Torsional impulse damper for direct connection to universal joint drive shaft

#This invention relates to a torsional impulse damper which can be coaxially secured to a flywheel or similar rotatable element of a prime mover and to which can be directly connected one end of a drive shaft that comprises a universal joint; and the invention is more particularly concerned with a simple and sturdy torsional impulse damper which does not have a shaft extending through it to pilot its driving and driven members but which can nevertheless be coupled to a universal-joint drive shaft.

#A fram tractor powered by a diesel engine exemplifies the conditions that call for the use of a torsional impulse damper. At any nominal speed of the diesel engine, the instantaneous speed of rotation of its crankshaft tends to fluctuate constantly, owing to events that occur during the engine cycle. If such speed variations are carried into the drive train, they produce vibration of the machine, may cause a certain amount of noise, and can subject the drive train to abrupt and constantly recurring high torsional loads that may damage its parts. A torsional impulse damper is therefore connected between the engine and the input shaft of the drive train, to smooth the torque variations of the engine.

#In general, such a damper comprises a rotatable driving member connectable with the engine and a driven member that is coaxially rotatable with the driving member and is coaxially rotatable relative to it to a limited extent. Springs are so connected between the driving member and the driven member as to permit yielding relative rotation between them whereby the driving member is allowed to accelerate and decelerate with the engine and relative to the driven member, and these accelerations and decelerations are damped by friction means reacting between the driving member and the driven member.

#In the accompanying drawings, which illustrate what is now regarded as a preferred embodiment of the invention:

#FIG. 1 is a view, partly in side elevation and partly in vertical section, of a torsional impulse damper of this invention in assembled relationship to an engine flywheel and a universal joint drive shaft whereby torque is transmitted from the engine to a driven mechanism;

#FIG. 2 is a view in section taken on the plane of the line 2--2 in FIG. 1;

#A torsional impulse damper 5 of this invention has a driving member 6 that is adapted to be rigidly coaxially secured to an engine flywheel 7 and has a driven member 8 that is adapted for direct connection to a universal joint drive shaft 9 whereby rotation of the flywheel 7 is transmitted to a driven mechanism 10. To accommodate a certain amount of shifting of the driven mechanism 10 relative to the flywheel 7, the drive shaft 9 comprises front and rear sections 11 and 12 that are splinedly connected, as at 13, and it has a front universal joint 14 for connection with the damper 5 and a rear universal joint 15 for connection with the driven mechanism 10. It will be apparent that the connection between the front universal joint 14 and the driven member 8 of the damper 5 must be maintained coaxial with the flywheel 7 for satisfactory torque transmission, and as the description proceeds it will become apparent that the damper 5 of this invention ensures such coaxiality.

#The driving member 6 of the damper 5 is a disc-like plate having axially opposite front and rear flat faces 16, 17. Circumferentially spaced holes 18 in the peripheral portion of the driving member provide for its coaxial securement to the flywheel 7, as by means of bolts 19 that extend through the holes 18 and are threaded into the flywheel.

#The driven member 8 comprises front and rear circular carrier elements 24 and 25, which are respectively adjacent to the front and rear faces 16 and 17 of the driving member 6, so that the driving member is between the two carrier elements. As explained hereinafter, the carrier elements 24, 25, which are substantially smaller in diameter than the driving member 6, are connected in rigidly fixed relation to one another and are maintained coaxial with the driving member 6. As is also explained hereinafter, the driven member 8 that comprises the connected carrier elements 24, 25 can have limited rotation relative to the driving member 6, and such rotation is yieldingly resisted by springs 28 that react between the driving and driven members and is frictionally retarded by friction rings 30, 31.