The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:
PRIOR ART
The Work taken up here proposes the usage of an Induction machine with suitable accessories to act as an integrated starter alternator for automotive applications. The complete system would be responsible for starting the engine initially taking electrical power from the battery and once the engine is running, start supplying the electrical power requirement of the Vehicle and simultaneously charge the battery.
Existing Conventional systems uses a dedicated Direct Current starter motor for starting the Engine and a dedicated Alternator for feeding the Electrical load of the Vehicle as well as charge the battery. Also only one of either the Alternator or the starter is operated at any given point of time.
Modern Automobiles have come up with an integrated starter alternator which acts as both the starter as well as alternator for performing the starting and charging functionalities. They are either Direct Current machines or Synchronous machines and also they are either Crankshaft mounted or Belt driven. Typical crankshaft mounted integrated starter alternators are in the form of thin discs transferring the starting torque directly to the engine without any gears as well as are driven directly by the engine during alternator mode.
OBJECT OF THE INVENTION
A three phase squirrel cage Induction Machine with suitable control accessories is proposed to perform the functionalities of starting an automotive engine and generating power once the engine is started. The proposed system would employ a gear driven approach to transfer mechanical power between the Engine shaft and the shaft of the IMSG (Induction Machine based integrated Starter Generator).

SUMMARY OF THE INVENTION
A system for integrated starter alternator for internal combustion engine with an induction machine and a gear drive arrangement having one starter gear that meshes with the flywheel during starter mode and another set of Alternator gears for the Alternator mode of operation. There is a synchromesh collar in the shaft of the starter alternator to shift the mode of operation by locking the synchromesh collar with either set of gears.
Gear shift mechanism (5) to move the collar between the starter gear and the Alternator gear in the shaft of the Induction Machine based Starter Generator (IMSG).
Control Electronics (9) to convert DC supplied by the battery (4) to the AC for motoring operation and also the AC output of the Induction Machine based Starter Generator (IMSG) back to DC.
A dedicated Electronic Control Unit (ECU) for controlling the operation of the Gear shift mechanism and also to monitor the control electronics. It also gets inputs from the battery (4), Engine ECU (1), Electrical load (3) of the vehicle.
The invention proposes the usage of an induction machine with suitable accessories to act as an integrated starter alternator for automotive applications. The complete system would be responsible for starting the engine initially taking electrical power from the battery and once the engine is running, the same machine acting as an alternator supplying the electrical power requirement of the vehicle and simultaneously charge the battery (4).
DESCRIPTION OF THE INVENTION:
The proposed system includes an induction machine drivingly connected with the crankshaft of the engine by a gear train (6) arrangement alongwith a gear shift mechanism (5). The system with a three phase induction machine is selectively capable of operating as a starter motor for transmitting starting torque to the engine and as an alternator, generating electrical power when driven by the said engine for supplying the electrical loads of the vehicle as well as charge the battery.
The gear train (6) arrangement coupling the Induction machine shaft and the crank shaft comprises a first set of starter gears which mesh with the flywheel (8) during starter mode and a second set of alternator gears for alternator

mode of operation alongwith a synchromesh collar on the shaft of induction machine to changeover the mode of operation from the starter mode to the alternator mode or vice versa by locking the synchromesh collar with the corresponding set of gears. The system also includes a gear shift mechanism (5) for movement of collar between starter gears and alternator gears along the shaft of induction machine.
The system also has control electronics (9) for conversion of DC supplied by battery (4) to AC for motoring operation and also for conversion of AC supplied by induction machine to DC during generation mode of operation.
The system has plurality of sensors connected with the engine sending signals indicative of engine performance to the engine ECU (1). The engine speed sensor is a sensor for monitoring the rotational speed of the engine and this sensor is connected to engine ECU (1). The system has a dedicated ECU (2) known as IMSG ECU for mode-shifting, operably connected with the battery (4), engine ECU (1) & load (3) to receive signals and monitors the gear shift mechanism (5) and the control electronics (9). The engine ECU (1) and IMSG ECU (2) are so connected that, the engine ECU (1) commands through IMSG ECU (2) for starting the engine. The induction machine IMSG ECU (2) commands gear shifting mechanism to lock the synchromesh collar with the starter gear and commands the control electronics (9) to supply designated AC voltage and frequency to the induction machine which is now in starter mode. The torque delivered by the starter gets multiplied by starter gear ratio and is applied at the engine shaft. After a period from start, when the engine reaches a predetermined speed, which is read by the engine speed sensor, engine ECU (1) commands the IMSG ECU (2), which in turn commands the gear shifting mechanism to unlock the synchromesh collar from starter gear and instead to lock the synchromesh collar with alternator gear. The engine now drives the induction machine which is shifted now to alternator mode and output of induction machine is 3-phase AC fed to control electronics (9). The IMSG ECU (2) commands the control electronics (9) to convert the AC and supply designated DC voltage to the battery (4) and to charge the electrical loads. The IMSG ECU (2) also regulates the voltage and frequency, based on engine speed, battery (4) condition and load (3).

When the engine is idling beyond a predetermined time period, the engine ECU (1) shuts off the engine, thereby IMSG ECU (2) in turn commands the gear shifting mechanism to unlock the synchromesh collar from the alternator gear and instead to lock the synchromesh collar with the starter gear. Hence the ability to shut off the engine while it is idling for a longer time and start the engine within a very short duration of time is achievable with the proposed system due to the virtue of very short response times in switching between the starter and alternator mode of operation. This short response time in switching between the modes is realizable because only the collar is moved for a very small distance between the alternator gear and the starter gear in the shaft of the induction machine
OPERATIONAL DESCRIPTION OF THE PROPOSED SYSTEM:
The proposed system uses a 3 phase Squirrel Cage Induction machine as a starter initially in the starter mode and later as an Alternator in the generation mode.
Starter Mode:
The Engine ECU (1) commands the IMSG ECU (2) for starting the Engine.
The IMSG ECU (2) gives a command to the Gear shifting mechanism (5) to
lock the synchromesh collar with the starter gear.
The IMSG ECU (2) controls the Inverter operation as well as the frequency in
such a way that the machine is fed with the designed Voltage and Frequency.
The torque delivered by the motor gets multiplied by the starter gear ratio and
is applied at the engine shaft.
Once the engine is started and is stable the IMSG ECU (2) sends a command
to the Gear shifting mechanism (5) to unlock the synchromesh collar from the
starter gear.
Alternator Mode:
The IMSG ECU (2) sends a command to the Solenoid to lock the Synchromesh collar with the Alternator gear.
In this mode of operation, the machine is driven by the engine through the alternator gear and the frequency of the supply is adjusted such that the machine operates as a generator.

The output of the IMSG is a three phase Alternating Current Voltage which is rectified and fed to the battery as well as to the Electrical load of the Vehicle. The Voltage Regulation and the Frequency Regulation are taken care by the IMSG ECU (2) based on the Engine Speed and the State of health of the battery (4), Load of the Vehicle as Inputs.
Start-Stop Mode:
During "Start-Stop" also the mode of operation is chosen by the ECU. Here,
when the engine idles for more than the pre-calculated time period, the ECU basically shuts-off the Engine in order to improve the fuel efficiency. Then again Operates the machine in the Starter mode to start the engine. This can be achieved with this setup as the shifting from one mode to the other can be performed easily due to virtue of very short response time in switching the mode. This leads to reduction in Fuel wastage and emissions.
Process of Mode Shifting:
The Logic stored in the IMSG ECU determines the current mode of operation based on the Engine Speed , state of health of the battery, Load of the vehicle which are taken as Inputs.
The switching of the mode is performed by commanding the Gear shift mechanism to move the synchromesh collar to lock with the required gear. In parallel, the IMSG ECU also monitors the operation of the Control Electronics to achieve desired Voltage and frequency.
Advantages of the proposed system over the Conventional Integrated starter Alternators:
It would be very cost- effective solution when compared to the Direct-current
integrated starter Alternators or the Synchronous machine based integrated
starter alternators.
As there are no brushes involved in the proposed system, there is no
requirement of replacement of the brushes due to mechanical wear and tear.
Thus calls for very less maintenance.
As gear trains are used between the shaft of the IMSG and the crank shaft,
with a suitable gear ratio the torque delivered to the engine can be improved.
With the usage of the gears the risk of belt being cut in the Belt driven ISG
can be avoided.

As there are no brushes involved in the proposed system, hence the problems of sparking can be avoided. Also the brush losses associated with conventional system can be eliminated.
The Integration of the proposed system with the engine is much simpler when compared to the flywheel mounted or the crankshaft mounted ISGs. In the Starter mode the machine is operated as a motor for a little longer duration than the conventional system, so that there is minimal emission during the start process. Here, the starter drives the engine up to the predetermined rpm and then the IMSG ECU communicates to the Engine ECU to start firing. Thus this makes sure that the Engine is not driven at very low speed ranges where the emissions are high and the engine efficiency is low. The reduced emission starting is very much possible with the proposed system as the Induction machines characteristics are well suited for it.
ILLUSTRATION OF DRAWINGS:
A 3 phase squirrel cage Induction machine
Gear train arrangement having one starter gear that meshes with the flywheel during starter mode and another set of Alternator gears for the Alternator mode of operation. There is a synchromesh collar in the shaft of the starter alternator to shift the mode of operation by locking the synchromesh collar with either set of gears.
Gear shift mechanism to move the collar between the starter gear and the Alternator gear in the shaft of the Induction Machine based Starter Generator (IMSG).
Control Electronics to convert DC supplied by the battery to the AC for motoring operation and also the AC output of the Induction Machine based Starter Generator (IMSG) back to DC.
A dedicated Electronic Control Unit (ECU) for controlling the operation of the Gear shift mechanism and also to monitor the control electronics. It also gets inputs from the battery, Engine ECU, Electrical load of the vehicle.

The Part Numbers of Fig-1:
1. Engine ECU.
2. IMSG ECU.
3. Load.
4. Battery.
5. Gear Shaft Mechanism.
6. Gear Train.
7. IMSG.
8. FlyWheel.
9. Control Electronics.

WE CLAIM
A system for integrated starter alternator for internal combustion engine with an induction machine and a gear drive arrangement, said system comprising:
(a) phase induction machine coupled operably to the internal combustion
engine,
(b) a battery (4),
(c) a gear train (6) arrangement comprising first set of starter gear wheel mounted on induction machine shaft adapted to mesh with a flywheel (8) in starter mode, a second set of alternator gear wheel mounted on induction machine shaft adapted to mesh with an alternator gear wheel also mounted on the crank shaft parallely adjacent to flywheel (8) in alternator mode, the gear train also having a movable synchromesh collar also mounted on the shaft of induction machine between the two gear wheels mounted on induction machine shaft,
(d) an engine speed sensor operably coupled to the engine to determine the engine speed,
(e) an engine ECU operably coupled to engine speed sensor and the engine,
(f) an IMSG ECU (2) operably coupled to the battery (4), loads (3) of vehicle and the engine ECU (1),
(g) a gear shift mechanism (5) operably coupled to the IMSG ECU (2) and the synchromesh collar for moving the synchromesh collar between the gear wheels and locking the synchromesh collar with one of the two gear wheels mounted on induction machine shaft, and
(h) a control electronic circuit for conversion between DC and AC operably coupled to the induction machine, the Battery (4), the IMSG ECU (2) and loads (3);
(i) the gear train arrangement characterized in having a first set of starter gears and a second set of alternator gears, each set further comprising of two gear wheels, one gear wheel mounted on induction machine shaft meshing with a corresponding gear wheel mounted on crank shaft to act as reduction gear in the case of starter and incremental gear in the case of alternator, wherein further the gear wheel mounted on the crank shaft of the starter gear set is the fly wheel of the engine;

(j) the gear shift mechanism characterized in that it is operably by a solenoid controlled by IMSG ECU (2) capable of moving the synchromesh collar along the induction machine shaft between the starter gear and the alternative gear and locking the synchromesh collar with the selected gear based on the mode of operation;
(k) the system is characterized in that the locking the synchromesh collar with the gear;
(I) the system is characterized in that the machine is a single three phase induction machine;
(m) the system is characterized in that engine ECU and IMSG ECU (2) each having a logic circuits stored within and communicate with each other;
(n) the system is characterized in that IMSG ECU (2) is a dedicated ECU coupled to and for controlling the gear shift mechanism and electronic circuit(9) for operating the machine in both the modes based on the inputs from the battery, engine ECU and electrical load of the vehicle;
(o) the said system characterized in that a single 3 phase induction machine selectively capable of operating as a starter motor initially for cranking the engine and also as an alternator for generating electric power when driven by the said engine to feed the electrical load (3) as well as charge the battery;
(p) the said system characterized in that the alternator gear is a reduction gear, thereby rotation of induction machine is directly dependant on the gear ratio;
(q) the said system characterized in that the gear trains are positioned between the shaft of induction machine and the crank shaft and thereby torque delivery to engine is dependent directly on the gear ratio,
(r) the said system characterized in that the dedicated IMSG ECU (2) communicates with the Engine ECU.
(s) the said system characterized in that starter drives the engine for a predetermined duration upto predetermined rpm, only after which IMSG ECU (2) commands ECU to commence firing ensuring that engine is not at very low speed, to achieve the minimal emission during starting, and

(t) the said system characterized in that the gears transfer the mechanical power between engine shaft and shaft of induction machine,
2. A system for integrated starter alternator for internal combustion engine with an induction machine and gear drive arrangement, wherein
(a1) an induction machine configured drivingly to couple with the crank shaft of the internal combustion engine,
(a2) a gear train (6) arrangement coupling the induction machine shaft and the crank shaft,
(b) a gear train (6) arrangement configured to transfer the starting torque from the induction machine shaft through the deduction starter gears when the internal combustion engine is started such that said crank shaft is rotated by the induction machine at a much lower rpm than the speed of induction machine shaft, said system facilitating the starting of internal combustion engine when said crankshaft is rotated,
(c) a gear train (6) arrangement configured to transfer a running torque from said crank shaft to induction machine shaft through the alternator gears when the internal combustion engine is running such that induction machine shaft is rotated by said crank shaft is at a lower rpm than the crank shaft speed, said system generating an electrical current when induction machine shaft is rotated,
(d) a gear shift mechanism (5) configured to move a synchromesh collar mounted on induction machine shaft and between the said starter gear and the said alternator gear alternatively engaged with only one of the said starter gear wheel and said alternator gear wheel, all three mounted on the induction machine shaft,
(e) an engine ECU electrically and operatively connected to engine and engine performance sensors,
(f) an IMSG ECU (2) electrically and operatively connected to ECU, battery (4) and loads (3) and also operatively connected to gear shift mechanism (5) and a control electronics (9).

3. A system for integrated starter alternator for internal combustion engine with an induction machine and a gear drive arrangement, wherein IMSG ECU (2) is configured to have a predetermined rpm at start so as to minimize the emission during starting.
4. A system for integrated starter alternator for internal combustion engine with an induction machine and a gear drive arrangement, the torque delivery to the engine is dependent on gear ratio of the starter gearwheels.
5. A system for integrated starter alternator for internal combustion engine with an induction machine and gear drive arrangement, as illustrated in Fig 1.
6. A system for integrated starter alternator for internal combustion engine with an induction machine and gear drive arrangement, as substantially described in theaccomDanvina comolete sDecification.