JP7168404B2 - Crosshead and crosshead internal combustion engines - Google Patents

Description

The technology disclosed herein relates to crossheads and crosshead internal combustion engines.

In internal combustion engines with a large bore-to-stroke ratio, such as marine internal combustion engines, a part 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, the crosshead disclosed in Patent Document 1 is a crosshead pin (crosshead journal) that is attached to the lower end of a piston rod and rotates a connecting rod with respect to the lower end. and passages (holes) provided inside the crosshead pin for distributing lubricating oil to the piston rod and the connecting rod.

In the second embodiment of Patent Document 1, the passage according to Patent Document 1 communicates with the passage (upward radial hole) communicating with the oil passage provided in the piston rod and the oil passage provided in the connecting rod. It branches into a passage (two obliquely downward holes). The two types of passages thus branched communicate with each other in a cross-sectional view passing through the piston rod and the connecting rod. That is, when viewed in cross section, the oil passage provided in the piston rod and the oil passage provided in the connecting rod are vertically connected through the passage provided inside the crosshead pin.

JP 2015-057570 A

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 vertically connected, it may hinder the well-balanced distribution of the lubricating oil. In particular, the inventors of the present application have noticed.

That is, the lubricating oil flowing from the crosshead pin to 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 configuration disclosed in Patent Document 1, the lubricating oil thus drawn may flow into the oil passage on the piston rod side. In this case, the amount of lubricating oil flowing through the oil passage on the piston rod side is greater than the amount of lubricating oil flowing through the oil passage on the connecting rod side, and the inventors of the present application have found that the pressure of the lubricating oil flowing on the connecting rod side may become negative. found out.

In general, the upper end of the connecting rod is provided with a bearing for supporting the crosshead pin and a bearing shell. It is inconvenient because

The technology disclosed herein has been made in view of this point, and its purpose is to distribute the lubricating oil supplied through the crosshead pin through the oil passage on the piston rod side and the oil passage on the connecting rod side. to be distributed in a well-balanced manner.

The technology disclosed herein relates to a crosshead connecting a piston rod and a connecting rod. The crosshead includes a crosshead pin that is attached to the lower end of the piston rod and rotates the connecting rod with respect to the lower end, and the crosshead pin is provided with the piston rod and the connecting rod from the crosshead pin. lubricating passages for distributing lubricating oil to the

The lubrication passage includes an introduction passage extending inwardly from the outer surface of the crosshead pin, a first branch passage extending from the introduction passage and communicating with an oil passage provided in the piston rod, and a first branch passage extending from the introduction passage. and a second branch path that branches and extends and communicates with the oil path provided in the connecting rod.

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

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

Therefore, when viewed at least 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 vertically connected. 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 negative pressure of the lubricating oil flowing on the connecting rod side can be suppressed. It becomes possible to In this way, 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 branched passage and the second branched passage may extend in directions away from each other in a cross-sectional view passing through the piston rod and the connecting rod.

The configuration described above is advantageous in appropriately partitioning the first branched passage and the second branched passage. This is effective in distributing lubricating oil in a well-balanced manner.

a bearing provided at the upper end of the connecting rod for supporting the crosshead pin; and a bearing shell disposed between the bearing and the lower half of the crosshead pin. may be provided with a through-hole communicating with an oil passage provided in the connecting rod.

According to the above configuration, the upper end of the connecting rod is provided with a bearing that supports the crosshead pin. 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 this through-hole communicates with an oil passage provided on the connecting rod side, if the amount of lubricating oil flowing through the connecting rod side becomes small, there is a risk that the bearing and the bearing shell will not be sufficiently lubricated.

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

Further, the second branch path may extend toward the outer edge side portion 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 positioned directly below the crosshead pin. A larger load is applied to this portion than to other portions. It is effective to form a thin film of lubricating oil in such areas. Excessive supply of lubricating oil does not form a thin film, which is rather disadvantageous.

On the other hand, according to the above configuration, the second branch path is directed to the outer edge side portion of the bearing shell rather than the central portion, so excessive supply of lubricating oil to the central portion can be avoided. This is advantageous for making the lubricating oil into a thin film.

Further, the first branch passage includes a first upstream passage connected to the introduction passage and extending in the axial direction of the crosshead pin, and a first downstream passage continuing from the first upstream passage and extending toward the piston rod. and a second branch path connected to the introduction path and extending in the axial direction of the pin; and a second upstream path continuing from the second upstream path and extending toward the connecting rod. 2 downstream flow paths, wherein the first upstream flow path and the second upstream flow path are partitioned so as to communicate via the introduction path, and the first downstream flow path and the second downstream flow path are connected to the piston A cross-sectional view through the rod and the connecting rod may be partitioned so as not to communicate with each other.

The configuration described above is advantageous in appropriately partitioning the first branched passage and the second branched passage. This is effective in distributing lubricating oil in a well-balanced manner.

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

As described above, according to the above-described 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 diagram illustrating the configuration of a crosshead internal combustion engine. FIG. 2 is a front view illustrating the configuration of the frame and 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 sectional view taken along line VI-VI of FIG. 5, illustrating a longitudinal section of the crosshead pin. FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6, illustrating a vertical cross-section of the crosshead pin. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 6, illustrating the cross-section of the crosshead pin. FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 6, illustrating the 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 view corresponding to FIG. 3 illustrating a conventional example of a crosshead. FIG. 12 is a diagram corresponding to FIG. 4 illustrating a conventional example of a crosshead.

Hereinafter, embodiments of the present disclosure will be described based on the drawings. Note that the following description is an example. FIG. 1 is a schematic diagram illustrating the configuration of a crosshead 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. This engine 1 is configured as a two-stroke, one-cycle engine employing a uniflow scavenging system, and is mounted on large ships such as tankers, container ships, and car carriers. An output shaft of the engine 1 is connected to a propeller (not shown). As the engine 1 operates, its output is transmitted to the propeller to propel the ship.

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

(1) Main Configuration The main parts of the engine 1 will be described below.

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 vertically extending tie bolts and nuts.

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 the upper portion of the cylinder liner 14 . An exhaust valve 17 is provided on the cylinder cover 16 . Exhaust valve 17 defines combustion chamber 18 together with cylinder liner 14 , piston 15 and cylinder cover 16 . The exhaust valve 17 opens and closes between the combustion chamber 18 and the exhaust pipe 19 .

Therefore, when fuel and gas are supplied to the combustion chamber 18 , combustion occurs within the combustion chamber 18 . The energy generated by this combustion causes the piston 15 to reciprocate in the axial direction of the piston. At this time, when the exhaust valve 17 is actuated to open the combustion chamber 18, exhaust gas generated by combustion is pushed out to the exhaust pipe 19, while gas is introduced into the combustion chamber 18 through 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 constitutes a so-called crankcase and accommodates a crankshaft 22 rotatably supported by bearings 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 vertical direction are arranged to face each other with a predetermined gap therebetween. Between the pair of guide plates 26, the aforementioned crosshead 40 is arranged 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 its vertical movement 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 connected to the connecting rod 25 so as to rotate with the upper end of the connecting rod 25 as a fulcrum. It is connected to the.

Therefore, when the piston 15 reciprocates along the vertical direction, the piston rod 21 reciprocates vertically together with the piston 15 . As a result, 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 pivot. Then, the crank 24 connected to the lower end of the connecting rod 25 cranks 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.

2 is a front view illustrating the configuration of the frame 12 of the engine 1 and the crosshead 40, and FIGS. 3 and 4 are cross-sectional views of the crosshead 40. FIG.

As shown in FIG. 2 , the frame 12 includes a top plate 31 , a bottom plate 32 , side plates 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 side portions of the frame 12 . A lower end portion of the side plate 33 is connected to the bottom plate 32 , and an upper end portion 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 (crankshaft direction) and are arranged at predetermined intervals from each other. Each partition wall 34 functions as a partition that divides the space inside the frame 12 .

The crosshead 40 described above is housed in a space defined by the top plate 31 , the bottom plate 32 , the side plates 33 , and the partition walls 34 and positioned between the pair of guide plates 26 .

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

Specifically, the crosshead pin 41 is formed in a columnar shape extending in a direction orthogonal to the planes of FIGS. 3 and 4, and a portion of the upper surface 41a thereof is cut off substantially flat. By fastening the lower end portion 21a of the piston rod 21 to the upper surface 41a, the crosshead pin 41 and the piston rod 21 can be vertically moved integrally.

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

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

As shown in FIG. 4, a bearing shell 44 is arranged between the bearing 43 and the lower half of the crosshead pin 41 . This bearing shell 44 is a so-called bearing metal and has an arcuate cross section. The bearing shell 44 is in sliding contact with the outer surface of the crosshead pin 41 (in particular, the outer surface of the lower half) and supports the outer surface from below. Further, the bearing shell 44 is provided with a plurality of through holes 44a extending therethrough in the thickness direction. These through holes 44a communicate with a crank-side oil passage 25b, which will be described later.

The crosshead 40 according to the present disclosure is configured to include a lubricating passage 50 for lubricating each part of the engine 1 . This lubricating 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 a "piston side oil passage") 21b 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). A lower end portion of the piston-side oil passage 21 b opens to the lower surface of the piston rod 21 and communicates with the lubricating passage 50 . On the other hand, the upper end of the piston-side oil passage 21b communicates with the piston 15. As shown in FIG. 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") 25b provided inside the connecting rod 25. The crank-side oil passage 25b is configured as a through hole extending along the direction in which the connecting rod 25 extends (vertical direction at top dead center). An upper end portion of the crank-side oil passage 25 b is open to the inner bottom surface of the bearing 43 and communicates with the lubricating 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, configurations of the crosshead pin 41 and the lubricating passage 50 will be described in detail.

FIG. 5 is a plan view illustrating the configuration of the crosshead pin 41. FIG. 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 a IX-IX cross-sectional view illustrating a cross-section of the crosshead pin 41, and FIG. 10 is a XX cross-sectional view illustrating a cross-section of the crosshead pin 41. be. The IX-IX cross section illustrated in FIG. 9 is an illustration of "the cross section passing through the piston rod and the connecting rod". This IX-IX cross section is the same as the cross section shown in FIG. As shown in FIG. 4, the IX-IX cross section runs through both the piston side oil passage 21b provided in the piston rod 21 and the crank side oil passage 25b provided in the connecting rod 25. As shown in FIG.

In the following description, one of the directions along the center axis of the crosshead pin 41 (pin axis direction) is defined as "forward direction" and the other is defined as "rearward direction". Further, as described above, in this configuration example, the piston axis direction coincides with the vertical direction. One of the directions orthogonal to both the front-back direction and the up-down direction is defined as the "left direction", and the other is defined as the "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 of the paper of FIGS. 1 to 4, respectively.

As shown in FIGS. 5-10, the lubrication passage 50 is formed by combining a plurality of perforations formed using a drill or the like. Specifically, the lubricating passage 50 according to the present disclosure includes an introduction passage 51 that extends inward from the outer surface of the crosshead pin 41, 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 branching from the introduction passage 51 and extending to communicate with the crank-side oil passage 25b.

As shown in each figure, both the first branched path 52 and the second branched path 53 are provided one each on the left and right sides of the central axis of the crosshead pin 41 . In addition, both the first branched path 52 and the second branched path 53 are provided on the left and right sides and are arranged vertically.

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 opens on the upper surface of the crosshead pin 41 on the front side and slightly to the left. Lubricating oil can be introduced into the crosshead pin 41 through this opening. As shown in FIG. 8, the vertical central portion of the upstream introduction passage 51a and the lower end portion of the upstream introduction passage 51a are each connected to the downstream introduction passage 51b.

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

Of the pair of downstream introduction passages 51 b , 51 b , the upper one communicates with the first branched passage 52 , and the lower one communicates with the second branched passage 53 .

Specifically, the downstream introduction path 51b positioned above has a first branch path 52 (specifically, a branch path 52, which will be described later) in the vicinity of the intersection with the upstream introduction path 51a and at the right end of the downstream introduction path 51b. is communicated with the first upstream channel 52a).

On the other hand, the downstream introduction path 51b located below has a second branch path 53 (specifically, a It communicates with the second upstream 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 are not communicated with each other except through the upstream introduction path 51a.

Although the pair of downstream introduction paths 51b, 51b are both open on the left side surface of the crosshead pin 41, those openings are closed by the guide shoe 42 as shown in FIG.

As shown in FIGS. 7 to 9, the first branch channel 52 includes a first upstream channel 52a connected to the introduction channel 51 and extending in the axial direction of the crosshead pin 41, and a first upstream channel 52a extending continuously from the first upstream channel 52a. and a first downstream flow path 52 b extending toward the piston rod 21 .

Specifically, the first upstream flow path 52a is configured as a pair of left and right passages, and extends substantially straight along the front-rear direction as the pin axial direction. Each first upstream flow path 52 a is arranged above the central axis of the crosshead pin 41 .

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

Here, the first downstream flow path 52b is configured as a pair of left and right passages similarly to the first upstream flow path 52a, and extends substantially straight upward. Each first downstream channel 52 b opens to the top surface 41 a of the crosshead pin 41 . Each of the first downstream passages 52b thus opened communicates with the piston-side oil passage 21b provided in the piston rod 21, as shown in FIG. Each first downstream channel 52b is also arranged on the IX-IX cross section. That is, each first downstream passage 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 downstream flow path 52 c radially extends obliquely upward and opens to the upper outer surface of the crosshead pin 41 . This third downstream passage 52c does not communicate with the piston-side oil passage 21b, and discharges lubricating oil so as to lubricate the guide shoe 42 and the like.

On the other hand, the second branch passage 53 includes a second upstream passage 53a connected to the introduction passage 51 and extending in the axial direction of the pin, and a second downstream passage continuously extending from the second upstream passage 53a and extending toward the connecting rod 25. 53b and .

Specifically, the second upstream flow path 53a is configured as a pair of left and right passages similarly to the first upstream flow path 52a, and extends substantially straight along the front-rear direction as the pin axial direction. Each second upstream flow path 53 a is arranged below the central axis of the crosshead pin 41 .

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

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

More specifically, the second downstream flow path 53b is not located at the center in the circumferential direction of the bearing shell 44, but at the outer edge side thereof (a portion closer to the outer edge than at the center in the circumferential direction), at least in the cross-sectional view of IX-IX. ). That is, the second downstream flow path 53b extends with a slight inclination with respect to the downward direction, and as a result, as already explained, it extends obliquely downward.

Each second downstream flow path 53b is arranged on the IX-IX cross section in the same manner as each first downstream flow path 52b. That is, the second downstream flow paths 53b, the piston-side oil path 21b, the crank-side oil path 25b, and the second downstream flow paths 53b are arranged on the same plane (see FIG. 4). ).

Then, the first branch passage 52 extends upward at least in the cross-sectional view taken along line IX-IX. On the other hand, the second fork 53 extends obliquely downward in the same cross-sectional view. As a result, the first branched passage 52 and the second branched passage 53 extend away from each other at least in a cross-sectional view passing through the piston rod 21 and the connecting rod 25 .

As a result of this configuration, the first branched passage 52 and the second branched passage 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 cross-sectional view shown in FIG. 9, the first branched path 52 and the second branched path 53 are constructed as mutually independent paths.

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

The lubrication passageway 50 further has a central passageway 54 passing through the central axis of the crosshead pin 41 and a return passageway 55 communicating with the central passageway 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 lubricating oil can be discharged.

On the other hand, the return passage 55 extends upward from the central portion of the central 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 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 conventional crosshead. Although the crosshead 140 shown in FIGS. 11-12 includes a crosshead pin 141, bearings 143 and bearing shells 144 similar to the previous embodiment, the lubrication passages 150 provided in this crosshead pin 141 are identical to those of the previous embodiment. It is configured differently.

That is, the lubricating passage 150 shown in FIGS. 11 and 12 has an introduction passage 151 opened to the outer surface of the crosshead pin 141 and a 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 channel 152 is configured as a pair of right and left channels, an upstream channel 152a communicating with the downstream introduction channel 151b and extending in the front-rear direction, a downstream channel 152b continuing from the upstream channel 152a and extending in the vertical direction, have.

As shown in FIG. 12 , one of the right and left downstream channels 152 b extends upward from the upstream channel 152 a and opens to the upper surface of the crosshead pin 141 . On the other hand, the downstream channel 152b on the left side extends upward and downward from a communicating portion with the upstream channel 152a and penetrates the crosshead pin 141 in the vertical direction.

12, the oil passage 121b provided in the piston rod 121 and the oil passage 125b provided in the connecting rod 125 are vertically connected via the left downstream passage 152b.

However, if the oil passage 121b on the piston rod 121 side and the oil passage 125b on the connecting rod 125 side are vertically connected as shown in FIG. , the inventors of the present application have noticed.

That is, the lubricating oil flowing from the crosshead pin 141 toward the oil passage 125b on the side of the connecting rod 125 is pulled upward due to the inertia force when the piston 15 moves up and down (see FIG. 12). See arrow F). When configured as in the conventional example, the lubricating oil thus pulled may flow into the oil passage 121b on the piston rod 121 side. In this case, the amount of lubricating oil flowing through the oil passage 121b on the side of the piston rod 121 is greater than the amount of lubricating oil flowing through the oil passage 125b on the side of the connecting rod 125, and the pressure of the lubricating oil flowing on the side of the connecting rod 125 may become negative. The inventors of the present application have found.

In general, 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, if the amount of lubricating oil flowing through the connecting rod 125 becomes small, these parts will be insufficient. This is inconvenient because there is a risk that it will not be lubricated.

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

Therefore, at least when viewed in 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 vertically connected. As a result, the lubricating oil pulled upward due to the inertial force can be prevented from flowing into the piston-side oil passage 21b, and the lubricating oil flowing through the connecting rod 25, bearing 43 and bearing shell 44 side can be prevented from flowing. It is possible to suppress 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 downstream channel 52b and the second downstream channel 53b in directions away from each other, the first branched channel 52 and the second branched channel 53 are prevented from communicating with each other. useful for configuration. This is effective in distributing lubricating oil in a well-balanced manner.

Further, as shown in FIG. 4, the upper end portion 25a of the connecting rod 25 is provided with a bearing 43 for supporting the crosshead pin 41. As shown in FIG. 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, there is a risk that the bearing 43 and the bearing shell 44 will not be sufficiently lubricated if the amount of lubricating oil flowing through the connecting rod 25 becomes small.

On the other hand, the configuration according to the above embodiment can distribute the lubricating oil 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 positioned directly below the crosshead pin 41 . A larger load is applied to this portion than to other portions. It is effective to form a thin film of lubricating oil in such areas. Excessive supply of lubricating oil does not form a thin film, which is rather disadvantageous.

On the other hand, as shown in FIG. 3, the second branch passage 53 is oriented not at the central portion of the bearing shell 44 but at the outer edge side, so that excessive supply of lubricating oil to the central portion is avoided. be done. This is advantageous for making the lubricating oil into a thin film.

1 engine (crosshead internal combustion engine)
21 Piston rod 21a Lower end 21b of piston rod Piston-side oil passage (oil passage provided inside the 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 upstream passage 52b first downstream passage 53 second branch passage 53a second upstream passage 53b second downstream passage

Claims (6)

A crosshead connecting the piston rod and the connecting rod,
a crosshead pin attached to the lower end of the piston rod for pivoting the connecting rod relative to the lower end;
lubricating passages in the crosshead pin for distributing lubricating oil from the crosshead pin to the piston rod and the connecting rod;
The lubrication passage is
an introduction path extending inwardly from the outer surface of the crosshead pin;
a first branch passage extending from the introduction passage and communicating with an oil passage provided in the piston rod;
a second branch path that branches off from the introduction path and communicates with an oil path provided in the connecting rod;
In a given cross-sectional view passing through the piston rod, the connecting rod, the first branched passage and the second branched passage and orthogonal to the pin axial direction of the crosshead, the introduction passage and the first branched passage and the second branch path are partitioned so as not to communicate with each other . A crosshead according to claim 1, wherein
A crosshead, wherein the first branched passage and the second branched passage extend in directions away from each other in a cross-sectional view passing through the piston rod and the connecting rod. In the crosshead according to claim 1 or 2,
a bearing provided at the upper end of the connecting rod and supporting the crosshead pin;
a bearing shell disposed between the bearing and the 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. A crosshead according to claim 3, wherein
The crosshead is characterized in that the second branch path extends toward an outer edge side portion of the bearing shell in a cross-sectional view passing through the piston rod and the connecting rod. In the crosshead according to any one of claims 1 to 4,
The first branch road is
a first upstream channel connected to the introduction channel and extending in the axial direction of the crosshead pin;
a first downstream channel continuous from the first upstream channel and extending toward the piston rod;
The second branch road is
a second upstream channel connected to the introduction channel and extending in the axial direction of the pin;
a second downstream channel continuous from the second upstream channel and extending toward the connecting rod;
The first upstream channel and the second upstream channel are partitioned so as to communicate via the introduction channel,
A crosshead, wherein the first downstream channel and the second downstream channel 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 internal combustion engine comprising the crosshead according to any one of claims 1 to 5.

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