Removable Inner-Outer Rotating Shaft Locking Assembly

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Solution Overview

Problem

The disassembly and assembly of rotating shafts in rotating electric machines are complicated due to the need for crimping or bonding between the inner and outer shafts to prevent idling, making it difficult to separate the inner shaft from the outer shaft during maintenance.

Innovation Solution

A rotating shaft design featuring a hollow tubular outer shaft and a removably inserted inner shaft, secured by a positioning and fixing member comprising a nut member, locking sleeve, locking ring, and retainer member, which restricts relative rotation and facilitates easy disassembly and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the outer shaft is crimped or bonded with respect to the inner shaft to prevent idle rotation, then the reliability of the connection is improved, but the ease of disassembly deteriorates

Engineering Contradiction:
Improveconnection reliabilityVSAvoidease of disassembly
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The positioning and fixing member is divided into multiple independent components: a retainer member with retaining portions, a locking member with locking projections, and a fastening member. This segmentation allows the connection to be reliably established through precise geometric interlocking while enabling easy disassembly by simply removing the fastening member, without requiring thermal or chemical processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retainer member and locking member are pre-configured with complementary geometric features (retaining portions and locking projections) that automatically engage when the fastening member is tightened. This preliminary configuration ensures reliable connection establishment while maintaining disassembly ease, as the geometric interlocking is already prepared and only requires the fastening action to activate.

Inventive Principle:
Principle #10Preliminary action

2Ease of repair

If a double structure of inner shaft and outer shaft is adopted to facilitate maintenance, then the ease of repair is improved, but the device complexity increases

Engineering Contradiction:
Improveease of maintenanceVSAvoidstructure complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The rotating shaft is segmented into an outer shaft and an inner shaft that can be independently assembled and disassembled. The positioning and fixing member is further segmented into retainer member, locking member, and fastening member. This multi-level segmentation enables easy maintenance by allowing the inner shaft to be removed independently, while the modular fixing mechanism keeps the overall structural complexity manageable through standardized components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inner shaft is nested within the outer shaft, forming a compact double-structure configuration. The positioning and fixing member components are nested together, with the locking member positioned within the retainer member and both secured by the fastening member. This nesting arrangement facilitates maintenance by allowing the inner shaft to be extracted from the outer shaft, while maintaining a compact overall structure that does not excessively increase device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If multiple locking mechanisms are introduced to prevent loosening, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvefastening reliabilityVSAvoidfixing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fixing mechanism is segmented into three functional components: the retainer member that provides retaining portions, the locking member that provides locking projections, and the fastening member that secures the connection. Each component has a specific function, creating a reliable multi-stage fastening system while keeping individual components simple and the overall mechanism manageable in complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retainer member and locking member are designed with self-aligning geometric features where the retaining portions and locking projections automatically engage in the correct orientation when the fastening member is tightened. This self-service characteristic ensures reliable fastening without requiring complex adjustment mechanisms, maintaining simplicity while achieving high reliability through precise geometric interlocking.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4446600B9Rotating shaft
Publication Date: 2026.03.18 HONDA MOTOR CO LTD
  • EP4446600B9 patent drawingFigure 1
  • EP4446600B9 patent drawingFigure 2
  • EP4446600B9 patent drawingFigure 3

AI summary

A rotating shaft (66) comprises an outer shaft (70) and an inner shaft (68) being inserted into a hollow interior of said outer shaft. A first end part (80) of the inner shaft includes an extending portion (90) being exposed outside of the outer shaft. A positioning and fixing member (120) prevents the inner shaft from coming off the outer shaft by a plurality of engaging and locking elements. It (120) includes a nut member (130) being screwed to outer circumferential surface of the extending inner shaft portion, a locking sleeve (160) surrounding and retaining the nut member, a locking ring (180) engaging with the nut member and the extending inner shaft portion and a retainer member (200) being retained, inserted or clamped inside of a plurality of axially projecting members (140,136) of said nut member.