A rotor shaft for an electric motor includes an axially extending tubular body having an inner circumferential surface defining a hollow interior thereof with at least a portion of the hollow interior configured to receive a coolant therein. A plurality of circumferentially spaced splines extends radially inwardly from the inner circumferential surface into the portion of the hollow interior configured to receive the coolant therein. Each of the splines is configured to provide a heat exchanging structure for transferring heat from the rotor shaft to the coolant. The splines are one of integrally formed with the tubular body or provided as inserts captured by the tubular body during a flow forming process.

The present invention provides a steel material which is excellent in both of the strength (particularly, fatigue strength) and the manufacturability (particularly, bending straightening properties), and thus can be used as an automobile component such as a crankshaft by being formed into a product shape, being subjected to a high strength treatment such as a nitrocarburizing treatment, and then being subjected to the bending straightening.

Method for producing a ball stud with a joint ball and a shank, wherein the shank includes at least a neck region adjoining the joint ball and a fastening section opposite the joint ball, characterized by the steps: a) plastically shaping a semi-finished ball stud product; b) mechanically machining the semi-finished ball stud product; c) rolling the surface of the joint ball; d) thermochemically hardening the surface of the semi-finished ball stud product; e) removing the surface-hardened layer at least in the neck region and/or the fastening section; f) oxidizing the semi-finished ball stud product; g) polishing the joint ball.

A bearing steel according to an embodiment of the present disclosure includes, as a chemical composition: 0.51 to 0.56 wt % of carbon (C); 0.30 to 0.55 wt % of silicon (Si); 0.60 to 0.90 wt % of manganese (Mn); 0.025 wt % or less (excluding 0 wt %) of phosphorus (P); 0.008 wt % or less (excluding 0 wt %) of sulfur (S); 0.01 to 0.20 wt % of chromium (Cr); 0.08 wt % or less (excluding 0 wt %) of molybdenum (Mo); 0.25 wt % or less (excluding 0 wt %) of nickel (Ni); 0.01 to 0.20 wt % of vanadium (V); 0.20 wt % or less (excluding 0 wt %) of copper (Cu); 0.003 wt % or less (excluding 0 wt %) of titanium (Ti); 0.01 to 0.05 wt % of aluminum (Al); 0.0015 wt % or less (excluding 0 wt %) of oxygen (O); 0.001 wt % or less (excluding 0 wt %) of calcium (Ca); and iron (Fe) and unavoidable impurities as a remainder.

A flanged inner ring for wheel hub bearings is disclosed, wherein a tubular supporting body for the bearing is coaxial with an axis (X), and is provided with a flange, transverse to the axis (X), is provided with a plurality of threaded through holes distributed around the axis (X), and is axially delimited by an outer annular mounting surface and by an inner surface axially facing an outer ring of the bearing.

A method of creating a roller bearing, comprising re-shaping a bearing ring blank utilizing cold impact intrusion, wherein the bearing ring blank includes a surface profile that forms at least one contour section within a contact side of the bearing ring upon the re-shaping, and wherein the contact side is configured to contact a support structure.

A thin-wall bearing, including an outer ring and an inner ring. The inner ring surface of the outer ring is provided with an outer ring raceway, and the outer ring surface of the inner ring is provided with an inner ring raceway. A steel ball and a cage for installing the steel ball are arranged between the outer ring raceway and the inner ring raceway. A plurality of screw holes are evenly distributed in a circle around the side wall of the outer ring, and knurled screws are provided in the screw holes, respectively. The fit between the knurled screw and the screw hole 10-Φ9 is to be N6/h5. The radial clearance of the thin-wall bearing is greater than or equal to 0.01 but less than or equal to 0.09. A processing method of the thin-wall bearing.

A process of manufacturing of segment for carbon thrust bearing uses stainless-steel (SS) round bars/sheets/logs of suitable grade as raw material. The SS round bars/sheets/logs undergo cutting operation to cut into SS billets. The billets successively undergo heating and hot forging processes to form segments of desired shapes. Thereafter, the segment is subjected to heat treatment process i.e. stress relieving, hardening and tempering process successively for obtaining consistent and uniform grain structure, mechanical properties and physical properties of segments which are cost-effective in terms of lower maintenance and lower handling efforts. After heat-treatment process, segment undergoes surface-finishing processes i.e. grinding, lapping and polishing successively for obtaining mirror like surface finishing that gives greater anti-friction property and lower co-efficient of friction. The manufacturing process according to present invention yields consistent grain structure, refine, dense and uniform microstructure of segments which imparts optimum strength, ductility, toughness and resistance to impact and fatigue.

Provided are a hollow drive shaft using an upsetting method and a method of manufacturing the same, in which hot forging and upsetting processes are applied to both ends of a workpiece so that an outer diameter at both ends of the workpiece is greater than an outer diameter of a middle part of the workpiece, thereby reducing a weight of the drive shaft and enabling the drive shaft to transmit higher driving power. According to the present invention, the upsetting process is applied during the hot forging process to manufacture the hollow drive shaft, portions to be substantially processed are limited to portions at both ends of the workpiece, and the number of upsetting processes is limited to a minimum number (2 or the like), such that initial investment costs and manufacturing costs are low because the number of processes is small.

Disclosed is a method for producing a forged crankshaft. This production method includes: a pressing step of pressing a part in a longitudinal direction (first region) of a bar-like member with a pair of first dies, thereby decreasing a cross sectional area of the first region; and a decentering step of decentering a second region of the bar-like member with a second die with the first region being held. The second region is at least a part of the region of the bar-like member excepting the first region. The decentering direction by the second die is a direction perpendicular to each of the pressing direction by the first dies and the longitudinal direction of the bar-like member.