Power transmission shaft and constant velocity joint
AssigneeNtn Corporation
InventorsKazuhiko Yoshida, Akira Wakita, Hiroaki Makino, Hideki Kondou
Life of this patent
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Abstract
A power transmission shaft using the constant velocity joint is manufactured by applying induction hardening to graphite steel thereby to harden the surface layer and form a 2-phase structure of ferrite and martensite in the core thereof. The graphite steel contains 0.35 to 0.70% of C, 0.4 to 2.0% of Si, 0.3 to 1.5% of Mn, 0.025% or less S, 0.02% or less P, 0.01 to 0.1% of Al, 0.001 to 0.004% of B and 0.002 to 0.008% of N by weight as the basic components, with the rest comprising Fe and inevitable impurities.
Claims31
A power transmission shaft employing a constant velocity joint, wherein surface layer thereof is hardened by applying induction hardening of graphite steel in which the effect of heat reaches the core and a 2-phase structure of ferrite and martensite is formed in the core.
A constant velocity joint comprising an outer member having a plurality of guide grooves formed on an inner circumference thereof, an inner member having a plurality of guide grooves formed on an outer circumference thereof, torque transmitting balls arranged in a plurality of ball tracks formed from the guide grooves of the outer member and the guide grooves of the inner member, and a cage for holding the torque transmitting balls, wherein
- the outer member is hardened in the surface layer thereof by applying induction hardening to graphite steel and a 2-phase structure of ferrite and martensite is formed in the core thereof.
A constant velocity joint comprising an outer member having three track grooves formed on an inner circumference thereof and roller guide surfaces disposed in the axial direction on either side of each track groove, a tripod member having three arms extending and protruding radially, and rollers rotatably mounted via a plurality of rolling elements on the three arms of the tripod member, the rollers being guided in the axial direction of the outer member by the roller guide surfaces disposed in the axial direction on either side of the track groove, wherein
- the outer member is hardened in the surface layer thereof by applying induction hardening to graphite steel and a 2-phase structure of ferrite and martensite is formed in the core thereof.
A constant velocity joint comprising an outer member having a plurality of guide grooves formed on an inner circumference thereof, an inner member having a plurality of guide grooves formed on an outer circumference thereof, torque transmitting balls arranged in a plurality of ball tracks formed from the guide grooves of the outer member and the guide grooves of the inner member, and a cage for holding the torque transmitting balls, wherein the cage is made of austempered graphite steel having a bainite structure, wherein the carbon content in the austempered graphite steel is limited to 0.45 to 0.75% by weight.
A constant velocity joint comprising an outer member having a plurality of guide grooves formed on an inner circumference thereof, an inner member having a plurality of guide grooves formed on an outer circumference thereof, torque transmitting balls arranged in a plurality of ball tracks formed from the guide grooves of the outer member and the guide grooves of the inner member, and a cage for holding the torque transmitting balls, wherein the inner member is made of austempered graphite steel having a bainite structure, wherein the carbon content in the austempered graphite steel is limited to 0.45 to 0.75% by weight.
A constant velocity joint comprising an outer member having three track grooves formed on an inner circumference thereof and roller guide surfaces disposed in the axial direction on either side of each track groove, a tripod member having three arms extending and protruding radially and rollers rotatably mounted via a plurality of rolling elements on the three arms of the tripod member, the rollers being guided in the axial direction of the outer member by the roller guide surfaces located on either side of the track groove, wherein the tripod member is made of austempered graphite steel having a bainite structure, wherein the carbon content in the austempered graphite steel is limited to 0.45 to 0.75% by weight.
A constant velocity joint comprising an outer member having guide grooves of curved shape formed in the axial direction on a spherical inner circumference thereof, an inner member having guide grooves of curved shape formed in the axial direction on a spherical outer circumference thereof, torque transmitting balls arranged in ball track formed from the guide grooves of the outer member and the guide grooves of the inner member, and a cage for holding the torque transmitting balls, a center of the guide grooves of the outer member and a center of the guide grooves of the inner member being offset to the opposite sides in the axial direction by the same distances with regards to a bisecting plane of the joint including centers of the torque transmission balls, the ball track being gradually reduced toward an opening or inner end of the joint, and the torque transmitting balls are elastically pressed toward reduced side of the ball track, wherein the outer member is made of austempered graphite steel having a bainite structure, wherein the carbon content in the austempered graphite steel is limited to 0.45 to 0.75% by weight.
Dependencies are inferred from the claim text.