Hermetic compressor

Abstract

A hermetic compressor comprising a pulsation damping flow path. The pulsation damping flow path is provided inside a discharge silencer, and is adapted to communicate the discharge silencer with a discharge chamber defined in a cylinder head. The pulsation damping flow path is formed to have a plurality of passages. Accordingly, by reducing a diameter of the respective passages down to a relatively small value compared to that of a conventional pulsation pipe, it is possible to considerably attenuate the pulsation of a refrigerant. Further, since the plural passages allow a constant amount of the refrigerant to continuously pass therethrough, it is possible to prevent an increase in a starting voltage of the compressor and the consumption of electricity thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 2003-58333, filed on Aug. 22, 2003 and Korean Patent Application No. 2004-19460, filed on Mar. 22, 2004 in the Korean Intellectual Property Office, the disclosure of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hermetic compressor, and, more particularly, to a hermetic compressor comprising a pulsation damping flow path, which is defined in a discharge silencer and is adapted to attenuate a pressure pulsation of a refrigerant being discharged.

2. Description of the Related Art

In general, hermetic compressors serve to compress a refrigerant for use in refrigerators. Such a hermetic compressor comprises a driving unit, which generates driving force by electric power applied from the outside, and a compressing unit, which compresses a refrigerant by receiving the driving force from the driving unit.

The compressing unit comprises a cylinder formed in a cylinder block and defining a compression chamber inside a hermetic casing, a piston reciprocating inside the compression chamber, and a cylinder head coupled to one side of the cylinder and internally defining a suction chamber and discharge chamber.

Between the cylinder and the cylinder head is interposed a valve plate. The valve plate has a suction port and discharge port, which serve to communicate between the compression chamber and the suction and discharge chambers, respectively. The valve plate further has a suction valve and discharge valve for selectively opening and closing the suction port and discharge port, respectively.

A discharge silencer is coupled to the discharge chamber of the cylinder head, and is adapted to attenuate the pulsation of a refrigerant being discharged, and noise generated during discharge of the refrigerant. The discharge silencer contains a pulsation pipe for attenuating the pulsation of the refrigerant.

The pulsation pipe has a multiply twisted spiral shape. One end of the pulsation pipe is welded to the cylinder head, which internally defines the discharge chamber, and the other end of the pulsation pipe communicates with the interior space of the discharge silencer.

With such a conventional hermetic compressor configured as stated above, the driving unit reciprocates the piston as electric power is applied thereto, thereby allowing a refrigerant inside the compression chamber to be compressed. The compressed refrigerant is discharged into the discharge chamber of the cylinder head, and in succession, moves into the discharge silencer via the pulsation pipe. While passing through the pulsation pipe, the pulsation of the refrigerant is attenuated.

The pulsation pipe, applied in the conventional hermetic compressor, is configured so that, as the diameter of the pulsation pipe decreases, the resistance of a flow path increases, thereby correspondingly attenuating the pulsation of the refrigerant. However, since the pulsation pipe has to continuously transfer a constant amount of the refrigerant therethrough, such a reduction in diameter of the pulsation pipe has limitations.

That is, although reducing the diameter of the pulsation pipe can considerably attenuate the pulsation and noise of the refrigerant, it may cause another problem in that a starting voltage of the compressor and the consumption of electricity rise due to an increase in the flow path resistance of the pulsation pipe.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above mentioned problem, and an aspect of the invention is to provide a hermetic compressor which can considerably attenuate the pulsation and noise of a refrigerant and can lower a starting voltage of the compressor and the consumption of electricity thereof by improving the structure of a pulsation damping structure defined in a discharge silencer.

In accordance with an aspect, the present invention provides a hermetic compressor comprising: a cylinder internally defining a compression chamber; a cylinder head coupled to one side of the cylinder and internally defining a discharge chamber, the discharge chamber communicating with the compression chamber; a discharge silencer coupled to the discharge chamber of the cylinder head and adapted to attenuate a pulsation of a refrigerant being discharged; and a pulsation damping flow path provided inside the discharge silencer so that one end thereof communicates with the discharge chamber and the other end thereof communicates with the interior of the discharge silencer, the pulsation damping flow path having plural passages.

The pulsation damping flow path may have a multiply twisted spiral shape.

Both the ends of the pulsation damping flow path may take the form of a single passage, respectively.

The pulsation damping flow path may include a plurality of hollow tubes coupled to each other.

The pulsation damping flow path may include a single tube, the interior of the single tube being divided to define a plurality of passages.

The respective passages have substantially the same sectional area as each other.

The respective passages have an inner diameter of 1.0 mm to 1.5 mm, a length of 70 mm to 120 mm, and the discharge silencer has a volume of 15 cc to 25 cc.

BRIEF DESCRIPTION OF THE DRAWINGS

The above aspect, and other features and advantages of the present invention will become more apparent after reading the following detailed description when taken in conjunction with the drawings, in which:

FIG. 1 is a side sectional view illustrating the general structure of a hermetic compressor in accordance with the present invention;

FIG. 2 is a perspective view illustrating a cylinder head of the hermetic compressor in accordance with the present invention;

FIG. 3 is a sectional view illustrating the interior structure of a discharge silencer for the hermetic compressor in accordance with the present invention;

FIG. 4 is a sectional view illustrating another shape of a pulsation damping flow path provided in the discharge silencer for the hermetic compressor in accordance with the present invention; and

FIG. 5 is a graph illustrating experimental results obtained by measuring and comparing noise generated from both the hermetic compressor in accordance with the present invention and a conventional compressor under the same conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described in detail with reference to the annexed drawings.

Referring to FIG. 1 illustrating a hermetic compressor in accordance with the present invention, it comprises a hermetic casing 10 which includes upper and lower casings 11 and 12 coupled with each other so as to internally define a hermetic interior space, a driving unit 20 which is installed inside the hermetic casing 10 and adapted to generate power, and a compressing unit 20 which is also installed inside the hermetic casing 10 and is adapted to compress a refrigerant by receiving power from the driving unit 20.

The driving unit 20 includes a stator 21 fixedly mounted inside the hermetic casing 10, and a rotor 22 loosely fitted inside the stator 21 and adapted to interact with the stator 21 in an electromagnetic manner. A rotating shaft 23 is coupled to the center of the rotor 22 so that it rotates along with the rotor 22. Arranged beneath the rotating shaft 23 are an eccentric portion 24 installed to eccentrically rotate, and a connecting rod 25 adapted to convert the eccentric rotation of the eccentric portion 24 into a rectilinear motion. For achieving such a conversion, one end of the connecting rod 25 is rotatably connected to the eccentric portion 24, and the other end of the connecting rod 25 is connected to a piston 32, which will be described hereinafter, in a rotatable and rectilinear movable manner.

The compressing unit 30 includes a cylinder block 33 provided at one side of a frame 31, a cylinder 32 provided inside the cylinder block 33 and internally defining a compression chamber 32a, a cylinder head 34 internally defining a suction chamber 34a (shown in FIG. 2) and a discharge chamber 34b, which serve to guide the suction and discharge of a refrigerant to and from the compression chamber 32a, and a piston 35 rectilinearly reciprocating inside the compression chamber 32a. Between the cylinder 32 and cylinder head 34 is interposed a valve plate 36, which is formed with a suction port 36a and a discharge port 36b for use in selective communication between the compression chamber 32a and the suction and discharge chambers 34a and 34b, respectively.

Referring to FIG. 2, a suction silencer 40 is coupled to the suction chamber 34a of the cylinder head 34 and is adapted to attenuate the pulsation of a refrigerant being sucked. The suction silencer 40 is installed at one side thereof with a suction tube 41 for guiding the suction of the refrigerant.

In addition to the suction silencer 40, a discharge silencer 50 is coupled to the discharge chamber 34b of the cylinder head 34 and is adapted to attenuate the pulsation and noise of a refrigerant being discharged. The refrigerant, after passing through the discharge silencer 50, is discharged to the outside via a discharge tube 41. The discharge tube 41 is installed at one side of the discharge silencer 50 so as to communicate with it.

Explaining the discharge silencer 50 in detail with reference to FIG. 3, it takes the form of a cylinder in which a pulsation damping flow path 52 is provided. The pulsation damping flow path 52 is adapted to guide the refrigerant discharged from the discharge chamber 34b of the cylinder head 34 into the discharge silencer 50, and to attenuate the pulsation of the refrigerant.

The pulsation damping flow path 52 is formed by multiply twisting a pair of coupled hollow tubes 52a and 52b in a spiral shape. In this case, the hollow tubes 52a and 52b are coupled to each other by brazing. Preferably, the hollow tubes 52a and 52b have substantially the same sectional area as each other.

Although the pulsation damping flow path 52 comprises the pair of the hollow tubes 52a and 52b, in order to secure more smooth inlet and outlet of a refrigerant, both ends of the pulsation damping flow path 52 take the form of a single tube 52c. One end of the pulsation damping flow path 52 is fixedly welded to the cylinder head 34 so as to communicate with the discharge chamber 34b, and the other end of the pulsation damping flow path 52 communicates with the interior space of the discharge silencer 50.

In the present embodiment, the pair of the hollow tubes 52a and 52b are provided to constitute the pulsation damping flow path 52, but there may be provided two or more hollow tubes.

Referring to FIG. 4 illustrating another pulsation damping flow path, which is designated as reference numeral 53, it may include a single tube 53a, and the interior of the single tube 53a may be divided into plural passages 53b and 53c. In this case, the plural passages 53b and 53c have the same sectional area and length as each other.

Now, the operation and effects of the hermetic compressor in accordance with the present invention will be explained.

When electric power is applied to the driving unit 20, the rotating shaft 23 rotates along with the rotor 22, and then, the eccentric portion 24 rotates in an eccentric manner according to the rotation of the rotating shaft 23. By virtue of the eccentric portion 24, the piston 32 reciprocates inside the compression chamber 32a, thereby allowing a refrigerant drawn from the suction chamber 34a of the cylinder head 34 to be compressed and then the compressed refrigerant to be discharged.

The refrigerant discharged into the discharge chamber 34b moves into the discharge silencer 50 by passing through the pulsation damping flow path 52. Since the pulsation damping flow path 52 comprises the plural hollow tubes 52a and 52b, by reducing the diameter of the hollow tubes 52a and 52b, the pulsation damping flow path 52 can considerably attenuate the pressure pulsation of the refrigerant while maintaining a flow rate of the refrigerant passing through the pulsation damping flow path 52 at a constant level.

Accordingly, the pressure pulsation and noise of the refrigerant being discharged to the outside of the compressor can be attenuated, resulting in a stable and quite operation of the compressor.

From an experiment performed by the inventors of the present invention under the assumption that the pulsation damping flow path 52 comprises the pair of the same hollow tubes 52a and 52b, it has been found that it can simultaneously attenuate the pulsation and noise of a refrigerant as well as a starting voltage of the compressor and the consumption of electricity when an inner diameter and length of the hollow tubes 52a and 52b and a volume of the discharge silencer 50 are in the following ranges: a) the inner diameter of the hollow tubes: 1.0 mm to 1.5 mm, b) the length of the hollow tubes: 70 mm to 120 mm, and c) the volume of the discharge silencer: 15 cc to 25 cc.

FIG. 5 is a graph illustrating experimental results obtained by measuring and comparing noise generated from the hermetic compressor in accordance with the present invention, wherein respective components are configured according to the above enumerated dimensions, and a conventional compressor under the same conditions.

As can be seen from the graph, compared to the conventional compressor, the hermetic compressor according to the present invention achieves a considerable reduction in noise generated in a low frequency band less than 1 KHz, which tends to resonate other components of refrigerators.

As apparent from the above description, in accordance with the hermetic compressor of the present invention, a pulsation damping flow path, which is provided in a discharge silencer and is adapted to communicate a discharge chamber defined in a cylinder head with the interior of the discharge silencer, is configured to have plural passages.

With such a configuration, by reducing a diameter of the respective passages down to a relatively small value compared to that of a conventional pulsation pipe, it is possible to considerably attenuate the pulsation of a refrigerant. Further, the plural passages are configured to enable a constant amount of the refrigerant to continuously pass therethrough, thereby being capable of preventing an increase in a starting voltage of the compressor and the consumption of electricity thereof.

Although the preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A hermetic compressor comprising:

a cylinder internally defining a compression chamber;

a cylinder head coupled to one side of the cylinder and internally defining a discharge chamber, the discharge chamber communicating with the compression chamber;

a discharge silencer coupled to the discharge chamber of the cylinder head and adapted to attenuate a pulsation of a refrigerant being discharged; and

a pulsation damping flow path provided inside the discharge silencer so that one end thereof communicates with the discharge chamber and the other end thereof communicates with the interior of the discharge silencer, the pulsation damping flow path having plural passages.

2. The compressor according to claim 1, wherein the pulsation damping flow path has a multiply twisted spiral shape.

3. The compressor according to claim 1, wherein both the ends of the pulsation damping flow path take the form of a single passage, respectively.

4. The compressor according to claim 1, wherein the pulsation damping flow path includes a plurality of hollow tubes coupled to each other.

5. The compressor according to claim 1, wherein the pulsation damping flow path includes a single tube, the interior of the single tube being divided to define a plurality of passages.

6. The compressor according to claim 1, wherein the respective passages have substantially the same sectional area as each other.

7. The compressor according to claim 6, wherein the respective passages have an inner diameter of 1.0 mm to 1.5 mm, a length of 70 mm to 120 mm, and the discharge silencer has a volume of 15 cc to 25 cc.