Oil separating and returning structure for low-backpressure rotor type compressor

Abstract

The invention provides an oil separation and oil return structure for a low-backpressure rotor type compressor. The oil separation and oil return structure comprises an oil-gas separator and an oil return channel, the oil-gas separator comprises a cavity, and an oil-gas separation unit used for separating a refrigerant from lubricating oil is arranged in the cavity. A gas inlet, an oil outlet and a second exhaust port are formed in the oil-gas separator; in the axial direction of the low-back-pressure rotor type compressor, the height of the second exhaust port is larger than the height of the air inlet and the height of the oil outlet. The air inlet is communicated with the first exhaust port; one end of the oil return channel communicates with the oil outlet, and the other end communicates with the interior of the cylinder; and the second exhaust port is communicated with the refrigerant circulating pipeline. According to the low-backpressure rotor type compressor, a mixture of a refrigerant and lubricating oil is separated through the oil-gas separator, and the separated lubricating oil enters the air cylinder from the oil outlet and the upper cylinder cover, so that the piston, the eccentric part of the crankshaft, the inner wall of the air cylinder, the inner wall of the upper cylinder cover and other parts are lubricated, and the oil storage amount, the performance and the reliability of the low-backpressure rotor type compressor are improved.

Description

Technical Field

[0001] The invention relates to the technical field of compressors, and in particular to an oil separation and return structure for a low back-pressure rotor compressor. Background Art

[0002] Rotary compressors include low back-pressure rotary compressors and high back-pressure compressors. The pressure inside the shell of a low back-pressure rotary compressor is relatively low, and the pressure inside the shell is the suction pressure; the pressure inside the shell of a high back-pressure compressor is relatively high. Since the pressure inside the shell of a low back-pressure rotary compressor is relatively low, the low back-pressure rotary compressor has a lower requirement for the shell's pressure resistance; the shell ambient temperature of a low back-pressure rotary compressor is relatively low, and the requirement for the motor's high temperature resistance is relatively low.

[0003] The lubrication of the sliding parts of the low back-pressure rotor compressor is mainly achieved in the following way: a lubricating oil pool is provided at the bottom of the compressor, and the bottom of the crankshaft extends into the lubricating oil pool. When the compressor is running, the lubricating oil is pumped into the through hole in the middle of the crankshaft by means of a centrifugal pump, and then the lubricating oil is transported to the upper cylinder head, lower cylinder head, piston, blades and other sliding parts through radial oil holes on the crankshaft connected to the through hole.

[0004] However, the lubricating oil is transported from the radial oil holes of the crankshaft to the sliding parts of the pump body. After lubricating the sliding parts, a part of the lubricating oil dissolves in the refrigerant and is discharged through the exhaust port of the compressor, causing the lubricating oil in the compressor to gradually decrease, affecting the performance and reliability of the compressor. Summary of the invention

[0005] The present invention provides an oil separation and oil return structure for a low back-pressure rotor compressor to solve the technical problem that the lubricating oil inside the low back-pressure rotor compressor is discharged from the shell to the outside of the shell, resulting in a gradual reduction of the lubricating oil in the compressor.

[0006] In order to solve the above technical problems, the present invention provides an oil separation and oil return structure for a low back pressure rotary compressor, the low back pressure rotary compressor comprises a housing, an upper cylinder cover and a cylinder, the housing is provided with a first exhaust port; the upper cylinder cover is provided with an oil return channel; the oil separation and oil return structure comprises an oil-gas separator and the oil return channel;

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

[0008] 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 rotor compressor, the height of the second exhaust port is higher than the heights 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 interior 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 arranged outside the shell.

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

[0012] Optionally, the oil return passage includes a first section, a second section, a third section and a fourth section which are connected in sequence; the first section, the second section and the third section are arranged along the radial direction of the upper cylinder cover, and the shapes of the first section, the second section and the third section are all cylindrical; one end of the first section is connected to the oil outlet; the fourth section is connected to the interior of the cylinder.

[0013] Optionally, the fourth section is an annular groove, and an opening of the annular groove is connected to the interior of the cylinder.

[0014] Optionally, the fourth section is a spiral groove, and an opening of the spiral groove is connected to the interior of the cylinder.

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

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

[0017] Optionally, the oil-gas separation unit includes a capillary tube, the capillary tube 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 port.

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

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

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

[0021] 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 rotor compressor, the height of the second exhaust port is higher than the heights 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] The present invention provides an oil separation and oil return structure for a low back-pressure rotary compressor, which separates a mixture of refrigerant and lubricating oil discharged from the low back-pressure rotary compressor through the oil-gas separator, and the separated lubricating oil enters the interior of the cylinder from the oil outlet and the oil return channel, thereby lubricating the piston, the eccentric part of the crankshaft, the inner wall of the cylinder, the inner wall of the upper cylinder cover and other parts; or, the separated lubricating oil flows back to the lubricating oil pool from the oil outlet, the oil return channel, the spiral groove and the oil return hole, thereby improving the oil storage capacity, performance and reliability of the low back-pressure rotary compressor. The refrigerant separated by the oil-gas separator is circulated through the refrigerant circulation pipeline of the low back-pressure rotary compressor, thereby preventing the refrigerant from being mixed with lubricating oil and reducing the performance of the low back-pressure rotary compressor. The oil separation and oil return structure is compact and easy to install. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0025] Figure 2 It is a structural schematic diagram of an upper cylinder cover provided by one embodiment of the present invention.

[0026] Figure 3 It is a structural schematic diagram of another oil separation and oil return structure for a low back-pressure rotor compressor provided by one embodiment of the present invention.

[0027] Figure 4 yes Figure 3 Schematic diagram of the structure of the cover plate.

[0028] Figure 5 It is a structural schematic diagram of another oil separation and oil return structure for a low back-pressure rotor compressor provided by one embodiment of the present invention.

[0029] [Description of reference numerals is as follows]:

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

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

[0032] Oil return channel-21; first section-211, second section-212, third section-213, fourth section-214;

[0033] Spiral groove-71, end of the spiral groove-711. DETAILED DESCRIPTION

[0034] In order to make the purpose, advantages and features of the present invention clearer, the oil separation and oil return structure for a low back pressure rotary compressor proposed by the present invention is further described in detail below in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0035] In the description of the present invention, the terms "first", "second", etc. are added for the convenience of description and reference, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined by the terms "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0036] like Figure 1 and Figure 2 As shown, the present embodiment provides an oil separation and oil return structure for a low back-pressure rotor compressor, the low back-pressure rotor compressor comprises a shell 3, an upper cylinder cover 2 and a cylinder, the shell 3 is provided with a first exhaust port; the upper cylinder cover 2 is provided with an oil return channel 21; the oil separation and oil return structure comprises an oil-gas separator 1 and the oil return channel 21; the oil-gas separator 1 comprises a chamber, 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 rotor compressor, the height at which the second exhaust port 13 is located is higher than the height at which the air inlet 11 and the oil outlet 12 are located; 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 rotor compressor. Figure 1 The arrows in the air inlet 11, the oil outlet 12 and the oil return passage 21 indicate the return direction of the lubricating oil.

[0037] The present embodiment provides an oil separation and return structure for a low back-pressure rotary compressor, which separates the mixture of refrigerant and lubricating oil discharged from the low back-pressure rotary compressor through the oil-gas separator 1, and the separated lubricating oil enters the interior of the cylinder from 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 cover 2, thereby 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 to prevent the refrigerant from being mixed with lubricating oil and reducing the performance of the low back-pressure rotary compressor. The oil separation and return structure is compact and easy to install.

[0038] Optional, such as Figure 1 As shown, the oil-gas separator 1 is arranged outside the housing 3. This makes it easy to install and maintain the oil-gas separator 1.

[0039] Optional, such as Figure 1 As shown, the air inlet 11 and the oil outlet 12 are both arranged at the bottom of the oil-gas separator 1, and the second exhaust port 13 is arranged at the top of the oil-gas separator 1. In this way, the refrigerant and the lubricating oil can be fully separated, the lubricating oil with a larger density flows out from the oil outlet 12, and the refrigerant with a smaller density is discharged from the second exhaust port 13.

[0040] Optional, such as Figure 2 As shown, the oil return passage 21 includes a first section 211, a second section 212, a third section 213 and a fourth section 214 which are connected in sequence; the first section 211, the second section 212 and the third section 213 are arranged along the radial direction of the upper cylinder head 2, and the shapes of the first section 211, the second section 212 and the third section 213 are all cylindrical; one end of the first section 211 is connected to the oil outlet 12; the fourth section 214 is connected to the inside of the cylinder. This makes it convenient to process the oil return passage 21.

[0041] Optional, such as Figure 2 As shown, the fourth section 214 is an annular groove, and the opening of the annular groove is connected to the interior of the cylinder. This can increase the direct contact area between the refluxed lubricating oil and the eccentric part of the piston and the crankshaft, thereby improving the lubrication effect. In order to reduce the material used in the upper cylinder head 2 and increase the lubrication effect, some of the existing upper cylinder heads 2 are provided with an annular groove, which can be used as the fourth section 214, so that the fourth section 214 does not need to be reprocessed. The shape of the opening of the groove can be circular or elliptical.

[0042] Optional, reference Figure 2As shown, the fourth section 214 is a spiral groove, the opening of which is connected to the interior of the cylinder. The fourth section 214 is in a spiral shape, which can further increase the direct contact area between the refluxed 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 section 211, the second section 212 and the third section 213 gradually decrease. In this way, the first section 211, the second section 212 and the third section 213 can have a decompression effect, so that the lubricating oil and the refrigerant are further separated.

[0044] Optional, such as Figure 2 As shown, the third section 213 is a capillary tube, which can improve the decompression effect of the third section 213 and further separate the lubricating oil and the refrigerant.

[0045] Optional, reference Figure 1 As shown, the oil-gas separation unit includes a capillary tube, the capillary tube includes 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 port 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 a baffle or a filter element for filtering oil.

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

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

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

[0049] In summary, the present invention provides an oil separation and oil return structure for a low back-pressure rotary compressor, which separates the mixture of refrigerant and lubricating oil discharged from the low back-pressure rotary compressor through the oil-gas separator 1, and the separated lubricating oil enters the interior of the cylinder from 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 cover 2; or, the separated lubricating oil flows back to the lubricating oil pool from the oil outlet 12, the oil return channel 21, the spiral groove 71 and the oil return hole 6, thereby 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 to prevent the refrigerant from being mixed with lubricating oil and reducing the performance of the low back-pressure rotary compressor. The oil separation and oil return structure is compact and easy to install.

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

Claims

1. An oil return structure for a low back pressure rotary compressor, characterized in that: The low back pressure rotor compressor comprises a housing, an upper cylinder cover and a cylinder, wherein the housing is provided with a first exhaust port; the upper cylinder cover is provided with an oil return passage; the oil separation and oil return structure comprises an oil-gas separator and the oil return passage; The oil-gas separator comprises a chamber, in which an oil-gas separation unit for separating refrigerant and lubricating oil is arranged; 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 rotor compressor, the height of the second exhaust port is higher than the heights 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 interior of the cylinder; the second exhaust port is connected to the refrigerant circulation pipeline of the low back-pressure rotor compressor.

2. The oil separation and return structure for a low back pressure rotary compressor according to claim 1, characterized in that: The oil-gas separator is arranged outside the housing.

3. The oil separation and oil return structure for a low back pressure rotary compressor according to claim 1, characterized in that: The air inlet and the oil outlet are both arranged on the bottom of the oil-gas separator, and the second exhaust port is arranged on the top of the oil-gas separator.

4. The oil separation and oil return structure for a low back pressure rotary compressor according to claim 1, characterized in that: The oil return passage includes a first section, a second section, a third section and a fourth section which are connected in sequence; the first section, the second section and the third section are arranged along the radial direction of the upper cylinder cover, and the shapes of the first section, the second section and the third section are all cylindrical; one end of the first section is connected to the oil outlet; the fourth section is connected to the interior of the cylinder.

5. The oil separation and oil return structure for a low back pressure rotary compressor according to claim 4, characterized in that: The fourth section is an annular groove, and an opening of the annular groove is communicated with the interior of the cylinder.

6. The oil separation and oil return structure for a low back pressure rotary compressor according to claim 4, characterized in that: The fourth section is a spiral groove, and an opening of the spiral groove is communicated with the interior of the cylinder.

7. The oil separation and oil return structure for a low back pressure rotary compressor according to claim 4, characterized in that: The diameters of the first section, the second section and the third section gradually decrease.

8. The oil separation and return structure for a low back pressure rotary compressor according to claim 7, characterized in that: The third section is a capillary tube.

9. The oil separation and return structure for a low back pressure rotary compressor according to claim 1, characterized in that: The oil-gas separation unit includes a capillary tube, and the capillary tube 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 port.

10. An oil return structure for a low back pressure rotary compressor, characterized in that: The low back pressure rotor compressor comprises 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 oil return holes that are connected in sequence; the upper cylinder head is provided with an oil return channel; and the cover plate is provided with a spiral groove; The oil separation and oil return structure comprises an oil-gas separator, the oil return channel, the spiral groove and the oil return hole; The oil-gas separator comprises a chamber, in which an oil-gas separation unit for separating refrigerant and lubricating oil is arranged; 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 rotor compressor, the height of the second exhaust port is higher than the heights 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.

Images