Motor-Protective Wheel Rim Structure for Impact Resistance
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Solution Overview
Problem
Electric motors in wheel drive assemblies of electric vehicles are prone to damage due to protrusion from the rim, making them susceptible to impact during encounters with sidewalks, potholes, and other road obstacles, which is unacceptable and poses a risk to the motor's integrity.
Innovation Solution
A rim design featuring a cylindrical extension that radially extends from the main axis to a greater radius, enveloping the internal volume and protecting the electric motor from impacts, while maintaining the rim's aesthetics and being economical to manufacture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor is arranged within the rim and juxtaposed with braking elements, then the drive wheel assembly can be compact and efficient, but the electric motor protrudes from the rim on the inner side, creating a risk of damage during impacts
Solution Approach 1:
The patent extends the rim structure in the radial dimension by adding a cylindrical extension that protrudes inward toward the motor. This dimensional change creates a protective envelope around the motor without affecting the overall wheel assembly footprint, effectively shielding the motor from impact forces while maintaining compact integration with braking elements
2Reliability
If a protective structure is added to envelop the electric motor, then the motor is protected from impact, but the rim complexity and manufacturing difficulty increase
Solution Approach 1:
The cylindrical extension is merged with the rim body as a single integrated structure, both made from the same material (aluminum alloy or composite). This combining approach eliminates the need for separate protective components, fasteners, or assembly steps, thereby reducing overall complexity while maintaining protection functionality
Solution Approach 2:
The cylindrical extension serves multiple functions simultaneously: it acts as a protective envelope for the motor, maintains structural integrity of the rim, and can be integrated with braking element mounting. This multi-functionality reduces the need for additional specialized components, simplifying the overall design
3Strength
If the rim structure is modified to protect the motor, then impact resistance improves, but manufacturing costs and production difficulty increase
Solution Approach 1:
The patent modifies the rim's geometric parameters by adding a cylindrical extension with specific dimensional relationships (radius between main radius and maximum rim radius, axial length covering the motor). These parameter changes are designed to be compatible with existing manufacturing processes for aluminum alloy or composite rims, allowing the protective feature to be integrated without fundamentally changing production methods
4Reliability
If the cylindrical extension is designed to envelop the motor, then the motor is protected from impact, but the external aesthetics of the rim may be impaired
Solution Approach 1:
The cylindrical extension is positioned specifically on the inner side of the rim, away from the outer visible surface. This localized placement ensures that the protective structure does not interfere with the external aesthetic appearance of the rim, as the extension is largely concealed within the wheel assembly when installed
Data Source
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AI summary
The invention relates to a rim 10 for a wheel 7 with main axis A comprising an internal cylindrical volume V with axis coinciding with the main axis A, the internal volume V having a main radius RV to house an electric motor 4, the rim comprising an external hook 11 and an internal hook 20 intended to hold a tire in position on the rim, the rim 10 comprising a cylindrical extension 30 with axis coinciding with the main axis A, the cylindrical extension 30 extending radially from the main radius RV to a radius greater than the main radius RV and extending axially in an axial direction D parallel to the main axis A directed towards the opposite of the external hook 11 so that the cylindrical extension 30 envelops the internal volume V beyond the internal hook 20 to protect the electric motor 4 in case of impact at the rim 10.