The Brushless Servo Motor Provides Commutation And Energy Transfer
A brushless servo motor is simply but a motor, controlled by a servo mechanism. A servo mechanism is, by definition, any mechanical construction that utilizes some sort of instrument to sense errors in its operation, and automatically correct them. An example would be the cruise control system of an SUV, which measures the movement of the car’s crankshafts to determine the speed at which the vehicle is moving, and hence alters the acceleration of the vehicle’s motor to maintain a constant speed regardless of whether the vehicle is traveling on flat land, uphill, or downhill.
The salient feature being indicated when one refers to a servo motor bushless is the inclusion of lengths of braided copper wire, or ‘brushes’ into its design. You see, in order for an electric motor to work, it’s required that the coils of the rotor be connected, thus completing an electrical circuit. In order to meet this requirement, in the past so-called slip rings are fitted around the shaft of the rotor, and compressible springs arranged so as to press the brushes onto the rings, which in turn would conduct the requisite current.
Such brushes provided very poor commutation, due to the sudden vertical movement of the brushes as they went from one slip-ring to the next. Over the years, innovations aimed at solving this problem greatly improved the functionality of brushed servo motors. High resistance copper-graphite brushes, for instance, provided a more gradual shift of current across the gaps. Still, the market was crying out for more dramatic changes, something that would remove the limitations and inaccuracies of brushed rotary technology once and for all.
Enter the brushless servo motor. Brushless servo motors run off DC current, and offer great advantages in terms of their efficiency and error-free functionality – mathematically speaking, the current, torque, voltage and RPM of these devices are linearly related. They also have much longer life spans than ‘brushed’ servo motors, as the abrasive motion of the brushes from one coil to the next within the devices would slowly lead to the wearing down of the brushes.
In a brushless servo motor, the electromagnets are not required to move. Rather, the permanent magnets rotate while the armature stays fixed in place. For various reasons this helps to circumvent the problems inherent in transferring current to an armature in motion.
This assembly allows the entire brush-system to be replaced with an electronic control system, a controller capable of delivering the exact same power distribution as that achieved in a brushed motor, but by using solid state circuits instead of brush-based commutators.
The Vickers Warnick lines of brushless servo motor are amongst the highest quality rotary devices in the industry, and are without question the way to go if you’re looking for reliable devices to control your hydraulic or pneumatic pumps or valves – indeed, the company is known as one of the top names in the entire industry of motion control. Vickers Warnick has over 12 000 standard models of servo motor available, including advanced AKM high performance motors, which provide users with an incredible range of feedback, speed, connectivity and mounting options, allowing the greatest flexibility even as the company guarantees smooth, reliable performance.
While their standard brushless servo motor is wound and optimized for use with their S600 and S200 servo drives (which offer pretty much unrivalled performance), the company offers its brushless servo motors in windings various enough to interface with any drive you please.
