Helical Gear Speed Reducers
Provide high-efficiency speed decrease through 1, 2, 3, or 4 units of gears. Power is usually transmitted from a high-rate pinion to a slower-speed gear. Helical gears generally operate with their shafts parallel to each other. Both most common types will be the concentric (input and output shafts are in range) and parallel shaft (input and output shafts are offset). Single-stage helical equipment right angle worm gearbox Reducers are usually used for gear ratios up to about 8:1. Where reduced speeds and higher ratios are required, dual, triple, and quadruple gear reduction stages may be used.
Worm Gear Speed Reducers
A single reduction quickness 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 one tooth for each 360-degree change of the worm. So, regardless of the worm’s size, the apparatus ratio is the ‘size of the worm equipment to 1′. 
Higher decrease ratios could be created through the use of double and triple reduction ratios.
Basic Types of Gearboxes
The objective of a gearbox is to increase or reduce speed. Consequently, torque output will be the inverse of the function. If the enclosed drive is certainly a quickness reducer, the torque result will increase; if the drive improves speed, the torque result will reduce. Gear drive selection factors include: shaft orientation, swiftness ratio, design type, character of load, gear ranking, environment, mounting position, operating temperature range, and lubrication.