Balanced Armature Bone Conduction Transducer Miniaturization
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Solution Overview
Problem
The existing bone conduction speakers in hearing aids face challenges in miniaturization due to complex assembly processes and physical volume constraints, limiting size reduction and increasing manufacturing complexity.
Innovation Solution
A balanced armature bone conduction transducer with a housing containing a motor assembly, coupling assembly, and acoustic assembly, including a U-shaped armature, drive magnets, and an end mass assembly, which facilitates efficient bone conduction of sound vibrations to the user's skeleton, with improved assembly methods and materials to enhance stiffness and frequency control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a traditional bone conduction speaker assembly is used with a vibration block mounted to the case through screws and a spring mounted to the housing, then the structural stability is maintained, but the manufacturing complexity increases and the device size cannot be reduced
Solution Approach 1:
The patent merges the vibration block and spring into a single integrated unit where the spring is formed as an integral part of the vibration block structure. This eliminates the need for separate mounting operations and reduces assembly steps while maintaining the mechanical function of vibration transmission and suspension.
Solution Approach 2:
The vibration block is designed to serve multiple functions simultaneously: it acts as the vibration transmitting element, the spring mounting structure, and the suspension mechanism for the armature assembly. This multi-functionality reduces the number of separate components needed and simplifies the overall assembly.
2Reliability
If the vibration block is centered to the case using multiple screws, then the structural stability is ensured, but the manufacturing process becomes labor intensive and time consuming
Solution Approach 1:
The vibration block and spring are combined into a single integrated component that is mounted as one unit to the housing. This eliminates multiple screw mounting operations and reduces assembly time while maintaining structural stability through the integrated design that ensures proper positioning and secure attachment.
3Strength
If the spring is embedded in the housing and mounted to the yoke, then the mechanical support is provided, but the physical volume of materials limits size reduction
Solution Approach 1:
The spring is nested within or integrated with the vibration block structure, allowing the spring to be formed as an integral part of the vibration block. This nested arrangement eliminates the need for separate spring housing and mounting space, significantly reducing the overall volume while maintaining the mechanical support and suspension functions.
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 transducer achieves improved vibration response and reduced size, enabling effective sound transmission and enhanced performance in hearing aids and other acoustic devices, particularly with a peak frequency at 500 Hz for speech perception.
Implementation Method 1
A coil is positioned within the yoke and defines an air gap to receive the armature. The coil generates a magnetic field that interacts with the armature to produce vibratory motion.
Implementation Method 2
bone conduction speaker have been developed in various types to sense audible sounds through bone vibrations and to transmit the converted vibrations to the cochlea
Data Source
AI summary
A bone conduction transducer suitable for use in a listening device, such as hearing aids, in-ear monitors, headphones, electronic hearing protection devices, and very small scale acoustic speakers, has an end mass assembly disposed within the housing. The end mass assembly is mounted to the acoustic assembly and operatively coupled to the motor assembly via a coupling assembly.