An inclined throttling hydrostatic gas bearing

Abstract

The present invention provides an inclined throttling type hydrostatic air bearing, belonging to the field of bearings, which includes an upper end cover and a lower support plate. A sealing ring is provided between the upper end cover and the lower support plate. An air cavity is provided on one side of the lower support plate close to the upper end cover. An air supply hole communicated with the air cavity is provided on the side surface of the lower support plate. A throttling hole communicated with the air cavity is provided at the lower end of the lower support plate. The throttling holes are evenly distributed and symmetrically arranged as multiple ones relative to the axis of the lower support plate, and the throttling holes are inclined downward and outward. The present invention ensures that the air flow realizes a smooth vector turn, making the flow inside the bearing from the throttling holes to the air film more stable, thereby improving the stability of the bearing.

Description

Technical Field

[0001] The present invention belongs to the field of bearings and relates to an inclined throttle type hydrostatic gas bearing. Background Art

[0002] Hydrostatic gas bearings have the advantages of frictionless, pollution-free, high precision, low cost, etc., and are widely used in the fields of aerospace, electronic information, special processing, precision machinery, etc. However, the disadvantages of traditional gas bearings such as small load-bearing capacity and low stiffness limit the development of gas bearings. Especially for precision machining and detection equipment, such as precision machine tools, precision measuring instruments, etc., higher requirements are placed on stiffness and stability.

[0003] Traditional hydrostatic gas bearings are usually small-hole throttle type gas bearings. Its basic principle is that the air flow in the bearing flows out through the throttle holes, so that a gas film is formed between the bearing and the lower plane, thereby making the bearing float. The axis of the throttle holes of traditional gas bearings is usually perpendicular to the lower plane, that is, the air flow needs to make a sharp 90° turn from the throttle holes to the gas film, which is very easy to generate vortex disturbances, thus affecting the stability of the gas bearing. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide an inclined throttle type hydrostatic gas bearing to ensure that the air flow makes a smooth vector turn, making the flow inside the bearing from the throttle holes to the gas film more stable, thereby improving the stability of the bearing.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: an inclined throttle type hydrostatic gas bearing, including an upper end cover and a lower support plate. A sealing ring is provided between the upper end cover and the lower support plate. An air cavity is provided on one side of the lower support plate close to the upper end cover. An air supply hole communicating with the air cavity is provided on the side surface of the lower support plate. A throttle hole communicating with the air cavity is provided at the lower end of the lower support plate. The throttle holes are evenly distributed and symmetrically arranged in multiple numbers relative to the axis of the lower support plate, and the throttle holes are inclined downward and outward.

[0006] Further, the throttle holes can be evenly distributed in multiple circles.

[0007] Further, the angle between the axis of the throttle hole and the horizontal line is 10 to 90 degrees.

[0008] Further, the angle between the axis of the throttle hole and the horizontal line is 30 to 60 degrees.

[0009] Further, the throttle hole includes a large-diameter hole at the upper end and a small-diameter hole at the lower end. The large-diameter hole and the small-diameter hole are coaxially arranged, and the large-diameter hole and the small-diameter hole are connected by a conical section.

[0010] Further, the angle between the conical surface of the conical section and the horizontal plane is 40 to 45 degrees.

[0011] Further, the diameter of the large-diameter hole is 2.5 to 4 times the diameter of the small-diameter hole.

[0012] Further, the length of the large-diameter hole is 1.5 to 2 times the length of the small-diameter hole.

[0013] Further, the length of the small-diameter hole is 2 to 3 times its diameter.

[0014] Further, a lower flat plate is correspondingly arranged on one side of the lower support plate away from the upper end cover. After the air flow is discharged through the throttle holes, an air film is formed between the lower flat plate and the lower support plate.

[0015] Further, an inclined throttle type hydrostatic air bearing is a flat thrust bearing, an arc radial bearing or a spherical bearing.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are as follows.

[0017] 1. The present invention is applicable to various air bearings such as flat surfaces and spherical surfaces. The throttle holes are distributed along the axis of the lower support plate and symmetrically designed, that is, to ensure that the resultant force of the horizontal components brought by the inclined throttle holes is zero, so that the air flow can smoothly flow from the throttle holes into the air film, thereby eliminating the flow instability problem brought by the sharp change of the air flow direction in the traditional air bearing. The bearing has been verified by experiments and has better stability;

[0018] 2. The present invention can be applied to equipment that puts forward high requirements for stiffness and stability of air bearings, such as aerospace micro low gravity simulation, ultra-high precision test turntables, microelectronic equipment, high-precision machine tools, etc., and has good social effects and economic value;

[0019] 3. According to the bearing air supply pressure and air flow velocity, throttle holes with a certain inclination angle are designed. The inclination angle can be changed between 10 and 90 degrees according to the design requirements, so as to ensure that the air flow can achieve smooth vector turning. Thus, the flow inside the bearing from the throttle holes to the air film becomes more stable, thereby improving the stability of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0021] Figure 1 is a schematic structural diagram of an inclined throttle type hydrostatic air bearing of the present invention;

[0022] Figure 2 is a cross-sectional view of the throttle hole of the present invention;

[0023] Figure 3 It is the layout diagram of the throttle orifice of the present invention.

[0024] Reference numerals:

[0025] 1. Upper end cover; 2. Lower support plate; 21. Air cavity; 3. Air supply hole; 4. Throttle orifice; 41. Large-diameter hole; 42. Small-diameter hole; 43. Conical section; 5. Sealing ring; 6. Lower flat plate; 7. Air film. Specific embodiments

[0026] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0027] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] The following will describe in detail the specific embodiments of the present invention with reference to the drawings.

[0030] As Figures 1 to 3 shown, an inclined throttle type hydrostatic air bearing includes an upper end cover 1 and a lower support plate 2. A sealing ring 5 is provided between the upper end cover 1 and the lower support plate 2. An air cavity 21 is provided on the side of the lower support plate 2 close to the upper end cover 1. An air supply hole 3 communicating with the air cavity 21 is provided on the side surface of the lower support plate 2. A throttle orifice 4 communicating with the air cavity 21 is provided at the lower end of the lower support plate 2. The throttle orifices 4 are uniformly distributed and symmetrically arranged in multiple numbers relative to the axis of the lower support plate 2, and the throttle orifices 4 are inclined downward and outward.

[0031] Preferably, the throttle holes 4 can be evenly distributed in multiple circles and should be symmetrically arranged to ensure that the resultant force of the horizontal components brought by the inclined throttle holes 4 is zero.

[0032] Preferably, the angle between the axis of the throttle hole 4 and the horizontal line is 10 to 90 degrees; more preferably, the angle between the axis of the throttle hole 4 and the horizontal line is 30 to 60 degrees, so as to ensure that the air flow can smoothly turn in a vector manner. Thus, the flow inside the bearing from the throttle hole 4 to the air film 7 becomes more stable, thereby improving the stability of the bearing.

[0033] Preferably, the throttle hole 4 includes a large-diameter hole 41 at the upper end and a small-diameter hole 42 at the lower end. The air flow is more balanced and stable. The large-diameter hole 41 and the small-diameter hole 42 are coaxially arranged, and the large-diameter hole 41 and the small-diameter hole 42 are connected by a conical section 43. Preferably, the angle between the conical surface of the conical section 43 and the horizontal plane is 40 to 45 degrees. Setting a certain transition is more conducive to the transition and machining between the large-diameter hole 41 and the small-diameter hole 42. If the taper of the conical section 43 is too large, the structural layout of the small-diameter hole 42 is not conducive to setting. If the taper of the conical section 43 is too small, the transition is not smooth enough and is not conducive to the stability of the air flow.

[0034] Preferably, the diameter of the large-diameter hole 41 is 2.5 to 4 times the diameter of the small-diameter hole 42; more preferably, the length of the large-diameter hole 41 is 1.5 to 2 times the length of the small-diameter hole 42, and the length of the small-diameter hole 42 is 2 to 3 times its diameter. Since the diameter of the small-diameter hole 42 is very small, calculated in microns, the ratio of length to diameter cannot be too large. For convenient machining and manufacturing, usually a larger drill bit is used to first machine the large-diameter hole 41, and finally the small-diameter hole 42. Setting the above reasonable ratio parameters makes the throttle hole 4 more convenient to manufacture, reduces costs, and ensures the stability of the air flow.

[0035] Preferably, a lower flat plate 6 is correspondingly arranged on the side of the lower support plate 2 away from the upper end cover 1. After the air flow is discharged through the throttle hole 4, an air film 7 is formed between the lower flat plate 6 and the lower support plate 2. The setting of the air film 7 realizes the existence of air floating.

[0036] Preferably, an inclined throttle type hydrostatic air bearing is a plane thrust bearing, an arc radial bearing or a spherical bearing, which is used for various air bearings such as planes and spheres, and has a wide range of applications.

[0037] During actual use, the air supply hole 3 is connected to an external air supply device, which can be nitrogen or ordinary gas, and is set according to actual conditions. The air chamber 21 is supplied with air through the air supply hole 3, and then the gas is ejected through the throttle hole 4 to form an air film 7, that is, an air floating layer, between the lower support plate 2 and the lower flat plate 6. Since the throttle hole 4 is set at a certain inclination angle and the throttle hole 4 is distributed along the axis of the lower support plate 2 and symmetrically designed, that is, to ensure that the resultant force of the horizontal component forces brought by the inclined throttle hole 4 is zero, so that the air flow can smoothly flow from the throttle hole 4 into the air film 7, thus eliminating the flow instability problem caused by the sharp change of the air flow direction in the traditional air float. This bearing has been verified by tests and has better stability.

[0038] The above has described in detail an embodiment of the present invention, but the content described is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A tilt throttling hydrostatic gas bearing, applied to aerospace micro low-gravity simulation, characterized in that: It includes an upper end cover and a lower support plate. A sealing ring is provided between the upper end cover and the lower support plate. An air cavity is provided on one side of the lower support plate close to the upper end cover. An air supply hole communicating with the air cavity is provided on the side surface of the lower support plate. A throttle hole communicating with the air cavity is provided at the lower end of the lower support plate. The throttle hole is inclined downward and outward. The throttle holes are evenly distributed and symmetrically arranged relative to the axis of the lower support plate in multiple numbers so that the resultant force of the horizontal component forces brought by the inclined throttle holes is zero, and the air flow smoothly flows from the throttle holes into the air film interior; the angle between the axis of the throttle hole and the horizontal line is 30 to 60 degrees; the throttle hole includes a large-diameter hole at the upper end and a small-diameter hole at the lower end. The large-diameter hole and the small-diameter hole are coaxially arranged, and the large-diameter hole and the small-diameter hole are connected by a conical section; The angle between the conical surface of the conical section and the horizontal plane is 40 to 45 degrees so that the air flow is stable; The diameter of the large-diameter hole is 2.5 to 4 times the diameter of the small-diameter hole, and the length of the large-diameter hole is 1.5 to 2 times the length of the small-diameter hole; the length of the small-diameter hole is 2 to 3 times its diameter so that the air flow smoothly makes a vector turn; The throttle holes can be evenly distributed in multiple circles; A lower flat plate is correspondingly provided on one side of the lower support plate away from the upper end cover. After the air flow is discharged through the throttle holes, an air film is formed between the lower flat plate and the lower support plate.

2. The inclined throttle type hydrostatic gas bearing according to claim 1, wherein: An inclined throttle type hydrostatic air bearing is a flat thrust bearing, an arc radial bearing or a spherical bearing.

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