INVOLUTE GEAR

PROBLEM TO BE SOLVED: To improve strength of teeth without hindering the rotation transmitting function, in regards to an involute gear. SOLUTION: The whole area of each of tooth flanks 20 and 22 is partitioned into a strip contact area including a locus of a contact point of both the tooth flanks and extended along the locus and a non-contact area positioned outside of the contact area. The contact area is formed into an involute helicoid to function as a tooth abutting surface against a tooth flank of a counter gear. The non-contact area is formed into a shape which does not contact with a tooth flank of the counter gear, and formed into a shape changed to directly or indirectly improve strength of the teeth of the involute gear in comparison with the basic tooth flank shape wherein the whole area is formed into an involute helicoid. For example, a tooth tip part 30 is cut in both sides in the tooth cross direction in relation to the basic tooth tip shape, and a tooth bottom part 32 is raised in both sides in the tooth cross direction in relation to the basic tooth bottom shape. COPYRIGHT: (C)2005,JPO&NCIPI