Device to suppress firing impulse torque induced vibrations in internal combustion engines

• US 5,341,780 A
• Filed: 07/30/1993
• Issued: 08/30/1994
• Est. Priority Date: 07/30/1993
• Status: Expired due to Term

• Current Assignee: Charles B. Rau, Fisher, Douglas D.
• Original Assignee: Charles B. Rau, Fisher, Douglas D.
• Inventors: Fisher, Douglas D., Rau, Charles B.
• Primary Examiner(s): Kamen, Noah P.
• Application Number:
  US08/099,744
• Time in Patent Office: 396 Days
• Field of Search: 123/192.1, 74/574
• US Class Current: 123/192.1
• CPC Class Codes: F02B 61/02 for driving cycles
• CPC Class Codes: F02B 75/06 Engines with means for equalising torque
• CPC Class Codes: Y10T 74/2128 Damping using swinging masses, e.g., pendulum type, etc.

Abstract

A device is set forth to suppress vibrations relating to intermittent or uneven piston firing impulse torque in an internal combustion engine. The device is particularly adapted as an after market device for motorcycle engines and includes first and second plates secured to the engine crankshaft and to the engine'"'"'s drive sprocket. Inertial rings are biased to, in cooperation with friction discs, frictionally couple the plates and rings for mutual rotation below pre-selected shaft torques. Firing impulses resulting in torques exceeding the predetermined value will cause the plates to rotate, restrained by friction, relative to inertial rings to suppress torque related vibration.

Claims

1. A device in a vehicle drive train at the output end of an internal combustion engine crankshaft to suppress firing impulse torque related vibration, said drive train including a drive sprocket freely coaxially rotatable relative to the crankshaft said drive sprocket providing input to a transmission to drive the vehicle, said device comprising:

a first plate adapted to be coupled to the drive sprocket for coaxial rotation therewith;

a second plate attached to the first plate for coaxial rotation therewith, at least one of said first or second plates attached to the crankshaft so that said plates and sprocket coaxially rotate with and are driven by the crankshaft;

a first inertial ring;

a second inertial ring, said first and second inertial rings coupled for mutual co-axial rotation, said inertial rings coaxially disposed between said first and second plates;

friction discs disposed between the inertial rings and plates; and

means for urging the inertial rings to press the discs between said rings and plates to frictionally slip couple the rings to the plates to rotate coaxially therewith below a pre-selected value of firing impulse torque, said plates frictionally slipping relative to the rings above said pre-selected value to suppress vibration related to firing impulse torques.

2. The device of claim 1 wherein one of said inertial rings includes a pair of axially projecting pins and the other of said inertial rings include a pair of bores, each adopted to receive a pin to couple said rings for mutual coaxial rotation.

3. The device of claim 1 wherein said sprocket includes axially projecting teeth, said first plate having axial disposed notches each adapted to receive a corresponding tooth to engage said first plate with said sprocket.

4. The device of claim 1 wherein said urging means are coil springs disposed between said inertial rings.

5. The device of claim 4 wherein said pre-selected firing impulse torque is 240 inch-pounds.

6. In a vehicle having an internal combustion engine with a crankshaft having an output end, a transmission and a sprocket freely rotatable about said output end, said sprocket engaging a chain which provides input to the transmission, said sprocket having axially projecting teeth, the improvement comprising:

a first plate fixed to the crankshaft output end to rotate therewith, said first plate including recesses to receive said teeth to couple the first plate to the sprocket for mutual coaxial rotation;

a second plate spaced from the first plate and attached thereto to rotate with the first plate and crankshaft;

a pair of inertial rings disposed between and coaxially rotatable relative to the first and second plates;

means for restraining said rings against mutual coaxial rotation;

a friction surface disposed between each of the first and second plates and the rings; and

means for axially urging said rings to cooperate with the friction surfaces to frictionally couple said rings to said plates to coaxially rotate their width below a pre-selected firing impulse torque, said plates frictionally slipping above said pre-selected firing impulse torque to suppress vibrations related to firing impulse torque.