Nearly all of the machines we use every day use some sort of gears. Whether you are using an electric screwdriver, old-fashioned pendulum clock or alarm clock, a washing machine, or a sprinkler that automatically shifts from side to side, these machines are — in turn — using spur gears to function. Some gears, like bevel gears and worm gears, even propel trains along their tracks or power the car that you drive every day. It may be relatively obvious that machines use some gears, but it may not be obvious exactly what gears you’ll need when it is time for repairs or maintenance. Here’s what you need to know.
Spur Gears
Spur gears are the most commonly used gears. They are simple and straightforward — and usually consist of two gears with straight teeth mounted on parallel shafts. Spur gears are also among the most rudimentary, and they do have some downsides. These particular gears, for example, make a lot of noise (think about the sounds it makes when you wind up an old alarm clock!), which makes them less than ideal for use in larger machines, like cars. Don’t worry. They’re still great for some age-old applications that everyone can appreciate, like those dancing Santa Clauses on a stand with a button that you’re likely to see around the holidays.
Bevel Gears
If you are repairing a car or vehicle, you’ll likely be working with bevel gears. These gears may have straight, hypoid, or spiral teeth, and they are typically mounted at perpendicular angles. That is not set in stone, however, and there is some freedom to change this angle as necessary.
Worm Gears
Worm gears closely resemble a screw, they may be paired with a helical gear or spur gear, and they are most commonly used in heavy-duty applications. Although these gears offer more reduction and resistance than other types, worm gear manufacturers advise saving them for large trucks and conveyor belts on industrial machinery (i.e. where they’re really needed). These gears require very specific lubrication with very specific viscosity, making them an impractical choice for small tasks or machines.
Are you on a DIY kick? That’s fine, but remember — all gears are not created equal. Know what type you’ll need before taking on a project, and consult worm gear manufacturers about their specific requirements for larger fixes.