Grease seal for bearing arrangement

An improved sealing construction for frictionless bearings having an outer housing with a passage therethrough and an axle located within the passage, the seal comprising inner and outer rings that are secured to the shafts and to the outer housing respectively, and wherein the rings include overlapping flanges that are dimensioned to create a labyrinth path precluding the escape of lubricant from the interior of the bearing.

BACKGROUND OF THE INVENTION 
This invention relates to frictionless bearings and more particularly to an 
improved sealing arrangement for frictionless bearings, particularly for 
those utilizing rollers as the bearing elements. 
A typical frictionless bearing is composed of an outer housing having a 
bore therethrough, a shaft extending through the bore, inner and outer 
races and bearing elements, either ball or roller, disposed between the 
two races. Due to the friction that is developed between the various parts 
that are rotating relative to each other, it is imperative that the volume 
defined by the bore of longitudinal opening of the casing be substantially 
filled with suitable lubricant. Further, it is equally important that the 
lubricant contained in the housing be prevented from escaping, for obvious 
reasons. In the past, a variety of ways of sealing frictionless bearing 
have been tried, such as rings and elastomeric cups which fit between the 
housing and the centrally disposed shaft. Such existing arrangements very 
greatly in cost and effectiveness. 
It is a principal object of the invention to provide an improved sealing 
arrangement for frictionless bearings which is easily and economically 
manufactured and which is effective for long periods of time. 
An additional object of this invention is to provide an improved seal for 
frictionless bearings in which inner and outer sealing elements are 
provided which cooperate to define a labyrinth path that effectively 
precludes escape of lubricant from the bearing.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
As was indicated earlier, the improved sealing construction disclosed 
herein is applicable for use with frictionless bearings in which a 
lubricating medium must be present to reduce the friction between the 
bearing races and the rotating bearing elements. Although the sealing 
construction could be used with bearings utilizing balls as the friction 
reducing elements, the description will relate to and describe the 
invention in connection with a tapered roller bearing. 
For a better understanding of the invention, reference is made to FIG. 1 of 
the drawings in which the numeral 10 indicates a frictionless bearing that 
includes a shaft 11, an outer housing 12, an outer bearing race 13, an 
inner bearing race 14 and a plurality of tapered roller bearing elements 
15 that are confined between the outer and inner races 13 and 14. It can 
be seen that the inner surface 20 of outer housing 12 had a raised portion 
21 that defines a web providing for the inclusion of two sets of roller 
members within the longitudinal opening or passageway that extends through 
housing 12 to receive the shaft 11. 
The improved sealing construction includes a first annular sealing element 
25 that has a body portion 26 that fits around the end corner of the outer 
housing 12 to form a tight seal. Sealing element 25 is thus mounted on the 
outer housing 12, by means of a press or interference fit, and also has a 
flange 27 that extends radially inwardly from the outer housing toward 
that shaft 11. A second sealing element 30 is provided that has an 
enlarged hub portion 31 mounted on shaft 11 and this second sealing 
element includes a flange portion 32. Flange 32 extends radially outwardly 
from hub portion 31 so that its inner surface is in sliding contact with 
the outer surface of flange 27 on first sealing element 25. This 
overlapping or interconnecting relationship creates a labyrinth path 35 
between adjoining surfaces of first sealing element 25 and second sealing 
element 30. 
Since the first and second sealing elements 25 and 30 are in frictional 
contact, it is preferred that one or the other be constructed of a 
suitable thermoplastic material such as Delrin or Nylon. Both of these 
materials have the required strength and lubricity to permit a sliding fit 
without harmful frictional heat developing. 
It can be seen that the sealing arrangment on each end of the bearing is 
identical. The sealing construction on one end of the bearing is held in 
place by means of a collar 36 formed on shaft 11, whereas the opposite end 
of the bearing is retained by means of washer 37, lock washer 38, and 
threaded fastener 39 that is retained on the threaded portion 40 of shaft 
11. 
Although the present invention has been described in connection with a 
preferred embodiment, it is to be understood that modifications and 
variations may be resorted to without departing from the spirit and scope 
of the invention as those skilled in the art will readily understand. Such 
modifications and variations are considered to be within the purview and 
scope of the invention and the appended claims.