초록 ▼

A self-lubricating and wear resistant valve/valve guide combination for an engine includes a self-lubricating coating deposited on one of (a) the inner surface of the valve guide, or (b) the outer surface of the valve stem. A wear-resistant coating deposited on one of (a) the outer surface of the va

A self-lubricating and wear resistant valve/valve guide combination for an engine includes a self-lubricating coating deposited on one of (a) the inner surface of the valve guide, or (b) the outer surface of the valve stem. A wear-resistant coating deposited on one of (a) the outer surface of the valve stem when the self-lubricating coating is deposited on the inner surface of the valve guide, or (b) the inner surface of the valve guide when the self-lubricating coating is deposited on the outer surface of the valve stem. The self-lubricating coating has a composition, by weight, consisting essentially of, (a) a first component, comprising, a metal-bonded chromium carbide in the range of about 60% to about 80%, (b) a second component, comprising, a soft noble metal in the range of about 1% to about 20%, and (c) a third component, comprising, a metal fluoride eutectic in the range of about 5 to about 20%. The wear-resistant coating has a composition, by weight, consisting essentially of, (a) chromium in the range of about 20% to about 30%, (b) nickel in the range of about 5% to about 15%, (c) tungsten in the range of about 1% to about 10%, and (d) cobalt in the range of about 50% to about 74%.

대표청구항 ▼

[ We claim:] [25.] A method of using a combination of a self-lubricating coating and a wear-resistant coating in a valve and valve guide for an engine, comprising the steps of:providing a valve guide having a tubular shape and an inner surface free of knurling;providing a valve having a valve stem,

[ We claim:] [25.] A method of using a combination of a self-lubricating coating and a wear-resistant coating in a valve and valve guide for an engine, comprising the steps of:providing a valve guide having a tubular shape and an inner surface free of knurling;providing a valve having a valve stem, said valve stem having an outer surface;plasma spraying a first coating on said inner surface of said valve guide, said first coating being selected from one of (a) a self-lubricating coating, or (b) a wear-resistant coating,said self-lubricating coating having a composition, by weight, consisting essentially of, (a) a first component, comprising, a metal-bonded chromium carbide in the range of about 60% to about 80%, (b) a second component, comprising, a soft noble metal in the range of about 1% to about 20%, and (c) a third component, comprising, a metal fluoride eutectic in the range of about 5% to about 20%, andsaid wear-resistant coating having a composition, by weight, consisting essentially of, (a) chromium in the range of about 20% to about 30%, (b) nickel in the range of about 5to about 15%, (c) tungsten in the range of about 1 to about 5%, and (d) cobalt in the range of about 50% to about 74%;plasma spraying a second coating on said outer surface of said valve stem, said second coating being selected from one of (a) a wear-resistant coating when said first coating is said self-lubricating coating, or (b) a self-lubricating coating when said first coating is said wear-resistant coating;locating said valve stem within said valve guide and causing a surface of said wear-resistant coating to be in sliding engagement with a surface said self-lubricating coating; andforming said valve/valve guide combination having a valve stem-to-guide clearance in the range of about 0.04 mm (0.00157 inch) to about 0.08 mm (0.003 inch).