limit ratio will be described for the case where the conductive wire 1 is a copper wire and the intermediate coating layer 2 is aluminum. The specific resistance of copper (mild copper) is 20 ° C. and 1.724
* 10 ^-6 ohms / cm ² , aluminum 2.828 *
10 ⁻⁶ ohm / cm ² , and when the specific resistance of copper is set to 1, the resistance ratio of aluminum is 1.640.
(= 1 / 0.6096). When the thickness t of the coating layer, the diameter of the copper wire (D-2t), and the diameter of the aluminum wire including the coating layer are D, the cross-sectional area is (π / 4) × (D-2t) ² = 0. 6096 × (π / 4) D ² D-2t = 0.78076D Therefore, 2t / D = 0.192 That is, the thickness t of the metal layer 3 made of aluminum is smaller than the outer diameter D including the t. T / D = 0.2192 / 2 = 0.1096, and when the thickness t of the coating layer occupies 10.96% of the diameter (D-2t) of the copper wire, the thickness t is limited. When the thickness t becomes less than this, the technical advantage of covering the copper wire 1 with the intermediate coating layer 2 is obtained, and when the thickness t is more than this, the conductor 1 is made of an aluminum wire. Is selected.

When the insulated wire 10 is used for a winding of an electric device, usually, the conductor 1 has a large cross-sectional area, that is, a diameter D in order to reduce copper loss due to the resistance of the winding.
It is preferable that the thickness t of the intermediate coating layer 2 is electrically thin and thick for corrosion resistance. Further, the thinness of the thickness t of the formed intermediate coating layer does not affect the securing of the effective cross-sectional area of the insulated wire 10,
The workability of connecting the insulated wires 10 to each other is as follows:
Since the absolute thickness is small, the coating layer can be easily peeled off, and the conductive wires 1 can be easily soldered to each other, which is extremely good.

Next, a description will be given of the insulated wire 10 in the case where the used electric equipment according to the embodiment of the present invention is applied to a can-type motor. When the drive shaft 11 of the electric motor 5 that communicates with the load 6 using the ammonia refrigerant through the equalizing tube 14 is driven to rotate, the lubricant G and the ammonia G are supplied to the stator core 9 on the electric motor 5 side together with the lubricating oil. , And the entire internal structure of the electric motor 5 together with the stator wire loop 7 is exposed to an ammonia atmosphere. However, the stator wire 7 is provided with an insulated wire 10 on which an ammonia-resistant electric insulating material is integrally provided together with the intermediate coating layer under the stator wire 7. Motor having a simple structure that has a good electrical conductivity of the conductive wire 1 and the intermediate coating layer, that does not generate eddy current loss, and that generates a small amount of heat. Can be developed and applied for driving the ammonia compressor, which is durable and has high motor efficiency.

[0025]

As described above, according to the present invention, it is possible to maintain electrical insulation and to make ammonia resistant.
For driving the ammonia refrigerant compressor, which actively solves the technical problems of insulated wires in an ammonia atmosphere while maintaining the integrity, flexibility, and durability of the structure without being affected by corrosion by oil and moisture. While providing a can-type electric motor, for example, a can-type motor that can solve the technical problems of the insulated wire in an ammonia atmosphere that satisfies the technical problems related to the motor efficiency, the device structure, the heat-generating element, the electric capacity, etc. It is possible to provide a can-type electric motor for driving an ammonia refrigerant compressor which is a type electric motor and which can meet the social demands including the chlorofluorocarbon regulation for the first time according to the present invention and can be used under an ammonia atmosphere, Its practical value is enormous.

[Brief description of the drawings]

1A and 1B show details of an embodiment of the present invention, wherein FIG. 1A is a cross-sectional view of a main part of the first embodiment, FIG. 1C is a perspective view of a main part of FIG.
(B) is a sectional view taken along the line YY of (C).

FIG. 2 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 3 is a cutaway side view of a main part of a can type electric motor for driving an ammonia compressor, showing electric equipment to be used according to the embodiment of the present invention.

4A and 4B illustrate a prior art of a can-type electric motor, and FIG.
FIG. 2 is a cutaway side view of the canned motor, and FIG. 2B is a sectional view of a main part of a stator wire loop of the motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Conductor (copper wire or aluminum wire) 2 Intermediate coating metal layer 3 Coating or baking layer of ammonia-resistant electrical insulation material 10 General-purpose insulated wire 18 Insulated wire for ammonia-resistant winding

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 3/30-3/52

Claims (2)

(57) [Claims] (1)Insulation placed inside the motor frame
The stator wire loop consisting of electric wires can be protected
An antenna with a metallic can inserted between the rotor core
In a can-type motor for driving a Monia refrigerant compressor, The insulated wire is an aluminum wire on the surface of a copper wire.
-Vapor deposition treatment of ammonia-resistant metal including aluminum, alumite
Of the intermediate coating layer by a treatment or die drawing method
And an ammonia-resistant electrical insulating material on the surface of the intermediate coating layer.
To form an insulated wire by forming a coating layer or baking layer.
Along with The thickness t of the coating layer is 10.96% with respect to the diameter of the copper wire.
Ammonia refrigerant compressor characterized by the following settings:
Can type motor for driving. (2)An insulated power supply located inside the motor frame
The stator wire loop consisting of wires can be protected so that the stator core
Ammo with metal can inserted between trochanter core
In a can-type motor for driving a near refrigerant compressor, The insulated wire is a surface of a conductive wire made of aluminum.
Aluminum oxide metal film by anodic oxidation
To form an intermediate coating layer, and the surface of the intermediate coating layer
Applying or baking layer of monic electrical insulation
Characterized by forming an insulated wire by performing
A Can type electric motor for driving the refrigerant compressor.