WO2008032507A1

WO2008032507A1 - Compressor

Info

Publication number: WO2008032507A1
Application number: PCT/JP2007/065327
Authority: WO
Inventors: Tsuyoshi Matsumoto
Original assignee: Panasonic Corporation
Priority date: 2006-09-13
Filing date: 2007-07-31
Publication date: 2008-03-20
Also published as: JP4577364B2; CN101341337A; JP2008542598A; CN101341337B

Abstract

A compressor includes a compressor element having a compression chamber for compressing a refrigerant therein and an entrance port, a hermetic case having a space for accommodating the compressor element therein, and a suction muffler having a silencer space. The suction muffler includes a connection tube, a first suction inlet port, and a second suction inlet port. The connection tube has a first open end communicating with the entrance port of the compressor element and a second open end communicating with the silencer space. The first suction inlet port has a first opening communicating with the silencer space and a first suction opening communicating with the internal space of the hermetic case. The second suction inlet port has a second opening communicating with the silencer space and a second suction opening communicating with the internal space of the hermetic case. The second suction opening is located under the first suction opening and has an opening cross-sectional area smaller than that of the first suction opening. The compressor has high reliability and high efficiency.

Description

DESCRIPTION

COMPRESSOR

TECHNICAL FIELD

The present invention relates to a compressor for use in refrigerating apparatuses, such as freezing refrigerators.

BACKGROUND ART A conventional compressor includes a suction muffler made of resin material for reducing the noise. An inlet of the suction muffler faces a suction conduit so as to drive the compressor efficiently.

Fig. 7 is a vertical cross sectional view of a conventional compressor 5001 disclosed in Patent Document 1. Figs. 8 and 9 are a plan cross sectional view and an enlarged cross sectional view of the compressor 5001, respectively.

A hermetic case 1 stores oil 2 therein. A suction conduit 3 opening in an inside of the hermetic case 1 is fixed to the hermetic case 1. A compressor element 5 driven with a motor 4 is accommodated in the hermetic case 1.

The compressor element 5 includes a piston 8 joined via a connecting rod 66 to a shaft 7, a cylinder 9 having the piston 8 reciprocate therein, a valve plate 11 provided at an open end of the cylinder 9 and including a suction valve 10 communicating with the cylinder 9, and a suction muffler 12.

The suction muffler 12 includes a silencer space 13, a connection tube 14 communicating with the suction valve 10, and a suction inlet port 15 opening in the hermetic case 1. The suction inlet port 15 is provided in a side surface of the suction muffler 12 facing the hermetic case 1. The suction conduit 3 faces the suction inlet port 15 closely, and opens to face the inlet port 15. An operation of the compressor 5001 will be described.

The motor 4 drives the shaft 7 to rotate, and the rotation is transmitted to the connecting rod 66, thereby allowing the piston 8 to reciprocate. This causes a refrigerant flown from an external refrigerating circuit to flow from the suction conduit 3 into the hermetic case 1 and then to flow via the suction inlet port 15 into the suction muffler 12.

The refrigerant then flows into the silencer space 13, and is conveyed through the connection tube 14 and the suction valve 10, and intermittently flows into the cylinder 9. The refrigerant flowing into the cylinder 9 is compressed with the piston 8, and discharged to the external refrigerating circuit.

Since the suction conduit 3 and the suction inlet port 15 face each other closely, the refrigerant is introduced into the suction muffler 12 while having its temperature remaining comparatively low. As the result, the amount (refrigerant circulating amount) of the sucked refrigerant per unit time of the refrigerant becomes large thus to increase the work per unit time, hence providing the compressor 5001 with high efficiency.

When the conventional compressor 5001 starts up, a pressure in the hermetic case 1 decreases, accordingly causes the refrigerant dissolved in the oil 2 to foam, thus producing bubbles. If the large amount of the refrigerant is dissolved in the oil 2, the bubbles may reach the suction inlet port 15 of the suction muffler 12. In this case, the suction muffler 12 sucks the oil 2 or the refrigerant dissolved in the oil 2 directly, and then, the compressor element 5 compresses the oil or the refrigerant. As the result, liquid compression in which liquid is compressed in the cylinder 9 occurs, and may cause the compressor element 5 to malfunction.

Patent Document l: Japanese Patent Publication No.7-62474

SUMMARY OF THE INVENTION

A compressor includes a compressor element having a compression chamber for compressing a refrigerant therein and an entrance port, a hermetic case having a space for accommodating the compressor element therein, and a suction muffler having a silencer space. The suction muffler includes a connection tube, a first suction inlet port, and a second suction inlet port. The connection tube has a first open end communicating with the entrance port of the compressor element and a second open end communicating with the silencer space. The first suction inlet port has a first opening communicating with the silencer space and a first suction opening communicating with the internal space of the hermetic case. The second suction inlet port has a second opening communicating with the silencer space and a second suction opening communicating with the internal space of the hermetic case. The second suction opening is located under the first suction opening and has an opening cross-sectional area smaller than that of the first suction opening.

The compressor has high reliability and high efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross sectional view of a compressor according to an exemplary embodiment of the present invention.

Fig. 2 is a vertical cross sectional view of the compressor according to the embodiment.

Fig. 3 is a plan cross sectional view of the compressor according to the embodiment.

Fig. 4 is a vertical cross sectional view of a suction muffler in of the compressor according to the embodiment.

Fig. 5 is a top view of the suction muffler according to the embodiment.

Fig. 6 is a cross sectional view of the suction muffler at line 6^*6 shown in Fig. 4

Fig. 7 is a vertical cross sectional view of a conventional compressor. Fig. 8 is a plan cross sectional view of the conventional compressor.

Fig. 9 is an enlarged cross sectional view of the conventional compressor.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENT Figs. 1 and 2 are vertical cross sectional views of a compressor 1001 according to Exemplary Embodiment 1 of the present invention. Fig. 3 is a plan cross sectional view of the compressor 1001.

A hermetic case 101 has an internal space 101A arranged to store oil 102. A suction conduit 103 opening in the internal space lOlAis fixed to the hermetic case 101. A compressor element 105 driven by a motor 104 is accommodated in the space lOlAof the hermetic case 101.

The compressor element 105 includes a cylinder 107 having a compression chamber 106 therein, a piston 108, a shaft 109, a connecting rod 110, a valve plate 111, and a suction muffler 112. The valve plate 111 is provided at an end 107A of the cylinder 107 and includes a suction valve 113 communicating with the cylinder 107. The suction valve 113 functions as an entrance port 113A for introducing a refrigerant into the compression chamber 106. The piston 108 is inserted in the cylinder 107 while being capable of reciprocating therein, and is joined with the connecting rod 110 to the shaft 109. A lower end 109A of the shaft 109 is arranged to be dipped in the oil 102. The shaft 109 has a helical groove 125 provided therein for delivering the oil 102 to movable components of the compressor element 105. The helical groove 125 functions as an oil delivering mechanism for delivering the oil 102 to the movable components of the compressor element 105.

The structure of the suction muffler 112 will be explained. Figs. 4 and 5 are a vertical cross sectional view and a top view of the suction muffler 112, respectively. Fig. 6 is a cross sectional view of the suction muffler 112 at line 6-6 shown in Fig. 4. The suction muffler 112 is made of resin, such as polybutylene terephthalate (PBT), and includes a silencer space 114, a connection tube 115, a first suction inlet port 116, and a second suction inlet port 117.

The connection , tube 115 has a first open end 115A thereof communicating with the suction valve 113 and has a second open end 118 thereof communicating with the silencer space 114.

The first suction inlet port 116 has a first opening 119 communicating with the suction muffler 112 and has a first suction opening 120 communicating with the silencer space 114, thus allowing the silencer space 114 to communicate with the internal space 101A of the hermetic case 101. The first suction inlet 116 extends upward to the upper part of the space lOlA of the hermetic case 101, and has the first suction opening 120 opening at the upper part of the space 101A.

The second suction inlet port 117 has a second opening 121 communicating with the silencer space 114 and has a second suction opening 122 communicating with the space 101A of the hermetic case 101, thus allowing the silencer space 114 to communicate with the space 101A. The second suction opening 122 opens in the space 101A at a position under the first suction opening 120, and closely faces the opening port 123 of the suction conduit 103.

The second suction opening 122 has an opening cross-sectional area smaller than that of the first suction opening 120. For example, the opening cross-sectional area of the first suction opening 120 is about 70mm². The second suction opening 122 has three apertures each having a diameter of about 2.5mm, thus having a total opening cross-sectional area of about 15mm². This structure allows the second suction opening 122 to have a sucking resistance larger than that of the first suction opening 120.

The second opening 121 of the second suction inlet port 117 located in the silencer space 114 does not face the second open end 118 of the connection tube 115 and is located at a position under the second open end 118. A partition wall 124 is provided between the second opening 121 of the second suction inlet port 117 and the second open end 118 of the connection tube 115.

An operation of the compressor 1001 will be described. Upon being energized, the motor 104 drives the shaft 109 to rotate.

The rotation of the shaft 109 is transferred via the connecting rod 110 to cause the piston 108 to reciprocate, thereby compressing the refrigerant flowing from an external refrigerating circuit.

The refrigerant flowing from the external refrigerating circuit is introduced via the suction conduit 103 into the space 101A of the hermetic case 101, then, flows through the first suction opening 120 and the second suction opening 122, and is sucked into the suction muffler 112. The refrigerant sucked into the suction muffler 112 is introduced into the silencer space 114, flows through the connection tube 115 and the suction valve 113, and is sucked into the cylinder 107. The refrigerant sucked into the cylinder 107 is compressed with the piston 108, and returns back to the refrigerating circuit.

While the compressor 1001 stops, the refrigerant partly dissolves in the oil 102 stored in the hermetic case 101 according to the lapse of time. Upon the compressor 1001 starting, the pressure in the space lOlAof the hermetic case 101 decreases. The refrigerant dissolving in the oil 102 accordingly foams, thus producing bubbles including the refrigerant and the oil, i.e., performing a foaming phenomena. In the case that, a large amount of the refrigerant dissolves in the oil 102, the bubbles is produced rapidly and fills the internal space 101A.

The first suction inlet port 116 extends to the upper part of the internal space 101A of the hermetic case 101 and has the first suction opening open there, hence preventing the bubbles including the refrigerant and the oil from reaching the first suction opening 120 even if the bubbles rises from the lower part of the space 101A.

The second suction opening 122 opens under the first suction opening 120, however, has the sucking resistance larger than that of the first suction opening 120, hence being prevented from sucking a liquid form of the refrigerant and the oil.

When the foaming phenomenon occurs, the bubbles arrives at the second suction opening 122 located under the first suction opening 120 earlier than at the first suction opening 120. During a period of time from the arriving of the bubbles at the second suction opening 122 to the arriving of the bubbles at the first suction opening 120, a large difference between the respective sucking resistances of the second suction opening 122 and the first suction opening 120 is produced due to the product of the opening cross-sectional area and the density of substance to be sucked at each opening. That is, the first suction opening 120 has the opening cross -sectional area larger than that of the second suction opening 122, and accordingly, has the sucking resistance smaller than that of the second suction opening 122. In addition, the substance to be sucked into the first suction opening 120 is a gaseous form of the refrigerant which reduces the sucking resistance of the opening 120, accordingly reducing the product. On the other hand, the second suction opening 122 has the opening cross -sectional area smaller than that of the first suction opening 120, and accordingly, has the sucking resistance larger than that of the opening 120. Further, the substance to be sucked into the second suction opening 122 is the oil and the liquid form of the refrigerant, which increases the sucking resistance of the opening 122, accordingly increasing the product.

As the result, the amount of the refrigerant which has a low density and which is sucked into the first suction opening 120 is much larger than the amount of the oil and the liquid form of the refrigerant sucked into the second suction opening 122.

When the compressor 1001 operates in an ordinary operation, the gaseous form of the refrigerant is sucked from the suction muffler 112 into the compression chamber 106 via the connection tube 115 and the suction valve 113. At this moment, the refrigerant may not be temporarily supplied into the suction muffler 112 from the first suction opening 120 or the second suction opening 122 of the suction muffler 112, accordingly reducing the pressure in the silencer space 114 and not supplying sufficient amount of the refrigerant. In this case, the refrigerant is supplied mainly through the first suction opening 120 having the larger opening cross— sectional area and the smaller sucking resistance. However, the first suction inlet 116 extends to the upper part i.e., has a long passage, accordingly having a sucking resistance larger than that of an inlet port having a shorter passage. Accordingly, the sufficient amount of the refrigerant is supplied into the suction muffler 112.

The refrigerant is supplied into the suction muffler 112 from the second suction opening 122, thereby supplying the sufficient amount of the refrigerant into the silencer space 114. This operation increases the amount of the refrigerant filling the compression chamber 106, thereby allowing the compressor 1001 to have a large work per unit time and high refrigerating performance and efficiency.

In order to decrease the sucking resistance, the first suction opening may have a large opening cross-sectional area. However, this increases the size of the suction muffler 112, and accordingly, requires increasing the size of the hermetic case 101. Even if the first suction opening 120 has a comparatively large sucking resistance, the second suction opening 122 provides a small sucking resistance, and easily reduces the size of the suction muffler 112.

When the foaming phenomenon occurs, small amounts of the oil and the liquid form of the refrigerant may be sucked into the second suction opening 122. The second opening 121 of the second suction inlet port 117 in the silence space 114 does not face the second open end 118 of the connection tube 115, and is located under the second open end 118. The partition wall 124 is provided between the second opening 121 and the second open end 118. This arrangement prevents the small amounts of the oil and the liquid form of the refrigerant sucked into the second suction opening 122 from flowing directly into the second open end 118 of the connection tube 115, and causes the oil and the liquid form of the refrigerant which have large specific gravities to accumulate on the bottom of the silencer space 114. Thus, the liquid form of the refrigerant is not sent to the compressor element 105, thus providing the compressor 1001 with high reliability.

The liquid form of the refrigerant sucked into the second suction opening 122 is mixed with the gaseous form of the refrigerant sucked into the first suction opening 120 in the silencer space 114. Then, the liquid form of the refrigerant is evaporated, and the oil change into mist oil. This operation further reduces the amount of the liquid form of the refrigerant sucked via the second open end 118 into the cylinder 107.

The second suction opening 122 closely faces the opening port 123 of the suction conduit 103 in the hermetic case 101. This arrangement prevents the hermetic case 101 from heat the refrigerant flowing from the refrigerating circuit during the ordinary operation, consequently allowing the refrigerant sucked into the second suction opening 122 to have a low temperature and a high density. Accordingly, the second suction opening 122 sucks a large amount of the refrigerant, providing the compressor 1001 with large work per unit time, high refrigerating performance, and high efficiency.

The opening cross-sectional area of the second suction opening 122 is smaller than that of the first suction opening 120. This arrangement prevents the liquid form of the refrigerant from being sucked into the second suction opening 122 even if the refrigerant flows from the refrigerating circuit. The second opening 121 of the second suction inlet port does not face the second open end 118 of the connection tube while the partition wall 124 is provide between the second opening 121 and the second open end 118. This arrangement reduces the amount of the oil and the liquid form of the refrigerant sucked directly into the cylinder 107 even if the liquid form of the refrigerant is sucked into the second suction opening 122. The partition wall 124 of the compressor 1001 according to this embodiment extends in the horizontal direction, however, may be extends in the vertical direction, providing the same effects.

In the compressor 1001 according to this embodiment, the motor 104 is located at the lower part while the compressor element 105 is located above the motor 104. Alternatively, the motor 104 may be located at the upper part while the compressor element 105 may be located under the motor 104, providing the same effects.

The present invention is not limited to the above embodiment.

INDUSTRIALAPPLICABILITY

A compressor according to the present invention has high reliability and high efficiency, and is useful to refrigerating systems with a large volume of refrigerant, such as a large scale freezing refrigerator for industrial use or an air conditioner.

Claims

1. A compressor comprising: a motor; a compressor element driven by the motor, the compressor element having a compression chamber and an entrance port, the compression chamber compressing a refrigerant therein, the entrance port being provided for introducing the refrigerant into the compression chamber," a hermetic case having an internal space therein for accommodating the compressor element, the hermetic case being arranged to store oil therein; and a suction muffler having a silencer space, wherein the suction muffler includes a connection tube having a first open end and a second open end, the first open end communicating with the entrance port of the compressor element, the second open end communicating with the silencer space, a first suction inlet port having a first opening and a first suction opening, the first opening communicating with the silencer space, the first suction opening communicating with the internal space of the hermetic case, and a second suction inlet port having a second opening and a second suction opening, the second opening communicating with the silencer space, the second suction opening communicating with the internal space of the hermetic case, and the second suction opening is located under the first suction opening and has an opening cross-sectional area smaller than an opening cross-sectional area of the first suction opening.

2. The compressor according to claim 1, wherein the hermetic case has an opening port for introducing the refrigerant from outside of the hermetic case to the internal space, and the second suction opening closely faces the opening port of the hermetic case.

3. The compressor according to claim 1, wherein the second opening of the second suction inlet port opens in the silencer space, and does not face the second open end of the connection tube.

4. The compressor according to claim 1, further comprising a partition wall provided between the second opening of the second suction inlet port and the second open end of the connection tube.

5. The compressor according to claim 1, wherein the second opening of the second suction inlet port is located under the second open end of the connection tube.

6. The compressor according to claim 1, wherein the compressor element includes a cylinder providing the compression chamber, a valve plate provided at an end of the cylinder, the valve plate having with the entrance port, and a suction valve provided at the entrance port, the connection tube of the suction muffler communicates with the entrance port of the compressor element.

7. The compressor according to claim 1, wherein the first suction inlet port extends upward to an upper part of the internal space of the hermetic case.