Offset Hydraulic Machine Gearbox for Vehicle Integration
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Solution Overview
Problem
The existing coupling of hydraulic machines with heat engines in vehicles is bulky, limits the choice of hydraulic machines due to size constraints, and results in increased center of gravity due to the proximity of drive shafts to the engine block, leading to inefficiencies and integration challenges.
Innovation Solution
A hydraulic assistance system where the hydraulic machine is offset from the axle, driven by a secondary shaft of the gearbox through a differential with additional toothing, allowing non-coaxial alignment and reducing size constraints, while ensuring lubrication and protection against impurities, and using a universal joint for flexible alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the hydraulic machine is arranged coaxially with the drive shaft to transmit rotational movement, then the mechanical coupling is straightforward, but the hydraulic machine becomes bulky and integration is difficult due to proximity constraints with the heat engine block
Solution Approach 1:
A bevel gearbox is introduced as an intermediary component between the drive shaft and the hydraulic machine. This allows the hydraulic machine to be positioned offset from the drive shaft axis, reducing its diameter constraints while maintaining functional connection through the gearbox's power transmission capability
Solution Approach 2:
The system transitions from a coaxial arrangement (one-dimensional alignment) to an offset arrangement where the hydraulic machine is positioned at a distance from the drive shaft axis. This dimensional change allows the hydraulic machine to have a larger diameter without interfering with the heat engine block
2Weight of moving object
If the drive shafts are placed close to the internal combustion engine to lower the center of gravity, then the vehicle's center of gravity is lowered, but the hydraulic machine becomes limited in diameter due to proximity constraints
Solution Approach 1:
The bevel gearbox serves as a mediator that decouples the spatial relationship between the drive shaft and hydraulic machine, allowing the hydraulic machine to be positioned further from the engine while still maintaining power transmission, thus enabling larger diameter hydraulic machines without compromising center of gravity positioning
3Adaptability or versatility
If a bevel gearbox is used to drive the hydraulic machine offset from the axle, then the hydraulic machine can be positioned offset, but additional mechanical elements increase friction losses and reduce power received by the hydraulic machine
Solution Approach 1:
The system allows for adjustment of the bevel gearbox's transmission ratio to optimize power transmission efficiency. By changing the gear ratio parameters, the system can minimize friction losses while maintaining the offset positioning capability of the hydraulic machine
4Adaptability or versatility
If the hydraulic machine is driven by a drive shaft, then the hydraulic machine can be positioned offset from the axle, but the drive speed varies causing flow rate and pressure variations during curved trajectory movement
Solution Approach 1:
The system incorporates sensors to detect variations in drive speed caused by curved trajectory movement. This feedback information is used to adjust the bevel gearbox's operation or the hydraulic machine's parameters to compensate for speed variations, maintaining stable flow rate and pressure output
Data Source
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AI summary
The invention concerns a hydraulic assist system of a vehicle comprising a secondary shaft of a gearbox of the vehicle, a differential comprising a differential case, the differential case comprising primary gear teeth, the primary gear teeth rotating the differential case via the output shaft of the gearbox, an axle, the differential rotating the axle, a hydraulic machine that is offset from the axle, such that the hydraulic machine and the axle are not coaxial, the differential case further comprising additional gear teeth, said additional gear teeth rotating the hydraulic machine.