This invention relates to small electric motors of the type used in axial flow air impeller units commonly found in computers, copy machines etc. More particularly, the invention relates to an improved bearing and seal assembly for use about a central shaft and within a stator or rotor of such a motor. The bearing and seal assembly in a motor of this type must be of a relatively simple and inexpensive construction and yet highly efficient and dependable in use throughout the substantial life span of the unit.
In U.S. Pat. No. 3,614,261 entitled BEARING SEAL MEANS FOR AN ELECTRICALLY DRIVEN FAN issued Oct. 19, 1971 to Karl E. Friese et al, a bearing and seal assembly is disclosed with a sleeve bearing disposed within a ferrule or sleeve which provides a capillary sealing function at one end and which is enlarged and closed at an opposite end to provide a lubricant chamber about the bearing. The ferrule or sleeve is, however, of relatively heavy and expensive construction and the capillary sealing function is provided by a cup-shaped projecting end portion of the sleeve and an associated annular felt ring. Close tolerances and precise concentricity or coaxial relationship between the sleeve bearing and the portion of the sleeve providing the capillary seal are of course desired but have been found somewhat difficult to achieve and the construction has also been found deficient in this regard.
It is the general object of the present invention to provide a bearing and seal assembly which includes a bearing and seal confining sleeve and which provides for the necessary close tolerances, precise concentricity or coaxial relationship of elements, and which is yet of a desirably simple and inexpensive construction yielding a high degree of efficiency and dependability in use.
A further object of the invention resides in the provision of an assembly method whereby the sleeve receives the bearing and seal in press fit engagement and precisely centers the elements about an assembly pin with the sleeve press fit or adhesively secured within the bore of a motor stator or rotor.