JP6182001B2 - Positive displacement compressor - Google Patents

Description

  The present invention relates to a compressor for a refrigeration cycle apparatus such as a refrigerator, a water heater, and an air conditioner.

  In patent document 1, the suction pipe of a simple structure without the coating | cover of a heat insulating material is disclosed by providing a gas heat insulation space part by making a suction pipe into a double pipe for the purpose of suppression of the suction heating in a scroll compressor. Patent Document 2 discloses a configuration of a double pipe structure that suppresses insufficient connection strength of the pipe.

JP 2008-169816 A JP 2012-36751 A

  However, the prior art does not disclose the securing of strength when a check valve that prevents the backflow of the compressed fluid (refrigerant) when the compressor is stopped is installed in the suction portion.

  This invention makes it a subject to provide the positive displacement compressor which can ensure intensity | strength etc. even if it is a case where the non-return valve which prevents the backflow of a compressed fluid at the time of a stop of a compressor is installed in a suction part.

The positive displacement compressor of the present invention includes a sealed container whose inside is a discharge pressure space, a suction pipe that leads the refrigerant from the outside to the suction port, a suction chamber through which the refrigerant led to the suction port flows, a suction pipe and a suction chamber, A check valve that prevents the reverse flow of the refrigerant from the suction chamber to the suction pipe, a compression chamber that compresses the refrigerant guided from the suction chamber, and a discharge port that discharges the refrigerant compressed in the compression chamber, An electric motor part that is a drive source for compressing the refrigerant in the compression chamber, and the suction pipe is constituted by a double pipe structure including a suction inner pipe through which the refrigerant flows and a suction outer pipe positioned outside the suction inner pipe And has a heat insulating space formed between the suction inner pipe and the suction outer pipe, and the heat insulating space has a suction at a position in the suction pipe that partitions the suction refrigerant guided to the discharge pressure space and the compression chamber. It provided between the inner tube and the suction outer tube, at the suction port, the suction on the inner wall of the inlet The outer wall of the pipe is in contact and the inner wall of the suction outer pipe is press-fitted and connected so that the outer wall of the suction inner pipe is in contact with the check valve. The refrigerant is prevented from flowing back to the suction pipe .

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where the check valve which prevents the backflow of a compressed fluid at the time of a stop of a compressor is installed in a suction part, a positive displacement compressor which ensures intensity | strength etc. can be provided.

Vertical section of scroll compressor State diagram of suction check valve closed (during stop) State diagram of suction check valve open (during operation) Transient state diagram from when the suction check valve opens to when it closes

  The positive displacement compressor of the present embodiment includes a sealed container whose inside is a discharge pressure space, a suction pipe that leads the refrigerant from the outside to the suction port, a suction chamber that temporarily stores the refrigerant led to the suction port, and a suction pipe Is located between the suction chamber and the suction chamber, prevents a reverse flow of refrigerant from the suction chamber to the suction pipe, compresses the refrigerant guided from the suction chamber, and discharges the refrigerant compressed in the compression chamber. A suction port and a motor part that is a drive source for compressing the refrigerant in the compression chamber, and the suction pipe is a double pipe composed of a suction inner pipe through which the refrigerant flows and a suction outer pipe located outside the suction inner pipe Constructed with a pipe structure, it has a heat insulation space formed between the suction inner pipe and the suction outer pipe, the suction outer pipe is made of copper-based material, and the suction inner pipe is made of iron-based material One end of the suction pipe is connected to the suction pipe and the suction outer pipe connected to the refrigeration cycle by welding. End side is connected to conclude pressed into the suction port in the double pipe structure, the check valve is the valve prevents back flow of refrigerant from the suction chamber by sealing the inlet inner pipe to the suction pipe.

  According to the positive displacement compressor of the present embodiment, the strength can be ensured even when a check valve for preventing the backflow of the compressed fluid is installed in the suction portion when the compressor is stopped. Specifically, first, since the heat insulating space is formed by a double pipe structure including a suction inner pipe and a suction outer pipe, a high-efficiency positive displacement compressor that suppresses suction heating can be provided. Moreover, since the check valve which is located between the suction pipe and the suction chamber and prevents the reverse flow of the refrigerant from the suction chamber to the suction pipe is provided, it is possible to prevent the refrigerant from flowing back when the compressor is stopped. In addition, the suction pipe of the double pipe structure is made of a copper-based material and the suction inner pipe is made of a ferrous material, and the valve body seals the suction inner pipe (iron material) to prevent backflow of refrigerant. Since it comprised so, the intensity | strength which can endure the collision of a valve body is securable compared with the case where a valve body seals a suction outer tube (copper material). In addition, the suction pipe with a double pipe structure is made of a copper-based material, the suction pipe is made of an iron-based material, and the suction pipe connected to the refrigeration cycle and the suction outer pipe are welded at one end of the suction pipe. Since the suction outer pipe connected to the suction pipe is a copper material, welding is facilitated. In addition, the suction pipe of the double pipe structure is made of a copper-based material, the inner pipe of the suction pipe is made of an iron-based material, and the other end of the suction pipe is press-fitted and connected to the suction port with a double pipe structure. Therefore, it is possible to secure the fastening strength with the iron material of the suction inner pipe and secure the sealing performance with the copper material of the suction outer pipe, and connect the suction pipe to the suction port.

Furthermore, in the positive displacement compressor of the present embodiment, a hole penetrating from the inside to the outside of the suction inner pipe is formed in the suction inner pipe. The heat insulation space is formed by the double pipe structure with the suction inner pipe and the suction outer pipe, but lubricating oil is mixed in the suction refrigerant, and if the oil accumulates in the heat insulation space, a sufficient heat insulation effect can be obtained. Can not. Therefore, by providing an oil drain hole in the suction inner pipe, even when operating in a state where the suction refrigerant contains a large amount of lubricating oil, oil accumulates in the heat insulating space provided between the suction outer pipe and the suction inner pipe. The gas insulation space can be filled with the suction refrigerant without any problem. Therefore, it is possible to provide a high-efficiency positive displacement compressor that suppresses suction heating regardless of operating conditions. This is particularly effective when a CO ₂ refrigerant whose volume change due to heating is large or when an R32 refrigerant whose discharge gas temperature is high is used.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1-4 by taking a scroll compressor as an example. FIG. 1 is a longitudinal sectional view of a scroll compressor according to the present embodiment, FIG. 2 is a state diagram in which a suction check valve is closed (stopped), and FIG. 3 is a state diagram in which a suction check valve is opened (during operation). 4 is a transient state diagram from the state where the suction check valve is opened to the time when it is closed.

  In FIG. 1, reference numeral 1 is a sealed container, 2 is a compression mechanism, 3 is a turning scroll, 3a is a spiral wrap of the turning scroll, 4 is a fixed scroll, 4a is a spiral wrap of the fixed scroll, and 5 is a crank. A shaft, 6 is a frame having a bearing for rotating the fixed scroll 4 and the crankshaft 5, 7 is an electric motor section, 8 is an Oldham ring related to a rotation preventing member for preventing the rotation of the orbiting scroll and causing the orbiting movement, and 11 is hermetically sealed A container lid, 12 is a terminal, and 13 is a terminal cover mounting pin.

  In the scroll compressor shown in FIG. 1, a compression mechanism unit 2 and an electric motor unit 7 are connected and stored in a sealed container 1 via a crankshaft 5. The compression mechanism 2 forms a compression chamber 9 by meshing the orbiting scroll 3 and the fixed scroll 4 each having spiral wraps 3a and 4a standing on the end plate. Further, an Oldham ring 8 which is a rotation preventing member of the orbiting scroll 3 and a frame 6 coupled to the fixed scroll 4 are provided.

  Next, the compression action of the scroll compressor will be described. The rotor 15 is given a rotational force by a rotating magnetic field generated by the stator 16. The crankshaft 5 fixed to the rotor 15 rotates as the rotor 16 rotates, and the orbiting scroll 3 rotates eccentrically (revolves) without rotating due to the action of the Oldham ring 8. By the eccentric rotation of the orbiting scroll 3, the compressed fluid (refrigerant) sucked through the suction outer tube 14 brazed and welded to the suction pipe 21 of the refrigeration cycle is gradually compressed in the compression chamber 9 from the suction chamber 10, It is discharged into the sealed container 1 from the discharge port 4c. The sealed container 1 is filled with a discharge pressure space 24. The discharged compressed fluid cools the electric motor unit 7 and is supplied from the discharge pipe 17 to the external refrigeration cycle. At this time, the lubricating oil is minutely mixed into the discharged refrigerant. The mixed lubricating oil circulates in the refrigeration cycle together with the refrigerant, mixes with the suction refrigerant, and returns to the compressor.

  The function and configuration of the suction double pipe provided with the suction check valve 18 will be described with reference to FIGS. FIG. 2 shows a state where the suction check valve is closed when the compressor is stopped, FIG. 3 shows a state where the suction check valve is opened while the compressor is operating, and FIG. 4 shows a state where the suction check valve is opened from the opened state. Each transient state until is shown.

  When entering the stop state from the time of the compressor operation, the compressed fluid flows backward from the compression mechanism portion 2 to the refrigeration cycle side through the fixed scroll suction port 4b. Since the pressure in the compression chamber 9 in the compression mechanism 2 is higher toward the center, the crankshaft 5 and the rotor 15 are rotated in reverse so that the compressed fluid in the compression chamber 9 tries to return to the suction side where the pressure is low. In order to prevent this reverse rotation, the suction check valve 18 is installed in the fixed scroll suction port 4b (between the suction pipe and the suction chamber), and the end face of the suction inner pipe 22 and the valve body 20 are in contact with each other, as shown in FIG. The suction check valve 18 is closed (the valve body seals the suction inner pipe 22 to close the suction check valve 18).

  When not only the compressed fluid in the compression process remaining in the compression chamber 9 but also the compressed fluid in the discharge pressure space 24 in the hermetic container 1 starts to flow back all at once, a large load is applied to the suction check valve 18. The collision force between the end face of the suction inner pipe 22 and the valve body 20 is relieved by using the biasing force.

  However, since it is difficult to ensure reliability only by such a mitigation measure for the collision force, in this embodiment, the suction inner pipe 22 is made of an iron-based material so as to ensure a strength that can withstand the collision force of the valve body 20. And

  Further, a suction inner pipe 22 is provided inside the suction outer pipe 14, and a suction double pipe (suction pipe) 23 that forms a gas heat insulation space portion between the suction outer pipe 14 and the suction inner pipe 22 is formed. Thus, the heating of the refrigerant through the suction outer pipe by the discharge pressure space 24 is suppressed, and volume efficiency is improved. Further, by adding an oil drain hole 22a penetrating from the inside of the pipe to the outside of the suction inner pipe 22, oil mixed in the suction refrigerant is prevented from accumulating in the gas heat insulating space.

  On the other hand, the suction outer pipe 14 is made of copper, and facilitates welding with the suction pipe 21 connected to the refrigeration cycle. Further, since the material of the suction outer pipe 14 is copper, it can be tightly sealed along the wall surface of the fixed scroll suction port 4 b, and the high pressure refrigerant can be prevented from flowing into the suction chamber 10 from the discharge pressure space 24. The pump parts such as the fixed scroll 4 that is the press-fitting partner of the suction outer pipe 14 are subjected to a high compressive load, and therefore, a high-strength iron-based material is generally used. However, the suction inner pipe that is an iron-based material is used. 22, the suction outer pipe 14, which is a copper-based material, is sandwiched and press-fitted to plastically deform the suction outer pipe 14 along the wall surface of the fixed scroll suction port 4 b (an iron-based suction inner pipe and a copper-based suction outer The pipe has a double pipe structure and is press-fitted and connected to the suction port).

  As described above, according to this embodiment, it is possible to provide a positive displacement compressor that ensures the strength even when the check valve is installed in the suction portion.

DESCRIPTION OF SYMBOLS 1 ... Sealed container, 2 ... Compression mechanism part, 3 ... Orbiting scroll, 3a ... Orbiting scroll spiral wrap, 3b ... Orbiting scroll end plate, 4 ... Fixed scroll, 4a ... Fixed scroll spiral wrap, 4b ... Fixed scroll suction 4..., 4 c... Fixed scroll discharge port, 5... Crankshaft, 6... Frame including a bearing that rotates the fixed scroll 4 and crankshaft 5, 7. DESCRIPTION OF SYMBOLS 9 ... Compression chamber, 10 ... Suction chamber, 11 ... Cover body of airtight container, 12 ... Terminal, 13 ... Terminal cover attachment pin, 14 ... Suction outer pipe, 15 ... Rotor, 16 ... Stator, 17 ... Discharge pipe, 18 ... Suction check valve, 19 ... Spring, 20 ... Valve, 21 ... Suction tube, 22 ... Suction inner pipe, 22a ... Suction inner pipe oil drain hole, 23 ... Suction double pipe (suction ), 24 ... the discharge pressure space

Claims (4)

A sealed container whose inside is a discharge pressure space;
A suction pipe for guiding the refrigerant from the outside to the suction port;
A suction chamber through which the refrigerant guided to the suction port flows;
A check valve that is located between the suction pipe and the suction chamber and prevents a reverse flow of refrigerant from the suction chamber to the suction pipe;
A compression chamber for compressing the refrigerant guided from the suction chamber;
A discharge port for discharging the refrigerant compressed in the compression chamber;
An electric motor section that is a drive source for compressing the refrigerant in the compression chamber,
The suction pipe is constituted by a double pipe structure including a suction inner pipe through which a refrigerant flows and a suction outer pipe positioned outside the suction inner pipe, and between the suction inner pipe and the suction outer pipe. Having a heat insulating space formed,
The heat insulation space portion is provided between the suction inner pipe and the suction outer pipe at a position that partitions the suction refrigerant guided to the discharge pressure space and the compression chamber in the suction pipe ,
In the suction port, the outer wall of the suction outer tube is in contact with the inner wall of the suction port, and is press-fitted and connected so that the outer wall of the suction inner tube is in contact with the inner wall of the suction outer tube,
The positive displacement compressor according to claim 1, wherein the check valve prevents a reverse flow of the refrigerant from the suction chamber to the suction pipe by a valve body sealing the suction inner pipe . The positive displacement compressor according to claim 1, wherein the suction inner pipe has a hole penetrating from the inside to the outside of the suction inner pipe. The suction inner pipe is formed of an iron-based material,
The suction outer pipe is formed of a copper-based material,
The positive displacement compressor according to claim 1 or 2, wherein one end side of the suction pipe is connected by welding a suction pipe connected to a refrigeration cycle and the suction outer pipe. An orbiting scroll having a spiral wrap standing on the end plate;
A fixed scroll having a spiral wrap standing on the end plate,
The displacement compressor according to any one of claims 1 to 3 , wherein the compression chamber is formed by meshing the orbiting scroll and the fixed scroll.