Patent Publication Number: US-2005137021-A1

Title: Method of reducing torque shock on a transmission

Description:
FIELD OF THE INVENTION  
      This invention relates to torque shock experienced between an engine and an automatic transmission when gears are shifted. More particularly this invention relates to a method of reducing this torque shock to prolong the life of engines, transmissions, and the entire power train in vehicles and heavy equipment.  
     BACKGROUND OF THE INVENTION  
      Torque shock between power sources and remotely mounted automatic transmissions has long been, and continues to be a problem. Torque shock is not only hard on automatic transmissions, but on the crank shaft of engines, and the entire drive train in vehicles. Particularly on larger trucks, and on heavy equipment having automatic transmissions, fast, forceful, and sudden contact between shifting gears roughly jerks the entire vehicle. High rpm shifts, either up or down, generate substantial torque shock. This torque shock results in a premature failure of engines, transmissions, drive shafts, and differentials. To correct the problem of torque shock, a torque shock absorbing apparatus that decreases the peak torque shock when gears are automatically shifted, is needed.  
      The inventor has determined that the best position for the torque shock absorber is directly on the engine or power source, before the automatic transmission. When installed, the torque shock absorber absorbs torque buildup during gear shifting. Drive shaft vibrations are eliminated. The torque shock absorber not only promotes smoother shifting of gears, and a smoother acceleration of the vehicle, but most importantly it reduces fatigue and wear on gears, bearings, and shafts within the transmission, as well as within all components within the entire remainder of the drive train. Peak torque and wear, and all of the resulting fatigue and failure of gears, shafts, bearings, universal joints, all along the entire drive train can be substantially reduced. While a torque shock absorber can compliment small vehicles having small engines and power transmission, the torque shock absorber has most immediate application on relatively large vehicles having large engines which transmit substantial power.  
     OBJECTS OF THE INVENTION  
      It is an object of this invention to disclose a method of substantially reducing maintenance, and extending the life of engines, automatic transmissions, and all other components in the drive train of a vehicle. It is an object of this invention to disclose a method of reducing peak torque caused by both up and down shifting of gears. It is yet a further object of this invention to disclose a method of producing smoother acceleration and deceleration of a vehicle.  
      One aspect of this invention provides for a method of reducing this torque shock to prolong the life of engines, transmissions, and the entire power train in vehicles and heavy equipment most generally comprises the steps of transmitting rotational power through a torque shock absorber having a generally cylindrical housing adapted for attachment to a drive on one cylindrical end and to a driven shaft on the other cylindrical end. Thereby peak torque loads transmitted through the torque shock absorber are reduced.  
      In a preferred aspect of this invention a preferred embodiment provides for the torque shock absorber comprising a housing having peripheral spaced bolts therethrough. Bolt openings therein are surrounded by a rubber bushing in the housing so that when the torque shock absorber is bolted to a driven flange peak torque loads are absorbed by the rubber bushings. The most preferred placement for the torque shock absorber in the power train is between an engine and an automatic transmission.  
      Various other objects, advantages and features of this invention will become apparent to those skilled in the art from the following description in conjunction with the accompanying drawings. 
    
    
     FIGURES OF THE INVENTION  
       FIG. 1  is a cross sectional view of a torque shock absorber mounted on a flywheel transmitting power to a driven shaft.  
       FIG. 2  is a front view of the torque shock absorber shown in  FIG. 1 . 
    
    
      The following is a discussion and description of the preferred specific embodiments of this invention, such being made with reference to the drawings, wherein the same reference numerals are used to indicate the same or similar parts and/or structure. It should be noted that such discussion and description is not meant to unduly limit the scope of the invention.  
     DESCRIPTION OF THE INVENTION  
      Turning now to the drawings and more particularly to  FIG. 1  we have a perspective view of a cross sectional view of a torque shock absorber  20  mounted on a flywheel  18  transmitting power to a driven shaft  32 . Most generally a method of reducing peak torque loads  25  caused by automatic gear shifting comprises the steps of: transmitting rotational power  24  through a torque shock absorber  20 , having a generally cylindrical housing  26  adapted for attachment to a drive shaft  28  on one cylindrical end, and to a driven shaft  32  on the other cylindrical end. Thereby peak torque loads  25  transmitted through the torque shock absorber  20  are reduced.  
      The torque shock absorber  20  comprises a housing  26  having peripheral spaced bolt openings  34  and having bolts  36  therethrough. Said bolt openings  34  are surrounded by a rubber bushing  38  in the housing  26  so that when the torque shock absorber  20  is bolted to a driven flange  40  peak torque loads  25  are absorbed by the rubber bushings  38 . Within this specification rubber is defined to include a resilient plastic.  
      In the most preferred embodiment of the invention the rubber bushings  38  are surround a steel bolt sleeve  42 . The rubber bushings  38  are surrounded by a cylindrical steel ring  44  to facilitate positioning them within the housing  26 . The rubber bushings are bonded between the steel bolt sleeve  42  and the cylindrical steel ring  44 . A centering flange  50  maintains the rubber bushings  38  within the bushing  26 . In the most preferred embodiment of the invention the drive shaft  28  and drive flange  46  comprises a fly wheel  48  turned by a crankshaft  30  on an internal combustion engine  49 . The driven shaft  32  is adapted to be driven by a driven flange  40  bolted to an inner central portion of the driven end of the generally cylindrical torque shock absorber  20 . The driven shaft  32  inputs power to an automatic transmission  45 .  
      While the invention has been described with preferred specific embodiments thereof, it will be understood that this description is intended to illustrate and not to limit the scope of the invention, which is defined by the following claims.