Non-Linear Torsional Analysis
One of the fundamental parameters for evaluating production machinery trouble is torque, whether on a bridle drive, a pinch roller or the primary drive shaft. However, as useful as torque data is for determining the true cause of expensive or annoying machine failures, many engineers and managers overlook a simple method for obtaining reliable torque data quickly and inexpensively -- radio telemetry.
Think of telemetry as an ECG for machinery. An ECG (electrocardiogram) shows how a heart reacts under specific stress conditions. Diagnostic telemetry reveals how a drive system reacts to various loads and conditions. In both cases the information obtained an be invaluable.
With the data recorded using a torque telemetry system, decision makers can invest time and money to attack the real cause rather than transferring the problem or setting themselves up for yet another shutdown. Just a few minutes of accurate torque data can save hundred of thousands of dollars and weeks of lost production.
As an example, a power plant had redesigned the drive system used to invert rail cars for unloading coal but the system was failing frequently. Plant personnel were relying on motor current to calculate torque. Radio telemetry quickly revealed that the actual torque was an order of magnitude higher than the calculated torque. The customer discovered that the wrong gear ratio had been used in the motor current torque calculations.
Another example occurred at a cement plant where production was being limited by insufficient air flow through the primary kiln. The draw fans were not generating the flow volume expected. The operations manager needed to determine if the fan itself was lacking, or was the drive system for the fan motor not producing the rated horsepower. Replacing either component was a half million dollar prospect not including lost production time. Radio telemetry torque readings (in conjunction with tachometer data) showed that the motor drive system was at fault, operating significantly below specifications.
Without reliable torque data, engineers are left to make decisions based on intuition, "second best" data (e.g. motor current readings) or trial and error. Many times the result is a redesign that "beefs up" one part of the system only to shift the failure point to the next weakest link. Admittedly, in a production environment, some hip-shot decisions are unavoidable and necessary. But in the long run, habitually implementing "fixes" based on incomplete or erroneous data is costly and time consuming
The easiest way to get the valuable torque data you need, especially if the project is urgent, is to hire a consultant, someone who has expertise measuring torque with radio telemetry equipment. A good consultant will be able to assess the project and confirm that telemetry will provide the data required. This drop-in-the-bucket investment in experience can pay great dividends.
Radio telemetry systems available today offer more features than ever before; features like digital data transmission, multiple channels, very compact transmitter size and even data processing software. All these features make radio telemetry an ideal tool for short term diagnostic torque measurements and troubleshooting. Many times it is the only way to get reliable torque data.
For diagnostic torque measurements, the sensor is most often a foil-type strain gage that is bonded to the shaft with a SuperGlue-type adhesive. In most applications a single stamp gage is all that is required, and alignment is easily accomplished by eye. System calibration using a shunt resistor or dead weight technique is simple and straightforward.
To measure is to know. And in many production environments, knowing torque can make the difference between run time and down time, between profit and loss--the ultimate bottom line. From ice drills to steel mills, radio telemetry is a great, easy-to-use tool for resolving torque related machinery problems.
Measuring Torque:
Ideal for measuring torque, our telemetry system can be used on any size shaft and installs quickly without machine disassemble or shaft modifications. Simply glue a sensor to the shaft, strap on a transmitter, then run the machine and record live torque data.
Need to measure torque on a rotating shaft? Consider VibroDynamics Torque Measurement Services. Our engineer will travel to your site, install the strain gage sensor(s) and telemetry instrumentation and record live torque data while you run the machinery. We'll provide a firm, realistic quotation in advance. And if you'd like, we'll even do the paper work, preparing a professional test report.
Real-time torque measurements can help:
- Evaluate overloads
- Isolate the true cause of expensive failures and minimize downtime
- Troubleshoot mechanical systems that are underperforming
- Determine load distribution
- Verify performance specifications
- Anticipate effects of increasing machine speed
- Quantify system improvements
- Evaluate prototype designs
Industrial Applications:
Vehicle testing Wood production Aluminum & steel production
Wind turbines Manufacturing machinery Gearbox troubleshooting
Paper manufacturing Ship propulsion evaluation Pump & compressor analysis
Movable bridges Mining & ore processing Railroad machinery