Abstract:
This invention is a fuel efficient, high torque power, offset piston engine. The basic invention is a 2-stroke 2-cylinder engine. A single idler gear provides ignition timing between a pair of out-of-phase power pistons as 1-way clutches transmit the power to the engine&#39;s power shaft. Displacing and replacing a special idler changes the engine between a 2 stroke and a 4 stroke. Power stroke overlap saves fuel. Deactivating pistons when not needed without load on the engine saves more fuel. Other benefits will be obvious upon perusing the disclosure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This is a continuation-in-part application of CIP application Ser. No. 11/083,789 filed Mar. 18, 2005 now abandoned which is a CIP of Ser. No. 10/935,402 filed Sep. 7, 2004 which is a CIP of Ser. No. 10/643,274 filed Aug. 18, 2003 which is a CIP of the original application Ser. No. 10/252,927 filed Sep. 24, 2002. 

   FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   BACKGROUND OF THE INVENTION 
   Engines that transmit an offset piston&#39;s power to a straight power shaft have been attempted since at least 1921, e.g. U.S. Pat. No. 1,365,666 but have not had practical success though they inherently offer high torque and high fuel efficiency. Their weakness lies in using many energy absorbing moving parts and combustion chambers to convert the piston&#39;s reciprocating rectilinear motion to the power shaft&#39;s unidirectional rotary motion which has made them inefficient and impractical, e.g. U.S. Pat. Nos. 2,239,663; and 5,673,665. For this reason, the simple, exhaust polluting, inefficient but reliable crankshaft engine survives as the search for a better power source continues. 
   Enormous funds and research have been poured into fuel cells, electric vehicles and crank engine hybrids for years to replace the ubiquitous crank engine. 
   The crank engine is very inefficient because the two angles at both ends of the connecting rod of length L and the crank angle α ( FIG. 10 ) combine to slow the piston&#39;s speed, which traps the very rapidly expanding combustion gases in a small chamber. The gases build up very high heat and pressure at and near tdc. Here, nearly all the force from the pressure is vectored against the crankshaft&#39;s bearings instead of rotating it. Parts inertia is combined with extra fuel on each power stroke to overcome the angles&#39; resistance. The result is excess exhaust pollution and waste heat. The waste heat is lost and the pollutants are partly scrubbed from the exhaust when it is too late. 
   A higher rpm increases efficiency but that has reached its limit and it is not good enough. The pollution and the waste heat must be reduced in the combustion chamber by converting them to mechanical motion with a more complete burn. To do that, all the rod and crank angles must be zero during the entire power stroke but that is impossible in a crank engine. The following mathematics explain why: 
     FIG. 10  is a schematic that represents a crank engine. FV 1 , FV 2 , FV 3  are force vectors that come from burn pressure driving the piston  38 . FV 1  is along a radial of the crankshaft axis C. Only FV 3 , being tangent to the crank circle d, rotates the shaft where FV 3 =FV 1 (Cos θ)(Cos Φ). The crank engine&#39;s efficiency is zero at tdc when angle θ=0 but angle Φ=90°, making FV 3 =FV 1 (1)(0)=0. When FV 2  is tangent to circle d, Cos Φ=1.0 and Tan θ=r/L and θ=Tan −1 r/L from which Cos θ is found. The efficiency at that point is FV 3 /FV 1 =Cos θ. The importance of angle θ=Tan −1 r/L is explained below. 
   The ratio of the displacement M along the crank circle d to the piston&#39;s displacement a at any chosen crank angle θ is easily found from  FIG. 10 . r is the crank arm length and α is in degrees:
 
 r=b+a  
 
 a=r (1−Cos α)
 
 M=παr/ 180
 
 M/a=πα/[ 180(1−Cos α)]
 
For instance, when α=10°, M/a=11.49:1. At this point, the rod&#39;s slow crank end must go 11.49 times as far as the piston. The slower the crank&#39;s rotation, the longer the gases are trapped in a small chamber and the lower the engine&#39;s efficiency. It is known that this is where the confined hot, pressurized gases create most of the pollution and waste heat. The crank&#39;s angular efficiency:
 
Cos θ= FV 2/ FV 1
 
Cos Φ= FV 3/ FV 2
 
 FV 2= FV 1(Cos θ)
 
 FV 2= FV 3/Cos Φ
 
 FV 3= FV 1(Cos θ)(Cos Φ)
 
 FV 3/ FV 1=(Cos θ)(Cos Φ) Crank engine&#39;s angular efficiency. It caps thermal efficiency.
 
     FIG. 10  is also the basis for the following indented equations that lead to the Cos θ and Cos Φ equations in terms of crank angle α, length L and crank arm r:
 180−β=γ γ+θ+Φ=180 β= 90 −α Note the rt. triangle (α+β+90) 180−(90−α)=γ or 90+α=γ (90+α)+θ+Φ=180 α+θ+Φ=90   n=r  Sin α Sin θ=( r/L )Sin α θ=Sin −1 [( r/L )Sin α] Cos θ=Cos{Sin −1 [( r/L )Sin α]} α+Sin −1 [( r/L )Sin α]+Φ=90 Φ=90−{α+Sin −1 [( r/L )Sin α]} Cos Φ=Cos(90−{α+Sin −1 [( r/L )Sin α]}) 
The equations Cos θ, Cos Φ are easily solved with a hand calculator.
 
   The importance of angle θ=Tan −1 r/L now follows. That is when FV 2  is tangent to the circle d at the arm r which makes angle Φ=0.0 and Cos Φ=1.0. The angular efficiency is Cos θ=Cos(Tan −1 r/L). Extend L relative to r so that angle θ goes to 0.0. Then 
                       1     ⁢     Lim     θ   →   0.0       ⁢           ⁢   Cos   ⁢           ⁢   θ     =     1.0   .           
That makes the angular efficiency FV 3 /FV 1 =Cos θ)(Cos Φ)=(1)(1)=100% because there is no angular resistance since the angles θ, Φ disappear. The variable angle α disappears. The crank arm r disappears. The variable length torque arm n ( FIG. 10 ) which requires torque buildup is replaced by the fixed length torque arm r′ ( FIG. 11 ) which gives instant peak torque.  1  This is the foundation for calculus.
 
   Unlike the crank, FV 1  in this invention ( FIG. 11 ) is always directed to rotating the output shaft  8  rather than directed against the shaft&#39;s bearings. FV 1  is transmitted with both angles θ, Φ=0.0 through the entire power stroke. The M/a=1:1 through the entire stroke. The circumference d′ replaces the crank circle d in  FIG. 10 . Shaft  8  receives shear force alone from the fixed length torque arm r′. 
   BRIEF SUMMARY OF THE INVENTION 
   This is an offset piston engine that can be easily switched between a 2-stroke and a 4-stroke. A pair of power pistons is connected through a single idler timing gear. Each piston is in its combustion cylinder with related parts, including 1-way clutches, to make the basic 2-stroke engine. A third idler connects two basic engines to make a 4-stroke engine. Computer controlled ignition between two basic 2-stroke engines allows power stroke overlap. The crankshaft is replaced by a straight power shaft. 
   One of the benefits of this engine is overlapping power strokes. For example: a 2-stroke 4 cyl engine with an 8″ piston stroke (there is no mechanical limit to the stroke) would simultaneously have the 1 st  piston 4″ after tdc and the 2 nd  piston igniting at tdc. The power added by the 2 nd  piston is reduced by the remaining power of the 1 st  piston resulting in fuel savings and smooth shaft rotation.  FIG. 9  illustrates power stroke overlap between a pair of 2-stroke engines. 
   Objects of this invention: 
   1. fuel efficient; 
   2. a single efficient idler for timing between out-of-phase pistons; 
   3. interchange able between 2-stroke and 4-stroke; 
   4. no mechanical limit to the piston stroke; 
   5. instant peak torque at the beginning of the power stroke; 
   6. power stroke overlap; 
   7. pistons square in the cylinders; 
   8. deactivating (stopping) pairs of pistons when not needed without load on the engine. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a view of the basic 2-cylinder 2-stroke engine with a single timing gear. 
       FIG. 2  is a view along line  2 — 2  in  FIG. 6 . 
       FIG. 3  shows a combination rack gear and conventional 1-way clutch. 
       FIG. 4  is a view essentially along  4 — 4  in  FIG. 1 . 
       FIG. 5  exposes the working parts of the torque transmitting unit. 
       FIG. 6  has an arc center line through the cylinder, piston, piston rod and 1-way clutch outer race. 
       FIG. 7  is a rough schematic of two engine computer controlled pairs of pistons for a 2-stroke. 
       FIG. 8  shows a 4-stroke engine by combining two 2-stroke pairs with a special idler  40 A. 
       FIG. 9  focuses on separation of idler  40 A in  FIG. 8  to create two 2-stroke engines. 
       FIG. 10  is a schematic of a crank engine used for mathematical reference in the text above. 
       FIG. 11  is a schematic of this invention used to compare with  FIG. 10 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   This invention uses a single idler gear  40  for ignition timing between two offset pistons  38 . The basic 2-stroke 2-cylinder engine uses a pair of 1-way clutches, each carrying a gear  12  that meshes with the single idler gear ( FIG. 1 ) as the 1-way clutches transmit piston power to power shaft  8 . There can be more than one basic engine positioned along the straight power shaft. Two basic engines can be combined through a special idler gear  40 A ( FIG. 8 ) to create a 4-stroke engine. 
   Two engine configurations are described in which the piston is square in the cylinder. Shear force is applied to power shaft  8  which permits smaller main bearings. 
   One configuration of this engine uses a rack gear  58  to transmit power between piston rod  18  and the 1-way clutch outer race  5  (FIGS.  3 , 4 ). A suitable guide  21 , secured to housing  15 , keeps the rack  58  aligned with the outer race  5 . A second configuration ( FIG. 6 ) uses an arc shaped cylinder  33  with a direct connection between the piston rod  18  and the 1-way clutch outer race  5  which eliminates the rack gear and the guide. A third configuration described in an earlier application Ser. No. 10/935,402 filed Sep. 7, 2004 uses a belt between the piston and race  5 . All transmit the power perpendicular to the piston offset  10  to give instant peak torque at the beginning of the power stroke. 
   An arc  47  in  FIG. 6  is centered on the shaft  8  axis. Its radius equals the length of the piston offset  10  that is also centered on the shaft  8  axis. This arc is the center line for the combustion cylinder  33 , piston  38 , piston rod  18 , and pin  52 . Pin  52  secures rod  18  directly to race  5 . The dashed part of arc  47  is the length of the piston stroke. Cylinder  33  is secured to housing  15  with a space between it and outer race  5 . The force vector of the expanding combustion gases is tangent to the arc  47  during the entire piston stroke which maximizes efficiency. This configuration is compact and has the benefits of the rack and pinion in  FIG. 4 , including the efficiency, but the rack and pinion and guide  21  are absent. 
   An engine computer  7  monitors input from the throttle  6  and shaft power from the sensor  22  on shaft  8  to determine the size of the combustion charge to transmit to the cylinders through injector lines  24 . The position of piston  38  is monitored through sensors  22  on shaft  43  and used for ignition timing. By monitoring the motion of each shaft  43  in several independent 2-stroke pairs, the computer controls timing between them. The computer begins a power stroke with a piston in one pair when a piston in another pair is partly through its power stroke ( FIG. 9 ). 
   Interchanging 4-Stroke and 2-Stroke 
   The arc centered configuration in  FIG. 6  and the rack configuration (FIGS.  1 , 4 ) use this feature, shown with a rack gear in the referenced FIGS.  8 , 9 . 
   In a 4-stroke, a sector gear  12  on each of two pairs engages idler  40 A ( FIG. 8 ). When changing from a 2-stroke to a 4-stroke, the pistons are correctly positioned before engaging idler  40 A with the sector gears  12 . One of the correct positions places two pistons, e.g. power and intake at top dead center and the compression and exhaust positions at bottom dead center as shown in  FIG. 8 . 
   To change from a 4-stroke to a 2-stroke, the special idler  40 A is disengaged from sector gears  12 . One of the relative positions of the active pistons under computer  7  control is shown in  FIG. 9 . Cylinder  1  begins its power stroke. Cylinder  2  begins its exhaust, intake stroke. Cylinder  3  is ½ way through its power stroke. Cylinder  4  is ½ way through its exhaust, intake stroke. 50% power stroke overlap and smooth rotation of the shaft  8  is gained. One pair of pistons can be deactivated (stopped) without load on the engine to continue with a basic 2-stroke 2-cylinder engine. 
   1-Way Clutches 
     FIG. 3  shows a gear  61  secured to a conventional 1-way clutch  59 . The clutch is secured to the power shaft  8  with torque transmitting cams close to the shaft  8  axis where maximum force is applied to them. A rack gear  58 , part of piston rod  18 , powers gear  61  which rotates shaft  8  through the clutch  59 . A sector gear  12  meshes with idler gear  40  and idler  40  meshes with a second gear  12  carried by a second gear  61  (not shown) to timely advance the second out-of-phase piston on its stroke. The guide  21 , secured to housing  15 , maintains alignment between the rack and gear  61 . There would be less force on the conventional 1-way clutch cams if they were carried by a unit  89  cartridge in a recess at the rim of a radially extended inner race  4 . 
   My U.S. Pat. No. 6,571,925 titled, “1-Way Clutch That Uses Levers” describes a 1-way clutch which is modified to fit this engine by securing two side plates  5 A and  5 C to the outer race  5  with bolts  39 . The plates secured to two clutches carry a sector gear  12  that meshes with opposite sides of idler  40  (FIGS.  1 , 4 ) to make the basic 2-stroke engine in this invention. Sealant gaskets  37  between race  5  and the side plates protect the clutch internal working parts from oil. 
   The modified 1-way clutch has torque transmitting units  89  in a recess at the rim of inner race  4  (FIGS.  4 , 6 ). This distance from the shaft  8  axis reduces force on the unit  89  working parts which contributes to a longer operational life and allows indexing at a high cpm. The inner race  4  is splined  31  to the power shaft  8  ( FIG. 2 ) and rotates in one direction. 
   Retaining nuts  25 , threaded to both ends of shaft  8 , prevent axial movement of the 1-way clutch assemblies. The diameter of the shaft&#39;s two threaded end parts extends only to the base of the splines  31  to create a narrow space  17  between nut  25  and the splines so that total nut  25  force is applied to race  4  at both shaft ends. There are two retaining nuts  57  for each race  4  that are threaded to the part of race  4  that extends along shaft  8 . Nuts  57  apply force to the inner race of each bearing  34  so that the bearings&#39; inner races rotate in one direction with race  4 . Pressure from plates  5 A and  5 C cause the outer races of both bearings  34  to index with race  5 . Nuts  25  at both shaft ends prevent axial movement. The splines prevent rotational slip. The combined parts operate as a strong, tight, efficient unit. 
     FIG. 5  exposes the working parts of unit  89  in the modified clutch. Pin  35  pivots in non-slip contact with band  30  as race  5  begins the drive direction to the right. The pivoting compresses spring  11  which tilts lever  36  on its fulcrum  32  to bring element  29  into contact with outer race  5 . Sealant gaskets  37  protect the contact surfaces from oil. Element  29  does not contact band  30 . Element  29  and race  5  have contact surfaces with high friction coated V-grooves. A space  64  between unit  89  and race  4  provides the needed clearance between the V-grooves to place unit  89  in the recess on race  4 . Unit  89  is then raised to contact the race  4  offset  65  for the correct operating clearance between the two sets of V-grooves. Shims  62  under unit  89  secure the correct operating clearance. 
   Force vector  41  is transmitted from the outer race  5  directly through element  29  to inner race  4 . The force vector can be expected to vary during drive causing pin  35  to instantly adjust its pivot to increase or decrease its contact pressure with the band  30  which instantly adjusts the needed pressure to prevent slip between the contact surfaces of elements  29  and race  5 . The lever arms  36  contact unit  89  to prevent spring  11  from excessively pivoting pin  35 . 
   The 1-way clutch overrun feature in this engine allows output shaft  8  and the clutch inner race  4  to rotate independently of the pistons  38  when the race  4  speed is greater than the outer race  5  speed. This feature makes engine braking energy available for regenerated energy. This feature also allows deactivating (stopping) a pair of pistons when not needed without load on the engine. Attempts to deactivate (stop) pistons have been unsuccessful with crankshaft engines for decades.