FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See section 10, rule 13)
"STARTER GENERATOR FOR VEHICLE"
MINDA CORPORATION LIMITED, an Indian company, of E-5/2, Chakan Industrial Area, Phase-Ill, M.I.D.C., Nanekarwadi, Tal: Khed, Dist. Pune - 410501, Maharashtra, India
The following specification particularly describes the invention.

STARTER GENERATOR FOR VEHICLES
FIELD OF THE PRESENT DICSLOURE
The present disclosure relates to the field of vehicles. Particularly, the present disclosure relates to a starter generator for vehicles, used for starting engine, generating electric power to charge the battery and controlling idle stop function.
BACKGROUND OF THE PRESENT DISCLOSURE
Generally, a generator is a three phase brushless motor with rotor plurality of sensors. The generator has three basic parts- stator, rotor and sensor assembly. Stator has n number of poles of coils wounded on iron core. Electric current flows through the coils, because of varying electric current magnetic flux generated. Rotor is a cup shaped part, having m number of poles of permanent magnets. Rotor is mounted on crank shaft of the engine. Because of magnetic flux generated by stator currents, rotor starts rotating and hence crank shaft rotates.
In a brushless motor, position of the rotor relative to the stator is required to be determined so that the windings in the stator can be energized based on position of the rotor to effect relative angular movement between the stator and the rotor. In order, to sense the position of the rotor, position sensors are placed inside the periphery of stator. Because of high current flow through the stator coils, temperature of the stator becomes high. As rotor position sensors are placed inside the periphery of the stator, performance of the sensors may degrade due to high temperature. On the other hand, only temperature sensors which can perform in such high temperature environment can be used in such assemblies. Moreover, mounting of the sensors inside periphery of the stator is cumbersome.

Accordingly, there is an immense need to develop a stator generator that addresses one or more problems as discussed above and other problems associated with the existing stators generators.
SUMMARY
The present disclosure provides a starter generator for vehicles. The starter generator is used for starting engine, generating electric power to charge the battery and controlling idle stop function, in vehicles. The starter generator for vehicles comprising a rotor, a base plate, a stator mounted on the base plate and a plurality of sensors. The stator is configured to accommodate said rotor. The plurality of sensors is placed on the base plate, at least partially outside the radial periphery of stator, for determining the relative positioning of the rotor and stator.
In an aspect, the plurality of sensors is placed on the base plate at electric angle of 120 ° apart from each other.
In an aspect, the plurality of sensors is connected with an electronic control unit to signal the positions of north and south poles of the magnets, for determining the relative positioning of the rotor and the stator.
In an aspect, a gap is provided between the rotor and the plurality of sensors.
In an aspect, the base plate comprises a protrusion for mounting the stator.
In an aspect, the stator is secured with the protrusion using fasteners.
In an aspect, the rotor comprises a plurality of magnets mounted on the inner surface of the rotor.

In an aspect, the rotor comprises an arrangement of north and south poles of magnets.
In an aspect, a boss is attached on a top surface of the rotor for facilitating the mounting of the rotor on a crank shaft of the engine.
In an aspect, the base plate (16) is made of a metallic material.
In an aspect, the starter generator comprises three sensors.
BRIEF DESCRIPTION OF THE FIGURES
The figure(s) are incorporated with the specification, and serve to further illustrate the embodiments and illustrate various principles and advantages, in accordance with the present disclosure wherein:
Figure 1 illustrates a perspective view of a starter generator in accordance with an embodiment of the present disclosure.
Figure 2 illustrates a perspective view of a base plate with the plurality of sensors in accordance with an embodiment of the present disclosure.
Figure 3 illustrates a perspective view of a stator and a base plate with the plurality of sensors in accordance with an embodiment of the present disclosure.
Figure 4 illustrates a perspective view of a base plate with the plurality of sensors in accordance with an embodiment of the present disclosure.
Figure 5 illustrates a cross-sectional view of the starter generator taken along line 5-5 of Figure 2.

Figure 6 illustrates arrangement of magnets in a rotor in accordance with an embodiment.
DETAILED DESCRIPTION OF THE PRESENT DISCLOSURE
The present disclosure provides a starter generator for vehicles. The starter generator may be integrated with an internal combustion engine of the vehicle (not shown). The starter generator may be used for starting engine, generating electric power to charge the battery and controlling idle stop function, in vehicles. The starter generator for vehicles comprising a rotor, a base plate, a stator mounted on the base plate and a plurality of sensors. The stator is configured to accommodate said rotor. The plurality of sensors is placed on the base plate, at least partially outside the radial periphery of stator, for determining the relative positioning of the rotor and stator.
Accordingly, the present disclosure provides a starter generator for vehicles. The starter generator is described with reference to the figures and alternative embodiments; this description is not meant to be constructed in a limiting sense.
Referring to Figures 1-5, the starter generator (10) has a rotor (12), a stator (14), a base plate (16), a boss (18) and a plurality of sensors (20, 22, 24). The starter generator (10) may be coupled to an electronic control unit (not shown). In the embodiment as shown, the starter generator (10) is a three phase brushless DC motor.
The rotor (12) includes magnets or magnetized portions as known in the art. Figure 6 illustrates an arrangement of the north and south poles of magnets in the rotor (12). The rotor (12) may be a cup shaped part, having m number of poles of permanent magnets. The magnets are mounted on an inner surface of the cylindrical

wall (28) of the rotor (12). The number of magnets may vary as per the design and configuration of the starter generator (10). The boss (18) is fitted with the rotor (12) in an opening (32) on a top surface (34) of the rotor (12) to facilitate mounting of the rotor (12) on a crank shaft of an engine, shown in figure 5.
Further, the stator (14) is rigidly mounted on the base plate (16). The windings on the stator (14) are not shown in the drawings for simplicity in illustration. The stator (14) comprises a longitudinal axis (x) as shown in figure 5, and the stator is rotated around the longitudinal axis (x). In the embodiment as illustrated, the stator (14) and the base plate (16) are provided with three corresponding holes to facilitate fixing of the stator (14) on the base plate (16).
The base plate (16) is in form of circular plate. The base plate (16) is provided with a protrusion (36) in the center to provide a supporting and guiding surface for mounting the stator (14) on the base plate (16), as shown in Figures 4 and 5. The stator (14) is secured with the protrusion (36) using fasteners. The fasteners may be screws, bolts or studs. In an embodiment as shown, the protrusion (36) may have circular shape. In an alternate embodiment the base plate (16) may be provided with a mere extension plate for facilitating the mounting of the plurality of sensors (20,22,24) thereon. Any other suitable provision may be provided for mounting of the position sensor outside the stator (14). The base plate (16) may be made of the any suitable metallic material.
As known, for operation of the brushless motor, it is required to provide current to the windings on the stator (14) based on the relative angular position of magnets of the rotor (12). The plurality of sensors (20,22,24) is used in the starter generator (10) as disclosed herein can be any magnetic sensors such as hall sensors, reed switch, etc. In the embodiment as illustrated, the plurality of sensors (20,22,24) are magnetic sensors. In another embodiment as shown, three sensors (20,22,24) are placed on the base plate (16), namely a first position sensor (20), a second position sensor (22) and a third position sensor (24). The plurality of sensors (20,22,24) are

elongated in shape. Further, the plurality of sensors (20,22,24) may have rectangular in cross-section.
Each position sensor is placed one after another at a gap of 120 degrees electric angle between two consecutive plurality of sensors (20,22,24). The plurality of sensors (20,22,24) of the starter generator (10) are mounted on the base plate (16). The plurality of sensors (20,22,24) are mounted such that the longitudinal length of the plurality of sensors (20,22,24) is oriented parallel to the planar surface of the base plate (16) as shown in figures 1-5. Further, the longitudinal length of the elongated plurality of sensors (20,22,24) is oriented radially with respect to the base plate (16). Any suitable mechanism may be provided for mounting of the plurality of sensors (20,22,24) on the base plate (16). Further, suitable provisions may be provided for connection of the plurality of sensors (20,22,24) with the Electronic Control Unit (ECU).
The plurality of sensors (20,22,24) is placed on the base plate (16) at least partially outside the radial periphery of stator (14), for determining the relative positioning of the rotor (12) and stator (14). The radial periphery of the stator (14) is defined as the volumetric region of stator (14) around the longitudinal axis (x). Further, the plurality of sensors (20,22,24) is placed such that they are located at least partially between the rotor (12) and the base plate (16), i.e. under the cylindrical wall (28) of the base plate (16) as shown in FIGURE 5, when the stator and the rotor (12) are mounted on the base plate (16). When the starter generator (10) is in assembled state, a gap is provided between a lower surface (30) of the cylindrical wall (28) and the plurality of sensors (20,22,24) such that the rotor (12) can freely move relative to the stator (14) and plurality of sensors (20,22,24) without any interference from the plurality of sensors (20,22,24) or the stator (14). The gap may be configured to allow the easy dissipation of the heat generated during the operation of the stator (14) and rotor (12). However, the gap between the plurality of sensors (20,22,24) and the lower surface (30) can be kept to minimum to ensure proper sensing of the magnetic poles by the plurality of sensors (20,22,24).

Accordingly, the plurality of sensors (20,22,24) are mounted outside the stator (14). Figures 1, 2 and 5 illustrate the assembled condition of the starter generator (10) as disclosed herein. In the embodiment as illustrated, to facilitate mounting of the plurality of sensors (20,22,24), the base plate (16) has been provided with a diameter at least equal to the diameter of the rotor (12).
The plurality of sensors (20,22,24) detect proximity of the magnets on the lower surface (30) to determine relative positioning of the rotor (12) and the stator (14). When the magnetic north pole is in proximity with the position sensor, the position sensor detects presence of north pole of the magnet of the rotor (12) and generates a corresponding signal to the ECU. For example, as shown in FIGURE 2 and FIGURE 5, the third position sensor (24) is in proximity with the sensing element, hence the third position sensor (24) will determine position of the north pole and accordingly signal the ECU to provide current to stator windings to effect angular movement of the rotor (12) relative to the stator (14). Similarly, when the north pole is away from the position sensor, the position sensor will determine absence of north pole, or in corollary, presence of south pole proximate to the position sensor. Accordingly, the position sensor will signal the ECU so that ECU can send current to the stator windings as required.
For ascertaining proximity, the plurality of sensors (20,22,24) may be configured to detect presence or absence of magnetic poles if the poles are present or absent within a threshold distance from the position sensor. Any suitable threshold distance value may be selected depending on the size and configuration of the starter generator (10).
The rotor plurality of sensors (20,22,24) are mounted outside the stator (14) and the rotor (12) of the generator. As shown in Figures 1-5, three plurality of sensors (20,22,24) are mounted on base plate (16) at 120° apart from each other. As shown in Figures 1, 2 and 5, magnets are mounted on the rotor (12).

Since the plurality of sensors (20,22,24) are mounted outside the stator (14), the plurality of sensors (20,22,24) will not be exposed to high temperatures which are generated in the stator (14). Therefore, the temperature configuration of the plurality of sensors (20,22,24) used herein may be comparatively lesser. Further, since the mounting of the plurality of sensors (20,22,24) are outside the stator (14), the mounting process is simple and less time consuming. Therefore, the starter generator (10) as disclosed herein is economic to manufacture.

We Claim:
1. A starter generator (10) for vehicles, comprising:
a rotor (12);
abase plate (16);
a stator (14) mounted on the base plate (16) and configured to accommodate said rotor (12); and
a plurality of sensors (20, 22, 24) placed on the base plate (16) at least partially outside the radial periphery of stator (14), for determining the relative positioning of the rotor (12) and stator (14).
2. The starter generator (10) as claimed in claim 1, wherein the plurality of sensors (20, 22, 24) is placed on the base plate (16) at electric angle of 120 ° apart from each other.
3. The starter generator (10) as claimed in claim 1, wherein the plurality of sensors (20,22,24) is connected with an electronic control unit to signal the positions of north and south poles of the magnets, for determining the relative positioning of the rotor (12) and the stator (14).
4. The starter generator (10) as claimed in claim 1, wherein a gap is provided between the rotor (12) and the plurality of sensors (20, 22, 24).
5. The starter generator (10) as claimed in claim 1, wherein the base plate (16) comprises a protrusion (36) for mounting the stator (14).
6. The starter generator (10) as claimed in claim 6, wherein the stator (14) is secured with the protrusion (36) using fasteners.
7. The starter generator (10) as claimed in claim 1, wherein the rotor (12) comprises a plurality of magnets mounted on the inner surface of the rotor (12).

8. The starter generator (10) as claimed in claim 1, wherein the rotor (12) comprises an arrangement of north and south poles of magnets.
9. The starter generator (10) as claimed in claim 1, wherein a boss (18) is attached on a top surface (34) of the rotor (12) for facilitating the mounting of the rotor (12) on a crank shaft of the engine.
10. The starter generator (10) as claimed in claim 1, wherein the base plate (16) is made of a metallic material.
11. The starter generator (10) as claimed in claim 1, comprises three sensors (20,22, 24).