Hi makers! Welcome you to the 2^nd post of the gear series. Hope you’re doing great.
In previous post we learned about some important and essential gear terminology. Now in this post we will learn about various Gear type and their uses in brief.
While discussing types of gears we may use some terminologies, that may be confusing for if you’re a beginner. In that case I will recommend you to go through Gear Terminology Explained (RenderWrench Gear Series #1). where I discussed all terminology in detail with image annotations. With that’s it lets start learning various of Gears.

Why knowing gear types matters

“From clock mechanisms to car transmissions- gears are everywhere!”. But there are many different types of gears are used for different purpose. Like for example in clocks, there are mainly Spur Gears are used. But in car transmissions Bevel Gears, Helical gears are used. That’s why knowing different types of gear in important. So that when you’re working on your projects it’s important to know – where to use which gears.

Having knowledge of various kinds of gears will affect design parameters like selecting modules, number of tooth, gear ratio, etc.

So let’s Start.

Spur Gears – the simplest and the most common types

Spur gears are the most common type of gears. And wildly used by engineers too. In this types of gear teeth are cut straight, parallel to the shaft. This gears are easy to manufacture. In trams of efficiency they are very efficient. But they come with some cons too. Spur gears are could be so noisy at high speed, it can cause very loud noise id put into high speed application. The noise cause by the direct impact of the teeth while meshing at high speed.
To design a Spur gear main design parameters are Number of teeth(z), Module(m), face width(A).

Helical Gears – Smooth and silent operation

Helical gears are Spur gears with a little twist. Literally twist. Unlike spur gears the teeth are cut with an angle. The angle is called Helix Angle.
This types of gears know for Smooth and quieter then spur gears. Unlike spurs while meshing teeth of helical gears don’t directly impact on each other. Here teeth are meshes at an angle, gradually. That’s makes it quieter and more durable against load,

but this also have some cons too. As the teeth are meshes at an angle it creates an axial thrust that can make it slip on the Shaft. This also have fix we will discuss that latter. Upon that it s not to simple to manufacture as spur gears. It cost more time and resource unlike spurs.
Helical gears are widely used in cars engines heavy machinery, air crafts, etc.

Bevel gears – For intersecting Shafts

Now things will start getting more interesting. Previously discussed gear types are useful when shafts are parallel to each other. But if the shafts meets at and angle or more specifically at an angle of 90 degree, then Bevel gears comes into the picture.
There are other types of bevel gears.

They are,

• Straight bevel gears – teeth are cut straight at an angle.
• Spiral bevel gears – teeth are cut in a spiral shape.

These are more like spur and helical but not exactly same.

Bevel gears widely used in differential drive in auto-mobile industries, Machines like hand Drill..etc.

Worm Gears – High Reduction, Compact setup

Another very interesting Gear type is Worm Gears. This type of gears setup mainly consist of two parts, Worm and Worm wheel. Worm looks a like Screw that meshes with a gear like Wheel that called Worm Wheel.
In the Fig. Follow the annotations for batter understanding.

This type of gear can provides great reduction ratio as compare to size. And its comes with a very unique feature- Self Locking. Means, when the worm is rotating the worm wheel rotates, but if some force tries to rotate the Worm wheel it would not move. Tats means its one directional.

That’s gives some a machines great mechanical advantage of position holding. For this property of this gear type. It used in Various machines like SMPs, Robot Arms, industrial Cranes, elevetors, conveyor systems etc.

Even though it’s have many good characteristics, it’s a very low efficient when type of gear due to Sliding Contact. The Worm slowly slides in the Worm wheel and makes it rotate.

Rack and Pinion – Liner motion Converter

until now all gear type we learned, we give rotary motion- we get rotary motion. But in Rack and pinion driver is rotating but driven in in linear motion. Simply it’s converts rotary motion to linear motion.

The pinion is basically a Spur gear and rack is Spur on plane surface. As shown in image.

This types of gears used in CNC machines, Auto-motive industries, etc.

I designed a dispensing-mechanism where I used in rack and pinion. We will discussed that latter on in another post. For that stay tuned with RenderWrench, follow RenderWrench on Social media.

Other special Gears

In this post we discuses some of Important types of Gears. But there is some other very interesting Gears. That I want to explore in dedicated post. This gears are following.

• Planetary Gears
• Herringbone Gears
• Cross Gears
• Cycloidal Gears
• Eccentrically Cycloidal Gears

Among them my favourite is last one, eccentrically cycloidal gear. So, with that it. Let’s warp up this post. Hope you learned about gears form this post.If you enjoyed the post please share this post with your friends and fellow Makers.And don’t forgot to follow RenderWrench on social media.
Happy making!!