CN110735791A

CN110735791A - oil-free enclosed roots blower using water vapor

Info

Publication number: CN110735791A
Application number: CN201911014896.8A
Authority: CN
Inventors: 孙属恺; 邵星宇; 李岱泽; 钟绍东; 陈红; 廖小虎
Original assignee: Nanchang University
Current assignee: Nanchang University
Priority date: 2019-10-23
Filing date: 2019-10-23
Publication date: 2020-01-31
Anticipated expiration: 2039-10-23
Also published as: CN110735791B

Abstract

The invention relates to an oil-free closed type water vapor roots blower, wherein gears and bearings are made of self-lubricating materials, lubricating oil can not be filled in a gear box, an air inlet is arranged in the gear box, through reasonable flow passage design in the gear box, air flow flows through friction parts of the gears and the bearings, the air flow can take away heat generated by friction, liquid foam in the water vapor can lubricate a friction pair with water, the influence of friction and temperature rise in an oil-free environment on the reliability of the roots blower is improved, non-contact type sealing is arranged between a cylinder and the gear box, the requirement of a dynamic sealing piece on the lubricating oil can be eliminated, a driving shaft of the roots blower adopts a non-contact type coupling, and the closed type static sealing of a shell of the roots blower is realized through an isolation sleeve of the coupling.

Description

oil-free enclosed roots blower using water vapor

Technical Field

The invention relates to the technical field of Roots blowers, in particular to an oil-free closed type water vapor Roots blower.

Background

The water vapor compressor is which is a key component for material concentration and seawater desalination by utilizing a mechanical steam recompression technology, secondary steam is sucked from an evaporation chamber, the pressure and the temperature of the secondary steam are improved through a self mechanical structure, so that the energy source grade of the secondary steam is improved, discharged gas reaches the process parameters of raw steam required by a production process, and then the discharged gas is led into a heating coil of the evaporation chamber to be used as heating steam, so that the dependence of a production system on a steam source is reduced, and the equipment investment is reduced.

The Roots blower as kinds of double-shaft positive displacement gas conveying pressurizing machinery has two working shafts as driving shafts connected to motor via shaft coupling or belt pulley and driven by the motor, and as driven shafts rotating with the driving shafts driven by synchronous gears.

However, for mechanical vapor recompression processes, the process is very sensitive to the oil and gas content of the vapor. Firstly, the mechanical vapor recompression process usually adopts vacuum evaporation, the pressure in the roots blower can be lower than the external atmospheric pressure, unreliable sealing can lead air to leak into a cylinder, so that vapor is entrained with air, and the condensation heat transfer coefficient of the subsequent process of the vapor can be reduced by 10% by containing 1% of air in the vapor, so that great waste and even failure of the production flow can be caused, and if the motor of the roots blower is designed in the roots blower according to a refrigerator compressor, the leaked vapor can lead to the damage of the motor. Thirdly, water vapor in the cylinder permeates into the gear box along the shaft and is condensed in the gear box, so that the oil in the gear box is emulsified, and the lubricating oil loses the lubricating effect; finally, the industries adopting the mechanical steam recompression process are food, biological, pharmaceutical and other industries, the cleanliness requirement on the steam working medium is very high, and the subsequent process cannot meet the standard requirement due to the fact that lubricating oil permeates into a cylinder to pollute the steam.

Disclosure of Invention

The invention aims to provide oil-free closed type water vapor roots blowers aiming at the defects of the roots blowers in the application of a mechanical vapor recompression process, the blowers adopt an oil-free design to avoid mutual pollution between water vapor and lubricating oil, and simultaneously, adverse effects of dry friction of gears, bearings and dynamic sealing parts, incapability of dissipating friction heat and the like caused by the lack of the lubricating oil are eliminated through reasonable flow passage and sealing design and material selection.

In order to achieve the purpose, the invention adopts the technical scheme that:

oil-free closed type water vapor Roots blower, which comprises a casing, a driving shaft and a driven shaft arranged in the casing, a wall plate, a gear box side plate, a flange plate, two closed cavities consisting of the gear box side plate, the casing, the flange plate and the wall plate which are fixed with each other, a cylinder and a gear box, and an air inlet pipeline arranged on the side surface of the gear box, wherein a driving gear arranged on the driving shaft is engaged with a driven gear arranged on the driven shaft, a driving shaft main bearing and a driving shaft end bearing are arranged on the driving shaft, a driven shaft main bearing and a driven shaft end bearing are arranged on the driven shaft, and;

the shell and the side plate of the gear box are internally provided with air inlet main flow passages, air inlet side flow passages, air guide rings, axial air guide grooves and flow passage spaces of a confluence passage, and the flow passage spaces surround the periphery of a driving shaft end bearing, a driven shaft end bearing, a driving shaft main bearing and a driven shaft main bearing; the non-air inlet end of the gear box is provided with a special-shaped flow passage which is communicated with the low-pressure end of the gear box and the cylinder; the shaft seal between the gear box and the cylinder adopts non-contact sealing; the non-contact coupling with an isolating sleeve is adopted at the extension end of the driving shaft to assist the shell to seal the whole Roots blower.

The interior of the air inlet pipeline is a plum blossom-shaped through hole, the end of the air inlet pipeline is a standard flange circular opening and can be connected with an upstream steam pipeline, and the end of the air inlet pipeline is plum blossom-shaped and is connected with an air inlet flow channel on an air flow distribution disc on a shell of the roots machine.

The air flow distribution disc is internally provided with an annular protrusion which divides the air flow distribution disc into an inner ring and an outer ring, the inner ring is internally provided with an air inlet main runner which is opposite to a meshing point of a driving gear and a driven gear, after water vapor from an air inlet pipeline is distributed by the air flow distribution disc, the gas in the inner ring is guided to a gear meshing part by the air inlet main runner to take away friction heat generated by high-speed meshing of the gears;

the air inlet side flow channel is connected with the airflow distribution plate and the axial air guide groove.

The converging flow passage is connected with the axial air guide groove and the gear box or the special-shaped flow passage.

The axial air guide grooves are four rectangular grooves which are arranged in a stepped hole for mounting the bearing at intervals of 90 degrees and play a role of communicating air guide rings at two sides of the bearing, wherein axial air guide grooves which are positioned at the horizontal positions are connected with an air inlet side runner, and axial air guide grooves are connected with a confluence runner.

The air guide rings are respectively arranged on two sides of the driving shaft end bearing, the driven shaft end bearing, the driving shaft main bearing and the driven shaft main bearing, and are two annular air flow channels which are parallel to the side face of the bearing and formed on two sides of the bearing through the stepped hole, the bearing retainer ring, the shaft and the flange plate part in the stepped hole for mounting the bearing. The high-speed water vapor containing liquid foam flows into the axial air guide grooves from the air inlet side flow channel and is distributed to the air guide rings on two sides of the bearing, because two sides of the bearing are the components of the two air guide rings, high-speed air flow is in full contact with the surface of the bearing, the liquid foam carried by the air flow can carry out water lubrication on the ceramic bearing while the generated friction heat is taken away through the evaporation of the air flow or the liquid carried by the air flow, and after the heat dissipation and the lubrication are finished, the air flow enters the opposite axial air guide grooves and flows out from the confluence channel.

The special-shaped flow passage is communicated with the cylinder and the gear box, and the steam in the gear box and the converging flow passage is led into the low-pressure end in the cylinder of the Roots blower. The special-shaped flow passage is gradually reduced from the gear box to the cylinder of the Roots blower, so that the air flow in the gear box can be stabilized, and the suction pulsation is reduced. The reason for adopting the special-shaped flow channel is to increase the sectional area of the flow channel as much as possible in the limited volume and reduce the flow resistance loss.

of the two gears in the gear box is made of high-strength self-lubricating engineering plastics, and is a corrosion-resistant metal material.

The driving shaft main bearing, the driving shaft end bearing, the driven shaft main bearing and the driven shaft end bearing are all ceramic bearings.

The non-contact seal is a labyrinth seal, labyrinth seals are arranged between the driven shaft and the upper flange plate and between the driving shaft and the lower flange plate, and the labyrinth seal is composed of a labyrinth seal static ring and a labyrinth seal moving ring.

The non-contact type coupler is a magnetic coupler and comprises a magnetic coupler inner ring, a magnetic coupler outer ring and a magnetic coupler isolation sleeve, wherein the magnetic coupler inner ring and the extension end of a driving shaft of the Roots blower are installed at , the magnetic coupler isolation sleeve is connected with a machine shell at , the magnetic coupler outer ring is connected with a driving motor shaft at , the three components are not in contact with each other, when the outer ring rotates along with the motor, the inner ring rotates along with the outer ring and drives a driving rotor to rotate under the action of magnetic coupling, but the isolation sleeve between the inner ring and the outer ring does not rotate, so that static sealing is realized between the isolation sleeve and the machine shell, the sealing reliability is extremely high, and water vapor leakage and outside air entering are avoided.

The roots type blower is characterized in that a gear in a gear box is made of a self-lubricating material, a bearing is made of a water-lubricated ceramic bearing, the bearing is free from dependence on lubricating oil on lubrication, a non-contact type seal is adopted between the gear box and a cylinder, the dependence on the lubricating oil on sealing is avoided, an air inlet pipeline is arranged on the side face of the gear box, an air inlet main runner, an air inlet side runner, an air guide ring and an axial air guide groove are arranged in the gear box through an air flow distribution disc and a machine shell, a junction point of a gear and a bearing are in relative motion through a confluence channel, liquid foam is inevitably entrained by the water vapor flowing into the blower, heat generated by relative motion friction of the junction point is taken away through high-speed air flow and liquid foam evaporation, the dependence on the lubricating oil on roots cooling is avoided, meanwhile, the air flow carries the liquid to carry out water lubrication on the gear and the bearing to a certain degree at , a special-shaped flow channel is arranged between the gear box and the cylinder, the water vapor which is collected in the gear box through the confluence flow channel and then is led into the cylinder of the roots type flow channel to pass through the Roots type flow channel, the gas flow channel, the non-contact type seal is adopted to avoid the requirement that the non-contact type seal is adopted to prevent the non-contact type seal, and the non-contact type seal is adopted to prevent the non.

Compared with the prior art, the invention has the following beneficial effects:

the gear and the bearing are made of self-lubricating or water-lubricating materials, so that oil does not exist in the working cavity of the Roots blower, the phenomenon that the lubricating oil is emulsified and failed or the water vapor is polluted by the lubricating oil when the traditional Roots blower compresses and transports the water vapor is avoided, heat is taken away by the Roots blower when the air is sucked and a large number of components generating friction heat, such as the gear and the bearing and the like, and the reliability of the Roots blower in an oil-free working state is improved.

Drawings

FIG. 1 is a longitudinal cross-sectional view of a ROOTS blower of the present invention;

FIG. 2 is a transverse cross-sectional view of the ROOTS blower of the present invention;

FIG. 3 is a Roots blower housing schematic

FIG. 4 is a partial sectional top view of the present invention

FIG. 5 is a sectional view taken along line A-A of FIG. 1

FIG. 6 is a B-B rotary step cross-sectional view of FIG. 2

FIG. 7 is a schematic view of an air intake circuit

In the drawing, the bearing comprises a driving shaft end bearing 1, a driving shaft end bearing 2, a third bearing retainer ring 2, a driven shaft end bearing 3, a fourth bearing retainer ring 4, a gearbox side plate 5, a 6 machine shell, a driving gear 7, a driven gear 8, a driven shaft sleeve 9, a driven shaft main bearing 10, a labyrinth seal movable ring 11, a driven rotor 12, a driven shaft 13, a labyrinth seal fixed ring 14, an upper flange 15, a lower flange 16, a gasket 17, a driving shaft 18, a driving rotor 19, an O-shaped ring 20, a driving shaft main bearing 21, a driving shaft sleeve 22, a special-shaped runner 23, a quincunx-shaped through hole 24, an air inlet pipeline 25, an air inlet pipeline 26, a wall plate 26, an air inlet main runner 27, an air inlet side runner 28- , a second air inlet side runner 29-a third air inlet side runner 30, a stepped third air inlet side runner 611, a fourth air inlet side runner 32-key 33-gearbox 34, an air cylinder 34, an air outlet 35, a circular air inlet nut 36, a circular air stop washer 38, a magnetic air nut 38-magnetic force nut 613, a magnetic force air gathering outer ring coupler 611, a fourth air ring coupler 38-39-57, a fourth air guide ring coupler 601-60, a fourth air guide ring coupler 57-57, a fourth air guide ring coupler 57, a fifth air guide ring coupler 57-seventh air guide ring coupler 57, a sixth air guide ring coupler 57-axial guide ring coupler 57, a third air guide ring coupler 57, a fifth air guide ring coupler 3635-60, a sixth air guide ring coupler 57-seventh air guide ring coupler 3635-60, a fifth air guide ring 26, a sixth air guide ring coupler, a fifth air guide ring coupler, a sixth air guide ring coupler 57-60-a sixth air guide ring coupler, a sixth air.

Detailed Description

The invention is further described in step with reference to the accompanying drawings in which:

referring to fig. 1, oil-free closed type water vapor roots blower comprises a casing 6, a driving shaft 18 and a driven shaft 13 arranged in the casing, a wall plate 26, a gear box side plate 5, a flange plate, two closed cavities consisting of the gear box side plate, the casing, the flange plate and the wall plate which are fixed with each other, namely a cylinder 34 and a gear box 33, and an air inlet pipeline 25 arranged on the side surface of the gear box, wherein a driving gear 7 arranged on the driving shaft is meshed with a driven gear 8 arranged on the driven shaft, a driving shaft main bearing 21 and a driving shaft end bearing 1 are arranged on the driving shaft, a driven shaft main bearing 10 and a driven shaft end bearing 3 are arranged on the driven shaft, and an.

The shell 6 and the gear box side plate 5 are internally provided with an air inlet main flow passage 27, an air inlet side flow passage, an air guide ring, an axial air guide groove and a confluence flow passage space which are surrounded at the peripheries of the driving shaft end part bearing 1, the driven shaft end part bearing 3, the driving shaft main bearing 21 and the driven shaft main bearing 10; the non-air inlet end of the gear box 33 is provided with a special-shaped flow passage 23 which is communicated with the low-pressure end of the gear box and the cylinder; the shaft seal between the gear box and the cylinder adopts non-contact sealing; the non-contact coupling with an isolating sleeve is adopted at the extension end of the driving shaft to assist the shell to seal the whole Roots blower.

Referring to fig. 3 and fig. 7, an end of an air inlet pipeline 25 is open so as to be connected with a process upstream steam pipeline, the other end is connected with a roots machine casing 6 at , a tapered plum blossom-shaped through hole 24 is formed inside the air inlet pipeline 25, the plum blossom-shaped through hole 251 corresponds to an air flow distribution disc 601 on the roots machine casing 6, an annular protrusion 602 is arranged in the air flow distribution disc 601 to divide the air flow distribution disc 601 into an inner ring 603 and an outer ring 604, an air inlet main flow passage 27 is arranged in the inner ring 603, four air inlet side flow passages, namely a air inlet side flow passage 28, a second air inlet side flow passage 29, a third air inlet side flow passage 30 and a fourth air inlet side flow passage 31, are uniformly and sequentially distributed in the outer ring 604, liquid-carrying steam introduced from the upstream steam pipeline flows to the air flow distribution disc 601 through the plum blossom-shaped through hole 251 in the air inlet pipeline 25, part of the flows into the air inlet flow passage 27 in the inner ring 603 under the action of the annular protrusion 602, and flows into the gear box 33, and part of the gear box 29 flows into the third air inlet side flow passage 30 and the fourth air inlet flow passage 31 along.

Referring to fig. 2, the air inlet main flow passage 27 directly faces the meshing point of the driving gear 7 and the driven gear 8 in the gear box 33, between the driving gear 7 and the driven gear 8 is made of high-strength self-lubricating engineering plastic, and of the driving gear 7 and the driven gear 8 are made of corrosion-resistant metal materials, based on the characteristics of the self-lubricating materials, the driving gear 7 and the driven gear 8 which are meshed and rotated at high speed in the gear box 33 can stably work under the conditions of no oil and no high temperature when the roots blower works.

With reference to fig. 1 and 6, a second stepped bore 621 is provided in the middle of the housing 6 of the roots machine for receiving the driven shaft main bearing 10, a 0 th retaining ring 631 is provided outside the second stepped bore 621, the 1 st stepped bore 621, the driven shaft main bearing 10, the 2 nd retaining ring 631 and the driven gear 8 enclose a 3-th annular space as a 4 th air guide ring 611, the 5 th stepped bore 621 further 6 ends communicate with the upper flange 15, the driven shaft main bearing 10, and the driven shaft 13 to enclose a second air guide ring 612, the 7 th stepped bore 621 is circumferentially spaced by 90 ° with 8 th axial air guide grooves 622(a), (b), (c), (d), the 9 th axial air guide groove communicates with the second air guide ring 611 and the second air guide ring 612, the two 0 th axial air guide grooves 622(a) and the 2 inlet side flow passage 28 in a horizontal position communicate with the 2 th air inlet side flow passage 28, the 3 other axial air guide grooves 622(c) communicate with the 4 th air guide passage 71, the 5 th air guide passage 71 communicates with the 6 th axial air guide groove 622(c) and the second air guide groove 71 (c) and the second axial air guide groove 23, the second main bearing ring 28, the second axial air guide ring main bearing ring 28, the second axial air guide ring 30, the second axial air guide ring 24, the second axial air guide ring 30, the second axial air guide groove 28, the second axial guide ring main bearing groove 28, the second axial guide ring guide groove 28, the second axial guide ring main bearing groove 28, the second axial guide ring 24, the second axial guide ring main bearing groove 23, the second axial guide ring main bearing groove 28, the second axial guide ring 24, the second axial guide groove 23, the second axial guide ring 24, the second axial guide ring main bearing groove 28, the second axial guide ring 24, the second axial guide ring guide groove 28, the second axial guide groove 23, the second axial guide ring main bearing groove 28, the third axial guide ring 24, the second axial guide ring main bearing groove 28, the second axial guide ring 24, the third axial guide groove 28, the third axial guide groove 23, the second axial guide groove 28, the second axial guide ring guide groove 28, the third axial guide groove 23, the second axial guide groove 28, the second axial guide.

Referring to fig. 1, fig. 4 and 6 show a third stepped bore 625 for receiving the driven shaft end bearing 3 in the upper portion of the gearbox side plate 5, a third bearing retainer 2 is provided outside the third stepped bore 625, the driven shaft end bearing 3, the third bearing retainer 2 and the driven shaft sleeve 9 enclose annular spaces as a fifth gas guide ring 615, the third stepped bore 625 further end communicates with the gearbox side plate 5, the driven shaft end bearing 3, and the driven shaft 13 enclose a sixth gas guide ring 616, the third stepped bore 625 is circumferentially spaced apart by 90 ° to form third axial gas guide grooves 626(a), (b), (c), (d), the third axial gas guide groove communicates with the fifth gas guide ring 615 and the sixth gas guide ring 616, the two third axial gas guide grooves 626(a) thereof in the horizontal position communicate with the third gas inlet side flow passage 30, the third axial gas guide groove 626(a) and the fourth axial gas guide ring 18 (b) are provided in the lower portion of the gearbox side plate 5 for receiving the fourth gas bearing end bearing 1, 627, the fourth axial

gas guide ring

618, 627, the fourth axial gas guide ring 70, the fourth axial flow passage 618, the fourth axial flow passage 70, the fourth axial gas guide ring 70, the fourth axial flow passage 618 (b) is provided in the fourth axial direction, the fourth axial gas guide ring 18, the fourth axial flow passage 618, the fourth axial flow passage 18, the fourth axial flow passage 618, the fourth axial flow passage 18, the fourth axial flow passage 70, the fourth axial flow passage 18, the fourth axial flow passage 618, the fourth axial flow passage 18, the fifth axial flow passage 18, the fourth axial flow passage 618, the fourth axial flow passage 18, the fourth axial flow passage 70, the fourth axial flow passage, the fifth axial flow passage, the fourth axial flow passage 18, the fourth axial flow passage, the fifth axial flow passage 18, the fourth axial flow passage 18, the fifth axial flow passage, the fourth axial flow passage 18, the fourth axial flow passage 18.

The driving shaft main bearing 21, the driven shaft main bearing 10, the driven shaft end bearing 3 and the driving shaft end bearing 1 are all ceramic bearings, and liquid foam in steam can lubricate the ceramic bearings when the steam passes through, so that friction and abrasion are reduced.

Referring to fig. 2 and 7, a special-shaped flow passage 23 communicating a gear box 33 and a cylinder 34 is arranged in a housing 6 of the roots machine, the special-shaped flow passage 23 is in a tapered design and can play a role of constant flow, and the gas flow entering the gear box 33 from an air inlet main flow passage 27 to cool

gears

7 and 8 and the gas flow after cooling bearings led out from a third collecting flow passage 73 and a fourth collecting flow passage 74 directly flow into the cylinder 34 from the gear box 33 through the special-shaped flow passage 23, and the gas led out from a collecting flow passage 71 and a second collecting flow passage 72 directly flows into the cylinder 34 through the special-shaped flow passage 23 and is then compressed and conveyed to an exhaust port 35 along with the rotation of a driven rotor 12 and a driving rotor 19.

Referring to fig. 1, labyrinth seals are arranged between the driven shaft 13 and the upper flange 15, and between the driving shaft 18 and the lower flange 16, and each labyrinth seal is composed of a labyrinth seal static ring 14 and a labyrinth seal moving ring 11, so that high-pressure high-temperature gas at the exhaust port 35 is prevented from leaking to the gear box 33 through gaps between the driven shaft 13 and the upper flange 15, and gaps between the driving shaft 18 and the lower flange 16. Through the non-contact dynamic seal between the labyrinth seal dynamic ring 11 and the labyrinth seal static ring 14, the low efficiency caused by leakage due to no sealing piece can be avoided, the extra resistance loss caused by the contact dynamic seal and the requirement on lubricating oil are avoided, and the Roots blower can work in an oil-free environment for a long time.

Referring to fig. 1, the motor end of the driving shaft 18 is connected to the driving motor by a magnetic coupling assembly, which includes a magnetic coupling outer ring 39, a magnetic coupling inner ring 38, and a magnetic coupling spacer 40. Wherein the inner ring 38 of the magnetic coupling is sleeved on the driving shaft 18, the circumferential sliding of the inner ring 38 of the magnetic coupling and the driving shaft 18 is prevented through the key 32, and the axial sliding is prevented through the round nut 36 and the round nut stop washer 37. The outer ring 39 of the magnetic coupling is connected with the motor shaft. The magnetic coupling outer ring 39 rotates along with the motor, the magnetic coupling inner ring 38 is driven by the coupled magnetic force to further drive the roots blower to operate, the magnetic coupling inner ring 38 is not in contact with the magnetic coupling outer ring 39, the magnetic coupling isolation sleeve 40 plays a role in isolating and sealing between the magnetic coupling inner ring 38 and the magnetic coupling outer ring 39, all seals in the roots blower shell are static seals, and gas leakage or external air entering the roots blower can be effectively prevented.

The foregoing merely represents preferred embodiments of the invention, which are described in some detail and detail, and therefore should not be construed as limiting the scope of the invention. It should be noted that, for those skilled in the art, various changes, modifications and substitutions can be made without departing from the spirit of the present invention, and these are all within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

The oil-free closed water vapor Roots blower is characterized by comprising a shell, a driving shaft, a driven shaft, a wall plate, a gear box side plate, a flange plate, two closed cavities consisting of the gear box side plate, the shell, the flange plate and the wall plate which are fixed mutually, an air cylinder, a gear box and an air inlet pipeline arranged on the side face of the gear box, wherein the driving gear arranged on the driving shaft is meshed with a driven gear arranged on the driven shaft, the driving shaft is provided with a driving shaft main bearing and a driving shaft end bearing, the driven shaft main bearing and a driven shaft end bearing are arranged on the driven shaft, an air flow distribution plate is arranged at the connecting part of the air inlet pipeline and the gear box, an air inlet main channel, an air inlet side channel, an air guide ring, an axial air guide groove and a converging channel space are arranged in the shell and the gear box side plate, the channel spaces surround the driving shaft end bearing, the driven shaft end bearing, the driving shaft main bearing and the driven shaft main bearing, a special-shaped channel is arranged at the non-air inlet end of the gear box and is communicated with the low.
2. An oil-free enclosed Roots blower for steam as claimed in claim 1, wherein the inlet conduit has a quincunx through-hole therein, a end of which is a standard flanged circular opening for connection to an upstream steam conduit, and a end of which is a quincunx shape for connection to an inlet flow channel in a flow distribution plate on the housing of the Roots blower.
3. An oil-free enclosed Roots blower for water vapor as claimed in claim 1, wherein the disk has an annular protrusion dividing the disk into an inner ring and an outer ring, the inner ring has a main inlet channel facing the meshing point of the driving gear and the driven gear, after the water vapor from the inlet pipe is distributed by the disk, the gas in the inner ring is guided to the meshing point of the gears by the main inlet channel to take away the friction heat generated by the high-speed meshing of the gears, the outer ring has four inlet side channels, namely, a inlet side channel, a second inlet side channel, a third inlet side channel and a fourth inlet side channel, the gas in the outer ring flows into the four inlet side channels uniformly, and the inlet side channels connect the disk and the axial guide channel.
4. An oil-free enclosed Roots blower for water vapor as set forth in claim 1, wherein the converging passage connects the axial air guide groove and the gear box or the contoured passage.
5. An oil-free enclosed Roots blower for water vapor as claimed in claim 1, wherein the axial air guide grooves are four rectangular grooves formed every 90 ° in the stepped hole for mounting the bearing and serving as air guide rings for communicating both sides of the bearing, wherein horizontal axial air guide grooves are connected to the inlet side flow passage, and axial air guide grooves are connected to the collecting flow passage.
6. An oil-free closed Roots blower for water vapor as claimed in claim 1, wherein the air guide rings are respectively disposed at two sides of the driving shaft end bearing, the driven shaft end bearing, the driving shaft main bearing and the driven shaft main bearing, and the air guide rings are two annular air flow passages formed at two sides of the bearing parallel to the side surfaces of the bearing through the stepped hole, the bearing itself and the bearing retainer ring, the shaft and the flange part in the stepped hole for mounting the bearing.
7. An oil-free enclosed Roots blower for water vapor as set forth in claim 1, wherein the contoured flow path communicates between the cylinder and the gear box to direct water vapor from the gear box and the converging flow path to the low pressure side of the Roots blower cylinder, and wherein the contoured flow path tapers from the gear box to the cylinder.
8. An oil-free enclosed type water vapor Roots blower as claimed in claim 1, wherein of the two gears in the gearbox is made of high-strength self-lubricating engineering plastic, is made of corrosion-resistant metal material, and the driving shaft main bearing, the driving shaft end bearing, the driven shaft main bearing and the driven shaft end bearing are all ceramic bearings.
9. An oil-free enclosed Roots blower for water vapor as set forth in claim 1, wherein the non-contact seals are labyrinth seals, and the labyrinth seals are disposed between the driven shaft and the upper flange plate and between the driving shaft and the lower flange plate, and are composed of a static labyrinth seal ring and a dynamic labyrinth seal ring.
10. The oil-free enclosed Roots blower for water vapor as claimed in claim 1, wherein the non-contact coupling is a magnetic coupling, the coupling is divided into three components, namely, a magnetic coupling inner ring, a magnetic coupling outer ring and a magnetic coupling isolation sleeve, the magnetic coupling inner ring and the drive shaft extension end of the Roots blower are mounted at , the magnetic coupling isolation sleeve is connected with the housing at , the magnetic coupling outer ring and the drive motor shaft are connected at , the three components are not in contact with each other, when the outer ring rotates with the motor, the inner ring rotates with the outer ring and drives the drive rotor to rotate due to the magnetic coupling, the isolation sleeve between the inner ring and the outer ring does not rotate, the isolation sleeve and the housing are static seal, the sealing reliability is very high, and water vapor leakage and external air entry are avoided.