CN110410153B

CN110410153B - Static pressure air bearing pneumatic motor

Info

Publication number: CN110410153B
Application number: CN201910678074.3A
Authority: CN
Inventors: 何立爽
Original assignee: Beijing Defeng Liuhe Technology Development Co ltd
Current assignee: Beijing Defeng Liuhe Technology Development Co ltd
Priority date: 2019-07-25
Filing date: 2019-07-25
Publication date: 2021-08-13
Anticipated expiration: 2039-07-25
Also published as: CN110410153A

Abstract

The invention provides a static pressure air bearing pneumatic motor, which improves the rigidity of an air film by optimizing a traditional air bearing pneumatic coating motor, and simultaneously enables a rotating shaft to rotate more stably and can bear higher rotating speed. The air bearing air motor includes: the device comprises a main body, a rotating shaft, a radial air bearing, a thrust bearing, an impeller, an equal-height ring and a power ring; the radial air bearing is integrally improved, so that the air supply layout is more reasonable, and the air film rigidity is improved. Through improving the power ring, make its interference immunity strong, the rotation of axis of rotation is more steady, and can bear higher rotational speed.

Description

Static pressure air bearing pneumatic motor

Technical Field

The invention relates to a pneumatic motor, in particular to a static pressure air bearing pneumatic motor, and belongs to the field of air lubrication bearings and pneumatic high-speed running motors.

Background

At present, the coating field mainly uses a high-pressure air spraying principle for spraying, and has the defects of uneven dispersion of the coating, large size difference of coating particles, and uneven atomization area formed by the coating due to unstable spraying air flow. Therefore, the coating effect formed on the surface of the coating body is not preferable.

In the field of middle-end coating, a centrifugal atomization mechanical bearing motor is applied to a spraying process. But the rotating speed can not reach the nano-scale atomization degree of the coating, so that the surface of the product can not achieve good light reflecting effect. The service life of the mechanical bearing motor is very low after the rotating speed exceeds 30000rpm, and the service life of the mechanical bearing motor can hardly meet the use requirement when the rotating speed exceeds 60000 rpm. Meanwhile, the mechanical bearing vibrates greatly, and the atomization uniformity is also influenced.

Air bearing pneumatic paint motors have been developed in the high end painting field. The coating motor overcomes the technology of combining an air bearing and a power impeller, and has the advantages of high rotating speed of 60000-. Therefore, the air bearing pneumatic coating motor is a development trend of the spraying process of the future high-end coating industry.

The existing coating motor air bearing has low air film rigidity and low dynamic balance level, so that the service life of the coating motor air bearing is very low when the coating motor air bearing is maintained at the highest rotating speed, meanwhile, the anti-interference performance is poor, the power air passage structure layout of a power ring is deviated to one side, and once the coating motor air bearing is interfered, the coating motor air bearing is easy to unbalance.

Disclosure of Invention

In view of this, the invention provides a static pressure air bearing pneumatic motor, which improves the rigidity of an air film, makes the rotation of a rotating shaft more stable and can bear higher rotation speed by optimizing the traditional air bearing pneumatic coating motor.

The static pressure air bearing pneumatic motor comprises: the device comprises a main body, a rotating shaft, a radial air bearing, a thrust bearing, an impeller, an equal-height ring and a power ring;

a shaft shoulder is arranged in the middle of the rotating shaft, one side of the shaft shoulder is a head part of the rotating shaft, and the other side of the shaft shoulder is a tail part of the rotating shaft; the head part of the rotating shaft is coaxially supported in the main body through a radial air bearing; the radial air bearing provides radial support for the rotating shaft after air is provided by the air bearing air inlet channel;

thrust air bearings serving as thrust bearings are arranged at two ends of a shaft shoulder of the rotating shaft respectively; the thrust bearing provides support in the thrust direction for the rotating shaft after gas is provided by the air bearing gas inlet channel;

the equal-height ring and the impeller are coaxially sleeved on a shaft shoulder in the middle of the rotating shaft, and the impeller is fixedly connected with the rotating shaft and used for driving the rotating shaft to rotate around the axis of the rotating shaft; a power ring is coaxially sleeved outside the impeller, and a power gas source air inlet channel supplies gas to the impeller through an air channel on the power ring so as to drive the impeller to rotate; the equal-height ring seals an air passage on the power ring, and the thickness of the equal-height ring is consistent with that of the power ring and the shaft shoulder of the rotating shaft;

the tail part of the rotating shaft is sleeved with an upper end cover, and the upper end cover, the equal-height ring and the power ring are fixedly connected;

more than two annular grooves are axially distributed on the outer circumferential surface of the radial air bearing to serve as air storage bins; the air storage bins are communicated with the air bearing air inlet channel, and more than two throttling holes are distributed on the inner bottom surface of each air storage bin along the circumferential direction and are used as radial air bearing high-pressure air inlet holes; two adjacent gas storage bins are communicated through a pressure equalizing channel;

the gas inside the pneumatic motor is discharged through an exhaust passage.

The air passage on the power ring comprises an air distribution groove and a jet hole; the air distribution groove circumferentially envelops an arc section outside an arc area where the exhaust holes and the brake holes are located on the end face of the power ring; the air distribution groove is communicated with the power air source air inlet channel;

more than two airflow channels distributed along the circumferential direction are arranged at the position of the air distribution groove on the power ring and are used as spray holes for spraying air into the impeller and driving the impeller to rotate;

and the brake hole sprays gas into the impeller through the brake air inlet channel along the brake direction for braking the impeller.

The radial air bearing is made of porous medium graphite.

Advantageous effects

(1) The radial air bearing is integrally improved, so that the air supply layout is more reasonable, and the air film rigidity can be effectively improved.

(2) Through improving the power ring, make its interference immunity strong, the rotation of axis of rotation is more steady, and can bear higher rotational speed.

(3) The pneumatic motor has high rotation stability and high rotation speed (which can reach 80000-.

(4) The high-pressure air passage, the negative-pressure air passage, the rotating air passage, the tail gas exhaust passage and other gas passages are reasonably distributed, and the space utilization rate is high.

(5) Meanwhile, the rotating shaft can rotate more stably and bear higher rotating speed by optimizing the balance mass.

Drawings

FIG. 1 is a schematic assembly view of a hydrostatic air bearing air motor of the present invention;

FIG. 2 is an exploded view of the pneumatic motor;

FIG. 3 is a schematic structural view of a power ring;

fig. 4 is a schematic structural view of a radial air bearing.

Wherein: 1-rotating shaft, 2-radial air bearing, 3-main body, 4-tail gas suck-back pore channel, 5-sealing groove, 6-negative pressure bin cover, 7-negative pressure bin, 8-equal high ring, 9-impeller, 10-power ring, 11-upper end cover, 12-power high pressure air inlet channel, 13-thrust bearing, 14-tail gas exhaust channel, 15-thrust bearing high pressure channel, 16-high pressure air inlet, 17-exhaust channel, 18-bearing high pressure air inlet channel, 19-radial air bearing high pressure channel, 20-gas storage bin, 21-exhaust channel, 22-orifice, 23-pressure equalizing channel, 24-gas distribution channel, 25-power air inlet hole, 26-exhaust hole, 27-brake hole, 28-brake air inlet channel, 29-nozzle hole

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

This embodiment provides a static pressure air bearing pneumatic motor for spraying, through carrying out the overall improvement to radial air bearing, makes the air feed overall arrangement more reasonable, has improved air film rigidity, improves through the power ring simultaneously, makes its interference immunity strong, and the rotation of axis of rotation is more steady, and can bear higher rotational speed.

As shown in fig. 1 and 2, the air bearing air motor includes: the device comprises a main body 3, a rotating shaft 1, a radial air bearing 2, a thrust bearing 13, an impeller 9, an equal-height ring 8 and a power ring 10.

The middle part of the rotating shaft 1 is provided with a shaft shoulder, one side of the shaft shoulder is the head part of the rotating shaft, and the other side is the tail part of the rotating shaft. The main body 3 is a cylindrical structure with a shaft shoulder at one end, the head of the rotating shaft is coaxially supported inside the main body 3 through a radial air bearing 2, the radial air bearing 2 is in clearance fit with the rotating shaft 1, and the radial air bearing 2 is used for supporting the rotating shaft 1 in a non-contact state in the radial direction; the front end of the head of the rotating shaft extends out of the main body 3. Thrust air bearings serving as thrust bearings 13 are respectively arranged on two sides of a shaft shoulder of the rotating shaft 1 and used for supporting the rotating shaft 1 in a non-contact state in a thrust direction; wherein, the contact surface between the thrust bearing at the front side of the shaft shoulder of the rotating shaft 1 and the radial air bearing 2 is a front thrust surface, and the rear end surface of the thrust bearing at the rear side of the shaft shoulder of the rotating shaft 1 is a rear thrust surface; an equal-height ring 8 and an impeller 9 are coaxially sleeved on a shaft shoulder in the middle of the rotating shaft 1, wherein the impeller 9 is fixedly connected with the rotating shaft 1 and used for driving the rotating shaft 1 to rotate around the axis of the rotating shaft, a power ring 10 is coaxially sleeved outside the impeller 9, the power ring 10 is used for providing an air passage for driving air rotating the impeller 9, the equal-height ring 8 is used for sealing the air passage on the power ring 10, and meanwhile, the distance between the front thrust surface and the rear thrust surface is fixed. The tail part of the rotating shaft 1 is sleeved with an upper end cover 11, and the upper end cover 11, the equal-height ring 8 and the power ring 10 are fixedly connected through connecting bolts.

A power air source air inlet channel, an air bearing air inlet channel and an exhaust channel are respectively arranged in an outer shell formed by the main body 3, the equal-height ring 8, the power ring 10 and the upper end cover 11; the power gas source air inlet channel is used for supplying high-pressure air to the impeller 9 so as to drive the impeller 9 to rotate; the air bearing air inlet channel is used for providing high-pressure air for the radial air bearing 2 and the thrust bearing 13 so as to form an air lubricating film; the exhaust passage is used for exhausting gas in the pneumatic motor to form gas circulation. The method specifically comprises the following steps:

two high-pressure air inlets 16 are arranged on the end surface of the upper end cover 11, and the two high-pressure air inlets 16 are respectively communicated with a bearing high-pressure air inlet 18 and a power high-pressure air inlet 12 which are arranged in the upper end cover 11; the power high-pressure air inlet channel 12 is communicated with the air distribution groove 24 on the power ring 10 to form a power air source air inlet channel which is used for providing high-pressure air for the impeller 9 in the power ring 10.

In order to overcome the problem that the traditional power ring is interfered and is easy to unbalance, the power ring 10 shown in figure 3 is adopted, and an air distribution groove 24, an exhaust hole 26 and a brake hole 27 are arranged on the power ring 10; the air distribution grooves 24 are circumferentially enveloped in the power ring 10 in the largest range, that is, the central angle corresponding to the arc-shaped air distribution grooves 24 on the end surface of the power ring 10 is increased as much as possible, and as shown in fig. 3, the air distribution grooves are arranged on the arc-shaped sections outside the arc-shaped areas where the air distribution holes 26 and the brake holes 27 are located on the end surface of the power ring 10. The position of the air distribution groove 24 on the power ring 10 is provided with a plurality of airflow channels distributed along the circumferential direction as spray holes 29 for spraying high-pressure air into the impeller 9 to drive the impeller 9 to rotate, and the diameter of the throat of the spray holes 29 is 1/2 of the diameter of the inlet of the spray holes to realize high-speed spraying of the high-pressure air. The brake hole 27 injects high-pressure air in the opposite direction (opposite to the air injection direction of the injection hole 29) to the impeller 9 through the brake air inlet channel 28, and is used for braking the impeller 9. The exhaust hole 26 serves as a part of an exhaust passage for exhausting gas inside the air motor.

The air bearing air intake passage includes: a bearing high pressure air inlet passage 18, a thrust bearing high pressure air passage 15 and a radial air bearing high pressure air passage 19. The tail end of the bearing high-pressure air inlet passage 18 is divided into two branches, wherein one branch is a thrust bearing high-pressure passage 15 arranged inside the upper end cover 11 and used for supplying high-pressure air to the two thrust bearings so as to form air lubricating films at the front thrust surface and the rear thrust surface; the other branch is communicated with a radial air bearing high-pressure passage 19 arranged inside the main body 3 through air holes on the equal-height ring 8 and the power ring 10, and the radial air bearing high-pressure passage 19 is communicated with orifices 22 distributed on the outer circumferential surface of the radial air bearing 2 for supplying high-pressure air to the radial air bearing 2, so that an air lubricating film is formed between the rotating shaft 1 and the radial air bearing 2.

In order to improve the air film rigidity between the rotating shaft 1 and the radial air bearing 2, the air supply layout on the radial air bearing 2 is designed as shown in fig. 4, specifically: four annular grooves are axially distributed on the outer circumferential surface of the radial air bearing 2 to serve as air storage bins 20, the radial air bearing high-pressure channel 19 is respectively communicated with the air storage bins 20, and two axial sides of each air storage bin 20 are provided with sealing grooves 5 to ensure the sealing of the air storage bins 20. The radial air bearing high pressure channel 19 is arranged in a mode that an inlet inclines downwards to an outlet, so that gas can rapidly enter the gas storage bin 20. Two gas storage bins 20 located at the front end of the four gas storage bins 20 are communicated through a pressure equalizing channel, and two gas storage bins 20 located at the rear end of the four gas storage bins 20 are communicated through a pressure equalizing channel, so that the gas pressure in the gas storage bins 20 is ensured to be uniform. A plurality of orifices 22 are uniformly distributed on the inner bottom surface of each air storage bin 20 on the outer circumferential surface of the radial air bearing 2 along the circumferential direction to be used as radial air bearing high-pressure air inlet holes for providing high-pressure air between the outer circumferential surface of the rotating shaft 1 and the inner circumferential surface of the radial air bearing 2. On the premise of ensuring the structural strength of the radial air bearing 2, the larger the size of the air storage bin 20 is, the better the diameter of the throttle hole 22 is D, the wall thickness of the radial air bearing 2 is H, the depth of the air storage bin 20 is H, and the width is D, so that the preferred ratio is: H/H is 1/3-1/4, and D/D is < 1/40.

The material of the radial air bearing 2 is preferably porous graphite, so that the intake air can be made uniform by its self-lubricating property and air permeability.

The exhaust channel is two paths, one path is directly exhausted to two ends of the radial air bearing 2 through a gap between the rotating shaft 1 and the radial air bearing 2, the other path comprises a tail gas exhaust channel 14 arranged inside the main body 3 and an exhaust channel 17 arranged in the equal-height ring 8 and communicated with the tail gas exhaust channel 14, an annular groove is arranged in the middle of the radial air bearing 2 and serves as an exhaust groove 21, a radial through hole is arranged on the inner bottom surface of the exhaust groove 21 and serves as an exhaust hole, and the tail gas exhaust channel 14 is communicated with the exhaust groove 21. The exhaust passage 17 communicates with exhaust holes provided in the power ring 10 and the upper end cap 11, thereby exhausting gas.

In order to avoid the interference of the gas discharged from the front end of the rotating shaft 1 on the spraying, the gas discharged from the front end of the rotating shaft 1 is subjected to negative pressure resorption treatment, and therefore, a truncated cone-shaped negative pressure cabin cover 6 is coaxially sleeved outside the main body 3, and the negative pressure cabin cover 6 is fixedly connected with the main body 3 through a connecting bolt; an annular space between the negative pressure bin cover 6 and the outer circumference of the main body 3 is used as a negative pressure bin 7, and a tail gas suck-back pore passage 4 communicated with the negative pressure bin 7 is processed on the end surface of the negative pressure bin cover 6; the negative pressure pump arranged at the tail part of the pneumatic motor is communicated with the negative pressure bin 7 through a negative pressure air pipe.

For convenience, the rotating shaft can rotate more stably by optimizing the balance mass, a plurality of round holes for placing mass blocks are arranged on the outer peripheral surface of the impeller 9, and the balance mass is optimized by adjusting the number and the position of the mass blocks during dynamic balance testing. Preferably: the circular holes for placing the mass blocks are evenly distributed at intervals along the circumference of the impeller 9.

Meanwhile, the back (non-working face) of the impeller 9 is provided with the light reflecting pieces for measuring the rotating speed of the impeller 9, and the rotating speed can be accurately measured by arranging the plurality of light reflecting pieces at intervals (with inconsistent intervals) along the circumferential direction.

The working principle of the pneumatic motor is as follows:

high-pressure air enters the radial air bearing 2 and the thrust bearing 13 through the bearing high-pressure air inlet channel 18, and an air lubricating film with certain thickness and rigidity is formed between the rotating shaft 1 and the radial air bearing 2 and between the rotating shaft 1 and the thrust bearing 13. The rotating shaft 1 is supported in a non-contact state by the radial air bearing in the radial direction and by the two thrust bearings in the thrust direction.

High-pressure air enters the power ring 10 through the power high-pressure air inlet channel 12 to drive the impeller 9 in the power ring 10, so that the impeller 9 rotates to generate power; the rotating speed of the impeller 9 can be changed by changing the pressure and the flow of the gas entering the power high-pressure gas inlet channel 12, and the impeller 9 is fixedly connected with the rotating shaft 1, so that the rotating shaft 1 is driven to rotate around the axis of the rotating shaft 1 by the rotation of the impeller 9.

The flowing air film between the rotating shaft 1 and the radial air bearing 2 (i.e. the air lubrication film between the rotating shaft 1 and the radial air bearing 2) is discharged to both ends of the radial air bearing 2 through the shaft surface gap, flows into the exhaust groove 17 through the exhaust gas exhaust passage 14, and is finally discharged through the exhaust hole at the tail part.

The gas discharged from the front end of the rotating shaft 1 needs to be subjected to negative pressure back suction treatment, and the working principle is that the tail gas discharged from the front end is sucked into a negative pressure cabin 7 through a tail gas back suction pore passage 4 and is sucked into a negative pressure pump through a negative pressure gas pipe at the tail part of the motor.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydrostatic air bearing air motor, comprising: the device comprises a main body (3), a rotating shaft (1), a radial air bearing (2), a thrust bearing (13), an impeller (9), an equal-height ring (8) and a power ring (10);

a shaft shoulder is arranged in the middle of the rotating shaft (1), one side of the shaft shoulder is a head part of the rotating shaft, and the other side of the shaft shoulder is a tail part of the rotating shaft; the head part of the rotating shaft is coaxially supported inside the main body (3) through a radial air bearing (2); the radial air bearing (2) provides radial support for the rotating shaft (1) after air is provided by an air bearing air inlet channel;

thrust air bearings are respectively arranged at two ends of a shaft shoulder of the rotating shaft (1) and are used as thrust bearings (13); the thrust bearing (13) provides support in the thrust direction for the rotating shaft (1) after air is provided by an air bearing air inlet channel;

an equal-height ring (8) and an impeller (9) are coaxially sleeved on a shaft shoulder in the middle of the rotating shaft (1), and the impeller (9) is fixedly connected with the rotating shaft (1) and used for driving the rotating shaft (1) to rotate around the axis of the rotating shaft (1); a power ring (10) is coaxially sleeved outside the impeller (9), and a power gas source air inlet channel supplies gas to the impeller (9) through an air channel on the power ring (10) so as to drive the impeller (9) to rotate; the equal-height ring (8) seals an air passage on the power ring (10), and the thicknesses of the equal-height ring (8) and the power ring (10) are consistent with the thickness of a shaft shoulder of the rotating shaft (1);

the tail part of the rotating shaft (1) is sleeved with an upper end cover (11), and the upper end cover (11), the equal-height ring (8) and the power ring (10) are fixedly connected;

more than two annular grooves are axially distributed on the outer circumferential surface of the radial air bearing (2) to serve as air storage bins (20); the air storage bins (20) are communicated with an air bearing air inlet channel, and more than two throttling holes (22) are distributed on the inner bottom surface of each air storage bin (20) along the circumferential direction and are used as radial air bearing high-pressure air inlet holes; the two adjacent gas storage bins (20) are communicated through a pressure equalizing channel;

the gas in the pneumatic motor is exhausted through an exhaust channel; the exhaust channel is divided into two paths, and one path is directly exhausted to two ends of the radial air bearing (2) through a gap between the rotating shaft (1) and the radial air bearing (2); the other path of the exhaust bearing comprises a tail gas exhaust channel (14) arranged in the main body (3) and an exhaust channel (17) arranged in the equal-height ring (8) and communicated with the tail gas exhaust channel (14), an annular groove is arranged in the middle of the radial air bearing (2) and serves as an exhaust groove (21), a radial through hole is arranged on the inner bottom surface of the exhaust groove (21) and serves as an exhaust hole, and the tail gas exhaust channel (14) is communicated with the exhaust groove (21); the exhaust passage (17) is communicated with exhaust holes arranged on the power ring (10) and the upper end cover (11);

still include the negative pressure resorption unit, the negative pressure resorption unit includes: a negative pressure bin cover (6), a tail gas suck-back pore passage (4) and a negative pressure pump;

a negative pressure cabin cover (6) is coaxially and fixedly connected outside the main body (3); an annular space between the negative pressure bin cover (6) and the outer circumference of the main body (3) is a negative pressure bin (7), a tail gas suck-back pore passage (4) communicated with the negative pressure bin (7) is processed on the front end face of the negative pressure bin cover (6), and the negative pressure bin (7) is connected with an external negative pressure pump; the tail gas back-suction duct (4) is used for carrying out negative pressure back suction on the gas discharged from the front end of the rotating shaft (1).

2. The hydrostatic air bearing air motor of claim 1, wherein the air passages on the power ring (10) include air distribution grooves (24) and spray holes (29); the air distribution groove (24) circumferentially envelops an arc section outside an arc area where the exhaust holes (26) and the brake holes (27) are arranged on the end face of the power ring (10); the air distribution groove (24) is communicated with the power air source air inlet channel;

more than two airflow channels distributed along the circumferential direction are arranged at the position of the air distribution groove (24) on the power ring (10) and are used as spray holes (29) for spraying air into the impeller (9) to drive the impeller (9) to rotate;

and the brake hole (27) sprays gas into the impeller (9) along the braking direction through a brake air inlet channel (28) for braking the impeller (9).

3. Hydrostatic air bearing pneumatic motor according to claim 1 or 2, characterized in that the material of the radial air bearing (2) is porous graphite.

4. The hydrostatic air bearing pneumatic motor according to claim 1 or 2, wherein, assuming that the diameter of the orifice (22) is D, the wall thickness of the radial air bearing (2) is H, the depth of the air receiver (20) is H, and the width is D, then: H/H is 1/3-1/4, and D/D is < 1/40.

5. The hydrostatic air bearing pneumatic motor according to claim 1 or 2, wherein two or more circular holes for placing the mass blocks are circumferentially distributed on the outer circumferential surface of the impeller (9).

6. The hydrostatic air bearing air motor as claimed in claim 1 or 2, wherein reflectors for measuring the rotational speed of the impeller (9) are provided on the non-working face of the impeller (9).

7. The hydrostatic air bearing air motor of claim 1 or 2, wherein the air bearing air intake passage includes: the radial air bearing high-pressure channel (19) is arranged in the main body (3) and communicated with the air storage bin (20), and the radial air bearing high-pressure channel (19) is a gas channel with an inlet end inclined downwards to an outlet end.