Internal-Fixed Waterproof Cover Structure for Speed Reducers

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Solution Overview

Problem

Conventional waterproof covers for speed reducers in industrial robots and machine tools face challenges in achieving complete waterproofness due to the need for fixing bolts that penetrate the cover, allowing water to enter through through holes, which compromises the waterproof performance.

Innovation Solution

A waterproof structure for speed reducers that fixes the cover to the case using an internal fixing unit, eliminating the need for external bolts and through holes, thereby enhancing the waterproof performance by integrating the cover with the speed reducer without external penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a waterproof cover is fixed to the speed reducer using fixing bolts from the outside, then the cover can be securely fixed to the case, but through holes are formed in the cover allowing water penetration

Engineering Contradiction:

Improvefixing strengthVSAvoidwaterproof performance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent inverts the conventional fixing approach by moving the fixing unit from the outer peripheral side to the inner peripheral side of the cover. The fixing unit now includes a holding member that contacts the inner peripheral surface of the cover and a fastening member that extends through the case (not the cover) to secure the assembly. This inversion eliminates through holes in the cover while maintaining secure fixing.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the dimensional approach by extending the fastening member through the case in the axial direction rather than through the cover in the radial direction. This dimensional shift allows the cover to remain intact without through holes while still achieving secure attachment via the holding member that contacts the inner peripheral surface.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If fixing bolts penetrate through the cover to secure it to the case, then reliable fixation is achieved, but water can enter through the through holes

Engineering Contradiction:

Improvefixation stabilityVSAvoidwater ingress

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the fixing mechanism by placing the holding member on the inner peripheral side of the cover rather than using external bolts. The fastening member extends through the case instead of the cover, eliminating the harmful through holes while maintaining fixation stability through the holding member's contact with the inner peripheral surface.

Inventive Principle:

Principle #13The other way round (Inversion)

3Ease of manufacture

If a conventional waterproof cover with external fixing is used, then the structure is simple to manufacture, but complete waterproofness cannot be achieved

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidwaterproof quality

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent inverts the fixing approach from external to internal, moving the holding member to contact the inner peripheral surface of the cover. This design maintains manufacturing simplicity while achieving complete waterproofness by eliminating through holes in the cover.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The holding member acts as an intermediary element that contacts the inner peripheral surface of the cover and transfers the fastening force from the fastening member (extending through the case) to the cover. This intermediary mechanism enables waterproof fixation without requiring through holes in the cover.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12140219B2Waterproof structure for speed reducer and rotation device

Publication Date: 2024.11.12 NABTESCO CORP

AI summary

A waterproof structure for a speed reducer according to one aspect of the disclosure includes: a speed reducer for decelerating a rotational driving force of an electric motor and transmitting the decelerated rotational driving force to a rotationally driven portion; a motor flange housing the speed reducer; a cover externally covering the speed reducer in a liquid-tight manner; and a holding plate and a first fixing bolt provided on an inner peripheral side of the cover to fix the cover to the motor flange.