CN216429930U

CN216429930U - Combined sealing structure of melt discharging gear pump

Info

Publication number: CN216429930U
Application number: CN202122240725.6U
Authority: CN
Inventors: 张胜国; 吴金亮; 韩君炎; 傅立峰; 潘洪良; 俞张炯; 朱秀庆
Original assignee: RONGSHENG PETROCHEMICAL CO Ltd
Current assignee: RONGSHENG PETROCHEMICAL CO Ltd
Priority date: 2021-09-15
Filing date: 2021-09-15
Publication date: 2022-05-03
Anticipated expiration: 2031-09-15

Abstract

The utility model discloses a fuse-element ejection of compact gear pump composite seal structure aims at solving the sealed filler of gear pump and the difficult control of gear bush's concentricity, leads to the easy wearing and tearing of sealed filler, has shortened the not enough of sealed filler's running life. The utility model comprises a sealing box body, a floating stuffing box and a spiral floating ring, wherein a step hole is arranged in the sealing box body, a shaft sleeve is sleeved in the step hole, the step hole comprises a stuffing sealing section and a spiral sealing section, and a medium spiral groove is arranged on the inner wall of the spiral sealing section; the floating packing box is sleeved on the packing sealing section, the inner wall of the spiral floating ring is provided with a liquid-passing spiral groove, inner floating gaps are respectively arranged between the inner wall of the spiral floating ring and the outer wall of the shaft sleeve and between the outer wall of the spiral floating ring and the inner wall of the floating packing box, and outer floating gaps are arranged between the outer wall of the floating packing box and the packing sealing section; an elastic preload piece is connected between the floating stuffing box and the sealing box body; packing rings are hermetically sleeved on both sides of the spiral floating ring on the shaft sleeve.

Description

Combined sealing structure of melt discharging gear pump

Technical Field

The utility model relates to a fuse-element gear pump structure, more specifically say, it relates to a fuse-element ejection of compact gear pump composite seal structure.

Background

The sealing of the kettle bottom melt discharging gear pump is generally realized by spiral filler sealing, mechanical sealing, magnetic fluid sealing and the like. For spiral filler sealing, because the high-pressure melt discharge gear pump adopts a dynamic pressure sliding bearing, the basic principle of the dynamic pressure sliding bearing shows that a gear shaft is not concentric with the sliding bearing, and simultaneously, the spiral filler sealing is not concentric with the gear shaft; the concentricity increases synchronously with the wear of the gear shaft and the bearing. The eccentric wear of the filler caused by the eccentricity of the spiral filler-added seal and the gear shaft increases the clearance between the filler and the gear shaft, so that the filler seal fails, and the spiral seal also fails due to the overlarge tooth crest clearance between the spiral and the gear shaft; causing outside air to leak into the gear pump chamber. On one hand, air entering the pump cavity can affect the feeding of the gear pump, so that the gear pump cannot stably discharge and normally work; on the other hand, material denaturation may be caused; furthermore, the continuity and stability of the oil film of the hydrodynamic plain bearing are damaged, and the gear pump is damaged. The pre-cooling of the melt in the sealing cavity of the gear pump can solidify, and the solid particles enter the sealing surface to cause the failure of mechanical sealing; the rotating speed of the melt discharging gear pump is very low, a lubricating and cooling system needs to be independently configured for mechanical sealing, the cost is high, the operation is unstable, and the melt discharging gear pump rarely uses the mechanical sealing. The magnetic fluid seal has no leakage, no abrasion and no pollution, but has overhigh cost and is not suitable for high-temperature working environment.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects, the utility model provides a fuse-element ejection of compact gear pump composite seal structure, it can maintain the concentricity of seal packing and gear shaft axle sleeve and slow down the wearing and tearing of seal packing, prolongs the operation life of seal packing in the requirement within range.

In order to solve the technical problem, the utility model discloses a following technical scheme: a combined sealing structure of a melt discharging gear pump comprises a sealing box body, a floating filling box and a spiral floating ring, wherein a step hole is formed in the sealing box body, a shaft sleeve used for connecting a gear shaft is sleeved in the step hole, and the step hole comprises a spiral sealing section and a filling sealing section; a medium spiral groove is formed in the inner wall of the spiral sealing section of the stepped hole; the shaft sleeve rotates to enable the melt leaked from the gear pump into the medium spiral groove to be reversely pushed and flow back into the gear pump under the spiral pushing action of the medium spiral groove; the floating packing box is sleeved on the packing sealing section, the spiral floating ring is sleeved between the shaft sleeve and the floating packing box, the inner wall of the spiral floating ring is provided with a liquid-passing spiral groove, inner floating gaps are respectively arranged between the inner wall of the spiral floating ring and the outer wall of the shaft sleeve and between the outer wall of the spiral floating ring and the inner wall of the floating packing box, and outer floating gaps are arranged between the outer wall of the floating packing box and the packing sealing section; the sealing box body is provided with a liquid inlet and a liquid outlet which are communicated with the outer floating gap, and the floating filling box is provided with a liquid through hole which is communicated with the outer floating gap and the inner floating gap; an elastic preload piece is connected between the floating stuffing box and the sealing box body; packing rings are hermetically sleeved on both sides of the spiral floating ring on the shaft sleeve.

The arrangement of the stepped holes can improve the partition sealing effect of the spiral sealing section and the packing sealing section. The medium spiral groove is arranged to enable the high-pressure melt leaked from the interior of the gear pump to generate axial movement in the process that the shaft sleeve and the gear shaft rotate together, and reverse pushing force is generated on the melt to enable the melt to continuously return to the inlet of the gear pump. The floating stuffing box and the sealing box body are connected with an elastic pre-tightening piece, so that the floating stuffing box is pushed to the spiral sealing section, and meanwhile, the sealing specific pressure required by sealing is maintained by means of the elastic force provided by the elastic pre-tightening piece. Through letting in sealed liquid in the outside clearance that floats of inlet, the axle sleeve rotates the in-process and under the spiral push effect that leads to liquid helicla flute, pushes sealed liquid to the atmosphere side of liquid outlet, prevents that the air from getting into the gear pump through the step hole. Because the medium spiral groove in the spiral sealing section can produce very big drive power in the axle sleeve rotation process, the direction of this drive power is inside towards the gear pump, consequently can produce very big suction to outside air, and through the inside structure setting of packing sealing section, outside air entering step hole has been blockked in the flow of sealing liquid to outside air has been avoided leaking in the gear pump. The spiral floating ring generates a pumping effect on the sealing liquid when the shaft sleeve rotates, so that the external circulation of the sealing liquid is realized, the sealing cavity can be flushed, the cleanness of the sealing cavity is maintained, and the sealing effect is ensured; but also can strengthen the lubricating and cooling functions of the sealing filler.

The pumping effect of the spiral floating ring increases the circulation amount of the sealing liquid, enhances the lubricating and cooling effects of the sealing filler and prolongs the service life of the sealing; and the flushing effect is realized on the sealing cavity, so that the liquid through spiral groove is prevented from being blocked by solid particles, and the sealing filler is prevented from being abraded by the solid particles. Because the inner floating gap and the outer floating gap are arranged, the floating stuffing box and the spiral floating ring can float radially in the rotation process of the shaft sleeve, the eccentricity between the shaft sleeve and the floating stuffing box is reduced, and the shaft sleeve and the floating stuffing box are ensured to be concentric as much as possible; even if the spiral floating ring is contacted with the shaft sleeve, the spiral floating ring can play a role in supporting, and the floating packing box is supported, so that the stress is very slight.

The combined sealing structure of the melt discharge gear pump can maintain the concentricity of the sealing filler and the shaft sleeve of the gear shaft within a required range, slow down the abrasion of the sealing filler and prolong the service life of the sealing filler. The spiral floating ring seal not only belongs to non-contact seal, but also belongs to dynamic seal, and has no abrasion in the operation process, thereby not only improving the sealing effect, but also prolonging the service life of the seal.

Preferably, a cooling ring cavity is arranged at the corresponding position of the spiral sealing section in the sealing box body, and a liquid inlet hole and a liquid outlet hole which are communicated with the cooling ring cavity are arranged on the sealing box body.

When the equipment is maintained, cooling liquid is introduced into the cooling ring cavity to cool the sealing box body, so that the melt is frozen to prevent the melt from leaking. Meanwhile, the tooth top clearance of the spiral seal can be finely adjusted by adjusting the temperature of the cooling medium, and the spiral seal fails due to the fact that the tooth top clearance is too large.

As preferably, connect the apron on the sealed letter body, the packing box that floats goes up to correspond with elasticity pretension piece and is equipped with the mounting hole, apron and the packing pad of installation between the packing box that floats, pack to fill up and should be equipped with the arch with the mounting hole, elasticity pretension piece is installed in the mounting hole, the mounting hole open position is arranged in to the arch and with elasticity pretension piece butt.

The cover plate plays a good role in axially positioning the floating packing box, and the packing pad is favorable for improving the sealing effect. The elastic pretensioning piece is installed in the installation hole and is stable and reliable.

Preferably, the sealing box body is connected with a filler end cover, and the filler end cover abuts against the filler ring on one side of the spiral floating ring. The filler end cover plays a good positioning role in the filler ring.

Preferably, the packing end cover and the sealing box body are connected through a bolt, a belleville spring is connected to the bolt, and the belleville spring abuts against the packing end cover. The belleville spring provides a reliable preload force for the packing ring.

Preferably, an anti-rotation pin is arranged between the floating stuffing box and the sealing box body, and an anti-rotation pin is arranged between the spiral floating ring and the floating stuffing box. The setting of anti-rotating pin can prevent that the relative unsteady stuffing box of spiral floating ring from rotating, prevents simultaneously that sealing liquid from at the internal circulation of unsteady stuffing box.

Preferably, the liquid inlet is arranged at the bottom of the sealing box body, and the liquid outlet is arranged at the top of the sealing box body.

Preferably, a plurality of liquid passing grooves are formed in the two end faces of the spiral floating ring. The liquid passing groove is convenient for the sealing liquid to pass between the outer floating gap and the inner floating gap.

Preferably, metal rings are arranged between both ends of the spiral floating ring and the packing ring.

Preferably, a sliding bearing is correspondingly arranged in the gear pump and the gear shaft, the gear shaft and the sliding bearing are sleeved together, a through flow groove is formed in the inner wall of the sliding bearing, and an annular groove is formed between the part, between the sliding bearing and the shaft sleeve, of the gear shaft and the gear pump.

The melt in the gear pump flows into the through flow groove to cool the sliding bearing and then is sent into the ring groove to flow into the medium spiral groove, and the medium spiral groove generates reverse pushing force on the melt in the process that the shaft sleeve and the gear shaft rotate together to promote the melt to continuously return to the inlet of the gear pump.

Compared with the prior art, the beneficial effects of the utility model are that: (1) the combined sealing structure of the melt discharging gear pump can maintain the concentricity of the sealing filler and the gear shaft sleeve within a required range, slow down the abrasion of the sealing filler and prolong the service life of the sealing filler; (2) the spiral floating ring seal belongs to non-contact seal and dynamic seal, and has no abrasion in the operation process, thereby not only improving the sealing effect, but also prolonging the service life of the seal; (3) because the medium spiral groove in the spiral sealing section can produce very big drive power in the axle sleeve rotation process, the direction of this drive power is inside towards the gear pump, consequently can produce very big suction to outside air, and through the inside structure setting of packing sealing section, outside air entering step hole has been blockked in the flow of sealing liquid to outside air has been avoided leaking in the gear pump.

Drawings

Fig. 1 is a schematic structural view of an installation state of the present invention;

fig. 2 is a cross-sectional view of the present invention;

FIG. 3 is a schematic structural view of the spiral floating ring of the present invention;

in the figure: 1. sealing box body, 2, floating packing box, 3, spiral floating ring, 4, shaft sleeve, 5, transition surface, 6, packing sealing section, 7, spiral sealing section, 8, medium spiral groove, 9, liquid through spiral groove, 10, inner floating gap, 11, outer floating gap, 12, liquid inlet, 13, liquid outlet, 14, liquid through hole, 15, elastic preload piece, 16, packing ring, 17, cooling ring cavity, 18, cover plate, 19, mounting hole, 20, packing pad, 21, bulge, 22, extension ring, 23, packing end cover, 24, metal ring, 25, liquid through groove, 26, butterfly spring, 27, packing ring, 28, anti-rotation pin, 29, sealing ring, 30, ring groove, 31, connecting key, 32, shaft shoulder, 33, gasket, 34, sliding bearing, 35, through groove, 36, gear pump, 37, gear shaft.

Detailed Description

The technical solution of the present invention is further described in detail by the following specific embodiments in combination with the accompanying drawings:

example (b): a melt discharge gear pump combined sealing structure (see attached figures 1 to 3) comprises a sealing box body 1, a floating packing box 2 and a spiral floating ring 3, wherein a step hole is formed in the sealing box body, a shaft sleeve 4 used for connecting a gear shaft 37 is sleeved in the step hole, a transition surface 5 is arranged between a large-diameter section and a small-diameter section of the step hole, the large-diameter section of the step hole is a packing sealing section 6, the small-diameter section of the step hole is a spiral sealing section 7, and a medium spiral groove 8 is formed in the inner wall of the spiral sealing section of the step hole; the rotation of the shaft sleeve enables the melt leaked from the gear pump into the medium spiral groove to be reversely pushed and flow back into the gear pump 36 under the spiral pushing action of the medium spiral groove; the floating packing box is sleeved on the packing sealing section, the spiral floating ring is sleeved between the shaft sleeve and the floating packing box, the inner wall of the spiral floating ring is provided with a liquid through spiral groove 9, inner floating gaps 10 are respectively arranged between the inner wall of the spiral floating ring and the outer wall of the shaft sleeve and between the outer wall of the spiral floating ring and the inner wall of the floating packing box, and outer floating gaps 11 are arranged between the outer wall of the floating packing box and the packing sealing section; the sealed letter body is provided with a liquid inlet 12 and a liquid outlet 13 which are communicated with the outer floating gap, the liquid inlet is arranged at the bottom of the sealed letter body, and the liquid outlet is arranged at the top of the sealed letter body. The floating stuffing box is provided with a liquid through hole 14 for communicating the outer floating gap and the inner floating gap; one end of the floating stuffing box is hermetically attached to the transition surface, and an elastic preload piece 15 is connected between the other end of the floating stuffing box and the sealing box body; the two sides of the spiral floating ring on the shaft sleeve are hermetically sleeved with carbon fiber packing rings 16.

The corresponding position of the spiral sealing section in the sealing box body is provided with a cooling ring cavity 17, and the sealing box body is provided with a liquid inlet hole and a liquid outlet hole which are communicated with the cooling ring cavity.

Connect apron 18 on the sealed letter body, the packing box that floats goes up to correspond with elasticity pretension piece and is equipped with mounting hole 19, apron and the packing box that floats between installation polytetrafluoroethylene packing pad 20, pack to fill up and should be equipped with arch 21 with the mounting hole, elasticity pretension piece is installed in the mounting hole, the mounting hole open position is arranged in to the arch and with elasticity pretension piece butt. The elasticity pretension piece equipartition is provided with a plurality of, and elasticity pretension piece is the spring.

One end of the floating packing box is provided with an extension ring 22 which extends inwards, the extension ring is in sealing fit with the transition surface, a packing end cover 23 is connected to the sealing box body, and the packing end cover is abutted against the packing ring on one side of the spiral floating ring. And packing rings are arranged between the extension ring and the spiral floating ring and between the packing end cover and the spiral floating ring. And metal rings 24 are arranged between the two ends of the spiral floating ring and the packing ring. The two end faces of the spiral floating ring are respectively provided with a plurality of liquid passing grooves 25 which are uniformly distributed and are radially arranged. The packing end cover and the sealing box body are connected through bolts, the bolts are connected with the belleville springs 26, the belleville springs abut against the packing end cover, and the belleville springs provide reliable pre-tightening force for the packing ring. A polytetrafluoroethylene packing ring 27 is arranged between one end face of the floating packing box and the transition face. The filler end cover and the cover plate are tightly sleeved together, and a filler sealing ring is arranged between the filler end cover and the cover plate. And a sealing gasket is arranged between the cover plate and the end surface of the sealing box body.

An anti-rotation pin 28 is arranged between the floating stuffing box and the sealing box body, and an anti-rotation pin is arranged between the spiral floating ring and the floating stuffing box. And a polytetrafluoroethylene sealing ring 29 is arranged between the outer wall of the spiral floating ring and the inner wall of the floating stuffing box. And the sealing liquid is ensured to flow to the other end from one end of the liquid through spiral groove along the spiral direction of the liquid through spiral groove.

Sliding bearings 34 are correspondingly arranged in the gear pump and the gear shaft, the gear shaft and the sliding bearings are sleeved together, a through groove 35 is formed in the inner wall of each sliding bearing, and an annular groove 30 is formed between the part, between the sliding bearing and the shaft sleeve, of the gear shaft and the gear pump. A connecting key 31 is installed between the gear shaft and the shaft sleeve. The shaft shoulder 32 is equipped with in the front portion of the axle sleeve on the gear shaft, and the sealed letter body is closely installed on the gear pump, all installs gasket 33 between sealed letter body terminal surface and the gear pump and between axle sleeve terminal surface and the shaft shoulder. The gear shaft sleeved with the shaft sleeve is inserted into the gear pump and sleeved with a sliding bearing in the gear pump.

The arrangement of the step hole on the sealing box body can improve the partition sealing effect of the spiral sealing section and the packing sealing section. The medium spiral groove is arranged to enable the high-pressure melt leaked from the interior of the gear pump to generate axial movement in the process that the shaft sleeve and the gear shaft rotate together, and reverse pushing force is generated on the melt to enable the melt to continuously return to the inlet of the gear pump. The gland packing box that floats seals up the laminating on the transition face, and the elasticity pretension piece is connected between the other end and the sealed letter body, guarantees to push the gland packing box that floats to the spiral seal section, relies on the elastic force that elasticity pretension piece provided to maintain sealed required specific pressure simultaneously. Through letting in sealed liquid in the outside clearance that floats of inlet, the axle sleeve rotates the in-process and under the spiral push effect that leads to liquid helicla flute, pushes sealed liquid to the atmosphere side of liquid outlet, prevents that the air from getting into the gear pump through the step hole. Because the medium spiral groove in the spiral sealing section can produce very big drive power in the axle sleeve rotation process, the direction of this drive power is inside towards the gear pump, consequently can produce very big suction to outside air, and through the inside structure setting of packing sealing section, outside air entering step hole has been blockked in the flow of sealing liquid to outside air has been avoided leaking in the gear pump. The spiral floating ring generates a pumping effect on the sealing liquid when the shaft sleeve rotates, so that the external circulation of the sealing liquid is realized, the sealing cavity can be flushed, the cleanness of the sealing cavity is maintained, and the sealing effect is ensured; but also can strengthen the lubricating and cooling functions of the sealing filler.

The above-described embodiments are merely preferred and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A combined sealing structure of a melt discharging gear pump is characterized by comprising a sealing box body, a floating filling box and a spiral floating ring, wherein a step hole is formed in the sealing box body, a shaft sleeve used for connecting a gear shaft is sleeved in the step hole, and the step hole comprises a spiral sealing section and a filling sealing section; a medium spiral groove is formed in the inner wall of the spiral sealing section of the stepped hole; the shaft sleeve rotates to enable the melt leaked from the gear pump into the medium spiral groove to be reversely pushed and flow back into the gear pump under the spiral pushing action of the medium spiral groove; the floating packing box is sleeved on the packing sealing section, the spiral floating ring is sleeved between the shaft sleeve and the floating packing box, the inner wall of the spiral floating ring is provided with a liquid-passing spiral groove, inner floating gaps are respectively arranged between the inner wall of the spiral floating ring and the outer wall of the shaft sleeve and between the outer wall of the spiral floating ring and the inner wall of the floating packing box, and outer floating gaps are arranged between the outer wall of the floating packing box and the packing sealing section; the sealing box body is provided with a liquid inlet and a liquid outlet which are communicated with the outer floating gap, and the floating filling box is provided with a liquid through hole which is communicated with the outer floating gap and the inner floating gap; an elastic preload piece is connected between the floating stuffing box and the sealing box body; packing rings are hermetically sleeved on both sides of the spiral floating ring on the shaft sleeve.

2. The melt discharging gear pump combined sealing structure of claim 1, wherein a cooling ring cavity is arranged at a position corresponding to the spiral sealing section in the sealing box body, and a liquid inlet hole and a liquid outlet hole which are communicated with the cooling ring cavity are arranged on the sealing box body.

3. The melt discharge gear pump combined sealing structure according to claim 1, wherein a cover plate is connected to the sealing box body, a mounting hole is formed in the floating packing box corresponding to the elastic preload piece, a packing pad is mounted between the cover plate and the floating packing box, a protrusion is correspondingly formed in the packing pad and the mounting hole, the elastic preload piece is mounted in the mounting hole, and the protrusion is arranged at an opening position of the mounting hole and abutted against the elastic preload piece.

4. The melt discharge gear pump combination seal structure of claim 1, wherein the seal box body is connected with a packing end cover, and the packing end cover abuts against a packing ring on one side of the spiral floating ring.

5. The melt discharge gear pump combination sealing structure of claim 4, wherein the packing end cover and the sealing box body are connected through a bolt, a belleville spring is connected to the bolt, and the belleville spring abuts against the packing end cover.

6. The melt discharge gear pump combination seal structure of claim 1, wherein an anti-rotation pin is installed between the floating packing box and the seal box body, and an anti-rotation pin is installed between the spiral floating ring and the floating packing box.

7. The melt discharge gear pump combination seal structure of claim 1, wherein the liquid inlet is disposed at the bottom of the seal box and the liquid outlet is disposed at the top of the seal box.

8. The melt discharging gear pump combined sealing structure of claim 1, wherein a plurality of liquid passing grooves are formed on both end faces of the spiral floating ring.

9. The melt discharging gear pump combined sealing structure of any one of claims 1 to 8, wherein metal rings are arranged between both ends of the spiral floating ring and the filler ring.

10. The melt discharging gear pump combined sealing structure according to any one of claims 1 to 8, wherein a sliding bearing is arranged in the gear pump corresponding to the gear shaft, the gear shaft is sleeved with the sliding bearing, a through flow groove is arranged on the inner wall of the sliding bearing, and an annular groove is arranged between the part of the sliding bearing between the shaft sleeve and the gear pump on the gear shaft.