Machine element or mechanism – Mechanical movements – Rotary to or from reciprocating or oscillating
Reexamination Certificate
1999-04-20
2001-06-05
Bucci, David A. (Department: 3682)
Machine element or mechanism
Mechanical movements
Rotary to or from reciprocating or oscillating
C074S044000
Reexamination Certificate
active
06240794
ABSTRACT:
FIELD OF THE INVENTION
The invention concerns a crank assembly for a piston machine.
In this specification a piston machine may include for example an internal combustion engine, a piston-type compressor, a piston-type pump and like machines involving a reciprocating piston.
BACKGROUND OF THE INVENTION
The term crank assembly is generally used to denote a connecting arrangement which is substantially in the form of a shaft assembly provided with offset crank portions, the purpose thereof being to transmit a force such as a drive force applied thereto at one location to a load connected thereto at another location. A distinction can be drawn between what can be referred to as horizontal crank assemblies and what can be referred to as vertical crank assemblies. If a power source such as a motor or engine is stationary with respect to the crank assembly and if a rotary movement is transmitted at the end from the output member of the power source to the crank assembly then such a design configuration is embraced by the term horizontal crank assembly, An example of this would be a crank assembly which is directly flange-mounted to the drive shaft of an electric motor. If in contrast the output of a drive assembly rotates about the horizontal, that is to say the longitudinal axis of a crank assembly, then that configuration is referred to by the designation vertical crank assembly. A drive arrangement of that kind would be for example a reciprocating piston engine whose piston rod or connecting rod moves around the crank assembly at one end in engagement with the offset crank portion of the crank assembly.
Crank assemblies are subjected to loadings resulting in flexural, torsional and oscillatory stresses. Oscillations for example progressively damage and destroy the structure of the material constituting the crank assembly and give rise to fatigue phenomena which ultimately can result in fracture of the crank assembly material. In order to obviate such fatigue fractures, crank assemblies can be provided with suitable devices, the purpose of which is to damp the oscillations involved. Suitable forms of mountings are increasingly used to counteract flexural phenomena while remedies are sought to counteract torsional phenomena in respect of the crank assemblies by virtue of a particular design configuration in respect of parts which trigger off inertia forces. In other respects crank assemblies are also characterized by the fact that the concentric portion of the crank assembly, more specifically the successively occurring drive input and drive output ends and the main bearing journals, and the eccentric portion of the crank assembly, more specifically the offset crank portions or crank throws and the crank journals, rotate at the same speed of rotation. When the concentric or the eccentric portion of the crank assembly is being driven, there is no possibility of causing the respective other portion of the crank assembly to rotate at a different speed. namely higher or lower.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved crank assembly which is less subject to the above-outlined limitations.
Another object of the present invention is to provide a crank assembly for a piston machine which is of a more flexible structure whereby forces acting thereon give rise to reduced detrimental effects thereon.
Still another object of the present invention is to provide a crank assembly for a piston machine, which affords variability in terms of the relationship between movements of the piston of the machine and the rotation of the crank assembly.
In accordance with the principles of the present invention the foregoing and other objects are achieved by a crank drive assembly for a piston machine such as an internal combustion engine, a piston compressor, a piston pump or the like comprising at least one cylinder with a piston reciprocable in the cylinder for performing stroke movements of given respective lengths. A piston rod connects the piston to the crank assembly which is operative for converting the reciprocating movements of the piston in the cylinder into a rotary movement of the crank assembly or vice-versa. The crank assembly includes first and second shafts which extend in mutually coaxial relationship, each having shaft ends which are disposed in mutually opposite relationship leaving a spacing between them. Arranged between the shaft ends is the end of the connecting rod, being supported at both sides thereof and being movable on a circular path at a spacing around the coaxial axes of the first and second shafts. The connecting rod end is adapted to be in rotational engagement with said shaft ends on both sides by way of pairs of gear wheels.
Further preferred features of the invention are set forth hereinafter.
Further objects, features and advantages of the invention will be apparent from the description hereinafter of a preferred embodiment thereof.
REFERENCES:
patent: 2140127 (1938-12-01), Chancellor
patent: 2506693 (1950-05-01), Voisin
patent: 3886805 (1975-06-01), Koderman
patent: 3971261 (1976-07-01), Matsushita
patent: 4073196 (1978-02-01), Dell
patent: 4152955 (1979-05-01), McWhorter
patent: 5465648 (1995-11-01), Cy
patent: 5964198 (1938-12-01), Wu
patent: 471253 (1947-02-01), None
patent: 3736527 (1861-07-01), None
patent: 2616372 (1977-11-01), None
patent: 3927535 (1991-03-01), None
patent: 1727 (1861-01-01), None
patent: 8804356 (1988-06-01), None
Patent Abstracts of Japan, vo. 007, No. 081 (M-205) Apr. 5, 1983 & JP 008233 (Isamu Nemoto), Jan. 18, 1983.
Bachman & LaPointe P.C.
Bucci David A.
Charles Marcus
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