Single-Motor Transmission Actuator Gate Design for Precise Gear Shifting

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Solution Overview

Problem

1-motor transmission actuators for motor vehicle transmissions face challenges in precisely controlling switching and selection movements, leading to potential incorrect operation and strain on the connecting device due to chamfers that can impair the actuator's function.

Innovation Solution

A 1-motor gear actuator design featuring a selector shaft with a fixed and axially displaceable/rotatable gate part, including grooves and webs, and an element that interacts with these features, utilizing an insertion chamfer to allow movement in the selection direction while preventing movement against it, ensuring precise control and preventing strain on the connecting device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If chamfers are provided on both sides of each groove on the webs to facilitate pivoting of the second link part into the first link part, then the ease of operation is improved, but the connecting device becomes braced overall and the function of the transmission actuator is impaired

Engineering Contradiction:
Improvepivoting of second link part into first link partVSAvoidfunction of transmission actuator
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by providing chamfers only at specific locations where needed for guidance, rather than on both sides of each groove. The first link part has chamfers at its ends to facilitate initial engagement, while the second link part has chamfers only at the leading edge where it enters the grooves. This localized application of chamfers provides sufficient guidance for pivoting while preventing the connecting device from becoming braced overall, thus maintaining the transmission actuator's function.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the second link part is made axially movable and rotatable to enable selection and shifting movements, then the adaptability is improved, but the precision of controlling switching and selection movements deteriorates

Engineering Contradiction:
Improveselection and shifting movementsVSAvoidcontrol of switching and selection movements
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent introduces the gate as an intermediary component between the first and second link parts. The gate with its fixed first link part and axially movable second link part acts as a mediator that guides and controls the movements. The grooves and webs structure of the gate provide precise geometric constraints that control the switching and selection movements, while still allowing the necessary adaptability for both selection and shifting operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the connecting device into distinct functional parts: the first link part with chamfers for engagement, the gate with grooves and webs for guidance, and the second link part with controlled chamfers for precise movement. This segmentation allows each component to perform its specific function optimally, with the gate's structured grooves providing precision control while the link parts maintain adaptability for different movements.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3123062B1Single-motor transmission actuator comprising a gate for selecting and shifting gears of a motor vehicle transmission device
Publication Date: 2020.06.03 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP3123062B1 patent drawingFigure 1~3
  • EP3123062B1 patent drawingFigure 4~7
  • EP3123062B1 patent drawingFigure 8~11

AI summary

The invention relates to a transmission actuator for a motor vehicle transmission device which has a plurality of transmission ratios for forming gears, wherein the transmission actuator has a shifting shaft which is mounted in a rotatable manner for shifting gears and is mounted in an axially displaceable manner for selecting gears, and wherein the transmission actuator has a gate having a first gate part which is arranged in a stationary manner and a second gate part which is rotatable and axially displaceable, wherein one gate part has grooves and lands alternating in one direction and the other gate part has at least one element that can cooperate with one land at a time and can be moved into one groove at a time; wherein the at least one element is moved past the lands and grooves during a selection movement in a defined direction and is moved into one of the grooves during a shifting movement; wherein a lead-in bevel is provided at least on the lands or on the element so that the movable gate part, in the event of a collision between the element and the land during a shifting movement, can continue to move over the lead-in bevel in the defined direction of the selection movement and the shifting movement can be continued; wherein substantially right-angled transitions are also provided so that, in the event of a collision between the element and the land during the shifting movement, the movable gate part cannot be moved counter to the selection movement but rather the shifting movement is stopped.