Page 12 - PortescapCatalog 0212_V012021Eng
P. 12
Glossary (for Brushless Slotless DC Motors)
Electrical Data
This voltage is used when measuring no-load speed, no-load current and other parameters. It does
Nominal voltage
not represent a recommended voltage or a limitation of the motor.
Brushless motors equipped with Hall sensors can be tuned so that the sensor positions
compensate for the electrical and electronic time response of the commutation sequence. This is
especially important for reducing motor losses in high-speed applications.
Optimization direction All the standard motors shown in this catalog are either symmetrical or optimized in the
counterclockwise (CCW) direction as seen from the output shaft side of the motor. For optimized
motors, optimization speed is mentioned in the specification document. Optimization speed and
direction can be customized by request.
This is the motor speed as measured without any attachment or friction on the output shaft, with
No-load speed
the driver being supplied by the nominal voltage.
This is the average current measured before the driver power stage, without any attachment
or friction on the output shaft and with the driver being supplied by the nominal voltage. This
Typical no-load current parameter can vary significantly depending on the driver used and the motor temperature. All
data are measured using the Hall-sensored version of the commutation, when available, after 30
seconds of running the motor at room temperature.
Within maximum continuous operation specifications (see power curve graph), and with proper
selection of speed and torque, this is the highest mechanical power output that can typically be
achieved without exceeding the thermal limitation of the motor windings. In some cases, this
Max continuous mechanical power (@ 25°C) maximum power can also be limited by the maximum recommended motor speed for the bearing
assembly. Maximum continuous power is calculated with the motor in the air at 25°C, with no heat
sink or forced air cooling. With improved cooling, it may be possible to exceed this value in short-
term operation.
Within maximum continuous operation specifications (see power curve graph), this is the current
drawn at the highest output torque the motor can continuously achieve without exceeding the
thermal limitations of the windings. Maximum continuous current is usually reached at a very low
speed where iron and friction losses are minimal.
Max continuous current
This value is calculated with the motor in the air at 25°C, with no heat sink or forced air cooling.
With improved cooling, it may be possible to exceed this value in short-term operation. This value
does not apply to the very short peak current at startup, which can typically reach several tens of
amps.
This is the torque corresponding to the maximum continuous current, usually reached at very low
speed.
Max continuous torque Stall torque, when the motor needs to start from a blocked position, may be lower than this figure
due to motor torque ripple.
12 V012021 • © 2021 Portescap. Specifications subject to change without notice.
