An oil separation and return structure for a low back pressure rotary compressor

Abstract

The application provides an oil separation and return structure for a low-back-pressure rotary compressor, comprising an oil-gas separator and an oil return channel; the oil-gas separator comprises a cavity, and an oil-gas separation unit for separating refrigerant and lubricating oil is arranged in the cavity; the oil-gas separator is provided with an air inlet, an oil outlet and a second exhaust port; in the axial direction of the low-back-pressure rotary compressor, the height of the second exhaust port is higher than the height of the air inlet and the oil outlet; the air inlet is communicated with the first exhaust port; one end of the oil return channel is communicated with the oil outlet, and the other end is communicated with the inside of the cylinder; the second exhaust port is communicated with a refrigerant circulation pipeline. The mixture of refrigerant and lubricating oil is separated by the oil-gas separator, the separated lubricating oil enters the inside of the cylinder from the oil outlet and the upper cylinder cover, thereby lubricating the piston, the eccentric part of the crankshaft, the inner wall of the cylinder and the inner wall of the upper cylinder cover, and the oil storage capacity, performance and reliability of the low-back-pressure rotary compressor are improved.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and in particular to an oil separator and oil return structure for a low back pressure rotary compressor. Background Technology

[0002] Rotary compressors include low-back-pressure rotary compressors and high-back-pressure compressors. Low-back-pressure rotary compressors have lower internal pressure, which is the suction pressure; high-back-pressure compressors have higher internal pressure. Because of the lower internal pressure, low-back-pressure rotary compressors have lower requirements for the pressure resistance of the casing; the lower ambient temperature of the casing also reduces the requirements for the high-temperature resistance of the motor.

[0003] The lubrication of the sliding parts of the low back pressure rotary compressor is mainly achieved in the following way: a lubricating oil sump is provided at the bottom of the compressor, and the bottom of the crankshaft extends into the lubricating oil sump. When the compressor is running, the lubricating oil is pumped into the through hole in the middle of the crankshaft by centrifugal pumping. Then, the lubricating oil is delivered to the sliding parts such as the upper cylinder head, lower cylinder head, piston, and blades through the radial oil holes on the crankshaft connected to the through hole.

[0004] However, the lubricating oil is delivered from the radial oil holes of the crankshaft to the sliding parts of the pump body. After lubricating the sliding parts, some of the lubricating oil dissolves in the refrigerant and is discharged through the compressor exhaust port, which causes the lubricating oil in the compressor to gradually decrease, affecting the performance and reliability of the compressor. Summary of the Invention

[0005] This invention provides an oil separator and oil return structure for a low back pressure rotary compressor to solve the technical problem that the lubricating oil inside the compressor is discharged from the casing to the outside, causing the lubricating oil inside the compressor to gradually decrease.

[0006] To solve the above-mentioned technical problems, the present invention provides an oil separator and oil return structure for a low back pressure rotary compressor. The low back pressure rotary compressor includes a housing, an upper cylinder head, and a cylinder. The housing is provided with a first exhaust port. The upper cylinder head is provided with an oil return channel. The oil separator and oil return structure includes an oil-gas separator and the oil return channel.

[0007] The oil-gas separator includes a chamber, in which an oil-gas separation unit for separating refrigerant and lubricating oil is provided;

[0008] The oil-gas separator is provided with an air inlet, an oil outlet, and a second exhaust outlet; in the axial direction of the low back pressure rotor compressor, the height of the second exhaust outlet is higher than the height of the air inlet and the oil outlet.

[0009] The air inlet is connected to the first exhaust port; one end of the oil return channel is connected to the oil outlet, and the other end is connected to the inside of the cylinder; the second exhaust port is connected to the refrigerant circulation pipeline of the low back pressure rotor compressor.

[0010] Optionally, the oil-gas separator is disposed outside the housing.

[0011] Optionally, both the air inlet and the oil outlet are located at the bottom of the oil-gas separator, and the second exhaust outlet is located at the top of the oil-gas separator.

[0012] Optionally, the oil return channel includes a first section, a second section, a third section, and a fourth section connected in sequence; the first section, the second section, and the third section are arranged radially along the upper cylinder head, and the first section, the second section, and the third section are all cylindrical in shape; one end of the first section is connected to the oil outlet; and the fourth section is connected to the interior of the cylinder.

[0013] Optionally, the fourth segment is an annular groove, and the opening of the annular groove communicates with the interior of the cylinder.

[0014] Optionally, the fourth segment is a spiral groove, and the opening of the spiral groove communicates with the interior of the cylinder.

[0015] Optionally, the diameters of the first segment, the second segment, and the third segment gradually decrease.

[0016] Optionally, the third segment is a capillary.

[0017] Optionally, the oil-gas separation unit includes a capillary tube, which includes a first interface, a second interface, and a third interface. The first interface is connected to the air inlet, the second interface is connected to the oil outlet, and the third interface is connected to the second exhaust outlet.

[0018] The present invention also provides another oil separator return structure for a low back pressure rotary compressor, the low back pressure rotary compressor comprising a housing, an upper cylinder head, a cover plate, a cylinder, and a lower cylinder head, wherein the housing is provided with a first exhaust port; the upper cylinder head, the cover plate, the cylinder, and the lower cylinder head are provided with sequentially connected oil return holes; the upper cylinder head is provided with an oil return channel; and the cover plate is provided with a spiral groove.

[0019] The oil return structure includes an oil-gas separator, the return oil channel, the spiral groove, and the return oil hole;

[0020] The oil-gas separator includes a chamber, in which an oil-gas separation unit for separating refrigerant and lubricating oil is provided;

[0021] The oil-gas separator is provided with an air inlet, an oil outlet, and a second exhaust outlet; in the axial direction of the low back pressure rotor compressor, the height of the second exhaust outlet is higher than the height of the air inlet and the oil outlet.

[0022] The air inlet is connected to the first exhaust port; one end of the oil return channel is connected to the oil outlet, and the other end is connected to the spiral groove; the end of the spiral groove is connected to the oil return hole; the second exhaust port is connected to the refrigerant circulation pipeline of the low back pressure rotor compressor.

[0023] This invention provides an oil separator and return structure for a low-back-pressure rotary compressor. The oil separator separates the refrigerant and lubricating oil mixture discharged from the compressor. The separated lubricating oil enters the cylinder through the oil outlet and return channel, lubricating the piston, the eccentric portion of the crankshaft, the inner wall of the cylinder, and the inner wall of the upper cylinder head. Alternatively, the separated lubricating oil flows back to the lubricating oil sump through the oil outlet, return channel, spiral groove, and return hole, improving the oil storage capacity, performance, and reliability of the low-back-pressure rotary compressor. The refrigerant separated by the oil separator is circulated through the compressor's refrigerant circulation pipeline, preventing the refrigerant from being mixed with lubricating oil and thus reducing the compressor's performance. The oil separator and return structure is compact and easy to install. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an oil separator and oil return structure for a low back pressure rotary compressor provided in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of an upper cylinder head provided in an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of another oil separator return structure for a low back pressure rotary compressor provided in an embodiment of the present invention.

[0027] Figure 4 yes Figure 3 A schematic diagram of the cover plate in the middle.

[0028] Figure 5 This is a schematic diagram of another oil separator return structure for a low back pressure rotary compressor provided in an embodiment of the present invention.

[0029] [The annotations in the attached figures are explained below]:

[0030] Oil-gas separator-1, upper cylinder head-2, housing-3, cylinder-4, lower cylinder head-5, oil return hole-6, cover plate-7;

[0031] Air inlet-11, oil outlet-12, second exhaust outlet-13;

[0032] Return oil channel -21; First section -211, Second section -212, Third section -213, Fourth section -214;

[0033] Spiral groove-71, end of spiral groove-711. Detailed Implementation

[0034] To make the objectives, advantages, and features of the present invention clearer, the following detailed description of an oil separator and oil return structure for a low back-pressure rotary compressor, proposed by the present invention, is provided in conjunction with the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0035] In the description of this invention, the terms "first," "second," and other qualifiers are added for convenience of description and reference, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with qualifiers such as "first" and "second" may explicitly or implicitly include one or more of that feature.

[0036] like Figure 1 and Figure 2 As shown, this embodiment provides an oil separator and oil return structure for a low back-pressure rotary compressor. The low back-pressure rotary compressor includes a housing 3, an upper cylinder head 2, and a cylinder. The housing 3 is provided with a first exhaust port. The upper cylinder head 2 is provided with an oil return channel 21. The oil separator and oil return structure includes an oil-gas separator 1 and the oil return channel 21. The oil-gas separator 1 includes a chamber, and the chamber is provided with an oil-gas separation unit for separating refrigerant and lubricating oil. The oil-gas separator 1 is provided with an air inlet 11, an oil outlet 12, and a second exhaust port 13. In the axial direction of the low back-pressure rotary compressor, the height of the second exhaust port 13 is higher than the height of the air inlet 11 and the oil outlet 12. The air inlet 11 is connected to the first exhaust port. One end of the oil return channel 21 is connected to the oil outlet 12, and the other end is connected to the interior of the cylinder. The second exhaust port 13 is connected to the refrigerant circulation pipeline of the low back-pressure rotary compressor. Figure 1 The arrows inside the air inlet 11, oil outlet 12, and oil return channel 21 indicate the direction of lubricating oil return.

[0037] This embodiment provides an oil separator and return structure for a low-back-pressure rotary compressor. The oil-gas separator 1 separates the refrigerant and lubricating oil mixture discharged from the compressor. The separated lubricating oil enters the cylinder through the oil outlet 12 and the return channel 21, lubricating the piston, the eccentric portion of the crankshaft, the inner wall of the cylinder, and the inner wall of the upper cylinder head 2, thereby improving the oil capacity, performance, and reliability of the low-back-pressure rotary compressor. The refrigerant separated by the oil-gas separator 1 is circulated through the compressor's refrigerant circulation pipeline, preventing the refrigerant from being mixed with lubricating oil and thus reducing the compressor's performance. The oil separator and return structure is compact and easy to install.

[0038] Optional, such as Figure 1 As shown, the oil-gas separator 1 is disposed outside the housing 3. This facilitates the installation and maintenance of the oil-gas separator 1.

[0039] Optional, such as Figure 1 As shown, the air inlet 11 and the oil outlet 12 are both located at the bottom of the oil-gas separator 1, and the second exhaust outlet 13 is located at the top of the oil-gas separator 1. This allows for thorough separation of the refrigerant and lubricating oil, with the denser lubricating oil flowing out from the oil outlet 12 and the less dense refrigerant being discharged from the second exhaust outlet 13.

[0040] Optional, such as Figure 2 As shown, the oil return channel 21 includes a first section 211, a second section 212, a third section 213, and a fourth section 214 connected in sequence. The first section 211, the second section 212, and the third section 213 are arranged radially along the upper cylinder head 2, and each of the first section 211, the second section 212, and the third section 213 is cylindrical. One end of the first section 211 is connected to the oil outlet 12; the fourth section 214 is connected to the interior of the cylinder. This facilitates the machining of the oil return channel 21.

[0041] Optional, such as Figure 2 As shown, the fourth segment 214 is an annular groove, and the opening of the annular groove communicates with the interior of the cylinder. This increases the direct contact area between the returning lubricating oil and the eccentric part of the piston and crankshaft, improving the lubrication effect. Existing upper cylinder heads 2, in order to reduce material usage and increase lubrication, sometimes have an annular groove. This groove can serve as the fourth segment 214, eliminating the need for reprocessing the fourth segment 214. The opening of the groove can be circular or elliptical.

[0042] Optional, see reference Figure 2As shown, the fourth segment 214 is a spiral groove, and the opening of the spiral groove communicates with the interior of the cylinder. The spiral shape of the fourth segment 214 can further increase the direct contact area between the returning lubricating oil and the eccentric part of the piston and crankshaft, thereby improving the lubrication effect.

[0043] Optional, such as Figure 2 As shown, the diameters of the first segment 211, the second segment 212, and the third segment 213 gradually decrease. This allows the first segment 211, the second segment 212, and the third segment 213 to have a pressure-reducing effect, further separating the lubricating oil and the refrigerant.

[0044] Optional, such as Figure 2 As shown, the third segment 213 is a capillary tube. This can improve the pressure reduction effect of the third segment 213, allowing for further separation of the lubricating oil and refrigerant.

[0045] Optional, see reference Figure 1 As shown, the oil-gas separation unit includes a capillary tube with a first interface, a second interface, and a third interface. The first interface is connected to the air inlet 11, the second interface is connected to the oil outlet 12, and the third interface is connected to the second exhaust outlet 13. When the mixture of lubricating oil and refrigerant flows in the capillary tube, the pressure of the mixture decreases, and the mixture of lubricating oil and refrigerant can be separated. In other embodiments, the oil-gas separation unit may include components such as baffles or filter elements for oil filtration.

[0046] like Figure 1 , Figure 3 and Figure 4As shown, based on the same technical concept as the oil separator and oil return structure for a low back pressure rotary compressor described above, this embodiment provides another oil separator and oil return structure for a low back pressure rotary compressor. The low back pressure rotary compressor includes a housing 3, an upper cylinder head 2, a cover plate 7, a cylinder 4, and a lower cylinder head 5. The housing 3 is provided with a first exhaust port. The upper cylinder head 2, the cover plate 7, the cylinder 4, and the lower cylinder head 5 are provided with sequentially connected oil return holes 6. The upper cylinder head 2 is provided with an oil return channel 21. The cover plate 7 is provided with a spiral groove 71. The oil separator and oil return structure includes an oil-gas separator 1, the oil return channel 21, the spiral groove 71, and the oil return holes 6. The separator 1 includes a chamber in which an oil-gas separation unit for separating refrigerant and lubricating oil is provided. The oil-gas separator 1 is provided with an inlet 11, an oil outlet 12, and a second exhaust port 13. In the axial direction of the low back pressure rotor compressor, the height of the second exhaust port 13 is higher than the height of the inlet 11 and the oil outlet 12. The inlet 11 is connected to the first exhaust port. One end of the oil return channel 21 is connected to the oil outlet 12, and the other end is connected to the spiral groove 71. The end 711 of the spiral groove 71 is connected to the oil return hole 6. The second exhaust port 13 is connected to the refrigerant circulation pipeline of the low back pressure rotor compressor.

[0047] This embodiment provides an oil separator and return structure for a low-back-pressure rotary compressor. The oil-gas separator 1 separates the refrigerant and lubricating oil mixture discharged from the compressor. The separated lubricating oil flows back to the lubricating oil sump through the oil outlet 12, the return channel 21, the spiral groove 71, and the return hole 6, improving the oil storage capacity, performance, and reliability of the low-back-pressure rotary compressor. The returned lubricating oil can be further depressurized in the spiral groove 71 to prevent excessive pressure in the oil sump. The refrigerant separated by the oil-gas separator 1 is circulated through the refrigerant circulation pipeline of the low-back-pressure rotary compressor, preventing the refrigerant from being mixed with lubricating oil and thus reducing the compressor's performance. The oil separator and return structure is compact and easy to install.

[0048] Optional, such as Figure 3 and Figure 5 As shown, the low back pressure rotary compressor is a single-cylinder compressor, a double-cylinder compressor, or a multi-cylinder compressor. The oil separator return structure is applicable not only to single-cylinder compressors but also to double-cylinder or multi-cylinder compressors.

[0049] In summary, the oil separator and return structure for a low-back-pressure rotary compressor provided by this invention separates the refrigerant and lubricating oil mixture discharged from the low-back-pressure rotary compressor through the oil-gas separator 1. The separated lubricating oil enters the interior of the cylinder through the oil outlet 12 and the oil return channel 21, thereby lubricating the piston, the eccentric part of the crankshaft, the inner wall of the cylinder, and the inner wall of the upper cylinder head 2. Alternatively, the separated lubricating oil flows back to the lubricating oil sump through the oil outlet 12, the oil return channel 21, the spiral groove 71, and the oil return hole 6, improving the oil storage capacity, performance, and reliability of the low-back-pressure rotary compressor. The refrigerant separated by the oil-gas separator 1 is circulated through the refrigerant circulation pipeline of the low-back-pressure rotary compressor, preventing the refrigerant from being mixed with lubricating oil and reducing the performance of the low-back-pressure rotary compressor. The oil separator and return structure is compact and easy to install.

[0050] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the present invention.

Claims

1. An oil separator return structure for a low back-pressure rotary compressor, characterized in that, The low back pressure rotary compressor includes a housing, an upper cylinder head, and a cylinder. The housing is provided with a first exhaust port. The upper cylinder head is provided with an oil return channel. The oil return structure includes an oil-gas separator and the oil return channel. The oil-gas separator includes a chamber, in which an oil-gas separation unit for separating refrigerant and lubricating oil is provided; The oil-gas separator is provided with an air inlet, an oil outlet, and a second exhaust outlet; in the axial direction of the low back pressure rotor compressor, the height of the second exhaust outlet is higher than the height of the air inlet and the oil outlet. The air inlet is connected to the first exhaust port; one end of the oil return channel is connected to the oil outlet, and the other end is connected to the inside of the cylinder; the second exhaust port is connected to the refrigerant circulation pipeline of the low back pressure rotary compressor. The oil return channel includes a first section, a second section, a third section, and a fourth section connected in sequence; the first section, the second section, and the third section are arranged radially along the upper cylinder head, and the first section, the second section, and the third section are all cylindrical in shape; one end of the first section is connected to the oil outlet; the fourth section is connected to the interior of the cylinder. The diameters of the first segment, the second segment, and the third segment gradually decrease; The fourth segment is a spiral groove, and the opening of the spiral groove is connected to the interior of the cylinder.

2. The oil separator and oil return structure for a low back-pressure rotary compressor as described in claim 1, characterized in that, The oil-gas separator is located outside the housing.

3. The oil separator and oil return structure for a low back-pressure rotary compressor as described in claim 1, characterized in that, The air inlet and the oil outlet are both located at the bottom of the oil-gas separator, and the second exhaust outlet is located at the top of the oil-gas separator.

4. The oil separator and oil return structure for a low back-pressure rotary compressor as described in claim 1, characterized in that, The third segment is a capillary.

5. The oil separator and oil return structure for a low back-pressure rotary compressor as described in claim 1, characterized in that, The oil-gas separation unit includes a capillary tube, which includes a first interface, a second interface, and a third interface. The first interface is connected to the air inlet, the second interface is connected to the oil outlet, and the third interface is connected to the second exhaust outlet.

6. An oil separator return structure for a low back-pressure rotary compressor, characterized in that, The low back pressure rotary compressor includes a housing, an upper cylinder head, a cover plate, a cylinder, and a lower cylinder head. The housing is provided with a first exhaust port. The upper cylinder head, the cover plate, the cylinder, and the lower cylinder head are provided with sequentially connected oil return holes. The upper cylinder head is provided with an oil return channel. The cover plate is provided with a spiral groove. The oil return structure includes an oil-gas separator, the return oil channel, the spiral groove, and the return oil hole; The oil-gas separator includes a chamber, in which an oil-gas separation unit for separating refrigerant and lubricating oil is provided; The oil-gas separator is provided with an air inlet, an oil outlet, and a second exhaust outlet; in the axial direction of the low back pressure rotor compressor, the height of the second exhaust outlet is higher than the height of the air inlet and the oil outlet. The air inlet is connected to the first exhaust port; one end of the oil return channel is connected to the oil outlet, and the other end is connected to the spiral groove; the end of the spiral groove is connected to the oil return hole; the second exhaust port is connected to the refrigerant circulation pipeline of the low back pressure rotor compressor. The oil return channel includes a first section, a second section, and a third section connected in sequence; The first segment, the second segment, and the third segment are arranged radially along the upper cylinder head, and the first segment, the second segment, and the third segment are all cylindrical in shape; one end of the first segment is connected to the oil outlet. The diameters of the first segment, the second segment, and the third segment gradually decrease.

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