A modified version of the company’s ERS Series of electrically released spring-engaged brakes serve as pitch brakes for wind-turbine applications that require both “static” holding power and the ability to withstand high-inertia dynamic stops in an emergency. To position the blades to the proper pitch, the electromagnetic brake is mounted outboard of an inductive encoder, which is mounted to the back of a motor. In normal use, the brake holds the blades from rotating in a power-off situation. The 11.3-lb ERS68 brake, tested to make 20,000 fully loaded dynamic stops, offers 100 lb-ft of static torque with a maximum of 2,000 rpm and a 0.2-sec brake release time. The one-piece, fully enclosed blade pitch brake is painted to withstand extreme environmental conditions, such as salt-spray, condensation, and water.
Warner Electric, an Altra Industrial Motion Co., 449 Gardner St., South Beloit, IL 61080, (800) 234-3369, warnerelectric.com