Transmission Shift Actuator Spring Module for Smooth Gear Engagement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing transmission systems face challenges in efficiently switching between gear positions, leading to reduced shifting comfort, increased wear, noise, and jerk, while also requiring complex constructions and higher costs.

Innovation Solution

A device featuring an actuator and a spring module that kinematically connects to a switching element on a shaft, allowing axial displacement for switchable connections between gear wheels, utilizing a brushless DC motor and a spring arrangement with distinct characteristic curves for efficient force distribution, enabling smooth and precise gear shifting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a spring module with predefinable elasticity is integrated into the force path between the actuator and the switching element, then shifting comfort is improved and wear is reduced, but the device complexity increases

Engineering Contradiction:
Improveshifting comfortVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The spring module is nested within the actuator assembly, with the spring element positioned between the actuator and the switching element. This integration allows the spring to be part of the compact actuator unit while providing elasticity to reduce impact during gear shifting, thereby improving shifting comfort without proportionally increasing overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The spring element is pre-loaded with a specific force before operation to cushion the impact during gear switching. By pre-defining the elasticity and pre-load force of the spring, the system prepares the cushioning effect in advance, reducing wear and improving shifting comfort during actual operation without requiring complex real-time control mechanisms.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If the spring element is pre-loaded with high force to ensure positive engagement, then engagement reliability is improved, but the risk of tooth jump and harmful forces increases

Engineering Contradiction:
Improveengagement reliabilityVSAvoidtooth jump and harmful forces
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The spring element's characteristics are precisely controlled by changing parameters such as spring constant, pre-load force, and spring geometry. By optimizing these parameters, the spring provides sufficient force for reliable engagement while avoiding excessive force that could cause tooth jump or harmful impacts. The parameter optimization balances engagement reliability with harm reduction.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If the actuator is designed with integrated spring module to reduce space requirements, then compactness is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvespace requirementsVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The spring module is merged with the actuator to form an integrated assembly, combining the actuator components and spring element into a single compact unit. This merging reduces the overall space required while consolidating manufacturing steps, as the spring module can be pre-assembled and tested as a module before integration into the final actuator assembly.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances shifting comfort by reducing switching time, wear, noise, and jerk, while simplifying construction and reducing costs by ensuring precise and efficient gear engagement with reduced space requirements.

Implementation Method 1

a spring assembly (9), in particular a pre-tensioned spring assembly (9), having a first spring end (14) and a second spring end (15)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

utilizing a brushless DC motor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3571428B1Device for moving a shifting element, and transmission
Publication Date: 2021.01.20 ZF FRIEDRICHSHAFEN AG
  • EP3571428B1 patent drawingFigure 1
  • EP3571428B1 patent drawingFigure 2~3
  • EP3571428B1 patent drawingFigure 4~5

AI summary

The invention relates to a device (5) for selectively moving a shifting element (4) in the direction of a first shift position and/or in the direction of a second shift position, said device (5) having an actuator (6) and a spring module (7) which acts between the actuator (6) and the shifting element (4). The spring module (7) has an actuator-side force application element, a shifting element-side force application element, and a spring assembly which acts between the force application elements and comprises a first spring end and a second spring end. The actuator-side force application element and the shifting element-side force application element have a respective first support section which acts in the direction of the first shift position and a respective second support section which acts in the direction of the second shift position for supporting the spring ends. The first spring end is paired with the first support section of the shifting element-side force application element and the second support section of the actuator-side force application element, and the second spring end is paired with the first support section of the actuator-side force application element and the second support section of the shifting element-side force application element. The invention also relates to a transmission, in particular for a motor vehicle, said transmission having at least one such device (5).