Dynamic Balancers
| ITEM | DESCRIPTION |
|---|---|
| 1 | Bearing outer race (quantity 4) |
| 2 | Left dynamic balancer |
| 3 | Left dynamic balancer gear |
| 4 | Bolt (quantity 2) |
| 5 | Bearing |
| 6 | Bearing |
| 7 | Idler gear |
| 8 | Right dynamic balancer gear |
| 9 | Right dynamic balancer |
The engine balance system consists of 2 eccentric weighted dynamic balancers which oppose vibrations created by the engine reciprocating components. The dynamic balancers are installed on outer races pressed into machined bores inside the cylinder block. The 2 dynamic balancers rotate in opposite directions, driven at twice the speed of the crankshaft by a dynamic balancer gear pressed onto the crankshaft. The equally sized eccentric weights are phased so that the inertia reaction to their counter-rotation cancels out vibration caused by the engine.
The left dynamic balancer has a 43 teeth drive gear that is driven by the 86 teeth ring gear on the crankshaft. The right dynamic balancer is also driven by the 86 teeth ring gear on the crankshaft through a 45 teeth idler gear. The idler makes sure that the 2 dynamic balancers rotate in opposite directions.
The idler gear is installed on to the cylinder block using a steel idler bush which is pressed into the cylinder block. Driven gears on 1 of the dynamic balancers and the idler gear are anti-backlash scissor gears in order to minimize noise. All the gears are helical to make sure that they operate smoothly. The dynamic balancers are located on needle roller bearings that run on outer races installed in the cylinder block machined bores. The bearings are lubricated by oil mist during engine operation.
It is important to make sure that the 2 dynamic balancers are timed correctly to the crankshaft, using specialized alignment tool(s).