Airfoil journal bearing

An airfoil journal bearing comprising:

• a bearing housing having an inner circumferential surface forming a hollow through which a rotation shaft is insertable, and when the rotation shaft is inserted through the hollow, a gap is formed between the inner circumferential surface of the bearing housing and an outer circumferential surface of the rotation shaft, and
• an airfoil that, when the rotation shaft is inserted through the hollow, is in the gap, the airfoil having a first airfoil edge fixed to the bearing housing and a second airfoil edge, opposite to the first airfoil edge, either fixed to the bearing housing or free, wherein
• the airfoil comprises:
• a first foil region that, when the rotation shaft is inserted through the hollow, is configured to receive pressure generated by rotation of the rotation shaft, wherein the first foil region extends in a circumferential direction of the rotation shaft in a range from 180 to 360 degrees around the rotation shaft, the first foil region having a first edge in a first axial direction of the rotation shaft and a second edge in a second axial direction of the rotation shaft that is opposite to the first axial direction, and
• a pair of second foil regions that, when the rotation shaft is inserted through the hollow, extend in in the circumferential direction in a range from 180 to 360 degrees around the rotation shaft, each second foil region comprising a plurality of elastic bumps in the circumferential direction of the rotation shaft on a surface of the respective second foil region and elastically operating by pressure upon the rotation of the rotation shaft,
• wherein a first of the second foil regions of the pair of second foil regions extends from the first edge of the first foil region and a second of the second foil regions of the pair of second foil regions extends from the second edge of the first foil region,
• wherein the first foil region has a smooth curved surface between the first edge and the second edge that is wider in the first axial direction than each of the pair of second foil regions, and
• wherein the airfoil is formed from a single member.

A mechanical device comprising:

• a housing;
• a motor inside the housing and including a rotation shaft extending in an axial direction;
• an impeller coupled to the rotation shaft and configured to rotate by operation of the motor;
• and
• an airfoil journal bearing for rotatably supporting the rotation shaft, the airfoil journal bearing comprising:
• a bearing housing having an inner circumferential surface forming a hollow through which the rotation shaft is inserted;
• and
• an airfoil in the hollow, forming, when the rotation shaft is rotating, an air layer between the airfoil and an outer circumferential surface of the rotation shaft, and extending along the inner circumferential surface of the bearing housing, the airfoil comprising:
• a first foil region having a smooth curved surface;
• and
• a pair of second foil regions respectively at edges of the first foil region and including a plurality of elastic bumps along a circumference of the airfoil and configured to generate elastic force upon the rotation of the rotation shaft,
• wherein the smooth curved surface of the first foil region is wider in the axial direction of the rotation shaft than each of the pair of second foil regions, and
• wherein the first foil region and the second foil regions are integrally formed.