Large bevel gears drive the crushing machines used to process ores and minerals in the hard-rock mining and aggregates industries. This paper is intended to help the reader understand the unique aspects of these machines, and why crushing applications fall outside the traditional automotive paradigm for bevel gears.
Contrary to what appears to be popular belief, 5-axis CNC gear manufacturing is not limited to milling with end mill, ball mill or CoSIMT (Conical Side Milling Tool — it is the generic form of the Sandvik InvoMill and Gleason UpGear tools.) tools, where throughput is too low to prevent production at any significant level. Straight and spiral bevel gear manufacturing on 5-axis CNC machines using face mill cutters provides essentially the same throughput as conventional gear cutting machines — with added benefits.
This paper analyzes the different influences of the deviations between nominal and actual geometry for a first-cut bevel gear. In each section, the customary tolerances are quantified and the possibilities to reduce them are discussed.
Deburring or chamfering of gear teeth is gaining attention in practical settings. And with a view to make the production sequence as efficient as possible, it is becoming increasingly important to be able to implement the deburring tasks directly on the cutting machine after spiral cutting.