CROSS-REFERENCE TO THE RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2019-0045244 filed on Apr. 18, 2019 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field

Apparatuses consistent with exemplary embodiments relate to a thrust supporting apparatus capable of preventing overheating of a thrust runner, and more particularly, to a thrust supporting apparatus in which a flow path of a cooling gas is formed in a thrust runner to cool the thrust runner.

2. Description of the Related Art

A bearing is a type of device that supports the load of a rotating shaft in a turbo device including a compressor, a pump, and a rotor such as a turbine and that facilitates the rotation of the rotor by minimizing the friction between the bearing itself and the rotary shaft. In particular, of different types of bearing, a thrust bearing is a type of bearing which supports the axial load of the rotary shaft.

The thrust bearing supports the axial load of the rotary shaft transmitted thereto through the thrust runner provided on the rotary shaft and rotating integrally with the rotary shaft. The thrust bearing is installed at the front and the rear of the thrust runner, and the thrust runner and the thrust bearing face each other.

A gas foil thrust bearing (hereinafter referred to as a “foil thrust bearing”) forms a high-pressure air film, instead of an oil film, between the foil thrust bearing and the thrust runner to support the thrust of the rotary shaft.

FIG. 1is a schematic view of a foil thrust bearing of the related art, andFIG. 2is a side cross-sectional view illustrating a foil thrust bearing installed to face a thrust runner of the related art.

Referring toFIGS. 1 and 2, a foil thrust bearing30includes a top foil33at which an air layer between the foil thrust bearing30and a thrust runner40is formed, a supporting structure32which supports the top foil33from below the top foil33, and a housing31below the supporting structure32. The foil thrust bearing30is classified into a bump type or a leaf type.FIGS. 1 and 2illustrate a bump-type foil thrust bearing30.

The foil thrust bearing30supports the axial load of a rotary shaft10by forming a high-pressure air layer between the top foil33and the thrust runner40. The foil thrust bearing30can provide excellent support for the rotary shaft10as compared to a ball bearing that uses an oil film instead of the gas film. Thus, the foil thrust bearing30are typically used in a turbo machine rotating at high speed in the related art.

However, because the thrust runner40rotates at high speed together with the rotary shaft10, the thrust runner40can be easily heated during the rotation of the rotary shaft10. As the temperature of the thrust runner40rises, damage of the bearing30, which is installed adjacent to the thrust runner40, may be caused, which may lead to many serious problems that hamper the normal operation of the turbo device including the bearing30.

Accordingly, in order to cool the thrust runner40more effectively, a turbo device of the related art may additionally be equipped with an apparatus for injecting a separate cooling gas, or a flow path of a cooling gas may be formed in a base plate of the foil thrust bearing30.

However, the incorporation of a separate cooling device in the turbo device results in a cost increase, and the formation of a flow path of a cooling gas in the base plate has a relatively low cooling efficiency to cool the thrust runner40.

SUMMARY

Exemplary embodiments of the disclosure provide a thrust supporting apparatus capable of preventing overheating of a thrust runner without the installation of additional cooling equipment in a turbo device.

However, exemplary embodiments of the disclosure are not restricted to those set forth herein. The above and/or other exemplary embodiments of the disclosure will become more apparent to one of ordinary skill in the art to which the present disclosure pertains by referencing the detailed description of the present disclosure given below.

According to an aspect of an exemplary embodiment, there is provided a thrust supporting apparatus including: a thrust runner configured to rotate integrally with a shaft; and a foil thrust bearing supporting an axial load of the shaft, the axial load being transmitted from the thrust runner. The foil thrust bearing includes a top foil facing a first surface of the thrust runner, and the thrust runner comprises first one or more grooves formed on the first surface.

The first one or more grooves are formed as spirals.

The first one or more grooves are curved from an inner portion to an outer portion of the thrust runner in a radial direction of the shaft in an opposite direction of a rotational direction of the thrust runner.

The first one or more grooves are formed as straight lines.

The first one or more grooves formed as the straight lines extend along a radial direction of the thrust runner in a direction opposite to a rotational direction of the thrust runner.

The thrust supporting apparatus further includes an additional foil thrust bearing. The additional foil thrust bearing includes a top foil disposed to a second surface opposite to the first surface of the thrust runner in an axial direction of the shaft. The second surface comprises second one or more grooves formed on the second surface of the thrust runner, and first extending directions of the first one or more grooves formed on the first surface of the thrust runner match second extending directions of the second one or more grooves formed on the second surface of the thrust runner.

A cross section of each of the first one or more grooves has at least one of a semicircular shape, a square shape, and a triangular shape.

Openings which do not overlap with the top foil are formed at opposite ends of each of the first one or more grooves.

The top foil is provided a predetermined distance apart radially from an inner diameter of the thrust runner, and inner ends of the grooves are disposed between the top foil and the inner diameter of the thrust runner.

The first one or more grooves extend to an outer diameter of the thrust runner so that outer ends of the grooves are disposed on an outer circumferential surface of the thrust runner.

According to an aspect of another exemplary embodiment, there is provided a thrust supporting apparatus including: a thrust runner configured to rotate integrally with a shaft and including: a first surface facing an impeller; and a second surface opposite to the first surface of the thrust runner; and foil thrust bearings supporting an axial load of the shaft being transmitted through the thrust runner and including: a first foil thrust bearing including a first top foil facing the first surface; and a second foil thrust bearing including a second top foil facing the second surface. The thrust runner further includes: first grooves formed on the first surface; and second grooves form on the second surface.

The first grooves and the second grooves are curved from an inner portion to an outer portion of the thrust runner in a radial direction of the shaft in an opposite direction of a rotational direction of the thrust runner.

The first grooves and the second grooves extend in straight lines from an inner portion to an outer portion of the thrust runner in a radial direction of the shaft in an opposite direction of a rotational direction of the thrust runner.

A cross section of each of the first grooves and each of second grooves has at least one of a semicircular shape, a square shape, and a triangular shape.

According to the aforementioned and other exemplary embodiments of the present disclosure, a thrust runner can be effectively cooled without the installation of additional cooling equipment.

Other features and other exemplary embodiments may be apparent from the following detailed description, the drawings, and the claims.

