JP5460448B2 - Lubrication structure of gear bearing - Google Patents

Description

  The present invention relates to a lubricating structure of a bearing portion of a gear that is rotatably supported on a rotating shaft.

A structure in which a gear is pivotally supported so as to be relatively rotatable with respect to a rotating shaft can be seen, for example, in an example in which a starter driven gear is pivotally supported on a crankshaft in an internal combustion engine (see Patent Document 1).
That is, a one-way clutch is interposed between the starter driven gear and the crankshaft, and the rotation of the starter driven gear driven by the starter motor is transmitted to the crankshaft to start the engine. The rotation of the crankshaft is not transmitted to the starter driven gear side. Therefore, the crankshaft and the starter driven gear do not rotate integrally, and the starter driven gear is pivotally supported by the crankshaft so as to be relatively rotatable.

JP 2005-69022 A

In the internal combustion engine disclosed in Patent Document 1, a crankshaft is rotatably supported on a bearing wall of a crankcase via a ball bearing, and a crank extension shaft portion extending outside the crankcase of the crankshaft is provided. A starter driven gear is pivotally supported via a needle bearing so as to be relatively rotatable.
Lubricating oil is supplied to the ball bearing that supports the crankshaft through an oil passage formed in the crankshaft, but the crankshaft extending shaft that supports the starter-driven gear is usually within the crankshaft. Since the oil passage does not extend, the lubricating oil cannot be forcibly supplied to the needle bearing, and it is difficult to sufficiently lubricate.

  Therefore, in the internal combustion engine disclosed in Patent Document 1, the communication hole is provided in the bearing wall of the crankcase at a position facing the starter driven gear, and splashed oil due to the rotation of the crank web is guided to the communication hole, and is communicated. Through the hole, the lubricant is discharged from the hole on the outer side of the crankcase to the opposite gear side of the starter-driven gear, so that the lubricating oil flows between the bearing boss of the starter-driven gear and the crank extension shaft along the side of the gear. Guided to lubricate needle bearings.

  Lubricating oil is naturally supplied only from the opening on the one bearing wall side of the annular gap between the bearing boss of the starter driven gear and the crank extension shaft. If the lubricating oil is not moved, it is difficult to spread the lubricating oil over the entire bearing portion and lubricate without unevenness.

As described above, in order to lubricate the entire bearing portion of the gear supported by the rotary shaft so as to be relatively rotatable, a rolling bearing is employed.
However, rolling bearings are expensive.

  The present invention has been made in view of the above points, and the object of the present invention is to make the bearing portion of the gear rotatably supported on the rotating shaft a low-cost plain bearing and to make the entire bearing portion uneven. It is in providing a lubricating structure that can be efficiently lubricated.

In order to achieve the above object, the invention according to claim 1 is characterized in that in the lubricating structure of the bearing portion (20) in which the gear (21) is rotatably supported on the rotating shaft (9), the gear (21) the bearing boss portion of the annular inner peripheral surface (23) is a bearing sliding surface of the sliding bearing (23s), a lubricating oil passage (24) is formed in the interior of the bearing boss portion (23), the lubricant An oil passage introduction port (24i) of the oil passage (24) is formed with a plurality of circumferentially spaced openings on the side surface of the bearing boss portion (23), and the oil passage outlet port of the lubricating oil passage (24) An inner circumferential groove (24e) as (24e) is formed over the entire circumference in the circumferential direction on the bearing sliding surface (23s) of the bearing boss portion (23), and the gear (21) Is rotatably supported by the rotary shaft (9) so as to face the bearing walls (2b, 3b) on which the rotary shaft (9) is supported, and the bearing boss portion (23 of the gear (21)). The plurality of oil passage inlets (24i) formed on the side surface of the rotary shaft (9) and the bearing wall (2 b, 3b) is formed so as to be opposed to the annular gap (25) on the gear (21) side of the gap between which the bearing member (15) is interposed between the bearing surfaces (b, 3b). This is a lubrication structure of the bearing portion.

According to a second aspect of the invention, the lubrication structure for the bearing portion of the gear according to claim 1, before Symbol lubricating oil passage (24) is formed by drilling axially from the oil passage inlet (24i), wherein said inner circumferential groove (24e) is to be formed in a depth reaching said lubricating oil passage that is drilled in the axial direction from the bearing sliding surface (23s) (24) of the bearing boss (23) And

According to a third aspect of the present invention, in the lubricating structure of the bearing portion of the gear according to any one of the first and second aspects, the sliding of the rotating shaft (9) and the bearing boss portion (23) is performed. A plain bearing member (20) is interposed between the surface (23s).

According to a fourth aspect of the present invention, in the lubricating structure of the bearing portion of the gear according to the third aspect , the sliding bearing member (20) is a metal bush (20) which is a cylindrical plate.

According to a fifth aspect of the present invention, in the lubricating structure for a bearing portion of the gear according to any one of the first to fourth aspects, the rotating shaft (9) is an engine case (2, 3) of an internal combustion engine. a bearing wall (2b, 3b) a crank shaft which is rotatably supported via the bearing member (15) to said wheel (21), starter driven to power the starter motor (51) is transmitted The starter-driven gear (21) is a crank extension shaft portion extending from the bearing wall (2b, 3b) of the engine case (2, 3) of the crankshaft (9) to the outside of the engine case ( 9L) is rotatably supported by the shaft and can be connected to the crankshaft (9) via a one-way clutch (30).

According to a sixth aspect of the present invention, in the lubricating structure of the bearing portion of the gear according to any one of the first to fifth aspects, the bearing wall (2b, 3b) on which the rotary shaft (9) is pivotally supported. An annular ridge (2bb, 3bb) is formed to protrude toward the gear (21) so as to form the annular gap (25) on the side surface on the gear (21) side. .

According to the lubricating structure of the bearing portion of the gear according to claim 1, the inner peripheral surface of the annular bearing boss portion (23) of the gear (21) is used as the bearing sliding surface (23 s) of the slide bearing. Is rotatably supported on the rotary shaft (9) via an inexpensive slide bearing, and at the downstream end of the lubricating oil passage (24) formed inside the bearing boss portion (23) of the gear (21). Since the lubricating oil lead-out portion (24e) is open to the bearing sliding surface (23s), the entire bearing portion of the slide bearing can be lubricated efficiently without unevenness, and an inexpensive bearing structure can be provided.
Also, a plurality of oil passage introduction ports (24i) are formed on the side surface of the bearing boss portion (23) so as to open at intervals in the circumferential direction, and the oil passage outlet port (24e) is a bearing of the bearing boss portion (23). Since it is an inner circumferential groove (24e) formed over the entire circumference in the circumferential direction on the sliding surface (23s), it is easy to supply lubricating oil to the slide bearing, and the oil passage inlet (24i) Further, it is easy to process the inner circumferential groove (24e).
The plurality of oil passage introduction ports (24i) formed on the side surface of the annular bearing boss portion (23) of the gear (21) is formed between the rotating shaft (9) and the inner peripheral surface of the bearing wall (2b, 3b). It is formed facing the gap (25) that is the annular opening on the gear (21) side of the gap between which the bearing member (15) is interposed, so that the bearing member (15) of the rotating shaft (9) The supplied lubricating oil can be discharged toward a plurality of oil passage introduction ports (24i) formed on the side surface of the annular bearing boss portion (23) of the gear (21), and the lubricating oil passage (24) can be efficiently used. The entire sliding bearing can be sufficiently lubricated by introducing lubricating oil into the oil passage and through the oil passage outlet (24e).

According to the lubrication structure of a bearing part of claim 2, wherein the gear, Jun Nameraaburaro (24) are formed by perforated oil passage inlet from (24i) in the axial direction, an inner circumferential groove (24e) bearing Since it is formed with a depth reaching the lubricating oil passage (24) drilled in the axial direction from the bearing sliding surface (23s) of the boss portion (23), the lubricating oil passage (24) together with the oil passage inlet (24i) In addition, the inner circumferential groove (24e) can be easily processed.

According to the lubricating structure of the bearing portion of the gear according to claim 3 , the sliding bearing member (20) is interposed between the rotating shaft (9) and the bearing sliding surface (23s) of the bearing boss portion (23). Therefore, it can be set as a cheaper bearing structure rather than using a rolling bearing member.

According to the lubricating structure of the bearing portion of the gear according to the fourth aspect , since the sliding bearing member is the metal bush (20), an inexpensive bearing structure can be obtained.

According to the lubricating structure for the bearing portion of the gear according to claim 5 , the rotating shaft is rotatably connected to the bearing wall (2b, 3b) of the engine case (2, 3) of the internal combustion engine via the bearing member (15). The crankshaft (9) is supported, the gear is a starter driven gear (21) to which the power of the starter motor (51) is transmitted, and the starter driven gear (21) is an engine case (2 , 3) is rotatably supported by a crank extension shaft portion (9L) extending from the bearing wall (2b, 3b) to the outside of the engine case, and is connected to the crankshaft (9) via a one-way clutch (30). It can be connected, and the lubricating oil passage (24) formed in the bearing boss portion (23) of the starter-driven gear (21) can easily supply lubricating oil to the entire sliding bearing portion. Thus, the bearing can be configured at low cost.

According to the lubricating structure of the bearing portion of the gear according to claim 6 , the annular gap (25) is formed on the side surface on the gear (21) side of the bearing wall (2b, 3b) on which the rotating shaft (9) is supported. The annular ridge (2bb, 3bb) is formed so as to protrude toward the gear (21) so that the gear (21) is axially positioned by the annular ridge (2bb, 3bb). And an annular gap (25) is formed.

1 is a side view of an internal combustion engine according to an embodiment. It is a fragmentary sectional view (II-II line sectional view of Drawing 1) of the internal-combustion engine. It is a side view of a starter driven gear. It is sectional drawing (IV-IV sectional view taken on the line of FIG. 3) of the starter driven gear. It is a principal part expanded sectional view.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
The internal combustion engine 1 according to the present embodiment is a front / rear V-type four-cylinder four-stroke internal combustion engine mounted on a motorcycle.
A side view of the internal combustion engine 1 with a part thereof omitted is shown in FIG.

  A crankshaft 9 oriented in the vehicle width (left and right) direction is pivotally supported so that the lower crankcase 2 as an engine case and the upper cylinder block 3 are sandwiched, and the upper cylinder block 3 is a front bank of the front two cylinders. The cylinder row 3F and the rear bank cylinder row 3R of the rear two cylinders project obliquely upward and backward with a depression angle.

The front cylinder head 4F and the rear cylinder head 4R are mounted on the upper surfaces of the front bank cylinder row 3F and the rear bank cylinder row 3R of the cylinder block 3, and the tops of the front cylinder head 4F and the rear cylinder head 4R are connected to the front cylinder head cover 5F. The rear cylinder head cover 5R covers each.
An oil pan 6 covers the lower side of the crankcase 2.

Referring to FIG. 2 showing a partial cross section of the internal combustion engine 1, the crankcase 2 and the cylinder block 3 are bearing walls that support the three journal portions 9j of the crankshaft 9 at three locations on the left side, the center, and the right side. 2b and 3b are formed vertically.
A semicircular arc bearing surface is formed on the mating surfaces of the bearing walls 2b and 3b so as to be opposed to each other, and the journal portion 9j of the crankshaft 9 is rotatable between the upper and lower bearing surfaces via the metal bearing 15. Be supported.

As shown in FIG. 5, the bearing wall 2b, the bearing surface of the 3b are lubricating oil groove 16 is an internal circumferential groove is formed in the circumferential direction, from a portion of Jun Namerayumizo 16 of the crankcase 2 bearing An oil passage 17 is formed inside the wall 2b and other walls. The oil passage 17 guides a part of oil discharged from an oil pump (not shown) to the metal bearing 15 and lubricates it.
The oil that has lubricated the metal bearing 15 is supplied to the crankpin 9p through an oil passage 18 formed inside the crankshaft 9, and the journal portion 9j of the crankshaft 9 that sandwiches the metal bearing 15 and the bearing wall 2b, It discharges to the left and right sides from the gap of the bearing surface of 3b.

  The front side of the cylinder block 3 is placed in the crank chamber C between the opposite left bearing walls 2b, 3b and the central bearing walls 2b, 3b and in the crank chamber between the central bearing walls 2b, 3b and the right bearing walls 2b, 3b, respectively. The cylinder bores of the bank cylinder and the rear bank cylinder face each other, and the connecting rod 11 connects the piston pin 10p of the piston 10 that reciprocates in the cylinder bore and the crank pin 9p provided on the crank web of the crankshaft 9. .

The left side wall of the crankcase 2 and the cylinder block 3 having the left side bearing walls 2b and 3b has peripheral walls 2s and 3s protruding from the left side so as to largely surround the periphery of the left side bearing walls 2b and 3b. , 3s is the mating surface with the ACG cover 7 that covers the AC generator 40 in the peripheral walls 2s, 3s.
The right side surfaces of the right side bearing walls 2 b and 3 b of the crankcase 2 and the cylinder block 3 are covered with the right side cover 8.

The crankshaft 9 penetrates the left bearing walls 2b and 3b and projects a left crank extending shaft portion 9L to the left.
The left crank extension shaft portion 9L is provided with a short cylindrical shaft portion 9a and a cylindrical shaft portion 9a that extend slightly with a reduced diameter from the journal portion 9j that is pivotally supported by the left bearing walls 2b and 3b via the metal bearing 15. And a long taper shaft portion 9b that is gradually reduced in diameter to the left and extended.

A metal bush 20 , which is a cylindrical plate, is fitted to the columnar shaft portion 9 a of the left crank extension shaft portion 9 </ b> L, and the starter driven gear 21 is rotatable about the crankshaft 9 through the metal bush 20. Be supported.
The metal bush 20 is a metal plate made of a material whose hardness is softer than that of the starter driven gear 21.

A rotor boss 41b having a taper inner peripheral surface of the outer rotor 41 of the AC generator 40 is fitted into the taper shaft 9b of the left crank extension shaft 9L, and a mounting bolt 44 passes through a washer 43 at the left end of the rotor boss 41b. Then, the outer rotor 41 is fitted to the taper shaft portion 9b by being screwed into the left crank extension shaft portion 9L.
An inner stator 42 around which a stator coil 42c is wound is supported and disposed on the ACG cover 7 inside a magnet 41m that is provided around the inner peripheral surface of the outer rotor 41 having a bowl shape of the AC generator 40.

A right side view of the starter driven gear 21 is shown in FIG. 3, and a sectional view (IV-IV sectional view of FIG. 3) is shown in FIG.
As shown in FIGS. 3 and 4, the starter driven gear 21 has a structure in which a hollow disk-like gear portion 22 is integrally fitted around a cylindrical bearing boss portion 23, and is axially A gear portion 22 having a small axial width is fitted to the bearing boss portion 23 having a large width so as to be biased to the right in the axial direction.

A lubricating oil passage 24 is formed in the bearing boss portion 23 of the starter driven gear 21.
Six lubricating oil passages 24 are formed by drilling in the axial direction from six oil passage introduction ports 24 i formed in the circumferential direction on the right side surface of the bearing boss 23. The outlet is an inner circumferential groove 24e drilled over the entire circumference in the circumferential direction on the bearing sliding surface 23s of the bearing boss 23.

  The six lubricating oil passages 24 are parallel to the central axis of the cylindrical bearing boss portion 23, are equidistant from the central axis, and are provided at equal intervals in the circumferential direction, and are oil passage outlets. The inner circumferential groove 24e is formed with a depth reaching the lubricating oil passage 24 pierced in the axial direction from the bearing sliding surface 23s, and serves as a common oil passage outlet for the six lubricating oil passages 24.

The inner circumferential groove 23e has a trapezoidal shape whose cross section gradually becomes wider from the lubricating oil passage 24 toward the bearing sliding surface 23s.
It is easy to excavate the inner circumferential groove 24e on the bearing sliding surface 23s of the bearing boss portion 23 which is a separate body from the gear portion 22, and the lubricating oil passage 24 is drilled from the side surface of the bearing boss portion 23. It is also easy to do and has very good workability.

A starter-driven gear 21 having a gear portion 22 fitted to the bearing boss portion 23 is pivotally supported by a cylindrical shaft portion 9a of a left crank extension shaft portion 9L of the crankshaft 9 through a metal bush 20 so as to be relatively rotatable. .
The starter driven gear 21 is adjacent to the crankcase 2 and the left bearing walls 2 b and 3 b of the cylinder block 3.

Referring to FIG. 5, the six lubricating oil passages 24 formed in the bearing boss portion 23 of the starter driven gear 21 are on the same cylinder as the metal bearing 15 supporting the crankshaft 9, and the lubricating oil passages. The 24 oil passage introduction ports 24 i face the metal bearing 15.
The inner circumferential groove 24e of the lubricating oil passage 24 surrounds the axial center of the outer circumferential surface of the metal bush 20.

  In addition, annular ridges 2bb and 3bb are slightly protruded and formed on the opening end face on the left side (starter driven gear 21 side) of the left side bearing walls 2b and 3b for supporting the crankshaft 9 via the metal bush 20. Thus, the starter-driven gear 21 is positioned in the axial direction so as to face the right side surface of the bearing boss portion 23.

Thus, on the left side of the starter-driven gear 21 that is pivotally supported by the cylindrical shaft portion 9a of the left crank extension shaft portion 9L of the crankshaft 9 via the metal bush 20 in the vicinity of the left bearing walls 2b and 3b, The outer rotor 41 of the AC generator 40 is fitted in close proximity to the tapered shaft portion 9b of the left crank extension shaft portion 9L.
That is, the starter driven gear 21 is located between the left bearing walls 2b and 3b and the outer rotor 41.

A one-way clutch 30 is provided in an annular space between the gear portion 22 and the outer rotor 41 at the outer peripheral portion of the bearing boss portion 23 of the starter driven gear 21.
In the one-way clutch 30, a clutch outer ring 31 is integrally fixed to the back surface of the outer rotor 41 by bolts 34, and a clutch element 33 is interposed between the clutch inner ring 32 and the clutch outer ring 31 on the outer periphery of the bearing boss portion 23. Yes.

  The one-way clutch 30 transmits power from the starter driven gear 21 to the crankshaft 9 via the outer rotor 41, but does not transmit power from the crankshaft 9 to the starter driven gear 21.

The left bearing wall 2b of the crankcase 2 bulges together with the peripheral wall 2s diagonally forward and downward (see FIG. 1), and a starter motor 51 is attached to the bulged wall of the left bearing wall 2b from the right side. A starter drive gear 52 is formed on a drive shaft that penetrates the bulging wall of the motor 51 and protrudes to the left.
An intermediate shaft 53 is rotatably supported between the starter drive gear 52 and the crankshaft 9, and a large-diameter gear 53 a formed on the intermediate shaft 53 meshes with the drive gear 52 and is also formed on the intermediate shaft 53. The small-diameter gear 53b meshes with the large-diameter starter-driven gear 21 that is pivotally supported on the crankshaft 9 via the metal bush 20 (see FIGS. 1 and 2).

  Accordingly, when the starter drive gear 52 is rotated by driving the starter motor 51, the starter driven gear 21 is decelerated and rotated via the large diameter gear 53a and the small diameter gear 53b of the intermediate shaft 53, and the rotation of the starter driven gear 21 is the one-way clutch. The internal combustion engine 1 can be started by forcibly driving the crankshaft 9 via 30 and the outer rotor 41.

  The starter driven gear 21 is rotatably supported on the crankshaft 9 via an inexpensive metal bush 20 that is a sliding bearing member, not a rolling bearing that can move the lubricating oil by its own rolling to lubricate the whole. However, the bearing boss portion 23 of the starter driven gear 21 has the lubricating oil passage 24 formed therein, and a lubricating structure for supplying the lubricating oil to the metal bush 20 without deflection is configured.

The lubricating oil passage 24 formed in the bearing boss portion 23 of the starter driven gear 21 has six oil passage introduction ports 24i opened on the right side surface, a metal bearing 15 that supports the crankshaft 9, that is, a journal portion of the crankshaft 9. 9j and a bearing surface between the bearing walls 2b and 3b are provided so as to face an annular opening on the starter driven gear 21 side.
As described above, since the lubricating oil is discharged from the gap between the journal portion 9j of the crankshaft 9 in which the metal bearing 15 is interposed and the bearing surfaces of the bearing walls 2b and 3b, the lubricating oil is discharged from the annular opening on the starter driven gear 21 side. The lubricated oil is efficiently introduced into the six oil passage introduction ports 24i facing each other.

Further, as shown in FIG. 5, annular protrusions 2bb and 3bb are formed to project from the opening end surface of the left bearing wall 2b and 3b on the starter driven gear 21 side of the bearing opening, and the right side surface of the bearing boss portion 23 is formed. Since the starter-driven gear 21 is positioned in the axial direction so as to face the bearing, the journal portion 9j and the bearing walls 2b and 3b are inserted into the gap 25 on the outer periphery of the crankshaft 9 inside the annular ridges 2bb and 3bb. Lubricating oil discharged from the annular opening in the gap between the surfaces tends to accumulate, and the lubricating oil accumulated in the gap 25 tends to be introduced into the six oil passage introduction ports 24 i of the bearing boss portion 23.
The lubricating oil collected in the gap 25 can directly lubricate the side portion of the metal bush 20.

Lubricating oil introduced from the six oil passage introduction ports 24i is led to the axial center of the outer peripheral surface of the metal bush 20 from the inner circumferential concave groove 24e which is a common outlet through the six lubricating oil passages 24. Therefore, it is possible to lubricate the metal bush 20 by supplying sufficient lubricating oil to the metal bush 20 without bias.
Therefore, the inexpensive metal bush 20 can be used.

  In the above embodiment, the starter driven gear 21 is pivotally supported on the cylindrical shaft portion 9a of the crankshaft 9 via the metal bush 20, but the cylindrical shaft portion of the rotating shaft (crankshaft) is directly connected to the gear (starter driven). It is also possible to adopt a structure in which the gear) is pivotally supported so as to be relatively rotatable.

A sliding bearing is formed by sliding contact with a slight gap between the outer peripheral surface of the cylindrical shaft portion of the rotating shaft and the inner bearing sliding surface of the bearing boss portion of the gear. By forming the lubricating oil passage as described above, the lubricating oil introduced into the lubricating oil passage is supplied to the center in the axial direction of the sliding contact portion from the inner circumferential concave groove which is the oil passage outlet, and thus lubrication is performed. The oil spreads evenly over the entire sliding contact portion and can sufficiently lubricate the slide bearing.
Therefore, it is possible to bearing the gear under sufficient lubrication without interposing a sliding bearing member between the rotating shaft and the gear, and the cost can be further reduced.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Crank case, 2b ... Left bearing wall, 3 ... Cylinder block, 3b ... Right bearing wall, 4F, 4R ... Cylinder head, 5F, 5R ... Cylinder head cover, 6 ... Oil pan, 7 ... ACG cover 8 ... right side cover, 9 ... crankshaft, 9L ... left crank extension shaft,
10 ... Piston, 11 ... Connecting rod, 15 ... Metal bearing, 16 ... Lubricant groove, 17 ... Oil channel, 18 ... Oil channel,
20 ... Metal bush, 21 ... Starter driven gear, 22 ... Gear part, 23 ... Bearing boss part, 24 ... Lubricating oil passage, 24i ... Oil passage inlet, 24e ... Inner groove, 25 ... Gap,
30 ... one-way clutch, 31 ... clutch outer ring, 32 ... clutch inner ring, 33 ... clutch element, 34 ... bolt,
40 ... AC generator, 41 ... outer rotor, 42 ... inner stator, 43 ... washer, 44 ... mounting bolt,
51 ... Starter motor, 52 ... Starter drive gear, 53 ... Intermediate shaft, 53a ... Large diameter gear, 53b ... Small diameter gear.

Claims (6)

In the lubrication structure of the bearing portion (20) in which the gear (21) is pivotally supported so as to be rotatable relative to the rotation shaft (9),
The inner peripheral surface of the gear ring of the bearing boss portion (21) (23) is a bearing sliding surface of the sliding bearing (23s), the internal lubricant passage of the bearing boss portion (23) (24) Formed,
And oil passage inlet (24i) are spaced in the circumferential direction on the side surface of the bearing boss portion (23) opening of said lubricating oil passage (24) formed in plurality,
An inner circumferential groove (24e) as an oil passage outlet (24e) of the lubricating oil passage (24) is oriented in the circumferential direction toward the bearing sliding surface (23s) of the bearing boss portion (23). Formed over the circumference,
The gear (21) is rotatably supported on the rotating shaft (9) so as to face the bearing wall (2b, 3b) on which the rotating shaft (9) is supported,
A plurality of the oil passage introduction ports (24i) formed on the side surface of the bearing boss portion (23) of the gear (21), the rotation shaft (9) and the bearing surface of the bearing wall (2b, 3b) A lubricating structure for a bearing portion of a gear, characterized in that it is formed to face the annular gap (25) on the gear (21) side of a gap in which a bearing member (15) is interposed . Before SL lubricating oil passage (24) is formed by drilling axially from the oil passage inlet (24i),
Wherein said inner circumferential groove (24e) is to be formed in a depth reaching said lubricating oil passage that is drilled in the axial direction from the bearing sliding surface (23s) (24) of the bearing boss (23) The lubricating structure of the bearing portion of the gear according to claim 1 . Said rotary shaft (9) and the bearing boss portion of claim 1 and claim 2 sliding bearing member between the bearing sliding surface (23s) (20) is characterized in that it is interposed in (23) A lubrication structure for a bearing portion of the gear according to any one of the preceding claims. The lubrication structure for a bearing portion of a gear according to claim 3 , wherein the sliding bearing member (20) is a metal bush (20) which is a cylindrical plate. Said rotary shaft (9) is a crankshaft which is rotatably supported via a bearing wall for an internal combustion engine engine case (2,3) (2b, 3b) the bearing member (15) to,
The gear (21) is a starter driven gear to which the power of the starter motor (51) is transmitted,
The starter driven gear (21) rotates to a crank extension shaft portion (9L) that extends from the bearing wall (2b, 3b) of the engine case (2, 3) of the crankshaft (9) to the outside of the engine case. is pivotally supported, the bearing portion of the gear according via the one-way clutch (30) from claim 1, characterized in that it is connectable to the crankshaft (9) to any one of claims 4 Lubrication structure. On the side surface on the gear (21) side of the bearing wall (2b, 3b) on which the rotating shaft (9) is pivotally supported, the annular protrusion (2bb, 2bb, 6. The lubricating structure for a bearing portion of a gear according to claim 1, wherein 3 bb) is formed so as to project toward the gear (21).

Images