Split gearing, another method, 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 escalates the effective tooth thickness so that it totally fills the tooth space of the 
mating gear, thereby getting rid of backlash. In another version, an assembler bolts the rotated half to the fixed half after assembly. Split gearing is generally found in light-load, low-speed applications.
The simplest and most common way to lessen backlash in a pair of gears is to shorten the distance between their centers. This moves the gears into a tighter mesh with low or even zero clearance between teeth. It eliminates the effect of variations in middle distance, tooth dimensions, and bearing eccentricities. To shorten the zero backlash gearbox china center distance, either adapt the gears to a set distance and lock them set up (with bolts) or spring-load one against the various other so they stay tightly meshed.
Fixed assemblies are usually used in heavyload applications where reducers must invert their direction of rotation (bi-directional). Though “set,” they may still need readjusting during support to compensate for tooth put on. Bevel, spur, helical, and worm gears lend themselves to fixed applications. Spring-loaded assemblies, however, 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-type material fillers, tapered gears, preloaded gear trains, and dual path gear trains.
Precision reducers typically limit backlash to about 2 deg and are used in applications such as for example instrumentation. Higher precision models that attain 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 modify the gears to a set 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 assistance lifestyle. They’re generally limited to light load applications, though.