Coversion of Elastic Couplings
Simple Conversion from Elastic Couplings to Gear-Couplings (August 2021).
Often used in the Steel- and Port-Industry: torsionally elastic claw couplings. Despite beeing technically not necessarily required, those coupling types are still popular.
If there would not be the matter with the usual high wear rate of the intermediate elastic (“spider”) ring…
This was always an annoiance of a German steelmill – but converting the elastic coupling to a Gear Coupling seemed so far to laborious. Replacing the disc, the hubs and the coupling itself and probably moving the motor and re-align it – just difficult in terms of costs, working hours and downtime of the equipment.
So the customer decided to go for the MALMEDIE® “S-NX”, a conversion kit with the same dimensions as the middle part (claw rings) of the elastic coupling. The conversion was done in shortest time, the existing hubs and the brake disc were re-used again. And now, a Gear Coupling is in operation, which is fully encapsulated and filled by MALMEDIE® with a longlife grease. For the next approx. 15000 operating hours, no maintenance or replacement of parts will be required.
Successful first installation in a Steel Mill (May 2020).
„Dillinger“ is one of the largest heavy plate manufacturers in Europe. At their Dillingen / Germany facility, “Dillinger” produces heavy plates for numerous industrial applications, e.g. for offshore wind turbines.
Recently, MALMEDIE® developed and installed a new technology of an
automatic self-reset (Patent DE10 2019 110 297 plus further patents pending) of the torque limiter. Dillinger has implemented this new development on their slitting shear. After disengagement, the Safety-Elements of the coupling are automatically reset by a simple and short change of the motor´s rotational direction.
By slowly running the motor “backwards”, the couplings halves (including the Safety-Elements) are automatically centered and then the reset levers push the pins back into their “locked” position. Now, the coupling is ready for full operation again.
The downtime of the slitting shear after disengagement of the torque limiter until full re-engagement is now only 30-60 seconds. This new technology also prevents the requirement for someone to enter the “hazard area” to reset the torque limiter manually.
12.100.000 Nm – new record!
The biggest ever build MALMEDIE® Safety Coupling was installed and commissioned in August 2015.
With an astonishing shut-off torque of 12.100.000 Nm, the Safety Coupling protects a test bench for wind turbines against overloads in a safe and reliable way.
At a diameter of 2.5 meters, 21 Safety-Elements type “ASE40” are installed. Additionally, the coupling has provisions to add another 3 Safety-Elements, increasing the shut-off torque to even 14.000.000 Nm.
Single Safety-Elements can be also de-activated with a special tool, so that the coupling can be operated also with less Nos. of Safety-Elements. That results in variable shut-off torques between 1.728.500 Nm and 14.000.000 Nm.
As usual with all MALMEDIE Safety Couplings, the Safety-Elements can be re-engaged after a coupling trip simply and fast with a plastic hammer.
The test bench can test complete assembled machinery houses of wind turbines of the 5-10 MW class – which is quite new, because so far single component test of wind turbines have been the standard in that industry.
No special tools – just a plastic hammer
No matter if shredding, crushing or breaking is the task, the operators of those machines desire a robust and easy to operate technology and at the same time a reliable safeguarding against overloads.
Developed together with the OEM, every machine is equipped in the future with a MALMEDIE® Safety Coupling…and in case of overload; only a simple plastic hammer is required for re-engagement…
Downtime reduced from hours to minutes
Using a Torque-Tube (Shear-Tube) as an overload protection at the main drives of a roughing mill in the USA was, decades ago, certainly “state of the art”
– but from today´s point of view, the replacement of the broken Torque-Tube after an overload event means a considerable long downtime. Together with the customer, MALMEDIE® developed a solution with a Safety Coupling to replace the existing Torque-Tube. Due to the same mounting dimensions, it was a 1:1 replacement, i.e. nothing needed to be modified at site at all. Now, after an overload event, no new parts need to be fitted and the recommissioning time is reduced from hours to minutes only.
No Time for Downtime
Target: Reduction of downtimes after overload situations
Maximum equipment availability is of highest priority with one of our Hot Mill customers, specifically on hot levelling machines. Downtimes after overload situations need to be reduced as much as possible. Having already experience with MALMEDIE® Safety Coupling and the short re-commissioning times, the customer decided to upgrade the existing couplings with automatic re-engagement devices to reduce downtimes even further. Now the coupling can be remotely re-engaged simply by pushing a key in the operating room.
30 years of operation – no problem!
After 30 years continuous operation of a MALMEDIE® Gear Coupling in a vertical roughing mill in Belgium, some parts needed replacement for the first time due to wear. Even after such a long time it´s not a problem at all for MALMEDIE® to supply single spare parts accordingly. A smart design, the use of high-quality materials and a good maintenance is the guarantee for a long service life.
Unhappy with competitor´s product – change to MALMEDIE®!
Sometimes decisions appear to be completely wrong afterwards – like in case of a Port Operator in Asia.
Nine big STS container cranes were initially equipped with competitors Drum Couplings at the Boom Hoist. After a short operational time, the first problems appeared – and the Port Operator did not issue the final acceptance of the cranes. All couplings were changed then to the original (Drum Coupling) of MALMEDIE®, and ever since the cranes are running trouble-free.
Optimized Gear Joint Spindles
Sometimes customer requirements are a real challenge – like in case of Gear Joint Spindles for a hot rolling mill in Germany.
The so far used products of a competitor were showing after only a few months of operation cracks and heavy wear. But the operating conditions have been also extreme in terms of high torques at small diameters. Together with the customer and with the aid of FEM design / simulation, MALMEDIE® developed and installed an optimized version – at full customer satisfaction.
SOS Snag Overload System for Container Cranes
A mechanical MALMEDIE® Safety Coupling separates motor and gearbox within a millisecond upon (snag) overloads
Known as to be the first Safety Coupling / Brake based and non-hydraulic Snag Overload Protection, the SOS is reaching new sales records. More than 150 units have been sold for Ship-to-Shore cranes all over the world by May 2016.