Success Stories

Success Stories

Golf Cart Transmission

Off-road Vehicle Differential Gearbox Noise and Functional Dynamic Test

The Challenge:

A unit of a major Tier 1 automotive supplier needed to upgrade their off-road leisure and utility vehicle differential NVH (Noise, Vibration and Harshness) test station. The existing PLC/PC controlled test station was a combination of vendor supplied hardware and internally supplied controls and software.  The controls engineer responsible for its programming and maintenance was relocated and the plant no longer had knowledge of the equipment operation to have confidence in the test data. A Dempsco sales engineer, who was in the plant on another project, discussed the current NVH test station issues with the customer and laid out a plan to explore development of a new test station. A key was to be able to find defective gears, bearings, and other internal components based upon unique noises which could be “heard” electronically and identified automatically while running the product on a dynamic test stand.

The Analysis:

The Dempsco sales engineer reviewed the existing test stand hardware, accelerometer, controls and software. Outdated hardware and software components were identified for upgrade or replacement. The limitations and strengths of the current system were compared to state-of-the-art signature analysis technology available from Sciemetric Instruments, of Ottawa, Canada, a manufacturer of signature (waveform) analysis production testing systems. A subsequent visit, by the Dempsco sales engineer with a Sciemetric applications engineer, obtained existing test stand data for later analysis.

Application analysis and testing were done at Sciemetric, using the customer’s test data. A goal was to be able to offer the customer a technologically advanced test system within the customer’s budget. A second goal was to provide a test based upon Sciemetric’s standard InspeXion software that would permit anyone in the customer’s plant to be quickly trained and ready to operate, program, and analyze data from the test stand.

It was determined that the existing test stand could be updated with a Sciemetric SigPOD NVH, an application-specific version of the standard Sciemetric SigPOD, and QualityWorX database archiving and SPC analysis server-based software.

The Solution:

Sciemetric provided a SigPOD NVH to gather signatures, uniquely identified by barcode serial number, for analysis and pass/fail determination.  Speed, torque and angular position of six different gearboxes can now be tested for noise above a certain dB level at run and coast speeds, as well as the detection of knocks.

Now, Sciemetric NVH tests can automatically pinpoint the failure mode, leading to a prompt repair of the gearbox and return to the production line for final assembly and shipment. The reliance upon operators to subjectively determine test results is eliminated, thereby guaranteeing consistent, measurable product quality. Failed parts are routed to the Repair area.

The Sciemetric QualityWorX test data archiving and analysis package allows for the storage and analysis of gearbox test signatures, what-if analysis, trending, history and other standard and custom analysis tools.

Complete training of plant personnel was provided by Sciemetric. Future training and upgrading of the software will be done on a scheduled, regular basis so that operators and engineers involved with testing will be as up to date as possible.

The 60-second test will assure this manufacturer that their customers receive assembled and tested differentials that will provide a long lasting, quiet vehicle ride. The project was successfully completed and kept within the customer’s budget.

  • 5 September 2015
  • Author: Randy Holdeman
  • Number of views: 2253
  • Comments: 0
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