UNIT 1

QUESTIONS

- What does the ray-diagram indicate?

2. What are the possible arrangements to achieve 12 speeds from a gear box?

3. What are the points to be considered while designing a sliding-mesh type multi-

Speed gear box?

4. What is step ratio? Name the series in which speeds of multi-speed gear box are

Arranged.

5. Distinguish between structural diagram and speed diagram.

6. Find the progression ratio for a 12 speed gear box having speeds between 100 and

3.55 r.p.m. Also find the spindle speeds.

7. Select spindle speeds, for 9 speed gear box, between 80 and 1285 r.p.m.

8. Design a 9 speed gear box to give output speeds between 280 and 1800 rpm. The input power is 5.5 kW at 1440 rpm. Draw the kinematic layout diagram and the speed diagram. Determine the number of teeth on all gears.

9. Design the layout of a 12 speed gear box for a lathe. The minimum and maximum speeds

Are 100 and 1200 rpm. Power is 5 kW from 1440 rpm. Draw the speed and kinematic

Diagram. Also calculate the number of teeth on all gears

10. A gear box is to be designed with the following specification:

Power = 14.72 kW. Number of speeds = 18. Minimum speed = 16 rpm. Step ratio = 1.25.

Motor speed = 1400 rpm. The 18 speeds are obtained as 2×3×3.

(i)Sketch the layout of the gear box.

(ii)Draw the speed diagram.

11. Design a 12 speed gear box for an all geared headstock of a lathe. Maximum and

Minimum speeds are 600 rpm and 25 rpm respectively. The drive is from an electric

Motor giving 2.25 kW at 1440 rpm.

12. The minimum and maximum speed of a six speed box are to be 160 and 500 rpm.

Construct the kinematic arrangement and the ray diagram of the gear box. Also find thenumber of teeth on all gears.