Recently, I got the chance to talk with Ross Rivard, the new president of Ringfeder Power Transmission USA, the North American arm of the global manufacturer of couplings, shock-absorbing, and keyless connection technologies. We expect more coupling news from Ringfeder in 2015 as the company leverages new synergies within a range of power-transmission components.

In 2014, Ringfeder acquired Tschan, a German manufacturer of torsionally soft and torsionally rigid couplings for the power-transmission industry. More specifically, Tschan designs and makes shaft-coupling technology tailored to applications, especially in heavy-duty engineering, such as mining and construction machinery, iron and steel production technology, pumps and compressors, cement works, and offshore.

“This acquisition represents a strategically important addition to the division’s product program … the Tschan brand is well-reputed in its industry and recognized for its high quality and performance. We have been keeping an eye on this company for some time now as part of our acquisition activities,” said Anders Birgersson, Managing Director and CEO of the VBG Group in a press release from VBG late last year.

It’s not the first acquisition. In 2009, Ringfeder’s parent company VBG Group acquired couplings-manufacturer Gerwah and joined the two divisions’ assets. There’s almost no crossover between the Tschan and Gerwah couplings products … and in fact, there are synergies between the brands, as Ringfeder was most known for shaft-hub connections but got an expanded couplings portfolio and expertise with Gerwah. So today, Gerwah mainly develops high-quality couplings for driving technology and conveying engineering.

For more about the technology offerings and the current direction of Ringfeder Power Transmission USA, listen to this podcast of my conversation with Rivard:

Two of Rivard’s most informative responses were on application specifics.

When asked for some tips to give application engineers sizing or selecting couplings for a machine, Rivard said that engineers should always collect as much information as possible about the application into which the coupling will go.

Engineers should also answer the following questions:

1. What is the application — a pump package, compressor package, or something else?
2. Does the lead engineer have a preference for a particular style or series of coupling?
3. Is maintenance an issue?
4. What is the horsepower, rpm, or torque that the coupling will need to deliver?
5. Are torque spikes expected on startup or any other time?
6. What is the required safety factor?
7. Does the coupling need to be backlash free?
8. Are there environmental concerns with the application?
9. How much mis-alignment does the coupling need to handle?
10. Is the coupling in a horizontal or vertical installation?
11. Must the coupling be fail-safe?
12. Is balancing required?

After getting all of the above information, the engineer can then select the best coupling that will meet all of the above requirements, said Rivard.

Specific application example: Mining-conveyor application

When asked to give a specific application example, Rivard explained how his company’s RfN5571 series rigid-flanged couplings go into large gearbox installations on a mining-conveyor application in Chile.

The 5571 couplings clamp to shafts with a Shrink Disc on each end to transmit torque from the motor to the driven component (with a zero misalignment capability). Here are the application specifics:

Customer: SM Cyclo De Chile LTD (Sumitomo Drive Technologies)

Year: 2012

End user: Cerrejon Mine in Columbia

Number of couplings: Nine

Approximate order: $150,000

Shafts connected: 220 x 250 mm (four couplings) and 220 x 280 mm (five couplings)

Approximate weight per coupling: 1,720 lb (780 kg)

Torque rating of coupling: 180,000 lb-ft (245,000 Nm)

“In the Cerrejon Coal Mine, our couplings were used to connect the motor to the gear box on the conveyor system of the coal mine.  Because the motor and the gearbox are fixed, they don’t need misalignment capabilities from the coupling.  Another factor in selecting the Ringfeder 5571 series — the end connections are made with Shrink Discs.  Those are suitable because Cerrejon wanted no keyways and easier coupling installation and removal … so the Ringfeder 5571 series with Shrink Discs was the perfect match,” said Rivard.

More from Ringfeder on the Design World Network:

New flange couplings more secure than standard press fits

New Gerwah product lineup |  A look at coupling-selection tools

From the archives: Certifications, conferences, and other couplings