Parking Lock Pawl Actuation for Compact Transmission Assembly
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Solution Overview
Problem
Vehicle transmission parking lock mechanisms require complex assembly and high precision components, leading to increased production complexity and component count, which is undesirable due to limited packing space.
Innovation Solution
A parking lock device with a pawl and actuator unit mechanically coupled by a pin and slot mechanism, allowing for simplified production and assembly by using a single actuator unit for both engagement and disengagement, and incorporating a hydraulic cylinder and spring for robust and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional actuation linkage system with multiple components is used, then the parking lock mechanism can achieve reliable engagement, but the device complexity and number of components increases
Solution Approach 1:
The patent combines multiple components (actuating rod, cone, spring, and interface elements) into a single integrated actuator unit. This unit directly engages the ratchet wheel through a unified structure, eliminating the need for separate linkage components while maintaining reliable engagement through the integrated design of the actuation mechanism.
Solution Approach 2:
The actuator unit is designed to perform multiple functions within a single component: it provides actuation force, maintains engagement pressure, stores energy for engagement, and directly interfaces with the ratchet wheel teeth. This multi-functional design reduces component count while ensuring reliable parking lock operation.
2Manufacturing precision
If multiple precision components with small tolerances are used, then the parking lock mechanism can achieve accurate engagement, but the manufacturing precision requirements and production complexity increase
Solution Approach 1:
By merging multiple precision components into a single actuator unit with standardized tolerances, the patent reduces the cumulative tolerance chain effect. The integrated design allows for more relaxed individual tolerances compared to assembling multiple tight-tolerance parts, simplifying manufacturing while maintaining engagement accuracy.
Solution Approach 2:
The patent changes the tolerance parameters from multiple tight tolerances across several components to fewer, more manageable tolerances on integrated features. This parameter optimization reduces manufacturing difficulty while preserving the accuracy needed for reliable pawl-wheel engagement.
3Reliability
If several components are assembled together, then the parking lock mechanism can achieve proper function, but the assembling process becomes complicated and time-consuming
Solution Approach 1:
The patent merges multiple assembly steps into a single unit installation. The actuator unit arrives pre-assembled and integrated, requiring only one installation operation rather than assembling multiple separate components. This dramatically reduces assembly time and complexity while maintaining full functional capability.
Solution Approach 2:
The actuator unit is pre-assembled and pre-configured before installation into the transmission. This preliminary assembly of critical components into a unified unit simplifies the final installation step and ensures proper functional alignment without requiring complex assembly procedures at the installation stage.
4Reliability
If more components are used in the parking lock mechanism, then the engagement function can be achieved, but the packing space required in the transmission increases
Solution Approach 1:
The patent consolidates multiple components into a single compact actuator unit, reducing the total volume occupied by the parking lock mechanism. The integrated design eliminates gaps and spacing requirements between separate components, allowing more efficient use of the limited transmission packing space while maintaining full locking functionality.
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
The solution simplifies the production and assembly of the parking lock mechanism, reducing the number of components while maintaining robustness and ensuring secure engagement of the pawl with the wheel, even with initial misalignment, through a compact and efficient design.
Implementation Method 1
the actuator unit comprises a spring arranged to counteract movement of the pawl from the locked position towards the unlocked position
Implementation Method 2
The actuator unit preferably comprises a hydraulic cylinder for movement of the pushrod
Data Source
AI summary
A parking lock device for a transmission of a vehicle. The device comprising a wheel, a pawl for locking the wheel against rotation and an actuator unit arranged for movement of the pawl relative to the wheel. The pawl has a locked position where the pawl and the wheel are engaged and an unlocked position where the pawl and the wheel are disengaged. The pawl and the actuator unit are mechanically coupled to each other by a pin and slot mechanism having a guide slot and a guide pin received by the guide slot.