FIELD OF INVENTION
The invention relates to the development of a connector for liquid-cooled stator winding
of electrical machines, in particular, turbo Alternator reducing overall size and improving
performance.
BACKGROUND OF THE INVENTION& PRIOR ART
Cooling of the windings is very critical in the design for sizing of the Turbo Alternator.
Liquid cooled windings aid in reducing the size and improve the performance of the
Turbo Alternator. Liquid connection and electrical connections in the winding are critical
to design in the available space. Generally, connector joints are made specifically for
only liquid flow to the windings and electrical joints are made separately by brazing
copper lugs. In the proposed design, connector is designed accommodating both the
electrical and liquid connections. Electrical connection is made between the two
connectors through a bolted joint. This method of connector joint aids in reduction in
length of the winding bar and there by reduction in size i.e. length of the Turbo
Alternator.
US005796189A describes the bar to bar electrical joint is made by brazing. In the
present invention, the bar to bar electrical joint is established by bolting and the coolant
flow is through nipple.

US20070158397A1 comprises to brazing generator armature winding bars to hydraulic
header clips, and to a method for sealing an armature winding bar to its header clips to
prevent or reduce corrosion due to coolant liquid flowing through the end fitting and
the armature winding bar. In the present invention, the bar to bar electrical joint is
established by bolting.
OBJECTS OF THE INVENTION
The main object of this invention is to make a connector, which accommodates both
the electrical and liquid connections of the winding.
Another object is to reduce the length of the stator winding.
A still another object is to optimum utilization of the space.
Further object is to minimize the complexity during the assembly by replacing
brazing/soldering with bolted joint.
SUMMARY OF THE INVENTION
In liquid-cooled stator winding, the main challenge is in liquid connection and electrical
connection to the stator winding bars. Connector is brazed at the end of the stator bar

for making the liquid connections. For electrical connections, the connecting pipe
between the bars is made up of conducting material, which will carry both electrical
current and liquid also. However, with the increase in the current rating of the
generators, the pipes cross-sections will increase i.e. thickness has to be increased.
Bending of thicker pipes in very limited space is difficult. Hence, a separate connection
for electrical and liquid is required. The present invention proposes a connector capable
of making both electrical and liquid connection.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure-1: shows cross sectional view of bar to bar connection along with strip cross
section.
Figure-2(A): shows an assembly of connector, of nipple for hose connection, high-
pressure hose, and locking hardware.
Figure-2(B): shows bolted connection between bar to bar.
Figure-3(A): shows top bar connector.
Figure-3(B): shows bottom bar connector

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE
INVENTION
The proposed invention has a connector (1) with provision for terminating the hollow
conductor strips (6) of the winding bar on one side and nipple (2) on the other side.
Cooling fluid enters in to the connector through the nipple and then in to the hollow
copper conductors.
Connector for top bar as shown in Fig.3A is designed with connection provision for
bolted joint at the bottom side and the connector for bottom bar as shown in Fig.3B is
designed with connection provision for bolted joint at the top side.
The connecting surfaces (7) of the connectors (1) are provided with holes (5) for fixing
the bolts (4).
In liquid cooled stator winding the basic challenge lies in the liquid as well as electrical
connection to the stator winding bars and connectors are brazed at the end of the
stator bar for making the liquid connections.
As in prior art the connecting pipe between the bars is made up of conducting material,
which may carry both electrical current and liquid, while with increase in the current
rating of the generators, the cross sections of the pipes gets increased, which becomes

very difficult in bending the thicker pipes in limited space. Hence requirement for a
separate connection for electrical and liquid has been felt.
The present invention therefore proposes a novel connector capable of making both
electrical and liquid connection, wherein insulated hose (3) has been introduced for the
passage of hollow electrical conductor strips (6) and the cooling fluid.
The Fig. 1 depicts a clear view for cross section of bar to bar connection along with
strip cross section, wherein the connection of bolt (4) through holes (5) make the
process of connection very simple in the connector (1).
The Fig. 2(A) & 2(B) represents more clear view of connector (1), nipple (2) for
connection of high pressure hose (3) and the locking hardware (4) through holes (5) for
bolted connection of the bars.
The Fig. 3(A) & 3(B) shows in isolation top bar connector and bottom bar connector in
isolation fitted with nipple.

WE CLAIM
1) A method of connection for liquid cooled stator winding of electrical machines
comprising :
- Connector (1)
- Nipple (2)
- Insulated liquid hose (3)
- Fixing bolt (4)
Characterized by accommodation of both electrical and cooling fluid connection.
2) The method as claimed in claim 1, wherein the connector (1) for top bar having
connection provision for bolted joint at the bottom side and connector for bottom
bar having provision for bolted joint at the top side are joined through fixing hole (5)
at the connecting surface (7) by fixing bolt (4), in half-lap joint between top bar and
bottom bar.
3) The method as claimed in claim 2, wherein the nipple (2) is disposed in connector
(1) for connection of high pressure hose (3).

4) The method as claimed in claim 3, wherein the insulated high pressure hose (3)
fitted in the nipple (2) making passage for the cooling fluid and hollow conductor
strips (6)
5) An assembly for connection for liquid cooled stator winding of electrical machines
comprising connector (1), nipple (2), insulated liquid hose (3), fixing bolt (4),
configured to accommodate both electrical and cooling fluid connection.