EP3455497A1

EP3455497A1 - A hermetic compressor with improved sealing

Info

Publication number: EP3455497A1
Application number: EP17725890.2A
Authority: EP
Inventors: Furkan Ahmet TOK; Husnu Kerpicci
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2016-05-10
Filing date: 2017-05-09
Publication date: 2019-03-20
Also published as: WO2017194516A1

Abstract

The present invention relates to a hermetic compressor (1) suitable for use for circulation of the refrigerant fluid in cooling devices, for example refrigerators, comprising a casing (2); a cylinder (3) that is disposed in the casing (2) and that enables the refrigerant to be sucked and pumped; a piston (4) that is operated in the cylinder (3); a body (5) that supports the cylinder (3) and the piston (4); a cylinder head (6) that enables the refrigerant sucked and pumped by means of the piston (4) into the cylinder (3) to be guided; an exhaust chamber (7) that is disposed in the cylinder head (6) and wherein the pumped refrigerant fluid is accumulated; a valve table (13) that is disposed between the cylinder (3) and the cylinder head (6); a suction muffler (14) that is produced from a plastic material and that enables the temperature of the refrigerant to be decreased and the noise caused by the refrigerant to be reduced; a top cover (15) that covers the suction muffler (14), and a connection tube (16) that extends from the interior of the cylinder head (6) toward the valve table (13).

Description

A HERMETIC COMPRESSOR WITH IMPROVED SEALING

The present invention relates to a hermetic compressor suitable for use in cooling devices.
In hermetic compressors, the refrigerant is sucked from and pumped back to the refrigeration cycle by means of a piston operating in a cylinder. One of the important factors determining the operational performance of hermetic compressors is the amount and temperature of the refrigerant gas entering the cylinder during the suction movement of the piston. Increased temperature of the refrigerant gas sucked from the refrigeration cycle causes a reduction in the amount of refrigerant gas entering the compression volume of the cylinder, thus decreasing the volumetric efficiency and capacity of the compressor. Excessive increase in the temperature at the inlet of the cylinder also causes an increase in the body temperature of the cylinder that adversely affects the compression process.
In the hermetic compressors, use of a suction muffler to reduce the noise caused by the refrigerant sucked from the refrigeration cycle is known. The refrigerant gas delivered from the refrigeration cycle to the suction muffler in the compressor is then transferred to the valve table by means of a connection tube. When the piston performs the suction movement in the cylinder, the refrigerant in gas state passes through the suction port on the valve table so as to be delivered to the cylinder. In the region where the connection tube contacts the valve table, an elastomer gasket is used to prevent the refrigerant gas from leaking. When the cylinder head is fixed to the compressor body by screwing (torquing) bolts, the connection tube applies pressure on the gasket on the valve table; however, due to high temperature and excessive torquing force applied during the assembly, the said gasket is subjected to deformation and the desired sealing performance cannot be achieved.
The International Patent Application No. WO2012166051 discloses a hermetic compressor wherein thermal insulation is provided between the suction muffler and the valve table.
The International Patent Application No. WO2014122931 discloses a hermetic compressor wherein a mechanical interlocking connection is performed between the suction muffler and the valve table.
The International Patent Application No. WO2014091764 discloses a hermetic compressor wherein the flow of refrigerant is improved by modifying the structure of the suction port arranged on the valve table.
The aim of the present invention is the realization of a compressor wherein the performance thereof is improved by preventing the temperature of the sucked refrigerant from increasing by means of an improved sealing between the suction muffler and the valve table.
The compressor realized in order to attain the aim of the present invention is explicated in the claims.
The hermetic compressor is provided with a valve table that is disposed between the cylinder and the cylinder head, that enables the refrigerant sucked from and pumped to the refrigeration cycle to be guided and whereon suction and exhaust ports and valves are disposed, and a suction muffler that is produced from a plastic material and that provides the reduction of the noise caused by the refrigerant. The compressor of the present invention comprises a suction plenum that is disposed between the suction muffler and the valve table in the region that is most critical in terms of the refrigerant gas leakage. The suction plenum is produced by pressing the top cover of the suction muffler, the connection tube of the suction muffler and a sealing plate disposed between the valve table and the cylinder head as a single piece from a plastic material in the plastic injection mold.
In an embodiment of the present invention, the suction plenum comprises a neck that connects the connection tube of the suction muffler to the top cover of the suction muffler, that expands from the connection tube toward the top cover and that reinforces the structure.
In another embodiment of the present invention, the suction plenum comprises a cut-out that is arranged on the sealing plate, that surrounds the exhaust pass port arranged at the height of the exhaust valve and the stopper and that allows the passage of the refrigerant from the exhaust port to the exhaust chamber.
In another embodiment of the present invention, the suction plenum comprises a side wall that surrounds the cylinder head seated onto the sealing plate and an O-ring groove that enables an O-ring to be placed between the sealing plate and the cylinder head.
In another embodiment of the present invention, the cylinder head comprises a housing wherein the connection tube is placed, that surrounds only the lateral surfaces of the connection tube while leaving the rear surface open and that prevents the cylinder head from exerting a pressure that may cause the deformation of the suction plenum.
In the compressor of the present invention, the suction plenum that is disposed in a region that is most critical in terms of the refrigerant gas leakage is produced as a single piece, thus providing a proper sealing.
The compressor realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 – is the cross-sectional view of the compressor of the present invention.
Figure 2 - is the perspective view of the suction plenum composed of a sealing plate, a connection tube and a muffler produced as a single piece.
Figure 3 - is the exploded view of a compressor body, the suction plenum and the cylinder head.
Figure 4 - is the perspective view of a suction plenum and a cylinder head in a separate manner.
Figure 5 - is the perspective view of a suction plenum and a cylinder head in a joined manner.
Figure 6 – is the perspective view of a suction plenum in an embodiment of the present invention.
The elements illustrated in the figures are numbered as follows:
1. Compressor
2. Casing
3. Cylinder
4. Piston
5. Body
6. Cylinder head
7. Exhaust chamber
8. Suction port
9. Suction valve
10. Exhaust port
11. Exhaust valve
12. Stopper
13. Valve table
14. Suction muffler
15. Top cover
16. Connection tube
17. Sealing plate
18. Neck
19. Cut-out
20. Exhaust muffler
21. Exhaust pass port
22. Housing
23. Side wall
24. O-ring groove
25. Suction plenum
The hermetic compressor (1) suitable for use for circulation of the refrigerant fluid in cooling devices, for example refrigerators, comprises a casing (2); a cylinder (3) that is disposed in the casing (2) and that enables the refrigerant to be sucked and pumped; a piston (4) that is operated in the cylinder (3); a body (5) that supports the cylinder (3) and the piston (4); a cylinder head (6) that enables the refrigerant sucked and pumped by means of the piston (4) into the cylinder (3) to be guided; an exhaust chamber (7) that is disposed in the cylinder head (6) and wherein the pumped refrigerant fluid is accumulated; a valve table (13) that is disposed between the cylinder (3) and the cylinder head (6) and whereon a suction port (8), a suction valve (9), an exhaust port (10), an exhaust valve (11) and a stopper (12), that limits the movement of the exhaust valve (11), are disposed; a suction muffler (14) that is produced from a plastic material and that enables the temperature of the refrigerant to be decreased and the noise caused by the refrigerant to be reduced; a top cover (15) that covers the suction muffler (14), and a connection tube (16) that extends from the interior of the cylinder head (6) toward the valve table (13), that is connected with the suction port (8) so as to provide the flow of the refrigerant and that enables the refrigerant coming from the suction muffler (14) to be delivered to the valve table (13) so as to be sucked into the cylinder (3) through the suction port (8). The connection tube (16) is also known as "muffler head".
The compressor (1) of the present invention comprises
- a sealing plate (17) that is disposed between the valve table (13) and the cylinder head (6), and
- a suction plenum (25) that is produced from a plastic material as a single piece with the sealing plate (17), the connection tube (16) and the top cover (15)
(Figure 2).
By producing as a single piece the top cover (15), the connection tube (16) and the sealing plate (17) that constitute the suction plenum (25), a complete sealing is obtained between the suction muffler (14) and the valve table (13) at the region where the refrigerant flows from the suction muffler (14) to the valve table (13), and the refrigerant gas circulating at high temperature in the casing (2) through between the connection tube (16) and the valve table (13) during the suction movement of the piston (4) is prevented from being sucked into the cylinder (3).
The suction plenum (25) composed of the sealing plate (17), the connection tube (16) and the top cover (15) is preferably produced in the same plastic injection mold from the same material used for the production of the suction muffler (14), such as Polyoxymethylene (POM), Polyamide (PA) or Polybutylene Terephthalate (PBT), thus providing ease of production and ease of assembly.
In an embodiment of the present invention, the suction plenum (25) comprises a neck (17) that connects the connection tube (16) to the top cover (15) and that has a structure expanding from the connecting tube (16) toward the top cover (15) (Figure 4, Figure 6). The neck (18) increases the mechanical strength of the connection between the connection tube (16) and the top cover (15) and facilitates the removal from the injection mold.
In another embodiment of the present invention, the suction plenum (25) comprises a cut-out (19) that is arranged on the sealing plate (17) aligned with the exhaust valve (11) and the stopper (12) and that allows the refrigerant passing through the exhaust port (10) during the compression movement of the piston (4) to enter the exhaust chamber (7) (Figure 4, Figure 6).
In another embodiment of the present invention, the suction plenum (25) comprises a side wall (23) that is disposed on the sealing plate (17), that surrounds the cylinder head (6) seated on the sealing plate (17), that enables the cylinder head (6) to be centered and that improves the sealing (Figure 4, 6).
In another embodiment of the present invention, an O-ring is disposed between the suction plenum (25) and the cylinder head (6), whereon the rim of the cylinder head (6) applies pressure. In this embodiment, the suction plenum (25) comprises an O-ring groove (24) that is arranged on the sealing plate (17), that surrounds the side wall (23) along the inner rim thereof and wherein the O-ring is disposed, thus improving the sealing between the suction plenum (25) and the cylinder head (6) (Figure 6).
In another embodiment of the present invention, the cut-out (19) arranged on the sealing plate (17) surrounds, besides the exhaust valve (11) and the stopper (12), the exhaust pass port (21) that is disposed on the valve table (13) and that enables the refrigerant to be delivered to the exhaust muffler (20) and therefrom to the refrigeration cycle, the cut-out (19) providing the delivery of the refrigerant gas in the exhaust chamber (7) to the exhaust muffler (20) through the exhaust pass port (21) (Figure 6).
In another embodiment of the present invention, the cylinder head (6) comprises a housing (22) wherein the connection tube (16) is disposed, that surrounds only the lateral surfaces of the connection tube (16) while leaving open the rear surface of the connection tube (16) of which the front end is connected to the sealing plate (17) (Figure 4, Figure 5)
In the compressor (1) of the present invention, the suction plenum (25) that is disposed in a region that is most critical in terms of the refrigerant gas leakage is produced as a single piece, and the need for using an elastomer gasket prone to deformation between the connection tube (16) and the valve table (13) to provide sealing is eliminated. The need for the connection tube (16) to exert pressure on the valve table (13) by the said elastomer gasket to provide sealing is eliminated. When the cylinder head (6) is attached to the body (5) by means of bolts, the cylinder head (6) does not contact the rear surface of the connection tube (16) thanks to the housing (22) and does not exert pressure on the suction plenum (25). The problem of deformation of the suction plenum (25) due to the forces exerted during the assembly of the cylinder head (6) to the body (5) by means of bolts and due to the high temperature and the problem of impairment of the sealing are eliminated. The transfer of heat from the cylinder head (6), that is constantly high during the operation of the compressor (1), to the connection tube (16) is reduced. The structure of the connection tube (16) is simplified, thus providing ease of production.

Claims

A hermetic compressor (1) suitable for use in cooling devices comprising a casing (2); a cylinder (3) that is disposed in the casing (2) and that enables the refrigerant to be sucked and pumped; a piston (4) that is operated in the cylinder (3); a body (5) that supports the cylinder (3) and the piston (4); a cylinder head (6) that enables the refrigerant sucked and pumped by means of the piston (4) into the cylinder (3) to be guided; an exhaust chamber (7) that is disposed in the cylinder head (6) and wherein the pumped refrigerant fluid is accumulated; a valve table (13) that is disposed between the cylinder (3) and the cylinder head (6) and whereon a suction port (8), a suction valve (9), an exhaust port (10), an exhaust valve (11) and a stopper (12), that limits the movement of the exhaust valve (11), are disposed; a suction muffler (14); a top cover (15) that covers the suction muffler (14), and a connection tube (16) that extends from the interior of the cylinder head (6) toward the valve table (13), that is connected with the suction port (8) so as to provide the flow of the refrigerant and that enables the refrigerant coming from the suction muffler (14) to be delivered to the valve table (13), characterized by

- a sealing plate (17) that is disposed between the valve table (13) and the cylinder head (6), and

- a suction plenum (25) that is produced from a plastic material as a single piece with the sealing plate (17), the connection tube (16) and the top cover (15).
A compressor (1) as in Claim 1, characterized by the suction plenum (25) produced from a material such as Polyoxymethylene (POM), Polyamide (PA) or Polybutylene Terephthalate (PBT).
A compressor (1) as in Claim 1, characterized by the suction plenum (25) comprising a neck (18) that connects the connection tube (16) to the top cover (15) and that has a structure expanding from the connecting tube (16) toward the top cover (15).
A compressor (1) as in Claim 1, characterized by the suction plenum (25) comprising a cut-out (19) that is arranged on the sealing plate (17) aligned with the exhaust valve (11) and the stopper (12) and that allows the refrigerant to pass through the exhaust port (10) to the exhaust chamber (7).
A compressor (1) as in Claim 4, characterized by the suction plenum (25) comprising the cut-out (19) that surrounds the exhaust pass port (21) arranged on the valve table (13).
A compressor (1) as in Claim 1, characterized by the suction plenum (25) comprising a side wall (23) that is arranged on the sealing plate (17) and that surrounds the cylinder head (6) seating on the sealing plate (17).
A compressor (1) as in Claim 1, characterized by the suction plenum (25) comprising an O-ring groove (24) that is arranged on the sealing plate (17) and that enables an O-ring to be disposed between the sealing plate (17) and the cylinder head (6).
A compressor (1) as in Claim 1, characterized by the cylinder head (6) comprising a housing (22) wherein the connection tube (16) is disposed, that surrounds only the lateral surfaces of the connection tube (16) while leaving open the rear surface of the connection tube (16) of which the front end is connected to the sealing plate (17).