Split gearing, another technique, consists of two gear halves positioned side-by-side. One half is fixed to a shaft while zero backlash gearbox springs cause the other half to rotate slightly. 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 half 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 length between their centers. This movements the gears right into a tighter mesh with low or even zero clearance between tooth. It eliminates the effect of variations in center distance, tooth sizes, and bearing eccentricities. To shorten the guts 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 typically used in heavyload applications where reducers must reverse their direction of rotation (bi-directional). Though “set,” they may still require readjusting during assistance 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 short center distance, spring-loaded split gears, plastic 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 for example instrumentation. Higher precision units that obtain near-zero backlash are used in applications such as for example robotic systems and machine tool spindles.
Gear designs can be modified in several methods to cut backlash. Some methods adjust the gears to a established tooth clearance during initial assembly. With this approach, backlash eventually increases due to wear, which requires readjustment. Other designs make use of springs to carry meshing gears at a constant backlash level throughout their services lifestyle. They’re generally limited by light load applications, though.
