A semi-floating bearing (bearing) including: a main body, which has an annular shape, extends in a direction intersecting with a vertical direction, and has a shaft inserted through the main body; a radial bearing surface formed on an inner peripheral surface of the main body; and a plurality of oil supply grooves, which extend in an axial direction of the main body, are formed in the radial bearing surface at positions excluding a lowermost portion of the radial bearing surface in the vertical direction at intervals in a circumferential direction, and are arranged so as to be line-symmetric with each other with respect to a vertical axis in a cross section orthogonal to the axial direction of the radial bearing surface such that the interval between the oil supply grooves in the circumferential direction is the largest on a vertically lower side.

An oil dispersion system uses an actuator for propellers and includes a pumping device that circulates oil when a driving motor is operated to drive a propeller, whereby the propeller and an oil circulation structure are integrated, and a circulation amount of oil is adjusted based on an angle of a swash plate of the pumping device when the driving motor is operated in order to drive the propeller, thereby controlling a supply of oil to no more than that required by oil-using parts.

An oil dispersion system uses an actuator for propellers and includes a pumping device that circulates oil when a driving motor is operated to drive a propeller, whereby the propeller and an oil circulation structure are integrated, and a circulation amount of oil is adjusted based on an angle of a swash plate of the pumping device when the driving motor is operated in order to drive the propeller, thereby controlling a supply of oil to no more than that required by oil-using parts.

A compressor wheel device comprises a compressor wheel attached to a rotary shaft and a thrust collar attached to the rotary shaft at a back surface of the compressor wheel. The compressor wheel includes: a wheel body part with a hub and at least one blade provided on an outer peripheral surface of the hub; and a sleeve part having a cylindrical shape projecting along an axis direction from a back surface of the hub and having an outer peripheral surface on which a sealing groove extending along a peripheral direction is formed. The thrust collar has a circular plate-like shape including: one surface including an abutting surface abutting on an end surface of the sleeve part and extending along a radial direction; and the other surface including a slidably-contacting surface slidably contacting a thrust bearing supporting the rotary shaft in a thrust direction and extending along the radial direction.

A compressor wheel device comprises a compressor wheel attached to a rotary shaft and a thrust collar attached to the rotary shaft at a back surface of the compressor wheel. The compressor wheel includes: a wheel body part with a hub and at least one blade provided on an outer peripheral surface of the hub; and a sleeve part having a cylindrical shape projecting along an axis direction from a back surface of the hub and having an outer peripheral surface on which a sealing groove extending along a peripheral direction is formed. The thrust collar has a circular plate-like shape including: one surface including an abutting surface abutting on an end surface of the sleeve part and extending along a radial direction; and the other surface including a slidably-contacting surface slidably contacting a thrust bearing supporting the rotary shaft in a thrust direction and extending along the radial direction.

A full-floating bearing includes: an outer peripheral groove having a groove width larger than a value of 0.69, which is a value obtained by subtracting a chamfer width as a width of a chamfered portions in a center axis direction and the groove width as a width of the groove in the center axis direction from a total width being a width of a main body in the center axis direction and dividing a net width by a total width.

A full-floating bearing includes: an outer peripheral groove having a groove width larger than a value of 0.69, which is a value obtained by subtracting a chamfer width as a width of a chamfered portions in a center axis direction and the groove width as a width of the groove in the center axis direction from a total width being a width of a main body in the center axis direction and dividing a net width by a total width.

Compressors having multi-speed gearboxes are disclosed. The apparatus comprises: a fluid channel to convey a fluid, a compressor fluidly coupled to the fluid channel, a gearbox operatively coupled to the compressor, the gearbox to control the compressor using a first gear ratio and a second gear ratio different from the first gear ratio to vary a flow rate of fluid in the fluid channel, and clutches to vary the gearbox between the first gear ratio and the second gear ratio.

Compressors having multi-speed gearboxes are disclosed. The apparatus comprises: a fluid channel to convey a fluid, a compressor fluidly coupled to the fluid channel, a gearbox operatively coupled to the compressor, the gearbox to control the compressor using a first gear ratio and a second gear ratio different from the first gear ratio to vary a flow rate of fluid in the fluid channel, and clutches to vary the gearbox between the first gear ratio and the second gear ratio.

A system includes a shaft body defining a longitudinal axis. A first internal fluid channel extends axially within the shaft body and includes an inlet opening through the shaft body for fluid communication of external fluid into the first internal fluid channel and an outlet opening through the shaft body for fluid communication of fluid from the first internal fluid channel to an area external of the shaft body. A second internal fluid channel extends axially within the shaft body and includes an inlet opening through the shaft body for fluid communication of external fluid into the second internal fluid channel and an outlet opening through the shaft body for fluid communication of fluid from the second internal fluid channel to an area external of the shaft body. The first and second internal fluid channels are in fluid isolation from one another within the shaft body.