Compact, modular, pump or turbine with integral modular motor or generator and coaxial fluid flow
A coaxial pump or turbine module includes an integral, modular motor or generator comprising a magnet structure containing radial or axial permanent magnets and/or induction coils detachably fixed to a rotor, and a stator housing detachably fixed to the module housing. Working fluid is directed axially through a flow path symmetrically distributed within an annulus formed between the module housing and the stator housing. The stator housing can be cooled by the working fluid, or by a cooling fluid flowing between passages of the flow path. The flow path can extend over substantially a full length and rear surface of the stator housing. A plurality of the modules can be combined into a multi-stage apparatus, with rotor speeds independently controlled by corresponding variable frequency drives. Embodiments include guide vanes and/or diffusers. The rotor can be fixed to a rotating shaft, or rotate about a fixed shaft.
1. A modular sealless pump or turbine system, comprising:
a plurality of pump or turbine modules including a first pump or turbine module and a second pump or turbine module, the first and second pump or turbine modules each respectively comprising:
a module housing surrounding the respective module, the module housing having a first end and an opposite second end, the first end being open and the second end having a socket;
a rotor suspended on a shaft within the module housing, the rotor disposed proximate the first end, and the rotor having a hollow protrusion;
a motor within the module housing configured to drive a rotation of the rotor, or a generator within the module housing configured to be driven by rotation of the rotor, the motor or generator comprising:
a stator within a sealed stator housing, the stator being axially offset from the rotor, the stator comprising at least one electromagnet directed axially and proximally toward the rotor, and
a plurality of magnetic devices assembled in a magnet structure that is removably constrained to be axially fixed and rotationally cooperative with the rotor, the magnetic devices being configured by the magnet structure to pass in axial proximity to the at least one electromagnet as the rotor rotates;
a flow path symmetrically distributed about the stator housing between the stator housing and the module housing, the flow path directing a flow of a working fluid between the first and second end,
wherein the flow of the working fluid that flows through the flow path is required to flow through the hollow protrusion and the socket;
the second end of the module housing of the first pump or turbine module being configured to form a first direct attachment with the first end of the module housing of the second pump or turbine module to close the open first end of the second pump or turbine module, and the first end of the module housing of the first pump or turbine module being configured to form an alternative second direct attachment with the second end of the module housing of the second pump or turbine module to close the open first end of the first pump or turbine module,
wherein said first direct attachment includes inserting the hollow protrusion of the first module into the socket of the second module and wherein said second direct attachment includes inserting the hollow protrusion of the second module into the socket of the first module,
the modular sealless pump or turbine system further comprising:
an inlet having a second socket, the inlet configured to seal the open first end of either of the first or second pump or turbine modules and configured to allow the hollow protrusion of either of the first or second turbine modules to be inserted into the second socket; and
an outlet having a second hollow protrusion, the outlet configured to directly attach to the second end of either of the first or second pump or turbine modules wherein the second hollow protrusion configured to be inserted into the socket of either of the first or second pump or turbine modules.
2. The system of claim 1 , wherein the flow path is an annular flow path surrounding the stator housing.
3. The system of claim 1 , wherein the flow path comprises a plurality of flow passages arranged symmetrically about the stator housing.
4. The system of claim 1 , wherein the rotor is suspended by a fixed shaft, and the rotor is configured to rotate about the shaft.
5. The system of claim 4 , wherein the rotor is supported on the fixed shaft by a pair of bearings, one of which maintains an axial position of the rotor while the other of which provides radial support of the rotor.
6. The system of claim 4 , wherein the rotor is supported axially and radially on the fixed shaft by a combined radial and one-way thrust bearing.
7. The system of claim 4 , wherein the rotor is supported on the fixed shaft by at least one bearing that is lubricated by the working fluid.
8. The system of claim 4 , wherein the fixed shaft is fixed to the stator housing by threaded attachment.
9. The system of claim 1 , wherein the magnetic devices are permanent magnets.
10. The system of claim 1 , wherein the magnetic devices are squirrel cage coils.
11. The system of claim 1 , wherein the flow path extends over at least 50% of an outer surface of the stator housing, and at least 90% of the working fluid that flows through the first or second pump or turbine module is in direct thermal contact with the stator housing.
12. The system of claim 1 , wherein the first or second pump or turbine module is configured such that all of the working fluid that flows through the first or second pump or turbine flows through the flow path.
13. The system of claim 1 , further comprising: thermal insulation interposed between the flow path and the stator housing; and a cooling fluid path formed between the thermal insulation and the stator housing, the cooling fluid path being in thermal communication with the stator housing and configured to enable an exchange of heat between the stator housing and a cooling fluid flowing through the cooling fluid path.
14. The system of claim 1 , wherein the at least one electromagnet of the stator is directed toward a radial periphery of the rotor, and the magnetic devices are fixed near the radial periphery of the rotor.
15. The system of claim 1 , wherein the at least one electromagnet of the stator is directed toward a side of the rotor, and the magnetic devices are fixed to the side of the rotor or to a disk that is coaxial with and proximal to the side of the rotor.
16. The system of claim 1 , wherein the magnet structure of at least one of the first and second pump or turbine modules is sealed, thereby excluding the working fluid from reaching the magnetic devices.
17. The system of claim 1 , wherein the motors or generators of the first and second pump or turbine modules can be independently controlled so as to cause the corresponding rotors to rotate at different rates.
18. The system of claim 17 , wherein the two, independently controlled motors or generators are controlled by separate variable frequency drives.
19. The system of claim 1 , wherein the first and second pump or turbine modules are configured such that the modular sealless pump or turbine system as a whole is able to continue functioning as a pump or as a turbine despite failure of at least one of the first or second pump or turbine modules included in the modular sealless pump or turbine system.
20. The a system of claim 1 , further comprising control electronics that provide shared support to at least the first and second pump or turbine modules.
21. The system of claim 1 , further comprising at least a third pump or turbine module.
22. The system of claim 1 , wherein the magnet structure in each of the first and second pump or turbine modules is sealed, thereby excluding the working fluid from reaching the magnetic devices.