JPH06330874A - Screw compressor - Google Patents

Abstract

PURPOSE:To make the commonization of parts achievable with a motor casing merely changed by constituting a main casing housing a screw rotor and the motor casing housing a rotor driving motor separably. CONSTITUTION:When a male rotor 1 is driven by a motor 41, low pressure gas is sucked into a motor casing 40 from a suction port 43 and, after this motor is cooled, it flows into a profile space between this male rotor 1 and female rotor from a suction port 12. When capacity of this profile space is decreased with the rotation of this male rotor 1 or the like, gas is compressed and discharged to a discharge port 22 from a discharge port 21. In this case, the motor casing 40 is clamped by a bolt 51 separably from a main casing 10. In addition, the male rotor 1 and a motor shaft 42 are made up of separate members each. With this constitution, even in the case where a size of the motor 41 differs, the male rotor 1 and the main casing 10 are made usable in common with the motor casing 40 merely changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic screw compressor used for refrigeration, air conditioners and the like.

[0002]

2. Description of the Related Art A conventionally known hermetic screw compressor drives a screw rotor and a casing for accommodating male and female screw rotors, as disclosed in, for example, JP-A-63-9694. In general, a casing for accommodating the motor is integrally formed, a suction port for sucking low-pressure gas is provided at one location of the casing, and the screw rotor shaft and the motor shaft are integrally formed.

[0003]

In the conventional compressor structure as described above, due to the difference in the specification of the power supply voltage of the motor,
If the size of the motor is different, the size of the casing that houses the motor and the size of the screw rotor shaft are also different, so a completely different compressor had to be manufactured.

Further, even when the discharge amount of the compressor, that is, the size of the screw rotor is the same, when the compressor of the open type in which the motor is provided separately from the compressor is to be manufactured, the same casing can be used. No, I had to make another one.

Further, in this type of hermetic compressor, it is general to cool the motor by using the motor part as a passage for the intake gas. However, when the motor is cooled more effectively, it is refrigerated. There is a method of introducing the liquid refrigerant in the cycle into the motor section. In this case, since the motor part is not used as a passage for the intake gas, it is necessary to provide an intake port in the main casing that houses the screw rotor so that the intake gas is directly guided to the screw rotor part. In the conventional compressor structure, the casing cannot be shared even in such a case, and it is necessary to manufacture a compressor having another structure.

As described above, when it is attempted to manufacture a compressor having a different structure from the conventional compressor structure, parts such as a casing cannot be shared, and a small amount of a wide variety of parts are required. There is a problem that the cost becomes high and a great deal of labor is required for production control.

An object of the present invention is to provide a screw compressor which can reduce costs even when producing compressors having different structures and which has a small number of types of parts and which is easy to manage production.

[0008]

To achieve the above object, in a screw compressor of the present invention, a pair of male and female screw rotors, a main casing for housing the screw rotors, a motor for driving the screw rotors, and a motor are provided. And a motor casing that houses the motor casing, and the main casing and the motor casing are separable.

Further, in the screw compressor of this structure, the main casing and the motor casing are respectively provided with
An intake port is formed for introducing the intake gas.

Further, in the screw compressor of this structure, the screw rotor shaft and the motor shaft are formed by separate members, both ends of which are supported by bearings, and the screw rotor shaft and the motor shaft are connected by a coupling. To be done.

[0011]

According to the present invention, since the screw rotor is configured as described above, only the motor and the motor casing portion for accommodating the motor need to be replaced even if the dimensions of the motor are different due to the difference of the power supply voltage of the motor. The same parts can be used for the main casing, which houses the screw rotor and the screw rotor.

When an open type compressor having the same discharge amount of the compressor, that is, the same size of the screw rotor is to be manufactured, the motor and the motor casing part are replaced with a casing having a shaft sealing device. do it.

Further, when the motor is cooled by using the liquid refrigerant in the refrigeration cycle, the liquid refrigerant is guided into the motor casing, and the suction gas is directly guided from the suction port provided in the main casing to the screw rotor portion. You can do it like this.

Therefore, even in the case of manufacturing compressors having different structures, many parts can be shared and production control becomes easy. Further, the user can be provided with a low-cost screw compressor by sharing the parts.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a screw compressor showing an embodiment of the present invention.

The main casing 10 accommodates a male rotor 1 and a female rotor (not shown) which are meshed with each other and supported by bearings 13 and 14, and a slide valve 31 disposed below the rotor. The suction port 11 for introducing the suction gas and the suction port 12 serving as the gas inlet to the rotor portion are formed. At one end of the main casing 10, a discharge port 21 that serves as an outlet for the gas compressed by the male and female rotors, and a discharge port 2 that is guided to the outside.
2 is provided, and a cylinder casing 30 accommodating a piston 33 for driving a slide valve 31 via a rod 32 is provided at one end of the discharge casing 20.

A motor casing 40 is provided at the other end of the main casing 10. Motor casing 40
Is a motor cover 4 having a main body 40a for accommodating a motor 41 and a suction port 43 for introducing a suction gas from the outside.
0b, the motor shaft 42 is supported at its both ends by bearings 44 and 45, and is coupled by a coupling 46 to the shaft 1a of the male rotor 1.
Are linked to.

In this embodiment, the main casing 10 and the motor casing 40 are separably fastened by bolts 51, and the intake port 11 provided in the main casing 10 is closed by a flange 15.

Next, the operation of this embodiment will be described.

When the male rotor 1 is driven by the motor 41, low-pressure intake gas flows into the motor casing 40 through the intake port 43, cools the motor 41, and then the intake port 12 indicates the male rotor 1. No flow into the tooth space of the female rotor. The volume of the tooth space decreases as the rotor rotates, and the gas is compressed to increase the pressure.
As the rotation progresses further, the tooth space communicates with the discharge port 21, and the high-pressure gas passes through the discharge port 21 and the discharge port 22.
Is discharged from the compressor to the outside of the compressor.

The slide valve 31 is configured to move in the axial direction by a piston 33 via a rod 32, and is used for capacity control, but a detailed description thereof will be omitted.

The motor casing 40 is separably fastened to the main casing 10 with bolts 51, and the male rotor 1 and the motor shaft 42 are formed as separate members. Even if the dimensions are different, by separating the motor casing 40 from the main casing 10 and replacing it, the male rotor 1
Parts such as the female rotor and the main casing 10 can be commonly used.

FIG. 2 is a vertical sectional view of an open type screw compressor using the components of the hermetic type screw compressor shown in FIG.

A suction side cover 50 having a shaft sealing device 52 is fastened to one end of the main casing 10 by a bolt 51, and the shaft 1a of the male rotor 1 projects to the outside of the compressor.

In the screw compressor of this embodiment, the driving means such as a motor is installed outside the compressor and is connected to the shaft 1a of the male rotor 1.

When the male rotor 1 is driven by the driving means installed outside, low-pressure suction gas flows in through the suction port 11, passes through the suction port 12, and the tooth profile of the male rotor 1 and the female rotor (not shown). Flow into space. The volume of the tooth space decreases as the rotor rotates, and the gas is compressed to increase the pressure. When the rotation further advances, the tooth space communicates with the discharge port 21, and the high-pressure gas is discharged from the discharge port 22 to the outside of the compressor through the discharge port 21.

According to the present embodiment, in addition to the parts of the hermetic screw compressor shown in FIG. 1, the open type can be achieved by using the minimum parts such as the male rotor 1 having a changed shaft size and the suction side cover. A compressor can be manufactured, production management is facilitated, and a user can be provided with a low-cost screw compressor by sharing parts.

FIG. 3 shows an embodiment of the hermetic screw compressor shown in FIG. 1 in which the motor is cooled by a liquid refrigerant.

In the present embodiment, the motor cover 40b is provided with a liquid refrigerant inlet port 48, and the suction port 43 is closed by a flange 47.

When the male rotor 1 is driven by the motor 41, low-pressure intake gas flows in through the intake port 11 and through the intake port 12 into the tooth space of the male rotor 1 and the female rotor (not shown). On the other hand, the liquid refrigerant introduced from the liquid line in the refrigeration cycle flows into the motor casing 40 through the inlet port 48, cools the motor 41, vaporizes, and flows into the tooth profile space together with the suction gas flowing from the suction port 11. To do.

According to this embodiment, a screw compressor having a different motor cooling system is provided only by providing the liquid refrigerant inlet port 48 in the motor cover 40b and changing the suction port of the suction gas from 43 to 11. it can.

[0032]

According to the present invention, since many parts can be shared even with screw compressors having different specifications, production management is facilitated, and users can share low-cost screw screws. A compressor can be provided.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a hermetic screw compressor according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of an open type screw compressor.

FIG. 3 is a vertical sectional view of a hermetic screw compressor showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Male rotor, 10 ... Main casing, 11 ... Suction port, 40 ... Motor casing, 41 ... Motor, 43 ... Suction port, 44 ... Liquid refrigerant inlet port, 46 ... Coupling, 5
1 ... bolt.

Claims (1)

[Claims] 1. A pair of male and female screw rotors, a main casing for housing the screw rotor, a motor for driving the screw rotor, and a motor casing for housing the motor, wherein the main casing and the motor casing are A screw compressor characterized by being separable.