适用范围：There is no abstract currently available for this document

适用范围：To clarify the effect of Titanium Nitride (TIN) coatings on thefailure resistance and frictional characteristic and compare thiseffect with that produced by the heat treated coatings, two rollertests have been made and the stress resulting from the combinationof the Hertzian stress field and frictional force field on andbelow zhe contacting surface as well as the flash temperature risewere calculated. The failure resistance of the TiN-coated rollerpair was greater than that of the heat treated roller pair. Themechanism of failure resistance can be explained by the shearingstress (Hertzian stress + frictional force) acting on the contactsurface. This stress modifies the structure in the vicinity belowthe TiN layer which is then sheared in the wear trackdirection.

适用范围：FOREWORD This system for the design of spiral bevel gears is a revisionof the original Gleason System adopted by the AGMA and revised in1942. Changes and additions are as following: a) Adoption of 20 degrees as the basic pressure angle, insteadof the former 141/2 degrees; b) Angular gear design data; c) Revision of tooth thickness calculations to giveapproximately equal stress in gear and pinion; d) Replacement ofthe table for gear addendums by the formula for the same. The textdescribes the general basis of the system and shows thecalculations used to obtain the tooth proportions and blankdimensions.

适用范围：Stress Analysis of Gear Drives Based on Boundary Element MethodDaniele Vecchiato, University of Illinois at Chicago The stressanalysis is performed as a part of TCA (Tooth Contact Analysis) fora gear drive. Unlike the existing approaches, the proposed one doesnot require application of commercial codes (like ANSYS or ABAQUS)for derivation of contact model and determination of contact andbending stresses. The contacting model is derived directly by usingthe equations of tooth surfaces determined analytically. Theboundary element approach allows to reduce substantially the numberof nodes of the model. Determination of stresses caused by appliedload is obtained directly for the applied contacting model for anyposition of meshing. The developed approach is illustrated bystress analysis of helical gears with modified geometry.

适用范围：Gears with an asymmetric involute gear tooth form were analyzedto determine their bending and contact stresses relative tosymmetric involute gear tooth designs which are representative ofhelicopter main drive gears. Asymmetric and baseline (symmetric)toothed gear test specimens were designed, fabricated and tested toexperimentally determine their single-tooth bending fatiguestrength and scuffing resistance. Also, gears with an analyticallyoptimized root fillet form were tested to determine theirsingle-tooth bending fatigue characteristics relative to baselinespecimens with a circular root fillet form. Test resultsdemonstrated higher bending fatigue strength for both theasymmetric tooth form and optimized fillet form compared tobaseline designs. Scuffing resistance was significantly increasedfor the asymmetric tooth form compared to a conventional symmetricinvolute tooth design.

适用范围：The load distribution measurement of gear teeth and thedetermination of the face load factor for contactstressKHβ are of fundamental importance for thegear manufacturing industry. The factorKHß is ameasure for theuniformity of the load distribution along the face width. Thecloser this factor is to one the more uniform is the loaddistributed along the face width. During the design phase thisfactor is determined with the help of approximation equations aswell as finite element analysis and is used to dimension the flankmodifications. In addition KHß is used in thelifetime calculations according to DIN 3990 and ISO 6336 requiredby the certification societies. In the testing phase this factor isexperimentally determined by strain measurements of tooth filletsin order to verify the load distribution calculations and thesuitability of the used modifications. For spur gears with no helix angle the interpretation of themeasurements to a face load factor is intuitively easy. For helicalgears, more frequently used in big gearboxes, the determination ofthe factor gets tougher. The line of contact of these gears runsinclined over the face width of the tooth flanks. In this contextthe question arises whether the face load factor is evaluated alongthe face width or along the path of contact. The evaluation of the measured values and the interpretation toa face load factor is a complex challenge and is not standardized.Alarge number of publications make suggestions; however, thesesuggestions differ to a large degree. The standardisation of theload distribution evaluation and a uniform definition ofKHß for helical gears enable a safer design forthemanufacturers and an easier comparability of the results for thecustomers. The paper compares the different suggestions to theKHß definition and will derive a suitable definition forthe calculation methods in DIN 3990 and ISO 6336.

适用范围：A new method is described for calculating the efficiency ofplanetary gear trains. An example, showing how the method can beapplied to the case of a fixed differential gear train isgiven.

适用范围：There is no abstract currently available for this document

适用范围：This part of ANSI/AGMA 2015 establishes an accuracy grade systemrelevant to tangential measurements on flanks of individualcylindrical involute gears. It specifies definitions for gear tooth accuracy terms, thestructure of the gear accuracy grade system, and allowablevalues. It is strongly recommended that any user of this part ofANSI/AGMA 2015 be very familiar with the methods and proceduresoutlined in AGMA 915--1--A02. Use of techniques other than those ofAGMA 915--1--A02 combined with the limits described in this part ofANSI/AGMA 2015 may not be suitable. This standard provides the gear manufacturer and the gear buyerwith a mutually advantageous reference for uniform tolerances. Tenaccuracy grades are defined in this standard, numbered A2 throughA11, in order of decreasing precision.

适用范围：Profile corrections on gears are a commonly used method toreduce transmission error, contact shock, and scoring risk. Thereare different types of profile corrections. It is a known fact,that the type of profile correction used will have a stronginfluence on the resulting transmission error. The degree of thisinfluence may be determined by calculating tooth loading duringmesh. The current method for this calculation is very complicatedand time consuming; however, a new approach has been developedwhich could reduce the calculation time. This approach uses an algorithm which includes the conventionalmethod for calculating tooth stiffness in regards to bending andshearing deformation, flattening due to Hertzian pressure, andtilting of the tooth in the gear body. The new method was tested bycomparing its results with FEM and LVR. This paper illustrates and discusses the results of this study.Furthermore the maximum local power losses are compared with thescoring safety calculated following the flash temperature criteriaof AGMA925 and DIN 3990.

适用范围：There is no abstract currently available for this document

适用范围：This document specifies procedures and requirements for the detection and classification of localized overheating on ground surfaces by chemical etch methods. The process described in this document is typically used on ground surfaces; however, it is also useful for the detection of surface anomalies that result from post-heat treatment machining such as hard turning, milling and edge breaking (deburring) processes. Surface metallurgical anomalies caused by carburization or decarburization are also readily detectable with this process. Some methods which have been used in the past are no longer recommended. Specifications are intended to be changed to use the methods in this document. These etching methods are more sensitive to changes in surface hardness than most hardness testing methods. This document applies to steel parts such as gears, shafts, splines and bearings. It is not applicable to nitrided parts and stainless steels. NOTE This process, although at times called "nital etch", is not intended to be confused with other processes also known as "nital etch". The surface temper etch procedure is performed after grinding and before additional finishing operations such as superfinishing, shot peening and honing.

适用范围：Molecular decomposition process (MDP) is an anodic dissolutionprocess (electrochemical) whereby the work piece is the anode andthe grinding wheel is the cathode. Specific controls of electrical,mechanical and chemical actions are applied to enable the MDPsystem to remove stock without mechanical or thermal deformation.This process enables stock removal rates in sample materials suchas nickel and titanium alloys to occur at rates more aggressivelythan conventional creep-feed grinding. Migrating the system toemploy super-abrasives greatly increases the rate of stock removal.The anodic process implemented permits the perishable wheelgeometry to be preserved which equates to longer perishable lifeand dimensional stability, which enables longer production runswith consistent dimensional results. MDP has proven to produce gearinvolute geometries from "as supplied" blanks with minimal stockfor finishing. Roughing and finishing of forms in full hardened4140 tool steel yielding an MDP produced product with surfaces toless than 1 Ra µin while maintaining dimensional stability toachieve a 1.67 CPK. The MDP system removes large or small amountsof stock while providing a safe work environment for operators andthe environment.

适用范围：The purpose of the paper is to discuss the development of smartgearbox technology using real-world application testing and dataanalysis, while keeping in mind the needs of the end-user in orderto assist them in developing their monitoring system. It willdescribe the previous maintenance methodologies used and how theever-changing needs of the industry require them to introduce aproactive maintenance system rather than a typically reactiveapproach. It will explain the testing performed at the user'sfacility which helps gather the data that cannot be duplicated on atest system. It will then explain how after all the data isreviewed and analyzed, it is then relayed back to the user so itcan be implemented by their maintenance departments. It willdiscuss reviewing the data of a failed gearbox during testing andhow looking at the data can give a glimpse of how to understandwhat the data is telling us in regards to the end goal of theproject ISBN: 978-1-61481-099-5Pages: 11 Author: A.J. Soder

适用范围：This paper will discuss a system from a point of view of "whathappens when a failure occurs". Gears were manufactured with seededfaults to simulate unexpected defects in various portions of thehighly loaded gear tooth and rim sections. Crack propagation wasmonitored by measuring effective mesh stiffness and applied loadingto provide both warning of an impending failure and a reasonableperiod operation after initiation of a failure for a safelanding.

适用范围：There is no abstract currently available for this document

适用范围：There is no abstract currently available for this document

适用范围：There is no abstract currently available for this document

适用范围：A super finishing study was designed and conducted for bendingfatigue. AMS6265 parts were created: with and without superfinishing. Bending fatigue was tested using Single Tooth Fatigue(STF) and RR Moore rotating beam methods. The STF parts weredesigned with tooth geometry replicating a spiral bevel gearsection. Two lots of material were processed. Thus, a minimum oftwo carburized and hardened lots, two shot peen batches and twosuper finishing cycles (if applicable) were processed per samplegroup. A detailed metallurgical evaluation was performed tocharacterize the material and compare to actual spiral bevel gears.Analysis of the test data concluded no statistical difference inbending fatigue strength.

适用范围：Isotropic superfinishing was applied to the third stage spurbull gear and mating pinions along with the second stage bevelgears of a Sikorsky S-76C+ main gearbox. The gearbox completed thestandard Acceptance Test Procedure (ATP) and a 200-hour endurancetest. During these tests noise, vibration, and operatingtemperatures were shown to be significantly reduced due to lowerfriction. A description of the tests, performance data and ageneral description of the process is presented.