Constant Torque Motor Using Moving Control Element

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Traditional mechanical watch barrels fail to provide a constant torque, leading to variable precision in timekeeping and striking frequency and intensity, as the mainspring's energy storage and release are not uniformly distributed.

Innovation Solution

A constant moment of force motor with an energy accumulator element, such as a blade, and a controller element that moves relative to the accumulator to maintain a consistent moment of force between fully armed and completely disarmed states, utilizing a rotating mechanism to release energy and minimize energy loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a traditional mainspring is used in a barrel, then energy can be stored and released, but the torque varies significantly from maximum when fully wound to minimum when almost unwound

Engineering Contradiction:
Improveenergy storage and releaseVSAvoidtorque
Core Design Contradiction:
Use of energy by moving objectVSForce

Solution Approach 1:

The patent applies the dynamics principle by making the control element movable along the blade rather than fixed. As the blade unwinds and its curvature changes, the control element automatically adjusts its position to maintain a constant distance from the blade's fixed end, thereby maintaining constant torque throughout the unwinding process. This dynamic adjustment resolves the contradiction between energy release and constant force.

Inventive Principle:
Principle #15Dynamics

2Duration of action of moving object

If the mainspring unwinds from fully wound to almost unwound, then energy is released, but the torque delivered to the movement varies causing variable time indication accuracy

Engineering Contradiction:
Improveenergy release durationVSAvoidtime indication accuracy
Core Design Contradiction:
Duration of action of moving objectVSMeasurement precision

Solution Approach 1:

The patent implements feedback through the control element that continuously monitors the blade's unwinding state and adjusts its position accordingly. The control element's movement along the blade provides real-time feedback about the blade's curvature changes, enabling automatic compensation to maintain constant torque and thus constant time indication accuracy throughout the energy release duration.

Inventive Principle:
Principle #23Feedback

3Force

If a helical spring operating in compression or tension is used, then constant torque can be achieved, but the device becomes complex and bulky

Engineering Contradiction:
Improveconstant torqueVSAvoidstructure complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent extracts the complexity from the spring mechanism itself and places it in the control element's simple linear movement along the blade. Instead of using a complex helical spring system, the invention uses a simple blade with a control element that moves along its length, thereby achieving constant torque with a much simpler and more compact structure.

Inventive Principle:
Principle #2Taking out (Extraction)

4Force

If an auxiliary spring is interposed between the wheel and rotating support, then constant torque drive can be achieved, but the mechanism becomes quite complex and bulky

Engineering Contradiction:
Improveconstant torqueVSAvoidmechanism complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent uses the control element as an intermediary between the blade and the gear train. This control element, which simply moves along the blade's length, mediates the energy transfer and enables constant torque delivery without requiring complex auxiliary springs or bulky mechanisms. The intermediary approach simplifies the overall mechanism while achieving the desired constant torque effect.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The motor ensures energy restoration with a substantially constant moment of force, independent of its arming state, improving timekeeping precision and reducing energy loss, suitable for incorporation in wristwatches, pocket watches, and clocks.

Implementation Method 1

a blade (14) which can be bent from an initial shape to a bent shape, thereby storing energy which can be used to drive a control element (12, 18, 24)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2515185B1Engine with constant torque
Publication Date: 2019.06.12 MFG & FAB DE MONTRES & DE CHRONOMETRES ULYSSE NARDIN LE LOCLE SA
  • EP2515185B1 patent drawingFigure 1A~1B
  • EP2515185B1 patent drawingFigure 1C~1D
  • EP2515185B1 patent drawingFigure 2

AI summary

The motor has a power accumulator i.e. strip (14), for accumulating and restituting power to drive a mechanical mechanism between armed state and unarmed state. A controller i.e. rotary part integrated control device (E), controls the accumulator by relative displacement between the controller and the accumulator such that torque created by the accumulator remains constant between the armed state and the unarmed state. The strip has side surface that is toothed and gripped with corresponding teeth on wheels (12, 18) of the controller. The strip is formed from silicon, silicon coated with silicon dioxide, silicon coated with diamond or diamond.