Mechanical sealing structure for shaft end of compressor and sealing, lubricating and cooling method

Abstract

The invention relates to a mechanical sealing structure for a shaft end of a compressor and a sealing, lubricating and cooling method. The compressor is characterized in that the compressor comprises a movable ring, a static ring and a lip-shaped sealing ring, an oil storage cavity and an oil supply ring cavity are formed in a compressor shell, the oil storage cavity and a rotor cavity are separated through a separation convex ring, and the lip-shaped sealing ring is installed between the separation convex ring and a compressor rotor; the movable ring and the static ring are both located in the oil storage cavity, the movable ring is fixed to a compressor rotor, the static ring is fixed to a compressor shell, a sealing convex ring on the movable ring abuts against a sealing plane of the static ring to form a mechanical sealing face, an inlet of the oil supply ring cavity is connected with an external high-pressure oil supply pipe, and a plurality of oil spraying openings are formed in the wall face between the oil supply ring cavity and the oil storage cavity. And the oil injection port is obliquely arranged and is aligned with the mechanical sealing surface. The sealing device is reasonable in structural design and good in sealing, lubricating and cooling effects.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular to a mechanical seal structure and a seal lubrication cooling method for a compressor shaft end, which are mainly used in screw compressors. Background Art

[0002] The shaft end of the compressor usually needs to be sealed and lubricated and cooled. The commonly used hybrid structure of oil injection and sealing is not designed reasonably. There is only one oil injection port, and the refrigerant oil is only supplied from one direction. The oil injection effect is not good, resulting in uneven cooling and lubrication of the shaft, and the refrigerant oil cannot fully cool and lubricate. In addition, when the compressor is just started, the refrigerant oil cannot be supplied to the seal immediately. The seal is not lubricated and cooled by the refrigerant oil when it starts to rub, which makes it easy for the seal to burn out. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a mechanical seal structure and a sealing, lubricating and cooling method for a compressor shaft end with reasonable structural design and good sealing, lubricating and cooling effects.

[0004] The technical solution adopted by the present invention to solve the above-mentioned problem is: the mechanical sealing structure for the shaft end of the compressor is provided with a rotor cavity in the compressor housing, the compressor rotor is installed in the rotor cavity, the input end of the compressor rotor extends to the outside of the compressor housing and is connected to the motor through a coupling, and its structural characteristics are: the mechanical sealing structure includes a dynamic ring provided with a sealing convex ring, a static ring provided with a sealing plane and a lip sealing ring, the compressor housing is also provided with an oil storage cavity and an oil supply ring cavity, the upper half of the oil storage cavity is provided with an oil drain hole, the oil storage cavity and the rotor cavity are separated by a separating convex ring, the separating convex ring and the compressor housing are an integrated structure, there is a rotor gap between the separating convex ring and the compressor rotor, the lip sealing ring is installed between the separating convex ring and the compressor rotor, and the lip edge of the lip sealing ring is in close contact with the compressor rotor; The moving ring and the stationary ring are both located in the oil storage cavity. The moving ring is fixed to the compressor rotor, and the stationary ring is fixed to the compressor housing. The sealing convex ring on the moving ring is pressed against the sealing plane of the stationary ring to form a mechanical sealing surface for isolating the section of the compressor rotor from the input end of the compressor rotor to the position of the moving ring from the bottom of the rotor gap, and the bottom of the mechanical sealing surface is lower than the bottom of the rotor gap. The inlet of the oil supply ring cavity is connected to the external high-pressure oil supply pipe, and the wall surface between the oil supply ring cavity and the oil storage cavity is provided with a plurality of oil spray ports. The oil supply ring cavity is connected to the oil storage cavity through the oil spray ports, and the oil spray ports are arranged obliquely. The outlet of the oil spray port is aligned with the mechanical sealing surface formed by the contact between the sealing convex ring on the moving ring and the sealing plane of the stationary ring, and is used for spraying the refrigeration oil with freezing and lubricating effects on the mechanical sealing surface.

[0005] Preferably, each fuel injection port of the present invention comprises two sections with different diameters, the inlet of the fuel injection port is located at the section with the thicker diameter, and the outlet of the fuel injection port is located at the section with the thinner diameter.

[0006] Preferably, the plurality of oil injection ports of the present invention are evenly distributed around the mechanical sealing surface formed by the contact between the sealing convex ring on the dynamic ring and the sealing plane of the static ring, and the oil injection direction of each oil injection port is tangent to the mechanical sealing surface.

[0007] Preferably, the number of the fuel injection ports of the present invention is 4 to 20.

[0008] Preferably, the outlet of the oil injection port of the present invention is close to a mechanical sealing surface formed by the contact between the sealing convex ring on the dynamic ring and the sealing plane of the static ring.

[0009] A sealing lubrication and cooling method using the mechanical sealing structure for the compressor shaft end is characterized in that the steps are as follows: When the compressor is in a long-term shutdown state, the oil storage cavity is stored with refrigerant oil at a portion below the rotor gap or at a portion below the oil drain hole, and the lower portion or most of the dynamic ring and the lower portion or most of the static ring are always immersed in the refrigerant oil in the oil storage cavity; When the compressor starts, since the lower parts of the moving ring and the lower parts of the static ring are always immersed in the refrigeration oil in the oil storage chamber, the moving ring is driven to rotate synchronously with the rotation of the compressor rotor, and the moving ring brings the refrigeration oil in the oil storage chamber to the entire mechanical sealing surface. The mechanical sealing surface in contact with the moving ring and the static ring can be cooled and lubricated by the refrigeration oil synchronously with the start-up of the compressor, ensuring that there is refrigeration oil when the moving ring starts to rub against the static ring. The mechanical sealing surface in contact with the moving ring and the static ring is lubricated and cooled from the moment the compressor starts, which effectively solves the problem of burning of the mechanical seal due to lack of cooling and lubrication of the refrigeration oil when the compressor starts. At the same time, the refrigeration oil input from the outside for cooling and lubrication is supplied through the external high-pressure supply The oil is transported to the oil supply ring cavity through the oil pipe, and the refrigerant oil is sprayed through the oil spray port to the mechanical seal surface formed by the contact between the sealing convex ring on the dynamic ring and the sealing plane of the static ring, further continuously lubricating and cooling the mechanical seal surface in contact with the dynamic ring and the static ring; as the compressor rotor rotates at high speed, the lip seal ring is subjected to the pressure difference, and under the sealing action of the lip seal ring, the refrigerant oil sprayed from the oil spray port is continuously accumulated in the oil storage cavity until the liquid level in the oil storage cavity is higher than the oil drain hole of the oil storage cavity, and the excess refrigerant oil is discharged from the oil storage cavity through the oil drain hole, so that the refrigerant oil in the oil storage cavity is continuously replaced, further reducing the temperature of the refrigerant oil in the oil storage cavity, and having a better cooling and lubricating effect on the mechanical seal surface in contact with the dynamic ring and the static ring; When the compressor is started and in normal operation, the refrigerant oil is continuously transported to the oil supply ring cavity through the external high-pressure oil supply pipe, and the refrigerant oil is continuously sprayed through the oil spray port to the mechanical sealing surface formed by the contact between the sealing convex ring on the dynamic ring and the sealing plane of the static ring. It is used to continuously lubricate and cool the mechanical sealing surface in contact with the dynamic ring and the static ring. The excess refrigerant oil in the oil storage cavity is discharged through the oil drain hole. At the same time, the refrigerant oil is supplied to the bearing cavity of the compressor and the compressor rotor through the internal oil channel, and is discharged from the compressor with the gas. The refrigerant oil and the refrigerant are separated by the oil separator. After the circulation, the refrigerant oil returns to the oil supply ring cavity, and then enters the oil storage cavity again through the oil spray port to realize the recycling of the refrigerant oil.

[0010] As a preferred embodiment, when the compressor is turned off, the compressor rotor loses driving force and gradually stops rotating. At the same time, the external high-pressure oil supply pipe stops delivering refrigerant oil to the oil supply ring cavity, and the oil spray port stops spraying refrigerant oil to the mechanical sealing surface formed by the contact between the sealing convex ring on the dynamic ring and the sealing plane of the static ring. The refrigerant oil stored in the oil storage cavity still lubricates and cools the mechanical sealing surface in contact with the dynamic ring and the static ring during the process of the compressor rotor gradually stopping rotating, until the compressor rotor stops rotating. As the compressor rotor stops rotating, the lip seal loses the pressure difference. If the lip seal is not sealed tightly, the refrigerant oil in the oil storage chamber will gradually flow into the rotor chamber of the compressor housing along the rotor gap, and the liquid level of the refrigerant oil in the oil storage chamber will gradually decrease until it is flush with the bottom of the rotor gap. As the bottom of the oil storage chamber is lower than the bottom of the rotor gap, the refrigerant oil below the bottom of the rotor gap is still stored in the oil storage chamber. At this time, the lower part of the oil storage chamber is still stored with refrigerant oil, and the lower part of the moving ring and the lower part of the static ring are always immersed in the refrigerant oil in the oil storage chamber, waiting for the next start of the compressor. When the compressor is started next time, the refrigerant oil stored in the oil storage chamber can simultaneously lubricate and cool the mechanical sealing surface formed by the contact between the sealing convex ring on the moving ring and the sealing plane of the static ring at the moment the compressor starts. Alternatively, because the compressor rotor stops rotating, the lip seal loses the pressure differential. If the lip seal still has a stable sealing effect, the refrigerant oil in the oil storage chamber will not flow into the rotor chamber of the compressor housing along the rotor gap. The oil storage chamber is stored with refrigerant oil at a position below the oil drain hole. The parts of the moving ring and the static ring below the oil drain hole are always immersed in the refrigerant oil in the oil storage chamber, waiting for the next start of the compressor. When the compressor is started next time, the refrigerant oil stored in the oil storage chamber can synchronously lubricate and cool the mechanical sealing surface formed by the contact between the sealing convex ring on the moving ring and the sealing plane of the static ring at the moment the compressor starts.

[0011] Compared with the prior art, the present invention has the following advantages and effects: when the compressor is in a shutdown state, since the lower part of the moving ring and the lower part of the static ring are always immersed in the refrigeration oil in the oil storage chamber, when the compressor is started, the moving ring is driven to rotate synchronously with the rotation of the compressor rotor, and the moving ring brings the refrigeration oil in the oil storage chamber to the entire mechanical sealing surface. The mechanical sealing surface in contact with the moving ring and the static ring can be synchronously cooled and lubricated by the refrigeration oil as the compressor is started, ensuring that there is refrigeration oil when the moving ring starts to rub on the static ring. The mechanical sealing surface in contact with the moving ring and the static ring is synchronously lubricated and cooled from the moment the compressor is started, effectively solving the problem of burning of the mechanical seal due to lack of cooling and lubrication of the refrigeration oil when the compressor is started. The currently commonly used mechanical seal structure cannot ensure that there is refrigeration oil when the mechanical seal starts to rub, resulting in the burning of the mechanical seal.

[0012] The present invention can improve the stability of compressor operation. The multiple oil injection ports are designed obliquely, so that the oil injection efficiency and cooling effect are improved, and the lubrication and cooling of the mechanical sealing surface in contact with the dynamic ring and the static ring are more uniform, ensuring the stability of the long-term operation of the compressor. The oil injection direction of the oil injection port is tangent to the mechanical sealing surface and follows the rotation direction of the compressor rotor, reducing the liquid impact force caused by the conventional oil injection direction and increasing the life of the dynamic ring and the static ring.

[0013] The present invention can improve the operating range of the compressor. The cooling effect of the refrigeration oil on the dynamic ring and the static ring enables the dynamic ring and the static ring to maintain a normal working state under a high rotation speed, thereby widening the operating range of the compressor.

[0014] The present invention improves the safety of the compressor. The design of the oil storage chamber can ensure that the dynamic ring and the static ring serving as the mechanical seal are always lubricated with refrigeration oil. Even when the compressor is shut down for a long time, the dynamic ring and the static ring can still be cooled and lubricated by the refrigeration oil, ensuring that the dynamic ring and the static ring serving as the mechanical seal have refrigeration oil when they just begin to rub at the moment the compressor is started, thus solving the problem of the mechanical seal burning due to lack of cooling and lubrication of the refrigeration oil when the compressor is started, and greatly improving the safety of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention and / or the technical solutions in the prior art, the drawings required for use in the embodiments and / or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the structure after the motor, coupling and compressor in the embodiment of the present invention are connected.

[0017] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure of the AA surface in the middle.

[0018] Figure 3 yes Figure 1 Schematic diagram of the left view structure.

[0019] Figure 4 yes Figure 1 Schematic diagram of the structure after the middle part is cut away.

[0020] Figure 5 yes Figure 4 Schematic diagram of the structure after enlargement at point Ⅰ in the middle.

[0021] Figure 6 yes Figure 2 Schematic diagram of the structure after enlargement at point II in the middle.

[0022] Figure 7 yes Figure 5 Schematic diagram of the enlarged structure at point III.

[0023] In the figure: 1-motor; 2-coupling; 3-compressor; 4-injection port; 5-moving ring; 6-stationary ring; 7-oil storage chamber; 8-lip seal ring; 9-compressor rotor; 10-compressor housing; 11-oil supply ring chamber; 12-rotor gap; 13-separating convex ring; 51-sealing convex ring; 61-sealing plane. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0025] Example

[0026] See also Figures 1 to 7 The compressor 3 includes a compressor rotor 9 and a compressor housing 10. A rotor cavity is provided in the compressor housing 10. The compressor rotor 9 is installed in the rotor cavity. The input end of the compressor rotor 9 extends out of the compressor housing 10 and is connected to the motor 1 through the coupling 2. After the motor 1 is energized, the compressor rotor 9 is driven to rotate through the coupling 2.

[0027] The mechanical sealing structure for the compressor shaft end in this embodiment includes a dynamic ring 5 provided with a sealing convex ring 51, a static ring 6 provided with a sealing plane 61 and a lip seal ring 8. An oil storage chamber 7 and an oil supply ring chamber 11 are also provided in the compressor housing 10. The upper half of the oil storage chamber 7 is provided with an oil drain hole. The oil storage chamber 7 and the rotor chamber are separated by a separating convex ring 13. The separating convex ring 13 and the compressor housing 10 are an integrated structure. There is a rotor gap 12 between the separating convex ring 13 and the compressor rotor 9. The lip seal ring 8 is installed between the separating convex ring 13 and the compressor rotor 9, and the lip edge of the lip seal ring 8 is in close contact with the compressor rotor 9.

[0028] The dynamic ring 5 and the static ring 6 in this embodiment are both located in the oil storage chamber 7. The dynamic ring 5 is fixed to the compressor rotor 9, and the static ring 6 is fixed to the compressor housing 10. The sealing convex ring 51 on the dynamic ring 5 is pressed against the sealing plane 61 of the static ring 6 to form a mechanical sealing surface for isolating the section of the compressor rotor 9 from the input end of the compressor rotor 9 to the position of the dynamic ring 5 from the refrigerant oil in the oil storage chamber 7. The bottom of the oil storage chamber 7 is lower than the bottom of the rotor gap 12, and the bottom of the mechanical sealing surface is lower than the bottom of the rotor gap 12.

[0029] The inlet of the oil supply ring cavity 11 in this embodiment is connected to the high-pressure oil supply pipe of the outside, and the wall surface between the oil supply ring cavity 11 and the oil storage cavity 7 is provided with a plurality of oil injection ports 4, and the oil supply ring cavity 11 is connected to the oil storage cavity 7 through the oil injection ports 4, and the number of the oil injection ports 4 is usually 4 to 20. The oil injection ports 4 are arranged obliquely, and the outlet of the oil injection ports 4 is aligned with the mechanical sealing surface formed by the contact between the sealing convex ring 51 on the dynamic ring 5 and the sealing plane 61 of the static ring 6, so as to spray the refrigeration oil with refrigeration and lubrication effects on the mechanical sealing surface.

[0030] In this embodiment, each fuel injection port 4 includes two sections with different diameters, the inlet of the fuel injection port 4 is located at the section with the thicker diameter, and the outlet of the fuel injection port 4 is located at the section with the thinner diameter. The outlet of the fuel injection port 4 is close to the mechanical sealing surface formed by the contact between the sealing convex ring 51 on the dynamic ring 5 and the sealing plane 61 of the static ring 6.

[0031] The plurality of oil injection ports 4 in this embodiment are evenly distributed around the mechanical sealing surface formed by the contact between the sealing convex ring 51 on the dynamic ring 5 and the sealing plane 61 of the static ring 6, and the injection direction of each oil injection port 4 is tangent to the mechanical sealing surface, and the tangent direction is consistent with the rotation direction of the compressor rotor 9.

[0032] The steps of the sealing lubrication and cooling method for the mechanical sealing structure of the compressor shaft end in this embodiment are as follows: When the compressor 3 is in a shutdown state, especially when it is in a shutdown state for a long time, the oil storage chamber 7 stores refrigerant oil in the portion below the rotor gap 12 or the portion below the oil drain hole, and the lower part or most of the dynamic ring 5 and the lower part or most of the static ring 6 are always immersed in the refrigerant oil in the oil storage chamber 7.

[0033] When the compressor 3 is started, since the lower parts of the moving ring 5 and the lower parts of the static ring 6 are always immersed in the refrigeration oil in the oil storage chamber 7, the moving ring 5 is driven to rotate synchronously with the rotation of the compressor rotor 9, and the moving ring 5 brings the refrigeration oil in the oil storage chamber 7 to the entire mechanical sealing surface. The mechanical sealing surface in contact with the moving ring 5 and the static ring 6 can be cooled and lubricated by the refrigeration oil synchronously with the start-up of the compressor 3, ensuring that there is refrigeration oil when the moving ring 5 starts to rub on the static ring 6. The mechanical sealing surface in contact with the moving ring 5 and the static ring 6 is lubricated and cooled from the moment the compressor 3 is started, which effectively solves the problem of burning of the mechanical seal due to lack of cooling and lubrication of the refrigeration oil when the compressor 3 is started. At the same time, the refrigeration oil input from the outside for cooling and lubrication is transported to the outside through the high-pressure oil supply pipe. It is sent to the oil supply ring cavity 11, and the refrigerant oil is sprayed through the oil spray port 4 to the mechanical sealing surface formed by the contact between the sealing convex ring 51 on the dynamic ring 5 and the sealing plane 61 of the static ring 6, thereby further continuously lubricating and cooling the mechanical sealing surface in contact between the dynamic ring 5 and the static ring 6; as the compressor rotor 9 rotates at high speed, the lip seal 8 is subjected to the pressure difference, and under the sealing action of the lip seal 8, the refrigerant oil sprayed out from the oil spray port 4 is continuously accumulated in the oil storage cavity 7, until the liquid level in the oil storage cavity 7 is higher than the oil drain hole of the oil storage cavity 7, the excess refrigerant oil is discharged from the oil storage cavity 7 through the oil drain hole, so that the refrigerant oil in the oil storage cavity 7 is continuously replaced, thereby further reducing the temperature of the refrigerant oil in the oil storage cavity 7, and achieving better cooling and lubrication effects on the mechanical sealing surface in contact between the dynamic ring 5 and the static ring 6.

[0034] When the compressor 3 is started and is in normal operation, the refrigerant oil is continuously transported to the oil supply ring cavity 11 through the external high-pressure oil supply pipe, and the refrigerant oil is continuously sprayed through the oil spray port 4 to the mechanical sealing surface formed by the contact between the sealing convex ring 51 on the dynamic ring 5 and the sealing plane 61 of the static ring 6, which is used for continuous lubrication and cooling of the mechanical sealing surface in contact between the dynamic ring 5 and the static ring 6. The excess refrigerant oil in the oil storage cavity 7 is discharged through the oil drain hole. At the same time, the refrigerant oil is supplied to the bearing cavity of the compressor 3 and the compressor rotor 9 through the internal oil channel, and is discharged from the compressor 3 along with the gas, and the refrigerant oil and the refrigerant are separated by the oil separator. After the circulation, the refrigerant oil returns to the oil supply ring cavity 11, and then enters the oil storage cavity 7 again through the oil spray port 4 to realize the recycling of the refrigerant oil.

[0035] When the compressor 3 is turned off, the compressor rotor 9 loses driving force and gradually stops rotating. At the same time, the external high-pressure oil supply pipe stops delivering refrigerant oil to the oil supply ring cavity 11, and the oil spray port 4 stops spraying refrigerant oil to the mechanical sealing surface formed by the contact between the sealing convex ring 51 on the dynamic ring 5 and the sealing plane 61 of the static ring 6. The refrigerant oil stored in the oil storage cavity 7 still lubricates and cools the mechanical sealing surface between the dynamic ring 5 and the static ring 6 during the process that the compressor rotor 9 gradually stops rotating until the compressor rotor 9 stops rotating.

[0036] Since the compressor rotor 9 stops rotating and the lip seal 8 loses the pressure difference, there are two possibilities as follows: 1. The lip seal 8 is not tightly sealed; 2. The lip seal 8 still has a stable sealing effect.

[0037] If the lip seal 8 is not sealed tightly, the refrigerant oil in the oil storage chamber 7 will gradually flow into the rotor chamber of the compressor housing 10 along the rotor gap 12, and the liquid level of the refrigerant oil in the oil storage chamber 7 will gradually decrease until it is flush with the bottom of the rotor gap 12. Since the bottom of the oil storage chamber 7 is lower than the bottom of the rotor gap 12, the refrigerant oil below the bottom of the rotor gap 12 is still stored in the oil storage chamber 7. At this time, the lower part of the oil storage chamber 7 is still stored with refrigerant oil, and the lower part of the dynamic ring 5 and the lower part of the static ring 6 are always immersed in the refrigerant oil in the oil storage chamber 7, waiting for the next start of the compressor 3. When the compressor 3 is started next time, the refrigerant oil stored in the oil storage chamber 7 can synchronously lubricate and cool the mechanical sealing surface formed by the contact between the sealing convex ring 51 on the dynamic ring 5 and the sealing plane 61 of the static ring 6 at the moment the compressor 3 is started.

[0038] If the lip seal 8 still has a stable sealing effect, the refrigerant oil in the oil storage chamber 7 will not flow into the rotor chamber of the compressor housing 10 along the rotor gap 12. The refrigerant oil is stored in the oil storage chamber 7 below the oil drain hole. The parts of the dynamic ring 5 and the static ring 6 below the oil drain hole are always immersed in the refrigerant oil in the oil storage chamber 7, waiting for the next start of the compressor 3. When the compressor 3 is started next time, the refrigerant oil stored in the oil storage chamber 7 can simultaneously lubricate and cool the mechanical sealing surface formed by the contact between the sealing convex ring 51 on the dynamic ring 5 and the sealing plane 61 of the static ring 6 at the moment the compressor 3 is started.

[0039] In this embodiment, multiple oil injection ports 4 are evenly distributed on the outer circle of the mechanical sealing surface formed after the dynamic ring 5 and the static ring 6 are in contact. The oil injection direction of the oil injection port 4 is tangent to the outer circle of the mechanical sealing surface and follows the movement direction of the compressor rotor 9; the lower parts of the dynamic ring 5 and the static ring 6 are always immersed in the refrigerant oil in the oil storage chamber 7, ensuring that the mechanical seal is lubricated with refrigerant oil when friction begins, ensuring that the mechanical seal can be lubricated with refrigerant oil for a long time, thereby ensuring that the mechanical seal can operate for a long time.

[0040] The oil injection port 4 in this embodiment is a channel for the refrigeration oil to lubricate the mechanical seal. The present invention adopts multiple oil injection ports 4, and the oil injection direction of the oil injection port 4 is tangent to the outer circle of the mechanical seal surface, which greatly increases the lubrication and cooling effect of the refrigeration oil on the mechanical seal surface and reduces the impact on the dynamic ring 5.

[0041] The dynamic ring 5 and the static ring 6 in this embodiment are parts that constitute the mechanical seal. The dynamic ring 5 is installed on the compressor rotor 9, and the static ring 6 is installed on the compressor housing 10. The dynamic ring 5 and the static ring 6 form a mechanical seal, and an oil storage chamber 7 is designed in the compressor housing 10. The oil storage chamber 7 is used to store refrigerant oil, which can ensure that the dynamic ring 5 and the static ring 6 are always immersed in the refrigerant oil in the oil storage chamber 7.

[0042] The lip seal ring 8 in this embodiment is a structure that separates the interior of the compressor 3 from the mechanical seal. The lip of the lip seal ring 8 is located inside the compressor 3. Under the action of the high-pressure gas of the compressor 3, the lip edge of the lip seal ring 8 is tightly attached to the compressor rotor 9 to achieve a sealing effect.

[0043] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the present invention. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A mechanical seal structure for a compressor shaft end, wherein a rotor cavity is provided in a compressor housing (10), a compressor rotor (9) is installed in the rotor cavity, an input end of the compressor rotor (9) extends outside the compressor housing (10) and is connected to a motor (1) via a coupling (2), and is characterized in that: The mechanical seal structure comprises a dynamic ring (5) provided with a sealing convex ring (51), a static ring (6) provided with a sealing plane (61), and a lip seal ring (8); an oil storage chamber (7) and an oil supply ring chamber (11) are further provided in the compressor housing (10); an oil discharge hole is provided in the upper half of the oil storage chamber (7); the oil storage chamber (7) and the rotor chamber are separated by a separation convex ring (13); the separation convex ring (13) and the compressor housing (10) are an integrated structure; a rotor gap (12) exists between the separation convex ring (13) and the compressor rotor (9); the lip seal ring (8) is installed between the separation convex ring (13) and the compressor rotor (9), and the lip edge of the lip seal ring (8) is in close contact with the compressor rotor (9); the dynamic ring (5) and the static ring (6) are both located in the oil storage chamber (7); the dynamic ring (5) and the compressor rotor (9) are fixed; the static ring (6) and the compressor housing (10) are fixed; the dynamic ring The sealing convex ring (51) on the stationary ring (6) is pressed against the sealing plane (61) of the stationary ring (6) to form a mechanical sealing surface for isolating the compressor rotor (9) from the input end of the compressor rotor (9) to the position of the moving ring (5) from the refrigerant oil in the oil storage chamber (7), the bottom of the oil storage chamber (7) is lower than the bottom of the rotor gap (12), and the bottom of the mechanical sealing surface is lower than the bottom of the rotor gap (12); the inlet of the oil supply ring chamber (11) and the external high pressure The oil supply pipe is connected, and a wall surface between the oil supply ring cavity (11) and the oil storage cavity (7) is provided with a plurality of oil injection ports (4). The oil supply ring cavity (11) is connected with the oil storage cavity (7) through the oil injection ports (4). The oil injection ports (4) are arranged obliquely, and the outlet of the oil injection ports (4) is aligned with the mechanical sealing surface formed by the contact between the sealing convex ring (51) on the dynamic ring (5) and the sealing plane (61) of the static ring (6) for spraying refrigeration oil with refrigeration and lubrication effects on the mechanical sealing surface.

2. A mechanical seal structure for a compressor shaft end according to claim 1, characterized in that: Each fuel injection port (4) comprises two sections with different diameters, the inlet of the fuel injection port (4) is located at the section with the thicker diameter, and the outlet of the fuel injection port (4) is located at the section with the thinner diameter.

3. A mechanical seal structure for a compressor shaft end according to claim 1, characterized in that: A plurality of oil injection ports (4) are evenly distributed around a mechanical seal surface formed by contact between a sealing convex ring (51) on a dynamic ring (5) and a sealing plane (61) on a static ring (6), and an oil injection direction of each oil injection port (4) is tangent to the mechanical seal surface.

4. A mechanical seal structure for a compressor shaft end according to claim 1, characterized in that: The number of the fuel injection ports (4) is 4 to 20.

5. A mechanical seal structure for a compressor shaft end according to claim 2, characterized in that: The outlet of the oil injection port (4) is close to a mechanical sealing surface formed by contact between a sealing convex ring (51) on the dynamic ring (5) and a sealing plane (61) of the static ring (6).

6. A sealing lubrication cooling method using the mechanical sealing structure for a compressor shaft end according to any one of claims 1 to 5, characterized in that: Here are the steps: When the compressor (3) is in a stopped state, the oil storage chamber (7) stores refrigerant oil in a portion below the position of the rotor gap (12) or in a portion below the position of the oil drain hole, and the lower portion or most portion of the moving ring (5) and the lower portion or most portion of the stationary ring (6) are always immersed in the refrigerant oil in the oil storage chamber (7); When the compressor (3) is started, since the lower part of the moving ring (5) and the lower part of the stationary ring (6) are always immersed in the refrigeration oil in the oil storage chamber (7), the moving ring (5) is driven to rotate synchronously with the rotation of the compressor rotor (9). The moving ring (5) brings the refrigeration oil in the oil storage chamber (7) to the entire mechanical sealing surface. The mechanical sealing surface where the moving ring (5) and the stationary ring (6) are in contact can be cooled and lubricated by the refrigeration oil synchronously with the start of the compressor (3), ensuring that the refrigeration oil is present when the moving ring (5) starts to rub against the stationary ring (6). The mechanical sealing surface where the moving ring (5) and the stationary ring (6) are in contact can be lubricated and cooled from the moment the compressor (3) is started. At the same time, the refrigeration oil input from the outside for cooling and lubrication The oil is transported to the oil supply ring cavity (11) through the external high-pressure oil supply pipe, and the refrigerant oil is sprayed through the oil spray port (4) onto the mechanical seal surface formed by the contact between the sealing convex ring (51) on the dynamic ring (5) and the sealing plane (61) of the static ring (6), thereby further continuously lubricating and cooling the mechanical seal surface in contact between the dynamic ring (5) and the static ring (6); as the compressor rotor (9) rotates at a high speed, the lip seal ring (8) is subjected to the pressure difference, and under the sealing effect of the lip seal ring (8), the refrigerant oil sprayed from the oil spray port (4) is continuously accumulated in the oil storage cavity (7), until the liquid level in the oil storage cavity (7) is higher than the oil discharge hole of the oil storage cavity (7), and the excess refrigerant oil is discharged from the oil storage cavity (7) through the oil discharge hole; When the compressor (3) is started and in normal operation, the refrigerant oil is continuously transported to the oil supply ring cavity (11) through the external high-pressure oil supply pipe, and the refrigerant oil is continuously sprayed through the oil injection port (4) onto the mechanical sealing surface formed by the contact between the sealing convex ring (51) on the moving ring (5) and the sealing plane (61) of the stationary ring (6), so as to continuously lubricate and cool the mechanical sealing surface between the moving ring (5) and the stationary ring (6). Excess refrigerant oil in the oil storage cavity (7) is discharged through the oil discharge hole.

7. The sealing, lubricating and cooling method according to claim 6, characterized in that: When the compressor (3) is turned off, the compressor rotor (9) loses driving force and gradually stops rotating. At the same time, the external high-pressure oil supply pipe stops supplying refrigerant oil to the oil supply ring cavity (11), and the oil injection port (4) stops spraying refrigerant oil to the mechanical sealing surface formed by the contact between the sealing convex ring (51) on the moving ring (5) and the sealing plane (61) of the stationary ring (6). The refrigerant oil stored in the oil storage cavity (7) still lubricates and cools the mechanical sealing surface between the moving ring (5) and the stationary ring (6) during the process of the compressor rotor (9) gradually stopping rotating, until the compressor rotor (9) stops rotating. As the compressor rotor (9) stops rotating, the lip seal (8) loses the pressure difference. If the lip seal (8) is not tightly sealed, the refrigerant oil in the oil storage chamber (7) will gradually flow into the rotor chamber of the compressor housing (10) along the rotor gap (12). The liquid level of the refrigerant oil in the oil storage chamber (7) gradually decreases until it is flush with the bottom of the rotor gap (12). Since the bottom of the oil storage chamber (7) is lower than the bottom of the rotor gap (12), the refrigerant oil below the bottom of the rotor gap (12) is still stored in the oil storage chamber. In the cavity (7), at this time, the lower part of the oil storage cavity (7) still stores refrigerant oil, and the lower part of the moving ring (5) and the lower part of the stationary ring (6) are always immersed in the refrigerant oil in the oil storage cavity (7), waiting for the next start of the compressor (3). When the compressor (3) is started next time, the refrigerant oil stored in the oil storage cavity (7) can simultaneously lubricate and cool the mechanical sealing surface formed by the contact between the sealing convex ring (51) on the moving ring (5) and the sealing plane (61) of the stationary ring (6) at the moment when the compressor (3) is started; Alternatively, since the compressor rotor (9) stops rotating, the lip seal (8) loses the pressure difference. If the lip seal (8) still has a stable sealing effect, the refrigerant oil in the oil storage chamber (7) will not flow into the rotor chamber of the compressor housing (10) along the rotor gap (12). The position below the oil drain hole in the oil storage chamber (7) is filled with refrigerant oil. The parts of the moving ring (5) and the stationary ring (6) below the oil drain hole are always immersed in the refrigerant oil in the oil storage chamber (7), waiting for the next start of the compressor (3). When the compressor (3) is started next time, the refrigerant oil stored in the oil storage chamber (7) can simultaneously lubricate and cool the mechanical sealing surface formed by the contact between the sealing convex ring (51) on the moving ring (5) and the sealing plane (61) of the stationary ring (6) at the moment when the compressor (3) is started.

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