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

Compound cycloidal gearboxes offer ratios ranging from as low as 10:1 to 300:1 without stacking phases, as in regular planetary gearboxes. The gearbox’s compound reduction and can be calculated using:

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

There are many commercial variations of cycloidal reducers. And unlike planetary gearboxes where variations are based on gear geometry, heat treatment, and finishing procedures, cycloidal variations share simple design principles but generate cycloidal movement in different ways.
Planetary gearboxes
Planetary gearboxes are made of three fundamental force-transmitting elements: a sun gear, three or even more satellite or planet gears, and an interior ring gear. In a typical gearbox, the sun gear attaches to the input shaft, which is connected to the servomotor. The sun gear transmits engine rotation to the satellites which, in turn, rotate in the stationary ring gear. The ring equipment is portion of the gearbox casing. Satellite gears rotate on rigid shafts linked to the planet carrier and cause the earth carrier to rotate and, thus, turn the result shaft. The gearbox provides output shaft higher torque and lower rpm.

Planetary gearboxes generally have one or two-equipment 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 inner 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 crucial, then cycloidal gearboxes offer the most suitable choice. Removing backlash can also help the servomotor handle high-cycle, high-frequency moves.

Next, consider the ratio. Engineers can do this by optimizing the reflected load/gearbox inertia and rate for the servomotor. In ratios from 3:1 to 100:1, planetary gearboxes offer the greatest torque density, weight, and precision. In fact, few cycloidal reducers offer ratios below 30:1. In ratios from 11:1 to 100:1, planetary or cycloidal reducers may be used. However, if the mandatory ratio goes beyond 100:1, cycloidal gearboxes keep advantages because stacking phases is unnecessary, therefore the gearbox could be shorter and less costly.
Finally, consider size. The majority of manufacturers offer square-framed planetary gearboxes that mate precisely with servomotors. But planetary gearboxes develop 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 yet are not for as long. The compound reduction cycloidal gear train handles all ratios within the same package deal size, therefore higher-ratio cycloidal gear boxes become actually shorter than planetary variations with the same ratios.

Backlash, ratio, and size provide engineers with a preliminary gearbox selection. But choosing the right gearbox also entails bearing capacity, torsional stiffness, shock loads, environmental conditions, duty routine, and life.

From a mechanical perspective, gearboxes have become somewhat of accessories to servomotors. For gearboxes to perform properly and provide engineers with a balance of performance, life, and worth, sizing and selection should be determined from the strain side back again to the motor as opposed to the motor out.

Both cycloidal and planetary reducers are appropriate in virtually any industry that uses servos or stepper motors. And even though both are epicyclical reducers, the distinctions between many planetary gearboxes stem more from equipment geometry and manufacturing procedures instead of principles of operation. But cycloidal reducers are more varied and share little in common with each other. There are advantages in each and engineers should consider the strengths and weaknesses when choosing one over the various other.

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

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

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

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

Torque Cycloidal gearbox magnification. Gearboxes provide mechanical advantage by not merely decreasing swiftness but also increasing result torque.

The EP 3000 and our related products that utilize cycloidal gearing technology deliver the most robust solution in the most compact footprint. The primary power train is comprised of an eccentric roller bearing that drives a wheel around a couple of internal pins, keeping the reduction high and the rotational inertia low. The wheel incorporates a curved tooth profile instead of the more traditional involute tooth profile, which eliminates shear forces at any stage of contact. This design introduces compression forces, instead of those shear forces that would can be found with an involute equipment mesh. That provides a number of performance benefits such as for example high shock load capacity (>500% of rating), minimal friction and put on, lower mechanical service factors, among numerous others. The cycloidal design also has a large output shaft bearing span, which provides exceptional overhung load features without requiring any extra expensive components.

Cycloidal advantages over various other styles of gearing;

Capable of handling 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 is the most reliable reducer in the commercial marketplace, and it is a perfect suit for applications in large industry such as oil & gas, principal and secondary steel processing, industrial food production, metal cutting and forming machinery, wastewater treatment, extrusion apparatus, among others.