1.Your personal experiences with Installation, Operation & Maintenance aspects of Elastomeric Couplings. I witnessed a severe torsional vibration in a Nissan bus driveline. This was solved using elastomeric couplings because it was possible to tune the resilient element constituents. Manufacturers will generally provide such a tuning service on a return basis.

2.Feasibility of its use in our typical system as shown above? It is just a matter of selection.

3.Who are renowned suppliers in & around India? Google around.

4.Your views on whether elastomeric couplings can replace Geared Couplings completely in future? It is purely a matter of availability and selection. I worked for a/the world leader in toothed roll crushers/sizers who saw an opportunity to supply geared couplings to the National Coal Board throughout the UK. Wing Nut, who ran the CAD for them in those days, made up the sales datasheet where the bottom range coupling was discarded as unprofitable. But he moved the capacity cell column up a notch in the process. This meant that the coupling sold with say 100Nm rating would only carry about 60Nm. Needless to say they were no longer in the business; but Reynolds Croft were. ■

I have more experience with geared couplings than I do with elastomeric. They both have their pros and cons. I always choose gear over elastomeric because I find that if they are installed correctly the life span is greater and require no maintenance. Preventative maintenance such as a monthly or weekly vibration analysis will monitor misalignment issues if they appear due to some unforeseen event.

As with any coupling good installation practices with tight tolerances are critical. Elastomeric will allow for greater misalignment at installation (millwrights like them for that reason) but be aware that the more you misalign the coupling the shorter the life of the coupling will be. Gear couplings force the millwright to take much more care during installation to get the required alignment tolerances.

Just as John says it all comes down to a personal preference and availability. ■

Choosing a coupling for many, stick with what they know, preference if you like. In our world of couplings we come across many different types and some couplings we have never seen before. The coupling as with all parts of the drive train are an integral component, the coupling transmits the torque to the next component for onward travel to the end of the machine. How you want that torque delivered is all important to the type of coupling you select along with the running variables it has to deal with, misalignment, shock loads, vibration etc.

As for Gear vs Elastomer, as above its all down to what you want to achieve. Gear couplings have been around for many years now, though still considered by some as the workhorse, as it will transmit high torque loads in a small factor. Elastomer couplings with give some degree of dampening to the load, having 3 in one drive train though may be too much dampening.

Gear couplings need periodic inspections of the grease and tooth wear. Elastomer couplings are generally easier to maintain.

Gear couplings have narrow parameters for dealing with misalignment compared to most Elastomer, though Gear couplings must a small amount of misalignment, this is needed to lubricate the teeth, lack of tooth lubrication will cause premature failure of the gear coupling.

You'll no doubt seeing that good coupling selection is not just a case of this or that. India has a benefit of many coupling manufactures these days, though not so good a lot of them seem to be making the Fenner style of couplings. My advice would be to search out at least three coupling manufacture or suppliers that deal with a different range of couplings than each other and have them look at your equipment and you can compare there offerings. Ensure they tell you what their couplings will not cope with, ALL couplings have parameters, the perfect coupling to deal with all applications is yet to be found. ■