Hybrid elastomer/metal on metal motor
A hybrid elastomer/metal on metal motor for a helical gear device includes a rotor and stator comprising a hydraulic motor that produces work when a working fluid is pumped therethrough. The improvement involves the stator being, for part of its length, a conventional or even wall stator, using an elastomer to form a seal against the moving rotor. The stator's remaining length comprises a profiled rigid surface that forms a seal directly with the moving rotor. This gives the motor the high efficiency of the elastomer sealing against the rotor, and simultaneously provides a backup of the stator's rigid section allowing continued motor operation at reduced efficiency, if the elastomer part failed in service. The invention also includes combinations of a regular disk stack with a rubber lining, a rigid material disk stack (or unitized element) and a circular rigid sleeve which react to rotor sideloading while permitting proper rotor orbiting.
1. A stator for a hydraulic motor having an elongated and helically-lobed rotor rotatably disposed therein, said stator comprising:
a cylindrical stator housing;
a first section within said cylindrical stator housing comprising a generally tubular configuration having elastically deformable elastomeric material defining a first helically convoluted chamber section; and
a second section adjacent said first helically convoluted chamber section and fixed within said cylindrical stator housing, said second section comprising:
a rigid section comprising a second helically convoluted chamber section matching said first helically convoluted chamber section, wherein the rigid section includes a saw tooth surface that creates a tortuous path for fluid flow between confronting surfaces of the rotor and the saw tooth surface, wherein said first and second helically convoluted chambers are rotationally aligned in a continuous helical relationship to form a helically convoluted chamber for supporting the rotor.
2. The stator of claim 1 wherein said rigid section comprises a unitized element comprising said second helically convoluted chamber section.
3. The stator of claim 1 wherein said rigid section comprises a plurality of rigid disks stacked together comprising said second helically convoluted chamber section.
4. The stator of claim 3 wherein said plurality of rigid disks are concentrically aligned face-to-face in a stacked helical relationship with one another with each of said plurality of rigid disks being rotated with respect to an adjacent one of said plurality of rigid disks progressively along a length of said plurality of rigid disks stacked in one direction of rotation to define said second helically convoluted chamber section.
5. The stator of claim 4 wherein said saw tooth surface is formed from the plurality of rigid disks.
6. The stator of claim 3 wherein said plurality of rigid disks are metal disks.
7. The stator of claim 1 further comprising a rigid sleeve that forms a third section adjacent said rigid section, said rigid sleeve defining a cylindrical chamber section for supporting the rotor and being aligned with said second helically convoluted chamber, said second and third sections forming a sequence of sections on a first side of said first section toward either a distal or proximal end of said cylindrical stator housing.
8. The stator of claim 7 further comprising a second side, opposite said first side of said first section, said second side comprising another rigid sleeve, adjacent said first section.
9. The stator of claim 7 further comprising a second side, opposite said first side of said first section, said second side comprising another rigid section, adjacent said first section.
10. The stator of claim 7 wherein another second section is positioned on a second side, opposite said first side, of said first section with another third section positioned adjacent said another second section toward the other one of said distal or proximal ends of said stator housing.
11. The stator of claim 7 wherein said second sections comprise a unitized element comprising said second helically convoluted chamber section.
12. The stator of claim 7 wherein said second sections comprise said rigid section having a plurality of rigid disks.
13. The stator of claim 12 wherein said plurality of rigid disks are concentrically aligned face-to-face in a stacked helical relationship with one another with each of said plurality of rigid disks being rotated with respect to an adjacent one of said plurality of rigid disks progressively along a length of said plurality of disks stacked in one direction of rotation to define said second helically convoluted chamber section.
14. The stator of claim 13 wherein said plurality of rigid disks forms a surface that comprises the saw tooth surface that, during nutative communication with the rotor, provides a labyrinth seal therebetween.
15. The stator of claim 14 wherein said plurality of rigid disks are metal disks.
16. The stator of claim 1 wherein said second section is located on a first side of said first section and wherein another second section is located on a second side, opposite said first side, of said first section.
17. The stator of claim 16 wherein another third section is located on said second side.
18. The stator of claim 1 further comprising a rigid sleeve defining a cylindrical chamber section for supporting the rotor.
19. The stator of claim 1 further comprising a rigid sleeve that forms a third section adjacent said first section, said rigid sleeve defining a cylindrical chamber section for supporting the rotor.
20. The stator of claim 1 wherein said generally tubular configuration having the elastically deformable elastomeric material comprises an elastically deformable liner that faces the elongated and helically-lobed rotor.
21. The stator of claim 20 wherein said generally tubular configuration having the elastically deformable elastomeric material comprises a supportive portion that is bonded to said cylindrical stator housing.
22. The stator of claim 21 wherein said supportive portion comprises another plurality of disks stacked together and having lobed shaped surfaces against which said elastically deformable liner is positioned.