Your Nanotec Stepper Motor Full Service Supplier

 

It’s not often people come across a supplier that goes above and beyond to deliver value added services that support customer needs from start to finish.

In fact, when it comes to automation controls and drive suppliers, it seems like the majority offer limited assistance; leaving you as the client to spend additional time and costs researching answers, identifying additional support or making purchases that ultimately don’t meet your project requirements.

As a full service supplier, All Drives and Controls’ ethos focuses on creating long term competitiveness with customers, by becoming a partner that delivers services and support before and after your manufacturing or automation ventures… all within an acceptable cost.

One area of expertise that All Drives and Controls prove their commitment to service is with Nanotec Stepper Motors.

As full service suppliers for Nanotec Stepper Motors and distribution partners, All Drives and Controls provide reliable support for the implementation of drive solutions, based on Nanotec high performance stepper motors and innovative controls.

Yet, how do All Drives and Controls demonstrate value added service as full service suppliers for Nanotec stepper motors?

Let’s consider some examples of support that you too can access as valued customers…

Examples of Full Service Supplier Support for Nanotec Stepper Motors

Nanotec Stepper Motor Issue: There is a need to match a stepper motor with an existing machine for product development purposes, however the only thing known about the motor required is the mounting hole pitch – 70mm mounting and 14mm shaft. The matched stepper motor drive card needs to run with PWM from the PLC.

Full Service Supplier Response: The motor required is a NEMA34 with torque range from 3.5Nm to 12Nm. Quotes for each torque version and range data was provided, including necessary parts that are required regardless of motor selection.

A recommendation of the 72V version was offered based on the best version and cost for the drive voltage needed.

Nanotec Stepper Motor Issue: Stepper motor stops rotating around 139Hz with the 24Vdc PSU that’s running. What RPM would be obtained from a 36Vdc?

Full Service Supplier Response: All stepper motors have a start stop limit value, where the stepper motor can start from zero without stalling or stop without losing position; the value ranges from 30 to 150 RPM depending on the motor size and rotor inertia.

Assuming the 139 Hz is from standstill with a 1.8 degree full step resolution, the RPM would equate to 41.

The customer was provided with the speed torque curve for the motor to get around 800-1000 RPM with a usable torque of 1Nm. Advice was provided to build in an acceleration ramp when using the motor from zero speed.

Nanotec Stepper Motor Issue: The datasheet on the Nanotec website doesn’t have a figure for the voltage to be applied when operating in the Serial Bipolar mode. There are some torque curves for the motor family which imply 24V-48V – is this too high?

Full Service Supplier Response: Currents for stepper motor devices are controlled by the driver. In the past, stepper motor voltage is typically 2-3Vdc, which is the minimum phase voltage required.

As stepper motors increase in speed, the generated back-EMF opposes the supply, requiring the supply voltage to be greater than the back-EMF +3V. In a 24V system, the available voltage to drive the current is 21V [Minimum phase voltage minus back-EMF].  Motors are operated with far higher voltages today via modern constant current controlled controllers in order to reach higher torques at higher speeds. Therefore, for serial bipolar, the minimum voltage is 2 x the minimum phase voltage.

Further detailed data for constant voltage operation was also supplied to the customer.

Nanotec Stepper Motor Issue: 1. Are longer versions available for SMC connection cable and encoder connection cables. If not, can they be extended by a metre by soldering new ribbon cable?

  1. Should capacitor wiring be wired as shown in the SMC135 manual between terminals 5 and 6 on connector X5, but to all controllers?
  2. In the SMC135 manual, motor wiring appears to be wired to terminals 1-4 of X3 but doesn’t show the colour coding.
  3. When running cables through 2 energy chains, is a shielded cable necessary and what are the recommendations?

Full Service Supplier Response: 1. Versions longer than 500mm are not available as these normally go to a local junction box, then a controller. However, it is ok to extend SMC connection cables a maximum of 4 metres for the none line driver version.

  1. Capacitor wiring only needs to be fit at the output of the PSU.
  2. Black wire is A to pin 1. Green is A to pin 2. Red is B to pin 3. Blue is B to pin 4.
  3. As the motor wires have switching power, shielding is required for EMC radiation protection for other electronic parts. The motor is not affected by EMC.

Nanotec Stepper Motor Issue: Regarding sourcing a driver for a stepper motor; will the system work without an encoder, and can the step type be set by serial communication port?

Full Service Supplier Response: The system will work without an encoder. Stepper motors are an open loop system and encoders allow closed loop control.

Regarding the step type, operating in the clock direction mode enables the PLC to have full command. Additionally, real time can be used with C++ programming from Windows or Mac based supervisory systems. Nano J software can be downloaded free from Nanotec.

Nanotec Stepper Motor Issue: Is a suppression capacitor needed when running a system from a battery?

Full Service Supplier Response: Following direct communication from Nanotec Technical, the client was advised from All Drives and Controls to fit a capacitor even if using the system with a battery.

When reading through the list of queries and solutions for Nanotec stepper motor support, you may have noticed the extra assistance, advice and in-depth understanding of automation requirements provided by All Drives and Controls.

The sound solutions and advice provided by the engineers of All Drives and Controls are just a small part of the full service supplier support offered for Nanotec stepper motors.

By choosing All Drives and Controls for your Nanotec stepper motor supplies and advice, you can be sure that you are able to finalise a development that is completely ready for serial production, quickly and affordably.

Do you have a question regarding Nanotec stepper motors? As full service suppliers ready to go above and beyond, All Drives and Controls hold the answers.

To speak with our expert team, complete the contact form or call 01543 478887.

 

Reduce Cost and Wear with NEW Nanotec Plastic Planetary Gears

With the advancements in resins, polymers and manufacturing capabilities, plastic gear production is taking the automation industry by storm.

Innovative drive solution company, Nanotec Electronic GmbH & Co. KG, has recently introduced a new effective means of reducing cost, weight, noise and wear that all automation system integrators and mechanical engineers are eager to implement; Nanotec® New Plastic Planetary Gears.

Introducing Nanotec® Plastic Planetary Gears

Ideally suited for a range of automation applications from mobile service robotics to heavier duty applications, Nanotec® Plastic Planetary Gears are now delivering far more efficient transmissions due to their considerably lighter and quieter units compared to metal planetary gears.

Always eager to develop and manufacture the latest solutions for automation assembly and systems, Nanotec® has continually made sure that their gear range delivers excellent output torques, with planetary gears offering the highest torque at a comparable volume and the highest efficiency with a concentric shaft outlet.

Now the plastic planetary gears available to purchase through All Drives and Controls can provide even more benefits for BLDC and stepper motors.

Instant Benefits with Plastic Planetary Gears

With the precision designs required for drive and automation systems, efficiency is key. Design engineers that are utilising plastic planetary gears have seen instant benefits over traditional metal planetary gears with the elimination of metal powder production and smooth motion that minimises wear, improving durability and cutting total costs significantly.

The benefits of introducing Nanotec® Plastic Planetary Gears can’t be underestimated, and with a range of options to suit your application needs, engineers can be confident of increased advantages and much wider design opportunities;

Nanotec® GPLK Gears: With a size of just 42mm, the new GPLK plastic planetary gears make up a compact unit when in combination with Nanotec® BLDC motor DF45, weighing just 300g. This makes the plastic gear a great option for mobile applications with its nominal torque of 5 Nm and super light and compact size. Just think what you could achieve using this lighter GPLK plastic planetary gear compared to the heavier, restrictive metal option.

Nanotec® GPLEP Gears: Suitable for motor sizes of between 42mm and 86mm, these plastic planetary precision gears are equipped with reinforced output bearings that allows them to withstand high radial and axial loads, perfect for small driverless transport systems. This specific precision gear type ensures a straightforward, simple construction without separate drive wheel bearings.

Nanotec® GPLEF Gears: As a plastic flange gear, the Nanotec® GPLEF is a cost effective alternative to cycloidal or shaft gears. Suited to motor sizes between 56 and 86mm, the noise reduction and suppressed vibration aren’t the only benefit, as this lightweight plastic flange gear delivers an efficiency rating of 97%. Produced to comply with EN ISO 9409 to retain precision orientation of end effectors, the GPLEF flange gear can meet your requirements for swivel arms and rotary tables.

Exploit Nanotec® Plastic Planetary Gears for your Automation Design Project

If the use of plastic planetary gears is the solution you’ve been looking for better design flexibility, reduced noise, weight and higher efficiency then the advanced facilities and stronger polymers used by Nanotec® can provide you with the best options.

For support on the best plastic planetary gear for your application and appliance design, contact your Nanotec® trained suppliers at All Drives and Controls.

Is High Efficiency green energy a reality for small wind turbines?

With the world focus on renewable energy sources, going green is a political statement that can gain a company some kudos, but are they really “green” in the renewable sense of the word?

Wind Turbine Technology

For the wind industry, the challenge is to design wind turbines to harness the wind energy and generate electricity efficiently.

Wind turbines have increased in size from 25 kW to 2500 kW and greater, with the cost of the energy generated reduced by a factor >5 as the industry moved from the “green” fringe activity, to an acknowledged power generation industry.

The engineering base has developed to match machine size and volume, but many technical challenges remain to meet the energy goals outlined in various government directives.

Evolution of Wind Turbine Technology

The concept of a wind driven rotor is ancient, and electric motors for generation of electricity have been widely used in domestic and commercial areas. A wind turbine may look simple, but to produce an efficient, green, wind turbine that meets frequency, voltage, harmonic content, specifications for electricity generation operating unattended, maximise the available cut in wind speeds, which on exploitable sites, may range from <3 m/s to >11 m/s with turbulence and have effective gust management to survive gusts up to 70 m/s to compete economically with other energy sources, is a challenge.

A draft of the European Union’s plans for wind and solar energy has recently been leaked (Reuters), revealing EU intentions to quickly build wind turbines and solar terminals throughout member states.

Italy is to increase its on-shore wind farm capacity by 230 percent, Ireland by 130 percent, Spain by 74 percent, and Germany by 30 percent.

Design Drivers for Modern Technology

The main design drivers for current large capacity wind technology are:

Low and high wind sites; Grid compatibility; Acoustic performance; Aerodynamic performance; Visual impact; Low mass nacelle arrangements; Rotor technology with advanced composite engineering, design for offshore. erection and maintenance.

The return of development interest to new production lines for the size ranges most relevant to the land-based market, from 800 kW up to about 3 MW.  Of the other main drivers, larger rotor diameters (in relation to rated output power) have been introduced in order to enhance exploitation of low wind speed sites.

But is this design drive suitable for the lower generation capacity markets?

Small wind turbines.

Small wind turbines (SWTs) are used in two main areas:

‘Autonomous’ electrical systems not connected to any larger electrical system.

‘Distributed generation’, systems with small generators connected to a larger public distribution network.

The technology of small wind turbines is different from that used in large wind turbines, and affects all of the subsystems, the control and electrical systems, and significantly the design of the rotor and the generator.  Most of the SWTs existing on the market are machines that have developed in an almost ‘hand crafted’ way, with lower maturity compared to that achieved by large wind turbines. A large amount of development has been carried out on developing small rotor configuration of the type shown in fig 1, but limited work on the generator until now.

Autonomous and distributed generation using small wind turbines are attractive as the price of conventional electricity and fossil fuels is increasing in the developed world which has a high interest in green energy and the cost is a lower barrier to installation..

In many developing countries, millions of people live without access to electricity, SWT have a major impact on the quality of life enabling access to remote services and the internet through mobile phone technology.

However, the state of the art for small wind turbines is far from technological maturity and economical competitiveness.

SWTs have great potential to produce reliable machines.  IEC standards do exist for SWTs IEC61400-2 for design requirements however, development of the standards is required to produce more appropriate and simpler ways to display the results obtained, to the end users.

In developed countries the market for SWT is promising for grid and off-grid applications due to promotion policies such as capital cost buy-down, feed-in tariffs, net metering, and for developing countries because of the reduction in manufacturing costs and the increasing energy requierments.

Classification of SWT from 0 watts to 100kW generation

Rated power (kW)                  Rotor swept area (m2)                        Sub-category

Prated < 1 kW A                      < 4.9 m2                                              Pico wind

1 kW < Prated< 7 kW A          < 40 m2                                              Micro wind

7 kW < Prated< 50 kW           A < 200 m2                                         Mini wind

50 kW < Prated< 100 kW       A < 300 m2                             (No clear definition adopted yet)

Source: CIEMAT

Direct drive, a new technology for SWT

Direct drive wind generators simplify the nacelle system, increase reliability, increase efficiency and avoid gearbox issues.  The trend towards direct drive systems in the large wind generator systems has been evident for some years in producing technology that is lighter or more cost-effective than the conventional geared drive trains.  Although these developments continue, direct drive turbines have not, as yet, had a sizeable market share.  Most direct drive designs are based on permanent magnets generator (PMG) technology, using high-strength Neodymium magnets.

Magnetic Motori, a well know motor designer and manufacturer based in Italy, set out to develop a direct drive solution to meet the needs of a reliable and efficient power generation permanent magnet motor/generator for renewable energy applications and high efficiency drive systems in SWT.

Overload Capacity

It is a fact of wind generation that the power train components of a wind turbine, regardless of the generation capacity, are subject to highly irregular loading input from turbulent wind conditions.

Fatigue cycles experienced by the structural components can be significantly greater than for other rotating machines.  Consider that a large, modern wind turbine operates about 13 years in a design life of 20 years virtually unattended as does a SWT.

The HTQ was designed with high overload capacity to usefully exploit the momentary increase in wind speeds, (turbulence and gust management), and wave variations seen in wave power (wave power is distinct from the diurnal flux of tidal power and the steady gyre of ocean currents), applications.

This leads to a high conversion performance considering that this is highly dependent on the speed itself.

Size & Cooling

The presence of a flow of outside air or the availability of water, in wind and wave power generation, was designed to be used as the cooling medium. An efficient cooling system allows the size of the machines to be smaller with a better power to weight ratio, and reduces the related costs.

The gearless solution (commonly called gearless direct-drive) is justified by economic returns resulting from increased efficiency, reduction of drive gear components and improved mechanical reliability.

The HTQ high efficiency series is, internally, literally green due to the colour of the special enamel used to coat the copper used for the windings. Starting from basic principles and understanding the real world end application, Magnetic identified key problems associated with renewable power generation and the efficient conversion needed to supply the power to the local electricity supply system, size, cooling, overload capacity, sealing protection,  and electrical reliability.

Sealing

With motor sealing protection greater than or equal to IP54 is linked with an extended range of torque / power ratios available.

Electrical Reliability

To usefully extract the electrical energy generated, the HTQ series use multi pole (up to 22) rare earth neodymium iron boron magnets, the strongest and most affordable type of rare-earth magnet, having the highest coercivity and size ratio. Fitted into the rotor in a propriety method and completely enclosed in an epoxy protection coating, the mechanic and magnetic circuits are defined, controlled, and stable under all operating conditions.

And the reason for the green coating of the copper wire?

The potential acceleration and deceleration conditions experienced in renewable power generation rotor can create very high rates of change of voltage, (dV/dT), back emf, high frequency and high amplitude harmonics etc. In the stator windings, and in normal enamels these conditions can electrically breakdown the enamel, leading to premature electrical failure.

The proprietary copper coating used by magnetic in the HTQ series has high dV/dT withstand capability, high frequency permittivity/dielectric isolation characteristics, linked with a high temperature rating class H for inverter applications, with double vacuum impregnation through autoclave with class H resins.

These characteristics ensure the motors have a very high resistance to transient spikes, high frequencies, and short rise time pulses.

And used as a motor, the same properties are required for inverter drive systems.

And the colour happens to be green.

Added Value Magnetic R&D

Market growths rates for wind generation are in the same range as those of high-tech technologies (internet, mobile phones and so on) with most of the top ten manufacturers being European.

There is a misconception to consider wind energy as a mature technology and R&D efforts is not required. Magnetic are continuing the development of the HTQ range and as a result, power generation capability up to 50kW are now available as standard with larger powers in preliminary design.

The European target is 20 per cent of energy production from renewable sources. In its recently published Strategic Research Agenda, the European wind energy platform, TPWind, proposed an ambitious, and feasible, vision for Europe. In this vision, 300 GW of wind energy capacity would be delivered by 2030, representing up to 28 per cent of EU electricity consumption. To implement this, an average 10 to 15 GW of additional renewable green capacity must be manufactured, delivered and implemented every year in Europe. This is equivalent to more than 20 large turbines of 3 MW being installed each working day, or a large number of SWT.

Thus in the use of the turbulent conditions and overcoming the severity of the fatigue environment, small wind turbine technology has a unique technical identity and unique R&D demands that magnetic has overcome with the HTQ series.

Summary

Going green is not an easy option, but the benefits to the industry the HTQ series can offer, in truly green renewable energy power generation, have been demonstrated. The conversion efficiencies greater than 80% are now posiable with the HTQ range. With cut in wind speeds and rotor speed close to zero, (depending on the rotor design) the HTQ is capable of generating useful amounts of energy from a wide range of climatic conditions.

Magnetic believes that high efficiency green energy is a reality when you use the HTQ series.

Light weight aluminium construction, hollow and shaft versions, available in a wider range of torque/RPM combinations, the Magnetic HTQ series fits most applications. If you need further technical information to find a suitable HTQ generator/motor for your application or a larger, that is up to1250mm diameter, contact:

 

 

Alldrives & Controls the UK representative for Magnetics Italy.

Nanotec® Stepper Motors – Powering the Cogs of Your Imagination

Screen Shot 2016-03-07 at 10.25.39

Are motors boring? Well we don’t think so, obviously.  But if when you think of motors all you visualise are washing machines, production lines or the circuit boards that you built at school then think again.

Mechatronics has advanced amazingly in recent times.  Think of the development of the printer. Originally only in black and white now we have full colour 3D printing and the endless possibilities that entails.  Advanced technology encasing some simple but very clever motors.

This mixing of the sciences with the arts is exactly what accelerates the advancements in technology – opening up new possibilities previously unimaginable.

A beautiful example of art meeting basic motor mechanics can be seen in the Corpus Clock at Corpus Christi College, Cambridge.  This public work of art is a mechanical time piece employing the minds of engineers, sculptors and jewellers working with gold, silver and neon lights in its creation.  But what’s at the heart of it, winding the mechanism and making the whole time-piece possible? – A  electric motor.

Using Motors in Art

At the opposite end of the spectrum both decoratively and mechanically is Richard Downing’s Fractal Clock.  This stunning paradigm of minimalist design uses more than eighty motors to control the precise movements of suspended triangles of slate.  The triangles themselves orbit and therefore the visual appearance of the clock changes depending on the time and your viewpoint of the installation.  And it’s the Nanotec® stepper motor that makes it possible.

V350-TL-WHTSC3518

However the adaptability and ease of use of the Nanotec® stepper motor means that you don’t have to have a degree in mechanical engineering to use them.  Nanotec® stepper motors are now so accessible and competitively priced that they are playing an increasingly bigger part within traditionally artistic environments.

It is the simplicity and versatility of a perfectly engineered motor such as the Nanotec® stepper motor that makes it the perfect choice for an inconceivable amount of applications. 

The Nanotec® stepper motors are simple to use and are easy to digitally control even with control panels or computers.  They have few parts so are mechanically reliable.  Of all the different motor types stepper motors have the highest torque in the low speed range and have extremely precise positioning making them perfect for repeatable movements.

Artists, university enterprises and even schools are benefiting from the additional innovation opportunities that using stepper motors offers.  Whether you’re doing scenography, robotics or animation, setting up an art installation, set design or lighting imagine how much more engaging it would be if it moved!

If you feel at a loss as to where to start, don’t worry, you’re not alone.  Firstly, the Nanotec® Company has the same creative ethos.  Their skilled employees focus their innovative abilities on research and advancing new developments to produce quality, competitively priced products.  Combine that with our dedicated, hands-on team at All Drives and Controls and you’ll be able to make your creative dreams a reality.

If you’d like to see just what level of support we give then take a closer look at the Fractal Clock mentioned earlier.  Yes, we helped with that.

So, just how creative can a stepper motor be?  We don’t know…yet.

Let your imagination run wild and let the creativity flow.  Challenge our team at All Drives and Controls and, with Nanotec® stepper motors, together we will make it happen.

Discuss your ideas with our friendly team here.

 

 

From 3D Printing to Packaging

Nanotec Stepper Motors are Making it Happen

Precision, efficiency and reliability. Our expectations for technology and its capabilities continue to rise with every new development.

Just take the technological advances with robotics. Industrial packaging machines sort, wrap, seal and box hundreds of products per minute. 3D printers create precise components from air ducts to bio-printed ears. Increasingly complex parts are meticulously manufactured by CNC machines.

Yet behind these amazing developments hides a seemingly simplistic device that makes this precision and accuracy possible. The stepper motor.

Stepper motors, such as produced by innovative company Nanotec®, enable drive systems to carry out precise increments of movements down to fractions of degrees. Its robust design, affordable cost and low noise make it the ideal partner for a range of applications, especially 3D printing technology.

Simplified Design, Straightforward Solution

As experts in the field, All Drives and Controls recommend Nanotec® stepper motors due to their ability to meet customer and industry needs. These robust motors effortlessly stand up to high demand with accuracy and a reassuringly long life span.

The well considered features of Nanotec® stepper motors happily match up to professional expectations and a variety of applications. With the option to be designed with or without the need for an open loop, life is made a little easier by negating the need for external encoders and simplifying the completion of drive systems; ensuring straightforward and cost effective solutions.

Featuring a high power to weight ratio, as well as high torque at low and zero speeds, Nanotec® stepper motors require no external braking system and boast high dynamic response. Their capability for high position accuracy instantly provide a great match for semiconductor, optics and pharmaceutical applications.

Unsure of your stepper motor torque requirement? Don’t worry. All Drives and Controls are keen to support you by providing drive torque calculations both static and dynamic.

With a wide range of stepper motor options available, it is reassuring to know that All Drives and Controls expert services remove the concern from the selection process by providing quality technical and mechanical advice; as well as assistance to determine the correct electrical controls and ancillary equipment. 

Taking Control with a Complete Support Package

Controllability of the Nanotec® stepper motors has been well considered with easily programmable controllers for speed and position, including options to use an external time base if required. With the choice for the motors to be configured to work like a servo system, it seems all possibilities have been covered.

Clearly, Nanotec® stepper motors complement any system requiring high torque at low speeds. The benefits go beyond its expert features by providing confidence in its durability within a range of environments as well as its ability to boost efficiency and performance.

With so many options, sizes and power outputs available, it can be difficult to determine which stepper motor will appropriately suit your environment or even if you need a bespoke customer-specific design. There is an easier way.

Simply contact2 All Drives and Controls and receive accurate advice on specifications and environments…whether you are sending the motor subsea or to outer space!

With All Drives and Controls you not only get the chance to purchase your stepper motor at low cost, but gain access to a whole package of support; from specification writing to system programming.

So with a great support network at your finger tips you can be certain whatever your requirements for an effective stepper motor, All Drives and Controls can supply them quickly and affordably.

Simply complete the request form with your part number (if known) or if you would like to benefit from All Drives and Controls expert knowledge regarding stepper motor selection, replacement or advice – just add your query to the form and await great customer service.

Resource: http://en.nanotec.com/

Motors for deep sea application

Motor Selection for Deep Sea Applications by Richard Halstead President Empire Magnetics, Inc.

Like few other hostile environments for industrial components, the deep sea is a forbidding place in which to launch a motion control application. Very cold temperatures, the corrosive effects of sea water and extremely high pressures (as much as 5,000 p.s.i. at 11,600 feet below the surface) combine to create an environment in which off-the-shelf components will quickly fail. Consider: in order to select a motor for deep sea operation, you must prevent water entry to the motor, assure that motor materials are resistant to corrosion, make allowances for material shrinkage (O-rings and other elastomeric materials compress in the depths), prevent water entry into electrical cables, account for power losses that occur over the 1,000+ ft. umbilical cable from the ship, and choose a filling oil whose thermal properties assure it is still a liquid at high pressures and low temperatures.

Magnetic Deep Sea Applications

Three current deep sea applications by Empire Magnetics make clear some of the problems and solutions in using motors undersea: * The Bedford Institute in Newfoundland, Canada is using waterproof stepper motors for research it is conducting in the Hudson River. The motors are required to operate at depths of 450 feet in very cold water, and are powered from aboard ship by means of an umbilical cable. Empire supplied a size 42 frame stepper motor with a stainless steel exterior, featuring an oil-filled motor and a piston pressure-compensated assembly. First specifying a depth of 200 feet, the initial motor design was used successfully at that depth. Now, the application requires operation at depths up to 450 feet, and the motor has been re-worked to meet their needs.

The Bedford Institute tests its equipment in a pressure vessel that can be used to test items at up to 5,000 p.s.i. While the previous model operated up to 1,000 p.s.i., the new model’s modifications will allow operation at much greater pressures. * Another deep sea application, at Woods Hole Oceanographic Institute (WHOI), Woods Hole, MA, is even more challenging. Requiring a stepper motor and brake assembly that would be submerged to a depth of 2,000 meters, WHOI specified a motor design for a new, unmanned remote undersea vehicle. The entire vehicle is oil-filled and pressure-compensated, and since it operates by remote control, the drive electronics are also carried in the vehicle.

To accomplish this goal, a stainless steel dry tank keeps the drive electronics at normal pressures, while the rest of the system is subject to the pressure generated 2,000 meters below the ocean surface. * The Scripps Institute in La Jolla, CA had a similar, but perhaps even more complicated problem. The Institute required motors to drive manned, undersea sleds, or ROVs. Among other complications, the motor assemblies had to provide a lot of power, but be very efficient, in order to maximize battery life.

On the other hand, the voltage had to be low, so there was no safety hazard to the divers. The system had to be lightweight enough that the divers could carry the ROVs across the beach; be rugged enough to take the pounding of the surf when the units were being launched and retrieved; be corrosion-resistant and tolerant of sand, sea life and other foreign materials; and be cost-effective, very reliable, fault-tolerant and redundant. The Scripps project is still a work-in-progress, but their current solution has been to experiment with battery-powered brushed DC motors. This technology meets most of the above requirements except for the reliability. A little water in the brush and commutator area of these motors, and it’s up to the diver to swim home. Scripps has tried to fill the DC motors with oil, but the oil gets between the brushes and the commutator, where the insulation properties of the oil causes problems.

Although it would be possible to use high voltage to break through the oil film, the high voltage is a safety hazard for the divers. Empire and Scripps are continuing to research the use of brushless motors, but the electronic control package is expensive, fragile, not waterproof and bulky. Development of custom electronics is currently out of the reach of the Scripps’ budget. As science and industry continue to expand their reach to the depths of the oceans, new and challenging requirements for remote controls and automation will continue to appear. If you would like more information about motors for deep sea applications, or information on other types of motors for hostile environments, contact Empire Magnetics, Inc.,