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Permanent Magnet DC Motors

Permanent magnet DC motors are used in pump applications worldwide. They are versatile and cost-effective. Electrician and scientific lecturer William Sturgeon invented the first commutator-type direct current electric motor capable of turning machinery in 1832 [i]. Since that time, permanent magnet direct current (PMDC) motors have been used in a countless applications in the pump industry. PMDC motors can be finely controlled, deliver power efficiently, are mechanically simple and release almost no pollutants.

Precise, Efficient Pump Control

Electric motors often achieve 90 percent conversion efficiency over a full range of speeds and power outputs and can be precisely controlled. PMDC can provide high torque, and unlike internal combustion engines, they do not need gears to match power curves. This removes the need or expense of gearboxes and torque converters. PMDC motors also feature the ability to operate at a low, variable rpm, which can be particularly useful for many pump applications.

Being able to vary the speed and torque of a PMDC is another benefit that drives original equipment manufacturers (OEMs) to the PMDC motor. By varying the voltage the motor receives through a motor control, the speed and torque can be manipulated to achieve the optimum performance that the application requires.

Get the Most from the Motor Investment

The simple design of PMDC motors make them cost effective. With a relatively low part count, they are also a great choice for low maintenance. As long as the system is operated so that amp and voltage draws do not exceed the motor's design specifications, occasionally changing brushes is the only maintenance required.

With rapidly advancing brush and brush holder technologies, the performance can be further refined to increase efficiencies and match ever-demanding requirements. Many users require the portability that PMDC motors provide. The use of a portable battery power source gives the end users the ability to take their jobs on the road, on the water or in the air. Common portable pumping applications include sump pumps, over the road air pumps, door operators and hydraulic fluid pumps.

Systems that depend solely on AC power are susceptible to failure in the event of a power supply failure. Many industries depend on the ability of a pump system with a battery backup to provide a safety mechanism should power fail.

When a PMDC and hydraulic pump system are coupled with hydraulic cylinders, the pump system becomes a flexible tool to provide the necessary power to handle a wide variety of tasks. Carefully designed, proprietary motors allow these systems to be long-lasting and worry-free.

Carbon Offsets and Green Energy

In the ever growing "green" movement, a PMDC motor is a strong ally. Since the magnets produce the flux field, a PMDC motor uses less power when compared to other types of DC motors that require power to excite the field. PMDC motors are also an option for solar-energy systems. For instance, swimming pool pumps can be retro-fitted with solar-powered pumps that run off a PMDC motor with portable power.

Motor design and manufacturing is increasingly returning to the U.S., where proprietary designs are more easily protected. This trend contributes to the local economy at the factory's location, reducing the motors' carbon emission costs. Fuel emission costs to ship the motors are reduced and carbon offsets can be earned.

Increasingly competitive business and labor costs, high electricity rates, rising replacement costs and a more competitive business climate leave motor users fighting to hold the line on costs while being tasked to improve overall reliability. PMDC motors offer a clean, long-running, minimal maintenance alternative.