Vacuum Degassed Bearings: Vacuum degassing is a process used in the purifying of steel for ball bearings ensuring a very dense and consistent bearing surface. This results in a longer lasting superior bearing. All ball bearings are vacuum degassed bearings.

Variable Torque: A multi-speed motor used on loads with torque requirements, which vary with speed as with some centrifugal pumps and blowers. The horsepower varies as the square of the speed.

Velocity: The change in position as a function of time. Velocity has both a magnitude and sign.

Vertical P Base Motor: A vertical motor with a special mounting face conforming to NA design P and with a ring groove on the shaft.

Vertical Motor: A motor being mounted vertically (shaft up or down) as in many pump applications.

Viscous Damping (KDV) (lb-in./kRPM): Inherent losses are present in all motors which result in lower torque delivered at the output shaft than developed at the rotor. Losses which are proportional to speed (i.e. speed dependent terms such as windage, friction, eddy current) are related through the motor's "viscous damping" constant, measured as the slope of the damping curve.

Voltage Constant (KE) (V/kRPM peak, line-to-line) : May also be termed back-EMF constant. When a motor is operated, it generates a voltage proportional to speed, but opposing the applied voltage. The shape of the voltage waveform depends upon the specific motor design. For example, in a brushless motor, the waveshape may be trapezoidal or sinusoidal in nature. For a sine waveform, the voltage constant can be measured from line-to-neutral or line-to-line and expressed as a peak value or "RMS" value.

Voltage Drop: Loss encountered across a circuit impedance from power source to applicable point (motor) caused by the resistance in conductor. Voltage drop across a resistor takes the form of heat released into the air at the point of resistance.

Voltage: The force that causes a current to flow in an electrical circuit. Analogous to pressure in hydraulics, voltage is often referred to as electrical pressure. The voltage of a motor is usually determined by the supply to which it is attached. NA requires that motor be able to carry its rated horsepower at nameplate voltage plus or minus 10% although not necessarily at the rated temperature rise.


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