Helical Gear Speed Reducers
Provide right angle worm gearbox high-efficiency speed decrease through 1, 2, 3, or 4 models of gears. Power is usually transmitted from a high-rate pinion to a slower-speed equipment. Helical gears generally operate with 
their shafts parallel to each other. The two most common types will be the concentric (insight and result shafts are in collection) 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 reduced speeds and higher ratios are necessary, dual, triple, and quadruple equipment reduction stages may be used.
Worm Gear Speed Reducers
A single reduction rate reducer can achieve up to a 100:1 reduction ratio in a little package. Known as right angle drives, these contain a cylindrical worm with screw threads and a worm. With a single start worm, the worm equipment advances only 1 tooth for each 360-degree change of the worm. So, whatever the worm's size, the gear ratio may be the ‘size of the worm equipment to 1′. Higher decrease ratios could be created through the use of double and triple decrease ratios.
Basic Types of Gearboxes
The objective of a gearbox is to improve or reduce speed. Consequently, torque output will be the inverse of the function. If the enclosed drive can be a acceleration reducer, the torque result will increase; if the drive improves speed, the torque result will decrease. Gear drive selection factors include: shaft orientation, swiftness ratio, design type, nature of load, gear ranking, environment, mounting position, working temperature range, and lubrication.