SE193317C1

SE193317C1 -

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Publication number: SE193317C1
Authority: SE
Publication date: 1964-01-01

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KLASS INTERNATIONELLSVENSK B 61 c20 b:5/02 PATENT- OCH REGISTRERINGSVERKET Ans. 11 979/1959 inkom den 19/12 1959 utlagd den 20/4 1964 SVENSKA ROTOR MASKINER AB, STOCKHOLM Anordning for begransning av det OverfOrda momentet vid en transmission innefattande en hydrostatisk koppling och hydrodynamisk momentomvandlare anordnade i serie Uppfinnare; K G Ahlen Vid transmissioner innefattande en hydrodynamisk momentomvandlare uppstar problem att vid tomgang forhindra att en viss effekt alltid overfores enom transmissionen. Detta inedfor speciellt vid fordonsdrift att fordonet Mr en tendens att krypa °eh dessutom ,uppstar svarigheter att skifta om fran framatgang till backgang oCh vice versa. For att losa ,detta problem har man hittills tillgripit den utvagen att anordna en mekanisk koppling i serie med transmissionen. CLASS INTERNATIONAL SWEDISH B 61 c20 b: 5/02 PATENT AND REGISTRATION AGENCY Ans. 11 979/1959 was received on 19/12 1959 issued on 20/4 1964 SVENSKA ROTOR MASKINER AB, STOCKHOLM Device for limiting the transmitted torque during a transmission comprising a hydrostatic clutch and hydrodynamic torque converter arranged in series Inventors; K G Ahlen In transmissions involving a hydrodynamic torque converter, problems arise when, at idle, a certain power is always transmitted through the transmission. This means, especially in vehicle operation, that the vehicle Mr has a tendency to crawl, and in addition, difficulties arise in shifting from forward to reverse and vice versa. To solve this problem, the chosen one has so far resorted to arranging a mechanical coupling in series with the transmission.

Pa senaste tid har emellertid speciellt for jarnrvagsdrift en hydrostatisk koppling anordnats i serie med sadana transmissioner for att upptaga svangningar, for att hindra snedbelastningar vid flermotordrift och for att utgora synkroniseringsartordning for en den hydrodynamiska momentomvandlaren forbikopplande mekanisk direktkoppling. Recently, however, especially for railway operation, a hydrostatic coupling has been provided in series with such transmissions to accommodate oscillations, to prevent skewed loads in multi-motor operation and to constitute a synchronization arrangement for a mechanical direct coupling bypassing the hydrodynamic torque converter.

I samband med denim hydrostatiska koppling ha forsOk utforts att anvanda denna som frildggningskoppling genom tvangsmdssigt styrd oppning av de i kopplingen inga.ende maximaltryckventilerna. Tanken var hdrvid att vatskan i kopplingen skulle eirkulera fritt och armed lute Overfora nagot moment. Dessa forsok visade emellertid att det var omojligt att uppna en losning pa den.na yds pa grund av att vdtskan av den roterande, drivande delen genom friktion bibringades en sá kraftig rotation att denna genom friktion mot den. andra kopplingsdelen bringade aven denna att rotera. In connection with the denim hydrostatic coupling, attempts have been made to use this as a release coupling by forcibly controlled opening of the maximum pressure valves included in the coupling. The idea was that the liquid in the coupling would circulate freely and armed lute Overfora some moment. However, these experiments showed that it was impossible to achieve a solution on the surface due to the fact that the fluid of the rotating, driving part was subjected by friction so strongly that it by friction against it. the other coupling part also caused it to rotate.

Foreliggande uppfinning har emellertid lyekats losa det ovannamnda problemet. However, the present invention has succeeded in solving the above-mentioned problem.

Vid hydrostatiska kopplingar av foreliggande typ uppstar till foljd av effektforluster en viss uppvarmning av arbetsvdtskan. Derma vatska maste darfor hibringas en viss Dupl. kl. 47 c: 14; 47 h: 18 cirkulation till en utanfor kopplingen heldgen kylare. Ndr den kombineras med en hydrodynamisk momentomvandlare Or det ddrvid lampligt att lata bagge transmissionsdelarna arbeta med samma cirkulerande olja. Harvid tillfores den kylda yitskan under ett relativt hogt tryck och bortledes vid ett avsevdrt lagre. Med hansyn till att de varmemangder sum behova bortkylas ur den hydrostatiska kopplingen d.po relativt sma, har det hdrvid visat sig lampligt att utfOra tilloppsoch avloppsoppningarna fOr _ arbetsvatskan med en starkt begransad area. In the case of hydrostatic couplings of the present type, a certain heating of the working fluid occurs as a result of power losses. This liquid must therefore be given a certain Dupl. at 47 c: 14; 47 h: 18 circulation to an out-of-clutch solid-state cooler. When it is combined with a hydrodynamic torque converter, it is therefore advisable to let the transmission parts work with the same circulating oil. In this case, the cooled surface is supplied under a relatively high pressure and is discharged at a considerable bearing. In view of the fact that the heat amounts which need to be cooled away from the hydrostatic coupling, i.e. relatively small, it has thereby proved expedient to make the inlet and drain openings for the work fluid with a strongly limited area.

Uppfinningen bygger pd. delta Taktum och kannetecknas av att lagtryckskamanaren i och for vdtsketillforsel till kopplingen frau en tryckvatskekalla kommunieerar rued denna medelst minst en med begransad area ut- ford inloppsoppning ochatt en selektivt paverkibar ventil Or anordnad att forbinda kopplingens hogtryckskaramare med en utanfor kopplingen anordnad vdtskebehallare genom rninst en utloppsoppning med storre kapacitet an inloppsoppningen, varigenom jute blott tryckskillnaden Indian hOgtrycks- och lagtryckskammare utan ¥ mangden vatska i kopplingen minskar. The invention is based on delta Taktum and can be characterized by the legal pressure chambers in and for fluid supply to the coupling from a pressurized water cooler communicating rued this by means of at least one with limited area designed inlet opening and that a selectively passable valve Or arranged to connect the coupling high pressure chamber with an outside connection with a larger capacity than the inlet opening, whereby only the pressure difference between the Indian high-pressure and low-pressure chambers without the amount of liquid in the coupling decreases.

En hydrodynamisk momentomvandlare har sasom Sr vdl kdnt den egenskapen att dess momentupplagningsformaga Sr proportionell mot kvadraten pa pumpvarvtalet. Genom den hydrostatiska kopplingens sliming sjunker .detta primarvarvtal och armed momentupptagningsforma.gan. Om varvtalet pa den utgencle axeln hos kopplingen, dvs. papumpaxeln, Or 50 % av varvtalet pa den ingaende axeln sjunker momentomvandlarens momentupptagningsformaga till Vo och vid 33 % av varvtalet pa den ingaende axeln till 11 % 2— — av momentupptagningsformagan, nar kopplingen inte slirar. Be nedsattningar som kan erhallas pa delta salt are tillrackliga for att forhindra krypning vid stillastaende fordon och for att anojliggora ormkoppling mellan back och fram. A hydrodynamic torque converter, like Sr, has the characteristic that its torque storage capacity is proportional to the square of the pump speed. Due to the sliming of the hydrostatic clutch, this primary speed and the armed torque absorption method decrease. If the speed on the extended shaft of the clutch, ie. papum shaft, Or 50% of the speed of the input shaft decreases the torque converter's torque absorption capacity to Vo and at 33% of the speed of the input shaft to 11% 2— - of the torque absorption capacity, when the clutch does not slip. Ask for reductions that can be obtained on delta salt are sufficient to prevent creep in stationary vehicles and to allow snake coupling between reverse and forward.

Vid en lamplig utforingsform är den selektivt paverkbara ventilen anordnad centralt i .kopplingen och forskjutbar i axiell riktning. In a suitable embodiment, the selectively actuatable valve is arranged centrally in the coupling and displaceable in the axial direction.

Bet är vidare lampligt att den selektivt verkbara ventilen ãr hydrauliskt manovrerad. Om en hydrostatisk kappling är anordnad i serie med saval en hydrodynamisk momentamvandlare som en. denna forbikapplande hydrauliskt paverkad rnekanisk direktkoppling ãr det desutam lampligt att vatsketillforseloppningen star i forhindelse med momentomvandlarens arbetskammare och att den selektivt paverkbara ventilen star i fOrbindelse med tryckkammaren for direktkopplingen. Vid en sa.dan transmission kan omkopplingen. mellan momentamvandlare och direktkoppling styras medelst ett gemensa.mt ventilorgan och det är darvid I vissa sammanhang lampligt att aven den selektivt paverkbara ventilen manOvreras medelst detta ventilorgan. It is also advisable that the selectively operable valve is hydraulically operated. If a hydrostatic coupling is arranged in series with saval a hydrodynamic torque converter as one. In the case of this by-pass hydraulically actuated mechanical direct coupling, it is also appropriate that the liquid supply is connected to the working chamber of the torque converter and that the selectively actuatable valve is connected to the pressure chamber for the direct coupling. In such a transmission, the switching can. between torque transducer and direct coupling is controlled by means of a common valve means and it is thereby in some contexts appropriate that the selectively actuatable valve is also operated by means of this valve means.

I andra fall ãr det fordelaktigt, att den selektivt pa'verkbara ventilen manovreras medelst tryekvatska frin en. separat pump. In other cases it is advantageous for the selectively actuable valve to be operated by means of pressure water. separate pump.

En lamplig utforingsform skall nedan beskrivas mera i detaIj i anslutning till bifogade ritningar, i vilka Fig. 1 visar en -vy av en transmission enligt uppfinningen, Fig. 2 visar en. langdsektion genom en del av transmissionen i Fig 1, Fig. 3 visar en tvarsektion langs linjen 3-3 1 Fig. 2, och. Fig. 4 visar en detalj av Fig. 2 i stOrre skala. A suitable embodiment will be described in more detail below in connection with the accompanying drawings, in which Fig. 1 shows a view of a transmission according to the invention, Fig. 2 shows one. longitudinal section through a part of the transmission in Fig. 1, Fig. 3 shows a cross section along the line 3-3 in Fig. 2, and. Fig. 4 shows a detail of Fig. 2 on a larger scale.

I Fig. 1 beteckna 10 den ingaende axeln, 12 huset till en hydrostatisk koppling, 14 huset till en direktkoppling, 16 huset till en. hydrody,namisk momentomvandlare, 18 huset till en fram- °eh backvaxel saint 20 den utgaende axeln. En elektrisk pump 22 är an-. bragt vid .huset 16 och är avsedd fOr att via en rorledning 24 leverera tryckvatska till en kanal 26 i huset 12 och genom denna till en ventil 28 (se Fig. 2 och 4) for frikoppling av den hydrostatiska kopplingen. In Fig. 1, 10 denotes the input shaft, 12 the housing of a hydrostatic coupling, 14 the housing of a direct coupling, 16 the housing of one. hydrody, namic torque converter, 18 housing to a forward reverse gear saint 20 the output shaft. An electric pump 22 is used. brought to the housing 16 and is intended to supply via pressure pipe 24 pressure vessel to a channel 26 in the housing 12 and through this to a valve 28 (see Figs. 2 and 4) for disengaging the hydrostatic coupling.

Fig. 2 visar ett langdsnitt genom en hydrostatisk koppling 30, en. direktkoppling 32 och partiellt aven genom en hydrodynamisk momentomvandlare 34. Med den ingitende axeln 10 Sr ett centralt kugghjul 36 fast forbundet. Detta kugghjul Sr anordnat inuti ett vatskefyllt hus 38, vars ena gavel 40 dr utformad med en axeltapp 42, pa vilken axeln 10 Sr lagrad och vars andra gavel 41 Sr avtatad mot axeln 10. Fig. 2 shows a longitudinal section through a hydrostatic coupling 30, a. direct clutch 32 and partly also by a hydrodynamic torque converter 34. With the input shaft 10 a central gear 36 is fixedly connected. This gear Sr is arranged inside a fluid-filled housing 38, one end of which 40 is formed with a shaft pin 42, on which the shaft 10 Sr is mounted and whose other end 41 Sr is inclined towards the shaft 10.

I huset 38 Sr radiellt utanfor kugghjulet 36 ett antal urtagningar 52 anordnade. I var och en av dessa Aro tvA. riled varandra ingripande kugghjul 54, 56 medelst nallager 58 roterbart lagrade p5 sina i huset anbragta axlar 60, 62. In the housing 38 a number of recesses 52 are arranged radially outside the gear 36. In each of these Aro tvA. gears engaging gears 54, 56 by means of needle bearings 58 rotatably mounted on their shafts 60, 62 arranged in the housing.

Del ena av !dessa kugghjul 54 star i ingrepp med kugghjuIet 36, varvid detta tjanstgor som ett solhjul, de &riga kugghjulen som planethjul och huset sam planethjulsbarare. Part one of these gears 54 is engaged with the gear 36, this serving as a sun gear, the other gears as planet gears and the housing as planet gears.

Be tva kugghjulen 54, 56 rotera i pilarnas 64 resp. 65 riktning och tjanstgora som en kugghjulspump, soni pumpar vatska fran husets 38 centrala rum 66 till ett radiellt utanfor pumpen anordnat tryckrum 68. Pa omse sidor am pumpen aro anordnade tatningsplattor 70, 72 vilka anpressas axiellt mot hjulen. 54, 56 german att tryakvatska fran pumpen infores p5 deras baksidor. Ask the two gears 54, 56 to rotate in the arrows 64 resp. 65 direction and serve as a gear pump, which pumps liquid from the central space 66 of the housing 38 to a pressure chamber 68. arranged radially outside the pump, sealing plates 70, 72 are arranged on either side of the pump which are pressed axially against the wheels. 54, 56 german to tryakvatska from the pump infores p5 their backs.

Mellan vane tryckrum 68 ocn det centrala rummet 66 Sr anordnad en cirkulationsledfling 71 riled en maximaltrycksventil 76. Arranged between the usual pressure chamber 68 and the central space 66 is a circulation guide flap 71 with a maximum pressure valve 76.

Det centrala rummet 66 still- genom kanalerna 80, 82, 84 i standig forbindelse med en utanfOr den hydrostatiska kopplingen anordnad kammare 86. Bet centrala rummet 66 star dessutom genom kanalen 88 i standig fOrbindelse med en annan utanfdr den hydrostatiska kopplingen anordnad kammare 90. The central space 66 is still through the channels 80, 82, 84 in permanent connection with a chamber 86 arranged outside the hydrostatic coupling. In addition, the central central space 66 is in permanent communication through the channel 88 with another chamber 90 arranged outside the hydrostatic coupling.

Varje tryekram 68 star genom kanaler 92, 91 1 forbindelse med ett ringformat spar 96 i en. urborrning 98 i axeltappen 42 anordnad axiellt fixerad bussning 100. Denna bussning Sr forsedd Tried en axiellt genomgaende central urborrning 102, vilken genom ininst en radial banning 104 star i forbindelse med det ringformiga sparet 96. I urbormingen 102 Sr ventile,n 28 axiellt forskjutbar. Each pressure hug 68 is connected through channels 92, 91 to an annular groove 96 in one. axially fixed bushing 100 arranged in the shaft pin 42. This bushing Sr is provided with an axially continuous central bore 102, which by means of at least one radial bore 104 communicates with the annular groove 96. In the bore 102 Sr valve, n 28 is axially displaceable.

Ventilen 28 bestar av en spindel 106, som noga tatar mot urborrningen 102. Denim spin-del ãr fOrsedd med en central mot spindelns ena ande oppen urborming 108. Spindeln Or dessutorn p5 tvS axiellt skilda stallen fOrsedd med tvargaende borrningar 110 resp. 112. Ett ringformigt spar 114 Sr upptaget i spindelns ytteryta, I vilket spar borrningarna 110 mynnar. Vid ett axiellt lage av ventilen 28 kommunicerar borrningen 104 med sparet 114 och armed genom bormingen 110 och urborrningen 108 med kammaren 115. Ventilspindein 106 Sr vid sin fran kammaren 115 vanda ande forsedd med en skivformad kolv 116, vilken Mande anligger mot urborrningen 98. Kolven 116 pressas medelst en fjader 118 i riktning fran kanunaren 115. Den pa andra sidan em kolven 116 belagna delen av urborrningen 98 kommunicerar medelst minst en radiell borrning 120 med ett cirkulart spar 122 i axeltoppens 42 yttre mantelyta. Detta spar 122 kommunicerar i sin tur medelst minst en radiell urborrning 124 1 axeln 10 med ett cirkulart spar 126 i axelns 10 yttre mantelyta. Deta spar 126 kommunicerar i sin tur medelst minst en radiell urborrning 128 i en. bussning 130 med ett eirkulart spar 132 i bussningen 130 yttre mantelyta. Detta spar ,slutligen star i standig fOrhindelse med kanalen 26 i husets 12 gaveldel 134. The valve 28 consists of a spindle 106, which carefully tugs against the bore 102. The denim spin part is provided with a central bore 108 open towards one end of the spindle. The spindle or also axially spaced stalls provided with transverse bores 110 resp. 112. An annular groove 114 is occupied in the outer surface of the spindle, into which the groove bores 110 opens. At an axial position of the valve 28, the bore 104 communicates with the spar 114 and is armed through the bore 110 and the bore 108 with the chamber 115. The valve spindle 106 is at its vane from the chamber 115 provided with a disc-shaped piston 116, which Mande abuts against the bore 98. The piston 116 is pressed by means of a spring 118 in the direction of the gun 115. The part of the bore 98 located on the other side of the piston 116 communicates by means of at least one radial bore 120 with a circular groove 122 in the outer circumferential surface of the shaft top 42. This groove 122 in turn communicates by means of at least one radial bore 124 in the shaft 10 with a circular groove 126 in the outer circumferential surface of the shaft 10. This groove 126 in turn communicates by means of at least one radial bore 128 in one. bushing 130 with an circular groove 132 in the bushing 130 outer sheath surface. This saves, finally standing in constant connection with the channel 26 in the end part 134 of the housing 12.

Momentomvandlaren 31 Sr av en i och for sig kiind typ. Med huset 38 dr ett roterande - -a hus 136 fast forbundet. I delta has 136 är en pumpskovelkrans 138 fast anordnad. Vidare aro i momentomvandlaren anordnade tva. turbinskovelkransar 140, 142 och en mellan dem placerad reaktionsskovelkrans 144. Turbinskovelkransarna 140, 142 aro, anordnade pa en turbinskiva 146, sum ãr rotationsvis fast forbunden med en turbinaxel 148. Reaktionsskovelkransen 144 ãr pa likartat salt medelst en reaktionsskiva 150 rotationsvis fast fdrbunden med en reaktionsaxel 152 koncentriskt med turbinaxein 148. Mellan dessa tva axlar 148 och 152 är en ringformad kanal 154 for tillforsel av vatska till momentomvandlaren 34 genom oppningen 155 i turbinskivan 146. The torque converter 31 Sr of a per se kiind type. With the housing 38 there is a rotating housing 136 fixedly connected. In delta has 136 a pump vane ring 138 is fixedly arranged. Furthermore, two are arranged in the torque converter. turbine vane rings 140, 142 and a reaction vane ring 144 placed between them. 152 concentric with the turbine shaft 148. Between these two shafts 148 and 152 is an annular channel 154 for supplying liquid to the torque converter 34 through the opening 155 in the turbine disk 146.

Direktkopplingen 32 utgores av en i huset 38 anordnad skalformad urtagning 156, i vii-ken en kolv 158 är axiellt forskjutbar mot ett lamellpaket bestaende dels av ett antal lameller 160, vilka aro ovridbart forbundna med huset 38, dels ett antal lameller 162, vilka aro ovridbart forbundna med ett nay 164, vilket i sin tur är ovridbart forbundet med turbinaxeln 148. Den mellan huset 38 och kolven 158 uppstaende kammaren 90 star genom. kanaler 166 genom bussningen 100 i forbindelse med kammaren 115, vilken i sin tur genom en inuti turbinaxeln 148 anordnad kanal 168 st5r i forbindelse med ett avlopp vid momentomvandlardrift och med en hogtrycksvatskekalla vid direkt drift. The direct coupling 32 consists of a shell-shaped recess 156 arranged in the housing 38, in which a piston 158 is axially displaceable against a lamella package consisting partly of a number of lamellae 160, which are inextricably connected to the housing 38, and partly of a number of lamellae 162, which are inextricably connected to a nay 164, which in turn is inextricably connected to the turbine shaft 148. The chamber 90 projecting between the housing 38 and the piston 158 stands through. ducts 166 through the bushing 100 in connection with the chamber 115, which in turn is connected through a duct 168 arranged inside the turbine shaft 148 in connection with a drain during torque converter operation and with a high-pressure water cooler during direct operation.

Den pa andra sidan em kolven 158 befintliga kammaren 86 star genom lagret 170 och lamellpaketet 160, 162 i direktfOrbindelse med momentomvandlaren 34. The chamber 86 located on the other side of the piston 158 stands through the bearing 170 and the lamella package 160, 162 in direct connection with the torque converter 34.

Anordningen fOr .momentbegransning genom den hydrostatiska kopplingen 30 arbetar pa. foljande salt. Vid hydrauldrift cirkulerar arbetsvatskan frail en tryckvatskelcalla genom kanalen 154, appningen 155, lagret 170, lamellpaketet 160, 162, kammaren 86 och kanalerna 84, 82, 80 till den hydrostatiska kopplingens centrala rum 66 och darifran genom kanalen 88, kammaren 90, kanalerna 166, kammaren 115 och kanalen 168 till ett avlopp. Vid tomgangsvary pa den drivand.e motorn arbetar den hydrostatiska kopplingen praktiskt taget utan sliming, dvs. utan att nagon vatska passerar genom kugghjulspuanparna. Huset 38 har darfar praktiskt taget samma varvtal som det centrala kugghjulet 36. The torque limitation device through the hydrostatic coupling 30 operates on. following salt. In hydraulic operation, the working fluid frail circulates a pressure water source through the channel 154, the opening 155, the bearing 170, the lamella package 160, 162, the chamber 86 and the channels 84, 82, 80 to the central space 66 of the hydrostatic coupling and thence through the channel 88, the chamber 90, the channels 166, the chamber 115 and the channel 168 to a drain. When idling on the drive motor, the hydrostatic clutch works practically without slimming, ie. without any liquid passing through the gear couplings. The housing 38 therefore has practically the same speed as the central gear 36.

Vid stillastaende fordon overfores pa detta satt en viss ,dragkraft till hjulen, vilket ger fordonet en viss tendens att rora sig. Dessutom uppstar ,svarigheter att koppla cm en tram- och backvaxel. In the case of a stationary vehicle, a certain traction is transmitted to the wheels in this way, which gives the vehicle a certain tendency to move. In addition, difficulties arise in connecting cm a tram and reverse gear.

Genom att tillfdra tryckvalska Iran pumpen 22 genom ledningen 24 och kanalerna 26, 132, 128, 126, 124, 122 och 120 till urborrningen 98 pressas koIven. 116 och dammed ventilen 28 at hoger till ett lage, dar sparet 114 kommunicerar med borrningen 104. Den i pumparnas tryckkammare 68 befintliga vatskan strommar darvid genoan kanalerna 92, 94, 96, 104, 114, 110, 108 ut i kammaren 115 och dd.rifran genom kanalen 168 till ett avlopp. Krugghjulen 54, 56 borja harvid rotera och pumpa vatska fran lagtryckskammaren 66 till hOgtryckskamrarna 68, varifran vatskan pa ovan namnt sat bortledes till avloppet. Till foljd av den begransade arean pa Oppningen 84 hinner inte lika rnycket vdtska strOmma in I lastryckskammaren 66 som den samtidigt genom pumparna 54, 56 borttransporterade. Lagtryckskamanaren tommes pa detta satt partiellt till dess ett jamviktstillstand mellan den tillforda och bortforda vatskemangden uppstar pa grun.d av centrifugalkraften och avloppsledningarnas dimensioner. Tomningen av kopplingen gar dock aldrig langre An att tillrackligt mycket vatska for att sakerstalla smorjning och kylning ar tillga.nglig. By supplying pressure roller Iran pump 22 through line 24 and channels 26, 132, 128, 126, 124, 122 and 120 to bore 98, the piston is pressed. 116 and dammed the valve 28 to the right to a position where the groove 114 communicates with the bore 104. The liquid present in the pressure chamber 68 of the pumps then flows through the channels 92, 94, 96, 104, 114, 110, 108 into the chamber 115 and dd. rift through channel 168 to a drain. The gears 54, 56 then begin to rotate and pump liquid from the low pressure chamber 66 to the high pressure chambers 68, from which the liquid on the above named is discharged to the drain. Due to the limited area on the opening 84, the amount of liquid liquid does not have time to flow into the load pressure chamber 66 as it is transported away simultaneously through the pumps 54, 56. The low-pressure chamber is partially emptied in this way until a state of equilibrium between the supplied and removed water basins arises due to the centrifugal force and the dimensions of the drainage pipes. However, emptying the coupling never takes longer than enough water to ensure lubrication and cooling is available.

Nar kugghjulen 54, 56 bOrja rotera, medlar detta att en motsvarande varvtalsskillnad uppstar mellan det centrala kugghjulet 36 och huset 38, dvs. att kopplingen slirar. Nar kopplingen slirar, sjunker varvtalet pa den hydrodynamiska momentomvandlarens purnpdel 136, 138, vilket medfor en avsevard minskning av momentonavandlarens momentupptagningsformaga, aftersom derma ar proportionell mot kvadrate,n pa pumpvarvtalet. En sliming i kopplingen, som minskar varvtalet med 50 % betyder darfor en minskning av momentet med 75 % och en. minskning av varvtalet med 67 % betyder en minskning av momentet med 89 %. PA detta salt erhalles en momentnedsattning sum ar fullt tillracklig for att i praktiken ersatta en fullstandig urkoppling. When the gears 54, 56 begin to rotate, this mediates that a corresponding speed difference arises between the central gear 36 and the housing 38, i.e. that the clutch slips. When the clutch slips, the speed of the torque section 136, 138 of the hydrodynamic torque converter drops, which results in a considerable reduction in the torque converter's torque absorption capacity, since it is proportional to squares, now at the pump speed. A sliming in the clutch, which reduces the speed by 50%, therefore means a reduction of the torque by 75% and one. reduction of the speed by 67% means a reduction of the torque by 89%. On this salt, a torque reduction is obtained which is fully sufficient to in practice replace a complete disconnection.

Innan fordonet Ater skall startas stoppas pumpen 22 varvid ventilen 28 medelst fjadern 118 Ater sluter forbindelsen mellan hogtryckskamrarna 68 tool]. avloppsledningen 168. Kopplingens lagtryckskammare 66 fylles hdrvid anyo med vatska och transmissionen dr pa nytt redo for full momentOverforing. Before the vehicle Ater is to be started, the pump 22 is stopped, the valve 28 by means of the spring 118 Ater closing the connection between the high-pressure chambers 68 tool]. the drain line 168. The clutch pressure pressure chamber 66 is then filled with liquid and the transmission there again ready for full torque transmission.

Claims

Patent claim:

A device for limiting the passing torque during a transmission comprising a hydrostatic coupling and a hydrodynamic torque converter arranged in series, the coupling dr of pump type and provided with high pressure and low pressure chambers, melba which liquid circulates during normal sliming Mom coupling, the legal pressure chamber (66) communicates with it by means of at least one inlet opening (80, 82, 84) which is selectively actuated with a limited area and that a selectively actuatable valve (28) is arranged to connect the high-pressure chamber of the coupling ( 68) with a liquid container arranged outside the coupling through at least one outlet opening (92, 94, 96, 101, 114, 110, 108, 115, 168) with a larger capacity than the inlet opening (80, 82, 84), whereby not only the pressure difference between high pressure and legal pressure chamber without even the amount of liquid in the coupling rainbox.

Device according to claim 1, characterized in that the selectively actuatable valve (28) is arranged centrally in the coupling and displaceable in the axial direction.

Device according to claim 2, characterized in that the selectively actuable valve (28) is hydraulically operated.

4. A device according to any one of patent claims 1-3, characterized in that the pressure roller Milan for the coupling consists of the working chamber of the torque converter (24)

Device according to claim 3, characterized in that the pressure vessel jaw operating the selectively actuatable valve (28) is regulated by means of a main valve common to the transmission.

Device according to the partition claim 3, characterized in that the pressure vessel maneuvering the selectively actuatable valve is supplied by a separate pump (22). Listed publications: