Speed Change Transmission Centrifugal Force Mitigation

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Solution Overview

Problem

Conventional speed-change transmission apparatuses face challenges in smooth clutch operation due to centrifugal force influences, especially when larger clutches are used, leading to potential speed-changing shocks and inefficiencies in torque transmission.

Innovation Solution

The apparatus employs a meshing clutch design with a hydraulic actuator for smooth switching, eliminating the need for oil passageways and allowing clutch operation without interference from centrifugal forces, enabling continuous speed adjustment and reduced shock during high-speed operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a hydraulic clutch with larger diameter is used to transmit greater torque, then torque transmission capability is improved, but centrifugal force influence on work oil increases causing rough clutch switching

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidclutch switching smoothness
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent extracts the harmful centrifugal force influence by relocating the clutch actuation mechanism from the rotating clutch assembly to the stationary transmission housing. The oil passage is now supplied from the stationary housing rather than rotating with the clutch, eliminating the centrifugal force that prevented smooth clutch engagement while maintaining the larger clutch diameter for torque transmission.

Inventive Principle:
Principle #2Taking out (Extraction)

2Power

If clutch diameter is increased to provide greater torque, then torque capacity is improved, but centrifugal force influence on work oil becomes significant causing switching delays

Engineering Contradiction:
Improvetorque capacityVSAvoidclutch switching delay
Core Design Contradiction:
PowerVSLoss of time

Solution Approach 1:

The patent removes the source of centrifugal force influence by extracting the oil supply mechanism from the rotating clutch assembly and relocating it to the stationary transmission housing. This allows the clutch to maintain a larger diameter for increased torque capacity while the oil is supplied from a stationary source, eliminating centrifugal effects that caused switching delays.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If conventional hydraulic clutch design is used with oil passageways in transmission shaft, then structure is simplified, but centrifugal force causes rough switching and potential speed-changing shocks

Engineering Contradiction:
Improvestructural simplicityVSAvoidspeed-changing smoothness
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent extracts the oil passage from the rotating transmission shaft and relocates it to the stationary housing structure. This maintains structural simplicity while eliminating the centrifugal force problem that caused rough switching, as the oil is now supplied from a stationary source rather than rotating with the clutch assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a stationary oil passage in the housing as an intermediary between the pump and the clutch. This intermediary structure allows oil to be supplied to the clutch without the oil passage itself rotating, thereby eliminating centrifugal force effects while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution ensures smooth speed changes without delay, reducing speed-changing shocks, and allows for a wide range of speed adjustments, enhancing the riding experience and operational efficiency, particularly during high-load hauling tasks.

Implementation Method 1

switched over between an engaged condition and a disengaged condition by a hydraulic piston incorporated within the clutch

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

an influence from a centrifugal force generated in the clutch to the work oil

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP1930627B1Speed change transmission device
Publication Date: 2012.08.08 KUBOTA CORP
  • EP1930627B1 patent drawingFigure 1
  • EP1930627B1 patent drawingFigure 2
  • EP1930627B1 patent drawingFigure 3~4

AI summary

A speed-change transmission apparatus for effecting a speed-changing on an engine drive force with utilizing a continuously variable speed-change device, a plurality of planetary transmission mechanisms and a plurality of clutches is constructed to be capable of effecting the speed-changing operation smoothly, regardless of a centrifugal force generated in the clutches. An output from the continuously variable speed-change device 30 and a drive force from the engine 3 are combined by a planetary transmission section P. The drive force from this planetary transmission section P is transmitted via a clutch section C to an output shaft 61. First, second, third and forth clutches 73, 74, 76, 78 of the clutch section C are configured to be switched over respectively between an engaged condition and a disengaged condition, as clutch members 75,77 are engaged with or disengaged from output side rotational members 73b, 74b, 76b, 78b.