A mechanical seal for a high-temperature oil pump

Abstract

The present invention provides a mechanical seal for a high-temperature oil pump, which includes a shaft sleeve, and a gland and a seal seat sleeved outside it. An installation ring is provided on the outer wall at one end of the shaft sleeve. A medium channel is formed between the outer peripheral wall of the installation ring and the inner wall of the first installation cavity inside the seal seat; A main seal is assembled between the first installation cavity and the installation ring. A first seal cavity is formed between the inner wall of the main seal and the outer wall of the shaft sleeve; A first isolation cavity is formed between the outer side wall of the seal seat and the inner wall of the oil pump cavity; A second isolation cavity is formed between the inner wall of the corresponding end of the shaft sleeve and the installation ring and the rotating shaft. The second isolation cavity is communicated with the first isolation cavity through the first seal cavity; Liquid inlet holes communicated with the first isolation cavity and liquid outlet holes communicated with the second isolation cavity are formed on the side wall of the gland. The mechanical seal for a high-temperature oil pump disclosed by the present invention is cooled before the high-temperature medium contacts the sealing friction surface, avoiding excessive heat generation on the main seal friction surface and ensuring stable sealing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical seals, and more particularly, to a mechanical seal for a high-temperature oil pump. Background Art

[0002] A mechanical seal is a shaft sealing device for a rotating machine. Since the rotating shaft penetrates inside and outside the equipment, there is a circumferential gap between the shaft and the equipment. The medium in the equipment leaks out through this gap. If the pressure inside the equipment is lower than the atmospheric pressure, air leaks into the equipment. Therefore, there must be a shaft sealing device to prevent leakage. There are many types of shaft seals. Due to the advantages of less leakage and long life of mechanical seals, mechanical seals are the main shaft sealing methods for these equipments.

[0003] In the existing conventional double-end mechanical seal device, in order to improve the sealing performance of the sealing surface, an isolation cavity, also called a sealing cavity, is usually provided between the inner wall of the sealing component and the outer wall of the shaft sleeve, and an isolation liquid is introduced into the sealing cavity to cool the sealing surface. However, in the high-temperature oil pump environment, due to the high temperature of the medium, the sealing surface not only needs to bear the heat generated by its own friction, but also needs to bear the high temperature from the medium. Therefore, higher requirements are put forward for the high-temperature resistance performance of the mechanical seal. Just relying on the cooling of the sealing cavity in the existing structure cannot meet the cooling requirements. On the other hand, if the heat of the sealing surface cannot be effectively cooled, a large amount of heat will be transferred to the rotating shaft, which is likely to cause the deformation of the rotating shaft and thus lead to the risk of shaft seal failure. Summary of the Invention

[0004] The problem solved by the present invention is to overcome at least one defect in the prior art, and provide a mechanical seal for a high-temperature oil pump, which is cooled before the sealing surface contacts the high-temperature medium, avoiding excessive heat generation of the main sealing surface, so as to ensure stable sealing in the high-temperature medium.

[0005] To solve the above problems, the present invention provides a mechanical seal for a high-temperature oil pump, which includes a shaft sleeve for sleeving outside a rotating shaft. An axially-connected gland and a seal seat are sleeved outside the shaft sleeve. An outwardly protruding mounting ring is provided on the radially outer wall of the shaft sleeve near one end of the seal seat. A first mounting cavity is provided inside the seal seat away from the gland. The mounting ring is rotatably received in the first mounting cavity along the circumferential direction, so that a medium channel is formed between the outer peripheral wall of the mounting ring and the inner wall of the first mounting cavity. A main seal is assembled in the first mounting cavity. One end of the main seal away from the first mounting cavity is assembled on the mounting ring. A first seal cavity is formed between the inner wall of the main seal and the outer wall of the shaft sleeve. An inwardly concave and annular first isolation groove is provided on the outer side wall of the seal seat along its axial direction. When the mechanical seal is installed in the oil pump cavity, a first isolation cavity is formed between the first isolation groove and the inner wall of the oil pump cavity. The inner wall of one end of the shaft sleeve is recessed towards the mounting ring to form a second isolation groove. A second isolation cavity is formed between the second isolation groove and the rotating shaft. And the second isolation cavity is communicated with the first isolation cavity through the first seal cavity. A liquid inlet hole communicated with the first isolation cavity and a liquid outlet hole communicated with the second isolation cavity are respectively provided on the side wall of the gland.

[0006] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0007] In the mechanical seal structure of the present invention, the gland and the seal seat structures outside the shaft sleeve are reasonably improved. A mounting ring is provided on the outer side of one end of the shaft sleeve, and the mounting ring is rotatably fitted in the inner cavity of the seal seat, so that a medium channel is formed between the outer side of the mounting ring and the inner wall of the first mounting cavity. And a first isolation cavity and a second isolation cavity are respectively provided on the inner and outer sides in the radial direction of the medium channel. By providing corresponding liquid inlet holes and liquid outlet holes on the gland, the coolant is circulated into the first isolation cavity and the second isolation cavity for cooling the medium in the medium channel, so that the high-temperature medium is fully cooled before contacting the main seal rubbing surface, reducing the heat of the main seal rubbing surface. On the other hand, a first seal cavity is also provided between the main seal and the rotating shaft, and the first seal cavity is also filled with coolant. Moreover, the first isolation cavity is communicated with the second isolation cavity through the first seal cavity, that is, only one liquid inlet hole and one liquid outlet hole need to be provided, and the structure is simple and the processing is convenient. The coolant in the first seal cavity is used to flush and cool the inner side of the main seal rubbing surface, further reducing the temperature of the main seal rubbing surface, avoiding the risk of thermal deformation or thermal cracking of the main seal ring, and improving the service life of the mechanical seal.

[0008] The sleeve is arranged in a two-piece structure between different parts, and the installation and positioning of the secondary seal can be achieved without adding additional structures. Additionally, through the setting of the skeleton oil seal, the axial blockage between the first sealing cavity and the second sealing cavity is carried out, and a corresponding cooling cavity is arranged between the inner wall of the first sleeve and the outer wall of the rotating shaft. Therefore, the main seal is sleeved outside the first sleeve and needs to bear higher pressure. Under high-pressure environments, the friction surface generates more heat. After the cooling cavity is set, the coolant in the first sealing cavity can flow through the position of the rotating shaft corresponding to the main seal at the same time to locally cool it; and the water inlet of the cooling cavity is located near the main seal. In this way, after the coolant entering from the liquid inlet hole enters the first sealing cavity, it first quickly passes through the main seal surface position for cooling, then enters the cooling cavity, and finally enters the second sealing cavity and flows out from the liquid outlet hole. The overall structure is reasonable, without complex structures, and the processing and installation are also very convenient, effectively solving the problem of local high temperature of the rotating shaft.

[0009] As an improvement, a drive seat for driving connection with the rotating shaft is sleeved outside one end of the sleeve away from the mounting ring. A second installation cavity is arranged inside one end of the gland away from the seal seat. A secondary seal is installed in the second installation cavity. One end of the secondary seal away from the gland is installed on the drive seat. A second sealing cavity is formed between the inner wall of the secondary seal and the outer wall of the sleeve, and the second sealing cavity is respectively communicated with the second isolation cavity and the liquid outlet hole; a skeleton oil seal is also installed inside one end of the seal seat near the gland, and the inner ring of the skeleton oil seal is in sealed and rotatable fit with the outer wall of the sleeve, for axially blocking the liquid flow between the first sealing cavity and the second sealing cavity. In the above improved structure, the axial blockage between the first sealing cavity and the second sealing cavity is achieved through the skeleton oil seal, so that the coolant in the first sealing cavity can only first flow into the second isolation cavity and then enter the second sealing cavity, fully ensuring that the main seal position is cooled first.

[0010] As a further improvement, an inner groove extending along its axis is opened on the inner wall of the sleeve. When the sleeve is installed outside the rotating shaft, a cooling cavity is formed between the inner groove and the outer wall of the rotating shaft, and one end of the cooling cavity is communicated with the second isolation cavity, and the other end of the cooling cavity is communicated with the second sealing cavity. In the above improved structure, an inner groove extending along its axis is opened on the inner wall of the sleeve to ensure that an effective cooling cavity is formed after it is matched with the rotating shaft, avoiding excessive frictional heat of the main seal and the secondary seal being transferred to the rotating shaft, preventing the rotating shaft from deforming, and ensuring its normal operation.

[0011] Further improved, the main seal includes a driving ring and a main stationary ring. A first mounting groove is provided at the bottom of the first mounting cavity, and one end of the main stationary ring is axially slidably fitted in the first mounting groove; one end of the mounting ring near the main stationary ring is provided with an annular second mounting groove, and one end of the driving ring is fitted in the second mounting groove, and a gap is left between the inner wall of the driving ring and the side wall of the second mounting groove; the other end of the driving ring and the other end of the main stationary ring are in circumferentially relatively rotatable abutment; a first elastic compensating member is provided between the bottom of the first mounting groove and the main stationary ring; a first channel communicating with the first mounting groove is provided on the side wall of the first isolation groove near the gland end; a second channel communicating with the second isolation cavity is provided at the bottom of the second mounting groove. In the above improved structure, a stationary ring compensation structure form is adopted. Since the main stationary ring part is stationary, that is, the first elastic compensating member is also stationary, the smooth compensation of the wear amount of the secondary seal friction surface is ensured; in addition, the positions of the first channel and the second channel can ensure that the coolant in the first isolation cavity can smoothly fill the first seal cavity and then enter the second isolation cavity again, ensuring the full cooling of the medium in the medium channel. At the same time, the coolant in the first seal cavity realizes the real-time flushing and cooling of the inner side of the main seal surface, avoiding the risk of thermal cracking of the seal ring caused by excessive heat generation of the friction pair composed of the driving ring and the main stationary ring.

[0012] Further improved, the secondary seal includes a secondary driving ring, a secondary stationary ring and a secondary stationary ring seat. An installation step is provided at one end of the driving seat near the gland, and one end of the secondary driving ring is fitted on the installation step; a third mounting groove is provided on the inner side of the gland away from the seal seat end, and one end of the secondary stationary ring seat is slidably fitted in the third mounting groove, one end of the secondary stationary ring and the other end of the secondary driving ring are in relatively rotatable abutment, and the other end of the secondary stationary ring is fitted at the other end of the secondary stationary ring seat; a second elastic compensating member is provided between the tail end of the secondary stationary ring seat and the bottom of the third mounting groove. In the above improved structure, the installation of the secondary driving ring directly borrows the driving seat, without adding a moving ring seat, which simplifies the structure, is convenient for disassembly and assembly, and reduces the cost; in addition, a stationary ring compensation structure form is adopted. Since the secondary stationary ring assembly part is stationary, that is, the second elastic compensating member is also stationary, the smooth compensation of the wear amount of the secondary seal friction surface is ensured.

[0013] Further improved, a metal sleeve ring is fitted on the outer circumferential wall of the secondary driving ring. In the above improved structure, the metal sleeve ring effectively increases the stability of the fitting structure between the secondary driving ring and the driving seat, avoiding the risk of cracking of the secondary driving ring.

[0014] Further improved, a third channel communicating with the second sealing cavity is formed in the side wall of the inner groove near one end of the driving seat, and the third channel corresponds to the sealing surface of the secondary seal in position; a fourth channel communicating with the second isolation cavity is formed in the side wall of the other end of the inner groove, and a fifth channel communicating with the liquid outlet hole is provided at the bottom of the second installation groove. In the above improved structure,

[0015] Further improved, a second installation cavity is provided inside the gland near one end of the sealing seat, and one end of the sealing seat is fitted in the second installation cavity; a plurality of connecting screws distributed circumferentially are provided on the gland, and each connecting screw is connected to the sealing seat. In the above improved structure, one end of the sealing seat is fitted in the second installation cavity of the gland and is axially connected and fixed by the connecting screws, with a simple structure and stable fitting. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the mechanical seal for high-temperature oil pump of the present invention installed on a rotating shaft;

[0017] Figure 2 is a cross-sectional view of the shaft sleeve in the present invention;

[0018] Figure 3 is Figure 1 the enlarged structure diagram at X in

[0019] Figure 4 is Figure 1 the enlarged structure diagram at Y in

[0020] Description of the Reference Numerals:

[0021] 1. Shaft sleeve; 1.1. Second isolation groove; 1.2. Inner groove; 1.3. Communication hole; 2. Gland; 2.1. Liquid inlet hole; 2.2. Liquid outlet hole; 2.3. Third installation groove; 2.4. Second installation cavity; 3. Sealing seat; 3.1. First installation cavity; 3.2. First isolation groove; 3.3. First installation groove; 3.4. First spring hole; 4. Installation ring; 4.1. Second installation groove; 5. Medium channel; 6. First sealing cavity; 7. First isolation cavity; 8. Second isolation cavity; 9. Driving seat; 9.1. Installation step; 10. Second sealing cavity; 11. Skeleton oil seal; 12. Cooling cavity; 13. Driving ring; 14. Main static ring; 14.1. First pin slot; 15. First channel; 16. Second channel; 17. Secondary driving ring; 18. Secondary static ring; 19. Secondary static ring seat; 19.1. Static ring groove; 19.2. Second spring hole; 19.3. Second pin slot; 20. Metal collar; 21. Third channel; 22. Fourth channel; 23. Fifth channel; 24. Connecting screw; 25. Set screw; 26. First spring; 27. First anti-rotation pin; 28. Second spring; 29. Second anti-rotation pin. Detailed implementation manners

[0022] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of specific embodiments of the present invention will be given with reference to the accompanying drawings.

[0023] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "external", "tail end", "outer side", "inner side", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. Additionally, in the descriptive terms, "first", "second", "third", "fourth", "fifth" are only for the convenience of distinction and understanding, without specific special or defined meanings. Among them, the tail end refers to the end away from the friction surface. For example, the tail end of the auxiliary stationary ring seat refers to the end of the auxiliary stationary ring seat away from the auxiliary stationary ring.

[0024] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0025] Such as Figure 1 、 2, as shown in FIGS. 3, the present invention provides a mechanical seal for a high-temperature oil pump, which includes a shaft sleeve 1 sleeved and fitted outside the rotating shaft, and a plurality of sealing rings are provided between the inner wall of the shaft sleeve 1 and the outer wall of the rotating shaft to achieve the sealing fit between the shaft sleeve 1 and the rotating shaft; in addition, a gland 2 and a sealing seat 3 are axially connected and sleeved outside the shaft sleeve 1, and a convex mounting ring 4 is provided on the outer radial wall of the shaft sleeve 1 near one end of the sealing seat 3. The mounting ring 4 is rotatably received in the first mounting cavity 3.1 in the circumferential direction, so that a medium channel 5 is formed between the outer peripheral wall of the mounting ring 4 and the inner wall of the first mounting cavity 3.1; a main seal is fitted inside the sealing seat 3 away from the gland 2, and the end seal of the main seal away from the sealing seat 3 is fitted on the mounting ring 4, and a gap is left between the inner wall of the main seal and the outer wall of the shaft sleeve 1 to form a first sealing cavity 6; a concave and annular first isolation groove 3.2 extending axially is provided on the outer side wall of the sealing seat 3. When the mechanical seal is installed in the oil pump cavity, a first isolation cavity 7 is formed between the first isolation groove 3.2 and the inner wall of the oil pump cavity; the inner wall of the shaft sleeve 1 corresponding to one end of the mounting ring 4 is recessed inwardly toward the outside of the mounting ring 4 to form an annular second isolation groove 1.2, so that a second isolation cavity 8 is formed between the second isolation groove 1.2 and the rotating shaft, and the second isolation cavity 8 is communicated with the first isolation cavity 7 through the first sealing cavity 6, as Figure 1 shown, the first isolation cavity 7 and the second isolation cavity 8 are respectively located on the inner and outer sides of the medium channel 5; on the other hand, a liquid inlet hole 2.1 communicated with the first isolation cavity 7 and a liquid outlet hole 2.2 communicated with the second isolation cavity 8 are respectively opened on the side wall of the gland 2. That is, during the installation and operation of the mechanical seal, the coolant is introduced from the liquid inlet hole 2.1, and the coolant sequentially enters the first isolation cavity 7, the first sealing cavity 6, and the second isolation cavity 8 and then is discharged from the liquid outlet hole 2.2. By circulating the coolant, the first isolation cavity 7, the second isolation cavity 8, and the first sealing cavity 6 are filled with the coolant, which is used to cool the medium channel 5 and the main seal in real time. That is, in the working condition of the high-temperature oil pump, the high-temperature medium is fully cooled before contacting the main seal, effectively reducing the frictional heat of the main seal; in addition, the coolant in the first sealing cavity 6 can also flush and cool the inner side of the main seal in real time, further ensuring that the main seal does not generate too much heat, avoiding the risk of thermal deformation or even thermal cracking of the sealing ring of the main seal, effectively ensuring the sealing performance of the main seal, and improving the service life.

[0026] On the other hand, in this embodiment, a drive seat 9 for driving connection with the rotating shaft is also sleeved on the outer side of the end of the bushing 1 away from the mounting ring 4. A secondary seal is fitted on the inner side of the end of the gland 2 away from the seal seat 3, and the end of the secondary seal away from the gland 2 is sealingly fitted on the drive seat 9. Specifically, in this structure, a plurality of set screws 25 extending radially are provided on the circumferential outer wall of the drive seat 9, and a plurality of communication holes 1.3 are correspondingly formed in the side wall of one end of the bushing 1. The inner ends of the set screws 25 pass through the corresponding communication holes 1.3 and are tightly fitted on the rotating shaft to realize the driving connection between the bushing 1 and the rotating shaft. And in this structure, the drive seat 9 also serves to mount the secondary seal, simplifying the mechanical seal structure and reducing the processing cost. Similarly, as Figure 1 shown, a second seal cavity 10 is formed between the inner wall of the secondary seal and the outer wall of the bushing 1, and the second seal cavity 10 is respectively communicated with the second isolation cavity 8 and the liquid outlet hole 2.2. That is, the coolant introduced from the liquid inlet hole 2.1 enters the second seal cavity 10 again after passing through the first isolation cavity 7, the first seal cavity 6, and the second isolation cavity 8 in sequence, for real-time flushing and cooling of the secondary seal, timely taking away the frictional heat of the secondary seal, better ensuring the sealing performance of the secondary seal, and extending its service life.

[0027] In addition, since the main seal in this embodiment is directly in contact with the high-temperature medium, it needs to be flushed and cooled in real time first. As Figure 1 shown, the first seal cavity 6 and the second seal cavity 10 are axially communicated. That is, in addition to entering the second isolation cavity 8, a large part of the coolant entering the first seal cavity 6 from the first isolation cavity 7 will enter the second seal cavity 10 along the outside of the bushing 1. Therefore, in this embodiment, a skeleton oil seal 11 is fitted on the inner side of the end of the seal seat 3 close to the gland 2, and the inner ring of the skeleton oil seal 11 is sealingly and rotatably fitted with the outer wall of the bushing 1. The skeleton oil seal 11 is used to axially block the liquid flow between the first seal cavity 6 and the second seal cavity 10, that is, the coolant in the first isolation cavity 7 can only flow into the second isolation cavity 8 along the first seal cavity 6 first, and then enter the second seal cavity 10, fully ensuring that the main seal position is cooled first.

[0028] More specifically, in this embodiment, an inner groove 1.2 extending along its axis is formed on the inner wall of the bushing 1. When the bushing 1 is installed outside the rotating shaft, a cooling cavity 12 is formed between the inner groove 1.2 and the outer wall of the rotating shaft, and one end of the cooling cavity 12 is communicated with the second isolation cavity 8, and the other end of the cooling cavity 12 is communicated with the second seal cavity 10. Since in a high-temperature medium environment, more heat is easily generated on the sealing friction surface, and the heat will be transmitted to the rotating shaft at the same time. If the temperature of the rotating shaft is too high, there is a risk of deformation, which will affect the performance of the rotating shaft. In this embodiment, a cooling cavity 12 is added, so that the coolant can enter the cooling cavity 12 to realize the cooling and temperature reduction of the rotating shaft, better ensuring the stable operation of the rotating shaft.

[0029] The main seal includes a driving ring 13 and a main stationary ring 14. A first installation groove 3.3 is provided at the bottom of the first installation cavity 3.1. One end of the main stationary ring 14 is axially slidably fitted in the first installation groove 3.3; an annular second installation groove 4.1 is provided at one end of the installation ring 4 close to the main stationary ring 14. One end of the driving ring 13 is fitted in the second installation groove 4.1. A sealing ring is fitted between the outer wall of one end of the driving ring 13 and the side wall of the second installation groove 4.1 to achieve a sealing fit; the other end of the driving ring 13 is in circumferentially relatively rotatable abutment with the other end of the main stationary ring 14 to form a main seal friction pair; in addition, a gap is left between the inner wall of the driving ring 13 and the side wall of the second installation groove 4.1, through which coolant can enter to increase the cooling area of the driving ring 13 and improve the cooling efficiency; in this structure, further, a first channel 15 communicating with the first installation groove 3.3 is provided on the side wall of the first isolation groove 3.2 close to the gland 2; a second channel 16 communicating with the second isolation cavity 8 is provided at the bottom of the second installation groove 4.1.

[0030] On the other hand, a first elastic compensation member is provided between the bottom of the first installation groove 3.3 and the main stationary ring 14 in the above structure, that is, the main seal is a stationary ring compensation type structure. After the end faces of the driving ring 13 or the main stationary ring 14 are worn, under the action of the first elastic compensation member at the tail end of the main stationary ring 14, the main stationary ring 14 is always driven to have a tendency to move towards the driving ring 13, ensuring that the sealing surfaces always fit and are not easily leaked. More specifically, as Figure 4 shown, in this structure, the first elastic compensation member includes a plurality of first springs 26. A plurality of first spring holes 3.4 distributed circumferentially are provided at the bottom of the first installation groove 3.3. One end of each first spring 26 is fitted in the corresponding first spring hole 3.4 and the end abuts against the bottom of the first spring hole 3.4. The other ends of the first springs 26 respectively abut against the tail end of the main stationary ring 14; and at least one first anti-rotation pin 27 is further provided at the bottom of the first installation groove 3.3, and a first pin slot 14.1 cooperating with the first anti-rotation pin 27 is provided at the tail end of the main stationary ring 14. A plurality of first springs 26 are used for axial compensation of the wear of the main sealing surface, and the structure is simple, and the compensation force is uniform and stable.

[0031] Additionally, in this embodiment, the secondary seal includes a secondary moving ring 17, a secondary stationary ring 18, and a secondary stationary ring seat 18. One end of the drive seat 9 near the gland 2 is provided with a mounting step 9.1. One end of the secondary moving ring 17 is fitted on the mounting step 9.1. A metal collar 20 is fitted on the outer circumferential wall of the secondary moving ring 17 to further ensure the structural strength of the secondary moving ring 17. Inside the gland 2 at the end away from the seal seat 3, there is a third mounting groove 2.3. One end of the secondary stationary ring seat 18 is slidably fitted in the third mounting groove 2.3. One end of the secondary stationary ring 18 abuts against the other end of the secondary moving ring 17 in a relatively rotatable manner to form a secondary seal friction pair. The other end of the secondary stationary ring 18 is fitted on the other end of the secondary stationary ring seat 18. Specifically, a stationary ring groove 19.1 is provided at the end of the secondary stationary ring seat 18 away from the third mounting groove 2.3. The end of the secondary stationary ring 18 away from the secondary moving ring 17 is fitted in the stationary ring groove 19.1. Additionally, a second elastic compensating member is provided between the tail end of the secondary stationary ring seat 18 and the bottom of the second mounting groove 4.1. In this structure, the secondary seal also adopts a stationary ring compensation structure. Specifically, as Figure 3 shown, the second elastic compensating member includes a plurality of second springs 28. A plurality of second spring holes 19.2 distributed circumferentially are provided at the tail end of the secondary stationary ring seat 18. One end of each second spring 28 is fitted in the corresponding second spring hole 19.2 and the end abuts against the bottom of the second spring hole 19.2. The other ends of the second springs 28 respectively abut against the bottom of the third mounting groove 2.3. And at least one second anti-rotation pin 29 is further provided at the bottom of the third mounting groove 2.3. A second pin groove 19.3 cooperating with the second anti-rotation pin 29 is provided at the tail end of the main stationary ring 14 seat. A plurality of second springs 28 are used for axially compensating the wear of the secondary seal surface, with a simple structure, uniform and stable compensating force.

[0032] In the above structure, a third channel 21 communicating with the second sealing cavity 10 is provided on the side wall of the inner groove 1.2 near one end of the drive seat 9, and the third channel 21 corresponds to the position of the seal surface of the secondary seal to improve the flushing and cooling effect. A fourth channel 22 communicating with the second isolation cavity 8 is provided on the side wall of the other end of the inner groove 1.2. A fifth channel 23 communicating with the liquid outlet hole 2.2 is provided at the bottom of the third mounting groove 2.3.

[0033] In this embodiment, a second installation cavity 2.4 is provided inside the gland 2 near one end of the seal seat 3. One end of the seal seat 3 is fitted in the second installation cavity 2.4. A plurality of connecting screws 24 distributed circumferentially are provided on the gland 2. Each connecting screw 24 is connected to the seal seat 3 to achieve the axial connection between the gland 2 and the seal seat 3, with a simple structure and convenient disassembly and assembly.

[0034] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. A mechanical seal for a high-temperature oil pump, characterized in that: It includes a bushing (1) sleeved outside the rotating shaft. An axially connected gland (2) and a seal seat (3) are sleeved outside the bushing (1). An outwardly convex mounting ring (4) is provided on the radial outer wall of the bushing (1) near one end of the seal seat (3). A first mounting cavity (3.1) is provided inside the seal seat (3) away from the gland (2). The mounting ring (4) is rotatably received in the first mounting cavity (3.1) along the circumferential direction, so that a medium channel (5) is formed between the outer peripheral wall of the mounting ring (4) and the inner wall of the first mounting cavity (3.1); A main seal is installed in the first mounting cavity (3.1). One end of the main seal away from the seal seat (3) is installed on the mounting ring (4). A first seal cavity (6) is formed between the inner wall of the main seal and the outer wall of the bushing (1); An inwardly concave and annular first isolation groove (3.2) is provided on the outer side wall of the seal seat (3) extending along its axis. When the mechanical seal is installed in the oil pump cavity, a first isolation cavity (7) is formed between the first isolation groove (3.2) and the inner wall of the oil pump cavity; The inner wall of one end of the bushing (1) is recessed towards the mounting ring (4) to form a second isolation groove (1.1). A second isolation cavity (8) is formed between the second isolation groove (1.1) and the rotating shaft, and the second isolation cavity (8) is communicated with the first isolation cavity (7) through the first seal cavity (6); Liquid inlet holes (2.1) communicated with the first isolation cavity (7) and liquid outlet holes (2.2) communicated with the second isolation cavity (8) are respectively provided on the side wall of the gland (2).

2. The mechanical seal for high-temperature oil pump according to claim 1, characterized in that: A drive seat (9) for driving connection with the rotating shaft is sleeved outside one end of the bushing (1) away from the mounting ring (4). A sub-seal is installed inside one end of the gland (2) away from the seal seat (3). One end of the sub-seal away from the gland (2) is installed on the drive seat (9). A second seal cavity (10) is formed between the inner wall of the sub-seal and the outer wall of the bushing (1), and the second seal cavity (10) is communicated with the second isolation cavity (8) and the liquid outlet holes (2.2) respectively; A skeleton oil seal (11) is also installed inside the seal seat (3) near one end of the gland (2), and the inner ring of the skeleton oil seal (11) is in sealed and rotatable fit with the outer wall of the bushing (1) to axially block the liquid flow between the first seal cavity (6) and the second seal cavity (10).

3. The mechanical seal for high-temperature oil pump according to claim 2, wherein: An inner groove (1.2) extending along its axis is provided on the inner wall of the bushing (1). When the bushing (1) is installed outside the rotating shaft, a cooling cavity (12) is formed between the inner groove (1.2) and the outer wall of the rotating shaft, and one end of the cooling cavity (12) is communicated with the second isolation cavity (8), and the other end of the cooling cavity (12) is communicated with the second seal cavity (10).

4. The mechanical seal for high-temperature oil pump according to claim 1 or 2, characterized in that: The main seal includes a driving ring (13) and a main static ring (14). A first mounting groove (3.3) is provided at the bottom of the first mounting cavity (3.1). One end of the main static ring (14) is axially slidably fitted in the first mounting groove (3.3). One end of the mounting ring (4) near the main static ring (14) is provided with an annular second mounting groove (4.1). One end of the driving ring (13) is fitted in the second mounting groove (4.1), and there is a gap between the inner wall of the driving ring (13) and the side wall of the second mounting groove (4.1). The other end of the driving ring (13) is in circumferentially relatively rotatable abutment with the other end of the main static ring (14). A first elastic compensating member is provided between the bottom of the first mounting groove (3.3) and the main static ring (14). A first channel (15) communicating with the first mounting groove (3.3) is provided on the side wall of the first isolation groove (3.2) near one end of the gland (2). A second channel (16) communicating with the second isolation cavity (8) is provided at the bottom of the second mounting groove (4.1).

5. The mechanical seal for high-temperature oil pump according to claim 3, characterized in that: The auxiliary seal includes an auxiliary driving ring (17), an auxiliary static ring (18) and an auxiliary static ring seat (19). One end of the driving seat (9) near the gland (2) is provided with a mounting step (9.1). One end of the auxiliary driving ring (17) is fitted on the mounting step (9.1). The inner side of one end of the gland (2) away from the seal seat (3) is provided with a third mounting groove (2.3). One end of the auxiliary static ring seat (19) is slidably fitted in the third mounting groove (2.3). One end of the auxiliary static ring (18) is in relatively rotatable abutment with the other end of the auxiliary driving ring (17). The other end of the auxiliary static ring (18) is fitted at the other end of the auxiliary static ring seat (19). A second elastic compensating member is provided between the tail end of the auxiliary static ring seat (19) and the bottom of the third mounting groove (2.3).

6. The mechanical seal for high-temperature oil pump according to claim 5, wherein: A metal collar (20) is fitted on the outer circumferential wall of the auxiliary driving ring (17).

7. The mechanical seal for a high-temperature oil pump according to claim 5, characterized in that: A third channel (21) communicating with the second sealing cavity (10) is provided on the side wall of the inner groove (1.2) near one end of the driving seat (9), and the third channel (21) corresponds to the sealing surface position of the auxiliary seal. A fourth channel (22) communicating with the second isolation cavity (8) is provided on the side wall of the other end of the inner groove (1.2). A fifth channel (23) communicating with the liquid outlet hole (2.2) is provided at the bottom of the third mounting groove (2.3).

8. The mechanical seal for high-temperature oil pump according to claim 1, characterized in that: The inner side of one end of the gland (2) near the seal seat (3) is provided with a second mounting cavity (2.4). One end of the seal seat (3) is fitted in the second mounting cavity (2.4). The gland (2) is provided with a plurality of connecting screws (24) distributed circumferentially, and each connecting screw (24) is connected to the seal seat (3).

Images