Split gearing, another technique, consists of two gear halves positioned side-by-side. Half is set to a shaft while springs cause the other half to rotate somewhat. This increases the effective tooth thickness so that it completely fills the tooth space of the mating gear, thereby removing backlash. In another version, an assembler bolts the rotated half to the fixed half after assembly. Split gearing is normally used in light-load, low-speed applications.
The simplest and most common way to lessen backlash in a set of gears is to shorten the length between their centers. This techniques the gears into a tighter mesh with low or actually zero clearance between the teeth. It eliminates the result of variations in center distance, tooth sizes, and bearing eccentricities. To shorten the guts distance, either change the gears to a set range and lock them in place (with bolts) or spring-load one against the various 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 could still require readjusting during services to pay for tooth use. Bevel, spur, helical, and worm gears lend themselves to fixed applications. zero backlash gearbox china spring-loaded assemblies, on the other hand, maintain a constant zero backlash and are generally used for low-torque applications.
Common design methods include short center distance, spring-loaded split gears, plastic material 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 systems that achieve near-zero backlash are found in applications such as for example robotic systems and machine tool spindles.
Gear designs can be modified in many methods to cut backlash. Some methods adapt the gears to a set tooth clearance during preliminary assembly. With this approach, backlash eventually increases because of wear, which requires readjustment. Other designs use springs to hold meshing gears at a continuous backlash level throughout their support life. They’re generally limited by light load applications, though.