Cycloidal gearboxes
Cycloidal gearboxes or reducers consist of four simple components: a high-speed input shaft, a single or compound cycloidal cam, cam followers or rollers, and a slow-speed output shaft. The input shaft attaches to an eccentric drive member that induces eccentric rotation of the cycloidal cam. In compound reducers, the first an eye on the cycloidal cam lobes engages cam supporters in the housing. Cylindrical cam followers act as teeth on the internal gear, and the amount of cam supporters exceeds the number of cam lobes. The second track of substance cam lobes engages with cam followers on the output shaft and transforms the cam’s eccentric rotation into concentric rotation of the result shaft, thus increasing torque and reducing quickness.

Compound cycloidal gearboxes provide ratios ranging from only 10:1 to 300:1 without stacking levels, as in regular planetary gearboxes. The gearbox’s compound decrease and will be calculated using:

where nhsg = the amount of followers or rollers in the fixed housing and nops = the number for followers or rollers in the gradual swiftness output shaft (flange).

There are several commercial variations of cycloidal reducers. And unlike planetary gearboxes where variations derive from gear geometry, heat therapy, and finishing procedures, cycloidal variations share basic design concepts but generate cycloidal motion in different ways.
Planetary gearboxes
Planetary gearboxes are made up of three basic force-transmitting elements: a sun gear, three or even more satellite or planet gears, and an interior ring gear. In an average gearbox, the sun gear attaches to the input shaft, which is linked to the servomotor. Sunlight gear transmits electric motor rotation to the satellites which, subsequently, rotate inside the stationary ring gear. The ring equipment is part of the gearbox casing. Satellite gears rotate on rigid shafts connected to the earth carrier and trigger the planet carrier to rotate and, thus, turn the result shaft. The gearbox provides result shaft higher torque and lower rpm.

Planetary gearboxes generally have single or two-gear stages for reduction ratios which range from 3:1 to 100:1. A third stage can be added for actually higher ratios, nonetheless it is not common.

The ratio of a planetary gearbox is calculated using the following formula:where nring = the amount of teeth in the internal ring gear and nsun = the number of teeth in the pinion (input) gear.
Comparing the two
When deciding between cycloidal and planetary gearboxes, engineers should 1st consider the precision needed in the application form. If backlash and positioning accuracy are necessary, then cycloidal gearboxes offer the most suitable choice. Removing backlash can also help the servomotor manage high-cycle, high-frequency moves.

Following, consider the ratio. Engineers can do that by optimizing the reflected load/gearbox inertia and swiftness for the servomotor. In ratios from 3:1 to 100:1, planetary gearboxes offer the best torque density, weight, and precision. In fact, not many cycloidal reducers provide ratios below 30:1. In ratios from 11:1 to 100:1, planetary or cycloidal reducers may be used. Nevertheless, if the mandatory ratio goes beyond 100:1, cycloidal gearboxes keep advantages because stacking stages is unnecessary, therefore the gearbox can be shorter and less expensive.
Finally, consider size. Most manufacturers offer square-framed planetary gearboxes that mate exactly with servomotors. But planetary gearboxes grow in length from one to two and three-stage designs as needed gear ratios go from less than 10:1 to between 11:1 and 100:1, and then to greater than 100:1, respectively.

Conversely, cycloidal reducers are larger in diameter for the same torque but are not for as long. The compound reduction cycloidal gear train handles all ratios within the same package size, therefore higher-ratio cycloidal gear boxes become also shorter than planetary variations with the same ratios.

Backlash, ratio, and size provide engineers with a preliminary gearbox selection. But selecting the most appropriate gearbox also involves bearing capability, torsional stiffness, shock loads, environmental conditions, duty cycle, and life.

From a mechanical perspective, gearboxes have grown to be somewhat of accessories to servomotors. For gearboxes to perform properly and provide engineers with a balance of performance, existence, and value, sizing and selection ought to be determined from the load side back again to the motor instead of the motor out.

Both cycloidal and planetary reducers work in any industry that uses servos or stepper motors. And although both are epicyclical reducers, the variations between many planetary gearboxes stem more from equipment geometry and manufacturing procedures rather than principles of operation. But cycloidal reducers are more varied and share small in common with each other. There are advantages in each and engineers should think about the strengths and weaknesses when selecting one over the various other.

Great things about planetary gearboxes
• High torque density
• Load distribution and sharing between planet gears
• Smooth operation
• High efficiency
• Low input inertia
• Low backlash
• Low cost

Great things about cycloidal gearboxes
• Zero or very-low backlash remains relatively constant during existence of the application
• Rolling rather than sliding contact
• Low wear
• Shock-load capacity
• Torsional stiffness
• Flat, pancake design
• Ratios exceeding 200:1 in a compact size
• Quiet operation
The need for gearboxes
There are three basic reasons to use a gearbox:

Inertia matching. The most typical reason for selecting a gearbox is to control inertia in highly dynamic circumstances. Servomotors can only just control up to 10 times their personal inertia. But if response period is critical, the motor should control less than four moments its own inertia.

Speed reduction, Servomotors run more efficiently at higher speeds. Gearboxes help to keep motors operating at their ideal speeds.

Torque magnification. Gearboxes offer mechanical advantage by not merely decreasing velocity but also increasing result torque.

The EP 3000 and our related products that use cycloidal gearing technology deliver the most robust solution in the most compact footprint. The main power train is made up of an eccentric roller bearing that drives a wheel around a set of inner pins, keeping the decrease high and the rotational inertia low. The wheel incorporates a curved tooth profile rather than the more traditional involute tooth profile, which removes shear forces at any point of contact. This style introduces compression forces, instead of those shear forces that could exist with an involute equipment mesh. That provides several performance benefits such as for example high shock load capacity (>500% of ranking), minimal friction and use, lower mechanical service factors, among many others. The cycloidal style also has a large output shaft bearing period, which provides exceptional overhung load capabilities without requiring any additional expensive components.

Cycloidal advantages over various other styles of gearing;

Able to handle larger “shock” loads (>500%) of rating in comparison to worm, helical, etc.
High reduction ratios and torque density in a concise dimensional footprint
Exceptional “built-in” overhung load carrying capability
High efficiency (>95%) per reduction stage
Minimal reflected inertia to motor for longer service life
Just ridiculously rugged as all get-out
The overall EP design proves to be extremely durable, and it needs minimal maintenance following installation. The EP may be the most reliable reducer in the commercial marketplace, in fact it is a perfect match for applications in weighty industry such as for example oil & gas, primary and secondary steel processing, industrial food production, metal reducing and forming machinery, wastewater Cycloidal gearbox treatment, extrusion devices, among others.