Products, Parts, Processes, and Poetry #4: Spur Gears

Transmitting torque is easy
When you know about spur gears.
They are simple yet effective
Spinning parallel shafts for years.

Modern spurs have their teeth cut
In a shape called an “involute”
Which allows for smooth gear meshing
And can be machined to boot!

The tooth surfaces are hardened
Then finished with a grinding wheel.
Afterwards the gears are installed
In gearboxes, I’ll reveal.

These gearboxes can do many things
Yet just one thing all the same:
They take input spinning motion
And output it down the chain.

Applications of spur gears are
Not quite few and far between:
They are used in cars and boats,
Clocks, blenders, and way more machines.

Pairs of spurs can speed up
Or slow down the motion they intake.
Just be wary of their limits:
You don’t want your gears to break!

So the next time you are marveling
At machines you encounter,
Take the time to give some love
To the most humble gear: the spur.

By Kanan R Wanha
Written 2025-8-10