Automatic Door Motor Assembly Without a Containment Casing

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Solution Overview

Problem

Existing electric motors for automatic doors, particularly pedestrian doors, suffer from high production costs due to the need for precise machining of the containment casing and stator core, which is not easily standardizable, leading to machining errors and increased prices.

Innovation Solution

The electric motor design eliminates the containment casing by using caps or shells with internal shoulders and protrusions to stabilize the stator core, compensating for machining errors and ensuring stable positioning without additional components like compensation rings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a containment casing is used to house the stator core, then the stator core is protected and positioned, but the machining costs increase due to the need for precise tolerances and the casing becomes non-standardizable

Engineering Contradiction:
Improvestator core positioning stabilityVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the containment casing from the motor structure. Instead of using a separate casing to house and position the stator core, the motor relies on the direct positioning of the stator core within the motor housing, supported by the rotor and end bells, thereby removing the expensive, non-standardizable component while maintaining structural integrity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The motor housing and end bells are designed to perform multiple functions: they provide structural support, position the stator core, and eliminate the need for a separate containment casing. This multi-functionality allows for standardization of the motor housing and end bells as universal components that can accommodate different stator core sizes and configurations

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If precise machining is applied to the containment casing to achieve tight coupling tolerances, then assembly quality is improved, but production costs increase

Engineering Contradiction:
Improvecoupling toleranceVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention replaces the expensive, precisely machined containment casing with simpler, less expensive components such as the motor housing, end bells, and rotor assembly that can be manufactured with standard tolerances. These components achieve the necessary positioning accuracy through their combined geometry rather than requiring individual precision machining of each part

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Productivity

If standardized components are used for the motor, then production efficiency is improved, but machining errors in the stator core cannot be compensated

Engineering Contradiction:
Improveproduction efficiencyVSAvoidmachining error compensation
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention introduces adjustable and adaptable elements into the motor structure, such as the positioning of the stator core within the motor housing that can accommodate variations in stator core dimensions. The end bells and rotor assembly are designed to dynamically adjust to machining variations, allowing standardized components to work together while compensating for individual component tolerances

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention allows for parameter variations in the stator core dimensions while maintaining functional performance. The motor housing and end bells are designed with tolerances and geometries that accommodate a range of stator core sizes and shapes, enabling the use of standardized components with varying machining precision without affecting the overall motor performance

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4611218A1Electric motor, in particular for automatic doors, and related assembly method
Publication Date: 2025.09.03 FACE
  • EP4611218A1 patent drawingFigure 1~2
  • EP4611218A1 patent drawingFigure 3~4
  • EP4611218A1 patent drawingFigure 5~6

AI summary

The present invention relates to an electric motor, in particular for automatic doors, for example an automatic pedestrian door, and to a method of assembling the same. Furthermore, the present invention also relates to an automatic door, for example an automatic pedestrian door, comprising such an electric motor.