Internal-combustion engines – Oscillating piston – Toroidal cylinder
Reexamination Certificate
1999-06-08
2001-05-08
Denion, Thomas (Department: 3748)
Internal-combustion engines
Oscillating piston
Toroidal cylinder
C074S025000, C074S050000, C123S507000, C123S549000, C417S481000, C417S482000, C092S022000, C091S339000, C091S177000
Reexamination Certificate
active
06227152
ABSTRACT:
This invention relates to an internal combustion engine comprising at least one cylinder and a crankcase which together with the cylinder forms a common, circular cylindrical tubular body, and comprising an oscillating piston rotatably mounted about the cylinder axis and separating a cylinder space defined by radial walls from the crankcase, which oscillating piston is in drive connection with a crankshaft parallel to the cylinder axis via a connecting link guide provided on the crankcase side of the oscillating piston for at least one crank pin of the crank shaft.
To produce a drive connection between the oscillating piston and the crankshaft in internal combustion engines with an oscillating piston performing a reciprocating rotary movement, and with a crankshaft parallel to the axis of rotation of the oscillating piston, it is known (U.S. Pat. No. 4,272,229) to pivotally mount on the oscillating piston a connecting rod, which is supported on the crank pin of the crankshaft, at a distance from the axis of rotation of the oscillating piston. This pivotal mounting of the connecting rod may, however, produce constraining forces, which should not only be considered when mounting the oscillating piston, but possibly also influence the sealing conditions for the oscillating piston. In this connection it should be noted that the efficient sealing of the cylinder space is very susceptible to deformations as a result of thermal or mechanical loads, which affect the sealing gap between the generally plate-shaped oscillating piston and the cylinder.
As regards such internal combustion engines it is in addition known (FR-PS 447 632) to mount on the crank pin a slide ring, which is held in a radial slideway connected with the oscillating piston. The crankcase is formed in a simple way by a circular cylindrical tubular body, which is enclosed by a cooling jacket. The oscillating piston substantially has the shape of a hollow semicylinder, whose outside diameter is adapted to the inside diameter of the tubular body, and which is stiffened by the radial slideway for the slide ring. This construction not only makes a crankcase scavenging impossible, but due to the slide ring guidance is also susceptible to wear. There is also a non-uniform thermal load of the tubular body, which as a result of the cooling-related, non-uniform distribution of heat around the periphery is subjected to different thermal expansions, so that there are difficulties as regards the sealing of the piston, which in turn restricts the possible compression of the air-fuel mixture.
It is therefore the object underlying the invention to design an internal combustion engine as described above with simple constructive means such that on the one hand advantageous power transmission conditions between the oscillating piston and the crankshaft and on the other hand favorable sealing conditions for the cylinder space can be ensured.
This object is solved by the invention in that the crank pin is supported on the connecting link guide via a roller, and that the tubular body forming the cylinder and the crankcase is thermally insulated to the outside.
By means of the roller on the crank pin, which cooperates with the connecting link guide, there is achieved a simple low-vibration power transmission between the oscillating piston and the crankshaft, which due to the substantial independence of manufacturing tolerances is free from constraints, where an appropriate choice of the lever ratios ensures an advantageous torque introduction. To take into account the thermal expansions inevitable in the operation of such an internal combustion engine, the entire tubular body, i.e. both the cylinder and the crankcase, is thermally insulated to the outside, so that a uniform thermal expansion of the tubular body including the oscillating piston is possible. By means of this measure a sufficiently narrow sealing gap between piston and cylinder can be ensured even under high thermal loads, to ensure a good efficiency without use of a sealing susceptible to wear between the oscillating piston and the cylinder walls. In this connection it should also be noted that the roller of the crank pin cooperating with the connecting link guide makes a heat dissipation to the crankshaft difficult as compared to a slide ring or a connecting rod, because between the roller and the connecting link guide there is substantially produced only a line contact.
Since due to the reciprocating oscillating piston oppositely directed forces must be transmitted via the connecting link guide, the connecting link guide may consist of an oblong hole accommodating the roller of the crank pin. In an oscillating piston constituting a double piston, the two piston halves extending diametrically from the common axis of rotation perform torsional vibrations offset against each other by 180° with respect to a crankshaft. This fact can be utilized to alternately use the two piston halves for power transmission. For this purpose, there may be provided two parallel crankshafts each associated to one piston half and in drive connection with each other, which each cooperate with a connecting link guide on the associated piston half. The connecting link guides, which in such a case merely represent a straight slideway for the associated rollers on the crank pins, each act on the associated crankshafts during the working stroke, but not during the return stroke of the piston halves, which creates simple constructional conditions. Due to the drive connection of the two alternately driven crankshafts there is nevertheless obtained a continuous crankshaft drive. In the case of an elastic bias of this drive connection between the two crankshafts, for instance via a toothed belt drive, a clearance-free connecting link guide can be achieved for the rollers of the crankshafts. The rollers associated to the two connecting link guides may, however, also be associated to a common crankshaft.
To ensure that in the operation of an internal combustion engine a separate drive for the fuel injection pump with a corresponding lift-dependent control can be omitted, there may be provided a fuel injection pump to be driven by the oscillating piston itself via a tappet protruding into the cylinder space. With the tappet actuation by the oscillating piston the fuel injection pump is actuated at the stroke frequency of the oscillating piston, where advantageously diaphragm pumps can be used because of the simple sealing. When for the actuation of the fuel injection pump the tappet carries at its end protruding into the cylinder space a piston cooperating with a blind hole recess in the oscillating piston, the tappet actuation at least at higher stroke frequencies is effected via a gas cushion, which is formed when the piston engages in the blind hole recess.
To be able to utilize the high exhaust gas temperature of the internal combustion engine for an improved ignition of the respective fresh gas charge, the cylinder space may have a possibly heatable heat storage grid in the vicinity of the radial walls, which absorbs part of the exhaust gas heat and dissipates the same to the fresh gas charge. To obtain favorable ignition conditions in the case of a cold start, the heat storage grid may in addition be heated.
REFERENCES:
patent: 837507 (1906-12-01), Rapp
patent: 988704 (1911-04-01), Goodrich
patent: 3408991 (1968-11-01), Davis
patent: 3834242 (1974-09-01), Seybold
patent: 4272229 (1981-06-01), Pape
patent: 4756377 (1988-07-01), Kawamura et al.
patent: 4884532 (1989-12-01), Tan
patent: 5168706 (1992-12-01), Kawamura
patent: 5297530 (1994-03-01), Kaneko et al.
patent: 5924411 (1999-07-01), Guettle et al.
patent: 54 778 (1890-12-01), None
patent: 16 01 818 (1971-01-01), None
patent: 26 39 530 (1978-03-01), None
patent: 447 632 (1913-01-01), None
patent: 481162 (1916-11-01), None
patent: 577 656 (1946-06-01), None
Collard & Roe PC
Denion Thomas
Trieu Thai-Ba
LandOfFree
Internal combustion engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Internal combustion engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Internal combustion engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2544191