Radially inner surface structure of a bearing

#1. Field of the Invention

#The present invention is related to a radially inner surface structure of a bearing and more particularly to a pair of guiding groove sets extending clockwise and counterclockwise on the radially inner surface from either end of the oil-impregnated bearing and terminating in the vicinity of a corresponding end to define a plurality of convergent points. Lubricant in each guiding groove set is guided to flow to the convergent points of the bearing at which the lubricant has been formed a plurality of convergent lubricant points. Lubricant of convergent lubricant points may spread into the guiding groove sets and thus these some lubricant return to the lubricant points such that the two guiding sets perform dynamically circulating lubricant.

#2. Description of the Related Art

#The present invention will now be described in details with references to the accompanying drawings herein:

#FIG. 1 is an exploded perspective view of a shaft and a bearing in accordance with a first embodiment of the present invention;

#FIG. 2 is a partial cross-sectional view of the shaft and the bearing in accordance with the first embodiment of the present invention;

#Referring now to the drawings, there are two embodiments of the present invention shown therein, which include generally a primary shaft member and a secondary bearing member.

#Referring initially to FIGS. 1 through 3, an oil-impregnated bearing 10 in accordance with the present invention mainly includes a first guiding groove set designated as numeral 20 and a second guiding groove set designated as numeral 30. Much of the other detailed structure of the oil-impregnated bearing 10 is omitted. The oil-impregnated bearing 10 is adapted to rotatably receive a shaft designated as reference symbol (a).

#Construction of the oil-impregnated bearing 10 shall be described in detail, referring now to FIGS. 1 and 2. The oil-impregnated bearing 10 in accordance with the first embodiment of the present invention generally includes a radially outer surface 11, a radially inner surface 12, a first distal end 13 and a second distal end 14. The bearing 10 further comprises a first guiding groove set 20 and a second guiding groove set 30. The first guiding groove set 20 is consisted of a plurality of first guiding grooves 21 extended in parallel and starts from the first distal end 13 and terminates in the vicinity of the second distal end 14 to define first convergent points 22. Similarly, the second guiding groove set 30 is consisted of a plurality of second guiding grooves 31 extended in parallel from the second distal end 14 and terminated in the vicinity of the first distal end 13 to define second convergent points 32. The first guiding groove set 20 is spiraled in clockwise with respect to its axis while the second guiding groove set 30 is spiraled in counterclockwise. The guiding groove sets 20 and 30 are intersected in a predetermined angle to thereby define a plurality of third convergent points (not labeled).