TW201309945A - Cartridge-type shaft-seal resistant to counter-pressure - Google Patents

Abstract

A cartridge-type shaft-seal resistant to counter-pressure is disclosed, which is to be installed in a mechanical equipment chamber. The cartridge-type shaft-seal resistant to counter-pressure consists of a closing cover unit mounted on the mechanical equipment chamber and having an accommodating room, a first sealing unit disposed on the closing cover unit, and a sleeve unit penetrating the closing cover unit and the first sealing unit. When the pressure of the accommodating room is greater than the side pressure of the process, the first auxiliary seal ring of the first sealing unit will be abutting the first flange of the sleeve unit, the first flange can support the first auxiliary seal ring and prevent the first auxiliary seal ring from being damaged by clamping of the first rotating ring or the first compression ring, when the first auxiliary seal ring closely adheres to the first flange, it is also possible to use the first auxiliary seal ring to accumulate pressure in order to balance the pressure undertaken by the first seal mechanism of the first sealing unit to achieve a superior adhesion effect.

Description

Card type anti-back pressure shaft seal

The invention relates to a shaft seal, in particular to a cassette type back pressure resistant shaft seal.

The shaft seal is a device that is installed in the gap between the cavity of the rotating mechanical device and the rotating mandrel to avoid leakage of fluid or gas in the rotating mechanical device from the gap.

Referring to Figure 1, the new patent specification of the Republic of China Announcement No. 592261 "Shaft Sealing Ring and Its Compression Fixing Guide" discloses a shaft seal 1 for a shaft 100 to be inserted. The shaft seal 1 includes a shaft sealing chamber. A body 11 of the 111, a sleeve 12 disposed on the body 11, and a leakage preventing unit 13 disposed between the sleeve 12 and the body 11, wherein the shaft 100 is inserted into the sleeve 12.

The sleeve 12 has an end cap 121 , a sleeve 122 extending outwardly from the end cap 121 and penetrating the body 11 , and a limiting ring opposite to the end cap 121 and combining the sleeve 122 and the rotating shaft 100 123.

The leakage preventing unit 13 includes a fixing ring 131 fixed to the body 11 and surrounding the sleeve 122, and a guiding member 132 spaced apart from the fixing ring 131. The two ends are respectively pushed against the fixing ring 131 and the guiding member. A spring 133 of 132 (only one of which is shown in the viewing angle view), a fixed friction ring 134 pushed by the guide 132, a rotational friction disposed in the end cover 121 and rotatable with the end cover 121 a ring 135, a first sealing ring 136 disposed between the body 11 and the fixed friction ring 134, a second sealing ring 137 disposed between the end cap 121 and the rotating friction ring 135, and a second sealing ring 137 disposed on the ring A third sealing ring 138 between the sleeve 122 and the rotating shaft 100.

The design in which the guide member 132 is fitted to the fixing ring 131 and the fixed friction ring 134 ensures that the fixed friction ring 134 can only move in the axial direction of the rotating shaft 100 to be elastic by the spring 133. The restoring force causes the fixed friction ring 134 to abut against the rotating friction ring 135 to improve the leakage prevention effect. However, when the fluid pressure of the shaft sealing chamber 111 is greater than the pressure of the process side 102, the first sealing ring 136 may be caused. Advancing toward the process side 102, and the accumulation pressure cannot be generated for the fixed friction ring 134, so that the fixed friction ring 134 and the rotating friction ring 135 are excessively rubbed to cause the seal to fail. In severe cases, the fixed friction ring 134 is more likely to be The guide 132 is disengaged resulting in structural damage.

Referring to FIG. 2, the Republic of China Announcement No. M375797 "Cartridge Double Shaft Seal" utilizes the second leakage preventing unit 14 to cooperate with the leakage preventing unit 13 to enhance the leakage preventing effect, but when the pressure of the shaft sealing chamber 111 is greater than the manufacturing process When the pressure of the side 102 is normal, the second stationary ring 141, the second leak-proof washer 142 and the washer 143 of the second leakage preventing unit 14 are still pushed toward the process side 102, so that the second leak-proof gasket 142 is easily pinched. At the same time, the first leak-proof gasket 145 and the gasket 146 are also easily squeezed and pinched by the sleeve 12 or the inner rotating ring 144. In addition, when the second stationary ring 141 is excessively moved toward the process side 102, the second stationary ring 141 and the inner rotating ring 144 are excessively worn to cause dry running, resulting in failure of sealing.

Accordingly, it is an object of the present invention to provide a cartridge-type back pressure resistant shaft seal that is structurally stable and has a long service life.

Therefore, the cartridge type back pressure resistant shaft seal of the present invention is mounted on a mechanical device cavity, and the mechanical device cavity includes an outer wall separating a process side and an atmosphere side. The cartridge type back pressure resistant shaft seal comprises a capping unit disposed on the outer wall, a first sealing unit disposed on the capping unit, and a shaft penetrating the capping unit and the first sealing unit Set of units.

The capping unit includes a gland disposed on the outer wall and on the atmospheric side and having a chamber; the first sealing unit includes a first portion disposed in the gland and having a first auxiliary seal a sealing mechanism, a first retaining ring spaced apart from the first sealing mechanism, and at least one of the two ends respectively pushing the first sealing member and the first elastic member of the first retaining ring, wherein the first sealing mechanism Having a first stationary ring disposed on the gland, a first rotating ring pushed against the first stationary ring, and a first rotating ring and the first elastic member being a first compression ring pushed by the first elastic element.

The sleeve unit includes a sleeve extending through the first retaining ring and the first sealing mechanism, a ring disposed on the outer peripheral surface of the sleeve and located between the first compression ring and the first auxiliary sealing ring a first flange capable of pushing against the first auxiliary sealing ring, and a shaft sealing ring disposed on the inner circumferential surface of the sleeve, wherein the first auxiliary sealing ring and the first stationary ring of the first sealing mechanism And the first rotating ring is circumferentially disposed on an outer circumferential surface of the sleeve.

The invention has the beneficial effects that when the pressure is greater than the process side of the chamber to prevent the toxic and volatile process fluid from overflowing to the chamber, or even volatilized to the atmosphere side, the first auxiliary seal can be used for accumulating pressure. To balance the pressure of the first sealing mechanism of the first sealing unit, to achieve a superior sealing effect and increase the service life, and cooperate with the first flange to support the first auxiliary sealing ring, the first flange can limit the first compression The movable space of the ring prevents the first auxiliary sealing ring from being pinched by the remaining members when moving to the process side.

The foregoing and other objects, features, and advantages of the invention will be apparent from the

Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to FIG. 3, a first preferred embodiment of the cartridge type back pressure resistant shaft seal 2 of the present invention is mounted on a mechanical device cavity 200. The mechanical device cavity 200 includes a zone separated from a process side A and An outer wall 201 of the atmospheric side B and a rotating shaft 202 rotatably disposed through the outer wall 201.

The cartridge type back pressure resistant shaft seal 2 includes a capping unit 3 disposed on the outer wall 201 of the mechanical device cavity 200, a first sealing unit 4 disposed on the capping unit 3, and a penetrating member The capping unit 3 and the sleeve unit 5 in the first sealing unit 4. The shaft 202 extends through the sleeve unit 5.

The cover unit 3 includes a gland 31 disposed on the outer wall 201 and located on the atmosphere side B, a flushing hole 32 and a second blocking hole 38 respectively formed on the gland 31, and a cover An inner seal 33 between the gland 31 and the outer wall 201 forms a chamber 310.

The first sealing unit 4 includes a first sealing mechanism 41 disposed on the gland 31 and having a first auxiliary sealing ring 411. The first sealing mechanism 41 is spaced apart from the first sealing mechanism 41 and disposed on the sleeve unit 5. The first retaining ring 42 and the plurality of ends respectively push the first sealing member 41 and the first elastic member 43 of the first retaining ring 42 (only one of them is in view), and a A first seal ring 44 between the gland 31 and the first sealing mechanism 41. The rinsing hole 32 faces the first sealing mechanism 41 and communicates with the process side A and the atmosphere side B to draw process liquid (not shown) in the process side A.

The first sealing mechanism 41 further has a first stationary ring 412 disposed on the gland 31, a first rotating ring 413 pushed against the first stationary ring 412, and a first rotating ring 413. a first compression ring 414 pushed between the first elastic member 43 and pushed by the first elastic member 43 , and a first retaining ring 42 disposed on the first retaining ring 42 to limit the range of movement of the first rotating ring 413 The first snap ring 415.

The sleeve unit 5 includes a sleeve 51 extending through the first retaining ring 42 and the first sealing mechanism 41. The sleeve 51 is disposed on the outer peripheral surface of the sleeve 51 and can be pushed against the first auxiliary sealing ring 411. a first flange 52, a shaft seal ring 53 disposed on the inner circumferential surface of the sleeve 51, and a drive cover 54 disposed on the one end of the sleeve 51 opposite to the first retaining ring 42 and located on the atmospheric side B An outer joint 55 extending through the drive cover 54 to engage the drive cover 54 and the sleeve 51, and a bushing 57 disposed on the atmosphere side B between the cover 31 and the sleeve 51. The shaft seal 53 is located between the shaft sleeve 51 and the first flange 52 between the first compression ring 414 and the first auxiliary seal ring 411 to push the first Auxiliary seal ring 411.

In the preferred embodiment, the sleeve 51 extends through the first retaining ring 42, the first stationary ring 412 and the first rotating ring 413, and the outer coupling member 55 is a bolt.

The first sealing unit 4 further includes a first coupling member 45 extending through the first retaining ring 42 to lock the first retaining ring 42 and the sleeve 51, and the first stationary ring 412 and the first rotating ring The first auxiliary sealing ring 413 and the first auxiliary sealing ring 411 are circumferentially disposed on the sleeve 51. In the preferred embodiment, the first coupling member 45 is also a bolt.

When the pressure of the chamber 310 is greater than the pressure of the process side A, the first auxiliary sealing ring 411 of the first sealing unit 4 abuts against the first flange 52 of the sleeve unit 5, and the first flange 52 can Pushing the first auxiliary sealing ring 411 to prevent the first auxiliary sealing ring 411 from continuously moving toward the first compression ring 414, limiting the movable space of the first compression ring 414, and avoiding the first auxiliary sealing ring 411 at the first The compression ring 414 is pinched when it is active; the first auxiliary sealing ring 411 can be used to reverse the pressure accumulation and the first rotating ring 413 is reversely pushed to balance the pressure of the first sealing mechanism 41 to avoid the first stationary ring 412 and The first rotating ring 413 generates dry running and excessive wear, achieving superior sealing effect and increasing service life. In addition, by injecting high-pressure vapor from the lower sealing hole 38 in FIG. 3, impurities and crystals in the chamber 310 can be flushed out from another blocking hole 38 (indicated by a broken line) in FIG. 3, and part of the vapor will be The gap between the bushing 57 and the sleeve 51 flows out to avoid affecting the sealing stability of the first rotating ring 413 and the first stationary ring 412, and also prevents impurities from being blocked between the first auxiliary sealing ring 411 and the first rotating ring 413. . Of course, the cartridge type back pressure resistant shaft seal 2 is also required to be made according to the actual application, and as shown in FIG. 4, it is not necessary to form the sealing hole 38 and the bushing 57, and the superior density can still be achieved. Combine the effect and increase the service life, but only for the process that is used in a purer and less impurity-free process.

Referring to FIG. 5, the second preferred embodiment of the cartridge type back pressure resistant shaft seal 2 of the present invention is substantially the same as the first preferred embodiment. The difference is that the first retaining ring 42 has an outer peripheral surface formed thereon. The conveying groove 421, and the capping unit 3 is formed with two flushing holes 32. The first retaining ring 42 can rotate with the sleeve 51, and the process liquid of the process side A can be used to design the process liquid of the process side A (Fig. Shown from one of the flushing holes 32, and then input by another flushing hole 32, providing a way of heat dissipation cycle of the process liquid, dedicated to high temperature process.

Referring to Figure 6, a third preferred embodiment of the cartridge type back pressure resistant shaft seal 2 of the present invention is mounted on the same mechanical device cavity 200 as the first preferred embodiment, and the cassette type back pressure resistant shaft seal 2 includes a cover unit 3, a first sealing unit 4 disposed on the cover unit 3, a second sealing unit 6 spaced apart from the first sealing unit 4, and a cover unit 3 extending through the cover unit 3 The first sealing unit 4 and the sleeve unit 5 of the second sealing unit 6.

The cover unit 3 includes a gland 31 disposed on the outer wall 201 and located on the atmospheric side B, and a flushing hole 32 formed on the gland 31 to flush the first sealing mechanism 41. An inner gland 33 between the gland 31 and the outer wall 201, an outer gland 34 disposed on the gland 31, and a gland 31 and the outer gland 34 are disposed. An outer gland seal 35, and an inflow hole 36 and a first-class outlet hole 37 formed on the outer gland cover 34 are spaced apart. The gland 31 is formed with a chamber 310.

The first sealing unit 4 includes a first sealing mechanism 41 disposed on the gland 31 and having a first auxiliary sealing ring 411, a first retaining ring 42 spaced apart from the first sealing mechanism 41, and a plurality of The first elastic member 43 of the first sealing mechanism 41 and the first retaining ring 42 and the first sealing ring 44 disposed between the gland 31 and the first sealing mechanism 41 are respectively pushed up at both ends.

The first sealing mechanism 41 further has a first stationary ring 412 disposed in the gland 31, a first rotating ring 413 pushed against the first stationary ring 412, and a first rotating ring 413. a first compression ring 414 pushed by the first elastic element 43 between the first elastic element 43 and a first compression ring 414 disposed on the first retaining ring 42 to limit the range of movement of the first rotating ring 413 A first snap ring 415 and a second snap ring 416 disposed on the gland 31 to engage the first stationary ring 412.

The second sealing unit 6 includes a second sealing mechanism 61 disposed on the outer gland 34 and having a second auxiliary sealing ring 611. The second sealing mechanism 61 is spaced apart from the second sealing mechanism 61 and has a conveying groove formed on the outer peripheral surface. a second retaining ring 62 of the 621, a plurality of second elastic members 63 for pushing the second sealing mechanism 61 and the second retaining ring 62, and a second sealing member disposed on the outer gland cover 34 and the second sealing mechanism A second sealing ring 64 between 61. In the preferred embodiment, the conveying groove 621 is a linear conveying groove 621 extending in the axial direction. Of course, in practical applications, the conveying groove 621 may be more than one, and may also be a spiral groove.

The second sealing mechanism 61 further has a second stationary ring 612 disposed on the outer gland 34, a second rotating ring 613 pushed against the second stationary ring 612, and a second rotating ring. a second compression ring 614 pushed between the second elastic member 63 and the second elastic member 63, and a second retaining ring 62 disposed on the second retaining ring 62 to limit the second rotating ring 613 The third snap ring 615. The second auxiliary sealing ring 611 is located between the second compression ring 614 and the second rotating ring 613.

The sleeve unit 5 includes a sleeve 51 extending through the first retaining ring 42, the first sealing mechanism 41, the second retaining ring 62 and the second sealing mechanism 61, and a ring is disposed on the outer peripheral surface of the sleeve 51. a first flange 52 that can be pushed against the first auxiliary seal ring 411, a shaft seal ring 53 disposed on the inner circumferential surface of the sleeve 51, and a bushing 51 disposed opposite to the first retaining ring 42 a driving cover 54 at one end of the atmosphere side B, an outer coupling member 55 extending through the driving cover 54 to engage the driving cover 54 and the sleeve 51, and a ring disposed on the outer circumferential surface of the sleeve 51 and pushing the positioning The second flange 56 of the second retaining ring 62. The first flange 52 is located between the first compression ring 414 and the first auxiliary sealing ring 411.

The first sealing unit 4 further includes a first coupling member 45 extending through the first retaining ring 42 to lock the first retaining ring 42 and the sleeve 51, and the second sealing unit 6 further includes a radial through hole. The second retaining ring 62 locks the second retaining ring 62 and the second coupling member 65 of the sleeve 51. The first auxiliary sealing ring 411 and the second auxiliary sealing ring 611 are circumferentially spaced apart from each other on the outer circumferential surface of the sleeve 51.

Since the preferred embodiment is substantially the same as the first preferred embodiment, the preferred embodiment has the same effect as the first preferred embodiment, and the pressure of the chamber 310 is greater than the process. When the pressure of the side A is pressed, the first auxiliary sealing ring 411 of the first sealing unit 4 abuts against the first flange 52 of the sleeve unit 5, and the first flange 52 can be pushed against the first auxiliary sealing ring 411. Preventing the first auxiliary sealing ring 411 from continuously moving toward the first compression ring 414 and restricting the 414 active space to prevent the first auxiliary sealing ring 411 from being pinched when the first compression ring 414 is active; The auxiliary sealing ring 411 and the space of the first rotating ring 413 generate back anti-accumulation pressure and push back the first rotating ring 413 to balance the pressure of the first sealing mechanism 41 to avoid the first stationary ring 412 and the first rotating ring 413. The dry running is excessively worn to achieve a superior sealing effect and the service life is increased, and the second auxiliary sealing ring 611 moves toward the driving cover 54 together with the second rotating ring 613, and the second compression ring 614 is separated and thus will not be pinched.

The design of the first sealing unit 4 and the second sealing unit 6 (double-sealed design) having the spacing between the first sealing unit 4 and the second sealing unit 6 can be introduced into the insulating fluid or the pressurized insulating fluid (not shown) from the inflow hole 36, and then guided to isolate The fluid or pressurized insulating fluid flows out from the outflow hole 37, which not only can enhance the cooling circulation effect, but also can effectively isolate the toxic substances which may be generated on the process side A from oozing out to the chamber 310 at the same time, so that it can be applied to The process liquid is a volatile substance (VOC), or a process that is toxic, corrosive, etc., or a process that requires cooling at a high temperature.

Referring to FIG. 7, a fourth preferred embodiment of the cartridge type back pressure resistant shaft seal 2 of the present invention substantially comprises a cover unit 3, a first sealing unit 4, and a sleeve unit 5 in the same manner as the third preferred embodiment. And a second sealing unit 6, the difference is that the sleeve unit 5 further includes a bushing disposed on the outer gland 34 and located between the outer gland 34 and the bushing 51. 57. The capping unit 3 further includes a sealing hole 38 formed on the outer gland 34 and communicating with the atmosphere side B, and the conveying groove 621 is in the form of a spiral conveying groove.

When the shaft seal is disposed in a low temperature or ice-prone environment, the process liquid needs to be insulated, and the heat-sealing or steam can be introduced and discharged by the sealing hole 38 to heat the process liquid, and the bushing 57 can block part of the process. The hot water or steam introduced into the sealing hole 38 is leaked between the sleeve 51 and the bushing 57. If the process liquid is a liquid which is likely to cause crystallization, hot water or steam introduced from the sealing hole 38 prevents crystals from adhering to the sleeve 51 and the second sealing unit 6, thereby prolonging the service life.

In summary, the card type back pressure resistant shaft seal 2 of the present invention utilizes the first sealing member 41 disposed on the gland 31, respectively, at both ends of the first elastic member 43 and is disposed at The first retaining ring 42 on the outer circumferential surface of the sleeve 51 can not only reduce the number of components, but also simplify the design and reduce the manufacturing cost. In operation, the gland seal 44, the shaft seal ring 53 and the first auxiliary seal ring 411 can be avoided. The process fluid leaks from the gap and absorbs the axial pressure by the elastic deformation of the first elastic member 43 while simultaneously abutting the first sealing mechanism 41 and the first retaining ring by the elastic restoring force of the first elastic member 43 42, improve the leakage prevention effect and increase the service life. In addition, when the pressure of the chamber 310 is greater than the pressure of the process side A, the first auxiliary seal ring 411 moves toward the process side A and abuts against the first flange 52, and the second auxiliary seal ring 611 moves toward the atmosphere side B. The first compression unit 414 can be prevented from being damaged by pinching, and the first sealing unit 4 and the second sealing unit 6 can be balanced, so that the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

2. . . Card type anti-back pressure shaft seal

3. . . Capping unit

31. . . Granga

32. . . Flush hole

33. . . Negra seal

34. . . Outer grange

35. . . Outer gland seal

36. . . Inflow hole

37. . . Outflow hole

38. . . Blocking hole

4. . . First sealing unit

41. . . First sealing mechanism

411. . . First auxiliary seal

412. . . First stationary ring

413. . . First rotating ring

414. . . First compression ring

415. . . First snap ring

416. . . Second snap ring

42. . . First retaining ring

421. . . Conveyor

43. . . First elastic element

44. . . First seal

45. . . First joint

5. . . Bushing unit

51. . . Bushing

52. . . First flange

53. . . Shaft seal

54. . . Drive cover

55. . . Outer joint

56. . . Second flange

57. . . Bushing

6. . . Second sealing unit

61. . . Second sealing mechanism

611. . . Second auxiliary seal

612. . . Second stationary ring

613. . . Second rotating ring

614. . . Second compression ring

615. . . Third snap ring

62. . . Second retaining ring

621. . . Conveyor

63. . . Second elastic element

64. . . Second seal

65. . . Second joint

200. . . Mechanical equipment cavity

201. . . Outer wall

202. . . Rotating shaft

A. . . Process side

B. . . Atmospheric side

310. . . Room

Figure 1 is a cross-sectional view showing the new patent of the Republic of China Announcement No. 592261 "Shaft Sealing Ring and Its Compression Fixed Guide";

Figure 2 is a cross-sectional view showing the new patent of the Republic of China Announcement No. M375797 "Cartridge Double Shaft Seal";

Figure 3 is a cross-sectional view showing a first preferred embodiment of the cartridge type back pressure resistant shaft seal of the present invention;

Figure 4 is a cross-sectional view showing another aspect of the first preferred embodiment;

Figure 5 is a cross-sectional view showing a second preferred embodiment of the cartridge type back pressure resistant shaft seal of the present invention;

Figure 6 is a cross-sectional view showing a third preferred embodiment of the cartridge type back pressure resistant shaft seal of the present invention;

Figure 7 is a cross-sectional view showing a fourth preferred embodiment of the cartridge type back pressure resistant shaft seal of the present invention.

2. . . Card type anti-back pressure shaft seal

3. . . Capping unit

310. . . Room

31. . . Granga

32. . . Flush hole

33. . . Negra seal

38. . . Blocking hole

4. . . First sealing unit

41. . . First sealing mechanism

411. . . First auxiliary seal

412. . . First stationary ring

413. . . First rotating ring

414. . . First compression ring

415. . . First snap ring

42. . . First retaining ring

43. . . First elastic element

44. . . First seal

45. . . First joint

5. . . Bushing unit

51. . . Bushing

52. . . First flange

53. . . Shaft seal

54. . . Drive cover

55. . . Outer joint

57. . . Bushing

200. . . Mechanical equipment cavity

201. . . Outer wall

202. . . Rotating shaft

A. . . Process side

B. . . Atmospheric side

Claims (20)

The utility model relates to a cassette type back pressure resistant shaft seal for mounting on a mechanical device cavity. The mechanical device cavity comprises an outer wall separated from a process side and an atmosphere side. The cassette type back pressure resistant shaft seal comprises: a cover unit includes a gland disposed on the outer wall and located on the atmosphere side and having a chamber; a first sealing unit including a first sealing mechanism disposed in the gland, and a first retaining ring spaced apart from the first sealing mechanism, and at least one of the two ends respectively pushing the first sealing member and the first elastic member of the first retaining ring, wherein the first sealing mechanism has a first auxiliary seal a first stationary ring disposed on the gland, a first rotating ring pushed against the first stationary ring, and a first rotating ring and the first elastic member a first compression ring pushed by the first elastic member; and a sleeve unit including a sleeve extending through the first retaining ring and the first sealing mechanism, and a ring disposed on the outer peripheral surface of the sleeve Between the first compression ring and the first auxiliary seal Pushing a first flange of the first auxiliary sealing ring, and a shaft sealing ring disposed on an inner circumferential surface of the sleeve, wherein the first auxiliary sealing ring, the first stationary ring of the first sealing mechanism and The first rotating ring is circumferentially disposed on an outer circumferential surface of the sleeve. The cassette-type back pressure-resistant shaft seal of the first aspect of the invention, wherein the capping unit further comprises an inner seal ring disposed between the gland and the outer wall, and the first seal The unit also includes a first sealing ring disposed between the gland and the first sealing mechanism. The cartridge type back pressure resistant shaft seal of claim 1, wherein the capping unit further comprises a flushing hole formed in the gland to flush the first sealing mechanism. The cartridge-type back pressure-resistant shaft seal of the first aspect of the invention, wherein the first sealing unit further comprises a first joint extending through the first retaining ring to lock the first retaining ring and the sleeve Pieces. The cartridge type back pressure resistant shaft seal of the first aspect of the invention, wherein the first sealing mechanism further has a first snap ring disposed on the first retaining ring to restrict the first rotating ring. The cartridge type back pressure resistant shaft seal according to claim 1, wherein the sleeve unit further comprises a bushing disposed on the atmosphere side and located between the gland and the sleeve, and the capping unit Also included is at least one obstruction aperture formed in the gland. The cassette type back pressure resistant shaft seal according to the first aspect of the invention, wherein at least one conveying groove is formed on an outer peripheral surface of the first retaining ring. The utility model relates to a cassette type back pressure resistant shaft seal for mounting on a mechanical device cavity. The mechanical device cavity comprises an outer wall separated from a process side and an atmosphere side. The cassette type back pressure resistant shaft seal comprises: a cover unit comprising a gland disposed on the outer wall and located on the atmospheric side, an outer gland provided on the gland, and an inflow hole and a first-class outlet; a sealing unit includes a first sealing mechanism disposed in the gland, a first retaining ring spaced apart from the first sealing mechanism, and at least one of the two ends respectively pushing the first sealing mechanism and the first a first elastic member of the retaining ring, wherein the first sealing mechanism has a first auxiliary sealing ring, a first stationary ring disposed on the gland, and a first pushing on the first stationary ring a rotating ring, and a first compression ring that is pushed between the first rotating ring and the first elastic element and pushed by the first elastic element; a second sealing unit includes a first gland cover disposed on the outer gland a second sealing mechanism; and a sleeve unit including a wearer The first retaining ring, the first sealing mechanism, the sleeve of the second sealing mechanism, and a ring are disposed on the outer peripheral surface of the sleeve and located between the first compression ring and the first auxiliary sealing ring and can be pushed against a first flange of the first auxiliary seal, and a shaft seal disposed on the inner circumferential surface of the sleeve. The cartridge-type back pressure-resistant shaft seal of the eighth aspect of the invention, wherein the second sealing unit further comprises a second retaining ring spaced apart from the second sealing mechanism, and at least one of the two ends is respectively pushed The second sealing mechanism and the second elastic member of the second retaining ring have a second auxiliary sealing ring disposed on the outer peripheral surface of the sleeve and spaced apart from the first auxiliary sealing ring. The cartridge-type back pressure-resistant shaft seal of claim 9, wherein the first sealing mechanism further has a first snap ring disposed on the first retaining ring to restrict the first rotating ring, and A second snap ring disposed on the gland to snap the first stationary ring. The cartridge-type back pressure-resistant shaft seal according to claim 9 or 10, wherein the second sealing mechanism of the second sealing unit further has a sleeve disposed on the outer gland and sleeved a second stationary ring, and a second rotating ring that pushes against the second stationary ring and surrounds the sleeve. The cartridge-type back pressure-resistant shaft seal of claim 11, wherein the second sealing mechanism of the second sealing unit further has a second rotating ring and the second elastic member a second compression ring pushed by the second elastic element, the second auxiliary sealing ring being located between the second compression ring and the second rotating ring. The cartridge type back pressure resistant shaft seal of claim 12, wherein the second sealing mechanism further comprises a third snap ring disposed on the second retaining ring to restrict the second rotating ring. The cartridge type back pressure resistant shaft seal according to claim 9, wherein at least one conveying groove is formed on an outer peripheral surface of the second retaining ring. The cartridge type back pressure resistant shaft seal according to claim 9, wherein a spiral conveying groove is formed on an outer peripheral surface of the second retaining ring. The cartridge-type back pressure-resistant shaft seal of the eighth aspect of the invention, wherein the first sealing unit further comprises a first sealing ring disposed between the gland and the first sealing mechanism, the first sealing ring The second sealing unit further includes a second sealing ring disposed between the outer gland and the second sealing mechanism, the capping unit further comprising a inner gland seal disposed between the gland and the outer wall a ring, and an outer gland seal disposed between the gland and the outer gland. The cartridge type back pressure resistant shaft seal of claim 8, wherein the capping unit further comprises a flushing hole formed in the gland to flush the first sealing mechanism. The cartridge-type back pressure-resistant shaft seal of claim 8, wherein the first sealing unit further includes a first joint extending through the first retaining ring to lock the first retaining ring and the sleeve Pieces. The cartridge-type back pressure-resistant shaft seal according to claim 9, wherein the sleeve unit further includes a second flange that is disposed on the outer circumferential surface of the sleeve and can push against the second retaining ring. The second sealing unit further includes a second coupling member extending through the second retaining ring to lock the second retaining ring and the sleeve. The cartridge-type back pressure-resistant shaft seal of claim 8, wherein the capping unit further comprises at least one obstruction hole formed on the outer gland and communicating with the atmosphere side, and a setting a bushing between the sleeve and the outer gland.