Electric Drive Axle Layout With Parallel Motor and Park Lock
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Solution Overview
Problem
Previous electric drive axles face challenges with axle assembly layout and packaging, as well as gear train longevity, due to clearance issues and increased complexity from gearbox clutches, leading to potential component degradation and shorter maintenance intervals.
Innovation Solution
An electric drive axle design that includes a motor-generator, a gearbox with a planetary gear set, and a differential, featuring a sun gear shaft coupled to the rotor shaft, an idler gear, and an output gear, which allows for a compact and parallel motor configuration, and a park lock mechanism with a parking gear that extends through the carrier, reducing space constraints and enhancing functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the electric motor is arranged coaxial with the axle shafts, then the axle assembly layout is compact, but clearance issues arise and tradeoffs must be made between axle structural integrity and compactness
Solution Approach 1:
The patent transitions from a coaxial motor arrangement to a parallel motor configuration where the motor shaft is positioned parallel to and offset from the axle shafts. This dimensional repositioning allows the motor to be integrated into the axle assembly without interfering with the structural integrity of the axle shafts, achieving both compactness and strength.
2Adaptability or versatility
If gearbox clutches are added to enable transient shifting, then gear train versatility is improved, but device complexity increases and gear train longevity decreases
Solution Approach 1:
The patent removes the clutch components from the gearbox assembly, eliminating the source of complexity and reliability issues. The simplified gear train without clutches maintains essential gear shifting functionality while removing the problematic elements that caused degradation and maintenance concerns.
3Adaptability or versatility
If a park lock mechanism is added to the axle, then functional versatility is improved, but space constraints are worsened
Solution Approach 1:
The patent integrates the park lock mechanism with existing axle components, specifically utilizing the gear train and housing structures already present in the axle assembly. This merging approach allows the park lock functionality to be added without requiring separate dedicated space, thus maintaining compactness while enhancing versatility.
Data Source
AI summary
An electric drive axle in a vehicle is provided. The electric drive axle includes, in one example, an electric motor-generator, a gearbox, and a differential. The gearbox comprises a planetary gear set that includes a sun gear configured to rotate on a sun gear shaft directly coupled to a rotor of the electric motor-generator and an intermediate shaft that includes an idler gear rotationally coupled to a pinion gear that is rotationally coupled to the carrier.