Balancing Shaft Transmission Layout for Compact Engine Integration
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Solution Overview
Problem
Existing internal combustion engines face challenges with large and costly mass balancing gears and lubricating oil pump drives, which require significant installation space and additional machining efforts, leading to inefficient lubrication and increased costs, especially when both systems need to be installed simultaneously.
Innovation Solution
The mass balancing gear is mounted in a gear frame below the crankshaft on the crankcase and driven by a gear on the crankshaft, with an integrated intermediate wheel bearing for the oil pump, minimizing installation space and eliminating unnecessary machining, and utilizing a roller bearing for self-lubrication and tapping into the main bearing's oil supply for lubrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mass balancing gears are mounted on the crankshaft webs, then the mass balancing function is achieved, but the gears become very large and difficult to install due to extremely restricted installation space
Solution Approach 1:
The mass balancing transmission is relocated from the traditional crankshaft web mounting location to the oil pan area below the crankshaft. This spatial relocation to a different dimension/zone provides adequate installation space while maintaining the mass balancing function through proper gear train design.
2Power
If intermediate gear bearings are mounted in the crankcase to drive the oil pump, then the drive function is achieved, but tighter tolerances and inadequate lubrication of the intermediate gear bearings occur
Solution Approach 1:
The intermediate gear bearing for the oil pump drive is integrated into the main bearing housing rather than being mounted separately in the crankcase. This merging of functions allows the intermediate gear to be lubricated by the same oil supply system that lubricates the main bearings, ensuring adequate lubrication while maintaining the drive function.
3Adaptability or versatility
If both the oil pump drive and mass differential systems are installed simultaneously, then both functions are achieved, but the system becomes bulky and expensive with additional machining efforts
Solution Approach 1:
The mass balancing transmission and oil pump drive are combined into a single integrated transmission unit housed in the oil pan. This merging eliminates the need for separate mounting systems and reduces overall complexity. Additionally, the transmission utilizes the existing main bearing housing oil supply system, avoiding additional machining operations on the crankcase.
Solution Approach 2:
The main bearing housing is designed to serve multiple functions: supporting the crankshaft main bearings and providing lubrication to the intermediate gear bearing of the mass balancing transmission. This multi-functionality eliminates the need for separate lubrication systems and reduces overall system complexity.
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 results in a space-optimized and cost-effective drive variant that minimizes angular errors and backlash, reduces the need for active lubrication, and provides sufficient oil supply to the intermediate wheel bearing, thereby reducing overall complexity and cost.
Implementation Method 1
utilizing a roller bearing for self-lubrication
Implementation Method 2
provides sufficient oil supply to the intermediate wheel bearing
Data Source
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AI summary
The invention relates to an internal combustion engine comprising a crankcase in which a crankshaft is rotatably mounted in bearings with bearing covers, to which at least one connecting rod supporting a piston is linked, wherein the piston can be moved 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 arranged on the crankshaft via a transmission, wherein a mass balancing transmission is provided with two balancing shafts, characterised in that the mass balancing transmission is arranged in a transmission frame and attached to the crankcase below the crankshaft and driven by a mass shaft drive gear wheel arranged on the crankshaft, which is arranged axially substantially next to the gear train gear wheel / idler gear and wherein the gear train gear wheel / idler gear is arranged on the main bearing cover.