A reciprocating compressor

Abstract

The present invention provides a reciprocating compressor, including a housing, the housing including a motor housing and a crankcase, a partition between the motor housing and the crankcase, an air intake channel on one side of the motor housing, the air intake channel does not pass through the crankcase, four rows of cylinders are provided on the crankcase, a valve plate and a cylinder head are provided above the cylinders, and there is a curved area between the air intake channel and the air intake chamber of the cylinder head. The air intake channel of the present invention does not pass through the crankcase, and the external gas enters the compressor from the air intake stop valve and reaches the air intake chamber in the cylinder head through the air intake channel on one side of the motor housing. In this process, the entering low-temperature gas cools the motor, and because the air intake channel does not pass through the crankcase, the amount of lubricating oil carried by the gas is very small, which can reduce the liquid impact of oil droplets during the compression process. At the same time, the curved area between the air intake channel and the air intake chamber of the cylinder head can cause the oil droplets to collide with the wall surface, which can also play a role in separating the gas and the oil droplets.

Description

Technical Field

[0001] The present invention relates to the technical field of reciprocating compressors, and in particular to a reciprocating compressor. Background Art

[0002] Traditional refrigerants have a high GWP and have an adverse impact on global warming, so a new environmentally friendly refrigerant is needed. Carbon dioxide, as a natural refrigerant, has a low GWP and little negative impact on the environment, making it an ideal alternative.

[0003] However, when carbon dioxide is used as a refrigerant, the working pressure of various components in the system, including the compressor, is very high, and the refrigerant is prone to leakage, which places high demands on sealing and the strength of the compressor. In addition, if the compressor intake carries a large amount of lubricating oil, liquid hammer is likely to occur during operation, causing damage to related parts. An unreasonable design of the compressor lubrication system will also cause excessive lubricating oil in the cylinder, resulting in liquid hammer. Summary of the invention

[0004] The object of the present invention is to provide a reciprocating compressor, which adopts a semi-enclosed structure to design the compressor housing, thereby avoiding the possibility of refrigerant leakage to the outside. At the same time, the air intake channel is separated from the crankcase, thereby reducing the amount of oil carried by the intake air and reducing the possibility of liquid hammer.

[0005] According to one object of the present invention, the present invention provides a reciprocating compressor, including a shell, the shell including a motor shell and a crankcase, a partition between the motor shell and the crankcase, an intake channel is provided on one side of the motor shell, the intake channel does not pass through the crankcase, four rows of cylinders are provided on the crankcase, a valve plate and a cylinder head are provided above the cylinders, and there is a curved area between the intake channel and the suction chamber of the cylinder head.

[0006] Furthermore, one side of the motor housing is provided with an intake stop valve, a filter and a motor; one side of the crankcase is provided with a crankshaft, a connecting rod, an oil slinger and an exhaust stop valve.

[0007] Furthermore, two inclined surfaces with an angle greater than 110° are provided at the inlet of the air intake passage to assist air intake.

[0008] Furthermore, a gap between the oil-slinging pan and the housing is between 1.5 mm and 2.5 mm.

[0009] Furthermore, the oil-slinging pan comprises a chassis, and thin welding sheets and thick welding sheets are symmetrically arranged on the chassis.

[0010] Furthermore, a high-pressure chamber is provided inside the shell, and the high-pressure chamber is connected to the exhaust chamber and the exhaust stop valve.

[0011] Furthermore, the volume of the high-pressure chamber is not less than three times the volume flow of the compressor.

[0012] Furthermore, the high-pressure chamber includes chambers extending in three directions, and the high-pressure chamber includes a first high-pressure chamber, a second high-pressure chamber and a third high-pressure chamber.

[0013] Furthermore, all corners inside the high-pressure chamber are rounded with a radius greater than 5 mm.

[0014] Furthermore, five annular fins are provided on the outer surface of the shell, and the height of the fins is 0.045 to 0.05 times the inner diameter of the shell.

[0015] In the technical solution of the present invention, the air intake channel does not pass through the crankcase. External gas enters the compressor from the air intake stop valve and reaches the air intake chamber in the cylinder head through the air intake channel on one side of the motor housing. In this process, the low-temperature gas entering cools the motor, and because the air intake channel does not pass through the crankcase, the amount of lubricating oil carried by the gas is very small, which can reduce the liquid impact of oil droplets during the compression process. At the same time, the curved area between the air intake channel and the air intake chamber of the cylinder head causes the oil droplets to collide with the wall, which can also play a role in separating the gas and the oil droplets. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0018] Figure 2 Schematic diagram of the cross-sectional structure of the air intake passage of the compressor according to an embodiment of the present invention;

[0019] Figure 3 It is a schematic structural diagram of a housing according to an embodiment of the present invention;

[0020] Figure 4 It is a schematic diagram of the partial structure of the inlet slope of the air inlet passage of the housing according to an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of an oil-slinging pan according to an embodiment of the present invention;

[0022] Figure 6 In the embodiment of the present invention Figure 1 Schematic diagram of the AA cross-section structure.

[0023] In the figure: 10-exhaust stop valve, 11-housing, 111-motor housing, 112-crankcase; 113-cylinder, 114-intake passage, 115-inclined surface, 116-high pressure chamber, 1161-first high pressure chamber, 1162-third high pressure chamber, 1163-second high pressure chamber; 117-rib;

[0024] 12-front end cover, 13-oil slinger plate, 131-thick welding piece, 132-chassis, 133-thin welding piece;

[0025] 14-crankshaft, 15-connecting rod, 16-partition, 17-sliding bearing, 18-motor, 19-rear end cover, 20-filter, 21-intake stop valve, 22-piston pin, 23-piston, 24-valve plate, 25-cylinder head, 26-low-pressure safety valve, 27-high-pressure safety valve. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Example 1

[0030] A reciprocating compressor, such as Figure 1 , Figure 2 and Figure 3 As shown, it includes a housing 11 of a compressor stage, and the housing 11 includes a motor housing 111 and a crankcase 112; one side of the motor housing 111 is provided with an intake stop valve 21, a rear end cover 19, a filter 20 and a motor 18; the motor 18 includes a stator 181 and a rotor 182. One side of the crankcase 112 is provided with a crankshaft 14, a connecting rod 15, an oil slinger 13, a front end cover 12 and an exhaust stop valve 10;

[0031] There is a partition 16 between the motor housing 11 and the crankcase 112, and a sliding bearing 17 is provided on the partition 16. The sliding bearing 17 is used to support the crankshaft 14. The connecting rod 15 is connected to the piston 23 through the piston pin 22. Under the rotation of the crankshaft 14, the connecting rod 15 drives the piston 23 to reciprocate in the cylinder 113. There are a valve plate 24 and a cylinder head 25 above the cylinder 113. In order to prevent the gas pressure in the compressor from exceeding the safety pressure, a low-pressure safety valve 26 and a high-pressure safety valve 27 are installed in the low-pressure chamber and the high-pressure chamber on the crankcase 112 side, respectively.

[0032] In this embodiment, the compressor air circuit is to inhale air from the intake stop valve 21 of the crankcase 112 of the shell 11, and after cooling the motor 18, enter the internal intake chamber of the cylinder head 25 through the intake channel 114 from the left side through the hole of the shell 11 through the valve plate 24, and then enter the cylinder 113 through the intake valve, enter the internal exhaust chamber of the cylinder head 25 after compression, and enter the high-pressure chamber in the crankcase 112 through the valve plate 24 again, and finally be discharged from the exhaust stop valve 10.

[0033] In this embodiment, the lubrication process of the compressor is as follows: the bottom of the crankcase 112 is used as an oil pool, the crankshaft 14 drives the oil-slinging plate 13 to rotate and throw the lubricating oil to the oil collecting area of ​​the front cover 12, and then the oil flows into the oil hole at the right end of the crankshaft 14. Through the rotation of the crankshaft 14, under the action of centrifugal force, the lubricating oil enters the sliding bearing 17 and the big end through the oil hole for lubrication. The lubricating oil will flow out from both ends of the sliding bearing 17. Under the action of the rotation of the crankshaft 14, part of the oil will return to the oil pool, and part will be thrown to the surface of the cylinder 113, and the reciprocating motion of the piston 23 will realize the lubrication of the entire surface of the cylinder 113. The scraper ring on the piston 23 will scrape the oil down and enter the inside of the piston 23 through the oil hole, and enter the small end of the connecting rod 15 through the oil groove for lubrication, and the excess oil will return to the oil pool.

[0034] like Figure 2 and Figure 3As shown, the compressor housing is provided with four rows of cylinders 113; an air intake passage 114 is provided on one side of the motor housing 111, and the air intake passage 114 does not pass through the crankcase 112. In this way, the airflow will not pass through the crankcase 112 where there is a large amount of oil and gas, reducing the amount of liquid in the air intake, avoiding liquid hammer caused by lubricating oil, and damaging parts such as air valves and gaskets. At the same time, the air intake will first cool the motor 18, which not only ensures the reliable operation of the motor 18, but also evaporates possible refrigerant droplets, avoiding liquid hammer caused by refrigerant droplets.

[0035] like Figure 2 As shown, in this embodiment, there is a curved area between the air intake passage 114 and the air suction chamber of the cylinder head 25. In this way, when the refrigerant gas flows through this curved area, the airflow direction is affected by the inner wall of the pipe and changes direction, and the lubricating oil droplets that may be carried in the gas will hit the inner wall of the pipe due to their own heavy mass, and thus be adsorbed on the wall surface, reducing the droplets brought into the cylinder 113. At the same time, this curved area will also reduce the gas flow rate, and when the speed decreases, the oil droplets carried by the airflow will also be reduced, and some of the oil droplets will be deposited on the pipe wall surface. Therefore, this curved pipe will avoid liquid hammer to a great extent.

[0036] like Figure 4 As shown, in this embodiment, two inclined surfaces 115 with an angle greater than 110° are provided at the entrance of the air intake passage 114 to assist air intake. After cooling the motor 18, the refrigerant gas will enter the air intake chamber inside the cylinder head 25 through the air intake passage 114, and the gas will flow through the small flow channel around the motor when passing through the motor 18. Therefore, after cooling the motor 18, the gas needs to enter the air intake passage above the housing 11 from all directions. The use of two inclined surfaces 115 with an angle greater than 110° at the entrance is conducive to receiving gas from all directions, making the flow smoother and reducing flow losses.

[0037] In this embodiment, the gap between the oil-slinging plate 13 and the housing 11 is between 1.5 mm and 2.5 mm. In this way, when the crankshaft 14 rotates to drive the oil-slinging plate 13 to rotate, the oil-slinging plate 13 can bring enough lubricating oil to the oil collecting area of ​​the front cover 12, and the lubricating oil can also be replenished in time from the gap and flow into the lower part of the oil-slinging plate 13. When the gap is too small, the lubricating oil cannot flow from the side of the oil-slinging plate 13 close to the crankcase 112 to the side close to the front cover 12 in time, so that the amount of oil brought into the oil collecting area is insufficient. When the gap is too large, the depth of the oil-slinging plate 13 into the oil pool is not deep enough, and the oil stirred up is too little, resulting in insufficient lubricating oil. Therefore, adjusting the gap to between 1.5 mm and 2 mm can ensure sufficient lubricating oil.

[0038] like Figure 5As shown, in this embodiment, a thick welding sheet 131 and a thin welding sheet 133 are symmetrically arranged on the bottom plate 132 of the oil-slinging plate 13 to assist in balancing the inertia force and inertia moment of the compressor. In this way, the two welding sheets with different thicknesses can stir up more oil to the oil collection area in each rotation. At the same time, since the radius of the oil-slinging plate is large, the rotation radius of the centroid of the welding sheet is relatively large, and the size of the centrifugal force can be changed by adjusting the thickness of the welding sheet, thereby balancing the inertia force and inertia moment of the compressor.

[0039] like Figure 6 As shown, in this embodiment, a high-pressure chamber 116 is arranged inside the compressor housing, and the high-pressure chamber 116 is connected to the exhaust chamber and the exhaust stop valve 10, and the volume of the high-pressure chamber 116 is not less than 3 times the volume flow of the compressor. In this way, the high-pressure chamber 116 is arranged inside the housing 11, and the idle space inside the housing 11, that is, the crankcase 112 part, can be fully utilized, so that the structure is more compact, the space occupied by the compressor as a whole is smaller, and there is no need to install a chamber for converging high-pressure gas externally. The gas converges in the high-pressure chamber inside the housing 11 and flows out through the exhaust stop valve 10, so that the number of parts can be reduced and the cost can be saved. The volume of the high-pressure chamber 11 is based on the volume flow, which can ensure that the volume of the high-pressure chamber 116 through which the exhaust gas flows is large enough to reduce the air flow pulsation and make it play the role of a buffer chamber.

[0040] like Figure 6 As shown, in this embodiment, the high-pressure chamber 116 has chambers extending in three directions, which are divided into the first high-pressure chamber 1161, the second high-pressure chamber 1163 and the third high-pressure chamber 1162. In this way, the compressed high-pressure gas will first enter the first high-pressure chamber 1161 and the second high-pressure chamber 1163 through the through holes on the valve plate, and the gases in the two chambers will flow upward and out through the exhaust stop valve 10 after merging. A high-pressure safety valve 27 is installed above the third high-pressure chamber 1162, and generally no gas will flow. Therefore, the third high-pressure chamber 1162 can act as a resonance chamber as a bypass chamber, which can reduce noise, vibration, and improve the reliability of the connection with the compressor.

[0041] In this embodiment, all corners in the high-pressure chamber 116 are rounded with a radius greater than 5 mm. In this way, the gas flows more smoothly and the flow loss is reduced. At the same time, since the crankcase 112 of the shell 11 is a low-pressure chamber except the high-pressure chamber 116, and the carbon dioxide pressure is high and the pressure difference is large, resulting in a large pressure difference between the high-pressure chamber and the low-pressure chamber, the use of a larger rounded corner can reduce stress concentration and improve the strength of the shell 11.

[0042] like Figure 3As shown, in this embodiment, five annular ribs 117 are provided on the outer surface of the compressor housing 11, and the height of the ribs 117 is 0.045 to 0.05 times the inner diameter of the housing 11. These five annular ribs 117 are concentrated on the motor housing 111 of the housing 11, which can enhance the heat dissipation of the motor 18 and enhance the strength of the motor housing 111. The height of the ribs 117 is based on the inner diameter of the housing 11, taking into account the actual problem that the larger the inner diameter, the smaller the ratio of the actual heat exchange area of ​​the outer surface to the volume, and the need to increase the height of the ribs. At the same time, the larger the inner diameter, the larger the force area, the higher the required strength of the housing 11, and the ribs 117 also need to be increased to improve the strength.

[0043] The reciprocating compressor of the present invention is used in a transcritical carbon dioxide heat pump system, is specially designed and developed for a transcritical carbon dioxide circulation system, and can adapt to the high pressure and large pressure difference working conditions of the system.

[0044] The air intake passage of the present invention does not pass through the crankcase. External gas enters the compressor from the air intake stop valve and reaches the air intake chamber in the cylinder head through the air intake passage on one side of the motor housing. In this process, the low-temperature gas entering cools the motor, and because the air intake passage does not pass through the crankcase, the amount of lubricating oil carried by the gas is very small, which can reduce the liquid impact of oil droplets during the compression process. At the same time, the curved area between the air intake passage and the air intake chamber of the cylinder head can cause the oil droplets to collide with the wall surface, which can also play a role in separating the gas and the oil droplets. The entrance of the air intake passage has two inclined surfaces with an angle greater than 100°, which increases the air intake port and reduces the flow resistance loss.

[0045] Two welding plates are symmetrically arranged on the oil-slinging plate of the present invention, which can balance the inertia force and inertia moment of the compressor on the one hand, and on the other hand, the two welding plates have different thicknesses, which is conducive to stirring up the lubricating oil at the bottom of the shell and bringing the oil to the oil storage position on the front cover of the crankcase.

[0046] The exhaust high-pressure chamber of the present invention is located inside the crankcase, which utilizes the space inside the crankcase, can make the compressor smaller in size and more compact in structure, does not require an external high-pressure chamber for collecting high-pressure gas, and reduces the number of parts.

[0047] The high-pressure chamber built into the crankcase of the present invention has chambers in three directions that are interconnected. The compressed high-pressure gas enters the first high-pressure chamber and the second high-pressure chamber, and is discharged after merging. The third high-pressure chamber acts as a bypass chamber to play the role of a resonance chamber, which can achieve a noise reduction effect. At the same time, the volume of the high-pressure chamber is increased, which can reduce airflow pulsation and vibration, making the interface connected to the compressor less prone to damage.

[0048] The motor housing of the present invention is provided with external ribs on the outside, which can enhance heat exchange, enhance heat dissipation of the motor, and play the role of reinforcing ribs, thereby increasing the strength of the housing to withstand the high pressure of carbon dioxide.

[0049] The reciprocating compressor of the present invention can reduce the amount of oil carried by intake air, the oil supply of the lubrication system is appropriate, the possibility of liquid hammer is small, the whole machine structure is compact, the exhaust gas pulsation is small, and it can adapt to higher gas pressure.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reciprocating compressor, characterized in that: The invention comprises a shell, wherein the shell comprises a motor shell and a crankcase, wherein a partition is provided between the motor shell and the crankcase, an intake passage is provided on one side of the motor shell, and the intake passage does not pass through the crankcase, four rows of cylinders are provided on the crankcase, a valve plate and a cylinder head are provided above the cylinders, and a curved area exists between the intake passage and the air intake chamber of the cylinder head.

2. The reciprocating compressor according to claim 1, characterized in that: One side of the motor housing is provided with an air intake stop valve, a filter screen and a motor; one side of the crankcase is provided with a crankshaft, a connecting rod, an oil slinger pan and an exhaust stop valve.

3. The reciprocating compressor according to claim 1, characterized in that: Two inclined surfaces with an angle greater than 110° are arranged at the entrance of the air intake passage to assist air intake.

4. The reciprocating compressor according to claim 2, characterized in that: The gap between the oil-slinging pan and the housing is between 1.5 mm and 2.5 mm.

5. The reciprocating compressor according to claim 2, characterized in that: The oil-slinging pan comprises a chassis, on which thin welding sheets and thick welding sheets are symmetrically arranged.

6. The reciprocating compressor according to claim 2, characterized in that: A high-pressure chamber is disposed inside the shell, and the high-pressure chamber is connected to the exhaust chamber and the exhaust stop valve.

7. The reciprocating compressor according to claim 6, characterized in that: The volume of the high-pressure chamber is not less than three times the volume flow of the compressor.

8. The reciprocating compressor according to claim 6, characterized in that: The high-pressure chamber includes chambers extending in three directions, and the high-pressure chamber includes a first high-pressure chamber, a second high-pressure chamber and a third high-pressure chamber.

9. The reciprocating compressor according to claim 6, characterized in that: All corners inside the high-pressure chamber are rounded with a radius greater than 5 mm.

10. The reciprocating compressor according to claim 1, characterized in that The outer surface of the shell is provided with five annular fins, and the height of the fins is 0.045 to 0.05 times the inner diameter of the shell.

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