Hybrid Power Unit Balancing for Twin-Cylinder Vibration Control
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Solution Overview
Problem
Hybrid vehicles equipped with twin-cylinder reciprocating piston engines experience vibrations during operation, which disrupt the quiet and vibration-free driving experience typical of battery-electric vehicles.
Innovation Solution
The power unit incorporates a twin-cylinder reciprocating piston engine with a tandem arrangement of pistons and counter-directional crankshafts, along with a generator, camshaft, flywheel mass element, and compensating camshaft to compensate for mass moments of inertia and mass forces of the second order, thereby reducing vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a twin-cylinder reciprocating piston engine is used in a hybrid vehicle, then the vehicle can be recharged via the electricity grid, but vibrations occur during power unit operation which disrupt the quiet driving experience
Solution Approach 1:
The patent employs counter-directional crankshafts that rotate in opposite directions to generate counterbalancing forces. The first crankshaft is coupled to the generator while the second crankshaft rotates counter-directionally, creating opposing inertial forces that cancel out vibrations from the reciprocating pistons. This counterweight principle eliminates the harmful vibrations while preserving the engine's recharging function.
Solution Approach 2:
The patent uses asymmetric cylinder arrangement with tandem-configured cylinders oriented at angles to each other. The cylinders are positioned such that their piston movements create balanced inertial forces. This asymmetric geometric arrangement of the engine components achieves vibration cancellation while maintaining compact packaging suitable for hybrid vehicles.
2Object-affected harmful factors
If a battery-electric vehicle is used, then the driving experience is quiet and vibration-free, but production costs are high due to large battery requirements
Solution Approach 1:
The patent segments the powertrain into a hybrid configuration with a downsized reciprocating piston engine and generator, replacing the need for a large battery pack. The engine is divided into twin-cylinder configuration with separate crankshafts for each cylinder, allowing independent vibration control. This segmentation enables cost-effective manufacturing while achieving quiet operation through the specialized engine design.
3Use of energy by moving object
If the power unit is switched on in hybrid vehicles, then the battery can be recharged, but intensive start-up vibrations occur which are perceptible to occupants
Solution Approach 1:
The counter-directional crankshafts are designed to provide immediate counterbalancing forces from the moment of engine start-up. The opposing rotational directions of the two crankshafts create continuous counterweights that neutralize the inertial forces generated during acceleration and start-up, eliminating the perceptible vibrations that typically occur when the power unit is activated.
Solution Approach 2:
The engine is pre-configured with balanced counterweights and counter-directional crankshaft orientation before operation begins. This preliminary design arrangement ensures that vibration cancellation is inherent to the engine structure itself, providing quiet operation from the very first start-up without requiring additional active control systems or post-start adjustments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration achieves a significantly quieter operation, eliminating the intense start-up vibrations typically associated with hybrid vehicles, resulting in a driving experience comparable to battery-electric vehicles.
Implementation Method 1
mass moments of inertia occur, wherein the flywheel mass element according to the invention is designed to compensate these mass moments of inertia
Implementation Method 2
The compensating camshaft, on the other hand, serves to compensate mass forces of the second order
Data Source
AI summary
A power unit for a hybrid vehicle is provided with a twin-cylinder reciprocating piston engine, which has two pistons which are guided in two cylinders in tandem arrangement. Two counter-directional crankshafts are connected with the pistons by connecting rods. At least one generator is rotatable co-directionally to the first crankshaft and counter-directionally to the second crankshaft. A camshaft with valve cams are operatively connected with control valves. A flywheel mass element is arranged on the second crankshaft or on a flywheel mass compensating shaft, and a compensating camshaft are provided. The compensating camshaft includes at least one compensating cam element which is operatively connected with a linearly guided compensating mass.