Park Lock Actuation Using a Shared Pump Motor and Eccentric Drive

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Solution Overview

Problem

Current systems for motor vehicle drive trains with hydraulic actuation and cooling require numerous valves and electrical drives, increasing costs and assembly work, especially in double-clutch transmissions where multiple components need to be actuated and cooled, and existing parking lock actuation methods are inefficient as they often require separate electric motors and complex mechanisms.

Innovation Solution

The system bundles the tasks of cooling and actuation by using an existing electric drive for a pump or actuator to also engage and disengage the parking lock, leveraging a freewheel mechanism and eccentric disc to convert rotary motion into linear motion for efficient actuation, thereby reducing the need for additional electric motors and simplifying the system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate electric motors are used for actuating each component in a dual-clutch transmission, then each component can be precisely controlled, but the number of electric motors and valves increases, leading to higher costs and greater assembly complexity

Engineering Contradiction:
Improvecomponent control precisionVSAvoidnumber of electric motors and valves
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A single electric motor is designed to perform multiple functions: it acts as both the actuator for the dual-clutch transmission and the drive for the hydraulic pump that supplies cooling fluid. This multi-functional design eliminates the need for separate electric motors and valves for each component, reducing overall system complexity while maintaining precise control capability

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

Solution Approach 2:

The patent combines the actuation function and cooling pump drive function into one integrated electric motor system. The motor's output is mechanically coupled to both the clutch actuation mechanism and the hydraulic pump, merging previously separate functional systems into a unified structure that reduces part count and assembly complexity

Inventive Principle:
Principle #5Merging (Combining)

2Temperature

If multiple separate coolant valve assemblies are provided for each component, then each component receives adequate cooling, but the assembly effort and system complexity increase significantly

Engineering Contradiction:
Improvecooling effectivenessVSAvoidassembly effort
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

A single hydraulic pump is designed to supply cooling fluid to multiple components (both clutches) through a unified cooling circuit. This centralized cooling system eliminates the need for separate coolant valve assemblies for each component, reducing assembly effort while ensuring adequate cooling distribution to all heat-generating components

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

Solution Approach 2:

The cooling system uses a single pump with segmented output paths that distribute cooling fluid to different components through controlled channels. This allows one pump to serve multiple functions of what would traditionally require multiple separate cooling systems

Inventive Principle:
Principle #1Segmentation

3Reliability

If a dedicated parking lock actuator is used, then the parking lock can be reliably actuated, but an additional electric motor is required, increasing costs and system complexity

Engineering Contradiction:
Improveparking lock actuationVSAvoidnumber of electric motors
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The single electric motor is designed with a mechanical coupling system that allows it to perform both the primary function of actuating the dual-clutch transmission and the secondary function of actuating the parking lock. This eliminates the need for a dedicated parking lock actuator while maintaining reliable parking lock engagement through the shared motor's mechanical output

Inventive Principle:
Principle #6Universality (Multi-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

This approach reduces costs and assembly complexity by utilizing existing electric drives for both cooling and actuation, allowing for efficient engagement and disengagement of the parking lock while maintaining system functionality without critical interruptions to the hydraulic system.

Implementation Method 1

the electric machine (2) in a first direction of rotation... the electric machine (2) actuates the pump (4), for example, to provide a flow rate for cooling and lubrication

Methodology Applied
Scientific EffectHydraulic pump operation: Pump

Implementation Method 2

with freewheels (3) on its output shafts... The structural design of the locking mechanism is not significant for the invention. Additional linkages and conversions can be provided

Methodology Applied
Scientific EffectFreewheel mechanism: Ratchet

Implementation Method 3

In an advantageous embodiment, the rotary motion of the electric machine is converted into a translational motion via an eccentric disc with a linkage

Methodology Applied
Scientific EffectEccentric mechanism: Eccentric

Data Source

PatentEP3921562B1System for activating a park lock
Publication Date: 2023.05.03 MAGNA PT B V & CO KG
  • EP3921562B1 patent drawingFigure 1~2b

AI summary

The invention relates to a system (1) for activating a park lock in a gear unit with an electric machine (2), which is connected, via at least one freewheel (3), to a pump (4) for the hydraulic system of the gear unit and to an eccentric arrangement (5), wherein the eccentric arrangement (5) engages and disengages a park lock (6).