Elastic porous controllable throttling thrust air bearing

Abstract

The application provides an elastic porous controllable throttling thrust air bearing, which comprises a sleeve, a main shaft, a thrust disc, left and right thrust pads arranged on both sides of the thrust disc and separated by an adjusting ring, left and right elastic partial porous throttlers embedded in the thrust pads, end covers, and left and right hydraulic adjusting devices; wherein the left and right elastic partial porous throttlers are both made of elastic porous materials. During the operation of the bearing, according to the change of external load, the left and right hydraulic adjusting devices cooperatively control the pressure acting on the non-working side of the left and right elastic partial porous throttlers, adjust the elastic deformation of the elastic partial porous throttlers, change the porosity and permeability of the elastic partial porous throttlers, regulate the throttling characteristics of the elastic partial porous throttlers, and then realize controllable throttling. The controllable throttling structure of the application is compact and reliable in operation, can make the closed thrust air bearing achieve optimal overall stiffness under different working conditions, and significantly improve the gas film stiffness and anti-micro-vibration capacity of the porous throttling thrust air bearing.

Description

Technical Field

[0001] This invention relates to the field of air bearing technology, specifically to an elastic porous controllable throttling thrust air bearing. Background Technology

[0002] Hydrostatic air bearings possess technological advantages such as extremely low frictional resistance, a wide applicable speed range, a broad applicable temperature range, and zero pollution. They are widely used in precision and ultra-precision engineering fields, such as high-speed precision machine tool spindles, precision instruments, micro-turbine compressors, space technology, and medical equipment. The throttling device is the core component of a hydrostatic air bearing, and its throttling characteristics significantly affect the bearing's performance. Compared to traditional throttling devices, porous throttling devices exhibit superior overall performance in terms of load-bearing capacity, support stiffness, and damping characteristics. Based on the area occupied by the porous material on the bearing's working surface, porous hydrostatic air bearings can be divided into integral porous air bearings and partially porous air bearings. Integral porous air bearings face difficulties in secondary processing and the challenge of ensuring uniform porosity and permeability, which limits their development to some extent. Partially porous air bearings, on the other hand, can be used directly without secondary processing, leading to their wider application in practical engineering.

[0003] Currently, the throttling devices of partially porous air bearings are mostly made of metallic materials such as bronze, aluminum, and lead, and non-metallic materials such as graphite, carbon fiber, and silicon carbide. Related research treats them as rigid components, neglecting their elastic deformation. Once the throttling device is designed, its porosity and permeability are constant, and the throttling ratio remains fixed. When the external load on the bearing changes, the throttling air resistance of this fixed throttling device cannot change accordingly, resulting in limitations in bearing air film rigidity, resistance to micro-vibrations, and improvement in spindle rotation accuracy. Therefore, it is necessary to design a porous, controllable throttling air bearing to overcome the performance defects of existing porous air bearings. Summary of the Invention

[0004] This invention provides an elastic porous controllable throttling thrust air bearing, which aims to adjust the elastic deformation of the elastic porous throttling device by hydraulic pressure according to changes in external load or bearing clearance, thereby changing the porosity and permeability of the elastic porous throttling device, and thus controlling its throttling characteristics to improve the bearing's air film stiffness and resistance to micro-vibrations.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A controllable throttling thrust air bearing with elastic porous material includes a sleeve, a main shaft disposed within the sleeve, a thrust plate disposed on the main shaft, left and right thrust pads disposed on both sides of the thrust plate and separated by an adjusting ring, left and right elastic local porous throttling devices disposed in the two thrust pads, left and right end caps disposed at both ends of the sleeve, and left and right hydraulic adjustment devices disposed in the sleeve and the thrust pads; wherein the left and right elastic local porous throttling devices are both made of elastic porous material, and their porosity and permeability vary with the amount of elastic deformation.

[0007] When the bearing is working, the pressure acting on the non-working sides of the left and right elastic local porous throttling devices is controlled by the left and right hydraulic adjustment devices in cooperation, according to the changes in external axial load or the size of the clearance between the two bearings. This adjusts the elastic deformation of the elastic local porous throttling devices, changes their porosity and permeability, and regulates their throttling characteristics, thereby achieving controllable throttling and improving the air film stiffness and micro-vibration suppression capability of the thrust bearing.

[0008] In a preferred embodiment of the present invention, both the left and right elastic local porous throttling devices are cylindrical; wherein, the non-working outer cylindrical surface is coated with sealant to make it airtight; the end of the outer cylindrical surface is inserted into the embedding hole of the left and right thrust pads by interference fit and adhesive bonding to ensure connection strength and reliable sealing; the middle part of the outer cylindrical surface is surrounded by the extrusion cavity in the thrust pad, and the extrusion cavity is filled with liquid plastic, and the liquid pressure in the extrusion cavity will directly act on the middle part of the outer cylindrical surface, causing it to undergo elastic deformation.

[0009] In a preferred embodiment of the present invention, the left and right hydraulic adjustment devices mainly include an adjustment screw, a plunger, liquid plastic and an extrusion chamber; when the bearing is working, the position of the plunger is changed by adjusting the adjustment screw to adjust the pressure of the liquid plastic in the extrusion chamber; the left and right hydraulic adjustment devices quantitatively control the elastic deformation of the left and right elastic local porous throttling devices by adjusting the hydraulic pressure in the extrusion chambers of the left and right thrust bearings.

[0010] In a preferred embodiment of the present invention, air inlets are provided on both the left and right end caps, air inlet ring grooves and static pressure chambers are provided on both the left and right thrust bearings, and inner and outer air inlets are provided on the adjusting ring and sleeve respectively. High-pressure air enters the bearing gap on both sides of the thrust bearing through the air inlets, air inlet ring grooves, elastic local porous throttling device and static pressure chamber to form a load-bearing air film, and finally exits to the outside through the inner main shaft gap and the inner and outer air inlets.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] 1. This invention realizes variable throttling of a porous throttling device. According to the change of external load or bearing clearance, the throttling characteristics of the elastic porous throttling device are adjusted by a hydraulic adjustment device, thereby improving the air bearing film stiffness and the ability to suppress micro-vibrations.

[0013] 2. The present invention can also coordinately regulate the throttling characteristics of the elastic porous throttling device in the two thrust bearings according to the change of external load or the size of the single-sided bearing clearance on both sides of the thrust bearing, so that the closed thrust air bearing can achieve the optimal overall stiffness under different working conditions.

[0014] 3. This invention adjusts the hydraulic pressure by adjusting the screw, thereby changing the elastic deformation of the elastic porous throttling device and thus controlling its permeability and throttling resistance. The controllable throttling structure is compact and reliable in operation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the cross-sectional structure of an elastic porous controllable throttling thrust air bearing.

[0016] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure at point AA.

[0017] Figure 3 for Figure 2 Enlarged view of section B in the middle.

[0018] Explanation of reference numerals in the attached drawings: 1-Sleeve, 101-Outlet vent, 2-Main shaft, 3-Thrust plate, 4-Left thrust bearing, 401-Left intake ring groove, 402-Left static pressure chamber, 403-Left embedding hole, 5-Right thrust bearing, 501-Right intake ring groove, 502-Right static pressure chamber, 503-Right embedding hole, 6-Left elastic local porous throttle, 7-Right elastic local porous throttle, 8-Adjusting ring, 801-Inner outlet 802 - Air outlet ring groove, 9 - Left end cover, 901 - Left air inlet, 10 - Right end cover, 1001 - Right air inlet, 11 - Left hydraulic adjustment device, 1101 - Adjusting screw, 1102 - Screw sleeve, 1103 - Plunger, 1104 - Plunger cavity, 1105 - Liquid plastic, 1106 - Liquid plastic ring groove, 1107 - Liquid plastic channel, 1108 - Liquid plastic extrusion cavity, 12 - Right hydraulic adjustment device. Detailed Implementation

[0019] The following will be combined with the appendix Figures 1 to 3 The present invention will be described in further detail, but this does not limit the invention to the scope of the embodiments.

[0020] See Figure 1In this embodiment of the invention, an elastic porous controllable throttling thrust air bearing includes a sleeve 1, a main shaft 2 disposed within the sleeve 1, a thrust plate 3 disposed on the main shaft 2, left and right thrust bearings 4 and 5 disposed on both sides of the thrust plate 3 and separated by an adjusting ring 8, left and right elastic local porous throttling devices 6 and 7 disposed in the left and right thrust bearings 4 and 5, left and right end caps 9 and 10 disposed at both ends of the sleeve 1, and left and right hydraulic adjustment devices 11 and 12 disposed in the sleeve 1 and the left and right thrust bearings 4 and 5; wherein the left and right elastic local porous throttling devices 6 and 7 are both made of elastic porous material, and their porosity and permeability change with the amount of elastic deformation.

[0021] See Figure 1 and 2 The left and right thrust bearings 4 and 5 are each uniformly provided with eight left and right embedding holes 403 and 503 along their circumference, respectively. Each left and right embedding hole 403 and 503 has a liquid plastic extrusion cavity 1108 in its center. The left and right elastic local porous throttling devices 6 and 7 are both cylindrical and are respectively embedded in the eight left and right embedding holes 403 and 503. Specifically, the non-working outer cylindrical surface is coated with sealant to make it airtight. The end of the outer cylindrical surface is embedded in the left and right embedding holes 403 and 503 by interference fit and adhesive bonding to ensure connection strength and reliable sealing. The middle of the outer cylindrical surface is surrounded by the liquid plastic extrusion cavity 1108, which is filled with liquid plastic 1105. The liquid pressure in the liquid plastic extrusion cavity 1108 will directly act on the middle of the outer cylindrical surface, causing it to undergo elastic deformation.

[0022] See Figure 1-3 The left hydraulic adjustment device 11 is disposed in the sleeve 1 and the left thrust bearing 4, including a screw sleeve 1102 disposed on the sleeve 1, an adjusting screw 1101 disposed in the screw sleeve 1102, a plunger cavity 1104 disposed in the sleeve 1, a plunger 1103 disposed in the plunger cavity 1104, a liquid plastic annular groove 1106 disposed on the outer circle of the left thrust bearing 4, eight liquid plastic channels 1107 disposed in the left thrust bearing 4, and a liquid plastic extrusion cavity 1108 disposed in the left thrust bearing 4; wherein, the bottom ball of the adjusting screw 1101 is in point contact with the upper end face of the plunger 1103, the outer cylindrical surface of the plunger 1103 is in close fit with the plunger cavity 1104, the lower end face of the plunger 1103 is close to the upper liquid surface of the liquid plastic 1105, the plunger cavity 1104, the liquid plastic annular groove 1106, the liquid channels 1107 and the liquid plastic extrusion cavity 1108 are interconnected and filled with liquid plastic 1105. Similarly, the right hydraulic adjustment device 12 is installed in the sleeve 1 and the right thrust bearing 5, and its structure is similar to that of the left hydraulic adjustment device 11.

[0023] See Figure 1The left and right end caps 9 and 10 are respectively provided with left and right air inlets 901 and 1001. The left and right thrust bearings 4 and 5 are respectively provided with left and right air inlet ring grooves 401 and 501 and eight left and right static pressure chambers 402 and 502 corresponding to the left and right elastic local throttles 6 and 7. The adjusting ring 8 is provided with an inner air outlet 801 and an air outlet ring groove 802. The sleeve 1 is provided with an outer air outlet 101. Filtered high-pressure air enters through left and right inlet ports 901 and 1001, respectively, and passes sequentially through left and right inlet ring grooves 401 and 501, left and right elastic local porous throttling devices 6 and 7, and left and right static pressure chambers 402 and 502, reaching the bearing gaps on both sides of the thrust plate 3 and forming a load-bearing air film. Finally, some air flowing out from the inside is discharged to the outside through the main shaft gap, while some air flowing out from the outside is discharged to the outside through the inner outlet port 801, the outlet ring groove 802, and the outer outlet port 101. Because a high-pressure air film is formed in the bearing gaps on both sides of the thrust plate 3, this closed thrust bearing can withstand bidirectional external axial loads.

[0024] See Figure 1-3 When the bearing is working, based on changes in the external axial load or the size of the clearance on both sides of the bearing, the adjusting screw 1101 in the left hydraulic adjusting device 11 is rotated to push the plunger 1103 to move up and down in the plunger cavity 1104, thereby adjusting the pressure of the liquid plastic 1105 in the liquid plastic extrusion cavity 1108. This changes the elastic deformation of the left elastic local porous throttling device 6, controlling its porosity and permeability, and thus regulating the throttling air resistance to achieve controllable throttling. Similarly, the elastic deformation and throttling air resistance of the right elastic local porous throttling device 7 are regulated by the right hydraulic adjusting device 12. In addition, the throttling characteristics of the left and right elastic local porous throttling devices 6 and 7 can be regulated by the cooperation of the left and right hydraulic adjusting devices 11 and 12, so that the closed thrust air bearing can achieve optimal overall stiffness under different working conditions.

[0025] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations will be apparent to those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the basic spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A controllable throttling thrust air bearing with elastic porous material, characterized in that: Includes a sleeve (1), a main shaft (2), a thrust plate (3), left and right thrust bearings (4, 5) set on both sides of the thrust plate (3) and separated by an adjusting ring (8), left and right elastic local porous throttling devices (6, 7) embedded in the left and right thrust bearings (4, 5), left and right end caps (9, 10), and left and right hydraulic adjustment devices (11, 12); wherein the thrust plate (3) can withstand bidirectional external axial loads; The left and right elastic local porous throttling devices (6 and 7) are both made of elastic porous material, and their porosity and permeability change with the amount of elastic deformation. When the bearing is working, according to the change of external load or the size of the gap between the two bearings, the pressure acting on the non-working side of the left and right elastic local porous throttling devices (6, 7) is controlled by the left and right hydraulic adjustment devices (11, 12) to adjust the elastic deformation of the left and right elastic local porous throttling devices (6, 7), change their porosity and permeability, regulate their throttling characteristics, and thus achieve controllable throttling. The left hydraulic adjustment device (11) is installed in the sleeve (1) and the left thrust bearing (4), and includes a screw sleeve (1102), an adjusting screw (1101), a plunger cavity (1104), a plunger (1103), a liquid plastic ring groove (1106), a liquid plastic channel (1107), and a liquid plastic extrusion cavity (1108); wherein, the bottom ball of the adjusting screw (1101) is in point contact with the upper end face of the plunger (1103), the outer cylindrical surface of the plunger (1103) is in close fit with the plunger cavity (1104), the lower end face of the plunger (1103) is close to the upper liquid surface of the liquid plastic (1105), the plunger cavity (1104), the liquid plastic ring groove (1106), the liquid plastic channel (1107), and the liquid plastic extrusion cavity (1108) are interconnected and filled with liquid plastic (1105).

2. The elastic porous controllable throttling thrust air bearing according to claim 1, characterized in that: The right hydraulic adjustment device (12) is installed in the sleeve (1) and the right thrust bearing (5). The right hydraulic adjustment device (12) also includes a screw sleeve (1102), an adjusting screw (1101), a plunger cavity (1104), a plunger (1103), a liquid plastic ring groove (1106), a liquid plastic channel (1107), and a liquid plastic extrusion cavity (1108). The bottom ball of the adjusting screw (1101) is in point contact with the upper end face of the plunger (1103). The outer cylindrical surface of the plunger (1103) is in close fit with the plunger cavity (1104). The lower end face of the plunger (1103) is close to the upper liquid surface of the liquid plastic (1105). The plunger cavity (1104), the liquid plastic ring groove (1106), the liquid plastic channel (1107), and the liquid plastic extrusion cavity (1108) are interconnected and filled with liquid plastic (1105).

3. The elastic porous controllable throttling thrust air bearing according to claim 1, characterized in that: Rotate the adjusting screw (1101) in the left hydraulic adjusting device (11) to push the plunger (1103) to move up and down in the plunger cavity (1104), adjust the pressure of the liquid plastic (1105) in the liquid plastic extrusion cavity (1108), change the elastic deformation of the left elastic local porous throttling device (6), control its porosity and permeability, and thus regulate the throttling air resistance to achieve controllable throttling; similarly, regulate the elastic deformation and throttling air resistance of the right elastic local porous throttling device (7) through the right hydraulic adjusting device (12).

4. The elastic porous controllable throttling thrust air bearing according to claim 1, characterized in that: The left and right thrust bearings (4, 5) are each provided with a number of left and right embedding holes (403, 503) evenly arranged along the circumference. The middle of the left and right embedding holes (403, 503) is provided with a liquid plastic extrusion cavity (1108). The left and right elastic local porous throttling devices (6, 7) are embedded in the left and right embedding holes (403, 503).

5. The elastic porous controllable throttling thrust air bearing according to claim 1, characterized in that: The left and right elastic local porous throttling devices (6, 7) are both cylindrical; the non-working outer cylindrical surface is coated with sealant; the ends of the outer cylindrical surface are embedded in the left and right embedding holes (403, 503) by interference fit and adhesive bonding; the middle part of the outer cylindrical surface is surrounded by the liquid plastic extrusion cavity (1108), and the liquid pressure in the liquid plastic extrusion cavity (1108) will directly act on the middle part of the outer cylindrical surface, causing it to undergo elastic deformation.

6. The elastic porous controllable throttling thrust air bearing according to claim 1, characterized in that: The filtered high-pressure air enters through the left and right air inlets (901, 1001), passes through the left and right air inlet ring grooves (401, 501), the left and right elastic local porous throttling devices (6, 7), and the left and right static pressure chambers (402, 502), and reaches the bearing gaps on both sides of the thrust plate (3) to form a bearing air film. Finally, part of the air flowing out from the inside is discharged to the outside through the main shaft gap, and part of the air flowing out from the outside is discharged to the outside through the inner air outlet (801), the air outlet ring groove (802), and the outer air outlet (101).

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