The Ontario Quasiturbine Application Promotion Association

What is a Quasiturbine?


  A Quasiturbine (also known as a Qurbine) is a no crankshaft rotary engine having a 4-faced articulated rotor with a free and accessible center.

  The Quasiturbine engine was invented by the Saint-Hilaire family and first patented with the Canadian and US Patent offices in December 1997.

  The engine makes use of a complex computer calculated oval shape stator housing, creating regions of increasing and decreasing volumes as the rotor turns.

  In the Quasiturbine engine, the four strokes of a typical Beau de Rochas (Otto) cycle [intake - compression - power - exhaust] are arranged sequentially around a near oval.

  This is unlike the reciprocating motion of a piston engine.

  • Because of the configuration of the rotor faces a Quasiturbine it:
    • Will rotate without vibration [the rotor faces are balanced within the housing]
    • Has no "dead time' between compression strokes [gas expansion is continuous]
    • Produces a strong torque at low RPM under a variety of modes and fuels.
  • The Quasiturbine can be used as:
  •             An air motor
  •             A steam engine
  •             A Stirling engine
  •             A compressor
  •             A pump
  •             An extremely compact and efficient Internal Combustion Engine. [IC Engine]

        It is capable of burning fuel using "photodetonation", the optimum combustion mode for fuels.  (Piston engines cannot accommodate detonation.)

  • The Quasiturbine is at the crossroads of the three modern engines:
  •             Inspired by the turbine,
  •             It perfects the piston engine,
  •             It improves upon the Wankel rotary engine.
  •   The Quasiturbine is "universal" in relation to energy sources.  It can use any liquid and gaseous "fuels" to run as:
    • An Internal Combustion Engine using liquid or gaseous fuels such as:
      • gasoline (petrol)
      • liquefied petroleum gas [LPG]
      • vapourized petroleum gas
      • compressed natural gas
      • kerosene (paraffin oil / Jet fuel)
      • Tractor vaporising oil [TVO]
      • hydrogen
      • diesel fuel
      • landfill gas
      • methanol
      • ethanol
      • biodiesel
      • biobutanol
      • peanut oil (or other vegoils)
      • bioethanol
      • biomethanol (methyl or wood alcohol)
      • any other biofuels
    • A Steam Engine
    • A Pneumatic Engine
    • A Hydraulic Engine

How it Works

  In the Quasiturbine engine, the four strokes of a typical cycle de Beau de Rochas (Otto) cycle are arranged sequentially around a near oval.

  In the basic single rotor Quasiturbine engine, an oval housing surrounds a four-sided articulated rotor which turns and moves within the housing.

  The sides of the rotor seal against the sides of the housing, and the corners of the rotor seal against the inner periphery, dividing it into four chambers.

Quasiturbine combustion cycle

Intake (aqua),
Compression (fuchsia),
Combustion (red),
Exhaust (black).

For internal combustion engines, the spark plug would be located at the top (green)

  As the rotor turns, its motion and the shape of the housing cause each side of the housing to get closer and farther from the rotor, compressing and expanding the chambers similarly to the "strokes" in a reciprocating engine.

  However, whereas a four stroke piston engine produces one [1] combustion stroke per cylinder for every two [2] revolutions,
    the chambers of the Quasiturbine rotor generate four [2] combustion "strokes" per one [1] rotor revolution.

  This is eight [8] times more than a four stroke piston engine.

Additional Characteristics:

  • Because the Quasiturbine has no crankshaft, the internal volume variations do not follow the usual sinusoidal engine movements.
    • This provides very different characteristics than a Piston or Wankel engine.
  • Each Quasiturbine rotor face rocks back and forth in reference to the engine radius, but stays at a constant distance from the engine center at all times.
    • This is contrary to the Wankel engine, where the crankshaft moves the rotary piston face inward and outward.
    • This produces only pure tangential rotational forces.
  • Engine noise is about 20 times less than a piston engine of comparable power because:
    • For the same power output (compared to a conventional engine), the volume capacity is divided by eight [8].
    • Relaxation of the exhaust gas is more complete
      • Less waste heat is expelled from the exhaust because of the greater expansion of the gas.
  • In smaller models:
    • The vibration is comparable an electric motor
    • The acceleration is faster than an electric motor
  • The density of power per volume and unit of weight is at least four [4] times better than that of the of a comparable piston engine.
  • A Quasiturbine can use continuous combustion.
  • A Quasiturbine has no crankshaft.
  • A Quasiturbine does not require a flywheel to maintain rotation [no inertia is required to maintain rotation].
  • No complicated accessories are required:
    • No piston rings
    • No camshaft
    • No valve trains
    • No valve stems
    • No lift rods
    • No push rods
    • No valve springs (coil springs)
    • No timing belts
    • No gears
    • No seals
    • No oil pan
    • No oil pump
    • No complicated ignition system
      • No distributor
  • A short pressure impulse makes it possible to reduce heat flow into the engine components during thermal relaxation.
    • An extended relaxation cycle allows for better extraction of mechanical energy.
  • The short pressure impulse:
    • Limits the time of containment, which
    • Limits the production of the NOx (estimated to be 500 times less than a piston engine)
  • Engine idle rotation is low:
    • Only about 150 rpm
    • Maximum of about 3000 rpm.
  • Low RPM means:
    • Better engine durability
    • Lower gear ratios
  • Note that a four-stroke piston has such a long "dead time", its average torque is only about 15% of the peak torque.
  • Since the Quasiturbine does not have any "dead time", the average torque is only 30% lower than the peak torque.
  • For this reason, a Quasiturbine does not need to be as robust as a piston engine with the same power output.
    • The outer housing of a Quasiturbine would only need to be about 1/5th (~20%) as thick as an equivalent piston engine.
    • This translates into both a savings of materials and additional engine weight savings. 


Quasiturbine Animation

Info: Lloyd Helferty, Thornhill, Ontario 905-707-8754

 (The contents of this website is independent of «Quasiturbine Agence» and its related partners)        
For further technical information see www.quasiturbine.com

Updated 2006-07-27