Shift Drum Stop Assembly for Extended Torsion Angle Referencing

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Solution Overview

Problem

Existing shift drum arrangements in transmission systems have limited torsion angles, making it difficult to detect the rotational position of the shift drum, especially in dual-clutch transmissions, and do not accommodate the increased requirements of hybridized transmissions.

Innovation Solution

A shift drum arrangement with a stop device that allows the stop element to rotate freely in relation to the shift drum body, increasing the maximum twisting angle by incorporating stop surfaces offset in the circumferential direction, enabling greater rotational range without altering the shift drum's periphery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a stop element is fixed to the shift drum body for referencing rotational position, then the rotational position can be detected, but the torsion angle range of the shift drum is limited

Engineering Contradiction:
Improverotational position detectionVSAvoidtorsion angle range
Core Design Contradiction:
Measurement precisionVSLength of moving object

Solution Approach 1:

The stop device is segmented into a stop element and a stop carrier that are rotatably connected to each other. The stop element is mounted on the stop carrier via a rotation bearing, allowing independent rotation. This segmentation enables the stop element to provide referencing while the stop carrier absorbs the torsion angle changes, resolving the contradiction between position detection and rotation range.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stop carrier acts as an intermediary between the shift drum body and the stop element. It is rotatably connected to the shift drum body and carries the stop element, which is also rotatably mounted on it. This intermediary structure allows the stop element to maintain its referencing function while the stop carrier accommodates the increased torsion angle requirements through its own rotational freedom.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the shift drum is designed with fixed stop surfaces for referencing, then position detection is possible, but additional functionalities cannot be added without altering the periphery

Engineering Contradiction:
Improverotational position referencingVSAvoidfunctional expansion capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The stop device is designed with dynamic rotational freedom between the stop element and stop carrier. This dynamic connection allows the stop element to rotate independently on the stop carrier, providing referencing functionality while accommodating the increased torsion angle requirements. The dynamic design enables additional functionalities to be integrated without altering the shift drum's periphery, as the stop carrier can absorb rotational variations.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If the stop element is made wide and solid for stable referencing, then positioning accuracy improves, but the available torsion angle of the shift drum is reduced

Engineering Contradiction:
Improvepositioning accuracyVSAvoidavailable torsion angle
Core Design Contradiction:
Measurement precisionVSLength of moving object

Solution Approach 1:

The stop device is divided into a stop element and a stop carrier that can rotate relative to each other. The stop element can be designed wide and solid for stable referencing, while the stop carrier provides the additional rotational freedom needed for increased torsion angle. This segmentation allows both requirements to be satisfied simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stop carrier serves as an intermediary that carries the wide and solid stop element for accurate positioning, while itself being rotatably mounted on the shift drum body. This intermediary structure allows the stop element to maintain its dimensional stability for referencing while the stop carrier accommodates the torsion angle variations through its rotational movement.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3617564B1Shift drum arrangement and transmission arrangement
Publication Date: 2021.01.20 MAGNA PT B V & CO KG
  • EP3617564B1 patent drawingFigure 1~2
  • EP3617564B1 patent drawingFigure 3~5
  • EP3617564B1 patent drawing

AI summary

Shift drum assembly (32) for a shifting device (30) of a transmission assembly (16), particularly for motor vehicles, comprising a shift drum body (34) rotatable about a shift drum axis (40), and a stop device (60) for referencing a rotational position of the shift drum body (34), wherein the stop device (60) has a stop element (62) designed such that it can come into contact with a housing stop (65) in a first reference position, the stop element (62) being mounted so as to be rotatable in the direction of rotation relative to the shift drum body (34). (Fig. 1)