Walking Tiller Sub-Transmission Case Segmentation

Solution Overview

Problem

Conventional walking type tillers require significant design changes and increased manufacturing costs to enhance the number of speed change stages, as the existing gear units need to be enlarged, which complicates the transmission case design.

Innovation Solution

The implementation of a sub-transmission case that houses a sub-speed change mechanism, allowing for additional speed change stages without substantial modifications to the main transmission case, utilizing a belt drive mechanism and a sealing type transmission case to facilitate easy assembly and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the gear unit in the transmission case is enlarged to increase the number of speed change stages, then the number of speed change stages is increased, but the manufacturing cost is increased and the design complexity is increased

Engineering Contradiction:

Improvenumber of speed change stagesVSAvoiddesign complexity of transmission case

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The transmission system is divided into a main transmission case and a sub-transmission case. The main transmission case contains the engine and primary transmission components, while the sub-transmission case contains additional gear units for speed multiplication. This segmentation allows the speed change stages to be increased without requiring the main transmission case to be enlarged, thus resolving the contradiction between increasing speed stages and reducing design complexity.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If the gear unit in the transmission case is enlarged to increase the number of speed change stages, then the number of speed change stages is increased, but the manufacturing cost is increased

Engineering Contradiction:

Improvenumber of speed change stagesVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The transmission system is divided into a main transmission case and a sub-transmission case. The main transmission case contains the engine and primary transmission components, while the sub-transmission case contains additional gear units for speed multiplication. This segmentation allows the speed change stages to be increased without requiring the main transmission case to be enlarged, thus resolving the contradiction between increasing speed stages and reducing design complexity.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If the transmission case is enlarged to accommodate more gear units, then the number of speed change stages is increased, but the size of the transmission case is increased

Engineering Contradiction:

Improvenumber of speed change stagesVSAvoidvolume of transmission case

Core Design Contradiction:

Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

The sub-transmission case is positioned adjacent to and integrated with the main transmission case, forming a compact nested arrangement. The sub-transmission case contains additional gear units that multiply the speed change stages without requiring the main transmission case to be enlarged. This nesting approach allows increasing the number of speed change stages while maintaining a compact overall size.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentEP3172952B1Walking type tiller

Publication Date: 2021.12.01 ISEKI & CO LTD

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AI summary

A walking type tiller which transmits a driving power from an engine (20) to a tilling device (60), characterized by including: a main transmission case (1300) which houses a main speed change mechanism (300) that transmits the driving power from the engine (20) to the tilling device (60) in a manner to be capable of changing speed, and a sub-transmission case (1400) which houses a sub-speed change mechanism (400) that transmits the driving power transmitted from the engine (20) to the main speed change mechanism (300) in a manner to be capable of changing speed, wherein the sub-transmission case (1400) is configured attachably to and detachably from the main transmission case (1300).