What is ISO 20816‑9 standard about?
ISO 20816 is a series of international standards that discuss the machine vibrations occurring in different parts of a mechanical system. ISO 20816‑9 is the ninth part of the ISO 20816 multi-series. ISO 20816‑9 specifies requirements for determining and classifying mechanical vibration of individually housed, enclosed, speed increasing or speed reducing gear units. It specifies methods for measuring housing and shaft vibrations, and the types of instrumentation, measurement methods and testing procedures for determining vibration magnitudes. Vibration grades for acceptance are included.
Torsional vibration measurements are outside the scope of ISO 20816‑9.
It applies to a gear unit operating within its design speed, load, temperature and lubrication range for acceptance testing at the manufacturer's facility. By agreement between manufacturer and customer and/or operator, it can be used for guidelines for on-site acceptance testing and routine operational measurements.
ISO 20816‑9 applies to gear units of nominal power rating from 10 kW to 100 MW and nominal rotational speeds between 30 r/min and 12 000 r/min (0,5 Hz to 200 Hz).
The evaluation criteria provided in ISO 20816‑9 can be applied to the vibration of the main input and output bearings of the gearbox and the vibration of internal shaft bearings. They can have limited application to the evaluation of the condition of those gears. Specialist techniques for evaluating the condition of gears are outside the scope of this ISO 20816‑9.
ISO 20816‑9 establishes provisions under normal steady-state operating conditions for evaluating the severity of the following in-situ broad-band vibration:
- Structural vibration at all main bearing housings or pedestals measured radially (i.e. Transverse) to the shaft axis;
- Structural vibration at the thrust bearing housings measured in the axial direction;
- Vibration of rotating shafts radially (i.e. Transverse) to the shaft axis at, or close to, the main bearings;
- Structural vibration on the gear casing.
NOTE: ISO 20816‑9 does not apply to special or auxiliary drive trains, such as integrated gear-driven compressors, pumps, turbines, etc., or gear type clutches used on combined-cycle turbo generators and power take-off gears.
NOTE: Vibration occurring during non-steady-state conditions (when transient changes are taking place), including run up or run down, initial loading and load changes are outside the scope of this document.
Who is ISO 20816‑9 standard for?
ISO 20816‑9 on measurement and evaluation of machine vibration is beneficial for
- Automobile industry
- Mechanical engineer
- Gearbox designer
- Manufacturer of gearbox
Why should you use ISO 20816‑9 standard?
In a power transmission gear system, the gear pair assembly remains one of the major sources of noise and vibration in the system.
ISO 20816‑9 provide information on vibration measurements, test conditions, evaluation criteria, test report, rating curves for vibration displacement and velocity measurements, effects of the system, vibration instruments and characteristics considerations
As a user of ISO 20816‑9, you can measure the vibration magnitudes in a gearbox.
ISO 20816‑9 assist the user in the selection of instrumentation, measurement methods and testing procedures. Overall ISO 20816‑9 helps the gearbox designers, mechanical engineers and other users in minimizing the gearbox vibration and improving its efficiency.
What’s changed since the last update?
BS ISO 20816‑9:2020 supersedes ISO 8579‑2:1993, which has been withdrawn.
The main changes compared to ISO 8579‑2:1993 are as follows
- It has been reformated to match other parts of the ISO 20816 series
- It has two new tables for values for vibration and displacement at zone boundaries
- A table with values for vibration acceleration rating at zone boundaries has been included
- The classifications table has been revised referring to these new rating tables
- The displacement and velocity rating graph have been moved into an informative annex
