Abstract:
A method for manufacturing a torque converter includes providing an outer race of a one way clutch, contacting the outer race with a side plate, and casting a stator housing together with the outer race and the side plate. A torque converter is also provided.

Description:
[0001]    Priority to U.S. Provisional Patent Application Ser. No. 60/962,700, filed Jul. 31, 2007, is claimed, the entire disclosure of which is hereby incorporated by reference herein. 
     
    
       [0002]    The present invention relates generally to hydraulic torque converters, and more particularly to hydraulic torque converters with one-way clutches. 
       BACKGROUND OF THE INVENTION 
       [0003]    The established state of the art for a torque converter stator assembly includes a cast aluminum stator housing, a one-way clutch outer race, a one-way clutch inner race, engaging elements such as rollers or sprags between the outer race and inner race, and side plates or retainer plates to retain the one-way clutch in the assembly. Side plates, commonly made of cast aluminum or steel, are typically attached to the stator housing after the casting process and after the one-way clutch has been assembled. 
         [0004]    The outer race is typically pressed into the aluminum housing but it may also be put into the aluminum during the casting process. U.S. Pat. Nos. 5,655,875 and 5,431,536 show molded stator hubs with molded outer races. U.S. Pat. Nos. 5,431,536 and 5,655,875 are hereby incorporated by reference herein. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides a method for manufacturing a torque converter comprising providing an outer race of a one way clutch, contacting the outer race with a side plate, and casting a stator housing together with the outer race and the side plate. 
         [0006]    Casting of the stator housing with the outer race and side plate advantageously can reduce an assembly step and improve one-way clutch wear. 
         [0007]    The present invention also provides a torque converter comprising a cast stator housing having a groove, a one-way clutch having an outer race connected to the stator housing, and a side plate located at least partially in the groove. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0008]    One embodiment of the present invention is shown with respect to the drawings in which: 
           [0009]      FIG. 1  shows a torque converter according to the present invention; 
           [0010]      FIGS. 2A ,  2 B,  2 C, and  2 D show a stator assembly in accordance with one embodiment of the present invention, and show a cross-sectional view, an end view, a side view and a further end view, respectively; 
           [0011]      FIG. 3  is a closer sectional view of a stator assembly embodiment of the present invention with a cast-in outer race and side plate; and 
           [0012]      FIG. 4  shows a section of the outer race of the stator assembly. 
       
    
    
     DETAILED DESCRIPTION  
       [0013]      FIG. 1  describes a torque converter  10  according to the present invention, having a torque converter housing  11 , a pump  13 , a turbine  15 , a stator housing  12 , a one-way clutch  38  having engaging elements  39 , two side plates  18 ,  20 , and a stator shaft  42  at an output side  80 . 
         [0014]      FIGS. 2A ,  2 B,  2 C,  2 D show details of stator housing  12  and one-way clutch  38  with engaging elements  39 . One way clutch  38  has an outer race  14 , an inner race  16 , and side plates  18  and  20 . Stator housing  12  has an inner rim  22 , an outer rim  24 , and a plurality of blades  26  formed between the inner and outer rims  22 ,  24 . Stator housing  12  is cast of aluminum or some other metal or solid material and outer race  14  together with side plate  18  is embedded into stator housing  12  during the casting process. The other side plate  20  can be attached after the casting process. 
         [0015]    An inner radial surface  40  of inner race  16  can be non-rotatably connected to a stator shaft  42  with, for example, splines  44 . 
         [0016]    By casting side plate  18  into housing  12  at the same time outer race  14  is cast into housing  12 , side plate  18  shields inner surfaces  34  of outer race  14  from aluminum contamination since outer race  14  is not adjacent to cast aluminum surfaces of stator housing  12 . Also, side plate  18  need not be separately attached, reducing an assembly step. 
         [0017]    As shown in more detail in  FIG. 3 , side plate  18  is attached to housing  12  during the casting process. Side plate  18  is located between outer race  14  and a flange  50 , so that an outer circumferential surface  118  is located within a groove  112  of cast stator housing  12 . Side plate  18  preferably can be made of stamped steel or can be made of cast aluminum, but is in any event a separate piece. 
         [0018]    Side plate  20  is attached after casting and may be made of the same material and have the same shape as side plate  18 . Outer race  14  and side plate  18  are positioned adjacent to one another, and inner axial surface  28  of side plate  18  is smooth. An axial outer surface  128  of side plate  18  can contact stator housing  12  at an inner side of flange  50 . 
         [0019]      FIG. 4  shows inner radial surface  34  of outer race  14  with pockets  36 . After one-way clutch  38  has been assembled, each pocket  36  of inner surface  34  may contain the engaging elements such as rollers or sprags, further retained by inner race  16  and side plates  18 ,  20 , as shown in  FIG. 1 . 
         [0020]    One-way clutch  38  allows stator housing  12  to rotate around stator shaft  42  and inner race  16  in only one direction. Rollers or sprags, between outer race  14  and inner race  16 , oppose rotation in the opposite direction by becoming wedged due to friction. 
         [0021]      FIG. 4  shows that the outer radial surface  30  of outer race  14  can contain ridges  32  to prevent relative axial and circumferential motion between outer race  14  and stator housing  12 . 
         [0022]    Side plate  20  may have the same shape and be made of the same material as side plate  18 . By making side plate  20  identical to side plate  18 , manufacturing costs and complexity are advantageously reduced. Also, both side plates  18 ,  20  advantageously can be made of stamped steel, although they also may be made of cast aluminum and then be machined to be smooth. 
         [0023]    If advantageous for a particular stator design, additional aluminum may be cast onto housing axial exterior surface  48 .