Shafting assembly and screw compressor

Abstract

The utility model discloses a shaft system assembly and a screw compressor. The shaft system assembly (AS) comprises a rotating shaft (10); the stator structure (20) supports the rotating shaft (10), so that the rotating shaft (10) rotates relative to the stator structure (20); the sealing assembly (30) is arranged between the rotating shaft (10) and the stator structure (20) and used for achieving sealing between the rotating shaft (10) and the stator structure (20); and the backflow liquid sealing structure (40) is arranged between the rotating shaft (10) and the stator structure (20) and is configured to enable a lubricating medium located between the rotating shaft (10) and the stator structure (20) to flow back towards the side, close to the sealing assembly (30), of the backflow liquid sealing structure (40), so that the liquid sealing effect is achieved.

Description

Technical Field

[0001] This disclosure relates to a shaft assembly and a screw compressor. Background Technology

[0002] In screw compressors used in refrigeration units, the shaft is rotatably mounted inside the casing, and is supported by a stator structure formed by the casing and its internal components. Based on this shaft assembly, the shaft can rotate freely within a predetermined space, thereby realizing processes such as the intake, compression, and discharge of the working medium.

[0003] The lubricating oil (also known as refrigerant oil) inside a screw compressor lubricates components such as the shaft, ensuring efficient operation and a longer service life. To control refrigerant oil leakage during screw compressor operation, some related technologies incorporate sealing components within the screw compressor to prevent leakage.

[0004] Sealing components can be installed at specific locations between the shaft and stator structure to prevent refrigerant oil leakage. However, due to the pressure difference between the compressor's interior and the external environment, some refrigerant oil leakage can still occur. With continuous operation, this can eventually reduce the amount of refrigerant oil inside the compressor to a level insufficient to ensure normal equipment operation, forcing users to periodically shut down the compressor for inspection and oil replenishment. This process not only increases maintenance costs but also impacts production efficiency due to frequent downtime.

[0005] Furthermore, refrigeration oil leaks are not merely a matter of internal resource waste; they also have negative impacts on the external environment. Especially when refrigeration oil contains certain chemicals, leaks can contaminate soil and water sources, and even pose potential risks to human health. Utility Model Content

[0006] In view of this, the present disclosure provides a shaft assembly and a screw compressor that can reduce the possibility of lubricating medium leakage.

[0007] In one aspect of this disclosure, a shaft system assembly is provided, comprising:

[0008] Shaft;

[0009] A stator structure supports the rotating shaft so that the rotating shaft can rotate relative to the stator structure;

[0010] A sealing assembly, disposed between the rotating shaft and the stator structure, is used to achieve a seal between the rotating shaft and the stator structure; and

[0011] A reflux liquid seal structure, disposed between the rotating shaft and the stator structure, is configured to allow the lubricating medium located between the rotating shaft and the stator structure to flow back towards the side of the reflux liquid seal structure adjacent to the sealing assembly, thereby forming a liquid seal effect.

[0012] In some embodiments, the reflux liquid seal structure includes:

[0013] A spiral reflux groove is formed on the outer peripheral surface of the rotating shaft.

[0014] The spiral direction of the spiral return groove is configured to be opposite to the rotation direction of the rotating shaft, so that during the rotation of the rotating shaft relative to the stator structure, the lubricating medium located between the rotating shaft and the stator structure is guided to return to the first end of the spiral return groove adjacent to the sealing assembly.

[0015] In some embodiments, the depth H1 of the spiral reflux groove along the radial direction of the rotating shaft is 3 to 10 times the radial clearance h between the rotating shaft and the stator structure.

[0016] In some embodiments, the pitch P of the spiral reflux groove is 3 to 10 times the radial clearance h between the rotating shaft and the stator structure.

[0017] In some embodiments, the rotating shaft rotates relative to the stator structure, and a pressure difference is formed along the axial direction of the rotating shaft on a first side and a second side of the sealing assembly, wherein the pressure on the first side is greater than the pressure on the second side; the second end of the reflux seal structure away from the sealing assembly is located on the second side of the sealing assembly.

[0018] In some embodiments, the reflux liquid seal structure further includes:

[0019] The liquid reservoir, which overlaps with at least a portion of the sealing assembly in the axial direction of the rotating shaft and communicates with the first end, is configured to form a liquid seal at the location of the sealing assembly.

[0020] In some embodiments, the liquid storage section includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, wherein the depth H2 of the annular liquid storage groove along the radial direction of the rotating shaft is not greater than 1 / 10 of the diameter D of the rotating shaft.

[0021] In some embodiments, the depth H2 of the annular liquid storage tank along the radial direction of the rotating shaft is greater than the depth H1 of the spiral reflux tank.

[0022] In some embodiments, the liquid storage section includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, wherein the width W of the annular liquid storage groove along the axial direction of the rotating shaft is not greater than 1 / 10 of the diameter D of the rotating shaft.

[0023] In some embodiments, the width W of the annular liquid storage tank along the axial direction of the rotating shaft is greater than the pitch P of the spiral reflux tank.

[0024] In some embodiments, the sealing assembly includes a mechanical seal assembly.

[0025] In some embodiments, the mechanical seal assembly includes:

[0026] Mechanical seal stationary ring, installed on the stator structure; and

[0027] A rotating mechanical seal ring is installed on the rotating shaft and seals with the stationary mechanical seal ring.

[0028] The liquid storage section includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, and the mating surfaces of the annular liquid storage groove and the mechanical seal moving ring and the mechanical seal stationary ring overlap at least partially in the axial direction of the rotating shaft.

[0029] In some embodiments, the stator structure includes:

[0030] A cover plate having a through hole extending axially along the shaft, the cover plate being used to limit the stationary ring of the mechanical seal along the axial direction of the shaft;

[0031] The rotating shaft passes through the through hole, and the spiral reflux groove overlaps with the through hole at least partially along the axial direction of the rotating shaft.

[0032] In some embodiments, the cover plate is provided with a drain outlet, which communicates with the second end of the spiral reflux groove away from the sealing assembly.

[0033] In one aspect of this disclosure, a screw compressor is provided, comprising:

[0034] The aforementioned shaft system components.

[0035] According to embodiments of this disclosure, a sealing assembly is used to achieve a seal between the shaft and the stator structure, thereby minimizing leakage of the lubricating medium between the shaft and the stator structure. By providing a return liquid seal structure between the shaft and the stator structure, the lubricating medium located between the shaft and the stator structure flows back towards the side of the return liquid seal structure adjacent to the sealing assembly, forming a liquid seal effect. The liquid seal effect reduces the leakage rate of the sealing assembly, improves the sealing effect of the sealing assembly, is beneficial for the long-term operation of the shaft system assembly, and reduces the risk of environmental pollution from leaked lubricating medium. Attached Figure Description

[0036] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0037] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0038] Figure 1 This is a cross-sectional structural schematic diagram of some embodiments of the shaft system assembly according to the present disclosure;

[0039] Figure 2 yes Figure 1 An enlarged schematic diagram of the region enclosed by the ellipse A;

[0040] Figure 3 This is a schematic diagram of the structure of the rotating shaft according to an embodiment of the shaft system assembly of this disclosure;

[0041] Figure 4 yes Figure 3 An enlarged schematic diagram of the region enclosed by the ellipse B.

[0042] It should be understood that the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components.

[0043] Explanation of reference numerals in the attached figures:

[0044] 10-Shaft; 20-Stator structure; 21-Cover plate; 211-Through hole; 212-Discharge outlet;

[0045] 30 - Sealing assembly; 31 - Mechanical seal stationary ring; 32 - Mechanical seal rotating ring;

[0046] 40 - Reflux seal structure; 41 - Spiral reflux groove; 411 - First end; 412 - Second end; 42 - Liquid storage section;

[0047] AS - Shaft assembly; MS - Mating surface; S1 - First side; S2 - Second side. Detailed Implementation

[0048] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0049] The terms "first," "second," and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0050] In this disclosure, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0051] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0052] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0053] In related technologies, for screw compressors that include shaft systems that enable power transmission, sealing components can be located at specific points between the rotating shaft and the stator structure to prevent refrigerant oil leakage.

[0054] However, due to the pressure difference between the compressor's internal structure and the external environment, some leakage of refrigerant oil can still occur. With continuous operation, the compressor may become deficient in refrigerant oil, affecting normal operation and necessitating periodic shutdowns for replenishment. Furthermore, leaked refrigerant oil can cause environmental pollution.

[0055] In view of this, the present disclosure provides a shaft assembly and a screw compressor that can reduce the possibility of lubricating medium leakage.

[0056] Figure 1 This is a cross-sectional structural schematic diagram of some embodiments of the shaft system assembly according to the present disclosure. Figure 2 yes Figure 1 An enlarged schematic diagram of the region enclosed by the ellipse A. Figure 3 This is a schematic diagram of the structure of the rotating shaft according to an embodiment of the shaft system assembly of this disclosure. Figure 4 yes Figure 3 An enlarged schematic diagram of the region enclosed by the ellipse B.

[0057] refer to Figures 1-4 In this embodiment of the disclosure, a shaft assembly AS is provided, including: a rotating shaft 10, a stator structure 20, a sealing assembly 30, and a reflux liquid seal structure 40. The stator structure 20 supports the rotating shaft 10 so that the rotating shaft 10 rotates relative to the stator structure 20. The sealing assembly 30 is disposed between the rotating shaft 10 and the stator structure 20 to achieve a seal between the rotating shaft 10 and the stator structure 20.

[0058] The reflux liquid seal structure 40 is disposed between the rotating shaft 10 and the stator structure 20 and is configured to allow the lubricating medium located between the rotating shaft 10 and the stator structure 20 to flow back toward the side of the reflux liquid seal structure 40 adjacent to the sealing assembly 30 to form a liquid seal effect.

[0059] The rotating shaft 10 can transmit rotational power. Various components that need to rotate intermittently or continuously during operation, such as impellers, gears, screws, and motor rotors, can be installed on it. Power is output to the rotating shaft 10 through power units such as motors or hydraulic motors to drive the components installed on the rotating shaft 10 to rotate.

[0060] The stator structure 20 is the non-rotating part of the shaft assembly AS, which can be realized by the housing structure and internal components (such as bushings, bearings, bearing housings, etc.) of the equipment on which the shaft assembly AS is mounted. The rotating shaft 10 is rotatable relative to the stator structure 20.

[0061] The sealing assembly 30 can achieve a seal between the rotating shaft 10 and the stator structure 20, thereby reducing leakage and protecting the interior of the shaft assembly from external contamination. The sealing method of the sealing assembly 30 can be a contact seal or a non-contact seal, such as a lip seal, mechanical seal, labyrinth seal, or pneumatic seal. The sealing assembly 30 can include a single type of sealing structure or a combination of multiple types of sealing structures.

[0062] The reflux liquid seal structure 40 allows the lubricating medium located between the rotating shaft 10 and the stator structure 20 to flow back towards the side of the reflux liquid seal structure 40 adjacent to the sealing assembly 30, thereby forming a liquid seal at or near the location of the sealing assembly 30. This liquid seal not only reduces the leakage rate of the sealing assembly 30 and improves its sealing effect, but also provides more reliable operational assurance for the shaft assembly AS, enabling it to support continuous operation for longer periods, thus reducing equipment performance degradation and maintenance requirements caused by lubricating medium leakage. Furthermore, this embodiment can also reduce the potential environmental pollution risk caused by leaked lubricating medium by reducing lubricating medium leakage.

[0063] In this embodiment, the lubricating medium refers to the medium within the equipment containing the shaft assembly AS that enables lubrication of the relative movement between components. The lubricating medium may include, but is not limited to, refrigeration oil (i.e., lubricating oil for refrigeration compressors), which can be applied to equipment such as screw compressors in refrigeration units. It can not only achieve lubrication but also perform functions such as cooling and auxiliary sealing within the screw compressor.

[0064] refer to Figure 2 and Figure 3 In some embodiments, the reflux seal structure 40 includes a spiral reflux groove 41. The spiral reflux groove 41 is formed on the outer peripheral surface of the rotating shaft 10. The spiral direction of the spiral reflux groove 41 is configured to be opposite to the rotation direction of the rotating shaft 10, so that during the rotation of the rotating shaft 10 relative to the stator structure 20, the lubricating medium located between the rotating shaft 10 and the stator structure 20 is guided back towards the spiral reflux groove 41 adjacent to the first end 411 of the sealing assembly 30.

[0065] The spiral reflux groove 41 can accommodate the lubricating medium located between the rotating shaft 10 and the stator structure 20 through the groove structure on the outer peripheral surface of the rotating shaft 10, so that the rotation of the spiral reflux groove 41 can drive the lubricating medium to reflux, preventing the lubricating medium from leaking outward. According to the design requirements, the spiral groove can be machined on the rotating shaft 10 by mature processes such as turning or milling, which is relatively easy to achieve.

[0066] The spiral reflux groove 41 has a spiral shape around the axis of the rotating shaft 10, and its spiral direction (refer to...) Figure 3 The inclination direction of the spiral groove is configured relative to the rotation direction of the rotating shaft 10 (see reference). Figure 3The direction of rotation (ω) shown is opposite. When the shaft 10 rotates, it drives the spiral return groove 41 to rotate relative to the inner circular surface of the stator structure 20. At this time, the lubricating medium that is between the shaft 10 and the stator structure 20 and leaks from the sealing assembly 30 into the return liquid seal structure 40 will flow back towards the first end 411 of the spiral return groove 41 near the sealing assembly 30 under the reverse pumping action of the spiral return groove 41.

[0067] refer to Figure 2 and Figure 4 In some embodiments, the depth H1 of the spiral reflux groove 41 along the radial direction of the rotating shaft 10 is 3 to 10 times the radial gap h between the rotating shaft 10 and the stator structure 20.

[0068] exist Figure 4 In this context, depth H1 refers to the vertical distance along the radial direction of the rotating shaft 10 from its outer surface to the bottom of the spiral reflux groove 41. Radial clearance h refers to the shortest distance along the radial direction of the rotating shaft 10, excluding the portion of the spiral reflux groove 41, between the rotating shaft 10 and the stator structure 20.

[0069] The ratio between depth H1 and radial clearance h can be determined based on factors such as the viscosity of the lubricating medium, the pressure difference between the inside and outside of the sealing structure, and the strength requirements of the rotating shaft. Compared with the radial clearance h, an excessively large depth H1 weakens the rotating shaft 10 to a greater extent, affecting the strength of the rotating shaft 10 itself, while an excessively small depth H1 accommodates less lubricating medium, affecting the reverse pumping capability of the spiral return groove 41 for the lubricating medium.

[0070] In this embodiment, by making the depth H1 equal to 3 to 10 times the radial clearance h, such as 3 times, 4.5 times, 6 times, 7 times, 8.8 times, 9 times or 10 times, the strength of the shaft 10 itself and the reverse pumping capability of the lubricating medium can be balanced as much as possible.

[0071] refer to Figure 2 and Figure 4 In some embodiments, the pitch P of the spiral reflux groove 41 is 3 to 10 times the radial clearance h between the rotating shaft 10 and the stator structure 20.

[0072] exist Figure 4 In this context, the pitch P refers to the axial distance between two adjacent grooves of the spiral return groove 41. The radial clearance h refers to the shortest distance along the radial direction of the rotating shaft 10, excluding the portion of the spiral return groove 41, between the rotating shaft 10 and the stator structure 20.

[0073] Compared to the radial clearance h, an excessively small pitch P causes the shaft 10 to remove more material, affecting the strength of the shaft 10 itself. On the other hand, an excessively large pitch P results in a larger helix angle, which affects the reverse pumping capability of the spiral return groove 41 for the lubricating medium.

[0074] In this embodiment, by making the pitch P equal to 3 to 10 times the radial clearance h, such as 3 times, 4.5 times, 6 times, 7 times, 8.8 times, 9 times or 10 times, the strength of the shaft 10 itself and the reverse pumping capability of the lubricating medium can be balanced as much as possible.

[0075] refer to Figure 1 and Figure 4 In some embodiments, the rotating shaft 10 rotates relative to the stator structure 20, and a pressure difference is formed on the first side S1 and the second side S2 of the sealing assembly 30 along the axial direction of the rotating shaft 10, wherein the pressure on the first side S1 is greater than the pressure on the second side S2; the spiral reflux groove 41 is located at the second end 412 away from the sealing assembly 30 on the second side S2 of the sealing assembly 30.

[0076] In this embodiment, since the sealing assembly 30 forms a pressure difference between the first side S1 and the second side S2 along the axial direction of the rotating shaft 10, the pressure difference may cause the lubricating medium to leak from the first side S1 to the second side S2 of the sealing assembly 30 without the backflow seal structure 40.

[0077] By positioning the spiral reflux groove 41 away from the second end 412 of the sealing assembly 30 on the second side S2 of the sealing assembly 30, and with its first end 411 adjacent to the sealing assembly 30, the lubricating medium in the reflux liquid seal structure 40 flows back toward the first end 411 of the reflux liquid seal structure 40 under the reverse pumping action of the reflux liquid seal structure 40 to form a liquid seal, thereby effectively reducing the leakage of the lubricating medium.

[0078] refer to Figure 2 and Figure 3 In some embodiments, the reflux liquid seal structure 40 further includes a liquid storage portion 42, which overlaps at least partially with at least a portion of the sealing assembly 30 in the axial direction of the rotating shaft 10 and communicates with the first end 411, and is configured to form a liquid seal at the location of the sealing assembly 30.

[0079] The reservoir 42 can hold a certain amount of lubricating medium to form a liquid seal at the location of the sealing assembly 30. The first end 411 of the spiral reflux groove 41 is connected to the reservoir 42, and the lubricating medium pumped in reverse in the spiral reflux groove 41 can flow into the reservoir 42. In addition, some of the lubricating medium leaking from the sealing assembly 30 will also flow into the reservoir 42.

[0080] The reservoir 42 can also overlap at least partially with at least a portion of the sealing assembly 30 in the axial direction of the rotating shaft 10. In this way, as the spiral return groove 41 continuously pumps the lubricating medium in the reverse direction and the sealing assembly 30 leaks the lubricating medium, the medium pressure in the reservoir 42 can be increased, forming a pressure zone between the reservoir 42 and the sealing assembly 30.

[0081] When the pressure in the pressure zone is consistent with the pressure on the first side S1 of the sealing assembly 30, pressure balance is achieved, thereby preventing the lubricating medium from leaking to the second side S2 of the sealing assembly 30. This results in a better leak prevention effect, further reducing the leakage rate of the sealing assembly 30, enabling the shaft assembly AS to operate continuously for a longer period of time, and reducing or eliminating the environmental pollution caused by leaked lubricating medium.

[0082] refer to Figures 2-4 In some embodiments, the liquid storage section 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, wherein the depth H2 of the annular liquid storage groove along the radial direction of the rotating shaft 10 is not greater than 1 / 10 of the diameter D of the rotating shaft 10.

[0083] exist Figure 4 In this context, depth H2 refers to the vertical distance along the radial direction of the rotating shaft 10 from its outer surface to the bottom of the annular liquid storage tank. Diameter D refers to the cross-sectional diameter of the rotating shaft 10 on the outer circumferential surface forming the annular liquid storage tank.

[0084] When designing the depth H2 of the annular liquid storage tank, factors such as the leakage of the sealing assembly and the pressure difference on both sides of the sealing assembly can be considered, as well as the strength of the rotating shaft 10 itself.

[0085] In this embodiment, if the depth H2 of the annular liquid storage tank is too large relative to the diameter D of the rotating shaft 10, the portion of the rotating shaft 10 corresponding to the annular liquid storage tank will be weakened, thereby affecting the strength of the rotating shaft 10 itself. Therefore, in this embodiment, the depth H2 can be made no greater than 1 / 10 of the diameter D, for example, the depth H2 can be 1 / 12 or 1 / 15 of the diameter D, to ensure the reliability of the rotating shaft 10.

[0086] refer to Figure 4 In some embodiments, the liquid storage section 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, wherein the depth H2 of the annular liquid storage groove along the radial direction of the rotating shaft 10 is greater than the depth H1 of the spiral reflux groove 41.

[0087] In this embodiment, by making the depth H2 of the annular reservoir along the radial direction of the rotating shaft 10 greater than the depth H1 of the spiral reflux groove 41, the capacity of the annular reservoir to hold the lubricating medium can be increased to accommodate the lubricating medium pumped into the spiral reflux groove 41 and the lubricating medium leaked from the sealing assembly 30, thereby forming a stable and reliable pressure zone at the location of the annular reservoir and reducing the risk of leakage.

[0088] refer to Figure 3 and Figure 4 In some embodiments, the liquid storage section 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, wherein the width W of the annular liquid storage groove along the axial direction of the rotating shaft 10 is not greater than 1 / 10 of the diameter D of the rotating shaft 10.

[0089] exist Figure 4 In this context, the width W refers to the distance between the two walls of the annular liquid storage tank along the axial direction of the rotating shaft 10. The diameter D refers to the cross-sectional diameter of the rotating shaft 10 on the outer circumferential surface forming the annular liquid storage tank.

[0090] When designing the width W of the annular liquid storage tank, factors such as the leakage of the sealing components and the pressure difference on both sides of the sealing components can be considered, as well as the stability of the pressure zone.

[0091] In this embodiment, if the width W of the annular reservoir is too large relative to the diameter D of the rotating shaft 10, the contact area between the lubricating medium and the rotating shaft will increase, thereby increasing the friction. This makes it difficult for the lubricating medium to form a stable static pressure in the annular reservoir after pumping. Therefore, in this embodiment, the width W can be no greater than 1 / 10 of the diameter D, for example, 1 / 12 or 1 / 15 of the diameter D, to improve the stability of the pressure zone.

[0092] refer to Figure 4 In some embodiments, the liquid storage section 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, wherein the width W of the annular liquid storage groove along the axial direction of the rotating shaft 10 is greater than the pitch P of the spiral reflux groove 41.

[0093] In this embodiment, by making the width W of the annular reservoir along the radial direction of the rotating shaft 10 greater than the pitch P of the spiral reflux groove 41, the capacity of the annular reservoir to hold the lubricating medium can be increased to accommodate the lubricating medium pumped into the spiral reflux groove 41 and the lubricating medium leaked from the sealing assembly 30, thereby forming a stable and reliable pressure zone at the location of the annular reservoir and reducing the risk of leakage.

[0094] refer to Figure 1In some embodiments, the sealing assembly 30 includes a mechanical seal assembly. A mechanical seal assembly is a device for preventing fluid leakage, consisting of at least a pair of end faces perpendicular to the axis of rotation that are kept in contact and slide relative to each other under the action of fluid pressure and the elastic force (or magnetic force) of the compensation mechanism, as well as the cooperation of auxiliary seals.

[0095] The mechanical seal assembly included in the sealing assembly 30 has good sealing performance and can effectively reduce leakage. Combined with the return fluid seal structure 40, it can achieve an even lower leakage rate or even completely stop leakage. Furthermore, for the shaft assembly AS sealed using the mechanical seal assembly, the return fluid seal structure 40 can further enhance the sealing performance of the mechanical seal assembly.

[0096] refer to Figure 1 and Figure 2 In some embodiments, the mechanical seal assembly includes a stationary mechanical seal ring 31 and a rotating mechanical seal ring 32. The stationary mechanical seal ring 31 is mounted on the stator structure 20. The rotating mechanical seal ring 32 is mounted on the rotating shaft 10 and has a sealing fit with the stationary mechanical seal ring 31.

[0097] The liquid storage section 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft. The mating surfaces MS of the annular liquid storage groove and the mechanical seal moving ring 32 and the mechanical seal stationary ring 31 overlap at least partially in the axial direction of the rotating shaft 10.

[0098] A mechanical seal assembly may include one or more sets of mating stationary mechanical seal rings 31 and rotating mechanical seal rings 32. For a mechanical seal assembly including multiple sets of mating stationary mechanical seal rings 31 and rotating mechanical seal rings 32, the multiple sets of mating stationary mechanical seal rings 31 and rotating mechanical seal rings 32 may be arranged in series along the axial direction.

[0099] In addition to the mechanical seal assembly including the stationary ring 31 and the rotating ring 32, it may include an elastic element 33, a first auxiliary seal 34, and a second auxiliary seal 35. The elastic element 33 may be in the form of a spring or the like, and it abuts against the axial end face of the rotating ring 32 to keep the rotating ring 32 and the stationary ring 31 in contact at the mating surface MS.

[0100] The first auxiliary seal 34 and the second auxiliary seal 35 can be in the form of O-rings, V-rings, etc. The first auxiliary seal 34 can be used to achieve the seal between the stationary ring 31 of the mechanical seal and the stationary structure 20, and the second auxiliary seal 35 can be used to achieve the seal between the rotating ring 32 of the mechanical seal and the rotating shaft 10.

[0101] In this embodiment, by making the mating surfaces MS of the annular reservoir, the mechanical seal moving ring 32, and the mechanical seal stationary ring 31 at least partially overlap in the axial direction of the rotating shaft 10, the lubricating medium leaking from the mating surfaces MS can directly enter the annular reservoir, which helps to build up the pressure in the pressure zone more quickly and reduces the leakage of the lubricating medium.

[0102] refer to Figure 1 and Figure 2 In some embodiments, the stator structure 20 includes a cover plate 21. The cover plate 21 has a through hole 211 extending axially along the shaft 10, and the cover plate 21 is used to limit the mechanical seal stationary ring 31 along the axial direction of the shaft 10. The shaft 10 passes through the through hole 211, and the spiral reflux groove 41 at least partially overlaps the through hole 211 along the axial direction of the shaft 10.

[0103] exist Figure 1 In this configuration, the shaft assembly AS is partially housed within the housing 22, and the cover plate 21 is located on the second side S2 of the sealing assembly 30, abutting against the mechanical seal stationary ring 31 axially to limit its position. Figure 2 In the middle, a gap h is formed between the through hole 211 and the rotating shaft 10.

[0104] The relationship in which the spiral reflux groove 41 and the through hole 211 overlap at least partially along the axial direction of the rotating shaft 10 means that the axial range of the spiral reflux groove 41 and the axial range of the through hole 211 at least partially overlap, which can be either partial or complete overlap.

[0105] In this embodiment, the reflux seal structure 40 and the through hole 211 overlap at least partially along the axial direction of the rotating shaft 10, so that the lubricating medium in the through hole 11 can be pumped in the reverse direction by the spiral reflux groove 41 to one side adjacent to the mechanical seal stationary ring 31.

[0106] In other embodiments, the spiral reflux groove 41 may not overlap with the through hole 211 along the axial direction of the rotating shaft 10.

[0107] refer to Figure 1 and Figure 2 In some embodiments, the cover plate 21 is provided with a drain outlet 212, which is connected to the second end 412 of the spiral reflux groove 41 away from the sealing assembly 30.

[0108] The cover plate 21 may be provided with a drain outlet 212 to allow the lubricating medium inside the through hole 211 to drain out. By connecting the drain outlet 212 to the second end 412 of the return liquid seal structure 40 away from the sealing assembly 30, the lubricating medium that has not been pumped back by the return liquid seal structure 40 can be drained out through the drain outlet 212 after pressure equalization.

[0109] The various embodiments of the shaft assembly AS described above are applicable to various power transmission devices that require lubrication and sealing, such as refrigeration compressors, centrifugal pumps, agitators, fans, etc.

[0110] In one aspect of this disclosure, a screw compressor is also provided, including a shaft assembly AS of any of the foregoing embodiments. When the shaft assembly AS is applied to a screw compressor, leakage of lubricating media (e.g., refrigeration oil) can be effectively reduced, enabling the screw compressor to operate for extended periods and reducing environmental pollution.

[0111] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0112] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A shaft system assembly, characterized in that, include: Rotating shaft (10); A stator structure (20) supports the rotating shaft (10) so that the rotating shaft (10) can rotate relative to the stator structure (20); A sealing assembly (30), disposed between the rotating shaft (10) and the stator structure (20), is used to achieve a seal between the rotating shaft (10) and the stator structure (20); and A reflux seal structure (40), disposed between the shaft (10) and the stator structure (20), is configured to allow the lubricating medium located between the shaft (10) and the stator structure (20) to reflux toward the side of the reflux seal structure (40) adjacent to the sealing assembly (30) to form a liquid seal effect.

2. The shaft assembly according to claim 1, characterized in that, The reflux liquid seal structure (40) includes: A spiral reflux groove (41) is formed on the outer peripheral surface of the rotating shaft (10). The spiral direction of the spiral return groove (41) is configured to be opposite to the rotation direction of the rotating shaft (10) so that during the rotation of the rotating shaft (10) relative to the stator structure (20), the lubricating medium located between the rotating shaft (10) and the stator structure (20) is guided to return to the first end (411) of the spiral return groove (41) adjacent to the sealing assembly (30).

3. The shaft assembly according to claim 2, characterized in that, The depth H1 of the spiral reflux groove (41) along the radial direction of the rotating shaft (10) is 3 to 10 times the radial gap h between the rotating shaft (10) and the stator structure (20).

4. The shaft assembly according to claim 2, characterized in that, The pitch P of the spiral reflux groove (41) is 3 to 10 times the radial clearance h between the rotating shaft (10) and the stator structure (20).

5. The shaft assembly according to claim 2, characterized in that, The rotating shaft (10) rotates relative to the stator structure (20) and forms a pressure difference on the first side (S1) and the second side (S2) of the sealing assembly (30) along the axial direction of the rotating shaft (10). The pressure on the first side (S1) is greater than the pressure on the second side (S2). The second end (412) of the spiral reflux groove (41) away from the sealing assembly (30) is located on the second side (S2) of the sealing assembly (30).

6. The shaft assembly according to any one of claims 2-5, characterized in that, The reflux liquid seal structure (40) further includes: The liquid reservoir (42), which overlaps with at least a portion of the sealing assembly (30) in the axial direction of the rotating shaft (10) and communicates with the first end (411), is configured to form a liquid seal at the location of the sealing assembly (30).

7. The shaft assembly according to claim 6, characterized in that, The liquid storage section (42) includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft (10), wherein the depth H2 of the annular liquid storage groove along the radial direction of the rotating shaft (10) is not greater than 1 / 10 of the diameter D of the rotating shaft (10).

8. The shaft assembly according to claim 7, characterized in that, The depth H2 of the annular storage tank along the radial direction of the rotating shaft (10) is greater than the depth H1 of the spiral reflux tank (41).

9. The shaft assembly according to claim 7, characterized in that, The liquid storage section (42) includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, wherein the width W of the annular liquid storage groove along the axial direction of the rotating shaft (10) is not greater than 1 / 10 of the diameter D of the rotating shaft (10).

10. The shaft assembly according to claim 9, characterized in that, The width W of the annular liquid storage tank along the axial direction of the rotating shaft (10) is greater than the pitch P of the spiral reflux tank (41).

11. The shaft assembly according to claim 6, characterized in that, The sealing assembly (30) includes a mechanical seal assembly.

12. The shaft assembly according to claim 11, characterized in that, The mechanical seal assembly includes: Mechanical seal stationary ring (31), installed on the stator structure (20); and The mechanical seal dynamic ring (32) is installed on the rotating shaft (10) and is sealed to the mechanical seal stationary ring (31); The liquid storage section (42) includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft. The mating surfaces (MS) of the annular liquid storage groove and the mechanical seal moving ring (32) and the mechanical seal stationary ring (31) overlap at least partially in the axial direction of the rotating shaft (10).

13. The shaft assembly according to claim 12, characterized in that, The stator structure (20) includes: The cover plate (21) has a through hole (211) extending axially along the shaft (10), the cover plate (21) being used to limit the mechanical seal stationary ring (31) axially along the shaft (10); The rotating shaft (10) passes through the through hole (211), and the spiral reflux groove (41) overlaps with the through hole (211) at least partially along the axial direction of the rotating shaft (10).

14. The shaft assembly according to claim 13, characterized in that, The cover plate (21) is provided with a drain outlet (212), and the drain outlet (212) of the cover plate (21) is connected to the second end (412) of the spiral return groove (41) away from the sealing assembly (30).

15. A screw compressor, characterized in that, include: The shaft assembly according to any one of claims 1-14.

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