A cycloidal gearbox is a type of low-friction gearbox that is ideal for brushless DC motors. These types of gearboxes can be adjusted for efficiency by varying the circumference of cycloids. Cycloid gears are typically made with fewer teeth than involute gears. This design also allows for reduced wear and mechanical service factors. The geometry of the cycloidal disk can drastically reduce rotation, and a cycloidal gearbox can transfer torques that are higher than planetary gears.
In a cycloidal gearbox, the input shaft is rotated at a different speed than the output shaft. Because of this, the input shaft bearing must be the same size as the input shaft bearing.
A cycloidal gearbox is used in compact actuators with permanent magnet synchronous motors. Designed to provide a smooth motion and low friction, cycloids are used to ensure that motion is efficient and quiet. They are especially useful for a wide variety of applications, such as servo drives, brushless DC motors, and other types of compact actuators.
To create a cycloidal gearbox, first, you must determine its basic shape. The shape of the cycloid is defined by the radius of the circle and its distance from the center. Ideally, the circle should end at the center of the output hole.
Once you have determined the basic shape of the cycloid, you can draw it. To do this, you will need to trace the path of the point on the circle’s circumference. Using the radial distance, you can find the centerline of the cycloid.
Next, you must find the radius of the pin circle. You can use the Desmos formula to obtain this value. It must be at least as large as the diameter of the cycloid’s exterior diameter. Also, it should be at least twice as large as the number of teeth in the cycloid.
Finally, you can calculate the angular velocity of the output shaft. It is important that you take into account the actual temperature of the gearbox components. For example, if the gearbox has a thermal inertia, this will affect the actual temperature.
Since the cycloidal gearbox has a large output shaft bearing span, this can be used to maximize overhung load capacity. As a result, the gearbox can hold a load even when the motor torque is low.
The gearbox can also be a useful tool to study a number of mathematical concepts. One such concept is the stiction model. Unlike the classic model, the stiction model considers the nonlinear characteristics of friction and provides a detailed calculation for the motor side of the cycloidal gearbox. Despite the fact that the stiction model does not cover backlash and torsional stiffness, it can be very accurate.
After developing the mathematical model of the cycloidal gearbox, it is necessary to measure the efficiency of the system. For this, a test bench was used. Before the test, the motor was pre-heated to a steady temperature. From there, the output angular velocity, the input torque, and the stiction breakaway speed were measured. Afterward, a simulation was conducted, and the results were compared to the measurement data. There was a high degree of agreement between the simulation and the actual measurements.