GB/T 43324-2023 in English

《GB/T 43324-2023箔片轴承 气体动压止推轴承性能 静态承载能力、摩擦力矩、摩擦因数和寿命测试》由TC236（全国滑动轴承标准化技术委员会）归口，主管部门为中国机械工业联合会。

GB/T 43324-2023 Foil bearings - Performance of hydrodynamic gas thrust bearings - Testing of static load capacity, bearing torque, friction coefficient and lifetime

1 Scope

This document specifies the method for comparing performance evaluation results for a foil thrust bearing that supports load with aerodynamic force generated by the rotation of a driving shaft and lubricates using air, not lubricating oil. The test procedure explained in this document measures and evaluates the static load capacity, bearing torque, friction coefficient and lifetime of the foil thrust bearing and compares the test results to those for different test conditions. The measured static load capacity can be varied depending on the capabilities of the test device used.

2 Normative references

There are no normative references in this document.

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

3.1
thrust runner; runner
circular disc connected to the rotating shaft and facing the surface of the top foil

Note: The surfaces of the thrust runner should be machined smoothly enough to form the air film between the runner and the top foil.

3.2
take-off
stage aimed to secure the distance between the thrust runner (3.1) and the top foil by developing an aerodynamic pressure between them

3.3
clearance
shortest distance between the thrust runner (3.1) and the top foil

3.4
bearing torque
torque value developed by rotational friction between the thrust runner (3.1) and the top foil

Note: The measurement of the bearing torque is as described in 7.3.

3.5
load
load capacity
weight that can be delivered by a bearing under steady-state conditions

3.6
initial load
load (3.5) exerted on the rotating system in the beginning

Note: It should be lower than the static load capacity and the load at which the lifetime of the bearing is determined, as explained in 7.4 and 9.2.

3.7
reference load
load expected to be supported by a bearing

Note: The calculation of the reference load is given in 7.2.

3.8
static load capacity
maximum load value of a bearing in static state

Note: The measurement of the static load capacity is explained in 7.4.

3.9
friction coefficient
flow resistance caused by rotational friction between the thrust runner and the top foil

Note: The measurement of the friction coefficient is described in Clause 8.

3.10
lifetime of bearing
total number of start-stop test cycles of the foil thrust bearing at which the coating layer disappears

Note: The measurement of the lifetime of bearing follows Clause 9.

4 Symbols

For the purposes of this document, the following symbols apply.

4.1 Basic characters - Roman alphabet

Basic characters - Roman alphabet see Table 1.

4.2 Basic characters - Greek alphabet

Basic characters - Greek alphabet see Table 2.

4.3 Additional signs - Subscripts

Additional signs - Subscripts see Table 3.

5 Purpose of test

The primary purpose of the test is to measure and evaluate the static load capacity, bearing torque, friction coefficients and lifetime of a foil thrust bearing. These are the primary performance metrics of a foil thrust bearing as a mechanical element with specific dimensions. They are closely related to the performance of the mechanical systems in which foil thrust bearings are used.

6 Test conditions

6.1 General

The static load capacity of a foil thrust bearing should be tested, after the ambient pressure, temperature and humidity of the environment in which the bearing operates have reached a state of equilibrium.