CN216842272U

CN216842272U - Heavy seal structure of turbine vacuum pump

Info

Publication number: CN216842272U
Application number: CN202220327574.XU
Authority: CN
Inventors: 李月仙
Original assignee: Zhenxin Turbine Machinery Co ltd
Current assignee: Zhenxin Turbine Machinery Co ltd
Priority date: 2022-02-18
Filing date: 2022-02-18
Publication date: 2022-06-28
Anticipated expiration: 2032-02-18

Abstract

A heavy sealing structure of a turbine vacuum pump belongs to the technical field of turbine machinery and is characterized in that the inner side of a volute is connected with a volute inner body, the front end of an impeller is connected with an air inlet pipe through an impeller pressure plate, an impeller sealing groove is formed in a rear cover plate of the impeller, a sealer is fixedly connected to the outer side of the volute and sleeved on a high-speed shaft, a sealer outer gear ring is correspondingly arranged at the matching position of the sealer and the impeller, the sealer outer gear ring extends into the impeller sealing groove and is in clearance fit with the impeller sealing groove, a sealer inner gear ring is correspondingly arranged at the matching position of the sealer and the high-speed shaft, and the sealer inner gear ring is in clearance fit with the high-speed shaft; this technical scheme adopts the double seal structure of axial seal and circumference seal, and reasonable seal clearance and sealed number of teeth design in addition can reduce large-scale turbine vacuum pump's tolerance loss to the at utmost, still simplifies and optimizes spiral case, sealer and cooperation structure simultaneously, has realized improving assembly efficiency, extension sealed tooth life-span, reduces beneficial effect such as maintenance frequency.

Description

Heavy seal structure of turbine vacuum pump

Technical Field

The utility model belongs to the technical field of turbo machinery, concretely relates to heavy seal structure of turbine vacuum pump.

Background

The turbo vacuum pump is popular among users due to the advantages of high efficiency, energy conservation, large suction flow and the like, and is widely applied to the fields of papermaking, chemical engineering and the like at home and abroad. The turbine vacuum pump adopts saturated steam as a conveying medium, comb-tooth labyrinth seals are generally adopted at the shaft end and the interstage, however, along with the continuous increase of the gas demand of the turbine vacuum pump by a user, the gas capacity of a single impeller of the cantilever type turbine vacuum pump reaches 800m³Min and above, when the vacuum degree of the motor side is higher than 60kPa, the gas amount of the free side inlet reaches 1300m³At and above min, with such a large flow, it is difficult to ensure the air loss in the shaft seal design in the prior art, thereby affecting the performance of the main engine.

Disclosure of Invention

The utility model aims at providing a be suitable for heavy seal structure technical scheme of large-traffic, high vacuum's turbine vacuum pump to overcome the problem that exists among the prior art.

The heavy sealing structure of the turbine vacuum pump comprises a volute, an impeller, a sealer and a high-speed shaft which are connected and matched, and is characterized in that the inner side of the volute is connected and provided with an inner body of the volute, the front end of the impeller is connected and provided with an air inlet pipe through an impeller pressure plate, a back cover plate of the impeller is provided with an impeller sealing groove, the sealer is fixedly connected to the outer side of the volute and is sleeved on the high-speed shaft, an outer gear ring of the sealer is correspondingly arranged at the matching position of the sealer and the impeller, the outer gear ring of the sealer extends into the impeller sealing groove and is in clearance fit with the impeller sealing groove, the inner gear ring of the sealer is correspondingly arranged at the matching position of the sealer and the high-speed shaft, and clearance fit is adopted between the inner gear ring of the sealer and the high-speed shaft.

The heavy sealing structure of the turbine vacuum pump is characterized in that the air inlet pipe and the impeller pressure plate are respectively and fixedly connected to the inner body of the volute.

The heavy sealing structure of the turbine vacuum pump is characterized in that O-shaped sealing rings are respectively arranged between the air inlet pipe and the inner body of the volute, between the impeller pressure plate and the inner body of the volute, between the inner body of the volute and between the volute and the sealer to form the sealing structure.

The heavy sealing structure of the turbine vacuum pump is characterized in that a sealer positioning ring is arranged on the sealer corresponding to the matching position of the volute, and the sealer positioning ring is in close tolerance fit with the volute.

The heavy sealing structure of the turbine vacuum pump is characterized in that an assembly gap between an outer gear ring of the sealer and an impeller sealing groove is 0.3-0.6 mm.

The heavy sealing structure of the turbine vacuum pump is characterized in that an assembly gap between the inner gear ring of the sealer and the high-speed shaft is 0.25-0.5 mm.

The heavy sealing structure of the turbine vacuum pump is characterized in that the impeller is of a semi-open type structure and is fixedly connected to the end of a high-speed shaft.

The heavy sealing structure of the turbine vacuum pump is characterized in that the outer gear ring of the sealer, the inner gear ring of the sealer and the positioning ring of the sealer adopt a one-time clamping and machining forming structure. .

The heavy type sealing structure of the turbine vacuum pump is novel in design and reasonable in conception, adopts a double sealing structure of axial sealing and circumferential sealing, and adopts reasonable sealing clearance and sealing tooth number design, so that the air loss of the large turbine vacuum pump can be reduced to the greatest extent, and meanwhile, the volute, the sealer and the matching structure are simplified and optimized, so that the beneficial effects of improving the assembly efficiency, prolonging the service life of the sealing teeth, reducing the maintenance frequency and the like are achieved.

Drawings

FIG. 1 is a schematic view of the connection structure of the present invention;

FIG. 2 is a schematic view of a connection structure of the sealer;

in the figure: the device comprises a 1-volute, a 2-impeller, a 2 a-impeller sealing groove, a 3-sealer, a 3 a-sealer outer gear ring, a 3 b-sealer inner gear ring, a 3 c-sealer positioning ring, a 4-high-speed shaft, a 5-air inlet pipe, a 6-impeller pressure plate and a 7-volute inner body.

Detailed Description

The following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings:

as shown in the figure, the heavy sealing structure of the turbine vacuum pump comprises a volute 1, an impeller 2, a sealer 3 and a high-speed shaft 4 which are connected and matched, wherein the impeller 2 is of a semi-open structure, the impeller 2 is fixedly connected to the shaft end of the high-speed shaft 4, the inner side of the volute 1 is connected with a volute inner body 7, the front end of the impeller 2 is connected with an air inlet pipe 5 through an impeller pressure plate 6, the air inlet pipe 5 and the impeller pressure plate 6 are fixedly connected to the volute inner body 7 through bolt connection structures respectively, and an impeller sealing groove 2a is formed in the rear cover plate of the impeller 2; the sealer 3 is fixedly connected to the outer side of the volute 1 and is sleeved on the high-speed shaft 4, a sealer outer gear ring 3a is correspondingly arranged at the matching position of the sealer 3 and the impeller 2, and the sealer outer gear ring 3a extends into the impeller sealing groove 2a and is in clearance fit with the impeller sealing groove 2 a; the inner ring gear 3b of the sealer is correspondingly arranged at the matching position of the sealer 3 and the high-speed shaft 4, and the inner ring gear 3b of the sealer is in clearance fit with the high-speed shaft 4; a sealer positioning ring 3c is arranged on the sealer 3 corresponding to the matching position of the volute 1, and the sealer positioning ring 3c is in close tolerance fit with the volute 1; o-shaped sealing rings are respectively arranged between the air inlet pipe 5 and the volute inner body 7, between the impeller pressure plate 6 and the volute inner body 7, between the volute inner body 7 and the volute 1 and between the volute 1 and the sealer 3 to form sealing structures, and the O-shaped sealing structures and the shaft seal 3 form a cantilever type turbine vacuum pump main machine part-to-part sealing system, so that effective guarantee is provided for preventing flow loss.

In the above embodiment, the impeller pressure plate 6 and the impeller 2 form an impeller working flow channel, the volute 1 and the volute inner body 7 form an exhaust flow channel, when the device works, gas is sucked from the air inlet pipe 5, and reaches the exhaust flow channel through the impeller working flow channel rotating at a high speed, and the exhaust flow channel corresponds to the flow channel outlet of the impeller 2, so that high-temperature gas is finally formed and discharged from the outlet of the volute 1 at a high speed. Because the flow rate inside the volute 1 is constant under the fixed rotating speed, if the external atmosphere is sucked into the volute 1 by the vacuum inside the volute 1, the actual flow rate of the pumping vacuum point of the turbine vacuum pump is necessarily reduced, and therefore the shaft seal design is directly related to the performance of the turbine vacuum pump. The flow channel of the large volute of the cantilever type turbine vacuum pump is formed by smoothly connecting a plurality of irregular flow channel sections, a volute rear cover is usually arranged on the outer side of the volute in the prior art, the volute rear cover is of a split structure along an axial lead, a shaft seal is also designed to be of a split structure along the axial lead, and the shaft seal is embedded in the volute rear cover. The utility model discloses reform transform prior art's subdivision formula inlay dress bearing seal structure, optimize to integral side-mounting structure, the lid behind the spiral case has been cancelled, the spiral case structure has been simplified, sealer 3 directly closely cooperates the hookup in the spiral case 1 outside through sealer position circle 3c, assembly efficiency has been improved effectively, and spiral case 1 has been reduced, the spiral case back cover, the concentricity accumulative error between the bearing seal three, integral sealer structure still makes the circumference clearance between sealed tooth and the high-speed shaft 4 balanced, can prolong the life-span of sealed tooth, reduce maintenance frequency.

In the above embodiment, the outer ring gear 3a of the sealer provided on the sealer 3 is in clearance fit with the impeller seal groove 2a to form a set of seal pair, and the seal pair is arranged at a vortex caused by the pressure difference between the inside and the outside of the volute, preferably, the outer diameter of the outer ring gear 3a of the sealer is as far away from the high-speed shaft 4 as possible, and the larger the suction flow rate and the higher the suction vacuum degree are, the larger the outer diameter of the seal tooth of the outer ring gear 3a of the sealer is recommended to be designed; the inner ring gear 3b of the sealer arranged on the sealer 3 is in clearance fit with the high-speed shaft 4 to form a set of sealing pairs, the sealing pairs have the effect equivalent to that of a shaft sealer in the prior art, and the larger the suction flow is, the higher the suction vacuum degree is, the more the recommended sealing tooth number is; the inner gear ring 3b of the sealer is a plurality of sequentially arranged annular sealing teeth arranged around the high-speed shaft 4, a series of closure gaps and expansion cavities are formed among the teeth, and the sealed medium generates a throttling effect when passing through the gaps of the labyrinth to achieve the purpose of leakage prevention, so that most of the pressure of the atmosphere outside the volute is relieved after passing through the inner gear ring 3b of the sealer, and the residual pressure difference is balanced by a sealing pair where the outer gear ring 3a of the sealer is located, thereby achieving the purpose of sealing. The sealing capacity of labyrinth seal is related to the sealing tooth pitch, the action length of the tooth and the size of the gap between the rotating shafts, the sealing effect and the sealing capacity of the shaft seal in the prior art are both limited due to the limitation of the structural space, and in the implementation process of the utility model, because the sealer 3 is an independent part, preferably, the assembly gap between the excircle of the outer gear ring 3a of the sealer and the excircle of the impeller seal groove 2a is 0.3-0.6 mm, the assembly gap between the inner ring of the inner gear ring 3b of the sealer and the high-speed shaft 4 is 0.25-0.5 mm, the number of teeth of the sealer outer gear ring 3a and the sealer inner gear ring 3b is not less than 4, in the specific implementation process, can reasonably determine each group of sealing gaps according to the vacuum degree and the air extraction quantity of the turbine vacuum pump, reasonably design the sealing teeth number of each group, the sealing capability is maximized, and the sealing reliability of the high-flow high-vacuum turbine vacuum pump is improved; taking a papermaking vacuum system as an example, the optimized double-sealing pair can effectively prevent the atmosphere outside the volute 1 from being sucked into the volute 1 by high vacuum in the volute, and the reduction of the actual air quantity of the vacuum suction point of the turbine vacuum pump is avoided, so that the production efficiency of the paper machine is improved, and the paper quality is stabilized.

In the embodiment, the outer gear ring 3a, the inner gear ring 3b and the positioning ring 3c of the sealer are of a one-time clamping and machining structure, the positioning ring of the sealer is tightly matched with the volute, and the positioning ring 3c of the sealer and each sealing tooth are machined and formed at one time, so that the coaxiality between the sealer 3 and the volute 1 is fully ensured, and the safety and reliability of the unit are improved.

Preferably, the volute casing 1 is made of conventional wear-resistant materials, the impeller 2 is made of titanium alloy with good comprehensive performance, the high-speed shaft 4 is made of high-strength forged pieces, and the sealer 3 is made of materials with good flexibility and low hardness.

A heavy seal structure technical scheme of turbine vacuum pump, be suitable for large-traffic, high vacuum's turbine vacuum pump, for the limitation that compensaties the sealed effect length between bearing seal and the rotation axis, set up a set of circumference seal on the impeller back shroud, when the inside suction of spiral case outside gas, earlier through the throttle of the axial seal between sealer and rotation axis, then reach the sealed throttle of circumference between sealer and impeller, and through rationally setting up sealed effect length, the seal clearance, the actual tolerance of suction point has been improved, sealed life has been prolonged, the maintenance frequency has been reduced.

Claims

1. A heavy sealing structure of a turbine vacuum pump comprises a volute (1), an impeller (2), a sealer (3) and a high-speed shaft (4) which are connected and matched, the novel spiral casing sealing device is characterized in that a spiral casing inner body (7) is connected and arranged on the inner side of a spiral casing (1), an air inlet pipe (5) is connected and arranged at the front end of an impeller (2) through an impeller pressure plate (6), an impeller sealing groove (2 a) is arranged at the rear cover plate of the impeller (2), a sealer (3) is fixedly connected to the outer side of the spiral casing (1) and is sleeved on a high-speed shaft (4), a sealer outer gear ring (3 a) is correspondingly arranged at the matching position of the sealer (3) and the impeller (2), the sealer outer gear ring (3 a) extends into the impeller sealing groove (2 a) and is in clearance fit with the sealer, a sealer inner gear ring (3 b) is correspondingly arranged at the matching position of the sealer (3) and the high-speed shaft (4), and clearance fit is adopted between the sealer inner gear ring (3 b) and the high-speed shaft (4).

2. A heavy duty seal construction for a turbine vacuum pump according to claim 1, characterized in that said inlet pipe (5) and said impeller pressure plate (6) are fixedly attached to the inner volute body (7), respectively.

3. The heavy-duty sealing structure of a turbo vacuum pump according to claim 1, characterized in that O-ring seals are disposed between the air inlet pipe (5) and the volute inner body (7), between the impeller pressure plate (6) and the volute inner body (7), between the volute inner body (7) and the volute (1), and between the volute (1) and the sealer (3) to form sealing structures.

4. The heavy-duty sealing structure of a turbine vacuum pump according to claim 1, characterized in that a sealer positioning ring (3 c) is provided on the sealer (3) corresponding to the fitting position of the volute (1), and the sealer positioning ring (3 c) and the volute (1) are in close tolerance fit.

5. The heavy type sealing structure of the turbine vacuum pump according to claim 1, wherein the assembly clearance between the sealer outer gear ring (3 a) and the impeller sealing groove (2 a) is 0.3-0.6 mm.

6. The heavy-duty sealing structure of a turbine vacuum pump according to claim 1, wherein an assembly clearance between the inner ring gear (3 b) of the sealer and the high-speed shaft (4) is 0.25 to 0.5 mm.

7. The heavy-duty sealing structure of a turbine vacuum pump according to claim 1, wherein said impeller (2) is a semi-open type structure, and the impeller (2) is fixedly coupled to the shaft end of the high-speed shaft (4).

8. The heavy-duty sealing structure of the turbine vacuum pump according to claim 4, characterized in that the sealer outer ring gear (3 a), the sealer inner ring gear (3 b) and the sealer positioning ring (3 c) are formed by one-time clamping.