Split gearing, another technique, consists of two gear halves positioned side-by-side. One half is fixed to a shaft while springs cause the other half to rotate somewhat. This increases the effective tooth thickness to ensure that it totally fills the tooth space of the mating equipment, thereby removing backlash. In another version, an assembler bolts the rotated fifty percent to the fixed half after assembly. Split gearing is normally found in light-load, low-speed applications.
The simplest & most common way to reduce backlash in a set of gears is to shorten the distance between their centers. This movements the gears right into a tighter mesh with low or actually zero clearance between tooth. It eliminates the result of 
variations in center distance, tooth sizes, and bearing eccentricities. To shorten the center distance, either adjust the gears to a fixed range and lock them in place (with bolts) or spring-load one against the other so they stay tightly meshed.
Fixed assemblies are usually found in heavyload zero backlash gearbox applications where reducers must reverse their direction of rotation (bi-directional). Though “set,” they may still need readjusting during program to compensate for tooth put on. Bevel, spur, helical, and worm gears lend themselves to set applications. Spring-loaded assemblies, on the other hand, maintain a constant zero backlash and tend to be used for low-torque applications.
Common design methods include brief center distance, spring-loaded split gears, plastic-type fillers, tapered gears, preloaded gear trains, and dual path gear trains.
Precision reducers typically limit backlash to about 2 deg and so are used in applications such as instrumentation. Higher precision devices that accomplish near-zero backlash are found in applications such as robotic systems and machine tool spindles.
Gear designs could be modified in a number of ways to cut backlash. Some strategies modify the gears to a arranged tooth clearance during preliminary assembly. With this process, backlash eventually increases because of wear, which needs readjustment. Other designs use springs to hold meshing gears at a continuous backlash level throughout their service life. They’re generally limited by light load applications, though.
