NON-COGGING MOTOR FOR HIGH PRECISION APPLICATIONS

ThinGap LLC, the leader in high power density DC motors, today announced its TG 2320 brushless motor is being used for an ultra high precision cylinder bore gage for measuring diesel, hydraulic or pneumatic cylinder inside bore diameter and form.A cylinder bore gage measures the inside bore diameter and imperfections in the cylinder wall by measuring as many as 8,000 points around the diameter.  The gage is similar to a spindle and composed of a rotary air bearing, motor, non-contact optical glass scale rotary encoder and probe.“The ThinGap motor enabled the spindle system to meet the plus/minus 0.1 micron runout requirement at 30 RPM operating speed,” said Brad Nelson, President, Nelson Air Bearing.  “We also measured runout at 500 and 1,000 RPM, although much higher than the operating speed.  Even at the increased speed the bearing and motor maintained accuracy of 0.1 micron.”“The ThinGap motor has virtually no cogging forces to cause spindle runout because it does not have an iron core, and therefore there is no magnetic attraction between the rotor and the frame as with conventional motors,” said Rean Pretorius, CEO, ThinGap LLC.  “Because ThinGap motors surpass customer specifications, they are gaining acceptance in a wide variety of applications including test and measurement equipment such as the Nelson bore gage.”The TG 2320 motor features smooth controllable power without cogging or hysteresis torque.  The motor delivers 425 oz-in. peak torque and 1,025 watts continuous power, yet weighs only 16.5 oz.  In addition to the cylinder bore gage, the TG 2320 is well suited for high efficiency compressors and pumps as well as semiconductor processing and handling equipment.