US 8,523,722 B2 · Pulley for continuously variable transmission

Abstract

Disclosed is a pulley capable of meeting requirements for both enhancement in friction coefficient, and maintenance of abrasion resistance, required of a belt CVT (continuously variable transmission). The pulley is a pulley of the continuously variable transmission for effecting power transmission between an element and the pulley, being composed of a steel stock containing a predetermined amount of Mn, wherein the surface of the steel stock has a surface-hardened layer of either a nitriding layer or a carbonitriding layer, containing the predetermined amount of Mn, and the surface-hardened layer has properties for stably securing friction coefficient not lower than 0.115, exceeding the friction coefficient of SCr420H steel currently in use, and maintaining abrasion resistance equivalent to the abrasion resistance of the SCr420H steel, or improving the same.

Claims16

Dependent claims

A pulley, comprising a steel stock that comprises:

Fe
C from 0.1 to 0.3 mass %;
Si from 0.1 to 0.5 mass %;
Mn from 2 to 6 mass %;
and
Cr from 6 to 10 mass %, respectively,
wherein
the surface of the steel stock has a surface-hardened layer of a nitriding layer, comprises 2 to 6 mass % of Mn and 6 to 10 mass % of Cr, and has an average thickness not less than 10 μm;
the surface-hardened layer has a nitrogen content ranging from 3 to 25 at. %;
and
the surface-hardened layer has a hardness in the range of Hv750 to 950.

8 more elements

Dependencies are inferred from the claim text.

Pulley for continuously variable transmission

Life of this patent

Pulley for continuously variable transmission

Life of this patent

Abstract

Claims16