Carbon/Graphite Bearings and Bushings
ROC Carbon self-lubricating bearings and bushings are available in material grades selected to meet the specified service requirements. We provide standard replacement styles as well as custom-designed parts for specific operating problems. Parts range from simple sleeve bushings to more complex styles incorporating notches, grooves or metal reinforcing sleeves.
Carbon/graphite grades selected should be compatible both with the fluids being handled and the operating parameters. The typical materials used are from our Groups A, C, E, and F grades. Group C and Group F grades are used in general purpose applications. Group A grades are resin-impregnated for seal applications. Group E grades are metal-impregnated for improved heat dissipation, wear and strength characteristics. Depending on the application, various types of metal-impregnated carbon/graphite can be used. For higher operating temperatures, Group B grades with an an oxidation inhibitor are used.
Metal-backed bearings for extreme service
ROC Carbon also manufactures metal-backed carbon/graphite bearings for use in extreme service. The metal selected should have good corrosion resistance, thermal conductivity, or other properties as required by the service. The coefficient of thermal expansion is a factor in metal selection due to the difference in expansion coefficients of metal and carbon/graphite materials.
Press fitting and shrink fitting
The method used to assemble the carbon into the metal housing depends on the carbon grade used, the metal selected, and the operating temperature. Press fitting is generally used for low-temperature applications, where relatively low interference is needed to keep the carbon from rotating independently. Shrink fitting is used for high-temperature applications requiring greater interference to prevent carbon rotation. In shrink fitting, the carbon is dropped into a heated metal housing. When the metal cools, the housing shrinks and seizes the carbon.
ROC Carbon's engineering staff is available to help you evaluate bearing and bushing problems and to recommend solutions involving seal geometry and material. For nonstandard parts for modified machines, we will recommend the proper bore sizes and materials for optimum performance.
For original equipment replacement parts, please furnish the OEM part number or the specifications of the machine. For custom-designed parts, we manufacture according to your drawings, or, if you wish, we will design a seal for you. For fastest response, call our toll-free number: