JP6727758B2 - Connecting rod and crosshead engine equipped with it - Google Patents

Description

The present invention relates to a connecting rod mainly used in a crosshead engine mounted as a main engine of a ship and a crosshead engine including the connecting rod.

FIG. 6 is a vertical sectional view of a crosshead engine for a ship. 7 is a sectional view taken along the line VII-VII of FIG. 6, FIG. 8 is a plan view taken along the line VIII-VIII of FIG. 7, and FIG. 9 is a longitudinal sectional view taken along the line IX-IX of FIG. is there.
In this crosshead engine EG, a piston 2 is slidably inserted in a cylinder liner 1 extending in the vertical direction, a crankshaft 3 is axially supported on an extension line of the axis of the cylinder liner 1, and the cylinder liner 1 and the crankshaft 3 A crosshead 5 is vertically slidably provided between a pair of sliding plates 4 provided between and.

A horizontal shaft-shaped crosshead journal 7 provided at the tip of a piston rod 6 extending downward from the piston 2 is connected to the crosshead 5. Further, a small end portion 8A of the connecting rod 8 is pivotally attached to the crosshead journal 7, and a large end portion 8B of the connecting rod 8 is pivotally attached to a crank pin 9 eccentrically provided on the crankshaft 3. It is pivotally supported. Therefore, when the piston 2 is pushed down by the pressure P caused by the combustion of fuel, the crosshead 5 is also pushed down, the connecting rod 8 rotates and the crankshaft 3 rotates, and this rotation causes the output of the crosshead engine EG. Becomes

Caps 81 and 82 are attached to the small end portion 8A and the large end portion 8B of the connecting rod 8, respectively, so that the crosshead journal 7 and the crank pin 9 are held in a clamp shape. Further, the bearing surface 8a of the small end portion 8A (81) and the bearing surface 8b of the large end portion 8B (82) are provided with bearing metal members 11 and 12 in the form of half halves formed of a bearing material such as white metal. It is installed.

As shown in FIGS. 7 to 9 and Patent Document 1, etc., the connecting rod 8 is shown with a small end portion 8A (bearing surface 8a) so as to extend along the inner longitudinal direction thereof, and in FIG. An oil supply passage 15 that communicates with the large end portion 8B (bearing surface 8b) is formed, and this oil supply passage 15 communicates with the bearing surface 8a of the small end portion 8A and the bearing surface 8b of the large end portion 8B. (See also FIG. 5 of Patent Document 1). In addition, a plurality of oil supply grooves 16 extending in the circumferential direction are formed on the bearing surface 8a.

As shown in FIGS. 7 and 8 and FIG. 5 of Patent Document 1, the inner diameter of the opening of the oil supply passage 15 in the bearing surface 8a of the small end 8A is larger than the width of the oil supply groove 16. .. Further, the opening position of the oil supply passage 15 is located at the center of the bearing surface 8a, that is, at the position corresponding to the center line C of the connecting rod 8 (see FIGS. 8 and 9).

During operation of the crosshead engine EG, the lubricating oil supplied from the lubricating oil pump (not shown) to the crosshead 5 lubricates the space between the crosshead journal 7 and the bearing metal 11, and then the lubrication groove 16 and the lubrication passage 15 are formed. The bearing metal 12 and the crank pin 9 are lubricated through the above.

Japanese Patent Publication No. 2007-532845

However, as described above, conventionally, the inner diameter of the opening of the oil supply passage 15 is larger than the width of the oil supply groove 16 and the opening of the oil supply passage 15 is located at the center of the bearing surface 8a. In the pressure range R in which the pressure P (see FIG. 6) applied from the journal 7 is highest, the opening of the oil supply passage 15 and the oil supply groove 16 overlap each other, and the area of the portion that does not come into contact with the back surface of the bearing metal 11 is It was getting bigger.

Therefore, when the load (pressure P) of the crosshead journal 7 acts on the bearing metal 11, pressure deformation occurs so that the bearing metal 11 enters the opening of the oil supply passage 15, and as indicated by a line D in FIG. In addition, the distribution state of the maximum oil film pressure on the sliding surface 11a of the bearing metal 11 drops sharply in the vicinity of the oil supply passage 15 and rises sharply around the oil supply passage 15 as indicated by the height H. It was

Therefore, at the position where the maximum oil film pressure sharply rises to the height H (around the opening of the oil supply passage 15), the oil film of the lubricating oil supplied between the sliding surface 11a of the bearing metal 11 and the crosshead journal 7 is formed. Therefore, the sliding surface 11a of the bearing metal 11 may be damaged such as uneven wear, and the durability and reliability of the crosshead engine EG may be impaired.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a connecting rod capable of suppressing damage to a bearing metal and improving engine durability, and a crosshead engine including the connecting rod. To do.

In order to solve the above problems, the present invention employs the following means.

That is, the connecting rod according to the first aspect of the present invention connects between a crosshead journal provided at the tip of a piston rod of a crosshead engine and a crankpin provided on a crankshaft, An oil supply passage formed to extend in the longitudinal direction inside the connecting rod and connected to a bearing surface at an end of the connecting rod, and the oil supply passage formed to extend along a circumferential direction of the bearing surface. A lubrication groove connected to an opening that opens on the bearing surface; and a half-cylindrical bearing metal that is mounted on the bearing surface, and the lubrication passage branches while sandwiching the center line of the connecting rod. The position of the opening is characterized in that the bearing surface is located on the outer side in the circumferential direction with respect to the pressure range in which the pressure applied from the crosshead journal is highest.

According to the connecting rod having the above-described configuration, the opening of the oil supply passage that opens to the bearing surface at the end thereof is located at the outer circumferential position with respect to the pressure range in which the pressure applied from the crosshead journal is highest. Since the opening of the oil supply passage is located in the pressure range unlike the conventional connecting rod, there is no portion where the bearing surface does not contact the back surface of the bearing metal in the pressure range.

Therefore, when the load (pressure) of the crosshead journal acts on the bearing metal, the bearing metal does not deform so as to enter the opening of the oil supply passage, and the maximum oil film pressure on the sliding surface of the bearing metal There is no sharp rising edge in the distribution. Therefore, the thin portion of the lubricating oil film does not occur, and the sliding surface of the bearing metal does not suffer damage such as uneven wear. Therefore, the durability of the crosshead engine can be improved.

A connecting rod according to a second aspect of the present invention connects between a crosshead journal provided at a tip of a piston rod of a crosshead type engine and a crankpin provided on a crankshaft. An oil supply passage formed to extend in the longitudinal direction inside the connecting rod and connected to a bearing surface at an end of the connecting rod, and the oil supply passage formed to extend along a circumferential direction of the bearing surface. An oil supply groove connected to an opening opening on the bearing surface, and a half-divided cylindrical bearing metal attached to the bearing surface, wherein the oil supply passage branches while sandwiching a center line of the connecting rod, The inner diameter of the opening of the oil supply passage is set to be equal to or less than the width dimension of the oil supply groove, and the lubricating oil supplied to the crosshead journal is supplied to the crank pin via the oil supply groove and the oil supply passage. And

According to the connecting rod having the above structure, the opening of the oil supply passage opening to the bearing surface at the end thereof opens inside the oil supply groove formed along the circumferential direction of the bearing surface, and the opening of the oil supply passage is formed. The inner diameter of is set to be equal to or smaller than the width dimension of the oil supply groove. Therefore, as in the conventional case, the opening of the oil supply passage having the inner diameter larger than the width of the oil supply groove exists in the pressure range together with the oil supply groove, so that the area that does not contact the back surface of the bearing metal increases in the pressure range. There is no.

Therefore, like the first aspect, when the load (pressure P) of the crosshead journal acts on the bearing metal, it is possible to suppress the pressure deformation such that the bearing metal enters the opening of the oil supply passage. As a result, the sliding surface of the bearing metal can be prevented from being damaged such as uneven wear, and the durability of the crosshead engine can be improved.

In the above-mentioned first and second aspects, the oil supply groove is formed at a position on the bearing surface, which is circumferentially outside with respect to a pressure range in which the pressure applied from the crosshead journal is highest. May be.

As a result, when the load (pressure P) of the crosshead journal acts on the bearing metal, pressure deformation due to the bearing metal entering the recess of the oil supply groove is eliminated, and damage such as uneven wear occurs on the sliding surface of the bearing metal. This can be prevented and the durability of the crosshead engine can be improved.

In each of the above aspects, the oil supply passage has a large-diameter portion extending in the longitudinal direction inside the connecting rod, and a branch from the end of the large-diameter portion to the bearing surface, and May have a plurality of small diameter portions each having a small inner diameter, and the tip end of each of the small diameter portions may be the opening in the bearing surface.

By doing so, a plurality of small diameter portions are branched from one large diameter portion to open at a plurality of positions on the bearing surface, and the area of each opening portion is reduced without reducing the amount of oil passing through the oil supply passage. be able to. Accordingly, even if the opening is opened within the pressure range of the bearing surface due to design reasons, for example, since the opening area is small, the area that does not contact the back surface of the bearing metal does not become large.

Therefore, when the load (pressure P) of the crosshead journal acts on the bearing metal, the bearing metal does not undergo pressure deformation so as to enter the opening of the oil supply passage, and the durability of the crosshead engine can be improved. it can.

In the above aspect, the inner diameters of the plurality of small-diameter portions are made different from each other, and the bearing surface has an inner diameter of the small-diameter portion located inside a pressure range where the pressure applied from the crosshead journal is highest. It may be smaller than the inner diameter of the small diameter portion located in a place other than.

In this way, since the inner diameter of the small diameter portion located inside the pressure range is small, the area that does not come into contact with the back surface of the bearing metal does not increase in the pressure range, and the load (pressure P) of the crosshead journal does not increase. When the metal acts on the metal, the bearing metal does not undergo pressure deformation so as to enter the opening of the small diameter portion, whereby the durability of the crosshead type engine can be enhanced.

In the above aspect, the plurality of small diameter portions may be branched from the large diameter portion at different angles.

From the viewpoint of structural mechanics, it is desirable that the large-diameter portion be arranged at the center of the cross-sectional range of the connecting rod. The distal end can be opened relatively freely at any position on the bearing surface. Therefore, it is possible to optimize the position of the opening on the bearing surface of each small diameter portion, suppress the pressure deformation of the bearing metal, and improve the durability of the crosshead engine.

A connecting rod according to a third aspect of the present invention connects a crosshead journal provided at a tip of a piston rod of a crosshead engine and a crankpin provided on a crankshaft, An oil supply passage formed so as to extend in the longitudinal direction inside the connecting rod, an oil supply groove formed so as to extend along the circumferential direction of the bearing surface at the end of the connecting rod, and the oil supply passage mounted on the bearing surface. And a half-cylindrical bearing metal that is formed, the end of the oil supply passage on the bearing surface side communicates with the bottom of the oil supply groove without reaching the bearing surface, and The length of the opening in the communicating portion to the bottom of the oil supply groove along the circumferential direction of the bearing surface is equal to the inner diameter of the oil supply passage, and the width of the opening along the axial direction of the bearing surface is the oil supply. It is characterized by being equal to the width of the groove .

According to the connecting rod having the above-described configuration, the oil supply passage does not directly communicate with the bearing surface but communicates with the bottom of the oil supply groove formed on the bearing surface, so that only the oil supply groove exists as a recess on the bearing surface. There are no other recesses. The lubricating oil collected in the oil supply groove can flow into the oil supply passage from an opening formed by overlapping the bottom of the oil supply groove and the end of the oil supply passage.

As described above, since no recess other than the oil supply groove exists on the bearing surface, when the bearing metal is mounted on the bearing surface, only the oil supply groove portion does not contact the back surface of the bearing metal. Therefore, when the load (pressure P) of the crosshead journal acts on the bearing metal, the bearing metal does not enter the recess and cause pressure deformation, which causes damage such as uneven wear on the sliding surface of the bearing metal. This can be prevented and the durability of the crosshead engine can be improved.

Further, the crosshead engine according to the present invention is characterized by including any one of the connecting rods described above, so that pressure deformation of the bearing metal can be suppressed and engine durability can be improved.

As described above, according to the connecting rod and the crosshead engine including the connecting rod according to the present invention, it is possible to suppress damage to the bearing metal and improve the durability of the engine.

It is a figure which shows 1st Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of the connecting rod which follows the Ib-Ib line of (a). It is a figure which shows 2nd Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of the connecting rod which follows the IIb-IIb line of (a). It is a figure which shows the reference embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of the connecting rod which follows the IIIb-IIIb line of (a). It is a figure which shows 3rd Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of the connecting rod which follows the IVb-IVb line of (a). It is a figure which shows 4th Embodiment of this invention, (a) is a top view of the bearing surface of a connecting rod, (b) is a longitudinal cross-sectional view of the connecting rod which follows the Vb-Vb line of (a), (c). FIG. 8B is a vertical cross-sectional view of the connecting rod taken along line Vc-Vc of FIG. It is a longitudinal cross-sectional view of a marine crosshead type engine. FIG. 7 is a vertical cross-sectional view of a piston rod and a connecting rod taken along the line VII-VII of FIG. 6, showing a conventional technique. FIG. 8 is a plan view of the bearing surface of the connecting rod as viewed from the arrow VIII-VIII in FIG. 7, showing a conventional technique. It is a longitudinal cross-sectional view of the connecting rod which shows the prior art and which follows the IX-IX line of FIG.

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
First, the connecting rod according to the first embodiment of the present invention will be described with reference to FIGS. 1(a) and 1(b). The connecting rod 18 shown here is provided with a small end portion 8A like the conventional connecting rod 8 shown in FIGS. 8 and 9, and a cap (not shown in FIG. 6) 81 is attached to the small end portion 8A. The crosshead journal (see reference numeral 7 in FIG. 6) provided on the piston side is rotatably held. A bearing metal 11 in the form of a half cylinder is attached to the bearing surface 8a (not shown in FIG. 1A).

An oil supply passage 15 is formed inside the connecting rod 18, and an oil supply groove 16 extending in the circumferential direction is formed on the bearing surface 8a (in this embodiment, three on each side with the center line C of the connecting rod 18 interposed therebetween. 6 in total) are formed. The oil supply passage 15 has a V-shaped large-diameter portion 15a extending in the longitudinal direction inside the connecting rod 18 and a center line C of the connecting rod 18 from the end of the large-diameter portion 15a. And a diameter portion 15b that branches into the bearing surface 8a and has an inner diameter smaller than that of the large diameter portion 15a (in this embodiment, one on each side with the center line C of the connecting rod 18 interposed therebetween, two in total). ing.

The tip (opening 15c) of each of these small diameter portions 15b is connected to the oil supply grooves 16 on both sides of the connecting rod 18 with the center line C interposed therebetween. Although the inner diameter of the opening 15c in this embodiment is larger than the width of the oil supply groove 16, it may be equal to or less than the width of the oil supply groove 16.

Pressure acts on the portion where the bearing surface 8a of the connecting rod 18 and the crosshead journal 7 (see FIG. 6) contact each other due to the vertical movement of the piston 2. Among these, the range of high pressure (pressure range) varies depending on the size of the engine, but there is at least the piston axial lowermost position where the crosshead journal 7 and the bearing surface 8a of the connecting rod 18 are in contact (connecting rod 18). Is about 120° around the crosshead journal, the range is at least 120° across the center line C).

In the bearing surface 8a, the highest pressure P applied from the crosshead journal 7 acts in the range of R shown in the figure. The position of this pressure range R is a position displaced in the circumferential direction with respect to the center line C of the connecting rod 18. The reason is that, as shown in FIG. 6, when the piston 2 starts to be pushed down by the pressure P accompanying the combustion of fuel, the crankshaft 3 comes to a rotation angle θ of about 20° from the top dead center position of the piston 2 and is connected. This is because the greatest pressure is applied when the rod 18 tilts. In this embodiment, the range in which the pressure P is highest is defined as the pressure range R, but a range in which the pressure is relatively high may be set as the pressure range.

In the bearing surface 8a, neither the small-diameter portion 15b (opening 15c) of the oil supply passage 15 nor the oil supply groove 16 is formed in the pressure range R. The opening 15c of the small-diameter portion 15b is located on the outer side in the circumferential direction with respect to the pressure range R, and is opened at the end of one of the three oil supply grooves 16 interrupted at this position. ..

As shown in FIG. 1B, the small-diameter portion 15b that branches from the upper end of the large-diameter portion 15a of the oil supply passage 15 in a V-shape branches from the large-diameter portion 15a at different angles α and β, and the oil supply groove 16 respectively. Connected to. In the present embodiment, the range in which the pressure P is highest is set as the pressure range R, and the pressure range R is deviated in the circumferential direction with respect to the center line C. Therefore, the small diameter portion 15 b is different from the oil supply passage 15 at a different angle. Although branched at α and β, the angles α and β may be equalized as long as the opening 15c opens near the outside in the circumferential direction of the pressure range R.

When the crosshead type engine EG (see FIG. 6) having the connecting rod 18 configured as described above operates, the lubricating oil supplied to the crosshead 5 from the lubricating oil pump (not shown) causes the crosshead journal 7 and the bearings. After lubricating the sliding surface 11a of the metal 11, it enters the oil supply groove 16 through an oil hole (not shown) formed in the bearing metal 11, and further flows from the opening 15c to the oil supply passage 15 (15a, 15b). Lubricate between the bearing metal 12 and the crank pin 9.

In the connecting rod 18, the opening 15c of the oil supply passage 15 that opens on the bearing surface 8a is located outside the pressure range R of the bearing surface 8a in the circumferential direction. Since the opening 15c is located within the pressure range R unlike the rod 8 (see FIGS. 8 and 9), the bearing surface 8a does not occur on the back surface of the bearing metal 11 within the pressure range R.

Therefore, when the load (pressure P) of the crosshead journal 7 acts on the bearing metal 11, it is possible to suppress the pressure deformation such that the bearing metal 11 gets into the opening of the oil supply passage 15 or the oil supply groove 16, and the bearing. It is possible to suppress the occurrence of a sharp rising portion in the distribution state of the maximum oil film pressure on the sliding surface 11a of the metal 11. Therefore, it is possible to suppress the occurrence of a portion where the oil film of the lubricating oil is thin, and to suppress damage such as uneven wear on the sliding surface 11a of the bearing metal 11, thereby improving the durability of the crosshead engine EG. You can

Further, in the connecting rod 18, the oil supply groove 16 formed in the bearing surface 8a is formed at a position outside the pressure range R in the circumferential direction. Therefore, when the load (pressure P) of the crosshead journal 7 acts on the bearing metal 11, the pressure deformation due to the bearing metal 11 entering the recess of the oil supply groove 16 can be suppressed. Therefore, it is possible to suppress the occurrence of damage such as uneven wear on the sliding surface 11a of the bearing metal 11 and improve the durability of the crosshead engine EG.

Further, the oil supply passage 15 includes a large diameter portion 15a extending in the longitudinal direction inside the connecting rod 18, and a small diameter portion 15b branched from an end of the large diameter portion 15a and communicating with the bearing surface 8a. Each tip of 15b is an opening 15c in the bearing surface 8a.

With this structure, one large-diameter portion 15a is branched into two or more small-diameter portions 15b to open at a plurality of positions on the bearing surface 8a, and the amount of oil passing through the oil supply passage 15 is reduced. Therefore, the area of each opening 15c can be reduced. Thus, even if the opening 15c opens in the pressure range R due to design reasons, for example, the opening area can be minimized.

Therefore, when the load (pressure P) of the crosshead journal 7 acts on the bearing metal 11, it is possible to suppress the pressure deformation such that the bearing metal 11 enters the opening 15c. The durability can be increased.

In the present embodiment, since the plurality of small diameter portions 15b are branched from the large diameter portion 15a at different angles α and β, the ends of each small diameter portion 15b with respect to the large diameter portion 15a whose arrangement position is restricted. The portion can be opened relatively freely to any position on the bearing surface 8a. Therefore, the position of the opening 15c in the bearing surface 8a can be optimized, the pressure deformation of the bearing metal 11 can be suppressed, and the durability of the crosshead engine EG can be improved.

[Second Embodiment]
Next, a connecting rod according to the second embodiment of the present invention will be described with reference to FIGS. 2(a) and 2(b). Also in this connecting rod 28, the oil supply passage 15 is branched from the large-diameter portion 15a in the shape of a circular hole formed so as to extend along the longitudinal direction inside the connecting rod 28, and the end of this large-diameter portion 15a. A plurality of small diameter portions 15b communicating with the bearing surface 8a are provided, and the tip end of each small diameter portion 15b is an opening 15c in the bearing surface 8a.

As shown in FIG. 2A, the small-diameter portion 15b is formed with three pieces on each side with the center line C of the connecting rod 18 interposed therebetween, six pieces in total. Further, as shown in FIG. 2B, the small-diameter portion 15b that branches in a V shape from the upper end of the large-diameter portion 15a to form the above two groups has the same center as in the first embodiment. It extends at different angles with respect to the line C.

As shown in FIG. 2( a ), the three small diameter portions 15 b open inside the pressure range R, and the other three small diameter portions 15 b open outside the pressure range R. The small-diameter portion 15b opening inside the pressure range R is opened at the tip of three oil supply grooves 16 formed similarly to the first embodiment, and the inner diameter of the opening 15c is the same as that of the oil supply groove 16. It is set equal to or less than the width dimension. Further, the small diameter portion 15b opening to the outside of the pressure range R is also opened at the tips of the three oil supply grooves 16 on the opposite side, and the inner diameter of the opening 15c is larger than the width dimension of the oil supply groove 16. It is set.

In the connecting rod 28 configured as described above, the openings 15c of the six small diameter portions 15b of the oil supply passage 15 that open on the bearing surface 8a have two kinds of inner diameters, large and small. The inner diameter of the opening 15c located in the range R is smaller than the inner diameter of the small diameter part 15b located outside the pressure range R, and the inner diameter is set to be equal to or less than the width dimension of the oil supply groove 16. ..

Therefore, as in the conventional connecting rod 8 (see FIGS. 8 and 9), the oil supply passage 15 having an inner diameter larger than the width of the oil supply groove 16 exists in the pressure range R together with the oil supply groove 16, so that the pressure range R The area that does not contact the back surface of the bearing metal 11 does not become large. Therefore, when the load (pressure P) of the crosshead journal 7 acts on the bearing metal 11, it is possible to suppress the pressure deformation of the bearing metal 11 so as to enter the opening 15c of the small diameter portion 15b. It is possible to suppress the occurrence of damage such as uneven wear on the sliding surface 11a and improve the durability of the crosshead engine EG.

[ Reference Embodiment]
Next, a connecting rod according to a reference embodiment of the present invention will be described with reference to FIGS. 3(a) and 3(b). In the connecting rod 38, two circular hole-shaped oil supply passages 15A and 15B are formed in parallel inside the connecting rod 38, and the openings 15c of these two oil supply passages 15A and 15B are located at different positions on the bearing surface 8a. Is in communication with. Specifically, the two opening portions 15c are spaced apart from each other in the circumferential direction of the bearing surface 8a with the center line C of the connecting rod 8 interposed therebetween, and the pressure range R of the bearing surface 8a is sandwiched therebetween. It is arranged at a position on the outer side in the circumferential direction with respect to R.

Further, the oil supply grooves 16 formed in the bearing surface 8 a (in the present reference embodiment, three on each side across the center line C of the connecting rod 18, six in total) are formed outside the pressure range R. .. The opening 15c of the oil supply passages 15A and 15B communicates with the tip of the oil supply groove 16 at the center thereof. The inner diameter of the opening 15c is preferably set to be equal to or smaller than the width dimension of the oil supply groove 16.

In the connecting rod 38 configured as described above, two oil supply passages 15A and 15B having the same inner diameter are formed in parallel inside the connecting rod 38, and the openings 15c of these oil supply passages 15A and 15B have different bearing surfaces 8a. Communicates with the place. Therefore, it is possible to reduce the inner diameter of each of the oil supply passages 15A and 15B and reduce the area of each opening 15c without reducing the total amount of oil supply.

In addition to being able to reduce the area of the opening 15c of the oil supply passages 15A and 15B as described above, the oil supply passages 15A and 15B (opening 15c) communicate with the pressure range R of the bearing surface 8a in the circumferential direction outside. Since the inner diameter of the opening portion 15c is set to be equal to or smaller than the width dimension of the oil supply groove 16, and the oil supply groove 16 is not formed in the pressure range R, the bearing metal 11 in the pressure range R is There is no recess on the back surface that the bearing surface 8a does not contact.

Therefore, when the load (pressure P) of the crosshead journal 7 acts on the bearing metal 11, it is possible to suppress the pressure deformation such that the bearing metal 11 enters the recess in the pressure range R, and the damage of the bearing metal 11 is prevented. And the durability of the crosshead engine EG can be improved.

Moreover, since the inner diameters of the oil supply passages 15A and 15B can be reduced as described above, the strength reduction of the connecting rod 8 due to the formation of the oil supply passages 15A and 15B is suppressed, and in this respect also, the durability and reliability of the crosshead engine EG are suppressed. You can improve your sex. Since the two oil supply passages 15A and 15B are formed parallel to the center line C of the connecting rod 38, the machining thereof is easy. Two or more oil supply passages 15A and 15B may be formed, or the inner diameters may be different.

[ Third Embodiment]
Next, a connecting rod according to the third embodiment of the present invention will be described with reference to FIGS. 4(a) and 4(b). Also in the connecting rod 48, the oil supply passage 15 is branched from the large-diameter portion 15a having a circular hole extending in the longitudinal direction inside the connecting rod 28 and the end of the large-diameter portion 15a to the bearing surface 8a. It is configured by combining a plurality of small diameter portions 15b, and each tip of each small diameter portion 15b serves as an opening 15c in the bearing surface 8a.

As shown in FIG. 4(a), the number of the small-diameter portions 15b is, for example, five, and extends radially from the large-diameter portion 15a, and the respective opening portions 15c of the small-diameter portions 15b open at a plurality of locations on the bearing surface 8a. ing. More specifically, all of the openings 15c open inside the three oil supply grooves 16 formed in the circumferential direction of the bearing surface 8a. The central oil supply groove 16 has three openings 15c, and the oil supply grooves 16 on both sides have one opening 15c. The inner diameter of each small-diameter portion 15b (opening 15c) is set to be equal to or smaller than the width dimension of the oil supply groove 16. It is not necessary to open all of the openings 15c in the oil supply groove 16, but only some of the openings 15c may be opened in the oil supply groove 16.

In the connecting rod 48 configured as described above, the large diameter portion 15a is branched into the multiple small diameter portions 15b to open at a plurality of positions on the bearing surface 8a, so that the amount of oil passing through the oil supply passage 15 is reduced. The area of each opening 15c can be reduced without reducing the area.

Further, although these openings 15c are arranged in the pressure range R of the bearing surface 8a, each opening 15c is opened inside the oil supply groove 16, and the inner diameter thereof is equal to or smaller than the width dimension of the oil supply groove 16. Therefore, the opening 15c having an inner diameter larger than the width of the oil supply groove 16 does not open in the pressure range R.

Therefore, when the load (pressure P) of the crosshead journal 7 acts on the bearing metal 11, it is possible to suppress the pressure deformation so that the bearing metal 11 enters the opening 15c, and to prevent the bearing metal 11 from being damaged. Therefore, the durability of the crosshead engine EG can be improved.

[ Fourth Embodiment]
Next, a connecting rod according to the fourth embodiment of the present invention will be described with reference to FIGS. 5(a), 5(b) and 5(c). The connecting rod 58 has, for example, three oil supply grooves 16 extending in the circumferential direction on the bearing surface 8a of the small end portion 8A, and the groove at the center thereof is formed deeper than the grooves on both sides. Has been done.

A circular hole-shaped oil supply passage 15 is formed inside the connecting rod 58 so as to extend along the longitudinal direction. The end of the oil supply passage 15 on the bearing surface 8a side reaches the bearing surface 8a. Without being communicated with the bottom of the central oil supply groove 16. Therefore, a slit-shaped opening 15c communicating with the oil supply passage 15 is formed in the center of the center oil supply groove 16 in the longitudinal direction. The length of the opening 15c is equal to the inner diameter of the oil supply passage 15, and the width of the opening 15c is equal to the width of the oil supply groove 16.

According to the connecting rod 58 configured as described above, the oil supply passage 15 is arranged so as to overlap the pressure range R of the bearing surface 8a as shown in FIGS. 5(a) and 5(c). Since 15 does not communicate directly with the surface of the bearing surface 8a but only with the bottom of the oil supply groove 16, the oil supply passage 15 is not exposed as a recess in the bearing surface 8a. Therefore, the bearing surface 8a has only three oil supply grooves 16 as concave portions, and no other concave portions. The lubricating oil collected in the oil supply groove 16 can flow into the oil supply passage 15 through an opening 15c formed by overlapping the bottom of the central oil supply groove 16 and the end of the oil supply passage 15.

As described above, since the bearing surface 8a has no recess other than the oil supply groove 16, when the bearing metal 11 is mounted on the bearing surface 8a, only the portion of the oil supply groove 16 does not contact the back surface of the bearing metal 11. .. Therefore, when the load (pressure P) of the crosshead journal 7 acts on the bearing metal 11, the bearing metal 11 does not enter into the recessed portion such as the opening 15c to cause pressure deformation, and thus the sliding movement of the bearing metal 11 occurs. It is possible to prevent damage such as uneven wear from occurring on the surface 11a and enhance the durability of the crosshead engine EG.

As described above, according to the connecting rods 18, 28, 38, 48, 58 and the crosshead type engine EG including the connecting rods 18, 28, 38, 48, 58 according to the above-described embodiments, the bearing surfaces of the end portions 8A of the connecting rods 18 to 58 are formed. 8a suppresses the pressure deformation of the bearing metal 11 due to the formation of the concave portion in the oil supply passage 15 and eliminates the place where the maximum oil film pressure on the sliding surface 11a of the bearing metal 11 suddenly increases, and thus the bearing metal 11 is biased. It is possible to suppress the occurrence of damage such as wear and improve the durability of the engine.

It should be noted that the present invention is not limited to the configurations of the above-described embodiments, and various modifications and improvements can be appropriately made without departing from the scope of the present invention. Are also included in the scope of rights of the present invention.

For example, in each of the above-described embodiments, the example in which the present invention is applied to the small end portion 8A side of the connecting rods 18 to 58 has been described, but the present invention may be applied to the large end portion 8B side. Further, the respective embodiments may be combined or another configuration may be added.

1 Cylinder Liner 2 Piston 3 Crankshaft 6 Piston Rod 7 Crosshead Journal 8A Small End (End)
8a Bearing surface 9 Crank pin 11 Bearing metal 15, 15A, 15B Oil supply passage 15a Large diameter part 15b Small diameter part 15c Opening 16 Oil supply groove 18, 28, 38, 48, 58 Connecting rod EG Crosshead type engine P Pressure R Pressure range α, β Angle of small diameter part

Claims (10)

A connecting rod that connects between a crosshead journal provided at the tip of a piston rod of a crosshead type engine and a crankpin provided on a crankshaft,
An oil supply passage formed to extend in the longitudinal direction inside the connecting rod and connected to a bearing surface at an end portion of the connecting rod;
An oil supply groove formed to extend along the circumferential direction of the bearing surface and connected to an opening in which the oil supply passage opens on the bearing surface;
A bearing metal having a half-cylindrical shape mounted on the bearing surface,
Equipped with
The oil supply passage branches off with the center line of the connecting rod interposed therebetween,
The connecting rod is characterized in that the position of the opening is a position on the bearing surface, which is outside in the circumferential direction with respect to the pressure range in which the pressure applied from the crosshead journal is highest. A connecting rod that connects between a crosshead journal provided at the tip of a piston rod of a crosshead engine and a crankpin provided on a crankshaft,
An oil supply passage formed to extend in the longitudinal direction inside the connecting rod and connected to a bearing surface at an end portion of the connecting rod;
An oil supply groove formed to extend along the circumferential direction of the bearing surface and connected to an opening in which the oil supply passage opens on the bearing surface;
A bearing metal having a half-cylindrical shape mounted on the bearing surface,
Equipped with
The oil supply passage branches off with the center line of the connecting rod interposed therebetween,
The inner diameter of the opening formed in the pressure range in which the pressure applied from the crosshead journal is highest is set to be equal to or less than the width dimension of the oil supply groove,
A connecting rod, wherein lubricating oil supplied to the crosshead journal is supplied to the crank pin via the oil supply groove and the oil supply passage. 3. The oil supply groove is formed on the bearing surface at a position on the outer side in the circumferential direction with respect to the pressure range in which the pressure applied from the crosshead journal is highest. Connecting rod. The oil supply passage has a large-diameter portion that extends in the longitudinal direction inside the connecting rod, and a plurality of branches that branch from the end of the large-diameter portion to the bearing surface and that have an inner diameter smaller than that of the large-diameter portion. The connecting rod according to any one of claims 1 to 3, further comprising a small-diameter portion, wherein each tip of the small-diameter portion serves as the opening in the bearing surface. The plurality of small diameter portions are different in inner diameter from each other, and the inner diameter of the small diameter portion located inside the pressure range where the pressure applied from the crosshead journal is highest on the bearing surface is located at other locations. The connecting rod according to claim 4, wherein the connecting rod is smaller than the inner diameter of the small diameter portion. The connecting rod according to claim 4 or 5, wherein the plurality of small diameter portions branch from the large diameter portion at different angles. A connecting rod that connects between a crosshead journal provided at the tip of a piston rod of a crosshead engine and a crankpin provided on a crankshaft,
An oil supply passage formed so as to extend along the longitudinal direction inside the connecting rod;
An oil supply groove formed so as to extend along the circumferential direction of the bearing surface at the end of the connecting rod;
A bearing metal having a half-cylindrical shape mounted on the bearing surface,
Equipped with
The end of the oil supply passage on the bearing surface side communicates with the bottom of the oil supply groove without reaching the bearing surface,
The length of the opening of the oil supply passage in the communication portion to the bottom of the oil supply groove along the circumferential direction of the bearing surface is equal to the inner diameter of the oil supply passage,
These openings, width along the axial direction of the bearing surface is rather equal to the width of the oil supply groove,
The opening communicates with a bottom portion of the oil supply groove located in a pressure range where the pressure applied from the crosshead journal is highest on the bearing surface.
The connecting rod , wherein the inner diameter of the oil supply passage is larger than the width of the oil supply groove . A connecting rod that connects between a crosshead journal provided at the tip of a piston rod of a crosshead type engine and a crankpin provided on a crankshaft,
An oil supply passage formed to extend in the longitudinal direction inside the connecting rod and connected to a bearing surface at an end portion of the connecting rod;
An oil supply groove formed to extend along the circumferential direction of the bearing surface and connected to an opening in which the oil supply passage opens on the bearing surface;
A bearing metal having a half-cylindrical shape mounted on the bearing surface,
Equipped with
The oil supply passage branches off with the center line of the connecting rod interposed therebetween,
The inner diameter of the opening of the oil supply passage is set to be equal to or less than the width dimension of the oil supply groove,
The connecting rod is formed in the bearing surface at a position on the outer side in the circumferential direction with respect to the pressure range in which the pressure applied from the crosshead journal is highest, on the bearing surface. A connecting rod that connects between a crosshead journal provided at the tip of a piston rod of a crosshead type engine and a crankpin provided on a crankshaft,
An oil supply passage formed to extend in the longitudinal direction inside the connecting rod and connected to a bearing surface at an end portion of the connecting rod;
An oil supply groove formed to extend along the circumferential direction of the bearing surface and connected to an opening in which the oil supply passage opens on the bearing surface;
A bearing metal having a half-cylindrical shape mounted on the bearing surface,
Equipped with
The oil supply passage branches off with the center line of the connecting rod interposed therebetween,
The inner diameter of the opening of the oil supply passage is set to be equal to or less than the width dimension of the oil supply groove,
The oil supply passage has a large-diameter portion that extends in the longitudinal direction inside the connecting rod, and a plurality of branches that branch from the end of the large-diameter portion to the bearing surface and that have an inner diameter smaller than that of the large-diameter portion. A connecting rod, comprising: a small diameter portion, wherein each tip of the small diameter portion serves as the opening in the bearing surface. A crosshead engine comprising the connecting rod according to any one of claims 1 to 9.

Images