Abstract:
A torque converter assembly comprises: a cover for driving engagement with a prime mover; a piston plate including an annular surface for engaging a clutch; and, a sealing plate comprising a substantially radial wall arranged between the cover and the piston plate and disposed radially inward of the annular surface, wherein: in a lockup mode for the torque converter, the sealing plate blocks fluid flow between the cover and the piston plate; and, in a release mode for the torque converter, the sealing plate is deflectable to enable a fluid flow between the cover and the piston plate via a pathway between the cover and the sealing plate.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of application Ser. No. 13/173,813, filed on Jun. 30, 2011, which claims the benefit of U.S. Provisional Application No. 61/360,382 filed on Jun. 30, 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 with a deflectable seal. 
       BACKGROUND 
       [0003]    Torque converters with seals are known. One example is shown in German Patent Application Publication DE 10 2008 048 031 A1. 
       BRIEF SUMMARY 
       [0004]    Example aspects broadly comprise a torque converter assembly including a cover for driving engagement with a prime mover, a piston plate including an annular surface for engaging a clutch, and a first seal disposed radially inward of the annular surface. In a lockup mode for the torque converter, the first seal blocks fluid flow through an orifice in the piston plate or between the cover and the piston plate and, in a release mode for the torque converter, the first seal is deflectable to enable a fluid flow through the orifice or between the cover and the piston plate and around the first seal. In an example embodiment, the torque converter assembly includes an apply chamber, the piston plate is displaceable in response to fluid pressure in the apply chamber, and the first seal is arranged to be deflected by the fluid pressure in the apply chamber. 
         [0005]    In some example embodiments, the torque converter assembly includes a sheet metal plate fixed to the piston plate. In some example embodiments, the first seal is fixed to the sheet metal plate and arranged for sealing engagement with the cover. In an example embodiment, the first seal includes a flap portion deflectable to block the fluid flow between the cover and the piston plate, or through the piston plate orifice, or, enable the fluid flow between the cover and the piston plate, or through the piston plate orifice. 
         [0006]    In some example embodiments, the first seal includes a sheet metal ring fixed to one of the piston plate or the cover and arranged for sealing engagement with the other of the piston plate or the cover when the torque converter is in the lockup mode. In an example embodiment, during the lockup mode, the sheet metal ring is in contact with the other of the piston plate or the cover. In an example embodiment, the first seal has a sealing portion including rubber or friction material bonded to the sheet metal ring and, during the lockup mode, the sealing portion is in contact with the other of the piston plate or the cover. 
         [0007]    In some example embodiments, the first seal includes a sheet metal plate and friction material bonded to the sheet metal plate. In the lockup mode, the friction material blocks the fluid flow through the piston plate orifice and, in the release mode, the friction material is displaceable to enable the fluid flow through the piston plate orifice. In some example embodiments, the torque converter includes a second seal assembly having a seal plate fixed to the piston plate and a second seal sealingly engaged with the cover. In an example embodiment, the seal plate includes an annular groove and the second seal is disposed in the groove. In an example embodiment, the seal plate includes a portion of an annular groove, the piston plate includes a portion of the annular groove, and the second seal is disposed in the groove. 
         [0008]    Other example aspects broadly comprise a torque converter assembly including a cover for driving connection to a prime mover, an impeller drivingly connected to the cover, a piston plate, first and second chambers, and a deflectable seal fixed to one of the cover or the piston plate. The first chamber is at least partially defined by the cover and the piston plate and the second chamber is at least partially defined by the cover, the impeller, and the piston plate. In a first position, the deflectable seal is disengaged from the other of the cover or the piston plate to enable a flow around the seal from the first chamber to the second chamber. In a second position, the deflectable seal is engaged with the other of the cover or the piston plate to block a flow from the second chamber to the first chamber. 
         [0009]    In an example embodiment, the torque converter assembly includes a sheet metal plate fixed to the piston plate. The deflectable seal is fixed to the sheet metal plate, arranged for sealing engagement with the cover, and includes a flap portion. The flap portion is deflectable to enable the flow from the first chamber to the second chamber or block the flow from the second chamber to the first chamber. In some example embodiments, the deflectable seal includes a sheet metal ring fixed to one of the piston plate or the cover and arranged for sealing engagement with the other of the piston plate or the cover to block the flow from the second chamber to the first chamber. In an example embodiment, the deflectable seal includes a sealing portion bonded to the sheet metal ring and contactable with the other of the piston plate or the cover to block the flow from the second chamber to the first chamber. 
         [0010]    In some example embodiments, the torque converter assembly includes a second seal assembly having a seal plate fixed to the piston plate and a second seal sealingly engaged with the cover to block the flow between the chambers. In an example embodiment, the seal plate includes an annular groove and the second seal is disposed in the groove. In an example embodiment, the seal plate includes a portion of an annular groove, the piston plate includes a portion of the annular groove, and the second seal is disposed in the groove. 
         [0011]    Other example aspects broadly comprise a torque converter assembly including a cover for driving connection to a prime mover, a piston plate, and a seal disposed between the cover and the piston plate, fixed to one of the cover or the piston plate, and including an orifice and/or at least one radial slot. In a first position, the seal is disengaged from the other of the cover or the piston plate to enable a flow around the seal between the cover and the piston plate. In a second position, the seal is engaged with the other of the cover or the piston plate to block the flow between the cover and the piston plate with the exception of a flow through the orifice and/or the at least one radial slot. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which: 
           [0013]      FIG. 1A  is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used in the present application; 
           [0014]      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; 
           [0015]      FIG. 2  is a top half cross-sectional view of a prior art torque converter; 
           [0016]      FIG. 3A  is a schematic view of the torque converter of  FIG. 2  with a deflectable sealing plate shown in an apply state, according to an example aspect; 
           [0017]      FIG. 3B  is a schematic view of the torque converter of  FIG. 2  with a deflectable sealing plate, shown in a release state, according to an example aspect; 
           [0018]      FIG. 3C  is a section view of a sealing plate shown with a zig-zag shape; 
           [0019]      FIG. 3D  is a section view of a sealing plate shown with circular sealing element  206 ; 
           [0020]      FIG. 4A  is a schematic view of the torque converter of  FIG. 2  with a deflectable sealing plate shown in an apply state, according to an example aspect; 
           [0021]      FIG. 4B  is a schematic view of the torque converter of  FIG. 2  with a deflectable sealing plate, shown in a release state, according to an example aspect; 
           [0022]      FIG. 4C  is a back view of the seal shown in  FIG. 4B ; 
           [0023]      FIG. 5  is a top half cross-sectional view of a portion of a clutch assembly with a deflectable seal, according to an example aspect; 
           [0024]      FIG. 6  is a top half cross-sectional view of a portion of a clutch assembly with a deflectable seal, according to an example aspect; 
           [0025]      FIG. 7  is a top half-cross sectional view of a portion of a clutch assembly with a deflectable seal, according to an example aspect; 
           [0026]      FIG. 8  is a top half cross-sectional view of a torque converter with a clutch assembly having a deflectable seal, according to an example aspect; 
           [0027]      FIG. 9A  is a front view the seal of  FIG. 8 ; 
           [0028]      FIG. 9B  is a front view of an alternative embodiment of the seal of  FIG. 8 ; 
           [0029]      FIG. 10  is a cross-sectional view of a portion of a clutch assembly, according to an example aspect; 
           [0030]      FIG. 11  is a cross-sectional view of a portion of a clutch assembly, according to an example aspect. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    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. 
         [0032]    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. 
         [0033]      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 . 
         [0034]    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. 
         [0035]      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. 
         [0036]    The following description is made with reference to  FIG. 2 .  FIG. 2  is a top half cross-sectional view of prior art torque converter  100 . Torque converter  100  includes impeller assembly  102  with blades  104 , shell  106 , core ring  108  and impeller hub  110 . Hub  110  is fixed to shell  106  by weld  112 . Hub  110  is for sealing to a transmission (not shown) and drivingly engaging a transmission pump (not shown). Converter  100  further includes turbine assembly  114  with blades  116 , shell  118 , and core ring  120 . 
         [0037]    Stator assembly  122  is axially disposed between impeller assembly  102  and turbine assembly  114 . Assembly  122  includes housing  124 , one-way clutch  126 , and side plate  128 . Clutch  126  may be a roller or sprag design as is commonly known in the art. Thrust bearings  130  and  132  are disposed on opposite axial sides of stator assembly  122 . 
         [0038]    Converter  100  includes cover assembly  134  fixedly attached to impeller assembly  102  at weld  136 . Cover  134  includes shell  138 , drive plate  140  with lugs  142 , and drive plate  144 . Plates  140  and  144  are attached to shell  138  at respective rivets  146  and  148 . One or both of rivets  146  and  148  may be extruded rivets as is commonly known in the art. 
         [0039]    Damper assembly  150  is disposed within converter  100 . Assembly  150  includes cover plates  152  and  154 , flange  156 , and elastic elements  158  and  160 . Elements  158  and  160  are in driving engagement with plates  152  and  154 , and flange  156 . That is, elements  158  and  160  transmit torque from plates  152  and  154  to flange  156 . Elements  158  and  160  may be coil springs, for example. Plate  154  is attached to shell  118  and thrust plate  156  by rivet  158 . Flange  156  is drivingly engaged with damper hub  160  at spline  162 . Bearing  164  is disposed axially between hub  160  and drive plate  144 , and radially positioned by axial extension  166  of plate  144 . 
         [0040]    Clutch assembly  168  transmits torque from cover  134  to damper  150 . Clutch  168  includes piston plate  170  and clutch plate  172 . Piston plate  170  may be an annular plate. Piston plate  170  is drivingly engaged to drive plate  144  by leaf springs  174  and rivet  176 . Piston plate  170  is sealed to damper hub  160  with dynamic seal  180 . Clutch plate  172  is axially disposed between piston plate  170  and cover  134 . Plate  172  includes friction material rings  186  and  188  disposed on axially opposite sides of plate  172 . Plate  172  further includes tabs  190  for engaging complementary tabs  192  and  194  in respective cover plates  172  and  174 . 
         [0041]    Piston plate  170  and damper hub  160  separate chambers  196  and  198  of torque converter  100 . Chamber  196  may be referred to as an apply chamber and is at least partially defined by impeller  102 , cover  134 , and piston plate  170 . Chamber  198  may be referred to as a release chamber and is at least partially defined by cover  134  and piston plate  170 . Clutch assembly  168  is engaged and disengaged by fluid pressure acting on piston plate  170 . Fluid pressure in apply chamber  196  urges piston plate  170  towards engagement with cover  134 , while fluid pressure in chamber  198  urges piston plate  170  away from engagement with cover  134 . Fluid enters chambers  196  and  198  through a transmission input shaft (not shown). 
         [0042]    In order to change from a clutch release state to a clutch apply state, pressure in chambers  196  and  198  is reversed. That is, torque converter  100  has a higher pressure in chamber  198  when clutch  168  is in release mode. In order to engage clutch  168 , pressure in chamber  196  must be higher than pressure in chamber  198 . Therefore, pressure in chamber  196  is raised and/or pressure in chamber  198  is lowered to engage clutch  168 . Even through pressure in chamber  196  may be higher, leakage between piston plate  170  and clutch plate  172  may equalize pressure in chambers  196  and  198  while the clutch is being engaged. That is, piston plate  170  seals to friction material  188  when clutch  168  is applied, but allows leakage before the two components are sealed. Leakage between piston  170  and friction material  188  may make it difficult to build pressure in chamber  196  to fully engage clutch  168 . 
         [0043]    Furthermore, hydrodynamic effects in the torque converter affect engagement of clutch  168 . For example, hydrodynamic effects urge piston plate  170  in the direction of the faster-spinning component. Therefore, since piston plate  170  is axially disposed between cover  134  and damper  150 , piston plate will be urged towards cover  134  when impeller  102  spins faster than turbine  114  (drive mode) and away from cover  134  when turbine  114  spins faster than impeller  102  (coast mode). Otherwise stated, piston plate  170  tends to be self-engaging in drive mode and self-disengaging in coast mode. Therefore, it may be difficult to engage clutch  168  when converter  100  is in coast mode because fluid pressure in chamber  196  leaks into chamber  198  through the axial gap between piston  170  and clutch plate  172 . It should be noted that, although  FIG. 2  shows the gap between piston  170  and plate  172 , the gap may be between cover shell  138  and plate  172 , or a portion of the gap may be between each pair. 
         [0044]    The following description is made with reference to  FIGS. 3A-3D .  FIG. 3A  is a schematic view of torque converter  100  of  FIG. 2  with deflectable sealing plate  200  shown in an apply state, according to an example aspect.  FIG. 3B  is a schematic view of torque converter  100  of  FIG. 2  with deflectable sealing plate  200 , shown in a release state, according to an example aspect.  FIG. 3C  is a section view of sealing plate  200  shown with a zig-zag shape.  FIG. 3D  is a section view of sealing plate  200  shown with circular sealing element  206 . Converter  100  includes cover  138  and piston plate  170  as described supra. In the embodiment shown in  FIGS. 3A-3D , converter  100  includes deflectable sealing plate  200 . 
         [0045]    Plate  200  is disposed axially between cover  138  and annular piston plate  170 , and is fixedly attached to piston  170  at attachment point  202 . Plate  200  may be attached to piston  170  with rivets or welding, for example. Plate  200  is arranged to seal to cover  138  at sealing portion  204  to minimize fluid exchange between chambers  196  and  198 . Although plate  200  is shown attached to piston plate  170 , other configurations exist and should be considered within the scope. For example, plate  200  may be fixed to cover  138  and arranged to seal to piston  170 . Therefore, as can be seen in  FIG. 3A , pressure from chamber  196  leaking between cover shell  138  and piston  170  is restricted from entering chamber  198 , improving engagement of clutch assembly  168 . 
         [0046]    Converter  100  requires significant cooling flow during release mode. Cooling flow enters chamber  198  from the input shaft (not shown) and exits to from port  196 . In the configuration shown in  FIG. 3A , seal  200  blocks flow between the chambers so the cooling flow may be insufficient and converter  100  may overheat. However, as can be seen in  FIG. 3B , seal  200  is deflectable to allow flow between the chambers when pressure is higher in chamber  198 . That is, pressure in chamber  198  urges seal  200  away from shell  138  allowing flow between the chambers to cool converter  100 . 
         [0047]    As described supra, piston  170  and cover shell  138  rotate together. Therefore, deflectable seal  200  may be a metal plate without risk of wear or grinding between seal  200  and shell  138  because there is no relative rotation. Seal  200  may include a seal material (not shown) at portion  204  to improve sealing between plate  200  and shell  138 . For example, seal  200  may include friction material at portion  204 . Seal  200  may include additional bends and radial walls between portions  202  and  204  for increased flexibility. For example, seal  200  may have a “zig-zag” form as shown in  FIG. 3C . Seal  200  may include ring  206  with a circular cross-section installed over portion  204  as shown in  FIG. 3D . 
         [0048]    The following description is made with reference to  FIGS. 4A-4C .  FIG. 4A  is a schematic view of torque converter  100  of  FIG. 2  with deflectable sealing plate  200 A shown in an apply state, according to an example aspect.  FIG. 4B  is a schematic view of torque converter  100  of  FIG. 2  with deflectable sealing plate  200 A, shown in a release state, according to an example aspect.  FIG. 4C  is a back view of seal  200 A. Plate  200 A is sealed to piston  170  with extruded rivet  208 . In general, plates  200  and  200 A perform the same function. However, plate  200  seals against a radial wall of shell  138  while plate  200 A seals against a conical wall of shell  138 . As shown in  FIG. 4C , seal  200 A is a metal ring with radial tabs  210  having apertures  212  for receiving rivets  208 . Ring  200 A may also include radial slots  214  for increased flexibility. Operation of seal  200 A is as described for seal  200 . 
         [0049]    The following description is made with reference to  FIGS. 5-7 .  FIG. 5  is a top half cross-sectional view of a portion of clutch assembly  300  with deflectable seal  302 , according to an example aspect. Seal  302  includes portion  304  fixed to piston plate  306  by riveting, for example, and portion  308  fixed to portion  304 . Portion  308  may be a rubber seal portion bonded to portion  304 . In general, seal  302  seals piston plate  306  to cover shell  310  in clutch apply mode and deflects in clutch release mode similar to seal  200  described above. Seal  302  may include orifice  312 . Orifice  312  prevents pressure buildup between clutch plate  314  and seal  302  during clutch apply. That is, any pressure trapped in chamber  316  during clutch apply drains into chamber  318  to improve clutch engagement. Although orifice  312  is shown in portion  308 , other embodiments may include orifice  312  in portion  304 . 
         [0050]      FIG. 6  is a top half cross-sectional view of a portion of clutch assembly  400  with deflectable seal  402 , according to an example aspect. Seal  402  includes portion  404  fixed to piston plate  406  by riveting, for example, and portion  408  fixed to portion  404 . Portion  408  may be a rubber seal portion bonded to portion  404 . In general, seal  402  seals piston plate  406  to cover shell  410  in clutch apply mode and deflects in clutch release mode similar to seal  200  described above. Cover  410  includes circumferential wall  412  in sealing engagement with seal  402 . Wall  412  is a coined, or stamped, feature of shell  410  and is integral with shell  410 . In other embodiments (described infra), wall  412  is a portion of an additional element fixedly attached to shell  410 . 
         [0051]      FIG. 7  is a top half-cross sectional view of a portion of clutch assembly  500  with deflectable seal  502 , according to an example aspect. Seal  502  includes portion  504  fixed to piston plate  506  by riveting, for example, and portion  508  fixed to portion  504 . Portion  508  may be a rubber seal portion bonded to portion  504 . Portion  508  includes flap  509  for deflecting. In general, seal  502  seals piston plate  506  to cover assembly  510  in clutch apply mode and deflects in clutch release mode similar to seal  200  described above. Cover  510  includes circumferential wall  512  in sealing engagement with seal  502 . Wall  512  is a portion of element  514  fixedly attached to shell  516  at weld  518 . 
         [0052]    The following description is made with reference to  FIG. 8 .  FIG. 8  is a top half cross-sectional view of torque converter  600  with clutch assembly  602  having deflectable seal  618 , according to an example aspect. Assembly  602  includes piston plate  604  and seal plates  606  and  608  fixed to piston plate  604  by riveting, for example. Seal  610  is disposed between plates  606  and  608  and seals piston plate  604  to cover shell  612  at circumferential surface  614 . 
         [0053]    Piston plate  604  includes orifice  616 . Clutch assembly  602  includes deflectable seal  618  fixedly attached to piston plate  604  by rivet  620 . Seal  618  is arranged to restrict fluid flow through orifice  616 . That is, during apply mode, seal  618  covers orifice  616  preventing flow of fluid between chambers  622  and  624 . In release mode, seal  618  deflects, allowing fluid flow between chambers  622  and  624  to cool converter  600  as described supra. 
         [0054]    The following description is made with reference to  FIGS. 8-9B .  FIG. 9A  is a front view of seal  618  of  FIG. 8 . Seal  618 A includes elongated body  650  with apertures  652  and  654 . Length of body  650  increases flexibility of seal  618 . Rivet  620  is disposed in aperture  652 . An additional rivet or protrusion (not shown) is disposed in aperture  654  to ensure seal  618 A is disposed over orifice  616 . That is, aperture  654  is to control circumferential position of seal  618 A relative to an axis passing through aperture  652 . Optional friction material pad  656  may be bonded to body  650  to improve sealing performance. Although friction material is specified, other materials may be used to improve sealing. For example, rubber or elastomers may be used to improve sealing. 
         [0055]      FIG. 9B  is a front view of an alternative embodiment of seal  618  of  FIG. 8 . Seal  618 B includes annular ring portion  660  with apertures  662  and radial tabs  664 . Rivets  620  is disposed in apertures  662 . Tabs  664  are disposed over orifices  616 . Option friction material pads  666  may be bonded to tabs  664  to improve sealing performance. 
         [0056]    The following description is made with reference to  FIGS. 10-11 .  FIG. 10  is a cross-sectional view of a portion of clutch assembly  700 , according to an example aspect. Clutch assembly  700  includes piston plate  702  and clutch plate  704 . Sealing plate  706  is fixed to piston plate  702  by weld  708 . Plate  706  includes annular groove  710 . Seal  712  is disposed in groove  710 , and seals plate  706  to cover assembly  714  at circumferential surface  716 . Surface  716  is a portion of element  718  fixed to cover shell  720  by weld  722 . Although element  718  is shown as a separate component, surface  716  may be integral with shell  720  as described supra. Operation of clutch assembly  700  is similar to operation of clutch assembly  602  described supra. 
         [0057]      FIG. 11  is a cross-sectional view of a portion of clutch assembly  800 , according to an example aspect. Assembly  800  includes piston plate  802  and sealing plate  804  fixed to piston plate  802  by rivet  806 . Plates  802  and  804  include respective circumferential walls  808  and  810 , and radial walls  812  and  814  forming portions of annular groove  816  for receiving a seal (not shown). Remaining features of clutch assembly  800  are similar to clutch assembly  700  described supra. 
         [0058]    Of course, changes and modifications to the above examples 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.