Title of Invention

"LUBRICATING ARRANGEMENT IN AN INTERNAL COMBUSTION ENGINE"

Abstract

A lubricating arrangement in an internal combustion engine comprising a crankshaft, an oil pump rotating member integrally fitted on said crankshaft characterised in that an input member of a one way clutch for transmitting a starting torque from a starting motor to the crankshaft is provided adjacent to said oil pump rotating member; a bearing member is interposed between said input member and said output member of said one-way clutch; a space between said input member and said output member where said bearing member is interposed is opened at an end portion thereof near said oil pump rotating member; and a rib member having a lead edge portion accessible to the outer side surface of said one-way clutch, said one way clutch surrounds the outer periphery of said oil pump rotating member.

Full Text

The present invention relates to a lubricating arrangement in an internal combustion engine. In a conventional internal combustion engine, as shown in Fig. 6, a drive sprocket 02 for driving an oil pump (not shown) is integrally fitted on a crank shaft 01; a clutch outer 04 of a starting one-way clutch 03 is integrally fitted on the crank shaft 01 at a position adjacent to the drive sprocket 02 by way of a key 06; a driven gear 07 meshing with a drive pinion of a starting motor (not shown) is integrally fitted on a clutch inner 05 of the starting one-way clutch 03 at a position adjacent to a side wall 09 of a lubricating oil reservoir 08 surrounding the starting one-way clutch 03 and the oil pump; a needle bearing 010 is interposed between the outer peripheral surface of the clutch outer 04 and the inner peripheral surface of the clutch inner 05; and the space where the needle bearing 010 is fitteeUs-openedx of the lubricating oil reservoir, to the side wall 09 of the lubricating oil reservoir. Lubricating oil is dipped up by the rotation of the driven gear 07 and is stuck on the upper portion of the lubricating oil reservoir 08 by the effect of centrifugal force. It flows down along the surface of the side wall 09, and permeates from an opening portion 011 into the space where the needle bearing 010 is fitted, thus lubricating needle bearing 010. Each ball bearing 012 pivotably supporting the crank shaft 01 is lubricated by lubricating oil passing through a lubricating oil passage 014 provided in a crank case 013. On the other hand, part of the lubricating oil passing through the lubricating oil passage 014 is introduced, from a short-cylinder shaped rib 016 projecting from the outer peripheral side of the ball bearing 012 to a crank weight 015, into a space between a side surface recessed portion 017 formed in the crank weight 015 at a position near the center thereof and an annular side plate 018 integrated with the crank weight 015. It is further fed to an oil supply hole 021 and oil injecting hole 022 of a crank pin 020 on the large diameter end side of a connecting rod 019. By the lubricating oil thus fed, a needle bearing 023 at the large diameter end portion of the connecting rod 019 is lubricated. [Problem to be Solved by the Invention] In the conventional internal combustion engine shown in Fig. 6, the lubricating oil reservoir 08 is large in volume because it contains the driven gear 07 and the oil pump (not shown); accordingly, lubricating oil dipped up by the driven gear 07 is dispersed on a wide inner wall surface of the lubricating oil reservoir 08. As a result, the lubricating oil flowing near the crank shaft 01 along the side wall 09 is not sufficient to lubricate the needle bearing 010. Moreover, the drive gear 07 is rotated only upon starting the internal combustion engine, and thereby it cannot be expected to ensure the sufficient amount of lubricating oil dripped up by the rotation of the driven gear 07. Thus, the needle bearing 010 is lubricated only by a part flowing along the side wall 09, of lubricating oil dipped up by means of the drive sprocket 02 and the chain for driving the oil pump. The needle bearing, therefore, cannot be sufficiently lubricated. The size of the short-cylinder shaped rib 016 is larger than the outside diameter of the ball bearing 012 and naturally the inside diameter of the annular side plate 018 is enlarged, so that the cylindrical oil surface of lubricating oil reserved on the outer peripheral side between the side surface recessed portion 017 on the crank weight near the center thereof and the annular side plate 018 by the effect of centrifugal force is separated from the center of the crank shaft 01. As a consequence, the oil supply hole 021 must be provided in such a manner that the center C2 of the oil supply hole 021 of the crank pin 020 is shifted on the outside diameter side from the center C1 of the crank pin 020. This makes difficult the machining of the oil supply hole 021, resulting in the increased cost. [Means for Solving the Problem and Functional Effect] According to the present invention there is provided a lubricating arrangement in an internal combustion engine comprising a crankshaft, an oil pump rotating member integrally fitted on said crankshaft characterised in that an input member of a one way clutch for transmitting a starting torque from a starting motor to the crankshaft is provided adjacent to said oil pump rotating member; a bearing member is interposed between said input member and said output member of said one-way clutch; a space between said input member and said output member where said bearing member is interposed is opened at an end portion thereof near said oil pump rotating member; and a rib member having a lead edge portion accessible to the outer side surface of said one-way clutch, said one way clutch surrounds the outer periphery of said oil pump rotating member. In the present invention having the above-described construction, as an internal combustion engine is started to be operated by the rotation of a crank shaft, lubricating oil dipped up by the rotation of an oil pump rotating member within a crank chamber is introduced, in the state not dispersed but concentrated, into a space between an input member and an output member of a one-way clutch by the rib member surrounding the rotating member. As a result, even in the usual operating conditions other than the starting, the bearing member interposed between the input and output members can be sufficiently lubricated by the lubricating oil thus introduced. In the present invention, as described in claim 2, by connecting a drive sprocket as the oil pump rotating member to a driven sprocket of the oil pump by way of a chain, it becomes possible to freely set the oil pump position irrespective of the position where the crank shaft is arranged, and to keep at a high level the amount of lubricating oil supplied to a bearing member interposed between the input and output members of the one-way clutch by the chain. In the present invention, as described in claim 3, even when the leading edge of the rib member is contacted with the outer side surface of the input member of the one-way clutch, the input member of the one-way clutch is rotated only upon starting the internal combustion engine and is not rotated in other operational states, so that any frictional force is, at all times, not applied between the leading edge of the rib member and the outer side surface of the one-way clutch. [Brief Description of the Drawings] [Fig. 1] A right side view of an internal combustion engine including one embodiment of a lubricating system of the present invention. [Fig. 2] A vertical sectional plan view taken along line II-II of Fig. 1. [Fig. 3] A vertical sectional elevation view taken along line III-III of Fig. 1. [Fig. 4] An exploded perspective view of a one-way clutch in the embodiment shown in Fig. 1. [Fig. 5] A view seen from the arrow IV-IV of Fig. 2. [Fig. 6] A vertical sectional view of a conventional internal combustion engine. [Embodiment] Hereinafter, one embodiment of the present invention will be described with reference to Figs 1 to 5. A swing power unit 1 mounted in a scooter type motor-bicycle (not shown) has an air-cooled four-cycle internal combustion engine 2 in which a cylinder block 6 and a cylinder head 7 are tilted slightly upwardly from the front side; and a V belt-type non-stage transmission 3 integrated with the engine 2 and directed rearwardly from the left side of the engine 2. The swing power unit 1 is divided into members: a left crank case 4 serving as both a left crank case of the engine 2 and the transmission case of the non-stage transmission 3; a right crank case 5 of the engine 2; a cylinder block 6 integrally connected to the left crank case 4 and the right crank case 5; a cylinder head 7 connected to the top end of the cylinder block 6; a transmission cover 8 removably mounted on the left side of the left crank case 4; and a right cover 9 connected to the right side of the right crank case 5. A large diameter end portion 15 of a connecting rod 14 is rotatably fitted by way of a needle bearing 13 on a crank pin 12 of a crank shaft 11 pivotably supported in the left crank case 4 and the right crank case 5 by way of bearings 10. A small diameter end portion 16 of the connecting rod 14 is connected to a piston 17 by way of a piston pin 18. With this arrangement, the crank shaft 11 is rotated by the reciprocation of the piston 17 within a cylinder 19. A crank chamber 20 surrounded by the left crank case 4 and the right crank case 5 is communicated to a chamber 21 surrounded by the right crank case 5 and the right cover 9 by way of a communicating hole 22. In the chamber 21, a drive sprocket 23 for driving an oil pump 55 is spline-fitted on the crank shaft 11 while a clutch flange 30 integrated with a clutch outer 28 as an output member of a one-way clutch 26 is spline-fitted on the crank shaft 11, and after a washer 24 is fitted on the crank shaft 11, the drive sprocket 23 and the clutch flange 30 are integrally fitted on the crank shaft 11 by screwing a nut 25. As shown in Fig. 5, the one-way clutch 26 includes members: a clutch inner 27 integrated with a driven gear 39 meshing with a drive pinion 57 of a starter motor 56; the above-described clutch outer 28; a clutch flange 30 integrated with the clutch outer 28 by means of a bolt 29; a needle bearing 32 interposed in a space 31 between the inner peripheral surface of the clutch inner 27 and the outer peripheral surface of the clutch flange 30; a coil spring 35 inserted in a hole 34 provided substantially along the peripheral direction from a recessed portion 33 of the clutch outer 28; a plunger 36 slidably fitted in the hole 34; and a roller 37 fitted in the recessed portion 33. When the driven gear 39 is rotated in the same direction as that of the crank shaft 11 by the power of the starter motor upon starting, the rotation of the roller 37 due to the rotational difference between the clutch inner 27 and the clutch outer 28 causes a wedge force which allows the roller 37 to move to the shallow portion of the recessed portion 33, and by the wedge force, the clutch inner 27 is integrally connected to the clutch outer 28, thus transmitting the power of the starter motor. The space 31 between the clutch inner 27 and the clutch flange 30 is opened to the drive sprocket 23, and it is communicated to the chamber 21, by way of a gap between the right side surface of the clutch inner 27 and the left side surface of the clutch flange 30, and by way of a hole 38 of the clutch flange 30. As shown in Figs. 2, 3 and 4, a hollow 40 for containing the oil pump 55 is formed on the right side surface of the right crank case 5; a chain guide rib 41 is formed on the outer periphery of the hollow 40; and two arcuate oil shielding ribs 42 are formed along the upper periphery of the bearing 10 pivotably supporting the crank shaft 11. An oil passage 43 is formed in both the right cover 9 and the right crank case 5, and part of oil discharged from the oil pump 55 is introduced in the oil passage 43 and is then discharged from a left side surface opening 44 near the outer periphery of the bearing 10 into the crank chamber 20. As shown in Fig. 2, an annular oil path plate 45 covering the left side surface opening 44 is integrally mounted on the left side surface of the right crank case 5 by a screw 47. An inner end cylindrical portion 46 of the oil path plate 45 is located on the center side of the crank shaft 11 from an oil supply hole 50 of the crank pin 12. A right side surface recessed portion 49 is formed on a crank weight 48 integrated with the crank shaft 11, and an annular side plate 51 covering the right side surface recessed portion 49 is mounted integrally with the crank weight 48 on the outside diameter side of the crank shaft from the inner end cylindrical portion 46 of the oil path plate 45. In the crank pin 12, an oil injecting hole 53 for injecting oil reserved in the oil supply hole 50 is provided in the needle bearing 13 interposed between the crank pin 12 and the large diameter end portion 15 of the connecting rod 14. In the embodiment shown in Figs. 1 to 5 having the above construction, when a starter motor 56 is rotated by applying a current, the driven gear 39 meshing with the drive pinion 57 of the starter motor 56 is rotated, and the clutch inner 27 integrated with the driven gear 39 is rotated in the same direction. As the clutch inner 27 is rotated in the same direction as that of the crank shaft 11, the one-way clutch 26 becomes in the connection state, so that a starting torque is transmitted to the crank shaft 11 and the air-cooled four-cycle internal combustion engine 2 is cranked and started. After that even when the starter motor 56 is stopped and thereby the driven gear 39 and the clutch inner 27 are stopped, the oneway clutch 26 becomes in the disconnection state and prevents the transmission of torque from the crank shaft 11 to the starter motor 56. The drive sprocket 23 in rotated by the rotation of the crank shaft 11, and the oil pump 55 is driven by way of the endless chain 54. In such a state, even when oil in the chain guide rib 41 is dripped up by the movement of the endless chain 54, part of the oil dripped up by the oil shielding rib 42 permeates in the space 31 between the inner peripheral surface of the clutch inner 27 and the outer peripheral surface of the clutch flange 30 by way of the left end opening portion of the space 31. The oil is then discharged from a gap between the clutch inner 27 and the clutch flange 30 into the chamber 21 by way of the hole 38 thus sufficiently lubricating the needle bearing 32 in the space 31. Since the oil shielding rib 42 is close to the space 31, oil dipped up by the oil shielding rib 42 is not extensively dispersed and is smoothly introduced in the space 31. Since the leading edge of the oil shielding rib 42 abuts the left side surface of the driven gear 39, the driven gear 39 can be stably rotated. Part of lubricating oil discharged from the oil pump 55 is fed to the left side surface opening 44 by way of the oil passage 43, and it lubricates the right side bearing 10 through the space between the oil path plate 45 and the left side surface of the right crank case 5. On the other hand, the remaining oil is supplied from the inner end cylindrical portion 46 to the oil supply hole 50 by way of the space 52 surrounded by the right side surface recessed portion 49 and the annular side plate 51, and it is fed from the oil supply hole 50 by way of the oil injecting hole 53, to thus lubricate the needle bearing 13. Since the inner end cylindrical portion 46 of the oil path plate 45 is located on the center side from the outer peripheral surface of the bearing 10, the inner edge of the annular side plate 51 extends on the center side of the crank shaft 11 from the center of the crank pin 12. As a result, even when the center of the oil supply hole 50 corresponds to the center of the crank pin 12, the amount of oil reserved in the space 52 separated from the crank shaft 11 and in the outside diameter portion of the oil supply hole 50 by the effect of centrifugal force is sufficient to continuously lubricate the needle bearing 13. Accordingly, since the center of the oil supply hole 50 of the crank pin 12 is made to correspond to the center of the crank pin 12, the crank pin 12 can be simply machined, resulting in the reduced cost. [Explanation of Symbols] 1: swing power unit, 2: air-cooled four-cycle internal combustion engine, 3: V-belt type non-stage transmission, 4: left crank case, 5: right crank case, 6: cylinder block, 7: cylinder head, 8: transmission header, 9: right cover, 10: bearing, 11: crank shaft, 12: crank pin, 13: needle bearing, 14: connecting rod, 15: large diameter end portion 16: small diameter end portion, 17: piston, 18: piston pin, 19: cylinder, 20: crank chamber, 21: chamber, 22: communication hole, 23: drive sprocket, 24: washer, 25: nut, 26: one-way clutch, 27: clutch inner, 28: clutch outer, 29: bolt, 30: clutch flange, 31: space, 32: needle bearing, 33: recessed portion, 34: hole, 35: coil spring, 36: plunger, 37: roller, 38: hole, 39: driven gear, 40: hollow, 41: chain guide rib, 42: oil shielding rib, 43: oil passage, 44: left side surface opening, 45: oil path plate, 46: inner end cylindrical portion, 47: screw, 48: crank weight, 49: right side surface recessed portion, 50: oil supply hole, 51: annular side plate, 52: space, 53: oil injecting hole, 54: endless chain, 55: oil pump, 56: starter motor, 57: drive pinion WE CLAIM: 1. A lubricating arrangement in an internal combustion engine comprising a crankshaft, an oil pump rotating member integrally fitted on said crankshaft characterised in that an input member of a one way clutch for transmitting a starting torque from a starting motor to the crankshaft is provided adjacent to said oil pump rotating member; a bearing member is interposed between said input member and said output member of said one-way clutch; a space between said input member and said output member where said bearing member is interposed is opened at an end portion thereof near said oil pump rotating member; and a rib member having a lead edge portion accessible to the outer side surface of said one-way clutch, said one way clutch surrounds the outer periphery of said oil pump rotating member. 2. A lubricating arrangement for an internal combustion engine as claimed in claim 1, wherein said oil pump rotating member hou^ o, drive sprocket which is connected to a driven sprocket by a chain. 3. A lubricating arrangement as claimed in claim 1, wherein said input member of said one-way clutch has a clutch inner and output member of said one way clutch has a clutch outer; said bearing member being disposed between the inner peripheral surface of said clutch inner and the outer peripheral surface of said clutch outer. 4. A lubricating arrangement substantially of the kind as herein before described with reference to the foregoing examples and figures 1 to 5 of the accompanying drawings.

Documents:

377-del-1995-abstract.pdf

377-del-1995-claims.pdf

377-del-1995-correspondence-others.pdf

377-del-1995-correspondence-po.pdf

377-del-1995-description (complete).pdf

377-del-1995-drawings.pdf

377-del-1995-form-1.pdf

377-del-1995-form-13.pdf

377-del-1995-form-2.pdf

377-del-1995-form-3.pdf

377-del-1995-form-4.pdf

377-del-1995-form-9.pdf

377-del-1995-gpa.pdf

377-del-1995-petition-124.pdf