Mass Differential Gear Layout for Compact Engine Balance Shaft Drive
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing internal combustion engine designs face challenges with bulky and expensive drive systems for lubricating oil pumps and mass differential gears due to limited installation space and complex machining requirements, leading to inefficient lubrication and increased costs.
Innovation Solution
The mass differential gear is integrated into a gear frame attached to the crankcase beneath the crankshaft, driven by a gear wheel on the crankshaft, with an idler gear bearing integrated into the main bearing block for efficient oil supply and minimized machining, allowing for a compact and cost-effective setup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mass differential gear is directly integrated into crankcase, then machining precision of bearing positions is improved, but device complexity and cost increase due to unnecessary machining operations
Solution Approach 1:
The mass differential gear is separated from the crankcase and mounted on a separate carrier assembly. This segmentation allows the crankcase to be manufactured without additional machining operations for the mass differential gear, while the gear assembly can be independently manufactured and precisely positioned on the carrier.
Solution Approach 2:
A carrier assembly is introduced as an intermediary component between the crankcase and the mass differential gear. The carrier provides mounting positions for the gear and balance shafts, eliminating the need to machine the crankcase directly for these components while maintaining precise positioning.
2Power
If gear wheels are mounted on crank webs, then mass differential gear is driven, but installation space is drastically limited and device complexity increases
Solution Approach 1:
The drive system is repositioned from the horizontal plane (crank webs) to the vertical dimension (beneath the crankshaft). The mass differential gear and balance shafts are arranged in a vertical configuration below the crankshaft, utilizing previously unused space and reducing interference with other components.
Solution Approach 2:
The mass differential gear assembly is nested within the existing engine structure beneath the crankshaft. The carrier assembly containing the gear and balance shafts is positioned in the space below the crankshaft, effectively utilizing available volume without increasing overall engine dimensions.
3Power
If idler gear bearings are attached in crankcase, then oil pump is driven, but tolerance chains increase and lubrication quality deteriorates
Solution Approach 1:
The idler gear bearing is merged with the main bearing block, combining the lubrication systems. The idler gear bearing is positioned adjacent to the main bearing, allowing it to be supplied with lubricating oil from the same oil supply channel that serves the main bearing, ensuring reliable lubrication without additional tolerance accumulation.
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 design optimizes installation space and reduces costs by eliminating unnecessary machining and providing effective lubrication for the idler gear, minimizing angle errors and flank clearance, and enabling simultaneous drive of oil pumps and mass differential gears with reduced complexity.
Implementation Method 1
In one alternative refinement, it is provided that the idler gear is equipped with a rolling bearing, so that no active lubricant supply from the bearing block is necessary.
Implementation Method 2
For lubricating the idler gear, the necessary amount of oil is provided by the main bearing block.
Data Source
AI summary
An internal combustion engine includes a crankcase in which a crankshaft is rotatably mounted in bearings including bearing covers, to which at least one connecting rod carrying a piston is linked. The piston is movable in a cylinder covered by a cylinder head forming a combustion chamber and gas exchange valves are arranged in the cylinder head, which are actuated by at least one camshaft, which is connected to a gear train gear wheel situated on the crankshaft via a differential gear. A mass differential gear including two balance shafts is present. The mass differential gear is situated in a gear frame and attached to the crankcase below the crankshaft and driven by a mass shaft drive gear situated on the crankshaft, which is arranged axially essentially next to the gear train gear wheel/idler gear. The gear train gear wheel/idler gear is arranged on the main bearing cover.