Vibrator Shaft Unbalanced Mass Retraction Mechanism
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Solution Overview
Problem
The existing vibrator assemblies in communication devices are prone to shaft damage or bending when the device is dropped, due to the extended unbalanced mass exposing the shaft to increased stress and torque, which can lead to deformation or breakage, and higher-grade materials may not withstand anticipated stresses while increasing costs.
Innovation Solution
A vibrator assembly with a shaft featuring a track that allows the unbalanced mass to travel along a path with a tension device providing a biasing force, causing the mass to retract when the motor is deactivated, reducing the stress on the shaft and minimizing the risk of damage during impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the unbalanced mass is extended away from the motor housing to avoid contact during rotation, then the vibration functionality is improved, but the shaft is exposed to increased stress and torque that can cause bending or breakage during drops
Solution Approach 1:
The unbalanced mass is made movable along the shaft through a track mechanism, allowing it to dynamically adjust its position between extended (for vibration) and retracted (for protection) states based on operational conditions
Solution Approach 2:
A biasing force (spring or gravity) continuously pushes the unbalanced mass toward a retracted position before impact occurs, proactively preventing the shaft from being exposed to damaging stresses during potential drops
2Strength
If high-grade materials with higher tensile strength are used for the shaft to resist bending, then the shaft strength is improved, but the fracture resilience decreases and cost increases
Solution Approach 1:
The unbalanced mass is retracted to a safe position before impact occurs, eliminating the need for the shaft to withstand extreme stresses that would require high-grade materials, thereby allowing use of lower-cost materials with better fracture resilience
Solution Approach 2:
The invention enables the use of less expensive shaft materials by preventing the extreme stress conditions that would necessitate expensive high-strength materials, making the overall system more cost-effective
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 the likelihood of shaft damage by retracting the unbalanced mass when the motor is deactivated, thereby minimizing the risk of bending or breakage during drops, and potentially using lower tensile strength materials to lower costs while maintaining functionality.
Implementation Method 1
a tension device with a first end that is coupled to the shaft and a second end that is coupled to the unbalanced mass. The unbalanced mass retracts under the action of a biasing force from the tension device when the motor is deactivated.
Implementation Method 2
When such alerts are received, the motor of the vibrator assembly is activated and the shaft connected to the motor starts rotating due to the action of a rotational force produced by the motor.
Implementation Method 3
The rotational speed of the unbalanced mass is less than the rotational speed of the shaft because of the rotational inertia of the unbalanced mass when the shaft is initially rotationally accelerated.
Data Source
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AI summary
A vibrator assembly (108) comprising a shaft (112) that is connected to a motor (110), to produce vibration in a communication device (500), is disclosed. The shaft (112) includes a track that defines a path with a first component that travels circumferentially around the shaft (112), and a second component that travels along the length of the shaft (112). The shaft (112) rotates due to a rotational force that is generated when the motor (110) is activated. The unbalanced mass (114) travels along the track towards an end of the path proximate a free-end of the shaft (112) when the motor (110) is activated, and retracts due to a biasing force from a tension device (212) when the motor (110) is deactivated.