Sept. 24, 1946. ' w, D, TlPTON 2,408,008 HYDRODYN AMI C TRANSM I S S ION Filed Feb. 17_, 1944 2 Sheets-Shea l INVENTOR ' WILL/HM D. T/P‘T'ON W/KW Y , ATTORN Y Patented Sept. 24, 1946 2,408,008 UNITED STATES PATENT OFFICE 2,408,008 ' HYDRODYNAMIC TRANSMISSION William D. Tipton, Stoneleigh, Md.; Elizabeth B. Tipton executrix of said William D. Tipton, deceased 1 Application February 17, 1944, Serial No. 522,735 7 Claims. ( Cl. 74-1895) This invention relates to hydrodynamic trans missions, particularly to those types which-em body a ?uid torque converter and a gearset in combination; and is an improvement over the arrangement disclosed and claimed in my previ ously issued Patent No. 2,306,834, issued Dec. 29, 2 usual starting gear ll. Bolted to the ?ywheel It] at i2 is a shell-like housing member I3 which encloses the hydraulic unit and has a rearwardly extending portion M to which is attached by means of a jaw clutch l5, a plate-like .member H3. The latter is fastened by bolts I‘! to a car 1942. rier member l3. _A resilient sealing assembly The principalobject of this invention is to pro 5 9 of any suitable design is provided between the vide an improved automatically variable ratio housing 23, and rearward extension M as illus power transmission of the aforesaid‘ type for 10 automotive use wherein the major portion of the The carrier l8 carries a plurality (preferably trated. » V engine torque is transmitted mechanically under three) of planetary gear elements 2|, each being vehicle direct drive conditions. provided with three sets of gear teeth, designated Another object is to provide an improved power respectively 22, 23 and 24, the purpose of which transmission of the ?uid type wherein the hy will be presently made clear. ‘ draulic power transmitting structure will func The hydraulic unit comprises three relatively tion as a torque multiplier during vehicle oper rotatable vaned wheels 25, 3| and 35. The wheel ation under conditions of high torque demand, 35 serves‘as an impeller and carries a sleeve 36. and as a ?uid coupling of the kinetic type under The wheel 25 is adapted to serve both as an im— conditions of low torque demand. 20 peller and as a guide or reaction wheel under .Still another object is to provide in such a different operating conditions and is fastened at transmission means for automatically adjusting 25 to a sleeve 21, the latter being splined at 28 the drivingratio to accommodate varying condi to the forwardly extending portion 29 of an an tions of drive. nulus gear 30. The runner or turbine wheel 3| A further object is to provide in such a device, is carried by a hub 32 splined at 33 on the out means for increasing the overall operating effi put shaft 34. ciency while maintaining the desirable cushioned Fig. 2 illustrates the shape of the vanes of the drive and good accelerating characteristics. three wheels. The impeller and runner wheels A still further object is to provide in connec 35 and 3| may have straight or curved vanes and tion with such a transmission, an automatically 30 the wheel 25 which‘ acts as either an impeller operable and foolproof “no-back” or “hill-hold.” or a guide wheel has curved vanes. Other objects and advantages of the device will The sleeve 36 carried by the impeller 35 is become apparent from a reading of the following splined at 31 to thelforwardly extended hub of description. Further objects and advantages of the inven tion will become apparent from the following de scription. Reference is now made to the accompanying drawings in which reference characters have been used to designate corresponding parts re ferred to in the description, and wherein Fig. 1 is a longitudinal central sectional view a sun gear 38. The gear 38 has teeth 39 which mesh with the teeth 22 of planet gears 2|. The teeth‘ 23 of the planet gears mesh with teeth 40 of an annulus gear 4|, and the teeth 24 of the planet gears mesh with teeth 42 of a smaller annulus gear 43. The gears 4| and 43 are dis posed in telescoping relationship as illustrated and are rotatable with respect to each other and shaft 34. of a preferred embodiment of the power trans Gear 4| has a rearwardly extending hub which mission. Fig. 2 is an enlarged fragmentary sectional 45 is adapted to be drivingly connected by means of a one-way clutch 44 with a brake drum 45. Gear view of the ?uid directing vanes, the three sets 43 has both forwardly and rearwardly extending of vanes being shown in a single plane for con. hubs. The forward extension thereof is adapted for driving connection with shaft 34 by one-way Fig. 1. ‘ ‘ 50 clutch 46, and the rearward extension is adapted Fig. 4 is an enlarged sectional View of valve F for driving connection with a brake drum 41 by of Fig. 1, and one-way clutch 48. ‘ Fig. 5 is a similar view of valve G. The clutches 44, 46 and 48 are of the well Referring to the drawings, I0 designates the known camland roller type and are so ‘arranged 1 ?ywheel of a vehicle engine which carries the 55 that shaft 34 can overrun gear 43, gear 4| can venience. ‘ Fig. 3 is a section taken along line 3--3 of 2,408,008 3 4 overrun brake drum 45 and gear 03 can overrun Solenoid S has the usual field coil I05 and core I06. A coil spring I01 biases the valve stem I08 (which is formed integrally with core I05) to venting position, The stem has a pair of en brake drum 4?. A third brake drum "35 is splined at 50 to the mainshaft 34 and thus functions when locked to hold the shaft 34 stationary. The drums 55, ‘ill and 49 are respectively con trolled by brake bands 5|, 52 and Y53. These bands are similar inconstruction and are hy draulically actuated. The mechanism for oper ating band 52 is shown in detail in Fig. 3. As illustrated, housing plate 54 carries a fluid cylin der 55 in which is disposed a, reciprocable piston 55. Piston 55 has a reduced extension 5'! sup ported in a boss 58. The brake band 52 has a pair of ears 59 normally urged apart by a coil spring 60. The piston extension 51 passes through holes in the ears and carries the spring v5|). vFluid under pressure introduced through port 6| will tighten the brake band and restrain rotation of the drum 5'5. Suitably attached to the rear end of the hous ing '52 is a housing 53 which contains a forward and reverse gearset. The latter comprises a gear 05 rotatably mounted by means of ‘a .ball bearing 57 in wall 55 of casing 53. Gear 55 is splined on shaft 30 at 08 and has teeth 55 disposed in mesh with a countershaft gear 69. The latter is larged portions I05, I|0 which permit communi cation between port 99 and either port I0! or I03 depending upon the valve positions. ' It is ‘clear therefore that‘valve G will remain in its illustrated position and brake drum 45 will be free for rotation so long as the mercury globule 9| remains in the bottom of tube 90. The tube ‘30 'will be revolved about the axis of shaft 85 whenever shaft 34 is rotated, and at some pre determined speed of shaft 35 the globule 9| will be forced upwardly in the tube by centrifugal force and contacts 32 will be bridged whereupon solenoid S will be energized and valve G will be operated to close off vent port I03 and open pres~ sure port IOI. Brake band 5| will thus be set. Brake bands 52 and 53 are operated manually by means of pedal I05’ and valve F. Pedal I05’ corresponds somewhat to the conventional clutch pedal in its operation. Valve F (Fig. 4) has a vent passage I05’ which vconnects vent ports I01’, I08’ with the sump through‘ pip-e I09’. A pipe H0’ supplies fluid pressure to pressure ports III, I I2. Port I I3 connects with the operating cylin der of brake band 53 through pipe I I5, and port I I4 connects with the operating cylinder of brake one of a cluster 10 carried on countershaft H. A second countershaft gear ‘I2 meshes with an , idler gear 73 which is suitably mounted in the 30 band 52 through pipe H6. Pedal I05’ is operably connected with a cross Casing. head III which is in turn operably connected _ ‘Piloted in the hollow bore of gear 651s one end ‘of a‘shaft ‘M, a roller bearing ‘I5 being dis with valve stems H8 and H9. Coil springs I20, I2I urge the respective stems I I8, I I3 toward the posed between the shaft and gear. The shaft 14 is rotatably supported at its rear end by a bearing 35 right of Fig. 4. Stem H5 has enlarged portions 13 and constitutes the ?nal driven shaft of the I24, I25 formed thereon and stem I I0 has similar transmission. 7 ‘ portions I22, I23. The respective enlarged stem ‘portions are so Slidably mounted on splines TI is a clutch mem arranged that depression of pedal I05’ one half ber ‘I8 which is adapted to be shifted axially of the housing by a shifter fork ‘I9 in the usual 40 of its stroke will cut off pressure port II2 and open vent port I07’ without affecting the rela manner. Clutch member ‘I8 has teeth 80 adapted tionship of ports in the lower valve chamber. to mesh with idler "I3 upon rearward shift thereof, Further depression of the pedal to ‘the limit of and clutch teeth 8| adapted to mesh with clutch teeth '82 carried by gear 65 upon forward shift. its stroke will close vent port I58’ and open 45 pressure port I II without affecting the relation As can be readily understood, the clutch mem ship of ports in the upper valve chamber. ber ‘I8 may be shifted from its illustrated neutral position rearwardly to engage idler ‘I3 for reverse The effect of this operation characteristic of drive, or forwardly to engage gear 65 for forward valve F is to release band 52 .(which is normally set as above explained in connection with Fig. 3) drive. Mounted on top of casing 63 is a governor by depression of pedal I05’ half way and to set mechanism 83. This comprises a shaft 85 having brake band 53 by, full depression of the .pedal while maintaining band 52 released. The signi? a worm pinion 85 at its lower end. The latter engages a worm 85 which is carried by a shaft cance of this will be more fully explained below. ‘The operation of my improved transmission is 8'! mounted in the wall 65. This shaft also car ries a gear 83 which engages and is driven by 55 as follows: With the Vehicle at rest with its engine running gear 65. Shaft 84 carries a collar 85‘ which in turn carries a. closed tube 90 of non-conducting and the parts in their illustrated positions, brake drum 4‘! is stationary because of the pressure material, mounted as shown. In the tube 90 is a globuleiof mercury 9|. The tube is inclined such in cylinder 55. Annulus gear 43 is therefore 60 that the globule normally rests in the lower end held against reverse rotation and forms a reac tion point for the planetary gearset. Flywheel thereof. The upper end Of the tube has .a pair I0, housing I3, plate It and carrier I8 are rotat of electrical contacts 92, which are connected by ing at engine speed, and planet gears 21 are ?exible conductors 93 to a pair .of slip rings 94, 95. Slip ring 55 is connected to one side of a bat rotated due to the teeth 42 being held. tery 95 (preferably the regular car battery) and 65 The hydraulic wheels 25 and 35 are thus caused to rotate forwardly with carrier I8, the impeller slip ring 54 is connected by a wire 0'! with a 35 turning in excess‘ of input speed and the wheel solenoid S (Fig. 5) which forms part of a control 25 turning slowly in accordance with the relation valve G. The other side of solenoid S is con ship set up by the planetary gear ratios and nected by wire 98 with the battery 9.5. Valve G is shown in venting position. Port ‘90 thereof is "Il thus functions as a reaction or guide wheel for the hydraulic unit. The vehicle remains station connected by a pipe I00 with the operating cylin ary because of clutch ‘I8 being in neutral. der of brake band 5|; port IOI is connected .by Pedal I05’ is now depressed fully releasing drum pipe I02 with a source of fluid pressure ‘(the 41 and setting band 53. This removes the ‘reac engine lubricating system for example) and port tion point from the planetary 'gearset and locks I03 vents to the sump through pipe I04. 2,408,008 5 6 shaft 34 and gear- 65 against rotation. Shifter fork 19 may now be manipulated to engage teeth If, when running in direct drive, the driver‘ desires to accelerate the vehicle, opening of the 80 with gear 13 for reverse drive or to engage teeth 8| with teeth 82 for forward drive. Let it be assumed that forward drive is established. Pedal 105' is then released locking gear 43. Gear 34 which is driven by wheel 25 may be larger than gear 43 as shown, but is preferably of the same size whereupon it remains stationary. throttle will cause asudden‘ torque increase on carrier 18 which because of the difference in gear sizes will speed up wheel 35. This will, in turn, cause increased ?uid velocity in the ?uid circuit andincrea-sed reaction on wheel 25. The latter will slow down and react against brake‘ drum 45 (which is set) through the action of gears 30, 2|, 10 43 and clutch 44, and will rotate at less-than Impeller 35 turns forwardly at greater-than-in put speed because of the step-up in ratio. Note that under these conditions, one-way clutch 46 which prevents reverse rotation of shaft 34, functions as a “no-back” or “hill-hold” device and prevents the car from rolling back ward when stopped on an upgrade. This “hill hold”. can be made ineffective ‘in case the driver desires to let the vehicledrift backwards by de pressing pedal Hi5’ half way. This releases drum 4'! which has held gear 43 stationary through one way clutch 43. , As the engine is speeded up, impeller 35 de . livers ?uid to guide wheel 25 which is turning input speed depending upon the predetermined ratio of gears 2| and 44. The vehicle has now returned to second speed ratio condition. This return or “step-down” is entirely automatic and is the result of additional torque supplied or in creased torque demand on shaft 34, or both. Thus it is seen that the equivalent of’ the well-known “kickdown” is present Without the necessity of any conscious eifort on the part of the driver; Restoration’ of direct drive is automatic when the torque difference between ?ywheel It and shaft 34 disappears. . _ . It may therefore be seen that I have provided forwardly slowly or is stationary in accordance an improved hydrodynamic drive which is simple _ with the relative diameters of gears 30 and 43. in construction, economical to build, entirely au The out?ow from wheel 25 enters the passages tomatic in operation, and which operates at a of runner 31 which drives the final drive shaft higher efficiency than those heretofore used.‘ 14 through shaft 34, gear 65 and clutch member ' Having thus described a speci?c embodiment of 18. This condition of drive corresponds to con my invention, I wish to point out that such has Ventional low speed drive. been done for illustrative purposes only and it is When the vehicle has reached a speed of, say not intended to limit the breadth or scope of the 8 M. P. H,, governor mechanism 83 functions invention in the broader aspects thereof except automatically to set brake band 5| and thus ‘stop as set forth in the claims appended below. drum 45; This stops gear 4| from rotating I claim: ' through the action of overrunning clutch 44 and 1. In a ?uid power transmission having a driv causes guide wheel 25 to be rotated forwardly ing structure and a driven structure, a runner at increased relative speed because of the relative wheel carried by the driven structure; a second sizes of gears 4! and 35. Car is now in second vaned wheel arranged in series relation with the speed stage and acceleration continues until the runner wheel and adapted to act either as a run torque demand of shaft 34 is less than that sup. 40 ner wheel or as a guide wheel; a vaned impeller plied by guide wheel 25. ‘ wheel arranged in series relation with the afore The diameters of wheels 25 and 35 and the said wheels; differential gear means for coupling ratios of gears 30 and 38 are such that, under said second wheel and said impeller to the driv normal conditions, the wheel 25 will tend to over ing structure, said gear means being constructed run wheel 35, and when there is a sudden increase and arranged such that the rotational speed of in torque demand such as during acceleration, the said second wheel and said impeller varies in ac increased reaction against wheel 25 will cause it cordance with the ?uid reaction imposed on said to lag behind and rest against brake drum 45 or second wheel as a consequence of torque demand 41 depending upon which of the brakes is set. . on said driven structure; and means operably as When torque demand decreases to a Value less ' sociated with said gear means for coupling said than that being supplied by wheel 25 under the second wheel to said driven structure in response above described second speed driving conditions, to equalization of torque demand on said. runner wheel 25 speeds up to the speed of runner 3!. and said second wheel. This causes a corresponding relative speed-up of gear 43 which now tends to overrun shaft 34. One-way clutch 46 now functions to clutch gear 43 to shaft 34 and the entire planetary unit ro tates as a unit, the gear 4! idling. This condi tion is the third speed ratio or direct drive con 2. In a ?uid power transmission having a driv ing structure and a driven structure, a runner transmitted mechanically to shaft 34 through brake means including a brake drum; an over wheel drivingly connected to the driven struc ture; a pair of hydraulic wheels of different di ameter disposed in driving relation with said runner wheel; a planet carrier driven by the dition. driving structure; a planet pinion on said carrier; Note that wheels 25 and 3| are now turning as two sets of teeth on said pinion; an annulus gear a unit, thus the wheel 25 functions in direct drive meshing with one set of teeth and drivingly con as a runner and wheel 35 functions as an impeller nected with the larger of said wheels; a sun gear slipping slightly with respect to wheels 25 and 3| as in a. two-element ?uid coupling of the kinetic 65 meshing with said teeth and drivingly connected with the smaller wheel; a second annulus gear type. meshing with the second set of pinion teeth; In direct drive, most of the engine torque is running brake device‘ operably disposed between shell l3, planet carrier I8, planet gear 2 I , annulus gear 43 and clutch 46. The remainder is trans 70 said second annulus gear and said brake drum for preventing reverse rotation of said gear when mitted hydraulically through runner 3! , thus the slippage present in ordinary torque converter and _ ‘ said brake is set; and an overrunning clutch de vice operably disposed between said second annu ?uid coupling transmissions is reduced to an ex tremely low value with consequent gain in over lus gear and said driven structure for drivingly 75 coupling said gear to said driven ‘structure in re all e?iciency. 2,408,008 7 8 sponse to tendency of said‘ gear to overrun said meshing with said teeth and Vdrivi-ngly connected structure. wheel drivingly connected to the driven struc with the smaller wheel; a second annulus gear meshing with a second set of pinion teeth; a third annulus gear of larger diameter than said second annulus gear’ meshing with'the third set of pin ture; a pair of hydraulic wheels of different di ion teeth; means for selectively restraining re . 3. In a fluid power transmission having a driv= ing structure and a driven structure, a ‘runner ameter, disposed‘ in driving relation with said verse rotation of said second and third‘ gears runner wheel; a planet carrier driven by the driv“ while permitting free forward rotation thereof; ing structure; a planet pinion on said carrier; meshing two sets of with teeth oneonsetsaid of teeth pinion; and andrivingly annulus con said means for restraining the annulus gear of larger diameter including a governor means're sponsive to the speed of said driven structure. 6. In a ?uid power transmission having a'driv lng structure and a driven structure, a runner nected with the larger of’said wheels; a sun gear meshing with said teeth and drivingly connected wheel drivingly connected to the driven struc with the smaller Wheel; a second annulus gear meshing second annulus with thebeing second theset diameter of pinion of teeth; or smaller 15 ture; a pair of hydraulic wheels of different di than said ?rst annulus; and means for auto~ matically clutching said second annulus to said driven structure in response to tendency. of said gear to overrun said structure. 4. In a ?uid power transmission'having a driv ing structure and a driven structure, a runner wheel drivingly connected to the driven struc’w ' ture; a pair of hydraulic wheels of different di- ameter disposed in driving relation with said run ner' wheel; a planet carrier'driven by the 'driv ing structure; a planet pinion on said carrier; two sets of teeth on said pinion; an annulus gear meshing with one set of teeth and drivingly con nected with the larger of said wheels; 2. sun gear meshing with said teeth and drivingly connected with the smaller wheel; a second annulus gear meshing with the second setv of pinion teeth; ameter disposed in driving relation with. said run ner wheel; a planet carrier driven by the driving structure; a planet pinion on said carrier; two - brake means including a brake drum; arr-oven sets of teeth on said pinion; an annulus gear meshing with‘ one set of- teeth and drivingly con nected with the larger of said wheels; 2. sun gear for preventing reverse rotation of said gear when said brake is set;,and an overrunning clutch de vice operably disposed between said second annu lus gear and said driven structure for preventing reverse rotation of said driven structure with re spect to said gear. meshing with said teeth and drivingly connected with the smaller wheel; a second annulus gear meshing with the second set of pinion teeth; means for restraining said second; annulus against reverse rotation whereby said larger _, wheel may act as a guide wheel; and means for running brake device operably disposed betweenv said second annulus gear and said brake drum , 7. In a hydrodynamic transmission for an au tomotive- vehicle, a pair of series arranged hy-' draulic wheels; planetary gear means for con automatically coupling said second annulus to necting said; wheels with the vehicle engine; a said driven structure in response to tendency of '7 third hydraulic wheel arranged in series with the said gear to'overrun said structure. aforesaid wheels and connected to the vehicle 5. In a ?uid power transmission having a driv 40 driving wheels; said planetary gear means in~ cluding a planet pinion having a plurality of sets ing structure and a driven structure, a runner wheel drivingly connectedto the driven struc~ of teeth; an annulus gear disposed in mesh with ture; a pair of hydraulic wheels of different di— one set of teeth; a second‘ annulus gear disposed ameter disposed in driving relation with said run~ in mesh with a second set of teeth; selectively op~ ner wheel; a planet carrier driven by the driving era-ble brake means for controlling rotation of said annulus gears, and means including gover structure; a planet pinion on said carrier; three nor means operably responsive to the speedof sets of teeth on said pinion; an annulus gear meshing with one set of teeth and drivingly con the‘ third wheel for controlling said brake means. nected with the larger of said wheels; a sun gear WILLIAM D. TIPTON.