Abstract:
An assembly for use in a vehicle driveline comprises a housing with an inner surface and an outer surface for a vehicle driveline component, a retention element disposed in the housing, and at least one deformation formed on the inner surface operatively in contact with the retention element to retain the vehicle driveline component in the housing. This design and method of manufacture eliminates the need for differently sized spacers because the location of the deformations and the retention element can be tailored relative to the actual location of the components to ensure proper distance between components and the retention element. Moreover, because the spacer may be used as the retention element, the need for a snap ring is eliminated.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a vehicle driveline assembly and more particularly to an assembly for housing clutch plates without using a conventional snap ring.  
           [0002]    A clutch permits selectively coupling a vehicle engine to the transmission for driving the wheels. The clutch generally comprises a series of vehicle driveline components such as a series of clutch plates. These components are all placed in a housing. A snap ring retains these components within the housing. To receive and hold the position of the snap ring, a slot or retainer typically is formed at a predetermined location on the housing prior to loading the plates into the housing. A spacer is also disposed in the housing to establish a proper distance between the plates to ensure proper clutch operation.  
           [0003]    The current method of producing clutch assemblies is inefficient. Due to variations in the distance between the components and the slot for the snap ring, an assembler must measure the distance between components and slot and then select by hand the proper spacer to employ prior to inserting the snap ring into the assembly. A variety of differently sized spacers must be available to the assembler during the manufacturing process. The additional assembly and operator time decreases the economies of clutch assembly.  
           [0004]    A need therefore exists for an inexpensive method of producing a transmission assembly without the requirement of maintaining an inventory of a variety of spacers.  
         SUMMARY OF THE INVENTION  
         [0005]    In general terms, this invention is an assembly for use in a vehicle driveline. In a disclosed embodiment of this invention, the assembly comprises a housing with an inner surface and an outer surface. At least one clutch component such as a set of clutch places is supported within the housing. A retention element is disposed in the housing and at least one deformation on the housing operates to contact the retention element and to retain the clutch component in the housing. The preferred retention element is a spacer that ensures proper clutch plate spacing within the housing. A significant advantage provided by this invention is eliminating the need for a snap ring.  
           [0006]    In one example, the housing deformation extends into a corresponding portion of the retention element and prevents the retention element from moving axially in either direction within the housing. The housing deformation extends radially inward in one example and radially outward in another version.  
           [0007]    In one example, the inventive assembly is manufactured by inserting an appropriate series of clutch plates into the housing. The retention element is axially positioned in the housing to a position that ensures proper distances between the plates. While at this point, a forming tool deforms the housing to maintain the retention element within the housing so that the desired clutch operation is possible. The housing deformations may extend into the retention element to lock its location relatives to the housing.  
           [0008]    The inventive method of manufacture eliminates the need for differently sized spacers and snap rings because the housing location of the deformation and the retention element can be tailored relative to the actual location of the stack of components to ensure proper distance between the components during operation after installation in a vehicle driveline. Also, the spacer may be used as the retention element, eliminating the need for a snap ring. In this way, only one sized spacer is required for producing a variety of clutches.  
           [0009]    The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiments. The drawings that accompany the detailed description can be briefly described as follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a perspective view of an assembly designed according to this invention.  
         [0011]    [0011]FIG. 2 schematically illustrates a first arrangement of deformations on a housing designed according to this invention.  
         [0012]    [0012]FIG. 3 schematically illustrates another arrangement of deformations.  
         [0013]    [0013]FIG. 4 schematically illustrates tooling designed according to this invention.  
         [0014]    [0014]FIG. 5 shows one feature of one example embodiment of this invention.  
         [0015]    [0015]FIG. 6 shows the embodiment of FIG. 5 at one stage of the method of this invention.  
         [0016]    [0016]FIG. 7 shows selected portions of the embodiment of FIG. 5.  
         [0017]    [0017]FIG. 8 schematically illustrates one example retention arrangement.  
         [0018]    [0018]FIG. 9 schematically illustrates another retention arrangement.  
         [0019]    [0019]FIG. 10 schematically illustrates another retention arrangement. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]    [0020]FIG. 1 shows portions of an example assembly  20  for use in a vehicle driveline. The assembly  20  includes a housing  22 , which is a clutch housing in the illustrated example. The housing  22  has inner surface  24  and an outer surface  26 . The housing  22  includes a series of splines  28  and grooves  30  around the circumference of the housing.  
         [0021]    A plurality of clutch plates  36  are supported within the housing between a spacer element  38  and a support portion  40  at one end of the housing. The clutch plates  36  are conventional.  
         [0022]    In previous designs of clutch housings, a snap ring groove was provided and a snap ring was inserted to maintain the spacer element  38  and the clutch plates  36  within the housing  22 . This invention provides a significant departure from conventional arrangements. This invention eliminates the need for a snap ring.  
         [0023]    The housing  22  preferably includes a plurality of deformations  42  that are formed into the housing  22  after the clutch plates  36  and spacer element  38  are in place. In the preferred embodiment, the deformations  42  directly engage the spacer element  38  and maintain the axial position of the spacer element  38  and, therefore, the clutch plates  36  within the housing  22 . As will be described below, a variety of configurations are within the scope of this invention for maintaining the position of the spacer element  38  within the housing  22 .  
         [0024]    As schematically shown in FIG. 2, a plurality of deformations  42  preferably are provided on the inward splines  28  of the housing  22 . In another example, shown in FIG. 3, the deformations  42  are provided on the grooves  30  of the housing  22 . In the two examples illustrated in FIGS. 2 and 3, the deformations are formed radially inward toward a center of the housing  22 . In another example, the deformations are formed radially outward to maintain the position of one or more driveline components around the outer circumference of the housing  22 .  
         [0025]    [0025]FIGS. 4 through 7 schematically illustrate the preferred method of manufacturing the assembly  20 . The housing  22  is preformed in a conventional manner. The clutch plates  36  are inserted into the housing  22 . A spacer element  38  is then placed on top (according to the drawings) of the set of clutch plates  36  within the housing  22 .  
         [0026]    A tooling arrangement  99  operates to position the spacer element  38  within the housing  22  into a desired position that maintains a selected arrangement of the clutch plates within the housing  22 . The illustrations schematically show a deformation tool portion  100  and a holding portion  102 . A base portion  104  preferably supports the clutch housing  22  at one end. The deformation tool  100  and the holding portion  102  preferably are indexed to move together in an axial direction relative to the housing  22 .  
         [0027]    In the preferred embodiment, the holding portion  102  effectively grabs onto the spacer element  38 . The clutch plates  36  preferably are biased toward the end of the housing supported by the base portion  104 . In this position, the clutch plates are all snugly fit together and there is no spacing between them.  
         [0028]    Depending on the particular clutch design, the spacer element  38  is then moved in an opposite axial direction relative to the compressed plates. A distance D preferably is established between the spacer element  38  and the plates  36 . This spacing D provides the necessary amount of axial play between the clutch plates  36  during normal clutch operation.  
         [0029]    The tooling  99  preferably maintains the spacer element  38  at an appropriate axial position within the housing  22  to establish the spacing D that is necessary for proper clutch operation.  
         [0030]    With the spacer element  38  in the appropriate axial position, the deformation tool portion  100  operates to deform the housing  22  in a manner that maintains the spacer element  38  in the desired position. In the example of FIG. 5 through  7 , the deformation tool  100  includes a punch portion  104  that deforms the housing  22  resulting in a deformation  110  that is received within a corresponding groove  108  that is preformed on the spacer element  38 .  
         [0031]    In one example, the tooling  99  establishes a single deformation upon each radially inward movement of the tooling portion  100 . In another example, multiple deformations are established with each operation of the tooling. The preferred embodiment includes indexing the housing  22  circumferentially about its axis to establish a plurality of deformations around the housing sufficient to maintain the desired axial position of the spacer element  38  within the housing  22  and, therefore, maintaining the desired spacing between the clutch plates. It is believed that a minimum of three deformations equally spaced about the circumference of the housing  22  are required to maintain the spacer element  38  in the desired position. In some examples, every spline  28  includes a deformation for maintaining the axial position of the spacer element  38 . In other example implementations of this invention, less then all of the splines  28  (or, alternatively, the grooves  30 ) include deformations for maintaining the desired axial position of the spacer element  38 .  
         [0032]    Once the deformation of the housing  22  is complete, the spacer element  38  operates as the retention element to maintain the clutch plates  36  within the housing  22  throughout the life of the eventual clutch assembly. There is no need for an operator on the assembly line to insert any further spacer elements or a snap ring as was done in the past. Therefore, this invention provides significant economies in the manufacturing process because the assembly  20  is premade and ready for any further assembly and installation onto a vehicle driveline as needed without requiring an operator to select from among various spacer elements and to insert a snap ring to maintain them within the housing.  
         [0033]    As seen in FIG. 8, the tool  210  may also be aligned so that punch  214  forms a deformation  218  on the inner surface  216  of the housing  220  above the retention element  222 . This configuration prevents retention element  222  from moving in the direction of arrow B′ but permits the retention element to move in the opposite direction. During operation of the clutch, the retention element  222  may create a force in the direction of arrow B′ on deformation  218 . Accordingly, the lip of housing  220  must extend to a minimum distance DD above retention element  222  to prevent the buckling of lip  220 . Also shown by FIG. 8 is the option to pierce housing  220  so that deformation  218  is a lanced portion of the housing.  
         [0034]    [0034]FIG. 9 shows another embodiment of this invention. In this instance, notch  226  is formed at the top edge of retention element  230 . Deformation  234  is extended into notch  226  by tool  238 . This arrangement facilitates placing the spacer element  230  closer to the open end of the housing without compromising the amount of material above the deformation  234  (according to the drawing).  
         [0035]    The examples of FIGS. 10 and 6 include locking an axial position of the spacer retention element. In the examples of FIG. 8 and  9 , axial movement is possible to an extent. Given this description those skilled in the art will be able to select the most appropriate arrangement for their particular situation.  
         [0036]    While varying embodiments of the prevent invention are shown, they all share the unique feature of deforming the housing after the spacer or retention element is inserted adjacent the clutch plates such that the retention element is held in place and proper clutch plate spacing is established. By employing the above method of manufacture, the location of the retention element relative to the set of plates is fixed into a desired position. In this way, spacers of varying sizes are no longer required. Additionally, the entire process is easily automated and manual snap ring insertion is eliminated, greatly improving the efficiency of the production of clutch housing assemblies.  
         [0037]    The preceding description is exemplary rather than limiting. Modifications and variations are possible in light of the above teachings. Workers skilled in the art may recognize that certain modifications are possible that come within the scope of this invention. Hence, the invention may be practiced otherwise than as specifically described above. For this reason the following claims should be studied to determine the true scope of legal protection given to this invention.