CALCULATION OF RC AND BL HELICAL GEAR

when given the module, MDL = PCD*N

where MDL...the module & N No. of teeth.

for metric gears the clearance CL= 0.157*MDL...with pressure angle 14.5deg

CL=0.2*MDL...with pressure angle 20deg

for imperial/inch gears CL=0.157/DP...for 14.5deg....CL=0.2/DP...for 2odeg

note that the DP...is the diametral pitch,..DP=N/PCD

just an undergrad comming off my final year summer party spree so really cant remember backlash equations....sorry

Dear Friend,

Thanks for the equation, but I had a doubt.

1. Does the formula hold good for helical as well spur gears ???

2. If the equation (root clearance) is dependent upon pressure angles, what will be generalised equation???

3. How can we conclude back lash by module???

Regards,

Shailesh