Patent ID: 8578817

Claim:
A gear unit comprising: a housing; a first shaft rotatably disposed at a fixed location in said housing, said first shaft having an angular pinion gear at one end thereof, and having a cylinder gear on an opposite end thereof; a bearing section of said housing, which bearing section supports an intermediate portion of said first shaft in said housing, in an opening in said bearing section, via first and second bearings mounted on said first shaft, wherein a first retaining ring is seated in the bearing section on a side of the second bearing that is opposite of a side of the second bearing that faces the first bearing, and wherein the first bearing abuts one outer surface of the cylindrical gear; an opening in said housing through which a cylindrical pinion on a motor shaft of a motor meshes with said cylinder gear when said motor is mounted on said housing; a second shaft rotatably disposed at a fixed location in said housing, said second shaft having a crown wheel at an intermediate portion thereof; first and second openings in said housing which openings support, within said housing, a first end of said second shaft and a portion of said second shaft that is on a side of said crown wheel that is opposite said first end, via third and fourth bearings mounted on said second shaft, with said crown wheel meshed with said angular pinion gear of said first shaft, and with a second end of said second shaft, opposite said first end, projecting out of said housing, wherein the fourth bearing contacts the crown wheel; a second retaining ring seated in the first opening in the housing, wherein the second retaining ring is arranged on a side of the third bearing that is opposite of a side of the third bearing that faces the fourth bearing; a third retaining ring seated in the second opening in the housing, wherein the third retaining ring is arranged on a side of the fourth bearing that is opposite of a side of the fourth bearing that faces the third bearing, wherein said first shaft, with said pinion gear and said first and second bearings mounted thereon, and said second shaft, with said crown wheel and said third and fourth bearings mounted thereon, together form an angular gear stage; said housing accepts interchangeably installation of different angular gear stages comprising gear pairs selected from a multiplicity of angular gear pairs with differing tooth configurations and gear ratios, including both cylindrical oblique tooth pinions that mesh with crown wheels having curved tooth flanks, and cylindrical pinions with a worm configuration that mesh with a crown wheel having curved tooth flanks.