JP2006183594A - Lubrication structure for bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubrication structure for a bearing collecting oil spattered from gears by ribs formed integrally with a crankcase and feeding the oil to the bearings of the crankshaft. <P>SOLUTION: The ribs 55 having surfaces extending in the rotating axis direction of the crankshaft 9 on the wall part 43a of a right side case half body 43 supporting the upper part of the roller bearing 30 are formed integrally with the right side case half body 43 so that its width in the rotating axis direction is narrowed from its upper end 55a toward its lower end 55b. The ribs 55 are positioned so that, as viewed in a direction orthogonal to a rotating axis, a part of a primary driven gear 37 in the rotating axis direction disposed in the right side case half body 43 and splashing the oil by drivingly rotating is overlapped with a part of the upper part of the ribs 55 in the rotating axis direction. Also, the ribs 55 are so formed that the lower ends 55b of the ribs are positioned near the roller bearing 30. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bearing lubrication structure in which oil is supplied to a bearing of a crankshaft by splashing of oil scattered from a gear located in the vicinity.

  The gear in the crankcase is lubricated by scooping up oil stored in the bottom of the crankcase as the gear is driven to rotate. At this time, since oil scatters around from the gear, there is known an oil supply structure that collects the oil scattered on the wall surface of the crankcase and supplies it to the bearing of the crankshaft (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 58-1212799 (FIGS. 2 and 3)

  However, in order to collect the scattered oil and supply it to the bearings, it is necessary to manufacture a dedicated member and attach it to the crankcase, which increases the manufacturing cost of the dedicated member and the assembly cost of the engine. It was.

  The present invention has been made in view of such problems, and provides a lubricating structure for a bearing that collects oil scattered from a gear by a rib formed integrally with a crankcase and supplies the oil to the bearing of the crankshaft. With the goal.

  In order to solve the above-described problems, a bearing lubrication structure according to the present invention is disposed between a housing (for example, the right case half 43 in the embodiment) and a rotating shaft (for example, the crankshaft 9 in the embodiment). The bearing (for example, the roller bearing 30 in the embodiment) that rotatably supports the rotating shaft with respect to the housing is lubricated, and the support wall (for example, the wall in the embodiment) of the housing that supports the upper portion of the bearing. A rib having a surface extending from the portion 43a) in the rotation axis direction of the rotation shaft is formed integrally with the support wall so that the width in the rotation axis direction becomes narrower from the upper end toward the lower end. Then, when the rib is viewed from the direction orthogonal to the rotation axis, the rotation shaft of the first gear (for example, the primary driven gear 37 in the embodiment) is disposed in the housing and rotationally driven to raise the splash of oil. It is configured such that a part in the direction and a part in the rotational axis direction of the upper part of the rib overlap each other, and the lower end of the rib is located in the vicinity of the bearing.

  At this time, a second gear (for example, the pump drive gear 36 in the embodiment) attached to the rotary shaft and adjacent to the bearing is disposed below the rib, and the bearing is disposed between the lower end of the rib and the second gear. A passage (for example, oil supply passage 56 in the embodiment) that communicates and supplies oil to the bearing is preferably formed.

  In addition, it is preferable that the lower end part of a rib has an inclination part inclined in a bearing direction. Or it is preferable that the lower end part of a rib has an inclination part which inclines in a 2nd gear direction.

  If the lubricating structure of the bearing according to the present invention is configured as described above, the oil adhering to the housing or the rib is supplied to the bearing through the rib, so that the rolling noise of the rotating shaft can be reduced. In addition, since a dedicated member for collecting and supplying the oil scattered from the first gear is not required, the manufacturing cost of the bearing lubrication structure can be reduced and the assembling work can be made efficient.

  At this time, the second gear attached to the rotating shaft is disposed below the rib, and a passage is formed between the lower end of the rib and the second gear, so that the rib can be directly or from the lower end of the rib. By applying, oil can be supplied to the bearing from this passage.

  In addition, by providing the inclined part which inclines in a bearing direction in the lower end part of a rib, the oil which flows through a rib can be flowed along this inclined part, and this oil can be directly supplied to a bearing. Or by providing the inclined part which inclines toward the 2nd gear in the lower end part of a rib, the oil which fell from the lower end of a rib can be applied to a gear, and can be supplied to a bearing.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Here, the case where the lubrication structure of the bearing according to the present invention is used for an air-cooled internal combustion engine (engine 1) mounted on a motorcycle will be described with reference to FIGS. The description will be made with the direction of the arrow U shown in FIG. 1 as the upward direction and the direction of the arrow F shown in FIG.

  The engine 1 includes a cylinder head 2, a cylinder block 3, and a crankcase 4. A piston 7 is disposed in a cylinder chamber 6 surrounded by a cylinder sleeve 5 fitted in the cylinder block 3 so as to be slidable up and down. The piston 7 is connected to a crankcase via a connecting rod 8. 4 is connected to a crankshaft 9 that is rotatably held in the cylinder 4. An intake port 11 and an exhaust port 12 communicate with the combustion chamber 10 formed by the cylinder sleeve 5, the cylinder head 2 and the piston 7 through an intake port and an exhaust port, respectively. The saddle-shaped intake valve 13 and the saddle-shaped exhaust valve 14 are each provided with an intake port by valve springs 15 and 16, one end of which is attached to the valve shaft and supported by the retainer, and the other end is supported by the cylinder head 2. The exhaust port is always biased in the direction of closing.

  Further, a camshaft 17 for opening and closing the intake valve 13 and the exhaust valve 14 is rotatably supported on the cylinder head 2. A cam driven sprocket 18 and a crankshaft 9 disposed on the camshaft 17 are supported. A timing chain 20 is wound around a cam drive sprocket 19 disposed on the front side. Therefore, the camshaft 17 rotates in accordance with the rotation of the crankshaft 9, and the cams 21 and 22 formed on the camshaft 17 push down the intake valve 13 and the exhaust valve 14 via the rocker arms 23 and 24. Open and close intake and exhaust ports. Further, a carburetor 26 is attached to the intake port 11 via an inlet pipe 25, and fuel is atomized by the carburetor 26 (sprayed) and supplied to the combustion chamber 10 together with air. Further, the cylinder head 2 is provided with a spark plug 27.

  The intake port 11 is formed so as to extend upward from the combustion chamber 10 in the cylinder head 2 and opens at the top, and the exhaust port 12 extends from the combustion chamber 10 downward in the cylinder head 2. Formed and open at the bottom.

  In the engine 1 configured as described above, a mixture of air and fuel that has been cleaned by an air cleaner (not shown) is supplied from the carburetor 26 to the combustion chamber 10 via the intake port 11 and compressed by the piston 7. After that, it is ignited by the spark plug 27 and burns to become energy for rotating the crankshaft 9 via the piston 7, and then discharged from the exhaust port 12 as exhaust gas.

  At this time, as shown in FIG. 3, the carburetor 26 is disposed above the cylinder block 3 and positioned on the crankshaft 9 side from the deck surface of the cylinder block 3. The carburetor 26 is configured to exhale air sucked from the rear, and the inlet pipe 25 is attached to the front portion of the carburetor 26. And the inlet pipe 25 which connects this carburetor 26 and the cylinder head 2 is arrange | positioned at circular arc shape centering on the crankshaft 9, and a channel | path is linear before and behind the connection part of the inlet pipe 25 and the intake port 11. FIG. It is attached as follows. Further, the intake port 11 is formed such that its axis extends in a substantially vertical direction from a connection portion with the inlet pipe 25, and the axis of the intake port 11a extends in the rear of the engine 1 in the vicinity of the intake port 11a. It is said that. Therefore, the air-fuel mixture discharged from the carburetor 26 flows upward (front side) in the inlet pipe 25 and the intake port 11 as indicated by the streamline L in FIG. Further, due to the inertial force of the air-fuel mixture flow, it is further biased toward the front side of the intake port 11 and flows into the combustion chamber 10. In this combustion chamber 10, the dumble flow is efficiently generated by the strong flow from the front side of the intake port 11. Is done. In addition, since the inlet pipe 25 and the intake port 11 are connected so as to be linear, useless ventilation resistance with respect to the air-fuel mixture does not occur, and intake efficiency can be improved.

  The crankshaft 9 is composed of a left crankshaft half body 9a and a right crankshaft half body 9b, and the connecting rod 8 is connected via a crankpin 28 arranged by connecting both the crankshaft half bodies 9a and 9b. It is connected. The crankcase 4 for storing the crankshaft 9 includes a left crankcase cover 41, a left case half 42, a right case half 43, and a right crankcase cover 44. The crankshaft 9 and the like are stored in the storage. That is, one end of the crankshaft 9 (the journal portion of the left crankshaft half 9a) is supported by the left case half 42 via the ball bearing 29, and the other end (the journal portion of the right crankshaft half 9b) is a roller bearing. 30, and is supported by the right case half 43. An ACG 31 is disposed at the tip of the journal portion of the left crankshaft half 9a.

  A primary drive gear 35 that rotates integrally with the right crankshaft half body 9b is disposed substantially at the center of the journal portion of the right crankshaft half body 9b. Further, a pump drive gear 36 that rotates integrally with the right crankshaft half 9b is disposed near the roller bearing 30 in the journal portion of the right crankshaft half 9b.

  In the crankcase 4, there is disposed a transmission 32 that shifts the rotational driving force of the crankshaft 9 and transmits it to the wheels. The transmission 32 has a transmission main shaft 33 and a transmission counter shaft 34 that are rotatably supported by the crankcase 4 with the rotation shaft extending in a substantially horizontal direction with respect to the rotation shaft of the crankshaft 9. On the transmission main shaft 33, a primary driven gear 37 and a clutch 38 that are rotatable relative to the transmission main shaft 33 and always mesh with the primary drive gear 35 are disposed. The primary driven gear 37 and the transmission main shaft 33 are The clutch 38 is engaged and disengaged. A clutch gear group 39 composed of a plurality of gear trains is provided between the transmission main shaft 33 and the transmission counter shaft 34. By changing the combination of the gear trains of the clutch gear trains 39, the gear ratio is changed. Is set.

  As described above, the rotational driving force of the crankshaft 9 is transmitted from the primary drive gear 35 to the primary driven gear 37 and is transmitted to the transmission main shaft 33 via the clutch 38. Then, this rotational driving force is shifted by the clutch gear group 39 and transmitted to the transmission countershaft 34, and from the rear wheel drive sprocket 50 disposed at the left end of the transmission countershaft 34 via the chain 51. It is transmitted to the rear wheel.

  On the other hand, the pump drive gear 36 disposed on the crankshaft 9 always meshes with the pump driven gear 52, and the rotational driving force of the crankshaft 9 is transmitted from the pump drive gear 36 to the pump driven gear 52 to drive the oil pump 53. The

  An inner wall 43a that divides the inside into right and left spaces is formed inside the outer wall 43c that forms the right case half 43, and a through-hole 43b that penetrates left and right is formed in the inner wall 43a. Has been. A cylindrical bush 54 is attached to the inner peripheral surface of the through hole 43b, and the roller bearing 30 described above is attached to the inner peripheral surface of the bush 54 to support the right crankshaft half 9b.

  Now, a lubricating structure for a bearing provided in the engine 1 configured as described above will be described. Inside the right case half 43, there is a rib 55 extending rightward from the inner wall 43a, that is, in the direction of the rotation axis of the crankshaft 9, between the upper portion of the through hole 43b and the outer wall 43c of the right case half 43. The right case half 43 is integrally formed. As for this rib 55, the upper end 55a is connected with the outer wall part 43c, and the lower end 55b protrudes in the through-hole 43b. The width in the left-right direction (rotational axis direction of the crankshaft 9) is wide at the upper end (portion connected to the outer wall portion 43c) 55a and gradually narrows toward the lower portion.

  At this time, as shown in FIG. 2, the rib 55 has a surface formed substantially parallel to the crankshaft 9, and when viewed from a direction orthogonal to the crankshaft 9, at least the upper portion of the rib 55 ( A part of the upper end 55a) in the left-right direction and a part of the primary drive gear 35 or the primary driven gear 37 in the left-right direction are arranged so as to overlap each other. On the other hand, as shown in FIG. 2, when the roller bearing 30 is attached to the through hole 43b, the lower end 55b is positioned on the right end side of the roller bearing 30 and has substantially the same height as the upper end portion of the roller. It is configured as follows. Further, the outer peripheral portion (outer peripheral portion of the tooth) of the pump drive gear 36 is disposed so as to be approximately the same size as the inner peripheral portion of the roller arranged concentrically with the crankshaft 9 of the roller bearing 30. Yes. The space between the upper end portion of the pump drive gear 36 and the lower end portion 55a of the rib 55 has a height substantially the same as the vertical dimension of the roller of the roller bearing 30 and is connected to this roller (oil supply passage). ) 56 is formed.

  In the engine 1 having such a configuration, the primary drive gear 35 rotates in the direction of the arrow 59 in FIG. 1, and the oil scattered from the primary drive gear 35 and the primary driven gear 37 is the right case half 43 and the right crankcase. It adheres to the inner wall of the cover 44 and the rib 55. Of the scattered oil, the oil adhering to the right case half 43 falls down along the inner peripheral surface of the right case half 43 (the inner peripheral surface of the outer wall portion 43c) and reaches the rib 55. It falls down along the rear surface of 55. Similarly, the oil adhering to the rib 55 also falls downward along the rib 55 (flows in the direction of the arrow 60 in FIG. 1). As described above, the width of the rib 55 in the left-right direction is such that the upper end 55a is wide and the width is narrower toward the bottom, so that most of the oil that has fallen along the rib 55 The oil is collected at the lower end 55 b, directly or against the tooth surface of the pump drive gear 36, enters the oil supply passage 56, and is supplied to the roller bearing 30.

  4 shows a case where the lower end 55b of the rib 55 is formed so as to extend in the direction of the rotation axis of the crankshaft 9, the lower end 55b is formed as shown in FIG. The right end side inclined portion 55c can be formed so as to incline downward toward the pump drive gear 36, or it can be formed in a wedge shape as shown in FIG. 5 (b). The inclined portion 55c on the side can be formed to be inclined toward the roller bearing 30. When the lower end 55b has a convex shape as shown in FIG. 5A, the oil that has dropped down through the rib 55 hits the tooth surface of the pump drive gear 36 and flows into the oil supply passage 56 as indicated by an arrow 60a. When the amount of oil increases and the lower end 55b has a wedge shape as shown in FIG. 5B, the amount of oil that flows directly into the oil supply passage 56 increases as indicated by the arrow 60b.

  The oil collected by the ribs 55 is not only the oil that scatters from the primary drive gear 35 and the primary driven gear 37 described above, but also the oil that scatters from the piston 7 and the cylinder sleeve 5 and adheres to the front surface of the rib 55. 30.

  As described above, the rib 55 is formed in the right case half 43 to constitute the bearing lubrication structure, so that sufficient oil can be supplied to the roller bearing 30 and the rolling noise of the crankshaft 9 is reduced. In addition, since a dedicated member for supplying oil is not required, the manufacturing cost of the engine 1 can be reduced and the assembly work can be made efficient.

1 is a side view of an engine having a bearing lubrication structure according to the present invention. 1 is a plan view of an engine having a bearing lubrication structure according to the present invention. It is principal part sectional drawing of the said engine. It is principal part sectional drawing of the right case half body in which the rib which comprises the lubricating structure of the bearing which concerns on this invention was formed. It is a modification of the lower end of a rib, (a) is a case where the inclination part which goes to a pump drive gear is provided, (b) is a case where the inclination part which goes to a roller bearing is provided.

Explanation of symbols

9 Crankshaft (Rotating shaft)
30 Roller bearing (bearing)
36 Pump drive gear (second gear)
37 Primary driven gear (first gear)
43 Right case half (housing)
43a Wall (support wall)
55 Rib 55a Upper end 55b Lower end 55c Inclined portion 56 Oil supply passage (passage)

Claims (4)

A lubrication structure of a bearing disposed between the housing and the rotating shaft and rotatably supporting the rotating shaft with respect to the housing;
A rib having a surface extending in the direction of the rotation axis of the rotary shaft from the support wall of the housing that supports the upper part of the bearing is integrated with the support wall so that the width in the direction of the rotation axis becomes narrower from the upper end to the lower end. Formed into
When the rib is viewed from a direction orthogonal to the rotation axis, a portion of the first gear in the rotation axis direction is disposed in the housing and rotationally driven to raise oil splash, and the rib A bearing lubrication structure, wherein an upper part of the rib is positioned so as to overlap, and a lower end of the rib is positioned in the vicinity of the bearing.   A second gear, which is attached to the rotating shaft and is adjacent to the bearing, is disposed below the rib, and communicates with the bearing between the lower end of the rib and the second gear to transmit the oil to the bearing. The lubricating structure for a bearing according to claim 1, wherein a passage for supplying to the bearing is formed.   The lubricating structure for a bearing according to claim 1 or 2, wherein a lower end portion of the rib has an inclined portion inclined in the bearing direction.   The bearing lubrication structure according to claim 2, wherein a lower end portion of the rib has an inclined portion inclined in the second gear direction.

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