A track roller shaft comprises a body including a revolved surface defining an axis of rotation, a radial direction, and a circumferential direction disposed about the axis of rotation. The body also defines a proximate axial end disposed along the axis of rotation, a radially extending hole that is disposed axially adjacent to the proximate axial end, and a guide member receiving pocket disposed axially further away from the proximate axial end than the radially extending hole.

Steel for a crankshaft includes 0.37 to 0.42 wt % of carbon (C), 0.55 to 0.70 wt % of silicon (Si), 1.45 to 1.65 wt % of manganese (Mn), 0.025 wt % or less (excluding 0 wt %) of phosphorus (P), 0.020 to 0.035 wt % of sulfur (S), 0.15 to 0.30 wt % of chromium (Cr), 0.035 to 0.055% of vanadium (V), and the remainder of Fe and other inevitable impurities. The steel for a crankshaft has strength that is maintained high even when reducing the amount of vanadium.

A torque transmission shaft includes a shaft and a clamp. The shaft includes: a male serration in one axial end portion; a slit in the other axial end portion, the slit axially extending and having a closed end on one side and an open end on the other side; a fitting cylinder portion in the other axial end portion; and a female serration provided in of the other axial end portion. The clamp includes: a discontinuous portion arranged at one place in the circumferential direction; a pair of flange portions arranged on both sides of the discontinuous portion; a connecting portion connecting the flange portions; and an insertion hole for fitting cylinder portion. The clamp is fitted onto the fitting cylinder portion to reduce the diameter of the fitting cylinder portion by narrowing the width dimension of the discontinuous portion.

The invention relates to a carburizing bearing steel and a preparation method thereof. The carburizing bearing steel of the invention comprises: 0.18˜0.24 wt % of C, 0.4˜0.6 wt % of Cr, 0.20˜0.40 wt % of Si, 0.40˜0.70 wt % of Mn, 1.6˜2.2 wt % of Ni, 0.15˜0.35 wt % of Mo, 0.001˜0.01 wt % of S, 0.001˜0.015 wt % of P, 0˜0.20 wt % of Nb, 0˜0.20 wt % of V and the remaining is iron, wherein the contents of Nb and V are not 0 at the same time. In the invention, an appropriate amount of Nb and V is added in combination with other elements so as to refine the grain size, inhibit the generation of large granular carbides in the steel during carburization and improve the uniformity of the microstructure of steel materials, thus further enhancing the contact fatigue life of the carburizing bearing steel.

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.

The invention relates to a carburizing bearing steel and a preparation method thereof. The carburizing bearing steel of the invention comprises: 0.18˜0.24 wt % of C, 0.4˜0.6 wt % of Cr, 0.20˜0.40 wt % of Si, 0.40˜0.70 wt % of Mn, 1.6˜2.2 wt % of Ni, 0.15˜0.35 wt % of Mo, 0.001˜0.01 wt % of S, 0.001˜0.015 wt % of P, 0˜0.20 wt % of Nb, 0˜0.20 wt % of V and the remaining is iron, wherein the contents of Nb and V are not 0 at the same time. In the invention, an appropriate amount of Nb and V is added in combination with other elements so as to refine the grain size, inhibit the generation of large granular carbides in the steel during carburization and improve the uniformity of the microstructure of steel materials, thus further enhancing the contact fatigue life of the carburizing bearing steel.

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.

An axial ball joint is provided with: a ball stud including a stud section and a ball section; a metallic housing which rotatably supports the ball section of the ball stud; and a resin-made ball seat which is provided to be interposed between the ball section and the housing. The housing is formed into a bottomed cylinder shape by pressing. The thickness of a bottom wall and the thickness of a circumferential side wall of the housing are set to be equal to each other. A plurality of bead sections are formed on the inner bottom of the housing by press-molding or forging.

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.

A method and tool for obtaining face teeth having a plurality of radial teeth on an annular collar of an inner ring of a wheel hub; in which annular roughed-out face teeth are first formed on the collar coaxial with an axis of symmetry (A) of the collar and having a plurality of radial first teeth arranged in a crown and alternating at constant pitch with a plurality of radial first concavities; then a shaping tool comprising a pressing head provided with annular calibration face teeth is axially pressed onto the collar to engage with the annular roughed-out face teeth, second radial concavities of the annular calibration teeth each being delimited by a bottom wall having a rounded circumferential profile exactly reproducing in negative the rounded circumferential profile of the tips or ridges of the radial teeth of the required face teeth.