Sept, 17, 1946„ H_ Q_ H||_1_ ` i 2,407,699 HYDRAULIC BRAKE Filed sept. 2o, 194s 2 sheets-Sheet 1 ,60 66 l. INVENTOR > HENRY C’. HILL I A TTORNEY sept. 17, 194e. „ H. c. HILL 2,407,699 HYDRAULIC BRAKE Filed Sept. 20, 1945 „ 2 sheets-sheet' 2 en Q , :Y ' l 1 Ei E l ì A . v -MVENTOR HENRY C. HILL. . ATTORNEY Patented Sept. 17, 1946 2,407,699v UNITED STATES PATENT OFFICE 2,407,699 HYDRAULIC BRAKE Henry C. Hin, Montclair, N. J., assigner to Wright` Aeronautical Corporation, a corporation of New York Application September 20, 1943, Serial No. 503,144 1 11 Claims. (Cl. 18S-152) This invention relates to a hydraulic clutch or brake and is particularly directed to a ñuid‘oper ated plate clutch or brake in which the engaging surfaces are lubricated by the actuating ñuid. The invention is illustrated and described in con nection with and as forming a part of the var 2 scription in connection with the drawings in which: Fig. l is an axial section through the invention, Fig. 2 is a view along line 2-2 of Fig. l, and Fig. 3 is an enlarged sectional view taken along line 3-3 of Fig. 2. i iable speed transmission and associated brake dis Referring to the drawings, an engine-driven closed in the copending application of Hill et al., shaft I Il is drivably connected to a gear I 2 by Serial No. 461,026, ñled October 6, 1942, now Pat means not shown and a driven shaft I4 jour ent No. 2,368,835, Feb. 6, 1945. However, as will 10 naled about the drive shaft is adapted to be driven appear from the following description, the inven by the gear I6. An annular cage I8 is concen tion is not limited to this specific use, but is of trically disposed about the shafts I0 and I4 and general application and may be used either with is provided with a plurality of double planet pin a frictionally engaging clutch or brake. ions 20 journaled about shafts 22 carried by the The aforementioned copending application'of 15 cage. Each of the double pinions 20 is meshed Hill et al. discloses a brake which, when engaged, with one ofthe gears I2 and I6 whereby, when locks up a cage carrying a plurality of double planet pinions to provide a gear drive through the cage or pinion carrier I8 is held stationary, the double pinions provide a step-up drive be the pinions and which, when disengaged, per tween the gears I2 and I6. mits rotation of the pinion carrier. The design 20 In order to hold the pinion carrier stationary of the transmission is such that upon rotation of a multi-plate brake 24 is provided about the ex the pinion carrier, the centrifugal force acting ternal periphery of the pinion carrier. As more on the pinions is of sumcient magnitude to lock fully described in the aforementioned copending the pinions about their journals, thereby pro application, when the pinion carrier is released viding a direct drive connection. In order to 25. the design is such that the rotation of the pinion effect a return to the gear drive through the pin carrier with its pinions subjects the pinions to ions, the brake is again engaged to prevent rota a centrifugal force sufficient to lock these pinions tion of the pinion carrier. In practice it has against rotation about their journals 22. There been found that‘the frictional forces locking the fore, upon release of the brake 24 'a direct drive pinions about their journals are of such magni 30 is provided between the gears I2 and I6. In tude that the brake must exert excessive friction order to return to the step-up drive ratio the torque to break the pinions loose from their jour brake 24 is engaged to stop rotation of the pinion nals in order to secure the pinion carrier against carrier. This requires a braking torque suiilcient rotation. This excessive friction torque has to-overcome the friction locking torque of the caused considerable scuiiing of the brake plates 35 pinions about their journals. `In practice :it has and it is an object of this invention to provide been found that the pinions lock up so tightly means to lubricate the friction engaging surfaces that the torque required of the brake 24 in its of the brake in order to eliminate or minimize slipping `condition in order to break the pinions this scufûng. loose is of such magnitude as to cause consid 4It is a further object of the invention to pro 40 erab'le scuiiîng of the friction engaging surfaces vide a fluid actuable brake in which the friction of the brake. This scuiiing has been eliminated surfaces are lubricated by the actuating ñuid. ' by lubricating the brake surfaces inthe manner A still further object of the invention Vis to pro hereinafter described. The construction is such vide a lubricated brake or clutch in which there *that upon initial engagement of the braking sur is a continual now of lubricant over the friction faces there is a considerable ñow of lubricant be surfaces while slippage occurs and in which the tween the surfaces and as the slippage gradually iiow of lubricant automatically ceases when the decreases the lubricating ñow also decreases un friction surfaces become clamped together. An til, when the brake is positively engaged, the ñow other object of the invention is to provide a self of lubricant automatically‘ceases. sealing lubricated clutch or brake in which the 50 The brake 24 comprises a series of ‘annular clutch or brake is constructed to insure uniform plates 2-6 which are splined at 28 to the outer lubrication over the entirefriction engaging sur periphery of 'the cage or pinion carrier I B and face. ' Other objects of the invention will become ap an interposed series of annular plates 30 are splined at 32 to an annularV drum 34. The an parent upon reading the annexed 'detailed de 55 nular drum 34 is resilientlysupported from. a 2,407,699 4 ment of these plates, In either construction the' oil ñows through the holes 12 and 14 in the vari housing structure 36 by an interposed supporting structure 38. A p-air of opposed annular mem bers @il and 42 are secured to each side of the ous brake plates and escapes radially over the adjacent surfaces of these plates to eiîectively supporting structure 38 by bolts 44 to provide lubricate and _cool these surfaces This flow of oil over the adjacent surfaces of the plates escapes axially over the .inner and vouter diam . an annular cylindrical space surrounding the se ries of brake plates 26 and 30. A pair of annular pistons e6 and 48 are sealingly disposed atthe e'tersfofj these plates and thence through appro priate passages to the engine sump. ends Vof 'said annular oylindernforselîecting en# gagernent of the brake plates 26 and 30. The pistons 46 and 48 are provided with a plurality of facing bosses 50 and a plurality of ‘springs 52 are disposed between the pistons 'about As the pressure builds up behind the pistons the plates 2S and 3€! are Vsqueezed closer and these bosses to urge each piston* away‘frorn thel closer together. The friction torque developed by the brake gradually increases and the escap brake plates and toward their respective ends oî_ ` the cylinder. The annular drum 34 is provided with an outwardly extending flange or tongue 54 torqueto ‘unlock the pinions 2B from their jour ing ’flow-¿ef oil .between the plates is gradually restricted until the plates develop sufficient hals 22.- When this point is reached the plates 26 andeä are locked or clamped together and having a plurality of openings SSf-tl'irough which ' the springs 52 extend. . Y. u ' this clamping engagement of the plates shuts off the Vflow of lubricating oil out between the Oil pressure is supplied to the control valve 5l preferably from the engine oil pressure system. annular A conduitgroove E3 interconnects 60 formed aboutr >this valve therperîph’e'ry' with of the Supporting structure 38. Froin the annu plates.; Passages le formed' inthe ~vannular inem be‘r‘s- 49 ‘d2’ perr'nit'return’of oil `escaping radi ally outward .from'ítheplates >:26"ano'l 30. lar 'groove Ell oil pressurel is fed to a plurality of transverse bores'62 thröugh'tl?ìé substantially ra dial passages B4. The ends of the transverse passages s2 respectively communicate with sub stantially radial passages Gif and B8 in the annu la`?_cylinder forming“ rn'einbersllZ and 46. At tneirinn'ejr ends-tile passages 66 and 68 eommu- - nícäitë with the ÉÍl'Illîl’ä? öylind?ícál ySpace behind the pistons' and 48 respectively. ' Therefore, when the' valve 5'! is in its Öp'eh Aposition aS illus friction isv considerably reduced ~-eiid vtnt-metete rn'uch fhigher yfluid ‘pressures are necessary -to effeet~lockiiigengagelnent ofthe brake. >There-Y foreja booster 'puinp'rrraii 'be lnecessary irl order tol augment tlie pressure/‘supplied 'by thev engine et and Ga'tpvtnewaiiiiiilai space behind the leise> erpijnien tangier .against _rotation relative to the housing' 36. The brake 24 In'âly >be released by Ifn'oving the valve "51 to its dotted _line position as’ illustiateziiii the drawing. In ‘this letter4 pesi derivedffroin 'the engine 'oil ‘pressure Ysyster'n as was Yalsc'i'the 'casei in theaior'eiirlerltionedl copend; ing'application of'liill et al. ‘Howevergyvhenthe brake plates ‘are lubricated their `‘coei‘licie'ent “of trated, fluid pressureis'supplied to the annular groove iiß,‘transve"r"se passages 52,_radial passages tons 46 and 4'8-~ ‘This ‘ñui'd pressure urges the pis-` tens 4t and 'da toward each stiletto clamp tlie brake plates together thereby locking the cage _ jï‘he Aia'b‘ove described' construction Ypro'vidl'es >a lubricating 'oilii'ow over‘the entire friction 'eng_a°-_ ing ‘surface of `the 'brake plates; 'which oil now will carry away the-"frictional'heat ydevelopedjoy the iterative slippage @fthe-*brake plates. 'The oil pressure' operating, tnejjbrake is preferably óiljpre'ssure system. 40 ' The'bi'al‘te 24'has beenjtiescribed in connection with ‘ti-particular transmission; however, it seems . obvious `that this_brakeiis‘of vgeneral application ai‘ldmay be use'dï‘wherever affliction-clamping tgiioiiegis- desired. 'lv-’ne new of nitricatingV eil- over tien> tiie conduit "sa is 'connected to e vent te, 45 the Vjfriction'Í engaging "surfaces lubricates ’these whereby the springs v’.52 are operative toV release surfaces and,r in addition, Y carries away f the 4heat In orde'rto lubricate the’br'ak'e' plates `each pis developed-during slippage ofthese surfaces. VÍIt ten is V'provided >withz e. plurality of 'eiieiiin'fereii-~ tially disposed restrictive openings 10 and each ing engagementof the‘fri'ction Yengaging' surfaces openings?? and "lil are provided with .so-called “Michel1ed" 'edges 1‘5' t‘o _help or otherwise ’aid the r'ja'dîal’fl'ow of lubricant 'frein the openings 72 and 1,4 over the V’surfaces "of> the plates 2B and 30. uniform torque v'distribution between the various platee and >the»prei/‘istitu»of vineens 'te-feed lubri thebralàe. n . _ ` ` is 'also' a feature ofY this-invention that the'locke ofîth‘e' brake plates' '26 and 3‘0 are 'providedi'with 50 auteiiietieall'y » operates >to seal or shut - en» this Í’lòvv‘ûf VOil'v'v‘hen‘ît"’is no‘lònigïe? needed. ¿In ät?ìltiì‘-t a >correslcäor‘iding number V4of similarly located tion, 'the 15Í‘(".l"vìsi0n`> 0f a piston- at bötl'l'e?lës ltlie openings 'and ç_'ljß respectively. Each of the Th‘at‘is, the edges of the holes 'l2y and 74 in effect are proyided'with a 'flat bevel. The openingsor series ef breite plates fil-t and et »provides-'foie' eating eil throught-ne series et plates-nem beth endsof the series insuresuiiiîorr‘n lubiieatien -e-f al1-the plates. Y ` \ n rI_‘he outer brake drum 34 preferably is resili tive tothe oil inlet‘pas‘sages B6 and 6B whereby, 60 ently connected 'to >the SuDpèì‘tingï'structure-SB -in holes 19V/in the piston are restricted in size rela when the valve i‘.iFi is opehed'the oil pressure will immediately bund up beliiiidtne pistonsv te attu-y ate the pistons toward engagement of the brake orner te provide ev radially vtti-iii e teisieiially yieldable ïsuppcli’rt.l The supperti‘ng structure 38 is provided »with radially disposed parallel .lianges 1'8 «beto/en which the `lflange lportieri ¿54 of 'the d'rurn '3e «adapted to be inter'ñtted. ’I‘lf'le-innerV diameters di tneflenges is alternately increase frequently so that tlierelwill be oil flow through and decrease i?nlagfniïtude andthe outerdiam these _holes and out over the plates from the holes etel- of the flange "portion 254 is similarly 'tone i2 and le to intricate vthe plates.v After the breite st'riiete‘d, whereby these ineiiiber’s maybe axially plates are ~lockedtogeth`e`rnolubrication is nec and then rotated to their-ìnteríitted essary so that it is l«imn'l'aterial Whether the holes 70 as'sernl'aled> position: î»The overlapping portions of the ii'anges are thenalined. If desired‘ailnulai- grooves inay ell-and ‘Hl are each 'provided with similar cutout be p`l^ol`1idedoifik each surface ofthe plates 26 and portions 3B. Each of these cutout portions is 30 across the holes 12ìan’d "14tò insure a 'con adapted to receive a pair of v.opposed bearing tinuous flow oflubric‘ating oil through and across the lplates 2S and Sllíprior to clamping `engage- 75 members $32 having'. a spring v84interposed, there; plates. Because ’of the relative slip of the brake pletestlie holes 1o, i2, 'energie ‘will line up quite È :Mondeo 6 between. With this construction thefspring 84 of said discs, and means for supplying oil -intd said passages at each end of said plurality of discs simultaneously with the application of oil permits slight relative rotative and radial move ment betweenthe supporting structure 38 and the drum 34,` The purpose of this resilient con.; to said piston means. " Q nection .is to prevent uneven loading of one or 5 >5. In combination with a pair of ,relatively more of the pinions 28, It should be noted that rotatable members, means to frictionally inhibit the previously described brake can be usedWith relative rotation of said members comprising a or without this resilient supporting structure. multiple disc-type clutch having aplurality- of While I have described my invention in detail annular friction discs disposed in side-by-side in its present preferred embodiment, it will be 10 relation and each connected to one or the other obvious to those skilled.V in the art, after under of said members such that adjacent discs are l standing my invention, that various changes and connected to different members, piston means modificationsY may be made therein without de-‘ engageable with each end of said plurality of parting from the spirit or scope thereof.` I aim discs, and means to apply oil pressure simultane in the appended claims to cover all such modi- 15 ously >to each piston for effecting clamping en flcations and changes. gagement of said discs, each of said piston means I claim as my invention: ‘ i having one or more restricted oil passages there 1. In combination, relatively rotatable mem bers having frictionally engageable surfaces, a through to the adjacent disc intermediate the inner outer diameters of said discs and each piston-cylinder assembly for effecting clamping 20 of saidand discshaving'one or more cooperating "oi1 engagement ofsaid surfaces upon the-applicaF passages 'i extending therethrough intermediateV tion of oil V pressure thereto, and oil passage their inner and outer diameters. » i . means from said assembly communicating with 6. In combination ‘with a pair‘ of relatively the space between said surfaces to provide for ñow rotatable members, means to frictionally inhibit of said oil over said surfaces upon the application 25 relative rotation of said members comprising a of oil pressure to said assembly such that clamp multiple disc-type clutch having a plurality of ing engagement of said surfaces is operative to annular friction discs disposed in side-:by-side shut off said iiow of oil. Y relation and each connected to one or the other 2. In combination, a pair of annular relatively of said members such that adjacent discs are rotatable friction discs, a piston-cylinder as- 30 connected to different members, piston means, sembly for effecting clamping engagement of said means to apply oil pressure to said piston means discs upon the application of oil pressure to said for eiîecting clamping engagement of said discs, assembly, one or more restricted oil passages and oil passage means extending through said extending from said assembly to the adjacent piston and through said plurality of discs inter friction disc intermediate the inner and outer mediate the inner and outer diameters of said diameters of said disc, and cooperating oil pas discs, whereby, upon application of said oil pres sages extending through said adjacent disc sure, oil ñows from said passage means over the whereby, upon application of oil pressure to said engageable surfaces of said discs prior to their piston-cylinder` assembly, oil flows through said complete clamping engagement and upon com passages and out between the engageable surfaces 40 plete engagement of said discs said oil flow is of said discs, the clamping engagement of saidr automatically interrupted thereby. surfaces being operative to shut off said flow of 7. In combination with a pair of relatively oil. rotatable members, means to frictionally inhibit :3. In combination with a pair of relatively ro- ` relative rotation of said members comprising a tatable members, means to frictionally inhibit 45 multiple disc-type clutch having a plurality of relative rotation of said members comprising a annular friction discs disposed in side-by-side multiple disc-type clutch having a plurality of relation and each connected to one or the other annular friction discs disposed in side-by-side of said members such that adjacent discs are relation and each connected to one or the other connected to different members, piston means, of said members such that adjacent discs are 50 means to apply oil pressure to said piston means connected to different members, piston means engageable with said plurality of discs, means to apply oil pressure to said piston means for effect ing clamping engagement of said discs, each of said annular discs having one or more oil pas sages extending therethrough intermediate their inner and outer diameters, and means for sup plying oil into said passages at each end of said plurality of discs simultaneously with the appli for effecting clamping engagement of said discs, and oil passage means spaced from the periphery of said piston means and discs and extending therethrough whereby, upon application of said 55 oil pressure, oil flows from said passage means over the engageable surfaces of said discs prior to their complete clamping engagement and upon complete engagement of'said discssaid oil flow is automatically interrupted thereby. cation of oil to said piston means. 60 8. In combination with a pair of relatively 4. In combination with a pair of relatively rotatable members, means to l'rictionally inhibit rotatable members, means to frictionally inhibit relative rotation of said members comprising a relative rotation of said members comprising a multiple disc-type clutch having a plurality of multiple disc-type clutch having a plurality of annular friction discs disposed in side-by-side 65 annular friction discs disposed in side-„by-side relation and each connected to one or the other relation and each connected to one or the other of said members such that adjacent discs are of said membersI such that adjacent discs are connected to different members, piston means connected to different members, piston. means engageable with each end of said plurality of engagea-ble with said plurality of discs, means to discs, means to apply oi1 pressure simultaneously apply oil pressure to said piston means for effect ing clamping engagement of said discs, each of 70 to each piston for effecting clamping engagement of said discs, and oil passage means spaced from said annular discs having one or more oil pas the periphery of said piston means and discs and sages extending therethrough intermediate their extending therethrough, whereby, upon applica inner and outer diameters, the ends of each of tion of said oil pressure, oil ñows from said pas said passages being .beveled at the faces of each 75 sage means over the engageable surfaces of said 8 discs lpriorto .compietefclamping engagement of said discs “and upon `complete"engagement of said discs said oil iiow .is automatically interrupted thereby. v I 9. In combinationfa pair of. relatively-rotatable pressure »in vcommunication with .said nrst«rneii-7 tioned ‘means and withsaid surfaces, and means operable «topontrol--said .passage means suchtnat liquid under pressure :fromvsaid source -is trans mitted to said first-mentioned means and -sub a source of liquid under pressure, means oper# stantially >sirrlultaneouslv is transmitted ' to . said surfaces for ñoW-thereov'en j _ ative upon the application ‘of said liquid pressure thereto for effecting >clamping engagement of said abl’e members having `frictionalliz engageable members having.frictionally-engageable surfaces, surfaces, liquid passage means fromv said source to said first-mentioned means andA to one or more points on said surfaces and spaced from the edges of said surfaces, 'and valve means operablewr to control saidy passage means to effect application of said liquid pressure from said source to said ñrst-mentioned means and to simultaneously supply liquid from Asaid source to said one or more points on said surfaces.' 10. In combination, a pair of relatively rotat»` i able members having frictionallyengageable sur 20 , faces, means operative upon .the application of liquid pressure thereto for effecting clamping frictional engagement 'of said'surfaces, passage means arranged ‘to place a source yof liquid under 11A. In combination; a pair 'of relatively rotat surfaces, means'operative upon the application of liquidpressure .thereto for [effect-ing clamping frictionalengagement of said surfaces, 1vpassage means arranged „to` place a source of liquid under pressurev in 'communication with said lirst-f mentioned means and with `said surfaces, and means operable to control :said passage means such that liquid under pressure l¿from `said source is transmitted to said mst-mentioned means and substantially 'simultaneously Vis transmitted to saî'd surfaces for Aiiow therebetween suchthat clamping engagement of saidfsurfaceszshuts‘off said ñow. Y '