This part of GB/T 9239 specifies requirements for evaluating the performance of machines for balancing rotating components by the following tests:
a) test for minimum achievable residual unbalance, Umar test;
b) test for unbalance reduction ratio, URR test;
c) test for couple unbalance interference on single-plane machines;
d) compensator test.
These tests are performed during acceptance of a balancing machine and also later, on a periodic basis, to ensure that the balancing machine is capable of handling the actual balancing tasks. For periodic tests, simplified procedures are specified. Tests for other machine capacities and performance parameters, however, are not contained in this part.
For these tests, three types of specially prepared proving rotors are specified, covering a wide range of applications on horizontal and vertical balancing machines. An annex describes recommended modifications of proving rotors prepared in accordance with the original national standard.
Moreover, this part also stresses the importance attached to the form in which the balancing machine characteristics are specified by the manufacturer. Adoption of the format specified enables users to compare products from different manufacturers. Additionally, in an annex, guidelines are given on the information by which users provide their data and requirements to a balancing machine manufacturer.
This part is applicable to balancing machines that support and rotate rotors with rigid behaviour at balancing speed and that indicate the amounts and angular locations of a required unbalance correction in one or more planes. Therefore, it is applicable to rotors with rigid behaviour as well as to rotors with shaft-elastic behaviour balanced in accordance with low-speed balancing procedures. It covers both soft-bearing balancing machines and hard-bearing balancing machines. Technical requirements for such balancing machines are included; however, special features, such as those associated with automatic correction, are excluded.
This part does not specify balancing criteria; such criteria are specified in ISO 1940-1 and ISO 11342 (only low-speed balancing procedures apply).
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1925 Mechanical Vibration — Balancing — Vocabulary
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in ISO 1925 apply.
4 Capacity and Performance Data of the Balancing Machine
4.1 General
The manufacturer shall specify the data listed in 4.2 for horizontal or 4.3 for vertical balancing machines, as applicable, and in a similar format.
Note: Information provided by the user to the balancing machine manufacturer is summarized in Annex A.
4.2 Data for horizontal balancing machines
4.2.1 Rotor mass and unbalance limitations
4.2.1.1 The maximum mass of a rotor, m, which can be balanced shall be stated over the range of balancing speeds (n1 , n2 , ...).
The maximum moment of inertia of a rotor with respect to the shaft axis, mr2, where m is the rotor mass and r is the radius of gyration, which the machine can accelerate in a stated acceleration time shall be given for the range of balancing speeds (n1 , n2 , ...) together with the corresponding cycle rate (see Table 1).
GB/T 9239.21-2019 The following standards are cited：
GB/T 9239.21-2019 Cited by the following standards：
