STRUCTURE OF WORM GEAR FOR ELECTRIC POWER STEERING SYSTEM

摘要

The present invention relates to a structure of a worm wheel of an electric power steering system, provided with an improved and simple buffering structure easily assembled and applying a buffering force to a load transferred from a steering shaft and a worm shaft. According to the present invention, the structure of the worm wheel of the electric power steering system comprises: a worm wheel main body; a worm wheel hub; a hub cover; a coupling means; a first protrusion part; a second protrusion part; and a damper. The worm wheel main body has a through hole formed on the center thereof and has a plurality of coupling holes formed on the outer edge of the through hole to be spaced from each other. The worm hub is coupled to the left side of the worm wheel′s main body to be in surface contact therewith and has a fitting hole formed at the center to allow the steering shaft to be axially and fittingly coupled thereto. The hub cover is coupled to the right side of the worm wheel′s main body to be in surface contact therewith. The coupling means couples the worm wheel and the hub cover to be in close contact with both the left and right sides of the worm wheel′s main body. The first protrusion part and the second protrusion part protrude from surfaces that are opposite each other in the worm wheel hub and the hub cover to fittingly be coupled to the coupling hole of the worm wheel′s main body. The damper is coupled to cover each outer periphery of the first protrusion and the second protrusion and is elastically deformed by an external load.