Why do precision planetary gearboxes need to be used with motors?

Characteristics of coreless motors:

High speed: Typically rated speeds range from several thousand to tens of thousands of RPM.

Low torque: Direct output torque is very small, unable to directly drive a load.

Fast response: Extremely low rotor inertia, resulting in extremely rapid start-stop and acceleration.

Functions of planetary gearboxes:

Reducing speed and increasing torque: This is the core function. Through gear transmission, the high speed of the motor is reduced proportionally, while the output torque is amplified proportionally (ignoring efficiency losses).

Improving system resolution: For servo systems, gearboxes can improve the position control accuracy at the output end.

The essence of matching: Finding a suitable gearbox so that the motor's output characteristic curve (speed-torque curve) can be transformed into a characteristic curve that matches the load requirements (required speed and torque).

II. Core Parameters and Calculation Steps for Matching

Step 1: Define Load Requirements
This is the starting point for all work. You need to know exactly what your load needs:

Required output speed (N_out): At what RPM does the load need to operate? Required Output Torque (T_out): How much torque is needed to drive the load? (Consider friction, acceleration torque, load weight, etc. in the calculation.)
Work Cycle: Is it continuous or intermittent operation?

Size and Weight Limitations: What is the total installation space for the motor and reducer?

Other Requirements: Are there any special requirements for backlash, noise, or lifespan?

Step Two: Analyze Motor Performance
Obtain the speed-torque curve for your selected coreless motor. It typically includes:

No-load Speed (N_nl): The maximum speed at zero torque.

Stall Torque (T_stall): The maximum torque at zero speed.

Optimum Efficiency Point: The area of highest efficiency is usually marked on the curve (typically a high-speed, low-to-medium torque region). During matching, the motor should be operated as close to this region as possible.