3. In the arrangement of gears shown diagrammatically in Fig. 12.14, the driving shaft
X runs at 1000 rev/min; the compound gears D and F rotate with the driven shaft Z, and
can be moved so as to engage D with C or F with E. All wheels are to have a module of 6,
wheels A and C have equal tooth numbers, and the distance between the lay shaft (Y)
axis and the axis of X and Z is fixed at 135 mm.
FIG. 12.14
If shaft Z is to run at 640 rev/min exactly, and 480 rev/min as nearly as possible,
determine suitable numbers of teeth for all wheels and the actual lower speed of Z.
(U. Lond.)
(Answer: A, 20; B, 25; C, 20; D, 25; E, 17; F, 28; 486 rev/min)