Abstract:
A seal protector assembly is provided. The seal protector assembly includes an expandable cylinder for protecting a seal. A plug or cap is removably attached to the expandable cylinder. After shipment of the transmission, the plug or cap is removed. Once any potential damage to the seal during assembly has passed, the expandable cylinder is then removed.

Description:
CROSS-REFERENCE 
     This application claims priority to U.S. Provisional Application No. 61/299,770, filed on Jan. 29, 2010, which is hereby incorporated in its entirety herein by reference. 
     TECHNICAL FIELD 
     The invention relates to a seal protector assembly operable to protect a seal during shipping and assembly, and more particularly a seal protector assembly that protects a seal attached to a transmission. 
     BACKGROUND 
     A typical multi-speed transmission uses a combination of torque transmitting devices, gear sets, and shafts controlled by an electro-hydraulic control system to provide a plurality of forward and reverse gear ratios for a motor vehicle. These components are encased within a protective transmission case or housing. During assembly of the motor vehicle, the transmission is shipped and washed prior to installation. Accordingly, openings must be sealed during shipment in order to prevent debris from entering the transmission and to prevent water from entering the transmission during washing. In addition, it is desirable to protect exposed components, such as rubber seals, that can be damaged during shipment or installation of the transmission. 
     For example, a typical transmission includes an opening for receiving an axle shaft that connects the output of the engine to the input of the transmission. The opening includes an axial seal that seals the transmission once the axle shaft has been installed. However, the typical axle shaft includes a splined end that is inserted into the opening of the transmission. This splined end can damage the axle seal that surrounds the opening, thereby leading to axle seal leaks that can damage the transmission. Accordingly, there is a need for a seal protector assembly that protects the transmission and the seal from damage during transportation and during installation, while remaining easy to remove during assembly. 
     SUMMARY 
     A seal protector assembly is provided. The seal protector assembly includes an expandable cylinder for protecting a seal. A plug or cap is removably attached to the expandable cylinder. After shipment of the transmission, the plug or cap is removed. Once any potential damage to the seal during assembly has passed, the expandable cylinder is then removed. 
     Further features, aspects and advantages of the present invention will become apparent by reference to the following description and appended drawings wherein like reference numbers refer to the same component, element or feature. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
         FIG. 1  is a cross-sectional view of a seal protector assembly according to the principles of the present invention shown in use with an exemplary axle seal and a portion of an exemplary transmission; 
         FIG. 2  is a side view of the seal protector assembly; 
         FIG. 3  is a front view of the seal protector assembly viewed in the direction of arrow  3 - 3  in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view of the seal protector assembly with a plug installed; 
         FIG. 5  is a cross-sectional view of a portion of a transmission having an axle seal with a portion of the seal protector assembly removed during installation of an axle shaft; 
         FIG. 6A  is a side perspective view of an alternate embodiment of the seal protector assembly; 
         FIG. 6B  is a side perspective view of another alternate embodiment of the seal protector assembly; 
         FIG. 7  is a side perspective view of another alternate embodiment of the seal protector assembly; and 
         FIG. 8  is a sectional view of another alternate seal protector assembly shown in use with an exemplary axle seal and a portion of an exemplary transmission. 
     
    
    
     DESCRIPTION 
     With reference to  FIG. 1  a seal protector assembly according to the principles of the present invention is generally indicated by reference number  10 . The seal protector assembly  10  is shown in use with an exemplary transmission  12  having an exemplary axle seal  14 . The transmission  12  includes a typically cast, metal housing or case  16  which encloses and protects the various components of the transmission  12 . The housing  16  includes a variety of apertures, passageways, shoulders and flanges which position and support these components. In particular, the housing  16  defines an input opening  18  that receives an axle shaft or other input from an engine (not shown) of the motor vehicle. It should be appreciated that the transmission  12  may be, for example, a front wheel drive transmission, a rear wheel drive transmission, a dual clutch transmission, a hybrid transmission, or any other type of transmission without departing from the scope of the present invention. 
     The axle seal  14  is annular and includes a metal flange  22  press fit or otherwise attached to the transmission housing  16 . The flange  22  extends radially inwardly and terminates in a distal end  24 . A rubber seal  26  is connected to the distal end  24  of the flange  22 . The rubber seal  26  is operable to seal against an axle shaft or other component, as will be described in greater detail below, to prevent oil leakage out of the transmission  12  during operation of the motor vehicle. It should be appreciated that the shape of the axial seal  14  and the specific configuration and materials used may vary without departing from the scope of the present invention. 
     The seal protector assembly  10  is operable to close and seal the opening  18  to the transmission  12  during shipment and preparation of the transmission  12  and to protect the rubber seal  26  during assembly of the transmission  12  within the motor vehicle. With combined reference to  FIGS. 2-4 , the seal protector assembly  10  includes a seal protector  32  and a plug or cap  34 . The seal protector  32  includes a cylindrical portion  36  and a guide portion  38 . The cylindrical portion  36  is hollow and includes a first end  40  and a second end  42  opposite the first end  40 . The first end  40  is open and defines a first aperture  41 . The guide portion  38  is integrally formed or otherwise connected with the second end  42  of the cylindrical portion  36 . The cylindrical portion  36  is preferably axially tapered such that end  40  has a smaller diameter than end  42 . The guide portion  38  is also hollow and has an inner diameter that increases relative to the cylindrical portion  36  as the guide portion  38  extends axially from the cylindrical portion  36 . The inner surfaces or inner diameters of the cylindrical portion  36  and the guide portion  38  define a cavity  44 , best seen in  FIGS. 3 and 4 . The guide portion  38  has an open end that defines a second aperture  45 . 
     The seal protector  32  is divided or separated axially and includes a first side  46  and a second side  48 , best seen in  FIGS. 3 and 4 . The first side  46  and second side  48  have thinned portions  46 A and  48 A, respectively, that overlap with one another to form the cylindrical shape of the seal protector  32 . The cross-section of the thinned portions  46 A and  48 B may vary without departing from the scope of the present invention. For example, the thinned portions  46 A and  46 B may be tapered. The location of the thinned portions  46 A and  48 A when overlapped is preferably directly opposite the location of the tether  50  used to pull the seal protector  32  out of the transmission  12 . 
     The plug  34  is connected with the seal protector via the tether  50 . The tether  50  is connected at one end with the guide portion  38  of the seal protector  32  and is connected at an opposite end with the plug  34 . In a preferred embodiment, the tether  50  is integrally formed from the guide portion. The tether  50  is preferably comprised of a flexible yet strong material, such as plastic, though other materials may be employed without departing from the scope of the present invention. 
     The plug  34  includes a cylindrical body  52  and an end cap  54 . The cylindrical body  52  has a first end  54  and a second end  56  opposite the first end  54 . The end cap  54  is integrally formed or otherwise connected to the cylindrical body  34  at the second end  56 . The end cap  54  has an outer diameter that increases relative to the cylindrical body  52  in an axial direction away from the cylindrical body  52 . While the cylindrical body  52  is illustrated as being hollow with the first end  54  open and the end cap  54  is solid, it should be appreciated that the cylindrical body  52  may be solid and the end cap  54  hollow without departing from the scope of the present invention, so long as the plug  34  is operable to seal the cavity  44  of the seal protector  32 . 
     The plug  34  is removably insertable within the cavity  44  of the seal protector  32 , as shown in  FIGS. 3 and 4 . The cylindrical body  52  of the plug  34  has an outer surface  58  having an outer diameter that is greater than the inner diameter of an inner surface  60  of the cylindrical portion  36  of the seal protector  32 . Accordingly, when the plug  34  is inserted within the seal protector  32 , the plug  34  forces the seal protector  32  to expand outward by reducing the overlap of the thin portions  46 A and  48 A. The thin portions  46 A and  48 A may be heat treated to form a breakable connection between the thin portions  46 A and  48 A without departing from the scope of the present invention. The end cap  54  has an outer surface  62  having an outer diameter that approximately matches an inner diameter of an inner surface  64  of the guide portion  38 . 
     In the example provided, the seal protector  32 , the plug  34 , and the tether  50  are formed as a unitary plastic component. The seal protector  32 , the plug  34  and the tether  50  may be created using known injection molding techniques. It should be appreciated, however, that the seal protector  32 , the plug  34 , and the tether  50  may be made of different materials, in different manners, and from separate pieces without departing from the scope of the present invention. 
     Turning to  FIG. 6A , the seal protector  10  may further include a retention feature  80 . The retention feature  80  is disposed proximate the first end  40  on an outer surface  82  of the cylindrical portion  36 . The retention feature  80  has a substantially rounded cross-sectional area and extends circumferentially around the cylindrical portion  36 . When the seal protector  10  is disposed within the opening  18 , the retention feature  80  moves past the seal  22  and is operable to retain the seal protector  80  within the opening  18 . Alternatively, the retention feature  80  may be a discrete or a plurality of discrete protrusions located on the outer surface  82  proximate the end  40 . 
     With reference to  FIG. 6B , an alternate retention feature  80 ′ is shown. The retention feature  80 ′ is an angled flange that extends axially and radially out from the first end  40 . The retention feature  80 ′ operates in a manner similar to that of the retention feature  80 . 
     With reference to  FIGS. 7 and 8 , the seal protector  10  may further include one or more limit flanges  90 . The limit flange  90  is connected to an end of the guide portion  38  and includes a radially extending portion  92  and an axially extending portion  94  disposed at a distal end of the radially extending portion  92 . As shown in  FIG. 8 , the limit flange  90  is configured to contact the seal  22  radially, and optionally axially, outboard of the transmission  12  in order to limit how far the seal protector  10  may be inserted into the opening  18  and to limit the compression of the seal  22  in a radial direction upon insertion of the shaft  70 . The limit flange  90  is preferably designed to contact the metal flange  24  of the seal  22 . 
     Returning to  FIG. 1  and with continued reference to  FIGS. 2-4 , during shipment or storage of the transmission  12 , the seal protector  32  is inserted into the opening  18  such that the cylindrical portion  36  is disposed between the rubber seal portion  26  of the seal  14 . The guide portion  38  is preferably at least partially disposed outside the transmission housing  16 . The plug  34  is press fit into the seal protector  32 . As noted above, the larger diameter of the plug  34  radially expands the seal protector  32  such that the outer surface of the cylindrical portion  36  seals to the rubber seal portion  26  of the seal  14 . The plug  34  has an axial length that is sufficient to assure that the cylindrical body  52  of the plug  34  is disposed in radial alignment with the seal  14  when fully installed in order to assure the seal protector  32  seals to the seal  14  due to radial expansion. The seal protector assembly  10  assures that the opening  18  is sealed from penetration of fluid or debris during shipment and/or processing of the transmission  12 . 
     In order to assemble the transmission  12  with the motor vehicle, the plug  34  is removed, thereby revealing the aperture  45  in the seal protector  32  that communicates with the opening  18  in the transmission  12 . The force required to remove the plug  34  is less than the force required to remove the seal protector  32 , therefore the seal protector  32  remains in place. Turning to  FIG. 5 , once the plug  34  has been removed, an axle shaft  70  is inserted into the aperture  45  and into the opening  18  of the transmission  12 . The guide portion  38  assists the axle shaft  70  by guiding the end of the axle shaft  70  into the transmission  12 . The axle shaft  70  has splines  72  on an end thereof as well as a reduced diameter portion  74  and an increased diameter portion  76 . The seal protector  32 , specifically the inner surface  60  of the cylindrical portion  36 , protects the rubber seal portion  26  from any contact with the splines  72  as the axle shaft  70  passes into the opening  18 . Once the splines  72  have passed the rubber seal portion  26  but before the increased diameter portion  76  has reached the seal protector  32 , the seal protector  32  is removed, preferably by pulling on the tether  50 . The seal protector  32  separates along the axial separation such that the thin portions  46 A and  48 A no longer overlap, and an opening is created. The seal protector  32  is able to deflect and be pulled off the axle shaft  70 . The axle shaft  70  is then further inserted until the axle seal  14  seals to the increased diameter portion  76  of the axle shaft  70 . It should be appreciated that the seal protector assembly  10  may be used with other seals and with other components and openings in the transmission  12  without departing from the scope of the present invention. 
     The description of the invention is merely exemplary in nature and variations that do not depart from the general essence of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.