Feature Drives, controls & transmissions New drives for stenting machine
Lenze Systems Partner Cornfield Engineering Solutions has engineered up-to-date replacement drives for the Portland Dyeing Company of Leek, Staffordshire which had been suffering from a loss of production due to faults with its existing system
ortland Dyeing have a Montforts stenting machine which is used to stretch and set fabric. The stenting process uses heat to give stability to the fabric and prevent subsequent shrinking. It is commonly used for cotton-based materials. A web of cloth is connected on each side by hooks to a tractor conveyor. Each side of the conveyor has independent drives so that, although they normally run in synchronisation, they can be advanced and retarded. Also the two sides of the conveyor can be adjusted in width to tension the cloth web. The conveyor takes the cloth through an oven where even and continuous motion is required to prevent burning. The effect of a drive failure is poten- tially calamitous as the surface of the cloth will burn in the oven resulting in scrappage.
P
Portland Dyeing called in Cornfield Engineering when the increasing over- current faults on the two Lenze 8608 inverters became a problem. Being 25 years old, it was no surprise that direct replacement drives were no longer available. Each inverter drives a 5.5kW planetary geared motor connected to the conveyor. The motors and drives were selected with a 87Hz setpoint, meaning that the nominal torque is
achieved with a 4-pole motor speed of 2500 r/min. This results in increased power from the motor, up from 5.5 to 9.4kW which in turn means the motor is compact and cost saving. The only special requirement for 87Hz opera- tion is that the motor should have con- nections for 230V Delta. The inverter has to be sized appropriately for the increased power – in this case 11kW models were chosen.
Montforts have chosen the 87Hz tech- nology as it increases the available speed range by 70 per cent. The motor nominal torque is generated at 2,500 r/min and the inverter can drive it down to 580 r/min without cooling or down to 145 r/min with a blower. The motor is effectively standard and runs with a small gain in efficiency at the higher speed. With a 132 frame motor giving the output of a 160 frame, there are fur- ther gains in size and purchase cost. Chris Timbey, director of Cornfield Engineering Solutions, investigated the application and selected up-to- date inverters from Lenze, the 8400 StateLine rated at 11kW. The inverters take in an analogue speed reference signal from a higher level control system. They are easily capable of the 87Hz settings and as a modern quality inverter they will give Portland Dyeing
Cornfield Engineering Solutions engi- neered up-to-date replacement drives for The Portland Dyeing Company which were up and running with only one day of downtime
the reliability they need. It is not just the motor that is small – over 25 years the footprint from the old to the new inverter has reduced by 78 per cent. Cornfield Engineering was able to support their customer from the initial assessment right through to installa- tion and commissioning. In fact their Director Chris Timbey is proud of how well the project went: “We prepared well with new drawings and programs written with the Lenze L-force Engineer parameterisation software. The drives were changed and the machine was up and running again in less than one working day.” Lenze T: 01234 753227
www.lenze.com Enter 323
Couplings span up to 10m for long length, low maintenance operation B
ased on its Torsiflex range, Bibby has developed a composite, carbon fibre shaft coupling which has the ability to operate over lengths of up to 10m without central bearings. The Turboflex’s coupling has an inherently low mass and generous misalignment capacity, which does not require routine maintenance. The couplings are ideally suited on equipment such as cooling tower fans, large vertical pumps and marine drives where a long drive shaft is required and maintenance and repair work is costly. The Turboflex range from Bibby, part of Altra Couplings, uses the latest material technology to provide high strength couplings with a low overall mass. The tubes are filament wound on accurate mandrels using computer controlled machinery, and are cured whilst on the mandrel. This results in highly accurate tube dimensions, roundness and straightness; all of which contribute to a coupling which can offer
24
operational reliability, even in hard wearing applications. Purpose developed software enables Bibby to offer the couplings with fibre windings at angles adjusted to give the optimum performance for specific lateral critical, torque and torsional stiffness requirements. In addition, Bibby offers the option to wind tubes using a variety of fibres: Carbon Fibre, Glass Fibre, Carbon/Glass Mix and High Modulus Fibre, all of which provide advantages in their relevant operating areas. The high quality materials and care that goes into the manufacturing means that Turboflex couplings are highly stable, lightweight units which, thanks to their low mass, suffer from minimal vibration even at lengths of 30m, where metal couplings would require support bearings. This makes them easier and quicker to install, and without the need to lubricate bearings they are essentially maintenance free. The couplings have been shown to be suitable in many applications where
traditional couplings have been inappropriate due to vibration – such as high speed engine test beds or ship propulsion systems – or where access is extremely limited – such as cooling tower fans or water and sewage pumping stations which employ deep well pumps. Bibby Transmissions
T: 01924 460801
www.bibbytransmissions.co.uk Enter 324
OCTOBER 2013 Factory Equipment
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36