Perhaps the most obvious is to increase precision, which really is a function of manufacturing and assembly tolerances, gear tooth surface finish, and the center distance of the tooth mesh. Sound is also suffering from gear and housing materials in addition to lubricants. In general, expect to spend more for quieter, smoother gears.
Don’t make the mistake of over-specifying the engine. Remember, the insight pinion on the planetary should be able handle the motor’s result torque. What’s more, if you’re utilizing a multi-stage gearhead, the output stage must be strong enough to absorb the developed torque. Obviously, using a better motor than required will require a larger and more costly gearhead.
Consider current limiting to safely impose limits on gearbox size. With servomotors, result torque can be a linear function of current. So besides protecting the gearbox, current limiting also defends the motor 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 simultaneously in mesh. Although you can’t really totally eliminate noise from such an assembly, there are several ways to reduce it.
As an ancillary benefit, the geometry of planetaries fits the shape 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 costly than lighter duty types. However, for quick acceleration and deceleration, a servo-grade gearhead may be the only wise choice. In this kind of applications, the gearhead may be seen as a mechanical spring. The torsional deflection resulting from the spring action increases backlash, compounding the effects of free shaft motion.
Servo-grade gearheads incorporate a number of construction features to minimize torsional stress and deflection. Among the more prevalent are large diameter output shafts and beefed up support for satellite-gear shafts. Stiff or “rigid” gearheads have a tendency to be the most costly of planetaries.
The kind of bearings supporting the output shaft depends on the strain. High radial or axial loads generally necessitate rolling element bearings. Small planetaries could get by with low-price sleeve bearings or various other economical types with relatively low axial and radial load ability. For bigger and servo-grade gearheads, heavy duty result shaft bearings are usually required.
Like most gears, planetaries make noise. And the quicker they operate, the louder they obtain.
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