Cycloidal gearbox

Cycloidal gearboxes
Cycloidal gearboxes or reducers consist of 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 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 fans in the casing. Cylindrical cam followers become teeth on the inner gear, and the amount of cam followers exceeds the number of cam lobes. The next track of substance cam lobes engages with cam supporters on the output shaft and transforms the cam’s eccentric rotation into concentric rotation of the result shaft, thus increasing torque and reducing swiftness.

Compound cycloidal gearboxes offer ratios ranging from only 10:1 to 300:1 without stacking levels, as in standard planetary gearboxes. The gearbox’s compound decrease and may 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 sluggish rate output shaft (flange).

There are several commercial variations of cycloidal reducers. And unlike planetary gearboxes where variations are based on gear geometry, heat treatment, and finishing procedures, cycloidal variations share basic Cycloidal gearbox design concepts but generate cycloidal motion in different ways.
Planetary gearboxes
Planetary gearboxes are made up of three fundamental force-transmitting elements: a sun gear, three or more satellite or world gears, and an internal ring gear. In an average gearbox, the sun equipment attaches to the input shaft, which is connected to the servomotor. Sunlight gear transmits engine rotation to the satellites which, in turn, rotate within the stationary ring equipment. The ring gear is section of the gearbox housing. Satellite gears rotate on rigid shafts linked to the planet carrier and trigger the planet carrier to rotate and, thus, turn the output shaft. The gearbox gives the output 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, but it is not common.

The ratio of a planetary gearbox is calculated using the next 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 among cycloidal and planetary gearboxes, engineers should first consider the precision needed in the application form. If backlash and positioning accuracy are crucial, then cycloidal gearboxes provide most suitable choice. Removing backlash may 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 swiftness for the servomotor. In ratios from 3:1 to 100:1, planetary gearboxes offer the best torque density, weight, and precision. Actually, 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 phases is unnecessary, therefore the gearbox can be shorter and less expensive.
Finally, consider size. The majority of manufacturers offer square-framed planetary gearboxes that mate precisely with servomotors. But planetary gearboxes grow in length from solitary to two and three-stage styles as needed equipment ratios go from significantly 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 decrease cycloidal gear teach handles all ratios within the same package deal size, therefore higher-ratio cycloidal equipment boxes become even shorter than planetary versions with the same ratios.

Backlash, ratio, and size provide engineers with an initial gearbox selection. But deciding on the best gearbox also involves bearing capability, torsional stiffness, shock loads, environmental conditions, duty cycle, and life.

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

Both cycloidal and planetary reducers work in virtually any industry that uses servos or stepper motors. And although both are epicyclical reducers, the distinctions between most planetary gearboxes stem more from gear geometry and manufacturing processes rather than principles of procedure. But cycloidal reducers are more different 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 additional.

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

Inertia matching. The most common reason for choosing the gearbox is to control inertia in highly powerful circumstances. Servomotors can only just control up to 10 times their personal inertia. But if response period is critical, the engine should control significantly less than four situations its own inertia.

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

Torque magnification. Gearboxes provide mechanical advantage by not merely decreasing quickness but also increasing output torque.

The EP 3000 and our related products that make use of 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 set of inner pins, keeping the reduction high and the rotational inertia low. The wheel includes a curved tooth profile rather than the more traditional involute tooth profile, which removes shear forces at any point of contact. This design introduces compression forces, instead of those shear forces that would exist with an involute gear mesh. That provides several overall performance benefits such as for example high shock load capacity (>500% of ranking), minimal friction and wear, lower mechanical service elements, among many others. The cycloidal design also has a big output shaft bearing span, which provides exceptional overhung load features without requiring any extra expensive components.

Cycloidal advantages over other styles of gearing;

Capable of handling larger “shock” loads (>500%) of rating compared 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 electric motor for longer service life
Just ridiculously rugged since all get-out
The overall EP design proves to be extremely durable, and it requires minimal maintenance following installation. The EP is the most dependable reducer in the commercial marketplace, in fact it is a perfect match for applications in heavy industry such as oil & gas, primary and secondary steel processing, industrial food production, metal reducing and forming machinery, wastewater treatment, extrusion apparatus, among others.