ARMY MIL-HDBK-404-1990 CALCULATION AND DESIGN OF MASTER GEARS《主齿轮的计算和设计》.pdf

1、Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-, MIL-HDBK-409 lC m 7799970 0056Ll58 I m MIL-HDBK-404 FOREWORD 1. This military handbook is approved for use by the U.S. Amy Tank-Automotive Command, Department of the Army, and is available for use by

2、all Departments and Agencies of the Department of Defense. 2. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to U.S. Army Tank-Automotive Command; AWN: AMSTA-GDS, Warren, MI 48397-5000; by using th

3、e self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. 3. This handbook provides a convenient means for implementing uniform design practices and calculation methods for master gears used in the final acceptance of Tank-Autom

4、otive component part gears. textbook for specialized programs of instruction for centralized or local training, and as a preparedness measure for accelerated training of product assurance personnel during mobilization. It also serves as a ii c Provided by IHSNot for ResaleNo reproduction or networki

5、ng permitted without license from IHS-,-,-4 5 5 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. MIL-HDBK-qOq QC M 9949770 0056460 T M MIL-HDBK-404 CONTENTS PARAGRAF“ CHAPTER 4 MASTER GEAR DRAWING 4.1 4.2 4.3 4.4 4.5 4.6 4.7 5.1 5.2 5.3 5.3.1 5.3.

6、2 5.3.3 . 5.3.4 5.4 5.5 5.6 5.6.1 5.6.2 5.6.3 5.6.4 5.6.5 5.6.6 5.6.7 5.6.8 5.7 5.7.1 5.7.2 5.7.3 5.7.4 5.7.5 5.8 5.9 6.1 6.2 6.3 6.4 General Interpretation Master gear drawing . Curve plotting Bore diameter . Holes to drive chart recorder . Planeofdata . CHAPTER 5 BEVEL GEAR INSPECTION General . In

7、spection procedure . Testing bevel gears Tooth shapes . Running test . Tooth bearing . Bevel gear testing machines Testing practice . Final test Bevel gear measuring instruments . Composite error test . Spacing errors or tooth defects Tooth spacing tester . Concentricity tester . Special checking fi

8、xtures . Checking of tooth profile . and hypoid bevel gears . Runout of a bevel gear Pitch variation Maximum index error Required tooth contact Backlash Bevel gear mounting Running test Trueness errors Runout Recognized errors in straight. spiral. zero1 CHAPTER 6 1NSPECTION.OF WORM GEARING General .

9、 . worms . Worm wheels Master worm . . throated) . . PAGE 11 11 11 11 11 11 11 12 12 12 12 12 12 12 13 13 13 13 14 14 14 14 14 15 15 15 15 15 15 15 15 16 16 17 17 17 17 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo r

10、eproduction or networking permitted without license from IHS-,-,-FIGURES 11. 12. 13. 14. APPENDIX PARTIAL LISTING OF GEAR INSPECTION EQUIPMENT SUPPLIERS . . 56 MIL-HDBK-404 OC 7777770 00564b2 3 MIL-HDBK-404 CONTENTS - PAGE Form D Design calculation sheets for Form E Design calculation sheets for For

11、m F Design calculation sheets for Form G Design calculation sheets for helical master gear (Ext. gear - Ext. mate) . . 40 helical master gear (Int. gear - Ext. mate) . . 44 helical master gear (Ext. gear - Int. mate) . . 48 helical master gear (Ext. gear - Ext. mate with askew axes) . . . . . . . .

12、. . . . . . . 52 I vi Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-404 dC 7777770 0056463 5 W MIL-HDBK-404 CHAPTER 1 INTRODUCTION 1.1. Purpose. instructional aid to the gage designer who is unfamiliar with both the theory and design of ma

13、ster gears. specifications for these master gears which are consistent and reliable. The purpose of this handbook is primarily for use as an It also provides a means of producing 1.2. Scope. This handbook includes the instructions for the design, development, and calculation and for specifying requi

14、rements of master gears for the functional inspection of external and internal, spur and helical, parallel and askew axis, involute profile gears. Materials pertinent to the inspection of bevel and worm gears and related inspection equipment are also covered. 1.3 Application. This handbook is applic

15、able to DOD product assurance personnel engaged in the preparation, maintenance and interpretation of final acceptance inspection equipment designs of inspection method control sheets (IMCs) for Tank-Automotive materiel and by gage designers engaged in the design of master gears. 1.4 Desiqner aualif

16、ications. While this handbook simplifies the task of developing a master gear for those not familiar with the required geometric hypotheses, the user must possess certain minimum qualifications. qualifications are listed below: These a. Must be a capable gage designer, able to determine suitable bod

17、y proportions with regard to fabrication and function. b. tolerances. Must be able to establish both the magnitude and direction of gage c. performance of algebraic and trigonometric formulae when proper values are given. Must have knowledge of mathematics that allows interpretation and 1.5 Suppleme

18、ntary publications. The designer must have access to a suitable table of natural trigonometric functions. should: To be suitable, the table a. Interrelate functions of angles measured in degrees and radians. b Have tabular divisions no greater than 0.01 degrees. c. Include tabular values of the invo

19、lute function. d. e. Be arranged for accurate linear interpolation, Have an accuracy of at least seven significant figures in the portion of the table to be used. meet the stated requirements and are recommended for use. See selected bibliography for publications that 1 Provided by IHSNot for Resale

20、No reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-Y04 dC W 7777970 0056464 7 W. MIL-HDBK-404 1.6 Fundamental inspection concepts. 1.6.1 Inspection Acceptance inspection of spur and helical involute gears can be effected by two different methods. circumstances involved dic

21、tate which method (or possibly both) will be used. The methods are generally referred to as “Analytical Inspection“ and “Functional Inspection“; the basic difference being that the first method determines each manufacturing error individually, while the latter views them compositely. Functional insp

22、ection, which is the primary consideration of this handbook, is performed by engaging the part gear in intimate (metal to metal) contact with a specifically designed conjugate mate called a master gear. The manufacturing errors are then displayed as variations in center distance between the two gear

23、s. the center distance variations are caused by simultaneous errors in both the gear and master. negative) of the actual errors in the gear. It follows that inaccuracies in fabrication of the master gear can be costly. A careful examination of the A shortcoming in this concept exists since This prod

24、uces a distorted indication (either positive or 1.6.2 Master aear. The master gear, to meet minimum requirements as an inspection tool, must contact the part gear over its entire active profile. The gears active profile, as the name implies, is efined as that portion of the tooth surface which is ac

25、tive during operation with its intended mate(s). specification. Unfortunately the nomenclature used for this feature is not consistent. diameter“, which simply means that the profile is active from this diameter to the addendum diameter. profile“ , “last point of contact“, “first point of contact“,

26、and, erroneously, “form diameter“ however available equipment may preclude the use of this result. The 3.7 Limitation on the pitch radius. The limitation of four inches maximum on the pitch radius of the master gear is intended as a guide only and may be exceeded if conditions warrant. where a size

27、limitation less than four inches is necessary. In either event, with almost no exception, the pitch diameter requirement of the master can be reduced by varying the operating pressure angle. If the master gear is too large because of its contact pressure angle requirement, increase the operating pre

28、ssure angle. If it is too large because of the clearance requirement between the addendum of the master and root of the gear, reduce the operating pressure angle. The reverse may also be true - 2/ 3/ Any plane normal to the axis of rotation. Any plane normal to the helix of the pitch cylinder. 7 Pro

29、vided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-11011 QC W 7777970 00561170 2 3.8 Desianinq master for internal uear. When designing a master for an internal gear, consideration of the possibility of tip fouling or trochoidal interference is ne

30、cessary. The graph, figure 3, showing the minimum difference between the nurnbers of teeth for a specific pressure angle and addendum will serve as a guide. verified by layout. be alleviated by varying the operating pressure angle. The possibility of fouling can also be If interference is present, t

31、he condition normally can 3.9 Tooth thickness at outside raius. The tooth thickness at the outside radius of the master gear-must be at least five thousandths inches (.05) to facilitate manufacture. design procedures, there are two means of correction. If this limitation is violated by normal a. b.

32、Increase the number of teeth of the master gear. Decrease the operating pressure angle. 3.10 Face width of master aear. The face width of the master gar as determined by the calculation sheet is a minimum value only, and not necessarily a suitable magnitude. relationship between its diameter and wid

33、th. intended gear rolling machine may also influence the face width. The master must also maintain a proper The requirements of the 3.11 Alqebraic emression for wire diameter. Unfortunately, the (following) exact algebraic expression for determining the theoretical measuring wire diameter for helica

34、l gears is bath involved and transcendental. Db inv arc tan +tf3“0)+-D- + i“0 (dwrPb dw*= sec #b As a substitute, the applicable calculation sheets have been provided with an approximate solution which has proven to be adequately reliable. The error in this solution is that it assumes the wire makes

35、 contact with the involute helicoid in a normal plane, but in reality, the wire contacts the flanks of adjacent teeth in a plane normal to the locus of a ball (equal in diameter to the wire) allowed to roll between the teeth of the gear 4/. solution is therefore least reliable as the difference betw

36、een the helix of the pitch cylinder and the helix described by the ball increases. -3.12 Profile of askew axis helical (seiral) uears. When askew axis helical (spiral) gears operate at a center distance other than standard s/, the determination of the active profile of the gear to be inspected usual

37、ly The approximate d 4/ Involutometry and trigonometry, by W.F. Vogel, Dr. Eng., Pages 294 thru 296. 5/ Standard center distance, here defined, is equal to the sum of the pitch radii of generation, which normally are those specified on the product drawings. 8 Provided by IHSNot for ResaleNo reproduc

38、tion or networking permitted without license from IHS-,-,-MIL-HDBM-404 becomes a complex problem. that o% parallel axis gearing; that is, that the path of contact is a cokmon internal tangent to the base dimeters of the gear WB its mate(s), regarless of the center distance. The added consideration i

39、s that the path 0% contact does not lie in a transverse plme of either gear, but rather in a plane csneaining the pitch point (y), and perpendicular to the helices described on the pitch cylinders of both gears. Again, the pitch cylinders and ehe corresponding helix angles (yl) vary directly as the

40、center distance varies. Consequently the shaft angle (c) varies 6/. See figure 4. The solution is based on a premise similar te, Referring to FORM G of the calculation sheets, when the operating center distance (Cr) is not equal to the standard center distance (Ci): V+Jy2+4xZ 2x tan #rl = Where rbi

41、sin n cinC x= sin o, rbt sin n COSC sin 0, rb2 sin n sin 2 - Y = Cr sin $, COS an sin 1- 1 ton however, if the bore is too small, it is almost impossible 20 machine it larger without reducing the overa11 accuracy. 4.6 Holes to drive chart recorder. The 0.1875 inch diameter holes shown If they are on

42、 each face of the illustration.master gear are used by some of the more common machines to drive a chart recorder (see figures 5 and 6). not applicable or if they interfere with other master gear features they are to be omitted. 4.7 Plane of data. When the basic data of the helical component gear is

43、 specified in a transverse plane, it is preferred that the diametral pitch and pressure angle of the master gear also be specified in a transverse plane. 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I NIL-HDBK-LI04 QC U 7977770 005b474 T MIL-WB

44、K-404 CHAPTER 5 BEWL GEAR INSPECTION 5.1 General. The successful manufacture of bevel gears, particularly precision gears and those requiring utmost quietness in operation, depends vitally on a most careful inspection procedure. configurations in bevel gears and the need for conjugate tooth action,

45、it is necessary that diligent inspection be carried out throughout the whole manufacturing process. Because of the complex 5.2 Inspection Procedure. The inspection procedure involves a progressive proving proqess known in the industry as “Testing“. in addition to all basic inspections, such as for d

46、iameters, thicknesses, shoulders, bores, etc. Testing is a functional, rotational check and is introduced in the manufacturing process immediately following cutting the teeth in the green blank and continues thru all subsequent operations which in any way affect the trueness, shape or size of the fi

47、nished gear. “Testing“ therefore is an essential phase of bevel gear inspecti0.n. Testing is 5.3 .Testinci Bevel Gears. 5.3.1 Tooth shapes. Smooth, quiet-running bevel gears must have correct tooth shapes, uniform spacing of the teeth and teeth concentric with the bore or shank. wear on high-speed o

48、r heavily-loaded installations, and non-uniform motion in the case o precision instruments and control equipment. Testing machines provide a practical method for determining that the gears are right before assembly, and for precisely controlling the quality of the gears during all the stages of thei

49、r manufacture. Inaccuracies in any of these conditions produces noise and rapid 5.3.2 Runninc? test. In the testing machine, the gears are mounted in the operating position and wn under power and light brake load, simulating operation under normal running conditions in their final mountings. Smoothness and quietness of operation, tooth bearing, tooth size, surface fi