FIELD OF THE INVENTION
The present invention generally relates to the field of traction machines. In particular, the
invention relates to wireless measurement and monitoring of strain and acceleration on
ventilators of traction motor and temperature on short circuit ring of the rotor.More
particularly, the invention relates to a device for mounting of radio telemetry system on the
traction motor,instrumentation, mounting & cable routing of sensors, for strain and
acceleration measurement on ventilators of traction motor and temperature measurement on
short circuit ring of the rotor of the traction motor, to the radio telemetry system.
BACKGROUND OF THE INVENTION
Ventilators constitute one of the critical components of traction motor. As the weight of the
component is to be kept minimum, it is made up of Aluminium alloy casting. But it has to
withstand high centrifugal acceleration and shock loads. Any failure of the ventilator shall
lead to consequential damages to the motor resulting in long outages and huge
expenditure. Drive end (DE) and Non-drive end (NDE) ventilatorsare developed using LP
die casting process for improved mechanical properties. In order to validate the mechanical
strength of the ventilators and to ensure trouble free performance, it is required to
measure strain during rotation at full speed and full load. Also temperature of the rotor bar
is an important parameter for the motor and needs to be limited to the specified
temperature limit. Hence measurement and monitoring of the rotor bar temperature is
required for validation and satisfactory performance of the rotor.
Measurement on rotating components requires transmission of sensor data from rotating
components to the stationary data acquisition system. Data transmission is usually done by
using telemetry system and sometimes using slip rings as well. As the traction machine is

subjected to vibratory and shock loads due to track joints in actual operation during
running condition, use of slip rings creates signal noise. Measurement of strain,
temperature and vibration/shock subjected by the traction motor ventilators and rotor
cannot be done during operating conditions using the conventional methodology and
instrumentation.
In view of the hostile environment, space constraints and high speed rotating components
of the traction motor an improved device with highly compact state of art telemetry system
iscustomised and used to obtain the above data during operating conditions.
Measurement and monitoring of strain, acceleration and temperature signal from rotating
components is done using telemetry system, where the signal from the sensors mounted
on the rotating components is transmitted using rotating transmitter to be mounted on the
rotating shaft to the stationary receiver located nearby.
For mounting various components of telemetry system with in the available space in the
traction motor and routing the sensor cables from different parts of the rotor to the
telemetry end, a suitable device/arrangement is made/designed with the required
modifications on the traction motor rotor, air inlet duct and suitable design of
adaptor/fixtures. The device is successfully used for wireless measurement and monitoring
of strain, acceleration and temperature on rotating components of traction motor using
radio telemetry system.
US006042265A (Kliman et. al.), D1, discloses estimation of rotor temperatures in induction
motors, and more particularly, how to obtain such temperature estimates from various
physical and electrical motor parameters without using temperature sensors.These use only
computer calculations which are based on data readily available in the motor control centre.
Thus for any given motor, it is generally possible to predetermine a relationship between
rotor temperature and rotor resistance, so that by determining rotor resistance, rotor

temperature can be calculated. Rotor resistance, in turn, can be calculated from measured
information relating motor slip and motor torque. Any of several methods can be employed
for determining torque and slip. Temperature estimation can be obtained by use of
equivalent circuit methods, and additional relationships can be obtained from a simplified
equivalent circuit. The invention in D1 is about estimation of temperature of the rotor
without actual measurement of the temperature on the rotor in view of the difficulty to use
non-contact method such as thermocouple along with telemetry system.
Whereas the present invention is abouta device for wireless measurement and monitoring of
strain and acceleration on the ventilators of the traction motor in addition to the actual
temperature on rotating components of traction motor using radio telemetry system.
OBJECTS OF THE INVENTION
The object of the present invention is to provide an improveddevice for wireless
measurement and monitoring of strain, acceleration and temperature on rotating components
of traction motor using radio telemetry system.
Another object of the present invention is to measure strain and acceleration during rotation
at full speed and full load.
Another object of the invention is to measure and monitor the temperature of the rotor bar.
Yet another object of the present invention is the measurement of vibration/shock
subjected by the traction motor and ventilators.
SUMMARY OF THE INVENTION
The present invention discusses an improveddevice for wireless measurement and
monitoring of strain, acceleration and temperature on rotating components of traction motor
using radio telemetry system.

In order to validate the mechanical strength of the ventilators of traction motor and to
ensure trouble free performance, it is required to measure strain and acceleration during
rotation at full speed and full load. Also temperature of the rotor bar is an important
parameter for the motor and needs to be limited within the design limits. Hence
measurement and monitoring of the rotor bar temperature is required for validation and
satisfactory performance of the rotor.
As the traction machine is subjected to vibratory and shock loads due to track joints in
actual operation during running condition, use of slip rings creates signal noise.
Measurement of strain, temperature and vibration/shock subjected by the traction motor
ventilators and rotor cannot be done during operating conditions using the conventional
methodology and instrumentation.
In view of the hostile environment, space constraints and high speed rotating components
of the traction motor a highly compact and state of art telemetry system is used to obtain
the above data during operating conditions.
For mounting various components of telemetry system within the available space in the
traction motor and routing the sensor cables from different parts of the rotor to the
telemetry end, a suitable device/arrangement is made/designed with the required
modifications on the traction motor rotor, air inlet duct along with adaptor/fixtures.
The invention will now be explained in detail with an exemplary embodiment as depicted in
the accompanying drawings. There can however be other embodiments of the same
invention, all of which are deemed covered by this description.
BRIEF DESCRIPTIONS OF THE ACCOMPANYING DRAWINGS
The above brief description, as well as further objects, features and advantages, of the
present invention can be fully appreciated by reference to the following detailed

description. These features of the present invention will become more apparent upon
reference to the drawings, wherein:
Fig. A:2-D assembly view of the device with telemetry system for wireless measurement of
strain, acceleration and temperature on fans/ventilators and rotor of the traction motor
Fig. B:Drawing of the modified shaft/rotor of the traction motor
Fig. C: Drawing of the adaptor to be fixed to the rotor for mounting of the telemetry rotor
Fig. D: Drawing of the customized telemetry rotor
Fig. E: Drawing of the Modified air inlet duct for mounting of the telemetry stator induction
loop and telemetry radio antenna
Fig. F: Drawing of the Z shape fixture with two right angled arms for fixing of the telemetry
stator induction loop
Fig. G: Drawing of the telemetry stator induction loop
Fig. H: Air inlet cover for mounting on the air inlet and fixing of the telemetry radio antenna
Fig. I: Drawing of the telemetry radio antenna
DETAIL DESCRIPTION OF THE INVENTION
The present invention will be described in detail below with reference to an embodiment as
shown in the drawings. It is to be noted that the size, material, shape, relative position of
components, sensors and application to rotating equipment described in the embodiment
do not limit the scope of this invention unless otherwise particularly mentioned, and the
embodiment is just illustrative example.

As shown in Fig. A, the device invented for wireless measurement and monitoring of strain,
acceleration and temperature on rotating components of traction motor using radio telemetry
system contains the following components:
1. One modified shaft (1) of the traction motor with through central holes, radial holes
and thread at non drive end.
2. an adaptor (2) for mounting to modified shaft (1) at one end and telemetry rotor at
other end.
3. aCustomised telemetry rotor assembly (3) for mounting on the traction motorshaft
using theabove adaptor (2).
4. amodified air inlet duct (4)with circular opening for mounting of the telemetry stator
induction loop and one telemetry radio antenna.
5. Three Z shape fixtures(5) with two right angled arms for fixing of the telemetry
stator induction loop.
6. acustomised telemetry stator induction loop (6).
7. anair inlet cover (7) for mounting on the air inlet and fixing of one telemetry radio
antenna.
8. Two telemetry radio antennas (8-a and 8-b).
Shaft (1)of the traction motor as shown in the Fig. A and Fig. B, is modified with provision
of radial holes and axial through hole to route the sensors cable from DE ventilator, SC
Ring and NDE ventilator. Screw thread at the non-drive end of the shaft (1) is provided to
fix the adaptor (2).
The Adaptor (2), as shown in Fig. C, has through holes for fixing with the screw on the
shaft (1). Also the Adaptor (2) contains screw thread to fix thecustomized telemetry rotor
(3). The customised telemetry rotor assembly (3) as shown in Fig. D have through holes for

fixing with the adaptor using the screws. The diameter and length of the telemetry rotor
assembly (3) is customised to fit inside the traction motor space.
The modified air inlet duct (4) as shown in Fig. E contains a circular hole to have the
visibility during the installation of the telemetry system and contains two sets of through
holes for fixing of three Z shape fixtures (5) and the air inlet cover (7) using the nuts &
bolts. Three Z shapes fixtures (5) as shown in Fig. F are mounted on the air inlet duct (4)
at one end and hold the customised telemetry stator induction loop (6) in the desired axial
and radial position around the customised telemetry rotor assembly (3). The fixtures are
designed for accurate alignment of the telemetry stator induction loop (6)w.r.t the
telemetry rotor assembly (3), however washers can be used on the air inlet duct for finer
adjustment in the axial direction and clearance in the hole on the fixture (5) at stator is
provided for finer adjustment in the radial direction. It may be noted that the accurate
positioning of the stator induction loop (6) is to be ensured for transmission of power and
data to the transmitter on the telemetry rotor assembly (3).
Telemetry stator induction loop (6) as shown in the Fig. G is customised to have a diameter
to fit inside the traction motor space in the non-drive end without obstructing the air flow
inlet of the NDE ventilator.
In Modified air inlet duct (4), also a provision is kept for fitting one telemetry radio antenna
(8b) as shown in the Fig. A.
An Air inlet cover (7) as shown in Fig. H is provided to cover the opening on the Modified
air inlet duct (4) and also a provision is kept for fitting one telemetry radio antenna (8a) as
shown in the Fig. A.
Telemetry radio antenna (8) is shown in Fig. I. Telemetry radio antennas are for receiving
the sensors signals transmitted by telemetry rotor/transmitter and is sent to the data
acquisition system. There are two radio antennas. One is fixed on the modified air inlet
duct (4) and other one is fixed on the air inlet cover (7) as explained above and shown in
the Fig. A.

WE CLAIM:
1. An improved device for wireless measurement and monitoring of strain, acceleration
and temperature on rotating components of traction motor using radio telemetry
system, the improvement is characterized by comprising:
The existing shaft (1) of the traction motor is modified along the through
central holes, radial holes and thread at non drive end;
an adaptor (2) having one set of through holes for fixing with the screws on
the modified shaft (1) at one end and having one set of screw threads at the other
end for mounting of a customised telemetry rotor (3) having matching through
holes;
a telemetry rotor assembly (3),customised to fit inside the traction motor
space at the non-drive end;
a telemetry stator induction loop (6) customised with outer diameter suitable
for fitting inside the traction motor space in the non-drive end without obstructing
the air flow inlet for the NDE ventilator ;
a set of two telemetry radio antennas (8-a and 8-b);
an air inlet duct (4)modified to have a circular view port including two sets of
through holes for fixing at least three Z-shaped members (5) for mounting of said
telemetry induction loop (6) and also a provision is kept in air inlet duct (4) for fitting
one telemetry radio antenna (8a);
an air inlet cover (7) which is mounted on said modified air inlet duct (4) and
said telemetry radio antenna (8b) is mounted on the air inlet cover (7).
2. The device as claimed in claim 1, wherein the shaft (4) is modified for,
instrumentation, cable routing of sensors to the radio telemetry system and for
wireless strain and acceleration measurement on ventilators of traction motor and
temperature measurement on short circuit ring of the rotor of the traction motor.

3. The device as claimed in claim 1, comprising of the said modified shaft (1)with
provision of radial holes and axial through holes to route the sensors cable from DE
ventilator, SC Ring and NDE ventilator.
4. The device as claimed in claim 1, wherein the three Z shape fixtures (5) have two
right angled arms for fixing of the said telemetry stator induction loop (6).The
fixtures (5) are designed for accurate alignment of the telemetry stator induction
loop (6) w.r.to the telemetry rotor assembly (3), however provision for finer
adjustment in the axial direction is made by using washers on the air inlet duct for
fixing fasteners. Also the fixture (5) contains clearance through holes which are used
for fastening with the stator (6) using the fasteners and the clearance provided can
be used for finer adjustment of the stator (6) in the radial direction.
5. The device as claimed in claim 1, wherein the telemetry radio antennas (8a and 8b)
are employed for receiving the sensor signals transmitted by the telemetry rotor (3)
and sending said received signals to a data acquisition system.