Lapping of Gears

After the hardening process is over the Gears and pinions are lapped. This ensures smooth and quiet running. Lapping is done in a lapping machine by running together of mating pairs. A liquid abrasive compound is fed under pressure into the gear pair. With gears rotating, this compound is able to remove small amounts of metal. The end result is refining of the tooth surface and getting the desired contact pattern. (Image showing a lapping process) With the advent of other finishing processes the lapping process has come under a bit of cloud especially from the fine grinding method. Let's see the major points of difference between the two.

 

Traditional Lapping	Fine Grinding
Functions with loose abrasive. Removal of stock through rolling action. Lapped surface looks dull and crater-like. No recycling of material and lapping compound. Lapping parts needs cleaning due to contamination. Stock removal rates are slow.	Functions with solid super abrasive or pelleted plates: Stock removal via scraping action. A fine-ground surface that contains irregular crossing marks. Recycling of coolant/swarf. Fine ground parts coated with a thin layer of coolant, no need of cleaning. Lapping parts needs cleaning due to contamination. Around 3 to 20 times faster than the lapping process.

 

Lapping Machine
There are a variety of Gear lapping machines available for use in the lapping operations. Features to look for in the gear lapping machine includes:

• Automatic workpiece meshing
• Automatic backlash
• Swing speed controller infinitely variable
• Hydraulic chucking
• Hydraulic brake

 

Gear Lapping Compound Gear Lapping Compound is utilized in the finishing process of hypoid and other types of matched gears in the lapping machines. This results in a noise free meshing in between the lapped machines.