Integrated Worm Wheel Reducer Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional gear housings for vehicle power window reducers are thicker due to external ribs, compromising their ability to achieve both high strength and thinness.

Innovation Solution

A worm wheel is integrated with an output shaft and features a circular flange with recessed portions that allow internal ribs, enhancing the casing's strength and rigidity while reducing its thickness, and the reducer's design includes a casing with inwardly protruding ribs to further achieve thinness and increased strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If ribs are formed on the outer surface of the wheel enclosure to ensure strength, then the strength of the gear housing is improved, but the thickness of the gear housing increases

Engineering Contradiction:

Improvestrength of gear housingVSAvoidthickness of gear housing

Core Design Contradiction:

StrengthVSLength of stationary object

Solution Approach 1:

Instead of forming ribs on the outer surface of the wheel enclosure, the invention inverts the approach by forming recesses on the outer surface and corresponding ribs on the inner surface. This allows the reinforcing ribs to be positioned inside the housing rather than outside, maintaining strength while reducing overall thickness.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention transitions from two-dimensional surface ribs to a three-dimensional configuration with recesses and internal ribs. By creating recesses that extend into the housing and forming ribs on the inner surface, the strengthening feature is moved to another dimension (internal vs. external), achieving both strength and thinness.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Length of stationary object

If the gear housing is made thinner to reduce size and weight, then the size and weight are reduced, but the strength and rigidity decrease

Engineering Contradiction:

Improvethickness of gear housingVSAvoidstrength and rigidity of gear housing

Core Design Contradiction:

Length of stationary objectVSStrength

Solution Approach 1:

The invention applies local quality by creating recesses at specific locations where structural support is needed and forming ribs on the inner surface at corresponding positions. This localized reinforcement allows the housing to be thinner overall while maintaining strength at critical areas through the strategically positioned internal ribs.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If multiple components are used for the worm wheel and output shaft, then assembly flexibility is improved, but the number of components increases

Engineering Contradiction:

Improveassembly flexibilityVSAvoidnumber of components

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention merges the worm wheel and output shaft into a single integrated component. The worm wheel is formed as one piece with the output shaft, eliminating the need for separate assembly of these parts. This reduces the total number of components while maintaining manufacturing ease through integrated forming processes.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS9222547B2Worm wheel, reducer, and motor with the reducer

Publication Date: 2015.12.29 MABUCHI MOTOR CO LTD

AI summary

A worm wheel (50) is structured integrally with an output shaft (52). The worm wheel (50) includes the output shaft (52), a circular flange (50a) with the output shaft (52) placed as the center, and teeth (50b) formed on the periphery of the flange (50a) and in mesh with a worm. The flange (50a) is provided with a first recessed flange portion (50c) opposite to the side of the output shaft (52), and the bottom (54) of the first recessed flange portion (50c) has a ring-shaped first planar portion (54a).