Oil separation mechanism, compressor, air conditioner, and compressor oil control method

Abstract

The application relates to the technical field of oil-gas separation, and particularly relates to an oil separation mechanism, a compressor, an air conditioner and a compressor oil return control method. The base, the middle plate and the upper cover of the oil separation mechanism form a first exhaust cavity and a second exhaust cavity to realize multi-stage separation and eliminate oil film thermal resistance so as to improve energy efficiency. A plurality of gas guide parts of the base separate the first exhaust cavity into a plurality of exhaust channels, guide airflow to rotate in a centrifugal manner and throw oil droplets towards a cavity wall. The base and the middle plate are respectively provided with a first oil return hole and a second oil return hole to form a staged oil return passage, lubricating oil separated by the second exhaust cavity is collected into the first exhaust cavity through the second oil return hole, and then the lubricating oil and primary separated oil liquid are returned to an inner cavity through the first oil return hole. A one-way valve assembly is automatically opened and closed by using the pressure difference between the inner cavity and the first exhaust cavity. During operation, the pressure difference pushes a movable part to move upwards to seal and prevent gas leakage. After oil liquid accumulates, gravity overcomes the pressure difference to push the movable part to move downwards to open the oil return, intermittent oil return is realized, and the risk of continuous leakage or oil shortage is avoided.

Description

Technical Field

[0001] This application relates to the field of oil-gas separation technology, and in particular to an oil separation mechanism, a compressor, an air conditioner, and a compressor oil return control method. Background Technology

[0002] In traditional vapor compression refrigeration systems, the mixing and circulation of lubricating oil and refrigerant is a conventional method to ensure compressor lubrication and normal system operation. The high-pressure gaseous refrigerant discharged from the compressor typically carries a certain amount of lubricating oil. This oil-gas mixture enters the condenser or heat exchanger of a heat pump water heater via the exhaust pipe for condensation and heat exchange. Because the thermal conductivity of oil is much lower than that of metals and refrigerant, this oil film significantly increases thermal resistance, leading to decreased heat exchange efficiency and a lower system COP (Coefficient of Performance). In the heating mode of a heat pump water heater, this can even prevent the outlet water temperature from reaching the set value. To reduce the amount of lubricating oil entering the system circulation, existing technologies typically employ centrifugal or filter-type oil separators installed outside the compressor to separate the lubricating oil from the high-pressure exhaust. The separated lubricating oil is then returned to the compressor via an external oil return pipeline and control components such as solenoid valves.

[0003] When the system is operating at low load, starting at low temperature, or in long piping conditions, the refrigerant flow rate is insufficient, making it difficult to effectively carry the lubricating oil back to the compressor. If there is a lack of an efficient internal oil separation mechanism, a large amount of oil accumulation will cause the compressor to lack lubrication, which will accelerate wear or even cause the shaft to seize, or excessive oil will enter the compression chamber, causing the risk of liquid slugging. Summary of the Invention

[0004] One embodiment of this application provides an oil separation mechanism, a compressor, an air conditioner, and a compressor oil return control method to solve the problem that when the system is operating under low load, low temperature start-up, or long piping conditions, the refrigerant flow rate is insufficient, making it difficult to effectively return the lubricating oil to the compressor. If there is a lack of an efficient internal oil separation mechanism, a large amount of oil accumulation will lead to insufficient lubrication of the compressor, which will accelerate wear or even cause the compressor to seize, or excessive oil entering the compression chamber will cause the risk of liquid slugging.

[0005] In a first aspect, one embodiment of this application provides an oil separation mechanism applied to a compressor, the compressor having an inner cavity, including: The system comprises a base, a middle plate, a top cover, and a one-way valve assembly. The base and the middle plate together form a first exhaust chamber, and the middle plate and the top cover together form a second exhaust chamber. The base has a first exhaust hole that connects the first exhaust chamber and the inner cavity. The middle plate has multiple second exhaust holes that connect the first exhaust chamber and the second exhaust chamber. Each second exhaust hole is spaced apart along the circumference of the middle plate. The top cover has a third exhaust hole that connects the second exhaust chamber and the gas pipeline. The base is provided with a plurality of air guides that abut against the middle plate. Each air guide divides the first exhaust chamber into a plurality of exhaust channels. Each air guide is used to guide the airflow to the inner wall of the first exhaust chamber. The base is provided with a first oil return hole connecting the first exhaust chamber and the inner cavity, and the middle plate is provided with a second oil return hole connecting the second exhaust chamber and the first exhaust chamber. The one-way valve assembly is located at the first oil return port. The one-way valve assembly includes a movable part and a limiting part. The movable part can move under the pressure difference between the inner cavity and the first exhaust cavity to open and close the first oil return port.

[0006] Optionally, the base has a first guide wall on the side facing the first exhaust chamber, and the middle plate has a second guide wall on the side facing the second exhaust chamber. The height of the first guide wall gradually decreases from the middle to the edge, and the first oil return hole is located at the edge of the first guide wall. The height of the second guide wall gradually decreases from the middle to the edge, and the second oil return hole is located at the edge of the second guide wall.

[0007] Optionally, a first cylindrical ring is provided around the first exhaust hole, and a second cylindrical ring is provided on the middle plate. The first cylindrical ring is disposed inside the second cylindrical ring, and there is a gap between the first cylindrical ring and the second cylindrical ring. The upper cover has a third cylindrical ring on the side facing the second exhaust chamber, and the middle plate has a fourth cylindrical ring on the side facing the second exhaust chamber. The third cylindrical ring is located inside the fourth cylindrical ring, and there is a gap between the third cylindrical ring and the fourth cylindrical ring.

[0008] Optionally, an annular filter screen is provided between the upper cover and the middle plate, and the two ends of the annular filter screen are respectively snapped into the upper cover and the middle plate.

[0009] Optionally, the upper cover is provided with a first snap-fit ​​part, and the middle plate is provided with a second snap-fit ​​part. The first snap-fit ​​part and the second snap-fit ​​part are respectively snapped to both ends of the annular filter screen. The second snap-fit ​​part is provided with a plurality of overflow grooves, and the bottom of each overflow groove is connected to the second guide wall.

[0010] Optionally, the first oil return hole includes a first connecting section and a second connecting section, the diameter of the first connecting section is smaller than the diameter of the second connecting section, the movable member is a movable ball movably disposed within the second connecting section, and the limiting member is connected to the periphery of the second connecting section; the limiting member has a connecting hole that connects the second connecting section and the inner cavity.

[0011] Optionally, the first oil return hole further includes a sealing section disposed between the first connecting section and the second connecting section, wherein the inner wall of the sealing section can seal against the outer wall of the movable ball.

[0012] Optionally, the inner walls of the first exhaust chamber and the second exhaust chamber are both provided with an oleophobic layer.

[0013] Secondly, this application proposes a compressor, including a housing, a distributor, a pump assembly, a motor, and an oil separation mechanism provided in the first aspect of this application. The housing has an inner cavity and an exhaust port communicating with the inner cavity. The distributor is connected to the housing. The pump assembly, the motor, and the oil separation mechanism are all located in the inner cavity. The base is connected to the inner wall of the inner cavity. The periphery of the third exhaust port has an exhaust portion, which is located at the exhaust port.

[0014] Thirdly, this application proposes an air conditioner, including the oil separation mechanism provided in the first aspect of this application or the compressor provided in the second aspect of this application.

[0015] Fourthly, this application proposes a compressor oil return control method, applied to the compressor provided in the second aspect of this application, comprising the following steps: The compressor is started so that the gas containing lubricating oil enters the first exhaust chamber from the inner cavity through the first exhaust port, and collides with the inner wall of the first exhaust chamber under the guidance of the gas guide. After the initial collision, the gas enters the second exhaust chamber through the second exhaust port, collides with the inner walls of the middle plate and the upper cover, and is then discharged from the third exhaust port. Under the influence of inertia and gravity, the lubricating oil in the gas separates from the gas and flows sequentially from the second return oil hole into the first return oil hole, and then flows back to the inner cavity through the one-way valve assembly; The one-way valve assembly automatically adjusts the opening and closing of the first oil return hole based on the pressure difference between the inner cavity and the first exhaust cavity and the gravity of the oil.

[0016] The technical solution provided in this application, compared with the prior art, has the following advantages: The oil separation mechanism provided in one embodiment of this application divides the separation chamber into a first exhaust chamber and a second exhaust chamber through a three-layer stacked structure of a base, a middle plate, and a top cover, forming a spatial basis for multi-stage separation. This eliminates the need for an external independent oil separator, enabling step-by-step oil-gas separation within the compressor. This reduces the amount of lubricating oil entering the system pipeline from the source, eliminates the adverse effects of oil film thermal resistance on heat exchange efficiency within the heat exchanger, and helps improve the system's energy efficiency ratio. Multiple air guides on the base divide the first exhaust chamber into multiple independent exhaust channels. Each air guide directs the airflow towards the inner wall of the first exhaust chamber, causing the oil-gas mixture to generate a centrifugal rotation effect upon entering the first exhaust chamber. Utilizing the density difference between oil droplets and gas, the denser oil droplets are thrown towards the chamber wall to achieve centrifugal separation, increasing the separation path length and the number of centrifugal actions, thus improving the primary separation efficiency. The parallel arrangement of multiple channels also ensures sufficient airflow cross-sectional area under large displacement conditions, avoiding deterioration of the separation effect or excessive pressure drop due to excessively high local flow velocities. The base has a first oil return hole connecting the first exhaust chamber and the inner cavity, and the middle plate has a second oil return hole connecting the second exhaust chamber and the first exhaust chamber, forming a staged oil return path. A small amount of lubricating oil separated in the second exhaust chamber can flow back to the first exhaust chamber through the second oil return hole. After being combined with the large amount of lubricating oil separated in the first exhaust chamber, they flow back to the compressor inner cavity through the first oil return hole. This ensures that the lubricating oil separated at each stage can be effectively recovered, and avoids the need to set up multiple independent oil return channels to the inner cavity, which would increase the number of openings in the housing and the processing complexity. The one-way valve assembly consisting of a moving part and a limiting part at the first oil return hole automatically controls the opening and closing of the oil return hole by using the pressure difference between the inner cavity and the first exhaust chamber. When the compressor is running, the pressure difference causes the moving part to move upward to seal the oil return hole, thereby preventing high-pressure gas from leaking through the oil return hole and causing energy loss. When the accumulated lubricating oil level rises, its gravity overcomes the pressure difference and pushes the moving part downward to open the oil return. This achieves adaptive intermittent oil return based on the actual oil return volume, avoiding the gas leakage problem caused by continuous oil return and the risk of compressor oil shortage caused by no oil return. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise specified, the figures in the drawings are not to be limited by scale.

[0020] Figure 1 A schematic diagram of the structure of a compressor provided in this application embodiment. Figure 1 ; Figure 2 for Figure 1 Sectional view along the AA direction; Figure 3 for Figure 2 A magnified view at point H; Figure 4 for Figure 2 Enlarged view at point I; Figure 5 for Figure 1 Sectional view in the BB direction Figure 1 ; Figure 6 for Figure 1 Sectional view in the BB direction Figure 2 ; Figure 7 This is a schematic diagram of the structure of an oil separation mechanism provided in an embodiment of this application; Figure 8 for Figure 7 Sectional view in the CC direction; Figure 9 This is a schematic diagram of the structure of the base provided in an embodiment of this application; Figure 10 for Figure 9 Sectional view in the DD direction; Figure 11 A schematic diagram of the structure of the middle plate provided in the embodiments of this application. Figure 1 ; Figure 12 for Figure 11 Sectional view in the EE direction; Figure 13 A schematic diagram of the structure of the middle plate provided in the embodiments of this application. Figure 2 ; Figure 14 This is a schematic diagram of the structure of the top cover provided in an embodiment of this application; Figure 15 for Figure 14 Sectional view in the FF direction; Figure 16 This is a schematic diagram of the structure of the limiting member provided in the embodiments of this application; Figure 17 for Figure 16 Cross-sectional view in the GG direction.

[0021] Explanation of reference numerals in the attached figures: 1. Base; 1a. First exhaust chamber; 1b. First exhaust hole; 11. Air guide section; 1c. Exhaust channel; 1d. First oil return hole; 12. First guide wall; 13. First cylindrical ring; 1d1. First connecting section; 1d2. Second connecting section; 1d3. Sealing section; 2. Middle plate; 2a. Second exhaust chamber; 2b. Second exhaust hole; 2c. Second oil return hole; 21. Second guide wall; 22. Second cylindrical ring; 23. Fourth cylindrical ring; 24. Second snap-fit ​​part; 24a. Overflow groove; 3. Top cover; 3a. Third vent; 31. Third cylindrical ring; 32. First snap-fit ​​part; 33. Vent part; 4. One-way valve assembly; 41. Moving part; 42. Limiting part; 43. Moving ball; 42a. Connecting hole; 5. Circular filter screen; 6. Housing; 6a. Inner cavity; 6b. Exhaust port; 7. Dispenser; 8. Pump body assembly; 9. Electric motor. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0024] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0025] To address the technical problem that insufficient refrigerant flow rate makes it difficult to effectively return lubricating oil to the compressor when the system is operating under low load, low temperature start-up, or long piping conditions, and that a lack of an efficient internal oil separation mechanism can lead to excessive oil accumulation, resulting in insufficient lubrication of the compressor and accelerated wear or even bearing seizure, or excessive oil entering the compression chamber and causing liquid slugging risk, this application provides an oil separation mechanism. Through a three-layered structure of base, middle plate, and top cover, the separation chamber is divided into a first exhaust chamber and a second exhaust chamber, forming a multi-stage separation spatial basis. This eliminates the need for an external independent oil separator, achieving step-by-step oil-gas separation within the compressor. This reduces the amount of lubricating oil entering the system piping from the source, eliminates the adverse effects of oil film thermal resistance on heat exchange efficiency within the heat exchanger, and helps improve the system's energy efficiency ratio.

[0026] Figures 1 to 17An oil separation mechanism provided in one embodiment of this application includes a base 1, a middle plate 2, a top cover 3, and a one-way valve assembly 4. The compressor has an inner cavity 6a for accommodating a motor 9, a pump assembly 8, and lubricating oil. The oil separation mechanism is integrally assembled in the inner cavity 6a of the compressor and can separate the oil and gas discharged from the compressor and guide it to the gas pipeline. The base 1 is generally a disc-shaped structure with multiple protrusions on its outer periphery. The protrusions are fixedly connected to the inner wall of the compressor housing 6, for example, by welding or interference fit. The oil-gas mixture discharged from the compressor enters the first exhaust chamber 1a through the first exhaust hole 1b opened in the base 1. The first exhaust chamber 1a is formed by the base 1 and the middle plate 2 being arranged vertically opposite each other. The middle plate 2 and the base 1 can be fixedly connected by bolts or buckles and maintain a predetermined distance to ensure the cross-sectional area for airflow. The upper surface of the base 1 is provided with a plurality of air guides 11. These air guides 11 can be arc-shaped guide ribs or spiral guide blades protruding from the upper surface of the base 1. Each air guide 11 is distributed circumferentially along the base 1 and extends outward from the central area of ​​the base 1 and bends. Adjacent air guides 11, together with the upper surface of the base 1 and the lower surface of the middle plate 2, form a plurality of independent exhaust channels 1c. The extension direction of each air guide 11 is set to guide the airflow toward the inner wall of the first exhaust chamber 1a, so that the oil-gas mixture impacts the inner wall in a roughly tangential or spiral direction after entering the first exhaust chamber 1a, and the primary separation of oil and gas is achieved by using centrifugal force. The middle plate 2 has multiple second exhaust holes 2b, which are spaced apart around the circumference of the middle plate 2. The position of each second exhaust hole 2b corresponds to the end area of ​​each exhaust channel 1c, so that the relatively clean airflow after primary centrifugal separation enters the second exhaust chamber 2a formed by the middle plate 2 and the upper cover 3 from the second exhaust holes 2b. The upper cover 3 has a third exhaust hole 3a in the center or off-center position, which is used to connect the second exhaust chamber 2a with the external gas pipeline (such as the air inlet pipeline of the condenser or heat exchanger), so that the clean high-pressure gas after multi-stage separation is discharged from the compressor.

[0027] Regarding the oil return path, the base 1 has a first oil return hole 1d that penetrates the plate of the base 1. This first oil return hole 1d is generally located at the lowest position on the upper surface of the base 1 (for example, the upper surface of the base 1 can be set as a slope surface that gradually decreases from the center to the periphery), so that the separated lubricating oil gathers at the first oil return hole 1d under the action of gravity. The one-way valve assembly 4 of the first oil return hole 1d includes a movable part 41 and a limiting part 42. The movable part 41 can be a ball (e.g., a steel ball or a ceramic ball) or a conical valve core. The limiting part 42 can be a screw plug with a connecting hole 42a or a retainer with a limiting claw. The limiting part 42 is fixedly installed at the lower end of the first oil return hole 1d (on the side adjacent to the inner cavity 6a) and restricts the movable part 41 in the internal space of the first oil return hole 1d. When the compressor is stopped or the pressure difference between the first exhaust chamber 1a and the inner chamber 6a is small, the movable part 41 can rely on its own gravity or spring force to leave the upper sealing surface of the first oil return hole 1d, thereby opening the first oil return hole 1d and allowing the lubricating oil to flow back to the inner chamber 6a. When the compressor is running stably, the pressure in the inner chamber 6a is greater than the pressure in the first exhaust chamber 1a. Under the action of this pressure difference, the movable part 41 is pushed upward and pressed against the periphery of the first oil return hole 1d to form a seal, thereby closing the first oil return hole 1d. When the lubricating oil level above the first oil return hole 1d rises to a predetermined height, the gravity of the liquid overcomes the pressure difference force and causes the movable part 41 to move downward, briefly opening the oil return channel to achieve intermittent oil discharge. Afterward, the liquid level drops and the movable part 41 moves upward again to seal, thereby achieving automatic intermittent oil return. The middle plate 2 has a second oil return hole 2c, which connects the second exhaust chamber 2a and the first exhaust chamber 1a. It is used to discharge the lubricating oil that is separated twice in the second exhaust chamber 2a downward into the first exhaust chamber 1a, and finally return to the compressor inner cavity 6a through the first oil return hole 1d.

[0028] The oil separation mechanism of this application divides the separation chamber into a first exhaust chamber 1a and a second exhaust chamber 2a through a three-layer stacked structure of base 1, middle plate 2, and upper cover 3, forming a spatial basis for multi-stage separation. This eliminates the need for an external independent oil separator, enabling step-by-step oil-gas separation within the compressor. This reduces the amount of lubricating oil entering the system pipeline from the source, eliminates the adverse effects of oil film thermal resistance on heat exchange efficiency within the heat exchanger, and helps improve the system's energy efficiency ratio. Multiple air guides 11 on the base 1 divide the first exhaust chamber 1a into multiple independent exhaust channels 1c. Each air guide 11 guides the airflow towards the inner wall of the first exhaust chamber 1a, causing the oil-gas mixture to generate a centrifugal rotation effect upon entering the first exhaust chamber 1a. Utilizing the density difference between oil droplets and gas, the denser oil droplets are thrown towards the chamber wall to achieve centrifugal separation, increasing the separation path length and the number of centrifugal actions, thus improving the primary separation efficiency. The parallel arrangement of multiple channels also ensures sufficient airflow cross-sectional area under large displacement conditions, avoiding deterioration of the separation effect or excessive pressure drop due to excessively high local flow velocities. The base 1 has a first oil return hole 1d connecting the first exhaust chamber 1a and the inner cavity 6a, and the middle plate 2 has a second oil return hole 2c connecting the second exhaust chamber 2a and the first exhaust chamber 1a, forming a graded oil return path. A small amount of lubricating oil separated in the second exhaust chamber 2a can flow back to the first exhaust chamber 1a through the second oil return hole 2c. After being combined with a large amount of lubricating oil separated in the first exhaust chamber 1a, they flow back to the compressor inner cavity 6a through the first oil return hole 1d. This ensures that the lubricating oil separated at each stage can be effectively recovered, and avoids increasing the number of openings and processing complexity of the housing 6 by setting up multiple independent oil return channels to the inner cavity 6a.

[0029] The one-way valve assembly 4, consisting of a movable part 41 and a limiting part 42 located at the first oil return port 1d, automatically controls the opening and closing of the oil return port using the pressure difference between the inner cavity 6a and the first exhaust cavity 1a. When the compressor is running, the pressure difference causes the movable part 41 to move upward and seal the oil return port, thereby preventing high-pressure gas from leaking through the oil return port and causing energy loss. When the accumulated lubricating oil level rises, its gravity overcomes the pressure difference and pushes the movable part 41 downward to open the oil return. This achieves adaptive intermittent oil return based on the actual oil return volume, avoiding the gas leakage problem caused by continuous oil return and the risk of compressor oil shortage caused by no oil return. At the same time, this mechanical pressure difference control structure can independently complete the automatic oil return control under all working conditions without external control components such as solenoid valves, simplifying the system control logic and improving reliability. The first exhaust port 1b, multiple circumferentially spaced second exhaust ports 2b, and the third exhaust port 3a create a progressively contracting and expanding cross-section along the airflow path. As the airflow flows between the chambers, its velocity changes periodically, facilitating the sequential separation of oil droplets of different sizes under varying flow velocities due to gravity settling. This broadens the separation range for oil droplet sizes and improves overall separation efficiency. The second exhaust ports 2b are spaced circumferentially along the middle plate 2, ensuring that airflow enters the second exhaust chamber 2a uniformly from each exhaust channel 1c of the first exhaust chamber 1a. This avoids localized overload caused by airflow deviation, improving the uniformity and stability of the second-stage separation. The entire oil separation mechanism is integrated inside the compressor, eliminating the need for an external oil separator, matching return oil lines, and solenoid valves. This reduces the number of system components and pipeline welds, lowers the risk of refrigerant leakage and production costs, and eliminates the pressure drop losses associated with an external oil separator.

[0030] Please see Figures 7 to 10In one embodiment, a first guide wall 12 is provided on the side of the base 1 facing the first exhaust chamber 1a (i.e., the upper surface of the base 1). The first guide wall 12 is the surface shape of the upper surface of the base 1 itself. Specifically, its configuration is such that its height (relative to the lower surface of the base 1 or the reference plane of the ground) gradually decreases from the middle region of the base 1 towards the outer peripheral edge. The first guide wall 12 can be a conical surface or a curved surface whose radial height decreases from the center to the periphery, or it can be composed of multiple inclined guide surfaces that are radially distributed from the central region to the edge. The inclined guide surfaces can be connected by arc-shaped transition edges. The first oil return hole 1d is opened on the base 1 and located at the edge of the first guide wall 12, that is, at the lowest point of the upper surface of the base 1. It can be a through hole opened at one or more points on the outer periphery of the base 1, or it can be a through hole opened at the lowest point of the annular oil collection groove provided in the edge region of the base 1. Based on the configuration of the first guide wall 12, which gradually decreases in height from the middle to the edge, the separated lubricating oil naturally flows towards the lower edge on the bottom surface of the first exhaust chamber 1a due to gravity, and finally converges at the first oil return hole 1d at the edge of the first guide wall 12. Similarly, a second guide wall 21 is provided on the side of the middle plate 2 facing the second exhaust chamber 2a (i.e., the upper surface of the middle plate 2). The configuration of the second guide wall 21 is also that the height gradually decreases from the middle region of the middle plate 2 towards the outer peripheral edge. The second guide wall 21 can be a conical surface, a curved surface, or a combination of multiple inclined guide surfaces. The second oil return hole 2c is opened on the middle plate 2 and located at the edge of the second guide wall 21, that is, at the lowest height of the upper surface of the middle plate 2. It can be a through hole opened at one or more locations on the outer periphery of the middle plate 2, or it can be a through hole opened at the lowest point of the annular oil collection groove in the edge region of the middle plate 2. The lubricating oil separated from the upper surface of the middle plate 2 flows naturally along the slope of the second guide wall 21 to the lowest edge, and is discharged downward into the first exhaust chamber 1a through the second oil return hole 2c.

[0031] The first guide wall 12 on the base 1 gradually decreases in height from the middle to the edge, providing a clear directional flow path from the middle to the edge for the lubricating oil separated in the first exhaust chamber 1a. This allows the oil droplets to automatically converge to the lowest edge under the action of gravity without the need for additional power, avoiding the large-area accumulation of lubricating oil in the middle region of the base 1 and the formation of an oil film layer. This reduces the risk of secondary entrainment caused by the oil film covering the airflow when passing through the first exhaust chamber 1a. The first oil return hole 1d is located at the lowest edge of the first guide wall 12, allowing the lubricating oil that has gathered to the edge to be discharged from the first exhaust chamber 1a via the shortest path. This reduces the residence time of the lubricating oil on the surface of the base 1 and improves the timeliness of oil return. The second guide wall 21 on the middle plate 2 gradually decreases in height from the middle to the edge, which also provides a directional guide path for the lubricating oil separated in the second exhaust chamber 2a. This allows the small amount of lubricating oil separated in the second stage to quickly converge along the upper surface of the middle plate 2 to the second oil return hole 2c at the edge and be discharged into the first exhaust chamber 1a. This avoids the lubricating oil from lingering on the bottom surface of the second exhaust chamber 2a (i.e. the upper surface of the middle plate 2) for a long time and forming an oil film. It also reduces the risk that the clean airflow will impact and disturb the oil film when passing through the upper surface of the middle plate 2 before being discharged, and will carry the tiny oil droplets out again. The first oil return hole 1d is located at the edge of the first guide wall 12, and the second oil return hole 2c is located at the edge of the second guide wall 21, with the two corresponding in the vertical direction. This allows the lubricating oil collected at the edge of the second guide wall 21 to drip through the second oil return hole 2c and fall precisely into the edge area of ​​the first guide wall 12. The lubricating oil then flows directly into the first oil return hole 1d along the slope of the first guide wall 12. This achieves the convergence and connection of the two-stage oil return paths at the lowest point of the edge, avoiding the need for the lubricating oil discharged from the second-stage oil return to cross the higher area of ​​the first guide wall 12 to reach the first oil return hole 1d. This reduces the length of the oil return path and the oil flow resistance, thereby improving the oil return efficiency.

[0032] Please see Figure 6 and Figure 9In this embodiment, a first cylindrical ring 13 is provided on the periphery of the first exhaust hole 1b (i.e., the edge of the opening of the first exhaust hole 1b located on one side of the first exhaust cavity 1a). The first cylindrical ring 13 is an annular tubular wall that protrudes upward from the upper surface of the base 1 (i.e. towards the middle plate 2). Its lower end is integrally connected to the upper surface of the base 1 or fixed by welding. The inner hole of the first cylindrical ring 13 is coaxially arranged with the first exhaust hole 1b and the inner diameter is consistent with the inner diameter of the first exhaust hole 1b, so that the airflow enters from the first exhaust hole 1b and flows directly upward along the inner hole of the first cylindrical ring 13. A second cylindrical ring 22 is provided on the side of the middle plate 2 facing the first exhaust chamber 1a (i.e., the lower surface of the middle plate 2). The second cylindrical ring 22 is an annular wall protruding downward (i.e. towards the base 1) from the lower surface of the middle plate 2. Its inner diameter is larger than the outer diameter of the first cylindrical ring 13. The second cylindrical ring 22 and the first cylindrical ring 13 are coaxially arranged, and the first cylindrical ring 13 is located inside the second cylindrical ring 22. The two do not contact each other in the radial direction and form a gap between the outer wall of the first cylindrical ring 13 and the inner wall of the second cylindrical ring 22. The width of the gap can be set according to the designed airflow velocity, for example, the gap width is 2mm to 10mm. A certain vertical distance is maintained between the upper end face of the first cylindrical ring 13 and the lower surface of the middle plate 2, or the upper end face of the first cylindrical ring 13 can extend into the internal space of the second cylindrical ring 22 but does not contact the upper end (i.e., the root) of the second cylindrical ring 22. Based on the above structure, the oil-gas mixture enters through the first exhaust port 1b and rises along the inside of the first cylindrical ring 13. After exiting through the upper opening of the first cylindrical ring 13, it is deflected by the obstruction of the second cylindrical ring 22 and passes through the annular gap between the outer wall of the first cylindrical ring 13 and the inner wall of the second cylindrical ring 22 to enter the first exhaust chamber 1a. A third cylindrical ring 31 is provided on the side of the upper cover 3 facing the second exhaust chamber 2a (i.e., the lower surface of the upper cover 3). The third cylindrical ring 31 is an annular tubular wall protruding downward (i.e. towards the middle plate 2) from the lower surface of the upper cover 3. It is integrally connected or welded to the upper cover 3, and the third cylindrical ring 31 is arranged around the third exhaust port 3a. A fourth cylindrical ring 23 is provided on the side of the middle plate 2 facing the second exhaust chamber 2a (i.e., the upper surface of the middle plate 2). The fourth cylindrical ring 23 is an annular wall protruding upward (i.e. towards the upper cover 3) from the upper surface of the middle plate 2. Its inner diameter is larger than the outer diameter of the third cylindrical ring 31. The third cylindrical ring 31 is located inside the fourth cylindrical ring 23 and the two are coaxially arranged. A gap is formed between the outer wall of the third cylindrical ring 31 and the inner wall of the fourth cylindrical ring 23. The width of the gap can be set according to the designed airflow velocity in the second exhaust chamber 2a. For example, the gap width is 1.5mm to 8mm. A vertical distance is maintained between the lower end face of the third cylindrical ring 31 and the upper surface of the middle plate 2, or the lower end of the third cylindrical ring 31 can extend into the interior of the fourth cylindrical ring 23 but does not contact the lower end (root) of the fourth cylindrical ring 23.

[0033] The first cylindrical ring 13 surrounding the first vent 1b is surrounded by the second cylindrical ring 22 on the middle plate 2, forming an annular gap between them. This structure prevents the oil-gas mixture entering from the first vent 1b from flowing directly radially to the second vent 2b. Instead, it must exit from the opening at the upper end of the first cylindrical ring 13 and then flow radially out through the annular gap between the outer wall of the first cylindrical ring 13 and the inner wall of the second cylindrical ring 22. This forced turning process causes oil droplets in the airflow to collide with the outer wall of the first cylindrical ring 13 or the inner wall of the second cylindrical ring 22 due to inertia, resulting in agglomeration and separation. At the same time, the existence of the annular gap expands the airflow cross-sectional area from the inner hole cross-sectional area of ​​the first cylindrical ring 13 to the annular cross-sectional area, and the change in flow velocity promotes the settling of oil droplets. In addition, the outer wall of the first cylindrical ring 13 The gap between the first cylindrical ring 13 and the inner wall of the second cylindrical ring 22 forms an annular buffer cavity around the first exhaust hole 1b, which makes the airflow uniformly distributed circumferentially before entering the first exhaust cavity 1a. This avoids the formation of a high-speed jet in a local area when the airflow is directly injected from the first exhaust hole 1b into the first exhaust cavity 1a, which would cause the separated oil film to be blown away and carried away again. This improves the uniformity and stability of centrifugal separation in the first exhaust cavity 1a. The meandering channel formed by the first cylindrical ring 13 and the second cylindrical ring 22 in the radial direction also prevents the lubricating oil separated at the bottom of the first exhaust cavity 1a from flowing back to the first exhaust hole 1b along the lower surface of the middle plate 2. This confines the lubricating oil to the outer area of ​​the first cylindrical ring 13, reducing the risk of lubricating oil flowing back to the first exhaust hole 1b.Similarly, the third cylindrical ring 31 on the side of the upper cover 3 facing the second exhaust chamber 2a and the fourth cylindrical ring 23 on the side of the middle plate 2 facing the second exhaust chamber 2a are nested inside each other and form a gap. This structure prevents the airflow entering the second exhaust chamber 2a through the second exhaust hole 2b of the middle plate 2 from flowing directly radially to the third exhaust hole 3a. Instead, it first flows from the outside of the fourth cylindrical ring 23 to the inside, passes through the annular gap, and then enters the interior of the third cylindrical ring 31 and is discharged. This path also forces the airflow to change direction multiple times. By utilizing the inertia of the oil droplets, they collide with the wall of the third cylindrical ring 31 or the fourth cylindrical ring 23 during the turning process, further coalescing and separating, thus improving the secondary separation effect in the second exhaust chamber 2a. At the same time, the annular gap between the third cylindrical ring 31 and the fourth cylindrical ring 23 has a throttling effect on the airflow, causing the airflow to flow before entering the interior region of the third cylindrical ring 31. The reduced speed facilitates the further settling of tiny oil droplets within the second exhaust chamber 2a by gravity. The staggered arrangement of the upper end of the third cylindrical ring 31 connected to the upper cover 3 and the lower end suspended, and the lower end of the fourth cylindrical ring 23 connected to the middle plate 2 and the upper end suspended, along with the annular gap between them, divides the second exhaust chamber 2a into an outer and inner region. Only airflow passing through the gap can reach the third exhaust port 3a, preventing the lubricating oil accumulated at the bottom of the second exhaust chamber 2a from being directly carried to the exhaust pipe by the airflow, thus playing a labyrinth seal role in preventing secondary oil carryover. Furthermore, the sleeve structure of the third cylindrical ring 31 and the fourth cylindrical ring 23 forms a mutually covering shielding area in the vertical direction. Even if the compressor tilts during operation, the sloshing of the liquid surface in the second exhaust chamber 2a will be effectively blocked by this annular wall, reducing the risk of lubricating oil being directly discharged through the third exhaust port 3a.

[0034] Please see Figure 2 and Figure 3In one embodiment, an annular filter 5 is provided between the upper cover 3 and the middle plate 2. The annular filter 5 is a circular sheet or cylindrical structure surrounding the third exhaust hole 3a. It is disposed within the second exhaust chamber 2a and located on the flow path from the second exhaust chamber 2a to the third exhaust hole 3a. The annular filter 5 can be made of materials such as woven metal wire mesh (e.g., stainless steel wire mesh), porous metal foam (e.g., nickel-based foam metal), organic fiber felt (e.g., polyester fiber or nylon fiber felt), or glass fiber filter media. Its mesh size can be determined according to the designed separation accuracy. The two ends of the annular filter 5, namely the upper end and the lower end in the axial direction, are fixedly connected to the upper cover 3 and the middle plate 2 by a snap-fit ​​method, respectively. Specifically, the upper cover 3 may be provided with an upper annular groove or an upper annular claw on the side (i.e., the lower surface) facing the second exhaust chamber 2a, and the middle plate 2 may be provided with a lower annular groove or a lower annular claw on the side (i.e., the upper surface) facing the second exhaust chamber 2a; the upper edge of the annular filter screen 5 may be provided with an upper flange or an upper snap-fit ​​part, which is embedded in the upper annular groove of the upper cover 3 and engaged with it; the lower edge of the annular filter screen 5 may be provided with a lower flange or a lower snap-fit ​​part, which is embedded in the lower annular groove of the middle plate 2 and engaged with it.

[0035] The annular filter screen 5, located between the upper cover 3 and the middle plate 2, provides a further filtration and separation mechanism based on primary and secondary separation methods such as centrifugal separation and gravity sedimentation. When the airflow passes through the fine mesh of the filter screen, the tiny oil droplets remaining in the airflow are intercepted because they cannot pass through the mesh. They then coalesce into larger droplets at the mesh and drip off under gravity, thus achieving the fine capture of ultra-fine oil droplets and improving the overall separation efficiency and exhaust cleanliness of the oil separation mechanism. The two ends of the annular filter screen 5 are respectively snap-fitted to the upper cover 3 and the middle plate 2. The snap-fit ​​structure can achieve axial positioning and radial limiting of the filter screen without additional fasteners such as bolts, screws, or welding, simplifying the assembly process and reducing parts costs. At the same time, the snap-fit ​​connection facilitates the disassembly and replacement of the annular filter screen 5. When the filter screen becomes clogged or its performance deteriorates due to long-term use, it can be directly pulled out from between the upper cover 3 and the middle plate 2 or removed from the snap-fit ​​structure for cleaning or replacement without disassembling the entire oil separation mechanism, thus improving maintenance convenience and product lifespan. The annular filter 5 is located in the second exhaust chamber 2a, upstream of the third exhaust port 3a. This allows the airflow, after multiple stages of separation, to undergo another filtration and separation in the final exhaust stage. This serves as a supplement to the previous separation process to capture any residual oil droplets that are not completely separated. Furthermore, because it is located in the final stage, it avoids the problem of rapid clogging and sudden pressure drop caused by the direct impact of the high-concentration oil-gas mixture from the previous stage on the filter, thus extending the single-use cycle of the filter.

[0036] Please see Figure 3 , Figure 13 as well as Figure 15In this embodiment, the first snap-fit ​​part 32 and the second snap-fit ​​part 24 are respectively annular ribs or annular claw structures protruding from the surface of the cover or the surface of the middle plate 2. The upper edge of the annular filter screen 5 is engaged and fixed with the first snap-fit ​​part 32 of the upper cover 3, and the lower edge of the annular filter screen 5 is engaged and fixed with the second snap-fit ​​part 24 of the middle plate 2. The first snap-fit ​​part 32 can be an annular rib provided on the lower surface of the upper cover 3, and the upper edge of the annular filter screen 5 is embedded in the inner side of the annular rib to achieve snap-fit ​​through interference fit. The second snap-fit ​​part 24 can be an annular rib provided on the upper surface of the middle plate 2, and the lower edge of the annular filter screen 5 is embedded in the inner side of the annular rib to achieve snap-fit ​​through interference fit. The second snap-fit ​​portion 24 is provided with a plurality of overflow grooves 24a. Each overflow groove 24a is a radial through groove, cut groove or notch that is opened at intervals along the circumference of the annular rib of the second snap-fit ​​portion 24. The plurality of overflow grooves 24a are evenly distributed along the circumference of the middle plate 2. The bottom of each overflow groove 24a is connected to the second guide wall 21, that is, the lower end of the overflow groove 24a is smoothly connected to the second guide wall 21 on the upper surface of the middle plate 2, so that the lubricating oil of the annular filter screen 5 located at the position of the second snap-fit ​​portion 24 can flow into the second guide wall 21 along the bottom of the overflow groove 24a.

[0037] The first snap-fit ​​part 32 of the upper cover 3 and the second snap-fit ​​part 24 of the middle plate 2 respectively snap-fit ​​the two ends of the annular filter screen 5, so that the filter screen is tensioned and fixed in the axial direction. Reliable connection can be achieved without bolts or other additional fasteners, simplifying the assembly process and facilitating disassembly and replacement. Moreover, the two snap-fit ​​parts are respectively set on the upper cover 3 and the middle plate 2, so that the disassembly of the annular filter screen 5 can be completed without disassembling the entire oil separation mechanism, improving maintenance convenience. The multiple overflow grooves 24a provided in the second snap-fit ​​part 24 allow the lubricating oil of the annular filter screen 5 located at the second snap-fit ​​part 24 to flow into the second guide wall 21 along the bottom of the overflow grooves 24a, thus preventing oil accumulation caused by the continuous annular wall structure of the second snap-fit ​​part 24 blocking the oil discharge path. The overflow grooves 24a are distributed circumferentially, so that the lubricating oil converging in all directions in the circumferential direction has the shortest discharge path, avoiding local oil accumulation, and the lubricating oil can be directly discharged into the first exhaust chamber 1a below without the need for additional oil discharge channels, simplifying the return oil path. The spaced arrangement of the multiple overflow grooves 24a ensures that the second snap-fit ​​part 24 has sufficient snap-fit ​​area to ensure the fixed reliability of the filter screen, and also provides a uniformly distributed oil discharge path.

[0038] Please see Figure 4 , Figure 8 as well as Figure 10In one embodiment, the first oil return hole 1d on the base 1 includes a first connecting segment 1d1 and a second connecting segment 1d2. The first connecting segment 1d1 is located on one side of the first exhaust chamber 1a (i.e., the upstream segment of the first oil return hole 1d), and the second connecting segment 1d2 is located on one side of the inner cavity 6a (i.e., the downstream segment of the first oil return hole 1d). The two segments are interconnected and arranged sequentially along the axial direction of the first oil return hole 1d. The diameter of the first connecting segment 1d1 is smaller than the diameter of the second connecting segment 1d2, so that the junction of the first connecting segment 1d1 and the second connecting segment 1d2 forms an annular stepped surface, which faces the second connecting segment 1d2. The movable component 41 is a movable ball 43 (e.g., a steel ball, stainless steel ball, or ceramic ball), which is movably disposed within the second connecting section 1d2. The diameter of the movable ball 43 is larger than the diameter of the first connecting section 1d1 but smaller than the diameter of the second connecting section 1d2, allowing the movable ball 43 to move freely axially within the second connecting section 1d2. When moving upward, it can fit against the annular stepped surface at the junction of the first connecting section 1d1 and the second connecting section 1d2 to form a seal. The limiting component 42 (e.g., a screw plug with a connecting hole 42a, a pressure plate with a central hole, or a retainer with limiting claws) is connected to the periphery of the second connecting section 1d2. Specifically, the inner wall of the lower end of the second connecting section 1d2 (adjacent to the inner cavity 6a) may be provided with internal threads, and the limiting component 42 is a screw plug with external threads on its outer periphery. The screw plug is tightened and fixed by engaging the internal threads of the second connecting section 1d2; or the limiting component 42 is fixed to the lower end of the second connecting section 1d2 by welding or interference fit. The limiting member 42 has a connecting hole 42a that connects the second connecting section 1d2 and the inner cavity 6a. This connecting hole 42a can be a cross groove connecting hole 42a in the center of the screw plug, a round hole, or a honeycomb hole, so that the separated lubricating oil can flow into the compressor inner cavity 6a through the first connecting section 1d1 of the first oil return hole 1d, the second connecting section 1d2, and the connecting hole 42a on the limiting member 42. The movable ball 43 is restricted in the second connecting section 1d2 between the annular stepped surface at the lower end of the first connecting section 1d1 and the upper end surface of the limiting member 42. That is, the upper limit position of the movable ball 43 is the sealing point where it abuts against the annular stepped surface, and the lower limit position is the point where it abuts against the limiting member 42, but the connecting hole 42a always remains connected to the second connecting section 1d2 and the inner cavity 6a.

[0039] The diameter of the first connecting section 1d1 of the first oil return hole 1d is smaller than the diameter of the second connecting section 1d2, forming an annular stepped surface at their junction. This stepped surface provides a sealing mating surface for the movable ball 43, eliminating the need for additional machining of a conical surface or installation of a sealing ring within the first oil return hole 1d, thus achieving a reliable seal, simplifying the manufacturing process and reducing costs. The movable part 41 uses a movable ball 43. When the ball moves within the second connecting section 1d2, it makes point or line contact with the hole wall, resulting in low movement resistance and a sensitive response to pressure differential changes. It can quickly open and close the first oil return hole 1d. Furthermore, the ball has a simple structure, low cost, and is easy to standardize and select. Different specifications of the ball can be adapted to oil return hole designs with different hole diameters. The limiting member 42 is connected to the periphery of the second connecting section 1d2, confining the movable ball 43 within the second connecting section 1d2 and preventing it from detaching into the compressor cavity 6a and losing its sealing function. The limiting member 42 is fixed in various ways, such as threaded connection, snap ring connection, or welding connection, offering high design flexibility and allowing for selection of appropriate connection methods according to different installation spaces and process requirements. The connecting hole 42a on the limiting member 42 connects the second connecting section 1d2 and the cavity 6a, providing a flow channel for oil return and acting as a limiting stop for the downward movement of the movable ball 43. This integrates the connection of the oil return channel and the limiting function of the movable ball 43 into the same limiting member 42, eliminating the need for separate oil return ports and limiting structures, thus reducing the number of parts and processing steps. The movable ball 43 moves freely between the annular stepped surface and the limiting member 42 within the second connecting section 1d2. When the compressor is running, the pressure difference pushes the movable ball 43 upward to seal with the stepped surface, thereby preventing high-pressure gas leakage. After the lubricating oil accumulates, gravity overcomes the pressure difference, causing the movable ball 43 to descend and rest on the limiting member 42. The oil return channel is opened through the connecting hole 42a of the limiting member 42 to achieve intermittent oil return. This structure utilizes the weight of the movable ball 43 and the pressure difference on both sides to achieve automatic control, eliminating the need for elastic elements such as springs, avoiding the risk of spring fatigue failure, and improving the long-term working reliability of the one-way valve assembly 4.

[0040] Please see Figure 4 , Figure 8 as well as Figure 10In this embodiment, the first oil return hole 1d on the base 1 includes, in addition to the first connecting section 1d1 and the second connecting section 1d2 as described above, a sealing section 1d3 located between the first connecting section 1d1 and the second connecting section 1d2. This sealing section 1d3 is a specific inner wall region of the first oil return hole 1d, located between the first connecting section 1d1 and the second connecting section 1d2, connecting the first connecting section 1d1 and the second connecting section 1d2 in series axially. The inner wall configuration of the sealing section 1d3 is adapted to the outer wall shape of the movable ball 43, so that when the movable ball 43 moves to the position of the sealing section 1d3 under pressure difference, the outer wall of the movable ball 43 can fit against the inner wall of the sealing section 1d3 to form a sealed connection, blocking the gas flow between the first exhaust chamber 1a and the inner cavity 6a. Specifically, the sealing section 1d3 can be constructed as a spherical hole section that smoothly transitions from the lower end of the first connecting section 1d1 to the upper end of the second connecting section 1d2. The inner wall of the spherical hole section forms a spherical sealing surface, and the diameter of the spherical surface matches the diameter of the movable ball 43. When the movable ball 43 rises to the spherical hole section, it forms a surface contact seal with the inner wall of the spherical hole section.

[0041] The sealing section 1d3, located between the first connecting section 1d1 and the second connecting section 1d2 in the first oil return hole 1d, provides a specially adapted sealing mating surface for the movable ball 43. This allows the outer wall of the movable ball 43 to fit tightly against the inner wall of the sealing section 1d3 when it rises to the position of the sealing section 1d3. Compared to the scheme where the movable ball 43 directly forms a seal with the lower end of the orifice of the first connecting section 1d1, the sealing section 1d3 increases the contact area between the movable ball 43 and the inner wall of the oil return hole and the length of the sealing path. This avoids the leakage of small gaps that may exist in line contact sealing, improves the sealing reliability, and effectively prevents the energy efficiency loss caused by high-pressure gas leaking into the inner cavity 6a through the first oil return hole 1d during compressor operation. The sealing section 1d3 adopts a spherical cavity section structure. Its spherical inner wall has an automatic guiding and automatic centering function for the movable ball 43. Even if the movable ball 43 is radially offset in the second connecting section 1d2 due to compressor vibration or liquid flow impact, it will be guided to the center position by the spherical wall when entering the sealing section 1d3 to achieve accurate sealing. This reduces the coaxiality machining requirements of the movable ball 43 and the oil return hole and improves the assembly tolerance. The sealing section 1d3 is set independently of the first connecting section 1d1 and the second connecting section 1d2, which separates the sealing function area from the oil return throttling function area (the small diameter section of the first connecting section 1d1) and the ball movement space area (the large diameter section of the second connecting section 1d2). Each section can be independently optimized according to its own functional requirements. The sealing section 1d3 focuses on sealing accuracy and surface finish, the first connecting section 1d1 focuses on controlling the oil return flow, and the second connecting section 1d2 focuses on providing sufficient movement stroke for the moving ball 43. This avoids the design contradiction caused by a single hole section having to take into account multiple functions at the same time, and improves design flexibility and overall performance.

[0042] Please see Figures 1 to 17 In one embodiment, the inner walls of both the first exhaust chamber 1a and the second exhaust chamber 2a are provided with an oleophobic layer. This oleophobic layer is a coating layer with oleophobic properties formed on the inner wall surface of the chamber. Its material can be polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), fluorinated ethylene propylene copolymer, or other fluoropolymer coatings, or it can be an organosilicon resin coating or a ceramic-based oleophobic coating. The oleophobic layer is formed by coating, for example, by spraying, dipping, or brushing the oleophobic coating evenly onto the inner wall surfaces of the first exhaust chamber 1a and the second exhaust chamber 2a, and then curing it to form a dense film. The oleophobic layer can also be formed by embedding or lining, for example, by attaching a pre-formed PTFE sheet or a fluoropolymer bushing to the inner wall of the chamber. The oleophobic coating covers the upper surface of the base 1 of the first exhaust chamber 1a (i.e., the first guide wall 12), the inner and outer walls of the second cylindrical ring 22, the outer wall of the first cylindrical ring 13, the lower surface of the middle plate 2, the upper surface of the middle plate 2 of the second exhaust chamber 2a (i.e., the second guide wall 21), the inner and outer walls of the fourth cylindrical ring 23, the inner and outer walls of the third cylindrical ring 31, and the lower surface of the upper cover 3, among other inner wall areas. The thickness of the oleophobic coating can be designed from 5 μm to 100 μm. Before coating, the inner walls can be sandblasted or chemically etched to increase the adhesion of the coating.

[0043] The inner walls of the first exhaust chamber 1a and the second exhaust chamber 2a are provided with an oleophobic layer. This prevents the separated lubricating oil from spreading into a continuous oil film on the inner wall of the chamber. Instead, the oil coalesces into spherical droplets. These droplets have a large contact angle with the wall surface and low adhesion, making them easier to roll or slide off the wall surface under gravity and discharge through the oil return hole. This avoids the problem of delayed oil return caused by the formation of a large oil film on the wall surface, accelerates the collection and discharge of the separated oil, and improves the timeliness of oil return. The low surface energy of the oleophobic layer makes the wall surface less likely to be wetted by oil. When a high-speed airflow passes through the inner wall of the chamber, the oil droplets that have been separated and adhered to the wall surface are less likely to be re-entrained by the airflow, reducing the amount of secondary oil carried by the airflow and ensuring the effectiveness of the separation at each stage. An oleophobic layer is provided on the inner wall of the first exhaust chamber 1a and the second exhaust chamber 2a, so that all wall surfaces in contact with the oil-gas mixture in the entire separation path from primary separation to secondary separation have oleophobic properties. This avoids the problem that when some wall surfaces have an oleophobic layer and some wall surfaces do not, the oil spreads and accumulates in the uncoated area, forming a continuous oil film, which is then sheared and broken by the airflow and carried away. This ensures that the oil droplets have low adhesion consistency on the inner wall surfaces of the entire separation chamber.

[0044] Secondly, please refer to Figures 1 to 5The housing 6 has an inner cavity 6a for accommodating the pump assembly 8, the motor 9, and the oil separator, and an exhaust port 6b that penetrates the wall of the housing 6 and communicates with the inner cavity 6a. This exhaust port 6b is used to discharge the clean, high-pressure gas separated inside the compressor to the external system pipeline. The distributor 7 is connected to the housing 6 (e.g., fixed with bolts or welded to the side wall of the housing 6) and is used to introduce low-pressure gaseous refrigerant into the pump assembly 8 for compression. Both the pump assembly 8 and the motor 9 are located in the inner cavity 6a. The motor 9 drives the pump assembly 8 to compress the refrigerant, and the compressed oil-gas mixture is discharged through the exhaust port of the pump assembly 8 to the upper region of the inner cavity 6a. The oil separation mechanism provided in the first aspect of this application is integrally assembled in the inner cavity 6a and located above the pump assembly 8 and the motor 9. The outer periphery of the base 1 of the oil separation mechanism is connected to the inner wall of the housing 6, for example, by welding and fixing it to the inner wall of the housing 6 through a boss on the edge of the base 1, or by press-fitting it to the housing 6 through an interference fit, so that the oil separation mechanism is stably positioned in the inner cavity 6a of the housing 6 and divides the inner cavity 6a into a lower compression space (accommodating the pump assembly 8 and the motor 9) and an upper separation space. The third exhaust hole 3a of the upper cover 3 is provided with an exhaust part 33 around its periphery. The exhaust part 33 is a tubular interface protruding from the edge of the third exhaust hole 3a to the outer side of the upper cover 3 (i.e., away from the second exhaust cavity 2a), and it has a predetermined outer diameter and height. The exhaust section 33 is located at the exhaust mounting port 6b, that is, the exhaust section 33 extends into or through the exhaust mounting port 6b of the housing 6 as the final exhaust interface of the compressor. Specifically, the outer wall of the exhaust section 33 and the inner wall of the exhaust mounting port 6b can be sealed and fixed by welding, or the exhaust section 33 can extend to the outside of the housing 6 after passing through the exhaust mounting port 6b and be connected to the external exhaust pipeline through a flange or threaded structure. The gap between the exhaust section 33 and the exhaust mounting port 6b is sealed by welding or sealing ring.

[0045] The oil separation mechanism is integrated into the inner cavity 6a of the compressor housing 6, and the base 1 is fixedly connected to the inner wall of the housing 6. This makes the oil separation mechanism an integral part of the compressor body, eliminating the need for a separate oil separator and matching connecting pipes outside the compressor. This reduces the number of system components and avoids the risk of refrigerant leakage at external connections. The exhaust section 33 around the third exhaust port 3a of the top cover 3 is directly installed in the exhaust mounting port 6b of the housing 6. This allows the clean, high-pressure gas, after multi-stage separation by the oil separation mechanism, to be directly discharged from the third exhaust port 3a through the exhaust section 33 to the external pipeline of the compressor. This eliminates the need for additional connecting pipes inside the compressor to lead the third exhaust port 3a to the exhaust port of the housing 6, shortening the exhaust path, reducing exhaust resistance loss, and avoiding the increased assembly complexity and leakage points caused by cross-cavity connecting pipes inside the compressor. Furthermore, the fit between the exhaust section 33 and the exhaust mounting port 6b of the housing 6 ensures the accurate positioning of the oil separation mechanism within the housing 6. The upper cover 3 achieves radial positioning through the fit between the exhaust section 33 and the exhaust mounting port 6b, and the base 1 achieves radial positioning through the fit between its outer periphery and the inner wall of the housing 6. The combined action of both ensures that the oil separation mechanism maintains stable coaxiality within the housing 6, guaranteeing the airflow sealing and reliability of the separation effect of each separation chamber.

[0046] Thirdly, this application proposes an air conditioner that includes either the oil separation mechanism provided in the first aspect of this application or the compressor provided in the second aspect of this application. When the air conditioner includes the oil separation mechanism of the first aspect of this application, the oil separation mechanism is disposed as an independent component in the refrigeration cycle loop of the air conditioner, specifically installed at the upper part of the compressor's inner cavity 6a near the exhaust port, to separate the oil-gas mixture discharged by the compressor. When the air conditioner includes the compressor of the second aspect of this application, the compressor is an integrated compressor with the aforementioned oil separation mechanism built in, directly installed in the outdoor or indoor unit of the air conditioner, and the compressor's exhaust section 33 is connected to the condenser's inlet end via a pipeline. The air conditioner also includes a condenser, a throttling device (e.g., a capillary tube or an electronic expansion valve), and an evaporator, the above components being sequentially connected via pipelines to form a complete vapor compression refrigeration cycle.

[0047] When an air conditioner adopts the oil separation mechanism of this application or a compressor with a built-in oil separation mechanism, the oil and gas are efficiently separated inside the compressor through a three-layer composite structure of base 1, middle plate 2, and top cover 3, and a multi-stage separation mechanism including centrifugal separation, gravity settling, and filtration separation. This reduces the amount of lubricating oil entering the air conditioning system piping, eliminates the oil film thermal resistance on the inner walls of the condenser and evaporator heat exchange tubes, improves the heat exchange efficiency and overall energy efficiency ratio of the air conditioning system, and reduces the energy consumption of air conditioning operation. The integrated compressor with a built-in oil separation mechanism replaces the external oil separator, matching oil return pipeline, and solenoid valve required in traditional air conditioning systems, simplifying the piping layout of the air conditioning system, reducing welding points and potential leakage points, lowering the production cost and installation space requirements of the air conditioner, and improving the system reliability of the air conditioner. At the same time, the one-way valve assembly 4 in the oil separation mechanism automatically controls the intermittent oil return through the pressure difference between the inner cavity 6a and the first exhaust cavity 1a, so that the separated lubricating oil returns to the compressor inner cavity 6a in a timely manner, ensuring that the compressor is in a good lubrication state under different operating conditions, and extending the service life of the compressor and the air conditioner.

[0048] Fourthly, the compressor oil return control method proposed in this application is applied to the compressor with the aforementioned built-in oil separation mechanism. The specific control process is as follows: The compressor is started, and the motor 9 drives the pump assembly 8 to start operating. High-pressure gas containing lubricating oil enters the first exhaust chamber 1a from the inner cavity 6a through the first exhaust port 1b of the base 1. Under the guidance of the air guide 11 (arc-shaped guide ribs or spiral guide vanes), the airflow flows tangentially or spirally toward the inner wall of the first exhaust chamber 1a. Oil droplets, due to their density being greater than that of gas, are thrown toward the wall under centrifugal force to achieve primary separation. After primary separation, the gas enters the second exhaust chamber 2a through the second exhaust port 2b. In the second exhaust chamber 2a, the airflow collides sequentially with the upper surface of the middle plate 2 and the lower surface of the upper cover 3. Residual oil droplets, due to inertia, cannot be redirected by the airflow and collide with the wall to aggregate. After multiple collisions and gravity settling, the clean gas is discharged from the third exhaust port 3a. After the lubricating oil in the gas is separated from the gas by the combined action of inertial centrifugal separation and gravity settling, the lubricating oil separated in the second exhaust chamber 2a flows downward into the first exhaust chamber 1a through the second oil return hole 2c of the middle plate 2. After being combined with the lubricating oil separated in the first exhaust chamber 1a, it flows back to the inner cavity 6a through the first oil return hole 1d of the base 1 under the control of the one-way valve assembly 4.

[0049] When the compressor is in a shutdown state before startup, the pressure P1 in the inner cavity 6a is equal to the pressure P2 in the first exhaust cavity 1a (P1=P2), the movable ball 43 only falls onto the stopper 42 under the action of its own gravity G1, and at this time the first oil return hole 1d is in an open passage state. After the compressor is started and enters stable operation, the pressure P1 in the inner cavity 6a is greater than the pressure P2 in the first exhaust cavity 1a (P1>P2), the movable ball 43 is subjected to an upward pressure difference acting force F1=P1×S1-P2×S2 (S1 is the acting area of the movable ball 43 subjected to upward pressure, and S2 is the acting area of the movable ball 43 subjected to downward pressure). By design, the gravity G1 of the movable ball 43 is smaller than the upward acting force F2 generated by the minimum pressure difference when the compressor operates stably (that is, G1<F2), therefore, the movable ball 43 moves upward under the action of the pressure difference to fit with the sealing section 1d3 of the first oil return hole 1d (or the annular step surface between the first communication section 1d1 and the second communication section 1d2) to form a seal, and at this time the first oil return hole 1d is closed to prevent high-pressure gas from leaking into the inner cavity 6a through the oil return hole. As the compressor continues to operate, the lubricating oil separated from the first exhaust cavity 1a gradually converges above the first oil return hole 1d, when the level of the accumulated lubricating oil rises to a predetermined height, the movable ball 43 is subjected to a downward additional force G2 (the gravity of the accumulated oil), and at this time the force balance equation of the movable ball 43 is F 总 =P1×S1-P2×S2-G1-G2; when G2 increases to make F 总 <0, the movable ball 43 moves downward to leave the sealing section 1d3, the first oil return hole 1d is opened, and the lubricating oil flows back to the inner cavity 6a through the communication hole 42a on the stopper 42; as the oil is discharged and the liquid level drops, G2 decreases, when F 总 >0, the movable ball 43 moves upward again and fits with the sealing section 1d3, the first oil return hole 1d is closed again, and the oil accumulates again in the first exhaust cavity 1a; such repetition realizes intermittent automatic oil return control according to the actual oil return amount.

[0050] In this oil return control method, after the compressor starts, the gas containing lubricating oil passes through the centrifugal separation of the first exhaust chamber 1a and the collision separation of the second exhaust chamber 2a in sequence, forming a multi-stage separation process. This allows oil droplets of different sizes to be gradually removed in the centrifugal force field and the inertial collision field, thereby improving the overall oil-gas separation efficiency. In the first exhaust chamber 1a, the gas is guided by the gas guide 11 and collides with the inner wall. In the second exhaust chamber 2a, the gas collides with the inner wall of the middle plate 2 and the upper cover 3. Through two forced deflections, the oil droplets cannot follow the airflow due to inertia and collide with the wall surface and coalesce. This fully utilizes the inertial difference between the oil droplets and the gas to achieve passive separation, and high-efficiency separation effect can be obtained without consuming additional energy. After separation, the lubricating oil flows sequentially through the second return oil hole 2c into the first return oil hole 1d, and then back to the inner cavity 6a through the one-way valve assembly 4. The second return oil hole 2c serves as the first-stage return oil channel, discharging a small amount of lubricating oil separated from the second exhaust chamber 2a into the first exhaust chamber 1a. This is combined with the large amount of lubricating oil separated from the first exhaust chamber 1a, and then flows back to the inner cavity 6a through the first return oil hole 1d. This avoids the structural complexity and increased processing difficulty caused by setting multiple independent return oil channels. The one-way valve assembly 4 automatically adjusts the opening and closing of the first oil return hole 1d based on the pressure difference between the inner cavity 6a and the first exhaust cavity 1a and the gravity of the oil, realizing fully mechanical adaptive intermittent oil return control. When the compressor starts up and the pressure difference has not yet been established, the oil return hole opens, allowing the lubricating oil accumulated during shutdown to flow back in a timely manner. During stable operation, the pressure difference causes the movable ball 43 to move upwards and seal, preventing exhaust short circuits and energy loss caused by high-pressure gas leakage through the oil return hole. After oil accumulation, its gravity overcomes the pressure difference, causing the movable ball 43 to move downwards and open the oil return hole. After oil discharge, the liquid level drops. The moving ball 43 moves upward and seals again, so that the oil return volume automatically matches the separated oil volume, which not only ensures that the compressor is not short of oil lubrication, but also avoids the risk of liquid slugging caused by excessive oil return. The entire control process does not require the intervention of electrical components such as solenoid valves, controllers or sensors, avoiding the risk of electrical control failure and reducing system cost and energy consumption. At the same time, the pure mechanical control has the ability to adapt to the compressor's operation under different speeds and pressure ratios, without the need to adjust control parameters for different operating conditions, which simplifies the system integration difficulty and debugging complexity of the compressor.

[0051] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0052] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0053] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An oil separation mechanism applied to a compressor, the compressor having an inner cavity (6a), characterized in that, include: The base (1), middle plate (2), top cover (3) and one-way valve assembly (4) are provided. The base (1) and the middle plate (2) enclose a first exhaust chamber (1a). The middle plate (2) and the top cover (3) enclose a second exhaust chamber (2a). The base (1) has a first exhaust hole (1b) that connects the first exhaust chamber (1a) and the inner cavity (6a). The middle plate (2) has a plurality of second exhaust holes (2b) that connect the first exhaust chamber (1a) and the second exhaust chamber (2a). Each second exhaust hole (2b) is spaced apart along the circumference of the middle plate (2). The top cover (3) has a third exhaust hole (3a) that connects the second exhaust chamber (2a) and the gas pipeline. The base (1) is provided with a plurality of air guides (11) that abut against the middle plate (2). Each air guide (11) divides the first exhaust chamber (1a) into a plurality of exhaust channels (1c). Each air guide (11) is used to guide the airflow to the inner wall of the first exhaust chamber (1a). The base (1) has a first oil return hole (1d) connecting the first exhaust chamber (1a) and the inner cavity (6a), and the middle plate (2) has a second oil return hole (2c) connecting the second exhaust chamber (2a) and the first exhaust chamber (1a). The one-way valve assembly (4) is located at the first return oil hole (1d). The one-way valve assembly (4) includes a movable part (41) and a limiting part (42). The movable part (41) can move under the pressure difference between the inner cavity (6a) and the first exhaust cavity (1a) to open and close the first return oil hole (1d).

2. The oil separation mechanism according to claim 1, characterized in that, The base (1) has a first guide wall (12) on the side facing the first exhaust chamber (1a), and the middle plate (2) has a second guide wall (21) on the side facing the second exhaust chamber (2a). The height of the first guide wall (12) gradually decreases from the middle to the edge. The first oil return hole (1d) is located at the edge of the first guide wall (12). The height of the second guide wall (21) gradually decreases from the middle to the edge. The second oil return hole (2c) is located at the edge of the second guide wall (21).

3. The oil separation mechanism according to claim 1, characterized in that, The first exhaust hole (1b) is provided with a first cylindrical ring (13) around its periphery, and the middle plate (2) is provided with a second cylindrical ring (22). The first cylindrical ring (13) is located inside the second cylindrical ring (22), and there is a gap between the first cylindrical ring (13) and the second cylindrical ring (22). The upper cover (3) is provided with a third cylindrical ring (31) on the side facing the second exhaust chamber (2a), and the middle plate (2) is provided with a fourth cylindrical ring (23) on the side facing the second exhaust chamber (2a). The third cylindrical ring (31) is located inside the fourth cylindrical ring (23), and there is a gap between the third cylindrical ring (31) and the fourth cylindrical ring (23).

4. The oil separation mechanism according to claim 2, characterized in that, An annular filter screen (5) is provided between the upper cover (3) and the middle plate (2), and the two ends of the annular filter screen (5) are respectively engaged with the upper cover (3) and the middle plate (2).

5. The oil separation mechanism according to claim 4, characterized in that, The upper cover (3) is provided with a first snap-fit ​​part (32), and the middle plate (2) is provided with a second snap-fit ​​part (24). The first snap-fit ​​part (32) and the second snap-fit ​​part (24) are respectively snapped to both ends of the annular filter screen (5). The second snap-fit ​​part (24) is provided with a plurality of overflow grooves (24a), and the bottom of each overflow groove (24a) is connected to the second guide wall (21).

6. The oil separation mechanism according to any one of claims 1-5, characterized in that, The first oil return hole (1d) includes a first connecting section (1d1) and a second connecting section (1d2). The diameter of the first connecting section (1d1) is smaller than the diameter of the second connecting section (1d2). The movable part (41) is a movable ball (43) movably disposed in the second connecting section (1d2). The limiting part (42) is connected to the periphery of the second connecting section (1d2). The limiting part (42) is provided with a connecting hole (42a) connecting the second connecting section (1d2) and the inner cavity (6a).

7. The oil separation mechanism according to claim 6, characterized in that, The first oil return hole (1d) further includes a sealing section (1d3) disposed between the first connecting section (1d1) and the second connecting section (1d2), wherein the inner wall of the sealing section (1d3) can seal against the outer wall of the movable ball (43).

8. The oil separation mechanism according to any one of claims 1-5, characterized in that, The inner walls of the first exhaust chamber (1a) and the second exhaust chamber (2a) are both provided with an oleophobic layer.

9. A compressor, characterized in that, The device includes a housing (6), a separator (7), a pump assembly (8), a motor (9), and an oil separation mechanism as described in any one of claims 1-8. The housing (6) has an inner cavity (6a) and an exhaust port (6b) communicating with the inner cavity (6a). The separator (7) is connected to the housing (6). The pump assembly (8), the motor (9), and the oil separation mechanism are all located in the inner cavity (6a). The base (1) is connected to the inner wall of the inner cavity (6a). The periphery of the third exhaust hole (3a) has an exhaust portion (33), and the exhaust portion (33) is located in the exhaust port (6b).

10. An air conditioner, characterized in that, Includes the oil separation mechanism as described in any one of claims 1-8 or the compressor as described in claim 9.

11. A compressor oil return control method, applied to the compressor as described in claim 9, characterized in that, Includes the following steps: The compressor is controlled to start so that the gas containing lubricating oil enters the first exhaust chamber (1a) from the inner cavity (6a) through the first exhaust port (1b) and collides with the inner wall of the first exhaust chamber (1a) under the guidance of the gas guide (11). After the initial collision, the gas enters the second exhaust chamber (2a) through the second exhaust port (2b), collides with the inner walls of the middle plate (2) and the upper cover (3), and is discharged from the third exhaust port (3a). Under the influence of inertia and gravity, the lubricating oil in the gas separates from the gas and flows sequentially from the second return oil hole (2c) into the first return oil hole (1d), and then flows back to the inner cavity (6a) through the one-way valve assembly (4); The one-way valve assembly (4) automatically adjusts the opening and closing of the first oil return hole (1d) according to the pressure difference between the inner cavity (6a) and the first exhaust cavity (1a) and the gravity of the oil.

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