Abstract:
A method of manufacturing an impeller and turbine assembly of a transmission includes providing an impeller housing and a turbine housing. An impeller blade defining an impeller receptor and a turbine blade defining a turbine receptor are provided. The impeller blade is mated to the impeller housing by deforming a portion of said impeller housing into the impeller receptor. The turbine blade is mated to the turbine housing by deforming a portion of the turbine housing into the turbine receptor. In this manner, the impeller blade is secured to the impeller housing and the turbine blade is secured to the turbine housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is the National Stage of International Patent Application No. PCT/US2013/029159, filed on Mar. 5, 2013, which claims priority to and all advantages of U.S. Provisional Patent Application No. 61/667,717 filed Jul. 3, 2012, the content of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present application relates generally to a method of manufacturing impeller and turbine assemblies. More specifically, the present application relates to forming joints between various elements of impeller and turbine assemblies without the use of brazing. 
     BACKGROUND 
     Various components of transmission assemblies such as, for example, impeller assemblies and turbine assemblies are subject to significant forces from transmission fluid flowing throughout transmission housing. The impeller assembly includes a plurality of impeller blades affixed to an impeller assembly. The blades extend radially and are circumferentially spaced around the entire housing. Adequate mechanical attachment of the impeller blades to the impeller assembly has not been achieved. Therefore, the impeller blades have been attached to the impeller assembly by way of a coating process known as brazing. Likewise, the turbine blades have also been attached to the turbine housing by brazing in a similar manner. 
     Brazing is achieved by applying alloys to the joints formed between the blades and the housing and raising the temperature of the assembly to the melting temperature of the alloy. Additionally, brazing is also known to cause a rough surface resulting in oil turbulence in the impeller and turbine assemblies, which adversely affects efficiency and performance. While the brazing process has generally proven acceptable to secure the blades to the housings, a number of drawbacks make it desirable to eliminate brazing by way of a more secure mechanical attachment. 
     For example, the alloy used to braze the joints described above cause significant environmental hazards requiring significant measures be taken to avoid a detriment to technician health and contamination to the environment at large. Furthermore, the temperatures at which the assemblies must be raised to melt the brazing material is known to significantly weaken the metallic structure of both the housing and the blades. Furthermore, the addition of brazing material to the assemblies increases the mass of these assemblies significantly, which reduces the efficiency of the transmission and the associated vehicle. 
     Therefore, it would be desirable to eliminate the addition of brazing material to the impeller and turbine assemblies of a transmission by way of providing a more secure mechanical attachment of these blades to their housing. 
     SUMMARY 
     A method of manufacturing an impeller and turbine housing of a transmission includes providing an impeller housing and a turbine housing. An impeller blade is provided defining an impeller receptor and a turbine blade is provided defining a turbine receptor. The impeller blade is mated to the impeller housing by deforming a portion of the impeller housing into the impeller receptor. The turbine blade is mated to the turbine housing by deforming a portion of the turbine housing into the turbine receptor. By way of deformation of the housings, the impeller blade is secured to the impeller housing and the turbine blade is secured to the turbine housing in a mechanically sound manner. 
     By forming a receptor into the impeller blade and the turbine blade, a deformation of the housing into the receptor provides an interlocking joint between the housing and the blades. By securely interlocking the blade and the housing, a mechanical attachment is achieved providing adequate strength to the joint between the housing and the blades to withstand the forces known to occur in a transmission. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  shows a partial sectional view of a transmission; 
         FIG. 2  shows a partial cross-sectional view of an impeller assembly of the present invention; 
         FIG. 3  shows a plan view of the impeller assembly along lines  3 - 3  of  FIG. 2 ; 
         FIG. 4  shows an exploded view of the impeller assembly of the present invention; 
         FIG. 5  shows an exploded view of an impeller blade and an impeller shroud of the present invention; 
         FIG. 6  shows a cross-sectional view of the exploded impeller assembly along lines  6 - 6  of  FIG. 4 ; 
         FIG. 7  shows a partial cross-sectional view of the impeller blade assembled to the impeller assembly and impeller shroud prior to deformation; 
         FIG. 8  shows the deformation step of the impeller assembly and the impeller blade; 
         FIG. 9  shows an exploded view of the turbine assembly of the present invention; 
         FIG. 10  shows a flange of the turbine assembly; 
         FIG. 11  shows an exploded, cross-sectional view of the turbine assembly; 
         FIG. 12  shows the turbine blade assembled to the turbine assembly and turbine shroud prior to deformation; and 
         FIG. 13  shows a partial cross-sectional view of the joints of the turbine assembly after deformation. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a partial cross-sectional view of a transmission assembly is generally shown at  10 . Although this view is of an automotive transmission, it should be understood to those of ordinary skill in the art that this is just an exemplary view and that the scope of this application is beyond automotive. An impeller assembly  12  is shown fixed to a torque converter cover  14  in a known manner. A turbine assembly  16  is shown in an opposing relationship to the impeller assembly  12  as is known to those of skill in the art. 
     By way of establishing an environmental orientation of the impeller assembly  12  and the turbine assembly  16 , a stator  18  is positioned between the impeller assembly  12  and the turbine assembly  16  in a known manner. The stator  18  is in running engagement with a one-way clutch  20  of the transmission assembly  10 , also in a known manner. 
     The impeller assembly  12  includes an impeller housing  22  as shown here with an impeller blade  24  being mechanically attached as will be explained further herein below. The impeller blade  24  is positioned between the impeller housing  22  and an impeller shroud  26 . 
     The turbine assembly  16  includes a turbine housing  28  as shown here with a turbine blade  30  affixedly attached. The turbine blade  30  is positioned between the turbine housing  28  and a turbine shroud  32 . As set forth above, the turbine assembly  16  interacts with the impeller assembly  12  and the transmission assembly  10  in a known manner. It should be understood to those of ordinary skill in the art that the inventive feature disclosed in the present application can be used to eliminate brazing when used to affix blades to housing in any type of torque converting assembly. 
     As best represented in  FIGS. 2-4 , the impeller blade  24  defines an impeller tab  34  that mates to a impeller groove  36  defined by the impeller housing  22 . As best represented in  FIG. 3 , a plurality of impeller grooves  36  extend radially outwardly between a central opening  38  defined by the impeller housing  22  and a distal impeller rim  40  of the impeller housing  22 . As best shown in  FIG. 4 , the impeller housing  22  defines an arcuate wall  42  into which the impeller groove  36  is defined. The impeller groove  36  extends substantially radially outwardly along the arcuate wall  42  defined by the impeller housing  22 . 
     The impeller tab  34  of the impeller blade  24  takes an arcuate shape and has a similar radius as the impeller groove  36  defined by the arcuate wall  42  so that a substantial portion of the impeller tab  34  contacts a base  44  of the impeller groove  36  when assembled, as best shown in  FIG. 2 . A receptor  46  is defined by the impeller tab  34 . The receptor  46  is shown as a plurality of apertures  48  shaped as a series of spaced slots extending substantially along the impeller tab  34 . 
     A shroud tab  50  is spaced radially inwardly of the impeller tab  34  on the impeller blade  24 . The shroud tab  50  is received through a shroud slot  52  defined in an arcuate wall  54  of the impeller shroud  26 . The shroud tab  50  of the impeller blade  24  includes a circumferential length that is substantially the same as the circumferential length of the shroud slot  52 . 
       FIGS. 5-7  show the impeller blade  24  being moved into engagement with the impeller housing  22  and the impeller shroud  26 . The impeller tab  34  is received into the impeller groove  36  so that a distal end of the impeller tab  34  is positioned in an abutting relationship with the groove base  44 . The receptor  46  defined by the impeller tab  34  is substantially perceived into the impeller groove  34 . The shroud tab  50  defined by the impeller blade  24  is received through the shroud slot  52  so that a distal end of the shroud tab  50  extends beyond the arcuate wall  54  of the impeller shroud  26  as best represented in  FIG. 7 . 
     Referring now to  FIG. 8 , the method by which the impeller blade  24  is fixedly attached to the impeller housing  22  and impeller shroud  26  will now be explained. A staking tool  56  deforms a portion of the impeller housing  22  adjacent the impeller groove  36  so that material from the impeller housing  22  is forced into the receptor  46  defined in the impeller tab  34  of the impeller blade  24 . Therefore, the impeller housing  22  is placed in locking engagement with the impeller blade  24  securely affixing the impeller blade  24  to the impeller housing  22 . Because the receptors  46  are defined as a plurality of slots  48 , that portion of the impeller housing  22  appearing as a protuberance  58  enters the slots  48  in locking engagement. 
     Located radially inwardly from the impeller housing  22 , the shroud tab  50  of the impeller blade  30  that extend through the shroud slot  52  of the impeller shroud  26  is deformed into locking engagement with the impeller shroud  26  securely affixing the impeller shroud  26  to the impeller blade  24 . It is contemplated by the inventor that a rolling device or equivalent is used to deform the shroud tab  50  into locking engagement with the impeller shroud  26 . 
     Referring now to  FIG. 9 , the method by which the turbine blade  30  is affixed to the turbine housing  28  and the turbine shroud  32  will now be explained. The turbine blade  30  defines a turbine tab  60  having a first member  62  and second member  64 . The turbine tab  60  is received into a turbine slot  66  defined by the turbine housing  28 . The first and second member  62 ,  64  are received by corresponding first and second apertures  68 ,  70  of the turbine slot  66 . 
     A shroud tab  50  is spaced radially inwardly on the turbine blade  30  from the turbine housing  28  and mates to a shroud slot  52  defined in the turbine shroud  32  in a manner substantially the same as that explained for the impeller shroud above. Therefore, further explanation of the shroud tab  50  defined by the turbine blade  30  and its mating engagement with the turbine shroud  32  is not included. 
     As best represented in  FIG. 10 , a flange  72  is formed around a circumferential edge  74  of the turbine housing  28  to improve hoop strength of the turbine housing  28 . It is contemplated by the inventors that the improved hoop strength of the turbine housing  28  may enable decreasing the thickness of the turbine housing  28  further reducing overall mass of the turbine assembly  16  beyond the elimination of brazing. 
       FIGS. 11-13  show the method of securely engaging the turbine blade  30  to the turbine housing  28  and the turbine shroud  32 . A turbine receptor  76  is defined in the turbine blade  30  as a groove  78 . The groove  78  is spaced from a distal end of the tab  60 , the purpose of which will be evident further below. An offset  80  is defined in the turbine housing  28  so that an edge  82  of the turbine slot  66  is displaced from a plane defined by the turbine housing wall  84 . 
     As best shown in  FIG. 12 , the tab  60  of the turbine blade  30  is inserted through the turbine slot  66  so that the receptor  76  defined by the turbine blade  30  is aligned with the plane defined by the turbine wall  84 . The offset  80  is forced in the direction of arrow  86  so that the edge  82  of the turbine slot  66  is forced into the receptor  76  defined by the impeller blade  30 , as best represented in  FIG. 13 . The tab  60  is also deformed into locking engagement with the turbine housing  28  so that the turbine blade  30  is fixedly attached to the turbine housing  28 . It is believe that roll forming or cold forming the tab  60  into locking engagement with the turbine housing  28  will suffice. However, other methods of facilitating the locking engagement between the turbine blade  30  and the turbine housing  28  have also been contemplated by the inventor. It is believed that the manner in which the receptor  76  receives the offset  80  in combination with the deformation of the turbine tab  60  will create a substantially leakproof joint. In this manner, brazing is also reduced or eliminated from use with the turbine assembly  16 . 
     It is further contemplated by the inventor that additional securement may be required in high torque applications. Therefore, it is contemplated that an adhesive such as, for example, Loctite® or an equivalent may be used to satisfy high torque requirements. 
     While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation while material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention but that the invention will include all embodiments falling within the scope of the appended claims.