CN113431840A - Dynamic pressure gas bearing - Google Patents

Abstract

The application provides a dynamic pressure gas bearing, which comprises a bearing sleeve and a plurality of groups of foil groups distributed on the inner side of the bearing sleeve along the circumferential direction; the foil group comprises a first foil and at least one second foil, the second foil is of an arc-shaped sheet structure and is arranged on the inner side of the bearing sleeve, and the second foil is used for forming a lubricating air film with the rotor; the first foil is of a straight sheet-shaped structure and is hollowed to form a plurality of sliding beams, the sliding beams are provided with two sliding ends along a first direction, the first foil can be assembled between the bearing sleeve and the second foil in a bending mode, and each sliding end can be supported on the inner wall of the bearing sleeve and can slide on the inner wall of the bearing sleeve after the first foil is bent; wherein, the sliding end comprises at least two sliding toes distributed along the second direction. This application has improved the contact adaptability of each sliding beam and bearing housing through the many sliding toes structural design to each sliding end on the first foil, has also reduced the rigidity of sliding beam at the sliding end department simultaneously, has then increased the coulomb damping of sliding beam, has improved the stability of rotor.

Description

Dynamic pressure gas bearing

Technical Field

The application belongs to the technical field of gas bearings, and particularly relates to a dynamic pressure gas bearing.

Background

Gas bearings can be divided into two major categories, static pressure gas bearings and dynamic pressure gas bearings. Compared with a static pressure gas bearing, the dynamic pressure gas bearing does not need to additionally provide a high-pressure gas source and has the advantages of simple structure, small size and the like, so that the dynamic pressure gas bearing is widely applied to the fields of micro gas turbines, micro turbojet engines and the like.

A wedge gap or other special form of gap exists between the hydrodynamic gas bearing and the rotor, in which gap aerodynamic pressure is generated when the rotor rotates. The hydrodynamic gas bearing includes a bearing housing, which typically has an elastic support structure, such as a foil structure, therein to improve the stability of the rotor system, and when subjected to an unstable load, the foil structure generates relative sliding due to deformation to generate coulomb friction. However, the structural damping of the existing dynamic pressure gas bearing is still insufficient, the ultimate bearing capacity is low, the running stability of the rotor is poor, and the foil structure of the rotor in the takeoff stage is seriously abraded.

Disclosure of Invention

An object of the embodiment of this application is to provide a dynamic pressure gas bearing to there is the poor technical problem of rotor operating stability in dynamic pressure gas bearing among the solution prior art.

In order to achieve the purpose, the technical scheme adopted by the application is as follows: the dynamic pressure gas bearing comprises a bearing sleeve and a plurality of groups of foil groups distributed on the inner side of the bearing sleeve along the circumferential direction; the foil group comprises a first foil and at least one second foil, the second foil is of an arc-shaped sheet structure and is arranged on the inner side of the bearing sleeve, and the second foil is used for forming a lubricating gas film with the rotor; the first foil is of a straight sheet structure and is hollowed to form a plurality of sliding beams, the sliding beams are distributed along a first direction and a second direction respectively, and the first direction is perpendicular to the second direction; the sliding beam is provided with two sliding ends along the first direction, the first foil can be assembled between the bearing sleeve and the second foil in a bending mode in which the second direction is axially parallel to the bearing sleeve, and each sliding end can be supported on the inner wall of the bearing sleeve and can slide on the inner wall of the bearing sleeve after the first foil is bent;

the sliding end comprises at least two sliding toes which are distributed along the second direction and can be supported on the inner wall of the bearing sleeve.

Optionally, a first gap is arranged between two adjacent sliding toes, and the first gap is formed by an etching process.

Optionally, a plurality of rows of sliding beams are distributed on the first foil, and each sliding beam in each row is spaced apart in the second direction; the adjacent two rows of sliding beams are arranged in a staggered manner in the second direction, and the adjacent two rows of sliding beams are at least partially arranged in a crossed manner in the first direction.

Optionally, two adjacent rows of the sliding beams intersect in the first direction to form a first length, the sliding beams have a second length along the first direction, and the first length is greater than one fourth of the second length and less than one half of the second length.

Optionally, the sliding beam includes a connecting arm and a sliding arm, the connecting arm is connected to the sliding arm in a crossing manner, both ends of the connecting arm are connecting ends, and both ends of the sliding arm are two sliding ends.

Optionally, the width of each sliding arm on the first foil along the second direction gradually increases along the rotation direction of the rotor;

the length of each sliding arm on the first foil along the first direction gradually increases along the rotation direction of the rotor.

Optionally, the number of sliding toes on each sliding end on the first foil increases in the direction of rotation of the rotor.

Optionally, the width of each sliding arm on the first foil in the second direction gradually increases from two ends to the middle.

Optionally, the radius of curvature of the second foil is larger than the radius of curvature of the inner wall of the bearing housing.

Optionally, the number of the second foils is 1 to 3, and the curvature radius of each second foil gradually increases in a direction away from the bearing housing.

The application provides a hydrodynamic gas bearing's beneficial effect lies in: compared with the prior art, the hydrodynamic gas bearing provided by the embodiment of the application forms a plurality of sliding beams through hollowing on the first foil, so that when the rotor rotates, each sliding beam can be supported between the bearing sleeve and the second foil, the vibration resistance of the hydrodynamic gas bearing is enhanced, and meanwhile, each sliding end is supported and slid on the inner wall of the bearing sleeve, so that the coulomb damping of the hydrodynamic gas bearing is increased, and the operation stability of the rotor is improved. Through the multi-sliding-toe structural design of each sliding end on the first foil, the contact adaptability of each sliding beam and the bearing sleeve is improved, meanwhile, the rigidity of the sliding beam at the sliding end is also reduced, the coulomb damping of the sliding beam is increased, and the stability of the rotor is improved. In addition, the multi-sliding-toe structure has the nonlinear foil stiffness characteristic, and abrasion between the rotor and the second foil in the starting stage is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic perspective view of a hydrodynamic gas bearing provided in an embodiment of the present application;

FIG. 2 is an exploded view of a hydrodynamic gas bearing according to an embodiment of the present application;

FIG. 3 is a schematic view of the first foil of FIG. 1 in a flat state;

FIG. 4 is a schematic side view of the first foil of FIG. 3 after bending;

FIG. 5 is a perspective view of the first foil of FIG. 3 after bending;

FIG. 6 is an enlarged view of a portion of the first foil of FIG. 3;

FIG. 7 is a schematic view of the construction of the sliding beam of FIG. 6;

FIG. 8 is a schematic view of the variation of the width and length of the sliding beam in the first foil of FIG. 1;

fig. 9 is a schematic structural view of the bearing housing of fig. 1.

Wherein, in the figures, the respective reference numerals:

10-a bearing sleeve; 20-a set of foils; 30-a first foil; 40-a second foil; 11-a mounting location; 12-a mounting block; 31-a sliding beam; 32-slotting; 121-mounting grooves; 311-sliding end; 312-connecting arm; 313-a sliding arm; 3111-sliding toe; 3112-a first gap; 3131 — a sliding section; x-a first direction; y-a second direction; h1 — first distance; h2 — second distance; l1-first length; l2-second length; l3-third length; l4-fourth length.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

Referring to fig. 1 to 5, a dynamic pressure gas bearing according to an embodiment of the present invention will be described.

The dynamic pressure gas bearing comprises a bearing sleeve 10 and three groups of foil groups 20. The bearing sleeve 10 is cylindrical, and the three groups of foil sheet groups 20 are uniformly distributed on the inner side of the bearing sleeve 10 along the circumferential direction and are abutted between the rotor and the bearing sleeve 10 to improve the running stability between the rotor and the bearing sleeve 10 during working. It is understood that in other embodiments of the present application, four or more sets of foils 20 may be disposed inside the bearing housing 10 according to the specific radial dimension of the bearing housing 10 and the actual supporting requirement of the sets of foils 20, which is not limited herein.

Specifically, in this embodiment, three mounting positions 11 are circumferentially distributed on the inner wall of the bearing housing 10, the number of the mounting positions 11 is equal to the number of the foil sets 20, that is, the adjacent ends of two adjacent foil sets 20 are both mounted on the same mounting position 11, that is, a distance of one mounting position 11 is spaced between two adjacent foil sets 20.

The foil set 20 comprises the first foil 30 and at least one second foil 40, i.e. the number of the second foils 40 can be limited according to practical requirements. The second foil 40 is of an arc-shaped sheet structure and is installed on the inner side of the bearing sleeve 10, the axial width of the second foil 40 is equal to the axial width of the bearing sleeve 10, the two circumferential ends of the second foil 40 are respectively installed on the two adjacent installation positions 11, the second foil 40 is used for forming a lubricating air film with the rotor, and namely the second foil 40 is arranged close to the rotor.

The first foil sheet 30 is a flat sheet-shaped structure and is hollowed to form a plurality of sliding beams 31, each sliding beam 31 is distributed along the first direction X and the second direction Y, and the sliding beam 31 has two sliding ends 311 along the first direction X, specifically, the sliding ends 311 are end portions that are suspended and can move under the action of external force. The first direction X is the up-down direction in fig. 3, the second direction Y is the left-right direction in fig. 3, and the first direction X is perpendicular to the second direction Y. The first foil 30 can be assembled between the bearing sleeve 10 and the second foil 40 in a manner that the second direction Y is parallel to the axial direction of the bearing sleeve 10, specifically, in order to be matched with the bearing sleeve 10 and the second foil 40, the bending manner of the first foil 30 is the same as the bending manner of the second foil 40 and the bearing sleeve 10, two ends of the first foil 30 in the second direction Y are respectively aligned with two ends of the bearing sleeve 10 in the axial direction, and two ends of the first foil 30 in the first direction X are respectively mounted on two adjacent mounting positions 11.

Each sliding end 311 can be supported by the inner wall of the bearing housing 10 after the first foil 30 is bent, and can slide on the inner wall of the bearing housing 10. It should be noted that, referring to fig. 3 and 4, since the sliding ends 311 are suspended and are less affected by the deformation of the first foil 30, when the first foil 30 is bent, each sliding end 311 basically remains in the original state, each sliding end 311 is ejected from the first foil 30 toward the inner side of the bearing housing 10 and supported on the inner wall of the bearing housing 10, and in the rotation process of the rotor, because the disturbed air film pressure acts on the second foil 40 and the first foil 30, each sliding end 311 slides on the inner wall of the bearing housing 10 along the circumferential direction, forming coulomb friction damping, and improving the support stability of the dynamic pressure air bearing to the rotor.

The sliding end 311 includes at least two sliding toes 3111, each of the sliding toes 3111 is distributed along the second direction Y, and each of the sliding toes 3111 is supported by and capable of sliding on the inner wall of the bearing housing 10 after the first foil piece 30 is bent. It should be noted that, the sliding toe 3111 is substantially configured to divide and reduce the contact area between the sliding end 311 and the inner wall of the bearing housing 10, so that the contact between the sliding end 311 and the bearing housing 10 is not too abrupt; at the same time, the sliding end 311 is also made relatively soft, and its plastic deformability is enhanced, reducing the rigidity of the sliding beam 31 at the sliding end 311.

Compared with the prior art, the dynamic pressure gas bearing provided by the application has the advantages that the plurality of sliding beams 31 are formed on the first foil sheet 30 in a hollow mode, so that when the rotor rotates, the rotor can be supported between the bearing sleeve 10 and the second foil sheet 40 through the sliding beams 31, the vibration resistance of the dynamic pressure gas bearing is enhanced, meanwhile, the sliding ends 311 are supported and slide on the inner wall of the bearing sleeve 10, the coulomb damping of the dynamic pressure gas bearing is increased, and the operation stability of the rotor is improved. By the design of the multi-sliding-toe 3111 structure of each sliding end 311 on the first foil 30, the contact adaptability of each sliding beam 31 and the bearing housing 10 is improved, meanwhile, the rigidity of the sliding beam 31 at the sliding end 311 is also reduced, the coulomb damping of the sliding beam 31 is increased, and the stability of the rotor is improved. In addition, the multi-sliding toe 3111 configuration has non-linear foil stiffness characteristics that reduce wear between the rotor and the second foil 40 during startup.

In this embodiment, referring to fig. 7, a first gap 3112 is disposed between two adjacent sliding toes 3111, and specifically, the first gap 3112 extends along the first direction X. In the second direction Y, the width of the first gap 3112 is less than half of the width of the sliding toe 3111, the width of each sliding toe 3111 on the same sliding end 311 is equal, and the width of the sliding toe 3111 is determined by the width of the sliding end 311, the width of the first gap 3112 and the number of the sliding toes 3111. The length of the sliding toe 3111 in the first direction X is equal to the length of the first slit 3112 in the first direction X.

The first gap 3112 is formed by an etching process, which is a technique for removing a material using a chemical reaction or a physical impact. It is to be understood that, in other embodiments of the present application, the first gap 3112 may also be formed by laser, machining, etc., and is not limited herein.

In the present embodiment, please refer to fig. 3 and fig. 6, wherein fig. 3 is an overall schematic view of the first foil 30, and fig. 6 is a partially enlarged schematic view of the upper three rows of sliding beams 31 in fig. 3. Seven rows of sliding beams 31 are distributed on the first foil 30, each sliding beam 31 in each row is distributed at equal intervals along the second direction Y, and specifically, a first distance H1 is provided between two adjacent sliding beams 31 in each row. The number of the sliding beams 31 in each row is different, specifically, in the second direction Y in fig. 3, the first row located at the top has 8 sliding beams 31, the second row has 9 sliding beams 31, the third row has 8 sliding beams 31, the fourth row has 9 sliding beams 31, the fifth row has 8 sliding beams 31, the sixth row has 9 sliding beams 31, and the seventh row has 8 sliding beams 31. It is understood that in other embodiments of the present application, three rows and three rows of the sliding beams 31 may be distributed on the first foil 30 according to the actual length and width of the first foil 30, and the number of the sliding beams 31 in each row may be set according to actual requirements.

Referring to fig. 3 and 6, two adjacent rows of sliding beams 31 are staggered from each other in the second direction Y, specifically, staggered from each other by a second distance H2, where the second distance H2 is half of the first distance H1. The adjacent two rows of sliding beams 31 are at least partially arranged crosswise in the first direction X, that is, each sliding beam 31 in the first row is inserted downwards between each sliding beam 31 in the second row, and each sliding beam 31 in the third row is inserted upwards between each sliding beam 31 in the second row; similarly, between the slide beams 31 in the third row, the slide beams 31 in the second row and the slide beams 31 in the fourth row are inserted vertically. Thus, referring to fig. 3, through the above layout of the sliding beams 31, two other sliding ends 311 are disposed between the two sliding ends 311 on the sliding beams 31 along the second direction Y, so that only two sliding ends 311 are supported by the inner wall of the bearing housing 10 in the areas corresponding to the sliding beams 31 in the second row, the fourth row, the sixth row, and the like, and then the four sliding ends 311 are supported by the inner wall of the bearing housing 10 at the same time, so that the sliding ends 311 in the areas corresponding to the sliding beams 31 in the second row, the fourth row, the sixth row, and the like are more compactly distributed on the inner wall of the bearing housing 10, thereby increasing the coulomb damping of the sliding beams 31 in the corresponding areas, and improving the stability of the rotor; meanwhile, the sliding ends 311 are arranged more compactly, so that the supporting function of the corresponding area of the first foil 30 on the second foil 40 is distributed uniformly, that is, the second foil 40 is prevented from being locally depressed under the action of the air film pressure.

In the present embodiment, it is assumed that the two adjacent rows of sliding beams 31 intersect with a first length L1 along the first direction X, and the sliding beams 31 have a second length L2 along the first direction X, so that the first length L1 is greater than a quarter of the second length L2 and less than a half of the second length L2, so as to increase the coulomb damping of the sliding beams 31 and avoid the mutual interference of the sliding beams 31.

Specifically, referring to fig. 6 and 7, a plurality of through slots 32 are hollowed out of the first foil 30, the number of the through slots 32 is equal to that of the sliding beams 31, and each sliding beam 31 is formed in one through slot 32.

In the present embodiment, referring to fig. 7, the sliding beam 31 includes a connecting arm 312 and a sliding arm 313, and the connecting arm 312 and the sliding arm 313 are connected in a crisscross manner. Both ends of the connecting arm 312 are connecting ends, and both ends of the connecting arm 312 are integrally connected with the inner walls of the through groove 32 along the second direction Y. The two ends of the sliding arm 313 are two sliding ends 311, that is, the two ends of the sliding arm 313 are suspended, and can be supported on the inner wall of the bearing housing 10 and can slide on the inner wall of the bearing housing 10 to form coulomb friction.

Specifically, the connecting arm 312 extends along the second direction Y, the sliding arm 313 extends along the first direction X, and the connecting arm 312 and the sliding arm 313 are perpendicular to each other and integrally connected, that is, the entire first foil 30 is an integral connecting structure. It is understood that in other embodiments of the present application, the connecting arm 312 may extend obliquely and form an acute angle with the second direction Y, the sliding arm 313 may extend obliquely and form an acute angle with the first direction X, and the connecting arm 312 and the sliding arm 313 may not be perpendicular to each other.

Referring to fig. 7, the sliding arm 313 includes two sliding sections 3131 respectively disposed on two sides of the connecting arm 312, two sliding ends 311 are respectively disposed on one ends of the two sliding sections 3131 away from the connecting arm 312, and the two sliding sections 3131 are disposed opposite to each other along the second direction Y. It is understood that, in other embodiments of the present application, the two sliding segments 3131 may be arranged in a staggered manner along the second direction Y according to practical design conditions, and this is not limited herein.

Referring to fig. 7, the sliding section 3131 is trapezoidal, and the width of the sliding section 3131 in the second direction Y gradually decreases from the end connected to the connecting arm 312 to the sliding section 3131, so that the connection strength between the sliding section 3131 and the connecting arm 312 can be improved, the structural rigidity of the sliding section 3131 can be reduced, the contact adaptability between each sliding section 3131 and the bearing housing 10 can be improved, the coulomb damping of the sliding section 3131 can be increased, and the stability of the rotor can be improved.

Referring to fig. 6, the through slot 32 has a third length L3 in the first direction X, and the connecting arm 312 has a fourth length L4 in the first direction X, so that twice the first length L1 plus the fourth length L4 is equal to the third length L3, so as to avoid the interference between the first row and the sliding beam 31 of the third row under the condition of maximizing the first length L1. It is understood that in other embodiments of the present application, the value of the first length L1 may be reduced as appropriate, and is not limited herein.

In the embodiment, referring to fig. 3 and 8, the width distribution of each sliding arm 313 on the first foil 30 along the second direction Y is not uniform, specifically, the width of each sliding arm 313 along the second direction Y gradually increases along the rotation direction of the rotor, that is, the width of the sliding arm 313 is smaller at a position close to the rotation start end of the first foil 30, and the width of the sliding arm 313 is larger at a position close to the rotation end of the first foil 30. By the above width distribution of the sliding arm 313, the uniformity of the distribution of the supporting rigidity of the first foil 30 is improved, and the bearing capacity of the dynamic pressure gas bearing can be improved.

Furthermore, the number of sliding toes 3111 on each sliding end 311 of the first foil 30 may also be different, in particular increasing in the direction of rotation of the rotor, i.e. the number of sliding toes 3111 is greater at positions where the width of the sliding end 311 is greater, and the number of sliding toes 3111 is smaller at positions where the width of the sliding end 311 is smaller. For example, in the present embodiment, the number of the sliding toes 3111 on each sliding end 311 in the first row and the second row is two, and the number of the sliding toes 3111 on each sliding end 311 in the third row to the seventh row is 3. In general, the width of each sliding toe 3111 in the second direction Y is not greatly different, and therefore, the number of the sliding toes 3111 is appropriately changed according to the change of the width of the sliding end 311, and in order to reduce the structural rigidity of the sliding end 311, the width of the sliding end 311 is not greatly increased, and therefore, the number of the sliding toes 3111 on each sliding end 311 is generally 2 or 3.

In the embodiment, referring to fig. 3 and 8, the lengths of the sliding arms 313 on the first foil 30 along the first direction X are not uniformly distributed, specifically, the length of each sliding arm 313 along the first direction X gradually increases along the rotation direction of the rotor, that is, the length of the sliding arm 313 is smaller at a position close to the rotation start end of the first foil 30, and the length of the sliding arm 313 is larger at a position close to the rotation end of the first foil 30. Through the length distribution of the sliding arm 313, the consistency of the support rigidity distribution of the first foil 30 is improved, the bearing capacity of the dynamic pressure gas bearing can be improved, and meanwhile, the support height of the sliding arm 313 on the inner wall of the bearing sleeve 10 is changed, so that an initial gas film convergence gap is formed in each flow field, and the gas film pre-tightening effect is achieved.

In the present embodiment, the width distribution of each sliding arm 313 on the first foil 30 along the second direction Y is not uniform, and specifically, the width of each sliding arm 313 along the second direction Y gradually increases from two ends to the middle, that is, the width of the sliding arm 313 in the middle area is larger, and the width of the sliding arm 313 at the end is smaller. During the rotation of the rotor, the pressure of the air film reaches a maximum value in the middle area in the axial direction, the pressures of the air films at the two ends are relatively small, and in order to prevent the sliding arm 313 near the middle from deforming too much, the sliding arm 313 at the two ends deforms too little, so that the width of the sliding arm 313 near the middle is set relatively large, the rigidity of the sliding arm 313 is made larger, and the deformation amount of the sliding arm 313 at each position on the first foil 30 can be made uniform.

In the present embodiment, the radius of curvature of the second foil 40 is greater than the radius of curvature of the inner wall of the bearing housing 10, so that after installation, an installation space can be formed between the second foil 40 and the inner wall of the bearing housing 10, and the first foil 30 is installed in the installation space. Furthermore, when the rotor vibrates, the perturbed gas film pressure acts on the second foil 40, causing the second foil 40 to slide over the first foil 30, providing coulomb damping.

In the present embodiment, the number of the second foils 40 is 1 to 3, and the radius of curvature of each second foil 40 gradually increases in a direction away from the bearing housing 10, that is, the closer to the rotor, the larger the radius of curvature of the second foil 40, so that when the rotor vibrates, the disturbed air film pressure acts on the closest second foil 40, so that relative sliding between the second foils 40 with different radii of curvature is generated to provide coulomb friction.

When the number of the second foils 40 is one, the bearing housing 10, the first foil 30 and the second foil 40 are sequentially arranged from the outside to the inside. When the number of the second foils 40 is two, the bearing housing 10, the first foil 30, the second foil 40 having a relatively small radius of curvature, and the second foil 40 having a relatively large radius of curvature are sequentially disposed from the outside to the inside.

Referring to fig. 9, in the present embodiment, the bearing sleeve 10 is cylindrical, three mounting blocks 12 are disposed on an inner wall of the bearing sleeve 10 corresponding to three mounting locations 11, each mounting block 12 is distributed at equal intervals along a circumferential direction of the bearing sleeve 10, and the mounting blocks 12 all extend along an axial direction of the bearing sleeve 10. Each mounting block 12 is formed with two mounting grooves 121 disposed opposite to each other in the circumferential direction, two ends of each group of foil sets 20 in the circumferential direction are respectively mounted in the two mounting grooves 121 disposed opposite to each other, that is, two ends of the first foil 30 in the first direction X are respectively clamped in the two mounting grooves 121 disposed opposite to each other, the second foil 40 is respectively clamped in the two mounting grooves 121 disposed opposite to each other in the circumferential direction, and the end of the first foil 30 is disposed outside the end of the second foil 40.

Specifically, the mounting grooves 121 axially penetrate the bearing housing 10, and both ends of the first foil piece 30 are inserted into two opposite mounting grooves 121 from axial ends of the bearing housing 10, respectively, and axially slide along the mounting grooves 121, so that the entire first foil piece 30 is mounted to the inside of the bearing housing 10, and the mounting direction of the second foil piece 40 is the same as that of the first foil piece 30.

Referring to fig. 1, the first foil 30, the second foil 40 and the bearing housing 10 have the same width in the axial direction. Therefore, the supporting strength of the first foil piece 30 and the second foil piece 40 can be uniformly distributed along the axial direction, and the stable operation of the dynamic pressure gas bearing can be ensured.

In this embodiment, a wear-resistant material layer is laid on a side surface of the second foil 40 facing away from the bearing housing 10, and the second foil 40 has higher wear resistance and longer service life to the rotor in the rotation process of the rotor through the arrangement of the wear-resistant material layer.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (10)

1. A dynamic pressure gas bearing, characterized in that: the device comprises a bearing sleeve and a plurality of groups of foil groups distributed on the inner side of the bearing sleeve along the circumferential direction; the foil group comprises a first foil and at least one second foil, the second foil is of an arc-shaped sheet structure and is arranged on the inner side of the bearing sleeve, and the second foil is used for forming a lubricating gas film with the rotor; the first foil is of a straight sheet structure and is hollowed to form a plurality of sliding beams, the sliding beams are distributed along a first direction and a second direction respectively, and the first direction is perpendicular to the second direction; the sliding beam is provided with two sliding ends along the first direction, the first foil can be assembled between the bearing sleeve and the second foil in a bending mode in which the second direction is axially parallel to the bearing sleeve, and each sliding end can be supported on the inner wall of the bearing sleeve and can slide on the inner wall of the bearing sleeve after the first foil is bent;

the sliding end comprises at least two sliding toes which are distributed along the second direction and can be supported on the inner wall of the bearing sleeve.

2. The hydrodynamic gas bearing as claimed in claim 1, wherein: a first gap is arranged between every two adjacent sliding toes and is formed by an etching process.

3. The hydrodynamic gas bearing as claimed in claim 1, wherein: a plurality of rows of sliding beams are distributed on the first foil, and the sliding beams in each row are distributed at intervals in the second direction; the adjacent two rows of sliding beams are arranged in a staggered manner in the second direction, and the adjacent two rows of sliding beams are at least partially arranged in a crossed manner in the first direction.

4. A hydrodynamic gas bearing as claimed in claim 3 wherein: two adjacent rows of the sliding beams are crossed to form a first length in the first direction, the sliding beams are provided with a second length along the first direction, and the first length is larger than one fourth of the second length and smaller than one half of the second length.

5. The hydrodynamic gas bearing as claimed in claim 1, wherein: the sliding beam comprises a connecting arm and two sliding arms, the connecting arm is in cross connection with the sliding arms, the two ends of the connecting arm are connecting ends, and the two ends of the sliding arms are two sliding ends.

6. The hydrodynamic gas bearing as claimed in claim 5, wherein: the width of each sliding arm on the first foil along the second direction gradually increases along the rotation direction of the rotor;

the length of each sliding arm on the first foil along the first direction gradually increases along the rotation direction of the rotor.

7. The hydrodynamic gas bearing as claimed in claim 6, wherein: the number of sliding toes on each of the sliding ends on the first foil increases in a rotational direction of the rotor.

8. The hydrodynamic gas bearing as claimed in claim 5, wherein: the width of each sliding arm on the first foil along the second direction is gradually increased from two ends to the middle.

9. The dynamic pressure gas bearing according to any one of claims 1 to 8, wherein: the curvature radius of the second foil is larger than that of the inner wall of the bearing sleeve.

10. The dynamic pressure gas bearing according to any one of claims 1 to 8, wherein: the number of the second foils is 1-3, and the curvature radius of each second foil is gradually increased along the direction departing from the bearing sleeve.

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