CN216642801U

CN216642801U - Radial dynamic pressure air bearing with half pretension structure

Info

Publication number: CN216642801U
Application number: CN202123127620.6U
Authority: CN
Inventors: 朱冰硕; 乔青满; 张博伦; 贾晓光; 王沾朴; 薛枫; 袁添泽; 张康; 张春华; 秦懂; 靳国梁; 陈少华
Original assignee: Hebei Kingston Technology Co ltd
Current assignee: Hebei Kingston Technology Co ltd
Priority date: 2021-12-13
Filing date: 2021-12-13
Publication date: 2022-05-31
Anticipated expiration: 2031-12-13

Abstract

The utility model discloses a radial dynamic pressure air bearing with a semi-pre-tightening structure, which comprises a bearing seat, a bump foil and a top foil which are sequentially assembled from outside to inside, wherein the bump foil is an elastic supporting member, and a plurality of slots are formed in the inner end of the bearing seat. The top foil is divided into a cantilever type top foil and a bump foil type top foil in the circumferential direction. The bearing top structure is integrated with the cantilever structure on the basis of the wave foil type structure, the original whole-circle top foil is changed into the cantilever type top foil on the premise that the bearing capacity is not reduced, and due to the pre-tightening effect of the cantilever structure, an air film can be generated above the bearing, so that the radial play of a shaft system is effectively inhibited, the whole structure is similar to a structure of embracing a rotor, and the running stability of the bearing-shaft system is improved.

Description

Radial dynamic pressure air bearing with half pretension structure

Technical Field

The utility model relates to the technical field of dynamic pressure gas bearings, in particular to a radial dynamic pressure air bearing with a semi-pretightening structure.

Background

Generally, foil radial hydrodynamic air bearings can be divided into two broad categories, namely bump foil and cantilever.

Generally we focus on such several criteria for a bearing: namely, the bearing capacity, the takeoff moment and the takeoff rotating speed under a certain load, the bearing temperature rise and the shafting running stability. With the rapid development of the air floating industry, attention is paid to the shock and vibration resistance of the bearing. A simple comparison of the same geometry for the foil and cantilever bearings can be made and found in the following table:

as can be seen from the above table, the bump foil type structural bearing seems to have many advantages, but in practical applications, the bearing performance indicators we are more concerned with are: bearing capacity, shafting operating stability and shock vibration resistance, and the shafting operating stability and shock vibration resistance are the most critical. These performance indicators have a negative rule. For example, in the hydrogen fuel cell air compressor industry, even if a certain type of bearing has good bearing capacity, low takeoff torque and takeoff rotating speed, low temperature rise and good shock vibration resistance, if a shafting cannot stably operate, all the bearing is in vain. Because the shafting can not stably operate, the air compressor is unstable, and the air compressor is likely to be burnt, so that great loss is brought to the whole vehicle.

At present, in the air flotation industry, no matter industries such as an air flotation blower, a hydrogen fuel cell air compressor or an ACM (acid-coupled mechanical Module), a wave foil type bearing is the most common, although the operation stability of a shaft system is theoretically inferior to that of a cantilever type and is really inferior to that of the cantilever type in practical application, the wave foil type bearing is not inferior to that of the cantilever type, but is not inferior to that of an unusable ground step. In a common rotating speed range, such as the rotating speed range of 0-100000 rpm, even 0-120000 rpm, the operation of the bearing shaft system can be stably supported by the wave foil type bearing by adjusting the parameters of the bearing, such as the wave foil geometric dimension, the radial clearance and the like.

However, at higher rotational speeds, the stability of the corrugated foil bearings with respect to the operation of the shafting begins to be disadvantageous, since it is difficult and often ineffective to maintain the stability by adjusting the parameters of the bearings. The development direction of the air floating industry is high-speed miniaturization, which is a not small challenge for a wave foil bearing, and if the operation of a bearing shaft system cannot be stably supported, all the way is meaningless. However, if the cantilever-type structural bearing is used, the problems of poor impact and vibration resistance and poor bearing capacity cannot be solved. Therefore, the structure of the existing foil type air bearing needs to be improved to ensure that the bearing can not only ensure the stable operation of a shafting but also meet the requirement of the bearing on impact vibration resistance under higher rotating speed.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem of providing a radial dynamic pressure air bearing with a semi-pre-tightening structure, which can effectively improve the running stability of a bearing-shafting and the shock resistance of the whole bearing.

In order to solve the technical problems, the technical scheme adopted by the utility model is as follows:

radial dynamic pressure air bearing with half pretension structure includes bearing frame, ripples paper tinsel and the top paper tinsel of assembling in proper order from outer to inner, the ripples paper tinsel is elastic support component, a plurality of slots have been seted up on the inner of bearing frame, its characterized in that:

the top foil is divided into a cantilever type top foil and a wave foil type top foil in the circumferential direction;

the wave foil type top foil is positioned on the lower half circle of the bearing seat, two ends of the wave foil type top foil are respectively provided with a first bending part formed by bending towards the centrifugal direction, and the first bending parts are inserted into the slots of the bearing seat;

the cantilever type top foil is provided with multiple independent sections, one end of each section of the cantilever type top foil is provided with a second bending part formed by bending towards the centrifugal direction, the second bending part is inserted into a slot of the inner ring of the bearing seat, and the other end of the cantilever type top foil is freely lapped on an adjacent single body along the circumferential direction;

the wave foil type top foil and each section of cantilever type top foil are respectively provided with a section of wave foil, one end of each section of wave foil is bent towards the centrifugal direction to form a third bent part, the third bent part is inserted into the slot of the inner ring of the bearing seat, and the other end of the third bent part extends along the inner circumferential wall of the bearing seat to form a free end.

The further technical scheme is as follows: the cantilever type top foil and the wave foil type top foil are distributed according to the circumferential proportion of 1 (1-1.5).

The further technical scheme is as follows: the third bending part is overlapped with the corresponding first bending part or the first bending part and is arranged in the same slot.

The further technical scheme is as follows: and the wave foils corresponding to the wave foil type top foils are assembled between the wave foil type top foils and the bearing seat in a pre-tightening manner.

The further technical scheme is as follows: the number of the slots on the bearing seat is the same as the total number of the first bending parts and the second bending parts.

The further technical scheme is as follows: the free end of the cantilever type top foil connected with the wave foil type top foil is freely lapped on the wave foil type top foil along the circumferential direction.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

the bearing top structure is integrated with the cantilever structure on the basis of the wave foil type structure, the original whole-circle top foil is changed into the cantilever type top foil on the premise that the bearing capacity is not reduced, and due to the pre-tightening effect of the cantilever structure, an air film can be generated above the bearing, so that the radial play of a shaft system is effectively inhibited, the whole structure is similar to a structure of embracing a rotor, and the running stability of the bearing-shaft system is improved.

The wave foil type flat foil and the corresponding wave foil section which are positioned at the bottom of the shaft system and adopt a nearly half circle can provide enough bearing capacity for the bearing-shaft system, and the whole circle of wave foil together generates corresponding self-adaptive deformation when being subjected to impact vibration, thereby providing better impact resistance for the bearing.

Drawings

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

FIG. 1 is a schematic structural view of a prior art wave foil structured air bearing;

FIG. 2 is a schematic representation of the operation of a prior art wave foil-shafting arrangement (rotor rotating counterclockwise);

FIG. 3 is a schematic diagram of a prior art cantilevered air bearing;

FIG. 4 is a schematic representation of the operation of a cantilevered-shafting arrangement of the prior art (rotor rotating counterclockwise);

FIG. 5 is a schematic view of the prior art air film pressure distribution in the air bearing load region of a wave foil configuration (with the bearing block and the wave foil omitted);

FIG. 6 is a schematic diagram of the air film pressure distribution of a cantilever-type air bearing in the prior art (bearing seat omitted);

FIG. 7 is a schematic structural view of a radial hydrodynamic air bearing of the present disclosure in an unloaded state;

FIG. 8 is a schematic view of the radial hydrodynamic air bearing of the present disclosure assembled with a rotor;

FIG. 9 is a schematic view of the radial dynamic pressure air bearing air film pressure distribution of the present disclosure (with the bearing housing omitted).

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

As shown in fig. 1 to 9, the radial dynamic pressure air bearing with the semi-pretightening structure comprises a bearing seat 10, a wave foil 20 and a top foil which are sequentially assembled from outside to inside, wherein the wave foil 20 is an elastic supporting member, a plurality of slots are formed in the inner end of the bearing seat 10, the slots are arranged to allow the fixed ends of the wave foil 20 and the top foil to be inserted, so that the connection between the wave foil 20 and the top foil and the bearing seat 10 is realized, and in order to meet the deformation of the bearing after bearing force is applied, the fixed ends of the wave foil 20 and the top foil can move in the slots to provide the deformation capability after the force is applied.

The operation stability of the cantilever type bearing shaft system is superior to that of a wave foil type bearing shaft system. As can be seen from the comparison between fig. 2 and fig. 4, the cantilevered bearing has a binding force on the shaft system along the whole circumferential direction, that is, a gas film acts on the shaft system along the whole circumferential direction and acts on the shaft system at all times, as shown in fig. 6, which is similar to the manner that the shaft system is tightly held by hands, so that the shaft system can stably operate. As can be seen from the comparison between fig. 1 and fig. 3, the wedge-shaped air film on the corrugated foil bearing is only present below the shaft system and is in a position to the right, that is, the binding force to the shaft system is local, as shown in fig. 5, which is just like "holding the shaft system by hand", and only "holding the shaft system by hand", the operation stability of the shaft system is naturally worse, because the shaft system is above without binding, the shaft system can move freely along the upper direction, and therefore the stability is slightly worse.

The shock resistance of the wave foil type bearing shaft system is superior to that of a cantilever type bearing shaft system. Due to the existence of the elastic component wave foil in the wave foil type bearing, the wave foil can generate self-adaptive deformation when being subjected to impact load, and the wave foil can provide a buffer effect like a spring. The cantilever type bearing is provided with only one top foil, so that the cantilever type bearing is quickly attached to the inner wall of the bearing seat when being subjected to impact vibration, and is similar to a structure that a rotor is in rigid contact with the bearing, so that the cantilever type bearing is poor in impact resistance and extremely easy to burn when being subjected to impact vibration. This also explains to some extent what the cantilevered load carrying capability is poor. In fact, it can be seen from the comparison between fig. 5 and fig. 6 that the pressure distribution under the bearing is greater in the wave foil type than in the cantilever type, so that the wave foil type has better bearing capacity.

Therefore, in the radial dynamic pressure air bearing with the semi-preloaded structure of the present disclosure, as shown in fig. 7 and 8, the top foil is divided into the cantilever type top foil 31 and the wave foil type top foil 32 in the circumferential direction, and the cantilever type top foil 31 and the wave foil type top foil 32 are distributed in a circumferential ratio of 1 (1-1.5).

The wave foil type top foil 32 is located at the lower half circle of the bearing seat 10, and both ends of the wave foil type top foil are provided with first bending parts 321 formed by bending towards the centrifugal direction, and the first bending parts 321 are inserted into the slots of the bearing seat 10.

The cantilever type top foil 31 has a plurality of independent sections, one end of each section of the cantilever type top foil 31 is provided with a second bending part 311 formed by bending towards the centrifugal direction, the second bending part 311 is inserted into the slot of the inner ring of the bearing seat 10, and the other end of the cantilever type top foil 31 is freely lapped on the adjacent single body along the circumferential direction. When the foil bearing is unloaded, the cantilevered top foil 31 is in line contact with the corresponding bump foil 20 near the fixed end, out of line contact at portions other than the fixed end, and adjacent cantilevered foils are in line contact at a free lap. Further, in order to increase the bearing damping, the free end of the one piece of the cantilever type top foil 31 in contact with the bump type top foil 32 is freely overlapped on the bump type top foil 32 in the circumferential direction.

The wave foil type top foil 32 and each section of cantilever type top foil 31 are respectively provided with a section of wave foil 20, one end of each section of wave foil 20 is bent towards the centrifugal direction to form a third bent part 201, the third bent part 201 is inserted into the slot of the inner ring of the bearing seat 10, and the other end extends along the inner circumferential wall of the bearing seat 10 to form a free end.

The third bending portion 201 is overlapped with the corresponding first bending portion 321 or the first bending portion 321, and is disposed in the same slot. The number of the insertion grooves of the bearing housing 10 is the same as the total number of the first bending portion 321 and the second bending portion 311, and the number of the insertion grooves of the bearing housing 10 is reduced.

And the bump foil 20 corresponding to the bump foil type top foil 32 is pre-loaded and assembled between the bump foil type top foil 32 and the bearing housing 10.

As the load experienced by the foil bearing increases, the cantilevered top foil 31 makes partial to full arch contact with the corresponding bump foil 20, with partial to full face contact between adjacent cantilevered foils at extended overlap. There is a frictional damping between adjacent cantilever foils which increases with increasing load. It can be seen that as the load increases, the line-to-surface contact of the bump foil 20 and the corresponding cantilevered foil, and the segment-to-surface contact between the adjacent cantilevered foils, are further enhanced, and the coupling stiffness of the bump foil 20 and the cantilevered foils is gradually enhanced.

The radial dynamic pressure air bearing is integrated with the cantilever structure on the basis of the corrugated foil 20 type structure, on the premise of not reducing the bearing capacity, the structure above the bearing is changed from the original full-circle type top foil to the cantilever type top foil 31, and due to the pre-tightening effect of the cantilever structure, an air film can be generated above the bearing, so that the radial movement of a shafting is effectively inhibited, as shown in figure 9, the whole structure is similar to a 'holding a rotor', and the running stability of the bearing-shafting is improved.

The wave foil 20 type flat foil which is positioned at the bottom of the shaft system and adopts a nearly half circle and the corresponding wave foil 20 section can provide enough bearing capacity for the bearing-shaft system, and the whole circle of wave foil 20 generates corresponding self-adaptive deformation when being subjected to impact vibration, thereby providing better impact resistance for the bearing.

The above are only preferred embodiments of the present invention, and many simple modifications, variations and equivalents of the present invention may be made by anyone in light of the above teachings.

Claims

1. Radial dynamic pressure air bearing with half pretension structure, include bearing frame (10), ripples paper tinsel (20) and the top paper tinsel of assembling in proper order from outer to interior, ripples paper tinsel (20) are elastic support component, a plurality of slots have been seted up on the inner of bearing frame (10), its characterized in that:

the top foil is divided into a cantilever type top foil (31) and a wave foil type top foil (32) in the circumferential direction;

the wave foil type top foil (32) is positioned on the lower half circle of the bearing seat (10), two ends of the wave foil type top foil are respectively provided with a first bending part (321) formed by bending towards the centrifugal direction, and the first bending parts (321) are inserted into the slots of the bearing seat (10);

the cantilever type top foil (31) is provided with multiple independent sections, one end of each section of the cantilever type top foil (31) is provided with a second bending part (311) formed by bending towards the centrifugal direction, the second bending part (311) is inserted into a slot of the inner ring of the bearing seat (10), and the other end of each cantilever type top foil (31) is freely lapped on an adjacent single body along the circumferential direction;

the wave foil type top foil (32) and each section of cantilever type top foil (31) are respectively provided with a section of wave foil (20), one end of each section of wave foil (20) is bent towards the centrifugal direction to form a third bent part (201), the third bent part (201) is inserted into an insertion groove in the inner ring of the bearing seat (10), and the other end of the third bent part extends along the inner circumferential wall of the bearing seat (10) to form a free end.

2. The radial hydrodynamic air bearing of claim 1, wherein: the cantilever type top foil (31) and the wave foil type top foil (32) are distributed according to the circumference proportion of 1 (1-1.5).

3. The radial hydrodynamic air bearing of claim 1, wherein: the third bending part (201) is overlapped with the corresponding first bending part (321) or the first bending part (321) and is arranged in the same slot.

4. The radial hydrodynamic air bearing of claim 1, wherein: the wave foil (20) corresponding to the wave foil type top foil (32) is assembled between the wave foil type top foil (32) and the bearing seat (10) in a pre-tightening mode.

5. The radial hydrodynamic air bearing of claim 1, wherein: the number of the slots on the bearing seat (10) is the same as the total number of the first bending parts (321) and the second bending parts (311).

6. The radial hydrodynamic air bearing of claim 1, wherein: the free end of the cantilever type top foil (31) connected with the wave foil type top foil (32) is freely lapped on the wave foil type top foil (32) along the circumferential direction.