Two-Speed Gearbox Layout for Compact Power Shift
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Solution Overview
Problem
Current electric vehicle gear assemblies are bulky and require large volumes for clutch actuation, making them inefficient in terms of space and maintenance, and they lack the ability to shift gears with controlled torque transfer without interrupting torque flow.
Innovation Solution
A compact gear assembly design with a shaft having gears at both ends connected to clutch members, where a force member axially moves the clutches to engage and disengage at relative circumferential speeds, allowing for smooth torque transfer and reduced radial forces, utilizing a controller and hydraulic actuators for clutch engagement and disengagement, and an interconnecting plate for easy assembly and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clutches are placed on the input shaft to enable power shift, then gear shifting without torque interruption is achieved, but centrifugal forces cause oil to be forced out at high speeds
Solution Approach 1:
The clutches are moved from the input shaft to an intermediate shaft, changing the spatial dimension and location where clutch engagement occurs. This dimensional relocation allows the system to maintain power shift capability while avoiding the harmful centrifugal forces present at the high-speed input shaft.
2Reliability
If a traditional layout with clutches on intermediate shaft is used, then power shift is achieved, but the radial volume required is relatively large
Solution Approach 1:
The force members for actuating both clutches are merged into a single integrated component that moves axially to engage/disengage both clutches simultaneously. This merging eliminates the need for separate actuation mechanisms, significantly reducing the radial volume required while maintaining the power shift function.
Solution Approach 2:
The single force member performs multiple functions by axially moving to engage or disengage both clutches at the same time. This multi-functional design reduces the number of separate components needed, thereby reducing the overall radial volume of the gearbox.
3Adaptability or versatility
If clutch actuation mechanisms are added to enable gear shifting, then gear selection capability is improved, but the device complexity and volume increase
Solution Approach 1:
The actuation mechanisms for both clutches are merged into a single force member that can engage or disengage both clutches by axial movement. This consolidation reduces device complexity while maintaining full gear selection capability.
Solution Approach 2:
The force member is designed to automatically engage or disengage both clutches through its axial movement, eliminating the need for complex separate actuation systems. The system serves itself by using the same component for both clutch operations.
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 enables a compact, efficient gear shifting system with constant torque transfer, reduced noise and wear, and simplified maintenance, while allowing for a cost-effective and flexible two-speed gearbox configuration.
Implementation Method 1
the first clutch members and the second clutch members can engage and disengage in a slipping manner at relative circumferential speeds
Implementation Method 2
utilizing a controller and hydraulic actuators for clutch engagement and disengagement
Data Source
AI summary
An assembly for use with an electric motor, including a shaft with on a first end and on a second end a rotatable gear. Each gear is fixedly connected to a first clutch member that can slipping engage a second clutch member extending around the shaft and connected to the shaft in a fixed angular position. A force member is axially situated between the clutch members for moving second clutch members relative to the first clutch members in an axial direction such that the first clutch members and the second clutch members can engage and disengage in a slipping manner at relative circumferential speeds.