One-piece power transmission casing and a method of assembling a transmission mechanism therein

A method for assembling a transmission within a one-piece casing comprising the steps of:

• fabricating a hollow transmission casing having axially spaced front and rear faces cojoined by an axially extending peripheral boundary wall, a first major opening penetrating the front face, a second major opening penetrating the rear face, an idler shaft access aperture penetrating the rear face and an aperture penetrating the front face in substantial alignment with the second major opening;
• machining axially spaced front and rear drive gear bearing supports located in general proximity to the respective front and rear faces;
• machining axially spaced front and rear idler gear bearing supports that are also located in general proximity to the front and rear faces but in laterally displaced relation relative to the front and rear drive gear bearing supports;
• machining a final drive front bearing support through said front face;
• inserting a drive gear, a drive gear shaft and drive gear bearings through the first major opening to be supported by the front and rear drive gear bearing supports;
• inserting front and rear idler bearings through the first major opening;
• positioning the front and rear idler bearings on the respective front and rear idler gear bearing supports;
• inserting an idler gear through the second major opening;
• manipulating the idler gear into engagement with the drive gear;
• inserting an idler gear support shaft through the idler gear shaft access opening operatively to engage the idler gear and the idler gear bearings to support the idler gear for rotation in response to rotation of the drive gear.