Abstract:
A hydraulic torque converter including a cover, a drive-plate driven by the cover, and a lock-up clutch having a piston plate, the piston plate being located between the drive plate and the cover, the piston plate and drive plate defining a hydraulic chamber for actuation of the piston plate.

Description:
[0001]    Priority to U.S. Provisional Application Ser. No. 60/962,772, filed Jul. 31, 2007, German Patent Application No. 10 2006 056 299.2, filed Nov. 29, 2006, U.S. Provisional Patent Application Ser. No. 60/874,104, filed Dec. 11, 2006, German Patent Application No. 10 2006 061 541.7, filed Dec. 27, 2006, German Patent Application No. 10 2006 061 553.0, filed Dec. 27, 2006, German Patent Application No. 10 2006 061 552.2, filed Dec. 27, 2006, U.S. Provisional Patent Application Ser. No. 60/934,235, filed Jun. 12, 2007, and U.S. Provisional Patent Application Ser. No. 60/964,855, filed Aug. 15, 2007, is claimed. 
     
    
       [0002]    The present invention relates generally to torque converters and more particularly to a torque converter having a combined sealing plate and leaf spring drive-plate. 
       BACKGROUND 
       [0003]      FIG. 1  shows the established state of the art for a torque converter  10  with three hydraulic passages entering torque converter  10 . Torque converter  10  includes a torque converter cover  4  and a stud  2  connected to cover  4  which receives the torque from the engine. Enclosed in cover  4  is a turbine  46  rotatable with respect to cover  4  and a stator  44  installed between an impeller  40  and turbine  46 . Cover  4  has a tubular impeller hub  16 . Impeller hub  16  is spaced from a stator shaft  8  splined to stator  44 . Turbine  46  is non-rotatably connected to a turbine hub  20 , and turbine hub  20  is connected to an input shaft  14  through a damper  38  and a damper hub  62 . There is relative rotation between turbine hub  20  and damper hub  62  when damper  38  is compressed. Torque converter  10  also includes a clutch piston  30  and clutch plates  6 . One clutch plate  6  is rotatably connected to a welding plate  48  and another clutch plate  6  rotatably connected to cover  4  by leaf springs  64 . The three passages entering torque converter  10  are: between impeller hub  16  and stator shaft  8 ; between stator shaft  8  and input shaft  14 , and inside a channel drilled into input shaft  14 . 
         [0004]    The advantages in the current state of the art are the passages give the ability to control three pressures inside torque converter  10  to engage, disengage and cool clutches. However, the disadvantages include the complexity of the three passage design. 
         [0005]    The three hydraulic passages of torque converter  10  allow for a closed piston chamber  12  which controls the engagement of torque converter clutch  60 . Piston  30  is typically sealed in torque converter cover  4  and input shaft  14 . Piston  30  applies clutch  60  towards turbine  46  which requires some type of axial stop for torque converter clutch  60 . Welded plate  48  made of thick steel, is welded into cover  4  of torque converter  10 . 
       SUMMARY OF THE INVENTION 
       [0006]    An object of the present invention provides a hydraulic torque converter comprising: a cover, a drive-plate driven by the cover, and a lock-up clutch having a piston plate, the piston plate being located between the drive plate and the cover, the piston plate and drive plate defining a hydraulic chamber for actuation of the piston plate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  illustrates state of the art of the upper half of a longitudinal section through a torque converter with the piston sealed in the torque converter cover and the input shaft. 
           [0008]    Further features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0009]      FIG. 2  illustrates one embodiment of a torque converter according to the present invention. 
           [0010]      FIG. 3  illustrates another embodiment of the present invention where the torque converter clutch applies pressure through the center of the input shaft. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]      FIG. 2  shows a section of a hydraulic torque converter  100  embodying the present invention. Torque converter  100  has a cover  104  and a stud  102  connected to cover  104 . Cover  104  has a tubular impeller hub  116 . Inside cover  104  is an impeller  140 , a turbine  146  connected to a turbine hub  120  and a stator  144 . Impeller hub  116  is spaced from a stator shaft  108  splined to stator  144 . A transmission input shaft  114  is splined  121  to turbine hub  120 . Stator shaft  108  is sealed to turbine hub  120 . Cover  104  also is fixed to a centering sleeve  142  which is fixed to a leaf-spring drive plate  110 . 
         [0012]    Torque converter  100  also has a lockup or bypass clutch  160 , which includes piston  130  and clutch plates  106 , and has a damper  138 . Piston  130  is sealed to leaf-spring drive plate  110  by a seal  132 . Piston  130  is also sealed to centering sleeve  142  with a seal  128 . Turbine hub  120  is sealed to leaf spring drive-plate  110  with a seal  122 . Centering sleeve  142  is sealed to input shaft  114  with a seal  124 . Turbine hub  120  rotates with respect to centering sleeve  142 , for example via an optional centering sleeve, turbine hub  120  being able to pass optional centering bearing  126 . Centering sleeve  142  also has at least one opening  143  permitting fluid to pass from an actuation conduit  109 , between stator shaft  108  and input shaft  114  to a chamber  112 . Pressure chamber  112  is an enclosed pressure chamber for actuating piston  130 . Outer diameter of chamber  112  is sealed between piston plate  130  and leaf spring drive plate  110  with seal  132   
         [0013]    Engine torque comes into converter  100  through stud  102  for example via an internal combustion engine. Torque from stud  102  is transmitted to cover  104 . Torque from cover  104  may be transmitted to impeller  140 , and to leaf spring drive-plate  110  through centering sleeve  142 . Cooling flow enters through the center of input shaft  114  and exits between stator shaft  108  and impeller hub  116 . 
         [0014]    To close clutch  160 , oil flows through actuation conduit  109  past turbine hub splines  121 , bearing  126 , through holes  143  to chamber  112  to engage piston  130 . Piston  130  applies clutch plates  106  against cover  104  to transmit torque into damper  138 . To open the clutch piston  160  the pressure in chamber  112  is vented through actuation conduit  109  between stator shaft  108  and input shaft  114 . Oil passes through centering bearing  126 . Centering bearing  126  may not be required depending on the design. It does not seal any portion of the chamber. 
         [0015]    The advantages of the present invention include a reduction in complexity of the three passage design with a sealed piston, turbine damper and high slip capacity clutch. The design can eliminate welding of the clutch plate inside the cover and a reduction in material and/or a number of parts. 
         [0016]      FIG. 3  shows another embodiment of the present invention. Similar to  FIG. 2 ,  FIG. 3  shows a section of a hydraulic torque converter  200 . Torque converter  200  has a cover  204  and is connected to a stud  202 . Cover  204  includes pilot  250 . Inside cover  204  is an impeller  240 , a turbine  246  with a turbine shell  248  and a stator  244 . Impeller hub  216  is spaced from a stator shaft  208  and an input shaft  214 . A turbine hub  220  is tightly riveted to shell  248  to create a fluid tight seal. Turbine shell  220  is sealed onto stator shaft  208  with a seal  218  creating a pressure chamber  212 . 
         [0017]    Torque converter  200  also includes a torque converter clutch  260  with a piston  230 , clutch plates  206  and a damper  238 . Piston  230  is sealed to leaf-spring drive plate  210  by seal  232 . Turbine hub  220  is sealed to leaf spring drive-plate  210  with a seal  222 . 
         [0018]    Engine torque comes into converter  200  through stud  202 . Torque from stud  202  is transmitted to cover  204 . Torque from cover  204  may be transmitted to impeller  240  and leaf spring drive-plate  210 . Cooling flow enters between stator shaft  208  and input shaft  214 , at actuation conduit  209 . The cooling flow passes through a cross drilled hole  252  to enter a chamber  256 . Cooling flow exits between stator shaft  208  and impeller hub  216 . To actuate clutch  260 , actuation fluid enters through the center of input shaft  214 . The pressure is channeled to chamber  212  through a cross drilled hole  254  in pilot  250  to enter pressure chamber  212 . Cross drilled hole  254  is in a different rotational plane that cross drilling  252 .