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Report Summaries

A-001 Final Report

The Measurement of Rim and Web Deformation of a Helical Gear Set Using Electronic Speckle Pattern Interferometry

This report sums up an experimental investigation of the deformation, under a static load, of different parts an helical gear set and its supporting test rig using Electronic Speckle Pattern Interferometry (ESPI) at the Laboratoire de Metrologie du Departement de Genie Mecanique de l'Universite Laval. Strain gage testing was also performed at various locations on the gear web, gear rim and at the root of four gear teeth in the meshing zone. The test rig was designed and built by the ASME Gear Research Institute. It incorporates a helical pinion and gear set in mesh, on which torques of up to 34000 lb-in can be applied. Four reference torque levels were tested, since the ESP! apparatus cannot continuously measure deformation over such a large torque range. At each reference torque level, a delta-torque was applied, and results are presented for the behavior under such delta-torque. The areas tested with ESP! on the gear and test rig are: the gear web, on both the concave and convex sides; the gear rim, on both the concave and convex sides; the test rig back plate, and side posts on both the concave and convex sides. Results show some level on randomness, attributed to the movement of the gear blank in the test rig gear shaft bore, which may induce some tilt and thus alter the ESP! results. Given that these movements are believed random, results were not compensated for such tilt It was found that the area of most consideration is the gear web, where the results on the concave and convex sides, along a crosshair perpendicular to the line of centers, do not match, while those along a vertical crosshair, parallel to the line of centers, do match quite closely. This phenomenon was found to be repetitive, and cannot be linked to randomness in test rig installation. Finally, an addition demanded by the GR!, that of the ESP! measurement of the mesh stiffness, will be available shortly.

A-002 Progress Report  

S-N Performance of X-2M Carburized, Ground, and Peened Tested at 200degrees F by Single Tooth Fatigue Method Project A1013 PR#-8

This report covers the work done in evaluating the single tooth fatigue properties of X-2M at 200°F. Comparisons are made with 9310 VIM-VAR and X-53 tested at 400°F and 9310 VIM-VAR, MSO-NiL, CBS-600 and X-53 tested at 200°F which were reported previously.

A-003 Progress Report  

S-N Performance of Carburized, Ground, Peened and Honed M50-NiL Tested at 200 degrees F and 400 degrees F by the Rolling/Sliding Contact Fatigue Method-Project#A1013-PR#12

This report deals with results of RCF tests of carburized, ground, peened, and honed M50-NiL at 200 degrees F and 400 degrees F. Some material originally reported in Related Douments #3 and #5 is repeated here for comparison. Tests at 200 degrees F were conducted in MOBIL Synthetic Jet Oil II, those at 400 degrees F were conducted in MOBIL Synthetic Jet Oil 254 (see section 4.0). 

A-004 Progress Report

 S-N Performance of X-53 Carburized, Ground, and Peened Tested at 200 degrees F by Single Tooth Fatigue Method-Project A1013-PR#-5 This report covers the work done in evaluating the single tooth fatigue properties of X-53 at 200°F. Comparisons are made with 9310 VIM-VAR and CBS-600 which were reported previously.

A-005 Progress Report

S-N Performance of Nitralloy-N Nitrided, Ground & Peened Tested at 200 degree F by Single Tooth Fatigue Method-Project A1013-PR#-14

This report covers the work done in evaluating the single tooth fatigue properties of nitrided Nitralloy-N at 200°F. Comparisons are made with 9310 VIM-VAR, M50-NiL, CBS-600, X-53 and X-2M tested at 200°F, which were reported previously. Tests at 400°F have not yet been conducted.

A-006 Progress Report 

S-N Performance of Carburized and Peened 9310 VIM-VAR, Silver Coated by the Rolling/Sliding Contact Fatigue Method Project A1011 PR#-11

This report deals with the results of RCF testing of silver coated carburized 9310 steel at 200°F. Some material originally reported in Documents #2 through #7 is repeated here for comparison.

A-008 Progress Report 

Pitting SN Performance Comparisons of Program Materials M50-NiL, CBS 600 and X-53    A-007         ProgressS-N Performance of Carburized, Ground, Peened and Honed M50-NiL TiN Coated Tested at 400degrees F by the Rolling/Sliding Contact Fatigue Method A1011-PR#-12This report deals with results of RCF tests of carburized, ground, peened, honed and TiN coated M50-NiL conducted at 400°F. Some material originally reported in Related Documents #3 and #10 is repeated here for comparison. Tests were conducted in MOBIL Synthetic Jet Oil 254. This is a different lubricant than was used in the previous RCF tests with coated surfaces, but the same lubricant used in the RCF tests with uncoated M50-NiL at 400" (see Related Document #10) .

A-010 Progress Report

S-N Performance of CBS-600 Carburized, Ground and Peened Tested at 200 degrees F by Single Tooth Fatigue Method-Project A1013-PR#4

This writing covers the work done in characterizing the bending fatigue performance of CBS 600 at 200°F. Comparisons are also made with 9310 at 200°F and 400°F which was reported previously (Related Documents 4 and 5).

A-011 Progress Report  

Pitting SN Performance of Nitralloy N Nitrided-Project A1013                  

Nitrided Nitralloy N was included in the original program plan, Related Document # 1, to be characterized in terms of single tooth fatigue (STF) and rolling/ sliding contact fatigue (RCF). This report deals with the RCF work. A subsequent report will address the STF work. RCF specimens and load rollers were nitrided at Bell Helicopter as indicated in Attachment #1. Grinding stock of 0.005" was provided to allow removal of the "white layer." The specimens were finish ground and peened. They were subjected to the standard run-in procedure as reported previously. Tests were conducted at 300 KSI in 200°F oil.

A-014 Progress Report 

S-N Performance of Uncoated, Carburized and Peened 9310 VIM-VAR at 400 degrees F, by Single Tooth Fatigue Method, Project#A1013-PR#1

The scope of this report is limited to the STBF tests for the 9310 VIM-VAR carburized and peened gears at 400°F. The STBF tests for the 9310 VIM-VAR carburized and peened gears at 200°F are covered in document 3. Gears manufactured from M50 Nil, X-53, CBS 600, Nitralloy N, and VASCO X-2M will be covered in separate reports. This report defines the parts that were tested and the results of the STBF tests at 400°F for carburized and peened 9310 VIMVAR. The data is presented along with an interpretation of the data.

A-015 Progress Report 

S-N Performance of Carburized and Peened 9310 (VIM-VAR) Gears Treated with Ion-Implantation of Chrome by Single Tooth Fatigue Method-Project#A1011-PR#6

The subject of the report is limited to the STBF tests for the gears treated with the ion-implantation of chrome. Gears coated with thin dense chrome (TDC), indium (IND) will be covered in separate reports.

A-016 Progress Report

S-N Performance of Indium Coated, Carburized and Peened 9310 (VIM-VAR) by Single Tooth Fatigue Method-Project#A1011-PR#7 

The scope of this report is limited to the STBF tests for the gears coated with indium (IND) . Uncoated gears are covered in document 3, gears coated with thin dense chrome (TDC) in document 4, and gears coated with ion-implanted chrome (IIC) in document 5. This report defines the parts that were tested and the results of the STBF tests for carburized and peened 9310 VIM-VAR that were coated with indium. The data is presented along with interpretation of the data.

A-017 Progress Report 

S-N Performance of TDC Coated, Carburized and Peened 9310 (VIM-VAR) by Single Tooth Fatigue Method-Project#A1011-PR#3 

The scope of this report is limited to the STBF tests for the gears coated with thin dense chrome (TDC). Gears coated withIon-implanted chrome (IIC) and indium (IND) will be covered in a separate report. This report defines the parts that were tested and the results of the STBF tests for carburized and peened 9310 VIM-VAR that were coated with Thin Dense Chrome. The data is presented along with interpretation of the data.  

A-019 Final Report

Electron Fractographic Analysis of STF Samples-Project A2002       

Early results of single tooth fatigue tests on carburized samples showed enough scatter to prompt a preliminary investigation to determine if there were abnormalities. In a meeting at MRL on January 28, 1987 with Falk personnel, several potential scatter inducing factors were identified and discussed as follows:

  1. Surface roughness
  2. Dimensional inaccuracies
  3. Bar stock vs. forgings
  4. Metallurgical variations

Origin sites can be influenced by all of the above, however, there was special concern over lead error, i.e. #2, which would result in end loading. This was a major concern. It is desired that fracture origins not be from corners. Electron fractography allows explicit description of origin sites.Samples 86T8 #1, 86T8 #2 and 86T3 #1 were selected for analysis. Sample 86T8-2 was examined macroscopically only. This sample was a run out.  

A-020 Interim Report 

Testing and Evaluation of Splines - Aerospace Block #A-1016           

The preliminary objective of this program was to refurbish the obtained spline test stand in order to make it into a functioning device. Concurrent with this refurbishment, a specific spline testing procedure would be developed for use in future testing. To develop these procedures a test matrix, shown in Table 2, dependent on the three previously mentioned variables was defined. However, due to rig limitations an alternate set of test conditions was developed and implemented. The ultimate objective is to develop a more accurate rating formula for use in spline design for which a more comprehensive test program would be defined and implemented in support of this effort. 

A-022 Progress

S-N Performance of Carburized & Peened 9310 (VIM-VAR) by the Rolling/Sliding Contact Fatigue Method           

This report deals with the results of RCF testing of carburized 9310 steel, i.e. development and interpretation of "baseline" data. This information also has utility in Project #A1010, High Temperature Materials. Some information previously reported in the February, 1991 preliminary report (Item 2 above) is repeated herein for completeness and continuity.

A-023 Progress Report  

S-N Performance of M50-NIL Carburized, Ground, and Peened Tested at 200 degree by Single Tooth Fatigue Method 

The report covers single tooth fatigue testing of M50-NIL at 200°F. Comparisons are made with 9310 VIM-VAR, CBS-600, and X-53 which were reported previously.  

A-024 Progress

S-N Performance of M50-NIL Carburized, Ground, and Peened Tested at 400 degree by Single Tooth Fatigue Method 

The report covers single tooth fatigue testing of M50-NIL at 400°F. Comparisons· are made with 9310 VIM-VAR, CBS-600, X-2M and X-53 some of which were reported previously.                   

A-028 Final Report 

Engineering Performance Data for Gears Made from High Hot Hardness Materials Project A-1013     

To performance characterize several candidate high hot hardness materials in terms of bending strength and surface durability, and compare this performance with that of9310 VIM-V AR. The candidate high hot hardness materials are M50-NiL, CBS-600, Nitralloy-N, Pyrowear 53 (noted X-53), and Vasco X-2M (noted X-2M). Bending strength was characterized via the Single Tooth Fatigue (STF) method. Surface durability was characterized via the Rolling/Sliding Contact Fatigue (RCF) method. Tests were conducted at 200°F and 400°F. 

A-029 Final Report 

Effect of Shot Peening and Super Finishing on Bending Strength and Surface Durability - A-1014         

To evaluate the effect of shot peening on bending strength and surface durability of aerospace quality ground gears. Bending strength to be evaluated using the Single Tooth bending Fatigue (STF) test. Surface durability to be evaluated using the Rolling/sliding Contact Fatigue (RCF) test. Evaluations to be conducted at 200°F with 9310 VIM-V AR specimens and at 400°F with Pyrowear 53 specimens. Three levels of peening to be evaluated being: high intensity with hard shot (data obtained in Project #A-1 013), moderate intensity with soft (regular) shot, and as ground. The original objective was altered after the project was started as described below. 

A-30 Draft Final 

Develop Design Allowables for AMS 6308: Phase I Develop Bending Strength Allowables - A1020       

The Gear Research Aerospace Bloc has requested support in developing design allowable bending strength, surface durability, and scoring resistance values for AMS 6308 using power recirculating gear tests. Due to the magnitude of the scope of this effort, it is broken down into three phases: Phase I- Develop Bending Strength Allowables for AMS 6308, Phase II Develop Surface Durability and Scoring Resistance Allowables for AMS 6308, and Phase III - Develop Base Line Data with 9310 VIM-VAR. This report covers efforts conducted under Phase I- Develop Bending Strength Allowables for AMS 6308.  

A-31 Final Report 

Engineering Performance Data for Gears Made from High Hot Hardness Materials - A-1013               

To performance characterize several candidate high hot hardness materials in terms of bending strength and surface durability, and compare this performance with that of9310 VIM-V AR. The candidate high hot hardness materials are M50-NiL, CBS-600, Nitralloy-N, Pyrowear 53 (noted X-53), and Vasco X-2M (noted X-2M). Bending strength was characterized via the Single Tooth Fatigue (STF) method. Surface durability was characterized via the Rolling/Sliding Contact Fatigue (RCF) method. Tests were conducted at 200°F and 400°F. 

A-32 Final Report 

Effect of Shot Peening and Super Finishing on Bending Strength and Surface Durability - Project #A-1014 

To evaluate the effect of shot peening on bending strength and surface durability of aerospace quality ground gears. Bending strength to be evaluated using the Single Tooth bending Fatigue (STF) test. Surface durability to be evaluated using the Rolling/sliding Contact Fatigue (RCF) test. Evaluations to be conducted at 200°F with 9310 VIM-V AR specimens and at 400°F with Pyrowear 53 specimens. Three levels of peening to be evaluated being: high intensity with hard shot (data obtained in Project #A-1 013), moderate intensity with soft (regular) shot, and as ground. The original objective was altered after the project was started as described below.  

IH-003 Progress #1 

Performance of Induction Hardened Gears     

The objective of this program is to characterize the performance of selected candidate induction hardened steel material system for gearing. Surface durability of induction hardened components will evaluated using RCF and PCSD tests and the bending strength will be determined by STBF and PCBF testing of induction hardened gears. The current Induction Hardened Gears program will be conducted in three phases. Detailed plans for the second and third phases of the program will be adapted to implement the findings of the earlier tasks/phases with the direction of the steering committee 

 IH-004 Progress #2 

Performance of Induction Hardened Gears     

The objective of the current program is to improve the strength and durability of induction hardened gears to achieve performance comparable to carburized and hardened 8620 steel gears. A prior cooperative Induction Hardened Gears program conducted by Gear Research Institute during I 993- I 996 had demonstrated the inherent higher bending strength of AF IRF induction hardened gears as compared to AF induction hardened gears, as well as carburized and hardened gears. However, AF/RF induction hardened gears generally exhibited lower surface durability and wear resistance. The specific goal of the current program is therefore to enhance the surface durability and wear resistance of dual frequency AF /RF induction hardened gears to achieve performance comparable to carburized and hardened gears, without compromising their inherent improved bending strength. 

IH-005 Progress #3 

Performance of Induction Hardened Gears     

This report briefly summarizes partial test results of phase II task I, which is ongoing. The purpose of this report is to solicit your input into the decision of prior structure for the test specimens for phase II, task II. A timely decision on this matter is imperative to continue the fabrication of specimens and to conclude this program in CY 2001.  

IH-006 Progress #4 

Performance of Induction Hardened Gears     

The current project is structured to optimize the prior metallurgical characteristics and AF 1RF induction hardening process for the 5160 steel test specimens, and to establish performance data of induction hardened steel gears. Surface durability of induction hardened components is being evaluated by rolling/sliding contact fatigue (RCF) tests on cylindrical RCF specimens and power circulating pitting (PC-Pitting) tests on gear specimens. The bending strength of induction hardened gears is being determined by gear single tooth bending fatigue (STF) tests and power circulating bending fatigue (PC-Bending) tests. 

S-036 Progress 

Data Base of Critical Technical Information for Austempered Ductile Iron-PR#3                   

This report summarizes the Phase A work performed by the AMAX Materials Research Center during the second year (1985) of the three-year program on austempered ductile iron for the Gear Research Institute. This work covers a portion of Items (2) 1 (3), (4), (5), (6), and (7) listed in Table II (a) in the Research Proposal submitted by the Gear Research Institute to the sponsors of this program.As mentioned in the first-year report, 1 the strategy in Phase A is to develop specific knowledge of the phase transformation occurring during austempering of ductile iron and to relate this knowledge to mechanical properties attainable in austempered ductile iron. The specific bank ot data should be of such a nature that ductile-iron compositions and heat-treatment parameters can be simply adjusted in a controlled manner to achieve the final mechanical properties required for certain engineering components. Keeping this strategy in mind, the following test programs were designed in this second-year project. Many of these programs are a continuation of the test programs initiated during the first-year project. 

S-037 Progress 

Data Base of Critical Technical Information for Austempered Ductile Iron-PR#5                   

This report summarizes the Phase A work performed by the AMAX Materials Research Center during the last year (1986) of the three year program on austempered ductile iron for the Gear Research Institute. This work covers a portion of Items (5), (7) and (9) listed in Table II(a) in the Research Proposal submitted by the Gear Research Institute to the sponsors of this program.As mentioned in the first- and the second-year report, 1, 2, the strategy in Phase A is to develop specific knowledge of the phase transformation occurring during austempering of ductile iron and relate this knowledge to mechanical properties attainable in austempered ductile iron. The specific bank of data should be of such a nature that ductile iron compositions and heat treatment parameters can be simply adjusted in a controlled manner to achieve the final mechanical properties required for certain engineering components. Keeping this strategy in mind, the following test programs were designed in this third-year project. Some of these programs are continuation of the test programs initiated during the first- and the second-year project.  

S-038 Final 

On Spalling Fatigue Gears             

By TUFFTRIDING gears of normalized SAE 1045 or SAE 4140, hardened and tempered to different core strengths, it is possible to achieve rolling fatigue strength values up to Kn = 4.5 (260,000 psi).To obtain these high load carrying capacity values which approach those of carburized and hardened gears, it is necessary to maintain the cyanate and iron content of the bath within the described limits.Gears of unalloyed material are less susceptible to accurate bath control than those of alloyed material.The load capacity of TUFFTRIDED gears depends on the gear size and design. Large gears; i.e., with large mean radii of curvature, cannot be loaded as highly as gears with smaller radii of curvature. Because the compound zone has a low coefficient of friction, the formation of tangential surface stresses is small; therefore, the formation of pitting due to overloading will generally originate below the surface. Pit occurrence, starting from cracks in the surface, will take place if the quality of the compound zone is sub-standard or if the compound zone has been removed. With the lower coefficient of friction of the TUFFTRIDE compound zone, the wear resistance is much greater than that found in carburized and hardened gears.

S-039 Final 

Power Circulating Gear Surface Durability Testing          

Gear Research has conducted 7 Power-Circulating surface durability tests with helical gear specimens supplied by John Deere. Tests were conducted at 200°F using "used" John Deere 30W Diesel Engine oil as the lubricant, also supplied by the sponsor. Tests were conducted at various torques with two different sets of PM gears (Set 1 had an error in the profile of the gears). The wear problems that were initially present while testing the first set of gears was not present during the testing of the corrected set of gears. It also reinforces the fact that proper alignment is a very important issue. The mounting surface on some of the gears, a tapered inner diameter, is not located properly with respect to the gear teeth. This is causing the gear to wobble on the test shaft as it rotates and is resulting in various contact patterns, from good to very uneven. If the mounting taper is always properly located so that the gears could maintain correct alignment, more consistent results and longer lives are obtained.  

V-001 Progress 

The Effect of Root Fillet Surface Finish on Bending Fatigue Strength / A-1036   

The original objective of this project was to develop factors to quantify the effect of surface roughness on bending fatigue strength. This original objective was altered to be to determine the effect of various manufacturing processes, which each produce a different root fillet surface roughness, on bending fatigue strength. Tests were conducted using the STF approach (see Background- Test Method), and specimens manufactured as described below (Background Test Variables, Specimen Manufacture) and as shown in Figure 1.  

V-002 Progress Report 

Material Performance, Quality and Residual Stress-Project# A1031-PR-#1         

To compare the engineering performance of selected carburized gear material systems utilizing gear and gear related acceptable "bench" test methods. Bending fatigue, pitting fatigue and toughness properties are to be developed.  

V-003 Progress Report  

Material Performance, Quality and Residual Stress-Project# A1031-PR-#2         

To compare the engineering performance of selected carburized gear material systems utilizing gear and gear related acceptable "bench" test methods. Bending fatigue, pitting fatigue and toughness properties are to be developed.  

V-004 Progress Report  

Material Performance, Quality and Residual Stress Project A1031-PR#-3           

To compare the engineering performance of selected carburized gear material systems utilizing gear and gear related acceptable "bench" test methods. Bending fatigue, pitting fatigue and toughness properties are to be developed.

 V-005 Progress Report  

Material Performance, Quality and Residual Stress Project A1031-PR#-4           

To compare the engineering performance of selected carburized gear material systems utilizing gear and gear related acceptable "bench" test methods. Bending fatigue, pitting fatigue and toughness properties are to be developed.

V-006 Progress Report 

Pitting Fatigue Performance of Ground Surfaces-Project A1033-PR#1 This report presents results of pitting fatigue performance tests conducted with ground surface specimens. Results of pitting fatigue performance tests conducted with shaved specimens (Project #A-1031 data) are presented for comparison purposes. Metallurgical and dimensional characterizations along with characterizations of distressed surfaces are also presented. Results of noise tests are still under analysis and are thus not included herein. Likewise, residual stress and transmission error measurements are not complete and are not presented here.  

V-007 Progress Report 

Preliminary Heat Treat Distortion Study #1 Specimen Evaluation-Project A1032-PR#-2       

To study the influence of non-critical geometric variations on the distortion tendency of the GRI 18T - 6P standard test pinion with the aim of developing a suitable specimen for future studies on distortion in heat treatment.  

V-008 Progress Report 

Preliminary Heat Treat Distortion Study #2 Helical Gear Specimen Evaluation-Project A-1032-PR#3    

This report includes before and after heat treatment dimensional characterizations of helical gears machined from the same size blanks as the GRI standard 30T - 6P mating gear. The blanks were cut from bar stock, some were oriented in the transverse direction, and others were oriented in the longitudinal direction. In addition some specimens were heat treated in a horizontal position while others were oriented in a vertical position. The following codes indicate the appropriate parameters for each helical gear specimen:  

V-009 Progress Report

Material Performance Quality and Residual Stress-Project A-1031-PR#5 

To compare the engineering performance of selected carburized gear material systems utilizing gear and gear related acceptable "bench" test methods. Bending fatigue, pitting fatigue and toughness properties are to be developed.  

V-010 Final Report 

Vibration/Noise Diagnostics of Manufacturing Errors on a 51 Tooth Pinion (A#1014)          

The original report, for which this document is an Addendum, provided a prediction of the rotational-harmonic kinematic-transmission-error contributions ("ghost tone" contributions) caused by manufacturing errors on the tooth working surfaces of a 51 tooth pinion. This pinion was provided by GM to the Pem1 State Applied Research Laboratory Drivetrain Technology Center. The manufacturing errors on the tooth working surfaces were measured in detail at Pem1 State using conventional gear metrology equipment located at the Drivetrain Technology Center (a total of24 scam1ing profile and lead measurements were made on each tooth of the 51 tooth pinion). Using these measurements, and computational algorithms and software developed by the report authors, the rotational harmonic amplitudes of the kinematic transmission error of the pinion were computed, along with diagnostic information pertaining to the causes of these harmonics, as described in the earlier report.  

V-010-A Addendum 

Vibration/Noise Diagnostics of Manufacturing Errors on a 51 Tooth Pinion (A#1014)          

A 51 tooth automotive pinion, supplied by General Motors Powertrain Division, was measured in detail by conventional dedicated gear metrology equipment (M&M Precision Systems equipment). The Fourier series coefficients of the rotational harmonic components of the static (kinematic) transmission error contributions from this pinion, attributable to the measured deviations of the tooth working surfaces from equispaced perfect involute surfaces, were computed. This computation produces the static (kinematic) transmission error contributions that would be generated under a gear loading of sufficient magnitude to produce full contact with the mating gear over the nominal dimensions of the tooth working surfaces. Other than the usual strong low-order rotational harmonics, strong contributions were observed for rotational harmonic numbers, n = 51, 72, 102, and 153. Harmonic numbers n =51, 102, and 153 are the expected tooth-meshing harmonics, but n = 72 would generally be described as a "ghost" harmonic. The deviations of the tooth working surfaces that are the source of the tooth-meshing harmonics n = 51, 102, and 153 are displaced in "three-dimensional" plots, and those that give rise to the "ghost" harmonic, n=72, also are displayed in similar fashion. In particular, the displays for this "ghost" harmonic are believed to illustrate a very powerful diagnostic tool for determining the manufacturing source of such "ghost" harmonics. Rotational harmonic numbers n = 69 (and n = 33) also are observed to be unusually strong in our computation of the tooth-working-surface "error spectrum." Deviations of the tooth working surfaces that are the source of these two harmonics also are displayed in "three-dimensional" plots.  

V-011 Final Report 

The Effect of Lubricant Viscosity, Surface Roughness, and Rolling and Sliding Velocities and EHD Film Thickness and Pitting Fatigue Project A-1034 

The original objective was to determine the influence of several important factors (lubricant viscosity, surface roughness, rolling velocity and sliding velocity) on surface origin pitting fatigue using the RCF approach. This was later expanded to include developing an empirical model to present the results that could ultimately form the basis for a design tool to predict life to surface origin pitting.  

W-001 Final Report 

Contact Patterns Under Various Loads for 30:1 Ratio 4.00" Center Worm Worm Set is Run in              

The objective of this test is to provide data to verify the contact patterns calculated with the finite element program designed by OSU. The gear set was run-in for a period of 100 hours under full load. The bearings were set with axial clearances that ranged from size on size to 0.001" preload. The alignment error between the worm and wheel due to the housing bores were not considered in the calculations. The contact is studied at several loads and will be compared with the calculations. 

W-002 Final Report 

Calculated Contact Patterns Using the Worm Gear Steering Committee Stress Program-Project#A1022               

This document provides the user instructions for installing the program on their computer. The detail of the input data is provided for each segment of the program as well as guide lines for certain values that are applicable to the operation of the program. Several tips have been learned from the users and the list of the tips will grow. A sample problem is worked out for the default settings and copies of the output are provided. It would be wise for the new user to input the sample problem and go through the exercise to work out the contact and bending stresses to make sure the program is properly installed on their machines.  

W-003 Final Report 

Scoring Project No.1 1.75" Tester 10:1 Ratio C907 Bronze Wheel     

The objective of this project was to run the 1. 75" CD worm gear tester with a 10:1 ratio at several temperatures and various loads to establish the load at which the gear set will score. The material tested is a C907 bronze worm wheel and a carburized and ground 8620 worm.  

W-004 Final Report 

Scoring Project No.6 4.00" Tester 30:1 Ratio C907 Bronze Wheel     

The objective of this project was to run the 4. 00" CD worm gear tester with a 30:1 ratio at several temperatures and various loads to establish the load at which the gear set will score. The material tested is a C907 bronze worm wheel and a carburized and ground worm made from 8620 steel. 

W-005 Final Report 

Scoring Project No.2 1.75" Tester 10:1 Ratio C673 Bronze Wheel-Project A1025                 

The objective of this project was to run the 1. 75" CD worm gear tester with a 10:1 ratio at several temperatures and various loads to establish the load at which the gear set will score. The material tested is a C673 bronze worm wheel and a carburized and ground worm made from 8620 steel.  

W-006 Final Report 

Comparison of Dimensions of Worm and Worm Wheels 

In order to establish a standardized set of worms and worm wheels, each company was asked to submit drawings for the 10:1 and 30:1 ratios for gear centers of 1 3/4" and 4". The submitted data is tabulated in the following tables.  

W-007 Report 

Fractography of Single Tooth Bending Fatigue Samples-Project A1023 

Four fractured specimens from a Single Tooth Bending Fatigue test were supplied for fractography. The specimens, two each, represent centrifugally cast tin bronze, C90700, and wrought manganese bronze, C67300 material. The specimens are identified in Table 1 along with data obtained from Ref. 1. Macrophotography in this reference had shown a different fracture surface texture for the two materials. The purpose of this examination was to further detail fracture differences and establish the fracture origin.  

W-008 Final Report 

Procedure of Pitting Project 6 Determination of Relation Between Load, Degree of Pitting and Time of Operation 4.00" CD Tester 30:1 Nominal Ratio (Actual 30:1) C907 Material-Project#A1025 

The procedure describes the method that will be followed in determining the relation between torque load, degree of pitting and time. A 4.00" center gear drive with a 30:1 ratio will be tested at 1750 rpm. The load will be varied and the degree of pitting will be studied in relation to time.  

W-009 Final Report 

Procedure of Pitting Project 2 Determination of Relation Between Load, Degree of Pitting and Time Operation 1.75" CD Tester 10:1 Ratio C673 Material Project#A1025

The procedure describes the method that will be followed in determining the relation between torque load, degree of pitting and time. A 1. 75" center gear drive with a 10:1 ratio will be tested at 1750 rpm. The load will be varied and the degree of pitting will be studied in relation to time.  

W-012 Final Report 

Procedure for Efficiency Project 1-1.75" Center Worm 10:1 Nominal Ratio (Actual 10.000) 

This procedure describes the method that will be followed in determining the gear drive efficiency under the following conditions.

  1. When oil is sprayed to the mesh and there is a "dry" sump.
  2. When oil is not sprayed to the mesh and the worm dips in a bath of oil. 

This test will be run for the 10:1 ratio of the 1.75" CD worm tester and in conjunction with pitting project #1.  

W-014 Final Report 

Procedure for Test 2 Determination of Relation Between Load, Degree of Pitting and Time of Operation

The procedure describes the method that will be followed in determining the relation between torque load, degree of pitting and time. A 1.75" center gear drive with a 10:1 ratio will be tested at 1750 rpm. The load will be varied and the degree of pitting will be studied in relation to time. The same test will be run in both testers to verify results and increase the reliability of the results.  

W-015 Final Report

Procedure for Scoring Project 6 Determination of Scoring Loads 4" Center Worm-30:1 Nominal Ratio (Actual 30.000) Project #A1025 

This procedure describes the method that will be followed in determining a scoring torque load for a 10:1 nominal ratio (Actual Ratio 30.000) of a 4.00" center gear drive running at 1750 rpm. The load is to be determined at two different temperatures of sump oil. The test will be run in only one tester. Additional tests will be required to verify results and increase the reliability of the data.  

W-016 Final Report 

Procedure for Scoring Project 4 Determination of Scoring Loads 1.75" Center Worm-30:1 Nominal Ratio (Actual 30.00) (C 673 Materials) 

This procedure describes the method that will be followed in determining a scoring torque load for a 30:1 nominal ratio (Actual Ratio 30.000) of a 1. 75" center gear drive running at 1750 rpm. The Material of the wheel is C673 bronze. The load is to be determined at two different temperatures of sump oil. The test will be run in only one tester. Additional tests will be required to verify results and increase the reliability of the data.

W-017 Final Report 

Procedure for Scoring Project 5 Determination of Scoring Loads 4" Center Worm-10:1 Nominal Ratio (Actual 9.667) 

This procedure describes the method that will be followed in determining a scoring torque load for a 10:1 nominal ratio (Actual Ratio 9.667) of a 4.00" center gear drive running at 1750 rpm. The load is to be determined at two different temperatures of sump oil. The test will be run in only one tester. Additional tests will be required to verify results and increase the reliability of the data.  

W-018 Final Report  

Procedure for Scoring Project 3 Determination of Scoring Loads 1.75" Center Worm-30:1 Nominal Ratio (Actual 30.00) (C907) Project#A1025 

This procedure describes the method that will be followed in determining a scoring torque load for a 30:1 nominal ratio (Actual Ratio 30.000) of a 1.75" center gear drive running at 1750 rpm. The load is to be determined at two different temperatures of sump oil. The test will be run in only one tester. Additional tests will be required to verify results and increase the reliability of the data.  

W-019 Final Report 

Procedure for Scoring Project 2 Determination of Scoring Loads 1.75" Center Worm-10:1 Nominal Ratio (Actual 10.00) (C 673 Material) 

This procedure describes the method that will be followed in determining a scoring torque load for a 10:1 nominal ratio (Actual Ratio 10. 000) of a 1.75" center gear drive running at 1750 rpm. The Material of the wheel is C673 bronze. The load is to be determined at two different temperatures of sump oil. The test will be run in only one tester. Additional tests will be required to verify results and increase the reliability of the data.  

W-021 Final Report 

Scoring Project No.5 4.00" Worm Tester 9.667 Ratio C907 Bronze Wheel 

The objective of this project was to run the 4. 00" CD worm gear tester with a 9.667 ratio at several temperatures and various loads to establish the load at which the gear set will score. The material tested is a C907 bronze worm wheel and a carburized and ground 8620 worm.  

W-023 Final Report 

Pitting Test Project 5 30:1, 4.00" Center Distance Tester Stopped After 368,000 Gear Cycles-Project#A1022        

The objective of this test is to provide data to determine the rate at which a worm wheel (gear) will pit when operating at a load equal to 200% of its rating.

W-025 Progress Report 

Scoring Project No.2 1.75" Tester 10:1 Ratio C673 Bronze Wheel-PR#-7

The objective of this project was to run the 1. 75" CD worm gear tester with a 10:1 ratio at several temperatures and various loads to establish the load at which the gear set will score. The material tested is a C673 bronze worm wheel and a carburized and ground worm made from 8620 steel.  

W-027 Progress Report 

Scoring Project No.4 1.75" Tester 30:1 Ratio C673 Bronze Wheel Project #A1025-PR#9 

1.75" Tester, 30:1 Ratio, Sump Temperature 200F, Radium for Backlash Measurements 4.75", Mean Diameter of Wheel 2.788", Gear 6, Side 1, I Side, Test #1, C673 Bronze, Input Speed 1750

W-028 Progress Report 

Scoring Project No.5 4.00" Worm Tester 10:1 Ratio C907 Bronze Wheel            

The objective of this project was to run the 4" CD worm gear with a 9. 677: 1 ratio at several temperatures and various loads to establish the load at which the gear set will score.  

W-029 Progress Report 

Scoring Project No.6 4.00" Tester 30:1 Ratio C907 Bronze Wheel Project A1025-PR#-8       

The objective of this project was to run the 4. 00" CD worm gear tester with a 30:1 ratio at several temperatures and various loads to establish the load at which the gear set will score. The material tested is a C907 bronze worm wheel and a carburized and ground worm made from 8620 steel.  

W-030 Progress Report 

Progress Report 3 Pitting Test Project 5.1 30:1, 4.00" Center Distance 6.06 Million Cycles 

This report contains the data from the test and includes the following.3.1 Tabulation of Pitted Surface Area - Photos will be included in the FinalReport.3.2 Surface Finish Measurements for Each Inspection Period3.3 Backlash Measurements3.4 Gear Drive Efficiency  

W-031 Progress Report 

Break-In Test 1.75" Center Distance 10:1 Ratio C907 Bronze Wheel-Project#A1025-PR#1   

This break-in test allowed GRI to become familiar with all of the equipment for the 1.75" tester. The lubrication system was tested at several temperatures, and the data logging program was tested and modified during the test. The gears were operated 15% above the rating calculated using per AGMA 6034A87. The original gear rating calculation used an inappropriate value of effective face width. The efficiency rose from 76% to 85.7%, and at shut down bronze pick-up was noted on the worm, even though there was no drop-off in efficiency.  

W-032 Progress Report

Progress Report 2 Contact Analysis-Worm Gears Work Conducted at The Ohio State University          

DEFINITION OF WORM GEAR GEOMETRYSTEPS: THE TOOL USED IS A WORM SHAPED HOB FOP WHICH THE THE NORMAL SECTION IS DEFINED.

W-033 Progress Report 

Progress Report 1- Contact Analysis-Worm Gear Work Conducted at The Ohio State Univerisity        

PROJECT SECTIONSDEFINING THE WORM GEOMETRY USING TRANSFORMATIONS, GIVEN THE TOOL GEOMETRY AND THE MANUFACTURING SETUP. 2) DEFINING THE WORM GEAR GEOMETRY USING THE WORM SHAPED HOB AND TRANSFORMATIONS. 3) GENERATING THE MESH AND PERFORMING THE CONTACT ANALYSIS USING FINITE QUASIPRISMATIC ELEMENTS.  

W-034 Progress Report 

Progress Report 3-Contact Analysis-Worm Gears Work Conducted at The Ohio State University         

Models describing their behavior under load, external, prespecified constraints on their motion, and the locations in space of the various constraints, external, prespecified loads, and friction laws 

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