JP2012013218A - Pressed ring foil dynamic pressure gas bearing and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problems: a ring foil of a gas bearing is costly manufactured by high-quality production method such as NC machining or wire cutting; the smallest thickness of the ring is about 0.2 mm; a small-diameter ring foil cannot be manufactured; and a small-diameter dynamic pressure type gas bearing cannot be manufactured, accordingly.SOLUTION: The ring foil is formed by bonding three or more divided ring foils manufactured by thin-plate press. A ring foil type dynamic pressure gas bearing is constituted by assembling a bearing case with springs formed by the thin-plate press.

Description

  Technical field on bearings using gas and air to support the rotating shaft of turbomachine

      Bearings that support the rotating shafts of turbomachines include oil-lubricated plain bearings, ball bearings, roller bearings, gas (air) bearings that use air or gas as a lubricant, and magnetic bearings that are supported by magnetism. In order to use the lubricating oil, the oil bearing requires a lubricating oil supply pump, an oil cooler for cooling the lubricating oil, a lubricating oil pipe, and the like, and the cost of these devices increases. Further, when the lubricating oil enters the working fluid, it becomes a cause of damage to the turbomachine and a factor of lowering the efficiency of the heat exchanger.

    Magnetic bearings are used as bearings in vacuum because they support the rotating shaft with magnetism. Equipment that generates and controls magnetism is expensive. In addition, if the magnetic levitation cannot be performed for some reason, it is necessary to install a separate bearing in order to cause serious damage to the shaft during rotation.

    There are two types of gas bearings, a static pressure type and a dynamic pressure type. The former is a bearing that requires gas supply from another system, and the latter is a gas bearing that does not require gas supply from another system. The gas bearing of the present invention is the latter dynamic pressure type. Dynamic pressure type gas bearings are expensive because they require high precision machining, spring support structure, lubrication and wear prevention at the time of contact, and are limited to expensive and limited fields. ing.

    Conventional gas bearings have a large number of parts and processing man-hours and require high-precision machining, so it is difficult to reduce costs.

    The shape and structure is not suitable for mass production and low-cost production such as pressing.

    The component parts were formed from thin plates.

    The component parts were shaped to be formed by press working.

    The shape is formed by a circle and a straight line that allow easy dimension measurement.

    The ring foil in contact with the rotating shaft is divided into three parts, arranged so as to be inscribed in the cylinder, and manufactured by joining the outer edges of the ring foil.

    FIG. 1 shows a three-part ring foil 110. The three-piece ring foil 110 includes an arc part 111, an inner part 112, an inner / outer edge part 113, an outer part 114, and an outer edge part 115.

    FIG. 2 shows an assembly structure of the ring foil. The ring foil is a combination of three three-piece ring foils 110 and is joined so that the outer peripheral surface 131 of the inner / outer edge portion 113 and the inner peripheral surface 151 of the outer / outer edge portion 115 are in contact with each other.

    FIG. 3 shows the configuration of the bearing case 200. The bearing case 200 has a cylindrical shape, and includes a press hole 230, a support plate 240, a presser 220, and a side disk 210 on the outer peripheral surface.

    The presser 220 is configured such that a part of the stretched cylinder is difficult to bend inward, and the support plate 240 is configured by a part in which a plate of a hole formed in the cylinder by a press is bent inward.

FIG. 4 shows an assembly drawing of the ring foil bearing. The ring foil bearing has a structure in which a spring 300 is housed between the ring foil 100 and the ring foil 100 and the bearing case 200 inside the bearing case 200.
The inner portion 120 and the outer portion 140 of the ring foil 100 are restricted from movement in the circumferential direction by the support plate 240, and are restricted from moving in the axial direction by the presser 220.

    The axial movement of the spring 300 is restricted by the presser 220.

The invention's effect

    A ring foil 100 with high accuracy and low cost can be manufactured by combining and joining the three divided ring foils 110 of FIG.

    In the conventional method, the ring foil 100 having a wall thickness of 0.2 mm or less can be manufactured, and a small-diameter gas bearing can be manufactured. .

    The ring foil 100, the bearing case 200, and the spring 300 can be manufactured by press working, and the manufacturing cost can be reduced.

    Here, the description is made on the three-divided ring foil, and the explanation on the three or more divisions is omitted. However, as can be easily inferred from the explanation on the three-divided, the three or more divisions have the same effect. .

3 split ring foil Ring foil Bearing case Bearing assembly drawing spring

DESCRIPTION OF SYMBOLS 100 Ring foil 110 Three-part ring foil 111 Arc part 112 Inner part 113 Inner edge part 114 Outer part 115 Outer edge part 131 Outer peripheral surface 151 Inner peripheral surface 230,240,220,210
200 Bearing case 210 Side disk 220 Presser 230 Press hole 240 Support plate 300 Spring

Claims (3)

  A hydrodynamic gas bearing comprising: a ring foil formed by pressing from a thin plate into a plurality of divided ring foils into a ring shape and having protrusions equal in number to the divided number.   2. The support plate which is formed by press working and protrudes to the inside having at least three rows of opening holes and the same size as the opening holes on the cylindrical surface, and faces inward to at least one of the end surfaces of the cylinder. A hydrodynamic gas bearing comprising a bearing case having a disc-like portion having a presser claw on the other side.   3. The hydrodynamic gas bearing according to claim 2, wherein at least three plate-like springs are provided between the ring foil and the bearing case.

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