Helical Gear Speed Reducers
Provide high-efficiency speed reduction through 1, 2, 3, or 4 units of gears. Power is definitely transmitted from a high-quickness pinion to a slower-speed gear. Helical gears generally operate with their shafts parallel to one another. Both most common types are the concentric (input and output shafts are in series) and parallel shaft (insight and result shafts are offset). Single-stage helical gear reducers are typically used for equipment ratios up to about 8:1. Where cheaper speeds and higher ratios are required, dual, triple, and quadruple gear reduction stages may be used.
Worm Gear Speed Reducers
A single reduction rate reducer can achieve up to a 100:1 decrease ratio in a little package. Referred to as right angle drives, these consist of a right angle worm gearbox cylindrical worm with screw threads and a worm. With a single start worm, the worm equipment advances only 1 tooth for each 360-degree convert of the worm. So, whatever the worm’s size, the gear ratio may be the ‘size of the worm equipment to 1′. Higher reduction ratios can 
be created by using double and triple decrease ratios.
Basic Types of Gearboxes
The purpose of a gearbox is to improve or reduce speed. Because of this, torque output would be the inverse of the function. If the enclosed drive is a speed reducer, the torque output increase; if the drive improves speed, the torque result will decrease. Gear drive selection factors include: shaft orientation, acceleration ratio, design type, character of load, gear rating, environment, mounting position, working temperature range, and lubrication.