With so much overlap in specifications nowadays, electric motors from different vendors can all start to seem alike. Yet, motors aren't all created equal in terms of how easily and cost-effectively they can be woven into the bigger fabric of the whole motion system. Some vendors are trying to make the integration mechanically easier - with new direct-drive models or integrated servo gearmotors that do away with power transmission components. Other vendors are making integration easier from a communications standpoint, allowing devices to talk to one another using standard motion commands. Here's a look at some recent examples that represent both approaches.
CANopen Steps Up
Quicksilver Controls Inc. has added a CANopen option to its IG-J1 motor controller, which transforms ordinary stepper motors into closed-loop servos. Company President Don Labriola says the IG-J1 supports the CAN in Automation (CiA) CANopen Drives and Motion Control Profile 402, which allows Quicksilver controllers and third-party devices to communicate with one another via a standardized set of motion commands. CANopen also allows the controllers to be configured in peer-to-peer or master-slave modes for easy creation of multi-axis systems. The IG-J1 drives QuickSilver's line of I-Grade NEMA 17-, 23- and some 34-frame motors, generating from 21 to 300 oz-inch continuous torque. It also includes serial communications with the RS-232/RS-485 serial network running in parallel with CAN for supervisory control from a host computer. The controller sports seven bi-directional I/O. Input power (12 to 48V) and communications signals are accessed through the DB15HD port and can be converted to terminal strips using one of the popular breakouts.
Direct Drive Shrinks
Now available in smaller sizes, direct-drive frameless motors from Applimotion have been making inroads in low-profile gimbal mechanisms. The new ULT-44 motor, the smallest model, measures just 44 mm in diameter and 10 mm in length. Despite its compact size, it has a large through hole of 38 mm. Applimotion still makes frameless motors as large as 533 mm, but the new small size opens up applications in imaging, sensing, pointing and scanning gimbals, according to company Vice President Rob Mastromattei. Applimotion's ULT Series' motors work with any three-phase motor controller, including board-mounted chip sets. They can be wound for operation from 5 to 300V, while speeds range from one revolution a day up to 10,000 rpm. High-torque and zero-cogging slotless versions are available.
GearMotors Get Torque Boost
Dynetic Systems has developed a new line of brushless PM servo gearmotors for use in aerospace, industrial and medical applications that require high torque and a space-saving package that integrates the motor with a planetary geartrain. These integrated gearmotors provide minimum rated torque values from 26.5 lb-inch rated torque for the NEMA 23 size and 224 lb-inch for the NEMA 34 model. Maximum gearmotor momentary torque is 198 lb-inch for the size 23 and 633 lb-inch for the size 34. Dan Jones, who designed the new motor and is Dynetic's acting engineering director, says the new motors get their torque performance from high-energy Neodymium magnets. The new design also features a proprietary bearing bore design to reduce noise. Dynetic supplies these gearmotors in single-, dual- and three-stage geartrains, spanning gear ratios from 16:1 up to 1,012:1. The new gearmotors support a wide variety of feedback devices and sinusoidal drives from 12 to 320V dc.