Claims:WE CLAIM:
1. A lubrication system (100) for an internal combustion engine, said system (100) comprising a rear bearing cap (215), said bearing cap (215) positioned at an operative rear end of the engine and defining at least one hole (115) formed thereon, said hole (115) configured for squirting a jet of lubricating oil directed onto the contact region between a fuel injection pump (FIP) lobe (205) of a camshaft (220) driven by the engine and a roller (230) of a roller follower (235) connected to the fuel injection pump.
2. The lubrication system (100) as claimed in claim 1, wherein said system (100) further comprises:
a. an oil pump for pressurizing the lubricating oil; and
b. an oil gallery (155) for facilitating flow of pressurized lubricating oil to said rear bearing cap (215),
said hole (115) is in fluid communication with said oil gallery (155).
3. The lubrication system (100) as claimed in claim 2, wherein said system (100) further comprising an oil sump for collecting the oil squirting from said hole (115) after it has lubricated the contact region and conduit means for drawing the lubricating oil from the sump to oil pump.
4. The lubrication system (100) as claimed in claim 1, wherein a piston type pressurizing mean is provided in said fuel pump for pressurising the fuel.
5. The lubrication system (100) as claimed in claim 1, wherein a reciprocating diaphragm type pressurizing means is provided in said fuel pump for pressurising the fuel.
6. The lubrication system (100) as claimed in claim 1, wherein the diameter of said hole (115) ranges from 1.5 mm to 2.5 mm.
7. The lubrication system (100) as claimed in claim 1, wherein a plurality of holes (115) is formed on said rear bearing cap (215).
8. The lubrication system (100) as claimed in claim 2, wherein a mesh filter or a sponge filter is configured before inlet of said oil pump.
9. The lubrication system (100) as claimed in claim 2, wherein a mesh filter is configured before inlet of said oil pump.
10. The lubrication system (100) as claimed in claim 2, wherein a sponge filter is configured before the inlet of said oil pump.
, Description:FIELD
The present disclosure relates to the field of lubrication.
DEFINITION
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicate otherwise.
Oil gallery - The term “Oil gallery” hereinafter refers to a pipe or drilled passageway in the engine or cylinder head that is used to carry engine oil through body of the engine.
HLA - The term “HLA” hereinafter refers to a Hydraulic Lash Adjuster in an engine that is specifically designed for automatically adjusting valve lash in the engine.
Valve lash - The term “valve lash” hereinafter refers to the mechanical clearance in a valve train between a camshaft and a valve in an internal combustion engine. The valve lash is intended to provide the greatest amount of valve opening on a high point of the camshaft lobe and assure that the valve is tightly closed on a low segment of the camshaft lobe.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Generally, a fuel injection pump (FIP) is powered by an engine. The power for operating the FIP is received through camshaft of the engine. An FIP lobe is provided at the rear end of the camshaft for driving the FIP. The FIP lobe cooperates with a reciprocating roller follower via a roller. The roller follower further drives the fuel injection pump. The contact between the FIP lobe and the roller is a line contact. Due to the line contact the contact pressure developed therein is of a significantly higher magnitude.
Conventionally, a mist type of lubrication is used for lubricating the contact region between the FIP lobe and the roller. The mist lubrication utilizes fine oil droplets available in the blow by gasses for lubricating various engine components. However, the conventional mist lubrication is not able to effectively lubricate the FIP lobe and roller contact.
There is, therefore, felt a need of a lubrication system of a fuel injection pump drive which ameliorates the aforementioned issues.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide an effective lubrication of a fuel injection pump drive.
Another object of the present disclosure is to provide a jet lubrication of a contact region between a fuel injection pump (FIP) lobe and a roller of a roller follower.
Yet another object of the present disclosure is to provide a hole in the body of a rear bearing cap for squirting a jet of lubricating oil on the contact region.
Still another object of the present disclosure is to reduce the friction between the FIP lobe and the roller.
Another object of the present disclosure is to increase the life of the FIP lobe and the roller.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a lubrication system of a fuel injection pump drive.
A lubrication system for an internal combustion engine comprises at least one hole formed on a rear bearing cap that is positioned at an operative rear end of the engine, such that the hole is configured for squirting a jet of lubricating oil directed onto the contact region between a fuel injection pump (FIP) lobe of a camshaft driven by the engine and a roller of a roller follower connected to the fuel injection pump.
In accordance with an embodiment of the present disclosure, the lubrication system includes an oil pump for pressurizing the lubricating oil.
In accordance with another embodiment of the present disclosure, an oil gallery is provided in the rear bearing cap for facilitating flow of the pressurized lubricating oil such that the hole provided for squirting the lubricating oil is in fluid communication with the oil gallery.
In accordance with an embodiment of the present disclosure, the lubrication system further comprises an oil sump for collecting the lubricating oil after it has lubricated the contact region and a conduit mean for drawing the lubricating oil from the sump to oil pump.
In accordance with another embodiment of the present disclosure, the diameter of hole provided for squirting lubricating oil ranges from 1.5 mm to 2.5 mm.
In accordance with another embodiment of the present disclosure, the fuel pump can be a piston-cylinder type or a diaphragm type pump.
Accordance to yet another embodiment of the present disclosure, a plurality of holes is provided on the rear bearing cap for effectively lubricating the contact region between the FIP lobe and the roller.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A jet lubrication system of a fuel injection pump drive of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates an isometric view of a fuel injection pump (FIP) drive depicting a an FIP lobe and a roller follower placed at an operative rear end of an engine;
Figure 2 illustrates an isometric view of the fuel injection pump depicting the fuel pump in an assembled configuration placed at the operative rear end of the engine;
Figure 3 illustrates a rear side view of the fuel injection pump of the Figure 2;
Figure 4 illustrates a sectional view of the fuel injection pump along a plane A-A shown in the Figure 3;
Figure 5 illustrates a side view of a camshaft of the engine;
Figure 6 illustrates a rear side view of a conventional rear bearing cap;
Figure 7 illustrates a rear side view of a modified rear bearing cap in accordance with an embodiment of the present disclosure;
Figure 8 illustrates a top view of the fuel injection pump;
Figure 9 illustrates a sectional view of the fuel injection pump along a plane B-B shown in Figure 8;
Figure 10 illustrates an isometric view of the rear bearing cap of Figure 7 and a roller follower;
Figure 11 illustrates a bottom view of the rear bearing cap and a roller follower; and
Figure 12 illustrates a sectional view of the rear bearing cap along a plane C-C shown in Figure 11.
LIST OF REFERENCE NUMERALS
100 – Jet lubrication system
101 – Cylinder head
105 – Fuel Injection Pump (FIP)
106 – FIP drive
115 – Hole provided on rear bearing cap
117 – Fuel inlet of FIP
118 – Fuel outlet of FIP
120 – FIP housing
145 – Chain drive
150 – HLA oil gallery in cylinder head
155 – Oil gallery in rear bearing cap
175 – Groove on rear bearing cap
215 – Rear Bearing Cap
220 – Camshaft
225 – FIP lobe
230 – Roller
235 – Roller follower
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including” and “having” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
The present disclosure envisages a lubrication system 100, specifically a jet lubrication system of a fuel injection pump (FIP) drive 106 positioned at an operative rear end of an internal combustion engine, which is illustrated in the accompanying figures. The jet lubrication system 100 as illustrated in Figure 1 comprises the fuel injection pump (FIP) drive 106, a cylinder head 101 of the engine, a camshaft 220, and a chain drive 145 for driving the camshaft 220. Figure 2 illustrates a fuel injection pump 105 positioned at the operative rear end of the engine. The FIP drive 106 is positioned inside an FIP housing 120. Figure 3 illustrates a side view of the fuel injection pump 105 mounted on the camshaft 220. An inlet 117 is provided for drawing fuel from fuel supply tank (not shown in figures). The fuel exits the fuel injection pump 105 from an outlet 118 provided on the fuel pump.
Figure 4 illustrates a detailed sectional view of the fuel injection pump 105 along a sectional plane A-A shown in Figure 3. The FIP drive 106 comprises an FIP lobe 225 configured at the rear end of the camshaft 220, a roller follower 235, a roller 230 in contact with the FIP lobe 225, and a fuel pressurizing means (not shown in figure) positioned inside the FIP housing 120. The fuel pressuring means can be of a piston-cylinder or a diaphragm type. The roller 230 is rotatably fixed at an operative bottom end of the roller follower 235. The rotational motion of the FIP lobe 225 is converted into oscillating motion of the roller 230 and the roller follower 235. There exists a line contact between the roller 230 and the FIP lobe 225. Due to the line contact the contact area is significantly smaller. As a result the magnitude of the contact pressure is significantly higher.
The camshaft 220 of the engine is shown in Figure 5. The FIP lobe 225 is positioned at an operative rear end of the camshaft 220. The camshaft 220 is driven by the chain drive 145 powered by the engine.
A rear side view of a conventional rear bearing cap 215 is illustrated in the Figure 6. In accordance with an embodiment of the present disclosure, the rear bearing cap 215 is modified for providing a jet lubrication of the contact region between the FIP lobe 225 and the roller 230. Figure 7 illustrates the modified rear bearing cap 215. A hole 115 is drilled on the operative rear side surface of the rear bearing cap 215 such that the drilled hole 115 is in fluid communication with an existing oil gallery 155 present in the rear bearing cap 215. The diameter of the oil gallery varies from 3 mm to 5 mm depending upon the size and configuration of the engine. Lubricating oil under pressure is continuously supplied by an oil pump (not shown in figure). A plurality of conduit means is provided on the cylinder head 101 and other engine components for the supply of the pressurized lubricating oil to different regions of the engine requiring lubrication.
A top view of the fuel injection pump 105 assembled on the cylinder head 101 is shown in Figure 8.
Figure 9 illustrates a sectional view of the fuel injection pump 105 along the plane B-B shown in Figure 8. An HLA oil gallery 150 carrying the lubricating oil under pressure is provided in the cylinder head 101. The oil gallery 155 in the rear bearing cap 215 is in fluid communication with the HLA oil gallery 150. A groove 175 is also provided in the rear bearing cap 215 for lubricating the contact region between the camshaft 220 and the surface of the rear bearing.
The hole 115 is drilled on the rear bearing cap 215 such that a jet of the lubricating oil is continuously squirted on the contact region between the FIP lobe 225 and the roller 230.
In accordance with an embodiment of the present disclosure, the hole 115 can be provided with a nozzle or an apertured-plate for issuing the jet of the lubricating jet on the contact region, such that the jet travels with increased velocity to reach the contact region.
Figure 10 illustrates an isometric view of the roller 230, the roller follower 235, and the rear bearing cap 215. The hole 115 for squirting the lubricating oil on the roller 230 is drilled in a manner such that the jet of lubricating oil exiting the hole 115 reaches the contact region between the FIP lobe 225 and the roller 230. The lubricating oil after lubricating the contact region drains to a sump (not shown in figures) of the engine where the oil is collected. Further, a conduit is provided for drawing the collected lubricating oil from the sump to the lubricating oil pump.
A top view of the rear bearing cap 215 is shown in Figure 11. The groove 175 of the bearing is formed on the inner surface of the rear bearing cap 215. Figure 12 illustrates a sectional view of the rear bearing cap 215 along the plane C-C shown in the Figure 11. The hole 115 is drilled on the rear bearing cap 215 such the hole 115 is in fluid communication with the oil gallery of the rear bearing cap 215. The hole 115 receives pressurized lubricating oil from the oil gallery (155). The exit of the hole is oriented in a direction such that the jet of lubricating oil exiting from the hole 115 reaches the contact region of the FIP lobe 225 and the roller 230.
The diameter of the hole is selected according to the type and size of the engine.
According to an embodiment of the present disclosure, a plurality of holes 115 is drilled in the rear bearing cap 215 for increased supply of oil to the contact region.
A passive type of flow control is employed for the lubricating oil flowing through the hole 115. The rate of flow of the lubricating oil is a function of the diameter of hole 115 and the pressure of the lubricating oil in the oil gallery 155.
When an element is referred to as being “mounted on”, “engaged to”, “connected to” or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a jet lubrication system of a fuel injection pump (FIP) drive, which:
• issues a lubricating jet on a contact region between an FIP lobe of a camshaft and a roller of a roller follower;
• ensures a continuous supply of a lubricating oil;
• eliminates the need of a separate lubrication system for lubricating the contact region;
• ensures an effective lubrication of the contact region;
• ensures a film of lubricating oil is maintained between the FIP lobe of the camshaft and the roller;
• uses an existing oil gallery in a rear bearing cap for supplying the lubricating oil to the contact region;
• increases the life of the FIP lobe and the roller;
• increases the efficiency of the FIP drive;
• is simple and easy to manufacture; and
• is economical.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments 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.
The foregoing description of the specific embodiments 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.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.