Patent ID: 7240759

Claim:
A transmission case housing a transmission mechanism for transmitting power to dirigible wheels, comprising: pivoting cases supporting axles of said dirigible wheels; an axle case divided into a first case half and a second case half at a split plane parallel to a direction of extension of said transmission mechanism housed therein, said axle case having a main body, a first vertical boss extending at an angle from one end of the main body, and a second vertical boss extending at an angle from the other end of the main body, each of the first and second vertical bosses being integral, one-piece with the main body wherein the split plane is a single flat plane that extends from a free end of the first vertical boss to a free end of the second vertical boss; connecting bolts for connecting said first case half and said second case half; and a bearing mounted on an outer surface of each of said first and second vertical bosses, the first and second vertical bosses formed by connecting said first case half and said second case half, the bearing additionally holding together the first case half and the second case half, and each of said pivoting cases being attached to a corresponding one of the first and second vertical bosses through said bearing to be pivotable relative thereto.