Synchronizing Device Overload Protection in Automatic Transmissions
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Solution Overview
Problem
Existing methods for protecting synchronizing devices in automatic transmissions from overloading are not optimally designed, leading to potential failure and significant repair costs and downtime.
Innovation Solution
A method where the synchronizing device is actuated only when the rotational speed difference between the shaft to be synchronized and the target gear reaches or falls below a predetermined threshold value of 3000 rpm, using a control unit to continuously monitor and control the speeds of involved shafts and clutches to prevent overloading and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the synchronizing device is actuated early to reduce shifting time, then productivity is improved, but the synchronizing device is subject to overloading and damage
Solution Approach 1:
The control unit continuously determines the rotational speed of the shaft to be synchronized and the synchronous speed of the target gear stage before actuation, calculates the speed difference, and only actuates the synchronizing device when the speed difference reaches or falls below the threshold value. This preliminary assessment prevents overload while enabling timely engagement.
Solution Approach 2:
The invention uses a predetermined speed difference threshold value (3000 rpm) as a critical parameter to control the actuation timing. By monitoring when the speed difference parameter reaches this threshold, the system optimizes the balance between shifting speed and synchronizing device protection.
2Reliability
If the speed difference threshold is set low to protect the synchronizing device, then reliability is improved, but shifting duration increases
Solution Approach 1:
The invention establishes an optimal threshold value of 3000 rpm for the speed difference. This parameter setting allows the synchronizing device to be actuated at the right moment - not too early to cause overload, not too late to delay shifting - thus balancing protection and timing.
Solution Approach 2:
The control unit continuously monitors the rotational speed of the shaft and the synchronous speed of the target gear stage, calculating the speed difference in real-time. This feedback mechanism ensures the synchronizing device is actuated precisely when the speed difference reaches the threshold, optimizing both protection and shifting duration.
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 approach effectively prevents overloading and damage to the synchronizing device, reducing repair costs and downtime while maintaining driving comfort by ensuring the synchronizing device is protected before overload occurs.
Implementation Method 1
The friction surfaces of the synchronizing device adjust the rotational speed of the respective shaft to be synchronized
Data Source
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AI summary
The invention relates to a method for protecting against overload of a synchronizing device of an automatic transmission of a motor vehicle, in particular an automated manual transmission, or a dual-clutch transmission, wherein the transmission has at least one clutch, at least one first and one second shaft, at least two gear stages, preferably several gear stages, at least one gear selector, preferably several gear selectors, for effectively engaging or disengaging the respective gear stages and at least two synchronizing devices, and wherein at least one control unit is provided for realizing the gear stage changes of the transmission and/or for controlling the clutch and/or for controlling the synchronizing devices and/or the gear selectors (VGS).Overloading of the synchronizing device of the target gear stage is prevented by determining the speed of the first shaft (nW1), by determining the speed difference between the first shaft and the synchronous speed corresponding to the target gear stage, whereby the synchronizing device of the target gear stage is only actuated when the speed difference determined in magnitude reaches or falls below a predetermined speed difference threshold.