Backlash measurement

[Abualnassr]

Hi guys. How can we measure the backlash without disassembling the gear for the gearbox ?

 

[mfgenggear]

how big is the gear box?

normally dial indicator with a magnetic base.
move the indicator pointer on the gear flank allow for the full movement.

or use feeler gages between the contacting gear teeth.

I prefer dial indicator

 

[MikeHalloran]

Lock the input shaft.

Clamp a bar to the output shaft. Rock it back and forth and indicate it.

If you indicate at the output gear's pitch radius, you've effectively measured, or at least estimated, the backlash without opening the box.



Mike Halloran
Pembroke Pines, FL, USA

 

[Abualnassr]

So, where should i put the tip of the dial indicator exactly ?
Should i put on the bottom of the gear teeth or on the circular pitch line ?

 

[MikeHalloran]

You said "without disassembly", so I assumed the teeth are not accessible... but you should know the pitch radius from the design documents.

So, you indicate the bar, tangent to the pitch circle, at the pitch radius.

The gearset only cares about lash on the pitch circle, so that's where you measure it.



Mike Halloran
Pembroke Pines, FL, USA