TWI431212B - Mixer for shaft seal - Google Patents

Description

Special shaft seal for mixer

The invention relates to a shaft seal, in particular to a shaft seal for a mixer.

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 Republic of China Announcement No. 459938 "Clip-on shaft sealing device for rotating machinery", the card-type shaft sealing device 1 comprises a gland 11 disposed on a mechanical device 100, a wearer a sleeve 12 disposed on the gland 11 , a shaft sealing chamber 13 defined by the sleeve 12 and the gland 11 , and a first leakage preventing interval disposed on the sleeve 12 Unit 14, and a second leakproof unit 15.

The use of the first and second leakage preventing units 14 and 15 can improve the leakage preventing effect. However, when the pressure of the shaft sealing chamber 13 is greater than the internal pressure of the mechanical device 100, the second stationary ring 151 and the second leak preventing washer 152 and the washer 153 of the second leakage preventing unit 15 are pushed toward the mechanical device. Propulsion in the 100 direction, since the Negran 111 cannot restrict the movement of the second stationary ring 151 and the second leak-proof washer 152 and the washer 153, causing the second leak-proof washer 152 and the washer 153 to be excessively pushed, and by the Nagrand 111 The second stationary ring 151 is pinched, and when the second stationary ring 151 is excessively moved toward the mechanical device 100, the second stationary ring 151 and the second rotating ring 154 are also excessively worn to cause dry running to cause sealing. Failure; when the internal pressure of the mechanical device 100 is greater than the pressure of the shaft sealing chamber 13, the second stationary ring 151 and the second leakage preventing washer 152 are pushed toward the first leakage preventing unit 14 The second stationary ring 151 directly presses the second leakage preventing washer 152. Therefore, the second leakage preventing washer 152 may be damaged by the second stationary ring 151 and the washer 153, thereby causing the sealing of the second leakage preventing unit 15 . Invalid.

In addition, when the pressure of the shaft sealing chamber 13 is greater than the internal pressure of the mechanical device 100 to excessively move the second stationary ring 151 toward the mechanical device 100, the second stationary ring 151 and the second rotating ring 154 may be excessively worn. Dry running causes the seal to fail.

Moreover, if the clip type shaft sealing device 1 is placed on a mixer (not shown), since the radial yaw of the shaft center is large and the second rotating ring 154 cannot be seated on the outer washer 155, When the sleeve 12 is yawed with the shaft center, the second rotating ring 154 cannot be used as the yaw fulcrum of the outer washer 155, so that the second rotating ring 154 cannot compensate for the yaw amplitude of the sleeve 12, resulting in the second rotating ring 154 being easily caused. Interference or collision and damage.

Accordingly, it is an object of the present invention to provide a shaft seal for a mixer that has a structurally stable and long service life.

Therefore, the special shaft seal of the mixer of the present invention is mounted on a mixer for a shaft to be inserted. The shaft seal of the mixer comprises a cover unit disposed on the mixer, a sleeve unit extending through the cover unit, a transmission unit disposed on the sleeve unit, an outer sealing unit and an inner sealing unit disposed on the sleeve unit and disposed on opposite sides of the transmission unit, and an elastic unit.

The cover unit includes a gland mounted on the mixer, a sealing cover disposed on the gland, an accommodation space defined by the gland and the sealing cover, and respectively connected to the cover An isolation liquid inlet and an isolation liquid outlet for accommodating the space and the outside.

The sleeve unit includes a sleeve extending through the sealing cover and being passed by the rotating shaft, and a shaft sealing ring between the sleeve and the rotating shaft, wherein the sleeve has a radially outward extension and is located The flange portion in the accommodating space.

The transmission unit includes a positioning seat disposed on the flange portion, an outer positioning pin that mostly passes through the outer rotating ring and the mounting portion outside the positioning seat, and a plurality of inner positioning pins.

The outer sealing unit includes an outer fixing ring disposed on the sealing cover, an outer rotating ring pushed against the outer fixing ring, an outer compression ring pushed against the outer rotating ring, and a set attached to the outer ring An outer auxiliary seal ring on the sleeve and between the outer rotating ring and the flange portion, wherein the inner surface of the outer rotating ring is formed with an outer ring step for the outer auxiliary sealing ring.

The inner sealing unit includes an inner fixing ring disposed on the gland, an inner rotating ring pushed against the inner fixing ring, an inner compression ring pushed against the inner rotating ring, and a set of attached An inner auxiliary seal ring on the sleeve and interposed between the inner rotating ring and the flange portion, wherein the inner surface of the inner rotating ring is formed with an inner ring step for providing an inner auxiliary sealing ring, and further, the transmission The inner positioning pins of the unit are mounted through the inner rotating ring and the inner mounting portion of the positioning seat. The elastic unit is disposed at the positioning seat to push the outer compression ring and the inner compression ring.

The invention has the beneficial effects of using an external auxiliary sealing ring and an internal auxiliary sealing The sealing ring accumulates pressure to balance the pressure applied by the outer sealing unit and the inner sealing unit to achieve superior sealing effect and increase service life, and the flange portion is used to simultaneously limit movement of the outer auxiliary sealing ring and the inner auxiliary sealing ring The inner auxiliary sealing ring and the inner auxiliary sealing ring are prevented from being pinched or squeezed by the sleeve and the outer rotating ring or the inner rotating ring due to excessive movement, and the inner auxiliary sealing ring and the outer auxiliary sealing ring are respectively used as inner rotation. The yaw fulcrum of the outer rotating ring makes the inner rotating ring outer ring free from the impact of the excessively large bushing, improving the stability and pendulum resistance of the overall structure.

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. 2, a first preferred embodiment of the shaft seal 2 for a mixer of the present invention is mounted on a mixer 200 for a shaft 201 to be inserted. The shaft seal 2 for the mixer includes a cover disposed on the mixer 200. The unit 3, a sleeve unit 4 extending through the cover unit 3, a transmission unit 5 disposed on the sleeve unit 4, and an outer portion of the sleeve unit 4 and located on opposite sides of the transmission unit 5 The sealing unit 6 and an inner sealing unit 7, and an elastic unit 8 that pushes against the outer sealing unit 6 and the inner sealing unit 7.

The capping unit 3 includes a gland 31 mounted on the agitator 200, a sealing cap 32 disposed on the gland 31, and a gland 31 and a sealing cap 32. The accommodation space 33. The Glanga 31 The mounting base 311 is disposed on the mixer 200, and an outer ring seat 312 is disposed between the mounting seat 311 and the sealing cover 32, and is formed on the outer ring seat 312 and communicates with the receiving space. The spacer inlet 313 of the 33, and the sealing cap 32 is formed with a spacer outlet 321 that communicates with the accommodating space 33.

The sleeve unit 4 includes a sleeve 41 extending through the sealing cover 32 and being passed by the rotating shaft 201, a shaft sealing ring 42 between the sleeve 41 and the rotating shaft 201, and a sleeve disposed on the sleeve The driving ring 43 of the rotating shaft 201 is tightened on the 41, and the sleeve 41 has a flange portion 411 extending radially outward and located in the accommodating space 33. The drive ring 43 is screwed to one end of the sleeve 41 opposite to the flange portion 411.

The transmission unit 5 includes a positioning seat 51 disposed on the flange portion 411 and having a spiral guiding groove 511 formed on the surface thereof. The positioning seat 51 has an outer mounting portion 512 facing the sealing cover 32, and a mixer body The inner mounting portion 513 in the 200 direction and the through hole 514 which are spaced apart from each other and communicate the outer mounting portion 512 and the inner mounting portion 513 (only one of which is shown in FIG. 2 due to the viewing angle relationship).

The outer sealing unit 6 includes an outer fixing ring 61 disposed on the sealing cover 32, an outer rotating ring 62 pushed against the outer fixing ring 61, and an outer compression ring pushed against the outer rotating ring 62. 63, and a set of outer auxiliary sealing ring 65 attached to the sleeve 41 between the outer rotating ring 62 and the flange portion 411, and an outer auxiliary sealing ring is formed on the inner surface of the outer rotating ring 62 The outer ring step 621 is provided at 65, and the outer compression ring 63 is located in the outer mounting portion 521.

The inner sealing unit 7 includes an inner fixing ring 71 disposed on the gland 31, an inner rotating ring 72 pushed against the inner fixing ring 71, and an inner compression pushing against the inner rotating ring 72. a ring 73, a set of inner auxiliary seals 75 attached to the sleeve 41 between the inner rotating ring 72 and the flange portion 411, and a gap between the inner fixing ring 71 and the mounting seat 311 An inner seal ring 76 is formed, and an inner ring step 721 is provided on the inner surface of the inner rotating ring 72 for the inner auxiliary seal ring 75. The inner compression ring 73 is located in the inner mounting portion 513.

The transmission unit 5 further includes an outer positioning pin 52 that is mostly threaded through the outer rotating ring 62 and the mounting portion 512 outside the positioning base 51 (only one of which is shown by the viewing angle relationship), and most of the shaft passes through the inner rotating ring 72 and An inner positioning pin 53 of the mounting portion 513 of the positioning seat 51 (only one of which is shown by the viewing angle relationship), an outer buckle 54 disposed in the outer mounting portion 512 to restrict the outer positioning pin 52, and a The inner mounting portion 513 is disposed to restrict the inner buckle 55 of the inner positioning pin 53. The elastic unit 8 has a plurality of compression springs 81 located in each of the through holes 514 and respectively abutting against the outer compression ring 63 and the inner compression ring 73.

When the pressure in the agitator 200 is greater than the pressure of the accommodating space 33, the inner auxiliary sealing ring 75 is pushed toward the sealing cover 32. At this time, the flange portion 411 can restrict the inner auxiliary sealing ring 75. Excessively moving in the direction of the sealing cover 32 prevents the inner auxiliary sealing ring 75 from being pinched by the inner rotating ring 72 and the inner compression ring 73 due to excessive movement, and can also be accumulated by the inner auxiliary sealing ring 75 to balance the The inner sealing unit 7 receives the pressure from the inside of the mixer 200; when the pressure in the accommodating space 33 is greater than the stirring When the pressure in the machine 200 is pushed, the inner auxiliary seal ring 75 and the inner static seal ring 76 are moved toward the mixer 200, and the outer auxiliary seal ring 65 is pushed against the seal cover 32 to cause the outer auxiliary seal ring 65 to be attached. Abutting against the outer rotating ring 62, a tighter sealing effect is produced with the outer fixing ring 61, and the inner auxiliary sealing ring 75 is attached to the inner rotating ring 72, and the inner fixing ring 71 is generated more. a tight sealing effect, and the internal static sealing ring 76 can be used to accumulate the inner fixing ring 71 to balance the inner sealing unit 7 from the accommodating space 33 to the inner rotating ring 72 and the inner auxiliary The back pressure of the seal ring 75 and the two-way pressure in the process side of the mixer 200.

When the inside of the agitator 200 is volatile or easily crystallized, the fluid can be introduced into the liquid inlet 313, and then flows out through the accommodating space 33, thereby effectively preventing the volatilization of volatile substances. Or avoiding crystallization in the accommodating space 33. If the agitator 200 is in a high temperature process, the heat dissipation of the inner sealing unit 7 and the outer sealing unit 6 can be improved. Specifically, the elastic restoring force of the compression spring 81 can compensate the force of the outer rotating ring 62 and the inner rotating ring 72 in both directions.

Referring to FIG. 3, the second preferred embodiment of the shaft seal 2 for the mixer of the present invention is substantially the same as the first preferred embodiment. The difference is that the sleeve unit 4 further includes two clamping members respectively. A pressing ring 44 on the driving ring 43 , a pair of slots 45 that should drive the ring 43 and extend axially along the rotating shaft 201 to the sleeve 41 , and a force for pressing the pressing ring 44 The bolts 46 are tightened, and the elastic unit 8 has a plurality of outer compression springs 82 located in the outer mounting portion 512, and most of them are located in the inner mounting portion 513. An inner compression spring 83, the two ends of each outer compression spring 82 are respectively abutted against the outer compression ring 63 and the positioning seat 51, and the two ends of each inner compression spring 83 are respectively abutted against the inner compression ring 73 and Positioning seat 51. Each of the pressing rings 44 has a guiding slope 441, and the driving ring 43 has two opposing faces 431 that cooperate with the guiding slopes 441.

The outer compression spring 82 and the inner compression spring 83 respectively abut against the outer compression ring 63 and the inner compression ring 73, so that the force of the outer rotation ring 62 and the inner rotation ring 72 can be compensated bidirectionally. It is also possible to increase the pressure that the outer sealing unit 6 and the inner sealing unit 7 can carry. The tightening bolts 46 are used to tighten the pressing ring 44, so that the driving ring 43 can be indirectly pressed by the guiding inclined surface 441 of the pressing ring 44 to press the slot 45 of the sleeve 41, thereby making the sleeve 41 and the bushing 41 The shaft 201 achieves a tight fit effect.

Referring to FIG. 4, the third preferred embodiment of the shaft seal 2 for the mixer of the present invention is substantially the same as the first preferred embodiment. The difference is that the cover unit 3 further includes a set of seal covers. a bearing cover 34 on the 32, and a bearing 35 disposed in the bearing cover 34, the sleeve 41 extends through the bearing cover 34, and the sealing cover 32 is formed with a second resistance sealing hole 331 (depending on the viewing angle relationship) Only one of them is shown). The bearing 35 can not only give the rotating shaft 201 a support point, but also makes the rotation of the sleeve 41 and the transmission unit 5 smoother, avoiding excessive radial deflection of the rotating shaft 201, resulting in the transmission unit 5 and the inner sealing unit 7 The structure of the outer seal unit 6 is broken, so that the shaft seal 2 for the mixer can be applied to the vertical/side/tilt/bottom mixer 200, and the applicable range of the shaft seal 2 for the mixer is increased.

In addition, when the inside of the mixer 200 is a process liquid which is easy to crystallize (not shown), A part of the process liquid is deposited on the outer fixing ring 61 and the outer rotating ring 62, and the butter of the bearing 35 also penetrates between the sealing hole 331 and the outer sealing unit 6 due to gravity, and at this time, by the resistance The sealing hole 331 is passed through a high pressure vapor to blow out the crystals and the butter. When the application is in an icy-free environment, the heat-insulating effect can be achieved by the high-temperature vapor passing through the sealing hole 331 to prevent the insulating liquid in the accommodating space 33 from freezing and affecting the life of the shaft seal.

Referring to FIG. 5, the fourth preferred embodiment of the shaft seal 2 for the mixer of the present invention is substantially the same as the third preferred embodiment. The difference is that the sleeve unit 4 further includes two clamping members respectively. A pressing ring 44 on the driving ring 43 , a pair of slots 45 that should drive the ring 43 and extend axially along the rotating shaft 201 to the sleeve 41 , and a force for pressing the pressing ring 44 Each of the pressing rings 44 has a guiding bevel 441, and the driving ring 43 has two opposing faces 431 that cooperate with the guiding bevel 441. The tightening bolts 46 are used to tighten the pressing ring 44, so that the driving ring 43 can be indirectly pressed by the guiding inclined surface 441 of the pressing ring 44 to press the slot 45 of the sleeve 41, thereby making the sleeve 41 and the bushing 41 The shaft 201 achieves a tight fit effect.

Referring to Figure 6, a fifth preferred embodiment of the shaft seal 2 for a blender of the present invention is substantially the same as the first preferred embodiment, and includes a capping unit 3 disposed on the blender 200, and a capping portion thereof. a sleeve unit 4 of the unit 3, a transmission unit 5 disposed on the sleeve unit 4, and an outer sealing unit 6 and an inner sealing unit spaced apart from the sleeve unit 4 and located on opposite sides of the transmission unit 5 7, the difference is that the gland 31 of the capping unit 3 has a mounting seat 311 locked to the agitator 200, and an outer ring seat disposed between the mounting seat 311 and the sealing cover 32. 312, a set of a cooling water jacket 314 at an outer circumference of the outer ring seat 312, and a cooling ring groove 315 surrounding the outer ring seat 312 by the outer ring seat 312 and the cooling water jacket 314, and the liquid inlet 313 The accommodating liquid outlet 321 is formed on the sealing cover 32 and communicates with the accommodating space 33, and the cooling water jacket 314 has a cooling ring groove. A cooling fluid inlet 316 of 315, and a cooling fluid outlet 317 that communicates with the cooling fluid inlet 316 to the cooling ring groove 315.

In use, the cooling fluid inlet 316 can be used to input the cooling fluid to the cooling ring groove 315 and then through the cooling fluid outlet 317 to reduce the frictional heat generated by the rotational friction between the components in the accommodating space 33, and the mixer. The heat transferred inside 200.

Referring to FIG. 7, the sixth preferred embodiment of the shaft seal 2 for the mixer of the present invention is substantially the same as the fifth preferred embodiment. The difference is that the sleeve unit 4 further includes two clamping members respectively. A pressing ring 44 on the driving ring 43 , a pair of slots 45 that should drive the ring 43 and extend axially along the rotating shaft 201 to the sleeve 41 , and a force for pressing the pressing ring 44 Each of the pressing rings 44 has a guiding bevel 441, and the driving ring 43 has two opposing faces 431 that cooperate with the guiding bevel 441. The tightening bolts 46 are used to tighten the pressing ring 44, so that the driving ring 43 can be indirectly pressed by the guiding inclined surface 441 of the pressing ring 44 to press the slot 45 of the sleeve 41, thereby making the sleeve 41 and the bushing 41 The shaft 201 achieves a tight fit effect.

Referring to Figure 8, the seventh preferred embodiment of the shaft seal 2 for the mixer of the present invention is substantially the same as the fifth preferred embodiment, and the difference is that: The capping unit 3 further includes a set of bearing caps 34 disposed on the sealing cap 32, and a bearing 35 disposed in the bearing cap 34, the bushing 41 extending through the bearing cap 34. The bearing 35 can not only give the rotating shaft 201 a support point, but also make the rotation of the sleeve 41 and the transmission unit 5 smoother, and avoid excessive radial deflection of the rotating shaft 201, thereby causing the transmission unit 5 and the inner sealing unit 7 to The structure of the outer sealing unit 6 is broken, so that the special shaft seal 2 for the mixer can be applied to the vertical/side/tilt/bottom mixer 200, and the applicable range of the shaft seal 2 for the mixer is increased.

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‧‧‧Special shaft seal for mixer

200‧‧‧Mechanical equipment

201‧‧‧ shaft

3‧‧‧Cover unit

31‧‧‧Grange

311‧‧‧ Mounting

312‧‧‧ outer ring seat

313‧‧‧Isolation fluid inlet

314‧‧‧Cooling water jacket

315‧‧‧Cooling ring groove

316‧‧‧Cooling fluid inlet

317‧‧‧Cooling fluid outlet

32‧‧‧ Sealing cover

321‧‧‧Isolation fluid outlet

33‧‧‧ accommodating space

331‧‧‧Resistance hole

34‧‧‧ bearing cap

35‧‧‧ bearing

4‧‧‧Sleeve unit

41‧‧‧ bushing

411‧‧‧Flange

42‧‧‧ shaft seal

43‧‧‧ drive ring

431‧‧‧ matching face

44‧‧‧Forcing the ring

441‧‧‧ guiding slope

45‧‧‧Axial grooving

46‧‧‧tightening bolts

5‧‧‧Transmission unit

51‧‧‧ Positioning Block

511‧‧ ‧ guide slot

512‧‧‧External Installation Department

513‧‧‧Installation Department

52‧‧‧External positioning pin

53‧‧ inside positioning pin

54‧‧‧Outer buckle

55‧‧‧ inner buckle

6‧‧‧Outer sealing unit

61‧‧‧ external fixing ring

62‧‧‧ outer rotating ring

621‧‧‧ outer ring steps

63‧‧‧External compression ring

65‧‧‧Outer auxiliary seal

66‧‧‧External seal

7‧‧‧Internal sealing unit

71‧‧‧Fixed ring

72‧‧‧ inner rotating ring

721‧‧‧ inner ring

73‧‧‧Inner compression ring

75‧‧‧Auxiliary seal

76‧‧‧Internal sealing ring

8‧‧‧elastic unit

81‧‧‧Shrink spring

82‧‧‧External compression spring

83‧‧‧Inner compression spring

Figure 1 is a cross-sectional view showing the Republic of China Announcement No. M375797 "Cartridge Double Shaft Seal" of the cartridge type double shaft seal; Fig. 2 is a cross-sectional view showing the first preferred embodiment of the shaft seal for the mixer of the present invention; Figure 3 is a cross-sectional view showing a second preferred embodiment of the shaft seal for the mixer of the present invention; Figure 4 is a cross-sectional view showing a third preferred embodiment of the shaft seal for the mixer of the present invention; Figure 5 is a cross-sectional view showing the present A fourth preferred embodiment of the invention relates to a shaft seal for a mixer; FIG. 6 is a cross-sectional view showing the fifth shaft seal for the mixer of the present invention BRIEF DESCRIPTION OF THE DRAWINGS Fig. 7 is a cross-sectional view showing a sixth preferred embodiment of a shaft seal for a mixer of the present invention; and Fig. 8 is a cross-sectional view showing a seventh preferred embodiment of a shaft seal for a mixer of the present invention.

2. . . Special shaft seal for mixer

200. . . Mixer

201. . . Rotating shaft

3. . . Capping unit

31. . . Granga

311. . . Mount

312. . . Outer ring seat

313. . . Isolation fluid inlet

32. . . Sealing cap

321. . . Isolation fluid outlet

33. . . Housing space

4. . . Bushing unit

41. . . Bushing

411. . . Flange

42. . . Shaft seal

43. . . Drive ring

5. . . Transmission unit

51. . . Positioning seat

511. . . Spiral guide

512. . . External installation

513. . . Internal installation

514. . . Through hole

52. . . External positioning pin

53. . . Internal positioning pin

54. . . Outer buckle

55. . . Inner buckle

6. . . Outer sealing unit

61. . . External fixing ring

62. . . Outer rotating ring

621. . . Outer ring

63. . . External compression ring

65. . . External auxiliary seal

66. . . External static seal

7. . . Inner sealing unit

71. . . Internal fixing ring

72. . . Inner rotating ring

721. . . Inner ring

73. . . Inner compression ring

75. . . Internal auxiliary seal

76. . . Internal static seal

8. . . Elastic unit

81. . . Shrink spring

Claims (12)

The utility model relates to a shaft seal for a mixer, which is mounted on a mixer for piercing a rotating shaft. The special shaft seal of the mixer comprises: a cover unit, comprising a gland mounted on the mixer, and a gland cover disposed on the gland a sealing cover, an accommodating space defined by the matching of the gland and the sealing cover, and an isolation liquid inlet and an isolation liquid outlet respectively connecting the accommodating space and the outside; a bushing unit including a penetration a sealing sleeve and a sleeve pierced by the rotating shaft, and a shaft sealing ring between the sleeve and the rotating shaft, wherein the sleeve has a flange extending radially outward and located in the receiving space a transmission unit includes a positioning seat disposed on the flange portion, an outer positioning pin that mostly passes through the outer rotating ring and the mounting portion outside the positioning seat, and a plurality of inner positioning pins; an outer sealing unit, The utility model comprises an outer fixing ring disposed on the sealing cover, an outer rotating ring pushed against the outer fixing ring, an outer compression ring pushed against the outer rotating ring, and a set attached to the sleeve And between the outer rotating ring and the flange portion a sealing ring, wherein the inner surface of the outer rotating ring is formed with an outer ring step for providing an outer auxiliary sealing ring; and an inner sealing unit includes an inner fixing ring disposed on the gland cover, and a push An inner rotating ring on the inner fixing ring, an inner compression ring that pushes against the inner rotating ring, and a set of inner auxiliary seal attached to the bushing between the inner rotating ring and the flange portion a ring, wherein the inner surface of the inner rotating ring is formed with an inner ring step for the inner auxiliary sealing ring, and The inner positioning pins of the transmission unit are mounted inside the inner rotating ring and the positioning seat; and an elastic unit is disposed on the positioning seat to push the outer compression ring and the inner compression ring. The shaft seal for a mixer according to the first aspect of the invention, wherein the positioning seat has an outer mounting portion facing the sealing cover, and an inner mounting portion facing the mixer, and the elastic unit has a majority An outer compression spring in the outer mounting portion, and an inner compression spring mostly located in the inner mounting portion, and an outer compression ring of the outer sealing unit and the outer compression spring are located in the outer mounting portion, and the inner seal The inner compression ring of the unit and the inner compression spring are located in the outer mounting portion. The shaft seal for a mixer according to the first aspect of the invention, wherein the sleeve unit further comprises a set of drive rings disposed on the sleeve and pressing the shaft, and the two respectively clamped against the drive ring a tightening ring thereon, a pair of slots formed on the sleeve extending along the axis of the shaft, and a plurality of tightening bolts for tightening the pressing ring, each of the tightening rings having A guiding bevel, and the driving ring has two opposing faces that cooperate with the guiding bevel. The shaft seal for a mixer according to the first aspect of the invention, wherein the sleeve unit further comprises a driving ring disposed on the sleeve and pressing the shaft, the driving ring is screwed on the sleeve Contrary to one end of the flange portion. The shaft seal for a mixer according to the first aspect of the invention, wherein the gland of the capping unit has a lock mounted on the mixer a seat, and an outer ring seat disposed between the mount and the sealing cover. The shaft seal for a mixer according to claim 1, wherein the capping unit further comprises a set of bearing caps disposed on the sealing cap, and a bearing disposed in the bearing cap, the bushing is worn Extend the bearing cap. A shaft seal for a mixer according to any one of claims 1 to 3, wherein the gland of the capping unit has a mounting seat locked to the agitator, and a mounting seat is disposed on the mounting seat An outer ring seat between the sealing covers, a cooling water jacket covering the outer circumference of the outer ring seat, and a cooling ring groove surrounding the outer ring seat by the outer ring seat and the cooling water jacket, and The cooling water jacket has a cooling fluid inlet connected to the cooling ring groove, and a cooling fluid outlet communicating with the cooling fluid inlet spaced apart from the cooling fluid inlet. The shaft seal for a mixer according to the second aspect of the invention, wherein the transmission unit further comprises an outer buckle disposed in the outer mounting portion to limit the outer positioning pin, and a outer ring disposed in the inner mounting portion To limit the inner buckle of the inner positioning pin. The shaft seal for a mixer according to the first aspect of the invention, wherein the outer edge of the positioning seat of the transmission unit is formed with a spiral guide groove. The shaft seal for a mixer according to claim 5, wherein the spacer inlet is formed on the outer ring seat, and the spacer outlet is formed on the seal cover. The shaft seal for a mixer according to claim 2, wherein each end of each outer compression spring is respectively abutted against the outer compression ring and the positioning seat, and the two ends of each inner compression spring are respectively topped Inner compression ring With the positioning seat. The shaft seal for a mixer according to the first aspect of the invention, wherein the positioning seat has an outer mounting portion facing the sealing cover, an inner mounting portion facing the mixer, and a plurality of spaced apart communicating outer mountings. a through hole with the inner mounting portion, and the elastic unit has a plurality of compression springs located in each of the through holes, and an outer compression ring of the outer sealing unit is located in the outer mounting portion, and the inner compression ring of the inner sealing unit It is located in the inner mounting portion, and both ends of the compression spring are respectively abutted against the outer compression ring and the inner compression ring.