Masao Eguchi

Friction characteristics of a paper-based facing for a wet clutch under a variety of sliding conditions

The coefficient of friction of paper-based facing for a wet clutch was determined under a variety of sliding conditions. It is important to investigate the transitional friction characteristics of a clutch during the engagement and disengagement processes. An experimental apparatus was designed to obtain the friction characteristics for both constant and transient sliding velocity conditions. The latter condition simulates the locking-up and breaking-away processes of an automatic transmission. Experimental data obtained under stable sliding conditions were summarized on the Stribeck diagram. The data obtained under transient sliding processes were compared with stable sliding data. Friction characteristics related to the porous paper-based facing were discussed, taking into account the conventional concept of lubrication for ordinary metallic materials. Presented as a Society of Tribologists and Lubrication Engineers paper at the STLE/ASME Tribology Conference in St. Louis, Missouri, October 14–16, 1991

Stress concentration in the vicinity of a hole defect under conditions of Hertzian contact

Two-dimensional photoelastic stress analyses were conducted for epoxy resin models containing a hole defect under the conditions of Hertzian contact. Stress concentrations around the defect were determined as a function of several parameters. These were hole diameter, its vertical distance from the contact surface, and the horizontal distance from the Hertzian contact area. Also determined was the effect of tangential traction (generated by a friction coefficient of 0.1) on the stress concentration. Sharp stress concentrations occur in the vicinity of both the left and the right side of the hole. The stress concentration becomes more distinct the larger the hole diameter and the smaller the distance between the hole and the contact surface. The stress concentration is greatest when the disk imposing a normal load is located at the contact surface directly over the hole. The magnitude and the location of stress concentration varies with the distance between the Hertzian contact area and the hole. Taking in...