1 Scope
Cleanliness for gear drive units is an examination index of product quality which is determined by the weight of impurity collected from the inner cavity of the gearbox by specified methods.
This standard specifies the determination of the cleanliness for gear drive units with separate box and its objective evaluation value, and is applicable to for the acceptance of finished products and the acceptance after overhaul.
This standard is not applicable to gear drive units which are lubricated by grease and centralized circulation oil.
This standard allows the acceptance of gear drive units according to the cleanliness determined by the agreement between the manufacturers and the users or the purchase contract.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
GB/T 6004-1985 "Test Sieves of Metal Wire Cloth"
GB/T 1922-1980 "Solvent Naphthas"
3 Determination Method
3.1 Apparatus and cleaning fluid for determination
3.1.1 Instruments
a) Brushes: including big round-shaped, cone-shaped and oblate-shaped nylon brushes etc;
b) Filter sieves: SSW 0.063/0.045 GB/T 6004 (235 meshes/inch in British system), SSW 0.032/0.028 GB/T 6004 (423 meshes/inch in British system)
c) Necessary vessels and tools.
3.1.2 Equipment
a) Analytical balance with the sensibility of 1/10000g;
b) Oven;
c) Dryer;
3.1.3 Cleaning fluid
Solvent naphthas (NY-120 GB/T 1922 is recommended), kerosene and acetone.
