Pivoting balancer system
First Claim
1. In an apparatus of the type having a cylinder defining a cylinder axis and a crankcase, a crankshaft rotatably mounted in the crankcase, said crankshaft defining a crankshaft axis substantially normal to said cylinder axis and having a crankpin flanked by a pair of crankarms that connect the crankpin to the crankshaft in eccentrically offset relation to the crankshaft axis, and a piston axially reciprocable in the cylinder and connected with the crankpin, counterbalancing means comprising:
- a counterbalance weight defining a center of gravity;
first mounting means for pivotally connecting said counterbalance weight to said crankcase to provide a stationary pivot axis for said weight;
second mounting means for pivotally connecting said counterbalance weight to said crankshaft to provide reciprocal motion for said weight; and
the center of gravity of said counterbalance weight being disposed between said cylinder axis and said stationary pivot axis.
1 Assignment
0 Petitions
Accused Products
Abstract
A balance system for an internal combustion engine or the like includes a counterbalance weight pivotally mounted to the crankcase and driven in a reciprocating manner by a link assembly connecting the weight to an eccentric on the crankshaft. The pivoting weight not only counterbalances the piston acceleration and deceleration forces but also cancels the torsional forces created by the weight as it pivotally moves through an arc in response to piston movement. This is accomplished by locating the center of gravity of the balance weight between the piston bore centerline and the stationary pivot of the balance weight itself. This location for the center of gravity causes a torque to be generated by a force couple created by the piston inertial force vector, the balance weight interial force vector, and the distance between them. This torque counteracts the torque generated by angular acceleration of the balance weight itself, to thereby substantially eliminate all torsional vibrations.
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Citations
17 Claims
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1. In an apparatus of the type having a cylinder defining a cylinder axis and a crankcase, a crankshaft rotatably mounted in the crankcase, said crankshaft defining a crankshaft axis substantially normal to said cylinder axis and having a crankpin flanked by a pair of crankarms that connect the crankpin to the crankshaft in eccentrically offset relation to the crankshaft axis, and a piston axially reciprocable in the cylinder and connected with the crankpin, counterbalancing means comprising:
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a counterbalance weight defining a center of gravity; first mounting means for pivotally connecting said counterbalance weight to said crankcase to provide a stationary pivot axis for said weight; second mounting means for pivotally connecting said counterbalance weight to said crankshaft to provide reciprocal motion for said weight; and the center of gravity of said counterbalance weight being disposed between said cylinder axis and said stationary pivot axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. In an apparatus of the type having a cylinder defining a cylinder axis and a crankcase, a crankshaft rotatably mounted in the crankcase, said crankshaft defining a crankshaft axis substantially normal to said cylinder axis and having a crankpin flanked by a pair of crankarms that connect the crankpin to the crankshaft in eccentrically offset relation to the crankshaft axis, and a piston axially reciprocable in the cylinder and connected with the crankpin, counterbalancing means comprising:
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a counterbalance weight, said counterbalance weight defining a mass providing substantially the entire counterbalancing for said piston; mounting means on the crankcase for pivotally connecting said counterbalance weight thereto to provide a stationary pivot axis for said weight; connection means for connecting said counterbalance weight to said crankshaft, said connection means comprises a member separate from said counterbalance weight having one end pivotally connected to said counterbalance weight and said one end provides less than about 10% of the mass effective for the counterbalancing of said piston; and eccentric means on said crankshaft for imparting reciprocal pivotal motion to said counterbalance means through said connection means. - View Dependent Claims (13, 14, 15, 16, 17)
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Specification