Nested Gear Select Clutch Layout for Compact Transmissions

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Solution Overview

Problem

The existing transmission mechanisms, such as those described in JP H7-9859 A, require additional space for a lever mechanism outside the coupling sleeve, leading to increased size and mountability issues when used in vehicles.

Innovation Solution

The transmission mechanism incorporates a gear select clutch that enters the recess portions of the second and third gears, positioning its center inside the recess of the third gear when the first gear is decoupled, eliminating the need for external gear change mechanisms and allowing for a compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lever mechanism is disposed on the outside of the coupling sleeve to control gear changes, then the gear change operation is achieved, but the transmission mechanism size increases

Engineering Contradiction:
Improvegear change operationVSAvoidtransmission mechanism size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The gear select clutch is nested inside the recess portions of the second and third gears, with its center positioned inside the recess of the third gear. This nesting arrangement eliminates the need for external lever mechanisms, allowing the gear change control mechanism to be integrated within the existing gear structure, thereby reducing the overall transmission mechanism size while maintaining operational capability

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If a lever mechanism is disposed on the outside of the coupling sleeve, then gear change control is achieved, but in-vehicle mountability deteriorates

Engineering Contradiction:
Improvegear change controlVSAvoidin-vehicle mountability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The gear select clutch is nested inside the recess portions of the second and third gears, integrating the gear change control mechanism within the existing gear structure. This eliminates external protruding components, creating a compact transmission mechanism that is more adaptable to vehicle mounting constraints and improves in-vehicle installability

Inventive Principle:
Principle #7Nested doll (Nesting)

3Volume of moving object

If the gear select clutch enters inside the recess portions of the gears, then the transmission mechanism size is reduced, but the gear change mechanism complexity changes

Engineering Contradiction:
Improvetransmission mechanism sizeVSAvoidgear change mechanism structure
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The gear select clutch is merged with the existing gear structure by positioning it inside the recess portions of the second and third gears. This integration combines the gear change control function with the existing gear components, reducing overall size while managing complexity through functional integration rather than adding separate external mechanisms

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3483474B1Transmission mechanism
Publication Date: 2021.05.12 UNIVANCE CORP
  • EP3483474B1 patent drawingFigure 1~2
  • EP3483474B1 patent drawingFigure 3
  • EP3483474B1 patent drawingFigure 4

AI summary

A transmission mechanism including: a first gear (18) coaxially fixed to a rotational shaft (17) having a hollow shape, a second gear (20) and a third gear (21), the second gear and the third gear being rotatably and coaxially disposed on an outer periphery of the rotational shaft such that the second gear and the third gear are opposed to each other; a gear select clutch (50) disposed between the second gear and the third gear, and configured to select one of a state in which the second gear and the first gear are coupled and the third gear and the first gear are decoupled, and a state in which the third gear and the first gear are coupled and the second gear and the first gear are decoupled; and a clutch operation unit (51) configured to couple an operation shaft (40) disposed in a hollow part of the rotational shaft to the gear select clutch to operate the gear select clutch by advancing and retreating the operation shaft in an axial direction.