Which of the following statements are correct
1. For constant velocity ratio transmission between two gear, the common normal at the point of constant must always pass through a fixed point on the line joining the centers of rotation of the gears
2. For involutes gears the pressure angle changes with change in center distance between gear
3. The velocity ratio of compound gear train depends upon the number of teeth of the input and output gears only
4. Epicyclical gear trains involve rotation of at least one gear exit about some other gear axis
Option (A)
1, 2 and 3
Option (B)
1 and 3
1, 2 and 4
2, 3 and 4
Correct Option:
Question Solution:
For involutes gears the pressure angle is always constant. This varies 14.5° to 22.5° to 22.5° the general value is 20°