Selector Shaft Shifting Mechanism for Duo-Synchro Gear Engagement
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Solution Overview
Problem
Existing manually shifted transmissions lack an efficient mechanism for achieving duo-synchro shifts, which require precise coordination of multiple shift elements for gear engagement and disengagement without the use of shift actuators or sensors.
Innovation Solution
A shifting device with a selector shaft that can be translated and rotated, allowing for the selection and actuation of shift elements in phase or with phase displacement, utilizing master and slave elements to transmit rotary movements to shift elements, ensuring that one shift element of the first group closes before the other in the second group, facilitating compact and efficient gear shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a manually shifted transmission uses traditional shift mechanisms, then the structure becomes complex and bulky, but achieving compact construction requires precise coordination of multiple shift elements
Solution Approach 1:
The shift elements are divided into two distinct groups (first group and second group), each with its own dedicated actuator. This segmentation allows independent control of shift elements, enabling precise coordination for duo-synchro shifts while reducing overall mechanism complexity through modular organization
Solution Approach 2:
The actuators are designed to perform multiple functions: they can actuate shift elements within their assigned group, coordinate with other actuators for duo-synchro shifts, and operate independently or in combination based on shifting requirements. This multi-functionality reduces the need for dedicated components for each function
2Productivity
If shift elements are actuated simultaneously, then the shifting process is faster, but precise engagement requires phased or overlapping actuation sequences
Solution Approach 1:
The actuators are designed to execute periodic actuation sequences with specific timing relationships. The control system coordinates actuators to operate in phased sequences (one after another) or with overlapping phases (simultaneously with time overlap), enabling precise gear engagement while maintaining efficient shifting speed through rhythmic, coordinated action
Solution Approach 2:
Before final gear engagement, the actuators perform preliminary synchronization actions to align the rotational speeds of interacting gear components. This preliminary action ensures that when the shift elements are fully engaged, the gears are already synchronized, enabling precise engagement without requiring extremely slow actuation
Data Source
AI summary
Shifting device for shifting a transmission, having a first group of shift elements and a second group of shift elements, a selector shaft, which is arranged in such a way that it can be moved in translation along a longitudinal axis and rotated about the longitudinal axis, wherein it is possible, by moving the selector shaft into one of a plurality of possible translational positions, to select at least one shift element of the first group and at least one shift element of the second group and, by rotating the selector shaft, to actuate the selected shift elements. The at least one selected shift element of the first group can be actuated in phase or with an overlapping phase displacement or an offset phase displacement with respect to the at least one selected shift element of the second group.