EP3017195A1

EP3017195A1 - Sealing assembly for reciprocating hermetic compressor

Info

Publication number: EP3017195A1
Application number: EP13733019.7A
Authority: EP
Inventors: Sarper Marasli; Cihan Gunduz
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2013-07-04
Filing date: 2013-07-04
Publication date: 2016-05-11
Also published as: WO2015000524A1

Abstract

Sealing assembly (1) for a valve plate placed between a cylinder block (3) and a cylinder head (4) in a reciprocating compressor (2). The sealing assembly (1) comprises a first sealing member (6) interposed between the cylinder block (3) and the valve plate (5) and a second sealing member (8) interposed between the cylinder head (4) and the valve plate (5). A first groove (10) is provided along one or more closed-contours on the rear surface (7) of the valve plate (5), for receiving a base portion of the first sealing member (6) such that an upper portion thereof projects out of the first groove (10). A second groove (11) is provided along one or more closed-contours on the front surface (9) of the valve plate (5) for receiving a base portion of the second sealing member (8) such that an upper portion thereof projects out of the second groove (11). The first sealing member (6) is made from a resilient material and is provided in form of one or more closed-loops which respectively match the first groove (10) along the one or more closed-contours on the rear surface (7) of the valve plate (5), and the second sealing member (8) is made from a resilient material and is provided is in form of one or more closed-loops which respectively match the second groove (11) along the one or more closed-contours on the front surface (9) of the valve plate (5).

Description

SEALING ASSEMBLY FOR RECIPROCATING HERMETIC COMPRESSOR

The present invention relates to a sealing assembly for use in a reciprocating compressor to seal a refrigerant flow path between a cylinder block and a cylinder head, and a refrigeration appliance in particular a domestic refrigerator, having the sealing assembly.
A refrigeration appliance such as a domestic refrigerator typically utilizes a reciprocating hermetic compressor to convey the refrigerant from an evaporator to a condenser. The reciprocating hermetic compressor generally comprises a compression chamber, an intake chamber, and a discharge chamber. The intake chamber is on a downstream side of evaporator. The discharge chamber is on an upstream side of the condenser.
The compression chamber is formed within the cylinder block whereas the intake chamber and the discharge chamber are separately formed within the cylinder head.
A valve plate (5´) is interposed between the cylinder block and the cylinder head (Figs. 6 and 7). By virtue of the valve plate (5´), the compression chamber is selectively brought in fluid communication with the intake chamber and the discharge chamber. The valve plate (5´) generally comprises an intake port (12´) and a discharge port (13´) (Figs. 6 and 7). The intake port (12´) fluidly connects the intake chamber with the compression chamber upon suction of a piston located in the compression chamber. The discharge port (13´) fluidly connects the compression chamber with the discharge chamber upon compression of the piston.
The refrigerant pressure in the vicinity of the valve plate (5´) is relatively high due to the reciprocating movement of the piston. Therefore, an interface between the valve plate (5´) and the cylinder parts such as the cylinder block and the cylinder head, must be sufficiently gas-tight to prevent any leakage of the refrigerant. It is common practice to place head gaskets (6´,8´) on both sides of the valve plate (5´), which respectively oppose the cylinder block and the cylinder head (Figs. 8 and 9).
US 5,609,476 (A) discloses a reciprocating compressor which includes: a valve plate arranged between a cylinder block and a cylinder head, a first head gasket arranged between the valve plate and the cylinder block and a second head gasket arranged between the valve plate and the cylinder head.
Head gaskets (6´,8´) used in reciprocating compressors are typically made of paper. They are cheap and easy to fabricate. However, such paper gaskets (6´,8´) have certain drawbacks. For instance, in case of unexpected high refrigerant pressures, the paper gaskets (6´,8´) are torn off. Consequently, the refrigerant begins to leak and the cooling efficiency gradually decreases. Hence, maintenance becomes inevitable.
The strength of a head gasket (6´,8´) can be increased by alternatively manufacturing the same from metal. Metal gaskets are very robust and durable. However, the surface of a metal gasket must be sufficiently flat to prevent leakage. In practice, a small degree of surface roughness or any warpage of a metal gasket may result in a leakage of the refrigerant.
An objective of the present invention is to provide a sealing assembly for a reciprocating compressor, and a refrigeration appliance having the same, which overcomes the aforementioned problems, and enables effective sealing of the refrigerant flow path between the cylinder block and the cylinder head.
This objective has been achieved by the sealing assembly according to the present invention as defined in claim 1, the reciprocating compressor according to the present invention as defined in claim 7, and the refrigeration appliance according to the present invention as defined in claim 8. Further achievements are attained by the subject-matters respectively defined in the dependent claims.
In the sealing assembly according to the present invention a first groove is provided along one or more closed-contours on a rear surface of the valve plate, for receiving a base portion of a first sealing member such that an upper portion thereof projects out of the first groove, a second groove is provided along one or more closed-contours on a front surface of the valve plate, for receiving a base portion of a second sealing member such that an upper portion thereof projects out of the second groove, the first sealing member is made from a resilient material and is provided in form of one or more closed-loops which respectively match the first groove along said one or more closed-contours on the rear surface of the valve plate and the second sealing member is made from a resilient material and is provided in form of one or more closed-loops which respectively match the second groove along said one or more closed-contours on the front surface of the valve plate.
In an assembled state of the sealing assembly, the upper portions of the first and the second sealing members which respectively project out of the first and the second grooves are firmly pressed onto the respective cylinder parts. Thereby, any surface irregularities of the valve plate and the cylinder parts are tolerated by the resilient sealing members. Moreover, by virtue of the first and the second grooves, the first and the second sealing members are tightly secured to their positions designated by said one or more contours against any lateral force exerted by the pressurized refrigerant. Thereby, a gas-tight sealing is achieved between the valve plate and the respective cylinder parts.
In an embodiment, each of the first and the second grooves has a semi-circular cross-section. In this embodiment, each of the first and the second sealing members has a corresponding circular cross-section. Thereby, a form fitting engagement between the sealing members and the grooves is attained. This improves gas-tightness of the sealing assembly.
In another embodiment, each of the first and the second grooves is provided with a circular captive cross-section. In this embodiment, each of the first and the second sealing members has a corresponding circular cross-section. Thereby, a form fitting engagement between the sealing members and the grooves is attained. In addition, the sealing members are prevented from falling out of the respective grooves when assembling the valve plate.
In another embodiment, the sealing members are made of silicone material suitable for compression fitting.
In another embodiment, the first sealing member is provided in form of one or more closed-loops which surround a region that includes the intake port and the discharge port. In this embodiment, the second sealing member is also provided in form of one or more closed-loops which surround a region that includes the discharge port.
In another embodiment, each of the first and the second sealing members is provided in form of a monolithic structure.
Additional advantages of the sealing assembly according to the present invention will now become apparent with the detailed description of an embodiment with reference to the accompanying drawings in which:
Figure 1 - is a schematic cross section of a reciprocating compressor having a sealing assembly according to an embodiment of the present invention.
Figure 2 - is a schematic partial perspective view of the reciprocating compressor having the sealing assembly shown in Fig. 1.
Figure 3 - is a schematic exploded partial perspective view of the reciprocating compressor having the sealing assembly shown in Fig. 2.
Figure 4 - is another schematic exploded partial perspective view of the reciprocating compressor having the sealing assembly shown in Fig. 2.
Figure 5 - is another schematic exploded partial perspective view of the reciprocating compressor having the sealing assembly shown in Fig. 2.
Figure 6 - is a schematic perspective view of a rear surface of a prior art valve plate.
Figure 7 - is a schematic perspective view of a front surface of the prior art valve plate shown in Fig. 6.
Figure 8 - is a schematic perspective view of a prior art gasket to be arranged on the rear surface of the prior art valve plate shown in Fig. 6.
Figure 9 - is a schematic perspective view of a prior art gasket to be arranged on the front surface of the prior art valve plate shown in Fig. 7.
Figure 10 - is a schematic perspective view of a rear surface of a valve plate according to an embodiment of the present invention.
Figure 11 - is a schematic perspective view of a front surface of the valve plate according to an embodiment of the present invention.
Figure 12 - is a schematic perspective view of a first sealing member according to an embodiment of the present invention, to be mounted on the rear surface of the valve plate shown in Fig. 10.
Figure 13 - is a schematic perspective view of a second sealing member according to an embodiment of the present invention, to be mounted on a front surface of the valve plate shown in Fig. 11.
Figure 14 - is a schematic enlarged top view of the front surface of the valve plate shown in Fig. 11.
Figure 15 - is a cross section taken along the line A-A of the valve plate shown in Fig. 14.
Figure 16 - is an enlarged view of the detail B shown in Fig. 15.
Figure 17 - is a schematic top view of the valve plate shown in Fig. 14 having the first and the second sealing members shown in Figs. 12 and 13 mounted thereon.
Figure 18 - is a cross section taken along the line A-A of the sealing assembly shown in Fig. 17.
Figure 19 - is an enlarged view of the detail C shown in Fig. 18.
The reference signs appearing on the drawings relate to the following technical features.

Sealing assembly
Reciprocating hermetic compressor
Cylinder block
Cylinder head
Valve plate
First sealing member
Rear surface
Second sealing member
Front surface
First groove
Second groove
Intake port
Discharge port
Screw hole

The sealing assembly (1) is suitable for use in a reciprocating hermetic compressor (2) which includes a cylinder block (3) and a cylinder head (4) (Fig. 1). The sealing assembly (1) comprises a valve plate (5) for interposing between the cylinder block (3) and the cylinder head (4), a first sealing member (6) for interposing between the cylinder block (3) and a rear surface (7) of the valve plate (5), which faces the cylinder block (3) and a second sealing member (8) for interposing between the cylinder head (4) and a front surface (9) of the valve plate (5), which faces the cylinder head (4) (Figs. 1 to 5).
In the sealing assembly (1) according to the present invention, a first groove (10) is provided along one or more closed-contours on the rear surface (7) of the valve plate (5), for receiving a base portion of the first sealing member (6) such that an upper portion thereof projects out of the first groove (10), a second groove (11) is provided along one or more closed-contours on the front surface (9) of the valve plate (5), for receiving a base portion of the second sealing member (8) such that an upper portion thereof projects out of the second groove (11), the first sealing member (6) is made from a resilient material and is provided in form of one or more closed-loops which respectively match the first groove (10) along the one or more closed-contours on the rear surface (7) of the valve plate (5) and the second sealing member (8) is made from a resilient material and provided in form of one or more closed-loops which respectively match the second groove (11) along the one or more closed-contours on the front surface (9) of the valve plate (5) (Figs. 10 to 13).
The valve plate (5), the cylinder block (3) and the cylinder head (4) each has four corresponding screw holes (14) for mounting the sealing assembly (1) (Fig. 3). In an assembled state of the sealing assembly (1), the upper portion of the first sealing member (6) and the upper portion of the second sealing member (8) which respectively project out of the first groove (10) and the second groove (11) are firmly pressed onto the flat surfaces of the respective cylinder parts, i.e., the cylinder block (3) and the cylinder head (4) (Figs. 4 to 5 and Figs. 17 to 19). There no grooves formed on the cylinder block (3) and the cylinder head (4) for respectively receiving the first sealing member (6) and the second sealing member (8). Therefore, the sealing assembly (1) of the present invention can be used with existing reciprocating hermetic compressors without modifying their cylindrical parts.
In an embodiment of the present invention, each of the first groove (10) and the second groove (11) has a semi-circular cross-section respectively along the one or more closed-contours (Figs. 14 to 16). In this embodiment, each of the first sealing member (6) and the second sealing member (8) has a corresponding circular cross-section respectively along the one or more closed-loops (Figs. 17 to 19). In this embodiment, the semi-circular cross-section of the first groove (10) and the second groove (11) and the respective circular cross-section of the first sealing member (6) and the second sealing member (8) each has substantially the same radius. Thereby, the resilient material is prevented from uncontrollably shrinking into any gaps which could otherwise compromise the effectiveness of the sealing. Hence, a form-fitting engagement is attained.
In another embodiment of the present invention, each of the first groove (10) and the second groove (11) is provided with a circular captive cross-section (not shown) along the one or more closed-contours. In this embodiment, each of the first sealing member (6) and the second sealing member (8) has a corresponding circular cross-section respectively along the one or more closed-loops.
In another embodiment of the present invention, each of the first sealing member (6) and the second sealing member (8) is made of silicone material suitable for compression fitting.
In another embodiment of the present invention, the valve plate (5) includes an intake port (12) and a discharge port (13) each for selectively letting a refrigerant pass through (Figs. 10 and 11). The intake port (12) and discharge port (13) are configured by lift-check valves. Alternatively, diaphragm check valves can be used. In this embodiment, the first sealing member (6) is provided in form of at least one closed-loop, wherein said at least one closed-loop matches a contour which surrounds a region that includes the intake port (12) and the discharge port (13) (Figs. 10 and 12). In this embodiment, the second sealing member (8) is provided in form of at least one closed-loop, wherein said at least one closed-loop matches a contour which surrounds a region that includes only the discharge port (13) (Figs. 11 and 13).
In another embodiment of the present invention, the said at least one closed-loop of the first sealing member (6) is provided in form of a monolithic structure (Fig. 12). In this embodiment, the said at least one closed-loop of the second sealing member (8) is also provided in form of a monolithic structure (Fig. 13).
The reciprocating hermetic compressor (2) according to the present invention comprises a sealing assembly (1) described in any of the above embodiments (Fig.1).
The refrigeration appliance according to the present invention comprises a reciprocating hermetic compressors (2) described in any of the above embodiments (Fig. 1). The refrigeration appliance is in particular a domestic refrigerator (not shown).

Claims

A sealing assembly (1) for use in a reciprocating hermetic compressor (2) including a cylinder block (3) and a cylinder head (4), the sealing assembly (1) comprising a valve plate (5) for interposing between the cylinder block (3) and the cylinder head (4), a first sealing member (6) for interposing between the cylinder block (3) and a rear surface (7) of the valve plate (5), which faces the cylinder block (3) and a second sealing member (8) for interposing between the cylinder head (4) and a front surface (9) of the valve plate (5), which faces the cylinder head (4), characterized in that

- a first groove (10) is provided along one or more closed-contours on the rear surface (7) of the valve plate (5), for receiving a base portion of the first sealing member (6) such that an upper portion thereof projects out of the first groove (10),

- a second groove (11) is provided along one or more closed-contours on the front surface (9) of the valve plate (5), for receiving a base portion of the second sealing member (8) such that an upper portion thereof projects out of the second groove (11),

- the first sealing member (6) is made from a resilient material and is provided in form of one or more closed-loops which respectively match the first groove (10) along the one or more closed-contours on the rear surface (7) of the valve plate (5) and

- the second sealing member (8) is made from a resilient material and provided is in form of one or more closed-loops which respectively match the second groove (11) along the one or more closed-contours on the front surface (9) of the valve plate (5).
The sealing assembly (1) according to claim 1, characterized in that each of the first groove (10) and the second groove (11) has a semi-circular cross- section respectively along the one or more closed-contours and each of the first sealing member (6) and the second sealing member (8) has a circular cross-section respectively along the one or more closed-loops.
The sealing assembly (1) according to claim 1, characterized in that each of the first groove (10) and the second groove (11) is provided with a circular captive cross-section along the one or more closed-contours and each of the first sealing member (6) and the second sealing member (8) has a circular cross-section respectively along the one or more closed-loops.
The sealing assembly (1) according to any one of claims 1 to 3, characterized in that each of the first sealing member (6) and the second sealing member (8) is made of silicone material suitable for compression fitting.
The sealing assembly (1) according to any one of claims 1 to 4, characterized in that the valve plate (5) includes: an intake port (12) and a discharge port (13) each for selectively letting a refrigerant pass through, the first sealing member (6) is provided in form of at least one closed-loop, wherein said at least one closed-loop matches a contour which surrounds a region that includes the intake port (12) and the discharge port (13) and the second sealing member (8) is provided in form of at least one closed-loop, wherein said at least one closed-loop matches a contour which surrounds a region that exclusively includes the discharge port (13).
The sealing assembly (1) according to claim 5, characterized in that the said at least one closed-loop of the first sealing member (6) is provided in form of a monolithic structure and the said at least one closed-loop of the second sealing member (8) is provided in form of a monolithic structure.
A reciprocating hermetic compressor (2) characterized in that the sealing assembly (1) according to any one of claims 1 to 6.
A refrigeration appliance, in particular a domestic refrigerator, characterized in that the reciprocating hermetic compressor (2) according to claim 7.