Gear Rattle Test Apparatus Using Mathematical Force Excitation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gear rattle in gear-trains is a dynamic acoustic disturbance caused by angular speed fluctuations and tooth profile errors, leading to repeated impacts and rebounds, which is difficult to replicate and analyze in controlled laboratory conditions for design verification and reduction.
Innovation Solution
A test apparatus that applies a force event defined by a mathematical function, such as a Ricker Wavelet, to elicit gear rattle from a gear-train, using a fixture, tie-rod, actuator, sensors, and a controller to detect and display acceleration, strain, and acoustically reproduce the rattle, allowing for controlled simulation of real-world conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gear rattle is analyzed in real-world vehicle conditions, then the authenticity of the rattle phenomenon is improved, but the controllability and repeatability of the test deteriorates
Solution Approach 1:
The patent extracts the essential excitation characteristics from real-world vehicle conditions and applies them in a controlled laboratory setting. By using a shaker table to apply predetermined force profiles that mimic road-induced vibrations, the system separates the critical rattle-inducing factors from the complex real-world environment, achieving both authenticity and controllability.
Solution Approach 2:
The patent employs parameter changes by varying the frequency, amplitude, and duration of the applied force events to replicate different driving conditions. The controller adjusts these parameters to match measured vehicle responses, allowing the laboratory test to reproduce authentic gear rattle while maintaining full controllability through programmed parameter sets.
2Measurement precision
If complex force profiles are applied to accurately replicate real-world conditions, then the measurement precision of gear rattle is improved, but the device complexity increases
Solution Approach 1:
The patent implements multi-functionality by integrating multiple measurement capabilities (acceleration sensors, force sensors, acoustic sensors) into a single coordinated test system. The controller manages multiple functions including force application, data acquisition, signal processing, and result analysis, reducing overall system complexity while maintaining high measurement precision through unified multi-functional operation.
3Measurement precision
If multiple sensors and actuators are used to comprehensively detect and reproduce gear rattle, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple sensing and actuation functions into an integrated test system. The controller consolidates the operation of the shaker table, sensors, and data processing into a unified control architecture. This merging approach maintains comprehensive detection precision while reducing operational complexity through integrated system management and coordinated component operation.
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 the reproduction and analysis of gear rattle in a controlled environment, facilitating the verification of design iterations and reduction of gear rattle in gear-trains, without the need for actual vehicle testing.
Implementation Method 1
an actuator, such as an electro-magnetic shaker, operatively connected to the tie-rod and configured to generate the force event
Implementation Method 2
a microphone configured to acoustically detect the elicited gear rattle
Implementation Method 3
a first sensor configured to detect acceleration of the device following, and as a result of, the application of the force event to the device
Data Source
AI summary
A test apparatus for eliciting a gear rattle from a gear-train employed in a device includes a fixture configured to support the device in a fixed starting position. The test apparatus also includes a tie-rod operatively connected to the device. Additionally, the test apparatus includes a controller configured to command the tie-rod to apply to the device at the starting position a force event defined by a mathematical function continuous in time. The force event is configured to elicit the gear-train rattle from the gear-train. A method for eliciting a gear rattle from a gear-train employed in a device is also disclosed.