Originally Published EMDM March/April 2002
Microsystems
A firm specializing in the production of miniature motors and microsystems is well known for its Smoovy product line. The company creates microdrives ranging in size from 3 to 8 mm. Medical applications include portable pumps, surgical tools, measurement instruments, and scanners, as well as the miniaturization of existing devices. myonic S.A., Biel-Bienne, Switzerland.
Linear actuators
PFL- and PFCL-series linear actuators are stepper motors that enable linear motion without any outside mechanical transformers. The actuators are available in a 25-mm format, with various leadscrew pitches and lengths, winding choices, magnet materials, and drive voltages to suit a range of applications. Nippon Pulse Motor Co. Ltd., Tokyo, Japan.
Stepper motor
A 10-mm disc-magnet stepper motor produces 24 steps per revolution with a holding torque of 1.85 mN•m. Measuring just 10 mm in diameter and 16.4 mm in length, the motor's strength derives from the use of samarium cobalt magnets and an optimized magnetic circuit. The small motor is designed for applications where space is limited and accurate positioning is called for. Portescap, La Chaux-de-Fonds, Switzerland.
Brushless dc motor
A compact, high-speed brushless dc motor is well suited for a variety of applications, including handheld tools, machine-tool spindles, and centrifuges. The motor offers quiet operation and the ability to accelerate rapidly with limited impact to the system. A 90% efficiency rating ensures that the motor remains cool during operation. Rated for ambient temperatures of up to 155° C, the motor is suitable for harsh environments. Servo Magnetics Inc., Canoga Park, CA, USA.
Slotless motors
Brushless, slotless dc motors are designed for applications where small package size, speed, and precision are critical. A unique motor design allows for smaller motors with greater power output, even in extremely high- or low-speed continuous operation. The motors' slotless stator winding and unique rotor construction provide zero cogging torque and vibration for high accuracy. Omega Dynamic, Rueil Malmaison, France.
High-precision actuators
Robust, high-precision actuators control physical processes in medical analysis applications. The compact actuators have travel speeds of up to 30 mm/sec and forces as high as 140 N. The 7000 series is suited for functions that require small size, low power consumption, and low price. The company develops and manufactures mechatronic systems, stepper motors, and linear actuators according to customer requirements. Sonceboz S.A., Sonceboz, Switzerland.
Encoder
An encoder supplies up to 1024 pulses per revolution and is unaffected by radial and axial play within mechanical tolerances. The MR encoder only adds 4 to 6 mm to a micromotor, and despite its small design can be given encoder signals to suit user requirements. Up to six binary or decimal incremental figures can be selected. The modular system of the encoder allows for simple combination with the company's motors. Maxon Motor AG, Sachseln, Switzerland.
Micromotor
Copyright ©2002 European Medical Device Manufacturer
A coreless dc micromotor features an optimal performance-to-volume ratio. The featherweight motor has an extremely low moment of inertia and rotates without cogging. The motor measures 12 x 24 mm and has a power rating of 1.3 W, a torque of 3.69 mN*m, and a speed of 13,900 rpm. The motor has linear voltage-to-speed and current-to-torque relationships. A low starting voltage and high precision ensure the durability and quality of the motor. Minimotor S.A., Croglio, Switzerland.
