Hybrid Power Unit Balancer Shaft Flywheel Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power units for hybrid vehicles with two-cylinder reciprocating piston engines face challenges in reducing output levels while maintaining quiet operation and reducing production costs, as they often require multiple generators and balancer shafts, leading to increased complexity and noise.
Innovation Solution
A power unit design featuring a two-cylinder reciprocating piston engine with counter-rotating crankshafts, a single generator, and a balancer shaft with a flywheel mass element that supports dynamic mass balancing, allowing for reduced output levels without adverse effects on quiet operation, and utilizing identical components for different output levels to simplify manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a second generator is used to maintain quiet operation at lower output levels, then noise and vibration are reduced, but device complexity and manufacturing costs increase
Solution Approach 1:
The patent combines the functions of the second generator with the balancer shaft by integrating a flywheel mass element directly onto the balancer shaft. This merging eliminates the need for a separate second generator while maintaining the quiet operation function through dynamic mass balancing of second-order mass forces.
Solution Approach 2:
The balancer shaft is designed to serve multiple functions: it acts as both a balancing mechanism and a flywheel energy storage device. The flywheel mass element on the balancer shaft performs dynamic mass balancing while also providing rotational inertia for smooth operation, replacing the need for a dedicated second generator.
2Object-affected harmful factors
If multiple generators and balancer shafts are used to maintain quiet operation, then noise and vibration are reduced, but series production costs increase
Solution Approach 1:
The patent merges the second generator function with the balancer shaft by placing a flywheel mass element on it, reducing the total number of components that need to be manufactured and assembled. This simplification directly reduces series production costs while maintaining quiet operation through dynamic mass balancing.
Solution Approach 2:
The invention extracts the essential function of the second generator (dynamic mass balancing) and relocates it to the balancer shaft with the flywheel mass element. This extraction eliminates unnecessary components and simplifies the manufacturing process for series production.
3Adaptability or versatility
If output level is reduced for lower power applications, then adaptability to diverse applications is improved, but quiet operation may be compromised
Solution Approach 1:
The patent changes the parameter of rotational mass distribution by placing a flywheel mass element on the balancer shaft. This parameter change enables dynamic mass balancing of second-order mass forces, allowing the power unit to maintain quiet operation across different output levels and applications.
Solution Approach 2:
The balancer shaft with flywheel mass element serves as a universal solution that maintains quiet operation across different power output levels. The same basic module can be adapted to various applications by adjusting the flywheel mass, providing both versatility and consistent quiet performance.
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
The design achieves quiet and low-vibration operation, reducing series production costs and enabling the production of hybrid vehicles with nearly silent starting and running, comparable to battery-powered vehicles, by balancing second-order mass forces and minimizing moving parts and noise emissions.
Implementation Method 1
By the now preferentially provided rotating mass of the flywheel mass element, which is arranged on the balancer shaft and/or the second crankshaft, corresponding to the sum of the rotating masses of the generator and the first crankshaft, a dynamic mass balancing is achieved. Specifically, second-order mass forces can be balanced.
Implementation Method 2
The two-cylinder reciprocating piston engine comprises two pistons and two counter-rotating crankshafts
Implementation Method 3
The crankshafts are connected to the pistons by connecting rods
Data Source
AI summary
The invention relates to a power unit, in particular for a hybrid vehicle, comprising a two-cylinder reciprocating piston engine comprising two pistons guided in two cylinders in tandem arrangement, and two counter-rotating crankshafts connected to the pistons by connecting rods, a generator which is rotatable in the same direction as the first crankshaft and in the opposite direction to the second crankshaft, and a balancer shaft which is rotatable in the same direction as the second crankshaft and in the opposite direction to the first crankshaft. The generator is operatively connected directly to the first crankshaft by a first traction mechanism and the balancer shaft is operatively connected directly to the second crankshaft by a second traction mechanism. The balancer shaft and/or the second crankshaft support(s) a flywheel mass element. The invention further relates to a vehicle, in particular a hybrid vehicle, having such a power unit.