Gear clearance

[Drei]

I have bought to spur gears one of them 30 and 60 teeth and the which specifications are: Module 0.8, pressure angle 20deg, PCD 24 and 48, and diameter 26.4, 49.6. Can you tell me the amount of backlash and clearance that I must leave beltween the teeth.
Thanks
Andrei

 

[Jasonb]

Have a look at page 6 of this pdf, it gives backlass allowances depending on gear pitch.

http://www.hpcgears.com/newpdf/technical_general.pdf

The otherway is to cut a thin strip of thin paper and put this between the gears, mesh them as tight as possible which will consatina the paper you can then measure the centres or use a depthing tool to mark the centers

Jason

 

[Ken I]

For manufactured gears the PCD's (theoretical) determine the axis centerlines - in your case 36.0mm the manufacturer would have allowed for clearance and lash.

In industrial designs I have always placed the axles on theoretical centres and assembled the "bought" gears without problems.

Regards,
Ken