Source: http://www.google.com/patents/US6851532?dq=6011510
Timestamp: 2015-05-04 05:15:08
Document Index: 722759928

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Patent US6851532 - Torque transmitting apparatus - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA hydrokinetic torque converter with a built-in bypass clutch is provided with an arrangement which regulates the cooling of the clutch at a rate dependent upon the slip between the coaxial driving and driven parts of the clutch, and hence upon the quantity of generated friction heat. The cooling unit...http://www.google.com/patents/US6851532?utm_source=gb-gplus-sharePatent US6851532 - Torque transmitting apparatusAdvanced Patent SearchPublication numberUS6851532 B2Publication typeGrantApplication numberUS 09/842,362Publication dateFeb 8, 2005Filing dateApr 25, 2001Priority dateApr 28, 2000Fee statusLapsedAlso published asDE10117746A1, US7000747, US20020027053, US20040050639, US20050126874Publication number09842362, 842362, US 6851532 B2, US 6851532B2, US-B2-6851532, US6851532 B2, US6851532B2InventorsGunnar Back, Hubert Friedmann, Paul Granderath, Jean-Francois Heller, Stephan Maienschein, Marc Meisner, Bruno M�ller, Wolfgang ReikOriginal AssigneeLuk Lamellen Und Kupplungsbau GmbhExport CitationBiBTeX, EndNote, RefManPatent Citations (13), Referenced by (9), Classifications (12), Legal Events (7) External Links: USPTO, USPTO Assignment, EspacenetTorque transmitting apparatus
US 6851532 B2Abstract
One feature of the present invention resides in the provision of a hydrokinetic torque converter which comprises a housing rotatable about a predetermined axis, a pump which is rotatable by the housing about the predetermined axis and can be of one piece with the housing, a turbine which is rotatable in the housing about the predetermined axis by the pump (actually by the supply of fluid which is circulated in the housing by the pump when the torque converter is in use), means for rotating the housing (such means can include a camshaft or a crankshaft receiving torque from a prime mover such as a combustion engine, an electric motor, a gas turbine, or a hybrid prime mover in the power train of a motor vehicle), an output element (such as the input shaft of the change-speed transmission in the power train of a motor vehicle) which is rotatable about the predetermined axis and is arranged to receive torque from the turbine, and a fluid-operated bypass clutch which is disposed in the housing and is arranged to transmit variable torque between the housing and the output element. The clutch includes a driving component rotatable with the housing and a driven component rotatable with the output element and movable axially of the housing into and from frictional engagement�with and without slip�with the aforesaid driving component. The improved torque converter further comprises means for moving the driven component relative to the driving component in the axial direction of the housing (such moving means comprises first and second plenum chambers containing bodies of hydraulic fluid at variable pressure with the provision for fluid flow between the chambers through the clutch), and means for regulating the fluid flow between the chambers in dependency upon the magnitude of torque being transmitted by the clutch when the latter is at least partially engaged.
A further feature of our invention resides in the provision of a hydrokinetic torque converter which comprises a housing rotatable about a predetermined axis, a pump rotatable by the housing about such axis, a turbine rotatable in the housing by and relative to the pump, means for rotating the housing, an output element which is rotatable about the axis of the torque converter housing and is arranged to receive torque from the turbine, and a fluid-operated bypass clutch which is arranged to transmit variable torque between the housing and the output element. The pump comprises a driving component rotatable with the housing and a driven component including a piston rotatable with the output element and movable in the housing axially into and from frictional engagement�with and without slip�with the driving component, and the torque converter further comprises means for moving the piston including first and second plenum chambers in the housing, means for supplying to the plenum chambers hydraulic fluid at variable pressure with the provision for fluid flow between the chambers through the clutch, and adjustable means for regulating the fluid flow between the chambers in dependency upon the magnitude of torque being transmitted by the clutch. Such adjustable regulating means is or can be adjacent at least one of the driving and driven components of the bypass clutch.
FIG. 13 a is an enlarged fragmentary sectional view substantially as seen in the direction of arrows from the line XIIIa�XIIIa shown in FIG. 13;
FIG. 15 is an axial sectional view of the piston as seen in the direction of arrows from the line XV�XV shown in FIG. 14;
FIG. 16 a is a fragmentary axial sectional view of a bypass clutch which can utilize a piston with bellows of the type shown in FIGS. 14 and 15, the bellows being shown in deflated condition;
FIG. 16 b shows the structure of FIG. 16 a but with the bellows inflated;
FIG. 17 a is a fragmentary axial sectional view similar to that of FIG. 16 a but employing a housing of the type shown in FIGS. 9, 13 and 13 a, the bellows being shown in inflated condition;
FIG. 17 b shows the structure of FIG. 17 a but with the bellows deflated;
FIG. 18 a is a view similar to that of FIG. 16 b or 17 a but showing a further bypass clutch;
FIG. 18 b shows the structure of FIG. 18 a but with the bellows deflated;
FIG. 19 a is a fragmentary axial sectional view of a bypass clutch similar to that shown in FIG. 3 but employing bellows one of which is shown in deflated condition;
FIG. 19 b shows the structure of FIG. 19 a but with the bellows deflated;
FIG. 20 a is a fragmentary axial sectional view of a bypass clutch constituting a modification of the clutch shown in FIGS. 19 a and 19 b, with the bellows inflated;
FIG. 20 b shows the bypass clutch of FIG. 20 a but with the bellows deflated;
FIG. 22 is an enlarged fragmentary sectional view as seen in the direction of arrows from line XXII�XXII shown in FIG. 21;
FIGS. 29 a to 29 k are fragmentary elevational views of eleven differently grooved or recessed friction linings which can be utilized in several versions of bypass clutches embodying the present invention;
FIG. 32 a is an enlarged sectional view substantially as seen in the direction of arrows from the line XXXIIa�XXXIIa shown in FIG. 31;
FIG. 32 b is a sectional view similar to that of FIG. 32 a but showing the pumping element of the illustrated pump of the cooling system in a different position relative to the pump housing;
FIG. 34 a is an enlarged fragmentary sectional view of the bypass clutch as seen in the direction of arrows from the line XXXIVa�XXXIVa shown in FIG. 33, the cooling system being operative to withdraw heat from the partly engaged bypass clutch;
FIG. 34 b illustrates the structure of FIG. 34 a but with a sealing element of the bypass clutch in a position in which the cooling unit for the bypass clutch is idle; and
Referring first to FIG. 1, there is shown a hydrokinetic torque converter 1 having a housing 4 a rotatable about a predetermined axis (see the axis X�X shown in FIG. 2) by a prime mover 2. The latter can constitute an internal combustion engine of the type employed in motor vehicles, an electric motor, a gas turbine or a hybrid drive means. The output shaft 3 of the prime mover 2 can be fixedly of force-lockingly connected with a portion 4 of the housing 4 a in any one of a number of different ways. The portion 4 which is shown in FIG. 1 is a flexible annular metallic washer-like wall which drives the other part or parts of the housing 4 a and also a rotary pump 5 of the torque converter 1. A turbine 6 of the torque converter is coaxial with and is normally rotated or can be rotated by the pump 5 by way of a body of hydraulic fluid in the housing 4 a. FIG. 1 further shows a stator 10 which constitutes an optional part of the torque converter 1.
The output element 7 of the torque converter 1 shown in FIG. 1 is the input shaft of a change-speed transmission 8 which can transmit torque to one or more wheels 9 of a motor vehicle by way of a differential and one or more wheel axles in a manner well known in the art and not forming part of the present invention. Reference may be had, for example, to commonly owned U.S. Pat. No. 5,501,309 granted Mar. 26, 1996 to Walth et al. for �HYDROKINETIC TORQUE CONVERTER WITH LOCKUP CLUTCH�, U.S. Pat. No. 5,674,155 granted Oct. 7, 1997 to Otto et al. for �METHOD OF AND APPARATUS FOR TRANSMITTING TORQUE IN THE POWER TRAINS OF MOTOR VEHICLES�, U.S. Pat. No. 5,738,198 granted Apr. 14, 1998 to Walth et al. for �FRICTION ELEMENT FOR USE IN CLUTCHES�, and U.S. Pat. No. 5,782,327 granted Jul. 21, 1998 to Otto et al. for �HYDROKINETIC TORQUE CONVERTER AND LOCKUP CLUTCH THEREFOR�.
The piston 16 is mounted on a hub (corresponding to the hub 106 a shown in FIG. 2) which is non-rotatably mounted on the shaft 7 and can also support the turbine 6. The connection between the piston 16 and the shaft 7 includes a first torsional vibration damper 23, and the connection between the turbine 6 and the shaft 7 includes a second torsional vibration damper 24.
The magnitude of torque which is being or which is to be transmitted by the bypass clutch 13 can be regulated by selecting the pressures of bodies of hydraulic fluid confined in or flowing through two chambers 17, 18 defined by the housing 4 a of the torque converter 1. The pressure of fluid entering the chamber 18 by way of a conduit 19 a is determined by a fluid conveying pump 19 having an intake arranged to draw fluid (such as oil or transmission fluid) from a sump 20 a or another suitable source. A pressure limiting relief valve 19 c is or can be installed in the conduit 19 a. A further conduit 19 b serves to convey fluid from the chamber 17 into a reservoir 20, e.g., a sump 20.
When the pressure differential between the bodies of fluid filling the chambers 17, 18 decreases to a predetermined value, one or more springs or other biasing means (not shown) are free to disengage the component 15 from the component 14, i.e., to disengage the bypass clutch 13. It is also possible to employ a throttle 19 d or any other suitable flow restrictor (shown schematically in FIG. 1) in the conduit 19 b to predetermine the circumstances under which the bypass clutch 13 is permitted or caused to open so that, from there on, the input shaft 7 can be driven by the wall 4 through the medium of the pump 5, the body of fluid which orbits the vanes of the turbine 6 in response to orbiting of vanes forming part of the pump 5, and the torsional vibration damper 24.
The sumps 20, 20 a can form parts of a single sump, they can constitute two discrete identical or different sumps, or they can be connected to each other by one or more conduits 20 b which preferably contain one or more fluid cooling units 20 c serving to ensure that the inlet of the pump 19 receives a flow of fluid having a temperature not exceeding a preselected maximum permissible value.
The structure which is shown schematically in FIG. 1 can be modified in a number of ways without departing from the spirit of this invention. For example, the pump 19 can be installed in the conduit 19 b to draw fluid from the sump 20 and to convey such fluid into the chamber 17 whence the fluid flows (when necessary or desired) into the chamber 18, conduit 19 a and sump 20 a. The chambers 17, 18 are sealed from each other in such a way that, when desired or necessary, they can communicate only by way of the bypass clutch 13 (and more specifically by way of the friction generating device 21 including the components 14 and 15).
A less pronounced heating of the components 14, 15 is desirable and advantageous because it involves a lesser wear upon the device 21 and also because the composition of the fluid remains unchanged (i.e., acceptable) for a longer interval or period of time. Furthermore, a damming of the fluid by the regulating arrangement 22 in response to a reduced slip exhibits the advantage that the operation of the pump 19 is more economical because the output of the pump must be increased due to higher losses resulting from the flow of fluid into the lower-pressure chamber (i.e., into the chamber 17 within the housing 4 a shown in FIG. 1) when the bypass clutch 13 is engaged, namely when the pump output is higher because the pressure of fluid in the chamber 18 (this entails an engagement of the bypass clutch) is raised by the pump.
The flow regulating or limiting arrangement 22 (or an equivalent thereof) does not constitute the only novel feature of the improved torque converter 1. Thus, this torque converter can be provided with auxiliary masses 25 a, 25 b, 25 c, and 25 d which serve to meet (satisfy) specific requirements regarding the damping and/or absorption (elimination) of torsional vibrations. For example, one can rely on the so-called dual mass flywheel effect by installing the auxiliary masses 25 b, 25 a upstream and downstream of the torsional vibration damper 23 and/or by instaling the auxiliary masses 25 c, 25 d up-stream and downstream of the damper 24. The auxiliary masses (or one or more such masses) need not constitute separately produced parts, i.e., at least one thereof can constitute a standard component or a group of two or more standard components of a torque converter wherein, in addition to their well known functions, they also serve as auxiliary masses associated with the torque converter 23 or 24. By way of example only, one of the auxiliary masses 25 a to 25 d can constitute or form part of the turbine 6, of the housing 4 a, of one or more portions of the housing 4 a and/or others, as long as the moment of inertia and/or the bulk or weight of such multiple-purpose auxiliary mass is satisfactory for utilization in conjunction with the damper 23 or 24.
Still further, it is within the purview of the invention to omit the auxiliary mass 25 aand/or 25 d, i.e., to utilize only the auxiliary mass(es) 25 b, and/or 25 c which is or which are installed in the power flow(s) upstream of the respective damper(s) 23 and/or 24. The single auxiliary mass (25 b, or 25 b) is preferably that mass which is more distant from the axis of the shaft 7, i.e., which is located radially outwardly of the respective torsional vibration damper 23 and/or 24. Stated otherwise, the single auxiliary mass (25 b, and/or 25 c) is installed in the power flow upstream of the respective damper (23 and/or 24); this enhances the moment of inertia.
It is advisable (and actually highly desirable and advantageous) to install the auxiliary mass(es) in such space or spaces which is or which are available in a hydrokinetic torque consorter; such spaces include, for example, that or those at the radially outer and/or inner torus of the turbine, and in a corner or region of the housing 4 a radially outwardly of the piston 16.
The auxiliary mass 25 a and/or 25 d can be directly or indirectly mounted on the input(s) of the respective damper(s) 23 and/or 24, and the mass 25 b and/or 25 c can be directly or indirectly mounted on the input(s) of the respective damper 23 and/or 24. For example, and as actually shown in FIG. 1, the auxiliary mass 25 b is provided on or forms part of the piston 16 upstream of the damper 23 (as seen in the direction of power flow from the bypass clutch 13 (i.e., from the wall 4) to the input shaft 7. Furthermore, and as also shown in FIG. 1, the auxiliary mass 25 c is mounted on or forms part of the turbine 6, i.e., such mass is located in the flow of power toward the input of the damper 24.
FIG. 2 is an axial sectional view of a torque converter 101 which is driven by the output shaft (such as a crankshaft) 103 of a prime mover, e,g, the engine of a motor vehicle. The shaft 103 has an axially extending centering projection 103 a engaging a flexible torque transmitting member 126 which is or which can be made of a metallic sheet material and can be said to form a detachable part of a housing 104 a of the torque converter 101. The means for fixedly but separably securing the radially innermost annular portion of the member 126 to the shaft 103 includes an annulus of threaded fasteners 103 b. Other types of fasteners can be utilized with equal advantage.
The annular radially outermost portion of the member 126 is non-rotatably connected with an annular starter gear 126 a in such a way that the latter cannot move axially of the housing 104 a. The rotation-preventing connection between the starter gear 126 a and the housing 104 a can include mating gear teeth, a caulking, a welded joint or the like. It is also possible to employ a starter gear which is shrunk onto the member 126 or onto another part of the housing 104 a. The member 126 and/or another part of the housing 104 a can also serve to carry a set of markers or other suitable indicia which rotate with the housing and form Apart of a means for regulating the operation of the prime mover. An annulus of receptacles 104 b is separably connected with the member 126 between the annulus of fasteners 103 b and the starter gear 126 a; the connection can include threaded fasteners 126 b, a self-locking device, a bayonet mount (not shown) or the like.
The receptacles 104 b can constitute circular or arcuate bodies and are affixed to the radially outermost portions of the housing 104 a, e.g., by welding, by rivets or the like; for example, the housing 104 a and/or the member 126 can be provided with projections which are riveted to the receptacles 104 b. The housing 104 a can be axially offset at the receptacles 104 b so that the receptacles are axially spaced apart and provided room for the fastening of the member 126 on the crankshaft 103. To this end, the radially outer portion of the member 126 (namely the portion adjacent the receptacles 104 b) can be configurated to extend axially of the torque converter 101 and away from the crankshaft 103.
The receptacles 104 b are provided with circumferentially spaced-apart axially extending lobes 104 c which are affixed to the housing 104 a. In addition to or in lieu of such lobes 104 c, the connection between the receptacles 104 b and the housing 104 a can be constructed and designed in such a way that, in accordance with a desirable aspect of the invention, it need not employ discrete fasteners (such as the lobes 104 c); instead, the housing 104 a can be provided with separately produced embossed portions 104 d which together constitute a cam ring affixed to the housing and such cam ring can be provided with teeth, profiled portions, Hirth gears or serrations and/or pins. This renders it possible to dispense with the fastener means 126 b. Moreover, such design (which can be employed with advantage in all or nearly al types of torque converters) renders it possible to simplify the mounting of the torque converter 101 on the flexible torque transmitting member 126 during the final stage of assembly of the power train of a motor vehicle.
The member 126 can be mounted on the housing 104 a in such a way that it stores energy and the axial torque of the torque converter is preferably applied in a direction toward the transmission case (not shown) or toward the transmission input shaft 107 by way of an abutment which is or which can be mounted in a bearing. The form-locking connection between the member 126 and the housing 104 a can be designed in such a way that it automatically orients itself during the assembly while the connection is being established.
It is clear that the lobes 104 c can be made of one piece with the member 126, e.g., by folding partially separated lugs of the member 126 over themselves. In addition, the fasteners 126 b and/or the receptacles 104 b and/or the starter gear 126 a can serve as auxiliary masses which positively influence the torsional vibration behavior of the power train by resorting to the so-called dual masses effect.
It is also possible to omit the member 126 and to establish a direct form-locking connection between the housing 104 a and the crankshaft 103. For example, the crankshaft 103 can be made of one piece with or can carry a hardened extension having a diameter less than that of the member 126 and being located at the same radial distance from the axis X�X as the fasteners 103 b. Such hardened extension can be affixed direztly to a complementary portion of the housing 104 a (e.g., to a stamped portion of the housing) to thus establish a form-locking connection. The form-locking connection can be configurated in such a way that it can simultaneously compensate for an offset between the crankshaft 103 and the transmission input shaft 107. The housing 104 a can be axially flexible between its periphery and the form-locking connection, e.g., by employing a sheet metal having varying thicknesss in the region of such connection.
The housing 104 a and the pump 105 of the torque converter 101 are form-lockingly connected to each other, as at 105 a, to constitute the input element of the torque converter 101. As can be seen in FIG. 2, the form-locking connection 105 a can comprise several equidistant parts (FIG. 2 shows three parts) disposed at the periphery of the pump 105 and each including a male part provided on the pump 105 and extending into a complementary female part of the housing 104 a. That end portion (104 e) of the housing 104 a which is remote from the member 126 (as seen in the direction of the axis X�X ) constitutes a sleeve surrounding an axially projecting tubular extension 108 a of the transmission. The extension 108 a is sealingly surrounded by the sleeve 104 e and is also surrounded by the freewheel 111 for the stator 110.
The pump 105 and the turbine 106 are provided with customary vanes or blades (not shown) which cooperate to ensure that the body of hydraulic fluid in the housing 104 a rotates the turbine 106 in response to rotation of the pump 105 by the crankshaft 103. The (optional) stator 110 is disposed between the pump 105 and the turbine 106 (as seen in the direction of the axis X�X) and is radially outwardly adjacent the freewheel 111.
The turbine 106 is non-rotatably connected with a hub 106 a, e.g., by an annular array of rivets, and this hub is non-rotatably but axially movably affixed to the transmission input shaft 107. An annular seal 107 a is interposed between the shaft 107 and the hub 106 a, and the latter abuts a thrust bearing 110 b which, in turn, abuts the stator 110.
The hub 106 a has an axial extension surrounded by the radially innermost portion of the axially movable piston 116 which forms part of the torque converter bypass clutch 113. An annular seal 106 c is inserted between the piston 116 and the hub 106 a; the latter has a disc-shaped extension 106 b which extends radially outwardly and is riveted to the turbine 106. The extension 106 b further serves as a stop which determines the extent of rightward axial movement of the piston 116 of the bypass clutch 113.
The piston 116 cooperates with the radial wall 104 of the housing 104 a to transmit torque from the crankshaft 103 (via wall 104) directly to the hub 106 a (i.e., to the transmission input shaft 107), namely to bypass the pump 105 and the turbine 106, when the bypass clutch 113 is engaged (with or without slip). More specifically, the piston 116 carries a friction lining 115 (or has a properly finished friction surface) which engages a complementary friction lining or friction surface 114 of the wall 104 when the clutch 113 is at least partly engaged. If used, the friction lining or linings (such as 115 and/or 114) can be glued, riveted and/or otherwise affixed to the piston 116 and/or to the wall 104. Certain presently preferred embodiments of the fluid flow regulating or limiting arrangement 122 of the bypass clutch 113 or an analogous bypass or lockup clutch will be described in greater detail with reference to FIGS. 9 to 13.
The piston 116 divides a part of the interior of the housing 104 a into plenum chambers 117, 118 which are sealed from each other (when the bypass clutch 113 is engaged, either entirely or with slip) to the extent determined by the flow regulating arrangement 122. Hydraulic fluid is admitted into the plenum chamber 118 by way of a conduit 119 a which is defined by an annular clearance between the sleeves 104 e and 108 a. A conduit 107 b which serves to permit hydraulic fluid to issue from the chamber 117 is a bore in the transmission input shaft 107 which discharges into an annular passage 119 b of the shaft 107. The sleeve 108 a and the shaft 107 are sealingly engaged by a friction bearing 108 b which serves as a means for sealing the passage 119 b from the surrounding atmosphere; in addition, the combined bearing element and seal 108 b prevents the flow of hydraulic fluid from the conduit 119 a into the chamber 118.
When the fluid pressure in the plenum chamber 118 rises above that in the plenum chamber 117, the piston 116 is moved axially and the friction generating device 121 including the frictionally engageable members 114, 115 having friction surfaces 114′, 115′ establishes a frictional engagement to transmit torque from the wall 104 of the housing 104 a to the piston 116.
If the fluid pressure in the chamber 117 thereupon rises above that in the chamber 118, the surfaces 114′, 115′ become separated from each other so that the bypass clutch 113 ceases to transmit torque; the transmission of torque from the crankshaft 103 to the transmission input shaft 107 then takes place by way of the housing 104 a, pump 105, fluid between the pump 105 and the turbine 106, and the turbine hub 106 a. When the bypass clutch 113 is fully or partly, engaged (i.e., when it operates without slip or with some slip), the piston 116 continues to transmit at least some torque to the hub 106 a. Vibrations of such torque can be damped by a damper 123 which operates between the piston 116 and the hub 106 a. The damper 123 includes an input member 123 a which is non-rotatably affixed to the piston 116, and an output member 123 b non-rotatably affixed to the hub 106 a. The input member 123 a comprises two discs which flank the disc-shaped output member 123 b. The discs of the input member 123 a are shown as being riveted to the piston 116. The disc of the output member 123 b is non-rotatably but axially movably mounted on the hub 106 a; to this end, the member 123 b has one or more axially parallel internal teeth mating with external teeth of the hub 106 a. One or more energy storing elements 123 c (one shown FIG. 2) yieldably oppose angular movements of the input and output members 123 a, 123 b relative to each other; to this end, the energy storing element(s) 123 c reacts or react against one or more abutments provided on the input member 123 a and bear upon one or more abutments on the output member 123 b. Reference may be had, for example, to commonly owned U.S. Pat. No. 5,860,863 granted Jan. 19, 1999 to Friedmann et al. for �APPARATUS FOR DAMPING VIBRATIONS�. The torsional vibration damper 123 is further provided with suitable means for limiting the extent of angular movability of the input and output members 123 a, 123 b relative to each other; such limiting means can provide first and second stops which are respectively mounted on or made of one piece with the members 123 a, 123 b. It is further possible and often advisable to provide a slip clutch 123 d which operates between the input and output members 123 a, 123 b and permits such members to turn relative to each other only when the torque being transmitted by the input member 123 a rises to a predetermined value. The illustrated slip clutch 123 d acts axially between the members 123 a, 123 b and can comprise one or more energy storing devices.
The wall 104 of the housing 104 a of the torque converter 101 carries a centering stub 104 f which extends into a recess 103 c of the crankshaft 103. The stub 104 f is welded to the wall 104 and is centered thereon by a projection 104 g which is a stamped out part of the wall 104; however, it is also possible to make the stub 104 f of one piece with the wall 104. The just described combined centering and torque transmitting means can serve to compensate for eventual angular and/or axial misalignments of the shaft 103 and the transmission input shaft 107 relative to each other.
The aforementioned axial projections 103 a of the crankshaft 103 are preferably profiled and dimensioned in such a way that they facilitate the insertion of the stud 104 f into the opening or recess 103 c during mounting of the torque converter 101 on the output shaft 103 of the prime mover.
The projection 104 g can further serve to facilitate accurate mounting (e.g., welding) of the stub 104 f on the wal 104, particularly to accurately center the stud. The latter need not be a solid body but can be replaced with a tube or sleeve. Moreover, welding of the stub 104 f to the wall 104 (as actually shown in FIG. 2) is optional, i.e., it can be replaced by riveting or the like.
It can be said that the stub 104 f forms part of a pilot bearing which ensures simple, predictable and accurate mounting of the torque converter 101 on the output shaft 103 of the prime mover; such pilot bearing can be utilized with advantage in many other types of torque converters, clutches and the like. Furthermore, a similar or analogous or at least substantially identical pilot bearing can be utilized for accurate and reliable mounting of the transmission input shaft 107 in the torque converter 101 and/or in the crankshaft 103. For example, the front end portion of the shaft 107 can be received in a sleeve-like central part of the housing 104 a of the torque converter 101. The housing 104 a can be provided with a projection similar to or analogous to the projection 104 g and extending into a sleeve-like member which, in turn, receives the front end portion of the transmission input shaft 107.
FIG. 3 is an axial sectional view of a torque converter 201 which differs from the torque converter 101 of FIG. 2 primarily in the design of the bypass clutch or lockup clutch 213. Thus, the radially outermost portion of the piston 216 of the clutch 213 is non-rotatably but axially movably secured to the radial wall 204 of the housing 204 a. A feature of the piston 216 (this feature can be embodied in the pistons of all or nearly all bypass clutches for torque converters) is that the radially outermost portion of the piston carries leaf springs 216 a which are affixed to the housing 204 a. The leaf springs 216 a are spaced apart from each other (as seen in the circumferential direction of the piston 216), one end portion of each leaf spring 216 a is affixed to the housing 204 a, and the other end portion of each such leaf spring is secured to the piston 216 of the bypass clutch 213. The leaf springs 216 a are preferably riveted to the wall 204; to this end, the wall 204 is provided with wart-like projections or protuberances 204 h. However, it is also possible to provide such or similar protuberances on the piston 216.
The piston 216 is turnable on a hub 206 a which surrounds the input shaft 207 of the transmission. A thrust bearing 206 d is interposed between the hub 206 a and the piston 216; the illustrated bearing 206 d is a disc which is installed between a radially outwardly extending portion of the hub 206 a and the adjacent radially extending annular portion of the piston 216.
When the bypass clutch 213 transmits torque (i.e., when the piston 216 rotates with the wall 204 with or without slip), the transmission input shaft 207 receives torque by way of the input member 223 a of the torsional vibration damper 223 which frictionally engages the output member 223 b. The latter is non-rotatably but axially movably mounted on the hub 206 a. The input member 223 a is riveted or otherwise affixed to a friction lamella 223 d the radially outermost portion of which carries two friction linings having friction surfaces 214 a′, 214 b′ disposed radially inwardly of the projections 204 h. The linings having the surfaces 214 a′, 214 b′ are respectively adjacent to complementary friction linings having friction surfaces 215 a′, 215 b′. The output member 223 b of the damper 223 is non-rotatably secured to the hub 206 a by annuli of mating teeth 223 e. The reliability of such connection is enhanced by providing the radially innermost portion of the output member 223 b with a sleeve having axially parallel internal teeth in mesh with complementary teeth of the hub 206 a. The torsional vibration damper 223 is similar to (or can be identical with) the damper 123 shown in FIG. 2.
The fluid flow regulator 222 can be provided on (or can utilize) the friction linings having the surfaces 214′, 215′ and/or 214 b′, 215 b′. Presently preferred embodiments of such regulator are depicted in FIGS. 22 to 25.
FIG. 4 shows certain features of a hydrokinetic torque converter 301 which is similar to the torque converter 201 of FIG. 3. The prime mover and the transmission are not shown in FIG. 4. The main difference between the torque converters 201 and 301 is that the latter employs a different bypass clutch 313 and a different torsional vibration damper 323. In accordance with a feature of the invention which is embodied in the torque converter 301, the torsional vibration damper 323 serves as a turbine damper as well as a means for damping vibrations being transmitted by the by pass clutch 313. To this end, the input 323 a of the damper 313 is non-rotatably secured to the hub 306 a for the turbine 306 (this turbine is non-rotatably secured to the hub 306 a) as well as to the friction lamella (energy storing device) 323 d. Thus, the input 323 a of the damper 323 can receive torque from the turbine 306 as well as from the bypass clutch 313.
The input 323 a of the damper 323 is form-lockingly secured to the hub 306 a by annuli of mating teeth 323 e, and the lamella 323 d is fixedly secured (e.g., by rivets) to the input 323 a radially outwardly of the energy storing elements 323 c. The hub 306 a is free to rotate relative to the input shaft (not shown) of the transmission; to this end, a discrete hub portion 306 f is provided with internal teeth 307 b mating with complementary teeth of the transmission input shaft. The hub 306 a is rotatable on the discrete hub portion 306 f, preferably in a friction bearing 306 g or on an anti-friction bearing (not shown) which surrounds the discrete hub portion 306 f. The output 323 b of the damper 323 is fixedly secured to the discrete hub portion 306 f, e.g., by welding (such as laser, impulse or spot welding) or by caulking.
In order to facilitate broaching of the teeth 307 c, there is provided a discrete hub portion or member 306 h which can be received in the hub 306 a; e.g., the hub 306 a can be a press fit on the discrete member 306 h and is also mounted on the transmission input shaft. The latter can be provided with bearings rotatably mounting the member 306 h. Damping of torsional vibrations is effected by causing the input 323 a of the damper 323 to turn relative to the output 323 b and/or vice versa against the opposition of the energy storing element(s) 323 c as well as by overcoming (a) the resistance of a friction generating device 323 d between an axially effective energy storing element 323 b′ sand the input 323 a and/or (b) the friction torque of the friction bearing 306 g and/or preferably a slip clutch 323 b″. The lateral part 323 b′ is connected with the output 323 b by an annulus of rivets 323 f′ and cooperates with the output 323 b to confine the input 323 a; the radially outer portion of the input 323 a is secured to the lamella 323 d by rivets 323 f. The input 323 a is disposed between the output 323 b and the lamella 323 d; these parts are provided with at least partially registering windows for the energy storing element(s) 323 c each of which can include a single coil spring or two or more suitably interfitted coil springs. The output 323 b and the lamella 323 d are or can be provided with suitable stops (not referenced) which determine the maximum compression of the coil spring(s) and the maximum extent of angular movability of the input 323 a and the output 323 b of the torsional vibration damper 323 relative to each other.
FIGS. 5 and 6 respectively illustrate parts of torque converters 401 and 401 a which are similar to but not identical with each other. All such parts of these torque converters which are plainly identical with each other are denoted by identical reference characters. The housing 404 a of each torque converter is driven by a prime mover (e.g., a combustion engine, not shown) and transmits torque to the respective pump 405. The latter can drive the turbine 406 which cooperates with the pump to flank an optional stator 410. The bypass clutch 413 can be engaged to transmit torque (with or without slip) from the washer-like annular part 404 i of the housing 404 a directly to the hub 406 a non-rotatably surrounding the input shaft (not shown) of the change-speed transmission in the power train of a motor vehicle. An entraining disc 416 b is riveted to the piston 416 of the bypass clutch 413 and is axially movably but non-rotatably mounted on the hub 406 a. The disc 416 b is provided with an annulus of axially parallel internal teeth 416 c mating with complementary external teeth of the hub 406 a. The connection between the piston 416 and the disc 416 b comprises an annular array of rivets 416 d (only one shown in each of FIGS. 4 and 5).
In accordance with a modification, the disc 416 b in each of the torque converters 401 and 401 a can be replaced with a torsional vibration damper having an input and an output which can be turned relative to each other against the resistance of one or more coil springs or other suitable energy storing elements and/or against the opposition of one or more slip clutches. The input and/or the output of the device which replaces the disc 416 b of the torque converter 401 or 401 a can consist of several laminations, and the input can be further affixed to the turbine 406 (in addition to or instead of the connection to the disc 416 b) or to a part which shares the angular movements of the turbine.
Frictional engagement between the piston 416 (driven part) and the housing 404 a (driving part) can be established by the cooperating friction generating members 414 and 415, and more specifically by the friction surfaces 414′, 415′ of the respective members. The driving member 414 receives torque from the aforementioned washer-like portion 404 i of the housing 404 a. The portion 404 i has an annular part which is welded to the major part of the housing 404 a (namely to the part which carries or is of one piece with the pump 405) and extends toward the prime mover (not shown), and a radially inwardly extending part which bears the member 415. The member 414 is affixed to the radially outermost portion of the piston 416. At least one of the members 414, 415 can constitute or comprise at least one friction lining having the respective one of the friction surfaces 414′, 415′.
The reference character 422 denotes the fluid flow regulator which, in certain parts of this specification, is denoted by the character x22 wherein x denotes the respective Figure of the drawings. This regulator corresponds to the previously described regulators (such as the regulator 222 shown in FIG. 3). The washer-like member 404 i replaces the walls 4, 104, 204, 304 respectively shown in FIGS. 1, 2, 3 and 4.
The mode of operation of the torque converter 401 or 401 a departs from that of the torque converters 1, 101, 201 and 301 in the following respects: In the torque converters 401 and 401 a, the pressurized fluid first flows into the plenum chamber 417 and the bypass clutch 413 is engaged when the pressure of fluid in the plenum chamber 417 exceeds that of fluid in the plenum chamber 418, i.e., when the fluid begins to flow through the fluid flow regulator 422. The bypass clutch 413 begins to transmit torque (with or without slip) when the pressure of fluid in the plenum chamber 417 reaches a level at which the bypass clutch 413 is at least partially engaged, i.e., when the piston 416 has moved axially toward the turbine 406 to a position in which the friction surfaces 414′, 415′ of the members 414, 415 frictionally engage each other so that the washer-like member 404 i of the housing 404 a (which is driven by the prime mover) begins to transmit torque to the hub 406 a (and hence to the input shaft of the transmission) by way of the members 414, 415 and the piston 416.
The bypass clutch 413 remains at least partly engaged as long as the pressure of fluid in the chamber 417 at least slightly exceeds the pressure in the chamber 418. It is often desirable to employ at least one energy storing device which automatically disengages the bypass clutch 413 as soon as the pressure of fluid in the chamber 417 begins to decrease; for example, such device can include one or more coil springs or other suitable springs which react against the hub 406 a and bear upon the piston 416 in a direction to move the piston axially to the left, as viewed in FIGS. 5 and 6. An advantage of such energy storing device or devices is that they reduce the likelihood of overheating of the fluid (such as oil or a transission fluid) which fills the chambers 417, 418 and is likely to be heated during prolonged operation of the bypass clutch 413 with slip, i.e., during that stage of operation of the clutch 413 when the fluid is caused to flow gradually through the fluid flow regulator 422 from the chamber 417 into the chamber 418. It is to be borne in mind that, in many instances, the fluid which fills the chambers 417, 418 is circulated through the transmission and is likely to adversely affect the heat-sensitive part(s) of the transmission if it is permitted to reach an elevated temperature during flow through the regulator 422 at a rate which is customary during operation of the clutch 413 with slip. The situation is different if the fluid leaving the chamber 418 is caused to enter an evacuating conduit which causes the heated fluid to flow through one or more fluid cooling units (hea exchangers). Such cooling unit(s) can be dispensed with if the fluid leaving the chamber 417 is caused to mix with the body of cooler fluid in the chamber 418 prior to entering the transmission.
The torque converters 401, 401 a respectively comprise fluid cooling units 427 a, 427 b of the type adapted to be utilized with advantage in the previously described torque converters 1, 101, 201 and 301 as well as in many other types of torque converters. The purpose of the cooling units is to agitate the fluid in the plenum chamber 418 adjacent the washer-like member 404 i of the housing 404 a. Such agitation takes place as soon as or as long as the parts 406 and 404 i turn relative to each other. Analogous results can be obtained by installing one or more cooling units in positions in which they become active as soon as the piston and the turbine begin to perform angular movements relative to one another.
The cooling unit 427 a of FIG. 5 comprises an annular array of blades or vanes 428 a which are mounted on or form part of the turbine 406 and are arranged to orbit adjacent the member 404 i of the housing 404 a. For example, the blades 428 a of the cooling unit 427 a can constitute separately produced parts which are riveted, welded and/or otherwise reliably affixed to the turbine 406. The blades 428 a of the cooling unit 427 a can also perform one or more additional functions, such as of securing the customary turbine vanes 406′ to the turbine 406; the blades 428 a can form suitably deformed integral lugs or analogous parts of the turbine 406.
When the cooling unit 427 a is in actual use, the blades 428 a cause the fluid which is heated in the region of the fluid flow regulator 422 to flow away from the parts 414, 415 and to intensively mix with cooler fluid in those portions of the chamber 417 which are remote from the parts 414, 415. Moreover, the blades 428 a cause the fluid (which has been heated by the parts 414, 415) to exchange heat with the portion 404 i of the housing 404 a. All such modes of preventing excessive localized heating of fluid at the regulator 422 contribute to prevention of overheating of the fluid in the chamber 417 as well as of fluid which issues from the chamber 417 to flow, for example, into the transmission of the power train employing the torque converter 401.
The cooling action of the cooling unit 427 b in the torque converter 401 a of FIG. 6 is analogous to that of the cooling unit 427 a in the torque converter 401 of FIG. 5. The difference is that the blades 428 b of the cooling unit 427 b form part of a separately produced disc-shaped member 428 c which is welded to the turbine 406 and is located in the plenum chamber 418. It is clear that the blades 428 b can constitute separately produced parts which are welded, riveted or otherwise affixed to the member 428 c. Again, the blades 428 b are adjacent the portion 404 i of the housing 404 a, i.e., next to the members 414, 415 which are a cause of heating of fluid in the chamber 418 or on its way from the chamber 417 into the chamber 418.
FIG. 7 shows a torque converter 501 wherein the rotary housing 504 a comprises a hollow pin 504 f having teeth meshing with the teeth of a hollow transmission input shaft 507. The latter receives torque from the prime mover (not shown) by way of the torque converter 501. The pin 504 f has an axial extension which non-rotatably but axially movably supports an auxiliary piston 516 e having a radially outermost portion in sealing engagement with the adjacent axially extending tubular part of the housing 504 a. The thus obtained annular compartment 518 a between the leftmost portion of the housing 504 a and the auxiliary piston 516 e can receive fluid to effect an axial movement of the auxiliary piston in a direction to the right, as viewed in FIG. 7.
The auxiliary piston 516 a abuts the axially movable piston 516 of the bypass clutch 513. The piston 516 is mounted on an extension or projection 506 i of a hub 506 a which is movable axially of but cannot rotate relative to the transmission input shaft 507. The piston 516 constitutes or is connected with a discrete output member of the torque converter 501; for example, the discrete output member can be welded (such as spot welded), riveted and/or otherwise non-rotatably affixed to the piston 516 so that it shares all axial movements of the latter.
The driving part is constituted by a washer-like member 504 i which is non-rotatably (such as form-lockingly) connected with the housing 504 a and is held against axial movement by an abutment or stop 504 k. The member 504 i extends radially inwardly from the radially outer or outermost portion of the housing 504 a. The form-locking connection is or can be established by a profiled (such as toothed) external surface which is provided on the member 504 i and mates with a complementary (e.g., put through) internal surface of the adjacent portion of the housing 504 a. Frictional engagement involves a lamella 523 d by way of friction surfaces 514 a, 514 b, 515 a, 515 b. The friction surfaces 514 a, 514 b can be provided on the friction linings which are preferably affixed to the lamella 523 d and, in order to establish a connection, are provided with a channel 530, e.g., a pattern or array of grooves. The lamella 523 d is non-rotatably but axially movably mounted on the hub 506 a radially outwardly of the piston 516, and preferably coaxially with the latter, by way of a torsional vibration damper 523 analogous to the damper 223 shown in and already described with reference to FIG. 3.
When the bypass clutch 513 is at least partially engaged, the piston 516 cooperates with the friction surfaces 514 a, 514 b, 515 a, 515 b to establish a fluid flow limiting or regulating arrangement 522 which determines the rate of fluid flow between the plenum chambers 517 and 518. In order to engage the bypass clutch 513, the compartment 518 a receives hydraulic fluid at a pressure higher than that in the chamber 518; on the other hand, the pressure of fluid in the compartment 518 a is reduced below that in the chamber 518 if the clutch 513 is to be disengaged. The compartment 518 a receives fluid from a source (not shown) by way of a bore or channel 504 p provided in a pipe 504 e of the stator. The channel 504 p communicates with a radial bore 504 n which, in turn, communicates with bores 507 e, 507 f respectively provided in the transmission input shaft 507 and the additional shaft 507 c. The latter has an axial passage or bore or channel 507 d which communicates with one or more radial bores 5041 discharging into the compartment 518 a. In the embodiment of FIG. 7, the admission of pressurized fluid into the compartment 518 a is preferably independent of the fluid flow through the fluid flow regulating arrangement 522, i.e., the flow of fluid through the plenum chambers 517, 518 can take place independently of the pressure of fluid in the compartment 518 a. The direction of fluid flow in and the sequence in which the chambers 517, 518 receive fluid depends upon the intended use and/or mode of operation of the torque converter 501 shown in FIG. 7.
In the embodiment which is shown in FIG. 7, the plenum chamber 517 is first to receive pressurized fluid; the admission of fluid into the chamber 517 takes place by way of a second conduit 504 p′ in the stator, an axial bore 504 o in the non-rotatable stator pipe 504 e, and at least one axially parallel bore 504 q in the hub 506 a. The fluid which leaves the chamber 517 enters the chamber 518 by way of the array of grooves 530 at the fluid flow regulating arrangement 522. The fluid which leaves the chamber 518 enters an evacuating conduit (not shown) provided in the stator pipe 504 by way of the chamber 517, grooves 530, compartment 518 a and an opening 504 r. The stator pipe 504 e and the transmission input shaft 507 are respectively provided with openings 504 m, 507 d which supply hydraulic fluid to the transmission, e.g., to the torque sensor of a continuously variable transmission (CVT), by way of at least one of additional conduits 504 p, 504 p′, 519 a between the shaft 507 c and the input shaft 507. It will be appreciated that certain bores, openings, channels and like fluid path establishing passages which are referred to hereinabove and at least some of which are shown in FIG. 7 must be temporarily, intermittently or permanently sealed from each other in order to establish paths for the flow of fluid to and from selected chambers and/or compartments during different stages of operation of the torque converter 501. The aforementioned CVT can be of the type disclosed in any one of a number of US and foreign patents owned by the assignee of the present application, for example, in U.S. Pat. No. 5,711,730 granted Jan. 27, 1998 to Friedmann et al. for �TORQUE MONITORING APPARATUS� and in the U.S. patents referred to in this patent to Friedmann et al.
It is further clear that the additional or auxiliary piston 516 e and the compartment 518 a can be utilized with advantage in numerous torque converters other than those specifically described and shown in the present case, i.e., in torque converters not employing a fluid flow regulating arrangement 522 (or an equivalent thereof) and/or an auxiliary drive. The required arrangements of conduits, channels, bores, holes and/or analogous paths for the flow of fluid will be selected in dependency upon the specific requirements of the modified torque converters. Furthermore, the flow of fluid from the various embodiments of the improved torque converter can be limited and/or otherwise regulated by specially designed and/or mounted valves. For example, a fluid flow regulating arrangement (such as the one shown at 522 in FIG. 7) can employ a valve which regulates the flow of pressurized fluid in dependency upon the temperature of such fluid, e.g., in such a way that, when the temperature of fluid rises while and/or because the bypass clutch operates with slip, the rate of fluid flow is increased. To this end, the valve need not or should not be disposed in immediate or close proximity to the regulator 522; for example, it often suffices to install a thermometer next to the regulator 522 and to utilize the thermometer as a means for transmitting signals to a fluid flow regulating valve which can be installed at a location close to or remote from the bypass clutch and from the fluid flow regulator.
FIG. 8 illustrates certain details of a torque converter 601 which constitutes a modification of the torque converter 101 shown in FIG. 2. The piston 616 of the bypass clutch 613 in the torque converter 601 differs from the piston 116 in order to establish a modified fluid flow regulating arrangement 622. Furthermore, the torque converter 622 employs modified friction generating members 614, 615 respectively having friction surfaces 614′, 615′. Such constituents of the arrangement 622 will be described in full detail with reference to FIGS. 16 a and 16 b. The piston 616 has a circumferentially distributed annulus of resilient pressure transmitting components 629; these parts will be fully described and their function explained with reference to FIGS. 14 and 15.
FIGS. 9 to 13 a illustrate four presently preferred embodiments x(9), x(10), x(11) and x(12) of the improved fluid flow regulating arrangement, and more specifically four embodiments of the arrangement 122 shown in FIG. 2. In FIG. 9, the piston 116 of the bypass clutch 113 cooperates with the radial wall 104 of the torque converter housing to regulate the flow of hydraulic fluid between the plenum cambers 117, 118 (refer to FIG. 2) when the bypass clutch 113 is engaged. The wall 104 has a cooling surface 104 k which confronts the piston 116 and is provided with radially extending grooves or channels 130; such grooves can be impressed into the surface 104 k of the wall 104. The non-depressed portions of the cooling surface 104 k (i.e., the radially extending surfaces alternating with the grooves 130 constitute one friction surface 114′ of the arrangement 122, and an annular friction lining 115 on the radially outermost portion of the piston 116 defines a second friction surface 115′ which bears upon the friction surface 114′ when the clutch 113 is at least partly engaged. At such time, hydraulic fluid can flow only through the grooves 130 when the pressure of such fluid in the chamber 117 exceeds that of fluid in the chamber 118.
In accordance with a presently preferred embodiment, the length l of the grooves 130 (as measured radially of the wall 104, i.e., at right angles to the plane of FIG. 13 a and as shown in FIG. 13), is between 10 and 50 mm, most preferably between 10 and 30 mm. As shown in FIG. 9, the length of the grooves 130 can exceed the width of the friction lining 115; this is desirable and advantageous because such dimensioning of the lengths l of the grooves 130 and of the radial width of the friction lining 115 ensures a practically unimpeded inflow of fluid into and a practically unimpeded outflow of fluid from the grooves 130.
As concerns the hydrodynamic aspects, the important parameters include the length l (FIG. 13), the width b (FIG. 13 a) and the depth t (FIG. 13 a) of the grooves 130, especially the ratio of t to b. The edges 130′ (see FIG. 13) of the surfaces bounding the grooves 130 may but need not be rounded. The width b of a groove 130 can be within the range of between about 0.2 and 20 mm, and the depth t can be less than 0.3 mm, preferably less than 0.15 mm. Still further, a groove 130 need not have an exactly rectangular cross-sectional outline; for example, the cross-sectional outlines of those end portions of the grooves 130 which are adjacent their radially outermost portions (at 130 a in FIG. 13) can have a trapeziform cross-sectional outline with each groove becoming wider as seen in a direction from the bottom toward the surface 114′ of the wall 104. The cross-sectional area of each groove 130 can increase radially outwardly toward the radially outermost portion 130 a shown in FIG. 13.
FIG. 10 illustrates a portion of a modified fluid flow regulating arrangement x(10) wherein the grooves 130 b are obtained by providing the wall 104 with radially extending rib-shaped projections 130 c at that side which faces away from the piston 116 of the bypass clutch. Thus, the grooves 130 b of FIG. 10 are obtained by displacing portions of the material of the wall 104 away from the piston 116, i.e., into the surface 114′.
FIG. 11 shows a portion of a fluid flow regulating arrangement x(11) which is the opposite of that shown in FIG. 10. Thus, the left-hand side of the wall 104 is provided with elongated grooves or recesses 130 d which are obtained by depressing the material of the wall 104 toward the piston 116. Consequently, the grooves (not shown) at the surface 114 are flanked by ribs which project beyond the surface 114. In other words, the grooves in the wall 104 of FIG. 11 are obtained as a result of raising elongated radially extending rib-shaped portions of the material of the wall 104 toward the adjacent left-hand surface of the piston 116.
The making of the projections shown at the right-hand side of the wall 104 depicted in FIG. 11 can involve the use of a suitable tool or implement (not shown) having raised portions which impress the grooves or recesses 130 d to thus provide the surface 114′ with raised portions which, in turn, flank grooves having open sides facing the surface 115′ of the friction lining 115 on the piston 116.
The fluid flow regulating arrangement x(12) of FIG. 12 does not employ any grooves in the surface 114′ and/or 115′. Instead, that side of the wall 104 which confronts the piston 116 carries a continuous or composite annular layer 131 of a material which is permeable to the fluid filling the chambers 117, 118. The layer 131 can be made of or can contain a sintered substance, a porous ceramic material (e.g., porous glass), a temperature-resistant porous organic plastic material or the like. The surface 114′ of such layer 131 a cooperates with the surface 115′ of the friction lining 115 on the adjacent surface of the piston 116.
The layer 131 is secured to the wall 104 by rivets 131 a (one shown in FIG. 12). Alternatively, the layer 131 can be secured to the wall 104 by a suitable adhesive, by projections provided on the wall 104 and extending into complementary recesses in the left-hand side of the layer 131, and/or in any other suitable manner. Furthermore, the layer 131 can be formed by applying to the wall 104 one or more films of a material which, when hardened or set, constitutes the layer 131.
FIGS. 14 and 15 illustrate the distribution of and the manner of mounting the resilient pressure transmitting members or components 629 one of which is shown in the upper part of FIG. 8. For the sake of simplicity, such components will be referred to as bellows since each thereof defines at least one internal space which can receive and discharge a quantity of fluid. As can be seen in FIG. 14, the piston 616 of the bypass clutch 613 carries an annular array of equidistant and rather closely adjacent oval bellows 629 each of which has its marginal portion affixed to the radially outermost portion of the piston 616 (as at 629 a). The connections 629 a can be established by an adhesive, by welding or in any other suitable manner.
The central portion of each bellows 629 registers with a discrete port 629 a of piston 616; each such port permits hydraulic fluid to enter into or to issue from the respective bellows. The ports 629 b together form a circular array. The bellows 629 change their volumes in dependency upon the pressure differentials between their interior and the surrounding atmosphere. Such volumetric changes are possible due to the deformability of the material of the bellows. The bellows 629 shown in FIGS. 8, 14 and 15 are assumed to consist of thin metallic sheet material.
FIG. 16 a shows an empty (deflated) bellows 629 and shows that this bellows is located at the side of the piston 616 facing away from the fluid flow regulator 622. FIG. 16 b shows an at least partially inflated bellows 629. Each of FIGS. 16 a, 16 b shows the bypass clutch including the wall 604 and the piston 616 in disengaged condition in order to facilitate the interpretation of the manner in which various constituents of the bypass clutch and of its fluid flow regulator 622 are affixed to each other. However, it is to be borne in mind that the regulator 622 is activated and that the bellows 629 can perform their intended functions only or primarily when the bypass clutch 613 is at least partly engaged.
FIG. 16 a shows that the friction lining 614 at the right-hand side of the wall 604 has a friction surface 614′ provided with a recess 630 a portion of which registers with the port 629 b of the piston 616. Each recess 630 has an open radially inner end and a closed radially outer end. When the piston 616 turns relative to the wall 604 and/or vice versa, each port 629 b communicates with each of the recesses 630 once during each complete revolution of the parts 604, 615 relative to each other.
It is now assumed that the pressure in the plenum chamber 618 shown in FIG. 16 a rises above that in the chamber 617 (reference should be had again to the description of the mode of operation of the torque converter 101 shown in FIG. 2). Therefore, the fluid in the chamber 18 deforms the bellows 629 whenever the respective ports 629 b communicate with the adjacent recesses 630 so that a certain amount of fluid can flow in the recesses 630 radially inwardly and into the chamber 617. An inflated bellows 629 is shown in FIG. 16 b, and a deflated bellows is shown in FIG. 16 a. The flow of fluid from the bellows 629, through the ports 629 b, through the recesses 630 and into the chamber 617 causes a cooling of the surfaces 614′, 615′ which slide relative to each other while the wall 604 and the piston 616 turn relative to each other when the bypass clutch operates with slip.
The bellows 629 are refilled, again and again, during successive stages of angular movements of the parts 604, 616 relative to each other when the ports 629 b communicate with radially outwardly extending recesses 630 a (see FIG. 16 b) which alternate with the recesses 630 and are also provided in the friction surface 614′ of the friction lining 614 on the wall 604. Each recess 630 a has a closed radially inner end (disposed radially inwardly of the ports 629 b) and a radially outer end communicating with the chamber 618. Each bellows 629 receives fluid from the chamber 618 when the respective port 629 b communicates with one of the radially outwardly open recesses 630 a. The just described repeated and at least partial emptying and at least partial refilling of the bellows 629 takes place as long as the wall 604 and the piston 616 turn relative to each other, i.e., as long as the bypass clutch operates with slip. Such repeated refilling and emptying of the bellows 629 is interrupted whenever the bypass clutch operates without slip and whenever the bypass clutch is disengaged (i.e., when the friction surfaces 614′, 615′ are out of frictional engagement with each other).
The number of ports 629 b and the numbers of recesses 630, 630 a can be readily selected in such a way that the likelihood of vibrations and/or noise generation, as a result of repeated (rhythmical) overlapping of the recesses 630, 630 a with the ports 629 b to bring about repeated filling and emptying of the bellows 629, is very remote or nil. This not only applies to the parts 613, 616 but also to all component parts of the improved torque converter as well as to other component parts in the power train and/or in other units of a motor vehicle.
The number of ports 629 b is preferably different from that of the recesses 630, 630 a, and such numbers preferably have a large common denominator.
FIGS. 17 a and 17 b show a modified assembly of parts in and at the fluid flow regulator of a bypass clutch 613 a. The bellows 629 (only one shown) are mounted on the radially outermost portion of the piston 616, the same as the friction lining 615; this friction lining is not provided with recesses 630, 630 a of the type shown in FIGS. 16 a and 16 b; instead, such recesses are provided in the friction surface 614's of the wall 604 and the friction lining 615 is provided with ports 629′ registering with the ports 629 b in the radially outermost portion of the piston 616. The grooves or recesses 630, 630 a are impressed or milled or eroded into the right-hand side of the wall 604.
FIGS. 18 a and 18 b illustrate a portion of a bypass clutch 613 c wherein the bellows 629 are borne by the outer side of the wall 604 and the piston 616 carries a friction lining 614 with recesses 630, 630 a of the type shown in FIGS. 16 a and 16 b. The recesses 630 a, 630 b are provided in the surface 614′ of the friction lining 614, and the ports 629 b are provided in the wall 604.
FIGS. 19 a and 19 b illustrate, drawn to a larger scale, certain details of a bypass clutch 213 a constituting a modification of the bypass clutch 213 shown in FIG. 3. The leaf springs 216 a of the torque converter 213 are omitted, and the piston 216 of the bypass clutch 213 a is non-rotatably but axially movably affixed to the inner side of the tubular radially outermost portion of the torque converter housing 204 a by two sets of mating gear teeth 216 a′. FIGS. 19 a and 19 b show the bypass clutch 213 a in disengaged condition in order to facilitate the understanding of the relationships between various interconnected and relatively movable parts; however it will be appreciated that the illustrated parts cooperate only when the clutch 213 a is at least partly engaged. The same applies for the friction clutch 213 b which is shown in FIGS. 20 a and 20 b. The friction lamella 223 d which is shown in FIGS. 19 a and 20 a carries a first friction lining 214 a having a friction surface 214 a′ confronting a friction surface 215 b′ at the inner side of the wall 204, and a second friction lining 214 b having an exposed friction surface 214 b′ confronting a friction surface 215 a′ of the piston 216. A set of inflatable receptacles (called bellows) 229 is provided at the right-hand side of the piston 216, and the latter has openings 229 b (hereinafter called ports) communicating with successive opening or ports 229 c in the lamella 223 d. The lamella 223 d further carries a second friction lining 214 b having an exposed friction surface 214 b′ confronting a friction surface 215 b′ on the piston 216. In FIG. 19 a, the illustrated bellows 229 can receive fluid from the chamber 217 via recesses 230 a provided in the friction surface 214 a′ of the friction lining 214 a, ports 229 c of the lamella 223 d and ports 229 b in the piston 216.
In FIG. 19 b, the reference character 230 denotes one of those recesses which alternate with the recesses 230 a (one shown in FIG. 19 b) but are open toward the chamber 217. Fluid can enter the bellows 229 via recesses 230 a, ports 229 c and ports 229 b. In FIG. 19 a, fluid can enter the bellows 229 from the chamber 218 via form-locking connection 216 a′ and/or through one or more openings (not shown in FIG. 19 a) in the pisron 216 between the connection 216 a′ and the friction surface 215 b′ and thereupon through the ports 229 b. The grooves 230 are provided in the surface 214′ of the friction lining 214 a which engages the friction surface 215 a′ of the wall 204 in the engaged condition of the friction clutch 213 a. In order to establish communication between the ports 229 b, the friction linings 214 a, 214 b and the lamella 223 d are provided with the ports 229 c. The emptying of the bellows 229 is shown in FIG. 19 b. The recesses 230 a (FIG. 19 a) alternate with the recesses 230 (FIG. 19 b). The exact manner in which the fluid is caused or permitted to leave the bellows 229 is the same as or analogous to that already described with reference to FIG. 16 a. FIGS. 20 a and 20 b respectively illustrate the emptying and refilling of bellows 229 in a manner analogous to that already described with reference to FIGS. 19 a and 19 b., The difference between the bypass clutches 213 a and 213 b of FIGS. 19 a-19 b and 20 a-20 b is that, in the clutch 213 a, recesses are provided in the friction surface 215 b′ of the friction lining 215. Consequently, the ports 229 c of FIGS. 19 a-19 b are not necessary in the friction clutch 213 b of FIGS. 20 a-20 b because the fluid flowing between the ports 229 b and the recesses 230 or 230 a shown in FIGS. 20 a-20 b need not flow through part 223 d. The features of the friction clutches 213 a, 213 b respectively shown in FIGS. 19 a-19 b and 20 a-20 b can be combined in a single torque converter, i.e., each of the friction linings 614 a, 614 b can be provided with recesses 230, 230 a. In such embodiment of the present invention, alternating bellows 229 are or can be arranged to respectively receive and/or discharge fluid by way of channels 230, 230 a provided in the friction linings 214 a and 214 b. FIG. 21 illustrates a portion of a torque converter having a bypass clutch 213 d which constitutes a further modification of the clutch 213 shown in FIG. 3. The friction lamella 223 d′ is flanked by two friction linings 214′, 214″ which are affixed to the wall 204 and to the piston 216, respectively. The piston 216 is axially movably but non-rotatably affixed to the housing including the wall 204 by leaf springs 216 a. The friction linings 214′, 214″ frictionally engage the respective sides of the lamella 223 d′ when the bypass clutch 213 d is at least partially engaged.
The left-hand side of the lamella 223 d′ is provided with a profile 230 b which varies in the circumferential direction and the details of which are shown in FIG. 22. The left-hand (233 b) and right-hand (233 a) sides of the lamella 223 d′ (as seen in FIG. 22) constitute friction surfaces which respectively engage the adjacent friction linings 214′ and 214″. The surfaces 233 b and 233 a are respectively provided with recesses 232 a, 232 b; these recesses form part of the fluid flow regulating arrangement 222, i.e., of the arrangement which regulates the flow of fluid between the plenum chambers 217, 218 (see FIG. 3) when the structure shown in FIGS. 21 and 22 is incorporated into the torque converter 201 of FIG. 3. The arrangement 222 then serves to determine the rate of fluid flow between the chambers 217, 218 in dependency upon the temperature (and hence the viscosity) of the fluid. As concerns the parameters (such as the depth, the width, the length, the number and the orientation) of the grooves 232 a, 232 b, reference should be had to the descriptions of the bypass clutches shown in FIGS. 16 a-16 b, 17 a-17 b and 18 a-18 b, especially in FIGS. 17 a-17 b and by bearing in mind that the structure actually shown in FIGS. 21 and 22 does not employ bellows (such as those shown at 629 in FIGS.16 a-18 b).
FIGS. 23 and 24 illustrate a structure which constitutes a modification of that shown in FIG. 12. In the bypass clutch 213 a of FIG. 23, a friction lamella 223 d″ carries two porous layers 231 a, 231 b which are respectively adjacent a friction lining 214″ on the wall 204 and a friction lining 214′ on the piston 216. The friction lining 214′ can be affixed to the porous layer 231 a instead of to the piston 216, and the friction lining 214″ can be affixed to the porous layer 213 b (instead of to the wall 204). Furthermore, the bypass clutch 213 a can utilize all of the parts shown in FIG. 23 plus at least one additional friction lining (affixed to the porous layer 231 a or 231 b).
In FIG. 24, the bypass clutch 213 b comprises a single porous layer 231 (e.g., a layer made of sintered metal) which is riveted to the friction lamella 223 d″. The layer 231 has friction surfaces 215, 215 a which (when the clutch 213 b is at least partly engaged) respectively bear upon friction linings 214′ (provided on the piston 216) and 214″ (provided on the wall 204). The radially outermost portion of the friction lamella 223 d″ is located radially inwardly of the friction linings 214′. 214″.
FIG. 25 shows certain details of a bypass clutch 613 d having a friction generating device 621 composed of parts 614, 615. A piston 616 d replaces the piston 116 or 616 of FIG. 2 or FIG. 8 to allow for an advantageous further modification of the fluid flow regulating arrangement 122 of FIG. 2 or 622 of FIG. 8. The fluid flow regulator embodying certain parts of the structure shown in FIG. 25 serves to regulate the flow of hydraulic fluid between the plenum chambers 617 and 618.
The wall 604 of FIG. 25 carries a friction lining 614′ which is provided with circumferentially distributed recesses or grooves 630 d extending radially outwardly to register with ports 629 b in the radially outer portion of the piston 616 d. The radially outer ends of the recesses 630 d are closed from the chamber 618 (when the bypass clutch 613 d of FIG. 25 is at least partly engaged) but the radially inner ends of such recesses are open toward the chamber 617.
The bellows 629 are not used in the bypass clutch 613 d; instead, the ports 629 b of the piston 616 d communicate directly with the chamber 618. When the piston 616 d and the housing (including the wall 604) are caused to turn relative to each other, the ports 629 b move into and beyond positions of register with the recesses 630 d of the friction lining 614′ on the wall 604 to thus respectively establish paths for the flow of fluid between the chambers 617 and 618. Such repeated flow of fluid between the chambers 617, 618 ensures that at least the friction lining 614′ is adequately cooled as soon and as long as the bypass clutch 613 d operates with slip.
If the pressure of fluid in the chamber 618 rises above that in the chamber 617, i.e., if the piston 616 d is moved axially toward the wall 604, the extent of relative angular movement of the piston 616 d and the housing (including the wall 604) of the torque converter decreases and comes to a halt when the clutch 616 d is fully engaged. The number of ports 629 b and/or the number of recesses 630 d can be selected in such a way that the likelihood of unsatisfactory or unacceptable overlap is remote or nil; this can be readily accomplished by proper selection of the numbers and/or proper distribution of the ports 629 b and recesses 630 d. Furthermore, and as actually shown in FIG. 25, one can provide a closing device or lid 635 which, when the bypass clutch 613 d is engaged, seals the ports 629 b from the plenum chamber 618 so that there can be no flow of fluid from the chamber 618, via ports 629 b and recesses 630 d, and into the chamber 617 (wherein the fluid pressure is assumed to be lower than in the chamber 618 when the bypass clutch 613 d is fully engaged, i.e., when such bypass clutch operates without slip). The reason for the provision of the closing device 635 is that there is no need to cool the friction lining 614′ when the bypass clutch 613 d is fully engaged so that the wall 604 and the piston 616 d cannot slip relative to each other.
It is clear that the closing device 635 can be designed to close and actually seal only some of the ports 629 b from the plenum chamber 618.
FIG. 26 shows, drawn to a larger scale, the structure within the phantom-line circle Y in FIG. 25. FIG. 27 is a view as seen in the direction of arrow X in FIG. 26, and FIG. 28 is a view as seen in the direction of arrow W in FIG. 25. The closing device 635 comprises a series of tongues or flaps 635 a which are pivotable to move substantially axially of the bypass clutch 613 d. The tongues 635 a form integral parts of or are pivotably mounted on a ring-shaped carrier 635 which is welded, riveted or adhesively or otherwise affixed to the piston 616 d. It is preferred to make the carrier 635 b of a resilient material and to ensure that the tongues 635 a tend to assume their inoperative or idle positions (shown in FIGS. 25 to 27) in which they permit fluid to flow from the chamber 618 into the ports 629 b. For example, the carrier 635 b and its tongues 635 a can be made of thin layers of spring steel. The thickness and/or the resiliency of the material of the carrier 635 b are selected in such a way that the tongues 635 a are compelled to yield and to pivot to their operative or closed positions (to seal the respective ports 629 b from the chamber 618) as soon as the pressure of fluid in the chamber 618 ries to a value indicating that the clutch 613 d of FIGS. 25-28 is engaged, i.e., that the wall 604 and the piston 616 d do not turn relative to each other. When the pressure differential between the bodies of fluid in the chambers 617, 618 decreases, the innate resiliency of the tongues 635 a suffices to initiate a movement of the tongues to the open positions shown in FIGS. 25 to 27.
In order to even more reliably ensure pivotal movements of the tongues 635 a to their open or inoperative positions as soon as the piston 616 d and the wall 604 are free to turn relative to each other, the friction lining 614′ of FIG. 25 is provided with at least one groove which is open radially outwardly; such groove or grooves permits or permit entry of fluid which exerts pressure upon the tongues 635 a and ensures or ensure that the tongues reassume the open positions of FIGS. 25-27 as soon as the wall 604 and the piston 616 begin to turn relative to each other. Otherwise stated, the just mentioned groove or grooves in the friction lining 614′ ensures or ensure that the pressure of fluid at the inner sides of the tongues 635 a is the same as at their outer sides (i.e., in the plenum chamber 618) as soon as the wall 604 and the piston 616 d begin to turn relative to each other so that the innate tendency of the tongues 635 a suffices to maintain them in open positions when the clutch 613 d is partially engaged so that it operates with slip.
By embodying the structure of FIGS. 25-28 in the bypass clutch of FIG. 2 and/or 8, one ensures that the respective fluid flow regulating assembly (122 or 622) even more reliably ensures adequate cooling of the hydraulic fluid by exchange of heat as long as the respective bypass clutch operates with slip, and that the extent of cooling is commensurate with (a) the speed of relative angular movement between the torque converter housing (wall 104 or 604) and the piston (116 or 616), and (b) the extent of pressure differential between the bodies of fluid in the plenum chambers (117 and 118 or 617 and 618). On the other hand, the tongues 635 a in the structure of FIGS. 25-28 also ensure that the circulation of fluid through the fluid flow regulating arrangement 122 or 622 is interrupted when a cooling of fluid is not necessary, i.e., when the bypass clutch embodying the structure of FIGS. 25-28 is disengaged or fully engaged.
The structure which is shown in FIGS. 25-28 (or one or more structural and functional equivalents thereof) can be utilized with equal or similar advantage in torque converters which are different from those shown in FIGS. 2 and 8, i.e., with differently configurated, mounted and assembled friction linings, friction lamellae and/or other constituents of the fluid flow regulating arrangements. By way of example only, the structure shown in FIGS. 25-28 can be incorporated into torque converters embodying the features of the structures shown in FIGS. 16 a to 20 b. FIGS. 29 a to 29 k respectively illustrate portions of friction linings 636 a to 636 k which can be utilized in lieu of previously described friction linings (such as those shown in FIGS. 16 a to 20 b) to ensure even more predictable flow of fluid between the two plenum chambers (not shown in FIGS. 29 a to 29 k).
For example, if one utilizes a fluid flow regulating arrangement 622 (FIG. 8) or 622 a (FIG. 25), it is advisable to employ radially inwardly opening grooves or recesses 636 a″-636 k″ (see FIGS. 29 a-29 k) as well as radially outwardly open recesses 636 a′-636 k′ in such numbers that the overall number of radially outwardly opening recesses (e.g., 636 a′) matches or approximates the overall number of radially inwardly opening recesses (e.g., 636 a″). Moreover, individual radially inwardly opening recesses (such as 636 a″) or groups of such recesses can alternate with individual radially outwardly opening recesses (such as 636 a′) or groups of such recesses, as seen in the circumferential direction of the respective friction ring (such as 636 a). The recesses or grooves of each set can be equidistant from each other and can be straight, arcuate, undulate, zigzag shaped, comb-shaped, T-shaped, V-shaped and/or otherwise configurated.
It is also possible to alternate groups of two or more inwardly opening recesses (such as 636 a″) with individual outwardly opening recesses (such as 636 a′); such arrangement can be resorted to in the embodiment of FIG. 25).
FIG. 29 a shows that the radially inner ends of the recesses 636 a ′, 636 a″ extend circumferentially of the friction lining 636 a. If such arrangement is used in the embodiment of FIGS. 16-16 b, it ensures longer-lasting communication of successive alternating recesses 636 a′ and 636 a″ with successive ports 629 b shown in FIGS. 16 a and 16 b. The recesses or grooves 636 b and 636 c of FIGS. 29 b and 29 c extend radially of the respective friction linings 636 b, 636 c; therefore, the intervals of communication with the ports 629 b of FIGS. 16 a-16 b (if the friction lining shown in FIGS. 16 a and 16 b is replaced with the friction lining 636 b or 636 c) are relatively short if and when the wall 604 and the piston 616 of FIGS. 16 a and 16 b are caused to turn relative to each other. The depths of the recesses 636 b′, 636 b″ are such that their closed inner ends communicate with successive ports 629 b if the friction lining 636 b replaces the friction lining shown in FIGS. 16 a and 16 b. The recesses 636 c′, 636 c 41 of the friction lining 636 c shown in FIG. 29 c are much longer than those shown in FIG. 29 b. The inclination of the straight recesses 636 d′, 636 d″ in the friction lining 636 of FIG. 29 d is dependent upon the desired duration of communication with successive ports 629 b if the friction lining 636 d replaces the one shown in FIGS. 16 a and 16 b. The illustrated recesses 636 d′, 636 d″ are inclined in the same direction, i.e., clockwise, as seen in FIG. 29 d; however, they can be inclined in opposite directions if so required or desirable or advantageous for a specific mode of fluid flow regulation.
Each of the recesses 636 e′, 636 e″ (in the friction lining 636 e of FIG. 29 e), 636 f′, 636 f″ (in the friction lining 636 f of FIG. 29 f) and 636 g′, 636 g″ (in the friction lining 636 g of FIG. 29 g) has two open ends which extend inwardly from the outer and inner edge faces of the respective friction lining. The recesses of the friction linings shown in FIGS. 29 e to 29 g can have identical (FIGS. 29 e, 29 g) or different (FIG. 29 f) shapes and/or sizes, such as part circular, U-shaped, trapeziform or U-shaped outlines.
FIGS. 29 h and 29 i respectively show recesses 636 h′, 636 h″ and 636 i′, 636 i″ having widths (as seen circumferentially of the respective friction rings 636 h, 636 i) greatly exceeding their depths. Furthermore, the depths of the recesses 636 i′, 636 i″ vary continuously, as seen in the circumferential direction of the friction ring 636 i. It is to be noted that the FIGS. 29 a-29 k illustrate merely a relatively small number of different recesses 636 a′-636 k′ and 636 a″-636 k″. Thus, it is possible to combine the shapes actually shown in these Figures to arrive at a host of additional configurations having constant or varying depths and/or widths and/or lengths, depending upon the desired nature, duration and other characteristics of fluid flow between the two plenum chambers.
FIG. 29 j shows a friction lining 636 j wherein the zig-zag shaped recesses 636 j′, 636 j″ are dimensioned, configurated and oriented to ensure extensive (pronounced) cooling of the friction lining because such recesses can come into frequent and long-lasting contact with successive ports 629 b (if the friction lining 636 j is utilized in the structure shown in FIGS. 16 a and 16 b).
The comb-shaped grooves 636 k′, 636 k″ in the friction lining 636 k of FIG. 29 k also ensure long-lasting communication of their ridges with successive ports 629 b if the friction lining 636 k is utilized in lieu of the friction lining shown in FIGS. 16 a and 16 b. At least some of the grooves or recesses shown in FIGS. 29 a-29 k can be utilized in parts other than friction linings, e.g., in lieu of the recesses 630 a, 630 respectively shown in FIGS. 17 a and 17 b; the recesses 630 a, 630 are provided in the inner side of the wall 604, i.e., in a portion of the housing of the torque converter including the structure shown in FIGS. 17 a and 17 b. Still further, it is possible to provide recesses or grooves of the type shown in FIGS. 29 a to 29 k in the piston of the bypass clutch or in a friction lamells (see the part 223 d′ shown in FIGS. 21 and 22).
FIG. 30 shows a hydrokinetic torque converter 701 having a fluid flow regulating arrangement 722 which is effective to influence the operation of the bypass clutch 713, namely to regulate the rate of fluid flow between the wall 704 of the housing 704 a of the torque converter and the axially movable piston 716. The controlling factor is the difference between the RPM of the wall 704 and that of the piston 716.
The reference character 737 denotes a metering pump which is installed in the hub 706 a of the turbine 706 in the housing 704 a. The piston 716 and the turbine constitute the output members of the bypass clutch 713. A torsional vibration damper 723 is employed to prevent the transmission of vibrations from the piston 716 and/or from the turbine 706 to the hub 706 a and hence to the transmission when the bypass clutch 713 is engaged to operate with or without slip.
The pump 737 is rotatable relative to and is confined in the hub 706 a. A safety ring 737 a is provided to prevent axial movements of the pump 737 relative to the hub 706 a. The housing 737 b of the pump 737 is non-rotatably connected with the wall 704 but is rotatable relative to the hub 706 a. The non-rotatable connection between the pump housing 737 b and the wall 704 comprises at least one projection or stud 737 c provided on the pump housing and extending into a socket 704 f′ of a plug or stud 704 f which is welded to the wall 704. The pump housing 737 b confines a pumping element 738 here shown as a sphere which is movable back and forth in a preferably cylindrical internal chamber or space 741 to seal the opening or outlet 739 or 740 of the pump 737. The openings 739, 740 are or can be surrounded by suitable sealing elements (such as elastic washers, O-rings or the like). The openings 739, 740 respectively confront conduits 742, 743 which are provided in the hub 706 a and respectively communicate with an inlet 719 a and an outlet 719 b for hydraulic fluid.
When the housing 704 a and the plug 704 f turn relative to the hub 706 a and/or vice versa, the openings 739, 740 alternately but simultaneously communicate with the conduits 742, 743 in response to successive 180� turns of the pump housing 737 b. Thus, when the wall 704 turns relative to the hub 706 a and the pressure of fluid in the conduit 743 exceeds that in the conduit 742, successive quantities of fluid entering chamber 741 are transferred from the conduit 743 into the conduit 742. The spherical pumping element 738 is caused to move in the chamber 741 back and forth first into sealing position relative to the opening 739, thereupon (as a result of rotation of the pump housing 737 b through 180� with the wall 704 relative to the hub 706 a) to the position in which it seals the opening 740, again into a position in which it seals the opening 739, and so forth. This causes the transfer of metered quantities of fluid from the conduit 743 into the conduit 742. Such pumping of successive metered quantities of fluid continues as long as the wall 704 and the hub 706 a turn relative to each other (this also involves rotation of one of these parts relative to the other part).
When the clutch 713 is disengaged, the pressure in the conduit 742 matches that in the conduit 743 so that the rate of fluid flow between these conduits is practically nil even if the wall 704 turns relative to the hub 706 a and/or vice versa (due to slip of the turbine 706 and the pump 705 relative to each other).
The means for conveying metered quantities of fluid from the conduit 742 into the region of the bypass clutch 713, namely to the locus of direct or indirect frictional engagement of the piston 716 with the wall 704, i.e., for removing heat from the friction surfaces 714′, 715′, includes a disc-shaped member 744 which cooperates with the piston 716 to define a chamber 745 which communicates with the conduit 742 and is sealed from the plenum chamber 718. The member 744 can constitute an injection molded plastic part or an embossed sheet metal part; this member is sealed outwardly against the piston 716 and inwardly against the hub 706 a. The reference character 723 g denotes a rivet constituting one of the fasteners which secure the the torsional vibration damper 723 to the piston 716; the member 744 can have a cutout for each of the fasteners 723 g, and each such cutout is surrounded by a seal (not shown) which ensures that fluid entering the chamber 745 is compelled to flow from the openings 739, 740 to the bypass clutch 713.
The radially outermost portion of the piston 716 has an annulus of ports 729 b which direct pressurized fluid from the chamber 745 against the friction lining 714′, and such fluid ultimately enters the plenum chamber 717 or 718 to exchange heat with the friction lining 714′ and to transfer such heat to the body of fluid in the chamber 717 or 718. The reference character 715 denotes a friction surface provided on the friction lining 714′ and having grooves of the type shown, for example, in FIG. 19 b to direct the fluid into the plenum chamber 717. The chamber 717 communicates with the outlet 719 b. The aforementioned grooves (e.g., in the surface 715) can be of the type shown in FIGS. 29 a to 29 k, except that all such grooves are laid out to convey hydraulic fluid from the ports 729 b (i.e., from the chamber 745) into the chamber 717 (reference should be had to the grooves 636 a″ to 636 k″ shown in FIGS. 29 a to 29 k. The plenum chamber 718 of the torque converter 701 receives fluid from the inlet 719 a for pressurized fluid in a manner not specifically shown in FIG. 30; the path for the flow of fluid from the inlet 719 a of the torque converer 701 to the chamber 718 is defined by parts not visible in the sectional view of FIG. 30.
FIGS. 31, 32 a and 32 b illustrate the details of a further fluid flow regulating arrangement 822 which constitutes a modification of the arrangement shown in FIG. 30. The piston 816 of the bypass clutch in the torque converter which embodies the structure of FIGS. 31, 32 a and 32 b is provided with an annular array of circumferentially spaced-apart metering pumps 837 (two shown in FIG. 31) which, in contrast to the centrally mounted pump 737 of the torque converter 701 shown in FIG. 30, are mounted in the region of frictional engagement between the parts of the fluid flow regulating arrangement 822 when the clutch including the piston 816 is at least partly engaged, i.e., when the wall 804 of the housing of the torque converter and the piston 816 turn relative to each other.
The ends of the elongated pumps 837 are provided with outlets 839, 840 constituted by pipes 839 a, 840 a (see FIG. 32 a) which are recessed in the piston 816 to the extent determined by the stops 839 c, 840 c, respectively. The pipes 839 a, 840 a and a length of a pipe 837 c between them together constitute the housing 837 b of the respective pump 837. The pumping element 838 is a sphere which is movable back and forth in the pipe 837 a all the way between the pipes 839 a, 840 a. The pipes 839 a, 840 a can constitute composite (such as two-part) components made, e.g., in an injection molding machine, of a suitable plastic material. The same applies for several or all other parts of each pump 837.
The friction lining 814′ of the torque converter shown in part in FIGS. 32 a and 32 b is assumed to be affixed to the wall 804 of the housing of the torque converter. This friction lining has radially outwardly extending recesses or cutouts 830 which alternate with radially inwardly extending recesses or cutouts 830 a. These recesses extend inwardly to an extent such that they communicate with the openings 839, 840 (these are used as inlets or outlets) of successive pumps 837 when the wall 804 and the piston 816 turn relative to each other. The spacing of the recesses 830, 830 a in the circumferential direction of the friction lining 814′ is such that one thereof registers with the opening 839 of a pump 817 while the other thereof registers with the opening 840. The illustrated recesses 830, 830 a constitute but one of numerous embodiments which can be provided in the friction lining 814′; reference may be had, for example, to FIGS. 29 a to 29 k. If a friction lining (replacing the friction lining 814′on the wall 804) is replaced with a friction lining on the piston 816, the recesses 830, 830 a or their equivalents are machined into or otherwise provided in that surface of the wall 804 which confronts the piston 816.
The mode of operation of the bypass clutch embodying the structure shown in FIGS. 31, 32 a and 32 b is such that, when the fluid flows from one of the two plenum chambers (e.g., from the plenum chamber 118 shown in FIG. 2), such fluid is caused to enter the recesses 830 a in the direction of arrows shown in FIG. 32 a to cause the spherical pumping element 838 to roll or to otherwise move in the pump chamber toward the opening 840 and to expel a metered quantity of fluid into the chamber 817. Such movement of the pumping element 838 results in entry of a stream of hydraulic fluid from the chamber 818 into the portion 841 of the pump chamber via opening 839 and in simultaneous expulsion (by the pumping element 838) of a stream of fluid from the portion 841 a of the pump chamber, via opening 840 and into the plenum chamber 117. The rate of fluid flow from the chamber 118 into the the chamber 117 is dependent upon the extent of angular movement of the piston 816 and the wall 804 relative to each other. When the pumping element 838 reaches the right-hand end of the pump chamber (841+841 a), it seals the opening 840 from the pump chamber and the latter is filled with fluid via opening 839.
As the angular displacement of the parts 804, 816 relative to each other continues, the openings 839, 840 respectively communicate with the recesses 830, 830 a (see FIG. 32 b). The recess 830 a admits pressurized fluid which causes the pumping element 838 to expel the contents of the pump housing 837 b via opening 839 and recess 830 into the chamber 817. At the same time, the chamber 841+841 a is filled with fluid entering via opening 840. This stage of operation of the pump 837 shown in FIGS. 32 a and 32 b is completed when the pumping element 838 seals the opening 839. The above described alternating stages of operation are repeated, again and again, as long as the bypass clutch including the piston 816 and the wall 804 operates with slip. When the bypass clutch is fully engaged, a cooling of the friction lining 814′ and/or of the neighboring parts of the torque converter is no longer necessary; at such time, the pumping element 838 of each pump 837 at least substantially seals one of the openings 839, 840 in the respective pump to thus interrupt the flow of fluid between the plenum chambers 117 and 118.
FIG. 34 b illustrates the lip of the sealing element 950 in full sealing engagement with the profiled inner side of the wall 904. The arrows indicate the directions of rotary movement of the parts 904 and 916 (the sealing element 950 rotates with the piston 916). If the piston 916 and the wall 904 begin to turn relative to each other, the stiffness of the reinforced lip 951 and/or the undulate shape of the profiled side 952 of the wall 904 and/or the drop of pressure in the chamber 918 (as compared with that of the chamber 917) causes the lip 951 to move away from the profile 952 and to establish pathways 953 for the flow of fluid between the chambers 917 and 918, e.g., from the chamber 918 into the chamber 917. This is shown in FIG. 34 a. The friction lining 914′ can be provided with recesses, channels, cutouts or like configurations which extend radially of such friction lining and permit the flow of fluid between the chambers 917, 918 at a desired optimum rate when the parts 904, 916 are caused or permitted to turn relative to each other. The structure shown in FIGS. 33, 34 a and 34 b also permits for an accurate regulation of fluid flow between the chambers 917, 918 to ensure adequate cooling of surfaces which are heated while the parts 904, 916 are caused or permitted to turn relative to each other.
The reference character 1062 denotes a cooling chamber which extends radially inwardly beyond the friction surfaces 1014, 1015 and, in the embodiment of FIG. 35, is defined by the wall 1004 and a sheet metal shroud 1063 which is sealingly secured (such as welded) to the outer side 1061 of the wall 1004. The cooling chamber 1062 has a sealable opening 1064 for admission or evacuation of a coolant 1065 partly filling the chamber 1062 and having a density which varies in response to heating by friction heat developing when the parts 1004, 1016 of he bypass clutch 1013 are caused or permitted to slip relative to each other. Such change of phase causes the body of coolant 1065 to store energy and to be accelerated radially inwardly due to a reduction of density and the lesser action of centrifugal force whenever the housing wall 1004 and the piston 1016 turn relative to each other. This enables the coolant 1065 to exchange heat with relatively cool (cooler) housing wall portions 1004 h and shroud portions 1063 a. Such cooling of the coolant 1065 entails a rise of density and an increased action of centrifugal force, i.e., the coolant flows radially outwardly and removes heat from the surface 1061 of the wall 1004 which is heated due to slippage relative to the piston 1016.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4969543 *Jul 10, 1989Nov 13, 1990Ford Motor Co.Slipping bypass clutch construction for a hydrokinetic torque converterUS5056631 *Nov 1, 1990Oct 15, 1991Ford Motor CompanySlipping bypass clutch construction for a hydrokinetic torque converterUS5501309Jul 27, 1994Mar 26, 1996Luk Getriebe-Systeme GmbhHydrokinetic torque converter with lockup clutchUS5674155Aug 21, 1993Oct 7, 1997Luk Gebriebe-Systeme GmbhMethod of and apparatus for transmitting torque in the power trains of motor vehiclesUS5711730Dec 6, 1995Jan 27, 1998Luk Getriebe-Systeme GmbhTorque monitoring apparatusUS5738198Jan 20, 1995Apr 14, 1998Luk Getriebe-Systeme GmbhFriction element for use in clutchesUS5779012 *Aug 5, 1997Jul 14, 1998Luk Getriebe-Systeme GmbhHydrokinetic torque converter with lockup clutchUS5782327May 16, 1996Jul 21, 1998Luk Getriebe-Systeme GmbhHydrokinetic torque converter and lockup clutch thereforUS5860863Aug 1, 1997Jan 19, 1999Luk Lamellen Und Kupplaungsbau GmbhApparatus for damping vibrationsUS5865283 *Apr 9, 1996Feb 2, 1999Nsk-Warner K.K.Torque converter with a lock-up mechanismUS5975260 *Aug 25, 1997Nov 2, 1999Luk Getriebe-Systeme GmbhHydrokinetic torque convertor with bypass clutch having grooved friction liningUS6047806 *May 5, 1998Apr 11, 2000Mannesmann Sachs AgHydrodynamic torque converter with depressions in the extension area of the friction liningsDE3614158A1Apr 26, 1986Oct 29, 1987Fichtel & Sachs AgTorsionsschwingungsdaempfer mit schwimmend gelagerten zwischenteilen* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6953185 *Sep 25, 2002Oct 11, 2005Siemens AktiengesellschaftElectromagnetical clutch, electromechanical actuator and turbineUS7513345 *Aug 1, 2006Apr 7, 2009Luk Lamellen Und Kupplungsbau Beteiligungs, KgSlip clutch cooling configurationUS7887240 *Dec 12, 2006Feb 15, 2011Luk Lamellen Und Kupplungsbau Beteiligungs KgThrust washer with enclosed channelsUS8146725 *Dec 19, 2006Apr 3, 2012Nsk-Warner K.K.Friction plate and wet-type multi-plate clutch having such friction plateUS8327992Dec 30, 2011Dec 11, 2012Nsk-Warner K.K.Friction plate and wet-type multi-plate clutch having such friction plateUS8714333Nov 1, 2012May 6, 2014Nsk-Warner K.K.Friction plate and wet-type multi-plate clutch having such friction plateUS8844691 *Aug 22, 2011Sep 30, 2014Schaeffler Technologies Gmbh & Co. KgThree-pass torque convertersUS9004253Jun 26, 2013Apr 14, 2015Ford Global Technologies, LlcControl of fluid flow in an automatic transmissionUS20120043173 *Aug 22, 2011Feb 23, 2012Schaeffler Technologies Gmbh & Co. KgThree-pass torque converters* Cited by examinerClassifications U.S. Classification192/3.3, 192/113.35, 192/113.36, 192/3.29International ClassificationF16H45/02, F16H61/14Cooperative ClassificationF16H2045/0278, F16H45/02, F16H2045/0294, F16H2045/0289, F16H2045/021European ClassificationF16H45/02Legal EventsDateCodeEventDescriptionApr 2, 2013FPExpired due to failure to pay maintenance feeEffective date: 20130208Feb 8, 2013LAPSLapse for failure to pay maintenance feesSep 24, 2012REMIMaintenance fee reminder mailedJul 24, 2008FPAYFee paymentYear of fee payment: 4Jul 5, 2005CCCertificate of correctionMay 31, 2002ASAssignmentOwner name: LUK LAMELLEN UND KUPPLUNGSBAU BETEILIGUNGS KG, GERFree format text: CHANGE OF NAME;ASSIGNOR:LUK LAMELLEN UND KUPPLUNGSBAU GMBH;REEL/FRAME:012937/0763Effective date: 20010116Owner name: LUK LAMELLEN UND KUPPLUNGSBAU BETEILIGUNGS KG INDUFree format text: CHANGE OF NAME;ASSIGNOR:LUK LAMELLEN UND KUPPLUNGSBAU GMBH /AR;REEL/FRAME:012937/0763Owner name: LUK LAMELLEN UND KUPPLUNGSBAU BETEILIGUNGS KG INDUFree format text: CHANGE OF NAME;ASSIGNOR:LUK LAMELLEN UND KUPPLUNGSBAU GMBH /AR;REEL/FRAME:012937/0763Effective date: 20010116Nov 14, 2001ASAssignmentOwner name: LUK LAMELLEN UND KUPPLUNGSBAU GMBH, GERMANYFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BACK, GUNNAR;FRIEDMANN, HUBERT;GRANDERATH, PAUL;AND OTHERS;REEL/FRAME:012320/0866;SIGNING DATES FROM 20011002 TO 20011026Owner name: LUK LAMELLEN UND KUPPLUNGSBAU GMBH INDUSTRIESTRASSFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BACK, GUNNAR /AR;REEL/FRAME:012320/0866;SIGNING DATES FROM 20011002 TO 20011026RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services