In purely scientific terms, gears are used to transmit motion. They’re really good at what they do, too, which is probably why they’ve been used by craftsmen and other laborers for centuries. One of the earliest recorded references to gear use was in 50 AD, though there’s more than a little evidence that suggests the ancient Greeks also used them as early as the third century BC.
And we keep using gears because they work.
Clocks, bicycles, automobiles and heavy-duty industrial machines all rely on common gears, and without those, we wouldn’t be able to live the modern, convenient lives we do today. There’s no question that custom gears, steel shafts and other industrial manufacturing parts play a huge role in delivering us the consumer goods we rely so desperately upon.
But even gears, the objects that make manufacturing so easy, require a bit of manufacturing themselves. Throughout the generations, human beings have more or less perfected the design and creation of these production wonders through a few key methods. The three main custom gear manufacturing processes are broaching, hobbing and machining, and they can be summed up as follows:
Gear Broaching
Broaching utilizes a steel tool lined with teeth, called a broach, to level the gear and remove excess material from it. Steel shafts and other splines that require precision in their manufacturing will benefit the most from broaching, as the actual broach tool works best in helping define oddly shaped gears. A broach looks similar to a saw, and it’s these specific tools that are used to create the largest gears of all.
Gear Hobbing
While broaching is used for creating steel shafts and other large gears, hobbing can be used to create smaller sprockets and splines in addition to regular gears. Hobbing machines are circular and toothed all the way around to create spur and helical gears, primarily. In addition, hobbing is the most widely used method of gear cutting because of its quick and inexpensive nature.
Gear Machining
Out of these three main types of gear cutting, machining is the most diverse because it’s used in general manufacturing, not just for gears. This is what you’d probably think of when you envisioned the production industry — man in blue jumpsuit with safety goggles edging a metal piece against a cutting tool. There tends to be a bit more variation in the available tools for machining simply because of the wide range of work these tools can perform
The list of what gears can do goes on and on. We know how they’ve helped us build modern civilization; it’ll be exciting to see what they help us accomplish in the future.