An elastic foil gas bearing with adjustable support stiffness

Abstract

The application discloses a support rigidity-adjustable elastic foil gas bearing, which comprises an elastic foil gas bearing body, an outer cylinder, an inner cylinder, elastic elements and a spiral guide mechanism, the inner cylinder is sleeved and fixed on the elastic foil gas bearing body, the outer cylinder is sleeved on the inner cylinder and can relatively rotate, a first elastic element groove is arranged on the inner wall of the outer cylinder, a second elastic element groove is arranged on the outer wall of the inner cylinder, the elastic elements are located in the first elastic element groove and the second elastic element groove along one part of the radial direction of the outer cylinder and the inner cylinder, and the two ends of the elastic elements respectively abut against the side walls of the first elastic element groove and the second elastic element groove; the spiral guide mechanism enables the inner cylinder to relatively spiral rotate, under the friction force of the shaft neck, the inner cylinder drives the elastic foil gas bearing body to relatively spiral rotate beyond the end of the shaft neck and compress the elastic elements. The application can change the rigidity of the bearing in real time, thereby improving the stability of the bearing rotor system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mechanical transmission, and more particularly, the present application relates to an elastic foil gas bearing with adjustable support stiffness. BACKGROUND

[0002] The elastic foil gas bearing has good self-adaptability, can be operated for a long time under high temperature, high speed and high pollution conditions, and does not need additional oil supply and other auxiliary devices, so the structure is simple. The elastic foil gas bearing is prone to instability when operated at high speed and large load due to its low specific bearing capacity and narrow stability region.

[0003] Changing the foil geometric parameters of the bearing can improve the stability of the bearing rotor system in a specific state, but it is difficult to meet the stability requirements of the bearing rotor system in multiple states. In the prior art, there are methods for actually adjusting the stiffness of the bearing, but most of them are driven by motors or motors, which require additional power and have high requirements for installation space. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application innovatively provides a method for automatically changing the overlapping area of the elastic foil gas bearing and the journal to change the stiffness of the bearing. This mechanism can adaptively adjust the stiffness of the bearing according to the current state of the bearing to improve the stability of the elastic foil gas bearing rotor system.

[0005] To achieve the above technical purposes, the present application discloses an elastic foil gas bearing with adjustable support stiffness, which is used to be sleeved on a matched journal, comprising an elastic foil gas bearing body, an outer cylinder, an inner cylinder, an elastic element and a spiral guide mechanism,

[0006] The elastic foil gas bearing body is sleeved on the journal, the inner cylinder is sleeved on the elastic foil gas bearing body and fixedly connected with the elastic foil gas bearing body, the outer cylinder is sleeved on the inner cylinder, and the inner cylinder can rotate relative to the outer cylinder,

[0007] A first elastic element groove is arranged on the inner wall of the outer cylinder, a second elastic element groove is arranged on the outer wall of the inner cylinder, the first elastic element groove and the second elastic element groove enclose a placement groove for placing the elastic element, the elastic element is located in the first elastic element groove along one part of the radial direction of the outer cylinder and the inner cylinder and in the second elastic element groove along the other part, and the two ends of the elastic element respectively abut against the side walls of the first elastic element groove and the second elastic element groove,

[0008] The spiral guide mechanism is arranged between the inner cylinder and the outer cylinder, and is used for guiding the spiral rotation of the inner cylinder relative to the outer cylinder.

[0009] Further, the spiral guide mechanism comprises a spiral groove and a protrusion matched with the spiral groove, the protrusion is clamped into the spiral groove and can slide along the spiral groove, and the spiral groove is arranged on one of the outer wall of the inner cylinder and the inner wall of the outer cylinder, and the protrusion is arranged on the other one.

[0010] Further, the number of the spiral grooves is multiple, and the multiple spiral grooves are arranged in the circumferential direction, and the thread taper angles of the multiple spiral grooves are the same or different.

[0011] Further, the first elastic element groove is arranged on one end of the outer cylinder, and the axial limiting device is arranged on the outer cylinder to prevent the elastic element from moving axially out of the first elastic element groove.

[0012] Further, the axial limiting device comprises an annular extension edge, the annular extension edge is fixed on the end face of the outer cylinder close to the elastic element, and the annular extension edge is used for preventing the elastic element from moving axially out of the first elastic element groove.

[0013] Further, the axial limiting device further comprises an outer cylinder sleeve, the outer cylinder sleeve is sleeved outside the outer cylinder and is fixedly connected or circumferentially rotatably connected with the outer cylinder, and the end of the outer cylinder sleeve is fixedly connected with the annular extension edge.

[0014] Further, the outer cylinder sleeve and the outer cylinder are connected through a first fixing member, the first fixing member is a bolt or a screw, a threaded hole penetrating the side wall is arranged on the side wall of the outer cylinder sleeve, and an annular groove is arranged on the outer wall of the outer cylinder at a position corresponding to the threaded hole, and the first fixing member is screwed into the threaded hole and the end is clamped in the annular groove.

[0015] Further, the elastic foil gas bearing body comprises a bottom layer arch foil and a top layer foil, the top layer foil is sleeved on the shaft neck, and the bottom layer arch foil is arranged on the outer side of the top layer foil.

[0016] Further, the inner wall of the inner cylinder is provided with a fixing groove, and a second fixing member is arranged on the elastic foil gas bearing body and fixed in the fixing groove.

[0017] Further, the elastic element is a bendable spring or a spring sheet.

[0018] The beneficial effects of the present application are as follows:

[0019] The present application can automatically adjust the bearing support stiffness by the cooperation of the inner cylinder, the outer cylinder and the elastic element, without additional power, simpler structure and smaller space occupation. The present application adjusts the stiffness by adjusting the coinciding area of the elastic gas bearing body and the shaft neck, without redesigning the elastic foil gas bearing body. The stiffness can be flexibly adjusted by changing the stiffness of the elastic element, and the structure can be adapted to different bearings or working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is an exploded schematic view of the support stiffness adjustable elastic foil gas bearing of the embodiment of the present application.

[0021] Figure 2 is an exploded schematic view of the support stiffness adjustable elastic foil gas bearing of the embodiment of the present application (second angle).

[0022] Figure 3 is a structural schematic view of the support stiffness adjustable elastic foil gas bearing of the embodiment of the present application (hidden axial limiting device).

[0023] Figure 4 is a structural schematic view of the support stiffness adjustable elastic foil gas bearing of the embodiment of the present application (inner cylinder rotated out state).

[0024] Figure 5 is a left view of the support stiffness adjustable elastic foil gas bearing of the embodiment of the present application (inner cylinder rotated out state, hidden axial limiting device).

[0025] Figure 6 is a C-C direction sectional view of the support stiffness adjustable elastic foil gas bearing of the embodiment of the present application (inner cylinder rotated out state).

[0026] Figure 7 is a structural schematic view of the support stiffness adjustable elastic foil gas bearing of the embodiment of the present application (inner cylinder rotated in state).

[0027] Figure 8 is a left view of the elastic foil gas bearing of the embodiment of the present application (inner cylinder rotated in state).

[0028] Figure 9 is a left view of the elastic foil gas bearing of the embodiment of the present application (inner cylinder rotated in state, hidden axial limiting device).

[0029] Figure 10 is a D-D direction sectional view of the elastic foil gas bearing of the embodiment of the present application (inner cylinder rotated in state, hidden axial limiting device).

[0030] In the drawings,

[0031] 1. Axial limit device; 11. Outer tube sleeve; 111. Threaded hole; 12. Annular extension; 2. Outer tube; 21. First elastic element groove; 22. Annular groove; 3. Inner tube; 31. Second elastic element groove; 32. Fixing groove; 4. Elastic foil gas bearing body; 41. Bottom arch foil; 42. Top foil; 43. Second fixing member; 5. Elastic element; 6. First fixing member; 7. Shaft; 71. Shaft neck; 8. Fixing block; 9. Spiral guide mechanism; 91. Spiral groove; 92. Protrusion. DETAILED DESCRIPTION

[0032] The elastic foil gas bearing with adjustable support stiffness provided by the present invention will be explained and illustrated in detail below with reference to the accompanying drawings.

[0033] This embodiment specifically discloses an elastic foil gas bearing with adjustable support stiffness, which is used to be sleeved on a matching shaft neck 71. Figures 1-2 As shown, it includes an elastic foil gas bearing body 4, an outer cylinder 2, an inner cylinder 3, an elastic element 5 and a spiral guide mechanism 9, as shown in FIG. Figure 3 and 4 As shown, the elastic foil gas bearing body 4 is sleeved on the shaft neck 71, and the elastic foil gas bearing body 4 is sleeved on the outside of the shaft neck 71, and there is a gap between the elastic foil gas bearing body and the shaft neck 71; the inner cylinder 3 is cylindrical, and the inner cylinder 3 is sleeved on the elastic foil gas bearing body 4 and fixedly connected to the elastic foil gas bearing body 4; the outer cylinder 2 is a cylindrical shape with basically the same thickness, and the outer cylinder 2 is sleeved on the inner cylinder 3, and the inner cylinder 3 can rotate relative to the outer cylinder 2.

[0034] like Figures 3-6 As shown, a first elastic element groove 21 is provided on the inner wall of the outer cylinder 2, and the first elastic element groove 21 is in the shape of a fan. A second elastic element groove 31 is provided on the outer wall of the inner cylinder 3, and the second elastic element groove 31 is also in the shape of a fan. The first elastic element groove 21 and the second elastic element groove 31 form a placement groove for placing the elastic element 5, and the placement groove is also in the shape of a fan. A part of the elastic element 5 along the radial direction of the outer cylinder and the inner cylinder is in the first elastic element groove 21, and the other part is in the second elastic element groove 31. The two ends of the elastic element 5 are respectively in contact with the side walls of the first elastic element groove 21 and the second elastic element groove 31. In this embodiment, the size of the first elastic element groove 21 is adapted to the size of the elastic element 5, and the depth of the first elastic element groove 21 along the axial direction of the outer cylinder 2 and the length along the circumferential direction of the outer cylinder 2 can just accommodate the elastic element 5. The length of the second elastic element groove 31 along the circumferential direction of the inner cylinder 3 can also accommodate the elastic element 5. As shown Figure 3As shown, when the first elastic element groove 21 and the second elastic element groove 31 are aligned, the elastic element 5 can be installed into the placement groove surrounded by the first elastic element groove 21 and the second elastic element groove 31. When installed, the elastic element 5 is in a natural state, not stretched or compressed. The elastic element 5 is placed in the first elastic element groove 21 and the second elastic element groove 31 along the arc direction of the outer cylinder 2 and the inner cylinder 3. The part of the elastic element 5 along the radial direction of the outer cylinder 2 and the inner cylinder 3 away from the cylinder center axis is installed in the first elastic element groove 21. The part of the elastic element 5 along the radial direction of the outer cylinder 2 and the inner cylinder 3 close to the cylinder center axis is installed in the second elastic element groove 31. One end of the elastic element 5 abuts against the groove side wall of the first elastic element groove 21 and the second elastic element groove 31 (i.e. the wall along the axial direction of the outer cylinder 2 and the inner cylinder 3). The other end of the elastic element 5 is fixedly connected to the other side groove side wall of the first elastic element groove 21 and the second elastic element groove 31.

[0035] The spiral guide mechanism 9 is arranged between the inner cylinder 3 and the outer cylinder 2, and is used to guide the spiral rotation of the inner cylinder 3 relative to the outer cylinder 2. As shown, Figures 4-6 Under the action of the friction force of the shaft neck 71, the inner cylinder 3 drives the elastic foil gas bearing body 4 to rotate relative to the outer cylinder 2 and the shaft neck 71 beyond the end of the shaft neck 71 and compresses the elastic element 5. When the inner cylinder 3 rotates relative to the outer cylinder 2, the arc length of the placement groove surrounded by the first elastic element groove 21 and the second elastic element groove 31 will be shortened, thereby compressing the elastic element 5.

[0036] When the elastic foil gas bearing of the application is installed on the shaft neck 71 of the shaft 7, the end of the elastic foil gas bearing body 4 close to the elastic element 5 is flush with the end of the shaft neck 71. The outer diameter of the other part of the shaft 7 except the shaft neck 71 is smaller than the outer diameter of the shaft neck 71.

[0037] When the shaft neck 71 is started, it will rub the elastic foil gas bearing body 4 more, thereby driving the inner cylinder 3 to rotate. Due to the guiding and limiting action of the spiral guide mechanism 9, the inner cylinder 3 can only rotate out of the outer cylinder 2 and the shaft neck 71 in a spiral manner. When the inner cylinder 3 rotates out, the shaft neck 71 will not axially dislocate. The inner cylinder 3 drives the elastic foil gas bearing body 4 to axially dislocate. Since the end of the elastic foil gas bearing body 4 close to the elastic element 5 is flush with the end of the shaft neck 71 in the initial state, the axial movement of the elastic foil gas bearing body 4 reduces the contact area between the elastic foil gas bearing body 4 and the shaft neck 71, and the support stiffness is reduced, thereby effectively reducing the unnecessary friction between the shaft neck 71 and the elastic foil gas bearing body 4. When the inner cylinder 3 rotates out of the outer cylinder 2 relative to the outer cylinder 2, as shown, Figure 5As shown, the arc length of the placement groove is shortened, one end of the elastic element only abuts against the side wall of the first elastic element groove 21, and the other end of the elastic element only abuts against the side wall of the second elastic element groove 31, the elastic element 5 is compressed, and since the outer cylinder 2 is fixed, a restoring force can be provided for the reset of the inner cylinder 3. When the shaft 7 is stably rotated, the friction between the shaft neck 71 and the elastic foil gas bearing body 4 is reduced, and the inner cylinder 3 is reset under the action of the restoring force of the elastic element 5. As shown, Figures 7-10 As shown, the inner cylinder 3 is screwed into the outer cylinder 2, and the initial state is restored. The inner cylinder 3 drives the elastic foil gas bearing body 4 to be axially screwed in, the contact area between the elastic foil gas bearing body 4 and the shaft neck 71 is increased, the support stiffness is increased, and the stability of the elastic foil gas bearing rotor system in normal operation is improved.

[0038] The elastic element 5 is a bendable spring or a spring sheet, which is bent to an arc shape and placed in the first elastic element groove 21 and the second elastic element groove 31. Taking the bendable spring as an example, the spring is installed in the first elastic element groove 21 along the outer side of the inner cylinder 3 and the outer cylinder 2 in the radial direction, and the inner side is installed in the second elastic element groove 31.

[0039] In this embodiment, as shown in Figure 6 and 10 , the depth of the first elastic element groove 21 in the axial direction and the size of the elastic element 5 in the axial direction when installed are the same, and the depth of the second elastic element groove 31 in the axial direction is greater than that of the first elastic element groove 21 in the axial direction. When the inner cylinder is screwed, the second elastic element groove will move axially with the inner cylinder, and the depth in the axial direction is greater than that of the first elastic element groove, which ensures that the elastic element 5 is always in the second elastic element groove 31 and is pressed by the side walls of the first elastic element groove and the second elastic element groove. The specific value of the depth of the second elastic element groove 21 in the axial direction is set according to the actual length of the inner cylinder screwed out of the shaft neck 71, which does not affect the screwing out of the inner cylinder.

[0040] Optionally, as shown in Figures 1-6 , 8 and 9, the screw guide mechanism 9 includes a spiral groove 91 and a protrusion 92 matched with the spiral groove 91, the protrusion 92 is clamped into the spiral groove 91 and can slide along the spiral groove 91, one of the outer wall of the inner cylinder 3 and the inner wall of the outer cylinder 2 is provided with the spiral groove 91, and the other is provided with the protrusion 92, so that the inner cylinder 3 can be screwed out of the outer cylinder 2 by screwing relative to the outer cylinder 2. In this embodiment, the inner wall of the outer cylinder 2 is provided with the spiral groove 91, and the outer wall of the inner cylinder 3 is provided with the protrusion 92. The protrusion 92 is a spiral protrusion, which can smoothly slide along the spiral groove 91.

[0041] The spiral guide mechanism 9 can be provided with only one spiral groove 91. In some embodiments, the number of spiral grooves 91 is multiple, the multiple spiral grooves 91 are arranged circumferentially, and the thread taper angles of the multiple spiral grooves 91 are the same or different. By arranging multiple spiral grooves 91 on the surface of the cylinder, the pre-compression amount of the elastic element 5 can be adjusted by selecting the position of the spiral groove 91 in which the protrusion 92 is clamped, and the stiffness can be adjusted. By rotating the protrusion 92 into the spiral grooves 91 with different thread taper angles, the length of the inner cylinder 3 rotated out relative to the shaft neck 71 under the same friction force is different, and then the contact area between the elastic foil gas bearing body 4 and the shaft neck 71 is adjusted, so as to adjust the stiffness. Of course, the support stiffness can also be adjusted by adjusting the stiffness of the elastic element 5, or the pre-compression amount of the elastic element 5 is adjusted by adjusting the positions of the first elastic element groove 21 and the second elastic element groove 31, and then the support stiffness is adjusted.

[0042] Optionally, as shown in Figure 1 、 2 , 4-10, the elastic foil gas bearing body 4 includes a bottom layer of arched foil 41 and a top layer of foil 42, the top layer of foil 42 is sleeved on the shaft neck 71, and there is a gap between the top layer of foil 42 and the shaft neck 71; the bottom layer of arched foil 41 is supported on the outside of the top layer of foil 42; the bottom layer of arched foil 41 is connected by a plurality of wave-shaped arches.

[0043] Optionally, the inner wall of the inner cylinder 3 is provided with a fixing groove 32, and the elastic foil gas bearing body 4 is provided with a second fixing member 43, and the second fixing member 43 is fixed in the fixing groove 32.

[0044] Optionally, the top layer of foil 42 is in the shape of a circular arc, the top layer of foil 42 is in the shape of a cylinder as a whole, the bottom layer of arched foil 41 is in the shape of a circular arc and in the shape of a cylinder as a whole, and the top layer of foil 42 and the bottom layer of arched foil 41 each include two end portions, and the second fixing member 43 is arranged on one of the end portions of the top layer of foil 42 and the bottom layer of arched foil 41.

[0045] The fixing groove 32 is an L-shaped groove or a T-shaped groove. When the fixing groove 32 is an L-shaped groove, the second fixing member 43 includes an L-shaped bend of the end portion of the top layer of foil 42 bent outward and an L-shaped bend of the end portion of the bottom layer of arched foil 41 bent outward, and the two L-shaped bends are folded and clamped into the fixing groove 32. When the fixing groove 32 is a T-shaped groove, the second fixing member includes a T-shaped bend of the end portion of the top layer of foil 42 bent outward and an L-shaped bend of the end portion of the bottom layer of arched foil 41 bent outward, and the L-shaped bend of the bottom layer of arched foil 41 is located in one of the side bend spaces of the T-shaped bend, and then clamped into the fixing groove 32.

[0046] In order to better fix the second fixing member 43 in the fixing groove 32, as Figure 4 、 5As shown in Figs. 7-9, the elastic foil gas bearing body 4 can be clamped by the fixing block 8, and the fixing block 8 and the bent transverse portion fill the transverse portion of the fixing groove 32, so that the elastic foil gas bearing body 4 is firmly fixed with the inner cylinder 3 and can rotate with the inner cylinder 3.

[0047] In order to facilitate assembly, the first elastic element groove 21 is arranged on one end of the outer cylinder, i.e., the first elastic element groove 21 extends to the end face of the end of the outer cylinder 2, and the first elastic element groove 21 is open at the end face and is closed at the end inside the outer cylinder 2. The second elastic element groove 31 is arranged on the end of the inner cylinder 3 on the same side as the outer wall provided with the first elastic element groove 21, and the corresponding side walls of the first elastic element groove 21 and the second elastic element groove 31 form a placing groove for placing the elastic element 5 when aligned.

[0048] In the initial state, the end of the inner cylinder 3 provided with the second elastic element groove is flush with the end of the outer cylinder 2 provided with the first elastic element groove.

[0049] In order to prevent the elastic element 5 from being pulled out of the first elastic element groove 21, the outer cylinder 2 is provided with an axial limiting device 1 for preventing the axial movement of the elastic element 5, such as Figure 1 、 2 , 4, 6-8, the axial limiting device 1 includes an annular extension edge 12 arranged in the radial direction, and the annular extension edge 12 is fixed to the end face of the outer cylinder 2 near the elastic element 5. The annular extension edge 12 is used to prevent the elastic element 5 from being pulled out of the first elastic element groove 21 in the axial direction, and the annular extension edge 12 is detachably connected to the outer cylinder. After the elastic element 5 is placed in the first elastic element groove 21, the annular extension edge 12 is fixed to the end of the outer cylinder. The inner edge of the annular extension edge 12 exceeds the groove bottom of the first elastic element groove 21, preventing the elastic element 5 from being pulled out of the first elastic element groove 21, limiting the elastic element 5 in the first elastic element groove 21, maintaining the good compressed state of the elastic element 5, and making it have sufficient restoring force.

[0050] The axial limiting device 1 further includes an outer cylinder sleeve 11 which is sleeved on the outer side of the outer cylinder 2 and fixedly connected or circumferentially rotatably connected to the outer cylinder 2. The end of the outer cylinder sleeve is fixedly connected to the annular extension edge 12, and the annular sleeve is used to fix the annular extension edge 12 to the end of the outer cylinder. In this embodiment, the inner diameter of the annular extension edge 12 is the same as the inner diameter of the part of the outer cylinder 2 which is not provided with the first elastic element groove 21, and the opening end of the first elastic element groove 21 is closed, which can prevent the axial movement of the elastic element and does not affect the movement of the inner cylinder. The outer diameter of the annular extension edge 12 is the same as the outer diameter of the outer cylinder sleeve 11.

[0051] As shown in Figs. 7-9, the elastic foil gas bearing body 4 can be clamped by the fixing block 8, and the fixing block 8 and the bent transverse portion fill the transverse portion of the fixing groove 32, so that the elastic foil gas bearing body 4 is firmly fixed with the inner cylinder 3 and can rotate with the inner cylinder 3. Figures 1-7As shown in Figures 9 and 10, the outer sleeve 11 and the outer cylinder 2 are connected via a first fixing member 6, which is a bolt or screw. A threaded hole 111 is provided through the side wall of the outer sleeve 11. An annular groove 22 is provided on the outer wall of the outer cylinder 2 at a position corresponding to the threaded hole 111. The first fixing member 6 is screwed into the threaded hole 111, with its end retained within the annular groove 22. The threaded hole 111 is provided on the side wall of the outer sleeve 11 near the annular extension 12, while the annular groove 22 is provided on the outer wall of the outer cylinder 2 near the first elastic element groove 21. The end of the first fixing member 6 can abut against the bottom of the annular groove 22 (i.e., the outer wall of the outer cylinder 2), firmly securing the outer cylinder 2 and the outer sleeve 11. Alternatively, the end of the first fixing member 6 can be free from contact with the bottom of the annular groove 22, allowing the first fixing member 6 to slide along the annular groove 22, allowing the outer sleeve 11 and the outer cylinder 2 to rotate circumferentially without causing axial misalignment.

[0052] The working principle of the elastic foil gas bearing with adjustable support stiffness according to the embodiment of the present application is as follows:

[0053] When the journal 71 is first started, it will cause more friction with the gas foil bearing body, thereby driving the inner cylinder 3 to rotate, while the outer cylinder 2 remains fixed. The inner cylinder 3 rotates to compress the elastic element 5. At the same time, since the outer wall of the inner cylinder 3 is provided with a spiral groove 91 and the inner wall of the outer cylinder 2 is provided with a protrusion 92, the spiral groove 91 and the protrusion 92 cooperate with each other. When the inner cylinder 3 rotates relative to the outer cylinder 2, the inner cylinder 3 is screwed out and the elastic element 5 is compressed. Since the end face of the journal 71 is flush with the end of the elastic foil gas bearing body 4 when the inner cylinder 3 is screwed in, the journal 71 will not be axially displaced when the inner cylinder 3 is screwed out, but the inner cylinder 3 drives the elastic foil gas bearing body 4 to axially displace, and the contact area between the elastic foil gas bearing body 4 and the journal 71 is reduced. Figures 4-6 In the state shown, the support stiffness is reduced, which effectively reduces unnecessary friction between the journal 71 and the elastic foil gas bearing body 4;

[0054] When the shaft 7 rotates stably, the friction force of the journal 71 on the elastic foil gas bearing body 4 is reduced, and the inner cylinder 3 is reset under the action of the restoring elastic force of the elastic element 5. The inner cylinder 3 is screwed into the outer cylinder 2, and the inner cylinder 3 drives the elastic foil gas bearing body 4 to be axially screwed in, and returns to Figures 7-10 In the state shown, the contact area between the elastic foil gas bearing body 4 and the shaft neck 71 becomes larger, the support stiffness increases, and the stability of the normal operation of the elastic foil gas bearing rotor system is improved.

[0055] The elastic foil gas bearing of this application has the following advantages:

[0056] 1. The present invention can automatically adjust the bearing support stiffness through the cooperation of the inner tube 3, the outer tube 2 and the elastic element 5, without the need for additional power, with a simpler structure and smaller space occupation.

[0057] 2. The present application adjusts the stiffness by adjusting the coincident area of the elastic gas bearing body and the shaft journal 71, without the need to redesign the elastic foil gas bearing body 4.

[0058] 3. By changing the stiffness of the elastic element 5, or using helical grooves 91 in different positions or helical grooves 91 with different thread taper angles, the stiffness can be flexibly adjusted, and the structure can be adapted to different bearings or working conditions.

[0059] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0060] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0061] In the description of the present application, the description of the terms "the present embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in at least one embodiment or example. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0062] In addition, the terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance or a specific number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0063] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and simple improvement made on the essential content of the present application shall be included in the protection scope of the present application.

Claims

1. An elastic foil gas bearing with adjustable support stiffness, used for being sleeved on a matching shaft neck (71), comprising an elastic foil gas bearing body (4), characterized in that: It also includes an outer cylinder (2), an inner cylinder (3), an elastic element (5) and a spiral guide mechanism (9). The elastic foil gas bearing body (4) is sleeved on the shaft neck (71), the inner cylinder (3) is sleeved on the elastic foil gas bearing body (4) and is fixedly connected to the elastic foil gas bearing body (4), the outer cylinder (2) is sleeved on the inner cylinder (3), and the inner cylinder (3) can rotate relative to the outer cylinder (2). A first elastic element groove (21) is provided on the inner wall of the outer cylinder (2), and a second elastic element groove (31) is provided on the outer wall of the inner cylinder (3). The first elastic element groove (21) and the second elastic element groove (31) form a placement groove for placing the elastic element (5). A portion of the elastic element (5) is located in the first elastic element groove (21) and another portion is located in the second elastic element groove (31) along the radial direction of the outer cylinder and the inner cylinder. Both ends of the elastic element (5) are respectively in contact with the side walls of the first elastic element groove (21) and the second elastic element groove (31). The spiral guide mechanism (9) is arranged between the inner cylinder (3) and the outer cylinder (2) and is used to guide the inner cylinder (3) to spirally rotate relative to the outer cylinder (2). Under the action of the friction force of the journal (71), the inner cylinder (3) drives the elastic foil gas bearing body (4) to spirally rotate relative to the outer cylinder (2) and the journal (71) beyond the end of the journal (71) and compress the elastic element (5).

2. The elastic foil gas bearing with adjustable support stiffness according to claim 1, characterized in that: The spiral guide mechanism (9) comprises a spiral groove (91) and a protrusion (92) matching the spiral groove (91); the protrusion (92) is inserted into the spiral groove (91) and can slide along the spiral groove (91); the spiral groove (91) is provided on one of the outer wall of the inner cylinder (3) and the inner wall of the outer cylinder (2), and the protrusion (92) is provided on the other.

3. The elastic foil gas bearing with adjustable support stiffness according to claim 2, characterized in that: There are multiple spiral grooves (91), the multiple spiral grooves (91) are circumferentially arranged, and the thread taper angles of the multiple spiral grooves (91) are the same or different.

4. The elastic foil gas bearing with adjustable support stiffness according to any one of claims 1 to 3, characterized in that: The first elastic element groove (21) is provided on one end portion of the outer cylinder (2), and an axial limiting device (1) is provided on the outer cylinder (2) to prevent the elastic element (5) from axially moving out of the first elastic element groove (21).

5. The elastic foil gas bearing with adjustable support stiffness according to claim 4, characterized in that: The axial limiting device (1) comprises an annular extension (12), which is fixed on the end surface of the outer cylinder (2) close to the elastic element (5), and the annular extension (12) is used to prevent the elastic element (5) from axially moving out of the first elastic element groove (21).

6. The elastic foil gas bearing with adjustable support stiffness according to claim 5, characterized in that: The axial limiting device (1) further comprises an outer cylinder sleeve (11), which is sleeved on the outside of the outer cylinder (2) and is fixedly connected to the outer cylinder (2) or circumferentially rotatably connected thereto, and an end portion of the outer cylinder sleeve (11) is fixedly connected to the annular extension (12).

7. The elastic foil gas bearing with adjustable support stiffness according to claim 6, characterized in that: The outer cylinder sleeve (11) is connected to the outer cylinder (2) via a first fixing member (6), wherein the first fixing member (6) is a bolt or a screw. A threaded hole (111) penetrating the side wall of the outer cylinder sleeve (11) is provided, and an annular groove (22) is provided on the outer wall of the outer cylinder (2) at a position corresponding to the threaded hole (111). The first fixing member (6) is screwed into the threaded hole (111) and the end portion is clamped in the annular groove (22).

8. The elastic foil gas bearing with adjustable support stiffness according to claim 1, characterized in that: The elastic foil gas bearing body (4) comprises a bottom arch foil (41) and a top foil (42), wherein the top foil (42) is sleeved on the shaft neck (71), and the bottom arch foil (41) is correspondingly supported on the outer side of the top foil (42).

9. The elastic foil gas bearing with adjustable support stiffness according to claim 1 or 8, characterized in that: The inner wall of the inner cylinder (3) is provided with a fixing groove (32), and the elastic foil gas bearing body (4) is provided with a second fixing member (43), and the second fixing member (43) is fixed in the fixing groove (32).

10. The elastic foil gas bearing with adjustable support stiffness according to claim 1, characterized in that: The elastic element (5) is a bendable spring or a spring.

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