Any machine that includes the generation of motion needs a mechanism to use that motion, that’s what cycloidal gearboxes are.
For example, a car engine handles a very high number of rotations, about 6,000 or 7,000 revolutions per minute, and this would not be manageable by the wheels, which could never turn at such a speed.
That’s why gearboxes exist, reducing the rotation speed and making it usable by the wheels ensuring that they don’t disintegrate (because that’s what would happen if we connected them directly to the engine spinning them 7,000 times a minute).
Planetary gearboxes are particular components for the transmission of motion and power, consisting of a series of gears, the purpose of which is to increase the torque in electromechanical systems, reducing the rotation speed.
On average, people do not ask themselves how the speed of motion is transformed into torque, capable of carrying out the work that machines do for us.
Gearboxes contribute to our well-being, and if we did not have them, we would revert mechanically hundreds of years back to the days of the first industrial revolutions, when people did not know how to turn speed into torque and therefore had to ride or walk.
When speed is reduced, the reducer multiplies the torque, that is the power, using the same principle by which the first gear has less speed, but more torque, compared to the fifth gear.
To understand its functionality, it is necessary to delve deeper and understand what it is and how it can increase company production.
What are Cycloidal gearboxes?
The term Cycloid, as well as its adjective form “Cycloidal”, are derived from the word Hypocyloid which describes a curve (red in the figure below) drawn by a fixed point “X” on a circumference with a smaller diameter “d” that rolls without crawling on a circumference of greater diameter “D” or on a straight line in the concept of diameter brought to infinity. Just like the terms helical, cylindrical and bevel gear; Cycloidal simply describes the operating mechanism of the internal elements of the speed reducer.
How Cycloidal gearboxes speed reducer works
To understand how these gearboxes work, it is essential to understand how to calculate the reduction ratio of a cycloidal gearbox. Let’s start with the concept of a planetary reducer with a planetary gear (P) which goes into planetary motion on an internally toothed fixed gear (S) with the help of an eccentric element. The fixed gear has one or two more “teeth” than the cycloid disk.
In the equation below, P identifies the number of teeth of the planetary gear, S those of the fixed gear, ω2 the angular velocity of the planetary gear around its axis. The relationship between the velocities ω2 and ω1 is represented as follows:
If SP = 1 the ratio between the speeds becomes:
If SP = 2 the ratio between the speeds becomes:
So, when the motor shaft rotates at angular speed ω1, the planetary gear will rotate at angular speed:
Where P indicates the number of teeth of the planetary gear and the symbol indicates that the gear rotates in the opposite direction to that of the crankshaft (eccentric).
The rotation of a planetary gear around its own axis, in cycloidal gearboxes, is caused by a constant acceleration generated by the output pins (and relative rollers) as shown in the picture above. In this mechanism the pins of the output shaft are equally distributed and spaced on a circle that is concentric with the axis of the fixed gear. The pins transmit the rotation of the planetary gear by internally rolling around the circumference of the holes of each cycloidal gear. The diameter of the holes minus the diameter of the pins of the output shaft is equal to twice the eccentricity value of the crankshaft.
Next Step
Since 1961, we have been satisfying very demanding customers, with great attention to service, a competitive advantage that has allowed us to build increasingly reliable machines. If we had to sum up our strength in one sentence: YOU DON’T HAVE TO ADAPT YOUR MACHINE TO THE GEARBOX, BUT WE ADAPT OUR GEARBOXES TO YOUR MACHINE, without any price increase for the prototype! Request a free consultation now to find out how our gearboxes can make your machines even more competitive.