.... and some things to do with it
I) Opening Accolade
Of Tesla's celebrated forgotten inventions the Mechanical Oscillator proudly stands second to none in obscurity. While many claim to have heard of and to have opinions about its much praised or maligned but generally completely misunderstood sophisticated younger brother, that Monarch of Machines, the Tesla Turbine, few will claim any knowledge at all about what is arguably the best piston fluid heat engine design ever.
Here are a few quotes from Tesla himself about the engine and how it came to be:
The Problem Of Increasing Human Energy, With Special References To The Harnessing Of The Sun's Energy
The Century Illustrated Magazine, June 1900.
".. I finally conceived a combination of apparatus which should make possible the obtaining of power from the medium by a process of continuous cooling of atmospheric air. This apparatus, by continually transforming heat into mechanical work, tended to become colder and colder, and if it only were practicable to reach a very low temperature in this manner, then a sink for the heat could be produced, and energy could be derived from the medium.".
".. the primary object of which was to secure the greatest economy of transformation of heat into mechanical energy. A characteristic feature of the engine was that the work-performing piston was not connected with anything else, but was perfectly free to vibrate at an enormous rate."
".. the engine which I have named "the mechanical oscillator." In this machine I succeeded in doing away with all packings, valves, and lubrication, and in producing so rapid a vibration of the piston that shafts of tough steel, fastened to the same and vibrated longitudinally, were torn asunder. By combining this engine with a dynamo of special design I produced a highly efficient electrical generator, invaluable in measurements and determinations of physical quantities on account of the unvarying rate of oscillation obtainable by its means. I exhibited several types of this machine, named "mechanical and electrical oscillator," before the Electrical Congress at the World's Fair in Chicago during the summer of 1893, in a lecture which, on account of other pressing work, I was unable to prepare for publication. On that occasion I exposed the principles of the mechanical oscillator, but the original purpose of this machine is explained here for the first time."
"In the process, as I had primarily conceived it, for the utilization of the energy of the ambient medium, there were five essential elements in combination, and each of these had to be newly designed and perfected, as no such machines existed. The mechanic oscillator was the first element of this combination, and having perfected this, I turned to the next, which was an air-compressor of a design in certain respects resembling that of the mechanical oscillator. Similar difficulties in the construction were again encountered, but the work was pushed vigorously, and at the close of 1894 I had completed these two elements of the combination, and thus produced an apparatus for compressing air, virtually to any desired pressure, incomparably simpler, smaller, and more efficient than the ordinary."
To more fully understand the significance of the features incorporated into the Mechanical Oscillator's design let's briefly discuss some of them:
First is the operating principle that the Prime Mover, 'the work-performing piston' Tesla mentioned above, be isolated from the load. This basic step which is ignored in offerings presented to the public today, except for a few gas-electric hybrid automobile power systems, ensures longer mechanical life and lower maintenance costs by the simple expedient of eliminating excessive stresses brought on by varying load demands.
It also allows for engines designed to run within a constant speed range commiserate with their most efficient operation thus lowering manufacturing as well as operating costs. Hydraulic systems pretty much accomplish the same thing through the use of an accumulator to respond directly to load demands while the primary pump supplies the accumulator. Most of Tesla's electrical systems did the same thing via banks of condensers which energized the secondary load circuits while the main generators supplied the condenser arrays. This same concept can be found in aircraft such as the legendary military cargo plane, the C-130 which uses constant speed engines in conjunction with variable prop blades to control thrust.
Also while this fact seems to be almost completely overlooked or ignored, the innovative use of an Air Spring to stop and reverse reciprocating motion eliminates the crank assembly and with it the costs and complexity of its shafts, bearings, lubrication system, etc., not to mention the attendant weight, friction, wear, maintenance, and breakage associated with it all. Since this 'bottom end' found in most steam and IC piston engines accounts for up to 60 - 80 percent of manufacturing and operational cost, weight, and maintenance, if this isn't a big deal, what is?
For those who will cry out: 'But what about getting that reciprocating motion turned into rotary motion?!' This is where the principle of separating the prime mover from the load comes into play. Tesla's gen-sets powered by Mechanical Oscillators use reciprocating magnets, not rotary; the exact same principle used by those emergency shake and shine flash lights so popular a few years ago. Tesla was the first proponent that I know of for hybrid power systems, in his case he advocated reciprocating steam Oscillator engines to run electrical generators to power rotary electrical motors for both boats and trains. In a similar fashion a Mechanical Oscillator driving a pump module can power a hydraulic system which feeds rotary hydraulic motors. Many industries with heavy duty in-house transport needs regularly use hydraulic powered vehicles because of their rugged and low maintenance attributes. These power systems are not used in public offerings partially because of the huge negative economic impact it would have on the parts and service industries.
For sheer elegance of design the Mechanical Oscillator is just about unmatched. Not only does its design eliminate the bottom end crank assembly, it also eliminates independent valves and timing mechanisms. If you have ever looked at the diagrams for large steam engines, especially large stationary ones for manufacturing plants, or seen them operating you can get an idea of the sheer mechanical complexity involved in just getting those valves timed correctly. The Mechanical Oscillator doesn't have independent valves or timing systems, it has a single moving shaft-piston component - lets say that again: 'it has a single moving shaft-piston component' - of which the power piston through the use of plenum grooves and internal channels together with precisely placed intake and exhaust cylinder ports, acts as its own valve assembly and timing mechanism.
And if that isn't enough, remember those bearings that got thrown out with the crank assembly? Well, all of those from the main crank bearings to the piston wrist bearings were load bearings subject to constant stress and requiring a dedicated lubrication system. The few bearings the Mechanical Oscillator does have are all sliding bearings which are a completely different animal altogether.
To finish up this opening accolade of the Mechanical Oscillator it is not out of place to point out that, just as in the case of hybrid power systems, Tesla anticipated the ***anese revolution in high speed automotive engines. And once again he out did his future competitors, as while the rpms of today’s engines range from 5,000 to 10,000, the Mechanical Oscillator worked at frequencies of 60,000 or so with a stroke of around three eighths of an inch or 9.5 mm for the intelligentsia amongst us.
All praise to the Magnificent Mechanical Oscillator.
References:
The Problem Of Increasing Human Energy, With Special References To The Harnessing Of The Sun's Energy
http://www.tfcbooks.com/tesla/1900-06-00.htm
Tesla's Oscillator and Other Inventions
by Thomas Commerford Martin
http://www.tfcbooks.com/tesla/1895-04-00.htm
1894-01-02, US Patent 511,916 Electrical Generator
1894-02-06, US Patent 514,169 Reciprocating Engine
1894-04-10, US Patent 517,900 Steam Engine
---
@ C. Kurtz 2014 This content is offered under CreativeCommons by sa-3.0
I) Opening Accolade
Of Tesla's celebrated forgotten inventions the Mechanical Oscillator proudly stands second to none in obscurity. While many claim to have heard of and to have opinions about its much praised or maligned but generally completely misunderstood sophisticated younger brother, that Monarch of Machines, the Tesla Turbine, few will claim any knowledge at all about what is arguably the best piston fluid heat engine design ever.
Here are a few quotes from Tesla himself about the engine and how it came to be:
The Problem Of Increasing Human Energy, With Special References To The Harnessing Of The Sun's Energy
The Century Illustrated Magazine, June 1900.
".. I finally conceived a combination of apparatus which should make possible the obtaining of power from the medium by a process of continuous cooling of atmospheric air. This apparatus, by continually transforming heat into mechanical work, tended to become colder and colder, and if it only were practicable to reach a very low temperature in this manner, then a sink for the heat could be produced, and energy could be derived from the medium.".
".. the primary object of which was to secure the greatest economy of transformation of heat into mechanical energy. A characteristic feature of the engine was that the work-performing piston was not connected with anything else, but was perfectly free to vibrate at an enormous rate."
".. the engine which I have named "the mechanical oscillator." In this machine I succeeded in doing away with all packings, valves, and lubrication, and in producing so rapid a vibration of the piston that shafts of tough steel, fastened to the same and vibrated longitudinally, were torn asunder. By combining this engine with a dynamo of special design I produced a highly efficient electrical generator, invaluable in measurements and determinations of physical quantities on account of the unvarying rate of oscillation obtainable by its means. I exhibited several types of this machine, named "mechanical and electrical oscillator," before the Electrical Congress at the World's Fair in Chicago during the summer of 1893, in a lecture which, on account of other pressing work, I was unable to prepare for publication. On that occasion I exposed the principles of the mechanical oscillator, but the original purpose of this machine is explained here for the first time."
"In the process, as I had primarily conceived it, for the utilization of the energy of the ambient medium, there were five essential elements in combination, and each of these had to be newly designed and perfected, as no such machines existed. The mechanic oscillator was the first element of this combination, and having perfected this, I turned to the next, which was an air-compressor of a design in certain respects resembling that of the mechanical oscillator. Similar difficulties in the construction were again encountered, but the work was pushed vigorously, and at the close of 1894 I had completed these two elements of the combination, and thus produced an apparatus for compressing air, virtually to any desired pressure, incomparably simpler, smaller, and more efficient than the ordinary."
To more fully understand the significance of the features incorporated into the Mechanical Oscillator's design let's briefly discuss some of them:
First is the operating principle that the Prime Mover, 'the work-performing piston' Tesla mentioned above, be isolated from the load. This basic step which is ignored in offerings presented to the public today, except for a few gas-electric hybrid automobile power systems, ensures longer mechanical life and lower maintenance costs by the simple expedient of eliminating excessive stresses brought on by varying load demands.
It also allows for engines designed to run within a constant speed range commiserate with their most efficient operation thus lowering manufacturing as well as operating costs. Hydraulic systems pretty much accomplish the same thing through the use of an accumulator to respond directly to load demands while the primary pump supplies the accumulator. Most of Tesla's electrical systems did the same thing via banks of condensers which energized the secondary load circuits while the main generators supplied the condenser arrays. This same concept can be found in aircraft such as the legendary military cargo plane, the C-130 which uses constant speed engines in conjunction with variable prop blades to control thrust.
Also while this fact seems to be almost completely overlooked or ignored, the innovative use of an Air Spring to stop and reverse reciprocating motion eliminates the crank assembly and with it the costs and complexity of its shafts, bearings, lubrication system, etc., not to mention the attendant weight, friction, wear, maintenance, and breakage associated with it all. Since this 'bottom end' found in most steam and IC piston engines accounts for up to 60 - 80 percent of manufacturing and operational cost, weight, and maintenance, if this isn't a big deal, what is?
For those who will cry out: 'But what about getting that reciprocating motion turned into rotary motion?!' This is where the principle of separating the prime mover from the load comes into play. Tesla's gen-sets powered by Mechanical Oscillators use reciprocating magnets, not rotary; the exact same principle used by those emergency shake and shine flash lights so popular a few years ago. Tesla was the first proponent that I know of for hybrid power systems, in his case he advocated reciprocating steam Oscillator engines to run electrical generators to power rotary electrical motors for both boats and trains. In a similar fashion a Mechanical Oscillator driving a pump module can power a hydraulic system which feeds rotary hydraulic motors. Many industries with heavy duty in-house transport needs regularly use hydraulic powered vehicles because of their rugged and low maintenance attributes. These power systems are not used in public offerings partially because of the huge negative economic impact it would have on the parts and service industries.
For sheer elegance of design the Mechanical Oscillator is just about unmatched. Not only does its design eliminate the bottom end crank assembly, it also eliminates independent valves and timing mechanisms. If you have ever looked at the diagrams for large steam engines, especially large stationary ones for manufacturing plants, or seen them operating you can get an idea of the sheer mechanical complexity involved in just getting those valves timed correctly. The Mechanical Oscillator doesn't have independent valves or timing systems, it has a single moving shaft-piston component - lets say that again: 'it has a single moving shaft-piston component' - of which the power piston through the use of plenum grooves and internal channels together with precisely placed intake and exhaust cylinder ports, acts as its own valve assembly and timing mechanism.
And if that isn't enough, remember those bearings that got thrown out with the crank assembly? Well, all of those from the main crank bearings to the piston wrist bearings were load bearings subject to constant stress and requiring a dedicated lubrication system. The few bearings the Mechanical Oscillator does have are all sliding bearings which are a completely different animal altogether.
To finish up this opening accolade of the Mechanical Oscillator it is not out of place to point out that, just as in the case of hybrid power systems, Tesla anticipated the ***anese revolution in high speed automotive engines. And once again he out did his future competitors, as while the rpms of today’s engines range from 5,000 to 10,000, the Mechanical Oscillator worked at frequencies of 60,000 or so with a stroke of around three eighths of an inch or 9.5 mm for the intelligentsia amongst us.
All praise to the Magnificent Mechanical Oscillator.
References:
The Problem Of Increasing Human Energy, With Special References To The Harnessing Of The Sun's Energy
http://www.tfcbooks.com/tesla/1900-06-00.htm
Tesla's Oscillator and Other Inventions
by Thomas Commerford Martin
http://www.tfcbooks.com/tesla/1895-04-00.htm
1894-01-02, US Patent 511,916 Electrical Generator
1894-02-06, US Patent 514,169 Reciprocating Engine
1894-04-10, US Patent 517,900 Steam Engine
---
@ C. Kurtz 2014 This content is offered under CreativeCommons by sa-3.0
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