A process of making a casting includes the steps of designing a mold, fabricating the layers of the mold, stacking and assembling the laminations into a mold, producing a casting and demolding the casting. The braking force control apparatus includes braking force control means which increases a braking force that is generated by the function of the electric power generator when the torque capacity of the torque capacity control device is decreased. The first gearset comprises a first sun gear, which is mounted to rotate about the axis and is in mesh with a plurality of first planet gears mounted to rotate about respective planet shafts carried by a first common carrier, which is mounted to rotate about the first axis.