Practical and benefi-cial industrial appli-

cations for linear motion have increased dramati-cally in the past decade, just as the demand for overall machine reliabil-ity. In response to this demand, linear motion components must pro-vide accurate position-ing, high speed, and long life with low mainte-nance. Of the linear mo-tion technologies avail-able today, a relative newcomer — the inte-grated stepper motor lin-ear actuator — exceeds these requirements. This integrated product com-bines a stepper motor lin-ear actuator with mechan-ical and electronic com-ponents to form a single, compact system. It also de-livers the added benefits of reduced machine size, low-er cost and shorter time-to-market.

There are a number of linear motion technologies available to machine de-signers, each with advan-tages and disadvantages. Where machine cost is crit-ical, stepper motor-based linear motion solutions can significantly reduce system cost. For applications re-quiring high accuracy and repeatability, linear mo-tion systems with belts and pulleys or rack and pinion are unlikely to meet perfor-mance specifications. For clean and quiet operation, hydraulic and pneumatic systems are inappropriate. Mechanical linear motion technologies that provide high performance and reli-ability, clean operation and

low maintenance include: linear motor, linear slide with rotary motor, and step-per motor linear actuator.

A linear motor is es-sentially a stepper motor where the stator has been “unrolled” so that instead of producing torque (rotation) it produces linear force along its length. Linear motors al-low direct coupling to the load and deliver high per-formance, but at a compar-atively high cost. Pricing of a linear motor system must include costs for a complete “stage”, or enclosure, with linear bearings, limit switch-es, cable track/carrier, pro-tective bellows and linear encoder.

A linear slide consists of a frame-mounted car-riage that travels along a lead or ball screw. A rota-ry motor is mounted to one end of the frame where it is coupled to the screw that it turns to produce linear mo-tion. Advantages of this technology are accuracy and repeatability, with sup-port provided by the frame already in place. Disadvan-

tages are the high cost of components and locating or designing an adapter for the motor interface.

A stepper motor linear actuator uses a threaded shaft inserted in a nut that is integral to the motor’s rotor. Linear motion is produced by the rotation of the thread-ed shaft, which can be cou-pled to a load using a vari-ety of methods. Versatile, low cost stepper motor lin-ear actuators are available with different shaft styles, including:

Non-captive shaft style: the threaded shaft, ex-tending through the mo-tor, moves axially with the rotation of the nut integral to the motor’s rotor. External shaft style: the threaded shaft, integral to the motor’s rotor, ro-tates to move a shaft-mounted nut axially.

For a complete linear mo-tion system, each of the previous linear motion tech-nologies requires addition-al components including a compatible standalone con-

troller, drive, encoder and cabling. The step-per motor linear actu-ator, is one technolo-gy available with all of these components in-tegrated into a single, compact linear motion product not much larger than the linear actuator alone. In addition, the in-tegrated stepper motor linear actuator can sig-nificantly lower cost and complexity for many lin-ear motion systems.

In response to in-creased demand for smaller, low-cost ma-

chines, machine designers are trending toward motion component solutions with reduced size and price. In-tegrated motion control so-lutions — all-in-one rota-ry motor with drive and/or controller and encoder — represent a rapidly growing market segment that can deliver savings. And now the same benefits are avail-able with integrated stepper motor linear actuator sys-tems, which integrate linear motion mechanics with the motor and electronics.

Integrated motion con-trol products, both rotary and linear versions, reduce the factors that impact the cost of designing and man-ufacturing a machine which include:

Simplified design pro-cess and machine com-plexityEliminating the need to specify individual com-ponents shortens the de-sign cycle Fewer components in-crease ease of manufac-turability and decrease

Linear motion systems reduce size, cost, and time-to-market

The CANopen-connectable devices are available in Nema sizes (14, 17, 23)

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potential for assembly errorsReduced complexity eliminates potential fail-ure points: fewer compo-nents, less wiring Shorter time-to-marketResearch, procurement and interoperability test-ing of individual compo-nents is eliminated when using an integrated mo-tion solutionSmaller machine sizeCompact products with reduced footprint dra-matically reduce space requirementsIncreased machine reli-abilitySignificantly decreasing wiring in a machine mini-mizes the largest source of electrical noiseReduced field service saves time and money, and increases positive perception of machine qualityLower machine costReducing the number of machine components lowers costs for design, procurement and inven-toryInstallation cost savings include reduced man

hours, with fewer errors requiring troubleshootingSmaller machines lower transportation costs to end-users

Stepper motor linear actua-tors, with integrated motor, electronics and mechanics, can enhance linear motion application design. They achieve this by increasing machine reliability and per-formance while reducing the basic factors that impact the cost of designing and man-ufacturing a machine which include cost of components, cost of labor, time-to-mar-ket and field service. Indus-try demand for smaller, less expensive and more flexi-ble machines will continue to increase. Integrated step-per motor linear actuators represent a solution that is transforming linear motion design, while increasing the profitability of OEMs and system integrators.

For many years, Intelli-gent Motion Systems (IMS) has been developing and manufacturing linear motion controllers with CANopen interfaces. In 2008, IMS be-came a member of the Sch-neider Electric group. To

more strongly indicate this, as of January 2010 the com-pany has changed its name to Schneider Electric Motion USA.

The MDrive linear ac-tuators are available in two shaft styles: Non-captive shaft and External shaft

Two control options are available for these prod-ucts:

MDrive Plus — provides an all-in-one (motor, me-chanical, electronics) so-lution that will satisfy a wide range of linear mo-tion applications. MDrive Hybrid — for more demanding appli-cations. Hybrid Motion Technology adds benefitsthat include: preventing loss of synchronization (unintentional stalling), offering torque mode, saving energy and reduc-ing heat through variable current control, allowing use of a motor’s maxi-mum torque.

The CANopen-con-nectable devices are avail-able in Nema sizes (14, 17, and 23).

www.schneider-electric.us

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The Silversterling is an OEM servo controller/

driver for Quicksilver’s line of NEMA 11, 17, and 23 frame drives, but is also ca-pable of driving third par-ty DC brush and voice coil motors.

The product is avail-able open framed (QCI-S2-IG-01) and enclosed (QCI-S2-IG) and designed to servo QCI’s I-Grade mo-tors through a single 15-pin connector. The connec-tor includes four digital I/O, CAN, EIA-485, and pow-er input lines. The device also features a 60-pin head-er to allow simple and direct connection to expansion boards.

The CAN interface is not isolated, but does in-clude transceivers, which have an extended ±80-V fault protection range. The CANopen protocol allows the unit to function as a NMT master and a NMT slave.

www.quicksilvercontrols.com

Servo controller with CANopen

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Nord Drivesystems has extended its SK 500E

series of compact frequen-cy inverters for control cab-inet installation, adding the top-of-the-line model SK 540E, which features an integrated basic PLC func-tionality. Without the sup-port of an external control-ler, the CANopen-connect-able is able to control ap-plications with sequences and links to counters, com-parators and flags that are programmed in accordance with the IEC 61131-3 lan-guages using the PC-based Nord Con tool. The PLC pro-vides control for up to eight digital inputs, three digital outputs, two relays, two an-alog inputs and one analog output. The device may be used for applications such as the integration of moni-

toring functions into pump drives, enabling them to au-tonomously react to flow rate fluctuations. All operat-

ing data can also be trans-ferred to host controllers via the CANopen interface. The inverters are available in seven sizes and cover mo-tor ratings between 0,25 kW to 37 kW.

The CANopen inter-face module supports data rates up to 500 kbit/s (opti-nally up to 1 Mbit/s). The module provides CANopen status LEDs as specified in CiA 303-3. The conflict and error recognition func-tion enables data security. The CANopen module sup-ports the CiA 402 profile plus manufacturer-specific extensions. The four pre-configured TPDOs and four pre-configured RPDOs are not compliant to CiA 402. The TPDOs support event timer and inhibit time func-tionality.

Frequency inverters with PLC functionality

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The AC 3000 CAN modular switching power supply by AEG Power Solutions is a is a pre-wired unit with easily accessible connections lo-cated on the front panel. It is compactly built (19 inch) and lightweighted, with an out-put current of 100 A (24 VDC).It provides secured DC pow-er in combination with a par-allel battery, for supply of all types of DC consumers in-cluding constant voltage and current sources. The unit offers full functionality in stand-alone mode but can additionally be controlled and monitored via CAN. Other features are sinusoi-dal input current, low inrush current, temperature com-pensated battery charging. It is siutable for all industri-al applications.

www.aegps.com

CAN power supply

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You CAN get itHardware & software for CAN bus applications…

www.peak-system.com