Sketch of Drivetrain Layout

Driveshaft

The driveshaft selected has a diameter 1 inch and made of mild steel. The driveshaft will be located higher than previous iterations due to the new driveshaft being in-line, removing the belt pulley that attaches the clutch shaft to the driveshaft. Removing the pulley allows the engine to sit lower allowing for a lower center of gravity which is favorable for better traction and safety. The driveshaft will have lovejoy quick-disconnect couplers on each end to allow for the driveshaft to be completely removed.  The shielding for the two couplers will be manufactured out of either 1/8" mild steel or 1/4" aluminum per competition rules.  Material selection will be dependent upon the pulling team's desired material which is to be determined by 11/16/2022.

There needs to be a change to the framing to account for the higher shaft entrance. A tunnel will be used to cover the driveshaft that will run into the control consule.   The Wildcat Pulling Team's frame subsystem team has also agreed to look into shifting the frame upwards relative to the transaxle in order to mitigate the effect of the higher driveshaft placement as it aligns well with the pulling team's goal of achieving additional ground clearance in this year's design. 

Transaxle

The Wildcat Pulling Team favors the aluminum-housed Cub Cadet Transaxle from Midwest Super Cub.  Calculations have shown that by appropriately re-gearing one of the team's older transaxles, the desired performance levels can be achieved without having to switch over to an entirely new transmission for this year's tractor.  Therefore, the Cub-Cadet transaxle from the Wildcat 3115 tractor will be torn down and re-geared based on the calculations from Milestone 3 to provide the transaxle for the Wildcat 3123 tractor.  This will save the pulling team both time and money while also allowing them to gain their desired performance metrics from components they are familiar with.

One change that will be implemented on the Wildcat 3123 when compared to the Wildcat 3122 is the transmission's gear-selecting mechanism.  The Wildcat 3122 used a parallel shifting lever mechanism.  This mechanism caused issues with gear engagement at last year's competition and received criticism from the design judges for being unintuitive.  Therefore, the drivetrain team has elected to use a modified MWSC H-pattern shifter on this year's transaxle.  The MWSC shifter provides the 3-speed H-pattern shift pattern that is common on many agricultural vehicles while also maintaining the ability to mechanically lock the transmission in gear.  This mechanism will be modified to have a custom shifting lever and shift know in order to place the lever in the optimum location for operator use.