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CN-121993497-A - Air bearing device and bearing clearance adjustment method

CN121993497ACN 121993497 ACN121993497 ACN 121993497ACN-121993497-A

Abstract

The invention relates to the technical field of air bearing, and discloses an air bearing device and a bearing clearance adjusting method, comprising a rotating shaft, a bearing substrate and an installation shell, wherein the bearing substrate comprises an inner substrate, a heat insulation layer and an outer substrate, the outer substrate is made of a low thermal expansion coefficient material, the inner substrate is made of a high thermal expansion coefficient material, when the bearing substrate is heated, the inner substrate is slightly heated and expanded, the outward expansion of the inner substrate is restrained by the outer substrate of the low expansion substrate, only uniform inward radial deformation is generated, and the inner diameter of the inner substrate is reduced slightly.

Inventors

  • LEI ZHONGXING
  • LIU XINGZHE
  • LOU YONGJIANG
  • SHI JUN

Assignees

  • 廊坊麦逊精密机械有限公司

Dates

Publication Date
20260508
Application Date
20260401

Claims (10)

  1. 1. An air bearing device is characterized by comprising a rotating shaft (100), a bearing base body (200) and a mounting shell (300); The rotating shaft (100) is provided with a heat insulation cylinder (110), and the outer wall of the heat insulation cylinder (110) is coplanar with the outer wall of the rotating shaft (100); The bearing substrate (200) comprises an inner substrate (210), a heat insulation layer (220) and an outer substrate (230), wherein the inner substrate (210), the heat insulation layer (220) and the outer substrate (230) are sequentially arranged outwards along the axis, the outer substrate (230) is made of a low thermal expansion coefficient material, the inner substrate (210) is made of a high thermal expansion coefficient material, an air supply pipeline (240) and a temperature control pipeline (250) are arranged in the inner substrate (210), the inner substrate (210) is slightly heated and expanded when the bearing substrate (200) is heated, and the outward expansion of the inner substrate is restrained by the outer substrate (230) of the low expansion substrate, so that only uniform inward radial deformation is generated, and the inner diameter of the inner substrate (210) is slightly reduced; The mounting shell (300) is provided with an air supply structure (310) and a temperature control structure (320) which are respectively used for supplying air to the air supply pipeline (240) and controlling the temperature of the temperature control pipeline (250).
  2. 2. The air bearing device according to claim 1, wherein the rotating shaft (100), the bearing base body (200) and the mounting shell (300) are coaxial and radially arranged outwards in sequence along the axis, the inner wall of the mounting shell (300) is tightly attached to the outer wall of the bearing base body (200), and a gap is formed between the bearing base body (200) and the outer wall of the rotating shaft (100), and is an air bearing film (400).
  3. 3. An air bearing device according to claim 1, wherein the length of the heat insulating cylinder (110) is longer than the length of the bearing base body (200), and both ends of the heat insulating cylinder extend out of both ends of the bearing base body (200).
  4. 4. An air bearing device according to claim 1, wherein the air supply pipeline (240) comprises an air vent groove (241) formed in the inner base body (210), a solid air supply pipe body (242) and a buffer wrapping layer (243) wrapping the air supply pipe body (242), and the air supply pipe body (242) is tightly arranged in the air vent groove (241) and is attached to the inner wall shape of the air vent groove (241) but does not extend to an air outlet hole at the outlet end of the air vent groove (241).
  5. 5. An air bearing device according to claim 1, wherein the temperature control pipeline (250) is in the shape of a micro pipeline array coaxial with the bearing base body (200), and a plurality of pipelines are uniformly arranged around the shaft.
  6. 6. An air bearing device according to claim 1 wherein said inner substrate (210) is comprised of a high coefficient of thermal expansion material selected from the group consisting of beryllium copper, titanium copper alloy and austenitic stainless steel.
  7. 7. An air bearing device according to claim 1 wherein said outer substrate (230) is comprised of a material having a low coefficient of thermal expansion selected from the group consisting of invar and pressureless sintered silicon carbide.
  8. 8. The air bearing device according to claim 1, wherein the heat insulating layer (220) is made of the same material as the outer substrate (230), and a silver coating is provided on the inner wall of the heat insulating layer.
  9. 9. An air bearing device according to claim 1, wherein the outer substrate (230) is provided with a temperature adjusting passage (231), an air inlet end of the temperature adjusting passage (231) is communicated with an air supply structure (310), the mounting shell (300) at a position corresponding to the air outlet end of the air adjusting passage is of a hollow structure, and in operation, the air supply structure (310) provides air to be discharged from the hollow part of the mounting shell (300) through the temperature adjusting passage (231) so as to enable the temperature of the outer substrate (230) to approach the air temperature.
  10. 10. A bearing clearance adjustment method for an air bearing device, characterized in that any one of the air bearing devices according to claims 1 to 9 is used, comprising the steps of: S1, starting an air supply structure (310), introducing compressed air into an air supply pipeline (240), discharging the compressed air to a gap between a bearing substrate (200) and a rotating shaft (100) through an air outlet hole at the outlet end of an air supply pipe body (242) and an air vent groove (241) to form a stable air floating film (400), suspending the rotating shaft (100), and introducing air into a temperature regulating passage (231) by a shunt of the air supply structure (310); S2, when bearing gaps are required to be adjusted and the thickness of the air-float film (400) is changed, firstly, a temperature control structure (320) is started, uniform temperature control is carried out on the inner matrix (210) of the bearing matrix (200) through a temperature control pipeline (250), the inner matrix (210) is heated at a low thermal power in the initial stage, heat is reflected by a silver coating on the inner wall of the heat insulation layer (220), heat transfer to the heat insulation layer (220) and the outer matrix (230) is reduced, and thermal deformation of the outer matrix (230) is avoided; S3, monitoring the gap size of the air-float membrane (400) in real time, combining with a preset bearing gap standard, adjusting the temperature control parameter of the temperature control structure (320), changing the heating degree of the inner matrix (210), and enabling the inner matrix (210) to generate uniform inward radial deformation under the constraint of the outer matrix (230) with a low thermal expansion coefficient by means of the characteristic of the high thermal expansion coefficient of the inner matrix (210), so as to gradually reduce the inner diameter of the inner matrix (210), and further finely adjusting the bearing gap; s4, in the gap adjustment process, the air supply pressure of the air supply structure (310) is synchronously maintained, the bearing capacity and stability of the air flotation film (400) are ensured, meanwhile, air is continuously introduced through the temperature adjustment passage (231), the temperature of the outer matrix (230) is ensured to be always close to the air temperature, the influence of temperature fluctuation on the outer matrix (230) is avoided, the gap adjustment precision is further influenced, the heat insulation effect of the heat insulation cylinder (110) is monitored, and the deformation of the rotating shaft (100) caused by the influence of the heat of the inner matrix (210) is prevented; And S5, when the bearing gap is monitored to reach a preset standard, reducing the power of the temperature control structure (320), keeping the temperature rising and natural temperature reducing efficiencies of the inner substrate (210) consistent, and simultaneously keeping the air supply of the air supply structure (310) and the temperature regulating passage (231) so as to keep the adjusted bearing gap stable.

Description

Air bearing device and bearing clearance adjustment method Technical Field The invention belongs to the technical field of air bearing, and particularly relates to an air bearing device and a bearing clearance adjusting method. Background The air bearing is a precise supporting component which utilizes a gas film to bear load and realize non-contact rotation of a rotating component, and is widely applied to the fields with extremely high requirements on rotation precision and stability such as high-speed precise machine tools, aerospace equipment, precise instruments, semiconductor manufacturing equipment and the like by virtue of the advantages of extremely low friction coefficient, high rotation precision, small abrasion, long service life and the like; The bearing clearance of current air supporting bearing device is mostly fixed structure, the internal diameter of bearing base member is fixed promptly, can't adjust the thickness of air supporting membrane in a flexible way according to the change of actual working scene, lead to air supporting bearing's suitability relatively poor, in practical application, when work load increases, fixed bearing clearance can lead to air supporting membrane bearing capacity not enough, the problem of air supporting membrane rupture appears easily, axis of rotation and bearing inner wall contact wear, influence the running stability and the life of equipment, when rotational speed adjustment or ambient temperature change, bearing base member and axis of rotation can produce the deformation because of thermal expansion shrinkage, the condition of too big or undersize can appear in fixed bearing clearance, the air supporting membrane stability is not enough, influence the rotation precision, the too little can lead to the air supporting membrane to be formed easily, produce dry friction, therefore, need one kind can adjust the bearing clearance, and then change air supporting membrane thickness's air supporting membrane. Disclosure of Invention The invention aims to solve the defects that in the prior art, an air bearing is fixed in bearing clearance and the thickness of an air bearing film cannot be flexibly adjusted, and provides an air bearing device and a bearing clearance adjusting method. In order to achieve the aim, the invention provides the technical scheme that the air bearing device comprises a rotating shaft, a bearing matrix and a mounting shell; the rotating shaft is provided with a heat insulation cylinder, the outer wall of the heat insulation cylinder is coplanar with the outer wall of the rotating shaft; the bearing matrix comprises an inner matrix, a heat insulation layer and an outer matrix, wherein the inner matrix, the heat insulation layer and the outer matrix are sequentially arranged outwards along the axis, the outer matrix is made of a low thermal expansion coefficient material, the inner matrix is made of a high thermal expansion coefficient material, an air supply pipeline and a temperature control pipeline are arranged in the inner matrix, when the bearing matrix is heated, the inner matrix is slightly heated and expanded, the outward expansion of the bearing matrix is restrained by the outer matrix of the low expansion matrix, only uniform inward radial deformation is generated, and the inner diameter of the inner matrix is slightly reduced; The mounting shell is provided with an air supply structure and a temperature control structure which are respectively used for supplying air to the air supply pipeline and controlling the temperature of the temperature control pipeline. As a further scheme of the invention, the rotating shaft, the bearing matrix and the mounting shell are coaxial and are radially arranged outwards in sequence along the axis, the inner wall of the mounting shell is clung to the outer wall of the bearing matrix, and a gap is arranged between the bearing matrix and the outer wall of the rotating shaft and is an air-float membrane. As a further proposal of the invention, the length of the heat insulation cylinder is longer than that of the bearing base body, and the two ends of the heat insulation cylinder extend out of the two ends of the bearing base body. As a further scheme of the invention, the air supply pipeline comprises an air vent groove formed in the inner substrate, a solid air supply pipe body and a buffer wrapping layer wrapping the air supply pipe body, wherein the air supply pipe body is tightly arranged in the air vent groove and is attached to the inner wall shape of the air vent groove, but does not extend to the air outlet hole of the outlet end of the air vent groove. As a further scheme of the invention, the shape of the temperature control pipeline is a micro pipeline array coaxial with the bearing matrix, and a plurality of pipelines are uniformly arranged around the shaft. As a further scheme of the invention, the inner matrix is made of high thermal expansion coefficient materials at least comprisi