Gears and Types in Robotics

Gears

Gears are essentially levers that work using rotational motion. They transfer one rotational motion into another. The radii of the different gears dictate if the effort required will be greater or less than the load. There are different types of gears, depending on what type of motion has to be transferred. These

are:

Spur Gears

Spur gears transfer rotational motion in the same plane.

Hellical Gears

Hellical gears also transfer rotational motion in the same plane; however, the gear teeth are designed to make the motion transfer smoother. An example is shown in Figure.

Bevel Gears

Bevel gears help in changing the direction of the rotational motion. An example is shown in Figure . The shafts in bevel gears do not have to be at right angles. They can be at any other angle such as 45 degrees.

 Worm Gears

Worm gears also change the direction of the rotational motion, but also create large gear reductions. Worm gear produces motion at right angle to the input gear.

Rack and Pinion Gears

Rack and pinion gears convert rotational motion into translational or vice versa. An example is shown .

 Planetary Gears

Planetary gears provide more complex control over rotational motion. An example is shown in Figure. It has a central gear (sun gear), planet gears, ring gear, and an arm. The input and output shafts can be connected to the ring gear, the sun gear or the arm, giving different angular speeds. One can have different number of planet gears including one.

 Compound Gears

Gears can be connected to each other to produce very large mechanical ad-vantages. These are called compound gears. An example is shown .