Segmented Positive Displacement Rotor Housing

Abstract

This disclosure concerns an advanced nutating positive displacement device having a high power to mass ratio and low production cost. This device in one example forms an exemplary pump as will be discussed in detail. The examples disclosed herein are of the rotary positive displacement type, but in a class by themselves. The devices are formed by a nutating rotor having a face comprising lobes and valleys, and a fixed stator also having a face with lobes and valleys. The face of the rotor opposes and cooperates with the face of the stator. The opposing faces define chambers that change volume with rotation of the rotor.

Therefore I claim: 
     
         1 . A fluid flow apparatus comprising:
 a. a housing;   b. the housing comprised of a first housing portion having a first inner surface and a second housing portion adjacent the first housing portion having a second inner surface defining a rotor cavity;   c. a first rotor within the rotor cavity having a first axis aligned with a first shaft having an axis of rotation, a front face comprising lobes and valleys, and a frusta-spherical radially outward surface;   d. a second rotor within the rotor cavity having a second axis offset from co-linear to the first axis, a front face comprising lobes and valleys which intermesh with the lobes and valleys of the first rotor;   e. an off-axis shaft aligned with the second rotor, fixed to rotate with the first shaft, and having an axis which is offset from the axis of the first rotor;   f. wherein the lobes and valleys of the first rotor are substantially in fluid tight seal to the lobes and valleys of the second rotor at least at two points during operation of the fluid flow apparatus; and   g. at least one shim positioned adjacent the off-axis shaft so as to re-position the first shaft relative to the second rotor non-collinear with the axis of the first shaft.   
     
     
         2 . The fluid flow apparatus as recited in  claim 1  further comprising:
 a. a first surface defining a reference void in the first housing portion in a surface adjacent the second housing portion; 
 b. a second surface defining a second reference void in the second housing portion in a surface adjacent the first housing portion; and 
 c. an alignment device inserted into the first reference void and second reference void with a precision fit. 
 
     
     
         3 . The fluid flow apparatus as recited in  claim 1  further comprising flat plane shim positioned between an upper surface of the first rotor and an inner surface of the first housing portion referencing the position of the first rotor to the inner surface of the first housing portion. 
     
     
         4 . A fluid flow apparatus comprising:
 a. a housing;   b. the housing comprised of a first housing portion having a first inner surface and a second housing portion adjacent the first housing portion having a second inner surface defining a rotor cavity;   c. a first rotor within the rotor cavity having a first axis aligned with a first shaft having an axis of rotation, a front face comprising lobes and valleys, and a frusta-spherical radially outward surface;   d. a second rotor within the rotor cavity having a second axis offset from co-linear to the first axis, a front face comprising lobes and valleys which intermesh with the lobes and valleys of the first rotor;   e. an off-axis shaft aligned with the second rotor, fixed to rotate with the first shaft, and having an axis which is offset from the axis of the first rotor;   f. wherein the lobes and valleys of the first rotor are substantially in fluid tight seal to the lobes and valleys of the second rotor at least at two points during operation of the fluid flow apparatus; and   g. at least one surface perpendicular to the axis of the second rotor formed by the process of material removal of the second rotor adjacent the off-axis shaft to re-position the first shaft relative to the second rotor non-collinear with the axis of the first shaft.   
     
     
         5 . A fluid flow apparatus comprising:
 a. a housing having a frusta spherical inner surface;   b. wherein the housing is fixed in space;   c. a stator having a center axis, and a front face comprising lobes and valleys;   d. the stator fixed to the housing;   e. a rotor having an axis, a front face comprising lobes and valleys, and a frusta spherical radially outward surface;   f. wherein the rotor nutates about the stator;   g. a gearing system indexed to the housing indexing the rotor position relative to the stator;   h. wherein the axis of the stator intersects the axis of the rotor;   i. wherein the axis of the stator is offset from the axis of the rotor by an alpha (α) angle;   j. the rotor having a front face with lobes and valleys configured to interoperate with the lobes and valleys of the stator; and   k. wherein the lobes and valleys of the stator are substantially in fluid tight seal to the lobes and valleys of the rotor at least at two points during rotation/precession of the rotor.   
     
     
         6 . The fluid flow apparatus as recited in  claim 5  wherein the number of lobes on the rotor are equal to the number of lobes on the stator such that there is no net rotation of the rotor relative to the stator. 
     
     
         7 . The fluid flow apparatus as recited in  claim 6  further comprising:
 a. a housing ring gear fixed to the housing; 
 b. a planet gear carrier fixed to an offset shaft aligned with and the axis of the rotor; 
 c. the gearing system comprises a plurality of planet gears rotating about an axis fixed to the planet gear carrier and indexed off of the housing ring gear; 
 d. a rotor ring gear attached to the rotor; 
 e. wherein the planet gears index the rotor ring gear; and 
 f. wherein the planet gears indexes the rotor relative to the stator. 
 
     
     
         8 . The fluid flow apparatus as recited in  claim 7  further comprising:
 a. an upper planet gear in a plane with the rotor; 
 b. indexed off of the housing ring gear; and 
 c. indexing the planet gears. 
 
     
     
         9 . The fluid flow apparatus as recited in  claim 7  further comprising:
 a. a double gear in a plane with the rotor; 
 b. indexed off of the housing ring gear via a bevel gear portion; and 
 c. indexing the planet gears via spur gear portion. 
 
     
     
         10 . A fluid flow apparatus made by the steps comprising:
 a. assembling a rotor sub assembly comprising:
 i. a first rotor having a frusta-spherical outer surface, lobes, valleys; and an axis perpendicular to a first rotor plane in which the tips of the lobes lie; 
 ii. a second rotor having lobes, valleys; and an axis perpendicular to a second rotor plane in which the tips of the lobes lie which is not parallel to the plane of the; 
 iii. a center ball attached at a radial center of the first rotor and second rotor; 
   b. following assembly of the rotor sub-assembly, inserting the rotor sub assembly into a housing comprising:
 i. a first housing portion having a frusta-sperical inner surface substantially identical in radius to the frusta-sperical outer surface of the first rotor; 
 ii. a second housing portion; 
   c. during assembly, attaching a shaft to the first rotor; and   d. mechanically adjusting the position of the shaft relative to the housing perpendicular to the first rotor plane.   
     
     
         11 . The process as recited in  claim 10  further comprising the steps of:
 a. following the step of inserting the rotor sub assembly into the housing, machining surfaces defining reference holes into the first housing portion and second housing portion; 
 b. removing the first housing portion from the second housing portion and inserting a flat plane shim there between; and 
 c. following the step of inserting the flat plane shim, reattaching the first housing portion to the second housing portion. 
 
     
     
         12 . The process as recited in  claim 10  further comprising the steps of:
 a. following the step of inserting the rotor sub assembly into the housing, rotating the shaft, while allowing the first housing portion to find it's natural position relative to the second housing portion; 
 b. machining surfaces defining reference holes into the first housing portion and second housing portion; and 
 c. tensioning the first housing portion to the second housing portion. 
 
     
     
         13 . The process as recited in  claim 10  further comprising the steps of:
 a. following the step of inserting the rotor sub assembly into the housing, machining surfaces defining reference holes into the first housing portion and second housing portion; and 
 b. inserting alignment devices into the reference holes to maintain radial alignment of the first housing portion to the second housing portion. 
 
     
     
         14 . The process as recited in  claim 13  wherein the alignment device is a dowel pin press-fit into the reference hole. 
     
     
         15 . The process as recited in  claim 13  wherein the alignment device is a threaded bolt threaded into a female threaded portion of the reference hole providing clamping force between the first housing portion and the second housing portion. 
     
     
         16 . The process as recited in  claim 13  wherein the alignment device is a threaded bolt positioned into a the reference hole and having a nut threaded onto the bolt providing clamping force between the first housing portion and the second housing portion. 
     
     
         17 . The process as recited in  claim 10  further comprising the step of material removal the second rotor adjacent and perpendicular to a rotation axis of an off-axis shaft to re-position the first shaft relative to the second rotor non-collinear with the axis of the first shaft.