Cross member for a universal joint for high torque loads

Abstract

A cross member for a universal joint has a base member (,) and four arms (,). The arms (,) extend away from a base member (,). To increase the torque bearing capacity of the cross member, the outer face of the arm (,) (if viewed in a longitudinal section) extends curve-like in a transition region (,) to the base member with a continually increasing diameter and with a decreasing radius of curvature (R). If viewed in a sectional plane extending through the axes (,), a distance (X) exists between a first tangent (,), on the outer face of the transition region, and a second tangent parallel to the first tangent (,). The first tangent (,) extends at an angle of 45 degrees relative to the axis (,). The second tangent (,), if viewed from the center (,), is positioned behind the first tangent (,). The second tangent (,) contacts the outer face of the base member (,) at a point (,) which is located on a line of symmetry (,) of the cross member. The line of symmetry (,) extends at an angle of 45 degrees relative to the axis (,). The distance (X) corresponds to {fraction (1/10)} of the smallest radius (B) of the respective arm (,). The arms (,) are induction-hardened. The hardness run-out occurs in a region of the base member (,) which is subjected to low stresses only under operational conditions.