JPH0599218A - Crosshead for piston engine - Google Patents

Abstract

PURPOSE: To provide a simple crosshead that is shorter than a traditional one in axial direction of the engine without reducing load capacity of a bearing. CONSTITUTION: A crosshead for a two-stroke piston engine is bolted in a piston bar 7 and has a crosshead pin pivoted on a crosshead bearing 10. The lower part 3 of the crosshead bearing 10 is fixed on a connecting bar 2 and the upper part 4 is bolted by plural bolts that are screwed in holes in its lower side through the lower part 3. A piston bar 7 extends through a concave part of the upper part 4. An oil supply pipe 19 and oil outlet pipe 28 connected with the oil pipe of the engine frame are fixed on the concave part in both sides of the piston bar 7. And the central part 1 of the crosshead pin is connected to two ends 5 pivoted on a direct guiding shoe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention comprises a crosshead bearing fixed to a connecting rod and a crosshead pin having a central portion, the central portion being supported by the crosshead bearing over substantially its entire length and Both end portions are respectively pivotally supported by the guide shoe, the crosshead bearing has an upward recess, the crosshead pin has a surface that supports the lower side of the lower end of the piston rod, and the lower end of the piston rod has the concave portion of the crosshead bearing. An oil supply conduit for supplying oil to the oil distribution conduit and having one end fixed to the engine frame for a two-stroke piston engine crosshead and piston rod.

[0002]

2. Description of the Prior Art Older engines equipped with crossheads by large or low speed combustion engines such as ship propulsion engines or stationary power generators are known. In that engine, the crosshead pin is fixed to the piston rod by screwing a bolt extending upward from below through the crosshead at the center of the bottom of the piston rod. The crosshead pins are pivotally supported on two separate crosshead bearings on either side of the piston rod, which securely bolt the oil supply conduit onto the middle portion of the crosshead pin between the two journal faces between the bearings. , And fixed to the connecting rod through the support flange in a central portion opposite the crosshead pin to provide sufficient space for firmly bolting the oil discharge conduit, the discharge conduit oriented laterally It is connected to the oil outlet opening at the lower end of the piston rod. The oil drain conduit is a lightweight tubular member that directs oil toward a grooved tube that receives the oil. The old crosshead has an effective bearing area installed on both sides of the piston rod, so that the length of the old crosshead increases in the longitudinal direction of the engine.

[0003]

Modern engines have been designed to handle power transmission through a crosshead which must be continuous so that the maximum pressure in the working cylinder is approximately doubled and its lower portion has a sufficiently large area. Greater demands. This provides an improvement on the type of crosshead described above, in which a transitional portion of sufficient width is provided between each end and the central portion to secure the oil supply conduit. Lubricating oil is supplied from the stationary passage of the engine frame to the crosshead through an oil supply conduit fixed at one transition between the guide shoe and the bearing, from which the inclined supply conduit and the multiple oil distribution of the crosshead pin Oil flows through the conduit to the bearing surface of the crosshead and to the oil conduit of the connecting rod and piston rod. Oil flows through the central tube in the center of the piston rod to the piston and exits the piston through an annular conduit that surrounds the central tube, the annular conduit at the lower end of the piston rod being connected to two separate heads. Connected to the longitudinal passages, where they lead through a horizontal passage to a common drain opening located in the second transition, to which the oil drain conduit is fixed.

The oil supply conduit is not only fixed to the engine frame, but also to the crosshead, so that the supply conduit must absorb the movement of the crosshead with respect to the engine frame,
This makes the oil supply conduit considerably stronger and therefore heavier than the used oil discharge conduit which has the shape of an integral tube. Given the relatively large weight of the oil supply conduit, the strength of the fastening device is highly demanded and the device becomes bulky. The piston rod receiving recess in the upper part of the crosshead is provided in the center of the bearing as a whole,
And axially defined at two bearing ends which extend in a circle along the upper part of the outer circumference of the crosshead pin.

An object of the present invention is to obtain a simple crosshead in which the longitudinal length of the engine is shorter than the conventional one without reducing the load capacity of the bearing.

[0006]

SUMMARY OF THE INVENTION It is an object of the invention that the oil supply conduit according to the invention extends to the lower end of the piston rod facing the inlet opening, the opening passing through the piston rod conduit into the crosshead distribution conduit. Achieved by a crosshead characterized by being connected.

Surprisingly, the present invention allows a relatively sturdy and sturdy oil supply conduit to be installed at the lower end of the piston rod, omitting the transitional portion of the crosshead pin and leaving the central portion at the end. As a direct extension of the pin, which reduced the pin length by the length of the transition. Shorter crosshead pins than before reduce the cylinder spacing of the engine and thus the overall length of the engine, while extending the central portion of the crosshead and thus the length of the support area. Since the lubricating oil is supplied to the piston rod, the supply conduit leading from the end of the pin to the distribution conduit is no longer required, which simplifies the manufacture of the pin.

The piston rod has a lower flange with a side surface located approximately in the bearing recess, in which case the oil supply conduit can be conveniently fastened to this side surface and the overall height of the crosshead is the stuffing of the piston rod. It is not affected by the position of the feed conduit on the piston rod, which is important for the vertical position of the box.

A piston rod receiving recess in the upper portion of the crosshead is formed generally in the center of the bearing and extends circumferentially along the upper portion around the crosshead pin.
Axial limited by one bearing end member. According to the invention, with respect to the construction of the crosshead, the essential requirement for the maximum possible bearing area is directed only to the lower part of the bearing, and the bearing area of the upper part of the bearing is such that the associated engine cylinder is not compressed. It only has to be sufficient to hold the crosshead pin in place on the bearing if operated at The axial widths of the two bearing end members are 15% to 30% of the width of the bearing surface in the lower part of the bearing.
When in the range of%, it has the necessary strength to hold the pin in place and the radial height of the bearing end member is adjusted for the selected width.

The small requirement for bearing area in the upper part of the crosshead means that, according to a preferred embodiment, at least one bearing end member is exposed axially outwardly thereof in the length of the central part of the crosshead pin. Having an axially outer recess, and an oil supply conduit support bracket secured to the exposed portion of the crosshead pin and supported by the oil supply conduit bracket,
The crosshead is characterized by having an end member fixed to the oil inlet opening at the lower end of the piston rod, thereby supporting a relatively heavy oil supply conduit without increasing the axial length of the bearing itself. Used to improve.

The present invention further relates to a piston rod used in connection with a crosshead of the above type, the piston rod having a central longitudinal bore terminating under the piston rod. The piston rod is manufactured as a separate unit that can be attached to the crosshead pin, and, according to the invention, the central bore is a lateral opening leading to a side oil outlet opening arranged near the bottom and adapted to be connected to an oil drain conduit. In communication with the bore, the piston rod also has an oil inlet conduit extending from a side inlet opening for connection to an oil supply conduit to a lower outlet of the piston rod. The piston rod is simple to manufacture due to its simple construction with a continuous central hole configured as a radial hole which leads to the lateral hole and the axial hole.

The lateral hole at the lower end of the piston rod is continuous from the oil outlet opening to the oil inlet opening, and the lower end is made as symmetrical as possible to prevent deformation of the piston rod by changing the rigidity of the foot. It is advantageous. Communication between the inlet and outlet conduits is blocked by a bushing which supports the tube in the central bore and extends upwardly through the lateral bore.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings.

The crosshead shown in FIGS. 1 and 2 has a crosshead pin with a cylindrical central part 1 pivotally mounted on a crosshead bearing fixed to a connecting rod 2, and also a lower part 3 and an upper part 4. And has two cylindrical ends 5 pivotally mounted on guide shoes (not shown) for transmitting lateral forces to the engine frame (not shown). The two ends 5 are an extension just before the intermediate part and are integral therewith.

The central part 1 of the crosshead pin has a flat surface 6 facing upwards, on which the piston rod 7 is mounted, the four pins provided on the lower foot or flange portion 9 of the piston rod 7. It is bolted by four bolts 8 extending through the holes.

During engine operation, the lower and upper parts 3, 4 of the connecting rod 2 and the bearing oscillate around the longitudinal axis of the crosshead pin, for which the upper part 4 of the bearing passes the piston rod 7. It has a series of recesses. The recess is defined downwards by two axially continuous bearing parts 10, which have threaded holes on the underside of the upper part which are respectively bolted to three upwardly extending lower parts 3. The upward protrusion of the bolt head above the bearing part 10 is avoided by bolting upwards from below through the lower part 3 and the bolting of three bolts on each part reduces the height of that part. It is possible to lower it, where the recess in the upper part 4 becomes deeper.

The flange portion 9 of the piston rod 4 has two side surfaces 11 and 12 located on the opposite side of the flange portion 9 and facing the lateral direction of the engine, as can be seen from FIGS. 3 and 4. A conduit forming a passage in the form of a lateral bore 13 and an axial bore 14 extends from an oil inlet opening 15 on the side 11 to an outlet opening 16 below the piston rod 7. Exit 16
Is installed vertically above the oil distribution conduit 17 of the crosshead pin and is connected to the individual lubrication points of the crosshead at the connecting rod 2
The lubricating oil is distributed to the oil conduit 18 of.

As can be seen from FIG. 1, the joint flange 20
The oil supply conduit 19 with is clamped on the side 11 of the flange 9 by means of four screws or bolts 21. The opposite end of the supply conduit 19 is fixed to the engine frame and the intermediate conduit member can be a drop-and-insert or articulating tube portion that can absorb movement of the crosshead relative to the engine frame.

The central longitudinal bore 22 of the piston rod 7 communicates with the oil distribution conduit 17 of the crosshead pin and has at its lower end an internal thread 23 and an externally threaded bush 24 clamped there. The bush 24 includes a central tube 25 inserted in the center of the hole and an annular conduit 26 surrounding the tube 25.
Is closed below. The lateral hole 27 connects the conduit 26 to the oil outlet opening on the side surface 12 of the flange part 9,
A joint flange 29 of the oil outlet pipe 28 is fixed to 2. An oil drain conduit is connected to the engine frame and is configured to be similar in length to the inlet conduit. Oil flows through the pipe 25 to the piston and out of the piston through the conduit 26, the side hole 27 and the outlet pipe 28.

A recess 30 is provided in the center of the bearing portion 10 so that the depth becomes deeper in the direction away from the crosshead pin. This recess 30 is a conduit 1 fixed to the piston rod 7.
9 or tube 28 ensures that it does not strike the outer end of the bearing part as it moves towards the piston rod and conduit or tube during the oscillatory movement of the bearing.

The flow of oil in and out of the crosshead is shown by the arrows in FIG.

The oil distribution conduit of the crosshead pin may be of other construction than that shown if only the conduit is connected to the feed inlet conduit and, for convenience, to the lower end of tube 25.

A second embodiment of the crosshead pin and piston rod according to the present invention will be described below. Details of the same parts with the same reference numbers as above will not be described further.

As can be seen in FIGS. 5 and 6, the two bearing parts 10 of the upper part 4 are connected through two bearing end members 31 which support the crosshead pins upwardly and define a central recess. ing. Here, a bearing end member 31 having an axial width corresponding to about 18% of the bearing width is shown,
Its width is equal to the length of the central cross section of the crosshead pin.
If the width of the bearing end member 31 is in the range of 17% to 25% of the bearing width, the bearing area is of a suitable size and the bearing end member has a suitable radial height.

The bearing end member 31 is provided with a recess on its outside in the axial direction, and the bearing end member is pushed axially against the lower bearing part 3. The crosshead pin is fixed to this pin by means of a bolt 33 in this recess, and the connecting housing 3
4, which has a flat-cut contact surface for the bracket 32 supporting the piston 4,
The oil supply conduit 19 leading to the oil inlet opening and the tubular end member 35 are fixed. Since the bracket 32 absorbs the gravitational force and the acceleration force generated from the supply conduit, the tubular end member can have a simple structure that does not transmit a large load to the piston rod.

The bearing is subjected to very high loads on its axial extension. When the oil inlet pipe at the end of the bracket 32 is displaced with respect to the longitudinal axis of the engine, even though the engine cylinders are mounted in close proximity to each other to take advantage of the short length of the vertical crosshead, the side of the engine cylinder Can be passed upwards.

7 and 8 show another structure of the piston rod 7, and the lateral hole 27 is continuous so as to extend to the oil inlet opening. As mentioned above, this results in a more uniform rigidity of the flange 9. The bush 36 is pushed into the hole 22 and supports the lower end of the pipe 25. The bush 36 is provided on the oil outlet side with an upright collar 37 having a hole 38 that closes the lateral hole on the oil inlet side and communicates between the conduit 26 and the oil outlet opening 39. Bush 36 is in the oil distribution conduit 1
Lower part 40 projecting at 7 and having an entrance slit 41
And the size of the slit 41 controls the oil flow to the piston. The tubular end member 35 has a steering flange 42 fixed to the flange 9 to position the supply conduit with respect to the oil inlet opening.

[0028]

In the present invention, the oil supply conduit is extended to the lower end of the piston rod facing the inlet opening, and the inlet opening is connected to the distribution conduit of the crosshead through the groove of the piston rod, so that the bearing load is increased. It is possible to obtain a simple crosshead in which the longitudinal length of the engine is shorter than that of the conventional engine without reducing the capacity.

[Brief description of drawings]

FIG. 1 is a perspective view showing a lower portion of a crosshead and a piston rod according to the present invention.

2 is a cross-sectional view of the crosshead and piston rod of FIG.

FIG. 3 is an axial sectional view of a lower portion of a piston rod according to the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is an explanatory view from above of a second embodiment of the crosshead bearing and the lower part of the piston rod according to the invention, with the crosshead pin removed for clarity.

6 is a partial cross-sectional view taken along line VI-VI of the piston rod and the bearing of FIG.

FIG. 7 is a sectional view of the lower portion of the piston rod.

FIG. 8 is a view of the piston rod of FIG. 7 viewed from below.

[Explanation of symbols]

 1 Central part 5 Both end parts 6 Support surface 7 Piston rod 9 Flange part 10 Bearing part 11 Side surface 13 Flow path 14 Flow path 15 Inlet opening 16 Outlet opening 17 Oil distribution conduit 19 Oil supply conduit 22 Support bracket 25 Central pipe 27 Horizontal hole 28 Outlet pipe 30 Recess 31 Bearing end member 32 Bracket 36 Bush

Claims (9)

[Claims] 1. A crosshead bearing fixed to a connecting rod (2).
(19) and a crosshead pin with a central part (1), the central part (1) being supported on the crosshead bearing over substantially its entire length and its two end parts (5) being respectively pivoted on the guide shoe. , The crosshead bearing (10) has an upward recess (30), the crosshead pin has a surface (6) that supports the lower side of the lower end of the piston rod (7), and the lower end of the crosshead bearing (10) It extends through the recess (30) in the (10) and the oil supply conduit (1
9) supplies oil to the oil distribution conduit (17), and at one end of the crosshead for a two-stroke piston engine fixed to the engine frame, the oil supply conduit (1
9) extends to the lower end of the piston rod (7) facing the inlet opening (15), and the inlet opening (15) is the flow passage (1) inside the piston rod (7).
Crosshead for a two-stroke piston engine, characterized in that it is connected to the crosshead distribution conduit (17) via 3, 14). 2. The piston rod (7) has a flange portion (9) at its lower end with a side surface (11), which side surface (11) is substantially a recess of the crosshead bearing (10) during engine operation. Located at (30),
Also, the oil supply conduit (19) is attached to the side surface (11) of the flange (9).
The crosshead according to claim 1, wherein the crosshead is fixed to the crosshead. 3. An oil supply conduit (19) in which at least one of the bearing end members (31) has a recess axially outward so that a certain length of the central part (1) of the crosshead pin is exposed. Support bracket (32) is fixed to this exposed part of the crosshead pin, the oil supply conduit (19) is supported by the bracket (32) and at the lower end of the piston rod (7) the oil inlet opening (15) Fixed to the crosshead bearing
Two bearing end members with a piston rod (7) receiving recess in the upper part (4) of the (10) formed in the center of the crosshead bearing (10) and extending circumferentially along the outer circumference of the crosshead pin.
Crosshead according to claim 1, characterized in that it is limited in the axial direction of the crosshead bearing (10) by (31). 4. The axial width of each bearing end member (31) ranges from 15% of the width to the bearing surface in the lower part of the crosshead bearing (10).
Crosshead according to claim 1, characterized in that it is in the range of 30%, preferably in the range of 17% to 25%. 5. An upward recess in which the axially continuous bearing portion (10) increases in depth in the direction away from the crosshead pin.
The crosshead according to any one of claims 1 to 4, which has (30). 6. A piston rod () having a central hole located near the bottom and communicating with a lateral hole (27) communicating with an oil outlet opening in a side surface (12) adapted to communicate with an oil outlet pipe (28). 7) has oil inlet conduits (13, 14) and these oil inlet conduits (1
(3, 14) communicates with the oil supply conduit (19), so that the oil inlet opening (15) on the side surface (11) extends to the lower outlet of the piston rod (7).
Crosshead according to any one of the preceding claims, wherein the crosshead has a central longitudinal bore (22) which extends to (16) and in which the piston rod (7) terminates on its underside. 7. An internal thread for connecting the central hole (22) of the piston rod (7) to the external thread of the bush (24) at its lower end and for supporting the central tube (25) of the hole in the conduit (26). 7. The crosshead according to claim 6, which has (23). 8. The central pipe (25) in the conduit (26) is supported by a bush (36) pressed into the bottom of the central hole (22). Crosshead. 9. A lateral hole (27) extends laterally through the piston rod (7) from the oil inlet opening (15) to the oil outlet opening (16),
Characterized by a bush (36) extending upwardly through the lateral hole (27) to prevent oil communication between the oil inlet conduit (13, 14) and the annular conduit (26) surrounding the central pipe (25). The crosshead according to claim 7 or 8.