Elastically Deformable Watch Motor Cage for Rotor Assembly

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for assembling a rotor in a cage for electromagnetic watch motors are complex and require precise manipulation, particularly due to the need for a two-part cage and challenging pivot alignment, leading to increased manufacturing costs and assembly difficulties.

Innovation Solution

A cage made of non-magnetic material with a lateral opening and elastically deformable parts allows for the easy lateral introduction of the rotor, with the first and second parts being capable of sufficient elastic deformation to accommodate the rotor's pivots, simplifying the assembly process and potentially being formed from a single piece of plastic for cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a two-part cage with a closing lid is used to house the rotor, then the rotor can be protected and positioned, but the assembly process becomes complex and difficult due to precise manipulation requirements for pivot alignment

Engineering Contradiction:

Improverotor positioningVSAvoidcage structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The cage is divided into a body and a separate lid, allowing the rotor to be assembled within the body first and then protected by the lid. This segmentation enables easier assembly of the rotor pivots into bearings before closing the cage, reducing the complexity of simultaneous alignment operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The rotor is preliminarily positioned and its pivots are inserted into the bearings while the cage is open. This preliminary action allows for easier alignment and insertion operations before the lid is closed to secure the rotor in its final protected position.

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If the cage is made in two separate parts with a lid, then the rotor can be introduced through one opening, but the introduction of the second pivot into the bearing of the lid poses serious assembly problems

Engineering Contradiction:

Improvecage fabricationVSAvoidpivot insertion

Core Design Contradiction:

Ease of manufactureVSEase of operation

Solution Approach 1:

The cage structure is segmented into a body portion with one opening for rotor introduction and a separate lid portion. This segmentation allows the rotor to be introduced through the body opening while the lid remains separate, eliminating the problem of inserting pivots into bearings located in opposite directions through a closed structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lid acts as an intermediary element that can be temporarily removed or opened during the pivot insertion process, allowing access to the bearings without requiring complex manipulation through a closed structure. After pivot insertion, the lid is reattached to complete the cage.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If precise manipulation is required for rotor assembly in the cage, then the rotor can be properly positioned, but manufacturing costs increase

Engineering Contradiction:

Improvepivot alignmentVSAvoidassembly cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The rotor and its pivots are preliminarily positioned and assembled within the open cage body before the lid is attached. This preliminary assembly allows for straightforward alignment and insertion operations without requiring complex precision manipulation tools or techniques, thereby reducing manufacturing costs while maintaining proper rotor positioning.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The assembly process is segmented into distinct stages: first assembling the rotor in the open body where access is easy, then separately attaching the lid. This segmentation of the assembly process into manageable stages reduces the precision requirements at each stage compared to attempting to assemble everything simultaneously through a closed structure.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution enables an efficient and cost-effective method for manufacturing the electromagnetic motor by allowing easy mounting of the rotor through a side opening, reducing assembly complexity and manufacturing costs while ensuring the rotor's pivots are securely seated in the bearings.

Implementation Method 1

The first part or together these first and second parts has (have) a capacity for elastic deformation, in the direction defined by the two bearings of the cage, which is sufficient to allow the mounting of the rotor in the cage by the side opening

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2717437B1Electromagnetic motor for electronic clock movement with analogue display

Publication Date: 2018.08.01 ETA SA MFG HORLOGERE SUISSE

Figure 1~2
Figure 3~4
Figure 5~6

AI summary

The unit has an electromagnetic motor, and an analog display, where the motor is formed of a rotor (4) housed in a frame (6) of non-magnetic material in an aperture in a stator. The frame has a lateral aperture having a maximum width equal to maximum diameter of the rotor. A part or a set of parts (20, 22) of the frame is elastically deformable along a direction of a rotation axis (5). The parts have sufficient elastic deformation capacity to allow the rotor to be assembled in the frame through the lateral aperture for insertion of rotor pivots in respective bearings. An independent claim is also included for a method for manufacturing a timepiece motor.