!• Field of the Invention The instant invention relates to freewheels and, i particular, relates to a novel unidirectional clutch/bearin assembly adapted to be used in connection with an automobile torqu converter and which accommodates loads in the axial, radial an circumferential directions.

2. Description of the Prior Art Virtually every motor vehicle equipped with an automati transmission uses some form of fluid coupling known as a torqu converter. The typical three-element single-stage converter i comprised of an impeller, driven by the output shaft of the engine fluidly coupled to a turbine. The turbine in turn is mechanicall connected to the transmission input shaft. The converter als employs a small, vaned, wheel known as the reactor or stator having its vanes positioned between the impeller and the turbine

and adapted to direct hydraulic fluid deflected off of the turbin blades along a more favorable path back to the impeller blades thereby providing a more efficient energy transfer with respect t the fluid coupling generally. Common practice requires the use of a one-way o unidirectional clutch to lock the reactor to the transmissio casing against rotation in one direction at low engine speeds t provide the aforementioned directing of the transmission fluid, ye allowing free rotation of the reactor in the opposite direction a higher rotational speeds, where the speed of the turbine approache that of the impeller. The conventional bearing system utilized reactors is comprised of a relatively heavy and large type free wheel in addition to axial thrust bearing positioned on either side thereof. The prior art freewheel does no actually perform a bearing function and is costly to manufacture wastes valuable space and adds unnecessary weight. In addition the axial bearing arrangement presently in use significantly add to friction losses. Fig. 1A illustrates, in cross section, the genera diagram of a torque converter 10 which is comprised of a flywhee 12 connected to an impeller 14. The impeller has connected to it curved outer shell a plurality of specially curved impeller vane 16 adapted to propel hydraulic fluid against turbine vanes 18 upo rotation of flywheel 12. Turbine blades 18 are connected to turbin shell 18' which in turn is rigidly connected to transmission inpu

shaft 19. Fluid striking turbine vanes 18, by natural physic forces, is deflected generally backwardly so that it proceeds circulate back into the path of impeller blades 16 whereupon it again propelled at turbine blades 18. This process is repeat while torque is being transferred between impeller 14 and turbi 18'. A device known as a reactor or εtator 20 has come in widespread use and has for its purpose the efficient re-directi of the hydraulic fluid from the impeller blades 18 through preferred path via reactor vanes 22 into smooth re-engagement wi impeller blades 16. Vanes 22 of the reactor are shaped in a fo which approximates an average ideal transmission fluid fl direction for the circulating fluid. However, the reactor 20 wi perform its function only if it is permitted to rotate about t axis of shaft 19 ir. one direction but to lock up, or transm torque, in the opposite direction. Thus, at low RPM, there is a n circumferential force in the direction of arrows F in Fig. against vanes 22 which must be counteracted by vanes 22 in ord for the reactor to perform its re-routing function properl Therefore, the freewheel 23, shown in Fig. IB, upon which t reactor rotates, must be a unidirectional clutch which transmi torque when acted upon by a force in one direction, as shown arrows F in Fig. 2A, yet which permits the reactor 20 to free whe in the opposite direction. The inner race of freewheel 23 connected to a stationary member 30 disposed in concentr relationship about shaft 19 and fixed with respect to the automat

transmission casing T. Once flywheel 12 and hence impeller 14 reach predetermined rate of rotation, the turbine 18' "catches up" to t impeller 14 at which point there is negligible energy transf therebetween. Under such condition, the reactor vanes 22 on create a drag on the rotational motion of the hydraulic flu rotating with the impeller 16 and turbine 18. Therefore, it desirable for the reactor to be permitted to spin freely when act upon by forces directed opposite that of the arrows F shown in Fi 2A. In general, the reactor is of a non-streamline inefficient shape due to the oversized traditional freewheel 23. a result, the "floor" 21 of the reactor presents a sha obstruction in the flow path of fluid returning from turbine blad 18 to impeller blades 16 which diminishes performance of the torq converter substantially. Further, it has heretofore been necessa to make the actual diameter of the overall torque convert unnecessarily large to provide clearance for convention freewheels. In addition, the ramp roller clutch does not resi force in the axial direction and hence requires the use of bul axial thrust elements 26. Reducing the size of the free wheel a related elements will permit a reduction in size of the torq converter, and hence transmission overall. Finally, the freewhee presently in use do not act as a true bearing in the freewheeli mode because the rollers thereof are not permitted to spin relati to the outer race.

It is desired, therefore, to provide a unidirectiona clutch member which acts as a free wheel and a bearing i association with a torque converter reactor which provides lockin action against one direction of rotation of the reactor and lo friction rotation thereof in the opposite direction while utilizin a minimum of space and material and providing resistance agains axial forces. SUMMARY OF THE INVENTION There is disclosed herein an improved unidirectiona clutch or freewheel adapted to rotatably support the reactor of torque converter so as to allow the reactor, in one direction, t spin freely yet prevent rotational movement thereof in the opposit direction, while also providing axial thrust resistance. The nove clutch is comprised generally of four elements: an inner rac member rigidly connected to the transmission housing; an outer rac surrounding the inner race and defining therewith confronting rac surfaces and an volume therebetween, the outer race being rigidl connected to the reactor; a plurality of cylindrical thrus transmitting rollers disposed in said annular volume and incline with respect to radial planes; and annular bearing means associate with one end of the clutch to permit slidable rotation of sai rollers relative to an annular shoulder connected to one of th races. The clutch has a first, larger diameter, end and second, smaller diameter end, between which the inner and oute race surfaces curve according to a special relationship, creatin

a ramp surface against which the rollers jam in the locki direction. The surface profiles of the inner and outer races a generated by the curved lines of constant contact between t rollers and the respective race surfaces. The positive clutch of the present invention is ful described in U.S. Patent Application Serial No. 07/418,795, t entire disclosure of which is incorporated by reference herein though fully set forth herein. By employing the above described technology in my fr wheel, it has become possible to achieve a substantial space savi in the construction of the torque converter, thereby allowing significant reduction in size and consequent cost of componetry. further advantage realized lies in the fact that, through the u of my novel invention, the floor of the reactor, the element which the reactor vanes integrally connect, may be contoured allow the torque transmitting fluid within the converter to trav smoothly from the turbine side to the impeller side of t converter without interruption. Previous free wheel technology i limited to impeded flow of fluid within the converter from t turbine to the impeller due to the non- uniformity of the floor o the reactor caused by the relatively large free wheels used in th prior art. By contrast, my invention, by occupying far less space permits the reactor floor to be contoured to coincide with th overall interior of the torque converter and to thereby improve th performance thereof. In addition, because the traditional (prior art

freewheel such as the ramp roller shown in Fig. IB does not resi axial loading, additional axial thrust bearing elements must incorporated into the torque converter presently used, increasi the weight thereof and space utilized. The instant invention, employing a freewheel of the hyperboloidal type which has slopi race surfaces, resists axial loading without the use of seconda axial thrust components. Also, because the needle rollers 32 us in the traditional ramp roller freewheel DO NOT spin in place the freewheel mode but actually slide along the inner race. contrast, by using a unidirectional clutch on the hyperboloid type disclosed herein, the needle rollers are not constrained wi respect to either the inner or outer race during the freewheel mo and hence the tendency of the races to wear is distributed even about both inner and outer race surfaces. It is a principal object of the instant invention provide an extremely compact and reliable unidirectional axi thrust bearing and freewheel which combines a one-way clutch wi axial thrust bearing features required of a torque converter fr wheel. It is another object of the instant invention to enhan the free wheeling capacity of a torque converter reactor replacing the ramp roller type free wheel with a hyperboloid unidirectional clutch. It is a still further object of the instant invention increase the efficiency of a torque converter by utilizing hyperboloidal-type freewheel which occupies less space than prio

art technology yet which transfers the same magnitude of torq thereof. In accordance with these and other objects which will apparent hereinafter, the instant invention will now be describ with particular reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A shows a cross sectional view of a standard torq converter utilizing a typical ramp roller clutch known in the ar Fig. IB shows a plan view of a typical ramp roller clut as shown in Fig. 1A. Fig. 1C is a plan view of a hyperboloidal-type clutc used with the present invention shown side by side for compariso purposes with the traditional ramp roller freewheel known in t prior art. Fig. 2 is a partial cut away perspective view of typical torque converter and transmission casing arrangemen employing a prior art freewheel. Fig. 2B is a partial cut away perspective view of typical torque converter and transmission casing arrangemen employing my uni-directional freewheel/bearing. Fig. 2C is an enlarged view of a portion of Fig. 2B. Fig. 3 is an exploded perspective view of the pair o clutches used in the preferred embodiment of the present invention Fig. 4 is an elevational view of the uni-directiona clutch used in the present invention with the outer race remove for illustration purposes.

Fig. 5 is a cross section of a torque converter employi a simplified embodiment of the unidirectional clutch in associati with a torque converter reactor. Fig. 6 shows a cross sectional elevation of t embodiment of my invention shown in Figs. 2B, and 3 wherein a pa of my unidirectional clutches of the hyperboloidal-type a employed in association with a torque converter reactor. DETAILED DESCRIPTION OF THE PREFERRBD EMBODIMENT Referring now to the drawings. Fig. 1A a shows a typic torque converter in cross sectional elevation comprised of a f wheel 12 mechanically connected to an impeller 14 via interconnect member such as member 13. Integrally connected impeller 14 are a plurality of vanes 16 spaced equally about t dish-shaped body of impeller 14 adapted to transfer kinetic ener from the rotational movement of the output shaft 11 of a moti source (not shown) such as an automobile internal combustion engi to the input shaft 19 of an automatic transmission. Fly wheel together with interconnecting member 13 and impeller member 14 fo a fluid tight partial housing for hydraulic fluid. Turbine vanes are connected to turbine member 18' and are impacted upon hydraulic fluid propelled by motion of impeller vanes 16, causi turbine 18' to move and to consequently cause torque convert output shaft 19, to which it is rigidly affixed, to rotate. React or stator 20 has specially curved vanes 22 spaced thereabout and positioned generally in the fluid return path between vanes 18 a 16. Reactor 20 is supported, in Figs. 1A and 2A, by a ramp roll

freewheel 23 commonly used in the art. Such a freewheel is shown i Fig. IB. Ramp roller freewheel 23 has an outer race member 2 rigidly affixed to reactor 20 and an inner race member 28 rigidl affixed via splines 29 to stationary member 30, which is fixe relative to transmission casing T. In operation, ramp roller 2 transmits torque from outer race member 26 to inner race member 2 when the outer race member 26 is acted upon by a force tending t rotate it in the direction of arrow J in Fig. IB relative t stationary inner race member 28. However, outer race member 2 freewheels with respect to inner race member 28 when outer rac member 26 is acted upon by a force tending to rotate it in th direction of arrow S. It has heretofore been necessary that the floor 21 o reactor 20 be manufactured generally flat to provide clearance fo the bulky ramp roller clutch 24, hence decreasing performance of the torque converter by presenting a flow obstruction in the hydraulic fluid return path between vanes 18 and 16. The instant invention, the preferred embodiment of which is shown in Figs. 2B, 3, 4 and 6, overcomes the disadvantages inherent in traditional free wheel technology such as that shown in Figs. 1A, IB and 2A by providing a pair of extremely compact and efficient unidirectional clutches 38 each comprised of an inner race member 40 defining an inner race surface 42 and an outer race member 60 defining an outer race surface 62. Said outer race member 60 is integrally connected to reactor 20 by any expedient known in the art, such as by splines, molding, welding, casting and the

like. A plurality of thrust transmitting rollers 50 are disposed the annular volume 49 formed by and between the confronti surfaces 42 and 62 of the inner and outer race members 40 and 6 respectively. Said rollers 50, of which there must be at lea three to obtain static and dynamic deter inance, are all similar inclined with respect to radial planes. The confronting inner and outer race surfaces 42 and are surfaces of revolution about the axis of rotation of t clutch. The inner race surface or surface of revolution 42 contac each of said rollers along a first line of contact, said first li of contact being the generating line for said first surface revolution. Said outer race or second surface of revolution 6 contacts each of said rollers along a second line of contact, sai second line of contact being the generating line of said secon surface of revolution. The clutch has a first end 44 and a secon end 46, said first end having a larger diameter than said secon end. Said rollers 50 each have a first end 54 and second end 5 corresponding to the first end 44 and the second end 46 of th clutch 38, said first end 54 of said rollers 50 and said first en 44 of said clutch meeting at an interface. Preferably, bearin means such as annular ring 70 is disposed at the interface of sai rollers 50 with said first end 44 to permit slidable movemen therebetween in a first direction while supporting the rollers 5 axially thereof. It should be noted that the rolling axes of rollers 5 constitute generators of true hyperboloids. Therefore, th

generating lines of the inner and outer race surfaces approac generators of a true hyperboloid as the radius of the roller approaches zero. According to the preferred embodiment, the bearing mean at the interface between the rollers and at least one of the firs and second members is an annular support ring 70 positioned on an supported by an annular shoulder 72 integrally connected to a least one of the members 40 or 60 beneath the rollers at th position of contact, or interface, between the rollers 50 and rac surfaces corresponding to the larger diameter end 44 of eac member. The annular support member 70 may be fabricated of self-lubricating material and is thereby capable of slidabl rotation relative to at least one of the members so as to freel support the rollers rotatably relative to said at least one member. Preferably, the supported end portions of the rollers 58 are arcuately or spherically shaped and the annular ring member 70 configured to define a plurality of correspondingly shaped depressions or cavities 64 on the roller supporting surface so as to receive the end portions of the rollers in nestled relation and thereby maintain the rollers in predetermined spaced relation corresponding to the distance between the cavities 64. The race surfaces 42 and 62 are capable of thrust transmitting contact with the rollers 50 so as to transmit torque between the members 40 and 60 in dependence upon the number and diameter of the rollers 50, the length of the rollers and the angle of inclination between the rollers with respect to radial planes.

It has been found that the use of a pair of hyperboloid unidirectional clutches disclosed herein, the first referred to the State I or first stage and the second referred as the Stage or second stage, would provide enhanced performance over a sing such clutch as twice the torque transmitting capacity is ma available. Further, because the race surfaces are sloping and t rollers 50 inclined, the clutches 38 transmit axial loading a hence perform the critical function of acting as axial thru bearings, in addition to the capacity of the hyperboloidal clut to act as a true roller bearing in the freewheeling stat Therefore, using two hyperboloidal clutches between the reactor and stationary shaft 30 provides a unidirectional clutch which ac as a true roller bearing when freewheeling, acts as an axial thru bearing to withstand loading along the axis of rotation R of t clutch, and which occupies a minimum of space and is extreme lightweight when compared to prior art technology. Biasing means such as coil spring 65 or Bellevil spring or wave washer 90, shown in Figure 6, or the like disposed between Stage I and Stage II of clutches 38 so as to bi the respective inner race members 40 thereof away from each othe In this way, still referring to Figure 6, the inner and outer ra members are maintained in proper alignment should wear occu Retaining means such as C-clips 92, 94 may be used to limit t positions of the Stage I and Stage II inner race members where t inner race members are axially movable on shaft 30. The ra members may be machined out of solid material or may be stamped o

of thin sheet material as shown for outer race member 60. In suc an embodiment, reactor 20 is rigidly connected to outer race membe 60 in any convenient manner. The torque transmitted between th members is dependent particularly upon the radius of the inne conical surface 42 at the smaller end 46 and the radius thereof a the larger end, as well as the length of the rollers 50 and th coefficient of friction between the materials used. Figs. 4 and 5 show a simplified version of the inventio shown in Figs. 2B and 2C using only one unidirectional clutch, where inner race member 40 is rigidly connected to splined inne race element 30, which in turn is rigidly connected to transmissio casing T. Outer race member 60 is located in surroundin relationship to inner race member 40 so as to position outer rac surface 62 as detailed in Figure 3, confronting relationship with inner race surface 42 and thus define an annular volume therebetween. A plurality of thrust transmitting cylindrical rollers 50 are disposed within said annular volume, all being inclined at an angle with respect to radial planes. Annular thrust ring 70 is slidably positioned between first ends 54 of said rollers and an annular shoulder member 72 connected to inner race member 40. An additional or secondary axial thrust bearing means may be employed when only one hyperboloidal unidirectional clutch is utilized with reactor 20. Such secondary axial thrust bearing means may be comprised of a plurality of roller bearings 98 disposed about the periphery of inner ball bearing race member 96 and within outer ball bearing race member 100. Because the

hyperboloidal-type clutch utilized with the present invention best suited for resisting axial loads in a direction from right left in Figure 5, or toward the larger diameter end of the clut a secondary or auxiliary axial thrust bearing may be desired f certain applications. The secondary axial thrust bearing mea disclosed herein is exemplary. However, it is contemplated th alternative forms of apparatus to resist axial loading are with the scope of the invention. A biasing means such as wave washer 90 may also employed in association with a retaining clip 92 to maintain inn race member 40 in proper alignment with respect to outer ra member 60. A second retaining means such as C-clip 94 may be us to limit the distance to which inner race member 40 may move shaft 30. Thus, when the reactor is urged to move in the directi of arrows F in Figures 2A or 23, the clutch 38 will lock up an hence, transmit torque between inner and outer races throu rollers 50. However, when turbine vanes 18 reach a predetermin speed with respect to impeller vanes 16, the forces acting reactor blades 22 are reversed from the direction of arrows F Figure 2B. Under the latter condition, the clutch 38 will fr wheel and needle rollers 50 will freely rotate with annular thru ring 70, without interference of shoulder 72. Annular thrust ri 70 may be solid, in which case the needle rollers actually sli over the top surface thereof, or, alternatively, the annular thru ring 70 used with the first embodiment of this invention may used having cavities 64, Figure 3, into which ends 54 of rollers

are inserted. For one direction of attempted relative rotation of t outer race relative to the inner race, the clutch transmits torq in one direction while in the other there is simply a free-wheeli action, which direction is determined by whether the rollers a located with right hand or left hand skew. The rollers 50 Figure 4 are oriented with a right hand skew. Engagement in the jamming direction is instantaneous direct, and virtually soundless, and is positive, i.e. without an slip beyond a nominal, virtually imperceptible, amount. Depicted in Figure 6 is a second embodiment of th instant invention wherein a pair of my unidirectional clutches ar used as a freewheel, roller and axial bearing for a torqu converter reactor but wherein a first stage clutch resists axia loading from left to right and second stage clutch resists fro right to left. Depicted in Figure 7 is a third embodiment of the instan invention wherein a pair of my unidirectional clutches are used a a freewheel, roller and axial bearing for a torque converte reactor but wherein the diameter of the stage 1 clutch about th axis of rotation R of the reactor, torque converter and clutches i greater than the diameter of the stage 2 clutch about axis R Because the oil flow direction in a torque converter chanαe frequently, to resist severe transmission fluid thrust forces which may at times be in the nature of shock waves, increasing th diameter of the stage 1 clutch, or alternatively, the stage

clutch if desired, provides additional axial thrust bear capacity as well as additional torque transmission capacity in lock up mode. Increasing the diameter of one of my clutc permits the use of additional rollers 50, which increases amount of surface area contact between the rollers 50 and the in and outer race surfaces 42 and 62. It is contemplated that more than two such clutches be used in heavy duty applications such as trucks, buses, e Further, the size of the clutches used is only limited by the s of the transmission components involved. Additionally, the in race member 40 may be machined directly out of stationary shaft and hence be integrally connected thereto. If desired, clutches may be used in such an embodiment where both the in races of the stage 1 and stage 2 clutches are machined direc from stationary member 30. It will be readily appreciated from the foregoing t the particular structure of the present inventive clutch makes possible to transmit torque by way of the principle which utili near-hyperboloidal surfaces and needle rollers without jamming the rollers or gouging of the races or support shoulder. particular, by the provision of an appropriate and unique interf means between the rollers and the respective supporting race, major impediment to practical utilization of this principle been overcome with the result that torque transmission can accomplished with high efficiency and low profile, while making possible to selectively control such major parameters as tor

rate of transmission, clutch profile and size, clutch lif expectancy, clutch engagements and many more. By employing the use of a pair of unidirectional clutche herein of the type described in U.S. Patent Application Serial No 07/418,795, which is incorporated by reference herein as thoug fully set forth herein, the axial thrust resisting feature thereo is used to the greatest benefit. A first stage clutch 38 resist axial loading from left toward right in Fig. 6, while second stag clutch 38' resists axial loading from right to left in that Figure. The instant invention has been shown and described herei in what is considered to be the most practical and preferre embodiment. It is recognized, however, that departures may be mad therefrom within the scope of the invention and that obviou modifications will occur to a person skilled in the art.