Design
All versions of the RKM incorporate a working chamber formed by smoothly conjugated circular arcs. The piston, shaped to conform to the chamber's walls, "jumps" from wall to wall, thus performing a rotary motion. The piston has an appropriately shaped aperture fitted with a gear structure, and this drives the power shaft (or two power shafts in some models).
The piston, its aperture and the working chamber of the RKMs represent, in their cross sections, multi-oval figures which, mathematically, are related to the class of figures of equal width. Those multi-ovals are non-analytical figures with a discontinuous second derivative of the contour line (the curvature). Hence, generally speaking, the trajectories of their centers of curvature are also non-analytical and, within the RKMs' geometry, have to have singular points.
In relation to the piston, the trajectory of the power shaft axis has corner points, which correspond to extreme positions of the piston as related to the working chamber. Those corners, which represent singular points of the power shaft's trajectory, cannot be avoided or rounded to provide for the kinematically closed functioning of the gear.
The reason why until now the geometry of curves of constant width could not be put to practical use in the gear design is that no conventional gear structure with the regular rolling on of the gears would permit the exact rolling-on of the singularities. The RKMs solve this problem by introducing the inversely conjugated gear system, which makes it possible to have singular trajectories of the axes of rolling-on gears and, thus, allows the transfer of the angular momentum during the passage of the piston through its stop positions.
In simple words, the gear mechanism introduces corrections to the piston's motion, correcting the axis of rotation as it leaves the stop positions, so as to create a smooth motion.
Read more about this topic: RKM Engine
Famous quotes containing the word design:
“For I choose that my remembrances of him should be pleasing, affecting, religious. I will love him as a glorified friend, after the free way of friendship, and not pay him a stiff sign of respect, as men do to those whom they fear. A passage read from his discourses, a moving provocation to works like his, any act or meeting which tends to awaken a pure thought, a flow of love, an original design of virtue, I call a worthy, a true commemoration.”
—Ralph Waldo Emerson (1803–1882)
“A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible. There are no prima donnas in engineering.”
—Freeman Dyson (b. 1923)
“I begin with a design for a hearse.
For Christ’s sake not black—
nor white either—and not polished!
Let it be weathered—like a farm wagon—”
—William Carlos Williams (1883–1963)