TABLE OF CONTENTS | a | distance between center lines of shafts in Oldham's coupling, m (in) | |
| A | area, m 2 (in 2) external area, m 2 (in 2) | |
| A r | radiating surface required, m 2 (in 2) | |
| A c | contact area of friction surface, m 2 (in 2) | |
| b | width of key, m (in) width of shoe, m (in) width of inclined face in grooved rim clutch, m (in) width of spring in centrifugal clutch, m (in) width of wheel, m (in) width of operating lever (Fig. 19-16), m (in) | |
| c | heat transfer coefficient, kJ/m 2 K h (kcal/m 2/ C/h) | |
| c 1 | specific heat of material, kJ/kg K (kcal/kg/ C) | |
| c 2 | radiating factor for brakes, kJ/m 2 K s (kcal/m 2/min/ C) | |
| d | diameter of shaft, m (in) diameter of pin, roller pin, m (in) | |
| d 1 | diameter of bolt, m (in) diameter of pin at neck in the flexible coupling, m (in) | |
| d 2 | diameter of hole for bolt, m (in) | |
| d ? | outside diameter of bush, m (in) | |
| D | diameter of wheel, m (in) diameter of sheave, m (in) outside diameter of flange coupling, m (in) | |
| D 1 | inside diameter of disk of friction material in disk clutches and brakes, m (in) | |
| D 2 | outside diameter of disk of friction material in disk clutches and brakes, m (in) | |
| D i |
