US3449023A - Air bearing - Google Patents

Description

June 10,- 1969 .1. H. SPERMAN 3,449,023

I Q AIR BEARING I Filed NOV" 24, 1967 INVICN'IOR. J 65 JACOB H. SPERMAN ATTORNEY United States Patent 3,449,023 AIR BEARING Jacob H. Sperman, 2199 E. 21st St., Brooklyn, N.Y. 11029 Filed Nov. 24, 1967, Ser. No. 685,496 Int. Cl. F16c 1/24, 33/10, 33/74 US. Cl. 308-5 7 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to an air bearing and it particularly relates to an air bearing having enhanced air support properties.

Although not limited thereto, the present invention is particularly directed to the enhancement of an air hearing having small plate members in which air is usually fed under substantial pressure and/or velocity and then discharged through one side of the bearing to give support to a relatively weighty object, or the work, as the case may be, which is to be readily moved.

It is among the objects of the present invention to provide an air bearing of the character described in which the elevating effect or hearing effect of the air is greatly enhanced without need for reconstruction of the bearing and without change in the design of-the bearing plate.

Another object is to provide a device for greatly improved and enhanced efliciency of the effective air bear-.

ing support for the object to be supported or carried by the air bearing.

Still further objects and advantages will appear in the more detailed description set forth below, it being understood, however, that this more detailed description is given by way of illustration and explanation only and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention.

It has been found desirable first to dry the air and subject the air to cooling or chilling by refrigeration or by the use of a liquified gas, such as, but not limited to carbon dioxide, nitrogen and helium. After the cooling gas has achieved its cooling effect, it may be fed directly into the air bearing in intermixture with the gas (if gas is used instead of refrigeration). All that is required is that there will be achieved a lift of between .002 inch to .005 inch and desirably about .004 inch.

The liquified gas or refrigeration should cool the air to 20 to 100 F. below the ambient air or room atmosphere. Air should be dried and then should also be fed in under a pressure varying from 5 to 200 pounds per square inch above atmospheric.

Where it is desired to regulate the lifting capacity of the bearing, water vapor may be fed into the air or carbon dioxide, or into the mixed gases, as they flow into the air bearing block or plate.

By the system described, it is possible to readily position jigs and fixtures and to move such jigs, fixtures, or tools, varying in weight from 25 to 10,000 pounds by light pressures. The supporting table on which the air 3,449,023 Patented June 10, 1969 bearing is rested may be a reasonably smooth surface, such as a chilling plate, cold rolled steel, hot rolled steel, or even a fibrous material, such as Masonite. The densified or chilled air, directed either downwardly or upwardly from the sides of the bearing plate, being ejected between the bearing surfaces, will tend slightly to separate the surfaces as much as a few thousandths of an inch and this will permit ready movement of the object which has been elevated without heavy frictional resistance.

The finer the surface of the air bearing and the finer the surface of the table and the closer the finish and fitting, the more effective is the bearing that is achieved. Generally, the average lift is .002 to .005 inch and a plurality of air bearings may be used. A preferred medium size is 6 to 10 inches with aheight of 1% inches and a spaced arrangement of about 16 to 24 apertures having an air flow space of 0.030 inch and with interior cored openings extending around the block directly in communication with the outlet orifices and having a size of about inch in diameter and a spacing of about 4 inches in width and 8 inches in length, interiorly of the block.

Brief description of drawings With the foregoing and other objects in view, the invention consists of the novel construction, combination and arrangements of parts as hereinafter more specifically described, and illustrated in the accompanying drawings, wherein is shown an embodiment of the invention, but it is to be understood that changes, variations and modi fications can be resorted to which fall within the scope of the claims hereunto appended.

In the drawings wherein like reference characters denote corresponding parts throughout the several views:

FIG. 1 is a diagrammatic lay-out showing the application of the invention to a bearing block with a heat interehanger, with the bearing block having its orifice directed upwardly toward the work.

FIG. 2. is a side diagrammatic view, showing the orifice.

Referring to FIG. 1, there is shown a support table A, an air bearing plate B and the work C. The support table A may be connected to the air bearing plate B by means of the dowels or bolts 20, which can be mounted in suitable openings extending partly or altogether through the air bearing plates B. The work C sits on the top face 21 of the air bearing plate B, while the bottom of the plate at the face 22 sits on the top face 23 of the supporting table A.

The bearing block B has a central cored opening 24 which usually extends rectangularly within the block, and from one side or the other of this opening 24 extends a large number of small orifices 25, through which air is propelled at a high velocity to achieve a small degree of separation at the contact face 21 of .002 to .004 inch. These orifices may be protected by means of non-corrosive tubular inserts, or brass tubes, since the block B itself desirably consists of non-porous cast iron of substantially uniform structure throughout.

The air is fed into the cored opening 26, which has a threaded connection 27 to the flexible hose 28. The flexible hose 28 may be connected by the connecting member 29 to the heat exchanger D. The heat exchanger D consists of a central tube 40 having an inlet at 41 to receive the dried air under pressure of 5 to 200 pounds per square inch and an outlet at 42 to the flexible tube 28. The incoming air will pass through the drier 9.

Coiled around the tube 40 is the cooling conduit 43 which has an inlet for the coolant, desirably carbon dioxide, refrigerated air, or other liquified gas under pressure, at 44, and which at its outlet 45- joins at 46 with the outlet 42 of the compressed air into the bearing plate or block B. The entire coil 41 and tube 40 may be embodied in or encircled by the aluminum body 47. The

coolant which is fed in at 44 is desirably carbon dioxide under super-pressure of about 700 to 800 pounds per square inch, while the dried air at 41 is fed in under a super-atmospheric pressure ranging from 5 to 200 pounds above atmospheric.

In the passage through the heat exchanger D the air should be chilled at least F. below room temperature or ambient temperature and desirably 50 to 100 F. below ambient temperature. This will result in the air having a greater lifting capacity by at least 10% and desirably to 50%. This lifting capacity may be controlled by admission of controlled amounts of water vapor into either the inlet 41 or the outlet 44. When the temperature of the air going into the mixer is to be less than F. a drier must be used before the mixer to remove all water vapor from the incoming pressurized air line so that the air does not freeze in the heat exchanger.

The achievement of a lift of between .002 to .005 inch is most readily achieved and one or more of the bearing blocks or plates B may be utilized to support the structure, such plates being held in position by the dowels or bolts 20, which if desired may be omitted, since normally the weight and reaction to the jets 25 will drive the bearing block B downwardly into close contact with the bearing table A.

In the embodiment of FIG. 2 the work E is shown as being supported by a bearing block or air bearing F at which it may be mounted by the dowels or bolts G. The table H will carry the bearing plate and the jets I will be directed downwardly against the table H. The jets I may vary from 16 to 24 or more in number and they will be fed from the heat interchanger K through the flexible tube L.

As shown, the air bearing F rests at its lower face 60 upon the top face 61 of the support plate H. The work E rests upon its lower face 62 upon the top face 63 of the bearing plate. The jets J in FIG. 2 are directed down- 'wardly so as to give a clearance between the contacting faces 60 and 61. The elements G may consist of dowels 0r bolts to hold the work E and the bearing plate F together so that they will be moved readily in respect to the table H, whereas in FIG. 1 the bearing plate B and the table A set together and the movement of the work C is in respect to the bearing plate B.

The flexible hose L has connections at 64 to the cored interior system 65 and it also has a connection at 65 to the feed conduit 66. Air under pressure is admitted to the tube 67 at the inlet 68. Carbon dioxide or coolant under pressure is admitted by the tube 69 through the inlet 70. Both will flow into the space 71 inside of the casing or expansion member K serving as a heat exchanger and then will flow outwardly through the con duit 72 which leads to the conduit 66 and the hose L.

This will result in the air being chilled to between 20 to 100 F. below ambient temperatures and to its lifting capacity being increased 10 to 50% so that it better serves the load-bearing characteristics required between the faces 60 and 61.

It is thus apparent that the applicant has enhanced the efliciency of air bearings and has greatly improved their function by providing additional lift capacity,

As many changes could be made in the above air bearing, and many widely different embodiments of this invention could be made without departure from the scope of the claims, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

Having now particularly described and ascertained the nature of the invention, and in what manner the same is to be performed, What is claimed is:

1. An air bearing system having an air bearing plate with a base table support for said plate, work supported upon said plate, said plate having a central cored opening extending around the area thereof, a plurality of spaced nozzle outlets on one bearing face of said plate from said central opening, a gas pressure supply to said central opening and means to chill the gas supply to the 10 to F. below ambient atmospheric temperature.

2. The system of claim 1, said last mentioned means including a refrigerator.

3. The system of claim 1, said last mentioned means including a source of a liquified gas.

4. The system of claim 1, said plate being rectangular and said cored opening being formed within the plate and extending adjacent the periphery thereof and said nozzles projecting jets of refrigerated gas to achieve a spacing of the bearing face of the plate of about .002 to .004 inch.

5. The system of claim '1, said gas consisting of compressed .air and said means including a supply of com-' pressed carbon dioxide to chill said compressed air and a heat exchanger to feed said carbon dioxide in heat exchange relationship with respect to said compressed air supply and means thereafter to feed said carbon dioxide directly into the compressed .air before entry into the central opening.

6. The system of claim 1, said last mentioned means consisting of a compressed .air conduit, a compressed carbon dioxide conduit supply coiled around said compressed air conduit, and means to combine the air and carbon dioxide and feed the combination to the central opening of the plate.

7. The system of claim 1, said last mentioned means including an expansion chamber and means to feed compressed air and compressed carbon dioxide into said expansion chamber to cause chilling and means to feed the chilled gases from said expansion chamber to said central opening.

References Cited UNITED STATES PATENTS 2,853,948 9/ 1958 Aspelin 308-76 X 3,106,431 10/1963 Hartley 308-5 3,245,334 4/1966 Long 3089 3,333,907 8/1967 Lamb 30877 MARTIN P. SCHWADRON, Primary Examiner. LUCIOUS L. JOHNSON, Assistant Examiner.

U.S. Cl. X.R. 308-76, 77

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