Ntn Corporation

Hiroki Fujiwara

Masato Yoshino

Mitsuo Kawamura

Jun Midoumae

The present invention provides a foil bearing (), including: a top foil portion (Tf); and a back foil portion (Bf), which is arranged on a back of the top foil portion (Tf), and is configured to elastically support the top foil portion (Tf), wherein the back foil portion (Bf) includes: an intermediate portion () being flat; first projecting portions () projecting on a front side of the intermediate portion (); and second projecting portions () projecting on a back side of the intermediate portion ().

Foil bearing

A foil bearing () includes foils () at a plurality of portions in a rotation direction of a shaft member (). A top foil portion (Tf) including a bearing surface (S) is formed in a region including a front end () of each of the foils (), and a back foil portion (Bf) is formed in a region including a rear end () of each of the foils (). A gap (C) is secured between, of two of the foils adjacent to the foil () in a rotation direction (R) and a direction opposite to the rotation direction, the rear end () of the foil on the rotation direction side and the front end () of the foil on the side opposite to the rotation direction side. A width of the gap (C) is set to be non-uniform in a direction (N) orthogonal to the rotation direction.

Foil bearing, production method therefor, and intermediate product of foil bearing

A foil bearing includes a foil holder and a plurality of foils fixed to the foil holder and arrayed in a circumferential direction. Each of the foils includes a top foil portion having a bearing surface, an extending portion formed on one circumferential side of the top foil portion, an underfoil portion formed on another circumferential side of the top foil portion, and an insertion slot formed between the top foil portion and the underfoil portion in the circumferential direction. The insertion slot includes a positioning portion and a wide portion that is larger in circumferential width than the positioning portion and is opened to an end portion of each of the foils. An edge of the top foil portion, which is opposed to the wide portion, retreats toward the one circumferential side with respect to an edge opposed to the positioning portion.

A thrust foil bearing () includes a foil holder () and a plurality of foils (). Each of the foils () includes: a top foil portion (); an extending portion (); and an underfoil portion (). The extending portion () of the each of the foils () is arranged behind another of the foils () that is adjacent to the each of the foils () on the one circumferential side. The underfoil portion () of the each of the foils () is arranged between the top foil portion () of the another of the foils (), which is adjacent to the each of the foils () on another circumferential side, and the end surface () of the foil holder ().

Thrust foil bearing

A foil bearing includes: a tubular foil holder (); and a plurality of foils () having a radial bearing surface (S) and being arrayed on an inner peripheral surface () of the foil holder () in a circumferential direction. Both circumferential ends (projecting portions () and projecting portion ()) of each of the foils () are held on the foil holder (). The foil bearing is configured to support a shaft () inserted along an inner periphery thereof in a freely rotatable manner. The plurality of foils () are held on the foil holder () under a circumferentially movable state.

Foil bearing, and foil bearing unit and turbo machine each having same

A foil bearing (thrust foil bearing ()) includes a foil holder () and a plurality of foils () arrayed in a circumferential direction. Each of the foils () includes a body portion () having a thrust bearing surface (S) and an extended portion () extending from the body portion () to a radially outer side. An end portion () of the body portion () of each of the foils () on one circumferential side is arranged so as to be overlapped on the body portion () of adjacent one of the foils (). The extended portions () of the plurality of foils () are fixed onto the same plane of the foil holder ().

Foil bearing and method for manufacturing thereof

Provided is a foil bearing, an air film is formed in a radial bearing gap between a first bearing surface arranged on a top foil and a second bearing surface along with rotation of a shaft, and the shaft is supported with a pressure of the air film. Lubricating powder is interposed between the bearing surfaces. The top foil is partially elastically deformed in a width direction of the radial bearing gap in accordance with the pressure of the air film generated in the radial bearing gap, thereby being alternately shifted between a first state in which a retaining portion capable of retaining the lubricating powder is formed and a second state in which the retaining portion substantially disappears, and shifted from the second state to the first state along with an increase in the pressure of the air film.

A foil bearing includes an outer member (), and a plurality of foils () that are mounted to an inner circumferential surface () of the outer member () and directly face the inner circumferential surface () of the outer member () in a radial direction without interposition of another member (such as back foils). The foils () each include: holding portions () that are formed at both circumferential ends and held while in contact with the outer member (); and a body portion () that is formed circumferentially between the holding portions () and has a bearing surface (A). At least an end portion on one side in a circumferential direction of the body portion () is raised radially inward with respect to the inner circumferential surface () of the outer member ().

A foil bearing unit includes: a first foil holder formed of a single component; a radial bearing foil mounted to an inner peripheral surface of the first foil holder; a thrust bearing foil mounted to an end surface of the first foil holder; and an inner member including: a shaft portion; and a flange portion projecting radially outward from the shaft portion. The inner member is supported in a radial direction by a fluid pressure that is generated in a radial bearing gap between a bearing surface of the radial bearing foil and an outer peripheral surface of the shaft portion, and the inner member is further supported in a thrust direction by a fluid pressure that is generated in a thrust bearing gap between a bearing surface of the thrust bearing foil and one end surface of the flange portion.

Foil bearing unit

A foil bearing includes a cylindrical outer member, a shaft inserted on an inner periphery of the cylindrical outer member, and a plurality of leaves arranged at a plurality of positions in a circumferential direction between an inner peripheral surface of the cylindrical outer member and an outer peripheral surface of the shaft. A region including a front end of each of the plurality of leaves serves as a top foil that has a bearing surface, and a region including a rear end of each of the plurality of leaves serves as a back foil that supports, from behind, the top foil of an adjacent one of the plurality of leaves. Any one or both of the front end and the rear end of each of the plurality of leaves are inclined with respect to an axial direction.

In a tapered roller bearing assembly, a crowning profile formed portion of the roller rolling surface is made up of a contact area crowned portion, which is held in contact with an inner ring raceway surface, and a non-contact area crowned portion which is held in non-contact with the inner ring raceway surface. The contact area crowned portion and the non-contact area crowned portion have their generatrices extending in an axial direction of a roller, which generatrices are represented by corresponding continuous lines represented by different functions and continued smoothly at a point of connection, and the curvature of the generatrix of the non-contact area crowned portion in the vicinity of the connection point is chosen to be smaller than the curvature of the generatrix of the contact area crowned portion.

Tapered roller bearing and method of designing the same

A rolling bearing assembly and a crown shaped retainer, in which the rotating torque of the bearing assembly can be reduced with no limitation in use of the bearing assembly and with no need to modify the grease and the sealing member are provided. The rolling bearing assembly includes a plurality of balls interposed between inner and outer rings, and a retainer for retaining the balls. The retainer is of a crown shaped configuration including a retainer ring body having one side face formed with pockets, each having a portion with an opening, defined at respective locations in a circumferential direction for accommodating therein the balls; a grease reservoir depressed portion provided between the neighboring pockets in the circumferential direction of the retainer ring body for reserving a grease; and a communicating port for communicating the grease reservoir depressed portion and the pocket.

Rolling bearing and crown-shaped retainer

A roller bearing includes: an inner ring having an inner ring raceway; an outer ring having an outer ring raceway; and a plurality of rollers interposed between the inner ring raceway and an outer ring raceway, wherein a crowning is formed on at least one of the inner ring raceway, the outer ring raceway, and a roller rolling contact surface, wherein an optimal value of a drop amount of the crowning at an end of an effective length is determined, from a diameter of a roller and an effective length of the roller, and wherein drop amounts of the crowning at a plurality of positions in a bus-line direction of the crowning are within an allowable range set forth in a specific table.

Growing community of inventors

Mie, Japan

Hiroki Fujiwara