Pneumatic motor

Abstract

A pneumatic motor includes a cylinder, a rotor and a drive shaft. The cylinder includes a cylinder body having two ends, a first cover and a second cover. The first cover is mounted on one of the ends of the cylinder body and has a first bearing housing, a first bearing and a first blocking ring. The first bearing is mounted in the first bearing housing and has an annular clearance. The first blocking ring is mounted between the first bearing housing and the first bearing and covers the annular clearance of the first bearing. The rotor is mounted rotatably in the cylinder body. The drive shaft is mounted securely through the rotor. When compressed air is expelled from the cylinder body, the compressed air does not blow lubricants out of the first bearing because the first blocking ring closes the annular clearance.

1 . A pneumatic motor comprising
 a cylinder comprising
 a cylinder body having two ends and a receiving space; 
 a first cover being mounted on one of the ends of the cylinder body and having
 a first bearing housing being formed on the first cover; 
 a first bearing being mounted in the first bearing housing and having
 an inner race; 
 an outer race being disposed around the inner race; and 
 an annular clearance being defined between the inner race and the outer race; and 
 
 a first blocking ring being mounted between the first bearing housing and the first bearing and covering the annular clearance of the first bearing; and 
 
 a second cover being mounted on the other end of the cylinder body; 
   a rotor being mounted rotatably in the receiving space of the cylinder body and having multiple blades protruding from the rotor; and   a drive shaft being mounted securely through the rotor and connected to the first bearing.   
   
   
       2 . The pneumatic motor as claimed in  claim 1 , herein the second cover has
 a second bearing housing being formed on the second cover;   a second bearing being mounted in the second bearing housing, being mounted around the drive shaft and having
 an inner race; 
 an outer race being disposed around the inner race, and 
 an annular clearance being defined between the inner race and the outer race; and 
   a second blocking ring being mounted between the second bearing housing and the second bearing and covering the annular clearance of the second bearing.   
   
   
       3 . The pneumatic motor as claimed in  claim 2 , wherein a sanding pad is further mounted eccentrically on the drive shaft. 
   
   
       4 . The pneumatic motor as claimed in  claim 1 , wherein a sanding pad is further mounted eccentrically on the drive shaft.