Abstract:
A torque converter comprising: a cover for receiving torque from a prime mover; an impeller fixed to the cover to form a housing for the torque converter; a turbine disposed in the housing for receiving torque from the impeller; a clutch backing plate fixed to the housing and arranged to receive a force, in an axial direction, from the turbine during operation of the torque converter; a thrust plate for thrust engagement with the clutch backing plate, and, a cover plate for driving engagement with a damper spring, wherein the thrust plate comprises the cover plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of application Ser. No. 13/214,433, filed on Aug. 22, 2011, which claims the benefit of U.S. Provisional Application No. 61/484,466 filed on May 10, 2011 and U.S. Provisional Application No. 61/375,867 filed on Aug. 22, 2010, which applications are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The invention relates generally to a torque converter, and more specifically to a torque converter arranged for operation in a three-pass transmission. 
       BACKGROUND 
       [0003]    Torque converters for three-pass transmissions are known. One example is shown in commonly assigned United States Patent Publication No. 2008/0277223. In known converter designs, turbine thrust loads, that is, the thrust force in the turbine acting towards the cover as a result of hydrodynamic pressure in the torus, is generally reacted by a turbine hub and a bearing or bushing. 
       BRIEF SUMMARY 
       [0004]    Example aspects broadly comprise a torque converter including a cover for receiving torque from a prime mover, an impeller fixed to the cover to form a housing for the torque converter, a turbine disposed in the housing for receiving torque from the impeller, and a clutch backing plate fixed to the housing and arranged to receive a force, in an axial direction, from the turbine during operation of the torque converter. In some example embodiments, the turbine includes a thrust plate for thrust engagement with the clutch backing plate. In an example embodiment, the turbine includes a turbine shell and the thrust plate is attached to the turbine shell. 
         [0005]    In some example embodiments, the torque converter includes a cover plate for driving engagement with a damper spring and the thrust plate includes the cover plate. In some example embodiments, the turbine has a turbine shell and the cover plate is fixed to the turbine shell. In some example embodiments, the torque converter includes a sealing plate fixed to the turbine shell and the cover plate at a first diameter, and pressingly engaged with the cover plate at a second diameter, different than the first diameter. In an example embodiment, the torque converter includes a sealing plate fixed to the cover plate and pressingly engaged with the clutch backing plate axially between the cover plate and the clutch backing plate. 
         [0006]    In some example embodiments, the torque converter has a centering plate and the turbine includes a turbine shell. The centering plate is fixed to the turbine shell, the cover plate is axially retained by the turbine shell and the centering plate, and the cover plate is at least partially rotatable relative to the turbine. In some example embodiments, the torque converter has a sealing plate fixed to the turbine shell and pressingly engaged with the cover plate. In an example embodiment, the torque converter includes a sealing plate fixed to the cover plate and pressingly engaged with the clutch backing plate axially between the cover plate and the clutch backing plate. 
         [0007]    Other example aspects broadly comprise a torque converter including a housing, a piston plate, a clutch backing plate fixed to the housing, a turbine, a thrust plate for transmitting axial force from the turbine to the clutch backing plate, and a clutch. The converter also has a first hydraulic chamber at least partially defined by the housing and the piston plate for engaging the clutch, a second hydraulic chamber at least partially defined by the piston plate, the clutch backing plate, and the thrust plate, and a third hydraulic chamber at least partially defined by the clutch backing plate, the thrust plate, and the housing. In an example embodiment, one of the second or third hydraulic chambers is for introducing a cooling flow to the clutch, and the other of the second or third hydraulic chambers is for receiving a cooling flow from the clutch. 
         [0008]    In some example embodiments, the clutch backing plate includes an orifice for exchanging fluid between the second and third hydraulic chambers. In some example embodiments, the torque converter has a sealing plate partially dividing the second and third hydraulic chambers. In some example embodiments, the sealing plate includes an annular friction material ring for sealing engagement with the clutch backing plate. In an example embodiment, the sealing plate is fixed to the clutch backing plate and pressingly engaged with the thrust plate. 
         [0009]    In some example embodiments, the sealing plate is fixed to the thrust plate and pressingly engaged with the clutch backing plate. In an example embodiment, the torque converter includes a cover plate and a sealing plate. The thrust plate includes the cover plate and the sealing plate is fixed to the cover plate at a first diameter, and pressingly engaged with the cover plate at a second diameter, different than the first diameter. 
         [0010]    Other example aspects broadly comprise a torque converter assembly including a cover assembly with a clutch backing plate, for receiving torque from an engine, an impeller assembly fixed to the cover assembly to form a housing for the torque converter, a stator for multiplying torque, and a turbine assembly. The torque converter also includes a thrust plate for transmitting axial force from the turbine assembly to the clutch backing plate and a damper assembly for transmitting torque to a transmission input shaft. In some example embodiments, the damper assembly includes a cover plate drivingly engaged with the turbine assembly and a flange including a hub for driving engagement with the input shaft, and the turbine assembly has a centering plate for centering the turbine assembly relative to the input shaft. In an example embodiment, the centering plate centers the turbine assembly relative to the flange hub. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The nature and mode of operation of the present invention will now be more fully described in the following detailed description taken with the accompanying drawing figures, in which: 
           [0012]      FIG. 1A  is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used in the present application; 
           [0013]      FIG. 1B  is a perspective view of an object in the cylindrical coordinate system of  FIG. 1A  demonstrating spatial terminology used in the present application; 
           [0014]      FIG. 2  is a top-half cross section of a three-pass torque converter with a turbine damper according to an example aspect; 
           [0015]      FIG. 2A  is partial view of the three-pass torque converter of  FIG. 2  showing an alternative thrust plate configuration; 
           [0016]      FIG. 3  is a top-half cross section of a three-pass torque converter with a pendulum damper according to an example aspect; 
           [0017]      FIG. 4  is a top-half cross section of a three-pass torque converter with a tilger damper according to an example aspect. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    At the outset, it should be appreciated that like drawing numbers appearing in different drawing views identify identical, or functionally similar, structural elements. Furthermore, it is understood that this invention is not limited only to the particular embodiments, methodology, materials and modifications described herein, and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. 
         [0019]    Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the following example methods, devices, and materials are now described. 
         [0020]      FIG. 1A  is a perspective view of cylindrical coordinate system  80  demonstrating spatial terminology used in the present application. The present invention is at least partially described within the context of a cylindrical coordinate system. System  80  has a longitudinal axis  81 , used as the reference for the directional and spatial terms that follow. The adjectives “axial,” “radial,” and “circumferential” are with respect to an orientation parallel to axis  81 , radius  82  (which is orthogonal to axis  81 ), and circumference  83 , respectively. The adjectives “axial,” “radial” and “circumferential” also are regarding orientation parallel to respective planes. To clarify the disposition of the various planes, objects  84 ,  85 , and  86  are used. Surface  87  of object  84  forms an axial plane. That is, axis  81  forms a line along the surface. Surface  88  of object  85  forms a radial plane. That is, radius  82  forms a line along the surface. Surface  89  of object  86  forms a circumferential plane. That is, circumference  83  forms a line along the surface. As a further example, axial movement or disposition is parallel to axis  81 , radial movement or disposition is parallel to radius  82 , and circumferential movement or disposition is parallel to circumference  83 . Rotation is with respect to axis  81 . 
         [0021]    The adverbs “axially,” “radially,” and “circumferentially” are with respect to an orientation parallel to axis  81 , radius  82 , or circumference  83 , respectively. The adverbs “axially,” “radially,” and “circumferentially” also are regarding orientation parallel to respective planes. 
         [0022]      FIG. 1B  is a perspective view of object  90  in cylindrical coordinate system  80  of  FIG. 1A  demonstrating spatial terminology used in the present application. Cylindrical object  90  is representative of a cylindrical object in a cylindrical coordinate system and is not intended to limit the present invention in any manner. Object  90  includes axial surface  91 , radial surface  92 , and circumferential surface  93 . Surface  91  is part of an axial plane, surface  92  is part of a radial plane, and surface  93  is part of a circumferential plane. 
         [0023]    The following description is made with reference to  FIG. 2 .  FIG. 2  is a top-half cross section of three-pass torque converter  100  with a turbine damper. Torque converter  100  includes impeller  102 , turbine  104 , and stator  106 . Stator  106  is for multiplying torque as is commonly known in the art. In the example embodiment shown in  FIG. 2 , stator  106  is a stamped stator with plates  108  and  110 . One-way clutch  112  includes outer race  114 , inner race  116 , and rollers  118 . Outer race  114  is drivingly engaged with plate  108 . Race  114  may be press-fit into plate  108 , for example Inner race  116  is axially retained between plates  108  and  110 , and centered by axial extension  120  of plate  110 . Stator  106  is axially retained between bearings  122  and  124 . Plate  108  includes centering features  126  and  128  for centering bearings  122  and  124 , respectively. 
         [0024]    Centering plate  200  and cover plate  202  are attached to turbine  104  by rivet  204 . In an example embodiment, plates  200  and  202  are attached to a shell of turbine  104 . Cover plate  202  is attached to cover plate  206  via rivet  208 . Springs  210  and  212  are in a torque flow between cover plates  202  and  206 , and flange  214 . Flange  214  is drivingly engaged with an input shaft (not shown) for a transmission at spline  216 . 
         [0025]    Torque converter cover  300  is drivingly engaged with an engine or prime mover (not shown) at lugs  302 . During operation of torque converter  100 , cover  300  receives torque from the engine. Lugs  302  may be a formed from folded sheet metal. Cover  300  is drivingly engaged with impeller  102  at weld  304 . That is, impeller  102  and cover  300  are fixed together to form a housing for the torque converter. Pilot  306  centers torque converter  100  in a crankshaft (not shown) for the engine. 
         [0026]    Clutch backing plate  308  is fixed to the housing. In the example embodiment shown in  FIG. 2 , clutch backing plate  308  is fixed to cover  300  by weld  310 . Plate  308  includes orifice  312  and sealing plate  314  with friction material ring  316  to control oil flow as described below. Turbine  104  is disposed in the housing and includes thrust plate  130  so that an axial thrust force of turbine  104  is reacted through, or received by, clutch backing plate  308  and sealing plate  314 . Otherwise stated, thrust plate  130  is arranged for thrust engagement with clutch backing plate  308 . By thrust engagement, we mean that the components are arranged for axial force transmission between the components. Thrust plate  130  may be attached to a shell of turbine  104 , for example. 
         [0027]    The following description is made with reference to  FIG. 2A .  FIG. 2A  is partial view of three-pass torque converter  100  showing an alternative thrust plate configuration. Plate  130  includes sealing plate  314 A with friction material ring  316 A. That is, sealing plate  314 A is fixed to thrust plate  130 A and pressingly engaged with clutch backing plate  308 . 
         [0028]    Returning to  FIG. 2 , piston plate  318  is drivingly engaged with cover  300  through leaf spring  320  attached to cover  300  and piston plate  318  through respective extruded rivets as is commonly known in the art. Piston plate  318  is sealed to cover  300  at seal  322 . Seal  322  may be a dynamic, Teflon® seal, for example. Clutch plate  324  includes friction material rings  326  and  328 , and is drivingly engaged with cover plate  202  at tabs  330 . 
         [0029]    In converter mode, torque received by cover  300  is transferred from impeller  102  to turbine  104 , and multiplied through stator  106 . Torque from turbine  104  is transmitted through cover plates  202  and  206 , through springs  210  and  212 , and flange  214 , to the transmission input shaft. Otherwise stated, plates  202  and  206 , and flange  214 , are drivingly engaged with damper springs  210  and  212 . In lockup mode, torque received by cover  300  is transferred through clutch backing plate  308  and piston  318 , through clutch plate  324 , cover plates  202  and  206 , springs  210  and  212 , and flange  214  to the input shaft. 
         [0030]    Lockup mode is initiated when pressure is introduced in chamber  400  between cover  300  and piston  318 , urging piston  318  towards clutch backing plate  308  to clamp clutch plate  324 . Piston  318  is sealed to cover  300  at seal  322 , so no cooling flow is available from the apply pressure to cool the clutch during slipping operation. Sealing plate  314  and friction material ring  316  divide the portion of converter  100  between piston  318  and impeller  102  into chambers  402  and  404  when thrust from turbine  104  urges thrust plate  130  towards clutch backing plate  308 . Cooling flow introduced into chamber  402  must pass through grooves (not shown) in friction material rings  326  and  328  and through orifice  312  to flow out of converter  100  through chamber  404 , or vice versa. Therefore, clutch plate  324  is supplied with cooling flow during slipping operation. Chambers  400 ,  402  and  404  are further divided by seals (not shown) between the input shaft and piston  318 , sealing plate  200 , and impeller hub  132 . 
         [0031]    The following description is made with reference to  FIG. 3 .  FIG. 3  is a top-half cross section of three-pass torque converter  500  with a pendulum damper. Torque converter  500  includes impeller  102 , turbine  104 , and stator  106 . In the example embodiment shown in  FIG. 3 , stator  106  is a stamped stator with plates  108  and  110 . One-way clutch  112  includes outer race  114 , inner race  116 , and rollers  118 . Outer race  114  is drivingly engaged with plate  108 . Race  114  may be press-fit into plate  108 , for example. Inner race  116  is axially retained between plates  108  and  110 , and centered by axial extension  120  of plate  110 . Stator  106  is axially retained between bearings  122  and  124 . Plate  108  includes centering features  126  and  128  for centering bearings  122  and  124 , respectively. 
         [0032]    Centering plate  600 , cover plate  602 , and sealing plate  603  are attached to turbine  104  by rivet  604 . Centering plate  600  centers turbine  104  relative to the input shaft. In an example embodiment, plate  600  centers turbine  104  on a hub portion of flange  614 . Sealing plate  603  is pressingly engaged with cover plate  602  radially outside of attachment at rivet  604 . By pressingly engaged, we mean that plate  603  is pressed against plate  602  when plate  603  is fixed to the turbine  104  by rivet  604 . Otherwise stated, plate  603  is installed in a deflected state to aid sealing with plate  602 . 
         [0033]    Cover plate  602  and sealing plate  605  are attached to cover plate  606  via rivet  608 . Sealing plate  605  is pressingly engaged with clutch backing plate  308 . That is, in the absence of hydraulic pressure in converter  500 , plate  605  is slightly deformed and pressed tightly against clutch backing plate  308 . Rivet  608  may be a sheet metal rivet, for example. Springs  610  and  612  are in a torque flow between cover plates  602  and  606 , and flange  614 . Flange  614  is drivingly engaged with an input shaft (not shown) for a transmission at spline  616 . An additional set of springs (not shown) are radially aligned and circumferentially offset from springs  610  and  612 , and disposed in a torque path between drive plate  618  and cover plates  602  and  606 . Pendulum masses  620  and  622  are swingly engaged with radial extension  624  of cover plate  602  by rollers  626 . 
         [0034]    Torque converter cover  300  is drivingly engaged with an engine (not shown) at lugs  302 . Lugs  302  may be a formed from folded sheet metal. Cover  300  is drivingly engaged with impeller  102  at weld  304 . Pilot  306  centers torque converter  100  in a crankshaft (not shown) for the engine. Clutch backing plate  308  is fixed to cover  300  by weld  310 , for example. Plate  308  includes orifice  312  to control oil flow as described below. Cover plate  602  includes thrust portion  630  so that an axial thrust force of turbine  104  is reacted through clutch backing plate  312  and sealing plate  605 . 
         [0035]    Piston plate  318  is drivingly engaged with cover  300  through leaf spring  320  attached to cover  300  and piston plate  318  through respective extruded rivets as is commonly known in the art. Piston plate  318  is sealed to cover  300  at seal  322 . Seal  322  may be a dynamic, Teflon® seal, for example. Clutch plate  324  includes friction material rings  326  and  328 , and is drivingly engaged with drive plate  618  at tabs  330 . 
         [0036]    In converter mode, torque received by cover  300  is transferred from impeller  102  to turbine  104 , and multiplied through stator  106 . Torque from turbine  104  is transmitted through cover plates  602  and  606 , through springs  610  and  612 , and flange  614 , to the transmission input shaft. In lockup mode, torque received by cover  300  is transferred through clutch backing plate  308  and piston  318 , through clutch plate  324 , drive plate  618 , springs (not shown), cover plates  602  and  606 , springs  610  and  612 , and flange  614  to the input shaft. Pendulum masses  620  and  622  operate on plate  602  to reduce fluctuations as is commonly known in the art. 
         [0037]    Lockup mode is initiated when pressure is introduced in chamber  400  between cover  300  and piston  318 , urging piston  318  towards clutch backing plate  308  to clamp clutch plate  324 . Piston  318  is sealed to cover  300  at seal  322 , so no cooling flow is available from the apply pressure to cool the clutch during slipping operation. Sealing plate  605 , cover plate  602 , and sealing plate  603  divide the portion of converter  500  between piston  318  and impeller  102  into chambers  402  and  404 . Cooling flow introduced into chamber  402  must pass through grooves (not shown) in friction material rings  326  and  328  and through orifice  312  to flow out of converter  500  through chamber  404 , or vice versa. Therefore, clutch plate  324  is supplied with cooling flow during slipping operation. Chambers  400 ,  402  and  404  are further divided by seals (not shown) between the input shaft and piston  318 , cover plate  602 , and impeller hub  132 . 
         [0038]    The following description is made with reference to  FIG. 4 .  FIG. 4  is a top-half cross section of three-pass torque converter  700  with a tilger damper. Torque converter  700  includes impeller  102 , turbine  104 , and stator  106 . In the example embodiment shown in  FIG. 4 , stator  106  is a stamped stator with plates  108  and  110 . One-way clutch  112  includes outer race  114 , inner race  116 , and rollers  118 . Outer race  114  is drivingly engaged with plate  108 . Race  114  may be press-fit into plate  108 , for example. Inner race  116  is axially retained between plates  108  and  110 , and centered by axial extension  120  of plate  110 . Stator  106  is axially retained between bearings  122  and  124 . Plate  108  includes centering features  126  and  128  for centering bearings  122  and  124 , respectively. 
         [0039]    Centering plate  800  and sealing plate  803  are attached to turbine  104  by spacer rivet  804 . Cover plate  802  is engaged with turbine  104  with rotational lash through spacer rivet  804 . That is, cover plate  802  is axially retained by turbine  104  and plate  800 , and is at least partially rotatable relative to turbine  104 . Cover plate  802  and sealing plate  805  are attached to cover plate  806  via rivet  808 . Rivet  808  may be a sheet metal rivet, for example. Springs  810  and  812  are in a torque flow between cover plates  802  and  806 , and flange  814 . Flange  814  is drivingly engaged with an input shaft (not shown) for a transmission at spline  816 . An additional set of springs (not shown) are radially aligned and circumferentially offset from springs  810  and  812 , and disposed in a torque path between drive plate  818  and cover plates  802  and  806 . Spring retainer  820  is fixedly attached to turbine  104 . 
         [0040]    Spring  822  operates between radial extension  824  of cover plate  802  and retainer  820  in a tilger configuration. That is, spring  822  is tuned so that, during a lock-up mode of torque converter  700 , a mass of turbine  104  oscillates out of phase with cover plate  802  to damp a natural frequency of cover plate  802 . The tilger configuration improves noise, vibration, and harshness (NVH) performance of torque converter  700 . 
         [0041]    Torque converter cover  300  is drivingly engaged with an engine (not shown) at lugs  302 . Lugs  302  may be a formed from folded sheet metal. Cover  300  is drivingly engaged with impeller  102  at weld  304 . Pilot  306  centers torque converter  100  in a crankshaft (not shown) for the engine. Clutch backing plate  308  is fixed to cover  300  by weld  310 , for example. Plate  308  includes orifice  312  to control oil flow as described below. Cover plate  802  includes thrust portion  830  so that an axial thrust force of turbine  104  is reacted through clutch backing plate  308  and sealing plate  605 . 
         [0042]    Piston plate  318  is drivingly engaged with cover  300  through leaf spring  320  attached to cover  300  and piston plate  318  through respective extruded rivets as is commonly known in the art. Piston plate  318  is sealed to cover  300  at seal  322 . Seal  322  may be a dynamic, Teflon® seal, for example. Clutch plate  324  includes friction material rings  326  and  328 , and is drivingly engaged with drive plate  818  at tabs  330 . 
         [0043]    In converter mode, torque received by cover  300  is transferred from impeller  102  to turbine  104 , and multiplied through stator  106 . When travel exceeds lash in connection at spacer rivet  804 , torque from turbine  104  is transmitted through cover plates  802  and  806 , through springs  810  and  812 , and flange  814 , to the transmission input shaft. In lockup mode, torque received by cover  300  is transferred through clutch backing plate  308  and piston  318 , through clutch plate  324 , drive plate  818 , springs (not shown), cover plates  802  and  806 , springs  810  and  812 , and flange  814  to the input shaft. Spring  822  and lash enabled by spacer rivet  804  allow swinging of turbine  104  to reduce fluctuations as is commonly known in the art. 
         [0044]    Lockup mode is initiated when pressure is introduced in chamber  400  between cover  300  and piston  318 , urging piston  318  towards clutch backing plate  308  to clamp clutch plate  324 . Piston  318  is sealed to cover  300  at seal  322 , so no cooling flow is available from the apply pressure to cool the clutch during slipping operation. Sealing plate  805 , cover plate  802 , and sealing plate  803  divide the portion of converter  700  between piston  318  and impeller  102  into chambers  402  and  404 . Otherwise stated, chamber  402  is at least partially defined by piston  318 , backing plate  308 , and thrust plate  830 , and chamber  404  is at least partially defined by backing plate  308 , thrust plate  830  and the housing formed by cover  300  and impeller  102 . 
         [0045]    Cooling flow introduced into chamber  402  must pass through grooves (not shown) in friction material rings  326  and  328  and through orifice  312  to flow out of converter  700  through chamber  404 , or vice versa. Orifice  312  is for exchanging fluid between chambers  402  and  404 . Therefore, clutch plate  324  is supplied with cooling flow during slipping operation. In an example embodiment, chamber  402  is for introducing a cooling flow to the clutch, and chamber  404  is for receiving cooling flow from the clutch. In an example embodiment, chamber  404  is for introducing a cooling flow to the clutch, and chamber  402  is for receiving cooling flow from the clutch. Chambers  400 ,  402  and  404  are further divided by seals (not shown) between the input shaft and piston  318 , cover plate  802 , and impeller hub  132 . 
         [0046]    Of course, changes and modifications to the above examples of the invention should be readily apparent to those having ordinary skill in the art, without departing from the spirit or scope of the invention as claimed. Although the invention is described by reference to specific preferred and/or example embodiments, it is clear that variations can be made without departing from the scope or spirit of the invention as claimed.