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