JP2020056449A - Crosshead and crosshead type internal combustion engine - Google Patents

Abstract

To distribute lubricating oil supplied through a crosshead pin, to an oil passage at a side of a piston rod and an oil passage at a side of a connecting rod in a balanced manner.SOLUTION: A crosshead 40 comprises: a crosshead pin 41 attached to a lower end part 21a of a piston rod 21, and for rotating a connecting rod 25 with respect to the lower end part 21a; and a lubricating passage 50 provided in the crosshead pin 41, and for distributing lubricating oil to the piston rod 21 and the connecting rod 25 from the crosshead pin 41. The lubricating passage 50 comprises: an introduction passage 51 extending inward from an outer surface of the crosshead pin 41; a first branch passage 52 branching and extending from the introduction passage 51, and communicating with an oil passage 21b provided in the piston rod 21; and a second branch passage 53 branching and extending from the introduction passage 51, and communicating with an oil passage 25b provided in the connecting rod 25. The first branch passage 52 and the second branch passage 53 are defined so as not to communicate with each other in a cross sectional view passing through the piston rod 21 and the connecting rod 25.SELECTED DRAWING: Figure 4

Description

  The technology disclosed herein relates to a crosshead and a crosshead internal combustion engine.

  In an internal combustion engine with a large bore stroke ratio, such as a marine internal combustion engine, a component called a crosshead is widely used to connect the piston rod that supports the piston from below and the connecting rod that is connected to the crankshaft. Are known.

  For example, a crosshead disclosed in Patent Literature 1 is attached to a lower end of a piston rod (piston rod) and rotates a connecting rod (connecting rod) with respect to the lower end of the crosshead pin (crosshead journal). And a passage (hole) provided inside the crosshead pin for distributing the lubricating oil to the piston rod and the connecting rod.

  The passage according to Patent Literature 1 is different from the passage according to the second embodiment of the same document in a passage (upward radial hole) communicating with an oil passage provided in a piston rod and an oil passage provided in a connecting rod. And a passage (two holes obliquely downward). The two types of passages thus branched communicate with each other in a sectional view passing through the piston rod and the connecting rod. That is, when viewed in this cross section, the oil passage provided in the piston rod and the oil passage provided in the connecting rod are connected vertically via a passage provided inside the crosshead pin.

JP-A-2005-057570

  However, as described in Patent Document 1, if the oil passage on the piston rod side and the oil passage on the connecting rod side are connected vertically, it may hinder distribution of lubricating oil in a well-balanced manner. In particular, the present inventors have noticed.

  That is, the lubricating oil flowing from the crosshead pin toward the oil passage on the connecting rod side is pulled upward due to the inertial force when the piston moves up and down. In the case of the configuration disclosed in Patent Document 1, the lubricating oil thus pulled may flow into the oil passage on the piston rod side. In this case, the inventors of the present application have stated that the amount of the lubricating oil flowing through the oil passage on the piston rod side becomes larger than the lubricating oil flowing through the oil passage on the connecting rod side, and the lubricating oil flowing on the connecting rod side may become negative pressure. Found.

  In general, a bearing and a bearing shell for supporting the crosshead pin are provided at the upper end of the connecting rod. However, if the amount of lubricating oil flowing on the connecting rod side becomes small, there is a possibility that these parts may not be sufficiently lubricated. This is inconvenient.

  The technology disclosed herein is made in view of such a point, and the purpose thereof is to supply lubricating oil supplied through a crosshead pin to an oil passage on a piston rod side and an oil passage on a connecting rod side. In a well-balanced manner.

  The technology disclosed herein relates to a crosshead that connects a piston rod and a connecting rod. The crosshead is attached to a lower end of the piston rod, and is provided on the crosshead pin for rotating the connecting rod with respect to the lower end, and the piston rod and the connecting rod are provided from the crosshead pin. And a lubrication passage for distributing the lubricating oil.

  The lubrication passage extends from an introduction surface extending from the outer surface of the crosshead pin to the inside, a first branch passage extending from the introduction passage and communicating with an oil passage provided in the piston rod, and And a second branch passage extending in a branched manner and communicating with an oil passage provided in the connecting rod.

  The first branch and the second branch are partitioned so as not to communicate with each other in a sectional view passing through the piston rod and the connecting rod.

  According to the above configuration, the lubricating oil that has flowed into the lubrication passage of the crosshead pin flows through the introduction path, and is then distributed to the first branch path and the second branch path. Here, the first branch and the second branch do not communicate with each other in a cross-sectional view passing through the piston rod and the connecting rod.

  Therefore, at least when viewed in the cross section, the oil passage on the piston rod side communicating with the first branch passage and the oil passage on the connecting rod side communicating with the second branch passage are not connected vertically. As a result, the lubricating oil pulled upward due to the inertial force can be suppressed from flowing into the oil passage on the piston rod side, and the lubricating oil flowing on the connecting rod side can be prevented from becoming negative pressure. It is possible to do. Thus, the lubricating oil supplied through the crosshead pin can be distributed to the piston rod-side oil passage and the connecting rod-side oil passage in a well-balanced manner.

  Further, the first branch path and the second branch path may extend in directions away from each other in a sectional view passing through the piston rod and the connecting rod.

  According to the above configuration, it is advantageous in appropriately dividing the first branch path and the second branch path. This is effective in distributing the lubricating oil in a well-balanced manner.

  Further, a bearing provided at an upper end of the connecting rod and supporting the crosshead pin, and a bearing shell disposed between the bearing and a lower half of the crosshead pin are provided. May be provided with a through hole communicating with an oil passage provided in the connecting rod.

  According to the above configuration, a bearing that supports the crosshead pin is provided at the upper end of the connecting rod. A bearing shell is provided between the bearing and the crosshead pin. Lubricating oil is supplied through a through hole provided in the bearing shell. Since the through-hole communicates with the oil passage provided on the connecting rod side, if the amount of lubricating oil flowing on the connecting rod side becomes small, the bearing and the bearing shell may not be sufficiently lubricated.

  On the other hand, in the above configuration, the lubricating oil can be distributed in a well-balanced manner, so that the bearing and the bearing shell can be sufficiently lubricated.

  Further, the second branch path may extend so as to be directed to a portion on the outer edge side of the bearing shell in a cross-sectional view passing through the piston rod and the connecting rod.

  Generally, the central portion of the inner peripheral surface of the bearing shell is located immediately below the crosshead pin. A greater load is applied to this part than to other parts. In such a portion, it is effective to make the lubricating oil into a thin film. If the lubricating oil is supplied excessively, the lubricating oil will not be formed into a thin film, but rather disadvantageous.

  On the other hand, according to the above configuration, since the second branch path is directed not to the central portion of the bearing shell but to a portion on the outer edge side, excessive supply of the lubricating oil can be avoided at the central portion. This is advantageous for making the lubricating oil into a thin film.

  Also, the first branch path is connected to the introduction path, and extends in the pin axis direction of the crosshead pin. A first downstream path extending from the first upper path and extending toward the piston rod. And a second branch path connected to the introduction path and extending in the pin axis direction, and a second upper path that is continuous from the second upper path and that extends toward the connecting rod. A first lower flow path and the second lower flow path, wherein the first upper flow path and the second upper flow path are partitioned to communicate with each other via the introduction path. In a sectional view passing through the rod and the connecting rod, the rod may be partitioned so as not to communicate with each other.

  According to the above configuration, it is advantageous in appropriately dividing the first branch path and the second branch path. This is effective in distributing the lubricating oil in a well-balanced manner.

  The technology disclosed herein also relates to a crosshead type internal combustion engine including the crosshead.

  As described above, according to the crosshead, the lubricating oil supplied through the crosshead pin can be distributed to the piston rod-side oil passage and the connecting rod-side oil passage in a well-balanced manner.

FIG. 1 is a schematic view illustrating the configuration of a crosshead type internal combustion engine. FIG. 2 is a front view illustrating the configuration of the frame and the crosshead. FIG. 3 is a diagram illustrating a cross section of the crosshead. FIG. 4 is a diagram illustrating a cross section of the crosshead. FIG. 5 is a plan view illustrating the configuration of the crosshead pin. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 5 illustrating a vertical cross section of the crosshead pin. FIG. 7 is a VII-VII cross-sectional view of FIG. 6 illustrating a vertical cross-section of the crosshead pin. FIG. 8 is a VIII-VIII cross-sectional view of FIG. 6 illustrating a cross-section of the crosshead pin. FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 6 illustrating a cross-section of the crosshead pin. FIG. 10 is a cross-sectional view taken along line XX of FIG. 6 illustrating a cross-section of the crosshead pin. FIG. 11 is a diagram corresponding to FIG. 3 illustrating a conventional example of a crosshead. FIG. 12 is a view corresponding to FIG. 4 illustrating a conventional example of a crosshead.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The following description is an example. FIG. 1 is a schematic diagram illustrating the configuration of a crosshead type internal combustion engine (hereinafter, simply referred to as “engine 1”).

  The engine 1 is an in-line multi-cylinder diesel engine having a plurality of cylinders. The engine 1 is configured as a two-stroke, one-cycle engine employing a uniflow scavenging method, and is mounted on a large ship such as a tanker, a container ship, or a car carrier. The output shaft of the engine 1 is connected to a propeller (not shown). When the engine 1 is operated, its output is transmitted to the propeller and the boat is propelled.

  The engine 1 disclosed herein is configured as a so-called crosshead type internal combustion engine in order to realize a longer stroke. That is, as shown in FIG. 2, in the engine 1, the piston rod 21 supporting the piston 15 from below and the connecting rod 25 connected to the crankshaft 22 are connected by the crosshead 40.

(1) Main Configuration Hereinafter, main parts of the engine 1 will be described.

  As shown in FIG. 1, the engine 1 includes a base plate 11, a frame 12 provided on the base plate 11, and a cylinder jacket 13 provided on the frame 12. The base plate 11, the frame 12, and the cylinder jacket 13 are fastened by a plurality of tie bolts and nuts extending vertically.

  A cylinder liner 14 as an inner cylinder is arranged in the cylinder jacket 13. A piston 15 is arranged inside the cylinder liner 14. The piston 15 reciprocates vertically along the inner wall of the cylinder liner 14. A cylinder cover 16 is fixed to an upper portion of the cylinder liner 14. An exhaust valve 17 is provided on the cylinder cover 16. The exhaust valve 17 defines a combustion chamber 18 together with the cylinder liner 14, the piston 15, and the cylinder cover 16. The exhaust valve 17 opens and closes a space between the combustion chamber 18 and the exhaust pipe 19.

  Therefore, when fuel and gas are supplied to the combustion chamber 18, combustion occurs in the combustion chamber 18. The piston 15 reciprocates in the axial direction of the piston due to the energy generated by this combustion. At this time, when the exhaust valve 17 is operated and the combustion chamber 18 is opened, the exhaust gas generated by the combustion is pushed out to the exhaust pipe 19, while the gas is introduced into the combustion chamber 18 via a scavenging port (not shown). .

  On the other hand, the lower end of the piston 15 is connected to the upper end of the piston rod 21. The base plate 11 forms a so-called crankcase, and houses a crankshaft 22 rotatably supported by a bearing 23. A lower end of a connecting rod 25 is rotatably connected to the crankshaft 22 via a crank 24.

  Inside the frame 12, a pair of guide plates 26 provided along the up-down direction are arranged so as to face each other at a predetermined interval. The crosshead 40 described above is disposed between the pair of guide plates 26 so as to be vertically movable. The crosshead 40 connects the lower end 21a of the piston rod 21 and the upper end 25a of the connecting rod 25, and the vertical movement thereof is guided by the guide plate 26 (see also FIG. 4). The crosshead 40 is connected to the piston rod 21 so as to move up and down integrally, while the crosshead 40 is rotated with respect to the connecting rod 25 using the upper end of the connecting rod 25 as a fulcrum. It is connected to the.

  Therefore, when the piston 15 reciprocates along the up-down direction, the piston rod 21 reciprocates up and down together with the piston 15. Accordingly, the crosshead 40 connected to the piston rod 21 reciprocates vertically along the guide plate 26. The crosshead 40 also allows the connecting rod 25 to rotate. Then, the crank 24 connected to the lower end of the connecting rod 25 performs a crank motion, and rotates the crankshaft 22.

(2) Configuration of Frame and Crosshead Here, the configuration of the frame 12 and the crosshead 40 will be briefly described.

  FIG. 2 is a front view illustrating the structure of the frame 12 and the crosshead 40 of the engine 1, and FIGS. 3 and 4 are diagrams illustrating a cross section of the crosshead 40.

  As shown in FIG. 2, the frame 12 includes a top plate 31, a bottom plate 32, a side plate 33, and a plurality of partition walls 34. The top plate 31 is arranged on the cylinder jacket 13 and forms the top of the frame 12. The bottom plate 32 is connected to the base plate 11 and forms the bottom of the frame 12. The side plates 33 form left and right sides of the frame 12. The lower end of the side plate 33 is connected to the bottom plate 32, and the upper end of the side plate 33 is connected to the top plate 31.

  The plurality of partition walls 34 are arranged along the direction in which the crankshaft 22 extends (the crankshaft direction), and are arranged at a predetermined interval from each other. Each partition 34 functions as a partition that partitions a space in the frame 12.

  The above-described crosshead 40 is configured to be accommodated in a space defined by the top plate 31, the bottom plate 32, the side plates 33, and the partition walls 34 and located between the pair of guide plates 26.

  Specifically, the crosshead 40 is attached to the lower end 21a of the piston rod 21, and the crosshead pin 41 for rotating the connecting rod 25 with respect to the lower end 21a, a guide shoe 42 attached to the crosshead pin 41, A bearing 43 is provided at the upper end 25a of the connecting rod 25 and rotatably supports the crosshead pin 41.

  More specifically, the crosshead pin 41 is formed in a column shape extending in a direction perpendicular to the paper surface of FIGS. 3 and 4, and a part of the upper surface 41a is cut out on a substantially plane. By fastening the lower end 21a of the piston rod 21 to the upper surface 41a, the crosshead pin 41 and the piston rod 21 can be moved up and down integrally.

  The guide shoe 42 is non-rotatably attached to the crosshead pin 41 and is configured to slidably contact the guide plate 26. Using this sliding contact, the reciprocating movement of the crosshead 40 can be guided.

  The bearing 43 is recessed in a substantially semicircular shape opened upward, and is configured so that the crosshead pin 41 is inserted along the crankshaft direction. By inserting the crosshead pin 41 into the bearing 43, the connecting rod 25 is rotatable about the crosshead pin 41 with the bearing 43 as a fulcrum.

  As shown in FIG. 4, a bearing shell 44 is disposed between the bearing 43 and the lower half of the crosshead pin 41. The bearing shell 44 is a so-called bearing metal and has an arc-shaped cross section. The bearing shell 44 comes into sliding contact with the outer surface (particularly, the outer surface of the lower half) of the crosshead pin 41 and supports the outer surface from below. The bearing shell 44 is provided with a plurality of through holes 44a penetrating the bearing shell 44 in the thickness direction. These through holes 44a communicate with a later-described crank-side oil passage 25b.

  The crosshead 40 according to the present disclosure has a configuration including a lubrication passage 50 for lubricating each part of the engine 1. The lubrication passage 50 is provided in the crosshead pin 41, and can distribute the lubricating oil introduced through the crosshead pin 41 to the piston rod 21 and the connecting rod 25.

  Here, the lubricating oil distributed from the crosshead pin 41 to the piston rod 21 is supplied to the piston 15 through an oil passage (hereinafter referred to as “piston-side oil passage”) 21 b provided inside the piston rod 21. The piston-side oil passage 21b is configured as a through-hole extending along the direction in which the piston rod 21 extends (that is, the vertical direction). The lower end of the piston-side oil passage 21 b is open to the lower surface of the piston rod 21 and communicates with the lubrication passage 50. On the other hand, the upper end of the piston-side oil passage 21 b communicates with the piston 15. Lubricating oil can be supplied to the piston 15 via the piston-side oil passage 21b thus configured.

  On the other hand, the lubricating oil distributed from the crosshead pin 41 to the connecting rod 25 is supplied to the crank 24 through an oil passage (hereinafter referred to as “crank-side oil passage”) 25 b provided inside the connecting rod 25. The crank-side oil passage 25b is formed as a through hole extending along the direction in which the connecting rod 25 extends (at the top dead center, the vertical direction). The upper end of the crank-side oil passage 25 b is opened at the inner bottom surface of the bearing 43 and communicates with the lubrication passage 50 via the bearing shell 44. On the other hand, the lower end of the crank-side oil passage 25 b communicates with the crank 24. Lubricating oil can be supplied to the crank 24 via the crank-side oil passage 25b thus configured.

(3) Configuration of Crosshead Pin Hereinafter, the configurations of the crosshead pin 41 and the lubrication passage 50 will be described in detail.

  FIG. 5 is a plan view illustrating the configuration of the crosshead pin 41. 6 is a VI-VI sectional view illustrating a longitudinal section of the crosshead pin 41, FIG. 7 is a VII-VII sectional view illustrating a longitudinal section of the crosshead pin 41, and FIG. 9 is an IX-IX cross-sectional view illustrating a cross-section of the crosshead pin 41, and FIG. 10 is an XX cross-sectional view illustrating a cross-section of the crosshead pin 41. is there. The IX-IX cross section illustrated in FIG. 9 is an example of the “cross section passing through the piston rod and the connecting rod”. This IX-IX section is the same as the cross section shown in FIG. As shown in FIG. 4, in the IX-IX section, both the piston-side oil passage 21 b provided in the piston rod 21 and the crank-side oil passage 25 b provided in the connecting rod 25 are longitudinally cut.

  In the following description, one of the directions (pin axis direction) along the central axis of the crosshead pin 41 is defined as “forward”, and the other is defined as “rearward”. Further, as described above, in this configuration example, the piston axial direction coincides with the up-down direction. Then, one of the directions orthogonal to both the front-rear direction and the up-down direction is defined as “left direction”, and the other is defined as “right direction”.

  In this specification, the up-down direction and the left-right direction correspond to the up-down direction and the left-right direction in FIG. 1 to FIG. 4, respectively.

  As shown in FIGS. 5 to 10, the lubrication passage 50 is formed by combining a plurality of perforations formed using a drill or the like. Specifically, the lubrication passage 50 according to the present disclosure includes an introduction passage 51 extending from the outer surface of the crosshead pin 41 to the inside, and a first branch passage that branches off from the introduction passage 51 and communicates with the piston-side oil passage 21b. 52, and a second branch passage 53 extending from the introduction passage 51 and communicating with the crank-side oil passage 25b.

  As shown in each figure, the first branch path 52 and the second branch path 53 are both provided one by one on the left and right sides of the center axis of the crosshead pin 41. The first branch 52 and the second branch 53 are both provided on the left and right and are vertically arranged.

  Specifically, the introduction path 51 includes an upstream introduction path 51a extending downward from the outer surface of the crosshead pin 41, and a pair of upper and lower downstream introduction paths 51b, 51b extending rightward from the left side surface of the crosshead pin 41. ,have.

  As shown in FIG. 5, the upstream introduction path 51 a is opened on the upper surface on the front side and slightly to the left of the crosshead pin 41. Through this opening, lubricating oil can be guided into the inside of the crosshead pin 41. As shown in FIG. 8, a vertically central portion of the upstream introduction passage 51a and a lower end portion of the upstream introduction passage 51a are connected to the downstream introduction passage 51b, respectively.

  As shown in FIGS. 7 and 8, the pair of downstream introduction paths 51b and 51b extend in parallel with each other along the left-right direction, and each communicates with the upstream introduction path 51a as described above. .

  One of the pair of downstream introduction paths 51b, 51b located above is in communication with the first branch 52, and the other located below is in communication with the second branch 53.

  More specifically, the downstream introduction path 51b located above the first branch path 52 (specifically, to be described later) in the vicinity of a portion intersecting with the upstream introduction path 51a and at the right end of the downstream introduction path 51b. Of the first upper flow path 52a).

  On the other hand, the downstream introduction path 51b located below is located near the portion intersecting with the upstream introduction path 51a and the right end of the downstream introduction path 51b at the second branch path 53 (specifically, described later). It communicates with the second upper channel 53a).

  As shown in FIG. 8, the pair of downstream introduction paths 51b, 51b communicate with each other via the upstream introduction path 51a. In other words, the pair of downstream introduction paths 51b, 51b does not communicate without passing through the upstream introduction path 51a.

  The pair of downstream introduction paths 51b, 51b are both open to the left side of the crosshead pin 41, but are closed by the guide shoe 42 as shown in FIG.

  As shown in FIGS. 7 to 9, the first branch channel 52 is connected to the introduction channel 51 and extends in the pin axis direction of the crosshead pin 41, and continuously extends from the first upper channel 52 a. And a first lower channel 52b extending toward the piston rod 21.

  Specifically, the first upper flow path 52a is configured as a pair of left and right passages, and extends substantially straight along the front-back direction as the pin axis direction. Each first upper channel 52a is disposed above the center axis of the crosshead pin 41.

  As shown in FIGS. 7 to 9, each of the first upper flow paths 52a communicates with the upper downstream introduction path 51b at a front portion (corresponding to the VIII-VIII cross section in FIG. 6) in the front-rear direction. Further, as shown in FIG. 9, each first upper channel 52a communicates with the lower end of the first lower channel 52b at the center (corresponding to the IX-IX cross section in FIG. 6) in the front-rear direction. Further, as shown in FIG. 10, of the first upper flow paths 52a, 52a arranged on the left and right, the first upper flow path 52a located on the left side communicates with the third lower flow path 52c near the rear end. .

  Here, the first lower channel 52b is configured as a pair of left and right channels similarly to the first upper channel 52a, and extends substantially straight upward. Each of the first lower channels 52b is open to the upper surface 41a of the crosshead pin 41. The first lower flow paths 52b thus opened communicate with a piston-side oil path 21b provided in the piston rod 21, as shown in FIG. Each first lower channel 52b is also arranged on the IX-IX section. That is, each of the first lower flow paths 52b, the piston-side oil passage 21b, and the crank-side oil passage 25b are arranged on the same plane (see FIG. 4).

  The third lower flow path 52c radially extends obliquely upward, and opens on the upper outer surface of the crosshead pin 41. The third lower flow path 52c does not communicate with the piston-side oil path 21b, and discharges lubricating oil so as to lubricate the guide shoe 42 and the like.

  On the other hand, the second branch channel 53 is connected to the introduction channel 51 and extends in the pin axis direction, and a second lower channel extending continuously from the second upper channel 53a and extending toward the connecting rod 25. 53b.

  More specifically, the second upper channel 53a is configured as a pair of left and right channels similarly to the first upper channel 52a, and extends substantially straight along the front-rear direction as the pin axis direction. Each second upper channel 53a is disposed below the center axis of the crosshead pin 41.

  As shown in FIGS. 7 to 9, each of the second upper channels 53 a communicates with the lower downstream introduction channel 51 b at a front portion (corresponding to the VIII-VIII cross section in FIG. 6) in the front-rear direction. . As shown in FIG. 9, each second upper channel 53a communicates with the upper end of the second lower channel 53b at a central portion (corresponding to the IX-IX cross section in FIG. 6) in the front-rear direction.

  Here, the second lower channel 53b is configured as a pair of left and right channels similarly to the second upper channel 53a, and extends radially obliquely downward. Each of the second lower channels 53b is open on the lower outer surface of the crosshead pin 41. Each of the second lower flow paths 53b thus opened communicates with the crank-side oil path 25b through a plurality of through holes 44a provided in the bearing shell 44, as shown in FIG.

  More specifically, the second lower flow path 53b is not located at the center in the circumferential direction of the bearing shell 44 at least in a cross-sectional view taken along the line IX-IX, but is located on the outer edge side thereof (a portion closer to the outer edge as compared with the central portion in the circumferential direction). ). That is, the second lower flow path 53b extends slightly inclining with respect to the lower direction, and as a result, extends diagonally downward as described above.

  The second lower channels 53b are arranged on the IX-IX cross section similarly to the first lower channels 52b. That is, each of the second lower flow paths 53b, the piston-side oil path 21b, the crank-side oil path 25b, and each of the second lower flow paths 53b are arranged on the same plane (see FIG. 4). ).

  The first branch 52 extends upward at least in the IX-IX sectional view. On the other hand, the second branch 53 extends obliquely downward in the same sectional view. As a result, the first branch path 52 and the second branch path 53 extend in directions away from each other at least in a sectional view passing through the piston rod 21 and the connecting rod 25.

  As a result of this configuration, the first branch 52 and the second branch 53 are partitioned so as not to communicate with each other in a cross-sectional view passing through the piston rod 21 and the connecting rod 25. That is, in the IX-IX sectional view shown in FIG. 9, the first branch path 52 and the second branch path 53 are configured as independent paths.

  Specifically, as shown in FIG. 8, the first upper flow path 52a and the second upper flow path 53a are indirectly connected via the introduction path 51. On the other hand, the first lower flow path 52b and the second lower flow path 53b are partitioned so as not to communicate directly or even indirectly on the cross section shown in FIG.

  The lubricating passage 50 further has a central passage 54 that passes through the central axis of the crosshead pin 41, and a return passage 55 that communicates with the central passage 54.

  Specifically, the central passage 54 extends in the front-rear direction so as to pass through the central axis of the crosshead pin 41. A device (not shown) is connected to one of the front and rear sides of the central passage 54 so that the lubricating oil can be discharged.

  On the other hand, the return passage 55 extends upward from a central portion of the center passage 54 in the front-rear direction and opens to the upper surface 41 a of the crosshead pin 41. The return passage 55 communicates with the piston-side oil passage 21b. The return passage 55 is a passage through which the lubricating oil that has cooled the piston 15 and returned to the crosshead 40 side flows.

(4) Distribution of Lubricating Oil FIG. 11 is a diagram corresponding to FIG. 3 illustrating a conventional example of a crosshead, and FIG. 12 is a diagram corresponding to FIG. 4 illustrating a crosshead of a conventional example. Although the crosshead 140 shown in FIGS. 11 to 12 includes a crosshead pin 141, a bearing 143, and a bearing shell 144 similar to the above-described embodiment, the lubrication passage 150 provided in the crosshead pin 141 is different from the above-described embodiment. Is configured differently.

  That is, the lubrication passage 150 shown in FIGS. 11 to 12 includes the introduction passage 151 opened on the outer surface of the crosshead pin 141 and the branch passage 152 communicating with the introduction passage 151.

  Specifically, the introduction path 151 has an upstream introduction path 151a extending in the vertical direction, and a downstream introduction path 151b communicating with the upstream introduction path 151a and extending in the left-right direction.

  On the other hand, the branch passage 152 has a pair of left and right sides, and includes an upper passage 152a communicating with the downstream introduction passage 151b and extending in the front-rear direction, a lower passage 152b continuous from the upper passage 152a and extending in the up-down direction, have.

  As shown in FIG. 12, one of the right and left lower passages 152b extends upward from the upper passage 152a and opens on the upper surface of the crosshead pin 141. On the other hand, the lower flow path 152b on the left side extends upward and downward from a communication portion with the upper flow path 152a, and penetrates the crosshead pin 141 in the vertical direction.

  Therefore, when viewed in the cross section shown in FIG. 12, the oil passage 121b provided in the piston rod 121 and the oil passage 125b provided in the connecting rod 125 are connected vertically via the lower flow path 152b on the left side.

  However, as shown in FIG. 12, if the oil passage 121b on the piston rod 121 side and the oil passage 125b on the connecting rod 125 side are connected up and down, it may hinder the distribution of the lubricating oil in a well-balanced manner. The present inventors have noticed.

  That is, the lubricating oil flowing from the crosshead pin 141 toward the oil passage 125b on the connecting rod 125 side is pulled upward due to the inertial force when the piston 15 moves up and down (FIG. 12). (See arrow F). In the case of the configuration as in the conventional example, there is a possibility that the lubricating oil thus pulled may flow into the oil passage 121b on the piston rod 121 side. In this case, the amount of the lubricating oil flowing through the oil passage 121b on the piston rod 121 side becomes larger than the amount of the lubricating oil flowing through the oil passage 125b on the connecting rod 125 side, and the lubricating oil flowing on the connecting rod 125 side may become negative pressure. Have been found by the present inventors.

  Generally, a bearing 143 and a bearing shell 144 for supporting the crosshead pin 141 are provided at the upper end of the connecting rod 125. However, when a small amount of lubricating oil flows on the connecting rod 125 side, these parts are sufficiently provided. This is inconvenient because it may not be lubricated.

  On the other hand, according to the embodiment, as shown in FIG. 3, the lubricating oil flowing into the lubrication passage 50 of the crosshead pin 41 flows through the introduction path 51, and then flows into the first branch path 52 and the second branch path. And the road 53. As shown in FIG. 4, the first branch 52 and the second branch 53 do not communicate with each other in a cross-sectional view passing through the piston rod 21 and the connecting rod 25.

  Therefore, when viewed at least in the cross section, the piston-side oil passage 21b communicating with the first branch passage 52 and the crank-side oil passage 25b communicating with the second branch passage 53 are not connected vertically. As a result, the lubricating oil pulled upward due to the inertial force can be suppressed from flowing into the piston side oil passage 21b, and the lubricating oil flowing on the connecting rod 25, the bearing 43, and the bearing shell 44 side can be suppressed. It is possible to suppress the negative pressure.

  Thus, according to the embodiment, the lubricating oil supplied through the crosshead pin 41 can be distributed to the piston-side oil passage 21b and the crank-side oil passage 25b in a well-balanced manner.

  Further, as shown in FIG. 9, by extending the first lower flow path 52 b and the second lower flow path 53 b in a direction away from each other, the first branch path 52 and the second branch path 53 do not communicate with each other. This is advantageous in configuration. This is effective in distributing the lubricating oil in a well-balanced manner.

  As shown in FIG. 4, a bearing 43 for supporting the crosshead pin 41 is provided at the upper end 25a of the connecting rod 25. A bearing shell 44 is provided between the bearing 43 and the crosshead pin 41. Lubricating oil is supplied through a through hole 44 a provided in the bearing shell 44. Since the through-hole 44a communicates with the crank-side oil passage 25b, if the amount of lubricating oil flowing through the connecting rod 25 becomes small, the bearing 43 and the bearing shell 44 may not be sufficiently lubricated.

  On the other hand, in the configuration according to the embodiment, the lubricating oil can be distributed in a well-balanced manner, so that the bearing 43 and the bearing shell 44 can be sufficiently lubricated.

  Generally, the central portion of the inner peripheral surface of the bearing shell 44 is located immediately below the crosshead pin 41. A greater load is applied to this part than to other parts. In such a portion, it is effective to make the lubricating oil into a thin film. If the lubricating oil is supplied excessively, the lubricating oil will not be formed into a thin film, but rather disadvantageous.

  On the other hand, as shown in FIG. 3, the second branch 53 is directed not to the center of the bearing shell 44 but to the outer edge thereof, so that excessive supply of lubricating oil is prevented at the center. Can be This is advantageous for making the lubricating oil into a thin film.

1 engine (crosshead type internal combustion engine)
21 Piston rod 21a Lower end 21b of piston rod Piston side oil passage (oil passage provided in piston rod)
25 Connecting rod 25a Upper end 25b of connecting rod Crank side oil passage (oil passage provided in connecting rod)
40 crosshead 41 crosshead pin 43 bearing 44 bearing shell 44a through hole 50 lubrication passage 51 introduction passage 52 first branch passage 52a first upper passage 52b first lower passage 53 second branch passage 53a second upper passage 53b second lower passage

Claims (6)

A crosshead for connecting the piston rod and the connecting rod,
A crosshead pin attached to a lower end of the piston rod and rotating the connecting rod with respect to the lower end;
A lubrication passage provided in the crosshead pin, for distributing lubricating oil from the crosshead pin to the piston rod and the connecting rod,
The lubrication passage,
An introduction path extending from the outer surface of the crosshead pin to the inside,
A first branch passage extending from the introduction passage and communicating with an oil passage provided in the piston rod;
A second branch path extending from the introduction path and communicating with an oil path provided in the connecting rod;
A crosshead, wherein the first branch and the second branch are partitioned so as not to communicate with each other in a cross-sectional view passing through the piston rod and the connecting rod. The crosshead according to claim 1,
A crosshead wherein the first branch and the second branch extend in directions away from each other in a cross-sectional view passing through the piston rod and the connecting rod. The crosshead according to claim 1 or 2,
A bearing provided at an upper end of the connecting rod and supporting the crosshead pin;
A bearing shell disposed between the bearing and a lower half of the crosshead pin,
A crosshead, wherein the bearing shell is provided with a through-hole communicating with an oil passage provided in the connecting rod. The crosshead according to claim 3,
The crosshead, wherein the second branch path extends so as to be directed to a portion on the outer edge side of the bearing shell in a sectional view passing through the piston rod and the connecting rod. The crosshead according to any one of claims 1 to 4,
The first fork,
A first upper flow path connected to the introduction path and extending in a pin axis direction of the crosshead pin;
A first lower flow path that is continuous from the first upper flow path and extends toward the piston rod;
The second fork,
A second upper flow path connected to the introduction path and extending in the pin axis direction;
A second lower flow path that is continuous from the second upper flow path and extends toward the connecting rod;
The first upper flow path and the second upper flow path are partitioned to communicate with each other via the introduction path,
A crosshead, wherein the first lower flow path and the second lower flow path are partitioned so as not to communicate with each other in a cross-sectional view passing through the piston rod and the connecting rod. A crosshead type internal combustion engine comprising the crosshead according to any one of claims 1 to 5.