Field of invention:-
The invention relates to a high temperature superconducting machine. In
particular, the invention relates to an integrated rotor hub for high
temperature superconducting motor/generator/synchronous condenser.
Background of invention:-
High Temperature superconducting (HTS) motor, consist of HTS field
windings in the rotor and the stator consists of air gap copper windings.
The HTSC motors are highly efficient, compact, lighter and noise free
motors. The HTS motor field coils are cooled with low temperature
Helium Gas (up to 30K). The helium gas is light gas (atomic number is
two) and leaks from even very minute orifice. So, the mounting
arrangement of the rotor HTS fields coils ( cooled by helium gas) of HTS
motor should be with less joints and good rigidity to avoid Helium gas
leakage and withstand the rotational forces. In conventional arrangement
each coil is mounted in each SS box which requires many joints
requirement and possibility of helium gas leakage is high. In this
invention the HTS field windings/coils are placed in an integrated rotor
hub for better cooling and minimum joint arrangement to avoid the
leakage of helium gas.
US20040017117A1 proposes a superconducting rotor with the field coil
supporting member. All the rotor field coils are cooled with conduction
cooling using single annular in and out pipe line at field coil supporting
member for effective cooling of field coils.
US20120274161A1 relates to a structure of the superconducting rotor

core. In this method superconducting field coils are mounted on the rotor
core. The rotor core is made up of a heavy solid member. The rotor core
comprises rod like members and each coaxially disposed in the cryogen
passage for effective cooling of field coils.
US20140217850A1: In this invention the superconducting coils are
mounted with yoke and bobbin with fibre connection type arrangement
for avoiding conduction type heat in leak. This method is incorporated for
better cooling effect to superconducting coils achieved with low heat in
leak through conduction.
In the present invention, a different technique, an is integrated rotor hub
type of structure arrangement for mounting the superconducting coils is
used for effective cooling of the field coils and minimum leakage of
helium gas.
Object of the invention:-
An object of the invention to develop a integrated rotor hub which can
hold the pole coils up to the speed of 500RPM.
Another object of the invention to develop a helium gas leak tight rotor
hub.
Yet another object of the invention to develop a helium gas leak light
rotor with reduced number of joints.
Brief description of accompanying drawing:-
It is to be noted, however, that the appended drawings illustrate only
typical embodiments of the present subject matter and are therefore

noted to be considered for limiting of its scope, for the invention may
admit to other equally effective embodiment. The detailed description is
described with reference to the accompanying figures. In the figures, the
digit(s) of a reference number that identifies the figure in which the
reference number first appears. The same number are used throughout
the figures to reference like features and components. Some
embodiments of system or methods in accordance with embodiments of
the present subject matter are now described, by way of example, and
with reference to the accompanying figures, in which:
Figure 1 shows a sectional side view of the rotor structure for HTSC
motor field coils in accordance to the invention.
Figure 2 shows a longitudinal sectional view of the rotor structure for
HTSC motor field coils in accordance to the invention.
Figure 3 shows a sectional views of field coil holding plates.
Figure 4 shows a three dimensional view of the rotor structure for HTSC
motor field coils in accordance to the invention.
Detailed description of the preferred embodiment:-
High temperature superconducting wire is used as the wire for making
field coils for High temperature superconducting (HTS) motor. These field
coils are required to cool up to 30K to generate the required flux for
operation of the motor. Helium gas of temperature 30K is used to cool
the field coils to obtain the superconductivity. To maintain the cryogenic
temperature at the field coils, the entire structure is surrounded by the
vacuum. The helium gas is a light gas (atomic number two) and leaks
from even very minute cracks. The structure should be made such a
way that, the helium gas should not enter into the vacuum space. This
can be achieved only with less joints and more reliable integrated
structure. In this invention, rotor hub was designed in such a way that,

the possibility of He gas leakage is very less and withstand the
centrifugal forces at the speed of 500 RPM.
Figure 1 illustrates a sectional side view of the rotor structure of the
HTSC motor field coils. According to an implementation of the present
subject matter, HTSC field coil hub (1) is provided to place the HTSC field
coil (2) and top plate (3) is fastened by means of bolts (4) to hold the
HTSC field coil (2). An enclosure (5) is provided to maintain the He gas
inside the HTSC field coil hub (1) without any leak to outside vacuum.
Figure 2 illustrates a sectional side view of the rotor structure of the
HTSC motor field coils. In another embodiment the figure, as explained
above, the HTSC field coil hub (1) is integral structure which receives the
HTSC field coil (2). On placing the field coil (2) within the HTSC field coil
hub(1) top plate (3) holds the coil which fastened by a countersunk bolt
(5) to the HTSC field coil hub (4). The enclosure (5) is welded to the rotor
structure to make provision for placing the entire structure under the
vacuum space.
The complete HTS field coil hub of HTS motor is made with one piece of
raw material without any joints. It also designed to withstand high
pressure helium gas (up to 5bar) with required gas flow provision while
rotation up to the speed of 500RPM and the design of enclosure for
arresting the helium leakage to vacuum. The holding plates are for
holding the field coils to withstand the centrifugal forces while rotation as
shown in Figure 4.
High Temperature Superconducting (HTS) motors consist of HTS
windings in the rotor and the air gap copper windings in the stator. This

technology will help in manufacturing of compact, lighter and noise free
motors. Motors with larger power ratings may be developed and the
superconducting generators can also be made thereby light weight and
higher efficiency.

We claim:
1. An integrated rotor hub for high temperature superconducting HTSC
field coil in a machine comprising:
a HTSC Field coils hub (1) which comprises a top plate (3) fastened by
means of fastening means (4) wherein the said top plate (3) is designed
to hold a HTSC field coil (2) atleast a HTSC field coil (2) disposed within
the HTSC field coil hub (1); wherein the Enclosure (5) and HTSC field coil
rotor hub (1) is constructed by a single price of raw material to limit the
leakage of a coolant and withstand rotational force.
2. An integrated rotor hub for high temperature superconducting HTSC
field coil as claimed in claim1, wherein the machine is generally a motor.
3. An integrated rotor hub for high temperature superconducting HTSC
field coil as claimed in claim1, wherein the coolant is Helium gas.
4. An integrated rotor hub for high temperature superconducting HTSC
field coil as claimed in claim1, wherein the field coil integrated rotor hub
can withstand the speed upto 500rpm.
5. An integrated rotor hub for high temperature superconducting HTSC
field coil as claimed in claim1, wherein the field coil integrated rotor hub
can withstand helium gas pressure upto 5 bar.
6. An integrated rotor hub for high temperature superconducting HTSC
field coil as claimed in claim1, wherein the arrangement of field coil is
made to provide efficient cooled.

7. An integrated rotor hub for high temperature superconducting HTSC
field coil as claimed in claim 1, as illustrated in the accompanying
drawings.