Electric Transmission Shifting With Oscillation to Clear Blocking
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Solution Overview
Problem
Pneumatically shiftable transmissions in commercial vehicles face issues with blocking positions due to shifting element sticking, leading to delayed shifting times and reduced service life, while electrically shiftable transmissions lack effective methods to prevent or eliminate such positions.
Innovation Solution
An electrically shiftable transmission method that detects and controls the movement of shifting elements by imposing oscillations on a target variable, using control signals to dynamically adjust force and prevent blocking positions, thereby improving shifting performance and reducing mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If force is increased to resolve blocking position, then shifting element can be moved from blocking position, but mechanical stress on transmission increases
Solution Approach 1:
The patent applies mechanical vibration by superimposing an oscillating component on the shifting element's movement when a blocking position is detected. This vibration helps to break the sticking between shifting elements through dynamic loading, allowing the blocking position to be resolved without applying excessive static force, thereby reducing mechanical stress on transmission components.
Solution Approach 2:
The patent implements periodic action by applying oscillating movements to the shifting element in a periodic manner when blocking is detected. This periodic oscillation creates varying force conditions that can progressively overcome the sticking between teeth or engagement surfaces, enabling resolution of blocking positions through repeated small movements rather than a single high-force application.
2Productivity
If force is increased to eliminate blocking position, then shifting can be completed, but service life of transmission elements is reduced
Solution Approach 1:
By using vibrational movements to resolve blocking positions, the patent reduces peak forces and impact loads on transmission elements. This approach maintains shifting completion while minimizing damage accumulation, thereby extending the service life of gears, shafts, and other transmission components.
Solution Approach 2:
The patent detects blocking positions in advance and responds with controlled oscillating movements before the blocking causes damage. This early intervention prevents the development of high-stress conditions that would otherwise lead to premature wear or failure of transmission elements.
3Speed
If force is increased to resolve blocking position, then shifting element can be moved, but shifting time is delayed
Solution Approach 1:
The periodic oscillating movements applied to resolve blocking positions can actually reduce total shifting time compared to traditional methods. By continuously applying small oscillations that prevent sticking, the system avoids the need for repeated high-force attempts and waiting periods, thereby accelerating the overall shifting process.
Solution Approach 2:
The patent maintains continuous useful action by applying oscillating movements throughout the shifting process when blocking is detected, rather than stopping to apply intermittent high forces. This continuous motion keeps the shifting element engaged in the shifting process, reducing idle time and accelerating completion.
4Strength
If transmission is designed to withstand high forces, then blocking positions can be resolved, but device complexity increases
Solution Approach 1:
The patent replaces a purely mechanical force-based blocking resolution system with a controlled oscillation system. Instead of relying on high-strength mechanical components to withstand and resolve blocking forces, the system uses controlled vibrational movements to prevent and eliminate blocking, allowing for simpler transmission design with reduced safety factors and component sizes.
Data Source
AI summary
A method (100) for shifting an electrically shiftable transmission (230) for a vehicle (200a), in particular a commercial vehicle (200b) includes detecting (110) a state (237) of a shifting element (235) relating to a blocking position (231) of a shifting element (235) relative to a further shifting element (236). A control signal (255) for controlling a movement of the shifting element (235) is determined, taking into account the detection of the blocking position (231). The control signal (255) defines a target variable (Z) of the movement of the shifting element (235) and an oscillation (O) about the target variable (Z). The control signal (255) is output and moves the shifting element (235) out of the blocking position and into a final position of engagement with the further shifting element (236).