June 8, 2009

5 Min Read
Motors and Motion Control

Originally Published MPMN June 2009

SPOTLIGHT

Motors and Motion Control

Medical motor control modules


ua4a_62744.jpgCompact, high-power electronic medical motor control modules are designed to fit into most cordless power surgical orthopedic instruments, or they can be customized to accommodate new products. Qualified to function after more than 1000 steam autoclave cycles, the sterilizable modules are suitable for use with three-phase brushless dc motors and have pulse-width-modulation power control. The 8- to 18-V dc units can survive current peaks up to 70 A in both forward and reverse directions. Rated for 800 W, the modules' electronics have full wave rectification and an ergonomically designed brake function.
StrenuMed Inc.
Ventura, CA
www.strenumed.com

Brush gearmotors
u9eb_62740.jpgDesigned for motorization of peristaltic positive-displacement pumps, a series of peristaltic pump gearmotors is suitable for liquid transporting, dosing, and ultrafiltration in such applications as dialysis machines. The motors can withstand the cyclical requirements of peristaltic pumps, developing significant torque at a relatively low operating rate and ensuring long service life and quiet operation. Capable of translating specific pump requirements into torque, speed, and current, the motors provide the response needed for peristaltic pumps to achieve the desired flow rate and pressure. Available in 16- and 30-W models, the motors feature a gearbox torque of 0.5 Nom nominal and an operating voltage of 24 V. The 16-W version is also available with an operating voltage of 12 V. A variety of gear ratios from 12.80 to 104 can create output speeds from 46 to 455 rpm. Encoders producing from 1 to 48 pulses are also available on some versions for controlling pump flow rate.
Crouzet North America
Vista, CA
www.crouzet-usa.com

Motion control technology
ua69_62739.jpgSuitable for use with step motors, motion controllers prevent the loss of synchronization caused by transient or continued overload, extreme acceleration or deceleration, or excessive slew speed. MDrive AccuStep systems perform a range of motion control applications, including point-to-point positioning, conveyor control, web handling, drilling, rotary and linear positioning to torque specifications, and low-end camming. In addition, by enabling variable current control, they can reduce motor heating and energy consumption. A model integrated with a step motor, microstepping driver, and internal encoder controls step, torque, and speed; a version integrated with a fully programmable motion controller, step motor, microstepping driver, and internal encoder controls motion.
Intelligent Motion Systems Inc.
Marlborough, CT
www.imshome.com

Magnetic hysteresis brakes and clutches
ua0a_62742.jpgA series of magnetic hysteresis brakes and clutches has a variety of features, including ball bearings or tapered roller bearings for overhung loads, a special clamping arrangement for easy disassembly and interchangeability, and a hysteresis disk that has been heat treated and ground to prolong service lifetime. Available with numerous shaft diameters and lengths, Magtork-series brakes and clutches are offered with torque capacities of 25, 50, 70, and 140 in.-lb. The 50-in.-lb unit is available with bores ranging in size from 38 to 1 in., and the 140-in.-lb unit is available with bores ranging in size from 58 to 1 in.
Magnetic Technologies Ltd.
Oxford, MA
www.magnetictech.com

Microstepping drive
ua89_62741.jpgIntended for applications requiring high-torque and high-speed stepping motors, a pulse-width-modulation stepping motor drive takes step-and-direction inputs and delivers up to 12 A of peak current in each winding of two-phase stepping motors. The 330-V HVS-series microstepping drive features insulated gate bipolar transistor H-bridge construction. It also contains a variable supply in the front end and an H-bridge amplifier with a recirculating-current scheme on the motor driver side. The voltage to the driver is adjusted to compensate for the motor back’s electromotive force voltage loss and the current-charging requirement, which is based on the speed, motor size, and the current of the winding. The drive reduces motor heating caused by hysteresis and eddy current losses while increasing the speed torque curve over conventional motor drivers, according to the manufacturer. With a self-contained power supply, the drive is suitable for use with NEMA 42– and NEMA 65–size motors. It accommodates a variety of motors producing 1000 to 8000 in.-oz. of torque.
Precision Motion Controls
San Jose
www.premotn.com

Brushless dc servomotors
ua2b_62743.jpgA series of brushless dc servomotors is based on a four-pole design that ensures continuous torque of up to 12.2 mN•m and an n/M-characteristic curve with a flat gradient. Faulhaber BX4 servomotors run smoothly, have low noise levels, and feature electronically commutated drives, which last longer than mechanically commutated drives, according to the manufacturer. While the commutation in the basic model is provided via an external controller, enhanced models are equipped with an integrated speed controller or an integrated encoder. The encoder version is available with four different preset resolutions of 32, 64, 128, and 256 quadrature impulses per revolution. Enhanced models are also available with an optional line driver and a differential output signal.MicroMo Electronics Inc.
Clearwater, FL
www.micromo.com

For more information on motors and motion control technologies, including additional suppliers, visit www.devicelink.com/mpmn/motors.
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