KR100187879B1 - Seal device for piston rod - Google Patents

Abstract

The piston rod seal apparatus comprises an annular oil removal ring body of steel having an M-, I- or H-shaped cross section; And a combined oil removal ring comprising an annular coil spring. The ring body has a notch at one location and also has a supporting portion having an annular groove having a plurality of oil holes circumferentially spaced apart from the outer side of the upper rail member, the lower rail member and the upper and lower rail members. The annular coil spring is fitted in the annular groove in a state of being stretched so that the inner peripheral surface of the upper and lower rail members is brought into pressure contact with the outer peripheral surface of the piston rod by the contractive force of the spring. The oil removal ring has the flexibility to follow the shape of the surface to contact the outer circumferential surface of the piston rod, thereby improving the oil seal effect.

Description

Sealing device for piston rod

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

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

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

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

FIG. 5 is a partial sectional view showing a state where the oil removing ring is mounted on the oil removing ring according to the third embodiment of the present invention; FIG.

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

FIG. 7 is a partial perspective view showing a modified example of the oil removing ring according to the fourth embodiment; FIG.

Fig. 8 is a partial perspective view showing another modification of the oil removing ring according to the fourth embodiment; Fig.

9 is a view showing a conventional split type oil removing ring shown in A, B, and C;

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

DESCRIPTION OF THE REFERENCE NUMERALS

1: Oil removing ring 2: Upper rail member

22: upper side rail 3: lower rail member

33: lower side rail 4:

5: Oil hole 6: Home

7: annular coil spring 8: piston rod

9: Surface treatment layer 10: Side rail support projection

11: lug 12: ring home

13: wall surface 14: piston rod outer peripheral surface

15: slope of lug 16: slit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for a piston rod for efficiently sealing the periphery of a piston rod shaft reciprocating in the axial direction, and more particularly, to a sealing device for a piston rod, .

Generally, in a large two-cycle diesel engine such as a marine vessel, a partition wall is provided between a crank chamber and an engine crankcase, and the piston rod is provided on a partition wall to reciprocate through a stuffing box accommodating a seal device.

The piston rod sealing device accommodated in the stuffing box generally has a chamfering ring for keeping the airtightness of the small chamber at the upper portion, that is, the small chamber side portion. And an oil removing ring for preventing the lubricating oil from leaking to the exhaust side is attached.

As shown in A of FIG. 9, the oil removing ring includes a combination of ring segments divided in a plurality of radial directions (three in the drawing) and a combination of ring segments divided in the tangential direction as shown in B of FIG. 9 . These two types of rings, designated a and b, are arranged so that coil springs are superimposed on each outer periphery as illustrated in C in FIG. The overlapping rings a and b are mounted in the ring groove as illustrated in FIG. The inner circumferential surface of the oil removing ring is pressed against the outer circumferential surface of the piston rod by the contracting force of the coil spring so as to adhere to the surface of the piston rod during the reciprocating movement of the piston rod to remove the lubricating oil moving to the small- And functions as a means.

Some conventional oil removing rings of this type used in a sealing device for a piston rod are provided with circumferential grooves on a circumferential surface which is in contact with the outer circumferential surface of the piston rod. This groove provides a pore extending in the radial direction from its groove to serve as a means for facilitating the removal and removal of the removed lubricating oil.

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

The conventional split type ring is pressed inward by the contractive force of the annular coil spring disposed on the outer peripheral side thereof and the inner peripheral surface of each ring segment is in sliding contact with the outer peripheral surface of the piston rod to thereby scrape off the lubricating oil on the outer peripheral surface of the piston rod .

In the case of a conventional cast iron or copper alloy oil removing ring, each of the ring segments constituting the split ring is formed into a highly rigid block shape. As a result, when there is a difference between the curvature of the inner circumference of each ring segment and the curvature of the outer circumference of the piston rod, regardless of the action of the shrinkage force applied by the annular coil spring, the ring segments can not follow- . This means that the inner circumferential surface of each ring segment can not contact the outer circumferential surface of the piston rod over the whole 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, due to local sliding contact between the piston rod and the ring segment, scratches and uneven wear are generated on the outer circumferential surface of the piston rod, and as a result, some lubricating oil is not removed and satisfactory oil removing performance is hardly obtained.

In addition, since the material of the copper alloy oil removing ring is relatively soft, the sliding surface is formed on the outer circumferential surface of the piston rod at the initial stage of use, so that the ring is immediately in harmony with the outer circumferential surface of the piston rod sliding. This has the advantage that relatively good airtightness can be obtained. On the other hand, as the wear progresses, the contact surface area of the piston rod with the sliding surface increases, and the contact surface pressure per unit contact area decreases. As a result, the oil removing function also deteriorates, thereby increasing consumption of lubricating oil.

As a means for solving the above problems such as a cast iron or copper alloy oil removing ring, a straighening heat tratment is performed in the fabrication step and a quartz process is performed again to remove deformation caused by the internal stress after the initial fabrication It has been proposed to obtain a high-precision product.

It has also been proposed that both assemblies are assembled so that they fit in dimension to each other at the time of installation of the oil removal ring.

However, these means increase the complicated process and expense. If the cylindrical shape of the piston rod is irregular, it is difficult to solve the above-mentioned problem even if a high precision (oil removing ring) is used or if the assembled parts are fitted well.

When a resin material such as ethylene tetrafluoride resin or the like is used as the material of the oil removing ring, the inner circumference of the ring rapidly adapts to the outer circumferential surface of the piston rod due to the low strength.

Thus, although excellent oil removal performance can be initially obtained, due to continued use, the resin material absorbs lubricant, eventually softens, and further increases wear. This necessitates the exchange of parts that require troublesome work and expense.

It is an object of the present invention to provide a seal device for a piston rod that exhibits excellent oil removing performance that makes contact with the outer circumferential surface of the piston rod and follows the shape of these surfaces to reduce the consumption amount of lubricating oil that is generated each time the piston rod moves .

According to the present invention, the above object can be attained by providing a sealing device for an engine piston rod as described below. That is, the sealing apparatus of the present invention comprises: (a) an annular upper rail member, a lower rail member, and a pair of rail members each having a notch at one location as a single piece of steel and supporting a plurality of oil holes in the circumferential direction And (b) an oil removing ring body which is mounted in a state of being stretched to the groove of the holding section and which is formed to have an inside diameter direction And an annular coil spring configured to press the inner circumferential surface of the upper rail member and the inner circumferential surface of the lower rail member against the outer circumferential surface of the piston rod.

In the present invention, in order to improve the durability of the oil removing ring, various nitriding treatments such as softening, ion nitriding, gas nitriding, chromium plating and Ni-P type composite dispersion plating , And CVD and PVD treatment to form a wear resistant treatment layer.

Further, it is desired to further improve the initial running property by forming the surface treatment layer by the formation treatment into the Fe ₃ O ₄ layer, the parking 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.

Hereinafter, the present invention will be described on the basis of embodiments. It should be understood, however, that these examples are for illustrative purposes only, and are not intended to limit the scope of the present invention.

1 is a partial sectional view showing the structure of the oil removing ring 1 according to the first embodiment of the present invention. The oil removing ring 1 has a piston rod 8 reciprocating in the direction of arrow A on its outer peripheral side As shown in Fig. 3 is a partial perspective view of the oil removal ring according to this embodiment.

The oil removing ring 1 is obtained by integrally connecting the upper rail member 2 and the lower rail member by the support portion 4. [ The support portion (4) has an annular groove (6) on its outer peripheral side and a plurality of oil holes (5) spaced apart in the main direction in the groove (6) thereof. The groove 6 is provided with an annular coil spring 7 stretched in a state of being in contact with the inclined surface constituting the groove so as not to interfere with the oil hole 5.

The oil removing ring body made up of the upper and lower rail members 2, 3 and the support portion 4 of this embodiment has an overall M-shaped cross section and is formed into a ring shape by a thin steel strip, And has a notch portion.

The annular coil spring 7 presses the support portion 4 in the inner diameter direction by its contractive force so that the inner peripheral ends of the upper and lower rail members 2 and 3 are brought into pressure contact with the outer peripheral surface 14 of the piston rod 8, The oil is effectively removed from the main surface of the piston rod.

The oil removing ring body of the above embodiment exhibits flexibility because it is integrally molded from a thin steel strip so as to have an M-shaped cross section as a whole. As a result, the inner circumferential ends of the upper and lower rail members 2, 3 are easily brought into contact with the outer circumferential surface of the piston rod through the entire circumference by the contracting force of the annular coil spring 7 to exhibit a good oil removing performance from the initial stage do. Further, since the upper and lower rail members have a thin plate-like structure, the contact area is not increased even when the wear progresses, thereby maintaining a good oil removing performance over a long period of time.

Reference numeral 9 denotes an effective surface treatment layer which improves the durability of the oil removing ring or further improves initial conformity.

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

In this embodiment also, the oil removal ring 1 is integrally connected to the upper rail member 2 and the lower rail member 3 by the support portion 4, and the support portion 4 is annularly formed on the outer peripheral side thereof. And a plurality of oil holes 5 spaced apart from each other in the main direction at a bottom portion thereof. An annular coil spring 7 in a stretched state is mounted on the groove 6.

The oil removing ring body made up of the upper and lower rail members 2, 3 and the support portion 4 of this embodiment has an I-shaped cross section or an H-shaped cross section as a whole, The shaped-sectin wire material obtained by the above method can be integrally formed into an annular shape having a notch at one place by coil machining.

The annular coil spring 7 presses the support portion 4 in the radial direction by the contractive force of the annular coil spring 7 to press the inner circumferential end of the upper and lower rail members 2 and 3 against the outer circumferential surface of the piston rod 8, Thereby making the oil removing action effective.

In the second embodiment, since the upper and lower rail members and the support portions of the oil removing ring are integrally formed so as to define the I-shaped section or the M-shaped section, the ring body also exhibits flexibility, The inner circumferential end of the upper and the lower helical members 2 and 3 are easily in contact with the outer circumferential surface of the piston rod through the entire circumference by the contractive force of the annular coil spring 7 so as to exhibit a good oil removing performance from the initial stage. In addition, the upper and lower rail members are of a thin plate type structure and do not increase the contact area with the progress of wear, thereby maintaining a good oil removing 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 formed by integrally forming the lower rail member 3 and the support portion 4, and the upper rail member 22 is formed as a separate body, i.e., the annular side rail 22 And also has a tackle and does not have his own tension. An annular side rail (22) is supported by a side rail support portion formed on the upper portion of the support portion (4) and held by a support portion.

The side rail support portion is brought into contact with the lower side surface in the vicinity of the inner circumferential side of the side rail 22 of the oil removing ring as shown in FIG. 5 exemplifying that the oil removing ring is fitted on the piston rod 8, A supporting protrusion 10 for supporting the side rail 22 and a lug 11 for pressing against the outer peripheral edge of the side rail 22 and pressing the side rail 22 in the inner peripheral direction, The piston 22 receives the action of the contractile force of the annular coil spring 7 through the lug 11 and presses against the outer peripheral surface 14 of the inner peripheral edge piston rod 8 of the side rail 22 to slide. At the same time, the inner peripheral end of the lower rail member 3 also presses against the outer peripheral surface of the piston rod in the same manner and slides.

The lug (11) has an inclined surface (15) which is in contact with the side rail (22). The inclined surface 15 is preferably slightly inclined in the radial direction as far as possible. The inclined surface 15 of the lug 11 presses the side rail 22 in the inner peripheral direction to press-contact the inner peripheral edge portion of the side rail 22 against the outer peripheral surface 14 of the piston rod 8 and the outer peripheral portion of the side rail 22 So that the rails 22 and 3 are pressed against the wall surface 13 of the ring groove 12 by being forced upward in the axial direction to improve the sealing performance (side seal) between the oil removing ring and the wall surface.

The inclination angle of the inclined face 15 of the lug 11 is not more than 5 degrees measured from the axial direction of the piston rod. When the inclination angle is 40 degrees or more, the wall surface 13 of the ring groove 12 and the rail 22, The traction force on the outer peripheral surface of the piston rod of the rail 22 is hardly followed.

Therefore, in the present invention, it is preferable to appropriately select the inclination angle in the range of 10 to 25 degrees. The side rail support portion, the support portion 6 and the lower rail member 3 are integrally manufactured by stamping and forming all the 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 removal ring 1 of this embodiment has separate bodies, namely upper and lower rail members, which are manufactured as annular side rails 22 and 23, each with a stop and no tension. The support portion 4 is provided with a support projection 10 and a side rail support portion having a lug 11 in the same way as in the third embodiment to support each of the annular side rails 22 and 23.

The supporting portion 4 and the side rail supporting portion thereof are defined as I-shaped or H-shaped in cross section as a whole, and the deformed wire obtained by drawing in a predetermined I- or H- So that it can be molded in a cubic shape by molding into a ring shape having a joint.

The annular coil spring 7 presses the support portion 4 in the radial direction by its contractive force and presses the inner circumferential end of the upper and lower rail members 2 and 3 against the outer circumferential surface of the piston rod 8, Thereby enabling the oil removing action of the oil pan.

Also in the fourth embodiment, the ring body is flexible because the oil removing ring, the lower rail member, and the support portion are integrally formed to define the I-shaped section or the H-shaped section. As a result, the inner peripheral end of the upper and lower side rails 22 and 23 is in good follow-contact with the entire circumference of the outer surface of the piston rod due to the contractive force of the annular coil spring 7 to achieve a good oil removing performance from the initial stage do. Further, since the upper and lower rail members have a thin plate-like structure, good oil removing performance can be maintained over a long period of time without increasing the contact area with the progress of wear.

In the fourth embodiment shown in FIG. 6, the members for supporting the side rails, that is, the members consisting of the supporting portions and the respective side rail supporting portions, are formed by the circumferentially spaced and radially extended slits 16, . In the modification of the fourth embodiment shown in Fig. 7, the slit extends in the radial direction from the inner peripheral side. In the modification of the fourth embodiment shown in Fig. 8, the slit extends radially from the outer peripheral side. These slits improve the flexibility of the members and allow the side walls to more reliably follow the outer circumferential surface of the piston rod.

Therefore, in the sealing apparatus for a piston rod according to the present invention, the inner peripheral end of the upper and lower rail members designed by the M-, I- or H- By using the oil removing ring having a good follow-up characteristic of sliding contact with the outer circumferential surface of the piston rod, there is no gap between the outer circumferential surface of the piston rod and the inner circumferential surface of the seal member from the initial stage, do. Therefore, the occurrence of the remaining phenomenon of the lubricating oil is suppressed to reduce the consumption of the lubricating oil, and a remarkable effect such as less frequent replacement of parts is obtained. Further, the oil removing ring used in the present invention exhibits a good follow characteristic. Consequently, even when the oil removing ring is fitted to the piston rod having a non-circular section, the oil removing ring has a good follow-up contact with the outer circumferential surface of the piston rod, Thereby facilitating part replacement work.

It is to be understood that the invention is not limited to those precise embodiments, since various embodiments of the invention are possible without departing from the spirit and scope of the invention.

Claims (1)

1. A sealing device for a piston rod of an engine having a cylinder block and an oil removing ring, characterized in that the oil removing ring is a single piece of steel and comprises an annular upper rail member (2) A rail member 3 and a support member 4 having upper and lower rail members vertically held and a plurality of oil holes 5 circumferentially spaced apart from each other in a circumferential direction, An annular oil removal ring body (2, 3, 4) having a cross section selected from the group consisting of an I-shaped, I-shaped or H-shaped cross section; And an inner peripheral surface of the upper rail member (2) and the lower rail member (3) are pressed against the piston (4) by pressing the supporting portion (4) And an annular coil spring (7) for pressing against the outer circumferential surface of the rod.