1、AGMA915-3-A99AGMA INFORMATION SHEET(This Information Sheet is NOT an AGMA Standard)AGMA 915- 3- A99ISO/TR 10064-3:1996 (MOD)AMERICAN GEAR MANUFACTURERS ASSOCIATIONInspection Practices - Gear Blanks, ShaftCenter Distance and ParallelismiiInspection Practices - Gear Blanks, Shaft Center Distance and P
2、arallelismAGMA 915-3-A99ISO/TR 10064-3:1996 (MOD)CAUTION NOTICE: AGMA technical publications are subject to constant improvement,revision, or withdrawal as dictated by experience. Any person who refers to any AGMAtechnical publication should be sure that the publication is the latest available from
3、the As-sociation on the subject matter.Tables or other self-supporting sections may be quoted or extracted. Credit lines shouldread: Extracted from AGMA 915-3-A99, Inspection Practices - Gear Blanks, Shaft Cen-ter Distance and Parallelism, with the permission of the publisher, the American GearManuf
4、acturers Association, 1500 King Street, Suite 201, Alexandria, Virginia 22314.Approved May 20, 1999ABSTRACTThis information sheet provides the description of recommended numerical values relating to the inspection ofgear blanks, shaft center distance and parallelism of shaft axes.Published byAmerica
5、n Gear Manufacturers Association1500 King Street, Suite 201, Alexandria, Virginia 22314Copyright 1999 by American Gear Manufacturers AssociationAll rights reserved.No part of this publication may be reproduced in any form, in an electronicretrieval system or otherwise, without prior written permissi
6、on of the publisher.Printed in the United States of AmericaISBN: 1-55589-738-XAmericanGearManufacturersAssociationAGMA 915- 3- A99AMERICAN GEAR MANUFACTURERS ASSOCIATIONiiiContentsPageForeword iv.1 Scope 1.2 References 13 Symbols and definitions 14 Accuracy of gear blanks 2.5 Center distance and par
7、allelism of axes 6Tables1 Symbols and terms 12 Form tolerances for datum and mounting surfaces 4.3 Tolerances on runout of mounting surfaces 5.Figures1 Datum axis defined by two “short” datum surfaces 3.2 Datum axis defined by one “long” datum surface 33 Datum axis defined by one cylindrical surface
8、 and one end-face 3.4 Internal ring gear datum axis defined by cylindrical surface and end-face 4.5 Center holes as manufacturing surfaces 46 High quality gear with reference bands 5.7 Shaft parallelism deviations 7.Bibliography 9.AGMA 915- 3- A99 AMERICAN GEAR MANUFACTURERS ASSOCIATIONivForewordThe
9、 foreword, footnotes and annexes, if any, in this document are provided forinformational purposes only and are not to be construed as a part of AGMA InformationSheet 915-3-A99, Inspection Practices - Gear Blanks, Shaft Center Distance andParallelism.In the course of revising ANSI/AGMA 2000-A88, Gear
10、 Classification and InspectionHandbook - Tolerances and Measuring Methods for Unassembled Spur and Helical Gears,the AGMA Inspection Handbook Committee agreed that the ISO information from ISO/TR10064-3:1996, relative to the inspection of gear blanks, shaft center distance andparallelism of axes sho
11、uld be published under separate cover as an AGMA InformationSheet.For the general replacement of ANSI/AGMA 2000-A88, a system of documents as listedbelow, together with this information sheet, has been established:- AGMA 915-1-AXX, Inspection Practices for Cylindrical Gears - TangentialMeasurements-
12、 AGMA 915-2-AXX, Inspection Practices for Cylindrical Gears - RadialMeasurements- AGMA 915-4-AXX, Inspection Practices - Recommendations Relative to SurfaceTexture- AGMA 2015-1-AXX, Accuracy Classification System for Cylindrical Gears -Tangential Measurements- AGMA 2015-2-AXX, Accuracy Classificatio
13、n System for Cylindrical Gears - RadialMeasurementsISO/TR 10064-3:1996 was prepared by ISO Technical Committee TC 60, Gears.AGMA 915-3-A99 is not identical to ISO/TR 10064-3:1996, Cylindrical gears - Code ofinspection practice - Part 3: Recommendations relative to gear blanks, shaft centredistance a
14、nd parallelism of axes. It was agreed to be sent directly to committee comment inMay of 1998, after project approval by the TDEC. The Committee, during commentresolution, made the following changes to the original ISO Technical Report:- Addition of reference to ISO 1101 in clause 4;- Changed the wor
15、ding of the first paragraph of 4.3;- Revised figure 4, reversing the datum and runout callouts;- Changed 4.11 and figure 5, replacing datum surfaces with reference bands.The Committee decided that these changes were sufficient enough to require an additionalcommittee comment in February, 1999.It was
16、 approved by the AGMA Technical Division Executive Committee on May 20, 1999.Suggestions for improvement of this standard will be welcome. They should be sent to theAmerican Gear Manufacturers Association, 1500 King Street, Suite 201, Alexandria,Virginia 22314.AGMA 915- 3- A99AMERICAN GEAR MANUFACTU
17、RERS ASSOCIATIONvPERSONNEL of the AGMA Inspection and Handbook CommitteeChairman Classification Section: E. Lawson Mahr CorporationChairman Measurement Section: R.E. Smith R. E. Smith these surfacesshould be defined to limits significantly tighterthan those of the individual gear teeth;- the relativ
18、e positions of the surfaces; ingeneral, the greater the distance spanned, inproportion to the reference diameter of the teeth,the more relaxed can be the tolerance.The accuracy of the surfaces must be specified onthe component drawings.AGMA 915- 3- A99 AMERICAN GEAR MANUFACTURERS ASSOCIATION4- B -fl
19、atness tol.- A -runout tol. Arunout tol. AMountingSurfaceMountingSurfaceFigure 4 - Internal ring gear datum axis definedby cylindrical surface and end- faceThe form tolerances on all datum surfaces shouldnot exceed the values specified in table 2. Thetolerance should be reduced to the minimum.4.5 Fo
20、rm tolerances of functional andmanufacturing mounting surfacesThe form tolerances of the functional mountingsurfaces should not exceed the values specified intable 2. When separate manufacturing mountingsurfaces are used, similar limits will need to beapplied.4.6 Runout tolerances of functional axis
21、This clause is not relevant if the functional mountingsurfaces have been chosen as the datum surfaces.When the datum axis does not coincide with thefunctional axis then the runout(s) of the functionalmounting surface(s) relative to the datum axis mustbe controlled on the drawing. The runout toleranc
22、esshould not exceed the values specified in table 3.runout tol. A-B runout tol.- A - - B -A-BFigure 5 - Center holes as manufacturing surfacesTable 2 - Form tolerances for datum and mounting surfacesTolerance featureAxis defined by Circularity Cylindricity FlatnessTwo “short” cylindrical orconical d
23、atum surfaces0.04 (L/b) For 0.1 Fpwhichever is leastOne long cylindrical orconical datum surface0.04(L/b) For 0.1 Fpwhichever is leastOne short cylindrical andone end-face0.06 Fp0.06 (Dd/b) FNOTE:The gear blank tolerances should be reduced to the minimum which can be economically manufactured.AGMA 9
24、15- 3- A99AMERICAN GEAR MANUFACTURERS ASSOCIATION5Table 3 - Tolerances on runout of mounting surfacesRunout (total indicated range)Axis defined by Radial AxialCylindrical or conical datum surface only 0.15 (L/b) For 0.3 Fp(whichever is greater)- -One cylindrical datum surface and one end datum face
25、0.3 Fp0.2 (Dd/b) FNOTE:The gear blank tolerances should be reduced to the minimum which can be economically manufactured.4.7 Mounting surfaces used during gear cuttingand inspectionTo manufacture the teeth to the tolerances specifiedand measure their resulting deviations with sufficientaccuracy, it
26、is essential to mount the gear for bothmanufacture and inspection so that its actual axis ofrotation during both processes corresponds asclosely as possible to the datum axis defined on thegear drawing.Unless the surfaces which are to be used to mountthe gear during manufacture or inspection are tho
27、seused as datums for the datum axis, then these toomust be controlled relative to the datum axis. Thevalues shown in table 3 are appropriate for use astolerances for these surfaces. For maximumprecision, a “highspot” giving the position andamount of the high point of runout can be markednear to datu
28、m surfaces and duplicated as appropri-ate at each step in the manufacture of high qualitygears.When strict process control during manufacturing ofthe gear blank, accurate expanding mandrels forcentering the blank, a fixture for supporting the blankwith appropriately limited runout and a high quality
29、gear cutting machine are used, the position of thegear blank on the gear cutting machine has to bechecked only for the first gear of a series. Thisprocedure is typically used in mass production ofgears on gear cutting machines.For high quality gears, special datum surfaces haveto be provided (see fi
30、gure 6). For very high qualitygears, the gear has to be mounted on the shaft, inwhich case the shaft journals can be used as datumsurfaces.runout tol. Acyl. tol.flatness tol.circ. tol.functional mountingsurface = manufacturingmounting surfacereference bandsA- A -manufacturingmounting surfacerunout t
31、ol. Arunout tol.Figure 6 - High quality gear with reference bandsAGMA 915- 3- A99 AMERICAN GEAR MANUFACTURERS ASSOCIATION64.8 Tip cylinderThe tolerance on the tip diameter should be chosenby the designer to ensure that the minimum designcontact ratio is achieved together with adequate rootclearance.
32、 If the tip cylinder of the blank is to be usedas a datum surface, however, while the above valuemay still be applied as a size tolerance, the formtolerance should not exceed the appropriate valuefrom table 2.4.9 Tolerance build upThe tolerances of table 3 are applicable when thefunctional axis coin
33、cides with the datum axis or canbe toleranced directly from it. When this is not thecase, then a tolerance chain exists between the two.It will then be necessary to reduce the individualtolerances to values smaller than those given in thetables 2 and 3. The degree of reduction will dependon the spec
34、ific arrangement, but in general will beapproximately proportional to the square root of n,where n is the number of links in the chain.For gears of the highest accuracy (for example, ISO1328, Part 1, accuracy grade 4 or better), it willnormally be necessary to assemble the gears ontheir shafts befor
35、e finishing the teeth. However,where this is not possible, the use of runoutmeasurements on datum surfaces after assemblymay be used to demonstrate that the required overallgear accuracy is actually being achieved. Thismeasurement detects errors caused not only by thecombined runout of all the funct
36、ional gear mountingsurfaces, but also those caused by runout of anybearing rings fitted to the shaft.4.10 Mounting surfaces for other gearsA shaft with an integral pinion will often have asection on which a gear wheel is to be mounted. Thetolerances of the mounting surface should beselected by prope
37、r consideration of the qualityrequirements of the teeth of the wheel to be mountedon it. It will usually be appropriate to specifyallowable runouts relative to the already defineddatum axis.4.11 Reference bandsReference bands are axial or radial surfaces that aremachined true with the datum axes of
38、gear blanks(see figure 6).These can be checked while mounted on themachine that finishes the teeth, while mounted onthe inspection machine or while mounted in the finalapplication. For even more accurate work, thereference bands are checked and marked for theamount and location of the high point of
39、runout. Thishigh point and amount are duplicated at every step inthe process to control very high quality gears.Many gear applications are, however, produced insmall quantities. In this case the position of the gearon the gear cutting machine has to be checkedbefore machining. Whether every blank or
40、 someportion has to be checked depends upon theexperience of the gear manufacturer. For mediumaccuracy grade gears, part of the tip cylinder can beused as a radial reference surface, while the axialposition can be checked using the mounting face forgear cutting.5 Center distance and parallelism of a
41、xesThe gear designer has to select the proper toler-ances for deviations in both the center distance, a,and the parallelism of axes. Tolerances should bechosen so as to ensure that backlash and alignmentof the meshing gear teeth are in accordance with theapplication requirements. Provision for the a
42、ssem-bly adjustment of bearing position may offer what isprobably the most effective technical solution to thedemands of high accuracy. However, the costs mayin many instances be unacceptably high.5.1 Center distance allowancesThe center distance tolerance is the allowabledeviation specified by the
43、designer. The nominalcenter distance is determined by considerations ofminimum backlash and interference between thetips of the teeth of each gear member with thenon-involute profile at the root of its mate.In the case where the gears carry load in only onedirection, with infrequent reversals, the c
44、ontrol ofmaximum backlash is not a critical consideration andthe allowance in center distance can be governed byconsideration of contact ratio.When backlash must be closely controlled, as inmotion control gears, or when the load on the teethreverses, the tolerance for center distance must becarefull
45、y studied, taking into account the effect of: deflections of shafts, housings and bearings; misalignment of gear axes due to housingdeviations and bearing clearances; skew of gear axes due to housing deviationsand bearing clearances;AGMA 915- 3- A99AMERICAN GEAR MANUFACTURERS ASSOCIATION7 mounting e
46、rrors; bearing runouts; temperature effects (a function of tempera-ture difference between housing and gear ele-ments, center distance and material difference); centrifugal growth of rotating elements; other factors, such as allowance for contami-nation of lubricant and swelling of non-metallicgear
47、materials.The recommendations in ISO/TR 10064-2 withregard to tooth thickness tolerances and backlashshould be followed when deciding on the tolerancefor all dimensions which affect the deviation inbacklash.The selection of center distance tolerance for highspeed drives involves other considerations
48、 whichare beyond the scope of this information sheet.In the case of gear transmissions in which one geardrives several other gear pairs (or vice versa), e.g., inthe case of epicyclic gear transmissions with severalplanet gears, or in the case of transfer gear boxes orpower take-off gears, it may be
49、necessary to restrictthe shaft center distance allowances in order toachieve proper load sharing and correct operatingconditions in all of the meshes. These conditionsrequire detailed study of operating and manufactur-ing restraints which are beyond the scope of thisinformation sheet.5.2 Shaft parallelism tolerancesSince the effect of a shaft parallelism deviationdepends on its vectorial direction, different specifica-tions have been established for the “in-planedeviation”, f, and for the “out-of-plan
