JP2011528076A - Refrigeration compressor with internal cooling system - Google Patents

Abstract

  The present invention relates to a refrigeration compressor provided with an internal cooling system. The compressor includes a compressor frame (1), a compression cylinder (2, 3), a piston that reciprocates inside the cylinder, an oil accumulation region (5) in a lower portion of the compressor frame, and a generally vertical direction. And a piston drive means having an upper end attached to the piston drive cam (7) and disposed in the compressor frame (1). The compressor comprises means in the upper part of the frame (1) for collecting the oil entering from the shaft (4) and released by the cam (7). The accumulated oil is discharged above the compression cylinders (2, 3) to cool the compression cylinders (2, 3) and improve the efficiency of the compressor.

Description

  The present invention relates to a refrigeration compressor having a collecting means for collecting oil discharged by a drive shaft via a cam in an upper portion of a compressor frame in an airtight refrigeration compressor with reciprocating motion. The accumulated oil is used to cool certain parts of the compressor block, increasing the efficiency of the compressor. The oil is then returned to the bottom of the compressor.

  Attempts to improve the performance of refrigeration compressors are becoming more and more common, and its main purpose is to reduce energy consumption. It is known that the majority of compressor losses are due to gas overheating in the path from the compressor inlet to the compressor cylinder inlet. Another factor that reduces compressor performance is inefficient gas compression due to the high operating temperature of the cylinder.

  Accordingly, ideas and solutions have been developed that focus on reducing the temperature of the cylinder in order to improve the efficiency of the compressor. Different approaches for this purpose can be found in the patent documents previously disclosed.

  For example, Patent Document 1 employs the concept of isolating a cylinder heating source. According to this document, a separation duct is formed in the valve plate and is open to the inside of the discharge chamber to maintain the compressor cylinder cover spaced from the valve plate and to connect the annular plenum to the separation duct. Has formed around. Therefore, the heat transfer from the cylinder cover to the valve plate is reduced, and finally the heating of the cylinder in the compressor chamber region is reduced to improve the efficiency of the compressor.

Patent Document 2 proposes another solution for improving the efficiency of the compressor, and uses heat tubes to remove heat from high-temperature components that contact the cylinder. The document proposes a hermetic compressor with a heat dissipation system, in which a heat energy transfer duct is attached to the cylinder block, the duct having a heat absorption end on one side and a heat dissipation on the other. The end is disposed away from the cylinder block. This is to absorb the heat generated by the compression of the cooling fluid in the cylinder and to dissipate that heat away from the cylinder, thus reducing the temperature of the cylinder and the efficiency of the compressor Has improved.
Another possible alternative to reduce the temperature of the cylinder is to make maximum use of the compressor lubricant as a cooling means. Currently, the main function of the oil is to lubricate the compressor mechanism to ensure the reliability and durability of the parts.

  Patent Document 3 is cited based on the use of oil for cooling the cylinder. In the same document, the inventors have proposed the use of a shaft outlet extension and a cylinder head deflector, which cools the cylinder by directing oil flow from the shaft outlet extension to the cylinder head. For the purpose of. The cylinder extension has an orifice through which oil is slung horizontally toward the deflector of the cylinder head, while the extension rotates. The deflector includes an orifice at a height substantially equal to the height at which the oil is injected, and cools the cylinder by flowing the oil through the cylinder head. In addition, the present invention allows for weight loss to prevent boiling and loss of essential properties.

  The inventors present as an object of the invention to reduce the temperature of the cylinder and to provide a more reliable compressor. Because a better cooled cylinder reduces the risk of oil overheating seen in the inner region of this component, and therefore can cause residual oil carbonization problems that can cause residue to damage the compressor. Because it prevents.

International Publication No. 2007/068072 International Publication No. 2007/014443 U.S. Pat. No. 4,569,639

It is an object of the present invention to improve the efficiency of an airtight refrigeration compressor, maximize the flow of oil around the compressor cylinder, and at the same time reduce the operating temperature of the cylinder.
Another object of the present invention is to reduce the overheating of the compressed gas and contribute to further improving the efficiency of the compressor.

  The object of the invention is achieved by a refrigeration compressor with an internal cooling system. The compressor includes a compressor frame, which includes a compression cylinder having a cylinder body and a cylinder head, a piston that reciprocates within the cylinder, an oil accumulation region in a lower portion of the compressor frame, The piston driving means for reciprocating the piston and the pumping means for pumping oil from the oil accumulation area to the piston driving means are arranged. The compressor frame includes an oil sump disposed in an upper portion inside the compressor frame, and the oil sump includes an oil discharge portion directed to the cylinder surface.

Preferably, the oil reservoir extends around the entire inner periphery of the frame body, and the oil discharge portion allows oil to spill out from the oil reservoir to the cylinder body.
The compressor frame may have a cover, and the oil sump is formed in the area of the cover and can be formed integrally with the cover, or formed integrally with the compressor frame, or It can be formed as an additional part connected to a part of the compressor frame. The oil sump can be formed by stamping in a part of the manufacturing process of the compressor frame.

  The piston drive means comprises a rotary shaft oriented generally vertically, the rotary shaft having an upper end attached to the piston drive cam and discharging pumped oil above the piston drive means. The oil sump preferably comprises an oil collecting area in which at least a part of the oil discharged by the piston drive means is collected, this oil collecting area being able to flow out so that the collected oil is discharged from the oil sump Have a good geometric shape.

It is sectional drawing of the refrigeration compressor of the prior art which is not equipped with the internal cooling system which concerns on this invention. 1 is a cross-sectional view of a refrigeration compressor according to the present invention with an internal cooling system.

Further details of the invention will now be described on the basis of examples of embodiments shown in the drawings.
FIG. 1 shows a prior art compressor for purposes of comparison only with the present invention. This compressor, which is of the hermetic refrigeration compressor type with reciprocating motion, does not include the internal cooling system according to the present invention. This compressor is arranged inside the frame 1. The compressor includes a cylinder having a cylinder body 3 and a cylinder head 2 and a piston that reciprocates inside the cylinder. In the lower part of the compressor frame, an oil accumulation region 5 is formed in the form of an oil well. The oil accumulated in this oil accumulation region has the purpose of originally improving the durability of the compressor by lubricating the compressor parts to reduce wear between the parts.

  The prior art refrigeration compressor is provided with piston driving means, which drives the reciprocating motion of the piston inside the cylinder and compresses the compressed fluid. The drive means usually comprises a rotor and a stator, which rotate the rotating shaft 4. The rotating shaft is oriented substantially vertically with respect to the compressor frame. The lower end 13 of the rotating shaft is immersed in the oil well, and the upper end opposite the rotating shaft is attached to the cam 7 that drives the piston motion. Are arranged to be.

  Therefore, when the compressor is operated, the rotary shaft 4 rotates inside the compressor, and the oil pump pumps up the oil accumulated in the oil accumulation region 5 upward toward the piston drive means, particularly around the rotary shaft 4. . As a result, also by the rotating cam 7, a part of the oil 14 is finally injected into the upper part of the rotating shaft (slung to the upper part of the shaft). As shown by the arrows in FIG. 1, the oil in this portion is formed above the upper surface of the compressor frame 1 or the inner surface of the compressor cover 6, and the side facing the inner wall surface of the upper region of the compressor frame. Is directed to. Another part of the oil released above the cam around the area formed between the compressor block and the upper surface of the frame again descends and flows as a whole over the compressor block.

  Therefore, most of the oil 14 injected toward the upper surface of the compressor frame 1 finally flows toward the upper surface or the end of the cover 6 and then flows downward on the side wall surface of the frame. Falls again to the oil accumulation region 5 where heat exchange with the compressor frame 1 takes place. The oil discharged centrally above the cylinder is optimized to specifically cool this part of the compressor.

  However, experimental analysis has shown that there is a significant temperature difference between the oil present in the oil accumulation area 5 at the bottom of the compressor (also referred to as carter) and the compression cylinder, which is more pronounced than the compression cylinder. Suggests that it is cold. Therefore, if it is possible to maximize the flow of oil around the cylinder and recover heat from the cylinder surface, there is room for reducing the temperature of the cylinder. A better cooled cylinder improves the efficiency of the compression process and reduces gas overheating during inhalation. This directly reflects the improvement in compressor efficiency. In view of this, the present invention proposes to maximize the oil flow in the cylinder in order to cool the cylinder.

  FIG. 2 shows a compressor according to the invention with an internal cooling system. This compressor comprises the same parts as described for the prior art compressor. That is, a compressor is disposed inside the frame 1, the cylinder has a cylinder body 3 and a cylinder head 2, and the piston 12 reciprocates inside the cylinder. An oil accumulation region 5 is formed in the lower part of the compressor frame 1.

  The refrigeration compressor according to the present invention includes piston drive means, which reciprocates the piston inside the cylinder and drives the rotary shaft 4 that is oriented substantially vertically with respect to the compressor frame. For example, a motor and a stator are provided. The lower end 13 of the shaft is immersed in the oil well, while the opposite upper end is attached to a cam 7 that moves the piston. The compressor includes a pump system that pumps oil accumulated in the oil accumulation region 5 upward toward the piston driving means, particularly around the rotating shaft 4. When the compressor is operated, as shown by arrows in FIG. 2, the upper surface inside the compressor frame 1 or the upper side facing the compressor cover 6 and the side facing the inner wall surface of the upper region of the compressor frame Some oil is released towards Another part of the oil released by the cam around the area formed between the compressor block and the upper surface of the frame again falls down and flows as a whole over the compressor block.

  Further, the compressor shown in FIG. 2 includes an oil sump 8 disposed in an upper portion inside the compressor frame. The oil sump 8 includes an oil collecting area 11 and an oil discharge part 9, and the oil discharge part 9 is directed so that oil spills out on the cylinder surface. Therefore, the oil accumulated in the oil sump 8 having a temperature significantly lower than the temperature of the cylinder is discharged so as to flow on the cylinder surface, preferably the surface of the cylinder body 3, so as to cool the cylinder. After this spill, the oil returns again to the oil accumulation area 5 located in the lower part of the compressor frame, where oil exchanges heat with the compressor frame 1.

  Thus, the oil flowing through the cylinder has increased remarkably, and the cooling capacity of the cylinder is maximized by the amount of lubricating oil normally flowing directly into the oil accumulation region 5 located at the bottom of the frame in the prior art. It has become.

  The oil sump preferably extends around the entire inner circumference of the compressor frame, for example, an edge 10 extending from the inner wall of the compressor frame toward the center and extending vertically upward from the inner end. It can be formed as a circumferential wing. An area formed on the circumferential wing and defined by the edge 10 forms an oil collecting area 11. Therefore, the oil 14 discharged from the cam 7 to the upper surface of the compressor frame 1 is accumulated in the oil collecting region 11 by dropping or flowing down the oil reservoir 8 and leaks from the oil reservoir 8 by the vertical edge 10. It is supposed not to. Part of the oil 14 discharged by the cam around the area formed between the compressor block and the upper surface of the frame can also be collected by the oil sump 8.

  As shown in FIG. 2, at the position above the compression cylinder, the oil discharge portion 9 is constructed, for example, in a wing shape inclined downward from the end of the oil sump 8. The oil is directed to spill out on the cylinder surface, and is preferably directed to spill out on the surface of the cylinder body. Alternatively, the discharge part may be constructed in the form of a hole formed in the surface or edge of the oil sump 8, or any oil capable of discharging the oil accumulated in the oil sump 8 to the cylinder surface of the compressor. It may be constructed in the form of The oil collecting area 11 is preferably shaped in a geometrical shape that allows the collected oil to flow out or easily drains 9 out of the sump, for example with a horizontal circumferential wing, This circumferential wing may be inclined slightly downward toward the discharge region 9.

In an embodiment of the present invention, the compressor frame is preferably provided with a cover on its upper part as shown in FIG. Accordingly, the oil sump 8 can be formed directly in the area of the cover 6, can be attached to the cover 6 in the form of an additional part, or a single part integrally connected with the cover 6. It may be formed in the form of
Alternatively, the oil sump 8 can be formed as an additional part directly attached to the upper region of the compressor frame 1, or fixed to any other part of the frame, for example, the frame It may be fixed to the side wall. In another embodiment of the present invention, the oil sump 8 is formed integrally with the compressor frame.
When the oil sump 8 is constructed integrally connected to an arbitrary part of the compressor frame 1, when it is constructed integrally connected to the cover 6 or another part of the frame body, its manufacture Sometimes this sump can be formed by adding additional steps in the stamping process of these parts.

  Furthermore, in another alternative embodiment of the invention not shown, the compressor may comprise an oil cooling device located in the upper sump 8. The oil cooling device can cool the oil accumulated in the oil sump before the oil falls to the cylinder, and promotes the reduction of the cylinder temperature. This cooling device may take the form of a heat exchanger, heat pipe or other cooling means for cooling the oil.

  While examples of preferred embodiments have been described, the scope of the invention encompasses other potential variations and is limited only by the claims appended hereto and other equivalents that may be employed. It should be understood that objects are also within the scope of the present invention.

Claims (12)

A refrigeration compressor having an internal cooling system, comprising a compressor frame,
A compression cylinder having a cylinder body (3) and a cylinder head (2);
A piston (12) reciprocating within the cylinder;
An oil accumulation region (5) in a lower portion of the compressor frame;
Piston driving means for reciprocating the piston inside the cylinder;
In the refrigeration compressor comprising an oil pumping means for pumping oil from the oil accumulation area (5) to above the piston driving means, inside the compressor frame,
The compressor frame (1) includes an oil sump (8) disposed in an upper part of the compressor frame (1), and the oil sump includes an oil discharge part (9) directed to the surface of the cylinder. And a refrigeration compressor.   The refrigeration compressor with an internal cooling system according to claim 1, characterized in that the oil sump (8) extends around the entire inner circumference of the compressor frame (1).   The refrigeration with an internal cooling system according to claim 1 or 2, characterized in that the oil discharge part (9) of the oil sump is directed to spill oil into the cylinder body (2). compressor.   Internal cooling according to any of the preceding claims, characterized in that the compressor frame (1) comprises a cover (6) and the oil sump (8) is formed in the area of the cover. Refrigeration compressor with system.   The refrigeration compressor with an internal cooling system according to claim 4, characterized in that the oil reservoir is formed integrally with the cover (6).   The refrigeration compressor provided with the internal cooling system according to any one of claims 1 to 4, wherein the oil sump (8) is formed integrally with the compressor frame (1).   The refrigeration with an internal cooling system according to any one of claims 1 to 6, wherein the oil sump is formed by stamping when producing a part of the compressor frame (1). compressor.   The refrigeration compressor provided with the internal cooling system according to any one of claims 1 to 6, wherein the oil sump is constructed as an additional part connected to a part of the compressor frame.   The piston drive means comprises a rotary shaft (4) oriented generally vertically, the rotary shaft (4) having an upper end attached to a piston drive cam (7), and the pumped oil is pumped Refrigerating compressor with an internal cooling system according to any one of claims 1 to 8, characterized in that it is discharged to the piston drive means through a drive cam (7).   10. The oil collecting area (11) according to claim 1, characterized in that at least part of the oil discharged by the piston drive means is collected in the oil collecting area (11). A refrigeration compressor comprising the internal cooling system according to any one of the above.   11. The interior according to claim 10, characterized in that the oil collecting area (11) has a geometric shape that allows the collected oil to flow out so that it is discharged (9) from the oil sump (8). A refrigeration compressor with a cooling system.   The refrigerating compressor provided with the internal cooling system according to any one of claims 1 to 11, further comprising an oil cooling device arranged in the oil sump (8).

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