Stall torque is the torque available from a motor whose output rotational speed is zero. Motors in a stalled condition may be prone to overheating and possible damage if the current flowing under these conditions becomes higher than the maximum continuous rating.
Why is stall torque important?
You should care because stall torque is the highest point of failure on a drive unit or a motor. The device is going to draw a lot of current at stall. In fact, it’s going to draw the highest amount of current you’ll ever see while under normal operating conditions. The keyword there being normal operating conditions.
What is DC motor stall?
Stalling is a condition when the motor stops rotating. This condition occurs when the load torque is greater than the motor shaft torque i.e. break down torque condition. In this condition the motor draws maximum current but the motor does not rotate.
What is stall torque and rated torque?
The rated torque is the maximum continuous torque that the motor produces at rated RPM when working normally and without overheating, whereas the stall torque is produced by the motor when RPM is 0 while the load is attached or at starting. DC Motors manufacturers usually provide the stall torque rating.
How does a stall torque motor work?
When the motor is stalled, the power is zero. As the speed increases, the torque falls linearly until it reaches zero at its free speed. This linear torque/speed relationship results in the power being a maximum at a speed equal to one-half the free speed.
Can a DC motor stall?
Yes, you can stall a smaller DC motor briefly (3 to 5 seconds is fine), at its rated full load current. The windings will heat up, and there will be some excessive heating of the commutator, but that usually doesn’t affect the service life.
How is stall torque measured?
The stall torque can be measured by clamping a lever to the motor and loading the lever with weights until the motor does not move, but this method is difficult as running the motor at stall for more than a few seconds can cause it to overheat. … At stalling condition, motor maximum torque is lower than load torque.
Why do DC motors stall?
DC Motor Torque speed Characteristics
Every motor is designed to spin a particular amount of load. When the load is further increased above its overload region, the speed of the motor gradually reduces and the motor stalls.
Why do motors stall?
In a simple definition, motor stalling means that the electric motor has more load on it than it is designed for and it can no longer supply enough torque to keep it spinning. … As the load increase beyond the capability of the induction motor, the slip increases and you move up the torque curve.
What is a stall torque tool?
Stall torque describes the torque produced by a mechanical device with output rotational speed equal to zero. … Stall torque nutrunners are very strong, compact and lightweight tools, ideal for maintenance precision bolting.
How is stall current calculated?
5) Now to get stall current at the rated motor voltage, use Ohm’s Law again: Stall Current = Rated Voltage / Resistance.
What is a stall current?
Voltage and current ratings. … The stall current of a DC motor is how much current the motor will draw when power is applied but it is not spinning (for example, if the motor shaft is prevented from rotating), producing maximum torque and minimum (zero) speed.
Does voltage affect stall torque?
Of course, the motor constant (k) doesn’t change, and resistance (R) in the motor windings is constant. Therefore, when supply voltage (V) is constant, torque (T) is inversely proportional to speed (ω). … This is the stall torque—the maximum torque when the motor is running at nominal voltage.