Powertrain Interface Module With Torsional Damping for Smooth EV Shifts
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Solution Overview
Problem
Conventional friction-type and interference-type clutches used in vehicle powertrains for torque modulation are impractical for heavy vehicles and high-speed electric machines, as they tend to slip under heavy loads, are expensive, and have short lifespans, and are difficult to package effectively.
Innovation Solution
A powertrain interface module with a torsional damper assembly and an overload clutch assembly that modulates torque between an input and an output, featuring a torsional damper with ramp arrangements and a damper preload member, and an overload clutch with inner and outer clutch plates, designed to absorb torque spikes and limit maximum torque transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If friction-type clutches are used for torque modulation, then torque control is achieved, but the clutch slips under heavy loads and has short lifespan
Solution Approach 1:
The patent replaces friction-type mechanical clutches with a torsional damper assembly that uses ramp arrangements and spring elements to mechanically engage and disengage clutch plates. This substitution eliminates slipping by using positive mechanical engagement through the ramp geometry, where the inclined surfaces force the clutch plates together with controlled force, preventing the滑移 that occurs in friction-based systems.
Solution Approach 2:
The torsional damper assembly incorporates spring elements and ramp arrangements that cushion the engagement process before full torque transfer occurs. The springs compress during engagement, absorbing shock and gradually transferring torque, which prevents sudden slips and reduces wear on the clutch plates, thereby extending lifespan while maintaining reliable torque control.
2Reliability
If interference-type clutches are used for torque modulation, then precise torque control is achieved, but the components are expensive and have short lifespan
Solution Approach 1:
The clutch assembly is segmented into modular components including the torsional damper assembly, ramp arrangements, spring elements, and clutch plates. This segmentation allows each component to be manufactured independently using standard machining processes, reducing overall cost. The modular design also enables easier assembly and maintenance, further reducing lifecycle costs while maintaining the precision torque control of interference-type clutches.
Solution Approach 2:
The patent uses adjustable spring preloads and ramp angle parameters to control torque characteristics. By changing these parameters, the same basic clutch design can be adapted for different torque requirements without requiring completely different components, reducing development and manufacturing costs while maintaining precise torque control capability.
3Reliability
If conventional clutches are used in high-speed applications, then torque modulation is achieved, but the clutches slip and have reduced reliability
Solution Approach 1:
The patent replaces friction-based torque modulation with a mechanical engagement system using ramp arrangements and spring-loaded clutch plates. This mechanical system maintains reliable torque transfer at high speeds by using positive engagement through the ramp geometry rather than relying on friction, which becomes less effective at high rotational velocities due to centrifugal forces and reduced contact pressure.
4Reliability
If conventional clutch packaging is used, then assembly is simple, but the clutch does not perform reliably in heavy vehicle applications
Solution Approach 1:
The patent merges the torsional damper assembly with the clutch assembly into a single integrated unit. The ramp arrangements serve dual functions as both torsional damping elements and clutch engagement surfaces, while the spring elements provide both damping and clutch plate actuation. This merging reduces the number of separate components and simplifies packaging while achieving the reliable torque modulation needed for heavy vehicle applications.
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
Enables efficient, predictable, and reliable torque modulation in heavy and high-speed applications without the need for expensive components or complex control systems, ensuring smooth gear shifting and extended component life.
Implementation Method 1
a torsional damper assembly disposed in the interior of the input drum about the rotational axis and operatively arranged between the input drum and the output shaft. The torsional damper assembly comprises an input-side damper body having a first ramp arrangement and an output-side damper body coupled to the output shaft and having a second ramp arrangement disposed in resilient engagement with the first ramp arrangement.
Implementation Method 2
The output-side damper body is arranged to move axially along the rotational axis between a first engagement position and a second engagement position, the second engagement position defined by a predetermined torque differential between the input and the output.
Implementation Method 3
a damper preload member abutting the output-side damper body to urge the output-side damper body arrangement toward the first engagement position.
Implementation Method 4
an overload clutch including an inner clutch plate mounted to the drive hub and an outer clutch plate mounted to the input-side damper body
Data Source
AI summary
Vehicles that are relatively heavy and/or configured to transport heavy loads may utilize a powertrain comprising an electric machine capable of operating at high speeds and a multispeed transmission to propel the vehicle. An interface module is configured to modulate torque between the electric machine and the multispeed transmission allowing the electric machine to smoothly match speed as the multispeed transmission shifts between gears. The interface module facilitates efficient, predictable, and reliable modulation of torque between an input and an output of the powertrain of the vehicle.