External cylindrical gearing

A gearbox comprising:

• a nonsplit casing having a pair of opposite walls spaced apart along an axis of said casing, said casing being axially open at one of said walls;
• an input pinion stem extending into said casing along said axis through an opening in the other of said walls, formed with a toothed rim, and capable of being driven;
• a plurality of intermediate pinion stems journaled between said opposing walls, having respective axes lying along a cylindrical surface centered on said axis, and each having respective end journals;
• respective cluster spur gears on said intermediate pinion stems meshing with said toothed rim of said input pinion stem, said intermediate pinion stems having respective toothed rims;
• an output shaft extending along said axis into said casing through said one of said walls and having an output gear meshing with the toothed rims of said intermediate pinion stems, said spur gears and said output gear having the same addendum circles;
• a pair of generally cylindrical opposite bearing housings on said walls for each of said intermediate pinion stems, said bearing housings on said one of said walls having radially open slots of a width greater than diameters of said journals to enable lateral insertion of said journals into said housings, said slots being formed as openings in a cylindrical surface of a diameter greater than addendum circles of said gears;
• respective radial roller bearings retaining each of said journals in a respective one of said housings, each of said radial roller bearings including an outer bearing race having a pair of inwardly projecting shoulders flanking an array of rollers thereof;
• and
• a detachable cover closing said casing at said one wall.