Toothed Wheel Rotation Using Piezoelectric Stroke Accumulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional linear piezoelectric motors have a limited maximum linear stroke, restricting the rotation of wheels in applications like watchmaking, where a short arm length limits the wheel's diameter, making complete revolution technically infeasible.
Innovation Solution
A device with a linear piezoelectric motor, a transmission member, and a movable jumper that allows bidirectional axial movement of the passive element to engage with a toothed wheel, enabling complete revolution by alternating movements without increasing the maximum linear stroke, with the jumper blocking rotation in one direction and allowing it in the other.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the arms of the resonator are shortened to minimize the size of the piezoelectric motor, then the maximum linear travel of the passive element is limited, but this limits the rotation of the wheel
Solution Approach 1:
The passive element performs periodic back-and-forth linear movements, with each forward stroke advancing the wheel by one tooth and each backward stroke resetting the transmission member while the jumper blocks reverse rotation. This periodic action allows the wheel to accumulate rotation over multiple cycles, enabling complete revolution despite limited stroke length
Solution Approach 2:
The jumper acts as an intermediary blocking element that prevents the wheel from rotating in the reverse direction during the backward stroke of the passive element. This mediator allows the system to convert bidirectional linear motion into unidirectional rotational motion, solving the contradiction between limited stroke and complete wheel rotation
2Length of moving object
If the passive element is moved bidirectionally to enable complete wheel rotation, then the wheel can rotate fully, but the transmission mechanism must prevent reverse rotation
Solution Approach 1:
The jumper serves as a simple intermediary blocking element that prevents reverse rotation of the wheel during the backward stroke. This single-component solution avoids complex mechanisms like ratchets or clutches, maintaining device simplicity while enabling complete wheel rotation through bidirectional passive element movement
Solution Approach 2:
Instead of using a complex one-way transmission mechanism, the invention inverts the approach by using a blocking element (jumper) that actively prevents reverse motion, allowing the simpler bidirectional linear motor to achieve unidirectional rotational accumulation
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
Enables complete revolution of the wheel in both directions using repeated back-and-forth movements of the passive element, overcoming the limitations of limited stroke and allowing for compact, feasible wheel diameters.
Implementation Method 1
a piezoelectric actuator capable of axially moving the passive element in a bidirectional manner
Implementation Method 2
the passive element 20 is also in local contact with the free ends 310, 320 of the arms 31, 32 of the resonator 30, so that the passive element 20 is displaced axially by friction of the free ends 310, 320 of the arms 31, 32 on the contact region
Data Source
Figure 1~3
Figure 4
AI summary
The invention relates to a rotation device (100) for a toothed wheel (61), comprising: - a linear piezoelectric motor comprising: • an elongated passive element (20), • a piezoelectric actuator (30) capable of axially displacing the passive element (20) in a bidirectional manner, - a transmission member (71) fixed to the passive element (20), engaging with a tooth (610) of the wheel (61) so as to rotate the wheel (61) by one tooth in a first direction of rotation (R1) when the passive element (20) is moved axially in a first direction of movement (T1), - a jumper (81) movable between two extreme positions, including a lowered position in which it blocks a rotation of the wheel in a second direction of rotation (R2) opposite to the first direction of rotation (R1).