Vibrating Actuator Leaf Spring Structure for Torsional Resonance
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Solution Overview
Problem
Conventional oscillatory actuators using rotary motors and dampers suffer from non-uniform magnetic fields and torsional resonance at frequencies other than natural resonance, leading to impaired haptic sensations and large oscillations.
Innovation Solution
The oscillatory actuator incorporates elastic members that bridge the arms of leaf springs to suppress torsional resonance and stabilize natural resonance frequencies, using a configuration with a cylindrical case, yoke, coils, and a movable magnet system with elastic support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a weight is added to the mover to increase oscillation force, then oscillation output is improved, but torsional resonance is generated at frequencies other than natural resonance frequency
Solution Approach 1:
The leaf spring is divided into multiple arms (first arm, second arm, third arm) that are arranged radially around the oscillation axis. This segmentation distributes the support function across multiple independent elements, reducing the concentration of stress and torque that causes torsional resonance while maintaining the overall oscillation force.
Solution Approach 2:
The patent specifies that the distance between adjacent arms should be 120 degrees or less, creating a non-uniform spatial distribution optimized for suppressing torsional resonance. This local geometric configuration provides enhanced damping characteristics at critical locations without compromising the overall oscillation output.
2Reliability
If assembly and component variations occur, then non-uniform magnetic field is generated, but large oscillation at frequencies other than natural resonance frequency is produced
Solution Approach 1:
The use of multiple radially arranged arms (at least three) distributes the magnetic circuit and mechanical support functions across multiple symmetric locations. This segmentation compensates for assembly variations by averaging out non-uniformities, maintaining magnetic field uniformity even when component tolerances exist.
Solution Approach 2:
The patent specifies that the distance between adjacent arms should be 120 degrees or less, which creates an asymmetric configuration optimized for suppressing torsional resonance. This asymmetric arrangement breaks the symmetry that would otherwise amplify certain frequency components, reducing large oscillations at non-resonance frequencies.
3Reliability
If multiple dampers (leaf springs) are used to support the reciprocating mover, then oscillation support is improved, but torsional resonance is generated
Solution Approach 1:
The leaf spring is segmented into multiple radial arms (first arm, second arm, third arm) that support the mover at different angular positions. This segmentation distributes the damping function across multiple elements, reducing the torsional moments that would be generated by a single concentrated support while maintaining overall stability.
Solution Approach 2:
The arms are arranged in a radial pattern around the oscillation axis, adding angular dimensionality to the support structure. This three-dimensional arrangement (radial + axial oscillation) provides stable mover support while the angular distribution suppresses torsional resonance by distributing loads uniformly around the axis.
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 configuration reduces torsional resonance and maintains stable natural resonance frequencies, ensuring sufficient oscillation outputs and improved haptic feedback.
Implementation Method 1
a coil (21) that surrounds the mover (111)
Implementation Method 2
an elastic member (150) that bridges adjacent arms of the first leaf spring (51) and the second leaf spring (251)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention has provided thereto: a first damper 51 and a second damper 251, which are attached to a case 1 and have a plurality of spiral arm parts, and first elastic material 150 and second elastic material 350, which bridge the adjacent arm parts of the first damper 51 and the second damper 251.