Crankshaft Vibration Damper And Cooling Valve

Courtesy of JAGUAR CARS, INC.

One of the remedies for obtaining a compact engine unit is to place the crankshaft vibration damper inside the engine block. The damper has been positioned at the front of the crankshaft between the end and the connecting rod pin for the crankshaft for cylinder 1.

Courtesy of JAGUAR CARS, INC.

The damper consists of a solid steel ring, placed in an enclosed housing filled with silicon fluid. The ring is radially journaled through a plastic bearing. There are buttons on the front and rear side surfaces, 4 on each side. These buttons are axially journaled.

The task of the damper is to even out fast unwanted increases and reductions in speed (i.e. crankshaft oscillations) and to give the crankshaft a smoother operation.

When the rotation speed of the crankshaft increases or reduces quickly, the change in speed of the steel ring is delayed due to the high viscosity of the silicon fluid. The function of the damper is based on the braking effect of the silicon fluid and the steel ring's own inertia. When the ring moves in the silicon fluid in the damper housing, a large amount of heat is generated that must be routed away.

Courtesy of JAGUAR CARS, INC.

Because the damper is located in an environment where the normal operating temperature can reach approximately 140°C (284°F), coupled with the fact that the damper also generates its own heat, it is necessary for it to be oil cooled. A separate oil circuit routes oil from the engine's oil cooler to a valve in the engine block, which opens at approximately 2 bar. The oil then flows to 3 jets, located on the crankshaft vibration damper cooling pipe, which then directs the oil to the lower section of the damper.

The oil flows through the jets at approximately 12 liters per minute.

At high temperatures, oil cooling reduces the damper temperature by approximately 7°C (45°F).