Systems and methods are provided for a compound bearing assembly including an offset coupler supporting an inner bearing and an outer bearing for distributing a rotational loading of the compound bearing assembly. In some embodiments, at least one of the bearings comprises a bearing cage with a plurality of elongated openings for receiving a respective plurality of balls. The compound bearing assembly is configured to support a drive shaft of a supercharger system of a vehicle or some other rotational system.

Systems and methods are provided for a compound bearing assembly including an offset coupler supporting an inner bearing and an outer bearing for distributing a rotational loading of the compound bearing assembly. In some embodiments, at least one of the bearings comprises a bearing cage with a plurality of elongated openings for receiving a respective plurality of balls. The compound bearing assembly is configured to support a drive shaft of a supercharger system of a vehicle or some other rotational system.

A holder has a protrusion which protrudes from a side surface at a side opposite in an axial direction with respect to a rolling element held in a pocket toward the side opposite in the axial direction. An oil supply hole which penetrates through the holder from the side surface to a surface at a side of the rolling element in the axial direction is formed in the holder. When the holder rotates, the protrusion guides oil into the oil supply hole, and the oil is introduced from the side surface of the holder to the surface on the side of the rolling element.

A holder has a protrusion which protrudes from a side surface at a side opposite in an axial direction with respect to a rolling element held in a pocket toward the side opposite in the axial direction. An oil supply hole which penetrates through the holder from the side surface to a surface at a side of the rolling element in the axial direction is formed in the holder. When the holder rotates, the protrusion guides oil into the oil supply hole, and the oil is introduced from the side surface of the holder to the surface on the side of the rolling element.

A method of forming a bearing cage is generally disclosed herein. The method includes (i) forming a bearing cage from either titanium or a titanium alloy; and (ii) applying a plasma-nitriding treatment to at least one surface of the bearing cage to form a compound layer of titanium nitride including TiN and Ti.sub.2N on an outer region of the at least one surface. Step (ii) further forms a diffusion zone adjacent to the outer region, in one aspect. A surface hardness of the bearing cage that is treated by the plasma-nitriding step is at least 1000 HV. The bearing cage is configured to be used in a turbofan, turboprop, or turboshaft engine or in a helicopter gearbox, in one aspect.

A method of forming a bearing cage is generally disclosed herein. The method includes (i) forming a bearing cage from either titanium or a titanium alloy; and (ii) applying a plasma-nitriding treatment to at least one surface of the bearing cage to form a compound layer of titanium nitride including TiN and Ti.sub.2N on an outer region of the at least one surface. Step (ii) further forms a diffusion zone adjacent to the outer region, in one aspect. A surface hardness of the bearing cage that is treated by the plasma-nitriding step is at least 1000 HV. The bearing cage is configured to be used in a turbofan, turboprop, or turboshaft engine or in a helicopter gearbox, in one aspect.

A cage for retaining one or more rolling bodies of a bearing unit, the cage including a rib having a plurality of spherical concave surfaces, and a plurality of circumferentially spaced tenons extending from a first axial side of the rib, each tenon of the plurality of tenons including a plurality of spherical concave surfaces and an armature defining a box shape, the armature including a plurality of first portions resting on a first plane and a plurality of second portions resting on a second plane, each first portion of the plurality of first portions alternating circumferentially with each second portion, and the spherical concave surfaces of the rib defining, with the spherical concave surfaces of the tenons, a plurality of spherical cavities to hold each rolling body of the row of rolling bodies in place.

A cage for retaining one or more rolling bodies of a bearing unit, the cage including a rib having a plurality of spherical concave surfaces, and a plurality of circumferentially spaced tenons extending from a first axial side of the rib, each tenon of the plurality of tenons including a plurality of spherical concave surfaces and an armature defining a box shape, the armature including a plurality of first portions resting on a first plane and a plurality of second portions resting on a second plane, each first portion of the plurality of first portions alternating circumferentially with each second portion, and the spherical concave surfaces of the rib defining, with the spherical concave surfaces of the tenons, a plurality of spherical cavities to hold each rolling body of the row of rolling bodies in place.

A holder has a protrusion which protrudes from a side surface at a side opposite in an axial direction with respect to a rolling element held in a pocket toward the side opposite in the axial direction. An oil supply hole which penetrates through the holder from the side surface to a surface at a side of the rolling element in the axial direction is formed in the holder. When the holder rotates, the protrusion guides oil into the oil supply hole, and the oil is introduced from the side surface of the holder to the surface on the side of the rolling element.

A holder has a protrusion which protrudes from a side surface at a side opposite in an axial direction with respect to a rolling element held in a pocket toward the side opposite in the axial direction. An oil supply hole which penetrates through the holder from the side surface to a surface at a side of the rolling element in the axial direction is formed in the holder. When the holder rotates, the protrusion guides oil into the oil supply hole, and the oil is introduced from the side surface of the holder to the surface on the side of the rolling element.