Patent Publication Number: US-2013230385-A1

Title: Turbine piston

Description:
FIELD 
     The invention relates generally to a torque converter, and more specifically to a torque converter with a turbine piston. 
     BACKGROUND 
     Torque converter turbines incorporating lockup clutches are known. One example is shown in commonly-assigned U.S. Pat. No. 7,445,099. 
     BRIEF SUMMARY 
     Example aspects broadly comprise a torque converter including an impeller with a plurality of impeller blades and a shell with a radial wall disposed radially outside of the blades. The converter also includes a cover fixed to the impeller shell to form a housing, and a turbine. The turbine includes a plurality of turbine blades and a shell with a radial wall disposed radially outside of the turbine blades. The turbine radial wall is arranged to frictionally engage the impeller shell radial wall. In some example embodiments, the turbine shell includes indented slots and the turbine blades include tabs disposed in the slots. In an example embodiment, the turbine blades are fixed to the turbine shell by brazing. 
     In an example embodiment, the impeller shell radial wall or the turbine shell radial wall includes a friction material ring for frictional engagement with the other of the impeller shell radial wall or the turbine shell radial wall. In an example embodiment, the torque converter includes a stator assembly and a release spring disposed between the turbine shell and the stator assembly to urge the turbine away from the impeller. 
     In an example embodiment, the torque converter includes a damper spring retainer fixed to the turbine shell and a damper spring disposed in the spring retainer. In an example embodiment, the torque converter includes a damper flange arranged for driving and sealing engagement with a transmission input shaft. The turbine shell is sealed to the damper flange. In some example embodiments, the damper flange includes a thrust plate axially disposed between the flange and the turbine shell for transferring a thrust load from the turbine shell to the cover. In an example embodiment, the thrust plate or the turbine shell has a friction material ring and the flange or the cover comprises a friction material ring. In an example embodiment, the thrust plate includes a tab drivingly engaged with the damper spring. 
     In some example embodiments, the torque converter includes a damper spring retainer arranged for driving engagement with a transmission input shaft and a damper spring disposed in the spring retainer. The turbine shell includes an axial tab engaged with the damper spring. In an example embodiment, the axial tab is radially aligned with the turbine shell radial wall. In an example embodiment, the torque converter includes a damper hub fixed to the spring retainer by compressive engagement. In an example embodiment, the torque converter includes a turbine shell bushing arranged for sealing engagement with a transmission input shaft. 
     Other example aspects broadly comprise a torque converter assembly including a torus portion and a lockup clutch. The torus portion includes an impeller, a turbine, and a stator. The lockup clutch is for connecting the impeller and the turbine. The clutch is axially aligned with the stator. In some example embodiments, the lockup clutch is disposed radially outside of the torus portion. In an example embodiment, the lockup clutch comprises respective impeller and turbine radial walls. In an example embodiment, the torque converter includes a damper with a damper spring radially aligned and axially offset from the lockup clutch. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1A  is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used in the present application; 
         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; 
         FIG. 2  is a top half cross section view of a first embodiment of a torque converter with a turbine piston according to an example aspect; 
         FIG. 3  is a top half cross section view of a second embodiment of a torque converter with a turbine piston according to an example aspect; 
         FIG. 4  is a top half cross section view of a third embodiment of a torque converter with a turbine piston according to an example aspect; 
         FIG. 5  is a top half cross section view of a fourth embodiment of a torque converter with a turbine piston according to an example aspect. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
     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. 
       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 . 
     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. 
       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. 
     The following description is made with reference to  FIG. 2 .  FIG. 2  is a top half cross section view of torque converter  100  with turbine piston  102 . Converter  100  includes impeller  104  with a plurality of impeller blades  106 , core ring  107 , and shell  108 . Blades  106  include tabs (not shown) installed in indented slots  110  of shell  108 . Blades  106  are fixed to the shell by brazing as is known in the art. Impeller  104  includes hub  112  fixed to shell  108  by weld  114 . Hub  112  is arranged for driving engagement with a hydraulic pump of a transmission (not shown). 
     Shell  108  includes radial wall  116  disposed radially outside of blades  106 . Converter  100  includes cover  118  fixed to shell  108  at weld  120  to form a housing as is known in the art. Cover  118  includes stud  122  arranged for driving engagement with an engine flexplate (not shown) and pilot extrusion  124  arranged for centering converter  100  with regards to a crankshaft for the engine (not shown). Cover may include balance weight  126  for balancing converter  100  about axis  128 . 
     Converter  100  includes turbine  130  with a plurality of turbine blades  132 , core ring  133 , and shell  134 . Shell  134  is generally thicker than typical turbine shells to withstand pressure forces as described below. In an example embodiment, blades  132  include tabs (not shown) installed in indented slots  136  of shell  134 . In an example embodiment, blades  132  are fixed to the shell by brazing. Shell  134  includes radial wall  138  disposed radially outside of blades  132 . Wall  138  is arranged to frictionally engage wall  116 . That is, upon application of a pressure force to shell  134  in direction  140 , wall  138  is pressed against wall  116  so that torque received by shell  108  through cover  118  from the engine (not shown) is transmitted directly to turbine shell  134 , bypassing the fluid circuit partially formed by blades  106  and  132 . Walls  116  and  138  may be jointly referred to as a lockup clutch. 
     In an example embodiment, wall  138  includes friction material ring  142  for improved frictional performance. Ring  142  prevents metal-on-metal contact between walls  116  and  138 , reducing contamination produced by the frictional engagement. Friction characteristics of ring  142  may further improve the engagement by increasing a friction coefficient between the clutch components or altering the friction coefficient gradient so that the clutch is more controllable and does not shudder. Although ring  142  is shown fixed to wall  138 , other embodiments (not shown) may include ring  142  fixed to wall  116 . 
     Converter  100  includes stator assembly  144  with housing  146 , one way clutch outer race  148  press-fit into housing  146 , inner race  150 , and roller  152 , and side plate  154 . In an example embodiment, the lockup clutch is axially aligned with the stator assembly. Side plate  154  axially retains the one-way clutch components within housing  146 . Thrust bearing  156  operates between housing  146  and shell  108 . In an example embodiment, release spring  158  is disposed between turbine shell  134  and stator assembly  144 , specifically side plate  154 , to urge turbine  130  away from impeller  104 . Release spring  158  may be a diaphragm spring, for example. Side plate  154  includes tab  160  and spring  158  includes tab  162  engaged with tab  160  for rotationally fixing the spring relative to the side plate. 
     Converter  100  includes damper assembly  164  with spring retainer  166 , spring  168 , drive plate  170 , and flange  172 . In an example embodiment, drive plate  170  is fixed to flange  172  by rivet  174 . In an example embodiment, damper spring retainer  166  is fixed to turbine shell  134  by weld  176 , for example, and damper spring  168  is disposed in the spring retainer. By disposed in, we mean the the spring retainer at least partially surrounds and retains the spring. In an example embodiment, the damper spring is radially aligned with the lockup clutch. 
     Damper flange  172  is arranged for driving and sealing engagement with a transmission input shaft at spline  178  and seal  180 , for example. Turbine shell  134  is sealed to flange  172  at seal  182 . That is, flange  172  includes groove  184  for receiving seal  182  and shell  134  includes cylindrical protrusion  186  engaged with the seal, effectively sealing the shell to the input shaft through seals  180  and  182 , and flange  172 . 
     In some embodiments, flange  172  includes thrust plate  188  axially disposed between the flange and the turbine shell for transferring a thrust load from the turbine shell to the cover. That is, thrust from turbine  130  is reacted by plate  188  to cover  118 . Thrust plate  188  may be integral with drive plate  170  and includes tab  190  engaged with spring  168 . In an example embodiment, the thrust plate includes friction material ring  192  and the flange includes friction material ring  194 . The rings prevent steel-on-steel contact to reduce contamination as described for ring  142  above. Although rings  192  and  194  are shown fixed to the thrust plate and flange, respectively, ring  192  may be fixed to shell  134  and ring  194  may be fixed to cover  118 . 
     The following description is made with reference to  FIG. 3 .  FIG. 3  is a top half cross section view of torque converter  200  with turbine piston  202 . In general, the description of torque converter  100  above is applicable to torque converter  200  by replacing 1XX reference numerals with 2XX reference numerals considering the exceptions noted below. Flange  172  extends radially outward for driving engagement with spring  269 . Drive plate  270  is engaged with spring  268  at tab  290  and fixed to cover plate  271  via rivet  275 . Plates  270  and  271  are drivingly engaged with spring  269  so that torque from shell  234  is transmitted to flange  272  through retainer  266 , spring  268 , plates  270  and  271 , and spring  269 . 
     The following description is made with reference to  FIG. 4 .  FIG. 4  is a top half cross section view of torque converter  300  with turbine piston  302 . In general, the description of torque converter  100  above is applicable to torque converter  300  by replacing 1XX reference numerals with 2XX reference numerals considering the exceptions noted below. Torque converter  300  includes damper spring retainer  367  arranged for driving engagement with a transmission input shaft (not shown) and damper spring  368  disposed in the spring retainer. In an example embodiment, damper hub  373  is fixed to retainer  367  by compressive engagement. That is, hub  373  and retainer  367  are fixed together using the method described in commonly-assigned pending U.S. Provisional Patent Application No. 61/548,424, hereby incorporated by reference as if set forth fully herein. 
     Hub  373  includes spline  379  for driving engagement with the transmission input shaft and friction material rings  393  and  395 . Together hub  373  and rings  393  and  395  provide a thrust path to the cover similar to flange  172 , plate  188 , and rings  192  and  194  in  FIG. 2 . 
     Spring  158  is replaced by friction material ring  359  so that shell  335  is released by a pressure force acting in direction  341 , opposite direction  340 , alone. Ring  359  prevents steel-on-steel contact between the shell and side plate  354  during a clutch engaged condition when shell  335  is urged in direction  340  or when stator  345  thrusts towards shell  335  in direction  341 . In an example embodiment, bearing  156  is replaced by friction material ring  357  to prevent direct contact between aluminum stator housing  347  and steel impeller shell  108 . Ring  357  may be fixed to shell  308  or housing  347 , though it is likely easier to bond to the steel housing. 
     Turbine shell  335  includes axial tab  391  engaged with the damper spring. Tab  391  is radially aligned with radial wall  338 . That is, radius R 1  of tab  391  is between inner radius R 2  and outer radius R 3  of wall  338 . Turbine shell  335  includes bushing  396  arranged for sealing engagement with the transmission input shaft. That is, instead of sealing through a flange as described in the example embodiments shown in  FIGS. 2 and 3 , shell  335  is directly sealed to the input shaft through bushing  396 . 
     The following description is made with reference to  FIG. 5 .  FIG. 5  is a top half cross section view of torque converter  400  with turbine piston  402 . In general, the description of torque converter  300  above is applicable to torque converter  400  by replacing 3XX reference numerals with 4XX reference numerals considering the exceptions noted below. Converter  400  includes stator assembly  449  with housing  441 , wedge one-way clutch outer race  449 , inner race  451 , and wedge plates  453 , and side plate  455 . Races  449  and  451  and plates  453  may be components of a friction one-way clutch as described in commonly-assigned U.S. Patent Application Publication No. 2009/0159390, hereby incorporated by reference as if set forth fully herein. Friction material ring  457  may be fixed to plate  455  or shell  408 . Ring  459  prevents contact between shell  435  and housing  441  during a clutch engaged condition when shell  435  is urged in direction  440  or when stator  449  thrusts towards shell  435  in direction  441 . 
     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.