Perhaps the most apparent is to increase precision, which is a function of manufacturing and assembly tolerances, gear tooth surface finish, and the center distance of the tooth mesh. Sound can be suffering from gear and housing components along with lubricants. In general, be prepared to spend more for quieter, smoother gears.
Don’t make the mistake of over-specifying the engine. Remember, the insight pinion on the planetary must be able handle the motor’s result torque. Also, if you’re utilizing a multi-stage gearhead, the output stage should be strong enough to soak up the developed torque. Obviously, using a better motor than required will require a larger and more expensive gearhead.
Consider current limiting to safely impose limitations on gearbox size. With servomotors, result torque can be a linear function of current. Therefore besides safeguarding the gearbox, current limiting also shields the engine and drive by clipping peak torque, which can be from 2.5 to 3.5 times continuous torque.
In each planetary stage, five gears are at the same time in mesh. low backlash planetary gearbox Although you can’t really totally remove noise from such an assembly, there are many methods to reduce it.
As an ancillary benefit, the geometry of planetaries matches the form of electric motors. Thus the gearhead could be close in diameter to the servomotor, with the output shaft in-line.
Highly rigid (servo grade) gearheads are generally more expensive than lighter duty types. However, for quick acceleration and deceleration, a servo-grade gearhead may be the only wise choice. In such applications, the gearhead may be seen as a mechanical springtime. The torsional deflection caused by the spring action adds to backlash, compounding the effects of free shaft motion.
Servo-grade gearheads incorporate a number of construction features to reduce torsional stress and deflection. Among the more common are large diameter output shafts and beefed up support for satellite-equipment shafts. Stiff or “rigid” gearheads have a tendency to be the most costly of planetaries.
The type of bearings supporting the output shaft depends upon the strain. High radial or axial loads generally necessitate rolling element bearings. Small planetaries can often get by with low-cost sleeve bearings or additional economical types with relatively low axial and radial load capability. For larger and servo-grade gearheads, durable output shaft bearings are usually required.
Like most gears, planetaries make noise. And the faster they run, the louder they obtain.
Low-backlash planetary gears are also available in lower ratios. Although some types of gears are generally limited to about 50:1 or more, planetary gearheads expand from 3:1 (solitary stage) to 175:1 or more, depending on the amount of stages.