Ski-Doo has revealed a new patent-pending technology for its pDrive clutch on the REV Gen 4 platform. This new technology minimizes the engine vibration issue that many large-displacement 2-cylinder snowmobile engines experience. And it does so without adding weight to the machine.
We’ve sung the praises of the new Rotax 850 E-TEC engine and the pDrive clutch since its debut last season. Part of what makes the package such a good consumer experience to ride is the counterbalancing pDrive fixed clutch sheave developed by Ski-Doo.
The following documentation of this newest clutch innovation was just released by Ski-Doo:
Those with a keen technical eye will notice the D-shaped crankshaft alignment and the twenty-four-thousandths (.024) of an inch (.6mm) precise offset or runout built into the clutch sheave. This runout keeps the belt more perfectly tensioned within the primary and secondary clutches to reduce vibrations sent into the chassis through the secondary clutch.
The timing of the runout’s high spot meeting the belt is synchronized with the engine’s firing to offer a counterbalancing effect without added weight or complexity. The net result is less vibration transferred into the chassis and the rider.
ENGINE MOVEMENT DIAGRAM
Because of reduced vibration transferred to the belt, the belt temperature remains stable or even cooler, compared to not having this runout.
[caption image="/resized-image.ashx/__size/550x0/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-39/1727.Pic-4.png" position="left"]Engine closest to driven[/caption]
[caption image="/resized-image.ashx/__size/550x0/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-39/7077.Pic-5.png" position="left"]Engine furthest from driven[/caption]