Question

For a helical gear having 40 teeth, a circular pitch of 0.30 in and a helix angle of 35°, calculate the normal diametral pitch, module and normal pressure angle. Assume this gear is an ANSI fine.

Answer 1

The normal diametral pitch for the helical gear is 0.0075 in, the module is 133.33 mm, and the normal pressure angle is 20 degrees.

Step-by-step explanation:

The normal diametral pitch is calculated by dividing the number of teeth on the gear by the pitch diameter.

In this case, the pitch diameter can be calculated using the formula D = N/P where D is the pitch diameter, N is the number of teeth, and P is the circular pitch.

So, the pitch diameter would be 40/0.30 = 133.33 in.

The normal diametral pitch is the reciprocal of the pitch diameter, so it would be 1/133.33 = 0.0075 in.

The module is the inverse of the normal diametral pitch, so it would be 1/0.0075 = 133.33 mm.

The normal pressure angle for an ANSI fine gear is 20 degrees. So, the normal pressure angle would be 20 degrees.