Multi-stage sealed high-pressure grease injection joint and high-pressure grease injection system

Abstract

The multi-stage sealing type high-pressure grease injection connector comprises a main body and an end cover, a hard sealing ball seat is elastically assembled in an inner cavity of the main body through a clamping structure, and the upper section of the hard sealing ball seat is matched with the cavity wall of the inner cavity of the main body to form a first-stage sealing mechanism; the lower section of the hard sealing ball seat is matched with the overflowing hole of the clamping structure to form a second-stage sealing mechanism, and the first-stage sealing mechanism and the second-stage sealing mechanism can be synchronously opened or closed along with the axial movement of the hard sealing ball seat so as to control the on-off of a grease injection path in the inner cavity of the main body. The problem that in the prior art, the sealing effect is poor can be effectively solved. By the adoption of the multi-stage linkage sealing mechanism, the sealing performance of the connector in the high-pressure or severe working environment is remarkably improved, and therefore grease leakage is reduced, and it is guaranteed that lubricating grease can reach key parts such as a valve rod bearing more accurately and effectively.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline valves, and in particular to a multi-stage sealed high-pressure grease injection joint and a high-pressure grease injection system. Background Art

[0002] Grease injection joints, as lubricating grease filling devices designed for core equipment such as large machinery, petrochemical equipment, ball valves, flat gate valves and wellhead devices, play a vital role in the rotating parts of valves. When the rotational lubrication performance of the valve stem is insufficient, the rotational lubrication effect of the valve stem can be significantly improved by installing a grease injection valve and injecting an appropriate amount of lubricating oil or grease.

[0003] Grease injection joints currently on the market, such as Figure 1 As shown in the figure, it is mainly composed of three parts: the main body, the inner part and the end cover. The main body, this component is equipped with external threads at both ends, and the middle part is designed as a hexagonal head for easy operation; the inner part cleverly combines steel balls and springs to achieve precise control; and the end cover is a cover body with integrated internal threads, which ensures sealing performance while facilitating maintenance and replacement.

[0004] Considering that the lubrication status of the valve stem bearing is directly related to the overall performance and stability of the equipment during valve operation, once the valve stem bearing becomes stuck, timely injection of lubricating oil or grease through the grease injection joint is of immeasurable value in ensuring the smooth rotation of the valve stem and the normal operation of the valve.

[0005] However, it is worth noting that the existing grease injection joints generally adopt a hard ball single seal structure. This design often fails to provide satisfactory sealing effects when dealing with high pressure or harsh working environments, resulting in frequent grease leakage problems. This not only weakens the lubrication effect of grease on the valve as a whole, but may also have a serious negative impact on the normal operation of the valve. Therefore, technical improvements and optimizations to address this issue have become an important issue in improving the performance of grease injection joints and ensuring stable valve operation. Summary of the invention

[0006] One of the purposes of the present invention is to provide a multi-stage sealed high-pressure grease injection joint, which can effectively solve the problem of poor sealing effect existing in the prior art. By adopting a multi-stage linked sealing mechanism, the present invention significantly improves the sealing performance of the joint under high pressure or harsh working environment, thereby reducing grease leakage and ensuring that the lubricating grease can reach key parts such as valve stem bearings more accurately and effectively. Another purpose of the present invention is to provide a high-pressure grease injection system based on the aforementioned multi-stage sealed high-pressure grease injection joint, which cooperates with a portable electric pressure pump station to greatly improve the efficiency of grease injection operations.

[0007] To achieve the above object, the present invention first provides a technical solution:

[0008] A multi-stage sealed high-pressure grease injection joint comprises a main body and an end cover, the key of which is that a hard sealing ball seat is elastically assembled in the inner cavity of the main body through a snap-fit ​​structure, the upper section of the hard sealing ball seat cooperates with the cavity wall of the inner cavity of the main body to form a primary sealing mechanism, and the lower section of the hard sealing ball seat cooperates with the flow hole of the snap-fit ​​structure to form a secondary sealing mechanism, the primary sealing mechanism and the secondary sealing mechanism can be opened or closed synchronously with the axial movement of the hard sealing ball seat to control the on-off of the grease injection path in the inner cavity of the main body.

[0009] Furthermore, the inner cavity of the main body is provided with a diameter-reducing section, and in a free state without external force, the cavity wall of the diameter-reducing section contacts the ball of the hard sealing ball seat to form a ball-line seal.

[0010] Furthermore, the clamping structure includes a circle of flanges protruding outwardly formed on the inner cavity wall of the main body, and the center hole of the flange serves as a channel for limiting the axial movement of the hard sealing ball seat. A number of clamping seats are evenly spaced along the circumference of the inner ring surface of the flange, and each of the clamping seats is provided with a flow hole. The hard sealing ball seat is connected to the clamping seat through a guide groove provided on the circumferential side, and a spring is installed between the upper end groove wall of each guide groove and the corresponding clamping seat. In a free state without external force, the lower end groove wall of the guide groove can contact the corresponding clamping seat to form a planar seal at the bottom of the flow hole.

[0011] Furthermore, a recessed platform is formed on the inner cavity wall of the main body below the hard sealing ball seat, and an abutment seat which can follow the hard sealing ball seat for axial movement is provided in the inner cavity of the main body below the recessed platform. A non-through central flow channel is provided in the abutment seat, and a bypass flow channel is provided in the upper section of the abutment seat to cooperate with the recessed platform to form a three-level sealing mechanism. The three-level sealing mechanism can be opened or closed synchronously with the primary sealing mechanism and the secondary sealing mechanism to control the on-off of the grease injection path in the abutment seat.

[0012] Furthermore, a plurality of inlets of the bypass channel are evenly distributed on the circumference of the upper end surface of the abutment seat outside the hard sealing ball seat. In a free state without external force, the abutment seat can abut against the recessed platform to close the inlet of the bypass channel through the lower surface of the recessed platform to form a planar seal.

[0013] Furthermore, the bottom of the abutment seat is configured as a downwardly tightened conical structure, and in the grease injection state, the conical structure abuts against the grease injection hole of the valve to form a conical surface seal.

[0014] Furthermore, a ejector pin is arranged at the center of the end cover, and the ejector pin is used to push the hard sealing seat to move axially along the inner cavity of the main body, so as to link and open the first sealing mechanism, the second sealing mechanism and the third sealing mechanism to realize pressure relief.

[0015] Based on the aforementioned structure, the present invention also provides a high-pressure grease injection system, comprising the multi-stage sealed grease injection joint described above and an electric pressure pump station, the electric pressure pump station comprising an oil tank, a reversing valve arranged on the oil tank, and an oil pump body arranged in the oil tank, a filter is installed at the oil suction port of the oil pump body, the oil outlet of the oil pump body is connected to the reversing valve through an oil pump pipeline, and the reversing valve can be connected to the main body cavity of the multi-stage sealed grease injection joint to realize grease supply.

[0016] Furthermore, an oil tank cap, an oil level gauge, a pressure gauge, an oil drain bolt and a drive motor of the oil pump body are arranged on the oil tank.

[0017] Compared with the prior art, the present invention has the following significant effects:

[0018] (1) The present invention forms multiple seals on the grease injection path by arranging at least two levels of sealing mechanisms inside the main body. When any level of sealing mechanism is worn, other sealing mechanisms can play a compensatory role, thereby effectively preventing medium leakage. This design has good sealing performance and a long service life, and is particularly suitable for high-pressure grease injection and lubrication of the main accessories of ball valves and flat gate valves in petroleum, chemical industry and pipelines;

[0019] (2) The multi-stage sealing mechanism is designed to combine ball-wire sealing with plane sealing, which is beneficial to improving the stability and effect of sealing and effectively preventing medium leakage. This multiple sealing strategy can adapt to more harsh working conditions, such as high temperature, high pressure and high speed, thereby improving the operating reliability of the equipment. Compared with a single sealing method, the combination of plane sealing and ball-wire sealing can reduce material and manufacturing costs while ensuring sealing performance. In addition, this combination can also reduce the failure rate of the joint and extend its service life. On the other hand, the improvement of sealing performance not only reduces the risk of medium leakage, but also enhances the safety of the grease injection process;

[0020] (3) In the design of the multi-stage sealing mechanism, an innovative method of mechanical linkage is adopted, so that when performing the grease injection operation, each sealing point can be opened synchronously under the action of fluid pressure. This design ensures that the grease injection path remains unobstructed during the operation, thereby effectively improving the efficiency and quality of the grease injection operation. Through this linkage mechanism, it can be ensured that the pressure distribution during the grease injection process is uniform, avoiding the problem of sealing failure or insufficient grease injection due to uneven pressure. In addition, this synchronous opening mechanism can also reduce the complexity of operation and structure, ensuring the long-term stable operation of the joint;

[0021] (4) Grease-injected joints do not use non-metallic materials as seals, ensuring that the sealing performance is not affected under extreme temperature conditions. This design improvement allows the joint to maintain a good sealing effect in high or low temperature environments, avoiding the aging, hardening or embrittlement of the seals caused by drastic temperature changes;

[0022] (5) An abutment seat that can move axially with the hard sealing ball seat is used, and a non-through central flow channel and multiple bypass flow channels are designed as grease injection paths. On the one hand, the bypass flow channel inlet is closed by the concave platform to construct a ring of the multi-stage sealing structure; on the other hand, the conical structure at the bottom of the abutment seat cooperates with the valve sealing hole to form a conical surface seal. In this way, on the basis of the thread preload, an additional layer of sealing force is added, which effectively prevents the leakage of the medium during the grease injection process;

[0023] (6) A pin is installed at the center of the end cap. By rotating the end cap, the pin can be forced to move axially in the inner cavity of the main body, thereby linking the first sealing mechanism, the second sealing mechanism and the third sealing mechanism to open and realize the pressure relief function. This design ensures the safety and convenience of the pressure relief operation of the grease injection joint;

[0024] (7) The high-pressure grease injection system uses a grease injection connector and an electric pressure pump station to coordinate and cooperate, making it possible to achieve automated control and remote operation, thereby improving work efficiency and safety. The electric pressure pump station can accurately control the grease injection pressure and flow rate to ensure the stability and reliability of the grease injection process. In addition, the use of the electric pressure pump station reduces the complexity and labor intensity of manual operation, making the entire grease injection process more efficient and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0026] Figure 1 It is a schematic diagram of the overall structure of an existing high-pressure grease injection joint;

[0027] Figure 2 Schematic diagram of the overall structure of the multi-stage sealed high-pressure grease injection joint in Example 1 (I);

[0028] Figure 3 This is a schematic diagram of the overall structure of the multi-stage sealed high-pressure grease injection joint in Example 1 (II);

[0029] Figure 4 FIG1 is an assembly diagram (I) of the multi-stage sealed high-pressure grease injection joint in Example 1;

[0030] Figure 5 It is the assembly drawing (II) of the multi-stage sealed high-pressure grease injection joint in the first embodiment;

[0031] Figure 6 A half-section view (I) of the multi-stage sealed high-pressure grease injection joint in Example 1;

[0032] Figure 7 It is a half-section view (II) of the multi-stage sealed high-pressure grease injection joint in Example 1;

[0033] Figure 8 A half-section view (III) of the multi-stage sealed high-pressure grease injection joint in Example 1;

[0034] Fig. 9 A half-section view (four) of the multi-stage sealed high-pressure grease injection joint in Example 1;

[0035] Fig.10 A half-section view (V) of the multi-stage sealed high-pressure grease injection joint in Example 1;

[0036] Fig.11 A half-section view (six) of the multi-stage sealed high-pressure grease injection joint in Example 1;

[0037] Fig.12 Schematic diagram of the overall structure of the high-pressure grease injection system in Example 1 (I);

[0038] Fig.13 Schematic diagram of the overall structure of the high-pressure grease injection system in Example 1 (II);

[0039] Fig.14 Schematic diagram of the overall structure of the high-pressure grease injection system in Example 1 (III);

[0040] Markings in the figure: 1-main body, 2-end cover, 3-clamping structure, 4-hard sealing ball seat, 5-reducing section, 301-flange, 302-clamping seat, 303-flow hole, 304-guide groove, 305-spring, 6-recess, 7-abutment seat, 8-center flow channel, 9-bypass flow channel, 10-conical structure, 11-limiting ring groove, 12-limiting boss, 13-thimble, 14-oil tank, 15-reversing valve, 16-oil pump body, 17-filter, 18-pump oil pipeline, 19-oil tank cover, 20-oil level gauge, 21-pressure gauge, 22-drain bolt, 23-drive motor. DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0043] Figures 2 to 11 The first embodiment of the present invention is shown: a multi-stage sealed high-pressure grease injection joint, including a main body 1 and an end cover 2, in which a hard sealing ball seat 4 is elastically assembled in the inner cavity of the main body 1 through a clamping structure 3, and the upper section of the hard sealing ball seat 4 cooperates with the cavity wall of the inner cavity of the main body 1 to form a primary sealing mechanism, and the lower section of the hard sealing ball seat 4 cooperates with the flow hole 303 of the clamping structure 3 to form a secondary sealing mechanism, and the primary sealing mechanism and the secondary sealing mechanism can be opened or closed synchronously with the axial movement of the hard sealing ball seat 4 to control the on-off of the grease injection path in the inner cavity of the main body 1.

[0044] like Figures 6 to 11 As shown, in a specific implementation, the inner cavity of the main body 1 is provided with a reducing section 5. In a free state without external force, the cavity wall of the reducing section 5 contacts the ball of the hard sealing ball seat 4 to form a ball line seal. The clamping structure 3 includes a circle of flanges 301 formed on the inner cavity wall of the main body 1. The center hole of the flange 301 serves as a channel to limit the axial movement of the hard sealing ball seat 4. A number of clamping seats 302 are evenly distributed along the circumference of the inner annular surface of the flange 301. Each of the clamping seats 302 is provided with a flow hole 303. The hard sealing ball seat 4 is connected to the clamping seat 302 through a guide groove 304 provided on the peripheral side. A spring 305 is installed between the upper end groove wall of each guide groove 304 and the corresponding clamping seat 302. In a free state without external force, the lower end groove wall of the guide groove 304 can contact the corresponding clamping seat 302 to form a plane seal at the bottom of the flow hole 303.

[0045] In this embodiment, a concave platform 6 is formed on the inner cavity wall of the main body 1 below the hard sealing ball seat 4, and an abutment seat 7 that can follow the hard sealing ball seat 4 to make axial movement is provided in the inner cavity of the main body 1 below the concave platform 6. A non-through central flow channel 8 is provided in the abutment seat 7, and a bypass flow channel 9 is provided in the upper section of the abutment seat 7 to cooperate with the concave platform 6 to form a three-level sealing mechanism, and the three-level sealing mechanism can be opened or closed synchronously with the primary sealing mechanism and the secondary sealing mechanism to control the on-off of the grease injection path in the abutment seat 7. Specifically, a number of inlets of the bypass flow channel 9 are evenly distributed on the circumference of the upper end surface of the abutment seat 7 outside the hard sealing ball seat 4. In a free state without external force, the abutment seat 7 can abut against the concave platform 6 to close the inlet of the bypass flow channel 9 through the lower surface of the concave platform 6 to form a plane seal. In actual use, the bottom of the abutment seat 7 is set to a downwardly tightened conical structure 10. In the grease injection state, the conical structure 10 abuts against the valve grease injection hole to form a conical surface seal. The three-level sealing mechanism enhances the sealing performance of the joint under extreme working conditions and ensures that the medium will not leak from the joint during high-pressure grease injection. In addition, the design of the conical structure also allows the precise control of the grease injection pressure by adjusting the position of the ejector pin 13 during high-pressure grease injection, thereby optimizing the grease injection effect.

[0046] In order to prevent the abutment seat 7 from falling off from the inner cavity of the main body 1 and ensure that the conical structure 10 is tightly attached to the grease injection hole to form a conical surface seal during the grease injection process, a section of the outer circumferential surface of the abutment seat 7 is sunken to form a limiting ring groove 11, and a section of limiting boss 12 is also formed on the inner cavity wall of the main body 1, and the limiting boss 12 cooperates with the limiting ring groove 11 to limit the axial travel of the abutment seat 7.

[0047] In order to achieve the pressure relief function, a ejector pin 13 is arranged at the center of the end cover 2, and the ejector pin 13 is used to push the hard sealing seat to move axially along the inner cavity of the main body 1 to link and open the first sealing mechanism, the second sealing mechanism and the third sealing mechanism to achieve pressure relief.

[0048] See also Figure 12 to Figure 14 Based on the structure described above, this embodiment further discloses a high-pressure grease injection system, including a multi-stage sealed grease injection joint and an electric pressure pump station, the electric pressure pump station includes an oil tank 14, a reversing valve 15 arranged on the oil tank 14 and an oil pump body 16 arranged in the oil tank 14, a filter 17 is installed at the oil suction port of the oil pump body 16, the oil outlet of the oil pump body 16 is connected to the reversing valve 15 through an oil pump pipeline 18, and the reversing valve 15 can be connected to the inner cavity of the main body 1 of the multi-stage sealed grease injection joint to realize grease supply.

[0049] like Fig.13 and Fig.14As shown, in a specific implementation, the oil tank 14 is provided with an oil tank cap 19, an oil level gauge 20, a pressure gauge 21, an oil drain bolt 22 and a drive motor 23 of the oil pump body 16. An observation window may be provided on the oil tank cap 19 so that the operator can monitor the oil level in the oil tank 14. The oil level gauge 20 is used to provide an accurate reading of the oil level to ensure that the amount of oil in the oil tank 14 remains within a safe and effective range. The pressure gauge 21 is used to monitor the pressure in the oil tank 14 to prevent the pressure from being too high or too low and to ensure the stable operation of the system. The oil drain bolt 22 is designed to quickly drain the oil in the oil tank 14 when necessary, which is convenient for maintenance and replacement of the oil.

[0050] The driving motor 23 is the power source of the electric pressure pump station. It is connected to the oil pump body 16 through a connecting shaft to provide rotational power for the oil pump. The speed and torque of the motor can be adjusted according to the requirements of the oil pump to meet different grease injection requirements. A filter 17 is installed at the oil suction port of the oil pump body 16 to remove impurities in the oil, protect the oil pump from wear and tear, and extend its service life.

[0051] The oil pump pipeline 18 connects the oil outlet of the oil pump body 16 with the reversing valve 15 to ensure that the oil can be smoothly transported from the oil pump to the multi-stage sealed grease injection joint. The reversing valve 15 is used to control the flow direction of the oil to facilitate switching between different grease injection points to meet the needs of multi-point grease injection. The entire high-pressure grease injection system is designed to provide stable and efficient grease injection capabilities to ensure long-term reliable operation of the equipment.

[0052] In some other embodiments, a temperature sensor may be provided near the oil level gauge 20 of the oil tank 14 to monitor the oil temperature in the oil tank 14 in real time. Excessive oil temperature may cause the oil performance to deteriorate and even cause safety hazards. Therefore, the role of the temperature sensor is to detect abnormalities in time and take measures to avoid the normal operation of the system being affected by excessive oil temperature. In addition, the oil tank cap 19 may be equipped with an emergency shut-off valve, which can quickly cut off the connection between the oil pump and the oil tank 14 in an emergency to ensure the safety of the operator.

[0053] In the design of the oil pump body 16 of the electric pressure pump station, in addition to the filter 17 at the oil suction port, a filter 17 can also be installed at the oil outlet to further ensure the cleanliness of the oil. The drive motor 23 of the oil pump body 16 can adopt frequency conversion technology to control the flow and pressure of the oil pump by adjusting the frequency of the motor, thereby achieving a more precise and efficient grease injection operation.

[0054] In order to further improve the automation level of the system, the electric pressure pump station can also be equipped with an automatic control system. The system can automatically adjust the working state of the oil pump according to the preset program, including start, stop, flow and pressure adjustment, etc. The automatic control system can also be connected to monitoring equipment such as pressure sensors and flow meters to monitor the operating status of the system in real time, and automatically alarm or shut down when an abnormality occurs to prevent equipment damage and safety accidents.

[0055] In summary, the present invention forms multiple seals on the grease injection path by arranging at least two levels of sealing mechanisms inside the main body 1. When any level of sealing mechanism is worn, other sealing mechanisms can play a compensatory role, thereby effectively preventing medium leakage. This design has good sealing performance and a long service life, and is particularly suitable for high-pressure grease injection and lubrication of the main accessories of ball valves and flat gate valves in petroleum, chemical industry and pipelines; the multi-level sealing mechanism is designed to combine ball line sealing with plane sealing, which is conducive to improving the stability and effect of sealing and effectively preventing medium leakage. This multiple sealing strategy can adapt to more harsh working conditions, such as high temperature, high pressure and high speed, thereby improving the operating reliability of the equipment. Compared with a single sealing method, the combination of plane sealing and ball line sealing can reduce material and manufacturing costs while ensuring sealing performance. In addition, this combination can also reduce the failure rate of the joint and extend its service life. On the other hand, the improvement of sealing performance not only reduces the risk of medium leakage, but also enhances the safety of the grease injection process; in the design of the multi-level sealing mechanism, the innovative method of mechanical linkage is adopted, so that when performing the grease injection operation, each sealing point can be opened synchronously under the action of fluid pressure. This design ensures that the grease injection path remains unobstructed during the operation, thereby effectively improving the efficiency and quality of the grease injection operation. Through this linkage mechanism, the pressure distribution during the grease injection process can be ensured to be uniform, avoiding the problem of sealing failure or insufficient grease injection caused by uneven pressure. In addition, this synchronous opening mechanism can also reduce the complexity of operation and structure, ensuring the long-term stable operation of the joint; the grease injection joint ensures that the sealing performance is not affected under extreme temperature conditions by abandoning the use of non-metallic materials as seals. This design improvement enables the joint to maintain a good sealing effect in high or low temperature environments, avoiding the aging, hardening or embrittlement of the seal caused by drastic temperature changes; an abutment seat 7 that can move axially with the hard sealing ball seat 4 is used, and a non-penetrating central flow channel 8 and multiple bypass flow channels 9 are designed as the grease injection path. On the one hand, the inlet of the bypass flow channel 9 is closed by the concave platform 6 to construct a ring of the multi-stage sealing structure; on the other hand, the conical structure at the bottom of the abutment seat 7 is used to cooperate with the valve sealing hole to form a conical surface seal. In this way, on the basis of the thread preload, an extra layer of sealing force is added, which effectively prevents leakage of the medium during the grease injection process; the ejector pin 13 is installed in the center of the end cap, and by rotating the end cap, the ejector pin 13 can be forced to move axially in the inner cavity of the main body 1, thereby linking the first sealing mechanism, the second sealing mechanism and the third sealing mechanism to open the pressure relief function. This design ensures the safety and convenience of the pressure relief operation of the grease injection joint; the high-pressure grease injection system adopts the coordination of the grease injection joint and the electric pressure pump station, which provides the possibility of realizing automatic control and remote operation, and improves work efficiency and safety. The electric pressure pump station can accurately control the grease injection pressure and flow rate to ensure the stability and reliability of the grease injection process.In addition, the use of electric pressure pumping stations reduces the complexity and labor intensity of manual operations, making the entire grease injection process more efficient and accurate.

[0056] Finally, it should be noted that the technical solution disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above-mentioned embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A multi-stage sealed high-pressure grease injection joint, comprising a main body and an end cover, characterized in that: A hard sealing ball seat is elastically assembled in the inner cavity of the main body through a snap-fit ​​structure, the upper section of the hard sealing ball seat cooperates with the cavity wall of the inner cavity of the main body to form a primary sealing mechanism, and the lower section of the hard sealing ball seat cooperates with the flow hole of the snap-fit ​​structure to form a secondary sealing mechanism, the primary sealing mechanism and the secondary sealing mechanism can be opened or closed synchronously with the axial movement of the hard sealing ball seat to control the on-off of the grease injection path in the inner cavity of the main body.

2. The multi-stage sealed high-pressure grease injection joint according to claim 1, characterized in that: The inner cavity of the main body is provided with a diameter-reducing section. In a free state without external force, the cavity wall of the diameter-reducing section contacts the ball of the hard sealing ball seat to form a ball-line seal.

3. The multi-stage sealed high-pressure grease injection joint according to claim 2 is characterized in that: The clamping structure includes a circle of flanges protruding outwardly formed on the inner cavity wall of the main body, and the center hole of the flange serves as a channel for limiting the axial movement of the hard sealing ball seat. A number of clamping seats are evenly spaced along the circumference of the inner ring surface of the flange, and each of the clamping seats is provided with a flow hole. The hard sealing ball seat is connected to the clamping seat through a guide groove provided on the circumferential side, and a spring is installed between the upper end groove wall of each guide groove and the corresponding clamping seat. In a free state without external force, the lower end groove wall of the guide groove can contact the corresponding clamping seat to form a planar seal at the bottom of the flow hole.

4. The multi-stage sealed high-pressure grease injection joint according to any one of claims 1 to 3, characterized in that: A recessed platform is formed on the inner cavity wall of the main body below the hard sealing ball seat, and an abutment seat which can follow the hard sealing ball seat for axial movement is arranged in the inner cavity of the main body below the recessed platform. A non-through central flow channel is opened in the abutment seat, and a bypass flow channel is opened in the upper section of the abutment seat to cooperate with the recessed platform to form a three-level sealing mechanism. The three-level sealing mechanism can be opened or closed synchronously with the primary sealing mechanism and the secondary sealing mechanism to control the on-off of the grease injection path in the abutment seat.

5. The multi-stage sealed high-pressure grease injection joint according to claim 4, characterized in that: A number of bypass channel inlets are evenly distributed on the circumference of the upper end surface of the abutment seat outside the hard sealing ball seat. In a free state without external force, the abutment seat can abut against the recessed platform to close the bypass channel inlet through the lower surface of the recessed platform to form a planar seal.

6. The multi-stage sealed high-pressure grease injection joint according to claim 5, characterized in that: The bottom of the abutment seat is configured as a downwardly tightened conical structure, and in the grease injection state, the conical structure abuts against the grease injection hole of the valve to form a conical surface seal.

7. The multi-stage sealed high-pressure grease injection joint according to claim 6, characterized in that: A section of the outer circumferential surface of the abutment seat is sunken to form a limiting annular groove, and a section of limiting boss is also formed on the inner cavity wall of the main body. The limiting boss cooperates with the limiting annular groove to limit the axial travel of the abutment seat.

8. The multi-stage sealed high-pressure grease injection joint according to any one of claims 5 to 7, characterized in that: A ejector pin is arranged at the center of the end cover, and the ejector pin is used to push the hard sealing seat to move axially along the inner cavity of the main body, so as to link and open the first sealing mechanism, the second sealing mechanism and the third sealing mechanism to realize pressure relief.

9. A high-pressure grease injection system, characterized in that: It comprises a multi-stage sealed grease injection joint and an electric pressure pump station as described in any one of claims 1 to 8, wherein the electric pressure pump station comprises an oil tank, a reversing valve arranged on the oil tank and an oil pump body arranged in the oil tank, a filter is installed at the oil suction port of the oil pump body, the oil outlet of the oil pump body is connected to the reversing valve through an oil pumping pipeline, and the reversing valve can be connected to the main body cavity of the multi-stage sealed grease injection joint to realize grease supply.

10. The high-pressure grease injection system according to claim 9, characterized in that: The oil tank is provided with an oil tank cap, an oil level gauge, a pressure gauge, an oil drain bolt and a driving motor of the oil pump body.

Images