Brushless DC motor has two kinds of power in terms of input power and output power.
Input Power: According to P = UI (P - Power U - Voltage I - Current), we can get the rated input power of the motor with known U and I.
Output power: We can calculate the rated output power of the motor according to the torque X speed / 9550 = power, given the torque and speed.
The relationship between torque, speed and power can be estimated based on the formula mentioned above. If the rotational speed increases and the torque decreases at the same time under the condition of constant power, the relationship between the three can be obtained by analogy.