Mechanical Engineering - Machine Design - Discussion

When two gears are running at the high speed it is found that the load experienced by those gears is increased. In an attempt to quantify this, experiments were carried out where gears were tangentially loaded to failure under zero velocity and then loaded to failure at a specific pitching velocity (velocity along the line of action).

The ratio of the static load at the failure to the dynamic load at failure was taken as the Velocity factor (Kv). This means that an identical gear pair running at this speed would have a dynamic load equal to Kv times the static tangential load.

What is the velocity factor for carefully cut gears operating at velocities up to 760 m/min? Please explain.

In case of ordinary cut gears B becomes correct.

In case of carefully cut gears C becomes correct.

As per my knowledge, wd v<20m/s follow the formula 6/(6+v).

As per my knowledge, wd v<20m/s follow the formula 6/(6+v).

For 12.5 it is 3/3+v.
For 20m/s it is 6/6+v.

Isn't option D is for carefully cut gear?

Yes, D is correct. I also agree.

How @Rohit?

Please tell me.

D is the correct option.