KR19980036878A - Sealing device for piston rod - Google Patents

Abstract

The piston rod sealing device includes an annular oil removing ring body of steel having an M-shaped, I-shaped or H-shaped cross section; And a combined oil removal ring comprising an annular coil spring. The ring body has a cutout portion at one place, and has a support portion having an upper rail member, a lower rail member, and an annular groove having a plurality of oil holes spaced in the circumferential direction on the outer circumferential side thereof. The annular coil spring is fitted into the annular groove so as to press the support in the inner diameter direction toward the piston rod so that the inner circumferential surface of the upper and lower rail members is in pressure contact with the outer circumferential surface of the piston rod by the spring contracting force. The oil removing ring is flexible to follow the shape of the surface so as to contact the outer circumferential surface of the piston rod, whereby the oil sealing effect is improved.

Description

Sealing device for piston rod

1 is a partial cross-sectional view showing a state in which the oil removing ring according to the first embodiment of the present invention is mounted.

2 is a partial cross-sectional view showing a state in which the oil removal ring is mounted according to a second embodiment of the present invention.

3 is a partial perspective view of the oil removing ring of the first embodiment.

4 is a partial perspective view of an oil removing ring according to a third embodiment of the present invention;

5 is a partial cross-sectional view showing a state in which the oil removal ring is mounted according to a third embodiment of the present invention.

6 is a partial perspective view of an oil removing ring according to a fourth embodiment of the present invention.

7 is a partial perspective view showing a modification of the oil removing ring according to the fourth embodiment.

8 is a partial perspective view showing another modified example of the oil removing ring according to the fourth embodiment.

9 is a view showing the conventional split oil removal ring A, B and C.

10 is a cross-sectional view showing a mounting state of a conventional split oil removing ring.

Explanation of symbols on the main parts of the drawings

1: Oil removal ring 2: Upper rail member

22: upper side rail 3: lower rail member

33: lower side rail 4: holding part

5: oil hole 6: outer groove

7: annular coil spring 8: piston rod

9: surface treatment layer 10: side rail support protrusion

11: Lug 12: Ring groove

13: Ring groove side wall 14: Piston rod outer peripheral surface

15: slanted surface of the lug 16: slits

The present invention relates to a piston rod sealing device for efficiently sealing the circumference of the shaft reciprocating in the axial direction, and more particularly to a piston rod sealing device used in large two-cycle diesel engines, such as for ships. .

In general, in a large two-cycle diesel engine for ships or the like, a partition wall is provided between the scavenging chamber and the crank chamber of the engine, and the piston rod is provided in the partition wall to reciprocate through a stuffing box for accommodating the sealing device.

The rod seal device accommodated in the stuffing box generally has an airtight ring for maintaining the airtightness of the airtight chamber at the upper side, that is, the side of the airtight chamber, and at the bottom thereof, that is, the crankcase side, the airtight air is blown out of the crankcase during the reciprocating movement of the piston rod. An oil removal ring is attached to prevent the outflow of lubricating oil to the actual measurement.

The oil removal ring is a combination of ring segments divided into a plurality of diameters (three divided in the drawing) as shown in FIG. 9A, and a combination of ring segments divided in a tangential direction as shown in B of FIG. It consists of. These two types of rings designated as a and b are arranged so that coil springs are superimposed on the outer periphery, as illustrated in Fig. 9C. Overlapping rings a and b are mounted in ring grooves as illustrated in FIG. The oil removal ring is pressed against the outer circumferential surface of the piston rod by the contracting force of the coil spring, thereby preventing excessive consumption of the lubricating oil by removing the lubricating oil attached to the piston rod surface and moving to the scavenging chamber side during the reciprocating movement of the piston rod. It functions as a means.

Some of the conventional oil removing rings of this type used in the seal device for the piston rod is provided with a circumferential groove on the circumferential surface in contact with the outer circumferential surface of the piston rod. The groove serves as a means for facilitating the removal and discharging of the removed lubricating oil by providing pores extending radially from the groove.

These conventional oil removal rings are made of high grade cast iron, low cast iron, copper alloy or resin material, and are mounted in multiple stages as shown in FIG.

The conventional split ring is pressed inward by the contracting force of the annular coil spring disposed on its outer circumferential side, and the inner circumferential surface of each ring segment is in sliding contact with the outer circumferential surface of the piston rod to scrape off the lubricant on the outer circumferential surface of the piston rod. Will be performed.

In the case of a conventional cast iron or copper alloy oil removal ring, each ring segment constituting the split ring is manufactured in a block shape with high rigidity. As a result, if there is a difference between the curvature of the inner circumference of each ring segment and the curvature of the circumference of the piston rod, the ring segment cannot follow the piston rod outer circumferential surface irrespective of the action of the retraction force applied by the annular coil spring. do. This means that the inner circumferential surface of each ring segment cannot contact the piston rod outer circumferential surface over the entire circumference, and as a result, a gap is formed between the outer circumferential surface of the piston rod and the inner circumferential surface of the ring segment.

In addition, by local sliding contact between the piston rod and the ring segment, scratches and uneven wear occur on the outer circumferential surface of the piston rod, and as a result, some lubricant is not removed and a satisfactory oil removal performance is difficult to be obtained.

In addition, in the case of the copper alloy oil removing ring, since the material is relatively soft, the sliding surface is formed on the outer circumferential surface of the piston rod in the initial stage of use, so that the ring is directly in harmony with the outer circumferential surface of the sliding piston rod. This has the advantage of obtaining a relatively good airtightness. On the other hand, as the wear progresses, the contact area with the sliding surface of the piston rod increases, so that the contact surface pressure per unit contact area is reduced, and as a result, the oil removal function is lowered, thereby increasing the consumption of lubricating oil.

As a means to solve the above problems, such as cast iron or copper alloy oil removal ring, by performing a straightening heat tratment in the manufacturing step, and then re-corrected to remove the deformation caused by the internal stress after the initial processing It has been proposed to obtain high precision products.

It has also been proposed that both assembly parts be assembled so that they fit well together in the installation of the oil removal ring.

However, their means increase the cumbersome process and expense. If the cylindrical shape of the piston rod is irregular, it is difficult to solve the above problems even if a high precision product (oil removal ring) is used or the assembly parts are well fitted.

In the case of using a resin material such as ethylen tetrafluoride resin as the material of the oil removing ring, the inner circumference of the ring is rapidly adapted to the outer circumferential surface of the piston rod due to the low strength.

Thus, although excellent duck removal performance can be initially obtained, due to continuous use, the resin material absorbs lubricating oil and eventually softens, further increasing wear. This is a necessity for parts replacement which is difficult and costly.

It is an object of the present invention to provide a piston rod seal device that exhibits excellent oil removal performance in contact with the outer circumferential surfaces of the piston rods and the shape of these surfaces to be followed to reduce the consumption of lubricating oil generated each time the piston rod moves.

According to this invention, the said objective is acquired by providing the sealing apparatus for engine piston rods as follows. That is, in the sealing apparatus of the present invention, (a) a plurality of oil holes are spaced in the circumferential direction on the outer circumferential side while supporting the annular upper rail member, the lower rail member, and both rail members having cutouts at one place as steel materials. It consists of a holding part and the cross section is mounted in the state of extending the oil removal ring body consisting of M type, I type or H type and (b) annular groove to press the supporting part in the inner diameter direction of the upper rail member and the lower rail member. And a combined oil removal ring composed of an annular coil spring for pressing the inner circumferential surface to the outer circumferential surface of the piston rod.

In the present invention, in order to improve the durability of the oil removal ring, various nitriding treatments such as soft nitriding, ion nitriding, gas nitriding, plating treatment such as chromium plating and Ni-P-based composite dispersion plating are applied to the sliding part of the oil removal ring. It is desired to form a wear resistant treatment layer by CVD and PVD treatment.

In addition, it is desired to further improve the initial runability by forming the surface treatment layer by the formation treatment to the Fe ₃ O ₄ layer, the parkenizing and the Sn-plating treatment.

Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

The present invention will be described based on the illustrated embodiments. However, this embodiment is intended to illustrate the present invention, but does not limit the scope of the present invention.

1 is a partial cross-sectional view showing the structure of the oil removal ring 1 according to the first embodiment of the present invention, the oil removal ring 1 is a piston rod 8 reciprocating in the direction of arrow A from the outer peripheral side Shows the mounted state for gripping. 3 is a partial perspective view of an oil removing ring according to this embodiment.

The oil removal ring 1 is obtained by the upper rail member 2 and the lower rail member being integrally connected by the support 4. The strut portion 4 has an annular outer circumferential groove 6 on its outer circumferential side and a plurality of oil holes 5 spaced circumferentially in its groove 6. The groove 6 is equipped with an annular coil spring 7 extended so as not to interfere with the oil hole 5, that is, in contact with the inclined surface constituting the groove.

The oil removal ring main body of the upper and lower rail members 2 and 3 and the support portion 4 of the present embodiment has a single M shape as a whole, and is formed by forming a thin steel strip into an annular shape by a molding roll. It is an integrated body having a cutout.

The holding portion 4 is pressed in the inner diameter direction by the contracting force of the annular coil spring 7, and the inner circumferential ends of the upper and lower rail members 2, 3 are pressed against the outer circumferential surface 14 of the piston rod 8, Effectively, the oil is removed from the main surface of the piston rod.

Since the oil removing ring body of the above embodiment is integrally molded from a thin steel strip to take the M-shaped cross section as a whole, the ring body exhibits flexibility. As a result, the inner circumferential ends of the upper and lower rail members 2 and 3 easily follow the piston rod outer circumferential surface over the entire circumference by the water output of the annular coil spring 7, thereby exhibiting good oil removal performance from the initial stage. Done. In addition, since the upper and lower rail members have a thin plate-like structure, the contact area is not increased even when wear progresses, whereby good oil removal performance is maintained for a long time.

Reference numeral 9 denotes an effective surface treatment layer for improving the durability of the oil removal ring or further improving the initial compliance.

2 is a cross-sectional view showing the structure of the oil removing ring 1 according to the second embodiment of the present invention, which corresponds to FIG.

In this embodiment, too, the oil removing ring 1 is connected to the upper rail member 2 and the lower rail member 3 integrally by the support 4, and the support 4 is annular to its outer circumference. The groove 6 and its groove bottom have a plurality of oil holes 5 spaced apart in the circumferential direction, and the groove 6 is equipped with an annular coil spring 7 in an extended state.

The oil removing ring body of the upper, lower rail members 2 and 3 and the support portion 4 of this embodiment has an I-shaped cross section or an H-shaped cross section as a whole, which is drawn to a predetermined I or H type. The shape-sectin wire nateial obtained by the coil processing can be integrally formed in an annular shape by having a cutout at one point by coil processing.

The annular coil spring 7 presses the support portion 4 in the inner diameter direction by its contracting force, and presses the inner circumferential ends of the upper and lower rail members 2 and 3 to the outer circumferential surface of the piston rod 8 to form a piston rod circumferential surface. To remove oil from the vessel.

In the second embodiment, since the upper, lower rail members and the support portions of the oil removing ring are integrally formed to define the I-shaped cross section or the M-shaped cross section, the ring body also exhibits flexibility, and as a result, Due to the contracting force of the annular coil spring 7, the inner circumferential ends of the upper and lower rail members 2 and 3 easily follow the piston rod outer circumferential surface over the entire circumference, thereby exhibiting good oil removal performance from the initial stage. In addition, the upper and lower rail members are thin plate-like structures do not increase the contact area with each other as the wear progresses, thereby maintaining a good oil removal performance over a long period of time.

4 is a partial perspective view illustrating the structure of the oil removing ring 1 of the third embodiment of the present invention. In this embodiment, the oil removing ring 1 is integrally molded with the lower rail part 3 and the support part 4, and the upper rail member 2 is molded as a separate body, that is, an annular side rail 22. In addition, it has a tread and does not have its own tension. The annular side rail 22 is supported by the side rail support formed on the top of the support 4 and is held by the support.

The side rail support is in contact with the lower side near the inner circumference of the side rail 22 of the oil removal ring, as in FIG. 5 illustrating that the oil removal ring is fitted on the piston rod 8. And a lug 11 for pressing the side rails 22 in the inner circumferential direction by contacting the supporting protrusions 10 for supporting the side rails 22 and the outer peripheral edges of the side rails 22. 22 receives the action of the contracting force of the annular coil spring 7 through the lug 11 so that the inner circumferential edge of the side rail 22 is pressed against the outer circumferential surface 14 of the piston rod 8 to slide. At the same time, the inner circumferential end of the lower rail member 3 slides against the piston rod outer circumferential surface in the same manner.

It has an inclined surface 15 which contacts the lug 11 with respect to the side rail 22. This inclined surface 15 is preferably slightly inclined in the outer diameter direction. The inclined surface 15 of the lug 11 presses the side rail 22 in the inner circumferential direction to press the inner circumferential edge thereof to the outer circumferential surface 14 of the piston rod 8 and at the same time the outer circumferential portion of the side rail 22. The rails 22 and 3 are pressed against the wall surface 13 of the ring groove 12 by forcing upward in the axial direction to improve the sealing performance (side seal) between the oil removing ring and the wall surface.

When the inclination angle of the inclined surface 15 of the lug 11 is measured from the axial direction of the piston rod, the effect is remarkable when it is 5 degrees or less, and when it is 40 degrees or more, the contact pressure between the ring groove side wall 13 and the rail 22 is This becomes so large that eventually the frictional force becomes large, so that the followability to the piston rod outer circumferential surface of the rail 22 is almost eliminated.

Therefore, in this invention, it is good to select the inclination-angle suitably in the range of 10-25 degree. The side rail support, the support 6 and the lower rail member 3 are integrally manufactured by punching and forming roll forming of steel strips.

6 is a partial perspective view illustrating the structure of the oil removing ring of the fourth embodiment of the present invention. The oil removing ring 1 of this embodiment has a separate body, i.e., upper and lower rail members, which are manufactured as annular side rails 22 and 23, each having a tread step and exhibiting no tension. The strut portion 4 is formed with side rail support portions having the support projections 10 and the lugs 11 in the same manner as in the third embodiment, supporting the annular side rails 22 and 23, respectively.

The strut portion 4 and its side rail support portion are generally limited to an I-shaped cross section or an H-shaped cross section, and the release wire obtained by drawing a predetermined I-shaped or H-shaped cut into one place by coil processing. It can shape | mold three-dimensionally by shape | molding in annular shape which has a connection part.

The holding portion 4 is pressed in the inner diameter direction by the contracting force of the annular coil spring 7, and the inner circumferential ends of the upper and lower rail members 2 and 3 are pressed against the outer circumferential surface of the piston rod 8 so as to be released from the piston rod main surface. The oil removal effect of is made effective.

Also in the fourth embodiment, the upper and lower rail members and the support portions of the oil removing ring are integrally formed to define the I-shaped cross section or the H-shaped cross section, so that the ring body is flexible. As a result, the inner circumferential ends of the lower side rails 22 and 23 are in good contact with the entire circumference of the outer circumference of the piston rod by the contracting force of the annular coil spring 7, so as to exert good oil removal performance from the initial stage. do. In addition, since the upper and lower side rail members have a thin plate-like structure, the oil removal performance is maintained for a long time without increasing the contact area with each other as the wear progresses.

In addition, in the fourth embodiment shown in FIG. 6, the members supporting the side rails, i.e., the members including the support portions and the respective side rail support portions, are slit 16 which are spaced in the circumferential direction and extend in the radial direction. It is formed to have. In the fourth embodiment shown in FIG. 7, in this modification, the slits extend radially from the inner circumferential axis. In another modification of the fourth embodiment shown in FIG. 8, the slits extend in the radial direction from the outer peripheral side. These slits improve the flexibility of the members so that the side walls can more reliably follow the outer circumferential surface of the piston rod.

Therefore, the seal device for piston rod of the present invention is designed by M-shaped cross section, I-shaped cross section or H-shaped cross section, and the inner circumferential end of the upper and lower rail members are adapted to the contracting force of the annular coil spring mounted on the outer circumferential side. By using an oil removal ring with a good tracking characteristic that is pressed against the piston rod outer circumferential surface and slides, a good close relationship is maintained according to the electric pole without any gap between the piston rod outer circumferential surface and the seal member inner peripheral end from the initial stage. do. Therefore, the occurrence of lubricating oil is suppressed, thereby reducing the consumption of lubricating oil and reducing the frequency of parts replacement. In addition, the oil removing ring used in the present invention exhibits good following characteristics. As a result, even when the oil removal ring is fitted to a piston rod having a non-round cross section, the oil removal ring has a good following contact with the outer circumferential surface of the piston rod, so that it does not require correction processing to be fitted with the spot in the field. Facilitate parts replacement work.

Since various embodiments of the invention can be made without departing from the spirit and scope of the invention, it is to be understood that the invention is not limited to only the specific embodiments thereof except as defined in the appended claims.

Claims (6)

In the sealing device of the piston rod of the engine, The sealing device has an annular upper rail member, a lower rail member, and an upper and lower rail members, each having a cutout in one place as steel, and the upper and lower rail members up and down, and an annular groove in which a plurality of oil holes are spaced in the circumferential direction. An oil removal ring body having an M-shaped, I-shaped or H-shaped cross section, which is composed of holding parts provided in the; And An annular coil spring mounted to the annular groove to pressurize the strut in the inner diameter direction to press-contact the inner circumferential end surfaces of the upper rail member and the lower rail member to the outer circumferential surface of the piston rod; Sealing device for a piston rod, characterized in that provided with an oil removal ring combined. The seal device for a piston rod according to claim 1, wherein the oil removing ring is formed into an M-type, an I-type, or an H-shaped cross section by integrating the upper rail member, the lower rail member, and the support portion. The method of claim 1, wherein the oil removal ring, A side rail member formed by forming a narrow metal strip into an annular shape having cutouts in one place; And And a side rail support portion for supporting the side rail member in the axial direction of the piston rod, and a lug for pressing the rail member in an inner diameter direction to abut against an outer circumferential end of the side rail member. Landlord Sealing device for a piston rod, characterized in that consisting of. The oil removal ring of claim 1, An upper side rail member formed by forming a narrow metal strip into an annular shape having cutouts in one place; A lower side rail member formed by forming a narrow metal strip into an annular shape having cutouts in one place; And An upper side rail support portion and a lower side rail support portion which respectively support the upper side rail member and the lower side rail member in the axial direction of the piston rod, and the respective outer peripheral surfaces of the upper side rail member and the lower side rail member. Abutment part having upper and lower lugs respectively for abutting each rail member in the inner diameter direction Piston rod sealing device comprising a. The piston rod sealing apparatus according to claim 3 or 4, wherein the inner circumferential side of each of the lugs is inclined at an angle range of 5 to 40 degrees from the axial direction of the piston rod to the outer diameter direction. The piston rod sealing device according to any one of claims 3 to 5, wherein the side rail support portion is formed as a protrusion supporting the side surface of the corresponding side rail member near the inner circumferential side of the side rail member.