US 5,399,078 A · Planetary-motion engine

Abstract

In a rotary-piston engine, the contour of a normal section of the piston is either a composite trochoid or a translated composite trochoid. Each vertex of the normal section is either a generating point of the trochoid or has the form of a circular arc whose center is the generating point of the trochoid and whose radius is a fixed distance. Thus all the edges of the piston slide continuously on the inside face of engine cavity. The piston describes a planetary motion about a point at the same time as it revolves around an origin. Thus the volume of the working chambers changes. The opening and closing of connecting ducts for gas exchange are controlled. The resulting engine has only rotating moving parts, and they are in complete balance. The engine has no constrictions on the minor axis of the contour. Thus the movement of combustion gases is not impeded near top dead center. The engine has a high compression ratio. Because the displacement of the working chambers changes slowly near top dead center, combustion is completed before expansion begins. Therefore the conditions for thermal efficiency, maximum expansion, and maximum pressure prior to expansion are fulfilled. A reciprocating engine can be formed from this rotary-piston engine by installing a reciprocating piston on the generating point of a composite trochoid, putting a cylinder together with the piston, and using a crank mechanism that exploits the reciprocating motion generated by the generating point.

A planetary-motion rotary-piston engine comprising:

a housing containing a tubular cavity shaped as a right noncircular cylinder having an axis, in which a curve that determines a contour of a normal section of the tubular cavity is a composite trochoid composed of a hypotrochoid and a peritrochoid;
said tubular cavity being bounded at each end by two side housings geometrically corresponding to two bases of said light noncircular cylinder;
the composite trochoid having a family of curves;
said family of curves having an inner envelope and an outer envelope with at least two points of osculation;
a crankshaft, pierced through said side housings of said tubular cavity along said axis;
an eccentric shaft, coaxially attached to a crank pin of said crankshaft, said eccentric shaft moving as a generating arm of said hypotrochoid and as an eccentric arm of said peritrochoid;
a rotating piston, shaped as a right prism having two bases, which bases slide continuously on said side housings of said tubular cavity;
a normal section of said rotating piston having at least two vertices corresponding to a like number of said points of osculation;
each vertex of said normal section of said rotating piston being a generating point of said composite trochoid;
a first gear unit comprising:
a first fixed gear being an internal gear and coaxially fixed to a one of said side housings of said tubular cavity, said first fixed gear moving as a base circle of said hypotrochoid;
a first rolling gear coaxially fixed to said eccentric shaft, said first rolling gear moving as a rolling circle of said hypotrochoid;
said first fixed gear and said first rolling gear engaging each other;
a second gear unit comprising:
a second fixed gear coaxially fixed to said crank pin, said second fixed gear moving as a base circle of said peritrochoid;
a second rolling gear coaxially fixed to said rotating piston, said second rolling gear moving as a rolling circle of said peritrochoid;
said second fixed gear and said second rolling gear engaging each other;
said generating point of said composite trochoid being defined by a pair of parametric equations, x=(a-b)cos .THETA.+c(r-b)cos(1-a/b).THETA.+dcr cos{(1-a/b+a/r).THETA.+.beta.} and y=(a-b)sin .THETA.+c(r-b)sin(1-a/b).THETA.+dcr sin{(1-a/b+a/r).THETA.+.beta.}, where .THETA. is an angular velocity of said crankshaft, (1-a/b).THETA. is an angular velocity of said eccentric shaft, (1-a/b+a/r).THETA. is an angular velocity of said rotating piston, (a-b) is equal to a distance between an axis of said crankshaft and an axis of said crank pin, c(r-b) is equal to a distance between said crank pin axis and an axis of said second rolling gear, dcr is equal to a distance between said second rolling gear axis and a one of said vertices of said normal section of said piston, and .beta. is a constant and is equal to a phase angle of said generating point of said composite trochoid;
and
connecting ducts for gas exchange whose opening and closing are controlled by said rotating piston.

17 more elements

Facts

Application

08/107,695Filed 18 Aug 1993

Priority

JP 3-22986321 Feb 1991

Granted

21 Mar 1995

Term ends

Not estimatedThe source records don’t support an estimate.

Classification10 codes

F01C 1/22
Rotary-piston machines or engines: of internal-axis type with equidirectional movement of co-operating members at the points of engagement, or…
F02B 55/00
Internal-combustion aspects of rotary pistons
F02B 55/14
Internal-combustion aspects of rotary pistons; Outer members for co-operation with rotary pistons: shapes or constructions of combustion chambers
F02B 75/021
Engines characterised by their cycles, e.g. six-stroke: having six or more strokes per cycle

Planetary-motion engine

Life of this patent

Planetary-motion engine

Life of this patent

Abstract

Claims12