Shafting assembly and screw compressor

Abstract

The invention 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] The present disclosure relates to a shaft system assembly and a screw compressor. Background Art

[0002] In a screw compressor that can be used in a refrigeration unit, the shaft is rotatably arranged in the casing, and the shaft is supported by a stator structure formed by the casing and the components inside the casing. Based on this shaft system assembly, the shaft can rotate freely in a predetermined space, thereby realizing the processes of suction, compression and discharge of the working medium.

[0003] The lubricating oil (also called refrigeration oil) in the screw compressor can achieve the lubrication of the rotating shaft and other parts to ensure the efficient operation and longer service life of the compressor. In order to control the leakage of refrigeration oil during the operation of the screw compressor, in some related technologies, a sealing component for preventing refrigeration oil leakage is set in the screw compressor.

[0004] The sealing assembly can be set at a specific position between the rotating shaft and the stator structure to prevent the leakage of refrigerant oil. However, due to the pressure difference between the inside of the compressor and the outside world, the refrigerant oil in the compressor will still leak to a certain extent under the effect of the pressure difference. As the compressor continues to operate for a long time, the amount of refrigerant oil in the compressor may be reduced to a level that is insufficient to ensure the normal operation of the equipment, forcing the user to stop the machine regularly to check and replenish the refrigerant oil. This process not only increases maintenance costs, but frequent downtime also affects production efficiency.

[0005] In addition, the leakage of refrigeration oil is not only a problem of internal resource waste, it also has a negative impact on the external environment. Especially when the refrigeration oil contains specific chemicals, once the refrigeration oil leaks into the environment, it may pollute the soil and water sources, and even pose a potential risk to human health. Summary of the invention

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

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

[0008] Rotating shaft;

[0009] a stator structure, supporting the rotating shaft so that the rotating shaft rotates relative to the stator structure;

[0010] A sealing assembly, disposed between the rotating shaft and the stator structure, for achieving sealing between the rotating shaft and the stator structure; and

[0011] The reflux liquid seal structure is arranged between the rotating shaft and the stator structure, and is configured to make the lubricating medium between the rotating shaft and the stator structure reflux toward the side of the reflux liquid seal structure adjacent to the sealing assembly to form 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] Wherein, the spiral direction of the spiral reflow 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 between the rotating shaft and the stator structure is guided by the spiral reflow groove to flow back toward the first end of the spiral reflow groove adjacent to the sealing assembly.

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

[0016] In some embodiments, the pitch P of the spiral recirculation 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 between the first side and the second side of the sealing assembly along the axial direction of the rotating shaft, and the pressure on the first side is greater than the pressure on the second side; the reflux liquid seal structure is located on the second side of the sealing assembly away from the second end of the sealing assembly.

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

[0019] The liquid storage portion overlaps with at least a portion of the sealing component in the axial direction of the rotating shaft and is communicated with the first end portion, and is configured to form a liquid seal at a setting position of the sealing component.

[0020] In some embodiments, the liquid storage portion includes an annular liquid storage groove disposed on the outer circumferential surface of the rotating shaft, and a 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, a depth H2 of the annular liquid storage groove along the radial direction of the rotating shaft is greater than a depth H1 of the spiral reflux groove.

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

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

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

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

[0026] A mechanical seal static ring, mounted on the stator structure; and

[0027] A mechanical seal dynamic ring is mounted on the rotating shaft and seals with the mechanical seal static ring;

[0028] The liquid storage portion includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, and the annular liquid storage groove at least partially overlaps with the matching surfaces of the mechanical seal dynamic ring and the mechanical seal static ring in the axial direction of the rotating shaft.

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

[0030] A cover plate having a through hole extending along the axial direction of the rotating shaft, wherein the cover plate is used to limit the static ring of the mechanical seal along the axial direction of the rotating shaft;

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

[0032] In some embodiments, a drain port is provided on the cover plate, and the drain port of the cover plate is connected to the second end of the spiral reflux groove away from the sealing assembly.

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

[0034] The aforementioned shafting assembly.

[0035] According to the embodiment of the present disclosure, sealing between the rotating shaft and the stator structure is achieved through a sealing assembly to minimize leakage of the lubricating medium between the rotating shaft and the stator structure. A reflux liquid seal structure is provided between the rotating shaft and the stator structure so that the lubricating medium between the rotating shaft and the stator structure refluxes toward a side of the reflux liquid seal structure adjacent to the sealing assembly to form a liquid seal. The liquid seal effect reduces the leakage rate of the sealing assembly and improves the sealing effect of the sealing assembly, which is beneficial to the long-term operation of the shaft system assembly and reduces the risk of environmental pollution caused by leakage of the lubricating medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0037] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0038] Figure 1 is a schematic diagram of a cross-sectional structure of some embodiments of a shafting assembly according to the present disclosure;

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

[0040] Figure 3 is a schematic structural diagram of a rotating shaft according to an embodiment of a shaft system assembly disclosed herein;

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

[0042] It should be understood that the size of each part shown in the accompanying drawings of the present disclosure is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components. Description of reference numerals:

[0043] 10-rotating shaft; 20-stator structure; 21-cover plate; 211-through hole; 212-discharge outlet;

[0044] 30-seal assembly; 31-mechanical seal static ring; 32-mechanical seal dynamic ring;

[0045] 40-reflux liquid seal structure; 41-spiral reflux groove; 411-first end; 412-second end; 42-liquid storage part;

[0046] AS-shafting assembly; MS-mating surface; S1-first side; S2-second side. DETAILED DESCRIPTION

[0047] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0048] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0049] In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other device without an intermediate device, or may not be directly connected to the other device but have an intermediate device.

[0050] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0051] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0052] In the related art, for a screw compressor including a shaft system assembly for realizing power transmission, a sealing assembly can be disposed at a specific position between a rotating shaft and a stator structure to prevent leakage of refrigeration oil.

[0053] However, due to the pressure difference between the compressor and the outside world, the refrigerant oil in the compressor will still leak. As the compressor runs continuously for a long time, there may be a shortage of refrigerant oil in the compressor, which affects normal operation and requires regular shutdown for refilling. In addition, the leaked refrigerant oil will also cause certain pollution to the environment.

[0054] In view of this, the embodiments of the present disclosure provide a shaft assembly and a screw compressor, which can reduce the possibility of leakage of the lubricating medium.

[0055] Figure 1 It is a schematic diagram of the cross-sectional structure of some embodiments of the shaft system assembly according to the present disclosure. Figure 2 yes Figure 1 An enlarged schematic diagram of the area enclosed by the middle ellipse A. Figure 3 It is a schematic diagram of the structure of the rotating shaft in the embodiment of the shaft system assembly according to the present disclosure. Figure 4 yes Figure 3 An enlarged schematic diagram of the area enclosed by the middle ellipse B.

[0056] refer to Figure 1-Figure 4 In an embodiment of the present disclosure, a shaft assembly AS is provided, comprising: a rotating shaft 10, a stator structure 20, a sealing assembly 30 and a reflux liquid sealing 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 sealing between the rotating shaft 10 and the stator structure 20.

[0057] The reflux liquid seal structure 40 is disposed between the rotating shaft 10 and the stator structure 20 and is configured to cause the lubricating medium between the rotating shaft 10 and the stator structure 20 to reflux toward a side of the reflux liquid seal structure 40 adjacent to the sealing assembly 30 to form a liquid seal.

[0058] The rotating shaft 10 can realize the transmission of rotational power, and various components that need to rotate intermittently or continuously during operation can be installed on it, such as impellers, gears, screws, motor rotors, etc. Power is output to the rotating shaft 10 through a power unit such as an electric motor or a hydraulic motor to drive the components installed on the rotating shaft 10 to rotate.

[0059] The stator structure 20 is a non-rotating part of the shaft assembly AS, which can be realized by the housing structure, internal components (such as sleeves, bearings, bearing seats, etc.) of the equipment on which the shaft assembly AS is installed. The rotating shaft 10 can rotate relative to the stator structure 20 .

[0060] The sealing assembly 30 can achieve sealing between the rotating shaft 10 and the stator structure 20 to reduce leakage, protect the interior of the shaft system assembly from external contamination, etc. The sealing method of the sealing assembly 30 can be a contact seal or a non-contact seal, such as a lip seal, a mechanical seal, a labyrinth seal, a pneumatic seal, etc. The sealing assembly 30 can include a single form of sealing structure, or a combination of multiple forms of sealing structures.

[0061] The reflux liquid seal structure 40 can make the lubricating medium between the rotating shaft 10 and the stator structure 20 reflux toward the side of the reflux liquid seal structure 40 adjacent to the sealing assembly 30, so as to form a liquid seal effect at the setting position of the sealing assembly 30 or at a position adjacent to the sealing assembly 30. Such a liquid seal effect not only reduces the leakage rate of the sealing assembly 30 and improves the sealing effect of the sealing assembly 30, but also provides a more reliable operation guarantee for the shaft assembly AS, enabling it to support continuous operation for a longer period of time, thereby reducing the equipment performance degradation and maintenance requirements caused by the leakage of the lubricating medium. In addition, this embodiment can also reduce the potential pollution risk of the leaked lubricating medium to the environment by reducing the leakage of the lubricating medium.

[0062] In this embodiment, the lubricating medium refers to the medium that realizes the lubrication of the relative movement between the components in the equipment where the shaft assembly AS is located. The lubricating medium may include but is not limited to refrigeration oil (i.e., lubricating oil for refrigeration compressors), which is applied to equipment such as screw compressors of refrigeration units, and can not only achieve lubrication, but also achieve functions such as cooling and auxiliary sealing in the screw compressor.

[0063] refer to Figure 2 and Figure 3 In some embodiments, the reflux liquid 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 between the rotating shaft 10 and the stator structure 20 is guided by the spiral reflux groove 41 to reflux toward the first end 411 of the spiral reflux groove 41 adjacent to the sealing assembly 30.

[0064] 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 drives the lubricating medium to reflux and prevents the lubricating medium from leaking outward. According to the design requirements, the spiral groove can be processed on the rotating shaft 10 through mature processes such as turning or milling, which is relatively easy to implement.

[0065] 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 to be aligned with the rotation direction of the shaft 10 (refer to Figure 3When the shaft 10 rotates, the spiral reflux groove 41 is driven to rotate relative to the inner surface of the stator structure 20. At this time, the lubricating medium between the shaft 10 and the stator structure 20 and leaking from the sealing assembly 30 to the reflux liquid seal structure 40 will flow back toward the first end 411 of the spiral reflux groove 41 adjacent to the sealing assembly 30 under the reverse pumping action of the spiral reflux groove 41.

[0066] refer to Figure 2 and Figure 4 In some embodiments, a depth H1 of the spiral recirculation groove 41 along the radial direction of the rotating shaft 10 is 3 to 10 times of a radial clearance h between the rotating shaft 10 and the stator structure 20 .

[0067] exist Figure 4 In the figure, the depth H1 refers to the vertical distance from the outer surface of the shaft 10 to the bottom of the spiral recirculation groove 41 along the radial direction of the shaft 10. The radial clearance h refers to the shortest distance between the part of the shaft 10 excluding the spiral recirculation groove 41 and the stator structure 20 along the radial direction of the shaft 10.

[0068] The multiple relationship between the depth H1 and the 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 shaft. Compared with the radial clearance h, an excessively large depth H1 weakens the shaft 10 to a greater extent, affecting the strength of the shaft 10 itself, while an excessively small depth H1 accommodates less lubricating medium, affecting the reverse pumping capability of the spiral reflux groove 41 for the lubricating medium.

[0069] In this embodiment, by making the depth H1 equal to 3 to 10 times the radial clearance h, for example, 3 times, 4.5 times, 6 times, 7 times, 8.8 times, 9 times or 10 times, the strength of the rotating shaft 10 itself and the reverse pumping ability of the lubricating medium can be taken into account as much as possible.

[0070] refer to Figure 2 and Figure 4 In some embodiments, the pitch P of the spiral recirculation groove 41 is 3 to 10 times the radial clearance h between the rotating shaft 10 and the stator structure 20 .

[0071] exist Figure 4 In the figure, the pitch P refers to the axial distance between two adjacent grooves of the spiral recirculation groove 41. The radial clearance h refers to the shortest distance between the part of the rotating shaft 10 excluding the spiral recirculation groove 41 and the stator structure 20 along the radial direction of the rotating shaft 10.

[0072] Compared with the radial clearance h, too small a pitch P causes more material to be removed from the shaft 10 , affecting the strength of the shaft 10 itself, while too large a pitch P causes a larger helix angle, affecting the reverse pumping capability of the spiral reflow groove 41 for the lubricating medium.

[0073] In this embodiment, by making the pitch P equal to 3 to 10 times the radial clearance h, for example, 3 times, 4.5 times, 6 times, 7 times, 8.8 times, 9 times or 10 times, the strength of the rotating shaft 10 itself and the reverse pumping ability of the lubricating medium can be taken into account as much as possible.

[0074] 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, and the pressure on the first side S1 is greater than the pressure on the second side S2; the spiral reflux groove 41 is located on the second side S2 of the sealing assembly 30 away from the second end 412 of the sealing assembly 30.

[0075] 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, without providing a reflux liquid seal structure 40, the pressure difference may cause the lubricating medium to leak from the first side S1 of the sealing assembly 30 to the second side S2.

[0076] By arranging the spiral reflux groove 41 away from the second end 412 of the sealing assembly 30 and locating it on the second side S2 of the sealing assembly 30, and arranging its first end 411 adjacent to the sealing assembly 30, the lubricating medium in the reflux liquid seal structure 40 refluxes 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.

[0077] refer to Figure 2 and Figure 3 In some embodiments, the reflux liquid seal structure 40 also includes a liquid storage portion 42, which at least partially overlaps with at least a portion of the sealing assembly 30 in the axial direction of the rotating shaft 10, and is connected to the first end portion 411, and is configured to form a liquid seal at the setting position of the sealing assembly 30.

[0078] The liquid storage portion 42 can contain a certain amount of lubricating medium so as to form a liquid seal at the location where the sealing assembly 30 is set. The first end portion 411 of the spiral reflux groove 41 is connected to the liquid storage portion 42, and the lubricating medium pumped in the spiral reflux groove 41 can flow into the liquid storage portion 42. In addition, part of the lubricating medium leaked from the sealing assembly 30 will also flow into the liquid storage portion 42.

[0079] The liquid storage portion 42 can also at least partially overlap with at least part of the sealing assembly 30 in the axial direction of the rotating shaft 10, so that with the continuous reverse pumping of the lubricating medium by the spiral reflux groove 41 and the leakage of the lubricating medium by the sealing assembly 30, the medium pressure in the liquid storage portion 42 can be increased, forming a pressure zone at the relative position of the liquid storage portion 42 and the sealing assembly 30.

[0080] 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, so that the lubricating medium no longer leaks to the second side S2 of the sealing assembly 30. This can achieve a better leakage prevention effect, further reduce the leakage rate of the sealing assembly 30, enable the shaft assembly AS to continue to operate for a longer period of time, and reduce or eliminate the pollution of the leaked lubricating medium to the environment.

[0081] refer to Figure 2-Figure 4 In some embodiments, the liquid storage portion 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, and a 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 .

[0082] exist Figure 4 In the figure, the depth H2 refers to the vertical distance from the outer surface of the rotating shaft 10 to the bottom of the annular liquid storage tank along the radial direction of the rotating shaft 10. The diameter D refers to the cross-sectional diameter of the outer peripheral surface of the rotating shaft 10 forming the annular liquid storage tank.

[0083] When designing the depth H2 of the annular liquid storage tank, factors such as the leakage of the sealing component and the pressure difference on both sides of the sealing component may be considered, and factors such as the strength of the rotating shaft 10 itself may also be considered.

[0084] In this embodiment, if the depth H2 of the annular liquid storage groove is too large relative to the diameter D of the shaft 10, the portion of the shaft 10 corresponding to the annular liquid storage groove will be weakened, thereby affecting the strength of the shaft 10. 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 made 1 / 12 or 1 / 15 of the diameter D, etc., to ensure the reliability of the shaft 10.

[0085] refer to Figure 4 In some embodiments, the liquid storage portion 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, and a depth H2 of the annular liquid storage groove along the radial direction of the rotating shaft 10 is greater than a depth H1 of the spiral reflux groove 41 .

[0086] In this embodiment, by making the radial depth H2 of the annular liquid storage groove along the rotating shaft 10 greater than the depth H1 of the spiral reflux groove 41, the capacity of the annular liquid storage groove to accommodate 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 liquid storage groove and reducing the risk of leakage.

[0087] refer to Figure 3 and Figure 4 In some embodiments, the liquid storage portion 42 includes an annular liquid storage groove arranged on the outer peripheral surface of the rotating shaft, and 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.

[0088] exist Figure 4 In the figure, the width W refers to the distance between the groove walls on both sides of the annular liquid storage groove in the axial direction of the rotating shaft 10. The diameter D refers to the cross-sectional diameter of the outer peripheral surface of the rotating shaft 10 where the annular liquid storage groove is formed.

[0089] When designing the width W of the annular liquid storage tank, factors such as the leakage of the sealing component and the pressure difference on both sides of the sealing component may be considered, and factors such as the stability of the pressure zone may also be considered.

[0090] In this embodiment, if the width W of the annular liquid storage tank is too large relative to the diameter D of the rotating shaft 10, the contact area between the lubricating medium and the rotating shaft is increased, thereby increasing the friction force, and it is difficult for the lubricating medium to form a stable static pressure in the annular liquid storage tank after being pumped. Therefore, in this embodiment, the width W can be made no greater than 1 / 10 of the diameter D, for example, the width W can be made 1 / 12 or 1 / 15 of the diameter D, etc., to improve the stability of the pressure zone.

[0091] refer to Figure 4 In some embodiments, the liquid storage portion 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, and 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.

[0092] In this embodiment, by making the radial width W of the annular liquid storage groove along the rotating shaft 10 greater than the pitch P of the spiral reflux groove 41, the capacity of the annular liquid storage groove to accommodate 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 liquid storage groove and reducing the risk of leakage.

[0093] refer to Figure 1In some embodiments, the sealing assembly 30 includes a mechanical sealing assembly. A mechanical sealing assembly refers to a device for preventing fluid leakage, which is composed of at least one pair of end faces perpendicular to the rotation axis, which are kept in contact and slide relative to each other under the action of fluid pressure and elastic force (or magnetic force) of a compensation mechanism and the cooperation of an auxiliary seal.

[0094] The mechanical seal assembly included in the seal assembly 30 has good sealing performance, can effectively reduce leakage, and can achieve a lower leakage rate or even completely prevent leakage in conjunction with the reflux liquid seal structure 40. On the other hand, for the shaft assembly AS sealed by the mechanical seal assembly, the reflux liquid seal structure 40 can further help to further improve the sealing performance of the mechanical seal assembly.

[0095] refer to Figure 1 and Figure 2 In some embodiments, the mechanical seal assembly includes: a mechanical seal static ring 31 and a mechanical seal dynamic ring 32. The mechanical seal static ring 31 is installed on the stator structure 20. The mechanical seal dynamic ring 32 is installed on the rotating shaft 10 and is sealed with the mechanical seal static ring 31.

[0096] The liquid storage portion 42 includes an annular liquid storage groove disposed on the outer peripheral surface of the rotating shaft, and the annular liquid storage groove at least partially overlaps with the matching surface MS of the mechanical seal dynamic ring 32 and the mechanical seal static ring 31 in the axial direction of the rotating shaft 10 .

[0097] The mechanical seal assembly may include one or more sets of matched mechanical seal stationary rings 31 and mechanical seal dynamic rings 32. For a mechanical seal assembly including multiple sets of matched mechanical seal stationary rings 31 and mechanical seal dynamic rings 32, the multiple sets of matched mechanical seal stationary rings 31 and mechanical seal dynamic rings 32 may be arranged in series along the axial direction.

[0098] In addition to the mechanical seal assembly including the mechanical seal stationary ring 31 and the mechanical seal dynamic 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, etc., which abuts against the axial end surface of the mechanical seal dynamic ring 32 to keep the mechanical seal dynamic ring 32 and the mechanical seal stationary ring 31 in contact at the mating surface MS.

[0099] 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 sealing between the mechanical seal static ring 31 and the stator structure 20, and the second auxiliary seal 35 can be used to achieve sealing between the mechanical seal dynamic ring 32 and the rotating shaft 10.

[0100] In this embodiment, by making the annular liquid storage groove at least partially overlap with the mating surface MS of the mechanical seal dynamic ring 32 and the mechanical seal static ring 31 in the axial direction of the rotating shaft 10, the lubricating medium leaked from the mating surface MS can directly enter the annular liquid storage groove, which helps to build up the pressure in the pressure zone more quickly and reduce the leakage of the lubricating medium.

[0101] 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 along the axial direction of the rotating shaft 10, and the cover plate 21 is used to limit the mechanical seal static ring 31 along the axial direction of the rotating shaft 10. The rotating shaft 10 is penetrated by the through hole 211, and the spiral reflow groove 41 at least partially overlaps with the through hole 211 along the axial direction of the rotating shaft 10.

[0102] exist Figure 1 In the embodiment, the shaft assembly AS is partially disposed in the housing 22, and the cover plate 21 is located on the second side S2 of the sealing assembly 30 and abuts against the mechanical seal stationary ring 31 in the axial direction to limit the mechanical seal stationary ring 31. Figure 2 In the embodiment, a gap h is formed between the through hole 211 and the rotating shaft 10 .

[0103] The relationship that the spiral reflow 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 reflow groove 41 and the axial range of the through hole 211 overlap at least partially, which can be either partial overlap or full overlap.

[0104] In this embodiment, the reflux liquid seal structure 40 and the through hole 211 are at least partially overlapped along the axial direction of the rotating shaft 10 , so that the lubricating medium in the through hole 11 can be reversely pumped to the side adjacent to the mechanical seal static ring 31 by the spiral reflux groove 41 .

[0105] In some other embodiments, the spiral reflow groove 41 may not overlap with the through hole 211 along the axial direction of the rotating shaft 10 .

[0106] refer to Figure 1 and Figure 2 In some embodiments, the cover plate 21 is provided with a drain port 212 , and the drain port 212 is connected to a second end 412 of the spiral reflux groove 41 away from the sealing assembly 30 .

[0107] The cover plate 21 may be provided with a drain port 212 to enable the lubricating medium in the through hole 211 to drain. By making the drain port 212 communicate with the second end 412 of the reflux liquid seal structure 40 away from the sealing assembly 30, the lubricating medium that is not reversely pumped in the reflux liquid seal structure 40 can be drained through the drain port 212 after pressure balance.

[0108] The various embodiments of the shaft assembly AS described above can be applied to various equipment that require lubrication and sealing for power transmission, such as refrigeration compressors, centrifugal pumps, stirrers, fans, etc.

[0109] In one aspect of the present disclosure, a screw compressor is provided, comprising a shaft assembly AS of any of the above embodiments. When the shaft assembly AS is applied to the screw compressor, the leakage of the lubricating medium (such as refrigeration oil) can be effectively reduced, so that the screw compressor can operate for a long time and reduce pollution to the environment.

[0110] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0111] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A shafting assembly (AS), characterized in that: include: Axis (10); a stator structure (20) supporting the rotating shaft (10) so that the rotating shaft (10) rotates relative to the stator structure (20); a sealing assembly (30), arranged between the rotating shaft (10) and the stator structure (20), and used to achieve sealing between the rotating shaft (10) and the stator structure (20); and A reflux liquid seal structure (40) is disposed between the rotating shaft (10) and the stator structure (20), and is configured to cause the lubricating medium located between the rotating shaft (10) and the stator structure (20) to flow back toward a side of the reflux liquid seal structure (40) adjacent to the sealing assembly (30), so as to form a liquid seal effect.

2. The shafting assembly (AS) according to claim 1, characterized in that: The reflux liquid seal structure (40) comprises: A 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 between the rotating shaft (10) and the stator structure (20) is guided by the spiral reflux groove (41) to flow back toward the first end (411) of the spiral reflux groove (41) adjacent to the sealing assembly (30).

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

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

5. The shafting assembly (AS) according to claim 2, characterized in that: The rotating shaft (10) rotates relative to the stator structure (20), and a pressure difference is formed between a first side (S1) and a 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); and the spiral reflux groove (41) is located on the second side (S2) of the sealing assembly (30) away from the second end (412) of the sealing assembly (30).

6. The shafting assembly (AS) according to any one of claims 2 to 5, characterized in that: The reflux liquid seal structure (40) further comprises: The liquid storage portion (42) overlaps with at least a portion of the sealing assembly (30) in the axial direction of the rotating shaft (10), is communicated with the first end portion (411), and is configured to form a liquid seal at the setting position of the sealing assembly (30).

7. The shafting assembly (AS) according to claim 6, characterized in that The liquid storage portion (42) comprises an annular liquid storage groove arranged on the outer peripheral surface of the rotating shaft (10), and 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 shafting assembly (AS) according to claim 7, characterized in that: 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).

9. The shafting assembly (AS) according to claim 7, characterized in that: The liquid storage portion (42) comprises an annular liquid storage groove arranged on the outer peripheral surface of the rotating shaft, and 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 shafting assembly (AS) according to claim 9, characterized in that 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).

11. The shafting assembly (AS) according to claim 6, characterized in that The sealing assembly (30) comprises a mechanical sealing assembly.

12. The shafting assembly (AS) according to claim 11, characterized in that The mechanical seal assembly comprises: A mechanical seal static ring (31) mounted on the stator structure (20); and A mechanical seal dynamic ring (32) is mounted on the rotating shaft (10) and sealably cooperates with the mechanical seal static ring (31); The liquid storage portion (42) comprises an annular liquid storage groove arranged on the outer peripheral surface of the rotating shaft, and the annular liquid storage groove at least partially overlaps with the matching surface (MS) of the mechanical seal dynamic ring (32) and the mechanical seal static ring (31) in the axial direction of the rotating shaft (10).

13. The shafting assembly (AS) according to claim 12, characterized in that The stator structure (20) comprises: A cover plate (21) having a through hole (211) extending along the axial direction of the rotating shaft (10), wherein the cover plate (21) is used to limit the position of the mechanical seal static ring (31) along the axial direction of the rotating shaft (10); The rotating shaft (10) is inserted into the through hole (211), and the spiral reflux groove (41) and the through hole (211) at least partially overlap along the axial direction of the rotating shaft (10).

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

15. A screw compressor, characterized in that: include: The shafting assembly (AS) as claimed in any one of claims 1 to 14.

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