Patent Publication Number: US-2015075323-A1

Title: Transmission wear plate

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/879,242, filed Sep. 18, 2013, which is incorporated herein by reference. 
    
    
     FIELD OF THE DISCLOSURE 
     This disclosure relates to vehicle automatic transmissions and in particular to a vehicle automatic transmission that exhibits improved resistance to damage upon failure of an associated torque converter or transmission pump. 
     BACKGROUND OF THE DISCLOSURE 
     Certain automatic transmissions often have a problem with torque converter and/or transmission pump failure. The torque converter, affixed to the rear of the vehicle&#39;s engine, is located in the front of the transmission. While the engine is running, the torque converter rotates the pump gear set of the transmission which creates the necessary hydraulic pressure that allows normal operation. 
     The pump gears are located in a machined cavity of a cast-iron housing which is located in a recess of an aluminum housing. These gears ride directly against the aluminum housing using inert transmission oil as lubricant. 
     When failure of the torque converter or pump occurs, debris from failed part(s) may cause serious damage to the pump assembly of the transmission. This debris will get caught in the spinning gears of the pump causing breakage of the gears. At this point, the torque converter is still turning with the engine and, in turn, is pulverizing the debris from both the failed torque converter and the now-failed pump gears. 
     SUMMARY OF THE DISCLOSURE 
     Disclosed herein is a transmission pump wear plate that reduces damage to transmission components upon failure of the torque converter and/or the transmission pump. 
     The transmission wear plate is a sheet metal material that can be harder than the aluminum of the bell housing of a typical vehicle transmission, and is configured to mimic the pump stator surface. Specifically, the transmission wear plate is configured to define an intake port, an exhaust port, a drain back port and a center hole for passage of a splined stator tube and converter hub. The various ports and holes have shapes generally corresponding with those defined in the transmission pump mating surface of the aluminum bell housing. 
     The transmission pump wear plate can be positioned between the pump body that contains the pump gears and an aluminum bell housing in order to protect the bell housing from damage in the event of catastrophic failure of the torque converter and/or transmission pump, without interfering with normal operation of the transmission. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a transmission pump wear plate. 
         FIG. 2  is a front view of the recess for the pump body and gears of an aluminum bell housing of a vehicle transmission. 
         FIG. 3  is a perspective view of a cast iron pump body with damaged gears. 
         FIG. 4  is a perspective view of an intact (not damaged) cast iron pump body with pump gears. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
     The wear plate  10  disclosed herein is designed to help prevent damage to the aluminum bell housing  12  ( FIG. 2 ) of certain transmissions. Wear plate  10  has a circular shape. 
     The plate  10  is designed to be placed between the pump body  14 , containing the pump gears, and the aluminum bell housing  12 . 
     The plate  10  can be laser-cut or water jetted from a grade of steel which is considerably harder than the aluminum used for the bell housing  12 . However, other materials can be used, with those materials having a hardness greater than aluminum being preferred. 
     The presence of the plate  10  protects the expensive bell housing  12  from damage should a catastrophic failure of the torque converter, and or pump body  14  occur. 
     The plate  10  is fabricated from sheet material (e.g., steel) to mimic or generally correspond to the shape and openings of the pump stator surface, including intake port  15 , exhaust port  16  and drain back port  17 , bolt holes  18 , center hole  19  to allow passage of a splined stator support tube. The intake port  18 , exhaust port  16  and drain back port  17  typically have irregular shapes (i.e., shapes that are not symmetrical). The center hole  19  typically has a circle shape. The bolt holes  18  are typically disposed adjacent a peripheral edge of plate  10 , each located substantially an equal distance from the center of the plate. 
     The plate  10  can be made of materials other than steel provided that the material is sufficiently hard and of sufficient thickness to protect the bell housing  12 . 
     The foregoing description of the specific embodiment of the invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the claims to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching.