Motorcycle Gearshift Torque Control for Clutchless Closed-Coupling Shifts

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing motorcycle shift assistants with springs in the power transmission path cause indifferent or spongy switching behavior, making it difficult for drivers to find neutral gear and are prone to failure due to complex and expensive structures.

Innovation Solution

A switching device that uses sensor devices to detect the rotational actuation of the shift shaft and shift drum, eliminating the need for a spring in the power transmission path, allowing gear changes without clutch operation and maintaining the driver's natural shifting force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a spring mechanism is used in the power transmission path between the shift lever and the shift shaft to enable gear changes with clutch engaged, then gear changing speed is improved, but the shifting behavior becomes indifferent or spongy making it difficult to find neutral gear

Engineering Contradiction:
Improvegear changing speedVSAvoidshifting behavior precision
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The patent removes the spring mechanism from the power transmission path between the shift lever and the shift shaft. Instead of using a spring to store and release energy for gear changes, the invention directly couples the shift lever to the shift shaft through a bearing, eliminating the intermediate spring element that caused indifferent or spongy shifting behavior while still enabling gear changes with the clutch engaged.

Inventive Principle:
Principle #2Taking out (Extraction)

2Extent of automation

If a spring mechanism is used in the power transmission path to assist gear changes, then the shifting process is automated, but the device complexity increases and becomes prone to failure

Engineering Contradiction:
Improveshifting automationVSAvoidsystem structure complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex spring mechanism from the shifting system. The simplified design directly couples the shift lever to the shift shaft through a bearing, eliminating the need for springs, spring accumulators, and associated complex control mechanisms while maintaining the ability to perform automated gear changes with the clutch engaged.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The shift lever system is designed to directly actuate the shift shaft and shift drum without requiring external spring energy storage or complex control systems. The rider's direct input on the shift lever is transmitted through the bearing to rotate the shift shaft, which in turn rotates the shift drum to engage gears, creating a self-service system that is both automated and simple.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If a spring mechanism is used to transmit force from the shift lever to the shift shaft, then gear changes can be performed without clutch operation, but the structure becomes expensive and difficult to manufacture

Engineering Contradiction:
Improveclutchless shifting capabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent removes the expensive and complex spring mechanism from the power transmission path. The simplified design uses a direct bearing connection between the shift lever and shift shaft, which is much easier to manufacture and assemble while still enabling clutchless gear changes. The bearing provides smooth rotation and reliable force transmission without the complexity of spring-based energy storage systems.

Inventive Principle:
Principle #2Taking out (Extraction)

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 provides a seamless gear-changing experience without adjusting to changed switching behavior, reduces wear, and simplifies the system by eliminating the need for force-measuring devices, ensuring reliable and comfortable shifting without clutch operation.

Implementation Method 1

the support bearing (12A) is provided with a receptacle (10) for the detachable attachment of a magnetic device (12) and the first sensor device (8) is provided for the direct detection of the rotation angle of the shift shaft (6) resulting from the rotary actuation of the shift lever (5) by means of the magnetic device (12)

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Implementation Method 2

the switching drum (7) has a recess (17) in the area of an end face section in which a magnetic device (16) is arranged and the switching device has a second sensor device (14) that detects the rotary actuation of the switching drum (7)

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Data Source

PatentEP3135960B2Shifting device for actuating a gearbox of a motorcycle for carrying out a shift of gears in closed coupling
Publication Date: 2023.09.20 KTM AG
  • EP3135960B2 patent drawingFigure 1
  • EP3135960B2 patent drawingFigure 2
  • EP3135960B2 patent drawingFigure 3

AI summary

A switching device is proposed for actuating a gearbox (4) of a motorcycle having a drive motor (2) for carrying out a gear change with the clutch (13) closed between the drive motor (2) and the gearbox (4), which has a rotatable shift shaft (6) and a rotatable shift drum (7), and the switching device has a shift lever (5) provided for actuating the shift shaft (6) and is designed to influence the output torque of the drive motor (2), wherein the switching device has a first sensor device (8) that detects the rotary actuation of the shift shaft (6) and the switching device is designed to influence the output torque of the drive motor (2) depending on a sensor signal of the first sensor device (8).