US 5,711,267 A · Internal combustion engine with optimum torque output

Abstract

An improved engine output shaft includes a crankpin assembly for operatively connecting the shaft to each reciprocating piston for translating the reciprocating motion of each piston to rotary motion of the shaft through a leverage arm between the axis of rotation of the shaft and the point of operative connection between each piston and the shaft. The crankpin assembly is fixed to rotate with the shaft and defines a plurality of fixed crankpin offsets and transition offsets which sequentially vary the moment arm in a predetermined manner during the rotation of the shaft to produce a substantially constant total engine torque output during each increment of rotational movement. A method for making the improved engine output shaft comprises the steps of providing aforedescribed crankpin assembly, determining a target value for total torque output for each increment of engine output rotation, selecting first estimated values for each of the plurality of fixed crankpin and transition offsets, calculating the engine output torque for each rotational increment for a single cylinder, summing the torque contributions and demands for all cylinders at each increment of shaft rotation to determine the total torque output for each increment, comparing the total torque output with the target value for each increment, selecting second estimated values for each of the plurality of fixed crankpin and transition offsets based upon the observed deviation from the target torque value and repeating the calculations until the selected offsets satisfactorily reproduce the target torque value.

Claims31

Dependent claims

A mechanism for translating reciprocating motion to rotary motion on a cyclic basis in combination with an internal combustion engine comprising:

at least one cylinder in said internal combustion engine, a reciprocating piston slidably provided within each said cylinder of said internal combustion engine;
synchronous control means which supplies a combustible mixture to each said cylinder and ignites the mixture for producing a combustion force causing the piston in said cylinder to move in one direction of its reciprocating motion to provide a power stroke for said cylinder;
and
an engine output shaft rotatably mounted with said internal combustion engine, connection means for operatively connecting said engine output shaft to each said reciprocating piston for translating the reciprocating motion of each said piston to rotary motion of said shaft through a variable moment arm between the axis of rotation of said engine output shaft and the point of operative connection between each said piston and said shaft for providing a substantially constant engine torque output throughout each increment of rotation of the engine output shaft, taking into consideration the torque contributions and demands of all cylinders, said connection means including crankpin means for each piston, said crankpin means being fixed to rotate with the engine output shaft and defining a plurality of fixed crankpin offsets which sequentially vary the moment arm in a predetermined manner during the rotation of the engine output shaft to produce a substantially constant engine torque output during each increment of rotational movement of said engine output shaft.

1 more element

A method of making an engine output shaft for use in an internal combustion engine in combination with at least one engine cylinder and a reciprocating piston slidably provided within each cylinder for converting reciprocating motion into rotary motion while providing a substantially constant level of torque from said engine output shaft at each increment of output shaft rotation taking into account the torque contributions and demands of all the cylinders, comprising the steps of:

(a) providing an engine output shaft including crankpin means for each piston, said crankpin means being fixed to rotate with the shaft and defining a plurality of fixed crankpin offsets which sequentially vary the moment arm between the axis of rotation of said engine output shaft and the point of operative connection between each said piston and said shaft in a predetermined manner during the rotation of the engine output shaft to produce a substantially constant total torque output during each increment of rotational movement of said engine output shaft;
(b) determining a target value of total torque output for each increment of engine output shaft rotation;
(c) selecting first estimated values of each of said plurality of fixed crankpin offsets;
(d) calculating the moment arms and engine output shaft torque for each rotational increment using the selected offsets for a single cylinder during at least its power and compression strokes;
(e) summing the torque contributions and torque demands for all cylinders at each increment of engine output shaft rotation to determine the total torque output for each increment;
(f) comparing the total torque output for each increment with the target value of total torque output for each increment;
(g) selecting second estimated values of each of said plurality of fixed crankpin offsets based upon the observed deviations from the target torque value;
and,
(h) repeating the calculations of steps (b) through (g) until the selected offsets satisfactorily reproduce the target torque value.

6 more elements

Dependencies are inferred from the claim text.

Internal combustion engine with optimum torque output

Life of this patent

Internal combustion engine with optimum torque output

Life of this patent

Abstract

Claims31