Rotary expander

Abstract

An improvement to an expander is disclosed. The expander is of the type that has vanes that extend and retract from a rotor body during rotation and create chambers that increase and decrease in size. The improvement comprises, for each vane, for each vane, a pivot axis orientated parallel to the rotational axis and about which said each vane pivots between the extended and retracted positions.

1 . An improved expander of the type that is used to extract power from a supply of pressurized fluid and that includes:
 a housing: having a rotation axis; defining a hollow interior having an annular surface orientated parallel to the rotation axis and through which the rotation axis extends; and defining one or more ports which extend through the housing to the interior;   a rotor mounted in the housing for rotation about the rotation axis, the rotor having
 a body having an outer tubular surface, the tubular surface having defined therein a plurality of voids; 
 for each of the voids of the plurality, a vane, the vane: having a seal defining a tip of the vane; being mounted in the void for which it is provided for movement between a retracted position and an extended position; and being adapted such that, upon rotation of the rotor in the housing, movement of the vane between the extended and retracted positions causes the tip seal to sweep the annular surface; 
   control means for controlling movement of the vanes and access to the ports such that the vanes create chambers which increase in volume when in communication with the source of pressurized fluid,   the improvement comprising:   for each vane, a pivot axis orientated parallel to the rotational axis and about which said each vane pivots between the extended and retracted positions.   
     
     
         2 . The expander according to  claim 1 , wherein the vane terminates in a pintle and the pivot axis is defined by a socket formed in the body in which the pintle is mounted for rotational movement. 
     
     
         3 . The expander according to  claim 1 , wherein the void is defined at least in part by an arcuate slot. 
     
     
         4 . The expander according to  claim 1 , wherein the body is cylindrical and disposed in offset relation to the interior. 
     
     
         5 . The expander according to  claim 1 , wherein the annular surface and the tubular surface are both oval and the body is centered in the interior. 
     
     
         6 . The expander according to  claim 1 , wherein the control means comprises springs which bias the vanes for movement towards the extended positions. 
     
     
         7 . The expander according to  claim 1 , wherein the rotor has a pair of end seals disposed axially apart from one another and defining, in combination with the tubular surface, the annular surface and the tip seal, the chambers. 
     
     
         8 . The expander according to  claim 7 , wherein the end seals are defined in part by body seals carried by and spring mounted to the body and in part by vane seals carried by and spring mounted to the vanes.