This invention relates to helical turbo charger.
PRIOR ART
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Nowadays, it is emphasised on improving the fuel consumption of an automobile due
to global move to reduce COa emissions. Ideally an engine should be able to
simultaneously offer a high power density & lower fuel consumption. I I
High pressure turbo charging is indispensible to improve the fuel consumption of an
engine by enabling downsizing & lean boost.
The exhaust gas with the kinetic energy from the exhaust port of the cylinder passes
through inlet of turbocharger, which hits the turbine wheel & is vented to the CAT &
tail pipe.
WORKING OF TURBOCHARGER
Turbo charger utilizes the exhaust gas kinetic energy & converts to
pressure energy or rotational force.
Exhaust manifold brings exhaust from cylinders to turbocharger.
Exhaust gases impinge on turbine blades & rotate it.
Turbine spins the compressor wheel mounted on the same shaft.
Compressor takes air from atmosphere & delivers to cylinder at high
pressure.
The turbocharger is having advantages given hereinbelow:-
Improved power/ weight ratio.
Better power and torque characteristics.
Lower emission.
Lower weight and a compact engine package. I
Lower fuel consumption.
Lower pumping loss.
However, the single stage turbo charger is associated with the following
disadvantages:
Restricts pressurizing at low loads/engine speed
Turbo lag at low end RPM i.e. at low end RPM car does not speed up at first,
but later it lunges.
Poor performance.
Kinetic energy of the exhaust gas is not predominantly used.
Disadvantages of 2 stage turbo charger and variable Geometry Turbocharger
High cost & more complex.
Hence, there is a requirement for turbocharger with wide flow range. Therefore, the
present invention has been proposed to address the aforesaid drawbacks.
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OBJECTS OF THE INVENTION
An object of the present invention is to provide helical turbo charger which overcomes
disadvantages associated with the prior art. i I
Another object of the present invention is to provide helical turbo charger with higher I I efficiency turbo, Rising pressure ratio, Rising rotational speed, Rising power and
Improvement of surge limit/low end drivability/More boost even at low rpm.
STATEMENT OF INVENTION I
According to this invention, there is provided helical turbo charger comprising a rotor shaft provided with a helical shape, which is disposed between turbine housingr oatnodr !I,
compressor housing. I
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the
ensuing description when read in conjunction with the accompanying drawings and
wherein:
Fig. 1 shows: Helical turbo charger according to the present invention.
Fig. 2 shows: One embodiment of helical shaft of the present invention.
Fig. 3 shows: Another embodiment of helical shaft of the present invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS:
I
The present invention discloses helical turbo charger. Now, reference may be made to
fig. 1, wherein a rotor shaft (1) connects turbine housing (2) and compressor housing 1
The rotor shaft (1) is provided with a helical shape with convergent and divergent 1
profile (C and D) as shown in fig. 2. The helical path is atleast one i.e. one or more,
depending upon the phase shift, diameter of the shaftlrotor, diameter of the helical
path, rotational force requirement etc.
The profile of the shaft according to the instant invention helps in carrying a part of
the exhaust gas through said profile in the same direction of rotation of the shaft.
This results in conversion of exhaust gas pressure and kinetic energy into useful
work, which causes increased rotation of the shaft and reduction of turbo lag.
Now, reference may be made to fig. 3 indicating another embodiment of helical shaft
of the present invention.
Further, magnet (s) may be provided across the rotating shaft (1) to generate
electrical energy. This can be used by the motor arrangement to control by
increasing/decreasing/maintaining the speed of the compressor.
Turbine housing/cover (2):
It comprises atleast one channelltubing for supplying exhaust gas, at least one I discharger channel/tubing for delivering the exhaust gas & at least one bypass I
channelltubing to deliver a part of exhaust gas to the helical geometry shaftlrotor, I wherein one end of rotor shaft extends into said turbine housing to support the 1
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I turbine wheel. I I
Turbine wheel/rotor (3) I I
Turbine wheel housed inside the turbine housing is axially mounted/fixed/fastened
on the rotor shaft. The exhaust gas with the kinetic energy VI received' through at
least one channelltubing of turbine housing strikes the periphery of the turbine
wheel, propels the turbine wheel & leaves via discharge channelltubing. The gas,
which is restricted by the turbine's flow cross-sectional area, results in a pressure
and temperature drop between the inlet and outlet. This pressure drop is covered by
the turbine into kinetic energy to drive the turbine wheel. Nozzle rings, maylmay not
be used to focus the exhaust gas to flow over the turbine blades, which is also used
to reduce vibrations.
Compressor housing/cover (4)
It is connected to the bearing housing including at least one air supply channel (may
be axial/circumferential to the compressor wheel) for supplying air to be compressed
& at least one discharge channel for delivering the compressed air. Other end of rotor
shaft extends into the compressor housing to support the compressor wheel.
Compressor Wheel/Rotor (5)
Compressor wheel housed inside the compressor housing is axially
mounted/f~ed/fastened on the rotor shaft. The atmospheric air from at least one air
supply channel is compressed & discharged through at least one discharge channel.
The compressed air is supplied to the engine may be via intercooler, throttle housing,
dump,etc., which in its turn collects the air and slows it down further before it
reaches the cylinder of the engine.
Bearing Housing/Centre Housing Rotating Assembly (6)
Bearing Housing: It is an intermediate between the compressor housing & turbine
housing & turbine housing, which connects the compressor housing & turbine
housing. It consists of bearingslbearing system to hold & support the helical
geometry rotor/ shaft, stop the axial movement (if any in case) & may have seal/
sealing rings arrangement to reduce/prevent mixing of the exhaust gas with oil in the
bearing housing/exhaust gas oil mixture mixing with compressed air in the
compressor housing.
The bearing housing can have at least one supply channel for entry of oil into the
bearing housing for lubricating the bearingslbearing system & at least one drain
channel for draining the oil to the oil sump.
The bearing housing can have cooling water circuit based on the type of engines.
The bearing housing can have at least one inlet (supply) channelltubing for the bypassed
exhaust gas to enter into the helical geometry shaft & the exhaust gas
passing via the helical geometry shaft can be discharged through at least one
discharge channelltubing in the bearing housing. This may be connected to exhaust
gas tubing to the CAT/connected to EGR through oil separator unit located down
stream.
Cooling Water Circuit
It may be used inside the bearing housing offsetting/surrounding the helical
geometry shaft in case of gasoline engines, since the exhaust gas temperature is high
in case of gasoline engines & may reduce the life of turbocharger in the long run.
Hence in order to improve the durability life of turbocharger, cooling water circuit
may be used to enhance additional cooling to the turbo system.
Actuator & Waste Gate System
The waste gate is a gate (of flap) that opens to divert waste (excess pressure from the
turbo) into the exhaust or the atmosphere rather than into the turbo. In this way, the
waste gate serves to regulate and protect the engine and turbocharger from excess
boost. When boost pressure reaches certain limit the flap/actuator of the waste gate
opens and diverts pressure away from the turbine wheel. Internallexternal waste
gate system may be used in this application.
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The variable (Helical) Geometry Turbocharger with motor actuation is effective at
improving the low speed torque (eliminating the surge limit) & transient response of
an engine.
The Helical shape fluid circuit/ turbo charger is used to rotate the compressor.
The charge/fluid/gas when passes through the helical shape rotates the shaft or the
body through which it passes, thereby generating the rotary motion.
The revolutions per minute achieved by turbocharger using the helical structure
along with centrifugal concept may be higher than the turbocharger with only the
centrifugal concept, wherein the fluidlgas pushes the surface it hits &
simultaneously the fluidlgas is pushes by the adjacent flowing gaslfluid particles
constantly when engine is ON, whereas in the existing rotary wheel type or
centrifugal concept, the exhaust gas after hitting the vaneslblades just leaves or
passes off the turbo charger circuit.
The permanent magnets installed over the rotating shaft, as a result of rotary action,
leads to the flux cuts, followed by generation of the electrical energy, which can be
storedlused to run the motor. This can be used .to rotate the shaft of low stage
I compressor or high stage compressor to meet the drivability demand at low speed.
This motor actuated turbocharger offers the possibility of resolving the problems of
insufficient low torque and the low transient response - which are being considered
as weak points of a present turbocharged engine. Further, the motor generator circuit
also helps in controlling (increasingldecreasing) the speed of the compressor based
on programming in ECU. This causes a significant improvement in fuel consumption.
In other words, generated energy can be used to run the motor so as to control the
over boost of the turbocharger at high speed & low stage compressing can improve
the surge phenomenon.
The kinetic energy of the gas after hitting the turbine wheels does not reduce very
predominantly (VI -> V2) (i.e., V2 still posses high kinetic energy).
The usable kinetic energy of the gas (i.e., V2) is further utilized.
The exhaust gas with K.E (V2) passes through the intercooler (with / without
accumulator - to stabilize the flow) to reduce the temperature & to gain density &
then fed into a helical geometry shaft.
(
As a result the gas passing through the helical geometry causes the shaft (Helical
Geometry Shaft) mounted on a bearing to rotate faster in addition to the rotation by
the turbine wheel.
The reason for fastness is the helical angle (a) geometry cut section inside/outside
the shaft, which is of convergent divergent nozzle shape, thereby accelerating the flow
(may include supersonic flow).
As a result of gas flow inside/outside the shaft & hitting the surface of the shaft (it
creates a rotating force/ tangential/normal force) "F", propels the shaft to rotate.
The rotation of shaft at lower rpm can be increased from a1 to m2.
I Test Result
As a result of increased rpm the compressor on the other end of shaft rotates at a
faster speed than a regular speed.
As a result the turbo lag, which is an existing problem can be eliminated.
The performance of the vehicle at low end rpm can be improved.
The exhaust gas may be mixed with fresh gas (sometimes) in order to reduce
emissions.
Final
Turbi
* =>Simulation result interpreted from GT Power Software V7.2
Advantageous features
- Use of shaft connecting the turbine and compressor as a secondary boost
source.
- Optimal use of the exhaust kinetic energy for secondary boost, which favors to
eliminate the low end turbo lag.
- Higher efficiency turbo.
- Rising pressure ratio.
- Rising rotational speed.
- Rising power
- Improvement of surge limit/low end drivability/More boost even at low rpm
- Optimized utilization of the kinetic, pressure energy of the exhaust gas (by
optimization of length of helical shaft).
- Using convergent divergent section inside the rotating shaft creates more speed
of exhaust gas even at low rpm.
- Cost can be optimized (since the invention eliminates use of high cost 2 stage
turbo charger & variable geometry turbocharger).
It is to be noted that the present invention is susceptible to modifications,
adaptations and changes by those skilled in the art. Such variant embodiments
employing the concepts and features of this invention are intended to be within the
scope of the present invention, which is further set forth under the following claims:-
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WE CLAIM:
1. Helical turbo charger comprising a rotor shaft provided with a helical shape,
which is disposed between turbine housing and compressor housing.
2. Helical turbo charger as claimed in claim 1, wherein the helical rotor shaft is
provided with the convergent and divergent profile.
3. Helical turbo charger as claimed in claim 1 or 2, wherein the helical rotor shaft
is provided with a profile as shown in fig. 3.
4. Helical turbo charger as claimed in any of the preceding claims, wherein the
helical path of the shaft is atleast one.
5. Helical turbo charger as claimed in any of the preceding claims, wherein
magnet may be provided across the shaft to generate electrical energy.
6. Helical turbo charger as claimed in any of the preceding claims, wherein the
profile of the shaft helps in carrying a part 'of the exhaust gas through said
profile in the same direction of rotation of the shaft, which leads to increased
rotation of the shaft and reduction of turbo lag.
7. Helical turbo charger as claimed in any of the preceding claims, wherein the
turbo charger is associated with the advantageous features and test result
such as herein described.
8. Helical turbo charger substantially as herein described with reference to the
accompanying drawings.