Brushless dc motors run fast and quiet

NEMA DIN34 series brushless dc motors are available in three standard frame lengths of 2.0, 2.6, and 3.2- in. with rear shaft extension as a provision for encoder mounting. The 3.4-in. diameter motors offer the benefits of brushless dc technology with operating speeds of 6,000 to 18,000 RPM, with continuous stall (and peak) torque ratings of 50 (120 peak), 100 (250), and 135 (350) oz.-in. The typical “inside-out” brushless dc (BLDC) motor provides greater output power, higher operating speeds and cleaner, quieter operation than its brush-type counterparts. BLDC motors are ideal for sterile environments because there are no brushes and they discharge no particulates. Because of their inherent reliability and long-term service life, BLDC motors can significantly contribute to lower overall cost of operation and maintenance.

BEI Kimco Magnetics, 2470 Coral Street, Bldg. D, Vista, CA 92081, (760) 597-6335, www.info.hotims.com/18361-250

Small motors for portable devices

The Edge is a small, lightweight motor for use in devices that interface with the body, such as ultrasound wands, biopsy tools, and motorized tweezers. It requires low voltage, working from a 3.3V battery and operating at 8V. As a direct drive, Edge eliminates the need for mechanical parts required to transfer rotary motion to linear motion. The motor consumes no power at rest, thereby extending battery life of portable devices. By providing a high-force-per-motor area, Edge allows for either size reduction in devices or creates additional space for other device features.

Johnson Medtech, (800) 661-5707, www.info.hotims.com/18361-252

High-load motion control eliminates drag and wear

The VHD series anti-backlash assembly provides the maximum load-carrying capability and the highest axial and radial stiffness of any Kerk nut assembly. The standard VHD assembly is recommended for dynamic loads up to 350 lbs/1.5 kN. Designed for smooth, quiet operation and long life, the assembly provides low drag torque by using a patented axial take-up mechanism, creating a stiff spacer which continually expands to accommodate wear. The self-lubricating VHD also reduces vibration and noise. Because there are no recirculating balls and thread forms are uniform, the nuts move smoothly with low friction. Particle generation is said to be lower than ball screws.

Kerk Motion Products Inc., 1 Kerk Dr, Hollis, NH 03049, (603) 465-7227, www.info.hotims.com/18361-251

Noncontact solid-state encoders provide frictionless, zero-wear operation

OnAxis magnetic encoders bring high performance, tough construction, a simple mounting system, and small size to demanding motor control, shaft position, and velocity measurement applications for OEM manufacturers. The solid-state units feature a Hall sensor, ASIC epoxy-embedded inside a rugged metal housing to deliver high IP ratings, temperature range of -40 to 125C, and good resistance to shock, vibration, G forces, and pressures. The hard-body sealed encoders also deliver high EMC immunity when shielded according to installation instructions. Non-contact, frictionless, zero-wear operation delivers “fit and forget” reliability. The encoder integrates easily on electric motors and other shaft-drive devices. An ASIC/metal case can be mounted to motor backs or fit into a cast or machined hole, and it simply fastens down with two screws. Actuator magnets can be mounted onto or inset into the shaft. No adjustment is needed after mounting.

Renishaw Inc., 5277 Trillium Blvd, Hoffman Estates, IL 60192, (847) 286-9953, www.info.hotims.com/18361-253

16-bit input board offers high resolution, precise data acquisition

The M36N M-Module is an analog input mezzanine board that provides high resolution and precise data acquisition for analog signals found throughout automation, measuring, and simulation applications. Available in 16 or 18-bit versions, the M36N can be used as an I/O extension for CompactPCI, PCI, PXI, or VME embedded systems as well as on stand-alone single board computers. The module provides up to 16 single-pole grounded channels for voltage or current, or alternatively, eight channels for differential voltage or current. Each channel and input range is adjusted separately and is fully automatic giving users exceptional flexibility for specific data acquisition requirements.

MEN Micro Inc., 24 North Main St, Ambler, PA 19002, (215) 542-9575, www.info.hotims.com/18361-254

Stepper drives eliminate resonance

ST10-Si stepper drives deliver 24 to 80 Vdc with an output current of up to 10.0 A peak, and they protect against over-voltage, under-voltage, over-temp, and external output shorts. They provide 8 digital inputs and 4 digital outputs. The drives are programmable for stand-alone operation with Si Programmer Windows-based software. A graphical point-and-click format combines motion, I/O, and operator interface functionality for simple machine sequencing. As a result, these drives easily integrate with other devices on a machine such as sensors and PLCs. A disadvantage of step motors is their tendency to resonate at some frequency. Entering some system data lets the controller calculate this natural frequency and a damping term which is entered into the control algorithm. This is said to significantly improve midrange stability, while allowing higher speeds and more use of the available torque.

Applied Motion Products, 404 Westridge Dr., Watsonville, CA 95076, (800) 525-1609, www.info.hotims.com/18361-255