Motors & Drives Information

One of the UK's leading manufacturers of liquid filling machines, Masterfil, has turned to Moeller Electric's new variable-speed AC Optidrive to provide precision motor control for its latest oil filling machine. Destined for Shell International Petroleum's lubricant facility in Greece, Masterfil's innovative inline weigh filling machine is the first of many heading for the petrochemical industry, and features six Optidrives controlling conveyor and pump motors. Uniquely, thanks to the Optidrive's Optistore program, the company has set up a central database to store for each machine produced all the drive's motor control parameters.

This enables quick and easy reprogramming of the drives, wherever they are located around the world, thus helping to ensure Masterfil's leading position in after sales service.

Based in Aylesbury, Masterfil produces a wide variety of liquid filling solutions capable of handling volumes from 2ml to 1500 litre.

This range comprises: semiautomatic, automatic inline pneumatic and electric drive volumetric fillers, weigh fillers and drum emptying systems.

The company's products are widely applied in the pharmaceuticals, petrochemical, food processing and toiletries-cosmetics industries.

Masterfil's lubricant oil filling machine is designed to fill 20 litre plastic buckets with the four head unit achieving a rate of 420 buckets per hour or 6.7 per minute.
The optional six head filler gives even greater output rates.

The plastic pails are fed into the machine along a roller conveyor powered by two 0.37kW motors which are each controlled by an Optidrive.

In the filling area four weigh scale platforms rise up and place a bucket directly under the filling nozzle.

Each weigh scale platform is linked to an Avery Berkel weigh controller.

A PLC controls the raising of the platforms and signals the Avery weigh controller to tare or zero the readings for each pail prior to commencement of filling.

When the pails are tared the Avery weigh controller then signals the PLC to open the nozzles and start the four 3kW pumps, with each feeding one of the four nozzles.

The pump flow rate is determined by programming the Avery weigh controller with different weight zones in the bucket corresponding to a particular pump rate.

For example: the first kilogram of oil is filled slowly, the second zone, filling is at the fastest rate, the third zone nearing the 16.5kg weight limit, filling is slow, reaching this limit then triggers the pump to stop.

Pump control is achieved by the Avery weigh controller signalling the Optidrive through an I/O link and a series of relays.

The Optidrive is programmed to enable the motor to run at a preset slow and fast speed, with speed selection dependant on the input received from the weigh scale controller.

Neil Schneider, Masterfil's electrical design engineer said: "We export about 70% of our machines and after sales service is a crucial element in our success.

Optidrive's Optistore facility offers us distinct service advantages as each drives' parameters can be stored enabling us to easily reprogram the drives in customer's machines should anything go wrong.

This is done simply by downloading the customer's drive parameters in Optistore into the Optiwand.

Then using Optiwand a replacement drive can be programmed and sent to the customer.

Alternatively, a customer or service agent with Optistore and Optiwand could receive the drive's parameters over the net to reprogram the drive locally.

In addition, Optidrive's user-friendliness has helped us to significantly reduce machine development and production time".

Spanning a 0.3 to 90kW power range, Optidrive is available in both single and three-phase formats in five case sizes.

Ready-to-run, the drives have three programmable digital inputs, an analogue input that is selectable for volts or amps, a programmable relay output, and a programmable analogue output.

All that is needed for basic pump and fan operation is the setting of five basic parameters from the 14 standard that are available.

Optidrive has four preset speeds and an auto start function.

Other features include skip frequencies, spinning start, silent running in 32kHz mode and mains dip ride through.

AC drives are notoriously complicated to set-up, so user-friendliness was high on the list of priorities for the designers of Optidrive.

A 'quick' set-up menu using only the 14 standard parameters, with plain English descriptions, allows the user to quickly configure the Optidrive.

An extended menu with a further 26 parameters is available for more advanced set-ups.

Drive parameters can be modified via the unit's five-button front panel or using the unique and innovative Optiwand.

This is a handheld remote control unit that employs infrared technology to communicate with the drive and/or a PC.

The Optiwand has the same five-button layout as the drive and can store up to 63 complete Optidrive settings.

Everything that can be done via the drive front-panel can also be done via the Optiwand, then subsequently downloaded to the Optidrive.

This greatly simplifies changing the drive settings once the drive is in-situ, given that drives can often be located in cramped not easily accessible places.

For example, parameters can be downloaded from the drive to the Optiwand, modified, and reloaded to the drive.

Using Optiwand, several drives with the same set-up can be very quickly configured, it taking less than 0.5s to transfer the parameters from the handheld unit to each drive.

The Optiwand can also be used to quickly monitor individual parameters and, if necessary, instantly change them, eg the drive speed.

Both the Optidrive and the Optiwand have a very high level of data integrity.

The facilities of Optidrive and Optiwand are backed by Optistore, which through the Optimouse infra red receiver and transmitter, enables all drive parameters to be stored on a PC or portable.

By simply aiming the Optiwand at the Optimouse, all drive parameters in the Optiwand can be downloaded into Optistore, which if required supports subsequent modification.

Conversely, if a set of stored drive parameters are required, via the Optimouse it can be uploaded into the Optiwand and then used to program one or more Optidrives.

Bearings for motors and generators combat the effects of electrical currents on both the bearing surfaces and lubricants, which can otherwise cause premature wear and potential failure.
The latest Insocoat coated bearings and Hybrid bearings from SKF have been launched to extend significantly the operating life of bearings used in motors and generators. In particular, the new Insocoat and Hybrid bearings have been developed to combat the effects of electrical currents on both the bearing surfaces and lubricants, which can otherwise cause premature wear and potential failure leading to equipment downtime and increased cost of maintenance. Although the effects of electrical currents on bearing life have been recognised for many years, the growing use of high capacity variable speed drives and frequency convertors, together with increasingly powerful motors and generators, is leading to a reassessment of the potential problems.

In particular, the risk of flashovers caused by charges induced in both shafts and bearings can dull the surface of ball bearings and cause cratering in metal surfaces and fluting in raceways.

Although it is possible to combat the effects of electrically generated currents by insulating either equipment housings or each rotating shaft, both these solutions are relatively expensive and require additional components, leading to increased maintenance costs.

By comparison, replacing standard bearings with SKF's latest Insocoat or Hybrid bearings, makes it possible to eliminate the need for additional insulation yet still provide an excellent degree of protection to each bearing.

Insocoat bearings feature a specially developed surface coating, just 50um in thickness, which acts as an electrical insulator to provide protection against electrically induced flashovers of up to 500V; thicker coatings are also available to withstand discharges of up to 1000V.

Just as importantly, the coating has minimal impact on overall operating temperatures, is unaffected by extremes of temperature or humidity and can be used with all common lubricants, while the bearings offer identical performance to conventional devices and can be fitted using normal techniques.

The latest Insocoat bearings are available in a range of sizes for shaft diameters of 55 to 150mm.

They can be supplied with brass or steel cages, and used in applications with dynamic loads of up to 276kN and shaft speeds of up to 6700rev/min, depending on the lubricants used.

SKF Hybrid bearings incorporate silicon nitride rolling elements to provide excellent insulation properties, making them ideal for isolating housings from shafts in AC and DC motors, as well as generators.

SKF Hybrid bearings have been developed for high speed applications, offering low weight and friction to reduce inertia and operating temperatures, and extend bearing service life.

Innovative porting technique with digitising routines, gives significant improvement over hand porting and 3-axis machining, allowing exact duplication of optimum IC engine port designs.
For Florida-based CNC Cylinder Heads, certain aspects of engine manufacture just didn't make sense. Why spend thousands of dollars on a precision-machined engine block, crank and pistons, just to bolt on a set of unported cylinder heads with mismatched port volumes and rough wall surfaces inherent to the casting process? For professional engine builders, precisely ported heads mean better engine efficiency and dyno results.

Hand porting is an art form, but from a manufacturing standpoint, it is impossible to identically size each port volume, or to accurately replicate an 'ideal' port design on another head.

It is also time-consuming, often taking a highly skilled person up to 40 hours to complete a set of heads - very inefficient for a high-variety, low-volume porting business.

From a performance standpoint, cleaning up ports by hand does assist flow by reducing restrictions, but the head cannot deliver its full horsepower potential because of mismatched port volumes.

Numerous manufacturers machine heads on 3-axis CNC machine tools, but machining only in 3-axes, leaves tool marks that cross over one another in various directions, requiring hand polishing and blending to smooth surfaces.

Not only does this add time to the process, but it also removes additional material, making the port larger than originally designed.
With these shortcomings in mind, Bob Hudgins, President of CNC Cylinder Heads, developed a system to solve both problems.

Employing a special combination of high-tech equipment, including vertical machining centres (VMCs), custom-built head fixtures with A- and B-axis CNC rotary tables, and specialised CAD/CAM software, he machines aluminum and cast iron heads in five axes simultaneously, producing a mirror-smooth surface finish, without toolmarks, straight off the machine.

But what to do about the duplication dilemma?

For that, Hudgins uses one additional piece of equipment - Renishaw's Cyclone scanning machine A continuous-contact, reverse engineering tool, the Cyclone scans port and combustion chamber wall surfaces collecting dimensional data to produce a 3D wireframe model of the internal features.

A 3-axis system, the Cyclone is fitted with Hudgins own-design thin probe styli and a special fixture that rotates the head in A- (rotation about the X-axis), and B- (rotation about the Y-axis) axes to allow access to hard-to-reach port areas.

From that data, SURFCAM CAD/CAM software creates 5-axis NC code that drives the machine tool through its cutting routines.

After machining and cleaning, heads are ready for immediate assembly.

Hudgins-designed cylinder heads can be found in various enthusiasts' cars, and NASCAR teams, where cars achieve speeds of 200-mph.

CNC Cylinder Heads also sells the 5-axis system as a turnkey package, offering the technology and training for other companies to duplicate and machine heads using this proven method.

The need for duplication comes from two sources - external and internal.

Professional engine builders approach CNC Cylinder Heads to replicate their new port designs and cut them into numerous other castings.

Builders for NASCAR teams may order up to twenty sets at the beginning of each new racing season, but often come back with new designs throughout the season since their R and D is ongoing - requiring a quick turnaround from Hudgins and his team.

CNC Cylinder Heads' in-house engineers are also continuously developing their own port designs on a variety of manufacturers' castings for street performance and racing applications.

After a newly designed head passes various flow bench and swirl meter tests, the Cyclone digitises the finalised design for duplication.

The company has hundreds of port designs and gigabytes of machining programs stored in a DNC workstation, to be downloaded to a machine tool at a moment's notice.

CNC Cylinder Heads sells these heads off-the-shelf, often packaging them with matching cam, intake and computer chip from other vendors, for purpose-built racing or street applications that often raise base horsepower by 40%.

Digitising deep inside a port - in effect, an angled tube - is more difficult than digitising the perimeter of an object.

Hudgins designed a special Cyclone fixture that can be rotated in A- and B-axes manually or by way of servomotors.

This rotation, combined with Hudgins' special thin styli, allows the Cyclone to digitise all areas of the port.

Rotary encoder's register the angular position of the fixture and a digital display shows position to one thousandth of a degree.

Once all port areas that can be accessed from the home position have been digitised, the fixture is rotated by the operator, to allow access to other areas of the head, and the new angular position is noted.

The Lenze range of synchronous and asynchronous geared motors has been extended by the addition of new motors matched to the Lenze gearboxes. There are now more than 5000 possible selections with nominal output torques from 3 to 7000Nm, rated speeds from 7 to 2500rev/min. servomotors are integrated into the gearboxes with long-life shaft seals and the first pinion on the motor shaft.

This eliminates a flexible coupling, creating a shorter and more economical assembly with reduced backlash often below 12arc-min from standard gearboxes.

Both synchronous and asynchronous motors are included in the Lenze range.

Motor options include resolvers, incremental and absolute encoders for feedback, also brakes, blowers and IP65 enclosure.

The motors are matched to the full range of Lenze gearboxes: helical, shaft mounted helical, bevel, helical bevel, helical worm and planetary.

These preconfigured selections represent the widest range available of matched servomotors and gearboxes.

Applications for linear motors are growing rapidly, but the one thing impeding even faster growth is engineers' lack of understanding of the devices. Simon Smith of Aerotech makes an introduction
Once the subject of futuristic speculation about maglev trains and super guns, linear motors have come of age as advanced and reliable alternatives for ball and roller screws for linear motion. Not only are the motors now affordable and practical, but the they are easy to control. Applications for linear motors are growing at a rapid rate, but the one thing impeding even faster growth is engineers' lack of understanding of the devices.

Without going into the basic physics, which are quite simple anyway, a linear motor is essentially a rotary motor that has been cut and made flat.

The forcer (rotor) is made up of coils of wires encapsulated in epoxy and the track is constructed by placing magnets on steel.

The forcer of motor contains the windings, Hall Effect board and the electrical connections.

The control for linear motors is identical as with rotary motors.

Like a brushless rotary motor, the forcer and track have no mechanical connection, i.e, no brushes.
Unlike rotary motors, where the rotor spins and the stator is held fixed, a linear motor system can have either the forcer or the magnet track move.

Most applications for linear motors, at least in positioning systems use a moving forcer and static track, but linear motors can also be used with a moving track and static forcer.

With a moving forcer motor the forcer weight is small compared to load, but there is the need for a cable management system with high flex cable, since the cable has to follow the moving forcer.

With a moving track arrangement, the motor must move the load plus the mass of the track.

However, there is the advantage that no cable management system is required.

Why use linear motors?

Linear motors overcome most of the disadvantages of the most commonly used ballscrews.

Ball screw systems are subject to screw wear and backlash and cannot tolerate high speeds or acceleration rates.

There is a temperature effect on the screw which reduces accuracy.

Ball bearings also reduce the smoothness in velocity and there is windup/compliance.

Because of wear, the characteristics change over time.

A linear motor directly converts electrical energy to linear mechanical force and is directly coupled to the load.

There is no compliance or windup, higher accuracy, and unlimited travel.

Today, linear motors typically reach high speeds, for example, 5msec, with high accelerations of 5g but can now reach up to 10g with 10msec velocity.

There is no wear, no lubrication and therefore minimal or no maintenance cost.

Finally, there is higher system bandwidth and stiffness.

A linear motor can be flat, U-channel, or tubular in shape.

The moving part of a flat motor, which is typically an iron core design, rides close to the surface of the secondary.

A U-channel motor's moving part rides within two rows of permanent magnets.

In all cases, the moving copper coil assembly is ironless, and thus has no attractive force, resulting in smooth velocities without mechanical disturbances.

The configuration that is most appropriate for a particular application depends on the specifications and operating environment.

Flat motors are often cheaper because they require fewer machined parts and magnets.

However, since the surface of the magnets is exposed, one limitation is that they cannot be used in environments that will be affected by magnetic flux that will "leak" out of the system.

In U-channel designs, this problem is significantly reduced since the magnets are contained within the motor casing.

As with any technology, there are always limitations and caution must be used to employ the correct solution in any application.

While cost was once a limitation over ballscrews, improved manufacturing methods and increasing volume, coupled with higher performance requirements of today's machine manufacturers, costs have reduced to be comparable with a typical ballscrew and motor alternative.

Indeed when cost of ownership is taken into account, in many cases a linear motor system may over time prove to be a considerably less expensive solution than the traditional screw alternative.

One area where a mechanical system will always be preferred is where a high load and hence high inertia is encountered.

Whereas a high torque to inertia ratio is beneficial in many instances, it must be considered that a linear motor is a servo system and therefore the usual inertia matching rules relating to motor and load must be applied.

There is none of the mechanical advantage inherent in a ballscrew and an unstable system running at high accelerations and velocity is a recipe for disaster! However, any reputable manufacturer or supplier would be pleased to aid in the sizing of a suitable motor, and should have a wide experience in applying the correct solution to each application.

Another disadvantage with linear motors is they are not inherently suitable for use in a vertical axis.

Due to its non contact operation, if the motor is shut down, any load that is been held vertically would be allowed to fall.

There are also no failsafe mechanical brakes for linear motors at present.

The only solution that some manufacturers have achieved is by using an air counterbalance.

Environmental conditions must also be considered.

Although the motor itself is quite robust, it cannot be readily sealed to the same degree that a rotary motor could be.

In addition, linear encoders are often employed as feedback devices and therefore care must be taken to ensure that the encoder is suited to the environment too.

That said, linear motors have been successfully employed in wafer dicing, an environment where highly abrasive ceramic dust has lead to the downfall of many supposedly more robust solutions.

Again, the motor supplier should be familiar with all the options, and would be pleased to offer advice in each case.

The new Starttec motor starter brings switchgear control to the motor location. This new development pushes further the current trend of transferring control from the cabinet and reducing the load on the central PLC. As well as providing a smooth soft start which reduces mechanical shocks and peak currents, it also simplifies cabling, reduces cabinet space and can be operated without any specialist expertise.

Its rated power of 0.25 to 4kW with a max output of 9.5A suits three-phase motors and it can be used with single motors, reversing operations or multi-motor control.

In the past motor starters have been electromechanical devices in the control cabinet, for switching and protecting three phase AC motors up to 4kW.

The systems were normally wired with each motor connected individually to the panel, requiring a great deal of time and cost to install.

With the introduction of Lenze's Starttec control has now moved to the heart of the material handling process.

Benefits of the Starttec electronic motor over conventional switchgear are that Starttec cuts wiring costs and installation time as it eliminates the need to individually wire from each motor back to the cabinet as power can be taken by spur from an energy bus or looped through from Starttec to Starttec.
Its design has many other benefits as starting is wear-free, and installation onto the motor or a nearby machine frame is possible due to a high protection class of IP65.

The Starttec can be programmed using logical functions such as AND, OR, XOR and NOT, meaning that a conveyor belt driven by one of Lenze's geared motors with Starttec only starts if the necessary conditions, eg sensor 1 and 2 are active, are fulfilled.

Each distributed Starttec performs its own intelligent operation, thereby relieving the load on the central PLC.

For a total system Lenze offer the Starttec for fixed speed distributed drives and the 8200 Motec frequency inverter for variable speed drives together with an extensive geared motor range.

Such a reliable and flexible drive system allows the material handling application to run efficiently.

Danfoss Motion Controls has responded to growing market demand for physical space and cable economies on multimotor installations with the launch of the Decentral range of motor controllers. The VLT Decentral FCD 300 is a totally enclosed frequency convertor while the simpler DMS 300 is a soft start motor controller. Both are designed for remote mounting close to or actually on the drive motor, dispensing with the need for a central control cabinet and the associated expensive cabling, giving Danfoss a full drive-motor-gear profile for the food and beverage and materials handling markets The trend towards decentralised control has grown rapidly as manufacturers have become ever more reluctant to allocate expensive real estate to large electrical control panels.

Lengthy cable runs out to the drives on the plant have become increasingly more expensive, and in the food industry particularly, a trap for dirt and germs.

Recent EMC legislation has also driven the trend since EMC filters are only effective for given cable lengths and hence shorter cable lengths between drive and motor simplifies filtering and gives a better EMC solution.

The evolution of reliable fieldbus control now means that digital control of a motor starter or variable speed drive mounted on the production plant itself, is fast, simple and incorruptible.

The VLT Decentral FCD 300 is an IP66 high-performance frequency convertor designed for demanding process line applications and featuring full protection for the drive and motor, including motor over temperature and mains loss protection.

Fully protected motor brake control and supply is included making the FCD300 ideal for use with mechanically braked motors.
A version with integral mains isolator switch is also available.

The new DMS 300, in a high durability IP66 enclosure similar to but smaller than its sibling FCD 300, offers full fixed speed motor control functions including soft start, reversing, mechanical brake control, thermistor and electronic thermal control via an integrated AS-interface.

Profibus is also available as an option and devicenet is planned for the future.

Five different cost and performance models are offered initially, from a simple mono-directional S version with thermistor control, through to the full functionality extended E version with fieldbus control.

Space provision is made on the base units for an isolating switch for full galvanic isolation of the motor without the need for a separate enclosure.

The new Decentral range offers the option of mounting the controllers either on the motor terminal box, or local to the motor since the robust die-cast case is configured to fit the terminal box of IEC standard cage motors of any manufacture.

Fieldbus control from RS485, Profibus DP or AS-i bus means that control cabling can be greatly simplified and cost reduced compared to a standard drive system installed in a central control cabinet, although standard analogue controls are also provided.

Initially for applications to 3kW, the FCD 300 and DMS 300 have been designed with a high integrity anticorrosive finish specially formulated to withstand hosing down on food production lines and ideally suited to the food and beverage industries.

The twin part construction makes for simple commissioning and fast service.

All installation work is completed in the bottom section while the top control section plugs into the bottom section and is clamped up with only four screws.

Fast, reliable service and commissioning could not be easier than with this simple plug-and-play concept.

Power cable looping facilities combined with the two part construction ensures trouble free mains cabling as cables can be looped in the installation section independently of the control section.

The control section can also be powered up on the bench for control commissioning offline without mains connection.

The Decentral motor control concept is becoming very popular with major manufacturers across Europe because of the simplicity of installation and the savings which accrue from locating the controllers on the production equipment rather than in a distant control cabinet.

According to Rockwell Automation, the Allen-Bradley PowerFlex 4 provides cost-effective powerful speed control for single- and three-phase AC motors from 0.2 to 3.7kW. This newest, small and low cost member of the PowerFlex family provides most of the benefits of its larger relations for panel builders and OEMs requiring accurate speed control in applications such as machine tools, fans, pumps and materials handling. The PowerFlex 4's compact design uses advanced heat sink and IGBT technology to minimise size, a zero stacking feature allows drives to be mounted side by side with no gaps, while commonality with other products in the range ensures familiarity for existing PowerFlex users.

For ease of installation and use, the PowerFlex 4 includes an integral keypad with local potentiometer, while the quick start feature provides fast start up.

There is easy access to the terminal block, and an integral RS485 port allows the use of Allen-Bradley DriveExplorer and DriveExecutive configuration software.

A range of configuration options make the PowerFlex 4 amazingly flexible.

Available in an IP20-rated package that can be DIN-rail or panel mounted, further options include an IP30/Nema 1 kit and plate drive or chassis mount configuration.

An integral filter version is also available for single-phase applications, further reducing the drive's footprint while still complying with EMC requirements.

OEMs exporting their machines around the world have the reassurance that the PowerFlex 4 meets worldwide power ratings, packaging requirements and electromagnetic compatibility - like all PowerFlex products, it is CSA/cUL Certified, UL-Listed, C-Tick and CE Marked.

Rockwell Automation is also able to offer the PowerFlex 4 preconfigured with a range of software, operator interfaces and power options.

This service allows the drive to be specified to meet the precise requirements of the application, further reducing the time required for installation and setup.

The Allen-Bradley PowerFlex family of advanced AC drives now covers the power range 0.2 to 3000kW.

All drives in the range share operator interfaces, programming and networking ability, giving a common look and feel, and enabling users and installers to program and run any PowerFlex drive with confidence.

Rockwell Automation has extended the Allen-Bradley MP Series of servo motors with models suitable for use in the damp and dusty environments found in food and beverage packaging and materials handling applications. Available in four frame sizes, they provide continuous stall torque from 1.6 to 19.4 Nm and peak torque from 3.6 to 48.6 Nm IP 66 and 67. Rated to resist liquid contamination, the MPF Series servo motors share the performance characteristics of the MP Series, with extra features including a stainless steel shaft with hardened seal, quadruple o-ring seals for the connectors and a two-part food grade epoxy coating said Rockwell.

The lightweight, high-energy neodymium magnets in the rotors reduce inertia and allow rapid acceleration and deceleration.

That significantly increases productivity because machinery is positioned more quickly - output in a typical application could jump from 1000 to 1800 units per hour.

The segmented core design of the motors increases copper density, producing up to 50 per cent more continuous torque than conventional servo motors of the same size claimed the company.

There is a hardened shaft wear sleeve to ensure a long lasting shaft seal and shaft and food grade grease is used on the shaft seal.

Cable assemblies with food grade 2090 cables are available to supply power to the motor and carry feedback signals to a controller.

The cable jackets are designed to withstand harsh chemicals and the corrosion-resistant, nickel-plated connectors swivel 180 degrees to simplify installation without compromising the seal integrity.

Brake wires are included inside the power cable, so there is no need for a separate cable.

The maximum speed of the motors is 5,000 rpm, and a 24 V brake is available as an option.

The MP Series is available with high-resolution, single turn; or high-resolution, multi-turn absolute feedback options.

Multi-turn absolute feedback offers up to two million counts per revolution and the position of the rotor is sent to the controller instantly when the system is powered up.

No homing sequence is necessary, so start-up is faster and product waste is minimised.

Users can further boost the durability of the MPF Series motors by adding a positive pressure option.

That increases pressure inside the motor to prevent the ingress of moist air - particularly useful when the motor temperature cycles in a humid environment and may draw moisture into the casing.

Users will need access to a source of clean air at a pressure between 0.06 bar and 1.14 bar to use that option said Rockwell.

MPF Series motors are available in 230 V and 460 V versions, and are interchangeable with MP Series motors.

The flexibility of Lenze's 8200 motec system to provide compact, integrated drive/geared motor solutions and decentralised control across almost any size of system has enabled Kannegiesser to develop DressCare Select (DCS), a revolutionary clothing storage and retrieval system. Designed to deliver greater efficiency and productivity in large-scale 24 hour working environments, the fully automated DCS system can provide up to 2500 items of clean work clothing at any time of the day or night. Round the clock working is an increasingly common feature of the modern global economy.

In hospitals, it has always been the norm, comprising multi-shift operations that pose problems for administrators who have to provide large quantities of clean working clothes for medical and general staff, 24 hours a day.

DressCare Select (DCS) is a unique, automated clothing issue system developed by Kanngeisser as a solution to this problem.

A modular system that can be adapted to meet the needs of small and large businesses, DCS is much more efficient and easy to use than conventional linear rack based systems.

With its carousel design it can reliably store and deliver from 10 to 2500 items of work wear at any time of the day or night, 365 days per year.

The central element of the DCS system is a slotted ring onto which work garments, each with a unique identity chip, are hung.

From these positions the garments are indexed backwards or forwards in the most efficient movement pattern to a central collection station.

The location data for this operation are stored in a PC.

Once garment retrieval is initiated, data from the PC are sent to a PLC.

The PLC interprets the data into an analogue signal and transmits them to the Lenze 8200 motec frequency inverter.

The Lenze unit then performs the final indexing movement to achieve garment retrieval via its integrated geared motor unit.

The modular 8200 motec system, with its fully integrated inverter/geared motor combination, is the ideal unit for this application, offering the equipment designer several cost, size and weight saving advantages.

First, the 8200 motec enables Kannegiesser to employ a compact and lightweight drive system that can be mounted directly above the clothes rail for maximum effectiveness and drive efficiency.

Secondly, the 8200's modularity means that the DCS system can easily be extended (to carry up to 2500 clothes hangers) without having to redesign the power transmission system.

In addition, the 8200 motec system is simply configured to account for the predicted weight of the clothing stored on the rack, providing Kannegiesser with the flexibility to develop different capacity systems with the minimum of configuration and programming time.

Thirdly, the decentralised control provided by the 8200 motec means that extended - and expensive - runs of shielded cable are avoided, together with excess wiring and switchgear.

These reductions, in turn, translate into cost and space savings as smaller control cabinets can be employed.

Finally, the 8200 motec offers the capability to interface to all current types of fieldbus systems, including Kannegiesser's PLC controllers.

As a result, it simplifies Kannegiesser's task of integrating the DCS system into the existing plant wide communication systems used by its customers.

One of Europe's leading suppliers of high performance waterjet cutting equipment has selected M'Ax servo drives and Unimotors from Control Techniques for its whole range of multi-axis tables. Power Jet Systems, based in Nelson, Lancashire, was established 10 years ago to build and integrate high pressure systems, initially for the nuclear decontamination and decommissioning market. Now, the company has built a reputation for pure and abrasive waterjet technology and, three years ago, moved into the system-build market, supplying robotics and multi-axis cutting tables for high-precision engineering applications.

Having used several servo-based systems, Power Jet has standardised on Servo systems from Control Techniques.

Director, Brett Cooper explains: "We have built up a team with considerable experience and they have strong ideas on systems requirements.

We made a decision to build up to a reliability standard, rather than down to a price.

This means using the best quality, most reliable components to reduce downtime for maintenance.

It makes good economic sense for us - and customers certainly appreciate the reliability and come back for more."
A key element in this philosophy was the choice of Control Techniques' M'Ax digital servodrives used in conjunction with SLM Unimotor servo motors.

"We have tried several systems, but have found M'Ax to be the most stable by far.

We considered using a cheaper belt drive for our budget machines, but decided that it wasn't worth cutting corners.

So we now offer this digital solution across the range, so our customers benefit from a terrific dynamic response and accuracies that many of our competitors simply can't match."

The Control Techniques servodrive system has also offered Power Jet savings in both engineering and set-up costs.

The Control Techniques' sizing software has meant that correct drive sizing is a task of just a few minutes and the easy set-up characteristics of M'Ax with the speed-loop Unimotors gave Power Jet engineers complete confidence and control to complete commissioning with no need for further assistance from Control Techniques.

M'Ax innovative SLM system uses the high resolution, motor-mounted Sin/Cos encoder with DSP technology to achieve a 500 fold increase in feedback resolution (8.3 million ppr), which is unaffected by digital noise, and a four-fold improvement in positioning too.

"We particularly like its simplicity in use," says Brett Cooper.

"It is virtually a 'plug-and-play' system - only three parameters need to be set - and, with just four wires to connect, it keeps both build and maintenance costs down.

And, reduced wiring has minimised panel size too!" M'Ax systems are used on all models of Power Jet's multi-axis tables, which use either precision ball screw drives with an accuracy of ñ69 microns/ 3 metres or belt drives with accuracies of ñ0.2 mm and linear bearing slides.

All models feature a heavy-duty box framework to support and enclose the drive axes and a free-standing water table within the drive structure, available in a wide range of sizes.

Configurations are available with 2,3 or 5 axes of motion, with the facility to feed abrasive being mounted directly on the Z-axis.

Cutting speeds of up to 30 m/min and traverse speeds of 40 m/min can be achieved.

Power Jet's dedicated water jet cutting software on the Delta Tau controller, with touch-screen (or tracker ball operator interface) communicates with the M'Ax servo-drives, which provide an extremely stable PID control loop for each axis.

Usually a machine is fitted with one Unimotor per axis, but larger machines sometimes have two motors, load-sharing, fitted to each of the X and Y axes.

In all cases, the Unimotors are of the SLM type, to give the performance benefits available when used in conjunction with M'Ax drives.

Unimotors also give market-leading thermal performance (typically 200-300% better) thanks to its unique finned motor housing and this is directly translated into a corresponding increase in torque of around 17%! The multi-axis tables are used in conjunction with a variety of cutting tools.

Water Jet utilises water pressurised up to 60,000 psi (4000 bar) and focused to produce a high energy beam of water which is used to cut softer materials such as paper, foam, soft rubber and food.

For harder tasks, such as the cutting of concrete, metals, stone and ceramics, abrasives are introduced into the water stream and focused into a narrow beam of typically 1 mm.

Plasma cutting and laser profiling solutions are also supplied by Power Jet.

"With M'Ax, we are able to offer a technically superior solution," concludes Brett Cooper.

"Our multi-axis tables offer good value for money and technical advantages of better accuracy and better dynamic response.

And, we offer less hassle - easy set-up, good diagnostics and lower maintenance costs."

Drive-based safety is a further evolution of the concept of drive-based automation, in which intelligence is built into decentralised drives.
In the past, developments in machine safety have added to machine complexity and cost. Now the tide has turned and safety functionality related to drives can actually reduce costs. One of the main requirements for machine safety is to control the potential hazards from moving parts.

If these movements are controller by servo drives - as is often the case with high speed precision machinery - the technology now exists to implement drive-based safety.

This philosophy, for which products fully approved by TUV are available, is a further evolution of Lenze's concept of drive-based automation, in which intelligence is built into decentralised drives, enabling them to perform many of the functions traditionally handled by motion controllers and/or PLCs (programmable logic controllers) or other control systems.

With drive-based safety, the drive is additionally able to perform safety functions that would otherwise require multiple safety relays, monitoring units and a dedicated speed/position sensor.

Starting with the machine builder or system integrator (SI), there is no longer a need to specify a number of different safety relays and monitors for use with emergency stop switches, safety light curtains and similar safety components, as all of these can be connected directly to the drive.

Furthermore, if a Profibus DP industrial fieldbus network is employed and the Profisafe option is selected, wiring can be simplified as well.

With the elimination of multiple safety relays and monitors, the requirement for cabinet space is reduced and, ultimately, so is the need for factory floor space.

If the designer also has to make provision for slow-speed running, hold-to-run or single-cycle operation, these are all far easier to implement using drive-based safety than by traditional methods, as the engineering is carried out largely in software instead of hard-wiring safety relays and monitors.

Machine builders and system integrators working on complex machinery are increasingly conforming to IEC/EN61508 (Functional safety of electrical/electronic/programmable electronic safety-related systems), rather than the simpler BS EN954-1 (Safety of machinery, Safety related parts of control systems, General principles for design) - which in fact does not permit the use of programmable safety systems.

IEC/EN61508 is soon to be complemented by a daughter standard for machinery (IEC62061 - Safety of machinery, functional safety of safety-related electrical, electronic and programmable electronic control systems), and both of these standards require the designer of the safety-related electrical control system (SRECS) to calculate the safety integrity level (SIL).

These calculations take account of factors such as the mean time to failure (MTTF) and, inevitably, the overall reliability of a system is adversely affected by high numbers of components.

In extreme cases, a complex safety system will require individual components of a higher SIL rating (which are therefore more expensive) than comparable components performing the same role within a less complex system, simply in order to achieve the required overall SIL rating.

However, by using drive-based safety and replacing numerous discreet safety relays and monitors with a single programmable module within the drive, the SIL calculations are simplified and there is a reduced possibility that higher integrity safety components will be called for - thereby potentially saving cost for the machine builder.

Other savings during the design phase accrue from a faster, easier design cycle, and simplified design verification and documentation.

Many of the major advantages of drive-based safety, however, are enjoyed by the end user.

With manufacturers today needing to optimise production, any saving in machine cycle time, however small, has a finite value.

When the safety functions are integrated within the drive, the safety system response time is faster than for a comparable circuit using conventional safety technology.

Stopping times are therefore shorter and, for example, safety light curtains can be positioned closer to the hazard; if an operator needs access via the light curtain for every machine cycle, the resultant time saving can amount to a considerable increase in throughput.

Furthermore, a facility for slow-speed operation can enable an operator to enter an area that would normally be classified as hazardous in order to rectify a problem without halting production.

In complex manufacturing systems - such as automotive production lines - it is hugely beneficial to keep the line running, even if one section is temporarily operating at reduced speed.

Whether the line is running at reduced speed or stopped altogether, drive-based safety also enables a faster startup to be achieved once the cause of the interruption has been removed.

A particular advantage of drive-based safety is that the power is not disconnected from the drive during a stop; this is important because it avoids having to wait for the drive's capacitors to recover and for the drive to be ready for use again.

Again, for plants where downtime is very expensive, seconds or even milliseconds saved on each interruption can add up to a substantial saving in the long term.

Another benefit for the end user is the extended life of the drive.

Disconnecting and reconnecting power causes premature aging of some internal components, but drive-based safety avoids this problem because the power is not routinely disconnected.

Currently Lenze is offering drive-based safety on the L-force 9400 series of servo drives that are rated from 0.37 to 11kW, and the intention is to launch models rated up to 400kW by the end of 2006.

All L-force 9400 series drives can have the safety modules installed, and there is scope to introduce more safety modules with additional or alternative functionality in the future.

Because the servo drives will operate with suitable motors from any manufacturer, the concept of drive-based safety is equally applicable to machine upgrades and new-builds.

Already DaimlerChrysler in Germany, a Technology Product Partner with Lenze, has installed a number of L-force 9400 drives with safety modules, and the benefits have been clearly demonstrated.

By implementing drive-based safety within a bodyshell manufacturing plant to achieve a 'safe torque off', the station cycle time has been reduced by an astonishing 46s.

Clearly drive-based safety offers major advantages for machine builders, system integrators and end users, but interested readers will want to know how this is achieved.

With the Lenze L-force 9400 servo drive, one of the beauties of the system is the simple plug-in module that delivers the safety functionality.

There are currently two types of module available, the SM 100 that provides a 'safe torque off' function and the SM 300 that is far more capable.

For applications that simply require 'safe torque off' (previously referred to as 'safe standstill') activated via a single emergency stop switch or other passive sensor - or multiple sensors connected in series - the SM 100 is a highly cost-effective module that delivers many of the advantages of drive-based safety.

It is suitable for use with safety related control systems conforming to the requirements of BS EN954-1 Category 4 or IEC/EN61508 SIL 3.

In addition to the safety input, this module has a single-channel output (for signalling to a PLC, for example) and two diagnostic LEDs.

The 'safe torque off' function of the SM 100 and SM 300 modules simply enables the torque to be removed from the motor so that it runs down to zero speed.

In fact control of the motor is retained by the intelligence within the drive at all times, and the safety module acts as a monitor to check that both the drive and motor are behaving as expected.

Should any deviation from the norm be detected, both gate drivers for the power stage of the drive are switched off by the fail-safe logic within the safety module.

Greater functionality is provided by the SM 300 safety module, which is approved for use in safety related control systems meeting the requirements of BS EN954-1 Category 3 or IEC/EN61508 SIL 3.

In addition to a 'safe torque off', the module also provides a Type 1 safe stop (in which the motor is ramped down to a controlled stop and the torque is then removed) and a Type 2 safe stop (in which the motor is ramped down to a controlled stop and the torque is then used to actively maintain zero speed - which also enables immediate resumption of an interrupted operation).

Other functions provided by the SM 300 are a 'safely limited speed' (reduced speed) operation, a 'safe tip' (hold-to-run) mode, a 'safe direction' mode (the motor is permitted to turn in one direction only) and a 'safely limited increment' mode.

In this last mode the motor moves in response to an input signal, but only for a limited increment before a safe stop (Type 1 or 2) is applied; after the predefined incremental move has been completed, another input signal is required before the next predefined incremental move is performed.

Programming the safety functions is a matter of setting the relevant parameters using the Lenze L-force Engineer windows-based programming software, and security measures are built in to ensure that the safety parameters are correctly transferred from the PC to the drive.

When the parameters have been entered on the PC, they are assembled into a frame with checksums; the values are then transferred to both the drive memory module and the safety module.

User-friendliness is becoming a major factor for machine builders today, and there are other patterns emerging in the field of drive technology.

Dr Erhard Tellbuscher, Chief Executive Officer at Lenze, comments: 'We are seeing a new trend towards safety being integrated within drive products for two reasons: the technical and economical benefits'.

'DaimlerChrysler, for example, will use our drive-based safety products on their production lines'.

Baldor has upgraded its intelligent servo motor drive for industrial positioning applications, Flex+Drive II. Now featuring an integrated motion controller compatible with the Mint language, the 'one-box' control solution has the real-time performance to execute much more complex movements like software gearing, sequenced moves and on-the-fly adjustments - as well as PLC-style machine control functions. Among the upgraded features of Flex+Drive II's motion control electronics are expansion interfaces which accept low-cost modular plugins to configure it for users' preferred fieldbus communications and position feedback technology.

This effectively provides machinery OEMs with a customised automation solution at an off-the-shelf price.

At the heart of the single-axis brushless servo drive is a new fast DSP-based controller providing users with a high degree of motion programmability.

Compatible with Baldor's renowned Mint motion software, which provides high-level Basic-style keywords for motion tasks - as well as PLC-style I/O handling - control programs can be written and tested in minutes.

Flex+Drive II servo drives will run these programs autonomously, providing a complete standalone solution for machinery and automation - optionally controlling further I/O including man machine interfaces using fieldbus communications.

Alternatively, the drive will function as a slave to a PC, for users who want to build automation equipment with sophisticated windows-based operator interfaces, using Baldor's free Mint ActiveX controls.
Users can choose from a comprehensive range of Flex+Drive II drives, in single- or three-phase versions for power ratings up to 20kW.

All may be software configured to drive linear or rotary motors.

Each drive includes a 14bit analog input and 11 digital I/O lines - enough to handle the associated I/O requirements for many simple automation applications.

Two of the digital inputs can capture data within a microsecond.

This provides the performance required for high-speed adjustments such as those required in registration applications.

This upgrade is designed to give automation engineers and OEMs great flexibility, via three forms of plugin module configurability.

Onboard I/O may be expanded with a further 15 digital I/Os.

Feedback technology is user-selectable from resolver, encoder or 'Endat' options - the latter providing state of the art absolute encoder data which eliminates the need to perform homing routines at power-up.

The drive additionally accepts a plug-on fieldbus interface, with a choice of CANopen, devicenet or Profibus-DP communications.

This option provides the means to expand the system very economically - linking to further I/O or drives distributed around the machine for example - as well as providing a communications mechanism to connect with factory equipment such as supervisory computers.

Baldor's new intelligent drive has a wide range of uses in packaging, conveying, loading, assembly and other areas of manufacturing.

For some applications - labelling for instance - its single axis capability is enough and the product can provide a compact and economic solution.

For larger automation requirements, the drive may be used an element of a distributed multi-axis motion system - communicating using industry-standard protocols.

Drives may be used with brushless AC servo motors or linear motors.

'Matched performance' speed-torque curves are available for Baldor's own motor brands, minimising the need to undertake detailed evaluations - or to incorporate costly performance margins in the design.

A wide range of other controllers sharing the same Mint motion language API are additionally available - providing automation engineers and OEMs with the means to select optimised solutions for every axis in the machine, and safeguard their development investment.

SIG Combibloc, a Tyne and Wear-based carton manufacturer, has used Siemens drives, motors and control gear to advantageous effect on one of its key Flamesealer machines.
Rather than buying new, many companies elect to refit machines when they become fatigued, unreliable or outmoded, saving money and, in many instances, gaining a machine with a superior specification. This was the preferred route for SIG Combibloc, a Tyne and Wear-based carton manufacturer, which used Siemens drives, motors and control gear to advantageous effect on one of its key Flamesealer machines. 'The machine was fitted with old American DC drives from the 1970s', explains SIG's Head of Electrical Services, John Duffell.

'We went through a period of repair but maintenance support for the machine in the area started to dwindle'.

'We knew we had to address the problem head on'.

The Flamesealer machine is at the heart of SIG's operation.

It takes a flat, blank substrate and folds it into a sleeve before applying a 'burn' process to its plastic coating to seal the carton.

Among the famous carton brands processed by SIG are Ambrosia, Birds and Cadbury.
Local automation specialist Appcon was asked to tender for the contract.

Appcon's Sales Manager Jason Johnson takes up the story: 'The machine wasn't reliable and failed to provide repeatability'.

'There was a lot of slack in the mechanics that were compounded by control problems so using our experience of high speed manufacturing applications, we designed a solution based on Siemens equipment'.

'SIG were astounded when they saw our proposal'.

'Not only was it more competitive than their other quotes, it offered extra functionality and was an all-round better technical solution'.

Appcon won the contract and configured the new control structure and drive system using three Siemens Micromaster 440 series drives (two rated at 15kW, one at 22kW) complete with additional encoder input cards.

The drives are connected to a Siemens S7-300 PLC via Profibus while production line characteristics are modified via a Siemens TP170B HMI.

The machine speed relating to the centre section of the machine is entered in metres per minute using the HMI and the PLC transmits this set point value to the drives.

Each slave drive can be offset from the master by entering a specific value into the HMI and the PLC stores these values so that they track any modifications in the speed of the centre section.

This allows line speed characteristics to be set rapidly during job changeover thanks to a memory facility that permits speed characteristics to be recalled when a job is repeated.

The use of the S7 PLC in conjunction with the drives allows the slave motors to run with a true offset rather than via a geared relationship, making it possible to maintain a constant gap between blanks for any desired line speed.

In addition, the PLC monitors the system, providing status of the emergency stop circuit, while the HMI offers a diagnostic display, showing the status of each drive including voltage levels, overload status and fault alarms.

All I/O can also be viewed from the HMI to assist in faultfinding.

'At Appcon we have made a conscious decision to align ourselves to Siemens', explains Johnson.

'Their equipment offers high quality and reliability'.

'Given a free choice we would use Siemens every time'.

The new drive system on the SIG Flamesealer has proved superior to the old analogue system.

Consistent speeds are achievable at each section of the line as the load is varied.

It is also notable that the new system introduces far less vibration into the line due to the tuning functions available on the Siemens Micromaster drive in conjunction with the use of encoder feedback.

Duffell says: 'It's so quiet that I often walk past and think - is it on?'.

The entire refit at SIG was completed in two and a half days.

'Appcon were hugely professional', states Duffell.

'Now the operators are screaming out for the remainder of our Flamesealers to be refitted'.

Needless to say, people power has won the day and SIG is using Appcon and Siemens to roll out a programme of refits across its entire range of Flamesealer machines.