A screw compressor

Abstract

The application discloses a screw compressor, which comprises a shell and a motor rotor assembly, and is characterized in that the shell is internally provided with a suction end bearing seat, a support and a discharge end bearing seat, the suction end bearing seat, the support and the discharge end bearing seat define a compression chamber therebetween, the suction end bearing seat is provided with a first bearing cavity and a second bearing cavity, and the discharge end bearing seat is provided with a third bearing cavity and a fourth bearing cavity; the outlet of the compression chamber is provided with a filtering assembly, the filtering assembly is provided with an oil outlet, the sidewall of the shell is provided with an oil supply system, the oil supply system comprises an oil distribution channel, a first oil supply channel and a second oil supply channel, the oil distribution channel is in communication with the oil outlet, the first oil supply channel and the second oil supply channel respectively, the two ends of the first oil supply channel are in communication with the first bearing cavity and the third bearing cavity respectively, and the two ends of the second oil supply channel are in communication with the second bearing cavity and the fourth bearing cavity respectively. The filtering assembly and the oil supply system are integrated into the shell, so that the structure is compact, the oil supply is clean, and the reliability is high.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more particularly to a screw compressor. Background Technology

[0002] Screw compressors are widely used in refrigeration, air conditioning, heat pumps, and energy storage / thermal management. Their core working principle involves a pair of meshing male and female screw rotors rotating within a compression chamber to complete the gas intake, compression, and discharge processes. During operation, the compressor requires continuous lubrication of the rotor meshing parts, bearings, and other moving components to achieve lubrication, sealing, and noise reduction, ensuring stable compressor operation. Traditional screw compressors have numerous lubrication lines and pipe joints, which occupy space, increase the risk of leakage, and make it difficult to precisely control the oil supply to each bearing and rotor chamber independently. Uneven oil distribution can easily lead to poor bearing lubrication or rotor wear. Furthermore, due to the complex pipeline, lubricating oil carried in the exhaust is difficult to completely separate, increasing oil consumption, contaminating downstream systems, and easily introducing impurities, accelerating bearing and rotor wear, and reducing compressor lifespan. Summary of the Invention

[0003] The purpose of this invention is to provide a screw compressor that integrates the filter assembly and oil supply system into the housing, resulting in a compact structure, clean oil supply, and high reliability.

[0004] To achieve this objective, the present invention adopts the following technical solution: a screw compressor, comprising a housing and a motor rotor assembly, wherein the housing contains an intake bearing housing, a support, and an exhaust bearing housing, and a compression chamber is defined between the intake bearing housing, the support, and the exhaust bearing housing; the intake bearing housing has a first bearing cavity, a second bearing cavity, and a first oil return channel, the first oil return channel communicating with the first bearing cavity, the second bearing cavity, and the compression chamber respectively; the exhaust bearing housing has a third bearing cavity, a fourth bearing cavity, and a second oil return channel, the second oil return channel communicating with the third bearing cavity, the fourth bearing cavity, and the compression chamber respectively; the motor rotor assembly includes a male screw and a female screw that mesh with each other, both the male screw and the female screw being confined within the... Within the compression chamber, the two ends of the male screw are rotatably mounted in the first bearing cavity and the third bearing cavity via two sets of bearings, respectively. The two ends of the female screw are rotatably mounted in the second bearing cavity and the fourth bearing cavity via two other sets of bearings, respectively. A filter assembly for separating lubricating oil is provided at the outlet of the compression chamber. The filter assembly has an oil outlet. An oil supply system is provided on the side wall of the outer casing. The oil supply system includes an oil distribution channel, a first oil supply channel, and a second oil supply channel. The oil distribution channel is connected to the oil outlet, the first oil supply channel, and the second oil supply channel, respectively. The two ends of the first oil supply channel are connected to the first bearing cavity and the third bearing cavity, respectively. The two ends of the second oil supply channel are connected to the second bearing cavity and the fourth bearing cavity, respectively.

[0005] Preferably, the outer casing sidewall is provided with an oil outlet hole communicating with the oil distribution channel, and the oil supply system further includes a third oil supply channel connected to the oil outlet pipe. One end of the third oil supply channel passes through the outer casing, and the other end passes through the bracket and communicates with the compression chamber.

[0006] Preferably, the outer wall of the housing is provided with two first adjustment holes and two second adjustment holes. The two first adjustment holes penetrate the housing and are connected to both ends of the first oil supply channel, and the two second adjustment holes penetrate the housing and are connected to both ends of the second oil supply channel.

[0007] Preferably, the input end of the screw compressor is connected to an evaporator, and the output end of the screw compressor is connected to a condenser. The evaporator and the condenser are connected to form a circuit. An oil-cooled heat exchanger is provided on the pipe between the evaporator and the condenser. The input end of the oil-cooled heat exchanger is connected to the oil outlet pipe, and the output end of the oil-cooled heat exchanger is connected to the first regulating hole, the second regulating hole, and the third oil supply channel pipe, respectively.

[0008] Preferably, the housing is provided with an exhaust chamber, an outlet chamber, and a filter chamber. The exhaust chamber and the outlet chamber are located on opposite sides of the exhaust end bearing seat, and the filter chamber is located on the side of the exhaust end bearing seat away from the compression chamber. The exhaust chamber is connected to the outlet chamber through the filter chamber. The filter assembly includes an oil separator screen disposed in the filter chamber and a precision filter disposed in the outlet chamber. The oil outlet is disposed at the output end of the precision filter.

[0009] Preferably, the side wall of the housing is provided with an air inlet communicating with the compression chamber, the air inlet being positioned corresponding to the female screw and the shape of the air inlet matching the profile of the female screw.

[0010] Preferably, the outer casing has a motor cavity located on the side of the intake bearing housing opposite to the compression chamber, the motor rotor assembly is installed in the motor cavity, and the side wall of the motor cavity has a water-cooling channel for the flow of chilled water.

[0011] Preferably, the outer casing is provided with an air intake chamber, which is located on the side of the motor cavity away from the compression chamber, and an air intake filter is installed between the air intake chamber and the motor cavity.

[0012] Preferably, the bracket has a vent near the top, a plunger is slidably installed in the housing along the vertical direction, the plunger is located above the vent, and a valve assembly is installed in the housing to drive the plunger to move to open or close the vent.

[0013] Preferably, the outer casing is provided with a soundproof chamber, which is located between the bracket and the inner wall of the outer casing, and the soundproof chamber is filled with soundproofing material.

[0014] The beneficial effects of this invention are as follows: When the screw compressor is running, lubricating oil enters the first and third bearing chambers through the first oil supply channel, thereby lubricating the bearings at both ends of the male screw. Simultaneously, lubricating oil enters the second and fourth bearing chambers through the second oil supply channel, thereby lubricating the bearings at both ends of the female screw. Then, the lubricating oil in the suction end bearing housing enters the compression chamber through the first oil return channel, and the lubricating oil in the discharge end bearing housing enters the compression chamber through the second oil return channel. The lubricating oil and refrigerant in the compression chamber mix and then enter the filter assembly through the compression chamber outlet. Subsequently, the lubricating oil is separated and enters the oil distribution channel through the oil outlet, restarting the circulation. By setting up the filter assembly upstream of the oil supply system, it is ensured that the lubricating oil entering each bearing chamber is fully filtered, effectively intercepting impurities, improving the cleanliness of the lubricating oil, and significantly extending the bearing life. By configuring the oil supply system, the first oil supply channel independently supplies oil to the bearings at both ends of the male screw, and the second oil supply channel independently supplies oil to the bearings at both ends of the female screw. The oil distribution in each bearing cavity is uniform and consistent, ensuring that each bearing receives sufficient lubricating oil to form a stable hydrodynamic oil film, effectively preventing bearing wear and burning caused by uneven oil supply. Furthermore, the filter assembly is integrated into the compression chamber outlet inside the housing. The oil distribution channel, the first oil supply channel, and the second oil supply channel of the oil supply system are all integrated inside the side wall of the housing, making the overall structure of the compressor simpler and more compact, with minimal external piping, significantly reducing the risk of leakage and improving the overall operational reliability of the screw compressor. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the screw compressor according to an embodiment of this application; Figure 2 This is a side view of a screw compressor according to an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the first oil supply channel according to an embodiment of this application; Figure 4 yes Figure 2 Sectional view at point AA; Figure 5 yes Figure 2 Sectional view at point BB; Figure 6 This is a schematic diagram of the structure of the third oil supply channel according to an embodiment of this application; Figure 7 This is an installation diagram of a screw compressor according to an embodiment of this application; Figure 8 This is a longitudinal cross-sectional schematic diagram of a screw compressor according to an embodiment of this application; Figure 9 This is a cross-sectional schematic diagram of a screw compressor according to an embodiment of this application; Figure 10 This is a schematic diagram of the air inlet structure according to an embodiment of this application; Figure 11yes Figure 10 Sectional view at CC; Figure 12 This is a comparison diagram of the COP of the screw compressor according to an embodiment of this application.

[0016] In the picture: 1. Outer shell; 101. First adjustment hole; 102. Second adjustment hole; 103. Air inlet; 104. Soundproof chamber; 105. Oil outlet; 11. Intake end bearing seat; 111. First bearing cavity; 112. Second bearing cavity; 12. Bracket; 13. Exhaust end bearing seat; 131. Third bearing cavity; 132. Fourth bearing cavity; 133. Second oil return channel; 14. Compression chamber; 141. Vent port; 142. Plunger; 15. Exhaust chamber; 151. Exhaust check valve; 16. Outlet chamber; 17. Filter chamber; 18. Motor chamber; 181. Water cooling channel; 19. Intake chamber; 110. Valve assembly; 2. Motor rotor assembly; 21. Male screw; 22. Female screw; 3. Filter assembly; 31. Oil separator filter; 32. Precision filter; 33. Suction filter; 4. Fuel supply system; 41. Fuel distribution channel; 42. First fuel supply channel; 43. Second fuel supply channel; 44. Third fuel supply channel; 45. Throttling orifice plug; 5. Evaporator; 6. Condenser; 7. Oil-cooled heat exchanger; 71. Oil outlet pipe; 72. Oil return pipe. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0018] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0020] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0021] Reference Figures 1 to 11As shown, a screw compressor according to an embodiment of this application includes a housing 1 and a motor rotor assembly 2. The housing 1 is provided with an intake bearing seat 11, a bracket 12 and an exhaust bearing seat 13. A compression chamber 14 is defined between the inner walls of the intake bearing seat 11 and the bracket 12 and the exhaust bearing seat 13. The intake bearing seat 11 is provided with a first bearing cavity 111 and a second bearing cavity 112. The side wall of the intake bearing seat 11 is provided with a vertical first oil return channel, which communicates with the first bearing cavity 111, the second bearing cavity 112 and the compression chamber 14 respectively. The exhaust bearing seat 13 is provided with a third bearing cavity 131 and a fourth bearing cavity 132. The side wall of the exhaust bearing seat 13 is provided with a vertical second oil return channel 133, which communicates with the third bearing cavity 131, the fourth bearing cavity 132 and the compression chamber 14 respectively. The motor rotor assembly 2 includes a male screw 21 and a female screw 22 that mesh with each other. The male screw 21 is located above the female screw 22. Both the male screw 21 and the female screw 22 are confined within the compression chamber 14. The two ends of the male screw 21 are rotatably mounted in the first bearing chamber 111 and the third bearing chamber 131 respectively via two sets of bearings. The two ends of the female screw 22 are rotatably mounted in the second bearing chamber 112 and the fourth bearing chamber 132 respectively via two other sets of bearings. A filter assembly 3 for separating lubricating oil is provided at the outlet of the compression chamber 14. The filter assembly 3 can be a filter or filter screen structure integrated into the exhaust end of the housing, or it can be an oil separator tank fixed inside the housing; further details are omitted here. The filter assembly 3 has an oil outlet, and the side wall of the housing 1 is provided with an oil supply system 4. The oil supply system 4 includes an oil distribution channel 41, a first oil supply channel 42, and a second oil supply channel 43. The oil distribution channel 41 is connected to the oil outlet, the first oil supply channel 42, and the second oil supply channel 43, respectively. The two ends of the first oil supply channel 42 are connected to the first bearing cavity 111 and the third bearing cavity 131, respectively. The two ends of the second oil supply channel 43 are connected to the second bearing cavity 112 and the fourth bearing cavity 132, respectively.

[0022] It should be noted that the outer shell 1 is a three-section structure formed by connecting the two end caps and the middle main body flange. The middle main body includes a front half with an intake bearing seat 11 and a bracket 12 and a rear half with an exhaust bearing seat 13. The oil distribution channel 41, the first oil supply channel 42 and the third bearing cavity 131 are connected at one end, and the second oil supply channel 43 and the fourth bearing cavity 132 are connected at one end of the rear half facing the front half. The oil distribution channel 41 is arranged vertically. The main body of the first oil supply channel 42 and the main body of the second oil supply channel 43 are blind holes opened on the end face of the front half facing the rear half. The other end of the first oil supply channel 42 extends radially towards the first bearing cavity 111 along the outer shell 1, and the other end of the second oil supply channel 43 extends radially towards the second bearing cavity 112 along the outer shell 1.

[0023] Understandably, when the screw compressor is running, lubricating oil enters the first bearing chamber 111 and the third bearing chamber 131 through the first oil supply channel 42, thereby lubricating the bearings at both ends of the male screw 21. At the same time, lubricating oil enters the second bearing chamber 112 and the fourth bearing chamber 132 through the second oil supply channel 43, thereby lubricating the bearings at both ends of the female screw 22. Then, the lubricating oil in the suction end bearing housing 11 enters the compression chamber 14 through the first oil return channel, and the lubricating oil in the discharge end bearing housing 13 enters the compression chamber 14 through the second oil return channel 133. The lubricating oil and refrigerant in the compression chamber 14 mix and enter the filter assembly 3 through the outlet of the compression chamber 14. Subsequently, the lubricating oil is separated and enters the oil distribution channel 41 through the oil outlet, and the circulation starts again.

[0024] It should be noted that the lubricating oil is heated by the motor rotor assembly 2 during lubrication. With the screw compressor running continuously, the lubricating oil may accumulate heat. In this application, the screw compressor's input end is provided with a flow channel for suction cooling. The space where the oil outlet of the filter assembly 3 is located partially overlaps with the space where the suction cooling flow channel is located, allowing the intake low-temperature refrigerant to cool the high-temperature lubricating oil and eliminate heat accumulation.

[0025] By installing filter assembly 3, located upstream of the oil supply system 4, it is ensured that the lubricating oil entering each bearing cavity is fully filtered, effectively intercepting impurities, improving the cleanliness of the lubricating oil, and significantly extending the bearing life. The oil supply system 4 provides independent oil supply to the bearings at both ends of the male screw 21 via the first oil supply channel 42, and independent oil supply to the bearings at both ends of the female screw 22 via the second oil supply channel 43. This ensures uniform oil distribution in each bearing cavity, guaranteeing that each bearing receives sufficient lubricating oil to form a stable hydrodynamic oil film, effectively preventing bearing wear and burning caused by uneven oil supply. Furthermore, filter assembly 3 is integrated into the outlet of the compression chamber 14 within the housing 1. The oil distribution channel 41, the first oil supply channel 42, and the second oil supply channel 43 of the oil supply system 4 are all integrated inside the side wall of the housing 1. This eliminates the need for traditional external inlet and outlet pipes corresponding to each bearing cavity, making the overall compressor structure simpler and more compact, with minimal external piping, significantly reducing the risk of leakage and improving the overall reliability of the screw compressor.

[0026] It should be noted that the screw compressor adopts a high-pressure head, high-rigidity tooth profile design. Typical screw tooth profiles are 5+6, 5+7, and 6+8, which are suitable for medium-pressure refrigerants such as R134a, R513A, R515A, R515B, R1234ze, and R1234yf used in energy storage thermal management, as well as high-pressure refrigerants such as R410A, R32, R454A, and R454B. Because the male screw 21 and female screw 22 are a double-support shaft system structure, the bearing layout has very high strength and rigidity, and the critical speed and deformation of the shaft system are very small. The maximum deformation of the middle part of the male screw 21 in this application is 0.003mm.

[0027] It should also be noted that both the male screw 21 and the female screw 22 use cylindrical roller bearings at the intake and exhaust ends to bear the radial gas force. The male screw 21 uses three sets of positive thrust and one set of negative thrust angular contact ball bearings at the exhaust end to bear the bidirectional heavy-duty axial gas force, ensuring the axial fixation of the entire screw shaft system and adapting to the requirements of high ambient temperature / high water temperature, large pressure difference and high load conditions. The female screw 22 uses one set of positive thrust and one set of negative thrust angular contact ball bearings at the exhaust end to provide stable radial support capacity and radial support stiffness for the female screw 22.

[0028] In some embodiments, throttling plugs 45 are installed at both ends of the first oil supply channel 42 and both ends of the second oil supply channel 43, so that users can individually control the oil flow of each bearing cavity through throttling plugs 45 of different diameters to ensure oil temperature and oil viscosity.

[0029] Reference Figure 5 and Figure 6 As shown, the outer casing 1 has an oil outlet 105 on its side wall that communicates with the oil distribution channel 41. The oil supply system 4 also includes a third oil supply channel 44 connected to the oil outlet 105. One end of the third oil supply channel 44 passes through the outer casing 1, and the other end passes through the bracket 12 and communicates with the compression chamber 14. An oil cooler, flow valve, or other accessories can be installed on the pipe between the oil outlet 105 and the third oil supply channel 44 to cool the lubricating oil and regulate the flow rate, etc., which will not be described in detail here.

[0030] By setting a third oil supply channel 44, some of the lubricating oil filtered by the filter assembly 3 enters the oil distribution channel 41 and can be led out of the housing 1 through the oil outlet 105. After cooling, it is reintroduced into the third oil supply channel 44 and then supplies oil to the male screw 21 and female screw 22 in the compression chamber 14. The lubricating oil in the compression chamber 14 can form an effective sealing oil film between the tooth surfaces of the male screw 21 and female screw 22. This not only seals the leakage gap between the tooth volume and the housing, improving volumetric efficiency, but also plays a damping and vibration reduction role when the rotor rotates at high speed, significantly reducing meshing noise. The third oil supply channel 44 works in conjunction with the first oil supply channel 42 and the second oil supply channel 43 to provide comprehensive coverage for key locations inside the housing 1 that require lubrication, such as the "male screw 21 suction end bearing - male screw 21 discharge end bearing - female screw 22 suction end bearing - female screw 22 discharge end bearing - screw meshing teeth". This ensures full-process built-in oil supply from the bearings to the rotor meshing parts, further improving the overall reliability of the screw compressor.

[0031] Reference Figure 3 and Figure 5As shown, it can be understood that the outer wall of the outer casing 1 is provided with two first adjustment holes 101 and two second adjustment holes 102. The two first adjustment holes 101 penetrate the outer casing 1 and are connected to both ends of the first oil supply channel 42, and the two second adjustment holes 102 penetrate the outer casing 1 and are connected to both ends of the second oil supply channel 43. At this time, the first adjustment holes 101, the second adjustment holes 102 and the oil outlet hole 105 located in the rear half are arranged sequentially from top to bottom.

[0032] By setting the first regulating hole 101 and the second regulating hole 102, compared to drilling a blind hole in the inner wall of the outer casing 1 to connect the oil supply system 4 and the two bearing seats, opening the through-holes 101 and 102 in the outer wall of the outer casing 1 facilitates the machining of the first oil supply channel 42 and the second oil supply channel 43. Furthermore, users can directly install and replace the throttling plug 45 through the first regulating hole 101 and the second regulating hole 102, thereby optimizing the oil supply to each bearing according to different refrigerant types, operating pressure ratios, and ambient temperatures. This ensures that each bearing receives the optimal oil quantity and temperature under different operating conditions, thus maintaining the best oil film viscosity and load-bearing capacity. In addition, users can use a plug to seal the channel above the oil outlet 105, allowing the filtered lubricating oil to be completely led out of the outer casing 1 through the oil outlet 105. After being cooled by the oil cooler, the lubricating oil returns to the outer casing 1 through the first regulating hole 101, the second regulating hole 102, and the third oil supply channel 44 to participate in circulation, improving the adaptability of the oil supply system 4 to the screw compressor with its higher internal temperature.

[0033] Reference Figure 7 As shown, it can be understood that the input end of the screw compressor is connected to the evaporator 5, and the output end of the screw compressor is connected to the condenser 6. The evaporator 5 and the condenser 6 are connected to form a loop. An oil-cooled heat exchanger 7 is provided on the pipe between the evaporator 5 and the condenser 6. The heat exchange channel inside the oil-cooled heat exchanger 7 is the pipe between the evaporator 5 and the condenser 6. The input end of the oil-cooled heat exchanger 7 is connected to the oil outlet 105 pipe through the oil outlet pipe 71. The output end of the oil-cooled heat exchanger 7 is connected to the first regulating hole 101, the second regulating hole 102 and the third oil supply channel 44 pipes respectively through the oil return pipe 72.

[0034] When the screw compressor is running, the filter assembly 3 continuously separates the refrigerant at the outlet of the compression chamber 14. After the lubricating oil is separated, it enters the oil-cooled heat exchanger 7 through the oil outlet 105 and the oil outlet pipe 71. After the lubricating oil exchanges heat with the refrigerant condensed in the circuit and cools down, it enters the first regulating hole 101, the second regulating hole 102 and the third oil supply channel 44 through the return oil pipe 72, thereby simultaneously supplying the first bearing chamber 111, the second bearing chamber 112, the third bearing chamber 131, the fourth bearing chamber 132 and the compression chamber 14, realizing the external cooling circulation of the lubricating oil.

[0035] In existing technology, the temperature of the lubricating oil in compressors is the same as the exhaust temperature, which is between 50℃ and 100℃. Prolonged high-temperature operation of the lubricating oil can easily lead to deterioration and failure, and the bearings through which the lubricating oil passes will also fail. The design with heat exchanger 41 ensures that after the lubricating oil flows out of the inner cavity, it first passes through filter assembly 3 for separation and purification, then passes through oil-cooled heat exchanger 7 to exchange heat with the low-temperature refrigerant for cooling, and then flows back to the screw compressor through oil supply system 4. This reduces the temperature of the lubricating oil in the first bearing cavity 111, second bearing cavity 112, third bearing cavity 131, fourth bearing cavity 132, and compression cavity 14 by approximately 15℃-25℃. When the exhaust temperature is 50℃-100℃, the lubricating oil temperature can be reduced to between 35℃ and 75℃. This reduction in lubricating oil temperature increases its viscosity, which in turn greatly extends the bearing's service life and significantly improves the compressor's reliability.

[0036] It should be noted that although the filter assembly 3 and the oil supply system 4 need to be connected to the oil-cooled heat exchanger 7 through external pipes, since the oil-cooled heat exchanger 7 is integrated into a known loop and the specific lubricating oil distribution is achieved through the built-in oil supply system 4, the oil outlet pipe 71 between the filter assembly 3 and the oil-cooled heat exchanger 7 and the oil return pipe 72 between the oil supply system 4 and the oil-cooled heat exchanger 7 can be simplified. This is in line with the design concept of simplifying external pipes in this application, rather than being presented as a counterexample to the design concept of this application. This is specifically stated here to avoid misunderstanding.

[0037] Reference Figure 4 and Figure 8 As shown, the outer casing 1 is provided with an exhaust chamber 15, an outlet chamber 16, and a filter chamber 17. The exhaust chamber 15 is located at the outlet of the compression chamber 14. The exhaust chamber 15 and the outlet chamber 16 are located on opposite sides of the exhaust end bearing seat 13. The filter chamber 17 is located on the side of the exhaust end bearing seat 13 away from the compression chamber 14. The exhaust chamber 15 is connected to the outlet chamber 16 through the filter chamber 17. The filter assembly 3 includes an oil separator 31 disposed in the filter chamber 17 and a precision filter 32 disposed in the outlet chamber 16. Specifically, the precision filter 32 can provide a filtration accuracy of 3µm. The bottom of the filter chamber 17 and the bottom of the outlet chamber 16 are connected to form an oil trough. The precision filter 32 is a horizontal cylindrical structure. The precision filter 32 is located in the oil trough at the bottom of the outlet chamber 16. On the projection plane perpendicular to the axial direction of the outer casing 1, the projection of the oil separator 31 covers the projections of the exhaust chamber 15 and the outlet chamber 16. The oil outlet is disposed at the output end of the precision filter 32.

[0038] By incorporating an oil separator filter 31 and a precision filter 32, the high-temperature, high-pressure exhaust gas from the compression chamber 14 first enters the filter chamber 17 through the exhaust chamber 15. Initial oil-gas separation occurs via the oil separator filter 31, where most of the lubricating oil is intercepted by the corrugated filter structure and deposited in the oil trough. Subsequently, the gas enters the outlet chamber 16 and is discharged from the outer casing 1. The lubricating oil in the oil trough undergoes secondary high-precision filtration via the precision filter 32, further capturing residual micro-oil droplets before recirculation. The oil separator filter 31 and the precision filter 32 form a two-stage filtration structure with a separation efficiency of approximately 1000 ppm (i.e., 99.9% oil separation efficiency). This significantly reduces the circulation volume of lubricating oil in the refrigeration system to approximately 0.1%, ensuring extremely low oil content in the exhaust gas from the compressor and effectively reducing the circulation volume of lubricating oil in the refrigeration system, further preventing oil blockage. Furthermore, the compact layout of the exhaust chamber 15, filter chamber 17, and outlet chamber 16 fully utilizes the internal space of the outer casing 1, eliminating the need for an external oil-gas separator and making the overall compressor structure more compact.

[0039] Reference Figure 9 As shown, it can be understood that an exhaust check valve 151 is provided between the exhaust chamber 15 and the filter chamber 17.

[0040] By setting up an exhaust check valve 151, during normal operation of the screw compressor, the exhaust check valve 151 opens under the action of exhaust pressure, allowing high-pressure gas to smoothly pass through and enter the filter chamber 17 for oil-gas separation. When the screw compressor stops or the pressure on the outlet side is higher than that on the exhaust side, the exhaust check valve 151 automatically closes, completely blocking the path of reverse airflow. This prevents the exhaust back pressure from flowing back into the rotor chamber during shutdown, which could cause the screw rotor to reverse, and avoids the reciprocating flow of oil and gas caused by pressure fluctuations, thus ensuring the pressure stability and oil supply continuity of the oil circuit system.

[0041] Reference Figure 10 and Figure 11 As shown, it can be understood that the side wall of the outer casing 1 is provided with an air inlet 103 that communicates with the compression chamber 14. The air inlet 103 corresponds to the position of the female screw 22, and the shape of the air inlet 103 matches the profile of the female screw 22. The air inlet 103 is connected to the external economizer pipe. Specifically, the air inlet 103 is a waist-shaped structure that extends along the spiral direction of the female screw 22 on the side wall of the outer casing 1. That is, on the unfolded surface of the profile of the female screw 22, the long axis of the projection of the air inlet 103 is parallel to the profile. The projection of the air inlet 103 on the unfolded surface of the profile of the female screw 22 does not coincide with the projection of the suction port between the screw teeth (the projection formed by the meshing lines of the male screw 21 and the female screw 22). Moreover, the opening width of the air inlet 103 is less than or equal to the width of a single screw groove.

[0042] By setting a gas inlet 103 on one side of the female screw 22 that matches the profile of the female screw 22, it is ensured that after the suction port of the previous tooth is closed (i.e., the refrigerant between the tooth grooves enters the sealed space and begins to compress), it is connected to the gas inlet 103 of the economizer. This ensures that the gas inlet of the economizer does not affect the suction volume of the compressor, avoids leakage of gas inlet to the low-pressure side, and significantly improves the overall energy efficiency.

[0043] Reference Figure 7 and Figure 8 As shown, the outer casing 1 is provided with a motor cavity 18, which is located on the side of the intake bearing seat 11 away from the compression chamber 14. The stator winding and rotor winding of the motor rotor assembly 2 are installed in the motor cavity 18. The side wall of the motor cavity 18 is provided with a water cooling channel 181 for the flow of chilled water.

[0044] By setting up a water-cooling channel 181, chilled water can directly exchange heat with the motor rotor assembly 2 inside the motor cavity 18. The thermal path between the cooling water and the motor stator core and windings is extremely short and the thermal resistance is extremely small, which can efficiently remove the heat generated by the motor operation.

[0045] Furthermore, the evaporator 5 is a plate heat exchanger structure used to cool the battery assembly. The coolant circuit in the battery assembly is connected in parallel with the water cooling channel 181 to provide circulating coolant.

[0046] For example, under a certain actual test condition at room temperature, the screw compressor 11 has an intake saturation temperature of 12.2℃, an exhaust saturation temperature of 50.0℃, an intake superheat of 13℃, and a liquid phase temperature of 35℃. At this time, the cooling capacity of the screw compressor 11 is 83kW, the input power (i.e., the motor input power) is 30kW, the intake mass flow rate is 0.4673kg / s, the intake density is 19.4kg / m³, the intake volumetric flow rate is 86.61m³ / h, and the intake specific heat capacity is 0.934. The reciprocal of the product of mass flow rate and suction specific heat capacity is the suction temperature rise per unit of motor heat: 2.3℃ / (kJ / s). Assuming the motor efficiency is 85%, the heat generated by the motor is 3.67kW (kJ / s). After the heat is carried away by the suction, the suction superheat of the screw compressor 11 will increase by 8.4℃. Therefore, the calculated volumetric efficiency VE of the compressor decreases by 4.45%, the isentropic efficiency AE decreases by 5.1%, and the COP decreases by 9.1%. At this time, the control system can open the water flow regulating valve 24 to use coolant to cool the motor. The heat of 3.67kW needs to be balanced by the cooling capacity. The cooling capacity loss provided to the coolant is 3.67kW, accounting for 4.4% of the total cooling capacity of 83kW. Therefore, the efficiency loss of the motor by using coolant to cool it can be reduced by about 4.7%.

[0047] Based on the suction cooling, by setting up a water cooling channel 181, during normal operation, the casing 1 uses a small amount of coolant diverted from the coolant circuit to cool the motor (the suction cooling capacity is negligible), which improves the motor efficiency; when the ambient temperature is high, the refrigerant suction cooling and coolant cooling act on the motor at the same time, avoiding heat accumulation inside the compressor, ensuring stable cooling of the refrigerant circuit 1 and extending the service life of the compressor.

[0048] In some embodiments, the compressor adopts a semi-hermetic motor layout and a high-speed direct-drive structure. The motor is a high-efficiency permanent magnet synchronous motor. The motor stator has a cooling groove gap, and the rotor is an embedded or labeled permanent magnet assembly with a cooling airflow channel. The male screw 21 and female screw 22 are arranged vertically. The male screw 21 is placed on top of the compression chamber 14. At the moment of startup, the lubricating oil in the compressor motor chamber 18 is immediately discharged into the compressor exhaust chamber 15 through the rotation of the screw and is pressurized and supplied to the bearing, ensuring that the screw rotor is lubricated before rotation. The volume in the suction chamber 19 is directly pressurized and discharged into the exhaust oil groove through the screw meshing self-priming method, which facilitates the lubrication of the bearing, the male screw 21 and the female screw 22.

[0049] Reference Figure 8 As shown, it can be understood that the bracket 12 is provided with a vent 141 near the top, and a plunger 142 is slidably installed in the housing 1 along the vertical direction. The plunger 142 is located above the vent 141. The housing 1 is equipped with a valve assembly 110, which is used to drive the plunger 142 to move to open or close the vent 141. Specifically, in this application, the valve assembly 110 includes two solenoid valves disposed on the motor housing 1. The two solenoid valves are respectively connected to an external high-pressure oil circuit. An oil injection chamber is provided above the plunger 142. Multiple oil passage holes are provided at intervals on the inner wall of the oil injection chamber. A guide post connected to the plunger is provided at the center of the oil injection chamber. The guide post can slide in the vertical direction. A pressurized oil channel is provided above the guide post. Multiple oil passage holes are connected to the pressurized oil channel. One of the solenoid valves adds oil to the oil injection chamber through the oil passage holes so that high-pressure oil enters the pressurized oil channel and presses down the plunger 142. The other solenoid valve discharges oil from the oil injection chamber through the oil passage holes so that high-pressure oil in the pressurized oil channel flows out, thereby unlocking the plunger 142 and venting the compression chamber 14 in advance.

[0050] By setting a vent 141 and a plunger 142, when the compressor needs to reduce its internal volume ratio, the valve assembly 110 activates, releasing high-pressure oil to unlock the plunger 142. Compressed gas then directly pushes open the plunger 142, opening the vent 141. With the vent 141 open, some gas in the compression chamber 14 is discharged early in the compression process, effectively reducing the effective compression volume of the compression chamber 14 and consequently lowering the internal volume ratio. Conversely, when the compressor needs to increase its internal volume ratio, the valve assembly 110 activates, injecting high-pressure oil to press down the plunger 142, which closes the vent 141. With the vent 141 closed, all gas in the compression chamber 14 is discharged through the exhaust chamber 15 after compression, effectively increasing the effective compression volume of the compression chamber 14 and consequently increasing the internal volume ratio. This staged variable internal volume ratio design enables the compressor to achieve precise matching between the internal and external compression ratios under partial load conditions, eliminating over-compression and under-compression losses.

[0051] Specifically, refer to Figure 12 As shown, by adopting graded variable volume ratio control, the unit's COP can be increased by a maximum of 5.7% and 14.0% under AHRI 50% and 25% partial load operation conditions, and the IPLV can be increased by 7.5%.

[0052] Reference Figure 8 and Figure 9 As shown, it can be understood that the outer casing 1 is provided with an air intake chamber 19, which is located on the side of the motor cavity 18 away from the compression cavity 14, and an air intake filter 33 is installed between the air intake chamber 19 and the motor cavity 18.

[0053] The intake filter 33 is located between the intake chamber 19 and the motor chamber 18, so that the refrigerant vapor drawn in by the compressor is coarsely filtered before entering the motor chamber 18, effectively intercepting all solid particles carried in the intake and ensuring the cleanliness of the entire airflow path from the intake end to the compression chamber 14.

[0054] Reference Figure 9 As shown, it can be understood that the outer casing 1 is provided with a soundproof chamber 104, which is located between the support 12 and the inner wall of the outer casing 1, and the soundproof chamber 104 is filled with soundproofing materials. Optionally, the soundproofing materials can be sound-absorbing cotton, soundproofing felt, etc., which will not be described in detail here.

[0055] By setting up a soundproof chamber 104 and filling it with soundproofing components, noise must first pass through the soundproof chamber and its internal soundproofing components during its propagation from the compression chamber 14 outward. The sound waves undergo multiple reflections, refractions, and absorptions when passing through the soundproofing material, resulting in significant energy attenuation and effectively reducing the operating noise of the screw compressor.

[0056] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A screw compressor, characterized in that, include: The outer casing (1) has an intake bearing seat (11), a bracket (12), and an exhaust bearing seat (13) inside. A compression chamber (14) is defined between the intake bearing seat (11), the bracket (12), and the exhaust bearing seat (13). The intake bearing seat (11) has a first bearing cavity (111), a second bearing cavity (112), and a first oil return channel. The first oil return channel is connected to the first bearing cavity (111), the second bearing cavity (112), and the compression chamber (14), respectively. The exhaust bearing seat (13) has a third bearing cavity (131), a fourth bearing cavity (132), and a second oil return channel (133). The second oil return channel (133) is connected to the third bearing cavity (131), the fourth bearing cavity (132), and the compression chamber (14), respectively. The motor rotor assembly (2) includes a male screw (21) and a female screw (22) that mesh with each other. Both the male screw (21) and the female screw (22) are confined within the compression chamber (14). The two ends of the male screw (21) are rotatably mounted in the first bearing chamber (111) and the third bearing chamber (131) respectively through two sets of bearings. The two ends of the female screw (22) are rotatably mounted in the second bearing chamber (112) and the fourth bearing chamber (132) respectively through two other sets of bearings. The compression chamber (14) is provided with a filter assembly (3) for separating lubricating oil at its outlet. The filter assembly (3) has an oil outlet. The side wall of the outer shell (1) is provided with an oil supply system (4). The oil supply system (4) includes an oil distribution channel (41), a first oil supply channel (42), and a second oil supply channel (43). The oil distribution channel (41) is connected to the oil outlet, the first oil supply channel (42), and the second oil supply channel (43) respectively. The two ends of the first oil supply channel (42) are connected to the first bearing cavity (111) and the third bearing cavity (131) respectively. The two ends of the second oil supply channel (43) are connected to the second bearing cavity (112) and the fourth bearing cavity (132) respectively.

2. The screw compressor according to claim 1, characterized in that, The outer shell (1) has an oil outlet (105) on its side wall that communicates with the oil distribution channel (41). The oil supply system (4) also includes a third oil supply channel (44) that is connected to the oil outlet (105). One end of the third oil supply channel (44) passes through the outer shell (1), and the other end passes through the bracket (12) and communicates with the compression chamber (14).

3. The screw compressor according to claim 2, characterized in that, The outer wall of the outer casing (1) is provided with two first adjustment holes (101) and two second adjustment holes (102). The two first adjustment holes (101) penetrate the outer casing (1) and are connected to both ends of the first oil supply channel (42). The two second adjustment holes (102) penetrate the outer casing (1) and are connected to both ends of the second oil supply channel (43).

4. The screw compressor according to claim 3, characterized in that, The screw compressor has an evaporator (5) connected to its input end and a condenser (6) connected to its output end. The evaporator (5) and the condenser (6) are connected to form a circuit. An oil-cooled heat exchanger (7) is provided on the pipe between the evaporator (5) and the condenser (6). The input end of the oil-cooled heat exchanger (7) is connected to the oil outlet (105) pipe. The output end of the oil-cooled heat exchanger (7) is connected to the first regulating hole (101), the second regulating hole (102), and the third oil supply channel (44) pipe, respectively.

5. The screw compressor according to claim 1, characterized in that, The outer casing (1) is provided with an exhaust chamber (15), an air outlet chamber (16) and a filter chamber (17). The exhaust chamber (15) and the air outlet chamber (16) are located on both sides of the exhaust end bearing seat (13). The filter chamber (17) is located on the side of the exhaust end bearing seat (13) away from the compression chamber (14). The exhaust chamber (15) is connected to the air outlet chamber (16) through the filter chamber (17). The filter assembly (3) includes an oil separator (31) disposed in the filter chamber (17) and a precision filter (32) disposed in the air outlet chamber (16). The oil outlet is disposed at the output end of the precision filter (32).

6. The screw compressor according to claim 1, characterized in that, The side wall of the outer shell (1) is provided with an air inlet (103) that communicates with the compression chamber (14). The air inlet (103) corresponds to the position of the female screw (22) and the shape of the air inlet (103) matches the profile of the female screw (22).

7. The screw compressor according to claim 1, characterized in that, The outer casing (1) is provided with a motor cavity (18), which is located on the side of the intake bearing seat (11) away from the compression chamber (14). The motor rotor assembly (2) is installed in the motor cavity (18), and the side wall of the motor cavity (18) is provided with a water cooling channel (181) for the flow of chilled water.

8. The screw compressor according to claim 7, characterized in that, The outer casing (1) is provided with an air intake chamber (19), which is located on the side of the motor cavity (18) away from the compression chamber (14). An air intake filter (33) is installed between the air intake chamber (19) and the motor cavity (18).

9. The screw compressor according to claim 1, characterized in that, The top of the compression chamber (14) is provided with a vent (141). A plunger (142) is slidably installed in the housing (1) along the vertical direction. The plunger (142) is located above the vent (141). A valve assembly (110) is installed in the housing (1). The valve assembly (110) is used to drive the plunger (142) to move to open or close the vent (141).

10. The screw compressor according to claim 1, characterized in that, The outer shell (1) is provided with a soundproof chamber (104), which is located between the bracket (12) and the inner wall of the outer shell (1), and the soundproof chamber (104) is filled with soundproofing components.

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