Cycloidal needle wheel Gearbox

How is the gear reduction ratio determined in the Cycloidal Needle Wheel Geared Motor?

The gear reduction ratio in a Cycloidal Needle Wheel Geared Motor is determined by the configuration of its cycloidal needle wheel mechanism. The gear reduction ratio, often denoted as "i" or "R," represents the relationship between the input speed and the output speed of the geared motor. In the context of a cycloidal needle wheel mechanism, the reduction ratio is influenced by the design parameters of the mechanism. Here's how the gear reduction ratio is determined:

Cycloidal Disc Configuration:

The core of the cycloidal needle wheel mechanism is the cycloidal disc, which typically has lobes or cams along its periphery. The number of lobes on the cycloidal disc plays a crucial role in determining the reduction ratio. The lobes create a cycloidal motion, and the arrangement affects how the mechanism transmits torque.
Needle Bearings and Eccentric Bearings:

The needle bearings interact with the lobes of the cycloidal disc. The eccentric bearings or needle bearing cam followers are mounted on an eccentric shaft. As the cycloidal disc rotates, the interaction with the needle bearings generates a unique motion that contributes to the gear reduction.
Cam Profile and Eccentricity:

The shape of the cam profile on the cycloidal disc, along with the eccentricity of the eccentric shaft, determines the motion imparted to the needle bearings. The eccentricity introduces variability in the distance between the center of rotation and the point of contact, creating the cycloidal motion.
Number of Eccentric Bearings:

The number of eccentric bearings on the eccentric shaft influences the gear reduction ratio. The more eccentric bearings there are, the more cycles the cycloidal disc completes for a full revolution, affecting the overall reduction.
Relationship Between Input and Output:

The cycloidal motion generated by the interaction of the cycloidal disc and needle bearings translates into an oscillating, non-uniform rotation of the output shaft. The relationship between the input (motor) speed and the output (gearbox) speed is determined by the design parameters of the cycloidal mechanism.
Output Shaft Configuration:

The output shaft is connected to the mechanism in a way that captures the cycloidal motion and converts it into a smooth, controlled output. The configuration of the output shaft, such as the number of lobes or pins, also contributes to the gear reduction.
Calculation of Reduction Ratio:

The gear reduction ratio is typically calculated as the ratio of the input speed to the output speed. For cycloidal needle wheel mechanisms, the specific design parameters, including the number of lobes and eccentric bearings, are used in mathematical formulas to determine the reduction ratio.