Abstract: A bearing device is configured to rotatably support a rotational shaft of a rotating machine and includes: a semi-floating bearing supported by a bearing housing; and an anti-rotation pin fixed to the bearing housing and having an insertion portion inserted from an outer peripheral side into an insertion hole formed on an outer surface of the semi-floating bearing. At least one of the insertion hole or the insertion portion has at least one protrusion that protrudes toward the other of the insertion hole or the insertion portion in a plan view perpendicular to an axis of the rotational shaft.

Abstract: An impeller includes: a disk-shaped hub centered on an axis; and a plurality of blades arranged in a circumferential direction and protruding from a surface of the hub facing one side in a direction of the axis. In a cross-sectional view including a blade height direction which is a direction away from the hub toward a tip of each blade, the blade has a recessed surface curved convexly toward a rear side in a rotational direction. In the cross-sectional view, when a distance between an imaginary line connecting a tip-side edge and a hub-side edge of the blade and a midspan of the blade along a direction perpendicular to the imaginary line is defined as a recess amount, the blade has a portion where the recess amount increases from a leading edge side to a trailing edge side.

Abstract: Provided is a bearing structure that can support a rotary shaft with a small number of components. The bearing structure includes: a cylindrical sleeve (32) provided so as to surround the outer circumference of a rotary shaft (4) that rotates about a center axis line (CL) and configured to rotate together with the rotary shaft (4); thrust collars (34a, 34b) provided so as to abut against both ends in the center axis line (CL) direction of the cylindrical sleeve (32), respectively, having a larger diameter than the cylindrical sleeve (32), and configured to rotate together with the rotary shaft (4); and a compressor-side journal bearing (12) arranged on the outer circumference side of the cylindrical sleeve (32) and between the thrust collars (34a, 34b).

Abstract: An impeller includes: a disk-shaped hub centered on an axis; and a plurality of blades arranged in a circumferential direction and protruding from a surface of the hub facing one side in a direction of the axis. In a cross-sectional view including a blade height direction which is a direction away from the hub toward a tip of each blade, the blade has a recessed surface curved convexly toward a rear side in a rotational direction. In the cross-sectional view, when a distance between an imaginary line connecting a tip-side edge and a hub-side edge of the blade and a midspan of the blade along a direction perpendicular to the imaginary line is defined as a recess amount, the blade has a portion where the recess amount increases from a leading edge side to a trailing edge side.

Abstract: A bearing device includes: a bearing housing; a floating metal having a cylindrical shape and disposed in a housing hole of the bearing housing and in which a rotational shaft is inserted; and a positioning pin for positioning the floating metal with respect to the bearing housing, the positioning pin being disposed along a radial direction of the rotational shaft. The positioning pin includes a first oil supply hole formed so as to penetrate the positioning pin and communicating with a first space between an inner peripheral surface of the floating metal and an outer peripheral surface of the rotational shaft, and a second oil supply hole formed inside the positioning pin so as to connect a second space to the first oil supply hole, the second space being disposed between an outer peripheral surface of the floating metal and an inner peripheral surface of the housing hole.

Abstract: A turbocharger (1A) includes a rotary shaft (2), a journal hearing (5A), and a bearing housing (10). The journal hearing (5A) includes load support surfaces (14 and 15), a first gap forming portion (F1), and a second gap forming portion (F2). The first gap forming portion (F1) firms a first gap (101) in a radial direction between the load support surfaces (14 and 15) adjacent to each other in a direction of a central axis (O). The second gap forming portion (F2) forms a second gap (102) smaller than the first gap in the radial direction between the load support surfaces (14 and 15) adjacent to each other in the direction of the central axis (O).

Abstract: Provided is a bearing structure that can support a rotary shaft with a small number of components. The bearing structure includes: a cylindrical sleeve (32) provided so as to surround the outer circumference of a rotary shaft (4) that rotates about a center axis line (CL) and configured to rotate together with the rotary shaft (4); thrust collars (34a, 34b) provided so as to abut against both ends in the center axis line (CL) direction of the cylindrical sleeve (32), respectively, having a larger diameter than the cylindrical sleeve (32), and configured to rotate together with the rotary shaft (4); and a compressor-side journal bearing (12) arranged on the outer circumference side of the cylindrical sleeve (32) and between the thrust collars (34a, 34b).

Abstract: A turbocharger includes a rotor shaft that is rotationally driven, a compressor impeller attached to the rotor shaft, and a cylindrical bearing portion that includes an inner cylinder and an outer cylinder, and that supports the rotor shaft in a rotatable manner. A first damping portion is provided between an axial first end portion of the inner cylinder and an axial first end portion of the outer cylinder, and an axial second end portion of the inner cylinder is connected with an axial second end portion of the outer cylinder. A second damping portion is provided between a housing and the axial second end portion. The housing and the bearing portion are fixed by a flange portion provided at the first end portion of the outer cylinder in such a manner as to restrict movement of the flange portion in a radial direction and in an axial direction.

Abstract: A turbocharger includes a rotor shaft that is rotationally driven, a compressor impeller attached to the rotor shaft, and a cylindrical bearing portion that includes an inner cylinder and an outer cylinder, and that supports the rotor shaft in a rotatable manner. A first damping portion is provided between an axial first end portion of the inner cylinder and an axial first end portion of the outer cylinder, and an axial second end portion of the inner cylinder is connected with an axial second end portion of the outer cylinder. A second damping portion is provided between a housing and the axial second end portion. The housing and the bearing portion are fixed by a flange portion provided at the first end portion of the outer cylinder in such a manner as to restrict movement of the flange portion in a radial direction and in an axial direction.

Abstract: A bearing device includes: a bearing housing; a floating metal having a cylindrical shape and disposed in a housing hole of the bearing housing and in which a rotational shaft is inserted; and a positioning pin for positioning the floating metal with respect to the bearing housing, the positioning pin being disposed along a radial direction of the rotational shaft. The positioning pin includes a first oil supply hole formed so as to penetrate the positioning pin and communicating with a first space between an inner peripheral surface of the floating metal and an outer peripheral surface of the rotational shaft, and a second oil supply hole formed inside the positioning pin so as to connect a second space to the first oil supply hole, the second space being disposed between an outer peripheral surface of the floating metal and an inner peripheral surface of the housing hole.

Abstract: A turbocharger (1A) includes a rotary shaft (2), a journal hearing (5A), and a bearing housing (10). The journal hearing (5A) includes load support surfaces (14 and 15), a first gap forming portion (F1), and a second gap forming portion (F2). The first gap forming portion (F1) firms a first gap (101) in a radial direction between the load support surfaces (14 and 15) adjacent to each other in a direction of a central axis (O). The second gap forming portion (F2) forms a second gap (102) smaller than the first gap in the radial direction between the load support surfaces (14 and 15) adjacent to each other in the direction of the central axis (O).