Motors - Motion Control Tips

ISL customizable stepper motors for industrial automation applications

January 18, 2019 By Lisa Eitel Leave a Comment

ISL Products Intl. Ltd., leader in value-added manufacturing and engineering services for electronic/electromechanical components, now sells value-added hybrid, permanent magnet (PM) and variable-reluctance stepper motors which meet the exact positioning, holding torque, and repeatability specifications of the broadest array of automation designs. As stepper motors employ the theory of operation for magnets to make the motor shaft turn a precise distance when a pulse of electricity is supplied, they are appropriate in a broad range of high-precision motion control designs. ISL’s brushless stepper motors provide either rotary or linear motion and are controlled by an open-loop system (non-feedback system) to facilitate robust, economical, repeatable, and low-maintenance operation.

ISL’s stepper motors are delivered in frame sizes ranging from NEMA 8 to NEMA 52 (20 mm – 130 mm) and feature a 1.8° (two-phase) step angle. Additionally, 0.9° (two-phase) and 1.2° (three-phase) step angle configurations are available. To ensure OEM’s unique requirements are met, ISL engineers help identify the optimal stepper motor solutions for each application. Included among ISL’s stepper motor customization capabilities are those pertaining to brake, gearhead, torque density, voltage, output speed, encoder/driver, power, current, lead screw/ball screw (linear stepper), all-in-one driver/controller, step angle, phase and pole count, lead wire/connector, shaft configuration and material.

These customizable, value-added stepper motors are commonly used in industrial automation, retail and vending machines, robotics, dispensing machines, 3D printers, machine tools, manufacturing equipment, conveyor and fluid control systems, automated guided vehicles (AGV), packaging, and food processing equipment. They are also specified for ticketing, gambling, labelling, textile, and carving machinery, as well as CNC (Computer Numeric Control) machines and medical devices.

Pricing for ISL’s value-added hybrid, permanent magnetic (PM) and variable reluctance stepper motors is determined based on customer specifications. Samples are available upon request. For more information, visit islproducts.com.

ISL Products Limited offers a comprehensive portfolio of supply chain and logistics management services. For more than 40 years, design engineers and OEMs have relied on ISL’s world-wide engineering sales and support network to deliver innovative and cost-effective solutions to help accelerate time-to-market. Products include audio components, motor and mechanical components, ballasts and power supplies, potentiometers-transformers, cable assemblies, and connectors. The company maintains a network of US sales representatives and is headquartered in Syosset, N.Y.

NORD to unveil new trade show booth and drive products at IPPE

January 15, 2019 By MCTips Staff Leave a Comment

NORD Gear Corporation is attending the world’s largest annual poultry, meat and feed industry event, the International Production & Processing Expo (IPPE). There, NORD will be discussing cost-saving aluminum alloy drive systems for the food processing industry.

The event, held February 12 to 14 at Atlanta’s Georgia World Congress Center, attracts more than 30,000 visitors. Drive system experts from NORD will present high-efficiency overhead conveyor, screw conveyor, bevel and in-line gearmotor solutions at booth #8013. Highlights include:

NORD’s modular Screw Conveyor Package is ideal for food processors. This high-efficiency design eliminates the need for costly separate V-belt drives by providing integral gearmotors or direct-coupled motors to a NEMA C-face reducer. Minimizing parts and eliminating the need for top motor mounts, pulleys, belts or guards provides easier system maintenance, increased reliability, and superior drive performance.
NORD’s alternative to stainless steel gear reducers, motors and VFDs is a high-strength NSD TUPH aluminum alloy surface conversion. Ideal for poultry and meat processing companies, this breakthrough material has the superior washdown advantages of stainless steel – with 30 percent less cost. Plus, aluminum is lighter than stainless steel, and has superior heat transfer properties. Sample NSD TUPH materials are available at the NORD booth for testing.
Designed for the food and beverage industry applications, NORD’s overhead conveyor drives offer heavy-duty construction and high-quality machined components. With high efficiency and minimal maintenance requirements, the SK9055 and SK9155 have a low overall cost of ownership while providing reliable operation in food processing plants around the world. These overhead conveyor drives are designed with a mounting flange and output shaft that easily drop into industry-standard footprints. The gear units incorporate the standard NORD VL3 spread bearing design with a dry cavity.

For more information, visit www.nord.com.

How do gearmotors impact reflected mass inertia from the load?

January 10, 2019 By Miles Budimir Leave a Comment

In any drive system (that is, a motor driving a load), there is going to be inertia. Specifically, the motor will have inertia as will the load. For a direct drive system (a direct motor-to-load connection) the individual inertias can just be added together in a straightforward way. However, for any other type of setup involving some additional mechanical drive components such as couplings or gears, the relationship changes.

Pictorial representation of a drive system with gears. (Image via Omron Industrial Automation)

Specifically, when looking at how gears impact a drive system’s inertia, there are some basic ways to look at it. The basics; any gear will reduce the load inertia reflected to the motor by a factor of the square of the gear ratio. When looking at a gearmotor, this is basically just a motor with an embedded gearset in it, so the calculations and formulas for calculating inertia are the same.

In high performance motion control applications, it’s ideal for the reflected load inertia to equal the motor inertia. If inertia matching is the only concern, then the gear ratio can be calculated as:

N = √ (J_Load/ J _Motor)

where N is the gear ratio, J_Load is the inertia of the driven load, and J_Motor is the inertia of the motor.

Note: Another way to calculate gear ratio is by reference to the individual gears. For instance, if N_In is the number of gear teeth on the input gear and N_Out is the number of gear teeth on the output gear, the gear ratio is then:

N = N_Out / N_In

As for reflected inertia itself, this is best understood as the inertia of the load that is translated back to the motor through various drive components, in this case the gearing of the gearmotor.

So in a simple direct-drive system, the total inertia would be calculated like this:

J_Total = J_Load + J_Motor

However, for a geared drive system such as a gearmotor, the total inertia is calculated using the equation:

J_Total = ( J_Load / N² ) + J_Motor

This is because, as stated earlier, the reflected load inertia is equal to the load inertia divided by the square of the gear ratio.

JVL integrated motors now feature fast, easy setup for Rockwell Automation/Allen-Bradley PLCs

January 8, 2019 By Miles Budimir Leave a Comment

JVL has released Add-On-Instructions for its ServoStep integrated motors for fast and easy setup and programming in Rockwell Automation’s Studio 5000 software. It makes commissioning fast and easy and the motors can be set up in 5 minutes or less.

The motors have the ability to be upgraded with other protocols or newer versions of the same protocol at any time. Because of the upgradeability, the JVL industrial Ethernet interface is also ‘future proof’ as newer versions of the protocols will always fit into the design. The user can switch between Profinet, EtherCAT, Powerlink, EtherNet/IP, Modbus TCP and SERCOS.

The ServoStep integrated motors are all-in-one units featuring a motor, absolute multiturn encoder, drive, controller, a PLC and Ethernet Switch as well as TÜV-approved STO option. The integrated design with the controller in the motor minimizes the size of the control cabinet. With less components in the cabinet, the cooling requirements will be lower, reducing both system cost and running costs.

ServoStep motors offer state-of-the-art performance that in some applications can rival servo motors at a lower cost. The high torque at low speeds make compact solutions without gears possible. The ServoStep family offers up to double the power in the same size compared to similar motors, due to higher current/voltage and advanced regulation.

JVL’s closed-loop ServoStep technology eliminates loss of steps and never stalls. Ultra-high torque enables direct drive without gearing. The motor series also has current control, which lowers power consumption and allows 100% duty cycle without overheating. The ultra-high step resolution of 409,600 step/rev decreases acoustic noise and results in a smooth-running motor.

The wide speed range from 0 to 3,000 rpm can be adjusted in increments of 0.01 rpm. Due to automatic tuning, programming is fast and easy.

The motors have 8 programmable inputs/outputs; each can be set up as digital input, digital output or analog input. Motors are equipped with EtherNet/IP interface and options include STO (Safe Torque Off) versions.

The motors are perfect for multi-axis applications and format adjustments where high positioning speed is required. Due to ultra-high torque, no gear is needed. For end-of-line packaging and food and beverage applications enclosure class IP65 can be delivered. To fulfil the demands for diagnostics and easy maintenance in factories of the future the motors are designed for IIoT and are Industry 4.0 ready.

The motors include a 2-port Ethernet switch to reduce wiring in daisy-chain configuration (DLR). Several LEDs enable technicians and operators to get a quick status overview.

For more information, visit www.jvl.dk.

Voice coil motor with internal shaft and bearing features high force-to-size ratio

December 26, 2018 By Miles Budimir Leave a Comment

Moticont’s GVCM-051-025-01 Linear Voice Coil Motor features high acceleration/deceleration, high speed, high reliability, zero backlash, high accuracy, high repeatability, and a 0.5 in. (12.7 mm) stroke length. Also referred to as an electric cylinder, this linear actuator is a low cost, high accuracy replacement for hydraulic and pneumatic linear actuators. This clean, compact, voice coil motor has a high force to size ratio with 5.3 lb (23.5 N) continuous force and 16.7 lb (74.4 N) of peak force at 10% duty cycle with a housing measuring just 2.00 in. (50.8 mm) dia. x 1.00 in. (25.4 mm) long.

The precision ground 0.1572 in. (3.993 mm) diameter shaft has an internal thread, and the housing has threaded mounting holes on each end for easy integration into current and future applications. This clean, quiet, efficient, low inertia, brushless actuator featuring an internal shaft and recirculating ball bearing is suitable for: medical devices, antenna positioning, testing, sorting, assembly equipment, work holding and clamping, scanners and laser-beam steering and filtering, laser machining and drilling, wafer handling, optical focusing, and dynamic vibration absorption, among others. Moticont’s GVCM-051-025-01 linear voice coil motor can also be ordered as a complete plug-and-play system including a position sensor and controller.

Is there a need for a smaller or larger diameter motor, one with longer stroke, or more force? There are currently seven series of Moticont’s GVCM motors based on diameter of the motor, and models based on length of stroke and/or force to select from with additional motors being added to select from.

To find out more, visit www.moticont.com.

Premium-efficiency, cast-iron three-phase ac motors from AutomationDirect

December 18, 2018 By Miles Budimir Leave a Comment

IronHorse MTCP2 industrial duty motors meet the premium efficiency requirements of the Energy Independence and Security Act of 2007. MTCP2 motors are offered in T-Frame (1 to 300 hp) and TC-Frame/C-Face (1 to 30 hp). C-face kits are available for motors over 30 hp.

These motors are available in 1,200, 1,800, and 3,600 RPM and have TEFC (Totally Enclosed Fan Cooled) enclosures with cast-iron frame and ribbed design for maximum cooling. The motors feature full length, cast-iron mounting feet, steel fan cover, and cast-iron junction box with rubber gasket and rubber dust cover.

MTCP2 motors have premium quality ball bearings (1 to 75 hp) or roller bearings (100 to 300 hp) with maintenance free bearings on 10 hp and below. V-ring shaft seals are used on the drive end and opposite drive end. The motors are electrically reversible and have Class F winding insulation.

MTCP2-series motors start at $180.00, have a two-year warranty, and are CSA and CE approved. Available accessories include bases, junction boxes, fans and fan shrouds.

To learn more, visit www.automationdirect.com.

Internationally certified stepper motor for hazardous locations from Applied Motion Products

December 11, 2018 By Miles Budimir Leave a Comment

Applied Motion Products introduces a commercially available step motor internationally certified for use in hazardous locations throughout the USA, Canada, Europe, and the Middle East. Offering high-performance motion control in the challenging environments of oil, gas, printing, and paint finishing applications, the HX56-100 Hazardous Location Stepper Motor features:

ATEX and IECEx certifications for Class 1, Zone 1 locations
UL-Listed for Class 1, Division 1, Group C and D locations
Type 4X and IP66 rated enclosure

Class I hazardous locations are areas where flammable gases, vapors or liquids are, or may be, present in the air in quantities sufficient to produce explosive or ignitable mixtures. Zone 1, also known as Division 1, defines a hazardous location in which flammable gases, vapors or liquids exist all of the time or some of the time under normal operating conditions.

“The HX56-100 Hazardous Location Stepper Motor is the only step motor in the world certified internationally by UL, ATEX, and IECEx,” notes Jason Jones, Regional Sales Manager, Applied Motion Products. “By providing a best-in-class solution for motion control applications in hazardous locations worldwide, the HX56-100 Stepper Motor minimizes the cost and time involved with gaining regulatory compliance for an OEM’s complete system.”

The HX56-100 Stepper Motor is specifically designed for use with the STAC6-Q-H Stepper Drive, the first and only step motor drive internationally certified for use in hazardous locations. The STAC6-Q-H features an advanced anti-resonance algorithm that ensures optimal torque performance from the HX56-100 over a wide speed range. Microstepping ensures smooth, high-resolution positioning. The drive is capable of running stored programs created with Applied Motion’s Q programming language, and has sufficient input/output signals to connect to multiple external devices or sensors.

For more Information on the HX56-100 Hazardous Location Step motor, visit www.applied-motion.com.

The truth about VFDs and power factor

December 7, 2018 By Danielle Collins Leave a Comment

Power factor is essentially a measure of how effectively a piece of equipment (or an entire facility) uses electricity to produce useful work, such as heating, lighting, or motion. Electricity companies monitor power factor and often charge customers a penalty if their power factor falls below a specified threshold — typically 0.90 or higher.

Fortunately, most electrical loads in residential buildings are resistive (heating and lighting, for example) and have a high power factor, so consumers aren’t normally subjected to this metric. Industrial plants, on the other hand, typically have high inductive loads that significantly reduce their power factor. For example, AC induction motors — which are used for driving pumps, fans, compressors, and conveyors — have relatively low power factors, even when their capacity is put to full use. And when these motors are lightly loaded, their power factor drops even lower — sometimes approaching zero.

When an induction motor is heavily loaded (top), the voltage and current waveforms are nearly in-phase (small displacement), and power factor is high. When the motor is lightly loaded (bottom), the wave forms are out of phase (large displacement) and power factor is low.
Image credit: Yaskawa America

There are several methods of improving power factor in an industrial facility, but when the main culprits are induction motors — especially induction motors not operating at full load — applying variable frequency drives (VFDs) is often the best solution.

Recall that in an AC induction motor, power is supplied directly to the stator and a magnetic field is induced in the rotor. The power supplied to the stator is referred to as “real,” or “active” power because it produces torque. The power used to induce the magnetic field in the rotor is referred to as “reactive” power because it does not actively produce work. The combination of real power and reactive power is referred to as “apparent” power. Real, reactive, and apparent power are often depicted on a power triangle.

In an ideal system, power factor (PF_D) is the cosine of θ, which equals real power (P) divided by apparent power (S).

Note the subscript, D, in the power factor notation. In the power triangle, θ represents the displacement (phase difference) between voltage and current. Thus, this expression of power factor is often referred to specifically as the displacement power factor, PF_D.

For resistive loads, all (or nearly all) of the power used is real power that produces useful work — heat or light, for example. Therefore, current and voltage remain in phase (θ = 0), and the power factor is near unity (i.e., 1). But the reactive power required for inductive loads — to induce a magnetic field in a rotor, for example — tends to pull the current out of phase with the voltage (hence, a larger θ angle), causing a lower power factor.

The amount of real power required by an induction motor varies with the load, but the amount of reactive power (power required to generate the rotor’s magnetic field) is constant regardless of the load. Thus, when an induction motor is lightly loaded, the ratio of real power to apparent power decreases, resulting in a lower power factor.

Using VFDs to drive induction motors can improve power factor — but it’s not the panacea that some manufacturers suggest.

Variable frequency drives typically have very high PF_D values. This is because the DC bus capacitors supply the necessary reactive current to the motor for inducing the rotor’s magnetic field, and the AC supply line only has to supply real power. This means voltage and current remain almost perfectly in phase, with very little displacement, and the power factor can be at or near unity.

But VFDs also introduce harmonic current distortion. And because harmonic currents don’t produce useful work, they are reactive, thus negating some of the power factor benefits of the VFD.

To determine the true power factor, PF_T, which includes the effect of harmonic distortions, we use the equation:

THD = total harmonic current distortion

Fortunately, there are ways to reduce this VFD-induced harmonic distortion and minimize its effects on power factor. For VFDs that use a standard, diode-based rectifier, adding impedance via a line reactor or DC link choke will reduce THD.

Another option is to use an active front end (AFE) drive, which is a VFD that uses IGBTs, rather than diodes, to rectify the incoming AC power to DC. Active front end drives have significantly lower THD than standard diode-based rectifier designs. For example, and AFE drive typically has THD around 5 percent, where a standard VFD with a diode-based rectifier can have THD in the range of 45 percent.

Q: Why does the utility care how efficiently a plant or equipment uses the power it supplies?

A: Because low power factor causes higher line currents, which put more stress (primarily in the form of heat) on cables, transformers, and other equipment. Also, the lower the power factor, the more apparent power (kVA) the utility must supply to meet the real power (kW) requirements.

New ICs for step-motor control from Performance Motion Devices

December 6, 2018 By Lisa Eitel Leave a Comment

Performance Motion Devices now sells new Juno Step Motor Control Integrated Circuits (ICs) in a 56-pin VQFN package. The new Juno Step Motor Control IC is the latest addition to the Juno Velocity and Torque Control IC family … the industry’s first family of compact ICs with full four-quadrant motion control; direct input accepted from quadrature encoders; profile generation; and advanced current control.

Juno ICs are for designs with limited space that need to control noise, vibration, and power consumption. Juno ICs are also easy to deploy with embedded motion commands and onboard intelligence.

Performance Medical Devices recently released the Juno Velocity and Torque Control IC series — the industry’s first family of compact ICs with full four-quadrant motion control, direct input quadrature encoder, profile generation, and advanced current control.

The Juno Step Motor Control IC 56-pin VQFN package has the highest PWM frequencies offered by Performance Motion Devices and the smallest IC parts — measuring 7.2 x 7.2 mm. Juno Step Motor Control ICs are available both with encoder input and without.

The Juno Step Motor Control IC also comes with numerous safety features … including stall detection, over- and under-voltage sense, overcurrent detection, over-temperature, and i²t current foldback. Coupled with compact MOSFETs, the Juno Step Motor Control IC can replace older step motor amplifiers and dramatically reduce the size and heat output.

“Juno Step Motor Control ICs offer embedded motion and use a proprietary current control technique that results in ultra-smooth, quiet, and efficient motion of the step motor,” said Chuck Lewin, CEO of Performance Motion Devices.

“By driving step motors more quietly and rapidly, existing step motor-based systems can get a performance boost and avoid an expensive transition to a brushless dc motor. In short, this IC lets step-motor users upgrade the controls but keep the motor … and get a big jump in machine performance.”

The Juno IC family is suitable for a wide range of applications including precision liquid pumping, packaging and lab automation, pick and place machines, flow rate control, XYZ tables, and many other robotic, scientific, and industrial applications. For more information, visit www.pmdcorp.com/JunoIC.

Performance Motion Devices supplies high-performance integrated circuit, board, and drive-based motion control solutions to OEMs and contract manufactures around the globe. Its technology controls more than five million motors worldwide, providing motion solutions to some of the world’s largest manufacturers. If speed, efficiency, and reliability are top of mind, Performance Motion Devices has proven motion control technologies that can decrease development time.

Hygienic, stainless gearmotor designs improve fish-processing plant

December 6, 2018 By Miles Budimir Leave a Comment

Processing fresh fish necessitates a hygienic environment with regular washdowns, followed by frigid temperatures for freezing final products. That’s why machinery in such settings must be extremely rugged — and why one fish supplier has used motors from Bauer Gear Motor for the last few years.

Van Der Lee Seafish processes approximately 200 tons of fresh fish every week. Fish is subject to conveyor-driven sorting, filleting, breading, freezing, and packaging processes. Drives for these conveyors must meet strict food-industry hygiene requirements.

Building reliable processing lines for hygienic environments subject to -43° C temperatures is challenging. One fish supplier recently upgraded its conveyor drives to stainless-steel variants for top reliability. Its fish-processing lines can be reconfigured for different products.

“Product quality is paramount, so fish must be processed quickly and efficiently,” said technical director Willem Van der Lee. “We can have seven processing and five packaging lines operating at any given time, and each one employs many motors and drives. That necessitates spare parts be kept to minimize downtime should a breakdown occur.”

That’s why Van Der Lee Seafish standardized on Bauer’s gearmotors throughout its food-processing facility a few years ago. The AsepticDrive from Bauer Gear Motor (of Altra Industrial Motion Corp.) has a hygienic gearmotor design with smooth surfaces and no cooling fins that can promote bacteria accumulation. Standardizing on the gearmotor minimized spare-parts inventory. What’s more, the permanent magnet synchronous motors (PMSMs) have high energy efficiency, especially under partial load. Plus the synchronous nature of the PMSM motors maintains constant speed independent of load. That means as long as the mains frequency is held constant the motor speed doesn’t vary, even under overloading or voltage drops.

Standardizing on the AsepticDrive units improved overall food-processing facility energy efficiency.

The gearmotors delivered the promised level of performance on almost all counts. One exception was on some motors subject to mechanical damage from other equipment. On these units, degradation of the hygienic coating threatened to compromise the hygienic design. So for certain locations in the plant, Bauer engineers supplied a newer gearmotor — a stainless-steel HiflexDrive variation with maximum mechanical resilience and the ability to withstand harsh washdowns.

VFDs run the gearmotors to allow precise control of conveyor speeds.

“The AsepticDrive has let us trim spare-parts inventory, and the HiflexDrive in stainless steel is a direct replacement for running in frozen storage areas,” added Van der Lee.

Bauer’s HiflexDrive comes in a modular design allowing gearbox, electric motor, and external finish selection. Motors rated up to IE5, according to IEC TS 60034-30-2, offer top energy efficiency, while pairing with variable speed drives allows exact conveyor-speed setting. Including a PMSM in the drives reduces heat losses from the rotor by 100% and total losses by approximately 25% — plus boosts total efficiency by 10% or more. Such savings are significant especially for stainless-steel motor variations that dissipate heat less efficiently than those built with aluminum or cast-iron housings.

HiflexDrive system flexibility lends itself to the food and beverage industry. The stainless-steel construction eliminates hygiene risks posed by mechanical impacts or extended operation subject to rigorous cleaning. Ingress protection is to IP69K — a washdown designation for applications subject to high temperature and high-pressure water.

A new stainless-steel gearmotor variant is now employed where the fish processor needed maximum machinery ruggedness.

Flexible designs also mean Van der Lee Seafish can move its conveyors around to various areas and not worry about drive reliability. Stainless-steel HiflexDrive units ensure maximum productivity.