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Anthony Michell’s Crankless Engines

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  • A Crankless Engine being tested in a Buick Chassis in 1921

Anthony George Maldon Michell was an English-born engineer that was educated at the Universities of Cambridge in England and Melbourne in Australia. He invented the Mitchell thrust bearing that was patented in 1905. This device when equipped with the one-half ball and pin seen below, and inserted into a matching cup in the bottom of a piston, could drive a round slanted plate as seen below and transfer reciprocating motion into rotary motion.

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  • The Mitchell thrust bearing adapted to this application

Crankless Engines LTD. was formed in Melbourne, Australia in 1920 to develop and  manufacture a new engine design Michell invented in the mid-teens using this idea. The crankless engine was based on a simple yet ingenious method of eliminating many moving engine parts by replacing the crankshaft, connecting rods and the bearings of a conventional engine with the assembly below.

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  • Two piston and slanted plate assembly

Starting in 1923, the shop in Melbourne produced a number of both large and small  engines. By 1927, the company had constructed over eighty of them in various different types. The general lack of interest in the design by major American and British auto manufacturers led the company to stop producing its engines around 1930, but it did licence the design to be built by others. Crankless Engines continued into closing in early 1945.

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  • A five-cylinder engine and transmission assembly produced in 1927

Shown above and below is a small five cylinder engine, clutch and transmission assembly. The head of the engine including: the intake, and exhaust manifolds (fined), valve train, twin spark plugs and carburetor can be seen below left. Below right is another view of the power plant with the valve cover installed. You can learn more about Mitchell and his designs at Engineers Australia, photos from the Museum Victoria. You can also view the Macomber Rotary Engine, a similar wobble-plate design that used connecting rods and was built here in the U.S..

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12 responses to “Anthony Michell’s Crankless Engines

  1. I’ve seen modern diagrams of these things. Have there been any recent attempts to build one? What were their performance characteristics like?

  2. This is the design used on GM a/c compressors starting in the 50s. It was called a axial 6 cylinder consisting of three double ended pistons driven by a wave plate. The texts sounds as though it was adapted to steam engines also. It’s always interesting that what some of us think is new has been around forever!!

  3. What an ingenious piece of mechanical wizardry. It would be interesting to see a modern update of this design and what kind of power output it could give. Wonder what kind of sound it made.

  4. The Michell thrust bearing was not this.It was a for ship and made bigger vessels practical and a wealthy man of Michell. May I direct you to Douglas Self’s site where a full exposition is ,the site is a treat.

  5. That double ended piston looks like a design that was in Popular Mechanics,I think, a few years ago. Labeled as a new 2 stroke, when one end fires, it powers and intakes while the other end compresses and exhausts. Eliminate the glitches and it’s revolutionary.

  6. The drive is usually called a swashplate since it rotates to “swash” around. A wobbly or wobble plate gyrates around and is variously a nutating disk with friction elements against the face as in West or a spider on a z-crank like the A. M. Stanley design for GE and similar. When these have high displacement for their volume and small diameter, the torpedo builders love them. For IC use they are perhaps more difficult to cool when the cylinders are all bunched together.

  7. Phil Irving, the Australian designer (Vincent motorcycle, Repco 1966 F1 engine) worked on these engines and there´s an account of their design and development in his autobiography.

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