EP3039292B1

EP3039292B1 - Thermally improved reciprocating hermetic compressor

Info

Publication number: EP3039292B1
Application number: EP13756871.3A
Authority: EP
Inventors: Ismail YESILAYDIN; Cihan Gunduz; Erhan Kasapoglu
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2013-08-29
Filing date: 2013-08-29
Publication date: 2017-11-01
Anticipated expiration: 2033-08-29
Also published as: WO2015028075A1; EP3039292A1

Description

The present invention relates to a reciprocating hermetic compressor for use in refrigeration appliance such as a domestic refrigerator and a refrigeration appliance having the same. The present invention more particularly relates to an exhaust passage to an exhaust silencer of a reciprocating hermetic compressor.
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 an exhaust chamber. The intake chamber is located on a downstream side of the evaporator whereas the exhaust chamber is located on an upstream side of the condenser. The compression chamber is formed within the cylinder block. The intake chamber and the exhaust chamber are separately formed within the cylinder head. A valve plate is interposed between the cylinder block and the cylinder head. By virtue of the valve plate, the compression chamber is selectively brought into fluid connection with the intake chamber and the exhaust chamber. The valve plate generally comprises an intake port and exhaust port. The intake port and exhaust port are typically configured by diaphragm check valves which allow the refrigerant to flow only in a single direction. The intake port fluidly connects the intake chamber with the compression chamber upon suction of a piston located in the compression chamber. The exhaust port fluidly connects the compression chamber with the exhaust chamber upon compression of the piston.
The reciprocating movement of the piston induces pressure waves in the refrigerant, which have a detrimental effect on the components of the compressor. Therefore, the refrigerant in the exhaust chamber is initially guided through an exhaust passage to an exhaust silencer for attenuating the pressure pulsation of the refrigerant, prior to returning the exhaust refrigerant to a refrigeration circuit of the refrigeration appliance. The exhaust passage is generally formed inside the cylinder block whereas the exhaust silencer is directly mounted onto the cylinder block. The exhaust silencer has an inlet which is fluidly connected to the exhaust passage. The outlet of the exhaust silencer is fluidly connected to an exhaust tube which returns the exhaust refrigerant to the refrigeration circuit.
The temperature of the refrigerant in the exhaust chamber is considerably higher than the temperature of the refrigerant in the intake chamber due to the compression effectuated to the refrigerant by the piston. Consequently, the excess heat of the refrigerant in the exhaust passage is partly released to the cylinder block, and therefrom transferred to other components of the compressor such as the compression chamber, the intake chamber, a motor and the like which are in the vicinity of the exhaust passage. Hence, an overall efficiency of the compressor decreases. Therefore, heat transfer from the exhaust refrigerant to the aforementioned critical components of the compressor must be reduced.
US 5,288,212 (A ) discloses a hermetic reciprocating compressor which includes an exhaust chamber and an intake chamber wherein the cover walls of the exhaust chamber and an intake chamber are spaced apart from each other by a predetermined clearance. In addition, a thermal insulation plate is installed in the intake chamber.
The technical measures implemented in the above prior art arrangement, increase a size of the hermetic reciprocating compressor and incur additional costs.
United States Patent US 4 782 858 discloses a compressor made of metallic components.
European Patent Application EP 1 942 274 A1 discloses a compressor for a car conditioner comprising a rear housing with a suction chamber and a discharge chamber that communicate via a valve plate with cylinder bores in a cylinder block. A muffler is formed by a cylindrical wall formed on the outer surface of the cylinder block, and a communication passage is formed through the cylinder block, the valve plate and the rear housing to communicate the muffler with the discharge chamber.
An objective of the present invention is to provide a reciprocating hermetic compressor, and a refrigeration appliance having the same, which overcomes the aforementioned problems, and effectively reduces heat transfer from the exhaust refrigerant to the critical components of the compressor.
This objective has been achieved by the reciprocating hermetic
compressor according to the present invention as defined in claim 1, and the refrigeration appliance according to the present invention as defined in claim 15. Further achievements have been attained by the subject-matters respectively defined in the dependent claims.
In the compressor according to the present invention, the exhaust silencer for attenuating pressure pulsation of a refrigerant received from the exhaust chamber is separately provided from the cylinder block and the cylinder head. The compressor according to the present invention further comprises a metal silencer tube for guiding the refrigerant from the exhaust chamber to the exhaust silencer and a metal mounting piece having a hollow part fluidly joined to an opening of an end portion of the silencer tube which are together form-fittingly embedded into a notch formed into the cylinder block, wherein the hollow part is arranged in fluid communication with the exhaust chamber via a through hole formed in the valve plate. By each stroke of the piston, the refrigerant in the compression chamber is exhausted into the exhaust chamber inside the cylinder head via an exhaust port. Therefrom, the exhaust refrigerant flows into the hollow part of the mounting piece by passing through the through hole in the valve plate. The exhaust refrigerant reaching the hollow part is further guided to the exhaust silencer via the metal silencer tube. According to the present invention, the silencer tube between the mounting piece and the exhaust silencer is installed external to the cylinder block. Thereby, the refrigerant in the exhaust chamber is fed into the remote exhaust silencer without contacting the cylinder block. Consequently, the aforementioned compressor components remain at relatively low operating temperatures. With each stroke of the piston, more refrigerant can be trapped into the compression chamber. Thereby, the volumetric efficiency of the compressor increases. In addition, the exhaust silencer is directly installed between the metal silencer tube and an exhaust tube which leads to an outside of the compressor housing. Thereby, any mechanical parts necessary for mounting the exhaust silencer onto the cylinder block have been dispensed with. Moreover, a compact compressor has been attained.
In an embodiment, a thermal insulation material is arranged into the notch for thermally insulating the metal mounting piece from the cylinder block. Thereby, a heat transfer from the exhaust refrigerant to the rest of the compressor is further reduced.
In another embodiment, a resilient material is arranged into the notch for biasing the mounting piece towards the front surface of the cylinder block. Thereby, in an assembled state, the mounting piece is tightly compressed between the cylinder block and the valve plate. In this embodiment, the resilient material also contributes to thermal insulation of the exhaust refrigerant.
In another embodiment, the hollow part has a circular aperture. In this embodiment, the aperture has an area which is equal to or larger than an area of an inner cross-section of the silencer tube. Thereby, uniform flow impedance is attained. A pressure drop in the exhaust refrigerant flow is prevented and an efficient operation of the compressor is safeguarded. In an alternative embodiment, the hollow part has an oval aperture. Thereby, a width of the hollow part is reduced without compromising flow impedance.
In another embodiment, the notch is formed into the cylinder block at a position which opposes the exhaust chamber. In this embodiment, the through hole is formed in the valve plate at a position which establishes the shortest refrigerant flow path from the exhaust chamber to the hollow part. Thereby, the exhaust refrigerant is immediately guided into the silencer tube.
In alternative embodiment, the notch is formed into an unthreaded portion of one anchor bore for receiving a fastening screw, particularly at a position opposing the exhaust chamber. In this embodiment, the through hole is similarly formed in the valve plate at a position which establishes the shortest refrigerant flow path from the exhaust chamber to the hollow part.
In another embodiment, the notch is configured as a combination of a blind bore and a slot which are joined together. The blind bore is formed into a front portion of the cylinder block whereas the slot is formed into a lateral portion of the cylinder block. The mounting piece is seated in the blind bore whereas the silencer tube sideways clamped into said slot.
In another embodiment, the mounting piece is a metal bushing fluidly joined to silencer tube by a welding joint.
In another embodiment, a base portion of the bushing is gas-tightly closed by a metal plate.
In alternative embodiment, a base portion of the metal bushing is only partly closed by a metal plate which has an annular opening for a screw to penetrate into a threaded portion of anchor bore when fastening the cylinder parts to each other.
In another embodiment, a flat ring gasket is arranged on a base portion of the metal bushing for gas-tightly sealing a refrigerant flow path.
In another embodiment, a head gasket is interposed between the cylinder block and the valve plate and another head gasket is interposed between the valve plate and the cylinder head. Both head gaskets have respective through holes opposing the through hole in the valve plate for providing a refrigerant flow path from the exhaust chamber to the mounting piece.
In another embodiment, the cylinder head is made of metal, preferably aluminum. The aluminum cylinder head has improved corrosion resistance. In this embodiment both the silencer tube and the mounting piece are made of metal, preferably steel. Thereby, the silencer tube can be easily joined to the mounting piece by welding. Such welding joint is robust and also reliable in view of gas-tightness.
Additional advantages of the compressor according to the present invention will now become apparent with the detailed description of the embodiments with reference to the accompanying drawings in which:

Figure 1 - is a schematic cross sectional side view of a reciprocating hermetic compressor.
Figure 2 - is perspective view of the cylinder block of the compressor shown in Fig. 1.
Figure 3 - is a schematic enlarged partial front view of the cylinder block shown in Fig. 2.
Figure 4 - is a schematic exploded partial perspective view of the cylinder block.
Figure 5 - is another schematic exploded partial perspective view of the cylinder block.
Figure 6 - is another schematic partial perspective view of the cylinder block.
Figure 7 - is a schematic enlarged view of the detail A shown in Fig. 6.
Figure 8 - is another schematic partial perspective view of a modified cylinder block.
Figure 9 - is a schematic enlarged view of the detail B shown in Fig. 8.
Figure 10 - is schematic cross sectional view, taken along the line I - I of the cylinder block shown in Fig. 3.
Figure 11 - is a schematic enlarged view of the detail C shown in Fig. 10.
Figure 12 - is a schematic enlarged partial perspective view of a cylinder block of the compressor according to another embodiment of the present invention.
Figure 13 - is a schematic enlarged partial front view of the cylinder block shown in Fig. 12.
Figure 14 - is a schematic exploded partial perspective view of the cylinder block shown in Figs. 12 and 13.
Figure 15 - is another schematic exploded partial perspective view of the cylinder block shown in Figs. 12 and 13.
Figure 16 - is a schematic enlarged view of the detail D shown in Fig. 15.
Figure 17 - is a schematic partial front view of the cylinder block shown in Figs. 12 and 13.
Figure 18 - is schematic cross sectional partial view, taken along the line II - II, of the cylinder block shown in Fig. 13.
Figure 19 - is a schematic enlarged view of the detail E shown in Fig. 18.
Figure 20 - is a schematic cross sectional partial view, taken along the line III - III of a modified cylinder block shown in Fig. 13.
Figure 21 - is a schematic enlarged view of the detail F shown in Fig. 20.

The reference signs appearing on the drawings relate to the following technical features.

1. Compressor
2. Cylinder block
3. Compression chamber
4. Cylinder head
5. Intake chamber
6. Exhaust chamber
7. Valve plate
8. Silencer tube
9. Mounting piece
10. Hollow part
11. Notch
12. Through hole
13. Insulation member
14. Resilient member
15. Screw hole
16. Anchor bore
17. Screw
18. Bore
19. Slot
20. First metal plate
21. Second metal plate
22. Flat ring gasket
23. First head gasket
24. First through hole
25. Second head gasket
26. Second through hole
27. Intake port
28. Exhaust port
29. Suction muffler

The reciprocating hermetic compressor (1) (briefly compressor (1)) is suitable for use in a refrigeration appliance, in particular a domestic refrigerator (not shown). The compressor (1) comprises a cylinder block (2) having a compression chamber (3) and a cylinder head (4) having an intake chamber (5) and separately therefrom, an exhaust chamber (6), each being in fluid connection with the compression chamber (3) through a valve plate (7) interposed between a front surface of the cylinder block (2) and the cylinder head (4) (Fig. 1).
The compressor (1) according to the present invention further comprises an exhaust silencer, separately provided from the cylinder block (2) and the cylinder head (4), for attenuating pressure pulsation of a refrigerant received from the exhaust chamber (6), a metal silencer tube (8) for guiding the refrigerant from the exhaust chamber (6) to the exhaust silencer and a metal mounting piece (9) having a hollow part (10) fluidly joined to an opening of an end portion of the silencer tube (8) which are form-fittingly embedded into a notch (11) formed in the cylinder block (2), wherein the hollow part (10) is in fluid communication with the exhaust chamber (6) via a through hole (12) formed in the valve plate (7) (Figs. 2-5; Figs. 12-15).
The valve plate (7) includes an intake port (27) and an exhaust port (28) each for selectively letting the refrigerant pass through (Fig.4 and 5; Figs. 14 and 15). The intake port (12) and exhaust port (13) are configured by lift-check valves. Alternatively, diaphragm check valves can be used. The refrigerant is drawn into intake chamber (27) through a suction muffler (29) (Figs. 4 and 5; Figs. 14 and 15). The cylinder head (4) and the cylinder block (2) respectively have a plurality of screw holes (15) and corresponding anchor bores (16) each having a threaded portion, for fastening the cylinder parts together by a plurality of corresponding screws (17) (Figs. 4 and 5; Figs. 14 and 15). The compressor (1) has a first head gasket (23) interposed between the cylinder block (2) and the valve plate (7) and a second head gasket (25) interposed between the valve plate (7) and the cylinder head (4) (Figs. 4 and 5; Figs. 14 and 15).
In an embodiment, the compressor (1) comprises a thermal insulation member (13) arranged into the notch (11) at an interface between the mounting piece (9) and the cylinder block (2) (Figs. 17, 20 and 21). The thermal insulation member (13) is made from a thermally insulating material such as a mineral fiber or the like.
In another embodiment, the compressor (1) comprises a resilient member (14) arranged into the notch (11) at an interface between the cylinder block (2) and a base portion of the mounting piece (9) to bias the mounting piece (9) towards the front surface of the cylinder block (2), opposing the valve plate (7) (Figs. 4 and 5; Fig. 14). The resilient member (13) is made from an elastomer material.
In another embodiment, the hollow part (10) has a circular cross-section along a direction perpendicular to the front surface of the cylinder block (2) (Figs. 6 and 7).
In an alternative embodiment, the hollow part (10) has an oval cross-section along a direction perpendicular to the front surface of the cylinder block (2) (Figs. 8 and 9).
In another embodiment, the cross-section of the hollow part (10) has an area which is equal to or larger than an area of an inner cross-section of the silencer tube (8) (Figs. 6 to 9).
In another embodiment, the notch (11) is formed into the cylinder block (2) at a location opposing the exhaust chamber (6) (Figs. 4 and 5). In this embodiment, the through hole (12) is formed in the valve plate (7) at a location intersected by a virtual straight line connecting the exhaust chamber (6) and the hollow part (10) (Figs. 4 and 5). Thus, the through hole is aligned with the exhaust chamber (6) and the hollow part (10) to form the shortest flow path.
In an alternative embodiment, both the notch (11) and through hole (12) are formed at an alternative position. In this embodiment, the notch (11) is formed into an unthreaded portion of one anchor bore (16) at a location opposing the exhaust chamber (6); and the through hole (12) is formed in the valve plate (7) at a location intersected by a virtual straight line connecting the exhaust chamber (6) and the hollow part (10) (Figs. 14 to 16). Thus, the through hole is again aligned with the exhaust chamber (6) and the hollow part (10) to form the shortest flow path.
In another embodiment, the notch (11) includes a blind bore (18) formed into a front portion of the cylinder block (2), extending in a direction perpendicular to the front surface of the cylinder block (2); and a slot (19) formed into a lateral portion of the cylinder block (2), joining to the bore (18) and extending in a direction perpendicular to a front surface of the cylinder block (2) (Figs. 4 and 5; Fig. 14 and 15). When assembling the mounting piece (9) and the silencer tube (8) with the cylinder block (2), the mounting piece (9) is seated in said bore (18) while clamping the silencer tube (8) into said slot (19) (Figs. 2 and 3; Figs. 12 and 13). The mounting piece (9) and the silencer tube (8) are tightly fastened into the notch (11) when cylinder parts are fixed together by the screws (17) (Figs. 4 and 5; Figs. 14 and 15). No further auxiliary fixing elements are required.
In another embodiment, the mounting piece (9) is a metal bushing. The interior of the bushing configures the hollow part (10) (Figs. 10 and 11; Figs. 18 to 21). The metal silencer tube (8) is fluidly joined to the hollow part (10), by a welding joint at an outer side portion of the bushing (Figs. 6 to 9).
In another embodiment, the base portion of the bushing which abuts against the cylinder block (2) is gas-tightly closed by a first metal plate (20) (Figs. 4, 5, and 11).
In an alternative embodiment, the base portion of the metal bushing which abuts against the cylinder block is only partly closed by a second metal plate (21) which has an annular opening to allow a corresponding screw (17) to penetrate into a threaded portion of said one anchor bore (16) (Figs. 15, and 18 to 21).
In another embodiment, a flat ring gasket (22) is arranged underneath the base portion of the metal bushing which abuts against the cylinder block (2), for gas-tightly sealing an interface between the mounting piece (9) and the cylinder block (2) (Figs. 19 and 21).
In another embodiment, the first head gasket (23) has a first through hole (24) formed at a location opposing said through hole (12) of the valve plate (7); and the second head gasket (25) has a second through (26) hole formed at a location opposing said through hole (12) of the valve plate (7). The first through hole (24) and the second through hole (26) define together with the through hole (12) in the valve plate (7) a refrigerant flow path from the exhaust chamber (6) to the hollow part (10) (Fig. 4 and 5; Figs. 14 and 15).
The refrigeration appliance (not shown) according to the present invention comprises refrigeration circuit for circulating a refrigerant, which includes a compressor (1) as defined in any one of the above embodiments, a condenser, and an expansion valve. The refrigeration appliance according to the present invention may be a refrigeration appliance particularly suitable for domestic use.

Claims

A compressor (1) for use in a refrigeration appliance, in particular a domestic refrigerator, comprising a cylinder block (2) having a compression chamber (3) and a cylinder head (4) having an intake chamber (5) and separately therefrom, an exhaust chamber (6), each being in fluid connection with the compression chamber (3) through a valve plate (7) interposed between a front surface of the cylinder block (2) and the cylinder head (4),
further comprising an exhaust silencer, separately provided from the cylinder block (2) and the cylinder head (4), for attenuating pressure pulsation of a refrigerant received from the exhaust chamber (6),
characterized in that it comprises
- a metal silencer tube (8) for guiding the refrigerant from the exhaust chamber (6) to the exhaust silencer and

- a metal mounting piece (9) having a hollow part (10) fluidly joined to an opening of an end portion of the silencer tube (8) which are form-fittingly embedded into a notch (11) formed in the cylinder block (2), wherein the hollow part (10) is in fluid communication with the exhaust chamber (6) via a through hole (12) formed in the valve plate (7),
wherein the silencer tube (8) between the mounting piece (9) and the exhaust silencer is installed external to the cylinder block (2).
The compressor (1) according to claim 1, characterized by a thermal insulation member (13) arranged into the notch (11) at an interface between the mounting piece (9) and the cylinder block (2).
The compressor (1) according to claim 1 or 2, characterized by a resilient member (14) arranged into the notch (11) at an interface between the cylinder block (2) and a base portion of the mounting piece (9) to bias the mounting piece (9) towards the front surface of the cylinder block (2), opposing the valve plate (7).
The compressor (1) according to any one of claims 1 to 3, characterized in that the hollow part (10) has a circular cross-section along a direction perpendicular to the front surface of the cylinder block (2).
The compressor (1) according to any one of claims 1 to 3, characterized in that the hollow part (10) has an oval cross-section along a direction perpendicular to the front surface of the cylinder block (2).
The compressor (1) according to claim 4 or 5, characterized in that said cross-section has an area which is equal to or larger than the area of inner cross-section of the silencer tube (8).
The compressor (1) according to any one of claims 1 to 6, characterized in that the notch (11) is formed into the cylinder block (2) at a location opposing the exhaust chamber (6) and the through hole (12) is formed in the valve plate (7) at a location intersected by a virtual straight line connecting the exhaust chamber (6) and the hollow part (10).
The compressor (1) according to any one of claims 1 to 6, characterized in that the cylinder head (4) and the cylinder block (2) respectively have a plurality of screw holes (15) and corresponding anchor bores (16) each having a threaded portion, for fastening the cylinder parts together by a plurality of corresponding screws (17), the notch (11) is formed into an unthreaded portion of one anchor bore (16) at a location opposing the exhaust chamber (6) and the through hole (12) is formed in the valve plate (7) at a location intersected by a virtual straight line connecting the exhaust chamber (6) and the hollow part (10).
The compressor (1) according to claim 7 or 8, characterized in that the notch (11) includes a blind bore (18) formed into a front portion of the cylinder block (2), extending in a direction perpendicular to the front surface of the cylinder block (2) and a slot (19) formed into a lateral portion of the cylinder block (2), joining to the bore (18) and extending in a direction perpendicular to the front surface of the cylinder block (2), wherein the mounting piece (9) is seated in said bore (18), and wherein the silencer tube (8) is clamped into said slot (19).
The compressor (1) according to any one of claims 1 to 9, characterized in that the mounting piece (9) is a metal bushing, wherein an interior of the bushing configures the hollow part (10) and the metal silencer tube (8) is fluidly joined to the hollow part (10) by a welding joint at an outer side portion of the bushing.
The compressor (1) according to claim 10, when dependent on claim 7, characterized in that a base portion of the bushing abutting against the cylinder block (2) is gas-tightly closed by a first metal plate (20).
The compressor (1) according to claim 10, characterized in that a base portion of the metal bushing abutting against the cylinder block is only partly closed by a second metal plate (21) having an annular opening to allow a corresponding screw (17) to penetrate into a threaded portion of said one anchor bore (16).
The compressor (1) according to claim 12, characterized by a flat ring gasket (22) arranged on a base portion of the metal bushing abutting against the cylinder block (2), for gas-tightly sealing an interface between the mounting piece (9) and the cylinder block (2).
The compressor (1) according to any one of claims 1 to 13, characterized by a first head gasket (23) interposed between the cylinder block (2) and the valve plate (7), wherein the first head gasket (23) has a first through hole (24) formed at a location opposing said through hole (12) of the valve plate (7) and a second head gasket (25) interposed between the valve plate (7) and the cylinder head (4), wherein the second head gasket (25) has a second through (26) hole formed at a location opposing said through hole (12) of the valve plate (7).
A refrigeration appliance, in particular a domestic refrigerator, comprising a refrigeration circuit for circulating a refrigerant, which includes a compressor (1) as defined in any one of claims 1 to 14.