Rick Halstead, CEO
“We specialize in providing superior quality motor products designed to perform in environments and applications where ordinary motors often fail on various grounds,” begins Rick Halstead, the CEO of Empire Magnetics. The company’s product suite encompasses robust 1.8o hybrid permanent magnet stepping motors and brushless servomotors, catering to a wide range of demanding applications. From space to highly hazardous and dusty environments to radiation and extreme temperature operations, Empire Magnetics’ offerings have left no stone unturned.
Founded in 1987, Empire Magnetics spun out of Compumotor, a pioneer in step motor systems and controls. Keeping customer satisfaction upfront requires the company to build its motor products with the highest quality materials. This helped them stay at the forefront in delivering sustainable motors that can be customized according to clients’ varying needs. Empire Magnetics’ prominent position in the industry is the result of its VP of Engineering, George Cinti, who gave the company a competitive edge with his prowess in providing specialty motors to the NASA Appollo programs.
When it comes to cryogenic temperature applications, the operational efficiency of ordinary motors is often far from optimum, or they are non-functional in many cases due to the contraction of metals. As the coefficient of thermal expansion varies from material to material, components within the motor—the magnet, copper wire, and insulations—contract at different rates, resulting in a locked-up motor.The resultant stress can create cracks and ultimately break the metal parts that have been made brittle by super-cooling. Empire Magnetics is committed to mitigating these functional hardships and builds cryogenic motors with stainless steel, brass, or bronze that barely lose ductility at low temperatures.The resultant stress can create cracks and ultimately break the metal parts that have been made brittle by super-cooling. Empire Magnetics is committed to mitigating these functional hardships and builds cryogenic motors with stainless steel, brass, or bronze that barely lose ductility at low temperatures.
The company ensures that all metal components of the motor have comparable coefficients of thermal expansion to avoid cracks.
As bearing grease hardens at extremely low temperatures, Empire Magnetics uses dry film lubrication or ceramic-type bearing that can operate without any lubrication to ensure the uninterrupted operation of its cryogenic motors.
While it’s necessary to avoid ferrous materials in the structural components to avoid cracking due to temperature-induced brittleness, performance can be enhanced by using them in a magnetic circuit. Due to the significant differences in the CTE of magnetic metals and copper/insulation materials of windings, techniques to allow for these changes have been developed. It is also significant to be aware of the changes that occur in some magnets. Neodymium magnets appear to lose about 30 percent of their flux at low temperatures due to a change in the molecular spin so that the direction of the magnetic field is shifted about 30 degrees, resulting in reduced motor performance. The specific construction of the magnetic circuit is one of the key design features of a successful cryogenic motor—at which Empire Magnetics takes a lead.
Being agile at our core, we are now in discussions with several prominent players in the industry to share our technological expertise for addressing the future needs
Such capabilities make Empire Magnetics’ cryogenic motors a go-to solution for a wide range of applications that include observatory equipment, deep space, bull semen storage, and scientific research, to name a few. The company collaborated with a university in Chile to design and develop a motor and a gear assembly for their moon rover. After having a holistic understanding of the client’s needs, Empire Magnetics developed a small and robust cryogenic motor and a gear assembly that not only served their operational needs but also withstood lunar temperatures that is below -100oC. In another instance, Empire Magnetics was part of the Brilliant eyes program, where the company provided motors that would survive 25 G shock at 24 Kelvin to Corning OCA, who was the subcontractor for Boeing. “Our cryogenic motors are also powering the Subaru Telescope in Hawaii for several years,” adds Halstead. Unlike its competitors, the company’s motors can be easily and quickly connected to various mechanical assemblies.
By adhering close to its mission of meeting clients’ highly demanding operational needs, the company continues to innovate and bring new, future-proof solutions to the table. Moving ahead, they intend to put more emphasis on expanding their footprints brushless motor space. “Being agile at our core, we are now in discussions with several prominent players in the industry to share our technological expertise for addressing the future needs,” concludes Halstead.