DESC:TECHNICAL FIELD
[001] The embodiments herein generally relate to internal combustion engines and more particularly, but not exclusively to compact cylinder head assembly and method for providing oil to camshaft bearings and hydraulic tensioner in internal combustion engines.

BACKGROUND
[002] Generally, lubrication system in an engine is used to supply lubrication oil to engine moving parts thereby reducing friction between each other. Conventional engine assembly includes a cylinder head having integrated lower bearing caps, where one lower bearing cap is used to facilitate mounting of an intake camshaft and the other lower bearing cap is to facilitate mounting of an exhaust camshaft. Separate upper bearing caps are mounted onto corresponding lower bearing caps of the cylinder head thereby securing intake camshaft and exhaust camshaft to the cylinder head and also provides space for housing the camshaft bearings. Separate oil galleries provided in the cylinder head are fluidly connected to corresponding lower bearing cap of the cylinder head for lubricating corresponding camshaft bearings. In the aforementioned engine assembly, a hydraulic tensioner is mounted to the cylinder head. The hydraulic tensioner is used to impart and maintain certain degree of tension in the secondary belt or chain that drives the intake camshaft and the exhaust camshaft. Oil is provided to the hydraulic tensioner through separate oil gallery provided in the cylinder head for maintaining the tension in the secondary belt or the chain. The arrangement and method of providing oil to camshaft bearings and the hydraulic tensioner in the aforementioned engine assembly is complex in design and incur high manufacturing costs. Further, the cylinder head of the aforementioned engine assembly is mounted to a cylinder block of the engine, where machined cavities and mounting holes are drilled on the cylinder block and the cylinder head respectively, which receives fasteners therein to secure the cylinder head to the cylinder block. The machined cavities and the mounting holes in the cylinder block and the cylinder head respectively are located away from front-end lower bearing cap of the cylinder head (lower bearing cap integrated in the cylinder head that is located to the front end of the cylinder head) thereby increasing a longitudinal length of the cylinder head and the cylinder block which in turn increases an overall weight of the engine.
[003] Therefore, there exists a need for a compact cylinder head assembly and a method of lubrication in an engine, which obviates the aforementioned drawbacks.

OBJECTS
[004] The principal object of an embodiment of this invention is to provide a cylinder head assembly for an engine, which includes a cylinder head having predefined longitudinal length and a camshaft bearing cap assembly for effectively providing oil to camshaft bearings and a hydraulic tensioner of cylinder head assembly in an engine.
[005] Another object of an embodiment of this invention is to provide a method for providing oil to camshaft bearings and a hydraulic tensioner of a cylinder head assembly in an engine.
[006] Yet another object of an embodiment of this invention is to provide a cylinder head assembly for an engine, which facilitates mounting of a hydraulic tensioner to a camshaft bearing cap assembly.
[007] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[008] The embodiments of this invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[009] FIG. 1 depicts an exploded view of a portion of an engine, according to an embodiment of the invention as disclosed herein;
[0010] FIG. 2 depicts a perspective view of the portion of the engine, according to an embodiment of the invention as disclosed herein;
[0011] FIG. 3 depicts a perspective view of a portion of a cylinder head, according to an embodiment of the invention as disclosed herein;
[0012] FIG. 4 depicts a perspective view of a portion of a cylinder head assembly of the engine, according to an embodiment of the invention as disclosed herein;
[0013] FIG. 5 depicts a perspective view of the cylinder head assembly, according to an embodiment of the invention as disclosed herein;
[0014] FIG. 6 depicts a perspective view of a camshaft bearing cap assembly of the cylinder head assembly, according to an embodiment of the invention as disclosed herein;
[0015] FIG. 7 depicts an exploded view of the camshaft bearing cap assembly, according to an embodiment of the invention as disclosed herein;
[0016] FIG. 8 depicts a perspective view of a first bearing cap of the camshaft bearing cap assembly, according to an embodiment of the invention as disclosed herein;
[0017] FIG. 9 depicts a front view of the first bearing cap of the camshaft bearing cap assembly, according to an embodiment of the invention as disclosed herein;
[0018] FIG. 10 depicts a top view of the first bearing cap of the camshaft bearing cap assembly, according to an embodiment of the invention as disclosed herein;
[0019] FIG. 11 depicts a bottom view of the first bearing cap of the camshaft bearing cap assembly, according to an embodiment of the invention as disclosed herein;
[0020] FIG. 12 depicts a perspective view of a second bearing cap of the camshaft bearing cap assembly, according to an embodiment of the invention as disclosed herein;
[0021] FIG. 13 depicts a bottom view of a second bearing cap of the camshaft bearing cap assembly, according to an embodiment of the invention as disclosed herein; and
[0022] FIG. 14 depicts a cross-sectional view of the cylinder head assembly, according to an embodiment of the invention as disclosed herein;
[0023] FIG. 15 depicts a flowchart showing the steps of a method for providing oil to camshaft bearings and a hydraulic tensioner of a cylinder head assembly in the engine, according to an embodiment of the invention as disclosed herein; and
[0024] FIG. 16 depicts a top view of the cylinder head, according to an embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0025] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0026] The embodiments herein achieve a cylinder head assembly for an engine, which includes a cylinder head having a reduced longitudinal length and a camshaft bearing cap assembly for effectively providing oil to camshaft bearings and a hydraulic tensioner of the cylinder head assembly in an engine. Further, embodiments herein achieve a method for providing oil to camshaft bearings and a hydraulic tensioner of a cylinder head assembly in an engine. Referring now to the drawings, and more particularly to FIGS. 1 through 16, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0027] FIG. 1 depicts an exploded view of a portion of the engine 10, according to an embodiment of the invention as disclosed herein. In an embodiment, the engine 10 (as shown in fig. 1 and fig. 2) includes a cylinder head assembly 100 (as shown in fig. 1, fig. 2, fig. 4, fig. 5 and fig. 14), a cylinder block (not shown), a primary camshaft drive system 12 (as shown in fig. 1 and fig. 2) and may include other standard components as present in standard engine.
[0028] FIG. 4 depicts a perspective view of a portion of a cylinder head assembly 100 of the engine 10, according to an embodiment of the invention as disclosed herein. In an embodiment, the cylinder head assembly 100 includes a camshaft bearing cap assembly 102 (as shown in fig. 1, fig. 4, fig. 6 and fig. 7), a cylinder head 104 (as shown in fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 14 and fig. 16), a hydraulic tensioner T (as shown in fig. 1 and fig. 5), an intake camshaft I (as shown in fig. 1, fig. 2, fig. 4 and fig. 5), an exhaust camshaft E (as shown in fig. 1, fig. 2, fig. 4 and fig. 5), a plurality of camshaft bearings B (as shown in fig. 14), a secondary camshaft drive system 106 (as shown in fig. 1) and may include other standard components as present in standard cylinder head assembly.
[0029] FIG. 6 depicts a perspective view of the camshaft bearing cap assembly 102 of the cylinder head assembly 100, according to an embodiment of the invention as disclosed herein. In an embodiment, the camshaft bearing cap assembly 102 includes a first bearing cap 102F(as shown in fig. 6, fig. 7, fig. 8, fig. 9, fig. 10 and fig. 11) and a second bearing cap 102S (as shown in fig. 6, fig. 7, fig. 12 and fig. 13). The camshaft bearing cap assembly 102 is used for providing lubricant to the camshaft bearings B and the hydraulic tensioner T, and also for mounting the hydraulic tensioner T. The first bearing cap 102F is used to facilitate mounting of the intake camshaft I and the exhaust camshaft E to the cylinder head 104. In an embodiment, the first bearing cap 102F includes at least one lubricant inlet 102i (as shown in fig. 11), at least one first lubricant outlet 102o (as shown in fig. 8 and fig. 9), at least one second lubricant outlet 102p (as shown in fig. 10), a tensioner mounting portion 102m (as shown in fig. 9) and a plurality of openings O (as shown in fig. 8, fig. 10 and fig. 11). The lubricant inlet 102i of the first bearing cap 102F is used to facilitate entry of the lubricant from the cylinder head 104 to the first bearing cap 102F. The first lubricant outlet 102o of the first bearing cap 102F is used to facilitate exit of the lubricant (oil) from the first bearing cap 102F to the hydraulic tensioner T. The second lubricant outlet 102p of the first bearing cap 102F is used to facilitate exit of the lubricant from the first bearing cap 102F to the second bearing cap 102S. The tensioner mounting portion 102m of the first bearing cap 102F is used for mounting the hydraulic tensioner T. It is also within the scope of the invention to mount the hydraulic tensioner T to the second bearing cap 102S. The tensioner mounting portion 102m of the first bearing cap 102F defines a plurality of tensioner openings C (as shown in fig. 8 and fig. 9) adapted to receive fasteners (not shown) therein to removably connect the hydraulic tensioner T to the first bearing cap 102F. It is also within the scope of the invention to provide the tensioner mounting portion 102m with cavities for mounting the hydraulic tensioner T to the cylinder head 104. The plurality of openings O of the first bearing cap 102F is used to receive fasteners there through and the fasteners are received by corresponding cavities 104b (as shown in fig. 3 and fig. 16) of the cylinder head 104 thereby removably connecting the camshaft bearing cap assembly 102 to the cylinder head 104. The second bearing cap 102S is used to facilitate mounting of the intake camshaft I and the exhaust camshaft E to the cylinder head 104. In an embodiment, the second bearing cap 102S includes a lubricant receiving portion 102q (as shown in fig. 7 and fig. 13) and a plurality of openings O (as shown in fig. 12 and fig. 13). The lubricant receiving portion 102q of the second bearing cap 102S is used to receive lubricant from the second lubricant outlet 102p of the first bearing cap 102F to provide the lubricant to the camshaft bearings B thereby lubricating the camshaft bearings B on operation of the engine 10. In an embodiment, the lubricant receiving portion 102q of the second bearing cap 102S is a groove. The plurality of openings O of the second bearing cap 102S is used to receive fasteners (not shown) there through and the fasteners (not shown) are received by corresponding cavities 104b of the cylinder head 104 through corresponding openings O of the first bearing cap 102F thereby removably connecting the camshaft bearing cap assembly 102 to the cylinder head 104.
[0030] The cylinder head 104 is mounted onto the cylinder block (not shown) of the engine 10. The cylinder head 104 includes a plurality of openings104a (as shown in fig. 3 and fig. 16), a plurality of cavities 104b (as shown in fig. 3 and fig. 16) and at least one lubricant outlet 104c (as shown in fig. 16). The plurality of openings 104a of the cylinder head 104 are adapted to receive fasteners (not shown) therein to removably connect the cylinder head 104 to the cylinder block (not shown) of the engine 10. The plurality of openings 104a of the cylinder head 104 is disposed below the camshaft bearing cap assembly 102 and adjacent to the cavities 104b of the cylinder head 104. It is also within the scope of the invention to dispose the plurality of openings 104a beneath/below corresponding cavities 104b of the cylinder head 104 for removably connecting the bearing cap assembly 102 and the cylinder head 104 to the cylinder bock (not shown) through fasteners (not shown). The plurality of cavities 104b of the cylinder head 104 are adapted to receive fasteners (not shown) therein to removably connect the camshaft bearing cap assembly102 to the cylinder head 104. In an embodiment, at least one cavity 104b is disposed substantially in-line to the openings 104a of the cylinder head 104 thereby enabling the cylinder head 104 to have reduced longitudinal length. The reduction in longitudinal length of the cylinder head 104 is at least 30mm. In an embodiment, a longitudinal axis of each cavity 104b of the cylinder head 104 is co-axial to a longitudinal axis of corresponding openings O of the first bearing cap 102F. The lubricant outlet 104c of the cylinder head 104 is used to facilitate exit of the lubricant from the cylinder head 104 to the first bearing cap 102F.
[0031] The hydraulic tensioner T is used to impart and maintain certain degree of tension in the chain 106c (as shown in fig. 1) of the secondary camshaft drive system 106 (as shown in fig. 1).
[0032] The intake camshaft I is used for operating intake valves (not shown) and the exhaust camshaft E is used for operating exhaust valves (not shown) of the cylinder head assembly 100. The plurality of camshaft bearings B is used to support the intake camshaft I and the exhaust camshaft E.
[0033] In an embodiment, the secondary camshaft drive system 106 includes a plurality of sprockets 106s and a chain 106c. The secondary camshaft drive system 106 is used for driving the exhaust camshaft E. The secondary camshaft drive system 106 is driven by a crankshaft (not shown) of the engine 10 through the primary camshaft drive system 12. One sprocket 106s is mounted to the intake camshaft I and another sprocket 106s is mounted to the exhaust camshaft E. The rotational motion of the intake camshaft I is transferred to the exhaust camshaft E by connecting the sprockets 106s through the chain 106c. The tension in the chain 106c is maintained by the hydraulic tensioner T. It is also within the scope of the invention to provide the secondary camshaft drive system106 with pulley and belt or any other power transmission members for driving the exhaust camshaft E.
[0034] In an embodiment, the primary camshaft drive system 12 includes a plurality of sprockets 12s (as shown in fig. 2) and a chain 12c (as shown in fig. 2). The primary camshaft drive system 12 is used for driving the intake camshaft I. One sprocket 12s is rotatably connected to the intake camshaft I and the other sprocket 12s is rotatably connected to the crankshaft (not shown) of the engine 10. The rotational motion of the crankshaft (not shown) of the engine 10 is transferred to the intake camshaft I by connecting the sprockets 12s through the chain 12c. The tension in the chain 12c is maintained by using a primary hydraulic tensioner (not shown) of the engine 10. It is also within the scope of the invention to provide the primary camshaft drive system 12 with pulley and belt or any other power transmission members for driving the intake camshaft I or the exhaust camshaft E.
[0035] The assembly of the cylinder head assembly 100 to the engine 10 is as follows. The cylinder head 104 is mounted onto the cylinder block (as shown) of the engine 10 and thereafter the fasteners (not shown) are fastened to the openings 104a of the cylinder head 104 there through and the fasteners are received by corresponding cavities (not shown) of the cylinder block (not shown) thereby assembling the cylinder head 104 to the cylinder block (not shown). Thereafter, the first bearing cap 102F is mounted to corresponding portion of the cylinder head 104. Thereafter, the intake camshaft I and the exhaust camshaft E are mounted to the first bearing cap 102F through the camshaft bearings B which is mounted to the intake camshaft I and the exhaust camshaft E. Thereafter, the second bearing cap 102S is mounted to the first bearing cap 102F and fasteners (not shown) are fastened to the openings O of the second bearing cap 102S there through and the fasteners (not shown) are received by corresponding cavities 104b of the cylinder head 104 through corresponding opening O of the first bearing cap 102F thereby assembling the camshaft bearing cap assembly 102 to the cylinder head 104. Thereafter, the hydraulic tensioner T is mounted to the tensioner mounting portion 102m of the first bearing cap 102F and fasteners (not shown) are fastened to the tensioner openings C of the first bearing cap 102F thereby assembling the hydraulic tensioner T to the camshaft bearing cap assembly 102. Thereafter, sprockets 106s of the secondary camshaft drive system 106 are assembled to the intake camshaft I and the exhaust camshaft E. Thereafter, the chain 106c of the secondary camshaft drive system 106 is assembled with the sprockets 106s. Thereafter, one of the sprockets 12s of the primary camshaft drive system 12 which is bigger in size is assembled to the intake camshaft I and the other sprocket 12s which is smaller in size is assembled to the crankshaft of the engine 10. Thereafter, the chain 12c is assembled by connecting the chain 12c with the sprockets 12s thereby rotatably connecting the primary camshaft drive system 12 with the secondary camshaft drive system 106.
[0036] FIG. 15 depicts a flowchart showing the steps of a method 200 for providing lubricant to camshaft bearings B and a hydraulic tensioner T of a cylinder head assembly 100 in the engine10, according to an embodiment of the invention as disclosed herein. In an embodiment, the method 200 for providing lubricant to camshaft bearings B and the hydraulic tensioner T of the cylinder head assembly 100 is as follows, the method 200 comprising, providing the engine 10 with the cylinder head assembly 100 comprising, a camshaft bearing cap assembly 102 comprising a first bearing cap 102F having a lubricant inlet 102i, a first lubricant outlet 102o, a second lubricant outlet 102p; and a second bearing cap 102S having a lubricant receiving portion 102q (step 202); allowing the lubricant from a cylinder head 104 of the cylinder head assembly 100 to flow to the first bearing cap 102F through the lubricant inlet 102i (step 204); allowing the lubricant from the first bearing cap 102F to flow to the hydraulic tensioner T through the first lubricant outlet 102o (step 206); and providing the lubricant receiving portion 102q of the second bearing cap 102F in fluid communication with the second lubricant outlet 102p of the first bearing cap 102F to provide the lubricant to the camshaft bearings B thereby lubricating the camshaft bearings B on operation of the engine 10 (step 208).
[0037] The working of the engine 10 in conjunction with the method 200 for providing lubricant to camshaft bearings B and the hydraulic tensioner T is as follows. During the operation of the engine 10, the lubricant flows from an oil gallery (not shown) of the cylinder head 104 to the first bearing cap 102F through the lubricant inlet 102i. Thereafter, the lubricant from the first bearing cap 102F flows to the hydraulic tensioner T and the second bearing cap 102S through the first lubricant outlet 102o and the second lubricant outlet 102p respectively. The lubricant from the second bearing cap 102S flows to the camshaft bearings B through the lubricant receiving portion 102q of the second bearing cap 102S thereby lubricating the camshaft bearings B. Therefore, a cylinder head assembly 100 comprising a cylinder head 104 having a reduced longitudinal length and a method 200 for providing the lubricant to the camshaft bearings B and the hydraulic tensioner T is provided for an engine 10.
[0038] The following description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
,CLAIMS:CLAIMS
We claim,
1. A cylinder head assembly 100 for an engine 10, said cylinder head assembly 100 comprising, a camshaft bearing cap assembly 102 having,
a first bearing cap 102F having at least one lubricant inlet 102i adapted to facilitate entry of a lubricant from a cylinder head 104 of said cylinder head assembly 100 to said first bearing cap 102F, at least one first lubricant outlet 102o adapted to facilitate exit of the lubricant from said first bearing cap 102F to a hydraulic tensioner T of said cylinder head assembly 100, and at least one second lubricant outlet 102p; and
a second bearing cap 102S having at least one lubricant receiving portion 102q adapted to receive the lubricant from the second lubricant outlet 102p of said first bearing cap 102F to provide the lubricant to at least one camshaft bearing B of said cylinder head assembly 100 thereby lubricating the camshaft bearing B on operation of the engine 10.
2. The cylinder head assembly 100 as claimed in claim 1, wherein said first bearing cap 102F includes a plurality of openings O, and said second bearing cap 102S includes a plurality of openings O, wherein the plurality of openings O of said first bearing cap 102F and the plurality of openings O of said second bearing cap 102S are adapted to receive fasteners therein to removably connect said camshaft bearing cap assembly 102 to said cylinder head 104.
3. The cylinder head assembly 100 as claimed in claim 1, wherein the lubricant is pressurized oil.
4. The cylinder head assembly 100 as claimed in claim 1, wherein the lubricant receiving portion 102q of said second bearing cap 102S is a groove.
5. A cylinder head assembly 100 for an engine 10, said cylinder head assembly 100 comprising:
a camshaft bearing cap assembly 102 comprising, a first bearing cap 102F having at least one lubricant inlet 102i , at least one first lubricant outlet 102o, at least one second lubricant outlet 102p and a tensioner mounting portion 102m; and a second bearing cap 102S having at least one lubricant receiving portion 102q;
a cylinder head 104 defining a plurality of openings 104a adapted to receive fasteners therein to removably connect said cylinder head 104 to a cylinder block of the engine 10,and a plurality of cavities 104b adapted to receive fasteners therein to removably connect said camshaft bearing cap assembly 102 to said cylinder head 104, wherein at least one cavity 104b is disposed substantially in-line to the openings 104a thereby enabling said cylinder head 104 to have predefined longitudinal length; and
a hydraulic tensioner T adapted to be mounted to the tensioner mounting portion 102m of said first bearing cap 102F,
wherein
the lubricant inlet 102i of said first bearing cap 102F is adapted to facilitate entry of a lubricant from said cylinder head 104 to said first bearing cap 102F;
the first lubricant outlet 102o of said first bearing cap 102F is adapted to facilitate exit of the lubricant from said first bearing cap 102F to said hydraulic tensioner T;
the second lubricant outlet 102p of said first bearing cap 102Fis adapted to facilitate exit of the lubricant from said first bearing cap 102F to said second bearing cap 102S; and the lubricant receiving portion 102q of said second bearing cap 102S adapted to receive the lubricant from the second lubricant outlet 102p of said first bearing cap 102F to provide the lubricant to at least one camshaft bearing B of said cylinder head assembly 100 thereby lubricating the camshaft bearing B on operation of the engine 10.
6. The cylinder head assembly 100 as claimed in claim 5, wherein said first bearing cap 102F includes a plurality of openings O, and said second bearing cap 102S includes a plurality of openings O, wherein the plurality of openings O of said first bearing cap 102F and the plurality of openings O of said second bearing cap 102S are adapted to receive fasteners therein to removably connect said camshaft bearing cap assembly 102 to said cylinder head 104.
7. The cylinder head assembly 100 as claimed in claim 6, wherein a longitudinal axis of each opening O of said first bearing cap 102F and a longitudinal axis of each opening O of said second bearing cap 102S are co-axial to corresponding cavity 104b of said cylinder head 104.
8. The cylinder head assembly 10 as claimed in claim 5, wherein the tensioner mounting portion 102m of said first bearing cap 102F defines a plurality of tensioner openings C adapted to receive fasteners therein to removably connect said hydraulic tensioner T to said first bearing cap 102F.
9. A method 200 for providing lubricant to at least one camshaft bearing B and a hydraulic tensioner T of a cylinder head assembly 100 in an engine 10, said method 200 comprising:
providing the engine 10 with said cylinder head assembly 100 comprising, a camshaft bearing cap assembly 102 comprising a first bearing cap 102F having a lubricant inlet 102i, a first lubricant outlet 102o, a second lubricant outlet 102p; and a second bearing cap 102S having a lubricant receiving portion 102q;
allowing the lubricant from a cylinder head 104 of said cylinder head assembly 100 to flow to said first bearing cap 102F through the lubricant inlet 102i;
allowing the lubricant from said first bearing cap 102F to flow to the hydraulic tensioner T through the first lubricant outlet 102o; and
providing the lubricant receiving portion 102q of said second bearing cap 102F in fluid communication with the second lubricant outlet 102p of said first bearing cap 102F to provide the lubricant to the camshaft bearing B thereby lubricating the camshaft bearing B on operation of the engine 10.

Dated this 26th of December 2016
Signature:
Name of the Signatory: Somashekar Ramakrishna