Lubricants and Lubrication Part 14 pot

73719.2 Simple Mechanical–Dynamic Lubricant Test Machines Category Type of test Test system Test conditions I Field trial - Normal operating conditions - Extended operating conditions II Test laboratory with complete vehicle (equipment) or plant - Close to normal operating conditions - Extended operating conditions III Test laboratory with plant or construction elements - Normal operating conditions - Extended operating conditions IV Experiment with standard construction element or scaled down plant V Experiment with test equipment operating close to normal conditions VI Experiment with simple laboratory test equipment (bench test) Experiment with model system Customer or field trial or trial under similar conditions Original equipment Experimental samples Fig. 19.1 Tribological system categories within lubricant testing. 19.2 Simple Mechanical–Dynamic Lubricant Test Machines 19.2.1 Four-ball Apparatus The four-ball apparatus is one of the oldest and best-known simple test benches for liquid and solid lubricants. The four-ball geometry is a popular test method, because test pieces are inexpensive and wear measurement is simple. This machine enables the precise determination of anti-wear properties and coefficient of friction. This simple geometry (Fig. 19.2) also enables the determination of extreme pressure characteristics of greases and oils based on welding tests that are standardized world-wide. A roller-bearing ball rotates under pressure and at constant speed on three fixed steel balls. The contact is lubricated with oil or a solid lubricant. The gradual increase of the normal force (contact pressure) enables determination of the weld load, anti-wear protection, and friction coefficients of a lubricant. During these 738 19 Mechanical–Dynamic Test Methods for Lubricants tests the ball’s surface will first produce wear marks on the fixed balls which lead to effects of different oils and additives. Fig. 19.2 Schematic diagram of the test principle of the four-ball apparatus. In recent years, several adapters have been developed for the four-ball apparatus to furnish information on the pitting load capacity and the shear stability of poly- mer-containing lubricants. Surface-modified steel balls (VW-PV-1444) and a variety of tapered roller bearings (VW-PV-1417, DIN 51354, part 6 or CEC L-45-T-98) are used (Fig. 19.3). In addition, further modifications of the test adapters enable the determination of friction coefficients and temperature behavior of a lubricant within the roller bearing. In accordance with VW-PV-1454 the test adapter used determines Fig. 19.3 Test adapter for determination of the shear stability of lubricants containing polymers. 73919.2 Simple Mechanical–Dynamic Lubricant Test Machines the steady-state operating temperature, temperature increase, and the friction of the test bearing in relation to the respective lubricant, using a axial thrust ball bearing. More recent results with this test adapter have shown that the steady-state oil sump temperatures measured can be transferred to transmissions and industrial gears, depending on the lubricant, after being adjusted to the realistic load and speed ratio referring to the application. As ever, today’s numerous specifications for gear and hydraulic lubrication oils and for all types of grease and paste require four-ball data for most of the lubricants. Table 19.1 lists the common test standards mostly used for the four-ball apparatus. Tab. 19.1 Four-ball apparatus test standards. Application Test method Standard test method for wear-preventive characteristics of lubricating fluids ASTM D 4172 Wear-preventive characteristics of lubricating grease (four-ball method) ASTM D 2266 Standard test method for the determination of the friction coefficient of lubricants using the four-ball apparatus ASTM D 5183 Measurement of extreme pressure properties of lubricating fluids (four-ball method) ASTM D 2783 Measurement of extreme pressure properties of lubricating grease (four-ball method) ASTM D 2596 Standard test method for determination of load-carrying capacity and mean Hertz load FTMS No. 791 b Method 6503.2 Determination of extreme pressure and anti-wear properties of lubricants – four-ball apparatus IP 239/85 Standard test method for lubricants using the Shell four-ball apparatus General working principles Weld load of liquid lubricants Wear load of liquid lubricants Weld load of solid lubricants Wear load of solid lubricants Shear stability of polymer-containing lubricants DIN 51350 DIN 51350, Part 1 DIN 51350, Part 2 DIN 51350, Part 3 DIN 51350, Part 4 DIN 51350, Part 5 DIN 51350, Part 6 Viscosity shear stability of transmission lubricants – tapered roller bearing CEC L-45-T-98 Mechanical shear stability of engine oils VW-PV-1450 Pitting load capacity of solid lubricants VW-PV-1417 Pitting load capacity of liquid lubricants VW-PV-1444 Standard test method for temperature increase in the axial thrust ball bearing adapter (ARKL) VW-PV-1454 740 19 Mechanical–Dynamic Test Methods for Lubricants 19.2.2 Reichert’s Friction-wear Balance, Brugger Apparatus The Reichert’s friction-wear balance and the Brugger apparatus (according to DIN 50347) are important tools for determination of the wear characteristics of water- containing and nonwater-containing metal-working fluids, hydraulic fluids, and greases. Most manufactures in the metal-working industry specify wear-data accord- ing to Reichert or Brugger to ensure an adequate quality standard and adequate quality control for their metal-working and hydraulic fluids. Almost each develop- ment of a new formulation includes these wear tests. By means of a lever-handle system a firmly clamped cylindrical roller is pressed axial-crossed against a slip ring by an applied normal force (normal load). The slip ring rotates cross-directionally to the roller. In accordance with to Reichert approximately the lower third of the test ring is dipped into the test fluid. After a walkway of 100 m at a constant speed of the rotating slip ring, the elliptical wear mark produced on the roller’s surface is mea- sured. According to Brugger the slip ring rotates for 30 s with 5 mL fluid lubricating the friction contact. The fluid must remain on the surface for the duration of the Brugger test. On the basis of the wear marks measured, the average specific contact pressure can be re-calculated from the known and constant normal force. The wear is a result of the wear rate. The Reichert friction-wear balance and the Brugger apparatus equalize the contact pressure by producing smaller or larger wear marks. Figure 19.4 shows a schematic diagram of the test arrangement and Fig. 19.5 gives exam- ples of wear marks measured with the Reichert friction-wear balance. Common test standards are listed in Table 19.2. Normal force Roller Ring Fig. 19.4 Schematic diagram of Reichert’s friction-wear balance. 74119.2 Simple Mechanical–Dynamic Lubricant Test Machines Fig. 19.5 Examples of wear marks determined in accordance with Reichert: A. canned milk; B. cola. Tab. 19.2 Reichert and Brugger test standards. Test machine Application Test method Reichert’s friction-wear balance Standard test method for determining the pressure compensation capacity using the frictional wear-balance according to Reichert VKIS – worksheet No. 6 Brugger rig Testing under boundary lubricating conditions using the Brugger apparatus General working principles Procedures for greases DIN 51347 DIN 51347, Part 1 DIN 51347, Part 2 19.2.3 Falex Test Machines Falex test machines are mostly standardized by ASTM. They are used for testing lubrication oils, greases and solids. World-wide these test machines are widely used to measure and evaluate the properties of lubricants. 19.2.3.1 Falex Block-on-ring Test Machine The Falex block-on-ring test machine is used as a development and quality-control instrument for simulation of sliding and oscillating wear between lubricated and dry conditions. The pressure chamber and heater cover enable testing at elevated temperature and in noncorrosive gases. Test geometry consists of a rectangular test block that is loaded on a rotating or oscillating ring. A uniform contact velocity pro- file is created. The block can be replaced by a ball (increase contact pressure) or con- forming block (reduce pressure). Test blocks can be machined to test a wide variety of products. The test machine has a variable test load (<4000 N) and speed (<3000 rpm). A heated test chamber (150 C; higher if special seals are used), a high pressure test chamber (<10 bar) for noncorrosive gases or regulation of humidity, and on-line measurement of friction, temperatures, and total wear are additional features. The test standards are listed in Table 19.3. 742 19 Mechanical–Dynamic Test Methods for Lubricants Tab. 19.3 ASTM test standards for Falex machines. Test machine Application Test method Falex block-on-ring Calibration and operation of the Falex block-on- ring friction and wear-testing machine ASTM D 2714 Wear life of solid-film lubricants in oscillating motion ASTM D 2981 Test method for wear-preventive properties of lubricating greases using the (Falex) block-on-ring machine in oscillating motion ASTM D 3704 Practice for ranking resistance of materials to sliding wear (using block-on-ring wear test) ASTM G 77 Falex pin and vee block Endurance (wear) life and load carrying capacity of solid film lubricants ASTM D 2625 Method for measuring wear properties of fluid lubricants (Falex method) ASTM D 2670 Measurement of extreme pressure properties of fluid lubricants (Falex pin and vee block methods) ASTM D 3233 Evaluating thin-film lubricants in a drain and dry mode using a pin and vee block machine ASTM D 5620 Falex high- performance multispecimen test machine Test method for wear rate and coefficient of friction of materials in self lubricated rubbing contact using a thrust washer testing machine ASTM D 3702 Test method for wear preventive characteristics of lubricating fluids (four-ball method) ASTM D 4172 Coefficient of friction using a four-ball wear test machine ASTM D 5183 Wear-preventive characteristics of lubricating grease (four-ball method) ASTM D 2266 Wear testing with a pin-on-disk apparatus ASTM G 99 Falex tapping torque Test method for comparing metal-removal fluids using the tapping torque test machine ASTM D 5619 19.2.3.2 The Falex Pin and Vee Block Test Machine The Falex pin and vee block test machine is the oldest industrially standardized fric- tion and wear-test machine. A rotating journal pin is pressed between two blocks with V-notches. At constant rotational speed the normal force is increased stepwise. The scuffing load is determined at the point at which the pin at a softer neck breaks at the designated breaking point. If a lubricant withstands the applied force, the wear-loss of the softer pin is measured. This test is conducted at ambient tempera- ture. Figure 19.6 shows a schematic diagram of the test arrangement and the test standards are listed in Table 19.3. This test runs at fixed speeds enabling loads up to 3000 lb (13 350 N) for different test materials while controlling on-line wear, fric- tion, load, and temperatures via the monitoring system. 74319.2 Simple Mechanical–Dynamic Lubricant Test Machines Fig. 19.6 Schematic diagram of the Falex pin and vee block test machine. 19.2.3.3 Falex High-performance Multispecimen Test Machine The Falex high-performance multispecimen test machine is extremely flexible test equipment for industrial simulations. The Multispecimen machine can be used for almost any tribological investigation that involves sliding or rolling contacts. Over 60 standard adapters are available for performing a variety of simulation tests in- cluding sliding wear, abrasion, erosion, forming, impact, and rolling/sliding. This test machine enables any combinations of high load (<10 000 N), high speed (<10 000 rpm), and high temperature testing (up to 800 C). The PC-controlled monitoring system enables programming of acceleration (1000 rpm s -1 ) and loading profiles (1000 N s -1 ). Automatic simulation of dynamic conditions and start–stop cycles, variable flexibility enabling simulation of the effects of low-component stiff- ness, and on-line measurement of friction, speed, load, and temperature are current standards. The test standards used worldwide are listed in Table 19.3. 19.2.3.4 Falex Tapping Torque Test Machine The Falex tapping torque test machine was developed to enable repeatable and pre- cise characterization of cutting lubricants. A Procunier tapping head performs tap- ping operations and a load cell monitors torque produced on a nut blank. The effi- 744 19 Mechanical–Dynamic Test Methods for Lubricants ciency of cutting fluids can be determined in accordance with ASTM D 5619 (Table 19.3). Tapping simulation by tapping operation in standardized nut blanks (aluminum, steel, and stainless steel), drilling, reaming and forming simulations are possible with this test machine. A roll-forming adapter characterizes rolling fluids. It has a dual speed range (10–450/20–900 rpm) and a data-acquisition system enabling torque trace and torque averages to be stored. Average torque values are plotted and compared with a reference to determine the efficiency of the fluid. 19.2.4 Timken Test Machine The Timken test machine is licensed by the company Timken, a steel-producer and bearing manufacturer. It is essentially used to determine the anti-scoring protection afforded by greases and oils, in accordance with ASTM D 2509 and D 2782. It can also be used to determine wear resistance or adhesion strength of coatings support- ing variable speed and pneumatic loading. Figure 19.7 shows a schematic diagram of the test arrangement. In the steel industry the Timken rig is still a very important tool. Gear oils and extreme-pressure greases for roller bearings used in these indus- tries must meet Timken specifications. The lubricant test is conducted in a friction arrangement comprising a cuboid-arranged block and a rotating test cup (Fig. 19.7). The test is run with a lubrication oil circulation system, which can be adjusted vari- ably, and with a grease feeder with a feed volume of 45 g min -1 . The normal force (load stage), which is increased gradually, is brought into friction contact via the test block. Weighing of the test block and the test cup enables the determination of the wear-loss. The duration of the test at each load stage is 10 min at a speed of 800 rpm. Scuffing between the test cup and the test block depends on the applied normal force and will, first, lead to score marks on the surfaces of the test pieces. Scuffing is con- nected with a sudden drop in rotational speed and/or with an increased noise level. If scuffing occurs during a load stage, a nonscuffing test run in the previous load stage must be proven and documented as the determined so-called “good-load-stage” Fig. 19.7 Schematic diagram of the Timken test machine. 74519.2 Simple Mechanical–Dynamic Lubricant Test Machines together with the total wear of the test block and test cup (test ring). Greases are tested at ambient temperature, lubrication oils at 40 C. The test standards are listed in Table 19.4. Timken specifies an EP lubricant for bearing applications as one with a good-load of 45 lb (200 N). To meet the requirement of anti-wear, the steel indus- try usually defines a maximum of 5 to 6 mg at a good-load-stage of 40 lb (178 N). Higher good-loads will very often lead to greater wear. Tab. 19.4 Test standards for Timken machines. Application Test method Measurement of load-carrying capacity of lubricating grease (Timken) ASTM D 2509 IP 326/83 Measurement of extreme-pressure properties of lubricating fluids (Timken) ASTM D 2782 IP 240/92 Standard test method in the mixed-lubrication regime using the Timken test machine General working principles Procedures for lubricating oils Procedures for lubricating greases E-DIN 51434 E-DIN 51434, Part 1 E-DIN 51434, Part 2 E-DIN 51434, Part 3 Standard test method for liquid and plastic lubricants using the Timken test machine VDEh SEB 181302 19.2.5 High-frequency Reciprocating Test Machines 19.2.5.1 High-frequency Reciprocating Rig (HFRR) The HFRR is a microprocessor-controlled reciprocating friction and wear test system which enables rapid, repeatable assessment of the performance of fuels and lubri- cants. It is particularly suitable for wear-testing relatively poor lubricants, for exam- ple diesel fuels, and for boundary friction measurements of engine oils, greases, and other compounds. The HFRR test for diesel fuel lubricity gained CEC “A’’ (approval) status in September 1996 after an extensive round-robin program. Other standards based on the HFRR system are listed in Table 19.5. 746 19 Mechanical–Dynamic Test Methods for Lubricants Tab. 19.5 Test standards for high-frequency reciprocating test machines. Test machine Application Test method HFRR Measurement of diesel fuel lubricity CEC F-06-A-96 Standard test method for evaluating the lubricity of diesel fuels by use of the high- frequency reciprocating rig (HFRR) ASTM D 6079 Assessment of lubricity by use of the high- frequency reciprocating rig (HFRR) Part 1 test method BS ISO 12156-1 IP 450/2000 Automotive fuels – diesel – requirements and test methods EN 590 Gas oil – testing method for lubricity JPI-5S-50-98 SRV Standard method for measuring the friction and wear properties of extreme-pressure (EP) lubricating oils by use of the SRV test machine ASTM D 6425 Standard test method for determining the extreme-pressure properties of lubricating greases by use of a high-frequency, linear- oscillation (SRV) test machine ASTM D 5706 Standard test method for measuring the friction and wear properties of lubricating grease using a high-frequency, linear-oscillation (SRV) test machine ASTM D 5707 Tribological test method using a high-frequency, linear-oscillation test machine (SRV); general working principles Determination of measured friction and wear quantities for lubricating oils Determination of the tribological behavior of materials in reaction with lubricants Definition of data formats for test results Tribological test method for solids using a high- frequency, linear-oscillation test machine (SRV) DIN 51834 DIN 51834, Part 1 DIN 51834, Part 2 DIN 51834, Part 3 DIN 51834, Part 5 DIN 51834, Part 6 Textile machinery and accessories – needle and sinker lubricating oils for weft knitting indepen- dent needle machines – part 2 Minimum requirements synthetic oil based DIN 62136, Part 2 19.2.5.2 High-frequency, Linear-oscillation Test Machine (SRV) The high-frequency, linear-oscillation test machine (SRV) is designed to simulate very small displacements under well known conditions of load, speed, and environ- mental control. It is used to investigate typical fretting phenomena occurring in automotive components, aircraft, and vibrating machines. The effects of humidity and operating conditions on the surface degradation of coatings and materials can be tested on such a machine. [...]... other gears and even play a role in the design and calculation of gears according to DIN 3990 [19.11] Further procedures, for example A/16.6/90 and A/16.6 /140 , are also used as variations which have not yet been standardized Tab 19.7 Test standards for gear and axle oil Test machine Application Test method Erdco universal test rig Standard test method for load-carrying capacity of petroleum oil and synthetic... Noise inspection of lubricating greases (computer-aided) Test method DIN 51819 DIN 51819, Part 1 DIN 51819, Part 2 DIN 51819, Part 3 ZF 702 232/2003 VW TL52512/2005 VW TL52182/2005 DIN 51821 DIN 51821, Part 1 DIN 51821, Part 2 FAG specification Test method - TS 14 E-DIN 51806 E-DIN 51806, Part 1 E-DIN 51806, Part 2 ASTM D 4170 IP 168/95 FAG-QV3.102FB MGG 11 SKF specification MVH 90 B 19.4.2 FAG Roller... further enhanced to provide faster and smoother shifting There is therefore a need for standardized test rigs Figure 19 .14 gives examples of synchronizer systems in current use Single and double cone synchronizers Fig 19 .14 Triple cone synchronizers Synchronizer systems currently in use 19.5.3 Standardized Test Rigs and Test Methods A very limited range of three standardized rigs, so-called “Synchromesh’’,... reduction of friction of the bearings and the rotary shaft seals, reduction of sliding of the gear flanks, and reduction of splashing and pumping of the lubricant Losses in a gear system are classified as load-dependent and speed-dependent losses, for example churning or sealing losses To identify and compare the effects of lubricants on gear efficiency test method VW-PV -145 4 (Table 19.1) [19.26], using... [19.37, 19.38] The method specified serves to test lubricants such as lubricating oils part 3 and greases of NLGI classes 1 to 4 (in accordance with DIN 51818 part 2 [19.39]) to assess the effect which these lubricants have under service conditions on the frictional behavior and wear of angular contact groove ball bearings, tapered roller bearings and cylindrical thrust roller bearings (cylindrical... Company and now built, distributed, and supported by the ZF in Passau (Germany) [19.50] This machine uses a complete synchronizer set and operates full up and down-shift during testing The test machine consists of an electric motor, two flywheels, actuating hydraulics, an oil heating and circulation system, and a test box The large main flywheel is connected to the electric motor via a belt -and- pulley... and the failure-load stage of the FVA–FZG micro-pitting test is good The DGMK-FZG micro-pitting short test is thus regarded as a standardized short-test method suitable for differentiation of the micro-pitting load capacity of different candidate lubricants FZG Wear Tests For maximum energy savings low-viscosity lubricants are frequently used Greater transmitted power leads to higher temperatures and. .. load-carrying capacity of gear lubricants For low-speed conditions a wear test using C-type gears at low pitch line velocity of 0.05 m s-1 (7.5 rpm) and two different temperatures, 90 and 120 C, has been developed and applied to many different lubricants to assess response to different additives at high loading of load stage 12 (C/0.05/90:120/12; DGMK project no 377-1; Table 19.8 and Ref [19.25]) Under such... instrument which enables fully automated traction mapping of lubricants and other fluids The machine simulates the lubrication regime found in nonconforming components 747 748 19 Mechanical–Dynamic Test Methods for Lubricants such as cams, valve trains, gears, and rolling element bearings The test contact is formed between a polished three-quarter-inch ball and a 46-mm diameter disk, each independently driven... to 1200 N for model SRV-I, 10 to 140 0 N for model SRV-II, and 10 to 2000 N for model SRV-III), frequencies (5 to 500 Hz) and stroke amplitudes (0.1 to 4.0 mm) can be varied if specified The precision of this test method depends on the conditions stated and on test temperature (50 or 80 C) Average wear scar dimensions on ball and coefficient of friction are determined and reported Further test modes . oils Procedures for lubricating greases E-DIN 5143 4 E-DIN 5143 4, Part 1 E-DIN 5143 4, Part 2 E-DIN 5143 4, Part 3 Standard test method for liquid and plastic lubricants using the Timken test machine VDEh SEB. load of solid lubricants Shear stability of polymer-containing lubricants DIN 51350 DIN 51350, Part 1 DIN 51350, Part 2 DIN 51350, Part 3 DIN 51350, Part 4 DIN 51350, Part 5 DIN 51350, Part 6 Viscosity. machine (SRV) DIN 51834 DIN 51834, Part 1 DIN 51834, Part 2 DIN 51834, Part 3 DIN 51834, Part 5 DIN 51834, Part 6 Textile machinery and accessories – needle and sinker lubricating oils for weft