Transmission Interlocking Device Prevents Shaft Blocking
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Solution Overview
Problem
Dual clutch transmissions face challenges in preventing shaft blocking due to complex interactions between tooth clutches, which can lead to mechanical damage and require costly, complex solutions to allow only certain orders of engagement/disengagement, especially in designs with multiple countershafts.
Innovation Solution
An interlocking device with a groove system and interlocking element allows specific combinations and orders of engagement/disengagement between two tooth clutches, using a movable interlocking pin or piston to prevent forbidden states, maintaining a simple and cost-effective design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an interlocking pin is used between grooves in shift actuation parts of two tooth clutches, then shaft blocking is prevented, but the design complexity increases and cost increases
Solution Approach 1:
The patent extracts the interlocking function from a complex multi-pin system and implements it through a single interlocking pin mechanism. The interlocking pin is selectively positioned to engage with grooves in shift actuation parts, preventing simultaneous engagement of incompatible tooth clutch pairs. This simplification maintains reliability while reducing device complexity and manufacturing cost.
2Reliability
If shift barrels are used to control tooth clutches, then shaft blocking is prevented, but sequential shifting is restricted and multi-step shifts are not possible
Solution Approach 1:
The patent implements a dynamic interlocking mechanism where the interlocking pin can selectively engage or disengage from grooves in shift actuation parts based on the current gear state. This dynamic positioning allows the system to prevent shaft blocking while permitting flexible shifting sequences including multi-step shifts, overcoming the rigidity of fixed shift barrels.
3Reliability
If active shift blocking systems are used, then shaft blocking is prevented, but system complexity and cost increase significantly
Solution Approach 1:
The patent implements a self-service mechanical interlocking system where the interlocking pin automatically engages with grooves in shift actuation parts when incompatible tooth clutch engagement is detected. The mechanism uses the existing mechanical motion of shift rods and grooves to activate the blocking function without requiring external sensors, control units, or active monitoring systems, thereby maintaining low complexity and cost while ensuring reliability.
Data Source
AI summary
An interlocking device arranged to prevent forbidden order of engagement/disengagement of two tooth clutches in a vehicle transmission is provided and includes a groove arranged in a first of shift rods, and a second and a third groove arranged in a second of shift rods, an interlocking element arranged coplanar with the shift rods, and directed and movable towards the shift rods. The length of the interlocking element is adapted to allow certain combinations and order of engagement/disengagement of the tooth clutches. A piston element partitions the second and third groove. The piston element is movably arranged in a hole in the second shift rod such that the interlocking element can push the piston element down in the hole, allowing the second shift rod to be displaced only one-way when the first shift rod is in an engaged position.