EP3277956B1

EP3277956B1 - Suction muffler for use in a hermetic compressor

Info

Publication number: EP3277956B1
Application number: EP15717824.5A
Authority: EP
Inventors: Mehmet Onur DINCER
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2015-03-31
Filing date: 2015-03-31
Publication date: 2020-02-12
Anticipated expiration: 2035-03-31
Also published as: EP3277956A1; WO2016155799A1; PL3277956T3

Description

The present invention relates to a hermetically sealed compressor of a refrigeration appliance such as a domestic refrigerator. The present invention particularly relates to the suction muffler of the hermetically sealed compressor.
Hermetically sealed compressors which are used in refrigeration appliances such as domestic refrigerators are commonly known. A hermetically sealed compressor generally comprises a reciprocating mechanism which conveys the refrigerant from the evaporator site to the condenser site of the refrigeration circuit in the refrigeration appliance. During the refrigeration cycle, both in the compression phase and in the suction phase of the compressor, the flow of the refrigerant and the moving parts of the reciprocating mechanism generate detrimental vibrations and uncomfortable noise. In order to reduce the noise and the vibrations, the refrigerant is generally passed through a suction muffler which is disposed into the hermetically sealed compressor on the upstream side of the valve plate. The suction mufflers which are used in the hermetically sealed compressors are commonly known. A suction muffler usually comprises a casing, at least one cavity inside the casing, an inlet port for admitting the refrigerant into the cavity, and an outlet port for discharging the refrigerant out of the cavity towards the valve plate, and therefrom into the cylinder bore. The effective operation of the suction muffler is crucial for the compressor as well as for the customer satisfaction. The installation place of the refrigeration appliance can easily become very noisy, and thus jeopardize a customer's living comfort. Therefore, the noise produced by the flow of the refrigerant must be damped to ensure the silent operation of the refrigeration appliance. The noise/vibration attenuation capability of the suction muffler depends, inter alia, on its size and shape. In general, an increase in the size of the suction muffler is not desired in view of the production costs. In addition, the size and shape of the suction muffler greatly influences the volumetric efficiency of the compressor, and thus the refrigeration performance of the appliance.
International Patent Application WO 2009/088180 A2 discloses a suction muffler with a case having an inlet that is connected via a connection member to a suction pipe. A plate film is formed in the connection member for blocking pressure pulsation or noise. KR200148573 discloses a refrigeration appliance according to the state of the art. An objective of the present invention is to provide a suction muffler for use in a hermetically sealed compressor of a refrigeration appliance which overcomes the aforementioned drawbacks of the prior art in a cost effective way and which enables a low-noise emission, an improved volumetric efficiency and an improved refrigeration performance.
This objective has been achieved by the refrigeration appliance as defined in claim 1. Further achievements have been attained by the subject-matters respectively defined in the dependent claims.
The suction muffler of the present invention comprises a backflow prevention device which is disposed into the cavity and adapted to prevent backflow of the refrigerant through the inlet port out of the cavity.
With the present invention, particularly by virtue of the backflow prevention device, the refrigerant can be prevented during the compression phase of the compressor from flowing back towards the evaporator and heating up, expanding in the suction tube and the evaporator. With the present invention, particularly by virtue of the backflow prevention device, the amount of refrigerant that remains trapped inside the cavity during the compression phase also becomes comparatively higher. Thereby, a comparatively larger amount of refrigerant can be sucked out of the cavity into the cylinder bore during the suction phase of the compressor, and thus the volumetric efficiency of the compressor can be increased. In addition, with the present invention, particularly by virtue of the backflow prevention device, the refrigerant inside the cavity is also decoupled from the suction tube during compression phase, and thus the pressure waves excited in the refrigerant due to the reciprocating movement of the piston can be at least partly prevented from propagating into the suction tube and therefrom out of the compressor. Thereby, the sound waves propagating in the refrigerant encounter an increased number of successive impingements on the inner surface of the cavity during compression phase, and thus attenuate stronger. With the suction muffler of the present invention, the noise generated by the flow of the refrigerant can be reduced to desired and bearable levels which comply with the standards without compromising the overall size of the compressor. Thereby, the refrigeration appliance can be prevented from causing any acoustic discomfort to the user. With the present invention, a refrigeration appliance has been provided which has a low noise emission and a comparatively high refrigeration performance. Thereby, the customer satisfaction can be increased.
The backflow prevention device comprises a valve unit in particular a one-way valve unit which has a valve member that entirely closes the inlet port in the compression phase and re-opens in the suction phase. In the present invention, various types of valve members can be utilized in the valve unit or in the one-way valve unit. For instance, the valve member can open/close the inlet port, through the action of elastic forces, electromagnetic forces, or gravity.
The one-way valve unit comprises a flexible leaf as a valve member that is attached to the inner surface of the casing so as to entirely cover the inlet port at the rest position. In the present invention, the flexible leaf is made of a heat-resistant flexible material. The flexible leaf can be made, for instance, from rubber. Alternatively metal can be used. Also composite materials can be used so as to reduce the risk of fatigue failures. In another embodiment, the stiffness of the flexible leaf is kept relatively small such that the inlet port easily re-opens at a relatively small differential pressure during the suction phase, but closes sufficiently tightly during the compression phase.
In the present invention, the flexible leaf can be attached to the inner surface by a chemical means such gluing or alternatively through any mechanical means which establishes the attachment by way of fitting, clamping, hinging, screwing or the like. In another embodiment, the flexible leaf is clamped into a retaining slot which is formed into the inner surface of the casing. In a version of this embodiment, the retaining slot is integrally formed onto the inner surface of the casing during the manufacturing process.
In another alternative embodiment, the flexible leaf is glued into the retaining slot on the inner surface of the casing. In another alternative embodiment, flexible leaf is fitted together with the pins which are disposed onto the inner surface of the casing. In a version of this embodiment, the pins are integrally formed onto the inner surface during the manufacturing process.
Additional advantages of the suction muffler and the hermetically sealed compressor of the present invention will become more apparent with the detailed description of the embodiments with reference to the accompanying drawings in which:

Figure 1 - is a schematic sectional view of a hermetically sealed compressor which has a suction muffler according to an embodiment of the present invention;
Figure 2 - is a schematic exploded perspective view of the suction muffler according to an embodiment of the present invention;
Figure 3 - is a schematic perspective view of the lower part of the casing of the suction muffler according to an embodiment of the present invention;
Figure 4 - is a schematic perspective view of the lower part of the casing of the suction muffler according to an alternative embodiment of the present invention.

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

1.: Muffler
2.: Compressor
3.: Casing
3a.: Upper part
3b.: Lower part
4.: Cavity
5.: Inlet port
6.: Outlet port
7.: Device
8.: Valve unit
9.: Leaf
10.: Attachment means
11.: Inner surface
12.: Side wall
13.: Slot
14.: Edge
15.: Pin
16.: Hole
17.: Slot
18.: Claw
19.: Upper casing
20.: Lower casing
21.: Sump
22.: Tube
23.: Motor
24.: Stator
25.: Rotor
26.: Crankshaft
27.: Bearing
28.: Cylinder Block
29.: Piston
30.: Cylinder Bore
31.: Connecting rod
32.: Pin
33.: Cylinder Head
34.: Exhaust chamber
35.: Exhaust port
36.: Valve plate
37.: Intake port

The suction muffler (1) is suitable for use in a hermetically sealed compressor (2) of a refrigeration appliance (not shown) which has a refrigeration circuit for circulating the refrigerant via the hermetically sealed compressor (2).
The suction muffler (1) comprises a casing (3), a cavity (4) inside the casing (3), an inlet port (5) for admitting the refrigerant into the cavity (3) and an outlet port (6) for discharging the refrigerant out of the cavity (3) (Fig. 1 to 4).
The suction muffler (1) of the present invention further comprises: a backflow prevention device (7) which is disposed into the cavity (3) and adapted to prevent backflow of the refrigerant through the inlet port (5) out of the cavity (3) (Fig. 1 to 4).
The hermetically sealed compressor (2) of the present invention comprises the suction muffler (1).
The refrigeration appliance (not shown) of the present invention comprises the hermetically sealed compressor (2).
In an embodiment, the backflow prevention device (7) comprises a one-way valve unit (8) which is adapted to open the inlet port (5) when the compressor (2) is in the suction phase and adapted to entirely close the inlet port (5) when the compressor (2) is in the compression phase.
In another embodiment, the one-way valve unit (8) comprises a flexible leaf (9) which is adapted to move, under the action of the differential pressure during the suction phase of the compressor (2), from a rest position towards a deflected position. The flexible leaf (9) is biased towards the rest position. The inlet port (5) is opened when the flexible leaf (9) is moved to the deflected position during the suction phase. The inlet port (5) is entirely closed when the flexible leaf (9) returns to its rest position during the compression phase. In this embodiment, the one-way valve unit (8) further comprises an attachment means (10) for the attachment of the flexible leaf (9) to the inner surface (11) of the casing (3) in close proximity to the inlet port (5) such that the flexible leaf (9) covers the entire inlet port (5) at the rest position.
In another embodiment, the flexible leaf (9) is made of a flexible material. In a version of this embodiment, the stiffness of the flexible leaf (9) is relatively small such that the inlet port (5) opens at a relatively small differential pressure during the suction phase of the compressor (2) and closes sufficiently tightly during the compression phase of the compressor (2) so as to prevent backflow (Fig. 1 to 4).
In another embodiment, the inlet port (5) opens into a side wall (12) of the casing (3). In this embodiment, the flexible leaf (9) is attached via the attachment means (10) to the inner surface (11) of the casing (3) immediately above the inlet port (5) such that the flexible leaf (9) abuts against the side wall (12) at the rest position (Fig. 1 to 4).
In another embodiment, the attachment means (10) comprises a retaining slot (13) which is disposed into the inner surface (11) of the casing (3). In this embodiment, the edge (14) of the flexible leaf (9) is clamped into the retaining slot (13) (Fig. 1 to 3).
In an alternative embodiment, the edge (14) of the flexible leaf (9) is glued into the retaining slot (13) (Fig. 1 to 3).
In another alternative embodiment, the attachment means (10) comprises at least two pins (15) which are disposed onto the inner surface (11) of the casing (3). In this embodiment, the flexible leaf (9) has counterpart holes (16) for fitting together with the pins (15) respectively (Fig. 1 to 2, and 4).
In another embodiment, the attachment means (10), namely the retaining slot (13) is integrally formed with the casing (3).
In another alternative embodiment, the attachment means (10), namely the pins (15) are integrally formed with the casing (3).
In another embodiment, the casing (3) is manufactured from a heat-resistant durable plastic material.
In another embodiment, the casing (3) comprises an upper part (3a) and a lower part (3b) which are releasably attachable to each other. In this embodiment, the outlet port (6) is disposed into the upper part (3a). And the inlet port (5) is disposed into the lower part (3b).
In another embodiment, the inlet port (5) and the outlet port (6) are aligned along mutually transverse directions. In this embodiment, the inlet port (5) and the outlet port (6) are located so as not to face each other.
In another embodiment, the refrigeration appliance, including the hermetically sealed compressor (2) of the present invention is provided as a domestic refrigerator (not shown).
In another embodiment, the upper part (3a) of the casing (3) has one or more than one slots (17), and the lower part (3b) of the casing (3) has one or more than one claw (18) for snugly fitting into the corresponding slot (18).
In the subsequent description, the operation of the hermetically sealed compressor (2) will be briefly explained by way of example. The compressor (2) is hermetically sealed through the upper casing (19) and the lower casing (20). The lower casing (20) serves as the lubricant sump (21). An oil pickup-tube (22) is partly immersed into the lubricant sump (21). The motor (23) has a stator (24) and a rotor (25). The crankshaft (26) is journalled into the main bearing (27) of the cylinder block (28). The rotor (25) is fixed around the crankshaft (26). The piston (29) is reciprocatingly disposed into the cylinder bore (30) so as to compress the refrigerant therein and convey from the evaporator (not shown) to the condenser (not shown). The piston (29) is coupled via the connecting rod (31) and the pin (32) to the crankshaft (26). The cylinder bore (30) is covered by the cylinder head (33). A valve plate (36) is arranged between the cylinder head (33) and the cylinder block (28). In the suction phase of the compressor (2) as the piston (29) moves rearwards towards the far dead center of the crankshaft (26), concurrently the exhaust port (35) of the valve plate (36) becomes closed and the intake port (37) of the valve plate (36) becomes opened, and thus the refrigerant is sucked from the suction muffler (1) via the intake port (37) into the cylinder bore (30). In the suction phase of the compressor (2), the one-way valve unit (8) inside the suction muffler (1) concurrently opens the inlet port (5), and the refrigerant flows from the evaporator via the suction tube (not shown) into the suction muffler (1). In the compression phase of the compressor (2) as the piston (29) moves forwards towards the close dead center of the crankshaft (26) concurrently the exhaust port (35) of the valve plate (36) becomes opened, and the intake port (37) of the valve plate (36) becomes closed, and thus the compressed refrigerant enters the exhaust chamber (34) of the cylinder head (33) via the exhaust port (35) of the valve (36). In the compression phase of the compressor (2), the one-way valve unit (8) inside the suction muffler (1) concurrently closes the inlet port (5), and the refrigerant inside the suction muffler (1) is prevented from flowing back to the evaporator (not shown) via the suction tube.
The noise is mainly generated in the vicinity of the intake port (37) and the exhaust port (35) of the valve plate (36) under the influence of the reciprocating movement of the piston (29). The suction muffler (1) attenuates the acoustic waves which are generated inside the refrigerant that flows through the cavity (4) during the suction phase. The suction muffler (1) and the one-way valve unit (8) also attenuate during the compression phase the acoustic waves that propagate towards the suction tube, and therefrom to outside of the compressor (2).
In another embodiment, the suction muffler (1) is mounted onto the cylinder head (33) such that the outlet port (6) is located immediately upstream of the valve plate (36).
In another embodiment, the casing (3) of the suction muffler (1) has a drainage opening (not shown) for draining the lubricant into the sump (21).
In another embodiment, the casing (3) comprises a piece (not shown) which partitions the cavity (4) into two or more than two fluidly connected chambers (not shown) for improving the acoustic attenuation.
With the suction muffler (1) of the present invention, the volumetric efficiency of the hermetically sealed compressor (2) can be increased in a cost-effective way. Also with the suction muffler (1) of the present invention, the noise level of the hermetically sealed compressor (2) can be reduced in a cost-effective way.

Claims

A refrigeration appliance, in particular a domestic refrigerator, comprising a hermetically sealed compressor, an evaporator and a refrigeration circuit for circulating the refrigerant via the hermetically sealed compressor (2) including a suction muffler (1) comprising:
- a casing (3);

- a cavity (4) inside the casing (3),

- an inlet port (5) that is connected via a suction tube to the evaporator for admitting the refrigerant into the cavity (3),

- an outlet port (6) for discharging the refrigerant out of the cavity (3), and

- a backflow prevention device (7) disposed into the cavity (3) of the suction muffler (1) and adapted to prevent backflow of the refrigerant through the inlet port (5) out of the cavity (3) to the evaporator, said backflow prevention device (7) comprising a one-way valve unit (8) which is adapted to open the inlet port (5) when the compressor (2) is in the suction phase and adapted to close the inlet port (5) when the compressor (2) is in the compression phase, wherein the one-way valve unit (8) comprises: a flexible leaf (9) which is adapted to move, under the action of the differential pressure during the suction phase of the compressor (2), from a rest position to a deflected position where the inlet port (5) is open, wherein the flexible leaf (9) is biased towards the rest position; characterized in that the one-way valve unit (8) further comprises an attachment means (10) for the attachment of the flexible leaf (9) to the inner surface (11) of the casing (3) in close proximity to the inlet port (5) such that the flexible leaf (9) covers and closes the entire inlet port (5) at the rest position, and the backflow prevention device (7) entirely closes the inlet port (5) when the compressor is in the compression phase.
The refrigeration appliance according to claim 1, characterized in that the inlet port (5) opens into a side wall (12) of the casing (3), and wherein the flexible leaf (9) is attached via the attachment means (10) to the inner surface (11) of the casing (3) immediately above the inlet port (5) such that the flexible leaf (9) abuts against the side wall (12) at the rest position.
The refrigeration appliance according to claim 1 or 2, characterized in that the attachment means (10) comprises a retaining slot (13) which is disposed into the inner surface (11) of the casing (3), wherein an edge (14) of the flexible leaf (9) is clamped into the retaining slot (13).
The refrigeration appliance according to claim 1 or 2, characterized in that the attachment means (10) comprises a retaining slot (13) which is disposed into the inner surface (11) of the casing (3), wherein an edge (14) of the flexible leaf (9) is glued into the retaining slot (13).
The refrigeration appliance according to claim 1 or 2, characterized in that the attachment means (10) comprises at least two pins (15) which are disposed onto the inner surface (11) of the casing (3), wherein the flexible leaf (9) has counterpart holes (16) for fitting together with the pins (15) respectively.
The refrigeration appliance according to claim 5, characterized in that the attachment means (10) is integrally formed with the casing (3).
The refrigeration appliance according to claim 6, characterized in that the casing (3) comprises an upper part (3a) and a lower part (3b) which are releasably attachable to each other, wherein the outlet port (6) is disposed into the upper part (3a), and wherein the inlet port (5) is disposed into the lower part (3b).
The refrigeration appliance according to any one of claims 1 to 7, characterized in that the inlet port (5) and the outlet port (6) are aligned along mutually transverse directions.