An air conditioning unit

Abstract

The application discloses an air conditioning unit which comprises a compressor, a condenser and an evaporator; the compressor comprises a motor, the motor comprises a motor shell, a cooling cavity is formed in the motor shell, a stator-rotor assembly and a main shaft are arranged in the cooling cavity; the condenser is communicated with the cooling cavity; a bearing is sleeved on the main shaft and located in the motor shell; a first oil tank is used for delivering lubricating oil to the bearing through an oil supply channel; a sealing structure is coaxially sleeved on the main shaft; an axle seal cavity is arranged between the sealing structure and the main shaft; one side of the axle seal cavity close to the bearing is communicated with the oil supply channel; the other side of the axle seal cavity away from the bearing is communicated with the condenser or the evaporator. When the pressure of the oil supply channel is relatively large, the other side of the axle seal cavity away from the bearing is communicated with the condenser or the evaporator, the pressure of the other side of the axle seal cavity away from the bearing is increased through the refrigerant pressure in the condenser or the evaporator, so that the pressure difference between both sides of the bearing cavity is reduced, and the leakage amount of the lubricating oil at the bearing is reduced.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and more particularly to an air conditioning unit. Background Technology

[0002] The compressor is the core component of an air conditioning unit, using a high-speed rotating impeller to compress low-temperature, low-pressure refrigerant vapor into high-temperature, high-pressure vapor. Bearings, as crucial supports for the impeller shaft, directly affect the unit's lifespan and stability through their lubrication. To ensure the compressor's reliability, bearings require lubricating oil. Maintaining sufficient and stable lubrication at the bearing is extremely important. Excessive oil leakage can prevent the formation of a stable lubricating film between the compressor shaft and the bearing, potentially leading to direct contact and friction. Under high-speed rotation, this can cause a rapid temperature increase at this point, ultimately damaging the bearing.

[0003] In related technologies, shaft seals are often installed at the front and rear end faces of the bearing to increase the resistance of the lubricating oil leakage path, thereby reducing the amount of lubricating oil leakage at the bearing.

[0004] However, when the lubricating oil supply pressure fluctuates or the load changes, the sealing effect of the shaft seal is prone to failure, leading to an increase in leakage. Summary of the Invention

[0005] This application provides an air conditioning unit that can solve the technical problem of large lubricating oil leakage at the bearing of the compressor.

[0006] This application provides an air conditioning unit, including: a compressor, a condenser, and an evaporator; the compressor includes: a motor, the motor including a motor housing, and a cooling cavity formed inside the motor housing; a stator-rotor assembly and a main shaft are disposed in the cooling cavity; the condenser is connected to the cooling cavity; a bearing, sleeved on the main shaft and located inside the motor housing, for supporting the stator-rotor assembly; a first oil tank, for supplying lubricating oil to the bearing through an oil supply channel; a sealing structure, coaxially sleeved on the main shaft with the bearing, and a shaft seal cavity is provided between the sealing structure and the main shaft; the side of the shaft seal cavity near the bearing is connected to the oil supply channel; the side of the shaft seal cavity away from the bearing is connected to the condenser or the evaporator.

[0007] In some embodiments, the condenser is connected to the shaft seal cavity via a first pipeline, and a first control valve is provided on the first pipeline; the condenser is connected to the cooling cavity via a second pipeline, and the evaporator is connected to the shaft seal cavity via a third pipeline, and a regulating valve is provided on the third pipeline.

[0008] In some embodiments, the compressor further includes a volute, which is connected to the motor housing. An impeller is provided inside the volute, which is located outside the motor housing and is fixedly connected to the main shaft. The bearing includes: a first bearing located between the stator and rotor assembly and the impeller; and a second bearing located at the end of the stator and rotor assembly facing away from the impeller. The sealing structure includes: The first sealing structure forms a first shaft sealing cavity with the main shaft, and the first shaft sealing cavity is located between the impeller and the first bearing; The second sealing structure forms a second shaft sealing cavity with the main shaft, and the second shaft sealing cavity is located between the stator and rotor assembly and the first bearing; The third sealing structure forms a third shaft sealing cavity with the main shaft, and the third shaft sealing cavity is located between the stator and rotor assembly and the second bearing.

[0009] In some embodiments, the first shaft seal cavity and the second shaft seal cavity are connected to the oil supply channel on the side near the first bearing; the third shaft seal cavity is connected to the oil supply channel on the side near the second bearing.

[0010] In some embodiments, the volute and the motor housing enclose a sealed cavity, which is connected to the side of the first shaft seal cavity away from the first bearing, and the condenser is connected to the sealed cavity through a first pipe. The cooling chamber is connected to the side of the second shaft seal chamber away from the first bearing, and the third shaft seal chamber is connected to the side of the third shaft seal chamber away from the second bearing; the evaporator is connected to the cooling chamber through a third pipe.

[0011] In some embodiments, a first pressure detector is used to detect the oil supply pressure P1 of the first oil tank; a second pressure detector is used to detect the pressure P2 in the sealed cavity; and a third pressure detector is used to detect the pressure P3 in the cooling cavity. In some embodiments, the condenser and the cooling chamber are connected via a fourth pipe, on which a second control valve is provided.

[0012] In some embodiments, the motor housing is provided with an oil return channel, one end of which faces the bearing and the other end of which is connected to the first oil tank.

[0013] In some embodiments, a second oil tank is included, which is connected to the first oil tank via an oil supply pipe, and the second oil tank supplies lubricating oil to the first oil tank via the oil supply pipe.

[0014] In some embodiments, the second oil tank is connected to the oil return channel via an oil return pipe, and the lubricating oil in the oil return channel flows back to the second oil tank via the oil return pipe.

[0015] In this embodiment of the air conditioning unit, the sealing structure is coaxially sleeved on the main shaft along with the bearing. The sealing structure is used to block the flow of lubricating oil. A shaft seal cavity is provided between the sealing structure and the main shaft. The side of the shaft seal cavity closest to the bearing is connected to the oil supply channel. Lubricating oil flows into the bearing through the oil supply channel. The shaft seal cavity can increase the resistance when the lubricating oil flows outward from the bearing, thereby reducing the amount of lubricating oil leakage at the bearing. When the pressure in the oil supply channel is high, the side of the shaft seal cavity away from the bearing is connected to the condenser or evaporator. By utilizing the refrigerant pressure in the condenser or evaporator, the pressure on the side of the shaft seal cavity away from the bearing is increased, thereby reducing the pressure difference on both sides of the bearing cavity and reducing the amount of lubricating oil leakage at the bearing. Attached Figure Description

[0016] To more clearly illustrate the implementation methods in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0017] Figure 1 A schematic diagram of the structure of an air conditioning unit according to an embodiment of this application is shown; Figure 2 A partial cross-sectional view of the compressor in an air conditioning unit according to an embodiment of this application is shown; Figure 3 It shows Figure 2 A magnified view of a portion of point P1 in the middle; Figure 4 It shows Figure 2 A magnified view of a portion of point P2 in the middle; Figure 5 The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 1 ; Figure 6 The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 2 ; Figure 7 The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 3 ; Figure 8 The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 4 ; Figure 9 The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 5 ; Figure 10 The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 6 ; Figure 11The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 7 ; Figure 12 The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 8 ; Figure 13 The control flow of the air conditioning unit according to an embodiment of this application is shown. Figure 9 .

[0018] Explanation of reference numerals in the attached figures: 10-Compressor; 110-Motor; 111-Motor housing; 1111-Cooling chamber; 1112-First sealing structure; 1113-Second sealing structure; 1114-Third sealing structure; 1115-Oil supply channel; 1116-Oil return channel; 112-Stator and rotor assembly; 113-Main shaft; 1131-First shaft sealing cavity; 1132-Second shaft sealing cavity; 1133-Third shaft sealing cavity; 114-First bearing; 115-Second bearing; 120-Impeller; 130-First oil tank; 140-Volume casing; 141-Sealing cavity; 20 - Condenser; 210 - First piping; 211 - First control valve; 220 - Second piping; 230 - Fourth piping; 231 - Second control valve; 30 - Throttling device; 40 - Evaporator; 410 - Third piping; 411 - Control valve; 50 - Second oil tank; 501 - Oil supply pipe; 502 - Oil return pipe; 60-oil pump; 70 - First pressure detector; 80 - Second pressure detector; 90 - Third pressure detector; 100-Controller. Detailed Implementation

[0019] To make the objectives and implementation methods of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments.

[0020] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0021] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0022] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0023] As stated in the background section, compressors in related technologies suffer from a problem of excessive lubricating oil leakage at the bearings. The inventors have discovered that this problem arises because the oil supply pressure at the bearings and the compressor load are dynamically changing during operation. These changes in oil supply pressure and load lead to an excessive pressure difference across the shaft seal, causing the shaft seal to fail in its ability to block and seal the lubricating oil, resulting in increased lubricating oil leakage at the bearings.

[0024] To address the aforementioned technical problems, this application provides an air conditioning unit that reduces the pressure difference between the two sides of the shaft seal cavity by adjusting the pressure on the side of the shaft seal cavity away from the bearing. This reduces the flow rate of the lubricating oil in the shaft seal cavity, thereby reducing the amount of lubricating oil leaking from the bearing through the shaft seal cavity and ensuring that the bearing maintains a sufficient and stable lubrication state.

[0025] 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, and 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.

[0026] refer to Figure 1 The air conditioning unit provided in this application includes a compressor 10, a condenser 20, a throttling device 30 and an evaporator 40 connected in series by pipes. Refrigerant flows in the pipes and circulates sequentially in the compressor 10, condenser 20, throttling device 30 and evaporator 40 to regulate the air temperature.

[0027] Compressor 10 compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant is then delivered to condenser 20, where it condenses and releases heat, becoming a room-temperature, high-pressure liquid refrigerant. This room-temperature, high-pressure liquid refrigerant is then throttled and depressurized at throttling device 30, becoming a low-temperature, low-pressure liquid refrigerant. This low-temperature, low-pressure liquid refrigerant enters evaporator 40, where it evaporates and absorbs heat, becoming a low-temperature, low-pressure gaseous refrigerant. This low-temperature, low-pressure gaseous refrigerant is again drawn into compressor 10 and continues to circulate through condenser 20, throttling device 30, and evaporator 40, causing the refrigerant to continuously release heat at condenser 20, raising its temperature, and absorb heat at evaporator 40, lowering its temperature.

[0028] In some embodiments, the air conditioning unit provided in this application can be used to reduce indoor temperature, and the evaporator 40 is used to cool indoor circulating water or indoor air to achieve refrigeration.

[0029] In other embodiments, the air conditioning unit provided in this application can be used to increase the indoor temperature, and the condenser 20 is used to release heat into the room to achieve heating.

[0030] In some possible implementations of the embodiments of this application, reference is made to Figure 1 and Figure 2 The compressor 10 may include a motor 110 and an impeller 120. The motor 110 drives the impeller 120 to rotate to do work on the gaseous refrigerant, converting kinetic energy into pressure energy of the gaseous refrigerant, thereby achieving compression and pressurization of the gaseous refrigerant.

[0031] refer to Figure 1 and Figure 2 The motor 110 may include a motor housing 111, a stator and rotor assembly 112, and a main shaft 113. A cooling chamber 1111 may be formed inside the motor housing 111. The stator and rotor assembly 112 is disposed within the cooling chamber 1111. The main shaft 113 is fixedly connected to the stator and rotor assembly 112 and is rotatably disposed relative to the motor housing 111. A portion of the main shaft 113 extends outside the motor housing 111 and is fixedly connected to the impeller 120.

[0032] The stator-rotor assembly 112 includes a stator assembly and a rotor assembly.

[0033] The stator assembly is fixed inside the motor housing 111. Its main function is to generate a rotating magnetic field through alternating current to provide a power source for the rotor assembly.

[0034] The rotor assembly is fixedly mounted on the main shaft 113, and the rotor assembly and the main shaft 113 together can rotate around the axis of the main shaft 113. Under the action of the rotating magnetic field generated by the stator assembly, the rotor assembly generates torque, thereby driving the main shaft 113 to rotate, and the main shaft 113 in turn drives the impeller 120 to rotate.

[0035] In some possible implementations of this application, the motor 110 may further include a bearing, which is sleeved on the outside of the portion of the main shaft 113 located within the cooling cavity 1111, that is, the bearing is located inside the motor housing 111. The bearing supports the rotor assembly and the main shaft 113, reduces the frictional resistance when the rotor assembly and the main shaft 113 rotate, and limits the radial and axial displacement of the rotor assembly, ensuring stable and efficient operation of the rotor assembly.

[0036] refer to Figure 1 and Figure 2 The bearing may include a first bearing 114, which is located between the stator and rotor assembly 112 and the impeller 120 to support the main shaft 113 located between the stator and rotor assembly 112 and the impeller 120.

[0037] refer to Figure 1 and Figure 2 The bearing may also include a second bearing 115 located at one end of the stator-rotor assembly 112 away from the impeller 120 to support the main shaft 113 located at one end of the stator-rotor assembly 112 away from the impeller 120.

[0038] In some possible implementations of the embodiments of this application, reference is made to Figure 1 and Figure 2 The motor 110 may also include a first oil tank 130 for storing lubricating oil. The first oil tank 130 is disposed on the top of the motor housing 111. The first oil tank 130 may be fixedly connected to the motor housing 111.

[0039] refer to Figure 2 The motor housing 111 may be constructed with an oil supply channel 1115. One end of the oil supply channel 1115 is connected to the first oil tank 130, and the other end of the oil supply channel 1115 faces the bearing. The lubricating oil in the first oil tank 130 can flow to the bearing through the oil supply channel 1115 to form an oil film on the surface of the bearing, separating the friction surfaces of the bearing and the spindle 113, avoiding direct metal-to-metal contact, significantly reducing the coefficient of friction, reducing wear, and extending the bearing life.

[0040] refer to Figure 1The motor housing 111 may also be equipped with an oil return channel 1116, one end of which faces the bearing and the other end of which is connected to the first oil tank 130. The lubricating oil at the bearing can flow back to the first oil tank 130 through the oil return channel 1116 and then flow back to the bearing through a common channel, so that the lubricating oil at the bearing circulates and reduces the possibility of local oil shortage in the bearing.

[0041] In some possible implementations of the embodiments of this application, reference is made to Figure 1 The air conditioning unit may also include a second oil tank 50, which may be located outside the compressor 10, and the second oil tank 50 is used to store lubricating oil.

[0042] The second oil tank 50 and the first oil tank 130 can be connected by an oil supply pipe 501, and the second oil tank 50 supplies lubricating oil to the first oil tank 130 through the oil supply pipe 501.

[0043] The second oil tank 50 and the return oil channel 1116 can be connected through the return oil pipe 502, and the lubricating oil in the return oil channel 1116 can flow back to the second oil tank 50 through the return oil pipe 502.

[0044] In some possible implementations of the embodiments of this application, reference is made to Figure 1 The air conditioning unit may also include an oil pump 60, which can be installed on the oil supply pipe 501. The inlet of the oil pump 60 is connected to the second oil tank 50, and the outlet of the oil pump 60 is connected to the first oil tank 130. When the oil pump 60 is working, the lubricating oil in the second oil tank 50 flows to the first oil tank 130 through the oil supply pipe 501. The oil pump 60 can increase the flow rate of the lubricating oil when it flows from the second oil tank 50 to the first oil tank 130, thereby increasing the flow rate of the lubricating oil from the first oil tank 130 to the bearing, improving the circulation flow rate of the lubricating oil at the bearing, and reducing the possibility of local lubrication shortage in the bearing.

[0045] In some possible implementations of this application, the motor housing 111 may be provided with a sealing structure, which may be a comb-shaped structure. A shaft sealing cavity is formed between the sealing structure and the main shaft 113, and the shaft sealing cavity is connected to the cooling cavity 1111.

[0046] The shaft seal cavity can be located between the bearing and the stator-rotor assembly 112, or the bearing can be located on the side of the shaft seal cavity away from the stator-rotor assembly 112. The shaft seal cavity can increase the resistance to the flow of lubricating oil from the bearing toward the stator-rotor assembly 112, thereby reducing the amount of lubricating oil leakage from the bearing toward the stator-rotor assembly 112.

[0047] refer to Figure 1 , Figure 2 and Figure 3In the implementation where the bearing includes a first bearing 114, the shaft sealing cavity may include a second shaft sealing cavity 1132. The sealing structure may include a second sealing structure 1113, and a second shaft sealing cavity 1132 is formed between the second sealing structure 1113 and the main shaft 113. The second shaft sealing cavity 1132 is located between the stator-rotor assembly 112 and the first bearing 114. The second shaft sealing cavity 1132 can increase the resistance when the lubricating oil at the first bearing 114 flows towards the stator-rotor assembly 112, thereby reducing the leakage of lubricating oil at the first bearing 114 in the direction towards the stator-rotor assembly 112.

[0048] refer to Figure 1 , Figure 2 and Figure 4 In the implementation where the bearing includes the second bearing 115, the shaft sealing cavity may include a third shaft sealing cavity 1133. The sealing structure may include a third sealing structure 1114, which forms a third shaft sealing cavity 1133 with the main shaft 113. The third shaft sealing cavity 1133 is located between the stator-rotor assembly 112 and the second bearing 115. The third shaft sealing cavity 1133 can increase the resistance when the lubricating oil at the second bearing 115 flows towards the stator-rotor assembly 112, thereby reducing the leakage of lubricating oil at the second bearing 115 in the direction towards the stator-rotor assembly 112.

[0049] refer to Figure 1 , Figure 2 and Figure 3 In the implementation where the bearing includes a first bearing 114, the motor housing 111 may be provided with a first sealing structure 1112, which may be a comb-shaped structure. A first shaft sealing cavity 1131 is formed between the first sealing structure 1112 and the main shaft 113. The first shaft sealing cavity 1131 is located between the first bearing 114 and the impeller 120, or in other words, the first bearing 114 is located between the stator / rotor assembly 112 and the first shaft sealing cavity 1131, and the impeller 120 is located on the side of the first shaft sealing cavity 1131 away from the first bearing 114. The first shaft sealing cavity 1131 can increase the resistance to the flow of lubricating oil at the first bearing 114 in the direction away from the stator / rotor assembly 112, thereby reducing the leakage of lubricating oil at the first bearing 114 in the direction away from the stator / rotor assembly 112.

[0050] refer to Figure 2 The compressor 10 may also include a volute 140, which is connected to one end of the motor housing 111 near the first bearing 114. An impeller 120 is disposed within the volute 140, and a portion of the main shaft 113 extends into the volute 140 and is fixedly connected to the impeller 120.

[0051] refer to Figure 2 and Figure 3The volute 140 and the motor housing 111 enclose a sealed cavity 141, which is connected to the side of the first shaft sealing cavity 1131 away from the first bearing 114.

[0052] In some possible implementations of the embodiments of this application, reference is made to Figure 1 The air conditioning unit may also include a first pressure detector 70, which may be a pressure sensor or other device capable of detecting fluid pressure. The first pressure detector 70 is used to detect the oil supply pressure P1 of the first oil tank 130.

[0053] refer to Figure 1 The air conditioning unit may also include a second pressure detector 80, which may be a pressure sensor or other device capable of detecting fluid pressure. The second pressure detector 80 is used to detect the pressure P2 within the sealed cavity 141.

[0054] refer to Figure 1 The condenser 20 and the sealed cavity 141 are connected by a first pipe 210, on which a first control valve 211 is installed. Since the refrigerant in the condenser 20 is a high-pressure refrigerant, when the first control valve 211 is open, the high-pressure refrigerant in the condenser 20 flows to the sealed cavity 141, increasing the pressure there. When the first control valve 211 is closed, the high-pressure refrigerant in the condenser 20 cannot flow to the sealed cavity 141.

[0055] refer to Figure 1 The air conditioning unit may also include a controller 100, which is electrically connected to a first pressure detector 70, a second pressure detector 80, and a first control valve 211. (Reference) Figure 5 The controller 100 is configured as follows: When P1 > P2 and P1 - P2 ≥ ΔP1, the first control valve 211 is opened; otherwise, the first control valve 211 is closed. Here, ΔP1 is a first preset difference value, which is greater than 0.

[0056] When P1 > P2, it means that the oil supply pressure of the first oil tank 130 is greater than the pressure in the sealing cavity 141. In other words, there is a pressure difference between the two sides of the first shaft sealing cavity 1131, and the pressure on the side of the first shaft sealing cavity 1131 facing the first bearing 114 is greater than the pressure on the side away from the first bearing 114. The lubricating oil in the first shaft sealing cavity 1131 will leak to the side away from the first bearing 114.

[0057] At this time, if P1-P2<ΔP1, it means that the pressure difference on both sides of the first shaft sealing cavity 1131 is small. At this time, the amount of lubricating oil leaking through the first shaft sealing cavity 1131 at the first bearing 114 is small. The controller 100 controls the first control valve 211 to close, and there is no need to adjust the pressure in the sealing cavity 141.

[0058] If P1-P2≥ΔP1 at this time, it means that the pressure difference between the two sides of the first shaft seal cavity 1131 is large. At this time, the amount of lubricating oil leaking from the first bearing 114 through the first shaft seal cavity 1131 is relatively large. At this time, the controller 100 controls the first control valve 211 to open, so that the high-pressure refrigerant at the condenser 20 flows to the sealing cavity 141, which increases the pressure at the sealing cavity 141, thereby reducing the pressure difference between the two sides of the first shaft seal cavity 1131 and reducing the amount of lubricating oil leaking from the first bearing 114 through the first shaft seal cavity 1131.

[0059] In some possible implementations of the embodiments of this application, reference is made to Figure 6 The controller 100 can also be configured as follows: When P1 > P2 and P1 - P2 ≥ ΔP1, the first control valve 211 is opened for a first set time and then closed.

[0060] The first set duration is a preset value. The first set duration is greater than 0. The first set duration can be set according to the capacity of the sealed cavity 141 and the flow rate of the refrigerant flowing from the condenser 20 into the sealed cavity 141, so that the refrigerant will not fill the sealed cavity 141 after the first control valve 211 is opened for the first set duration.

[0061] The controller 100 controls the first control valve 211 to close after opening for a first set time, which simplifies the control logic of the controller 100 for the first control valve 211 and reduces the failure rate of the air conditioning unit.

[0062] In some possible implementations of the embodiments of this application, reference is made to Figure 7 The controller 100 can be configured as follows: When P1 > P2, P1 - P2 ≥ ΔP1, and the duration is greater than or equal to the first maximum set duration, the first control valve 211 is opened.

[0063] The duration refers to the time during which the condition "P1 > P2 and P1 - P2 ≥ ΔP1" is satisfied. The first maximum set duration is greater than 0, and can be 240 seconds, 300 seconds, 330 seconds, 360 seconds, etc.

[0064] When P1 > P2, P1 - P2 ≥ ΔP1, and the duration is less than the first maximum set duration, it indicates that the large pressure difference across the first shaft seal cavity 1131 lasts for a short period. Therefore, the total amount of lubricating oil leaking from the first bearing 114 through the first shaft seal cavity 1131 is small and insufficient to affect the lubrication effect at the first bearing 114. The controller 100 controls the first control valve 211 to close, eliminating the need to adjust the pressure within the seal cavity 141.

[0065] When P1 > P2, P1 - P2 ≥ ΔP1, and the duration is greater than or equal to the first maximum set duration, it indicates that the pressure difference between the two sides of the first shaft seal cavity 1131 is large for a long time, and the total amount of lubricating oil leaking from the first bearing 114 through the first shaft seal cavity 1131 is large, which has affected the lubrication effect at the first bearing 114. At this time, the controller 100 controls the first control valve 211 to open, so that the high-pressure refrigerant at the condenser 20 flows to the first shaft seal cavity 1131, which increases the pressure in the sealing cavity 141, thereby reducing the pressure difference between the two sides of the first shaft seal cavity 1131 and reducing the amount of lubricating oil leaking from the first bearing 114 through the first shaft seal cavity 1131.

[0066] In some possible implementations of the embodiments of this application, reference is made to Figure 8 The air conditioning unit may also include a counter, which is used to record the number of times the first control valve 211 is opened (N).

[0067] Controller 100 can also be configured as: When P1 > P2, P1 - P2 ≥ ΔP1, and N reaches the maximum set number of times, the first control valve 211 is kept closed for a second set duration, and then the control counter is reset to zero.

[0068] The maximum number of times can be set as a positive integer, and can be two, three, four, or five times, etc. The second time limit can be 240 seconds, 300 seconds, 330 seconds, or 360 seconds, etc.

[0069] When P1 > P2, P1 - P2 ≥ ΔP1, and N reaches the maximum set number of times, it indicates that the number of times the first control valve 211 has been opened has reached the maximum set number of times. However, the pressure difference between the two sides of the first shaft sealing cavity 1131 is still large. At present, it is difficult to further reduce the leakage pressure difference between the two sides of the first shaft sealing cavity 1131 by adjusting the first control valve 211. At this time, the controller 100 controls the first control valve 211 to remain closed and continues for the second set time. After the second set time ends, the controller 100 controls the counter to clear N to zero, which is regarded as the end of the current adjustment cycle of the pressure difference between the two sides of the first shaft sealing cavity 1131. The next adjustment cycle of the pressure difference between the two sides of the first shaft sealing cavity 1131 is then executed to continuously detect and adjust the pressure difference between the two sides of the first shaft sealing cavity 1131.

[0070] In some possible implementations of the embodiments of this application, reference is made to Figure 8 The controller 100 can be configured as follows: When P1 > P2, P1 - P2 ≥ ΔP1, and the duration is greater than or equal to the first maximum set duration, the first control valve 211 is controlled to open for the first set duration and then close. When P1 > P2, P1 - P2 ≥ ΔP1, and N reaches the maximum set number of times, the first control valve 211 is kept closed for a second set duration, and then the control counter is reset to zero. When P1 < P2, or P1 > P2 and P1 - P2 < ΔP1, control the first control valve 211 to close.

[0071] In some possible implementations of the embodiments of this application, reference is made to Figure 1 The condenser 20 can be connected to the cooling chamber 1111 through the second pipe 220, so that the high-pressure liquid refrigerant at the condenser 20 can flow into the cooling chamber 1111 through the second pipe 220. The liquid refrigerant evaporates and absorbs heat in the cooling chamber 1111 to absorb the heat of the stator and rotor assembly 112 in the motor 110, thereby reducing the temperature of the stator and rotor assembly 112.

[0072] refer to Figure 1 The evaporator 40 and the cooling chamber 1111 are connected by a third pipe 410. The refrigerant in the cooling chamber 1111 is transported back to the evaporator 40 through the third pipe 410, so that the refrigerant after cooling the stator and rotor assembly 112 can return to the circulation of the compressor 10, condenser 20, throttling device 30 and evaporator 40 connected in series through the pipes.

[0073] refer to Figure 1A regulating valve 411 can be installed on the third pipeline 410. The opening of the regulating valve 411 is adjustable to regulate the flow rate of refrigerant from the cooling chamber 1111 to the evaporator 40. When the opening of the regulating valve 411 decreases, the amount of refrigerant flowing back to the evaporator 40 from the cooling chamber 1111 will decrease, and the pressure in the cooling chamber 1111 will increase.

[0074] refer to Figure 1 The air conditioning unit also includes a third pressure detector 90, which can be a pressure sensor or other pressure-detecting device. The third pressure detector 90 is used to detect the pressure P3 inside the cooling chamber 1111.

[0075] The controller 100 can be electrically connected to the first pressure detector 70, the third pressure detector 90, and the regulating valve 411, respectively. (Reference) Figure 9 The controller 100 is configured as follows: When P1 > P3 and P1 - P3 ≥ ΔP2, the opening of the control valve 411 is reduced; otherwise, the opening of the control valve 411 remains unchanged; where ΔP2 is the second preset difference and ΔP1 is greater than 0.

[0076] When P1 > P3, it means that the oil supply pressure of the first oil tank 130 is greater than the pressure in the cooling chamber 1111. There is a pressure difference on both sides of the shaft seal chamber (1132, 1133), and the pressure on the side of the shaft seal chamber (1132, 1133) facing the bearing is greater than the pressure on the side away from the bearing. The lubricating oil in the shaft seal chamber (1132, 1133) will leak to the side away from the bearing.

[0077] At this time, if P1-P3 < ΔP2, it means that the pressure difference between the two sides of the shaft seal cavity (1132, 1133) is small. At this time, the amount of lubricating oil leaking through the shaft seal cavity (1132, 1133) at the bearing is small. The controller 100 controls the opening of the regulating valve 411 to remain unchanged, and there is no need to adjust the pressure in the cooling cavity 1111.

[0078] If P1-P3≥ΔP2 at this time, it means that the pressure difference between the two sides of the shaft seal cavity (1132, 1133) is large. At this time, the amount of lubricating oil leaking from the bearing through the shaft seal cavity (1132, 1133) is relatively large. At this time, the controller 100 controls the opening of the regulating valve 411 to reduce the amount of refrigerant flowing back from the cooling cavity 1111 to the evaporator 40, thereby increasing the pressure in the cooling cavity 1111, thus reducing the pressure difference between the two sides of the shaft seal cavity (1132, 1133) and reducing the amount of lubricating oil leaking from the bearing through the shaft seal cavity (1132, 1133).

[0079] In the implementation where the bearing includes the first bearing 114 and the shaft sealing cavity includes the second shaft sealing cavity 1132, when P1 > P3 and P1 - P3 ≥ ΔP2, it indicates that the pressure difference across the second shaft sealing cavity 1132 is large. At this time, the amount of lubricating oil leaking from the first bearing 114 through the second shaft sealing cavity 1132 is relatively large. At this time, the controller 100 controls the opening of the regulating valve 411 to decrease, so as to reduce the amount of refrigerant flowing back from the cooling cavity 1111 to the evaporator 40, thereby increasing the pressure in the cooling cavity 1111, thereby reducing the pressure difference across the second shaft sealing cavity 1132 and reducing the amount of lubricating oil leaking from the first bearing 114 through the second shaft sealing cavity 1132.

[0080] In the implementation where the bearing includes the second bearing 115 and the shaft sealing cavity includes the third shaft sealing cavity 1133, when P1 > P3 and P1 - P3 ≥ ΔP2, it indicates that the pressure difference across the third shaft sealing cavity 1133 is large. At this time, the amount of lubricating oil leaking from the second bearing 115 through the third shaft sealing cavity 1133 is relatively large. At this time, the controller 100 controls the opening of the regulating valve 411 to decrease, so as to reduce the amount of refrigerant flowing back from the cooling cavity 1111 to the evaporator 40, thereby increasing the pressure in the cooling cavity 1111, thereby reducing the pressure difference across the third shaft sealing cavity 1133 and reducing the amount of lubricating oil leaking from the second bearing 115 through the third shaft sealing cavity 1133.

[0081] The controller 100 controls the opening of the regulating valve 411 to decrease, which can simultaneously reduce the pressure difference between the two sides of the second shaft sealing cavity 1132 and the two sides of the third shaft sealing cavity 1133, thereby reducing the amount of lubricating oil leaking from the first bearing 114 through the second shaft sealing cavity 1132 and the amount of lubricating oil leaking from the second bearing 115 through the third shaft sealing cavity 1133.

[0082] In some possible implementations of the embodiments of this application, reference is made to Figure 10 The controller 100 can also be configured as follows: When P1 > P3 and P1 - P3 ≥ ΔP2, the opening of the control valve 411 is reduced by the set step size.

[0083] The controller 100 controls the regulating valve 411 to reduce the set step size each time, which simplifies the control logic of the controller 100 for the regulating valve 411 and reduces the failure rate of the air conditioning unit.

[0084] In some possible implementations of the embodiments of this application, reference is made to Figure 11 The controller 100 can also be configured to reduce the opening of the regulating valve 411 when P1 > P3, P1-P3 ≥ ΔP2, and the duration is greater than or equal to the second maximum set duration.

[0085] The second maximum set duration is greater than 0, and the second maximum set duration can be 240 seconds, 300 seconds, 330 seconds, or 360 seconds, etc.

[0086] When P1 > P3, P1 - P3 ≥ ΔP2, and the duration is less than the second maximum set duration, it indicates that the pressure difference between the two sides of the shaft seal cavity is large for a short period of time, and the total amount of lubricating oil leaking through the shaft seal cavity at the bearing is small. The controller 100 controls the opening of the regulating valve 411 to remain unchanged, and there is no need to adjust the pressure in the cooling chamber 1111.

[0087] When P1 > P3, P1 - P3 ≥ ΔP2, and the duration is greater than or equal to the second maximum set duration, it indicates that the pressure difference between the two sides of the shaft seal cavity is large for a long time, and the total amount of lubricating oil leaking from the bearing through the shaft seal cavity is large. At this time, the controller 100 controls the opening of the regulating valve 411 to reduce the amount of refrigerant flowing back from the cooling cavity 1111 to the evaporator 40, thereby increasing the pressure in the cooling cavity 1111, thereby reducing the pressure difference between the two sides of the second shaft seal cavity 1132, and reducing the amount of lubricating oil leaking from the first bearing 114 through the second shaft seal cavity 1132.

[0088] In some possible implementations of the embodiments of this application, reference is made to Figure 12 The controller 100 can also be configured as follows: When P1 > P3, P1 - P3 ≥ ΔP2, and the opening of the regulating valve 411 reaches the minimum opening, the regulating valve 411 is controlled to maintain the minimum opening and after maintaining it for a third set time, the opening of the regulating valve 411 is restored to the initial opening.

[0089] When the opening of the regulating valve 411 reaches its minimum opening, it indicates that fluid flow is no longer allowed through the regulating valve 411, or that the refrigerant recirculation from the cooling chamber 1111 to the evaporator 40 has been affected.

[0090] The initial opening of the regulating valve 411 can be the maximum opening of the regulating valve 411, or the maximum opening that can maintain the cooling effect of the refrigerant in the cooling chamber 1111.

[0091] When P1 > P3, P1 - P3 ≥ ΔP2, and the opening of regulating valve 411 reaches its minimum opening, it indicates that the opening of regulating valve 411 has been reduced to its minimum opening. However, the pressure difference between the two sides of the shaft sealing cavity (the second shaft sealing cavity 1132 and the third shaft sealing cavity 1133) is still relatively large. At present, it is difficult to further reduce the pressure difference between the two sides of the shaft sealing cavity by adjusting the opening of regulating valve 411. The controller 100 controls regulating valve 411 to maintain the minimum opening and continues for a third set time. After the third set time, the controller 100 controls regulating valve 411 to return to the initial opening. This is considered as the end of the current adjustment cycle of the pressure difference between the two sides of the shaft sealing cavity, and the next adjustment cycle of the pressure difference between the two sides of the shaft sealing cavity is started. The pressure difference between the two sides of the shaft sealing cavity has been continuously detected and adjusted.

[0092] In some possible implementations of the embodiments of this application, reference is made to Figure 12 The controller 100 can also be configured as follows: When P1 > P3, P1 - P3 ≥ ΔP2, and the duration is greater than or equal to the second maximum set duration, the opening of the control valve 411 is reduced by the set step. When P1 > P3, P1 - P3 ≥ ΔP2, and the opening of regulating valve 411 reaches the minimum opening, control regulating valve 411 to maintain the minimum opening, and after maintaining it for a third set time, restore the opening of regulating valve 411 to the initial opening. When P1 < P3, or P1 > P3 and P1 - P3 < ΔP2, the opening of the control valve 411 remains unchanged.

[0093] In some possible implementations of the embodiments of this application, reference is made to Figure 1 The condenser 20 and the cooling chamber 1111 can also be connected through a fourth pipe 230, and a second control valve 231 can be installed on the fourth pipe 230.

[0094] Controller 100 can also be configured as: When P1 > P3 and P1 - P3 ≥ ΔP2, the opening of the control valve 411 is reduced, and the second control valve 231 is opened.

[0095] When P1 > P3 and P1 - P3 ≥ ΔP2, it indicates that the pressure difference across the shaft seal cavity is large. At this time, the amount of lubricating oil leaking through the shaft seal cavity at the bearing is relatively large. At this time, the controller 100 controls the opening of the regulating valve 411 to decrease, so as to reduce the amount of refrigerant flowing back from the cooling cavity 1111 to the evaporator 40, thereby increasing the pressure in the cooling cavity 1111. At the same time, it controls the second control valve 231 to open, so as to increase the flow rate of refrigerant from the condenser 20 to the cooling cavity 1111, further increasing the pressure in the cooling cavity 1111, increasing the rate at which the pressure difference across the shaft seal cavity decreases, and rapidly reducing the amount of lubricating oil leaking through the shaft seal cavity at the bearing.

[0096] refer to Figure 13 The controller 100 can simultaneously adjust the pressure difference between the two sides of the first shaft seal cavity 1131, the second shaft seal cavity 1132, and the third shaft seal cavity 1133 to reduce the amount of lubricating oil leaking from the first bearing 114 through the first shaft seal cavity 1131 and the second shaft seal cavity 1132, and also reduce the amount of lubricating oil leaking from the second bearing 115 through the third shaft seal cavity 1133.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0098] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the above embodiments and various different variations of embodiments suitable for specific application considerations.

Claims

1. An air conditioning unit, characterized in that, include: Compressor (10), condenser (20), evaporator (40); The compressor (10) includes: The motor (110) includes a motor housing (111), and a cooling chamber (1111) is formed inside the motor housing (111). The cooling chamber (1111) is provided with a stator and rotor assembly (112) and a main shaft (113). The condenser (20) is connected to the cooling chamber (1111). The bearing is sleeved on the main shaft (113) and located inside the motor housing (111) to support the stator and rotor assembly (112). The first oil tank (130) supplies lubricating oil to the bearing through the oil supply channel (1115); A sealing structure is coaxially sleeved on the main shaft (113) with the bearing, and a shaft sealing cavity is provided between the sealing structure and the main shaft (113); The side of the shaft seal cavity closest to the bearing is connected to the oil supply channel (1115); the side of the shaft seal cavity away from the bearing is connected to the condenser (20) or the evaporator (40).

2. The air conditioning unit according to claim 1, characterized in that, The condenser (20) is connected to the shaft seal cavity through a first pipe (210), and a first control valve (211) is provided on the first pipe (210). The condenser (20) is connected to the cooling chamber (1111) via a second pipe (220). The evaporator (40) is connected to the shaft seal cavity through a third pipe (410), and a regulating valve (411) is provided on the third pipe (410).

3. The air conditioning unit according to claim 1 or 2, characterized in that, The compressor (10) also includes a volute (140), which is connected to the motor housing (111). An impeller (120) is provided inside the volute (140). The impeller (120) is located outside the motor housing (111) and is fixedly connected to the main shaft (113). The bearing includes: The first bearing (114) is located between the stator and rotor assembly (112) and the impeller (120); The second bearing (115) is located at the end of the stator-rotor assembly (112) opposite to the impeller (120); The sealing structure includes: The first sealing structure (1112) forms a first shaft sealing cavity (1131) with the main shaft (113), and the first shaft sealing cavity (1131) is located between the impeller (120) and the first bearing (114); The second sealing structure (1113) forms a second shaft sealing cavity (1132) with the main shaft (113), and the second shaft sealing cavity (1132) is located between the stator and rotor assembly (112) and the first bearing (114); The third sealing structure (1114) forms a third shaft sealing cavity (1133) with the main shaft (113), and the third shaft sealing cavity (1133) is located between the stator and rotor assembly (112) and the second bearing (115).

4. The air conditioning unit according to claim 3, characterized in that, The first shaft seal cavity (1131) and the second shaft seal cavity (1132) are connected to the oil supply channel (1115) on the side near the first bearing (114); the third shaft seal cavity (1133) is connected to the oil supply channel (1115) on the side near the second bearing (115).

5. The air conditioning unit according to claim 4, characterized in that, The volute (140) and the motor housing (111) enclose a sealed cavity (141), the sealed cavity (141) is connected to the side of the first shaft seal cavity (1131) away from the first bearing (114), and the condenser (20) is connected to the sealed cavity (141) through the first pipe (210); The cooling chamber (1111) is connected to the side of the second shaft seal chamber (1132) away from the first bearing (114), and the third shaft seal chamber (1133) is connected to the side of the second bearing (115) away from the second bearing; the evaporator (40) is connected to the cooling chamber (1111) through the third pipe (410).

6. The air conditioning unit according to claim 5, characterized in that, Also includes: The first pressure detector (70) is used to detect the oil supply pressure P1 of the first oil tank (130); The second pressure detector (80) is used to detect the pressure P2 inside the sealed cavity (141); The third pressure detector (90) is used to detect the pressure P3 inside the cooling chamber (1111).

7. The air conditioning unit according to claim 6, characterized in that, The condenser (20) is connected to the cooling chamber (1111) through a fourth pipe (230), and a second control valve (231) is provided on the fourth pipe (230).

8. The air conditioning unit according to claim 1, characterized in that, The motor housing (111) is provided with an oil return channel (1116), one end of which faces the bearing, and the other end of which is connected to the first oil tank (130).

9. The air conditioning unit according to claim 8, characterized in that, It includes a second oil tank (50), which is connected to the first oil tank (130) via an oil supply pipe (501). The second oil tank (50) supplies lubricating oil to the first oil tank (130) via the oil supply pipe (501).

10. The air conditioning unit according to claim 9, characterized in that, The second oil tank (50) is connected to the oil return channel (1116) through the oil return pipe (502), and the lubricating oil in the oil return channel (1116) flows back to the second oil tank (50) through the oil return pipe (502).

Images