JP2015169244A - Outboard engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outboard engine which enables improvement in lubricity of a sliding contact surface of a thrust bearing and cooling performance of the thrust bearing when a crank shaft is arranged in parallel to a gravity direction.SOLUTION: An outboard engine includes: a journal support part 30 which rotatably supports a crank journal 20a connected with a crank arm 20c; a journal bearing 34 which is provided between the crank journal 20a and the journal support part 30 and receives a radial load of the crank journal 20a; a thrust bearing 36 which is provided between the crank arm 20c and the journal support part 30 and receives an axial load of the crank shaft 20; and a hydraulic pump which supplies a lubrication oil to the journal bearing 34 through a first oil passage 60 connected with the crank shaft 20 and formed in the journal support part 30. A second oil passage 62 which is branched from the first oil passage 60 and supplies a part of the lubrication oil to the thrust bearing 36 is provided in the outboard engine.

Description

  The present invention relates to an outboard motor.

  Conventionally, in outboard motors and automobiles, it has been provided between the journal support part of the cylinder block that rotatably supports the crank journal connected to the crank arm, and between the crank journal and the journal support part. Bearing structure including a journal bearing that receives a load in the direction (radial direction) and a thrust bearing that is provided between the crank arm and the journal support and receives a load in the axial direction (thrust direction) of the crankshaft Various techniques have been proposed. For example, the technique described in Patent Document 1 can be cited.

  The technique described in Patent Document 1 is not particularly limited to an outboard motor. However, in this case, an inclined part or the like is provided on a sliding contact surface with a crank arm of a thrust bearing, so that a journal is secured by bolting at the time of engine assembly. Even when the support portion is deformed, a technique for preventing a contact between the sliding contact surface of the thrust bearing and the crank arm is disclosed.

JP 2013-238277 A

  By the way, in the so-called vertical engine in which the crankshaft is arranged so as to be parallel to the gravity axis (vertical axis) like an outboard motor, for example, the weight of the crankshaft or the like is always added to the thrust bearing from above, The thrust bearing and the crank arm are in contact with each other. Therefore, if the engine is still new and the initial break-in (fitting of the sliding contact surface) is insufficient, or if the cylinder block is thermally deformed as the engine temperature rises, the thrust bearing sliding contact surface Load and heat were generated, which caused problems such as surface peeling and abnormal wear of the thrust bearing.

  Accordingly, the object of the present invention is to solve the above-mentioned problems and improve the lubricity of the sliding surface of the thrust bearing and the cooling performance of the thrust bearing when the crankshaft is arranged in parallel to the direction of gravity. Is to provide a machine.

  In order to solve the above-described problem, according to claim 1, a crank journal is provided with an engine that can be attached to a hull so that the crankshaft is parallel to the direction of gravity, and is connected to a crank arm of the crankshaft. A journal support that rotatably supports the journal, a journal bearing that is provided between the crank journal and the journal support, and receives a radial load of the crank journal, and the crank arm and the journal support. A thrust bearing that is provided between the thrust bearing and receives the axial load of the crankshaft and a first oil passage that is connected to the crankshaft and formed in the journal support portion, and supplies the lubricating oil to the journal bearing. In an outboard motor comprising a hydraulic pump, the water is branched from the first oil passage. Some of the oil was composed as to form the second oil passage supplied to the thrust bearing.

  In the outboard motor according to claim 2, the thrust bearing has a contact surface that contacts the journal support portion and a slide contact surface that contacts the crank arm, and the second oil passage includes the A part of the lubricating oil is supplied to at least the contact surface of the thrust bearing.

  In the outboard motor according to claim 3, the thrust bearing is formed with a through hole penetrating the contact surface and the sliding contact surface, and the through hole is connected to the second oil passage. did.

  In the outboard motor according to claim 4, an arcuate first oil groove extending along a circumferential direction of the crank journal is formed on the sliding contact surface of the thrust bearing, and the first oil groove is formed. The second oil passage is configured to be connected.

  The outboard motor according to claim 5 is configured such that a first branch groove that branches from the first oil groove and extends to an edge of the sliding contact surface is formed on the sliding contact surface of the thrust bearing. .

  In the outboard motor according to claim 6, an arc-shaped second oil groove extending along a circumferential direction of the crank journal is formed on the contact surface of the thrust bearing, and the second oil groove is The second oil passage is configured to be connected.

  The outboard motor according to claim 7 is configured to form a second branch groove that branches from the second oil groove and extends to an edge of the contact surface on the contact surface of the thrust bearing. .

  The outboard motor according to claim 8, wherein the thrust bearing is in contact with the journal support portion from above in the gravity direction, and is in contact with the journal support portion from below in the gravity direction. The hydraulic pump is configured to supply a part of the lubricating oil to the first thrust bearing through the second oil passage.

  According to the first aspect of the present invention, the engine includes an engine that can be attached to the hull so that the crankshaft is parallel to the direction of gravity, a journal support portion that rotatably supports the crank journal, and a crank journal and a journal support portion. A journal bearing for receiving a radial load of the crank journal, a thrust bearing for receiving an axial load of the crankshaft, connected to the crankshaft; In an outboard motor having a hydraulic pump that supplies lubricating oil to a journal bearing through a first oil passage formed in a journal support portion, a part of the lubricating oil is supplied to a thrust bearing by branching from the first oil passage. Since the second oil passage is formed, lubricating oil is supplied to the thrust bearing, so that the thrust bearing Thereby improving the cooling performance of the lubricity and the thrust bearing of the sliding surface. Therefore, even in an outboard engine in which the crankshaft is arranged in parallel to the direction of gravity, no large load or heat is generated on the sliding surface of the thrust bearing, which causes surface layer peeling or abnormal wear of the thrust bearing. Can be suppressed.

  In the outboard motor according to claim 2, the thrust bearing has a contact surface that contacts the journal support portion and a sliding contact surface that slides on the crank arm, and the second oil passage is a part of the lubricating oil. In addition to the above-described effects, lubricating oil can be directly supplied to the thrust bearing contact surface, so that the cooling performance of the thrust bearing can be further improved. Can do.

  In the outboard motor according to the third aspect, the thrust bearing is formed so as to penetrate the contact surface and the sliding contact surface, and the through hole is connected to the second oil passage. In addition to the effect, since the lubricating oil passes through the through-hole and is also supplied to the sliding contact surface, the lubricity of the sliding contact surface of the thrust bearing and the cooling performance of the thrust bearing can be further improved.

  In the outboard motor according to claim 4, the arcuate first oil groove extending along the circumferential direction of the crank journal is formed on the sliding surface of the thrust bearing, and the first oil groove is formed as the second oil passage. In addition to the effects described above, the lubricating oil supplied to the sliding contact surface of the thrust bearing by the first oil groove spreads over the entire sliding contact surface, so that the sliding contact surface of the thrust bearing It is possible to further improve the lubricity and the cooling performance of the thrust bearing.

  In the outboard motor according to the fifth aspect, the first branch groove is formed on the sliding contact surface of the thrust bearing so as to branch from the first oil groove and extend to the edge of the sliding contact surface. In addition to the effect, the lubricating oil flowing through the first oil groove can be discharged to the outside of the sliding contact surface by the first branch groove, so that a larger amount of lubricating oil can flow through the sliding contact surface, and the thrust bearing The lubricity of the sliding contact surface and the cooling performance of the thrust bearing can be further improved.

  In the outboard motor according to the sixth aspect, the second oil groove is formed on the contact surface of the thrust bearing while the arc-shaped second oil groove extending along the circumferential direction of the crank journal is formed. In addition to the effects described above, the lubricating oil supplied to the abutment surface of the thrust bearing by the second oil groove spreads over the entire abutment surface, so that the cooling performance of the thrust bearing is improved. This can be further improved.

  In the outboard motor according to the seventh aspect of the present invention, the second branch groove that branches from the second oil groove and extends to the edge of the contact surface is formed on the contact surface of the thrust bearing. In addition to the effect, the lubricating oil flowing through the second oil groove can be discharged out of the contact surface by the second branch groove, so that a larger amount of lubricating oil can flow through the contact surface, and the thrust bearing The cooling property can be further improved.

  In the outboard motor according to claim 8, the thrust bearing includes a first thrust bearing that comes into contact with the journal support portion from above in the direction of gravity, and a first thrust bearing that comes into contact with the journal support portion from below in the direction of gravity. Since the hydraulic pump is configured to supply a part of the lubricating oil to the first thrust bearing via the second oil passage, in addition to the above-described effect, the hydraulic pump is configured to have a larger load on the sliding contact surface. Lubricity and cooling can be improved with respect to the first thrust bearing that generates heat.

1 is a partial cross-sectional side view of an outboard motor according to an embodiment of the present invention. FIG. 2 is a partially enlarged cross-sectional view of the crankshaft shown in FIG. 1 in the vicinity of a crank journal viewed from the axial direction. FIG. 2 is a partially enlarged cross-sectional view showing an enlarged vicinity of a journal support portion shown in FIG. 1. It is explanatory drawing for demonstrating the oil groove and branching groove which were formed in the sliding contact surface of the thrust washer shown in FIG. It is explanatory drawing for demonstrating the oil groove and branch groove formed in the contact surface of the thrust washer shown in FIG.

  Hereinafter, an embodiment for carrying out an outboard motor according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a partially sectional side view of an outboard motor according to an embodiment of the present invention, FIG. 2 is a partially enlarged sectional view when the vicinity of a crank journal of the crankshaft shown in FIG. 1 is viewed from the axial direction, and FIG. It is a partial expanded sectional view which expands and shows the journal support part vicinity shown in FIG.

  In FIG. 1, reference numeral 10 denotes an outboard motor. The outboard motor 10 is attached to the rear (stern) of the hull 16 via the stern bracket 12 and the tilting shaft 14. An engine (internal combustion engine) 18 is mounted on the upper portion of the outboard motor 10. The engine 18 is a spark-ignition water-cooled gasoline engine having a displacement of about 2000 cc, and is disposed so that the crankshaft 20 is parallel to the direction of gravity when mounted on the outboard motor 10. In the outboard motor 10, the engine 18 is disposed on the water surface and is covered with the engine cover 22.

  The crankshaft 20 is accommodated in the cylinder block 24 of the engine 18. The crankshaft 20 is positioned on the rotation center axis of the crankshaft 20, and is connected to a plurality of crank journals 20a constituting the main rotation axis of the crankshaft 20 and a piston 28 (see FIG. 2) via a connecting rod 26. It comprises a plurality of crank pins 20b and a plurality of crank arms 20c that connect the crank journal 20a and the crank pin 20b in an eccentric state.

  The crankshaft 20 is rotatably supported by the cylinder block 24. Specifically, the crank journal 20a of the crankshaft 20 is rotatably supported by a journal support portion 30 formed on the cylinder block 24.

  As shown in FIG. 2, the journal support portion 30 corresponds to the bulk portion 30 a that supports a portion corresponding to approximately one half of the outer periphery of the crank journal 20 a from the piston direction (left side in the drawing), and the remaining half. The bearing cap 30b supports the portion to be supported from the direction opposite to the bulk portion 30a (crankcase side (right side in the drawing)).

  A semicircular journal support surface 30a1 that supports the outer peripheral surface of the crank journal 20a is formed in the bulk portion 30a. The bearing cap 30b also has a semicircular journal support surface 30b1 that supports the outer peripheral surface of the crank journal 20a, as in the bulk portion 30a.

  Therefore, when the bulk part 30a and the bearing cap 30b are fastened by the bolt 31, the crank journal support surfaces 30a1 and 30b1 of the bulk part 30a and the bearing cap 30b are arranged to face each other, and these two crank journals facing each other. A cylindrical journal insertion hole 32 for inserting the crank journal 20a is formed by the support surfaces 30a1 and 30b1.

  A main metal (journal (radial) bearing) 34 that slides on the outer peripheral surface of the crank journal 20a and receives the radial load of the crank journal 20a is provided on the inner peripheral surface of the journal insertion hole 32. The main metal 34 is a sliding bearing made of a cylindrical member having a two-part (half) structure. The main metal 34a constituting one semi-cylindrical member is disposed on the journal support surface 30a1 of the bulk portion 30a, and the other The main metal 34b constituting the semi-cylindrical member is disposed on the journal support surface 30b1 of the bearing cap 30b.

  As shown in FIG. 3, at least one bulk portion 30a among the plurality of bulk portions 30a has both side surfaces in the axial direction (the vertical direction in the drawing) of the crankshaft 20, in other words, the vertical direction of the bulk portion 30a. A semicircular (half donut shape; see FIG. 2) thrust groove 30a2 is formed along the peripheral edge of each journal insertion hole 32 on the surface facing the crank arm 20c located at the center.

  A thrust washer (thrust bearing) 36 having substantially the same shape (semicircular shape) as the thrust groove 30a2 is fitted into the thrust groove 30a2. The thrust washer (thrust bearing) 36 is a slide bearing that receives a load in the axial direction of the crankshaft 20. The thrust washer 36 is fitted into two thrust grooves 30a2 formed on both side surfaces in the axial direction of the bulk portion 30a, so that one bulk portion 30a is brought into contact with the bulk portion 30a from above. A total of two thrust washers (first and second thrust bearings) 36 are provided, that is, a thrust washer (first thrust bearing) 36 and a thrust washer (second thrust bearing) 36 that contacts the bulk portion 30a from below. .

  Thus, the journal support portion 30 is provided with the main metal 34 that receives the load in the radial direction of the crankshaft 20 and the thrust washer 36 that receives the load in the axial direction of the crankshaft 20.

  Returning to the description of FIG. 1, a flywheel 40 is connected to one end of the crankshaft 20 (an end portion on the lower side of the drawing) via a flywheel boss 38, and a vertical shaft 42 is rotatable about the gravity axis. Connected to.

  The vertical shaft 42 is arranged coaxially with the rotation center axis of the crankshaft 20, that is, the rotation axis of the crank journal 20 a, and in parallel with the gravity axis, and outputs the engine 18, that is, the rotation of the crankshaft 20. Is rotated around the gravity axis. The rotation of the vertical shaft 42 is transmitted to the gear mechanism 44, where it is converted into rotation around the horizontal axis, and then transmitted to the propeller 48 via the propeller shaft 46.

  The gear mechanism 44 includes a pinion gear 44a provided at the lower end (lower end) of the vertical shaft 42, a forward bevel gear 44b and a reverse bevel gear 44c that are engaged (engaged) with the pinion gear 44a and rotated in opposite directions. The propeller shaft 46 includes a clutch 44d that can be engaged with either the forward bevel gear 44b or the reverse bevel gear 44c. The shift position is set to forward, reverse, or neutral by operating the clutch 44d by a shift electric motor (not shown). Can be switched.

  An oil pump (hydraulic pump) 52 that is connected to the vertical shaft 42 and sucks the lubricating oil stored in the oil pan 50 and supplies it to each part of the engine 18 is provided below the cylinder block 24. The oil pump 52 is a gear pump arranged in the vicinity of the connection portion between the oil tube 54 and the main gallery 56. The oil pump 52 sucks lubricating oil stored in the oil pan 50 through the strainer 58 and the oil tube 54. 56 is pumped.

  The main gallery 56 is configured to extend from below to above in the cylinder block 24 in parallel with the axial direction of the crankshaft 20. In the middle of the main gallery 56, four sub-gallerys (first oil passages) 60 branching toward the respective crank journals 20a of the crankshaft 20 are formed.

  The sub gallery 60 is formed in the bulk portion 30 a of the journal support portion 30 and is configured to extend from the main gallery 56 to the tip of the bulk portion 30 a, that is, the main metal 34. Accordingly, part of the lubricating oil flowing through the main gallery 56 is supplied to the main metal 34 through the sub gallery 60.

  As shown in FIG. 3, the main metal 34 is formed with a through hole 34c that penetrates a contact surface 34a with the bulk portion 30a (journal support portion 30) and a sliding contact surface 34b with the crank journal 20a. . Therefore, the lubricating oil supplied to the contact surface 34a of the main metal 34 via the sub gallery 60 flows to the sliding contact surface 34b of the main metal 34 through the through hole 34c. An oil groove 34d is formed in the sliding contact surface 34b of the main metal 34 along the circumferential direction of the crank journal 20a. Therefore, the lubricating oil supplied to the slidable contact surface 34b of the main metal 34 is distributed over the entire slidable contact surface 34b through the oil groove 34d, and the lubricity between the main metal 34 and the crank journal 20a is improved.

  As shown in FIG. 2, the crankshaft 20 is formed with a communication passage 20d that communicates the outer peripheral surface of the crank journal 20a and the outer peripheral surface of the crank pin 20b. Therefore, the lubricating oil supplied to the outer peripheral surface of the crank journal 20a flows from the inlet 20d1 of the communication passage 20d formed on the outer peripheral surface of the crank journal 20a, passes through the communication passage 20d, and reaches the outer peripheral surface of the crank pin 20b. It is discharged from the outlet 20d2 of the formed communication passage 20d and improves the lubricity between the crankpin 20b and the connecting rod bearing (illustration shown).

  As shown in FIG. 3, the sub gallery 60 is formed with a branch passage (second oil passage) 62 that branches upward near the tip of the bulk portion 30a and in the vicinity of the thrust washer 36. . The branch path 62 extends from the sub gallery 60 to a thrust washer (a thrust washer disposed on the upper side of the bulk portion 30 a) 36, and is configured so that a part of the lubricating oil flowing through the sub gallery 60 can be supplied to the thrust washer 36. The

  The thrust washer 36 is formed with a through hole 36c that penetrates the contact surface 36a with the bulk portion 30a (journal support portion 30) and the sliding contact surface 36b with the crank arm 20c. Since the through hole 36c is connected to the branch path 62, the lubricating oil from the branch path 62 flows through the through hole 36c to the sliding contact surface 36b and lubricates the sliding contact surface 36b.

  Note that “the through hole 36 c and the branch path 62 are connected” means that the openings of the through hole 36 c and the branch path 62 are directly or partially connected to each other (in this case, the lubricating oil is connected to the branch path 62. In addition, the through hole 36c flows almost straight upward and reaches the sliding contact surface 36b), and the openings of the through hole 36c and the branch path 62 are not in direct communication with each other (the openings are shifted and the openings are open). Although they do not overlap each other, the lubricating oil that has flowed out of the branch path 62 flows into the through hole 36c after passing through the gap between the bulk portion 30a and the contact surface 36a (in this case, from the branch path 62). The lubricant once bends along the contact surface 36a and flows laterally, and then reaches the through hole 36c and then bends upward along the through hole 36c and flows to reach the sliding contact surface 36b). Including.

  FIG. 4 is an explanatory diagram for explaining oil grooves and branch grooves formed on the sliding contact surface 36b of the thrust washer 36. FIG. 4A shows a case where only the oil grooves are formed on the sliding contact surface 36b. (B) shows a case where oil grooves and branch grooves are formed on the sliding contact surface 36b.

  As shown in FIG. 4A, an arcuate oil groove (first oil groove) 36b1 extending along the circumferential direction (outer periphery) of the crank journal 20a is formed on the sliding contact surface 36b of the thrust washer 36. . The oil groove 36b1 extends in a circular arc shape along the shape of the slidable contact surface 36b from right above the through hole 36c in the left-right direction (the vertical direction in the drawing). Accordingly, the lubricating oil that has flowed in through the through hole 36c spreads over the entire sliding contact surface 36b through the oil groove 36b1, and sufficiently lubricates and cools the sliding contact surface 36b.

  As shown in FIG. 4B, at least one or more branch grooves (first branch grooves) 36b2 extending to the edge of the sliding contact surface 36b may be formed in the oil groove 36b1 (six in the figure). Branching groove 36b2 is shown). By forming the branch groove 36b2, not only the lubricating oil spreads over the entire sliding contact surface 36b but also the lubricating oil is discharged from the branch groove 36b2 to the outside of the sliding contact surface 36b. The flow rate of the lubricating oil flowing through the slidable contact surface 36b through the branch groove 36b2 can be increased, and therefore the lubricity and cooling performance of the slidable contact surface 36b can be further improved.

  FIG. 5 is an explanatory diagram for explaining oil grooves and branch grooves formed on the contact surface 36a of the thrust washer 36. FIG. 5A shows a case where only the oil grooves are formed on the contact surface 36a. (B) shows the case where an oil groove and a branch groove are formed on the contact surface 36a.

  As shown in FIGS. 5 (a) and 5 (b), the oil groove (second oil groove) 36a1 and the branch groove (second branch groove) 36a2 are formed on the contact surface 36a of the thrust washer 36 as well as the sliding contact surface 36b. It may be formed. By forming the oil groove 36a1 and the branch groove 36a2 on the contact surface 36a of the thrust washer 36, the thrust washer 36 can be further cooled and the lubricity of the sliding contact surface 36b can be improved ( By causing a large amount of lubricating oil to flow through the contact surface 36a, a large amount of the lubricating oil on the contact surface 36a flows along the side surface of the thrust washer 36 and also flows into the sliding contact surface 36b. The lubricity of the contact surface 36b is also improved).

  As described above, according to the embodiment of the present invention, the crankshaft 20 includes the engine 18 that can be attached to the hull 16 so that the crankshaft 20 is parallel to the direction of gravity, and the crank connected to the crank arm 20c of the crankshaft. A journal support portion 30 that rotatably supports the journal 20a; a journal bearing (main metal) 34 that is provided between the crank journal and the journal support portion and receives a radial load of the crank journal; and the crank A thrust bearing (thrust washer) 36 that is provided between the arm and the journal support portion (bulk portion 30a) and receives an axial load of the crankshaft, and connected to the crankshaft (a crankshaft via a vertical shaft 42) Connected to the shaft 20), the jar In the outboard motor 10 including a hydraulic pump (oil pump) 52 that supplies lubricating oil to the journal bearing through a first oil passage (sub-gallery) 60 formed in the barrel support portion, from the first oil passage Since the second oil passage (branch passage) 62 that branches and supplies part of the lubricating oil to the thrust bearing is formed, a thrust washer (particularly a thrust washer that contacts the bulk portion 30a from above). (Thrust washer disposed on the upper side of the bulk part 30a)) By supplying the lubricating oil to 36, the lubricity of the sliding contact surface 36b of the thrust washer 36 and the cooling performance of the thrust washer 36 can be improved. Accordingly, the engine 18 of the outboard motor 10 has the crankshaft 20 disposed in parallel to the direction of gravity, and the thrust washer 36 and the crank arm 20c are constantly added to the thrust washer 36 from above, with the weight of the crankshaft 20 and the like being constantly added. Even in the contact state, a large load or heat is not generated on the sliding contact surface 36b of the thrust washer 36, and surface layer peeling or abnormal wear of the thrust washer 36 can be suppressed.

  The thrust bearing has a contact surface 36a that contacts the journal support portion and a sliding contact surface 36b that contacts the crank arm, and the second oil passage includes at least a portion of the lubricating oil. Since the bearing is configured to be supplied to the contact surface of the bearing, the lubricating oil can be directly supplied to the contact surface 36a of the thrust washer 36. Therefore, the cooling performance of the thrust washer 36 can be further improved.

  In addition, since the thrust bearing is formed with a through hole 36c penetrating the contact surface and the sliding contact surface, and the through hole is connected to the second oil passage, the lubricating oil has the through hole 36c. Since it passes and is supplied also to the sliding contact surface 36b, the lubricity of the sliding contact surface 36b of the thrust washer 36 and the cooling performance of the thrust washer 36 can be further improved.

  Further, an arcuate first oil groove (oil groove) 36b1 extending along the circumferential direction of the crank journal is formed on the sliding surface of the thrust bearing, and the first oil groove is formed in the second oil passage. Since it is configured to be connected, the lubricating oil supplied to the sliding contact surface 36b of the thrust washer 36 by the oil groove 36b1 spreads widely over the entire sliding contact surface 36b, so that the lubricity of the sliding contact surface 36b of the thrust washer 36 is increased. Further, the cooling performance of the thrust washer 36 can be further improved.

  In addition, since the first branch groove (branch groove) 36b2 branched from the first oil groove and extending to the edge of the sliding contact surface is formed on the sliding contact surface of the thrust bearing, the branch groove 36b2 Since the lubricating oil flowing through the oil groove 36b1 can be discharged out of the sliding contact surface 36b, more lubricating oil can flow through the sliding contact surface 36b, and lubrication of the sliding contact surface 36b of the thrust washer 36 is achieved. And the cooling performance of the thrust washer 36 can be further improved.

  Further, an arc-shaped second oil groove (oil groove) 36a1 extending along the circumferential direction of the crank journal is formed on the contact surface of the thrust bearing, and the second oil groove is formed in the second oil passage. Since it is configured to be connected, the lubricating oil supplied to the abutting surface 36a of the thrust washer 36 by the oil groove 36a1 spreads widely over the entire abutting surface 36a, so that the cooling performance of the thrust washer 36 is further improved. Can do.

  In addition, since the second branch groove (branch groove) 36a2 that branches off from the second oil groove and extends to the edge of the contact surface is formed on the contact surface of the thrust bearing, the branch groove 36a2 Since the lubricating oil flowing through the oil groove 36a1 can be discharged to the outside of the contact surface 36a, more lubricating oil can be flowed to the contact surface 36a, and the cooling performance of the thrust washer 36 is further improved. Can be made.

  The thrust bearing includes a first thrust bearing (a thrust washer disposed on the upper side of the bulk portion 30a) 36 that contacts the journal support portion from above in the gravity direction, and the journal support portion from below in the gravity direction. And a second thrust bearing (a thrust washer disposed on the lower side of the bulk portion 30a) 36, and the hydraulic pump passes a part of the lubricating oil through the second oil passage. Since it is configured to be supplied to the first thrust bearing, lubricity and cooling performance can be improved with respect to the thrust washer 36 disposed above the bulk portion 30a where a large load and heat are generated by the sliding contact surface 36b.

  In the embodiment, the lubricating oil is supplied only to the thrust washer 36 disposed on the upper side of the bulk portion 30a via the branch path 62. However, the branch path 62 is extended from the sub gallery 60 to the lower side. The lubricating oil may be supplied also to the thrust washer 36 disposed below the bulk portion 30a.

  In the embodiment, the oil groove 36b1 and the branch groove 36b2 are provided only on the sliding contact surface 36b of the thrust washer 36, and the oil grooves 36a1 and 36b1 are provided on both the contact surface 36a and the sliding contact surface 36b of the thrust washer 36. Although the case where the branch grooves 36a2 and 36b2 are provided has been described, for example, the oil groove 36a1 and the branch groove 36a2 are provided only on the contact surface 36a without providing the oil groove 36b1 and the branch groove 36b2 on the sliding contact surface 36b of the thrust washer 36. You may make it provide. When the oil groove 36a1 and the branch groove 36a2 are provided only on the contact surface 36a, the thrust washer 36 may or may not be formed with the through hole 36c.

10 Outboard motor, 16 Hull, 18 Engine, 20 Crankshaft, 20a Crank journal, 20c Crank arm, 24 Cylinder block, 30 Journal support part, 30a Bulk part, 30b Bearing cap, 34 Main metal (journal bearing), 36 Thrust Washer (thrust bearing), 36a Thrust washer contact surface, 36a1 oil groove (second oil groove), 36a2 branch groove (second branch groove), 36b Sliding contact surface of thrust washer, 36b1 oil groove (first oil groove) ), 36b2 Branching groove (first branching groove), 36c Thrust washer through hole, 52 Oil pump (hydraulic pump), 60 Sub gallery (first oil passage), 62 Branching passage (second oil passage)

Claims (8)

  A journal support portion that includes an engine that can be attached to the hull so that the crankshaft is parallel to the direction of gravity, and that rotatably supports a crank journal that is coupled to a crank arm of the crankshaft, and the crank journal and the journal A journal bearing that is provided between the crank arm and the journal support portion, and a thrust bearing that is provided between the crank arm and the journal support portion and receives an axial load of the crankshaft. And an outboard motor that is connected to the crankshaft and that supplies lubricating oil to the journal bearing via a first oil passage formed in the journal support portion, and branches from the first oil passage And forming a second oil passage for supplying a part of the lubricating oil to the thrust bearing. Outboard motor, characterized in that the.   The thrust bearing has a contact surface that contacts the journal support portion and a sliding contact surface that slides on the crank arm, and the second oil passage receives at least a portion of the lubricating oil at the contact of the thrust bearing. The outboard motor according to claim 1, wherein the outboard motor is supplied to a contact surface.   3. The outboard motor according to claim 2, wherein a through-hole penetrating the contact surface and the sliding contact surface is formed in the thrust bearing, and the through-hole is connected to the second oil passage.   An arc-shaped first oil groove extending along a circumferential direction of the crank journal is formed on the sliding contact surface of the thrust bearing, and the first oil groove is connected to the second oil passage. The outboard motor according to claim 3.   5. The outboard motor according to claim 4, wherein a first branch groove that branches from the first oil groove and extends to an edge of the sliding contact surface is formed on the sliding contact surface of the thrust bearing.   An arc-shaped second oil groove extending along a circumferential direction of the crank journal is formed on the contact surface of the thrust bearing, and the second oil groove is connected to the second oil passage. The outboard motor according to any one of claims 2 to 5.   The outboard motor according to claim 6, wherein a second branch groove that branches from the second oil groove and extends to an edge of the contact surface is formed on the contact surface of the thrust bearing. The thrust bearing includes a first thrust bearing that contacts the journal support portion from above in the direction of gravity and a second thrust bearing that contacts the journal support portion from below in the direction of gravity. The outboard motor according to any one of claims 1 to 7, wherein the pump supplies a part of the lubricating oil to the first thrust bearing through the second oil passage.

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