JPH10220353A - Semi-closed type screw compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semi-closed screw compressor having high reliability, in which much labor for maintenance work is reduced and a floor space occupied thereby requires small, and a water-proof refrigerator unit in which the screw compressor is mounted. SOLUTION: This semi-closed screw compressor is formed in a manner that an electric motor and a compressor mechanism part 1 comprising a pair of female and male screw rotors which is engaged with each other and rotated, are directly connected to each other and stored in a disassemble casing 7, and a power supply connecting terminal box 9 for the electric motor is mounted in a terminal structure having airtightness in which the conductor 13 of a stator 5 is connected to the casing 7. The power supply connecting terminal box 9 for the electric motor is formed to have a water-proof structure having water- tightness that a bare live part and an insulated live part are separated from the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semi-hermetic screw compressor.

[0002]

2. Description of the Related Art A compressor mounted on a conventional waterproof refrigerator unit is, for example, an open reciprocating compressor as described in Japanese Utility Model Application Laid-Open No. 54-78014, or a conventional reciprocating compressor. It was an open screw compressor as described in JP-A-54-67844. The drive system of these compressors employs a waterproof electric motor as a belt or a direct connection type, and is provided with a protection device having a waterproof structure.

[0003] Here, the definition of the waterproof structure is based on Japanese Industrial Standard JI.
SF8001 "Waterproof test for marine electrical equipment", that is, a water head of 8 m with a nozzle with an inner diameter of 12.5 mm or more from a distance of 3 m from the aircraft
The above-mentioned compressor unit equipped with a waterproof protection device has a structure that does not allow water to enter inside the body even if water is injected from various directions for 10 minutes in total from various directions. It can be mounted on a cooling system or a waterproof refrigerator unit of a cooling system installed in a tunnel in a high humidity environment.

Further, for example, in the semi-hermetic reciprocating compressor described in Japanese Patent Application Laid-Open Nos. 5-215073 and 7-167057, the former is connected between a stator of a motor and a terminal of a terminal board. There is a description about the means for connecting the lead wires, and in the latter, a means for cooling the coil end of the motor. Had not been.

Further, a compressor protection device (pressure switch,
The waterproof structure of the temperature switch) was not described.

That is, the semi-hermetic compressor cannot be mounted on a waterproof refrigerator unit.

[0007]

The open-type compressor mounted on the prior-art waterproof refrigerator unit employs a waterproof electric motor as a belt drive or a direct connection type for the drive system of the compressor. There was such a problem.

(1) Periodic maintenance is required because a shaft sealing device is provided in a press vertical machine.

(2) Alignment work between the compression mechanism section and the electric motor section is required.

(3) Since the vibration is large, a sturdy foundation or a vibration isolator is required.

(4) The installation area in the combined state of the compression mechanism and the motor is large.

Also, in the prior art semi-hermetic compressor, consideration is given to the fact that the power supply terminal box for the motor has a watertight waterproof structure in which the bare charging portion and the insulated charging portion are isolated from the outside. And could not be mounted on a waterproof refrigerator unit.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and a highly reliable semi-hermetic compressor which requires less maintenance work and requires a smaller installation area, and has the compressor mounted thereon. An object of the present invention is to provide a waterproof refrigerator unit.

[0014]

In order to achieve the above object, a first configuration of a semi-hermetic screw compressor according to the present invention is configured to rotate while meshing with an electric motor including a stator and a rotor. A power supply connection terminal box for an electric motor is connected directly to a compression mechanism section comprising a pair of male and female screw rotors, housed in a disassemblable casing, and having a hermetic terminal structure in which a conductor of the stator is connected to the casing. In a semi-hermetic screw compressor in which an oil recovery unit having an oil separation unit built in on the discharge side of the compression mechanism unit is attached to the casing via an airtight flange, the power connection terminal box for an electric motor is The naked charging portion and the insulated charging portion have a watertight waterproof structure that is isolated from the outside.

Further, in order to achieve the above object, a second configuration of the semi-hermetic screw compressor according to the present invention comprises a male and female low-powered pair of male and female rotating together with an electric motor including a stator and a rotor. A stage-side screw rotor and a compression mechanism section composed of a high-stage side screw rotor are directly connected to each other and housed in a disassemblable casing, and the casing is connected to the conductor of the stator. In a semi-hermetic screw compressor equipped with a power connection terminal box, the power connection terminal box for the motor has a watertight waterproof structure in which a bare charging portion and an insulated charging portion are isolated from the outside.

Further, in order to achieve the above object, a semi-hermetic reciprocating compressor according to the present invention has a configuration in which a motor including a stator and a rotor and a motor directly connected to the motor and driven by the motor. A compression element comprising a rotating crankshaft and a cylinder containing a piston coupled to the crankshaft via a connecting rod is housed in a decomposable hermetic casing, and the casing has a power supply connection terminal for an electric motor. In a semi-hermetic reciprocating compressor equipped with a box, the power supply terminal box for a motor has a watertight waterproof structure in which a bare charging portion and an insulated charging portion are isolated from the outside.

Further, in order to achieve the above object, the structure of the semi-hermetic compressor according to the present invention is provided when the discharge pressure of the compressor is abnormally increased or when the suction pressure of the compressor is abnormally increased. A pressure switch for stopping the operation of the compressor when the temperature decreases, and a temperature switch for stopping the operation of the compressor when the discharge gas temperature of the compressor rises abnormally. It is a structure.

In order to achieve the above object, the present invention provides a compressor for compressing a refrigerant gas and a condenser for cooling and condensing the compressed, high-temperature, high-pressure refrigerant gas to generate a liquid refrigerant. The above-mentioned semi-hermetic compressor is mounted on a waterproof refrigerator unit that constitutes a refrigeration cycle and includes an evaporator that evaporates the liquid refrigerant and removes heat of evaporation from an object to be cooled to cool the object.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

The refrigerating unit according to the refrigerating apparatus described herein is a semi-enclosed screw pressure vertical machine for compressing the refrigerant gas, and cools and condenses the compressed high-temperature and high-pressure refrigerant gas to generate a liquid refrigerant. A cooling cycle is provided with a condenser and an evaporator that removes the heat of evaporation from surrounding objects to be cooled with an evaporating coil containing the liquid refrigerant and forms a cooling cycle, and is further provided with a semi-hermetic screw compressor. And a protection device such as a pressure switch and a temperature switch.

First, the components of the semi-hermetic screw compressor and the flow of the refrigerant will be described with reference to FIG.

FIG. 1 is a schematic diagram showing the configuration of a semi-hermetic screw compressor according to one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a compression mechanism comprising a pair of male and female screw rotors 2 meshing and rotating with each other; 3, a rotor shaft integrated with the screw rotor 2; 4, a rotor fitted to the rotor shaft 3; Reference numeral 5 denotes a stator fixed to the casing 7 side, and the rotor 4 and the stator 5 constitute an electric motor. 6A and 6B are bearings that support the rotor shaft 3, 7 is a casing that supports the bearings 6A and 6B and the stator 5 on its inner surface, 8A is a cover that covers the motor side of the casing, and 8B is a compression mechanism side of the casing 7. Cover 9; power supply terminal box 9 for electric motor;
6 is an oil separation device provided in the oil recovery device. 12 is a winding end of the stator 5, 13 is a conductor of the winding end 12, 14
Indicates a terminal bolt. Reference numeral 15 denotes a suction port provided in the cover 8A, and reference numeral 17 denotes a discharge port provided in the oil recovery device 10.

The semi-hermetic screw compressor shown in FIG. 1 has a casing 7 which is directly connected to an electric motor consisting of a stator 5 and a rotor 4 and a compression mechanism 1 consisting of a pair of male and female screw rotors 2 which mesh with each other and rotate. It is stored inside. An electric motor power supply connection terminal box 9 is mounted on the casing 7, and an oil recovery unit 10 having an oil separating unit 16 built in on the discharge side of the compression mechanism 1 is joined to the casing 7.
The casing 7, the covers 8A and 8B, the power supply terminal box 9 for the electric motor, and the oil recovery unit 10 are connected to each other with bolts 11 to form a closed container, which can be disassembled, and has a semi-closed structure. . The conductor 13 of the winding end 12 of the stator 5 is connected to the casing side end of the terminal bolt 14 of the electric power supply connection terminal box 9.

The refrigerant gas is sucked through a suction port 15 formed in the cover 8A, passes around the rotor 4 and the stator 5 and is compressed by the screw rotor 2, and
Through an oil separation device 16 built in the oil recovery device 10 and a discharge pipe 17 (not shown) from a discharge port 17 formed in the oil recovery device 10.
It is discharged to a condenser (not shown).

Next, the motor power supply connection terminal box 9 will be described with reference to FIGS. 2 is a plan view showing the configuration of a power supply terminal box for a motor provided in the semi-hermetic screw compressor of FIG. 1, and FIG. 3 is a side sectional view of FIG.

The power supply connection terminal box 9 for a motor is formed at right angles to the bottom plate 18 and the bottom temporary 18 and has one side welded to the bottom plates 18 and 19B, and the bottom plates 18 of these frames 19A, 19B. And a flange 20 welded to the opposite side.

The lid 21 is fastened to the flange 20 with bolts 23 via a water-resistant sheet packing 22, and the motor power supply connection terminal box 9 has a watertight waterproof structure.

A trapezoidal terminal block 24 is formed on the casing 7 so as to protrude from the casing 7, and the bottom plate 18 of the terminal box 9 is connected to the terminal block 24 via bolts 26 via a sheet packing 25 for a refrigerator. Has been concluded. A plurality of terminal bolts 14 penetrate the terminal block 24, one end of which is located in the power supply connection terminal box 9 for the electric motor and the other end is located in the terminal block 24, that is, in the casing 7 (inside the compressor). , Via an insulator 27 and a rubber sheet 28. The rubber sheet 28 maintains the airtightness between the power supply connection terminal box 9 for the electric motor and the inside of the casing 7.

A waterproof screw-in protective pipe joint 29 is provided on the frame plate 19A.
Is open. The waterproof screw-in protection pipe joint 29 is attached to the connection port 30, and the power supply connection wire 31 is guided from the outside into the motor power supply connection terminal box 9 through the waterproof screw-in protection pipe joint 29. As described above, the power supply connecting wire 31 is provided through the waterproof screw-in protection pipe joint 29 and is connected to the inner side end of the motor power supply connecting terminal box 9 by the terminal bolt 14. The conductor 13 of the stator 5 shown in FIG. 1 is connected to the terminal bolt 14 inside the compressor.

The power supply connection terminal box 9 for the motor shown in FIGS. 2 and 3 is made of a steel plate formed by welding, and a lid 21 and a flange 20 are formed.
The water-resistant sheet packing 22 is provided on the joint surface between the bottom plate 18 and the terminal block 24, and the seat packing 25 for refrigerator is provided on the joint surface between the bottom surface 18 and the terminal block 24.
And are fastened with bolts.

Since the power supply connecting wire 31 is disposed through the waterproof screw-in protection pipe joint 29, the naked charging portion and the insulated charging portion are isolated from the outside and have a watertight waterproof structure. The watertight power supply terminal box 9 for a motor having a watertight structure prevents water from entering the terminal box 9. The terminal box 9 is also applicable to the semi-hermetic compressor according to claims 2 and 3.

Here, the definition of the waterproof structure is based on Japanese Industrial Standard.
JISF8001 "Waterproof test for marine electrical equipment", i.e., water does not penetrate into the airframe even when water is injected from a distance of 3m from the airplane with a nozzle with an inner diameter of 12.5mm or more and a head pressure of 8m from various directions for a total of 10 minutes from various directions. It is a structure.

Next, the refrigerating cycle configuration of the compressor protection device and the refrigerating unit will be described with reference to FIG.

FIG. 4 is a system diagram showing the construction of a refrigerating cycle of a compressor protection device and a refrigerating unit of a semi-hermetic screw compressor according to one embodiment of the present invention. In FIG. 4, 1 is FIG.
Corresponds to the semi-hermetic screw compressor shown in FIG. 32 is a suction pipe for the compressor 1, 33 is a discharge pipe for the compressor 1, 34 is a condenser for cooling and condensing a high-temperature, high-pressure refrigerant gas compressed by the compressor 1 to generate a liquid refrigerant, Reference numeral 35 denotes a pressure reducer, and reference numeral 36 denotes an evaporator that evaporates the liquid refrigerant, removes heat of evaporation from the object to be cooled, and cools the object.

The compressor 1, condenser 34, and evaporator 35
Are connected by refrigerant pipes such as a suction pipe 32 and a discharge pipe 33 to form a refrigeration cycle.

A high pressure switch 38 is connected to the compressor 1 via a conduit 37A, and a low pressure switch 39 is connected via a conduit 37B. A temperature sensing tube 40 is connected to the discharge pipe 33.
A discharge gas temperature switch 42 is connected to the temperature sensing cylinder 40 via a conduit 41.

When the discharge pressure of the compressor 1 rises abnormally, the high pressure switch 38 operates within the set value tolerance and automatically stops the operation of the compressor.

When the suction pressure of the compressor drops abnormally, the low-pressure switch 39 operates within the tolerance of the set value, and automatically stops the operation of the compressor.

When the discharge gas temperature of the compressor rises abnormally, the discharge gas temperature switch 42 operates within the set value tolerance and automatically stops the operation of the compressor.

A waterproof structure is applied to these pressure switches and temperature switches.

In each of the embodiments described with reference to FIGS. 1 to 4, the screw compressor is built in the same casing as the compression mechanism and the electric motor, and is further provided with a waterproof structure applied to the electric power supply connection terminal box. Since it is a hermetic compressor and equipped with a protection device such as a pressure switch and temperature switch with a waterproof structure, it is installed in a high-humidity environment such as a cooling facility installed outdoors or a tunnel where rainwater or water droplets are splashed. It is possible to obtain a semi-hermetic screw compressor device having the waterproof performance required for mounting on a waterproof refrigerator unit of a cooling facility for washing with water.

As shown in FIG. 4, a compressor 1 for compressing a refrigerant gas, a condenser 34 for cooling and condensing the refrigerant gas which has been compressed to a high temperature and a high pressure to generate a liquid refrigerant, and evaporating the liquid refrigerant In the refrigerating apparatus including the evaporator 35 for removing the heat of evaporation from the object to be cooled to form a refrigerating cycle, the use of the semi-hermetic compressors of the above-described embodiments reduces the maintenance work. A highly reliable waterproof refrigerator unit requiring a small installation area can be provided.

Further, when the above-described semi-hermetic compressor is used as compared with the waterproof refrigerator unit using the conventional open compressor, the following effects are obtained.

(1) Since it has a semi-hermetic structure with a built-in motor, it does not require a shaft sealing device, and therefore does not require replacement of a shaft sealing element, thereby improving reliability and simplifying maintenance.

(2) No centering of the motor is required.

(3) The installation area is reduced.

[0048]

According to the present invention, it is possible to provide a highly reliable semi-hermetic compressor and a waterproof refrigerating unit equipped with the same which require less maintenance work and a smaller installation area. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a semi-hermetic screw compressor according to an embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of a power supply terminal box for a motor provided in the semi-hermetic screw compressor of FIG. 1;

FIG. 3 is a sectional view of FIG. 2;

FIG. 4 is a system diagram showing a configuration of a refrigeration cycle of a compressor protection device and a refrigerator unit of a semi-hermetic screw compressor according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compression mechanism part, 2 ... Screw rotor, 4 ... Rotor,
DESCRIPTION OF SYMBOLS 5 ... Stator, 7 ... Casing, 9 ... Power supply terminal box for electric motor, 10 ... Oil recovery unit, 13 ... Lead wire, 14 ... Terminal bolt, 29 ... Waterproof screw-in protective pipe joint, 38 ... High pressure switch, 39 ... Low pressure switch, 42 ... Discharge gas temperature switch.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shoji Kikuchi 390 Muramatsu, Shimizu-shi, Shizuoka Pref. Air Conditioning Systems Division, Hitachi, Ltd.

Claims (1)

[Claims] An electric motor including a stator and a rotor is directly connected to a compression mechanism comprising a pair of male and female screw rotors which rotate while meshing with each other, and are housed in a disassemblable casing. A power supply connection terminal box for an electric motor is mounted on an airtight terminal structure to which the conductor wires are connected, and an oil recovery device incorporating oil separation means on the discharge side of the compression mechanism is provided with an airtight flange on the casing. In a semi-hermetic screw compressor, the semi-hermetic screw compressor is characterized in that the power supply terminal box for the electric motor has a watertight waterproof structure in which a bare charging portion and an insulated charging portion are isolated from the outside. Compressor.