ASTM D5182 Evaluating the Scuffing Load Capacity of Oils (FZG Visual Method)
6. Apparatus
6.1 FZG Gear Test Rig:
6.1.1 A more complete description of the test rig and operating instructions may be found in the instruction manuals available from the manufacturers/suppliers identified in A2.1.2.
6.1.2 The FZG gear test rig utilizes a recirculating power loop principle, also known as a four-square configuration, to provide a fixed torque (load) to a pair of precision test gears. A schematic of the test rig is shown in Fig. 1a and Fig. 1b. The drive gearbox and the test gearbox are connected through two torsional shafts. Shaft 1 contains a load coupling used to apply the torque through the use of known weights hung on the loading arm.
6.1.3 The test gearbox contains heating and cooling elements to maintain and control the temperature of the oil. A temperature sensor located in the side of the test gearbox is used to control the heating/cooling system as required by the test operating conditions.
6.1.4 The test rig is driven by an electric motor capable of delivering at least 5.5 kW (7.4 HP) at 1440 rpm.
6.2 Test Gears - The test gearset (pinion and gear) are commonly referred to as type A profile and conform to the information supplied in Table 2. A schematic of the profile is shown in Fig. 2. Both sides of the test gear flanks can be used for testing purposes since only one side is loaded during the evaluation. It should be noted that these gears have been designed with a large profile modification which increases their sensitivity to adhesive wear modes of failure.
6.3 Timer Mechanism - A suitable timer or revolution counter must be used to control the number of revolutions during each load stage of the test. The timer should be capable of shutting down the test rig at the appropriate time.
6.4 Hot Plate - A hot plate or suitable heating device is required to warm the gears to 60 to 80°C for assembly on to the shafts.
7. Reagents and Materials
7.1 Mineral Spirits (Stoddard Solvent). (Warning - Combustible. Vapor harmful. Keep away from heat, sparks, and open flame (see Annex A1.1). Type I conforming to the requirements outlined in Specification D235.)
