A converter converts mechanical energy of a piston to and from electrical energy

[Lloyd]

A patent filed by Bill Gates.



http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220090091138%22.PGNR.&OS=DN/20090091138&RS=DN/20090091138

SUMMARY

[0001]In one aspect, an internal combustion engine includes a first piston slidably disposed in a first cylinder with a closed end, a first port configured to admit a reactant to the first cylinder, and a first converter operable with the first piston to convert mechanical energy of the first piston from and to electrical energy within a piston cycle. The first converter may be configured to convert mechanical energy of the first piston to electrical energy during a power stroke, and to drive the first piston during any or all of an exhaust stroke, an intake stroke, and a compression stroke. The first piston may include a magnet (e.g., a permanent magnet or an electromagnet), and the first converter may include an armature configured to generate electric current in response to movement of the magnet or to move the magnet by driving electric current through a coil. The first converter may include a plurality of coils, in which case a first subset of the plurality may be operable to convert electrical energy to mechanical energy of the first piston, and a second subset to convert mechanical energy of the first piston to electrical energy. The engine may further include a thermal controller that acts to limit thermal excursions of all or a portion of the engine (e.g., a cooling system or insulation). The first piston may include an armature configured to interact with a magnetic field through a variable reluctance or variable inductance magnetic circuit.

[0002]The engine may further include a reaction trigger (e.g., an electrical igniter such as a spark plug, a thermal igniter, a chemical igniter, a catalyst, a hypergolic injector, particle beam igniter, or a plasma injector) configured to initiate a chemical reaction in a reactant disposed between the first piston and the closed end of the first cylinder. The reaction trigger may be disposed at the closed end of the first cylinder, on the first piston, or elsewhere. The reaction trigger may draw power from the first converter, may be electrically coupled to the first converter, or may draw power from an energy management system coupled to the first converter. The first port may include a valve, which may be configured to open and close via a camshaft, which may in turn be configured to be rotated by an electromagnetic actuator such as a stepper motor, or the valve may be mechanically actuated. The engine may include a second port configured to allow a reaction product to escape from the first cylinder (e.g., on the first cylinder or on the first piston), in which case the first port may include an intake valve and the second port an exhaust valve. The intake and exhaust valves may each be configured to open and close at selected times during the piston cycle (e.g., by mechanical or electronic coupling to the first piston). The intake and exhaust valves may be electronically coupled to the first piston via the first converter. The converter or an energy management system may be configured to supply power to the intake valve and the exhaust valve. The first port may be configured to allow a reaction product to escape from the first cylinder (e.g., on the first cylinder or on the first piston), in which case the engine may include a valve configured to switch the first port from connection with an intake path to connection with an exhaust path.

[Jedon]

http://en.wikipedia.org/wiki/Free-piston_engine

[mobile_bob]

if Gates and associates are granted a patent on that one, i will have lost all faith in our system.

all of this is under public domain, having been done over and over again over the last century plus.

bob g

[rcavictim]

I fail to see how by driving the coil with electricity that gasoline or other hydrocarbon fuel will somehow magically appear and to flow out the other end of the device. 

[M61hops]

Maybe 30 years back on the cover of an issiue of Popular Science magizene was a free piston engine that the output was AC electricty.  The inventor had built several prototypes that supposedly ran well and put out 200HP from a 400cc engine.  Open the throttle and the frequency soared as well as the output power!  Should have been a long life piston and bore as there was no side thrust.  Needed heavy springs on armature to adsorb a misfire!  Another one of those things you never hear about again  !                Leland

[mobile_bob]

apparently it takes an input pulse of electricity to start the piston on the compression stroke, once it fires then from then on
it will produce electrical power.

the problem is one of efficiency and also one of epa certification as most of these free piston jobs are two stroke, even though
the one in the Gates and associates patent application appears to have valves,

not sure how the valve train would work, as there is no rotary motion to activate the valves, and solenoids would be too fast
valve action requires a fairly sophisticated control scheme to provide for gradual opening and closing, otherwise you wear out the
keepers very quickly and  drop a valve into the chamber, which ends badly every time.

i don't see the patent application as passing to a full on patent for a number of reasons, and i don't see the idea coming to much other
than very specific applications where light weight, and high output are paramount and lifespan is measured in a few hundred hours
along with poor efficiency.

i may be wrong, but i don't see one of these units displacing a lister/oid or changfa genset anytime soon.

bob g