A method for producing a bearing component includes providing a bearing component blank with an iron-based metal substrate, hardening the metal substrate, treating the metal substrate by an alkaline treatment bath in a region to form an iron oxide-based blackening layer as a conversion layer with an initial layer thickness (db) on the region, and rolling a spherical body over the region to compress the conversion layer in the region to form a bearing component with a protective layer having a final layer thickness (de) that is less than 95% of the initial layer thickness (db). The spherical body may be a component part of a hydrostatic finish rolling tool or a hydrostatic deep rolling tool. The spherical body may include a hard metal or a ceramic.

On an inner peripheral surface of a bearing hole into which a shaft is inserted, concave oil supply surfaces arranged dispersively like separated islands and a sliding surface continuous around the oil supply surfaces to hold an outer peripheral surface of the shaft are formed: a maximum height difference between the sliding surface and the oil supply surfaces is not less than 0.01% and not more than 0.5% of an inner diameter Di of the sliding surface; a surface aperture area ratio of pores at the sliding surface is not more than 10%; a surface aperture area ratio of pores at the oil supply surfaces is more than 10% and less than 40%; and an area of each of the oil supply surfaces is not less than 0.03 mm.sup.2 and not more than 0.2×Di.sup.2 (mm.sup.2).

On an inner peripheral surface of a bearing hole into which a shaft is inserted, concave oil supply surfaces arranged dispersively like separated islands and a sliding surface continuous around the oil supply surfaces to hold an outer peripheral surface of the shaft are formed: a maximum height difference between the sliding surface and the oil supply surfaces is not less than 0.01% and not more than 0.5% of an inner diameter Di of the sliding surface; a surface aperture area ratio of pores at the sliding surface is not more than 10%; a surface aperture area ratio of pores at the oil supply surfaces is more than 10% and less than 40%; and an area of each of the oil supply surfaces is not less than 0.03 mm.sup.2 and not more than 0.2Di.sup.2 (mm.sup.2).

A control device within an actuator includes control logic for a second actuator, the second actuator being connected with the first actuator through a communications interface. By storing the control logic in the second actuator, the construction space for this second actuator is optimized. By integrating the control logic into a control device of the first actuator, the power density of the control device is increased.

An oil-impregnated sintered bearing (8) includes a copper-iron-based sintered compact containing 40 mass % or more of copper, and has inner pores impregnated with an oil. The sintered compact has: a copper structure derived from copper powder (13) of partially diffusion-alloyed powder (11) in which copper powder (13) having a particle diameter of 20 m or less is diffused on and joined to a surface of iron powder (12) in advance; and a copper structure derived from elemental copper powder (14).

An oil-impregnated sintered bearing (8) includes a copper-iron-based sintered compact containing 40 mass % or more of copper, and has inner pores impregnated with an oil. The sintered compact has: a copper structure derived from copper powder (13) of partially diffusion-alloyed powder (11) in which copper powder (13) having a particle diameter of 20 m or less is diffused on and joined to a surface of iron powder (12) in advance; and a copper structure derived from elemental copper powder (14).

A method for chipless machining of a surface region of a rolling-element bearing ring includes rotating the rolling-element bearing ring relative to a first tool having a first tool tip and a second tool having a second tool tip, positioning the first and second tool tips at start positions at first and second opposite axial ends of the surface region, and moving the first and second tools in opposite axial directions such that the first tool tip follows a first helical or spiral path on the surface region and the second tool tip follows a second helical or spiral path on the surface region, the first and second paths crossing at multiple points within an overlap region located between axial ends of the surface regions.

This invention concerns a burnishing head for smooth rolling of the ring-shaped flat end faces (3, 4) at the thrust bearing of crankshafts by means of two cylindrical burnishing rollers (1, 2) which are arranged to be rotated and are side by side in parallel to each other within a burnishing head housing (12) that is pivotable about its longitudinal axis (20) to reach its the working position. Each burnishing roller (1, 2) is pivoted in a cage (10, 11) which is provided in the burnishing head housing (12) with low play (13) and lateral relocatability.