Search Images Maps Play YouTube News Gmail Drive More »
Advanced Patent Search | Web History | Sign in

Patents

An engine comprises an output shaft journalled in a crankcase for rotation about an axis, an even number of cylinders, each having its axis parallel to the shaft axis, arranged in diametrically opposite pairs radially equidistant from the shaft axis and equally spaced-apart circumferentially, and a piston movable axially along each cylinder. A cross-head beam for each pair of pistons is connected to the respective pistons and journalled on a carrier that is received on the shaft for rotation with and movement axially along the shaft. A mechanism selectively moves the carrier axially along the shaft to vary the clearance volumes of the cylinders. The engine operates on a six-stroke cycle consisting of a four-stroke combustion cycle followed by a two-stroke steam cycle. The water injected for the steam cycle cools the engine. The intake air for the combustion cycle is supercharged and preheated before induction. There are two intake ports for each cylinder, each having a cam-actuated...

Inventor: Gregory J. Larsen
Original Assignee: Medicor Science, N.V.
Current U.S. Classification: 123/64; 123/25.00C; 123/56.4; 123/318
International Classification: F02B 7526

View patent at USPTO
Search USPTO Assignment Database

Citations

Cited PatentFiling dateIssue dateOriginal AssigneeTitle
US1339176Sep 18, 1915May 4, 1920INTERNAL-COLFFLBTTSTION ENGINE
US1433650Feb 2, 1921Oct 31, 1922A BODY CORPORATE
US1501392May 11, 1920Jul 15, 1924VALVE GEAR FOR INTERNAL COMBUSTION ENGINES
US1698102Jul 1, 1927Jan 8, 1929CONSTRUCTION AND METHOD OEI OPERATING CRANKLESS INTERNAL COMBUSTION
US1950970Jun 8, 1931Mar 13, 1934TWO-CYCLE ENGINE
US2280375Sep 10, 1938Apr 21, 1942PISTON MECHANISM
US2465638May 24, 1945Mar 29, 1949STROKE VARYING MECHANISM FOR
US2532254Nov 24, 1945Nov 28, 1950DEVICE FOR CONVERTING MOTION
US2671311Mar 16, 1951Mar 9, 1954ROHRBACH
US3074228Dec 9, 1960Jan 22, 1963COMBINED INTERNAL COMBUSTION AND STEAM ENGINES
US3319874Dec 16, 1964May 16, 1967VARIABLE DISPLACEMENT-VARIABLE CLEARANCE DEVICE
US3356080Dec 29, 1965Dec 5, 1967INTERNAL COMBUSTION ENGINE WITH WOBBLE PLATE SHAFT DRIVE
US3416502Apr 22, 1965Dec 17, 1968INTERNAL COMBUSTION ENGINES
US3964263Dec 31, 1974Jun 22, 1976Six cycle combustion and fluid vaporization engine
US4090478Jul 26, 1976May 23, 1978Multiple cylinder sinusoidal engine
US4143518May 22, 1978Mar 13, 1979Internal combustion and steam engine
US4144771Apr 7, 1977Mar 20, 1979Vadetec CorporationVariable stroke piston type engine
US4174684May 23, 1977Nov 20, 1979Variable stroke internal combustion engine
US4281626Apr 30, 1979Aug 4, 1981Vaporizable liquid injection system and method for internal combustion engine
US4294139Nov 30, 1979Oct 13, 1981U.S. Philips CorporationDrive for a machine comprising variable-stroke reciprocating pistons
US4357917May 9, 1979Nov 9, 1982Nissan Motor Company, LimitedVariable valve timing system for induction control of an internal combustion engine
US4433596Mar 13, 1981Feb 28, 1984Wabbler plate engine mechanisms
US4470394Jan 7, 1983Sep 11, 1984Toyo Kogyo Co., Ltd.Supercharger control means for internal combustion engine

Referenced by

Citing PatentFiling dateIssue dateOriginal AssigneeTitle
US4976226Jul 11, 1989Dec 11, 1990CKD Praha, KombinatMethod for increasing the heat efficiency of a piston combustion engine
US5140953Jan 15, 1991Aug 25, 1992Dual displacement and expansion charge limited regenerative cam engine
US5377112Dec 19, 1991Dec 27, 1994Caterpillar Inc.Method for diagnosing an engine using computer based models
US5442971Oct 13, 1993Aug 22, 1995Tsentralny Nauchno-Issledovatelsky Avtomobilny I Avtomotorny InstitutMechanism for transforming rotary motion of a shaft into translational motion of actuating members
US5526266Oct 13, 1994Jun 11, 1996Caterpillar Inc.Method for diagnosing an engine using a computer based boost pressure model
US5572959Feb 28, 1995Nov 12, 1996Fanja Ltd.Method for controlling the working cycle in an internal combustion engine and an engine for performing said method
US5585553Jul 28, 1995Dec 17, 1996Caterpillar Inc.Apparatus and method for diagnosing an engine using a boost pressure model
US5604306Jul 28, 1995Feb 18, 1997Caterpillar Inc.Apparatus and method for detecting a plugged air filter on an engine
US5646341Jul 28, 1995Jul 8, 1997Caterpillar Inc.Apparatus and method for diagnosing an engine using an oil pressure model
US6279520Jul 17, 2000Aug 28, 2001Adiabatic, two-stroke cycle engine having novel scavenge compressor arrangement
US6311651Dec 17, 1999Nov 6, 2001Computer controlled six stroke internal combustion engine and its method of operation
US6443108Feb 6, 2001Sep 3, 2002Ford Global Technologies, Inc.Multiple-stroke, spark-ignited engine
US6561139Oct 4, 2001May 13, 2003Evan Guy Enterprises, Inc.Method and apparatus for reducing emissions of internal combustion engines
US6571749Nov 5, 2001Jun 3, 2003Computer controlled six-stroke cycle internal combustion engine and its method of operation
US6968751Jan 21, 2004Nov 29, 2005Innovation Engineering, Inc.Axial piston machines
US7021272Jun 3, 2003Apr 4, 2006Computer controlled multi-stroke cycle power generating assembly and method of operation
US7025022Jun 28, 2001Apr 11, 2006Exhaust valve and intake system
US7117828Jul 23, 2002Oct 10, 2006Shuttleworth Axial Motor Company LimitedAxial motors
US7418928Apr 28, 2006Sep 2, 2008Caterpillar Inc.Engine and method for operating an engine
US7549412Feb 13, 2006Jun 23, 2009System and method for recovering wasted energy from an internal combustion engine
US8006654Sep 9, 2010Aug 30, 2011High efficiency eight stroke internal combustion engine

Claims

1. An engine comprising an output shaft journaled in a crankcase for rotation about an axis, an even number of cylinders, each having its axis parallel to the shaft axis, arranged in diametrically opposite pairs radially equidistant from the shaft axis and equally spaced-apart circumferentially, a piston movable axially along each cylinder, a crosshead beam for each pair of pistons connected to the respective pistons and journalled on a carrier that is received on the shaft for rotation with and movement axially along the shaft, the pistons being connected by connecting rods to the crosshead beams by slider assemblies, each of which includes a cylindrical slideway affixed to a crankcase housing and having an axis aligned with the corresponding cylinder, a slider received in each slideway, and means coupling the corresponding crosshead beam to the slider for biaxial rotation and for axial sliding motion of the beam relative to the connecting rod, whereby the piston connecting rods move solely axially of the cylinders, means for selectively moving the carrier axially along the shaft to vary the end clearance volumes of the cylinders, at least one intake port for each cylinder having a cam-actuated valve, the cams that actuate the intake valves being timed to open the intake valve of each cylinder for induction of a mixture of fuel and air every third downstroke of the corresponding piston, a combustion gas exhaust port for each cylinder having a cam-actuated valve, a steam exhaust port for each cylinder having a cam-actuated valve, the combustion exhaust and steam exhaust valves being timed such that the engine operates in a six-stroke cycle consisting of a four-stroke combustion cycle and a two-stroke steam cycle, means for injecting water into each cylinder at the end of each combustion exhaust stroke of the corresponding piston, an intake manifold communicating with the intake ports of all of the cylinders, means for supplying air to the intake manifold, and means for injecting fuel into the intake manifold including at least one fuel injector, the intake manifold being a chamber defined in part by head walls of the engine cylinders, whereby the air and fuel supplied to the manifold are preheated by the cylinder head walls to vaporize the fuel, and the cylinder head walls are cooled by the incoming air and fuel, and the fuel injector comprising a body defining a chamber, an inlet opening to the chamber, and an outlet opening from the chamber, a poppet valve member adapted to seat in sealed relation in the outlet opening, and an elastically tensioned thin wire fastened at one end to the valve member, extending through the chamber and fastened at the other end to the body.

2. An engine comprising an output shaft journaled in a crankcase for rotation about an axis, an even number of cylinders, each having its axis parallel to the shaft axis, arranged in diametrically opposite pairs radially equidistant from the shaft axis and equally spaced-apart circumferentially, a piston movable axially along each cylinder, a crosshead beam for each pair of pistons connected to the respective pistons and journalled on a carrier that is received on the shaft for rotation with and movement axially along the shaft, the pistons being connected by connecting rods to the crosshead beams by slider assemblies, each of which includes a cylindrical slideway affixed to a crankcase housing and having an axis aligned with the corresponding cylinder, a slider received in each slideway, and means coupling the corresponding crosshead beam to the slider for biaxial rotation and for axial sliding motion of the beam relative to the connecting rod, whereby the piston connecting rods move solely axially of the cylinders, means for selectively moving the carrier axially along the shaft to vary the end clearance volumes of the cylinders, at least one intake port for each cylinder having a cam-actuated valve, the cams that actuate the intake valves being timed to open the intake valve of each cylinder for induction of a mixture of fuel and air every third downstroke of the corresponding piston, a combustion gas exhaust port for each cylinder having a cam-actuated valve, a steam exhaust port for each cylinder having a cam-actuated valve, the combustion exhaust and steam exhaust valves being timed such that the engine operates in a six-stroke cycle consisting of a four-stroke combustion stroke and a two-stroke steam cycle, and means for injecting water into each cylinder at the end of each combustion exhaust stroke of the corresponding piston, the means for moving the crosshead beam carrier axially along the shaft including a spider received adjacent the carrier for rotation with and axial movement along the shaft and carrying rotatable bevel gears, a first threaded portion on the shaft on the side of the spider nearer the beam carrier, a second threaded portion of opposite hand from the first on the shaft on the other side of the spider, a first ring having a bevel ring gear meshing with the bevel gears and threaded internally onto the first threaded portion, a thrust bearing interposed between the first ring and the carrier, a second ring having a bevel ring gear meshing with the bevel gears and threaded internally onto the second threaded portion, first and second conical brake surfaces on the respective first and second rings, a brake sleeve having first and second brake surfaces matching the respective brake surfaces on the first and second rings, and control means for selectively shifting the brake sleeve axially of the shaft in one direction to engage the first brake sleeve surface with the brake surface of the first ring and in the other direction to engage the second brake sleeve surface with the brake surface of the second ring, whereby the rotation of the ring that is so engaged is retarded relative to the shaft, the bevel gears advance the rotation of the other ring and the two rings thread themselves along the threaded portions of the shaft and move the carrier axially along the shaft.

3. An engine according to claim 2 and further comprising a lubricating oil supply port opening at an internal surface of each slideway at a location swept by the slider, an elongated oil intake port opening at an external surface of each slider at a location for register with the supply port for a varying but predetermined time before and after bottom-dead-center of the slider and oil passages through the slider, connecting rod and piston communicating the intake port of each slider to a lubricating ring on a lower portion of the corresponding piston, whereby a controlled amount of oil is supplied during a part of each piston stroke to the lubricating ring, which in turn wipes a thin film of oil on the cylinder wall.

4. An engine comprising an output shaft journaled in a crankcase for rotation about an axis, an even number of cylinders, each cylinder having a bore portion defined by a bore tube and having its axis parallel to the shaft axis, arranged in diametrically opposite pairs radially equidistant from the shaft axis and equally spaced-apart circumferentially, a piston movable axially along each cylinder, a crosshead beam for each pair of pistons connected to the respective pistons and journalled on a carrier that is received on the shaft for rotation with and movement axially along the shaft, the pistons being connected by connecting rods to the crosshead beams by slider assemblies, each of which includes a cylindrical slideway affixed to a crankcase housing and having an axis aligned with the corresponding cylinder, a slider received in each slideway, and means coupling the corresponding crosshead beam to the slider for biaxial rotation and for axial sliding motion of the beam relative to the connecting rod, whereby the piston connecting rods move solely axially of the cylinders, means for selectively moving the carrier axially along the shaft to vary the end clearance volumes of the cylinders, at least one intake port for each cylinder having a cam-actuated valve, the cams that actuate the intake valves being timed to open the intake valve of each cylinder for induction of a mixture of fuel and air every third downstroke of the corresponding piston, a combustion gas exhaust port for each cylinder having a cam-actuated valve, a steam exhaust port for each cylinder having a cam-actuated valve, the combustion exhaust and steam exhaust valves being timed such that the engine operates in a six-stroke cycle consisting of a four-stroke combustion cycle and a two-stroke steam cycle, means for injecting water into each cylinder at the end of each combustion exhaust stroke of the corresponding piston, means defining a supercharging chamber adjacent each cylinder, said means including the underside of the piston, a wall having an opening through which the corresponding connecting rod passes, a wall surrounding and spaced from the bore tube, thus to define an annular portion of the supercharging chamber, and a seal between the rod and the wall at the opening, first one-way valve means for admitting ambient air to the supercharging chamber upon each upstroke of the piston, second one-way valve means for discharging compressed air from the supercharging chamber upon each downstroke of the piston, an intake chamber communicating with the supercharging chambers through the second one-way valves and with the cylinder intake ports, and a plurality of spaced-apart discharge openings having said second one-way valve means adjacent the head end of the annular portion, whereby air inducted into the supercharging chamber passes through the annular portion to the discharge openings.

5. An engine according to claim 4 wherein the supercharging chamber associated with each cylinder communicates with the supercharging chamber associated with another cylinder that is out of phase with it but in which the piston downstrokes partially overlap, whereby the combined effective displacement volume of the paired chambers is less than the total of the individual displacement volumes of the paired chambers.

6. An engine comprising an output shaft journaled in a crankcase for rotation about an axis, an even number of cylinders, each having its axis parallel to the shaft axis, arranged in diametrically opposite pairs radially equidistant from the shaft axis and equally spaced-apart circumferentially, a piston movable axially along each cylinder, a crosshead beam for each pair of pistons connected to the respective pistons and journalled on a carrier that is received on the shaft for rotation with and movement axially along the shaft, the pistons being connected by connecting rods to the crosshead beams by slider assemblies, each of which includes a cylindrical slideway affixed to a crankcase housing and having an axis aligned with the corresponding cylinder, a slider received in each slideway, and means coupling the corresponding crosshead beam to the slider for biaxial rotation and for axial sliding motion of the beam relative to the connecting rod, whereby the piston connecting rods move solely axially of the cylinders, means for selectively moving the carrier axially along the shaft to vary the end clearance volumes of the cylinders, at least one intake port for each cylinder having a cam-actuated valve, the cams that actuate the intake valves being timed to open the intake valve of each cylinder for induction of a mixture of fuel and air every third downstroke of the corresponding piston, a combustion gas exhaust port for each cylinder having a cam-actuated valve, a steam exhaust port for each cylinder having a cam-actuated valve, the combustion exhaust and steam exhaust valve being timed such that the engine operates in a six-stroke cycle consisting of a four-stroke combustion cycle and two-stroke steam cycle, means for injecting water into each cylinder at the end of each combustion exhaust stroke of the corresponding piston, an intake manifold communicating with the intake ports of all of the cylinders, means for supplying air to the intake manifold, and means for injecting fuel to the intake manifold including at least one fuel injector and an injection pump having a housing, a rotor rotatably received in the housing, an internal lobed cam in the housing, a pair of diametrically opposed pistons received in pumping cylinders in the rotor and spring-loaded into enagement with the cam, a chamber in the rotor communicating with the pumping cylinders and having an inlet with a check valve and an outlet with a check valve, a regulator cylinder in the housing in constant communication with the rotor chamber, a regulator piston in the regulator cylinder resiliently biased toward a fixed stop establishing a minimum regulator cylinder volume, and an adjustable stop in the regulator cylinder establishing a selected variable stroke of the regulator piston away from the fixed stop.

7. An engine according to claim 6 wherein the adjustable stop is adapted to establish a regulator piston stroke in the range from substantially zero to a stroke providing a displacement volume of the regulator cylinder substantially equal to the total displacement volumes of the pumping cylinders.

8. An engine according to claim 6 wherein the injection pump further includes an annular discharge chamber defined between an internal circular cylindrical wall portion of the housing and the rotor, circumferentially spaced-apart discharge passages in the housing opening at said wall portion into the discharge chamber, and a sealing strip connected to the rotor for rotation therewith and resiliently and slidably engaging a major portion of said housing wall portion and adapted sequentially to lose all but one of the discharge passages, whereby the discharge passages are opened seriatim to the discharge chamber.

9. An engine comprising an output shaft journaled in a crankcase for rotation about an axis, an even number of cylinders, each having its axis parallel to the shaft axis, arranged in diametrically opposite pairs radially equidistant from the shaft axis and equally spaced-apart circumferentially, a piston movable axially along each cylinder, a crosshead beam for each pair of pistons connected to the respective pistons and journalled on a carrier that is received on the shaft for rotation with and movement axially along the shaft, the pistons being connected by connecting rods to the crosshead beams by slider assemblies, each of which includes a cylindrical slideway affixed to a crankcase housing and having an axis aligned with the corresponding cylinder, a slider received in each slideway, and means coupling the corresponding crosshead beam to the slider for biaxial rotation and for axial sliding motion of the beam relative to the connecting rod, whereby the piston connecting rods move solely axially of the cylinders, means for selectively moving the carrier axially along the shaft to vary the end clearance volumes of the cylinders, at least one intake port for each cylinder having a cam-actuated valve, the cams that actuate the intake valves being timed to open the intake valve of each cylinder for induction of a mixture of fuel and air every third downstroke of the corresponding piston, a combustion gas exhaust port for each cylinder having a cam-actuated valve, a steam exhaust port for each cylinder having a cam-actuated valve, the combustion exhaust and steam exhaust valves being timed such that the engine operates in a six-stroke cycle consisting of a four-stroke combustion cycle and a two-stroke steam cycle, and means for injecting water into each cylinder at the end of each combustion exhaust stroke of the corresponding piston, each piston having a ring of porous thermally conductive material around the perimeter of the top, such material having a high ratio of surface area to mass, and the means for injecting water including nozzle means associated with the top of the cylinder wall for injecting water generally radially into and substantially entirely around the porous conducting ring, whereby the water permeates the ring and flashes to steam that provides the steam power stroke of the steam cycle, and further including control means for regulating the quantity of water injected for the steam cycles in relation to the engine temperature by varying the duration of each injection, the times of the beginnings of the injections being varied and the ends of the injections being fixed and being substantially at top dead center at the beginning of each steam power stroke.

10. An engine according to claim 9 wherein the porous ring is a band of fine wire mesh wrapped in numerous layers around the top of the piston.

11. An engine according to claim 9 wherein each piston includes a head member, the porous material being received on the head member, a skirt member, at least one ring on the skirt member engaging the cylinder wall and forming a sliding seal therewith, and a member of a thermally insulating material interposed between the head member and the skirt member for inhibiting heat flow from the head member to the cylinder wall via the skirt member and ring.

12. An engine according to claim 9 wherein the means for injecting water into each cylinder includes an injection pump having a housing, a rotor rotatably received in the housing, an internal lobed cam in the housing, a pair of diametrically opposed pistons received in pumping cylinders in the rotor and spring-loaded into engagement with the cam, a chamber in the rotor communicating with the pumping cylinders and having an inlet with a check valve and an outlet with a check valve, a regulator cylinder in the housing in constant communication with the rotor chamber, a regulator piston in the regulator cylinder biased toward a fixed stop establishing a minimum regulator cylinder volume, an adjustable stop in the regulator cylinder establishing a selected variable stroke of the regulator piston away from the fixed stop, outlet distributor valve means downstream from the outlet from the chamber, and lines communicating the distributor means to each engine cylinder.

13. An engine according to claim 12 wherein the adjustable stop is adapted to establish a regulator piston stroke in the range from substantially zero to a stroke providing a displacement volume of the regulator cylinder substantially equal to the total displacement volumes of the pumping cylinders.

14. An engine according to claim 12 wherein the distributor valve means of the injection pump includes an annular discharge chamber defined between an internal circular cylindrical wall portion of the housing and the rotor, circumferentially spaced-apart discharge passages in the housing opening at said wall portion into the discharge chamber, and a sealing strip connected to the rotor for rotation therewith and resiliently and slidably engaging a major portion of said housing wall portion and adapted sequentially to close all but one of the discharge passages, whereby the discharge passages are opened seriatim to the discharge chamber.

15. An engine comprising an output shaft journaled in a crankcase for rotation about an axis, an even number of cylinders, each having its axis parallel to the shaft axis, arranged in diametrically opposite pairs radially equidistant from the shaft axis and equally spaced-apart circumferentially, a piston movable axially along each cylinder, a crosshead beam for each pair of pistons connected to the respective pistons and journalled on a carrier that is received on the shaft for rotation with and movement axially along the shaft, the pistons being connected by connecting rods to the crosshead beams by slider assemblies, each of which includes a cylindrical slideway affixed to a crankcase housing and having an axis aligned with the corresponding cylinder, a slider received in each slideway, and means coupling the corresponding crosshead beam to the slider for biaxial rotation and for axial sliding motion of the beam relative to the connecting rod, whereby the piston connecting rods move solely axially of the cylinders, means for selectively moving the carrier axially along the shaft to vary the end clearance volumes of the cylinders, two intake ports for each cylinder, each having a cam-actuated valve, the cams that actuate the intake valves being timed to open the intake valve of each cylinder for induction of a mixture of fuel and air every third downstroke of the corresponding piston, a combustion gas exhaust port for each cylinder having a cam-actuated valve, a steam exhaust port for each cylinder having a cam-actuated valve, the combustion exhaust and steam exhaust valves being timed such that the engine operates in a six-stroke cycle consisting of a four-stroke combustion cycle and a two-stroke steam cycle, means for injecting water into each cylinder at the end of each combustion exhaust stroke of the corresponding piston, means for selectively varying the timing of one of the intake valves of each cylinder to vary the mass of a mixture of fuel and air inducted into the respective cylinder by delaying the closing of the variable timed valve until a selected time during the next upstroke of the piston, and means for actuating the means for moving the carrier and the means for varying the intake valve timing in a predetermined relationship, the cam actuating the other intake valve of each cylinder operating at a fixed timing, relative to the rotation of the shaft, and the cams of the variable time valves and the cams of the fixed time valves being adapted to open the respective valves for substantially equal rotational durations and the means for varying the timing of the variable time valves varying the phase relationship between the cams thereof and the cams of the fixed time valves, the variable time valves thus opening and closing at a rotational time that varies from zero to a predetermined variable rotational time later than the fixed time valves, whereby part of the inducted mass of the mixture is expelled during the upstroke as a function of the phase delay between the opening of the fixed time valve and the variable time valve of each cylinder.

16. An engine according to claim 15 wherein the means for moving the carrier axially along the shaft includes a spider received adjacent the carrier for rotation with and axial movement along the shaft and carrying rotatable bevel gears, a first threaded portion on the shaft on the side of the spider nearer the beam carrier, a second threaded portion of opposite hand from the first on the shaft on the other side of the spider, a first ring having a bevel ring gear meshing with the bevel gears and threaded internally onto the first threaded portion, a thrust bearing interposed between the first ring and the carrier, a second ring a bevel ring gear meshing with the bevel gears and threaded internally onto the second threaded portion, first and second conical brake surfaces on the respective first and second rings, a brake sleeve having first and second brake surfaces matching the respective brake surfaces on the first and second rings, and control means for selectively shifting the brake sleeve axially of the shaft in one direction to engage the first brake sleeve surface with the brake surface of the first ring, and in the other direction to engage the second brake sleeve surface with the brake surface of the second ring, whereby the rotation of the ring that is so engaged in retarded relative to the shaft, the bevel gears advance the rotation of the other ring and the two rings thread themselves along the threaded portions of the shaft and move the carrier axially along the shaft.

17. An engine according to claim 16 and further comprising linkage means coupling the means for varying the timing of the variable time valves and the control means of the means for moving the carrier for automatically providing a predetermined relationship between the mass of the fuel-air mixture inducted into the cylinders and the end clearance volumes of the cylinders.

18. An engine according to claim 17 wherein the linkage means includes a fork lever carrying the brake sleeve for pivoting about an axis extending diametrically of the brake sleeve and means mounting the lever and brake sleeve in the crankcase for free-floating in a neutral position in which the brake surfaces of the first and second rings run on oil films within the brake surfaces of the brake sleeve in the absence of an external force applied to the lever to move the pivot axis of the brake ring axially of the shaft.

19. An engine according to claim 15 wherein the cam actuating the fixed time valves is a first rotary annular face cam driven by the shaft in a fixed phase relationship to the rotation of the shaft, the cam actuating the variable time valves is a second rotary annular face cam and the means for varying the timing of variable time valves includes a coupling connecting the second cam to the first cam in any selected one of an infinite number of relative angular positions within a range between a fully in-phase relation for full power and a substantially out-of-phase relation for substantially less than full power.

20. An engine according to claim 19 wherein the first cam lies radially outwardly of the second cam and is carried by a shaft that rotates about an axis aligned with the main shaft, the second cam includes a tubular shaft surrounding and supported by the shaft of the first cam, and the coupling comprises phase control cam slots in the valve cam shafts and control cam followers received in the control slots for movement lengthwise and circumferentially of the valve cam shafts.

21. An engine according to claim 20 wherein the control followers are carried by a ring, and further comprising a controllable linear actuator coupled through a thrust bearing to the ring.

Drawings