Removable Differential Gear Assembly for Electric Motor Rotor
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Solution Overview
Problem
The durability and serviceability of internally mounted differentials in active core electric motors can affect the performance and reliability of electric vehicles, and existing hybrid drivetrains are complex, costly, and emit harmful pollution due to the inclusion of both internal combustion engines and electric motors.
Innovation Solution
A removable differential gear assembly is designed for integration within the hollow rotor of an electric motor, featuring a hollow cross member with extension members, gears, and pins that can be easily assembled and disassembled, along with spring members and washers for secure mounting, allowing for a compact and durable powertrain configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the differential is integrated within the rotor of the electric motor to achieve a compact powertrain assembly, then the powertrain envelope is reduced, but the durability and serviceability of the differential becomes compromised
Solution Approach 1:
The differential assembly is segmented into modular components including the cross member with extension members, gears, pins, and retaining rings. This segmentation allows the differential to be installed as a complete unit within the rotor while enabling individual component replacement for maintenance, thus preserving both compactness and serviceability
Solution Approach 2:
The differential assembly is nested within the hollow rotor structure. The cross member fits within the rotor cavity, extension members extend into rotor openings, and gears are mounted on these extensions. This nesting achieves compact integration while the open structure allows access for serviceability
2Ease of repair
If a removable differential assembly is used to improve serviceability, then maintenance becomes easier, but the assembly complexity increases
Solution Approach 1:
The differential assembly is pre-assembled as a complete unit with all gears, pins, and cross members configured before installation. This preliminary assembly simplifies the service process because the entire differential can be removed and replaced as one unit, and individual components can be pre-repaired off-vehicle, reducing the complexity of in-situ maintenance
Solution Approach 2:
The assembly incorporates movable pins that can be extended or retracted, and retaining rings that can be easily installed or removed. These dynamic features allow the differential to transition between a compact installed state and a disassembled serviceable state, managing complexity through controlled mobility rather than permanent complexity
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 provides a durable and easily serviceable differential assembly that enhances the reliability and performance of electric vehicles by simplifying maintenance and reducing drivetrain complexity while eliminating internal combustion engine emissions, thus achieving a greener and more efficient powertrain.
Implementation Method 1
differential for an active core electric motor having pin with friction fit
Data Source
AI summary
A gear assembly is provided that simplifies the integration of a differential assembly into the hollow rotor of an electric motor. The gear assembly utilizes a hollow cross member that includes a central portion and a plurality of hollow extension members onto which the gears are mounted. Within each of the hollow extension members is a pin. When the pins are withdrawn, the assembly fits unimpeded within the hollow rotor. When the pins are partially extended out of the corresponding extension members, the ends of the pins fit within apertures in the rotor. A plug fits within a centrally located thru-hole in the central portion of the hollow cross member, thereby locking the pins in the extended position and locking the gear assembly in place.