ASTM D5969 Test Method for Corrosion-Preventive Properties of Lubricating Greases
ASTM D5969 Standard Test Method for Corrosion-Preventive Properties of Lubricating Greases in Presence of Dilute Synthetic Sea Water Environments
8. Standardization of Thrust Loading Device
8.1 Pack a bearing, and install it into the holder. Place the assembly into a plastic jar as described in 10.1-10.4. Place the jar onto the base of the motor drive spindle and center it under the indexing pin of the drive. Lower the drive until the O-ring just contacts the 1-kg weight. Run the bottom nut of the depth gage (see Fig. 2) down to the stop. Place a 3-mm spacer on top of this nut. Bring the top nut down to the spacer. While holding the top nut in position, remove the spacer and run the bottom nut up and tighten it against the top nut. When the O-ring is compressed against the 1-kg weight until the adjustment nut hits the stop, there will be a 29-N load added, giving a total load of 39 N on the bearing. (The loads described are provided by the forces of the spring in the thrust loading spindle and the sum of the 1-kg weight and spring, respectively. These loads are approximate. The 1-kg weights should be within 0.010 kg of their stated values. The thrust loading spindle should be calibrated by some suitable method when it is first put into service, recalibrated periodically, and replaced if its spring does not provide sufficient force to spin the test bearings without slippage during the 60-s run to distribute the grease.) Examine the O-ring periodically, and replace it if it shows any cracks or other signs of deterioration.
8.2 The thrust loading device should be standardized before use, once per day if used daily, and again if there is reason to believe that the standardization has changed. The thrust loading device may be standardized using one of the greases to be tested.
9. Preparation of Bearings
9.1 Examine the test bearings carefully and select only bearings that have outer races (cups) and rollers entirely free of corrosion. During the bearing preparation, handle the bearings with tongs or rubber or plastic gloves. Do not touch bearings with the fingers at any time.
9.2 Wash the selected bearings thoroughly in hot (52 to 66°C) Stoddard solvent (Warning - see Note 3) to remove the rust preventive. To ensure complete removal of the rust preventive, subject the bearings to a second wash in fresh hot Stoddard solvent.
NOTE 5 - The washing temperatures specified are considerably above the flash point of the solvent. Accordingly, the washing operation should be carried out in a well-ventilated hood where no flames or other ignition sources are present.
9.3 Transfer the bearing from the Stoddard solvent to the solvent rinse solution (Warning - see Note 2) to remove the Stoddard solvent and any fingerprints that may be present. Then rinse the bearing and slowly rotate it in fresh hot (66 +/- 5°C) solvent rinse solution.
NOTE 6 - Fresh solvent rinse solution must be used to avoid selective evaporation of the components at the rinse temperature.
9.4 Remove the bearing from the solvent rinse solution and place it on filter paper to drain. After draining, dry the bearing in an oven at 70 +/- 5°C for 15 to 30 min.
9.5 Permit the bearing to cool to room temperature and reexamine its surfaces to ensure that corrosion-free and free-turning specimens have been selected. (Take care not to spin the bearings after cleaning and drying.)
9.6 Wash and dry the bearing packer using the same technique as for the preparation of the bearings.
