Even though the economy is in the toilet and record-high energy prices persist, the market for low-voltage AC and DC motors seems to be holding its own. According to a study by ARC (arcweb.com), the worldwide market for low-power AC drives is expected to grow at a compounded annual growth rate of 8.9% over the next five years. The market surpassed $7 billion in 2007 and is forecasted to be nearly $11 billion in 2012, the study predicts.
“Emerging economies, such as those in the BRIC countries (Brazil, Russia, India and China) and Eastern Europe, helped propel this growth,” says Senior Analyst Himanshu Shah, principal author of the study. “The regional expansion was led by China, where real GDP grew robustly as exports and investments accelerated, and by India, where gains in domestic demand and particularly investment underpinned strong growth. Increasing consumer demand from the growing middle class in emerging economies, new infrastructures, a friendly financial environment for capital investments and a need for producing and saving energy were primary factors for huge market growth.”
Efficiency Is Key
Challenges for the motor and drive manufacturers are to increase the efficiency of a system. Efficiency improvements in motors and drives can have a large impact on energy consumption. Challenges include extending the application areas of variable-speed drives through reduction of power, electronic and control costs, integrating the drive and the driven load to maximize system efficiency and increasing the efficiency of the electrical drive itself.
For the end user, there are specific criteria to consider before matching the right drive with your applications. These include:
- Motor service application and duty cycle requirements
- Load inertia
- Starting requirements
- Speed range and regulation requirements
- Size limitations
- Driven equipment
- Natural frequency of system
- Tuning for hot response
- Critical speeds
- Torque characteristics
- Enclosure requirements
Other considerations that can affect your drive and motor selection when dealing with an existing facility include an inventory of which other drives and motors are in your plant. If an installation uses one particular brand throughout the facility, it is highly likely that management will stick with the brand, rather than upset the apple cart for the electricians and technicians who service the equipment and will have to be retrained at a significant cost to management.
There also is a trend toward drive and motor combinations that are half the size of classic servo drives, toward motors that reduce wiring costs and toward cabinets that are much smaller than previous products.
|DRIVE + MOTOR
STM space-saving stepper drive and motor unit features advanced current control, anti-resonance technology, torque ripple smooth and microstep emulation for use in a variety of automation applications in motion control. It comes standard with protection against over and under voltage, over-temperature, motor shorts and motor open phase. The unit is RoHS compliant and CE certified. STM is available in lengths of 92.4 mm with an output torque of up to 125 oz-in. or 114.4 mm with an outp ut torque of up to 245 oz-in. They provide three digital inputs, one digital output and one analog output. Users can choose from an RS232/485 communication interface and an optional encoder that is integrated to the motor body without increasing the size of the unit. The encoder provides direct and stall prevention functionality.
Applied Motion Products
S120 AC drive uses a modular concept that separates power and intelligence. Freely selectable combinations of power sections and controllers allow a user to select the right controller, dictated by the builder’s current needs, but to protect the drive investments in circumstances where the application changes. Drives are available in single-phase 230 V in the power range of 0.25–1 hp, and three phase 460 V in the power range of 0.5–400 hp. The power modules are available in compact block construction (0.25–125 hp) or as chassis units (150–400 hp).
Siemens Energy & Automation
Telemecanique brand Altivar 21 small footprint AC drive is designed for HVAC pump and fan applications. Its design optimizes the diode bridge and capacitance to provide effective harmonic mitigation without using additional line reactors or DC chokes. The drive is environmentally friendly, conforming to RoHS and available in two voltage ranges: 1–40 hp at 200/240 V and 1–100 hp at 380/480 V.
|MOTION CONTROL SOLUTIONS
DSM324i motion controller now supports six Alpha HVi series servo modules for use in general machine automation. The servos are high-voltage models with AC voltage input range of 400–480 Vac and includes separately mounted shared power supply modules. This series extends the motor speed and torque rating for the company’s motion control products.
GE Fanuc Intelligent Platforms
InfraDrive Mi servo/control system has a motor casing that serves as the heat sink which is attached to the long axis of the motor, adding only a small amount to the cross-sectional profile. This results in up to 30% less area required compared to other integrated systems where the electronics are fitted behind the motor, and over 50% less total space compared to a traditional servo system with separate motor and drive packages. A single cable carries both power and SERCOS communications. When several IndraDrive Mi systems are connected in series, the wiring costs are reduced further. All connections, as well as the IndraDrive Mi itself, are rated to protection class IP65.
|ETHERNET POWERLINK ENABLED
Compax3 digital servo drives have been enabled with Ethernet Powerlink (EPL) motionbus technology. Ethernet Powerlink is a high-speed, digital motionbus solution connecting a motion controller to multiple drives and I/O points using standard Ethernet networking hardware. This centralized, real-time communication system for automation and control makes Ethernet deterministic for real-time industrial applications and decreases installation time for machine builders.
Parker Electromechanical Automation
Movitrac LTE B frequency inverter is designed to simplify control of asynchronous motors. It is available in three sizes and with either a standard IP20 or rugged IP55/NEMA 12k housing. Designed for 15 hp for NEMA 1 units and 10 hp for NEMA 12 units, the inverters include a remote keypad to remotely control operation and diagnostics, while a copy stick makes it easy to copy parameters from one drive unit into another for fast machine setup. The onboard S-bus is compatible with SEW’s gateway fieldbus devices for DeviceNet, Profibus, EtherNet/IP and Profinet.
Dodge Quantis Gold C-face energy efficient gearmotors are available in pre-selected motor and gearbox combinations up to 100 hp. Both Quantis ILH (in-line helical) and RHB reducers (right angle helical bevel) have NEMA clamp-collar design, foot mounted housing configurations, standard inch output shafts, nitrile input and output lip seals, A1 mounting and Mobilgear 600 XP 220 oil. The motors run at 1800 rpm, 60 Hz, with voltages ranging 230–460 V, are inverter-capable and are suited for use on inverter drives in both variable torque and 20:1 constant torque applications.
|FAST MACHINE BUILDING
ACS350 R4-frame general machinery drives are designed and built to make it easy for volume machine builders to increase average throughput time via an average two-second programming time per unit. Ratings range from 20–25 hp at 480 V. The units are RoHS compliant, with coated boards, and are suited for a range of machinery applications in the food processing, material handling, textiles, printing, rubber and plastics, semiconductor, automotive and woodworking industries. The 25 hp units are 7.13 in. long, 6.65 in. deep and 10.24 in. wide. These measurements make it easy to arrange cable tunnels in straight runs to power the units and control motors.
Line of AC drives includes the 3G3JX series for simple applications and offers V/Hz control; the compact 3G3MX for side-by-side mounting offers open loop control; and the 3G3RX provides both open- and closed-loop control. All drives were designed to be easy to install and maintain for fast commissioning.
IronHorse general-purpose AC motor line includes rolled steel and cast iron styles. Available up to 300 hp, all motors have a base speed of 1800 rpm and are electrically reversible. The MTR series 56C frame motors, in 1/3–2 hp sizes, are housed in rolled steel, totally enclosed fan cooled (TEFC) enclosures. Three-phase industrial duty MTC series motors are T frame TEFC units available in 1–300 hp sizes, featuring ribbed cast iron frames to ensure maximum cooling.
MDrivePlus QuickStarter kits aid rapid design by bundling any of more than 156,000 MDrivePlus products built to specification and shipped in less than one week for products with standard lead times, with a single sheet instruction guide, software/manuals CD and connecting cabling including communications converter and protype development cables.
Intelligent Motion Systems
8LT series three-phase synchronous motors, for machine and system manufacturers, are available in two sizes. They’re also available with self-cooled or externally-cooled options. The supply voltage of the high-torque motors ranges from 400–480 Vac. With a rated power of 0.11–21 kW, the motors can be integrated in a range of applications. The motors have a high power rating with a stall torque of 50–900 Nm.
B&R Industrial Automation
RBK RoHS-compliant two-phase bipolar stepping motor and drive package with DC input divides the basic 1.8 in. step angle up to 128 microsteps (0.018° step angle) in 16 selectable resolutions using built-in switches located in the driver. The third-harmonic-suppression function reduces step motor torque vibrations by connecting or shaping the driver current waveforms, especially at low motor shaft speeds.
Oriental Motor USA
|AC MOTOR SPEED CONTROLS
Pacesetter Models 2994 and 2998, three-phase AC motor speed controls drive 230 Vac, 50/60 Hz, inverter-duty, gearmotors and motors ranging 1/8–1 hp. Both operate from single-phase 115 or 208/230 Vac. Model 2994 is NEMA4X/IP 65-rated and Model 2998 is NEMA1/IP 40-rated for basic protection in packaging and conveyor systems.
Cartridge DDR direct-drive rotary servomotors are available in five frame sizes from 4.25 in. square to 13.78 in. square with four stack lengths per frame. The motors feature pre-engineered components, an integrated, factory-aligned high-resolution feedback device and a bearingless design that facilitates maintenance-free mount-and-run operation in less than 30 minutes.
AM3500 series servo motors have a high moment of inertia suited for machine tool axis with stringent synchronization requirements. They can eliminate a gear box in high-inertia applications such as rotary tables. Motors are available with flange sizes 3 to 6, torques between 1.9 and 15 Nm and rated speeds of 3,000–6,000 rpm. Resolvers or absolute encoders (single or multi-turn) are available as a feedback system. The standard protection class is IP64 with IP65/67 optional. Motors are CE-, UL- and CSA-listed.
|INTEGRATED MOTION SOLUTION
TL-Series (TLY) servo motors have motor enhancements such as robust connectors, grounding and shielding enhancements, RoHS compliance as well as brake leads incorporated into the power connector (brake versions only). The motors can be combined with Kinetix 2000 servo drive and CompactLogix programmable automation controller to provide an integrated motion solution for small and mid-sized OEMs.
CFW-11 frequency inverter has an optimal flux feature that minimizes losses in TEFC induction motors used with constant and variable-torque loads, especially at low speeds when motor ventilation systems are inefficient. Features include high-level language programming based on IEC 61131-3 to configure applications, flash memory card for storing parameters/software, and safety stop in compliance with EN954-1 Cat III.
WEG Electric Motors
Sigma Series AC servo system is rated at 5,310 in.-lb peak torque and up to 500 rpm maximum without gearboxes for semiconductor, material handling, high-speed assembly and packaging/processing lines. Direct Drive SGMCS servo motors include six frame sizes and 17 models from 15 in.-lb peak in a 135-mm-diameter package to 5,310 in.-lb peak torque in a 360 mm diameter.
Yaskawa Electric America
|DRIVE IN A BOX
SMVector drive is available with a NEMA 4X (IP65) enclosure. NEMA 4X options are available to 3 hp for food and beverage applications, where dust, water and corrosion are present. With a power range to 25 hp, the drive offers four modes of operation, high starting torque, auto-tuning and dynamic speed regulation.
|EASY TO COMMISSION
VTL variable-frequency drive lets users connect the motor and power cables, turn the control knob and watch the motor speed change. It’s a general-purpose drive designed for out-of-the-box, plug-and-play control of AC motors up to 3 hp. The drive provides IP20 protection, even without the terminal cover.
|DIGITAL SERVO DRIVE
Didge digital servo drive is available in three models that provide up to 6 A continuous output power and 12 A peak power in a metal, non-ventilated industrial assembly. It operates in current, velocity, position or advanced position modes for AC/DC brushless or brush motors, linear motors or voice coils. It operates in trapezoidal or sinusoidal commutation with vector control as a stand-alone unit or as part of a distributed multi-axis system in a real-time network.
Elmo Motion Control
|DRIVE CUT COSTS
SM2 Series Flux Vector drive offers a power range to 25 hp for environments where inverter technology was considered too costly, including packaging machinery, food processing machinery, material handling/conveying systems and HVAC systems. It offers four modes of operation (V/Hz, Enhanced V/Hz, Vector speed, and torque).
IGF servo controller/drive, in NEMA 11, 17 and 23 frame sizes, offers high torque, direct drive servo motors, a DIN-rail mounting, seven TTL level I/O (optional 24 V), RS232/485 serial interface, ASCII/Modbus protocol and memory for several thousand lines of programming. The IGF comes with a built-in regenerative braking circuit, single connector to motor, an on/off switch and status LEDs.
SM2315DT SmartMotor has an eight-pole compact rotor design with higher copper filling factor compared to conventional techniques for more energy density, better efficiency and more torque in the same physical size. It delivers 112 oz-in. peak torque and 57 oz-in. continuous torque with a maximum speed of 4,700 rpm, and features standard NEMA 23 frame dimensions.
ULT Series direct-drive frameless motors are available in sizes down to 27-mm diameter with axial length as short as 8 mm and up to 20 mm through hole. Motors operate from traditional three-phase trapezoidal or sinusoidal motor controllers ranging from 12–320 Vdc and can achieve speeds to 10,000 rpm. Hall devices and special cable/connector options are available.
|MINIATURE DC DRIVE SYSTEM
Series 122 SR DC micro motor has an external motor-diameter of 12 mm and length of 24 mm. A combination of the System Faulhaber ironless rotor and Neodymium rare earth magnets achieve a stall torque of 5.43 mNm and speeds to 13,800 rpm. The precious metal commutation allows operation at low starting voltages due to inherent low contact resistance.
|INTELLIGENT PLUG-IN SERVO DRIVE
PIM2403 intelligent plug-in servo drive reduces the time needed to assemble a machine by using simple pins without the cables. PIM2043 controls DC, brushless, linear and step motors to 75 W (24 V, 3 A) and embeds motion control, drive and PLC functionalities in one open frame unit. The drive is programmable using EasyMotion Studio software.
This line of planetary brush and brushless gearmotors is designed for applications requiring high torque and speed reduction in ratios 3:1 to 3,729:1. These 22-to-56-mm diameter gearmotors can be supplied with 3-36 V dc motors, plastic, powder metal, or cut metal gears and 2/3 channel quadrature optical encoders. Designed for input speeds to 6,000 rpm continuous, rated torque is 392.0 kg-cm, and max torque typically is three times rated torque.
BRUSHLESS DC MOTORS