1、91 FTM 4AvLow Noise Marine Gearsby: W. Haller and T. Deeg, MAAG Gear CompanyAmerican Gear Manufacturers AssociationI ITECHNICALPAPERLow Noise Marine GearsW. Haller and T. DeegMAAG Gear CompanyThe Statements andopinionscontainedhereinare thoseofthe author andshouldnotbe conslrued as an official actio
2、noropinion of the American Gear Manufacturers Association.ABSTRACT:Reduction gearsfor frigates,corvettes,destroyersand submarineshave tobe reliable, durable,easyto maintain,small insize and as light aspossible. Inprinciple, there are two ways of reducing sllucture borne noise emission of gear boxes:
3、primary and secondary. Thispaper will deal with primary measures,those which tend to eliminate the generationofnoise at its source.Copyright 1991American Gear Manufacturers Association1500 King Street, Suite 201Alexandria, Virginia, 22314October, 1991ISBN: 1-55589-601-4ALOW NOISE MARINE GEARSDesign
4、Principles and New Developments in Finishing Hardened GearsSpeaker: Dr. W. HALLER,President of MAAG Gear Company,Zurich/SWITZERLANDAuthor: T. DEEG,Vice President, Design and Engineering,of MAAG Gear Company,Zurich/SWITZERLANDi. INTRODUCTION ate the generation of noise at itssource. Since the gear me
5、sh is theReduction gears for frigates, corvettes, main source of gearbox noise, aspectsdestroyers and submarines have to be reli- such as general gear design, toothingable, durable, easy to maintain, small in design and machining accuracy becomesize and as light as possible, critical. The know-how o
6、f the gearboxmanufacturer has a major influence onToday, electronic warfare has an increasing noise radiation.importance. The Gulf war has clearly shownthat such instruments may be responsible b) Secondary measuresfor success or failure of military opera- With secondary measures one attemptstions. T
7、herefore, it is of great importance to damp the structure borne noise onthat warships are not to be detected by its path from the gear to the sea water.modern sonar instrumentation of the enemy, Commonly known methods are resilientor that detection is delayed as long as mounting of the gear or dampi
8、ng struc-possible. This leads to the requirement tures with changing impedances in thethat modern warship propulsion equipment, gears or ships structures. Secondarysuch as gas turbines, diesel engines, measures can only be applied, if allpropellers and gears, must radiate only a boundary conditions
9、are met. A resilientminimum of structure borne noise into the mounting for example, only makes sensesea water. That requirement has reached if the main propeller thrust bearing isalmost the same importance as reliability not integrated in the gearbox. In addi-and low weight, tion, secondary measures
10、 always meanmore weight and more complications indesiQn and maintenance.The gears in a propulsion system willradiate very characteristic and discrete The gearbox manufacturer has the fullfrequencies. A main source of gearbox noise responsibility and all possibilities tois the gear mesh itself. The r
11、elated fre- make use of primary measures. They mustquency is a function of both rotating speed and can be applied for any marine gear.and number of teeth which makes it possible Secondary measures if applicable, shouldnot only to detect a ship, but also to just be an addition to primary measures.ide
12、ntify the gearbox and the ship. The special know-how of the gear manufac-turer is not needed, general rules ofIn principle, there are two ways of redu- structural physics can be applied by bothcing structure borne noise emission of the yard and the propulsion unit manufac-gearboxes: turer.a) Primary
13、 measures This paper will deal with primary measu-These are measures which tend to elimin- res.12. GENERAL DESIGN PRINCIPLES ing, oil system, clutches and control sys-tems has to be a highly integrated part ofModern warships are most often eguipped the whole propulsion system.with a combined propuls
14、ion system. Theycombine diesel motors and gas turbines to Fiaure 2 shows a recently built CODOG gear vwork with one or two propellers. CODOG and for a destroyer with one gasturbine and oneGOGOG (combined diesel or gas, gas or gas) diesel acting on each propeller. Figure 3systems are in operation on
15、many frigates, illustrates the cross connect gearing for-_destroyers and corvettes. Namely on sub- frigate propulsion system.marines, one or two steam turbines perpropeller are used as prime movers.The given propulsion power often exceeds 20MW per propeller. The gears have to reducethe relatively hi
16、gh input speed of the gasturbine to the slow propeller speed. Gearratios of 15 or more are reauired. This canonly be done with two stage reductiongears. The following types are basicallyknown and have been designed for manyapDlicat ions :Type T : TandemType TA: Tandem ArticulatedType DT : Dual Tande
17、mType DTA: Dual Tandem Articulated(Figure 1 )AZ: Rigid flange Fi._22: Destroyergear (DDG)2AZZ / F _t bearingAZ_F“_ “L_, i _ ,C_l_ V/A_t gasturbinetC 15 machines capability. The data of theA_ent _, I (2) I (_ 15 pinion are as follows:Profile dem_ion Pitch diameter 16,73 inchesT0_d F_ 0 (I) (1)2 15 Fa
18、ce width 2x ii, 8 inches_u_ shoe f_ 0 (I) I (2) Number of teeth 57Pro_e _rm ff_ I 2 Helix angle 20 Hel_d_i_ion The specified tooth modifications andTot_ too_nm_t Fp _ I 15 tolerances have been fed into the computerT00_aU_,ment f_ 0 (I) 1 of the machine. After grinding the integralLon_mdiu_ _rm ff# (
19、i)2 i measuring center measured the actual shapeT00_ Da_: of profiles and leads. The results areshown in Figure ii. The outer lines mark_tchdiameter 18_mm the tolerance field, the inner line repro-Face_d_ 200 nun sorts the actual ground shape. SectionsNumber oftee_ _3 outside the tolerances can be c
20、orrected byHe_ _ 12 entering new machine setting data and re-Table 3: Quality grades _ _ _ ground grindina. Fiqure Ii shows tooth profiles ofon SE-202 “ one tooth across the face width and leaddiagrams at various heights of the flank.It is clearly visible that the pressureGears and pinions under loa
21、d suffer elastic angle (base pitch) as well as the shape ofdeformations; they bend and twist and the the profile are different at each section.meshing teeth get deformed. Friction andquenching in the toothing during powertransmission raise the temperature of the Tiprotors. The average temperature of
22、 the 910pinion becomes higher than that of the gearand the temperature distribution across theface width is uneven. The hottest point ina single helical gear mesh is approximatelyat one third of the face width from thetooth extremity which enters the mesh last.Consequently, there is a difference in
23、basepitch between pinion and gear which isdifferent at each point across the facewidth.285 270230i_ 15ollO vo 3o 15_.oThese elastic and thermal deformations I_ 0 _ _ 20 _mresult in non-uniform load distribution inthe gear mesh. The true involute of thepinion must therefore be modified during 0 3_gri
24、nding in a way, that under predetermined . _.2operating conditions all the deformations 20_L “ /_/are compensated for and the gear mesh is iI_ _.5close to ideal. Ideal conditions are equalload distribution across the face width andequal base pitches at each point across the _ _ /659face width. The m
25、odifications which are l_I _ /75“7_normally ground on a pinion involute, areprofile and longitudinal modifications _k_.-:_ 85“9(Figure5). This is not a truly three-dimensional modification because the _profile, i.e. the base pitch still remainsconstant across the face width.The new SE grinders are n
26、umerically con-trolled by computers. That allows one togrind nearly any desirable shape on a true Fig. II: Profile and lead diagram of oneinvolute tooth flank which can be mechani- tooth (experimental)cally handled by the grinding wheels.On the SE grinder the contact between the Figure 12 shows a mu
27、ltitude of measuredtooth flank and grinding wheel is a single tooth flank diagrams of another testpoint contact. With single point contact, pinion. The three-dimensional character oftrue three-dimensional modifications with such modifications becomes evident.!_g_J _ -. _. AZdxo(o| -4-_- : : _ , , _-
28、“_-T- _-.-F-“-_,_ . , j “_,=,Fp- IIlNm =. 12._1.48ofa)_LSS,_O7O50 a/,:om40- - _, r , . Fct:lO_0 2 4 6 $ : -_Z F_= 3.1_m *_4/_rnFig. 12: Three-dimensional toothmodifications (experimental) Fig. 13 : Tooth pitch deviation recordsHSS 460 and SE-202I I I I I4.2.2 Comparison SE 202 vs. HSS 460 Non-ru_.in
29、g _id_propulsion units has recently been ground z= 125on the old HSS 460 dry grinding machine and m = 6.70one gear set on the new SE machine. These a = 1730single helical gears have the following .Be. = 15 14 28“tooth data: /_x = 15 14 23“Profile 2:1 500x_ Pitch diameter 34,3 inchesFace width 12,6 i
30、nches _ I f J _l-_I _ Number of teeth 125 , i IPressure angle 17, 5 - L F i -_Helix angle 16 _ _-_- _fJThe tooth flanks are of the true involute i-I- I V I - -_-shape, all the necessary modifications are Running sideground on the primary pinion. The wheelsare carburized and case hardened. I I I I _.
31、-(a) HSS 460Figures 13, 14 and 15 show the measureddeviations for p_ch, profile and lead.Each figure compares records from the oldwith the new grinding machine. The improve-ment in accuracy with the SE machine isquite evident: Quality grades of ISO 0 orbetter than AGMA 15 can be realised withnormal
32、production grinding. Note that all z-125values are in millimeters or micrometers, m = 6.70The SE machine is not only superior with = i730“regard to productivity, but also inaccuracy .Bb = 15 D 14“28“compared with the HSS 460. _= = 151435“Profile 2: I 500xThe recorded value of 3.1_m (or 1.2 tenthousa
33、ndths of an inch) for the accumulatedpitch deviation is much better than AGMA15, i.e. not defined in the AGMA-2000(1987) quality grade tables.The conclusion is that with the new SEgrinders one is able to produce highest_ quality toothings at a productivity typicalfor wet grinding machines. This will
34、 have amajor influence on lowering the noise level b)SE202- in the gear mesh of marine propulsion gear Fig. 14: Profile deviation HSS 460units, and SE-202_.004 HelixI.1500Clutch -_(a) HSS 460Helix 1.1 500xClutch(b)SE 202Fig. 15: Lead deviation HSS 460 and SE-2025. SUMMARY AIqD OUTLOOKThe gear mesh i
35、s the primary noise source A new wet grinding machine type SE-202 isin marine gears. Transmission errors have a presented. The accuracies that have beenmajor influence on noise generation around ground are on the best possible levelthe gear mesh frequency. These errors must covered by international
36、standards. Qualitybe minimized. Besides a correct design of grades of ISO 0 or better than AGMA 15 forthe gear train and the toothing itself, the wheels of up to 80 inches diameter havebest possible manufacturing accuracy must been realised with normal productionbe reached. The importance of toothin
37、g grinding.accuracy for low noise levels has beenproved by measurements on a complete gear A new machine type 402, which will coverset under full load conditions, dimensions up to 200 inches outside dia-meter, will be installed for production atDesign principles for low noise gears are: Zurich by th
38、e end of 1991. In the nearfuture, ground marine gears of big size- Single helical toothing, hardened and with ISO 0 quality will be available. Withground the new SE machines involute modifications- Power split with rigid torsional shafts of practically any shape deemed advanta-(DTA) geous can be gro
39、und. Consequently, the- A minimum of loose parts meshing conditions of gears can be - If necessary, thrust collars to increase improved. This will benefit the loadthe overlap ratio capacity and reduce noise generation in the _- Correct modifications of the true pinion gear mesh.involutesi0REFERENCES
40、- i.D.B. Welbourn, Fundamental Knowledge ofGear Noise2. A.K. Dale, Gear Noise and the SidebandPhenomenon3. H. Sigg, Marine Gearing - Developmentand Technology, Sixty-second ThomasLowe Gray Lecture, January 1990, London,The Institution of Mechanical Engi-neers.4. MAAG Gearbook 19905. G.W. Nagorny and
41、 R.A. Stutchfield, GearNoise - The Generation of RotationalHarmonic Frequencies in Marine Propul-sion Gears, AGM_ Paper P-299.06,presented at the AGMA 1981 Fall Tech-nical Meeting.6. W.D. Mark, Analysis of the VibratoryExcitation of Gear Systems. I BasicTheory and Analysis of the VibratoryExcitation of Gear Systems. II ToothError Representations, Approximations,and Application. J. Acoustical Soc. Am.63(5), May 1978, and 66(6), Dec. 1979respectively.7o J.F. Shannon, Marine Gearing, TheInstitute of Marine Engineers, 1977Marine Media Managementii
