Rotor and rotor housing for pneumatic abrading or polishing tool

Abstract

A power driven abrading or polishing tool is provided that includes a motor having a rotor; a carrier part having a shaft and a key extending from the shaft; and an abrading or polishing head attached to the carrier part. The rotor includes an outer body of a first material and a core of a second material having a resistance to wear greater than the first material. The core includes an inner passage with a keyway which receives the key on the shaft of the carrier part such that a rotation of the rotor is transmitted to the carrier part and the head. In one embodiment, the rotor rotates in a housing having an inner surface with a hardness of at least approximately 80 on the Rockwell scale and/or a microfinish of 14 or better.

1 . A power driven abrading or polishing tool comprising:
 a motor having a rotor;   a carrier part having a shaft and a key extending from the shaft; and   an abrading or polishing head attached to the carrier part;   wherein the rotor comprises an outer body comprised of a first material and a core of a second material having a resistance to wear greater than the first material, and wherein the core comprises an inner passage with a keyway that receives the key on the shaft of the carrier part such that a rotation of the rotor is transmitted to the carrier part and the head.   
   
   
       2 . The tool of  claim 1 , wherein the core is metallic. 
   
   
       3 . The tool of  claim 2 , wherein the rotor has upper and lower surfaces with cavities extending downwardly from the upper surface and upwardly from the lower surface, at least one of said cavities containing absorbent material for absorbing oil introduced into the motor for lubrication. 
   
   
       4 . The tool of  claim 3 , wherein the absorbent material is felt. 
   
   
       5 . The tool of  claim 2 , wherein the outer body comprises aluminum. 
   
   
       6 . The tool of  claim 1 , wherein the outer body of the rotor is non-rotatably attached to the core of the rotor. 
   
   
       7 . The tool of  claim 6 , wherein the outer body of the rotor is molded or cast onto the core of the rotor, such that an integral part is formed by the outer body and the core. 
   
   
       8 . The tool of  claim 1 , wherein the outer body of the rotor comprises a plurality of radial slots extending from an outer diameter of the rotor toward a center of the rotor, and wherein each radial slot receives a vane for transmitting rotary force to the rotor. 
   
   
       9 . The tool of  claim 8 , wherein an inner surface of the outer body includes an alternating series of radial protrusions and recesses which mate with a complementary alternating series of radial recesses and protrusions on an outer surface of the core to non-rotatably couple the outer body to the core. 
   
   
       10 . The tool of  claim 9 , wherein each radial slot is aligned with a corresponding one of the protrusions on the inner surface of the outer body of the rotor, such that an increased slot depth is achieved. 
   
   
       11 . The tool of  claim 10 , wherein each protrusion on the outer surface of the core is disposed between adjacent ones of the radial slots to provide support to the radial slots. 
   
   
       12 . The tool of  claim 11 , wherein the outer body comprises a cavity extending downwardly from an upper surface thereof and extending substantially between at least one adjacent pair of the radial slots. 
   
   
       13 . The tool of  claim 1 , wherein the power driven abrading or polishing tool is a pneumatic orbital abrading or polishing tool. 
   
   
       14 . A power driven orbital abrading or polishing tool comprising:
 a motor having a rotor;   a carrier part having a shaft and a key extending from the shaft; and   an abrading or polishing head attached to the carrier part;   wherein the rotor further comprises:
 a metallic core and having an inner passage with a keyway that receives the key on the shaft of the carrier part such that a rotation of the rotor is transmitted to the carrier part and the head, and 
 a generally cylindrically-shaped outer body disposed in surrounding relation to the core and comprised of a material having a resistance to wear lower than the metallic core. 
   
   
   
       15 . The tool of  claim 14 , wherein the metallic core comprises steel. 
   
   
       16 . The tool of  claim 14 , wherein the outer body of the rotor comprises a synthetic polymeric material. 
   
   
       17 . The tool of  claim 14 , wherein the outer body of the rotor comprises a plurality of radial slots extending from an outer diameter of the rotor toward a center of the rotor, and wherein each radial slot receives a vane which is acted upon by a force from a stream of compressed air to rotate the rotor. 
   
   
       18 . The tool of  claim 17 , wherein an inner surface of the outer body includes an alternating series of radial protrusions and recesses, which mate with a complementary alternating series of radial recesses and protrusions on an outer surface of the core to non-rotatably couple the outer body to the core. 
   
   
       19 . A power driven abrading or polishing tool comprising:
 a motor having a rotor mounted for rotation in a rotor housing, such that vanes carried by the rotor contact an inner cylindrical surface of the housing as the rotor rotates;   a carrier part having a shaft and a key extending from the shaft; and   an abrading or polishing head attached to the carrier part;   wherein the inner cylindrical surface of the rotor housing has a hardness of at least approximately 80 on the Rockwell scale.   
   
   
       20 . The tool of  claim 19  in which the rotor housing has a microfinish of 14 or better. 
   
   
       21 . The tool of  claim 19  wherein the inner cylindrical surface of the rotor comprises a thin film of titanium nitride(TiN). 
   
   
       22 . The tool of  claim 21  wherein the thin film of titanium nitride (TiN) is a PVD thin film.