ENGINEERING RESEARCH INSTITUTE UNIVERSITY OF MICHIGAN ANN ARBOR Progress Report No. 1 EVALUATION OF "ZYTEL" AS A GEAR MATERIAL K. W. HALL Associate Professor of Mechanical Engineering H. H. ALVORD Assistant Professor of Mechanical Engineering Project 2176 E. I. du PONT de NEMOURS AND COMPANY, INC. WILMINGTON, DELAWARE December, 1954

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN TABLE OF CONTENTS Page LIST OF TABLES iii LIST OF FIGURES iv LIST OF ILLUSTRATIONS v ABSTRACT vi I. INTRODUCTION 1 II. EXPERIMENTAL APPARATUS 2 A. Test Machines 2 B. Instrumentation 8 C. Test Gears 8 III. EXPERIMENTAL WORK AND TEST RESULTS 9 A, Machine Assembly 9 B. Flexure-Plate Calibration 10 C. Bearing Tests 10 D, Gear Tests 12 IV. DISCUSSION OF TEST RESULTS 14 A, Bearing Tests 14 B. Gear Tests 14 V, PROPOSED FUTURE WORK 15....... ii

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN LIST OF TABLES Table Page I. Flexve-,Plate Calibration, Machine A 17 II. Flexure-Plate Calibration, Machine B 18 III. Flexure-Plate Calibration, Machine C 19 IV. Flexure-Plate Calibration, Machine D 20 V. Flexure-Plate Calibration, Machine E 21 VI. Bearing Test, Machine A 22 VII. Bearing Test, Machine B 23 VIII. Bearing Test, Machine C 24 IX. Bearing Test, Machine D 25 X* Bearing Test, Machine E 26 XI. Gear Test, Machine A 27 XII. Gear Test, Machine B 28 XIII. Gear Test, Machine C 29 XIV* Gear Test, Machine D 31 XV. Gear Test, Machine E 32 XVI. Five Gear Tests, Machine B 34 XVII, Composite Gear Test Data, Machines A, B, C, D, and E 35. iii -

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN LIST OF FIGURES Figure Page 1. Flexure-Plate Calibration, Machine A 17 2. Flexure-Plate Calibration, Machine B 18 3. Flexure-Plate Calibration, Machine C 19 4. Flexure-Plate Calibration, Machine D 20 5. Flexure-Plate Calibration, Machine E 21 6. Bearing Test, Machine A 22 7. Bearing Test, Machine B 23 8. Bearing Test, Machine C 24 9, Bearing Test, Machine D 25 10. Bearing Test, Machine E 26 11. Gear Test, Machine A 27 12. Gear Test, Machine B 28 13. Gear Test, Machine C 29 14. Gear Test, Machine D 30 14a. Gear Test, Machine D 30 15. Gear Test, Machine E 32 16. Five Gear Tests, Machine B 33 17. Gear Losses, Average 35 iv

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN LIST OF ILLUSTRATIONS Illustration Page 1. Test Machine Installation Viewed from Left 3 2. Test Machine Installation Viewed from Right 4 3. Schematic Layout of Test Machine 4. Gear Tooth Loading Setup 5 5 Flexure-Plate Assembly, Top View6 6. Flexure-Plate Assembly, Oblique View6 7. Sketch of Flexure-Plate Wiring Diagram 7 8. Alemite Oil-Mist Lubricators 7 9. Gear, Blank, and Chart 7 10, Flexure-Plate Calibration 11 11. Bearing Test Setup 11 12. Bearing Test Setup 11 13. Gear Test 13 14. Backlash Measurement Setup 13 15. Backlash Measurement Setup 13 16. Setting Center Distance 13 -- v —.._. -.-. -,

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN ABSTRACT The object of this project is to evaluate molded "Zytel" as a gear material. Five identical testing machines were designed and built. Preliminary tests, aimed at checking the performance of the machines, have been completed. These tests show the machines to be consistent with one another, and capable of measuring very small values of losses in the teeth of the test gears. Further study will endeavor to correlate gear losses and gear wear.. vi

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN EVALUATION OF "ZYTEL"AS A GEAR MATERIAL I. INTRODUCTION This project was undertaken for the Polychemicals Department of E. I. du Pont de Nemours and Company, Wilmington, Delaware. The purpose of the project is to evaluate molded "Zytel" as a gear material and to establish design data for gears made of "Zytel". This is outlined in detail in the proposal of May, 1953, entitled "Design Data for Nylon Gears," submitted to E. I. du Pont de Nemours and Company by the Engineering Research Institute of the University of Michigan. The evaluation of any gear material requires a good deal of testing to obtain necessary data. Testing, however, can be very time-consuming and expensive. This is especially so when obtaining data on useful life and wear rates of gear teeth over a wide range of gear sizes and operating conditions. It was therefore decided that in the testing work, an attempt would be made to correlate the power losses in the gear teeth with the rate of wear or other type of deterioration of the teeth and the useful life of the gears under various operating conditions. If such a correlation can be soundly established it will then only be necessary to measure the power losses in the teeth of the gears being tested in order to accurately predict the *rate of wear and useful life of these gears. Thus a lot of time-consuming test work can be eliminated. All of the work described, covered by this report, was done with the above thoughts in mind. This report covers the work done from August 1, 1953, when the project started, to the present time, a period of 16-1/2 months. All of this work was financed by the initial grant of $25,000. 1

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN II. EXPERIMENTAL APPARATUS A. Test Machines Five identical test machines were designed and built to carry out the proposed testing program. Illustrations 1 and 2 show the completed installation of these five test machines The test machines are of the "4 square" or "back-to-back" type in which two pairs of gears are tested simultaneously by loading one pair of gears against the other pair of gears. Each of the four gears are mounted on 5/8-inch, outside-diameter, splined, hollow shafts. These hollow shafts are supported in ball bearings and are joined together by steel torsion bars. Illustration 3 shows a schematic layout of the test machine. Gear tooth loading is obtained by applying a twisting moment to the outer half of a friction coupling while the inner half of the coupling is anchored. This is shown in Illustration 4. The outer half of the coupling is splined to the torsion bar which in turn is splined to the hollow shaft of the upper left-hand gear in Illustration 3. The inner half of the coupling is splined to the hollow shaft of the lower left-hand gear in Illustration 35 Thus the loading shown imposes a twisting moment, or torque, on the entire gear system, putting the same load on the teeth of all four gears being tested. The two halves of the coupling are clamped together by the four screws shown in Illustration 4, thus keeping the torque in the system when the loading and anchoring cables are removed to permit rotation of the gears. Movable bearing supports allow the center distance between the gear shafts to be varied from a minimum of 1 inch to a maximum of 4 inches, thus the machines can test gears of various sizes. The maximum torque which can be exerted on the gears is approximately 300 lb-in. The driving motor on each machine supplies only the power needed to overcome the losses in the system due to friction, windage, etc. The power supplied to overcome these losses is measured by use of a flexure-plate drive unit located between the motor and the gears being tested. Details of this drive are shown in Illustrations 5, 6, and 7* Illustrations 5 and 6 show the driving half of the uit entaining the flexure plate which is directly coupled to the drivi;ngr-otor. 3le driven ~half of the unit is an'aluminum shroud containing two steel pins l80~ apart. The flexure plate contacts these pins, thus driving the aluminum shroud. The ------— 2.

C~) m m!i~ ~............~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~....... Z m m Z "I' mm Z I T10 r" z_ Illustration 1 Test Machine Installation Viewed froLeft.:: 5C) Illustration 1. Test.achine Installation Viewed from Left.

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ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN BEARING SUPPORT FRICTION COUPLING, OUTER HALF —/ TEST GEAR FRICTION COUPLING, INNER HALF // SPACER / GEAR SHAFT LONG TORSION BAR /........................ SHORT TORSION BAR \\\ PIN \ V -GEAR SHAFT FLEXURE PLATE \ SPACER DRIVEN SHROUD TEST GEAR DRIVING SHAFT Illustration 3. Schematic Layout of Test Machine. Illustration 4. Gear Tooth Loading Setup. ----------------- ~~ ~~~5 —— 1_

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ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN PIN SPACING BALDWIN-LIMA- HAMILTON 2.75 SR.4 STRAIN GAGE TYPE A-18, 1/8" LENGTH W ~~I,/ F120 OHMS LE0.78 1.87.050 THICK X.375 WIDE LEVER GAGE ARM SPACING FLEXURE PLATE TO B-LH TYPE M STRAIN GAGE INDICATOR 4 STRAIN GAGE BRIDGE CIRCUIT Illustration 7. Sketch of Flexure-Plate Wiring Diagram. Illustration 8. Alemite Oil-Mist Illustration 9. Gear, Blank, and Lubricators. Chart...................

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN shroud in turn is splined to a gear shaft. Power is transmitted through the fleure pla bonded wire sexure plate, and bond wire strain es mounted on the lexue pate permit measurement of flexure-plate load. Four gages on the flexure plate form a complete Wheatstone bridge. The bridge signal is taken out through four silver slip rings, each in contact with two carbon brushes. Illustration 7 shows the flexure-plate circuit diagram and the position of the pins in the driven member. Lubrication for the gears and bearings of each machine is provided by an Alemite oil-mist lubricator as shown in Illustration 8. Individual oilmist tubes go to each bearing from common headers, and a separate tube carries the oil mist to the gears. When it becomes desirable to run the gears without lubrication, the tube carrying the oil mist to the gears can be removed. A sheet-metal housing is then slipped over each pair of gears to keep the oil mist supplied to the bearings from reaching the gears. As a further precaution the oil mist leaving the bearings is drawn off through a suction hose to an overhead venting duct. During the work covered by this report, Socony-Vacuum turbine oil was used with each lubricator 1/2 turn open and with 5 psi air pressure. Both gears and bearings were lubricated. B. Instrumentation To date the following instrumentation has been used: 1. Baldwin SR-4 strain gage indicator, model M 2. James G. Biddle No. K-0 continuous reading tachometer, range 30 to 12,000 rpm 3. General Radio Strobotac, type 631-B, range 600 to 14,400 rpm 4. Pratt and Whitney hoke precision gage blocks 5. Cenco sling psychrometer 6. Buffalo platform scale C. Test Gears All work to date has been done on 50-tooth, 20~ pressure angle, 20-pitch spur gears 7/16-inch wide. These gears have hob-cut teeth rather -3 8: —

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN than molded teeth. The teeth are of the AGMA full height proportions, cut to have.002 to.004 inch backlash when operating at the theoretical center distance of 2.500 inches. Illustration 9 shows one of the test gears, one of the molded "Zytel" blanks from which the gears were machined^ and an inspection chart supplied by the vendor who made the gears. The molded "Zytel" blanks were supplied by du Pont. This material was formerly designated du Pont nylon FM-10001. Whether or not the gear blanks were moisture conditioned is not known. The gear teeth were machined with AGMA commercial class 3 hobs. Actual inspection of the gear teeth after manufacture showed total composite errors of about.001 inch and tooth-to-tooth composite errors of about.0004 inch, thus meeting the requirements for AGMA precision class 1. III. EXPERIMENTAL WORK AND TEST RESULTS A. Machine Assembly The five test machines were assembled without difficulty. Considerable trouble was encountered with the drive setup from the.motor to the flexure-plate unit, however. As originally designed, each test machine was mounted on an individual table and was driven by V-belts from the motor underneath the table. A Speedmaster variable speed unit was incorporated in the belt drive to allow speed adjustments over a relatively wide range. When put in operation it was found that the belts vibrated so violently that the entire output of the 1/4 horsepower, 3450 rpm a-c motor was absorbed by the drive unit leaving no power to drive the test machine, The belt vibrations also vibrated the entire table and test machine. Experimentation failed to improve this situation, so the Speedmaster variable speed units were discarded. At this same time the individual tables were discarded and the test machines mounted on the large tables shown in Illustrations 1 and 2. With the machines on the large tables, a V-belt drive was again tried but without the Speedmaster units. The motors were mounted on the tables, and a single belt was used; this also proved to be unsatisfactory. Small variations in the cross section of the belt caused the flexure-plate unit to have small but continuous variations in speed, making strain gage readings from the flexure plate impossible. With this setup the indicating --------------- 9,....

- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN needle on the Baldwin strain gage indicator fluctuated continuously over a wide range. Adding inertia to the flexure-plate unit failed to help the situation so the belts were discarded. The motors were directly coupled to the flexure-plate units by means of a 6-inch length of rubber hose. This provided a fairly vibrationless drive and to date has proven to be very satisfactory. The ball bearings which support the gear shafts are mounted with a slight interference fit in split cast iron bearing supports. This construction is readily seen in Illustration 4. Although the castings had been stress relieved prior to machining, the bored holes in the bearing supports distorted slightly several weeks after the machines had been assembled. This distortion resulted in excessive clamping forces that prevented free rotation of bearings. The condition was corrected by hand scraping of bearing support holes. Fortunately, further distortion has not been detected. B. Flexure-Plate Calibration Illustration 10 shows the method used to calibrate the flexure plates. The motor shaft was held by a pipe wrench to prevent rotation while a known torque was applied by hanging weights on the cords attached to the friction coupling. The strain reading, in microinches per inch, was then read on the Baldwin strain indicator. During the calibration a motor of one of thee other machines on the same table was kept running to provide a slight vibration tohe table, thus minimizing the effects of friction. Figures 1 through 5 show the flexure-plate calibration curves for-the five test machines. The data from which the curves are plotted are shown in Tables I through V. It will be noted that the flexure plates are calibrated statically but are used dynamically. It is felt that very little error is thus introduced, however. C. Bearing Tests The test machines were set up as shown in Illustrations 11 and 12 for determination of the friction in the ball bearings. The two bearings from each of the two rear gear shafts were installed in a steel ring and then mounted in place of the gears on the two front gear shafts. Weights hanging on rods fastened to the rings provided equal loads on all four bearings of each assembly. The machines were run at 1770 and 3540 rpm with various loads on the bearing assemblies. The torque required to overcome bearing friction was determined by the flexure-plate strain readings. 10

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN tion. BEARINGS FROM REAR GEAR SHAFT BEARING RING.........__l__|___ Illustration 12. B earing Test Setup. --------------------------- 11 --

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN Figures 6 through 10 show the results of these tests at 1770 and 3540 rpm, respectively. The data from which the curves are plotted are shown in Tables VI through X. D. Gear Tests Illustration.13 shows a machine in operation testing the gears made of "Zytel". Preliminary tests run on the five machines showed a rather wide variation in the amount of torque required to drive the various machines under supposedly identical load and speed conditions. Investigation showed there was considerable variation in backlash between the gears in the five machines, and it was felt that this was a contributing factor. The way in which the backlash was measured is shown in Illustrations 14 and 15. The rather elaborate setup shown was required because it was found that the teeth tended to deflect so readily that it was difficult to tell just where backlash stopped and deflection started. In Illustrations 14 and 15, the clamp on the left-hand gear prevents that gear from rotating, while the clamp on the right-hand gear is free to rotate with that gear so far as the backlash allows. The weight of the dial indicator produces a small clockwise torque on the right-hand gear, thus turning that gear as far as the clearance between the gear teeth will allow. The above test condition is shown by Illustration.14 where counterweights are shown inactive, due to manual support. After reading the dial indicator in this position the weights are applied as shown in Illustration 15. The weights produce a counterclockwise torque on the righthand gear approximately equal to the clockwise torque originally applied. The difference between the indicator readings for the two positions, multiplied by the ratio of the levers involved, is taken as the backlash between the teeth. So that all the gears would be operating with essentially the same conditions in regard to backlash, the center distances -were adjusted to be within 2.4994 to 2.5001 inches on all pairs of gears. Illustration 16 shows how this was done. The rear gear shafts and bearings were removed and a dummy shaft ground to the same diameter as the outside diameter of the bearings was installed in the rear bearing supports. By the use of gage blocks, the distance between the dummy shaft and the outer diameter of the front shaft bearings was carefully gaged to provide the desired center distance. A spacer block visible in the lower right corner of Illustration 16, was used with shims to establish the position of the rear bearing supports. Jack screws, visible in Illustrations 14 and.15 forced the rear bearing support casting against the shimmed spacer block while the bearing support casting was tightened to the base casting. 12.

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN Illustration 13. Gear Test. Illustration 14. Backlash Measurement Setup. Illustration 15. Backlash Measurement Illustration 16. Setting Center DisSetup. tance. 13

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN After setting the gear center distances as described, variable gear torque tests were run on each of the five test machines at speeds of approximately 1760 and 3530 rpm. These were not intended to be life tests but were short duration tests to establish the relative performance of the five test machines. These speeds were selected because a-c motors having said characteristics were available. The results of these tests are shown in Figs. 11 through 17. Tables XI through XVII show the data from which the curves are plotted. The curves of Figs. 11 through 17 show drive torque, plotted vertically, against gear torque, plotted horizontally. The gear torque is that torque supplied to the system by the loading device shown in Illustration 4, and hence is the torque transmitted by each of the gears being tested. The drive torque is measured by the flexure plate and is the torque required to overcome losses in the gear teeth and bearings. IV. DISCUSSION OF TEST RESULTS A. Bearing Tests Figures 6 through 10 show that the bearing losses are reasonably consistent for the five machines, with the exception of machine E. The losses in machine E were considerably higher than in the other machines. Tle reason for this was not investigated but it is felt that the bearings in this machine might be a tighter fit in their supports than those of the other machines. B. Gear Tests The curves of Figs. 11, 12, 13,.14, and 15 showing the total loss in the gear teeth and bearings all have essentially the same slope, but the displacement from zero is not the same for all curves. This variation in the zero displacement may be due to the fact that the bearings of the two rear gear shafts are mounted differently when testing gears than when testing bearings. This may introduce some error into the test results since these bearings are slipped into the ring used for bearing testing, but are clamped into their supports when mounted in the test machine to determine the total loss, All of the total loss curves shown in these same figures are consistent in deviating upward from a straight line at high values of gear torque. ---------------- U_14

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN The 5530 rpm test on machine D was -runtwice with results as shown in Fig. 14a. Prior to the start of the first test the gears in this machine had not operated under load. Comparison of the two curves shown suggests that losses in machine-cut gears made from "Zytel" reduce somewhat after a short period of operation under load. Five gear tests were made on machine B on different dates under different atmospheric conditions and at varying gear center distances, Results shown in Table XVI and plotted on Fig. 16 indicate that the above variables may not appreciably influence gear losses. Figure 17 shows the composite or average results of the gear tests on all five machines. Table XVII contains the data from which the curves are plotted. The curves show the loss, expressed as driving torque, for one pair of gears, plotted against the torque transmitted by one pair of gears. The displacement of the two curves of Fig..17 from one another can be reasonably attributed to differences in windage loss due to the differences in speed. The upward deviation of the curves from a straight line at high values of gear torque may be due to interference brought about by tooth deflection. As previously mentioned, the object of these tests was to establish the relative performance of the five test machines. The results show that drive torques of a very small order of magnitude can be successfully measured, indicating that the flexure plates are sensitive but at the same time consistent. The five machines seem entirely capable of producing comparable results. V. PROPOSED FUTURE WORK The work done to date completes the first phase of the project, namely, the procuring of the test machines and the preliminary testing necessary to establish the performance of the test machines. It is felt that a sound basis has now been established from which to proceed to future work The next phase should logically be directed toward obtaining the evaluating and design data for gears made of "Zytel". With this in mind, the following proposals for future work are set forth: A. Tests will be run to establish wear rates and useful life of the gear teeth. These tests will be conducted with gears and teeth of various sizes and various tooth proportions operating with different conditions of speed and load. Information from 15

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN such tests will be the basis for establishing the desired design data. Bo In conjunction with the wear and life tests will be investigations of the effects of backlash and interference, and of lubrication and absence of lubrication. With regard to lubrication it might be added that all future tests will be conducted using the same kind of lubricating oil as is used in the du Pont Company laboratories. C. Tests will be conducted on steel gears to evaluate the losses and noise level as compared to gears made of "Zytel". D. A photomicrographic study of the gear teeth under static load will be made to determine clearance and interference conditions of the deflected teeth. This will be helpful in determining the most desirable tooth form and proportions. E. Methods of determining gear tooth temperatures may be investigated. Since power lost in the gear teeth must be dissipated in the form of heat and the heat in turn may affect the wearing properties of the teeth, such investigations may prove to be worthwhile. 16

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 2 J 0 0 200 400 600 800 1000 1200 1400 STRAIN- MICROINCHES/ INCH Fig. 1. Flexure-Plate Calibration, Machine A TABLE I FLEXURE-PLATE CALIBRATION, MACHINE A Couple Couple *Torque, Strain, Force, oz lb-in. }in./in. 8 1.47 334 4 0.73 163 8 1.47 341 12 2.20 521 16 2.94 680 20 3.67 868 24 4.41 1042 28 5.14 1212 52 5.88 1380 12 2.20 548 *Couple Distance = 2.9575" 17

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN X Ist CALIBRATION 9/27/54 0 RE-CALIBRATION 9/28/54 4_ / -J 0 200 400 600 800 1000 1200 1400 STRAIN- MICROINCHES/ INCH Fig. 2, Flexure-Plate Calibration, Machine B TABLE II FLEXUIRE-PLATE CALIBRATION, MACHINE B Couple *Torque, Strain, Force, f oz lb-in, 4in./in. 4 0.73 179 8.1.47 37 12 2.20 555 16 2.94 740 20 35.67 936 24 44.1 1094 4 0.753 195 8 1.47 386 12 2.20 570.16 2.94 753 20 3.67 933 24 4.4.1 1098 28 5.14 1302 32 5.88 1480 16 2.94 755 *Couple Distance = 2.9375" 8.4___73________- 718

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN z -J 0D 0i 2 0 200 400 600 800 1000 1200 1400 STRAIN- MICROINCHES / INCH Fig. 3, Flexure-Plate Calibration, Machine C TABLE III FLEXTJRE-PLATE CALIBRATION, MACHINE C Couple *Torque, Strain, Force, oz lb-in..in./in. 4 0.73 205 8 1.47 410 12 2.20 629 16 2.94 848 20 3.67 1055 24 4.41 1267 28 5.14 1489 32 5.88 1688 *Couple Distance = 2.9575" 19

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 0 200 400 600 800 1000 1200 1400 STRAIN TABLE IV FLEXURE-PLATE CALIBRATION, MACHINE D SI. Couple *Torque, Strain, Force, oz lb-in.. in./in. 4 0.73 154 8 1.47 337 0 2 22 0 544 0 16 2.94 695 20 3.67 882 24 44.1 C1076 28.14 1242 32 5.88.1421 12 2.20 518 16 2.94 709 16 2.94 706 *Couple Distance = 2.9375" 20

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN C5 2 j/ i 3 02 0- 0 200 400 600 00 1000 1200 140( STRAIN- MICROINCHES/INCH Fig. 5. Flexure-Plate Calibration, Machine E TABLE V FLEXURE-PLATE CALIBRATION, MACHINE E Couple FCoule *Torque, Strain, Force,. oz -.. lb-in in/in. 4 0.75 172 8 1.47 377 12 2.20 570 16 2.94 804 20 3.67 994 24 4.41 1203 28 5.14 1409 32 5.88 1612 *Couple Distance s 2.9375" 21

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN 200,.. I_.'.. 180 160 ~. 10 20 30 40 50 60 70 LOAD ON BEARING ASSEMBLY-LBS Figo 6, Bea:ring Test, Ilachi:rie A TAgBL.E V".I BEARI.N:Y! ATST, M ("INIE: A Seed, Load, Strain, rpmr 1b'1rg aszsb n.in.l 1770 f0C8 154 1770.8 14000 0 0.1767 5 0 8 141 1765 40).8 145 17765 DC,o 3.15.1 353(F 60.8 177T 3S2ee2 d8.16Load 3552 40..' i6o 5415 50.8 159 5548 2o.. 8 153 1769 60.8 1543 5550 60,8 15. 554~5 3o.8 159 5550 o08 146 -----.......................... 2.2.... —----------

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 200 18..0 z 120 100 10 20 30 40 50 60 70 LOAD ON BEARING ASSEMBLY-LBS Figo 7- Bearing Test, Machine B TABLE VII Speed, Load Strain, rpm Ib/brg assb yin./in. 1795 0.8 133 1795 10.-8 132 1790 20.8 139 1790 30.8 140 1778 40.8 147 1774 50.8 15.1 1774 60.8 153 3588 60.8 184 3588 50.8 164 3581 40.8 162 3570 30.8 149 3570 20.8 144 3570 10 8 135 3570 0o.8 139 LOAD ON BEARING ASSEMBLY-BS Speed. Load Strain 25

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 220 200 180 z J z140 120 a -. - co 0 10 20 30 40 50 60 70 LOAD ON BEARING ASSEMBLY Fig. 80 Bearing Test,.Mchine C TABLE IIE BEA-I.2T _2 ESTl MACNSE C Speed Load, Strs.a rpm.n _ IHeb/hbrg alsISDb p..in /in. 1778 0.8 117 1778 o1.8 16.1775 20 8,147 1775 50.8 5 1773 4o.8 159 1772 50.8 165 1772 60.8 174 3550 60.8 205 3550 5o.8 193 5545 40o.8.1814 3550 30.8 180 3550 20.8 166 5550.10.8 148 3570 0,8 1.45 24

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 200 20 100 C,/) 0 10 20 30 40 50 60 70 Fig. 9. Bearing Test, Machine D TABLE IX BEARING TEST, MACHINE D Speed, Load Strain, rpm ________ Ib/brg aassb ______ iiin^/in. 1775 0.8 133 1775 10.8 130 1775 20.8 152 1775 30.8 135 1775 40.8 138 1780 50.8 141 1775 60.8 147 3550 60.8 173 3540 50.8 165 3550 40.8 157 3545 30.8 153 3550 20.8 150 3550 10.8 146 3550 0.8 144 25 ---

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 240 _Eo _____._. —-'r 10- ______ 16A 120 0 10 20 30 40 50 60 70 LOAD ON BEARING ASSEMBLY-LBS Fig. 10. Bearing Test, Machine E TABLE X BEARING TEST, MACHINE E Speed, -'Load Strainr rpm lb/ brg assb in./in. 1775 0.8 186 1775 10.8 184 1775 20.8 187 1775 30.8 191 1775 40.8 198 1775 50.8 202 1775 60.8 205 3550 60.8 254 3550 50.8 252 3550 40.8 247 3550 30.8 244 3550 20.8 240 3550 10.8 254 35550 08 235 26

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN. —-* — TOTAL TORQUE, 3515- 3550 RPM -**-X —- BEARING TORQUE, 3550 RPM 0 —-TOTAL TORQUE, 1740-1780 RPM -- -- BEARING TORQUE, 1780 RPM D 2.0, 2..0 —----— xi —----------— ^ 0 0 10 20 30 40 50 60 70 80 GEAR TORQUE- LB-IN. Fig, 11o Gear Test, Machine A TABLE XI GEAR TEST, MACHINE A Gears: Nos. 5 and 6, 7 and 8 Shaft C.D.: 2.4995" to 2.4996" Backlash: 5 and 6, 0.0025" to 0.0053" 7 and 8, 0o0038" to 0.0060" Gear Bearing Drive Total Drive -Gear Drive Speed, Torque, Load, 1Strain, 2Torque, Strain, Torque, 2orque,,r, Ib-i. -.n. l, in./in. lb-in. in./in. lb- lb-in. 1780 o 0 135 o.60 176. 76 o 16 1775 14.7 12.45 137 0.61 241 1.02 0 o41 1770 29.4 24.9 140 0.62 292.1.25 Oo6.1.1765 44.1 57.4 143 0.63 352.1.49 0o86 1755 58,8 49.9 149 0o65 40.1 168 1o05 1740 73-4 62.4 157 0o68 471 1.98.lo30 5so o0 0 146 0.63 243.102 0.59 3530 14.7 12.45 151 o.65 285 1.2.1 0o56 3530 29.4 2409 156 0.67 337 1.41 0o47 3525 44.1 37.4 162 0.70 594 1.66 0.96 3525 58.8 49.9 170 0 73 456 1.84 1 1.1 3515 7534 62.4 180 0~77 514 2.17 1o40 5550 01 0 16 4O 63 224. 97 0.4 1 Strain at gear load from Fig. 6 2a3 Torque at given strain from Fig0 1 4 s minus 2 27..

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN 2.0 - ~ -== — TOTAL BERQUE, 3515-3550 RPM -.. m= —.BEARING TORQUE, 3550 RPM 0 o — T TOTAL TORQUE, 1765-1780 RPM ------ BEARING TORQUE, 1780 RPM 0 0 10 20 30 40 50 60 70 80 GEAR TORQUE -LB-IN. Fig. 12, Gear Test, Machine B TABLE XII GEAR TEST, MACHINE B Gears: Nosc 9 and 10, 11 and 12 Shaft C.D: 2.5001" to 2,4994" Backlash: 9 and 10, 0.0015" to 0.0055" 11 and 12, 0.0032" to 0.0040" Gear Bear4 rig rive Total Drive Gear Drive Speed, Torque, Load, 1xStrairn, eorque, Strain,..Torque, 4~Torque, rpm Ib-in, lb j../in. lb-in?, kin,/ino/ 1'b-in, lb-in, 1780 0 0 0 131 050 112 0.42 -0o08 1780 14.7 12.45 155 0.51 169 0.65 0.14 1775 29.4 24.9 139 0.53 228 o0.87 0,534 1775 44.1 37.4 143 0.55 284 1.10 0.55 1765 58.8 49.9 149 149 0.57 550 1.55 0.78 1765 75.4 62.4 155 0,59 452 1S66 1.07 3550 0 0 156 0.51 147 0.56 0.05 353550 14,7 12,45 141 0.553 216 0.82 0.29 35525 29.4 24.9 147 0,56 265 1.01 0.45 3520 44.1 57.4 155 0.59 321 1.24 0.65 5520 58.8 49.9 167 0.63 385 1.47 0,84 3515 75.4 62.4 188 0.71 470 1.80 1.09 5550 0 0 156 0.51 131 0.50 -0.01. Strain at gear load from Fig. 7 2S 3 Torque at given strain from Fig. 2 4 S minus 2 28

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN -— G TOTAL TORQUE, 3520-3550 RPM —..X- BEARING TORQUE, 3550 RPM 0 — TOTAL TORQUE, 1750-1780 RPM - -A-BEARING TORQUE, 1780 RPM 2.0 0 10 20 30 40 50 60 70 80 i1.50[ "' -GEAR TORUE-LB-IN iGears Nos 1 and0, and. and 4, 0021" to 0.0040" Ger Total Drive Gear Drivest Machine C Speed, ToqGE, Load, Strain, TorquE Strain Torque, Corq, 1780Gears: Nos. 1 and20.48, 20 02and 4 147Shaft C.D.: 2.14996"1 0.50 28 2.499 8",49 1770Backlash: 1 and 2, 0.0040" to121 0.670056" 7651 44.1 7n4 14 4 057 421 14 0.0040" 7Speed,0 T8ue,8 49.9 1str4 0ain1 Torque41 1.89 13T28rque, 4Torque, 1780 0 0 127 0.48 2019 0.71 0.25 177550 14.7 12.45 157 0.508 0.996 0.4958 17740 29.4 24.9 1845 0.54 3545 1.218 0.677 1765 44.1 37.4 15479 0.57 421 1.47 0.90 176525 58.8 49.9 16492 0.6170 541 1.89 1.28 17520 735.4 62.4 207 0.675 608 2.1127 1.4652 35550 0 0 146 0.54 279 0.90 0.45.. Strain at gear load from Fig. 8 2,3 Torque at given strain from Fig, 3 4 3 minus 2 29

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN 2.0.............. -— D-TOTAL TORQUE, 3525-3550 RPM (REPEAT TEST) — X- BEARING TORQUE, 3550 RPM -0-OTOTAL TORQUE, 1765-1780 RPM. —-— BEARING TORQUE, 1780 RPM.0 |0 1.5 O 0 0 10 20 30 40 50 60 70 80 Fig. 14. Gear Test, Machine D 2.0C_ _ _ 2.0 - X —lIst TEST l0 --— ZERO CHECK AFTER X REPEAT TEST GEAR TORQUE-LLB-IN. Fig. 14a. Gear Test, Machine D 1.5 0 10 20 30 40 50 60 70 80 GEAR TORQUE- tB-IN. ----------------------—.50 ------

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN TABLE XIV GEAR TEST, MACHINE D Gears: Nos. 13 and 14, 15 and 16 Shaft C.D.: 2.4995" to 2.500" Backlash: 13 and 14, 0.0015" to 0.0044" 15 and 16, 0.0045" to 0.0056" Gear Bearing Drive Total Drive Gear Drive Speed, Torque, Load, 1Strain, 2Torque, Strain, 3Torque, 4Torque rpm lb-in. lb In,/in lb-in. tin./in. lb-in, Ib-in. 3550 0 0 144 0.70 220 1.00 0,30 3550 14.7 12.45 147 0.71 292 1.27 o.56 3540 29.4 24.9 151 0.72 346 1.50 0.78 3535 44.1 37.4 156 0.73 388 1.66 0.93 3520 58.8 49.9 163 0.77 419 1.79 1.02 3520 7354 62.,4 175 0.81 492 2.07 1.26 Gear test repeated for 35520 to 3550 rpm 3550 0 0 144 0.70 184 0.85 0.15 35540 14.7 12.45 147 0.71 260 1.16 0.45 3540 29,4 24.9 151 0.72 308 1.35 0.63 3535 44.1 37.4 156 0.75 551 1.52 0.79 3525 58.8 49.9 163 0,.77 405 1.73 0.96 3525 735.4 62.4 175 0.81 479 2.02 1.21 35550 0 0 144 0,70 167 0.78 0.08 1780 0 0 129 0.63 116 0.58 -0,05 1775 14*7 12.45 131 0.64 196 0.90 0.26 1775 29.4 24.9 155 0.65 243 1.09 0.44 1775 44.1 37.4 136 0.66 5305 1.33 0.67 1770 58.8 49.9 141 0.68 371 1.59 0.91 1765 735.4 62.4 148 0.71 425 1.81 1.10 1780 0 0 129 0.63 120 o.6o -0.03 - Strain at gear load from Fig. 9 2,3 Torque at given strain from Fig. 4 4 3 minus 2 351

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN --— 0 —— TOTAL TORQUE,3490-3550 RPM --— X-BEARING TORQUE, 3550 RPM --— TOTAL TORQUE, 1765-1780 RPM —, —BEARING TORQUE, 1780 RPM _ _ 0.5 I ------------- 0 10 20 30 40 50 60 70 80 GEAR TORQUE - LB-IN. Fig. 15. Gear Test, Machine E TABLE XV GEAR TEST, MACHINE E Gears: Nos. 17 and 18, 19 and 20 Shaft C.D.: 2.5001" to 2.5000" Backlash: 17 and 18, 0.0010" to 0.0037" 19 and 20, 0.0031" to 0.0042" Gear Bearing Drive Total Drive Gear Drive Speed, Torque, Load,'Strain, -Torque, Strain, Torque, 4Torque rpm lb-in. lb n./in. lb-in..in in. lb-in, lb-in. 3550 0 0 255 0.96 230 0.95 -0.01 3545 14.7 12.45 238 0.97 304 1.20 0.23 3530 29.4 24.9 241 0.98 379 1.46 0.48 *5490 44.1 37.4 245 0.99 460 1.75 0.76 3535 58.8 49.9 250 1.01 555 2.08 1.07 3525 73.4 62.4 252 1.02 671 2.50 1.48 35550 0 0 235 0.96 233 0.96 0.00 1780 0 0 184 0.77 158 0.69 -0.08 1780 14.7 12.45 186 0.78 228 0.95 0.15 1775 29.4 24.9 189 0.79 301 1.18 0.59 1775 44.1 37.4 193 0.81 3571 1.43 0.62 1765 58.7 49.9 199 0.83 454 1.73 0.90 1750 75.4 62.4 209 0.87 563 2.11 1.23 1780 0 0 184 0.77 172 0.72 -0.05 Hose coupling slippng, wire clamp added 1 Strain at gear load from Fig. 10 2,s Torque at given strain from Fig. 5 ___ 4 3 minus 52_ __2

2.0 m -+ -^TEST 1 3465-3550 RPM m -*- -*-TEST mI hmI3-iTEST U} 1760-1790 RPM I. _ _ _ _ _ _ C00) T -.-it.-TEST -J ~~~~~~~~~~~~~I 00~~~ ~~~~~~~~~~~ I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~e~~~~~~~ ~. ~~~~~~N~~~GA TOQU-.-N ~m x~~~~~~~ w~~~~~~~~~~~~~~~ 0 w~~~~~~~~~~~~~~~ m Fig. l6. Five Gear Tests, Machine B ^ 0 10 20 30 40 50 60 7 GEAR TORQUE-'LB-IN. Fig. 16. Five Gear Tests., Machine BZ

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN TABLE XVI FIVE GEAR TESTS, MACHINE B Gears: Nos. 9 and 10, 11 and 12 Gear Total Drive Air Conditions No. Date Speed, Torque, Strain, 1Torque, Shaft C.D., DB,, W.B., RBH., rpm lb-in...in./in. lb-in, in. ~F'OF 355545 0 154 0.59 81.5 68,0 553 3530 14.7 195 0.75 2.499 I 9/28/54 3525 29.4 255 0.98 to 82,5 69.0 55 3510 44.1 311 1.20 2.494 3500 58.8 366 1.40 3465 73.4 424 1.63 82.5 69.0 55 1790 0 92 0.35 1788 14.7 149 Oo57 1786 29.4 194 0.75 2.499 II 9/28/54 1786 44.1 251 0.96 to 1778 58.8 303 1.16 2.494 1772 73.4 413 1.60 83.0 69,2 55 1788 0 lo9 0.41 1775 0 128 o,49 74.5 57 52 1770 14.7 190 0.72. 2.499 *III 10/7/54 1770 29.4 242 0.93 to 76,0 56,0 26 1770 44.1 303 1.16 2.494 1765 58.8 343 1.52 1760 7354 442 1.70 77~0 56,05 26 1780 0 112 0.42 1780 14,7 169 0.65 2.5001 IV 10/21/54 1775 29.4 228 0.87 to 1775 44.1 284 1.10 2.4994 74o0 56.7 32 1765 58.8 350 1.55 1765 735.4 432 1.66 3550 0 147 0.56 69.7 52.2 29 5530 14.7 216 0,.82 3525 29.4 265 1,01 2.5001 69.8 52.3 29 V 11/2/54 3520 44.1 321 1.24 to 3520 58.8 385 1.47 2,4994 3515 735.4 470 1.80 69.8 52,3 29 35550 0 131 0. 50'Torque at given strain from Fig. 2 ~*Gears picked up dirt particles during test 34

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN 0.7.......... -----— 3515-3550 RPM e — X —— 1740-1780 RPM 0.6 Gear river 1755-1770 580.8 - -4 — - — 5 0,390 -,640 0-4- 5 0-450 0-490 — 01-7 z 3550 0 0 0*~3 -2 0-0-10 0 202 0-0-7- ---— 002 O — Q 90 O. J 825 0280 30 40 50 0 22 0 80 11 0118 1780 o o o.o8o -0.00- 0.120 -0.020 -0.052 0.022 o.ooo6 1770525-3540 29.4 0.82147 0.5370 0.170 0.55385 0.23152 0.19240 0.2450 0.006972 34901765-1735 44.1 1.24609 0.480 0.325 05.450 0.55395 0580 0.6 0.010127 1755-1770 58.8 3,64282 0.555 0.59420 0.630 0,48055 0.450 0.490 0.0293.15 351740-17652 753^4 2.0400 0.65700 0.555 0.760 0.60550 0.6.1540 0.6670 0o.07 5550 0 0 0.12 0.0.10 0.202 0.057 -0.002 0090 0.005,1 5520-5525 8.8 282 0.555 0420.6 0.480 O 5 0.524 0295 *Gear drive torque, Tables XI to XV, divided by two. 1755-1770 ---— 0.-390 0.640 0.455 0.450 0.490 —---