| Title of Invention | A LUBRICATION MECHANISM FOR A CRANKCASE ASSEMBLY |
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| Abstract | The present subject matter is directed to a crankcase 101 implemented within a crankcase assembly 100 of an internal combustion engine. The crankcase 101 includes a clutch side compartment 103 to house at least a clutch assembly 104 and a primary compartment 102 provided adjacent to the clutch side compartment 103. The primary compartment houses at least a primary gear 102-1. Further, the crankcase 101 includes a baffle profile 205 provided in the clutch side compartment 103 along a circumference of the clutch assembly 104. The baffle profile 205 is connected to the crankcase 101 and extends till an interface between the clutch assembly 104 and the primary gear 102-1, In addition, the crankcase 101 includes an oil catching pocket 210 provided above the clutch assembly 104. The oil catching pocket 210 is flow-connected to the baffle profile 205. |
| Full Text | TECHNICAL FIELD The subject matter described herein, in general, relates to a lubrication mechanism for an internal combustion engine and in particular, relates to a lubrication mechanism for a crankcase assembly of the internal combustion engine. BACKGROUND An internal combustion (IC) engine employs a lubrication mechanism to prevent wear and tear among various operating parts of the engine. Typically, various operating components of the IC engine are subjected to rubbing against one-another during operation, thereby leading to rapid wear and tear thereof. As an example, these operating components may include crankshaft, bearings, clutches, camshaft, fuel cam, gears and so on. Specifically, the application of lubricating oil tends to form a thin film of lubricating oil on the surface of these operating parts. The formation of film helps to reduce friction between the abovementioned operating components to prevent the wear and tear. Apart from reducing the friction, the lubricating oil is also employed in the IC engines to act as a coolant for removing heat away from various operating components of the IC engine. As known in the art, an operation of various motion transmitting components causes a large amount of heat to be generated. The heat generated in such a manner has to be conducted away from the components to ensure structural integrity, provide durability and to keep intact the geometry of the components. Typically, the lubricating oil is stored in an oil sump inside the IC engine and circulated for lubrication. The IC engine requires effective circulation of the lubricating oil to ensure smooth and continuous operation of the operating parts of the IC engine. To facilitate the circulation and lubrication, the IC engine includes oil ducts for delivering lubricating oil to various operating parts such as a camshaft, pistons, and other bearings. Conventional lubrication mechanisms that are commonly employed within the IC engines include a splash lubrication mechanism and a shower lubrication mechanism. Splash lubrication mechanism uses the principle of splashing lubricating oil by a moving member which may include a slinger and a rotating member. The moving member lifts the lubricating oil from the oil sump and directs the lubricating oil on to the operating components that require lubrication. In contrast, the shower lubrication mechanism employs an oil pump that pumps the lubricating oil to the various locations at an optimized pressure. However, the requirement of the oil pump for the shower lubrication mechanism of the operating components makes the IC engine cost ineffective due to power consumption by the oil pump and due to reduced reliability of additional components, which support pumping of the lubricating oil. In addition, the conventional lubrication mechanisms employ a number of mechanized steps for the shower lubrication mechanism, such as transportation of the lubricating oil with force to various parts of the IC engine using the oil pump, a gallery and a shower pipe. The implementation of these mechanisms requires a significant number of components which directly leads to an increase in the overall weight and size of the automobile IC engine. SUMMARY The subject matter described herein is directed to a crankcase implemented within a crankcase assembly of an internal combustion engine. The crankcase includes a clutch side compartment to house at least one clutch assembly. In addition, the crankcase includes a primary compartment provided adjacent to the clutch side compartment- The primary compartment houses at least one primary gear. Further, the crankcase includes a baffle profile provided in the clutch side compartment, along a circumference of the clutch assembly. The baffle profile extends till an interface between the clutch assembly and the primary gear. In addition, the crankcase includes an oil catching pocket provided above the clutch assembly in the clutch side compartment. The oil catching pocket is flow connected to the baffle profile. The present subject matter achieves a combined effect of a splash and a shower lubrication mechanisms through a single driving mechanism. Accordingly, such combination eliminates the requirement of a separate pump for pumping the lubricating oil in the crankcase, thereby decreasing the weight, size, and overall cost of the IC engine. These and other features, aspects, and advantages of the present subject matter will become better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF DRAWINGS The above and other features, aspects, and advantages of the subject matter will become better understood with regard to the following description, appended claims, and accompanying drawings where; Fig. 1 illustrates a schematic view of a crankcase assembly of an internal combustion (IC) engine, in an embodiment of the present subject matter. Fig. 2 illustrates a sectional view of the crankcase assembly as shown in Fig 1, in an embodiment of the present subject matter. Fig. 3 illustrates a sectional view of a transmission compartment of the crankcase assembly of Fig 1 along a sectional line M-M, in an embodiment of the present subject matter. Fig. 4 illustrates a front view of a magneto electric starter compartment of the crankcase assembly of Fig 1, in an embodiment of the present subject matter. Fig. 5a illustrates a side view of the crankcase assembly of Fig 1, in an embodiment of the present subject matter. Fig. 5b illustrates a sectional view of the crankcase assembly of Fig 5a along a sectional line A-A, in an embodiment of the present subject matter. Fig. 5c illustrates a sectional view of the transmission compartment of the crankcase assembly of Fig 5a, in an embodiment of the present subject matter. Fig. 5d illustrates a schematic view of the crankcase assembly of Fig 1, in an embodiment of the present subject matter. Fig. 5e illustrates a sectional view of the transmission compartment of the crankcase assembly of Fig 5d, along a sectional line D-D, in an embodiment of the present subject matter. Fig. 5f illustrates a sectional view of a clutch side compartment of the crankcase assembly of Fig 5c, along a sectional line E-E, in an embodiment of the present subject matter. DETAILED DESCRIPTION The present subject matter relates to a lubrication mechanism for various systems provided within a crankcase assembly of an IC engine. Such systems may include a transmission system, a drive train system, flywheel-starting system and so on. More particularly, the present subject matter describes the lubrication mechanism as a combined splash-and-shower lubrication mechanism. In one implementation, the crankcase assembly includes a crankcase and a crankshaft. The crankcase includes a clutch side compartment, a primary compartment, a transmission compartment, and a magneto electric starter compartment. The clutch side compartment houses a clutch assembly and a clutch side oil reservoir. The primary compartment houses a primary gear which is mounted on a crankshaft. The transmission compartment houses a gear box assembly and a gearbox oil reservoir. Further, the magneto electric starter compartment houses a magneto gear, an electric starter gear, and a magneto oil reservoir. All the aforesaid oil reservoirs act as a seat for the lubricating oil and are connected to each other through a number of passages provided within the crankcase. In operation, a rotation of the clutch assembly lifts the lubricating oil stored in the clutch side oil reservoir and splashes the oil onto the operating components adjacent to the clutch assembly. The operating components may include the primary gear connected to a fuel cam of the IC engine. A portion of the splashed lubricating oil is flows upward guided by the baffle profile. The baffle profile is rigidly disposed in the clutch side compartment, along a circumference of the clutch assembly. The flow of the lubricating oil created by the baffle profile is received by an oil catching pocket rigidly connected to the crankcase. The oil catching pocket is located over the clutch assembly in the clutch side compartment. The oil catching pocket allows transport of the lubricating oil to the transmission compartment through a shower pipe. In the transmission compartment, the shower pipe is disposed directly above the gearbox assembly provided therein. A shower of the lubricating oil by the shower pipe lubricates gears and shafts in the gear box assembly. The showered lubricating oil gets collected in the gearbox oil reservoir located at the bottom of the transmission compartment and is transported to the clutch side oil reservoir through a set of oil channels within the crankcase. Some of the lubricating oil also gets forwarded to the magneto oil reservoir through another set of oil channels provided within the crankcase. The lubricating oil received by the magneto oil reservoir is used to lubricate the operating components of the magneto electric starter compartment. For this purpose, a magneto gear of the magneto electric starter compartment rotates and pressurizes the lubricating oil arrived in the magneto oil reservoir. In the process, the lubricating oil is splashed onto the operating components of the magneto electric starter compartment. In accordance with the foregoing description, both the splash and the shower lubrication mechanisms may be implemented together within the IC engine. This combined splash-and-shower lubrication mechanism is cost-effective and requires fewer components than conventional lubrication mechanisms used in the IC engines. In addition, the present lubrication mechanism provides a reliable alternative to an oil pump powered lubrication mechanism. Fig. 1 illustrates a schematic view of an exemplary crankcase assembly 100 of an internal combustion (IC) engine, in an embodiment of the present subject matter. The crankcase assembly 100 of the IC engine includes the crankcase 101 and a crankshaft (depicted in Fig 4). The crankcase 101 includes a primary compartment 102, which houses a primary gear 102-1. In addition, a clutch side compartment 103 is provided within the crankcase 101 for a clutch driven motion transmission. The clutch side compartment 103 houses the clutch assembly 104 and a clutch side oil reservoir (not shown in Fig). The clutch assembly 104 may be operable connected to a plurality of operating components of the IC engine. In one implement ion, the primary gear 102-1 is in mesh with a primary driven gear, which is axially connected to the clutch assembly 104. The primary gear 102-1 may be mounted on the crankshaft, whereas the primary driven gear and the clutch assembly 104 may be mounted on a counter-shaft (depicted in Fig 5d). In addition, the clutch assembly 104 is dipped partially in a lubricating oil stored in the clutch side oil reservoir. The clutch side oil reservoir is located at the bottom of the clutch side compartment 103. The lubricating oil may flow from the clutch oil reservoir to the crankcase 101 through a number of passages provided on a portion of the crankcase 101. This portion of the crankcase 101 may lie toward the bottom of the clutch side compartment 103. Fig. 2 illustrates a sectional view of the exemplary crankcase assembly 100 as shown in Fig 1, according to an embodiment of the present subject ratter. The sectional view of the crankcase assembly 100 depicts the operating components of the clutch side compartment 103. As shown in Fig 2, the clutch side compartment 103 houses the clutch assembly 104. The clutch assembly 104 is operable connected to the primary gear 102. The primary gear 102-1 acts as a primary motion transmitting means to the clutch assembly 104 and to all other movable components of the C engine. In one implementation, the primary gear 102-1 may include a fuel cam (not shown in Fig1) mounted thereon. The clutch side compartment 103 further houses a baffle profile 205, which facilitate creation of a flow of lubricating oil. The baffle profile 205 is provided along the circumference of the clutch assembly 104 and rigidly connected to the crankcase 101. The baffle profile 205 extends from the crankcase 101 till a point of interface between the clutch assembly 104 and the primary gear 102. An oil catching pocket 210 is provided in the clutch side compartment 103 above the clutch assembly 104 and rigidly connected to the crankcase 101. A line N-N illustrates a level of the lubricating oil contained in the clutch side compartment 103 below the clutch assembly 104. In operation, a rotation of the crankshaft rotates the clutch assembly 104 across the level N-N. This causes the clutch assembly 104 to splash lubricating oil onto the neighboring components of the clutch assembly 104 such as the primary gear 102-1, the fuel cam (not shown in Fig), and a roller tappet assembly (not shown in the Fig). A particular volume of the lubricating oil splashed by the clutch assembly 104 is partly guided by the baffle profile 205 towards the oil catching pocket 210. In one embodiment, the contour of the baffle profile 205 is designed in such a way that the cross-section of the baffle profile 205 increases in the direction of rotation of clutch assembly 104. This variation in cross section of the baffle profile 205 causes the lubricating oil to be drawn in an upward direction in the form of a flow, thereby simulating a typical pump delivery mechanism. The passage created by the baffle profile 205 around the clutch assembly 104 finally opens into the oil catch pocket 210, which is connected to a shower pipe (shown in Fig 3) included within a transmission compartment (depicted later in Fig 3) provided in the crankcase 101. Accordingly, the oil catching pocket 210 flow connects the clutch side compartment 103 to a transmission compartment 300. The combination of clutch assembly 104 and the baffle profile 205 within the crankcase 101 works together as a pump to lift the lubricating oil and then guide it to the oil catch pocket 210. The lubricating oil is transported from the clutch side oil reservoir to the shower pipe of the transmission compartment through the oil catching pocket 210 to lubricate operating components of the transmission compartment. Fig. 3 illustrates a sectional view of a transmission compartment 300 of the crankcase 101 implemented within the crankcase assembly 100 of Fig 1, along a sectional line M-M and in accordance with an embodiment of the present subject matter. The transmission compartment 300 houses a gear box assembly 302, the shower pipe 305, and the gearbox oil reservoir (not shown in Fig). The gear box assembly 302 includes a plurality of components, such as the counter shaft, a drive shaft (depicted in Fig 5b), and a plurality of meshed gears. The shower pipe 305 is located above the gear box assembly 302 and includes a plurality of orifices. The gearbox oil reservoir is located at the bottom of the transmission compartment 300 and is flow connected to the crankcase 101 through multiple passages provided on a portion of the crankcase 101, This portion of the crankcase 101 may lie toward the bottom of the transmission compartment 300. In an implementation, the lubricating oil received by the oil catching pocket 210 flows through the shower pipe 305 into the transmission compartment 300. The shower pipe 305 facilitates showering of the lubricating oil on to the gear box assembly 302 through the orifices provided therein. This enables effective lubrication of gear-gear interfaces and gear-shaft interfaces of the drive shaft and the counter shaft included in the gear box assembly 302. This mechanism of showering the lubricating oil on to the components is referred to as shower lubrication. Further, the showered lubricating oil is collected in the gearbox oil reservoir at the bottom of the transmission compartment 300 and is transported back to the clutch side oil reservoir through a first set of oil channels included within the clutch side compartment 103. Some of the lubricating oil gets forwarded to a magneto oil reservoir of a magneto electric starter compartment (depicted in Fig 4) through a second set of oil channels. It will be understood that these oil channels are hollow passages provided within the crankcase 101. Fig. 4 illustrates a front view of a magneto electric starter compartment 400 of the crankcase 101 implemented in the crankcase assembly 100 of Fig 1, in an embodiment of the present subject matter. The crankcase 101, in addition to the components discussed previously, includes a magneto electric starter compartment 400 having a plurality of operating components such as a magneto gear 402, an electric starter gear 404, a starter gear (not shown in the figure), and a one way clutch (not shown in figure). The magneto electric starter compartment 400 includes a magneto oil reservoir (not shown in Fig.), a first opening 406, and a second opening 408. Both of the first opening 406 and the second opening 408 are provided on a portion of the crankcase 101 surrounding the magneto electric starter compartment 400. The magneto oil reservoir is placed at a bottom position inside the magneto electric starter compartment 400. The magneto gear 402 is dipped partially in the magneto oil reservoir. The first opening 406 is located at the bottom of the magneto electric starter compartment 400 and along the magneto gear 402. The second opening 408 is located above the first opening 406 at an upper section of magneto electric starter compartment 400. In an implementation, when the IC engine is activated, the magneto gear 402 is rotated by the rotation of the crankshaft 410. As the magneto gear 402 rotates, the lubricating oil that has arrived in the magneto oil reservoir is pressurized to flow through the first opening 406. The pressure of the lubricating oil is used to splash the lubricating oil onto the operating components of the magneto electric starter compartment 400. The second opening 408 returns the lubricating oil to the clutch side oil reservoir through a third set of oil channels provided within the crankcase 101. With respect to the foregoing description, it may be understood that all the aforementioned oil reservoirs are connected to the crankcase 101 and to one another other through the aforementioned sets of oil channels. In one embodiment, these oil channels may be provided on inner walls of the crankcase 101. These inner walls act as boundaries to separate the clutch side compartment 103, the transmission compartment 300, and the magneto electric starter compartment 400, Accordingly, the sole lubricating oil is circulated among the aforementioned compartments. In this manner, a combined splash and shower lubrication mechanism may be achieved within the crankcase assembly 100 of the IC engine. Fig. 5a illustrates a side view of the crankcase assembly 100 of Fig 1, in an embodiment of the present subject matter. As aforesaid, the crankcase l01 of the crankcase assembly 100 includes the transmission compartment 300. As mentioned under the description of Fig 3, the transmission compartment 300 includes a plurality of operating components included in the gearbox assembly 302. These operating components of the gearbox assembly 302 may include a number of drive gears and counter gears mounted on the dive shaft and the counter shaft, respectively. Correspondingly, the drive gears and the counter gears are meshed together. One pair of the meshed gears of the gearbox assembly 302 is located outside the transmission compartment 300 and may be referred to as the primary drive gear 102-1 and the primary driven gear, which is mounted on the counter shaft. The primary driven gear has been mentioned before under the description of Fig 1. This pair may be positioned on the outer side of the crankcase 101 towards the clutch side compartment 103. The remaining gears of the gearbox assembly 302 may be located inside the transmission compartment 300. Fig. 5b illustrates a sectional view of the crankcase assembly 100 of Fig 5a along a sectional line A-A, in an embodiment of the present subject matter. The sectional view illustrated by Fig 5b depicts the orientation of the drive shaft 502 within the transmission compartment 300. The drive shaft 502 may include a first pair of radial openings (depicted in Fig 5c) for lubrication of the gear-shaft interfaces of the gearbox assembly 302. As aforementioned, the rotation of the clutch assembly 104 facilitates transportation of the lubricating oil from the clutch side oil reservoir to the oil catching pocket 210, The transported lubricating oil is canalized through an oil conduit 508 and a manifold 510 into a first passageway 504. The first passageway 504 is created within the drive shaft 502 by drilling the drive shaft 502 longitudinally at the center. In another embodiment, the manifold 510 may also be placed around the drive shaft 502. Fig. 5c illustrates a sectional view of the transmission compartment 300 of the crankcase 101 implemented within the crankcase assembly 100 of Fig 5a, in an embodiment of the present subject matter. As depicted by Fig 5c, the drive shaft 502 includes the first pair of radial openings 511-1 and 511-2, hereinafter referred to as 511, for providing lubrication to the gear-shaft interfaces of the drive shaft 502 provided within the gearbox assembly 302. In one embodiment, the drive shaft 502 may have more than two radial openings 511, As described in Fig 5b, the lubricating oil is canalized through the oil conduit 508 and the manifold 510 into the first passageway 504. To facilitate this canalization, the oil conduit 508 is connected to the oil catching pocket 210 and is directed towards the manifold 510. Accordingly, the lubricating oil from the oil catching pocket 210 is forwarded through the oil conduit 508 to the manifold 510 and then enters the first passageway 504. Subsequently, the lubricating oil from the first passageway 504 lubricates the gear-shaft interfaces through the first pair of radial openings 511 provided on the drive shaft 502. In this manner, the first passageway 504 provides lubrication to the gear-shaft interfaces of the gearbox assembly 302. Accordingly, the first passageway 504 facilitates lubrication of the gear shaft interfaces together with the shower pipe 305. As explained under the description of Fig, 3, the shower pipe 305 facilitates lubrication of the gear shaft interfaces of the drive shaft and the counter shaft of the gearbox assembly 302, Fig. 5d illustrates a schematic view of the crankcase assembly 100 of Fig 1, in an embodiment of the present subject matter. As shown, the clutch side compartment 103 includes a hub clutch 512 mounted on the counter shaft 515. Specifically, the hub clutch 512 is integral to the clutch assembly 104 and mounted on the countershaft 515 within the clutch side compartment 103. The hub clutch has multiple radial slots (depicted in Fig, 5f) located thereon. The multiple radial slots facilitate transfer of the lubricating oil from the clutch side oil reservoir onto the counter shaft 515. Fig. 5e illustrates a sectional view of the exemplary transmission compartment 300 of the crankcase assembly 100 of Fig 5d along a sectional line D-D, in an embodiment of the present subject matter. The view as illustrated depicts the counter shaft 515 of the transmission compartment 300 having a second pair of radial openings 516-1 and 516"2, hereinafter referred to as 516, for the lubrication of the gear-shaft interfaces provided on the countershaft 515. In addition, the countershaft 515 is drilled longitudinally at its centre to provide a second passageway 517. Fig. 5f illustrates a sectional view of the clutch side compartment 104 of the crankcase 101 implemented within the crankcase assembly 100 of Fig Se, along a sectional line E-E, in an embodiment of the present subject matter. As shown in Fig 5e, the hub clutch 512 mounted on the counter shaft 515 includes at least four radial slots 518-1, 518-2, 518-3 and 518-4, hereinafter referred to as 518. Without limiting the scope of the present subject matter, the hub clutch 512 may have more than four radial slots 518. In operation, the rotation of the clutch assembly 104 splashes the lubricating oil stored in the clutch side oil reservoir, as explained in the detailed description of Fig. 1. The splashed lubricating oil may be received by the counter shaft SIS through the radial slots 518 provided on the hub clutch 512. Subsequently, the splashed lubricating oil is entrapped through these radial slots 518 in the second passageway 517. This entrapped lubricating oil in the second passageway 517 is delivered to the gear-shaft interfaces provided on the countershaft 515 through the second pair of radial openings 516, thereby providing the lubrication for the gear-shaft interfaces. Accordingly, the second passageway 517 facilitates lubrication of the gear shaft interfaces together with the shower pipe 305. The previously described versions of the subject matter and its equivalent thereof have many advantages, including those which are described below. The present crankcase assembly 100 obviates employment of an oil pump, which is otherwise required for providing shower lubrication and for pumping the lubricating oil inside the IC engine. Accordingly, the present crankcase assembly 100 facilitates a decrease in weight and size of the IC engine, thereby improving reliability of an IC engine assembly. In addition the present crankcase assembly 100 facilitates a reduction in various intermediate components such as shafts and gears, which are otherwise required for separately driving the splash lubrication mechanism and the shower lubrication mechanism. Accordingly, the present crankcase assembly 100 minimizes the cost of the IC engine. Although the subject matter has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. As such, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiment contained therein. I/We claim: 1, A crankcase (101) comprising: a clutch side compartment (103) to house at least a clutch assembly (104); and a primary compartment (102) to house at least a primary gear (102-1), wherein the primary compartment (102) is adjacent to the clutch side compartment (103); characterized in that, a baffle profile (205) is provided in the clutch side compartment (103) along a circumference of the clutch assembly (104), wherein the baffle profile (205) extends till an interface between the clutch assembly (104) and the primary gear (102-1); and an oil catching pocket (210) is provided above the clutch assembly (104) in the clutch side compartment (103), wherein the oil catching pocket (210) is flow-connected to the baffle profile (205). 2. The crankcase (101) as claimed in claim 1, wherein the crankcase (101) further comprises a transmission compartment (300) to house at least a drive shaft (502). 3. The crankcase (101) as claimed in claim 2, wherein the oil catching pocket (210) flow-connects the transmission compartment (300) with the clutch side compartment (103). 4. The crankcase (101) as claimed in claim 2, wherein the drive shaft (502) comprises a first passageway (504) flow-connected to the oil catching pocket (210) through an oil conduit (508). 5. The crankcase (101) as claimed in claim 2, wherein the drive shaft (502) comprises a first pair of radial openings (511). 6. The crankcase (101) as claimed in claim 2, wherein the clutch side compartment (103) is flow-connected to the transmission compartment (300) through a first set of oil channels. 7. The crankcase (101) as claimed in claim 2, further comprising a magneto electric starter compartment (400) flow-connected to the transmission compartment (300) through a second set of oil channels. 8. The crankcase (101) as claimed in claim 1, wherein the magneto electric starter compartment (400) is flow-connected to the clutch side compartment (103) through a third set of oil channels. 9. An internal combustion engine comprising a crankcase (101) as claimed in any of the preceding claims. |
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| Patent Number | 272978 | ||||||||||||
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| Indian Patent Application Number | 21/CHE/2009 | ||||||||||||
| PG Journal Number | 20/2016 | ||||||||||||
| Publication Date | 13-May-2016 | ||||||||||||
| Grant Date | 06-May-2016 | ||||||||||||
| Date of Filing | 05-Jan-2009 | ||||||||||||
| Name of Patentee | TVS MOTOR COMPANY LIMITED | ||||||||||||
| Applicant Address | JAYALAKSHMI ESTATE, 24 (OLD # 8), HADDOWS ROAD, CHENNAI - 600 006 | ||||||||||||
Inventors:
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| PCT International Classification Number | F02M | ||||||||||||
| PCT International Application Number | N/A | ||||||||||||
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