Integrated Motor-Planetary Drive Unit With Shared Bearing Support
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Solution Overview
Problem
Existing drive units for vehicles are cumbersome, complex, and inefficient due to mechanical losses and structural challenges, requiring numerous components for stability and space optimization.
Innovation Solution
A drive unit with a compact structure comprising a housing, stator, rotor, planetary gear set, and interface system, utilizing support and auxiliary bearings to reduce mechanical losses and simplify assembly, while minimizing volume and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If traditional separate housings for motor and gear set are used with intermediate walls, then structural stability is improved, but device complexity and weight increase
Solution Approach 1:
The patent combines the motor housing and gear set housing into a single integrated housing structure. The stator is directly mounted on the housing, and the gear set is positioned within the same housing, eliminating the need for separate housings and intermediate connecting walls. This merging reduces the number of components while maintaining structural stability through the unified housing design.
2Reliability
If multiple bearings are used to support rotor and gear set, then reliability is improved, but device complexity and power loss increase
Solution Approach 1:
The patent uses a single support bearing that simultaneously supports both the rotor shaft and the gear shaft. The bearing is positioned to receive both shafts, allowing one bearing to perform the support function for both rotating components. This reduces the number of bearings from two to one, thereby reducing bearing churning losses while maintaining the reliability of component support.
3Volume of moving object
If thin housing walls are used, then volume is reduced, but structural strength decreases
Solution Approach 1:
By integrating the motor and gear set into a single housing, the patent eliminates intermediate walls that would be required to connect separate housings. The unified housing structure allows for optimized wall thickness distribution, where walls can be thinner in non-critical areas and adequately thick in load-bearing areas, reducing overall volume while maintaining necessary structural strength.
4Reliability
If numerous components are used for stability, then reliability is improved, but ease of manufacture deteriorates
Solution Approach 1:
The patent integrates multiple functions into fewer components: a single housing serves as the structural framework for both motor and gear set, and a single support bearing supports both the rotor and gear shafts. This reduction in component count simplifies the assembly process, as fewer parts need to be manufactured, procured, and assembled, while the integrated design maintains the reliability needed for drive unit stability.
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
The solution achieves reduced power-flow losses, simplified structure, and enhanced efficiency with fewer components, resulting in a more durable and lightweight drive unit.
Implementation Method 1
bearings that couple the moving portions of the assembly with the static ones to reduce to a minimum the mechanical losses between the various components involved
Implementation Method 2
a planetary gear set, also placed inside the housing, comprising a ring gear, a plurality of planet gears and a planet carrier
Data Source
AI summary
Disclosed is a drive unit. The drive unit comprises a housing, a stator, a rotor, a planetary gear set, and an interface system. The rotor comprises a rotor shaft rotatable around a rotation axis and a sun gear coupled to said rotor shaft. The planetary gear set comprises a ring gear fixed to said housing, a plurality of planet gears in meshing engagement between the sun gear and the ring gear, and a planet carrier supporting them. Furthermore, the planet carrier comprises an axial protrusion developing along the rotation axis and defining a gear shaft concentric to the rotor shaft. The interface system interfaces the rotor with the planetary gear set and comprise at least one support bearing interposed between the rotor shaft and the gear shaft.