Parking Lock Assembly Integrating Shift Drum Actuation

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Solution Overview

Problem

Existing parking lock arrangements for motor vehicle transmissions are costly, complex, and inefficient, requiring separate components and mechanisms for actuation and locking, which limits their robustness and adaptability across different transmission types.

Innovation Solution

A parking lock arrangement that utilizes a large angular range actuation mechanism, integrating the parking lock pawl with a shift drum, allowing the parking lock to be actuated using existing drive elements, reducing component count and space requirements, and enabling cost-effective production by leveraging existing transmission components, with a second angular section for holding the pawl in the release position, eliminating the need for separate detent elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex lever linkage or separate actuation mechanism is used for the parking lock, then the parking lock function can be achieved, but the device complexity and cost increase

Engineering Contradiction:
Improveparking lock functionVSAvoidactuation mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The parking lock actuation mechanism is merged with the shift drum mechanism. The actuating arrangement is rotatably mounted on the shift drum and uses the same rotational movement to actuate both the shift elements and the parking lock pawl, eliminating the need for separate actuation mechanisms and reducing overall device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The shift drum is given multi-functionality by enabling it to actuate both the shift elements and the parking lock arrangement. The actuating arrangement on the shift drum can selectively engage different components depending on the rotational position, allowing one mechanism to serve multiple functions

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If separate detent elements are provided for holding the parking lock pawl, then the parking lock can be securely held, but the device complexity and component count increase

Engineering Contradiction:
Improveparking lock holdingVSAvoiddetent mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The actuating arrangement on the shift drum serves its own detent function through its engagement with the parking lock pawl. The mechanical engagement between the actuating arrangement and the pawl inherently provides the holding function, eliminating the need for separate detent elements

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The detent function is merged with the actuating arrangement. The same components that actuate the parking lock pawl also provide the detent/holding function through their mechanical engagement, reducing the need for separate components

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If existing drive elements like shift drum are integrated for parking lock actuation, then cost and space requirements are reduced, but the angular range and actuation mechanism must be carefully designed

Engineering Contradiction:
Improvecomponent countVSAvoidangular range compatibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The actuating arrangement is designed with dynamic engagement capabilities, allowing it to be rotatably mounted on the shift drum and engage different components at different rotational positions. This dynamic design enables the mechanism to adapt to the angular range requirements of both shift actuation and parking lock engagement

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mechanism allows for parameter changes in the angular range of operation. The actuating arrangement can be designed with different angular ranges depending on the specific transmission type and requirements, providing versatility across different applications while using the same basic principle

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2657578B1Parking lock assembly and a vehicle transmission
Publication Date: 2016.11.16 MAGNA PT BV & CO KG
  • EP2657578B1 patent drawingFigure 1
  • EP2657578B1 patent drawingFigure 2~3
  • EP2657578B1 patent drawingFigure 4~5

AI summary

The parking lock arrangement (40) has a parking lock wheel (42), which is pivoted about an axis (43), and a parking-lock pawl (48), which is movably mounted between a locking position and a release position. An actuating arrangement (56) is provided, which actuates the parking lock pawl and is rotatably mounted about another axis (58) over an angular range. The angular range has an angular section (66), within which the parking lock pawl is actuated, and another angular section (68), within which the parking lock pawl is held in a position. An independent claim is included for a motor vehicle transmission with a switching arrangement.