Transducer Assembly with Passive Radiator for Vibration Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Consumer electronics devices, such as smartphones and laptops, experience undesirable vibrations and dynamic imbalances due to the force output from moving coil motors in their speakers, leading to rattling, shaking, or hopping, which can affect user experience and potentially cause mechanical stress or failure.
Innovation Solution
A transducer assembly with a tuned stiffness configuration that includes a spring or compliant member between the transducer and the enclosure, utilizing both mechanical and air springs to balance forces and reduce vibrations, ensuring that forces acting on the enclosure are cancelled at specific frequencies, thereby minimizing unwanted movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a moving coil motor is used to drive sound output in compact devices, then acoustic output is achieved, but force is transmitted to the device enclosure causing vibration and instability
Solution Approach 1:
A counter-mass is attached to the enclosure opposite the transducer assembly. This counter-mass generates a counterbalancing force that offsets the vibratory forces transmitted by the transducer to the enclosure, reducing overall vibration and improving device stability during audio playback
Solution Approach 2:
The enclosure incorporates both rigid structural components and compliant vibration-damping materials. The rigid portions maintain structural integrity while the compliant portions absorb and dampen vibratory energy, reducing the transmission of forces to the device surface
2Stability of the object's composition
If the transducer is rigidly mounted to the enclosure, then structural stability is maintained, but vibrations are transmitted to the enclosure causing rattling and shaking
Solution Approach 1:
A compliant mounting structure with vibration-damping properties is used to attach the transducer assembly to the enclosure. This flexible mounting reduces the transmission of high-frequency vibratory forces that cause rattling, while still providing sufficient mechanical support and structural stability
Solution Approach 2:
A compliant intermediate layer or mounting structure is positioned between the transducer assembly and the enclosure. This intermediary element decouples the rigid connection, allowing vibratory forces to be absorbed and dampened rather than directly transmitted to the enclosure and device surface
3Object-affected harmful factors
If soft springs or foam pads are used to mount the product, then vibration transmission is reduced, but the product becomes squishy and controls become difficult to press
Solution Approach 1:
The mounting system is segmented into separate functional elements: rigid structural support components provide mechanical stability and control responsiveness, while separate compliant vibration-damping elements absorb vibratory energy. This segmentation allows each component to perform its specific function without compromising the other
4Strength
If screws are used to mount the product to a wall, then structural attachment is achieved, but dynamic imbalance stresses the attachment joints causing fatigue and failure
Solution Approach 1:
A counter-mass is positioned opposite the transducer assembly to balance the dynamic forces generated during operation. This balancing reduces the cyclic stress imposed on wall attachment joints, preventing fatigue failure and improving long-term reliability of the mounted installation
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 solution effectively reduces or eliminates excessive vibrations and dynamic imbalances, enhancing the user experience by minimizing mechanical stress and maintaining device stability, even at varying altitudes and temperatures.
Implementation Method 1
Representatively, in one aspect, the disclosure is directed to a transducer assembly having a spring or other compliant member with a constant k2 between the transducer and the case/enclosure
Implementation Method 2
The instant disclosure is directed to a transducer assembly having a stiffness (or other parameter) that is tuned for reducing or eliminating imbalanced dynamic forces within the system which can cause the product to excessively vibrate
Implementation Method 3
the second suspension member includes an air spring component that allows the magnet assembly to move relative to the enclosure
Implementation Method 4
The moving coil motor may include a diaphragm, voice coil and magnet assembly positioned within a frame
Data Source
AI summary
A transducer assembly including an enclosure having a bottom enclosure wall and a side enclosure wall that together define an enclosure volume; a first mass movably coupled to the enclosure and defining a first radiating area; a second mass movably coupled to the enclosure and defining a second radiating area; and a third mass movably coupled to the enclosure and defining a third radiating area, the third mass comprising a passive radiator and a third suspension member coupling the passive radiator to the enclosure, and wherein the first radiating area and the second radiating area have a combined radiating area that is different than the third radiating area and the combined radiating area is balanced relative to the third radiating area to reduce enclosure vibrations caused by a movement of the first mass and the second mass relative to the enclosure.