Henfel's HFPM Variable Speed Hydrodynamic Coupling Animation and Application

[@sumanthkumarbatchu7070]

Very good explanation sir.One small doubt even scoop is IN condition will oil go to tank ?

[@RingfederHenfel]

Yes, if I understand your question well, whenever scoop tube is totally in, most of the fluid will remain in the tank.

[@huleshkumarbareth3877]

Thanks you sir

[@brayancamilo6455]

excellent

[@aoz2695]

As I can understand; if sleeve is insert position we can obtain low rotation speed, if sleeve is retract position we can obtain high rotation speed Is it true ?

[@RingfederHenfel]

yes, in short, that is it. If the scoop tube is in, the volume of fluid in the operating chamber is smaller, speed output will be lower. If the scoop tube is out, is the opposite, more speed.

[@andrerousseau5730]

The word "efficiency" get's flashed around like a casual by-word. I have asked and asked yet no-one (so far) has been able to quote specific numbers or present graphical test results of the efficiency of the Fottinger hydraulic coupling. My general understanding from the automotive world is that it is unlikely to exceed much above ~80% whereas a well-designed fully-geared drive can exceed 90%. This is an important detail in respect of fuel consumption. My understanding is that ROLLS-ROYCE dyno tested salvaged DB's and analysed their supercharger drive design and efficiency. This must have generated an official report as this testing was commissioned by the R.A.E. I would like to see that report. It would go a long way toward explaining the mystery as to why R-R (and others) never copied it. Does any know for sure??

[@RingfederHenfel]

Our models of Variable speed fluid coupling, which are usually applied to bulk material handling equipment such as long distance belt conveyor drives, transmit 97% of the input RPM and torque to the driven machine, in average. Our models of hydrodynamic couplings have only industrial applications, we can't respond for other manufacturers of automotive technologies that are based on Fottinger's principle.

[@andrerousseau5730]

@@RingfederHenfel Thanks for that. I assume the 97% figure you quote is for a fixed-speed, fixed-load installation. I am interested to know how that efficiency number chances as these two parameters vary especially as achieving speed-change is by means of varying the fluid volume. This couldn't possibly be efficient due to the high level of frictional heating arising from the fluid agitation. Can you quote me some numbers and/or supply a graph illustrating how these change?

[@RingfederHenfel]

@@andrerousseau5730 thanks for the interesting debate. Yes, you are right about that, this figure is at nominal operating speed of the equipment, not during start up and acceleration. Nevertheless, you have to consider the kind of application we are using this technology for. Take a belt conveyor, for instance, and imagine you have to start it up under loaded conditions, e.g, with the belt full of iron ore. You don't want to start it up abruptly, it'd tear up the belt. Besides, the motor would take this load directly, if it doesn't break immediately it would break eventually. With this technology, there's no mechanical contact between drive and driven machine, and therefore, you can let the acceleration take its course. It's actually one of the purposes of using a fluid coupling, since you can set a time frame to achieve the desired and ideal nominal speed of the equipment. As for the temperature issue you mentioned, there is a heat exchanger to cool the fluid down in case of overloads and sensors to shut it down if a set value is reached. To conclude, hydrodynamic transmission have many possible applications, but it's not ideal for all of them. But when you consider it as an startup aid, it is suitable for many industrial equipment, such as belt conveyors, ship loaders, pumps, fans, etc...

[@henryway8771]

Nice explanation of operating principle. The translation needs a little work. Clearly the voiceover was a nontechnical person.

[@RingfederHenfel]

Thanks Henry, I appreciate the feedback. I'd love to hear your suggestions to improve the translation. Could you e-mail them to me? [e-mail]