Claims:We Claim:
1. A supercharger (106) for an internal combustion engine (100), said supercharger (106) characterized in having,

at least a first lobe (105) mounted on a cam shaft (103) of said internal combustion engine (100), and
a drive gear (104) mounted on a cam shaft (103) of said internal combustion engine (100), said drive gear (104) engages with at least a driven gear (107) mounted on the shaft of said supercharger (106).

2. The supercharger (106) of claim 1, wherein said supercharger (106) comprises a cover plate (201), said cover plate (201) in mechanical engagement with a cylinder head housing (203) of said internal combustion engine 100.

3. An internal combustion engine (100), comprising

at least an engine block (101) and a cylinder head (102) attached to said engine block (101),
said cylinder head (102) comprising at least one cam shaft (103), characterized in that
a drive gear (104) and at least a first lobe (105) of a supercharger (106) mounted on said cam shaft (103); and
a driven gear (107) engaging said drive gear (104), said driven gear (107) rotates a shaft (108), and at least a second lobe (109) mounted on said shaft (108).

4. The internal combustion engine (100) of claim 1, wherein said supercharger 106 is integrated with said cylinder head (102).
, Description:Field of the invention
[0001] This invention relates to the field of internal combustion engines.

Background of the invention
[0002] In internal combustion (IC) engine, a supercharger is used to increase the mass/ volume of air supplied to the intake of the IC engine. In the current state of art superchargers are powered mechanically by belt- or chain-drive from the engine's crankshaft. It is observed that the superchargers in the state of art are available in the form of a separate housing, the housing of the supercharger is assembled onto the engine housing with the help of different mechanical elements. This presents a challenge in terms of space and design. Hence, there is a need to bring about a change in the configuration of IC engine, so that it can accommodate a supercharger within the available space constraints.

[0003] Prior art patent application US6453890 discloses a compact supercharged internal combustion engine, wherein the supercharger is mounted above the twin overhead cam cylinder head of the engine but is readily detachable from it. The drive for the pumping elements of the supercharger including counter rotating shafts to which balance masses are added so as to assist in engine balancing. In addition to supplying compressed air to the combustion chambers of the engine for combustion, the supercharger also supplies air to an air injection system that cooperates with the exhaust system for reducing the emissions of undesirable pollutants to the atmosphere.

Brief description of the accompanying drawing
[0004] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0005] FIG. 1 illustrates a supercharger for an internal combustion engine; and

[0006] FIG. 2 illustrates the supercharger with mounting arrangements.

Detailed description of the embodiments
[0007] FIG. 1 illustrates a supercharger for an internal combustion engine 100. The internal combustion engine 100 comprises at least an engine block 101 and a cylinder head 102 attached to the engine block 101. The cylinder head 102 comprises at least one cam shaft 103. The internal combustion engine 100 is characterized in that, a drive gear 104 and at least a first lobe 105 of a supercharger 106 mounted on the cam shaft 103. The supercharger 106 may be integrated with the cylinder head 102. A driven gear 107 engages with the drive gear 104, the driven gear 107 rotates a shaft 108, and at least a second lobe 109 mounted on the shaft 108.

[0008] The engine block 101 of the internal combustion engine 100 houses at least one piston and cylinder. The piston drives the crankshaft. The piston reciprocates within the cylinder to compress and expand the fuel charge that is received from the inlet of the cylinder. The inlet opens and closes with the help of inlet cam shaft. The outlet of the cylinder opens with the help of an outlet cam shaft. The inlet cam shaft 103 and the outlet cam shaft 103 are located in the cylinder head 102. The proposed supercharger 106 may derive drive from one of the inlet cam shaft 103, outlet cam shaft 103 or a combination of both. The configuration of the supercharger 106 with respect to the engine cylinder hear will now be described in further detail.

[0009] FIG. 2 illustrates the supercharger with mounting arrangements.The supercharger 106 comprises at least a first lobe 105 mounted on the cam shaft 103 of the internal combustion engine 100. A drive gear 104 is mounted on the cam shaft 103 of the internal combustion engine 100, the drive gear 104 engages with at least a driven gear 107 mounted on the shaft of the supercharger 106. The rotation of the driven gear 107 rotates the shaft 108 so as to rotate the second lobe 109 located on the supercharger 106 with respect to the first lobe 105 located on the cam shaft 103. Since the supercharger 106 is driven by the gear that is attached to the cam shaft 103, no separate drive arrangement like belt, housing and the like for supercharger 106 is necessary. As can be seen from FIG. 2, the supercharger 106 has a cover plate 201. The cover plate 201 has an outlet 202 for allowing compressed air to exit from the supercharger 106 and enter into the engine intake manifold, the cover plate 201 may be in mechanical engagement with the cylinder head housing 203 of the internal combustion engine 100. The cylinder head housing 203 may have an inlet 204 for allowing air to enter into the supercharger.

[00010] The working of the supercharger 106 that is integrated with the cylinder head 102 of the engine will now be explained in further detail. As the engine is cranked, the rotation of the crankshaft will cause the piston to reciprocate within the housing of the cylinder. The movement of the piston causes the fuel charge to enter the inlet of the cylinder get compressed produce power and exhaust. The exhaust is sent to the atmosphere via the outlet. The opening of the inlet and the outlet of the engine may be controlled with the help of cam shaft 103. The cam shaft 103 disclosed herein also acts as a drive for the supercharger 106. In other words, the cam shaft 103 provides power required to run the supercharger 106. Mounted on the cam shaft 103, is a first lobe 105 of a supercharger 106 and a drive gear 104. The cam shaft 103 is driven by the engine. As the cam shaft 103 rotates, the drive gear 104 also rotates, a driven gear 107 engages with the drive gear 104. The driven gear 107 is mounted on a shaft of the supercharger 106. The rotation of the driven gear 107 rotates the second lobe 109 located on shaft of the supercharger 106 with respect to the first lobe 105 located on the cam shaft 103. The rotation of the first lobe 105 and the second lobe 109 causes additional mass of air to be sucked in and this is given as a charge to the inlet of the engine through the intake air manifold along with fuel.

[00011] By integrating the supercharger 106 with the cylinder head 102 of the engine leads to reduction in cost in comparison to supercharger available in the state of art. This is because of having only lobe (second lobe 109) directly mounted on the cam shaft 103 while the first lobe 105 is mounted on the shaft of supercharger 106. The oil used for lubricating the engine components may also be used to lubricate the parts of the supercharger 106. A separate housing for supercharger 106 is no longer required. The supercharger 106 is mounted so that a straight lobe design is possible with radial air inlet and outlet leading to compactness in packing and mounting of the supercharger 106. The clearance between the lobes, the cylinder head 102 and the cover plate of the supercharger 106 may be kept as small as possible in order to increase the efficiency of the supercharger 106. Moreover, the supercharger 106 may also receive drive from any other shaft of the engine, like for example, the crankshaft, the balancer shaft, by changing the gearing arrangement and may also be integrated with the crankcase.

[00012] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention in terms of the type of supercharger, gear and drive arrangement and the camshaft and / or the crankshaft used to drive the supercharger. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.