In today's changing environment, there is sometimes a need for motor solutions not provided by traditional motor suppliers. A variety of suppliers invent, manufacture and sell specialty motors from miniature ceramic motors and positioning systems using patented piezoelectric designs, to linear arc motors that come in an extremely low profile package, to pancake-style motors for vacuum, radiation and other harsh environments and others.
These suppliers are usually targeting specific markets that would benefit from new and innovative solutions, and provide alternatives to conventional technologies. Many times, these vendors also provide engineering services and work with customers to design customized products, including any associated test equipment and tooling, and work to provide a competitive manufacturing solution.
MOTORS DRIVE TINY LINEAR POSITIONING STAGES
A piezoelectric SQUIGGLE® motor from New Scale Technologies Inc. is used to drive a motorized linear positioning stage used for biological research, optical instruments and other micropositioning needs. At 25 × 25 × 10 mm, the company says the SQL-3405 is the smallest closed-loop stage on the market. It delivers automated, “set and hold” micropositioning for optical microscopy, laser alignment, and applications where space is at a premium. The stage provides precise incremental motion of 100 nm and a position sensor provides closed loop control with a resolution of 10 micrometers. Its long 5 mm travel range provides positioning without manual pre-alignment and tweaking. The SQUIGGLE® motor uses a threaded nut and screw to create precise linear movement in a very small space. Piezoelectric ceramics create ultrasonic vibrations in the nut, causing the screw to rotate and translate with high precision. The motors are smaller and more precise than conventional electromagnetic motors, use 90 percent fewer parts and require no gear reduction.
Applimotion's LARC Series motors achieve custom arc shapes and zero cogging in an extremely low profile package. These motors can easily be applied to any integrated mechanical system requiring limited angle of rotation at large diameters. With a 360 degree magnet track, they can also run continuously. They are excellent for precision positioning using a high-resolution encoder and operate from standard three phase brushless amplifiers and controllers. This technology is a natural combination of the disk drive voice coil motor and the traditional brushless linear motor. LARC series motors can be driven by standard three phase brushless motor controllers from 24-300V with speeds ranging from 0.1 to 1,000 rpm. Axial low profile is an advantage with options as low as 10 mm axial thickness at up to 800 mm diameter. Torque output is approximately 15 lb-inch per radial inch of arc. Hall Devices are a standard option.
CUSTOM HOLLOW MOTORS
Custom Hollow Series motors from Empire Magnetics are pancake-style motors available on a custom basis in large bore or hollow shaft configurations for vacuum, radiation and other harsh environments. Models include two-phase stepper or three-phase brushless motors. They are available with a power range of 25 to 2,500W in diameters ranging from 8 to 60 inch and with a maximum bore size of 20-25 percent of the motor diameter. Comprehensive design services are available. Magnetic and other computer modeling methods allow the envelope and performance to be accurately predicted in advance of fabrication which allows the engineer to customize his design with a high degree of confidence. Hollow motors are useful in beam line applications where a clearance hole at the centerline is vital to proper machine operation. Raster scanning, hologram generating, laser scanning, filter adjustments and instrument insertions for x-ray, electron, proton and optical light beams have been deployed.