Slide valve, screw compressor and mechanical equipment

Abstract

The utility model provides a slide valve, a screw compressor and mechanical equipment. According to the sliding valve, the sealing structure is arranged in the sliding valve, after the sealing structure is arranged in the containing groove in the sliding valve body, the hydraulic compensation cavity is formed between the groove wall of the containing groove and the sealing structure, the hydraulic compensation cavity is communicated with the oil injection opening of the sliding valve, and therefore hydraulic oil is injected into the hydraulic compensation cavity. When the sliding valve runs for a long time and the sealing structure is abraded, hydraulic oil in the hydraulic compensation cavity can apply pressure to the sealing structure. When pressure is large enough, the sealing structure can be tightly attached to the surface of the sliding valve cavity, meanwhile, due to interaction force, the whole sliding valve can be jacked up by a certain distance, and therefore the gap between the sliding valve and the rotor can be reduced. According to the sealing structure, the sealing effect is well improved, the leakage amount is remarkably reduced, the compression efficiency is improved, meanwhile, due to elastic buffering of hydraulic compensation, abrasion of the sealing structure can be reduced, and the service life of the sealing structure is greatly prolonged.

Description

Technical Field

[0001] This disclosure relates to the field of compressor technology, and in particular to a slide valve, a screw compressor, and mechanical equipment. Background Technology

[0002] Screw compressors typically use the reciprocating motion of a slide valve and an oil piston to achieve capacity or pressure ratio regulation. Whether regulating capacity or pressure ratio, the principle of this reciprocating motion is the same. In screw compressors using slide valves, the reliability of the slide valve sealing system is crucial to the equipment's energy efficiency and service life. If the seal between the slide valve and the valve chamber in the compressor body is poor, high-pressure gas will flow back to the rotor's suction side during compression, reducing the compressor's volumetric efficiency and leading to a decrease in energy efficiency.

[0003] The sealing of traditional screw compressor slide valves has the following technical defects:

[0004] If no sealing device is used and the gap between the slide valve and the slide valve cavity of the machine body is controlled solely by machining precision, a certain gap will inevitably remain (e.g., a gap of 3-4 micrometers, where 1 micrometer equals 0.01 millimeters). This inevitably leads to the problem of high-pressure gas leakage. Furthermore, with the long-term operation of the slide valve, the gap between the outer circle of the slide valve and the slide valve cavity of the machine body will gradually increase, and the leakage problem will become more and more serious.

[0005] However, when a fixed sealing ring is used, the sealing ring cannot automatically compensate for the gap after wear. After long-term operation, the slide valve sinks as a whole, which increases the gap between the upper end face of the slide valve and the rotor, resulting in more gas leakage during the compression process, which will also reduce the energy efficiency of the equipment. Utility Model Content

[0006] In view of this, in order to solve the technical problem of poor sealing of slide valves in the prior art, this disclosure provides a slide valve, a screw compressor and mechanical equipment.

[0007] According to a first aspect of the present disclosure, a slide valve is provided for use in a screw compressor. The slide valve includes a slide valve body and a sealing structure. The slide valve body is located within the slide valve cavity of the screw compressor. The slide valve body is provided with a mounting groove adapted to the sealing structure. The mounting groove is located on the outer surface of the slide valve body opposite to the slide valve cavity. The sealing structure is mounted within the mounting groove, and a hydraulic compensation cavity is formed between the sealing structure and the groove wall of the mounting groove. The hydraulic compensation cavity communicates with the oil inlet of the slide valve.

[0008] In one alternative implementation,

[0009] The sealing structure includes a first sealing strip and a second sealing strip, and the mounting groove includes a first arc groove and a second arc groove. The first sealing strip is mounted in the first arc groove, and the second sealing strip is mounted in the second arc groove.

[0010] The first arc groove and the second arc groove both extend circumferentially along the slide valve body. The first arc groove is located on the side where the male rotor of the screw compressor is located, and the second arc groove is located on the side where the female rotor of the screw compressor is located. In the axial direction of the slide valve body, the first arc groove and the second arc groove are at the same position.

[0011] In one alternative implementation,

[0012] The sealing structure includes a third sealing strip and a fourth sealing strip, and the mounting groove includes a third arc groove and a fourth arc groove. The third sealing strip is mounted in the third arc groove, and the fourth sealing strip is mounted in the fourth arc groove.

[0013] The third arc groove and the fourth arc groove both extend circumferentially along the slide valve body. The third arc groove is located on the side where the male rotor of the screw compressor is located, and the fourth arc groove is located on the side where the female rotor of the screw compressor is located. In the axial direction of the slide valve body, the third arc groove and the fourth arc groove are in the same position, and the first arc groove and the third arc groove are in different positions.

[0014] In one alternative implementation,

[0015] Along the axial direction of the slide valve body, the position of the first arc groove is denoted as the first axial position, and the position of the third arc groove is denoted as the second axial position. The interval between the first axial position and the second axial position is greater than or equal to the tooth pitch of the male rotor in the screw compressor.

[0016] In one alternative implementation,

[0017] The outer surface of the slide valve body is provided with a first spiral groove, which is located between the first arc groove and the third arc groove. The first half cavity of the hydraulic compensation cavity is formed between the first sealing strip and the groove wall of the first arc groove, and the third half cavity of the hydraulic compensation cavity is formed between the third sealing strip and the groove wall of the third arc groove. The first half cavity and the third half cavity are respectively connected to the first spiral groove.

[0018] And / or,

[0019] The outer surface of the slide valve body is provided with a second spiral groove, which is located between the second arc groove and the fourth arc groove. The second sealing strip and the groove wall of the second arc groove form the second half cavity of the hydraulic compensation cavity, and the fourth sealing strip and the groove wall of the fourth arc groove form the fourth half cavity of the hydraulic compensation cavity. The second half cavity and the fourth half cavity are respectively connected to the second spiral groove.

[0020] In one alternative implementation,

[0021] The slide valve body is provided with an oil delivery channel communicating with the oil inlet. The oil delivery channel extends along the axial direction of the slide valve body and communicates with the first half-cavity, the second half-cavity, the third half-cavity and the fourth half-cavity. The oil delivery channel is used to deliver the oil injected into the oil inlet to the first half-cavity, the second half-cavity, the third half-cavity and the fourth half-cavity.

[0022] In one alternative implementation,

[0023] The slide valve body is provided with a first oil unloading channel. The first half-cavity and the second half-cavity are both connected to the first oil unloading channel. The first oil unloading channel is used to transport the oil from the first half-cavity and the second half-cavity to the rotor meshing area of ​​the screw compressor.

[0024] And / or,

[0025] The slide valve body is provided with a second oil unloading channel. The third half-cavity and the fourth half-cavity are both connected to the second oil unloading channel. The second oil unloading channel is used to transport the oil from the third half-cavity and the fourth half-cavity to the rotor meshing area of ​​the screw compressor.

[0026] In an optional embodiment, the outer surface of the sealing structure is provided with a plurality of grooves, wherein the sealing structure is placed in the mounting groove, the grooves extend circumferentially along the slide valve body, and the plurality of grooves are arranged axially along the slide valve body.

[0027] In one alternative embodiment, the sealing structure comprises a strip structure made of a composite material of polytetrafluoroethylene and graphite.

[0028] In one alternative embodiment, the placement groove includes a V-groove.

[0029] According to a second aspect of the present disclosure, a screw compressor is provided, the screw compressor including a rotor and a slide valve as described in any of the first aspects.

[0030] According to a third aspect of the present disclosure, a mechanical device is provided, the mechanical device comprising a screw compressor as described in the second aspect.

[0031] The technical solutions provided by the embodiments of this disclosure can include the following beneficial effects: In this disclosure, not only is a sealing structure provided in the slide valve, but also, after the sealing structure is placed in the mounting groove on the slide valve body, a hydraulic compensation chamber is formed between the groove wall and the sealing structure. The hydraulic compensation chamber is connected to the oil injection port of the slide valve, thereby injecting hydraulic oil into the hydraulic compensation chamber. By using "hydraulic compensation" to replace the traditional mechanical pre-tightening sealing ring, adaptive compensation can be achieved after the sealing structure wears. When the sealing structure wears during long-term operation of the slide valve, the hydraulic oil in the hydraulic compensation chamber will apply pressure to the sealing structure. When the pressure is high enough, the sealing structure will tightly adhere to the surface of the slide valve cavity. Simultaneously, due to the interaction force, the entire slide valve will be lifted a certain distance, thereby reducing the gap between the slide valve and the rotors (male and female rotors). The slide valve of this disclosure, through adaptive compensation, not only significantly improves the sealing effect and maintains long-term stable sealing performance, thereby significantly reducing leakage and improving compression efficiency, but also reduces the wear of the sealing structure due to the elastic buffering of hydraulic compensation, greatly improving the service life of the sealing structure.

[0032] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0036] Figure 1 This is a schematic diagram illustrating the cooperation between a slide valve and a rotor according to an exemplary embodiment.

[0037] Figure 2 This is a schematic diagram of the oil circuit of a slide valve according to an exemplary embodiment.

[0038] Figure 3This is a schematic diagram of the structure of a slide valve according to an exemplary embodiment.

[0039] Figure 4 This is a schematic diagram showing the male rotor side and the female rotor side of a slide valve according to an exemplary embodiment.

[0040] Figure 5 This is a cross-sectional view of a screw compressor according to an exemplary embodiment.

[0041] Figure 6 This is a schematic diagram of a sealing structure according to an exemplary embodiment.

[0042] Figure 7 This is a cross-sectional schematic diagram of a sealing structure according to an exemplary embodiment.

[0043] in:

[0044] 1. Spool valve; 11. Spool valve body; 12. Sealing structure; 121. Groove; 13. Mounting groove; 131. First arc groove; 132. Second arc groove; 133. Third arc groove; 134. Fourth arc groove; 14. Spiral groove; 141. First spiral groove; 142. Second spiral groove;

[0045] 2. Engine body; 3. Rotor; 31. Male rotor; 32. Female rotor; 4. Hydraulic cylinder body; 5. Intake end cover; 6. Exhaust end bearing seat;

[0046] 100, Oil inlet; 200, Rotor meshing area; 300, Oil unloading channel; 301, First oil unloading channel; 302, Second oil unloading channel; 400, Oil delivery channel. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] The following disclosure provides numerous different embodiments or examples for implementing various aspects of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0049] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0050] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0051] The embodiments of this application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be understood that the preferred embodiments are only for illustrating this application and are not intended to limit the scope of protection of this application.

[0052] To address the technical problem of poor sealing in existing slide valves, this disclosure provides a slide valve, a screw compressor, and mechanical equipment.

[0053] In this disclosure, the spool valve not only incorporates a sealing structure, but also, when the sealing structure is placed in a mounting groove on the spool valve body, a hydraulic compensation chamber is formed between the groove wall and the sealing structure. This hydraulic compensation chamber is connected to the spool valve's oil inlet, allowing hydraulic oil to be injected into it. By replacing the traditional mechanical pre-tightening sealing ring with "hydraulic compensation," adaptive compensation is achieved after the sealing structure wears. When the spool valve operates for an extended period and the sealing structure wears, the hydraulic oil in the hydraulic compensation chamber applies pressure to the sealing structure. When the pressure is sufficiently high, the sealing structure presses tightly against the spool valve cavity surface. Simultaneously, due to the interaction force, the entire spool valve is lifted a certain distance, thus reducing the gap between the spool valve and the rotors (male and female rotors). This disclosed spool valve, through adaptive compensation, not only significantly improves the sealing effect and maintains long-term stable sealing performance, thereby significantly reducing leakage and improving compression efficiency, but also, due to the elastic buffering of hydraulic compensation, reduces wear on the sealing structure, greatly extending its service life.

[0054] In one exemplary embodiment, a screw compressor and its slide valve are provided. (Reference) Figures 1 to 3 as well as Figure 5 As shown, the slide valve 1 includes a slide valve body 11 and a sealing structure 12. The slide valve cavity is disposed within the body 2 of the screw compressor, providing movement space for the slide valve body 11. The slide valve body 11 is located within the slide valve cavity, and the two work together to realize the capacity regulation or pressure ratio regulation function of the screw compressor.

[0055] The valve body 11 is provided with a mounting groove 13 adapted to the sealing structure 12. The mounting groove 13 is located on the outer surface of the valve body 11 opposite to the valve cavity. The sealing structure 12 is placed in the mounting groove 13, and a hydraulic compensation cavity is formed between the sealing structure 12 and the groove wall of the mounting groove 13. The hydraulic compensation cavity is connected to the oil inlet 100 of the valve 1. That is, the thickness of the sealing structure 12 matches the depth of the mounting groove 13. After installation, the outer surface of the sealing structure 12 is tightly fitted with the inner wall of the valve cavity, and a hydraulic compensation cavity is formed between the inner surface and the groove wall of the mounting groove 13.

[0056] The sealing structure 12 may include a strip structure made of a composite material of polytetrafluoroethylene (PTFE) and graphite. That is, the sealing structure 12 can be a PTFE-based composite sealing strip, and the sealing strip may contain graphite material. This helps to improve the high leakage rate and short lifespan of the sealing ring in the traditional slide valve 1, thus enhancing the sealing effect. Additionally, the mounting groove 13 can be a V-shaped groove to facilitate reliable installation of the sealing structure 12. Of course, the mounting groove 13 can also have other shapes; this is not limited.

[0057] In this embodiment, not only is a sealing structure 12 provided in the slide valve 1, but when the sealing structure 12 is placed in the mounting groove 13 on the slide valve body 11, a hydraulic compensation chamber is formed between the groove wall of the mounting groove 13 and the sealing structure 12. The hydraulic compensation chamber is connected to the oil injection port 100 of the slide valve 1, thereby injecting hydraulic oil into the hydraulic compensation chamber. By using "hydraulic compensation" to replace the traditional mechanical pre-tightening seal of the sealing ring, adaptive compensation can be achieved after the sealing structure 12 wears. When the slide valve 1 has been running for a long time and the sealing structure 12 wears, the hydraulic oil in the hydraulic compensation chamber will apply pressure to the sealing structure 12. When the pressure is large enough, the sealing structure 12 will be tightly attached to the surface of the slide valve cavity. At the same time, due to the interaction force, the slide valve 1 as a whole will also be lifted by a certain distance, thereby reducing the gap between the slide valve 1 and the rotors 3 (male rotor 31 and female rotor 32). That is, the slide valve 1 in this embodiment, through adaptive compensation, not only improves the sealing effect and maintains long-term stable sealing performance, thereby significantly reducing leakage and improving compression efficiency, but also reduces the wear of the sealing structure 12 due to the elastic buffer of hydraulic compensation, thus greatly improving the service life of the sealing structure 12.

[0058] For screw compressors equipped with the aforementioned slide valve 1, regardless of the operating conditions (high load, low load, pressure ratio, etc.), the hydraulic compensation chamber can adjust in real time according to pressure changes and the wear of the sealing structure 12, ensuring stable sealing performance. This is particularly suitable for industrial applications with complex and variable operating conditions, improving equipment reliability. Furthermore, the slide valve 1 can better reduce the clearance between the slide valve 1 and the rotor 3, optimizing the internal gas flow path of the screw compressor, reducing volumetric losses, and improving volumetric efficiency. Simultaneously, it reduces vibration and noise caused by leakage, improving the equipment operating environment and enhancing overall equipment performance and user experience.

[0059] In one exemplary embodiment, a screw compressor and its slide valve are provided. (Reference) Figures 1 to 5 As shown, in this embodiment, the sealing structure 12 includes a first sealing strip and a second sealing strip, and the mounting groove 13 includes a first arc groove 131 and a second arc groove 132. The first sealing strip is mounted in the first arc groove 131, and the second sealing strip is mounted in the second arc groove 132.

[0060] Both the first arc groove 131 and the second arc groove 132 extend circumferentially along the valve body 11. The first arc groove 131 is located on the side where the male rotor 31 of the screw compressor is located, and the second arc groove 132 is located on the side where the female rotor 32 of the screw compressor is located. Furthermore, the first arc groove 131 and the second arc groove 132 are positioned identically along the axial direction of the valve body 11. Based on this, the first and second sealing strips can achieve a complete seal between the valve body 11 and the valve cavity, thereby improving the sealing effect.

[0061] During the operation of the screw compressor, the slide valve body 11 moves axially within the slide valve cavity to achieve different working states. At this time, the first and second sealing strips are in close contact with the inner wall of the slide valve cavity, preventing gas leakage from the gap between the slide valve body 11 and the slide valve cavity. Furthermore, since the first arc groove 131 and the second arc groove 132 are located on the sides of the male rotor 31 and the female rotor 32 respectively, and are axially aligned, the first and second sealing strips can effectively seal the areas of the male rotor 31 and the female rotor 32 respectively, thereby improving the overall sealing effect of the slide valve 1. When the sealing structure 12 wears, the hydraulic oil in the hydraulic compensation chamber applies pressure to the sealing structure 12, enabling the sealing structure 12 to adaptively compensate for wear and maintain good sealing performance.

[0062] The sealing structure 12 may further include a third sealing strip and a fourth sealing strip. The mounting groove 13 may include a third arc groove 133 and a fourth arc groove 134. The third sealing strip is mounted in the third arc groove 133, and the fourth sealing strip is mounted in the fourth arc groove 134. Both the third arc groove 133 and the fourth arc groove 134 extend circumferentially along the valve body 11. The third arc groove 133 is located on the side where the male rotor 31 of the screw compressor is located, and the fourth arc groove 134 is located on the side where the female rotor 32 of the screw compressor is located. In the axial direction of the valve body 11, the third arc groove 133 and the fourth arc groove 134 are in the same position, while the first arc groove 131 and the third arc groove 133 are in different positions. Based on this, the third and fourth sealing strips can achieve another layer of sealing between the valve body 11 and the valve cavity. Combined with the first and second sealing strips to achieve a final layer of sealing, the sealing effect can be further improved. The sealing principle achieved by the third sealing strip, the third arc groove 133, the fourth sealing strip, and the fourth arc groove 134 can be referred to the sealing principle achieved by the first sealing strip, the first arc groove 131, the second sealing strip, and the second arc groove 132, as described above, and will not be repeated here. In addition, the double-ring seal setting can better balance the force and prevent the valve body 11 from tilting relative to the valve cavity.

[0063] In the axial direction of the valve body 11, the first arc groove 131 and the third arc groove 133 can be symmetrical about the center position of the valve body 11, thereby better balancing the force and better preventing the valve body 11 from tilting relative to the valve cavity. In addition, the structures of the first arc groove 131, the second arc groove 132, the third arc groove 133 and the fourth arc groove 134 can be the same, and the structures of the first sealing strip, the second sealing strip, the third sealing strip and the fourth sealing strip can be the same, thereby better balancing the force and better preventing the valve body 11 from tilting relative to the valve cavity, improving the stability of the entire screw compressor.

[0064] Furthermore, in the axial direction of the slide valve body 11, the position of the first arc groove 131 is designated as the first axial position, and the position of the third arc groove 133 is designated as the second axial position. The interval between the first axial position and the second axial position is greater than or equal to the tooth pitch of the male rotor 31 in the screw compressor. Based on this, when the screw compressor starts running, high-pressure oil can enter the hydraulic compensation chamber through the oil inlet 100. Under the action of oil pressure, the four sets of sealing strips are squeezed against the inner wall of the slide valve chamber to form a double-ring sealing structure 12. Since the interval between the first axial position and the second axial position is greater than or equal to the tooth pitch of the male rotor 31, the double-ring sealing structure 12 can completely cover the rotor meshing area 200. During the operation of the compressor, if a gap appears between a sealing strip and the inner wall of the slide valve chamber due to wear, the corresponding oil pressure in the hydraulic compensation chamber will be unbalanced. The hydraulic oil will automatically push the sealing strip to expand towards the gap, fill the gap, and restore the sealing effect. At the same time, the double-ring sealing structure 12 can double-intercept the gas in the rotor meshing area 200, greatly reducing the possibility of high-pressure gas leaking to the suction end.

[0065] In this embodiment, by setting up a double seal formed by multiple sealing strips and multiple arc grooves, the sealing effect between the slide valve body 11 and the slide valve cavity can be better improved. This can effectively block the path of high-pressure gas flowing back to the suction end through the gap between the slide valve 1 and the slide valve cavity, significantly reducing gas leakage, improving the volumetric efficiency of the screw compressor, and significantly increasing the overall energy efficiency ratio of the machine.

[0066] In one exemplary embodiment, a screw compressor and its slide valve are provided. (Reference) Figures 1 to 5 As shown, in this embodiment, a first spiral groove 141 is provided on the outer surface of the slide valve body 11. The first spiral groove 141 is located between the first arc groove 131 and the third arc groove 133, that is, the first spiral groove 141 is located on the side where the male rotor 31 of the screw compressor is located. The first half-cavity of the hydraulic compensation chamber is formed between the first sealing strip and the groove wall of the first arc groove 131, and the third half-cavity of the hydraulic compensation chamber is formed between the third sealing strip and the groove wall of the third arc groove 133. The first half-cavity and the third half-cavity are respectively connected to the first spiral groove 141. Based on this, the oil in the hydraulic compensation chamber can be transferred to the first spiral groove 141.

[0067] When the screw compressor is running, hydraulic oil enters the hydraulic compensation chamber through the oil inlet 100. Since the first spiral groove 141 is connected to the first and third half of the hydraulic compensation chamber, the oil flows into the first spiral groove 141 under pressure. As the valve body 11 moves axially within the valve chamber, the hydraulic oil in the first spiral groove 141 forms an oil film. This oil film further enhances the sealing effect and effectively reduces the possibility of gas leakage. Simultaneously, the oil film also acts as a lubricant, reducing the frictional resistance between the valve body 11 and the valve chamber, reducing component wear, and improving the operating efficiency and service life of the equipment.

[0068] The outer surface of the slide valve body 11 is provided with a second spiral groove 142, which is located between the second arc groove 132 and the fourth arc groove 134, that is, the second spiral groove 142 is located on the side where the female rotor 32 of the screw compressor is located. The second sealing strip and the groove wall of the second arc groove 132 form the second half of the hydraulic compensation chamber, and the fourth sealing strip and the groove wall of the fourth arc groove 134 form the fourth half of the hydraulic compensation chamber. The second half of the chamber and the fourth half of the chamber are respectively connected to the second spiral groove 142, so that the oil in the hydraulic compensation chamber can be transferred to the first spiral groove 141.

[0069] When the screw compressor is running, hydraulic oil enters the hydraulic compensation chamber through the oil inlet 100. Since the second spiral groove 142 is connected to the second and fourth halves of the hydraulic compensation chamber, the oil flows into the second spiral groove 142 under pressure. As the spool valve body 11 moves axially within the spool valve chamber, the hydraulic oil in the second spiral groove 142 forms an oil film. This oil film further enhances the sealing effect and effectively reduces the possibility of gas leakage. Simultaneously, the oil film also acts as a lubricant, reducing the frictional resistance between the spool valve body 11 and the spool valve chamber, reducing component wear, and improving the operating efficiency and service life of the equipment.

[0070] In this embodiment, the first spiral groove 141 and the second spiral groove 142 correspond to the male and female rotors 32 respectively, forming a better seal with the double-ring sealing strip. This can better reduce gas leakage, effectively improve volumetric efficiency, and significantly improve the compressor's energy efficiency. Furthermore, the linkage design between the hydraulic compensation chamber and the spiral groove 14 gives the sealing system self-adjusting capabilities. When the sealing strip wears or operating conditions change, the oil can respond quickly, automatically filling gaps and adjusting the oil film thickness, extending the life of sealing components and reducing downtime maintenance costs. In addition, the continuous oil film within the spiral groove 14 can significantly reduce the friction coefficient between the slide valve 1 and the slide valve chamber, reducing wear on key components, effectively improving equipment reliability, and extending the overall service life. Moreover, the symmetrically distributed double spiral grooves 14 and the hydraulic compensation chamber ensure that the slide valve 1 is subjected to uniform force during operation, avoiding tilting or jamming of the slide valve 1 due to uneven pressure on one side, thus ensuring operational stability.

[0071] In addition, in this embodiment, the slide valve body 11 may be provided with an oil delivery channel 400 communicating with the oil inlet 100. The oil delivery channel 400 extends along the axial direction of the slide valve body 11 and communicates with the first half cavity, the second half cavity, the third half cavity and the fourth half cavity. The oil delivery channel 400 is used to deliver the oil injected into the oil inlet 100 to the first half cavity, the second half cavity, the third half cavity and the fourth half cavity.

[0072] When the screw compressor is running, oil (such as the oil in the screw compressor lubrication system) enters the oil delivery channel 400 through the oil inlet 100. The oil delivery channel 400 distributes the oil to the first, second, third, and fourth half-cavities. Under oil pressure, the first, second, third, and fourth sealing strips are pressed against the inner wall of the slide valve cavity, forming a double-ring seal to effectively seal the areas where the male rotor 31 and female rotor 32 are located. As the slide valve body 11 moves axially within the slide valve cavity, the oil pressure in each hydraulic compensation cavity remains relatively stable, ensuring that the sealing strips are always in close contact with the inner wall of the slide valve cavity. At the same time, the presence of the oil delivery channel 400 ensures that even during the movement of the slide valve body 11, each hydraulic compensation cavity can continuously receive a sufficient supply of oil, maintaining a good sealing effect. This embodiment simplifies the oil circuit structure of the entire sealing system by setting the oil delivery channel 400 within the slide valve body 11 and directly connecting the oil inlet 100 to each hydraulic compensation cavity. Compared to complex multi-oil-line connection methods, this design is easier to manufacture, install and maintain, reducing the maintenance cost and difficulty of the equipment.

[0073] It should also be noted that, in addition to the slide valve 1 and rotors 3 (male rotor 31 and female rotor 32), the screw compressor may also include an intake end cover 5, a casing 2, an exhaust end bearing seat 6, and a hydraulic cylinder 4. The casing 2 contains a slide valve chamber for housing the slide valve 1. The intake end cover 5 is the primary component for gas entry into the screw compressor. Its intake port is used to connect to an external gas source, allowing the gas to be compressed to smoothly enter the compressor. The casing 2 forms the main frame of the screw compressor, providing the mounting base and support for all components. The casing 2 has machined cavities, including the slide valve chamber for housing the slide valve 1. The slide valve chamber provides space for the movement of the slide valve 1; by moving the slide valve 1 within the chamber, the volumetric flow rate of the compressor can be adjusted, thus controlling the compression process. The exhaust end bearing seat 6 is installed at the exhaust end of the casing 2 and supports the exhaust end of the rotor 3, ensuring the stability and coaxiality of the rotor 3 during operation. The hydraulic cylinder 4 is an important component of the screw compressor's slide valve 1 drive system. Hydraulic oil is injected into the cylinder body 4 via the hydraulic system, which pushes the piston and piston rod to move, thereby causing the slide valve 1 to move axially within the slide valve chamber. The oil in the slide valve 1 can be supplied by the cylinder body 4.

[0074] The slide valve body 11 is provided with a first oil unloading channel 301. Both the first half-cavity and the second half-cavity are connected to the first oil unloading channel 301, and the oil unloading port of the first oil unloading channel 301 faces the rotor meshing area 200 of the screw compressor. That is, the first oil unloading channel 301 is used to transport the oil from the first half-cavity and the second half-cavity to the rotor meshing area 200 of the screw compressor.

[0075] After the screw compressor starts, oil enters the oil delivery channel 400 from the oil inlet 100, and is then distributed to the first, second, third, and fourth half-cavities, pushing the sealing strip to press tightly against the inner wall of the slide valve cavity to achieve a seal. As the slide valve body 11 moves axially, the oil in the first and second half-cavities is sprayed out towards the rotor meshing area 200 under pressure through the oil discharge port of the first oil discharge channel 301. The oil forms a lubricating film in the rotor meshing area 200, which reduces friction between the male rotor 31 and the female rotor 32 on the one hand, and fills the meshing gap on the other hand, reducing gas leakage. When the sealing structure 12 wears, the oil in the hydraulic compensation chamber prioritizes maintaining the sealing pressure, while excess oil is still delivered to the rotor meshing area 200 through the first oil discharge channel 301, ensuring the coordinated operation of lubrication and sealing functions.

[0076] The slide valve body 11 is provided with a second oil unloading channel 302. The third and fourth half-cavities are both connected to the second oil unloading channel 302, and the oil unloading port of the second oil unloading channel 302 faces the rotor meshing area 200 of the screw compressor. That is, the second oil unloading channel 302 is used to transport the oil from the third and fourth half-cavities to the rotor meshing area 200 of the screw compressor.

[0077] Referring to the working principle of the first unloading channel 301, as the slide valve body 11 moves axially, the oil in the third and fourth half-cavities, under pressure, can be sprayed towards the rotor meshing area 200 through the unloading port of the second unloading channel 302. The oil forms a lubricating film in the rotor meshing area 200, reducing friction between the male rotor 31 and the female rotor 32 on one hand, and filling the meshing gap on the other, reducing gas leakage. When wear occurs in the sealing structure 12, the oil in the hydraulic compensation chamber prioritizes maintaining the sealing pressure, while excess oil is still transported to the rotor meshing area 200 through the first unloading channel 301, ensuring the coordinated operation of lubrication and sealing functions. It should be noted that by setting the first unloading channel 301 and the second unloading channel 302, sufficient oil can be supplied to the rotor meshing area 200 more effectively, and the oil in the first, second, third, and fourth half-cavities can be better balanced, thereby improving the overall sealing effect of the screw compressor, better preventing increased gas leakage during compression, and thus improving equipment energy efficiency.

[0078] In addition, in the axial direction of the slide valve body 11, the position of the first oil unloading channel 301 can be the same as the position of the first arc groove 131, and the position of the second oil unloading channel 302 can be the same as the position of the third arc groove 133. That is, the interval between the two oil unloading channels 300 can be greater than or equal to the tooth pitch of the male rotor 31 (preferably the interval between the two oil unloading channels 300 can be equal to the tooth pitch of the male rotor 31). Therefore, the lubrication and sealing effects can be improved under different pressure ratios and different capacity adjustment conditions.

[0079] In this embodiment, the high-pressure oil from the screw compressor first enters the hydraulic compensation chamber through the oil delivery channel 400. Part of the oil is used to support the sealing structure 12, reducing the gap between the slide valve body 11 and the slide valve chamber. The other part enters the first spiral groove 141 and the second spiral groove 142 to form an oil film at the spiral groove 14, achieving both lubrication and sealing. When the hydraulic compensation chamber is full, the oil enters the first unloading channel 301 and the second unloading channel 302. Due to the high oil pressure, the oil is sprayed directly into the rotor meshing area 200 through the unloading channel 300, achieving sealing and lubrication supply to the leakage triangle of the rotor meshing area 200. Ultimately, by forming a self-circulating lubrication and sealing system with the oil delivery channel 400, the hydraulic compensation chamber, the spiral groove 14, and the unloading channel 300, and the rotor meshing area 200, the system simultaneously solves the problems of gap compensation after seal strip wear and the lack of active oil film sealing in the leakage triangle area, thereby improving the volumetric efficiency of the screw compressor. This embodiment not only improves oil utilization but also enhances the sealing performance of the leakage triangle area.

[0080] In one exemplary embodiment, a screw compressor and its slide valve are provided. (Reference) Figures 1 to 7As shown, in this embodiment, the outer surface of the sealing structure 12 is provided with a plurality of grooves 121. When the sealing structure 12 is placed in the placement groove 13, the grooves 121 extend circumferentially along the slide valve body 11, and the plurality of grooves 121 are arranged axially along the slide valve body 11.

[0081] When the sealing structure 12 includes strip-shaped structures such as a first sealing strip, a second sealing strip, a third sealing strip, and a fourth sealing strip, after each sealing strip is placed into its corresponding placement groove 13, the grooves 121 on the sealing strip can extend circumferentially along the valve body 11, that is, the grooves 121 extend along the length direction of the sealing strip. Furthermore, the multiple grooves 121 on the sealing strip are arranged axially along the valve body 11, that is, the multiple grooves 121 are arranged along the width direction of the sealing strip. It should be noted that when the sealing strip is placed into its corresponding placement groove 13, the depth direction of the sealing strip is the groove depth direction of the placement groove 13, which is the radial direction of the valve body 11; the length direction of the sealing strip is the circumferential direction of the valve body 11; and the width direction of the sealing strip is the axial direction of the valve body 11.

[0082] In this embodiment, the groove 121 is provided on the surface of the sealing structure 12, which can better reduce the coefficient of friction between the sealing structure 12 and the slide valve cavity, thereby better reducing the wear of the sealing structure 12 and extending the service life of the sealing structure 12.

[0083] In one exemplary embodiment, a screw compressor and its slide valve are provided. (Reference) Figures 1 to 7 As shown, in this embodiment, a V-shaped arc groove is formed on the outer surface of the slide valve body 11, that is, the cross-section of the arc groove is V-shaped. A sealing strip made of PTFE-based composite material is embedded in the groove. The sealing strip may contain graphite material, which helps to improve the problems of high leakage rate and short life of the sealing ring of the traditional slide valve 1.

[0084] The system comprises four sealing strips and four arc grooves, each used to house one of the sealing strips. The first sealing strip is positioned in the first arc groove 131, and the second sealing strip is positioned in the second arc groove 132, forming a sealing ring, which can be referred to as the first sealing ring. It should be noted that the first sealing ring can be a closed, complete ring or an open ring with at least one opening. Similarly, the third sealing strip is positioned in the third arc groove 133, and the fourth sealing strip is positioned in the fourth arc groove 134, forming another sealing ring, which can be referred to as the second sealing ring. The structure of the second sealing ring can be the same as or different from that of the first sealing ring; this is not limited. Preferably, both have the same structure, which will not be elaborated upon here.

[0085] The sealing strips described above may have multiple grooves 121 on their front side (i.e., the side facing away from the bottom of the mounting groove 13), and the shape of the grooves 121 is not limited. The grooves 121 help to further reduce the coefficient of friction, thereby reducing wear. A hydraulic compensation chamber is formed between the back of the sealing strip and the mounting groove 13. The hydraulic compensation chamber is connected to the main lubrication oil circuit of the screw compressor through the oil inlet 100 to provide oil to the hydraulic compensation chamber. A spiral groove 14 is also formed between the two sealing rings (i.e., the first sealing ring and the second sealing ring). The spiral groove 14 on the side where the male rotor 31 is located is designated as the first spiral groove 141, and the spiral groove 14 on the side where the female rotor 32 is located is designated as the second spiral groove 142. When oil is injected into the spiral groove 14, an oil film can be formed at the location of the spiral groove 14, which helps to seal the gap between the slide valve body 11 and the machine body 2 (i.e., the cavity wall of the slide valve chamber), further improving the sealing effect of the slide valve 1.

[0086] This embodiment uses "hydraulic compensation" instead of the traditional mechanical pre-tightening seal of the sealing ring, which can achieve adaptive compensation after the sealing ring wears. A V-shaped mounting groove 13 is opened on the surface of the slide valve 1, and a PTFE-based composite material sealing strip is embedded in the groove. The back of the strip is provided with a hydraulic compensation chamber that is connected to the main lubrication oil circuit of the screw compressor. When the sealing strip wears after the slide valve 1 has been running for a long time, the hydraulic oil in the hydraulic compensation chamber will apply pressure to the sealing strip. When the pressure is high enough, the sealing strip will press tightly against the surface of the slide valve cavity of the machine body 2. At the same time, due to the interaction force, the slide valve 1 as a whole will be lifted by a certain distance, which will also reduce the gap between the upper surface of the slide valve 1 and the rotor 3. Through adaptive compensation, not only is the sealing effect greatly improved, but the service life of the sealing ring is also greatly extended.

[0087] Furthermore, this embodiment can simultaneously address both adaptive compensation for the clearance of the slide valve 1 and sealing of the leakage triangle in the rotor meshing area 200. High-pressure oil first enters the hydraulic compensation chamber; part of it supports the sealing ring, reducing the clearance between the slide valve 1 and the machine body 2, while the other part enters the spiral groove 14 to form an oil film, serving both lubrication and sealing purposes. When the hydraulic compensation chamber is full, the oil enters the unloading channel 300 through the oil passage above the mounting groove 13. Due to the high oil pressure, the oil is sprayed directly into the rotor meshing area 200 through the unloading channel 300, achieving sealing and lubrication supply for the leakage triangle in the rotor meshing area 200. Ultimately, by forming a self-circulating lubrication and sealing system between the slide valve 1 sealing ring compensation chamber oil passage and the unloading channel 300 and the rotor meshing area 200, the problem of clearance compensation after slide valve 1 sealing ring wear and the lack of active oil film sealing in the leakage triangle area can be solved simultaneously, thereby improving the volumetric efficiency of the screw compressor. Furthermore, the distance between the oil discharge ports of the two oil discharge channels 300 in this embodiment can be equal to the tooth pitch of the rotor 3. Therefore, the lubrication and sealing effects can be improved under different pressure ratios and different capacity adjustment conditions.

[0088] In one exemplary embodiment, a mechanical device (not shown in the figure) is provided. This mechanical device can be an air conditioning unit, an air compressor, or other equipment requiring a screw compressor; there is no limitation thereto. In this embodiment, because the mechanical device is equipped with the screw compressor described in the above embodiment, the screw compressor has higher energy efficiency, better stability, and a longer lifespan. Therefore, it can significantly improve the energy efficiency, stability, and lifespan of the mechanical device, thereby enhancing the user experience.

[0089] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0090] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0091] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A slide valve, used in a screw compressor, characterized in that, The slide valve includes a slide valve body and a sealing structure. The slide valve body is located inside the slide valve cavity of the screw compressor. The slide valve body is provided with a mounting groove adapted to the sealing structure. The mounting groove is located on the outer surface of the slide valve body opposite to the slide valve cavity. The sealing structure is installed in the mounting groove, and a hydraulic compensation cavity is formed between the sealing structure and the groove wall of the mounting groove. The hydraulic compensation cavity is connected to the oil injection port of the slide valve.

2. The slide valve according to claim 1, characterized in that, The sealing structure includes a first sealing strip and a second sealing strip, and the mounting groove includes a first arc groove and a second arc groove. The first sealing strip is mounted in the first arc groove, and the second sealing strip is mounted in the second arc groove. The first arc groove and the second arc groove both extend circumferentially along the slide valve body. The first arc groove is located on the side where the male rotor of the screw compressor is located, and the second arc groove is located on the side where the female rotor of the screw compressor is located. In the axial direction of the slide valve body, the first arc groove and the second arc groove are at the same position.

3. The slide valve according to claim 2, characterized in that, The sealing structure includes a third sealing strip and a fourth sealing strip, and the mounting groove includes a third arc groove and a fourth arc groove. The third sealing strip is mounted in the third arc groove, and the fourth sealing strip is mounted in the fourth arc groove. The third arc groove and the fourth arc groove both extend circumferentially along the slide valve body. The third arc groove is located on the side where the male rotor of the screw compressor is located, and the fourth arc groove is located on the side where the female rotor of the screw compressor is located. In the axial direction of the slide valve body, the third arc groove and the fourth arc groove are in the same position, and the first arc groove and the third arc groove are in different positions.

4. The slide valve according to claim 3, characterized in that, Along the axial direction of the slide valve body, the position of the first arc groove is denoted as the first axial position, and the position of the third arc groove is denoted as the second axial position. The interval between the first axial position and the second axial position is greater than or equal to the tooth pitch of the male rotor in the screw compressor.

5. The slide valve according to claim 3, characterized in that, The outer surface of the slide valve body is provided with a first spiral groove, which is located between the first arc groove and the third arc groove. The first half cavity of the hydraulic compensation cavity is formed between the first sealing strip and the groove wall of the first arc groove, and the third half cavity of the hydraulic compensation cavity is formed between the third sealing strip and the groove wall of the third arc groove. The first half cavity and the third half cavity are respectively connected to the first spiral groove. And / or, The outer surface of the slide valve body is provided with a second spiral groove, which is located between the second arc groove and the fourth arc groove. The second sealing strip and the groove wall of the second arc groove form the second half cavity of the hydraulic compensation cavity, and the fourth sealing strip and the groove wall of the fourth arc groove form the fourth half cavity of the hydraulic compensation cavity. The second half cavity and the fourth half cavity are respectively connected to the second spiral groove.

6. The slide valve according to claim 5, characterized in that, The slide valve body is provided with an oil delivery channel communicating with the oil inlet. The oil delivery channel extends along the axial direction of the slide valve body and communicates with the first half-cavity, the second half-cavity, the third half-cavity and the fourth half-cavity. The oil delivery channel is used to deliver the oil injected into the oil inlet to the first half-cavity, the second half-cavity, the third half-cavity and the fourth half-cavity.

7. The slide valve according to claim 5, characterized in that, The slide valve body is provided with a first oil unloading channel. The first half-cavity and the second half-cavity are both connected to the first oil unloading channel. The first oil unloading channel is used to transport the oil from the first half-cavity and the second half-cavity to the rotor meshing area of ​​the screw compressor. And / or, The slide valve body is provided with a second oil unloading channel. The third half-cavity and the fourth half-cavity are both connected to the second oil unloading channel. The second oil unloading channel is used to transport the oil from the third half-cavity and the fourth half-cavity to the rotor meshing area of ​​the screw compressor.

8. The slide valve according to any one of claims 1-7, characterized in that, The outer surface of the sealing structure is provided with a plurality of grooves. When the sealing structure is placed in the mounting groove, the grooves extend circumferentially along the slide valve body, and the plurality of grooves are arranged axially along the slide valve body.

9. The slide valve according to any one of claims 1-7, characterized in that, The sealing structure comprises a strip structure made of a composite material of polytetrafluoroethylene and graphite.

10. The slide valve according to any one of claims 1-7, characterized in that, The placement groove includes a V-shaped groove.

11. A screw compressor, characterized in that, The screw compressor includes a rotor and a slide valve as described in any one of claims 1-10.

12. A mechanical device, characterized in that, The mechanical equipment includes the screw compressor as described in claim 11.

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