Torque transmission shaft having universal joint yoke and method of manufacturing the same
AssigneeNsk Ltd.
InventorYoshifumi Kurokawa
Life of this patent
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Abstract
A rod-shaped element having an outer diameter, which is the same as an outer diameter of a completed rod part, has one axial end portion and the other axial end portion to which a base end portion of a bifurcated yoke is fixed. The one axial end portion is subject to plastic working for diametrically deforming an outer periphery of the one axial end portion. Thereby, the outer periphery of the one axial end portion is formed with a male spline part having a groove bottom diameter smaller than an outer diameter of a rod part and having a tooth tip diameter larger than the outer diameter of the rod part.
Claims3
A torque transmission shaft having a universal joint yoke, the torque transmission shaft comprising:
- a rod part which has a round rod shape and includes a male spline part provided on an outer periphery of a first axial end portion thereof;
- and
- a yoke which is fixed to a second, opposite, axial end portion of the rod part and includes a pair of arm parts configured to pivotally support end portions of a cross shaft configuring a cross shaft type universal joint,
- wherein a groove bottom diameter of the male spline part is smaller than an outer diameter of a part of the rod part axially distant from the male spline part,
- wherein a surface of the male spline part is provided with a coating layer made of a low friction material,
- wherein in the coating layer, a groove bottom layer formed on each of all groove bottoms of the male spline part has a diametrical thickness larger than a diametrical thickness of a tooth tip layer formed on each of all tooth tip portions of the male spline part.
Dependencies are inferred from the claim text.