Technical terms - コアレスモータ株式会社

Technical terms

General Coreless brushless DC motor Driver Gear-in motor AC servo motor IC FAN Power generator

No.Classification Technical termsDefinition
1 CM (Continuous) Rated voltage The input voltage which can satisfy the condition specified by the specification in continuous operation.
2 CM (Continuous) Rated output The maximum output that can be safely and continuously used under the conditions specified in the specification.
3 CM (Continuous) rated torque Torque when the rated output is continuously emitted at the rated voltage.
4 CM (Continuous) rated RPM The rotational speed at which the motor is continuously rated, at the rated voltage.
5 CM (Continuous) rated current The current when the motor is continuously rated and the rated torque is generated.
6 CM Maximum efficiency The maximum value of the power consumed by the motor and the ratio of the mechanical output exerted.
7 CM No load rotational speed  Stable revolutions when the rated voltage is added when the load is zero.
8 CM No load current Even if the external load is zero, there is bearing friction and load by wind loss. So, constant torque is still required to turn at a constant rotational speed, that is the current necessary for that.
9 CM Torque parameter Since the generated torque is approximately proportional to the current, the Torque ÷ current (Nm/A) is a constant, and this constant is called the torque parameter.
10 CM Reverse Voltage parameter The Reverse voltage of the motor is proportional to the rotational speed of the motor, and the proportional coefficient to the reverse electromotive voltage parameter. e = Ke x ω (e: Inverse voltage, ω: angular velocity, Ke reverse voltage parameter. )
11 CM Resistance between terminals Resistance values measured between coil terminals
12 CM Rotor Inertia The moment of inertia of the rotor, the higher the value is less responsive


CM Cogging torque The suction force torque caused by the magnetic suction force generated when the rotor is rotated in a non-excited state
 14 CM Terminal inductance Inductance measured between coil terminals
 15 CM Mechanical time parameter Indicates the rise time of the motor startup and the time to reach 63.2% of the rated RPM
 16 CM Electrical time parameter When the motor is fixed so as not to rotate, the time until the current reaches the 63.2% of the saturation current after applying the rated voltage
 17  CM Motor weight Average weight of standard type motors
 18 CM Maximum temperature of the coil The maximum temperature allowed in the coil and the temperature that cannot be exceeded even when the customer uses it
 19 CM Insulation grade It is classified by the heat resistance of the insulating material which is composed, and the E species is 120 ℃. This does not mean that it can operate in 120 ℃ environments, and is expected to be 120 ℃ or less, including temperature rise due to heat generation