Methods for manufacturing bearings and wear resistant surfaces usable in various downhole tools are described herein. A housing is provided. A laser configured for insertion into the housing, such as an inner diameter laser, is used to connect a fusible material to the inner surface of the housing or an insert disposed therein to form a hard facing layer on the inner surface. Simultaneously or independently, the laser can be used to connect the fusible material to the outer surface of a mandrel within the housing to form a second hard facing layer. The present methods thereby produce durable radial bearings having extended operational life, which can be produced within a bearing housing, or externally for transport and installation in existing bearing housings.

Construction is achieved that, together with preventing the occurrence of damage to a mandrel, is able to improve precision of the shape of a ring-shaped member after processing. A mandrel includes a pair of support shaft sections that are provided so as to be separated in the axial direction and so as to be concentric with each other, and a rolling shaft section that is concentrically provided in the axial direction between the pair of support shaft sections. One of the support shaft sections is provided in a state in which displacement in the axial direction with respect to the rolling shaft section is regulated. The other support shaft section is provided in a state in which displacement in a direction going away from the rolling shaft section is possible when a pressing force is applied in that direction.

A method for surface treatment of a workpiece includes providing the workpiece with hardened workpiece surface, clamping the workpiece, removing material from the hardened workpiece surface with a material removal tool to produce a machined surface with first machining tracks, and rolling the machined surface with a rolling tool by overlapping the first machining tracks to produce a rolled surface with second machining tracks. A distance between the material removal tool and the rolling tool measured in an axial direction of the workpiece is varied in an oscillating manner. The material removal tool may be advanced in the axial direction at a constant speed and the rolling tool may be advanced in the axial direction at an oscillating speed, or the rolling tool may be advanced in the axial direction at a constant speed and the material removal tool may be advanced in the axial direction at an oscillating speed.

A method is used to forge an outer joint member of a constant velocity universal joint. Track grooves of the outer and inner joint members each have an arc-shaped ball raceway center line having a curvature center that is not offset in an axial direction with respect to a joint center. The forging method includes performing ironing by press-fitting a cylindrical portion of one end of a shaft portion of a pre-processing material of the outer joint member including the shaft portion and the cylindrical portion into a die hole of a die while a punch set that is radially expandable and contractable is fitted to an inner peripheral surface of the cylindrical portion. The punch set includes punches and a punch base to guide the punches to enable advancing and retreating. Each of the punches has a pair of forming surfaces for forming the adjacent track grooves.

A method for surface treatment of a workpiece includes providing the workpiece with hardened workpiece surface, clamping the workpiece, removing material from the hardened workpiece surface with a material removal tool to produce a machined surface with first machining tracks, and rolling the machined surface with a rolling tool by overlapping the first machining tracks to produce a rolled surface with second machining tracks. A distance between the material removal tool and the rolling tool measured in an axial direction of the workpiece is varied in an oscillating manner. The material removal tool may be advanced in the axial direction at a constant speed and the rolling tool may be advanced in the axial direction at an oscillating speed, or the rolling tool may be advanced in the axial direction at a constant speed and the material removal tool may be advanced in the axial direction at an oscillating speed.

A method is used to forge an outer joint member of a constant velocity universal joint. Track grooves of the outer and inner joint members each have an arc-shaped ball raceway center line having a curvature center that is not offset in an axial direction with respect to a joint center. The forging method includes performing ironing by press-fitting a cylindrical portion of one end of a shaft portion of a pre-processing material of the outer joint member including the shaft portion and the cylindrical portion into a die hole of a die while a punch set that is radially expandable and contractable is fitted to an inner peripheral surface of the cylindrical portion. The punch set includes punches and a punch base to guide the punches to enable advancing and retreating. Each of the punches has a pair of forming surfaces for forming the adjacent track grooves.

Construction is achieved that, together with preventing the occurrence of damage to a mandrel, is able to improve precision of the shape of a ring-shaped member after processing. A mandrel includes a pair of support shaft sections that are provided so as to be separated in the axial direction and so as to be concentric with each other, and a rolling shaft section that is concentrically provided in the axial direction between the pair of support shaft sections. One of the support shaft sections is provided in a state in which displacement in the axial direction with respect to the rolling shaft section is regulated. The other support shaft section is provided in a state in which displacement in a direction going away from the rolling shaft section is possible when a pressing force is applied in that direction.

An outer ring 6a for a shell-type radial needle bearing having a cylindrical shape with a bottom is achieved for which fatigue life of the bottom plate section 9a and the continuous section between the bottom plate section 9a and the cylindrical section 8a is improved, as well as the anti-corrosion characteristic of the outer ring 6a is improved and the outer ring 6a can be prevented from coming out of the bearing without an increase in cost. After obtaining an intermediate raw material 35 having a cylindrical section and a bottom plate section from a metal raw material, shot peening is performed on the intermediate material 35 to create residual compressive stress in the surface and surface layer section on the outer surface side of the cylindrical section 8a and the bottom plate section 9a such that the residual compressive stress in the surface layer section on the outer surface side is greater than the in the surface layer section on the inner surface side, and from the surface to a depth of 0.03 mm is 700 MPa to 1600 MPa.

A refrigeration chiller employs a centrifugal compressor the impellers of which are mounted on a shaft which is itself mounted for rotation using rolling element bearings lubricated only by the refrigerant which constitutes the working fluid of the chiller system. Apparatus is taught for providing liquid refrigerant to (1.) the bearings immediately upon chiller start-up, during chiller operation and during a coastdown period subsequent to shutdown of the chiller and (2.) the drive motor of the chiller's compressor for motor cooling purposes. By use of a variable speed-driven motor to drive the compressor, optimized part load chiller performance is achieved in a chiller which does not require or employ an oil-based lubrication system.

The present invention relates to a structure and a method for coupling a wheel bearing that include a wheel hub for mounting a vehicle wheel, a hollow inner ring press-fitted into an end portion of the wheel hub, an annular outer ring disposed at a radial exterior of the wheel hub and the inner ring, and rolling elements disposed between the wheel hub or the inner ring and the outer ring, wherein the wheel hub and the inner ring are splined to each other and the inner ring and the joint member are coupled through facial spline. According to the present invention, driving torque of a constant velocity joint may be stably delivered to the wheel hub and noise may be reduced.