Transmission System Automated Directional Shift Braking
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Solution Overview
Problem
Existing transmission systems for mobile machines face challenges in smoothly and efficiently shifting directions, particularly at high speeds, due to the need to dissipate momentum and avoid shock-loading of drivetrain components, which can lead to clutch wear and potential damage.
Innovation Solution
A transmission system with a controller that disengages the current clutch and applies retarding torque via a brake when shifting directions, selectively increasing the torque based on output speed errors and transferring it to the opposing clutch when the speed is below a threshold, allowing for smooth and efficient directional changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the second clutch slips to dissipate momentum during directional shift, then the machine can change direction, but the friction material of the clutch is worn away
Solution Approach 1:
The patent introduces a brake device as an intermediary component to assist in momentum dissipation during directional shifts. The brake works in conjunction with the clutch to reduce the burden on clutch friction material, thereby extending clutch life while maintaining directional shift capability. The controller coordinates brake application timing and pressure to optimize the shift process.
Solution Approach 2:
The system applies the brake before or during the clutch engagement process to pre-dissipate momentum. This preliminary braking action reduces the speed differential that the clutch must accommodate, minimizing slip and friction material wear while enabling smoother directional transitions.
2Productivity
If the operator manually brakes during shifting, then clutch wear is reduced and shifting is faster, but it is difficult to properly time engagement/disengagement for smooth shifting
Solution Approach 1:
The system implements automated control where the controller manages brake application and clutch engagement timing based on sensor feedback. This self-service approach eliminates the need for operator judgment and manual coordination, automatically optimizing the shift process for both speed and smoothness while reducing operator workload.
Solution Approach 2:
The controller uses feedback from speed sensors and clutch position sensors to dynamically adjust brake pressure and engagement timing. This closed-loop control ensures smooth shifting by continuously monitoring system state and making real-time adjustments, eliminating the timing difficulties associated with manual operation.
3Reliability
If the vehicle control unit prevents shift change at high speed, then component damage is avoided, but shift quality during desired high-speed shift is not improved
Solution Approach 1:
The brake serves as a mediator that enables high-speed directional shifts by handling momentum dissipation separately from the clutch. This allows the clutch to engage without excessive slip even at higher speeds, improving shift quality and productivity while maintaining drivetrain protection through controlled braking assistance.
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
This solution enables smooth directional shifts at higher speeds with reduced clutch wear and component stress, improving shift quality and extending the life of drivetrain components.
Implementation Method 1
This momentum is generally dissipated via friction material inside the engaging clutch
Implementation Method 2
the second clutch will generally slip until sufficient power has been dissipated to avoid shock-loading and damage to the remaining drivetrain components
Data Source
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AI summary
A transmission system (22) is disclosed for use with a machine (10). The transmission system may have a first clutch (34) to transfer power in a first direction, a second clutch (36) to transfer power in a second direction, a brake (43), a sensor (46) to generate a first signal indicative of speed, and an input device (18) to generate a second signal indicative of a desire to shift directions. The transmission system may also have a controller (44) to cause disengagement of the first directional clutch in response to the second signal, and to cause the brake to apply retarding torque. The controller may also be configured to determine an error value based on the first signal and a target transmission system speed, to selectively increase retarding torque when the error value increases, and to selectively transfer retarding torque to the second directional clutch when a value of the second signal is less than a threshold value.