Special Couplings for High Voltage Application

To meet the specific motion control needs of high voltage systems Huco Dynatork is exporting its expertise to Japan.  Its customer specialises in the design and manufacture of high voltage capacitors, one application for which is in an electronic assembly for plasma screens.  A miniature misalignment coupling is also part of this assembly but because standard materials of manufacture are unsuitable for this high voltage application the capacitor manufacturer turned to Huco Dynatork in the UK for a solution.

As one of Europe’s largest specialists in motion control technology Huco Dynatork is often asked to provide solutions to specific problems.  The answer for this particular application was to machine the required couplings in a non-standard, high dielectric constant material to prevent voltage leakage across the drive.

Victrex PEEK™ proved ideal for the job. The polymer is characterised by excellent mechanical properties maintained to high temperatures. As well as excellent electrical, chemical and temperature resistance it is hard wearing and provides dimensional stability. Trials of the special couplings proved successful and resulted in a substantial ongoing order for a range of the Huco Dynatork MultiBeam couplings made from PEEK™.

The general-purpose Huco Dynatork MultiBeam couplings readily accommodate any combination of axial motion and angular/parallel misalignment and as standard are machined in aluminium or stainless steel … and other materials by special order.

Sliding Disc Coupling Provides Design Flexibility

The design and manufacture of customised linear positioning systems on short lead times is key to LinTech’s success. This California-based company offers an exceptionally wide range of options enabling its customers to create the optimum system for the job. 

To compensate for misalignment between the motor shaft and screw (or belt) drive shaft extension LinTech’s product programme includes the choice of three different coupling types. The middle option is especially apposite to LinTech’s policy as it too can be tailored to suit the specific needs of the application. This flexibility is provided by the Oldham Series couplings, which are manufactured and supplied by Huco Dynatork. 

This British manufacturer of precision drive products was the first to employ the sliding coupling designed by the 19th century engineer, John Oldham, for locomotive applications. It introduced a plastic torque disc to achieve zero backlash and applied the principle to modern precision drives. The Oldham coupling has been central to the Huco product programme since the mid ‘80s. 

The 3-part sliding disc Oldham coupling is typically recommended by LinTech for applications that involve high acceleration and the starting and stopping of high inertial loads. Naturally it is supplied in a choice of diameter and length sizes and with bore diameters to accommodate various NEMA and metric motor shafts. However, it is the choice of hub styles and disc materials associated with this coupling that has particular appeal for LinTech. The hubs determine the method of installation and shaft attachment and the discs, the quality of motion. 

The Oldham is precision engineered throughout and comprises two hubs with inward facing tenons. These engage with matching slots spaced at 90° in a central lightweight torque disc. As the coupling rotates, the disc compensates for any parallel shaft offset by sliding the commensurate distance along each tenon in turn. A hard, low friction facing on the working surface guarantees long, trouble-free operation. 

Quality of motion is a function of the carefully controlled relationship between the tenons and the torque disc. The disc is precision moulded from high grade engineering polymers and, being easily replaced at low cost, is the sacrificial element in the drive train. A choice of torque discs is available including those resistant to radiation and heat. If severely overloaded the torque disc will break, acting as a mechanical fuse, thereby protecting associated equipment from damage. A replacement torque disc quickly restores the drive without the need to dismantle the drive system. 

“We like the flexibility of mixing and matching different bore hubs to create a total coupling for an application,” explains Gary Wester, Vice President of Sales. “And we favour standard nylon torque disc that provides a nice degree of system damping between the motor output vibrations and the input shaft on our positioning slide.” 

This ability to fine-tune the component to the exact performance requirements of the application has earned LinTech a substantial customer base. Its systems are used in a broad variety of general automation applications but particularly for precise positioning in the medical, automotive and packaging sectors.

www.huco.com

Couplings deal effectively with hostile environments

The sorts of hostile environment faced routinely by the military present challenges for engineering as well as personnel. An army has to be totally effective whether operating in deserts, jungles, swamps, mountains or arctic conditions. Similarly, the HUCO Dynatork coupling selected for position sensing in a rocket launcher control system had to prove its reliable operation in extremely aggressive environments. 

The brand of coupling initially chosen for the job failed consistently. A cocktail of heat, dust, debris and combustion products resulting from a missile launch created a viscous mass that completely solidified the coupling rendering it rock-hard and useless. 

World leading precision coupling manufacturer HUCO Dynatork was able to engineer a simple but clever solution. The resultant coupling is based on its standard 19mm diameter, stainless steel, Multibeam, a design that is ideal for accommodating both angular and parallel misalignment. A stretched version of the original was made – nearly double the standard length – and modified to accept a specially moulded neoprene gaiter that effectively shields the beam mechanism from debris attack. 

Nearly a year of exhaustive trials proved this tailored product to be the ideal solution and a quantity has now been ordered for retrofitting onto armoured vehicles and for stockholding. 

This is just one example of HUCO Dynatork’s ability to provide products for operation in hostile environments. The company produces a wide range of standard stainless steel motion components that resist aggressive solvents and are therefore ideal for use in wash-down conditions. It also offers a range of composite plastic products for a variety of applications including isolating high voltage. Beyond the standard range HUCO Dynatork welcomes the challenge of unusual applications.

Multibeam Production cuts days o hours

 
By applying value stream mapping Huco Dynatork has made radical changes to the way it manufactures its range of Multibeam couplings, increasing capacity, simplifying flow and drastically cutting lead times in the process.  It also opens up new opportunities for customers with special design requirements.

The Multibeam is one of Huco Dynatork’s most popular product lines whose potential is now greatly enhanced by better production flow. To boost productivity and shorten lead times Huco Dynatork had already been manufacturing it’s single, three- and six-beam Multibeams from pilot bored stock.  And although this initiative had shortened the lead time of the most popular sizes and models, it wasn’t a comprehensive fix.  Unusually large orders or those for less popular sizes and specials were still subject to lengthy lead times. For Huco Dynatork this was unacceptable.
 
Historically Multibeams have been produced in a series of individual process cells at the Huco Dynatork factory in Hertford.  Value stream mapping has now led to the company to invest in a single, multi-process cell that manufactures every Multibeam from scratch rather than from pre-bored stock. So whether it be in stainless steel, aluminium, acetal or PEEK, total production lead time for Huco Dynatork Multibeam has been cut by 80%. Typical lead time for batches of 50 to 100 is now less than five days.

 
“We’re well on the way to providing a next day delivery service for every Multibeam we make,” explained Joint Managing Director, David Lockett.  “This investment also allows us to provide a fast turnaround for non-standard sizes and other specials too such as shafts with machined helical beams at either end to accommodate misalignment.”

New Look for Huco Dynatork

In February 2006 HUCO DYNATORK joined global Power Transmission group Altra Industrial Motion. 

Altra Industrial Motion is a leading global supplier of quality power transmission and motion control products to most major industrial markets including, but not limited to food processing, packaging machinery, material handling, turf and garden and most others. Along with unparalleled delivery programs and superior customer service, the power transmission consumer, distributor and OEM who demand the best can count on Altra Industrial Motion.

Huco Dynatork is proud to be included in the presitgious list of Altra brands and we are delighted to unveil our new style, logo and color scheme with this exciting brand identity.

For more information about the Altra group visit www.altramotion.com

Huco Tools Assist Coupling Selection for Design Engineers

Huco Dynatork, an Altra Industrial Motion company, offers the worlds most comprehensive range of small precision couplings from a single manufacturer. Huco’s precision couplings are ideal for use in high-end servo drives, pulse generators, scanners, X-Y positioning slides, high speed dynamometers, measuring instruments, robotics, machine tools and in many other applications where specific dimensional or performance criteria is required.

Because there is such a wide range of different motion control couplings from which the design engineer can choose, Huco offers a complete Design Guide to coupling performance characteristics on the company’s website.

The website also contains a unique Coupling Selector designers can use as a tool to identify the coupling types that meet their design criteria for angular, radial or axial misalignment, or a combination of all three. The interactive tool helps designers understand whether they need a bellows, membrane, sliding disc or helical beam, or another design.

The Coupling Selector takes the key information provided about the application and presents all the couplings that fit the criteria, with a link to the detailed specification of each coupling. Selection is based upon coupling type (mechanism), dimensions, shaft connections, performance, displacement and other conditions.

www.huco.com