Nested Electric Machine Layout for Compact Vehicle Drive Trains
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Solution Overview
Problem
Electric machines acting as vehicle drives require significant installation space due to their large dimensions, limiting their coaxial arrangement with internal combustion engines due to insufficient available space.
Innovation Solution
The electric machines are arranged in a radially nested configuration, with the smaller second electric machine positioned radially within the larger first electric machine, allowing for a coaxial arrangement that optimizes installation space usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If electric machines are arranged coaxially next to each other, then they can be positioned close to the internal combustion engine, but the available installation space is insufficient
Solution Approach 1:
The patent applies radial nesting by positioning the second electric machine (starter generator) radially inside the first electric machine (vehicle drive). This nested configuration allows both machines to share the same radial space around the internal combustion engine crankshaft, enabling coaxial arrangement while significantly reducing the total volume occupied and solving the installation space insufficiency problem.
Solution Approach 2:
The patent transitions from a conventional axial side-by-side arrangement to a radial nested arrangement. By utilizing the radial dimension more effectively and positioning machines at different radial distances from the crankshaft axis, the solution optimizes the three-dimensional space utilization, allowing both electric machines to be accommodated in the limited space available in the vehicle tunnel.
2Power
If the first electric machine has larger dimensions for vehicle drive function, then it provides sufficient power, but it occupies more installation space
Solution Approach 1:
The larger first electric machine (vehicle drive) is positioned radially outward, while the smaller second electric machine (starter generator) is nested radially inside it. This nesting allows the system to accommodate the large power-capable first machine without proportionally increasing the total installation space, as the second machine utilizes the unused radial space within the first machine's envelope.
Solution Approach 2:
The patent merges the spatial envelopes of the two electric machines by positioning them concentrically around the same crankshaft axis. The first electric machine serves dual purposes: as the primary vehicle drive and as the housing/space provider for the second electric machine, thereby combining their spatial requirements into a more compact integrated assembly.
Data Source
AI summary
A drive train for a vehicle includes an internal combustion engine (VM) coaxial to the first axis (A1), at least one first electric machine (EM1) and one second electric machine (EM2), and a transmission arrangement (G) connectable to an output (Ab). The first electric machine (EM1) has larger dimensions than the second electric machine (EM2). The second electric machine (EM2) is connectable at least to the internal combustion engine (VM), and the first electric machine (EM1) is connectable at least to the transmission arrangement (G). The first electric machine (EM1) and the second electric machine (EM2) are coaxial to the first axis (A1). The first electric machine (EM1) and the second electric machine (EM2) are radially nested, or the first electric machine (EM1), when viewed axially, is associated with the internal combustion engine and the second electric machine (2), when viewed axially, is associated with the output.