This standard specifies the determination of shear stability of lubricants containing polymer by adopting the gear machine method.
This standard is applicable to the determination of shear stability of gear oil, hydraulic oil and internal combustion engine oil containing polymer.
2 Normative References
GB/T 265 Petroleum Products-Determination of Kinematic Viscosity and Calculation of Dynamic Viscosity
GB 1922 Solvent Naphthas
3 Method Summary
Add a certain amount of samples to the gear box, and make it operate for a certain time at the specified temperature, load and rotation rate. The shear stability of the sample shall be assessed according to the permanent viscosity loss caused by the mechanical shearing action during the test.
4 Equipment and Material
4.1 Equipment
4.1.1 Gear testing machine (model CL-100 or FZG): It shall be modified in accordance with those specified in Appendix A (Additional) of this method.
4.1.2 Test gear: Model QCL -003 (made in China) or model FZG “A” (made in the Federal Republic of Germany) with a specification corresponding to Appendix B (Additional).
4.1.2.1 For each face of the gear, 20 times shearing tests may be conducted at the most. If the face of the gear is damaged, the test is invalid.
4.1.3 Pipette: 25mL.
4.1.4 Bulb
4.1.5 Injector: 5~20mL.
4.2 Material
4.2.1 Solvent naphtha: in accordance with those specified in No. 190 of GB 1922.
4.2.2 Petrolic ether: 60~90℃, analytical reagent.
