KR102389308B1 - Oil seal - Google Patents

Abstract

The oil seal is installed between the crankshaft and the crankcase to form a space for accommodating the oil therein, and is in close contact with the crankshaft and the crankcase by an elastic restoring force to maintain airtightness inside the crankcase; One end is fixed to the inside of the first sealing member, the other end is in slidable contact on the outer circumferential surface of the crankshaft, and as the crankshaft rotates, a spiral groove for returning oil flowing out along the outer circumferential surface of the crankshaft to the inside of the crankcase is provided. a second sealing member having a second sealing member, and a pressing member surrounding the outer surface of the second sealing member in contact with the crankshaft and pressing the second sealing member in the crankshaft direction. In this case, the second sealing member may be polytetrafluoroethylene (PTFE).

Description

Oil seal {OIL SEAL}

The present invention relates to an oil seal. More particularly, it relates to an oil seal for preventing oil inside a crankcase from leaking to the outside along an outer circumferential surface of a crankshaft.

An engine of an internal combustion engine reciprocates a piston using power generated by burning fuel, and the reciprocating motion of the piston is transmitted to a crankshaft through a connecting rod. The crankshaft may convert the reciprocating motion of the piston into rotational motion. The converted rotational kinetic energy may be transmitted to the drive shaft of the wheel through a flywheel and a transmission.

The crankshaft is connected to the connecting rod, and can rotate at high speed in the crankcase. At this time, oil is supplied into the crankcase to prevent wear and seizure of the connecting rod and crankshaft.

On the other hand, the oil inside the crankcase may leak to the outside along the outer peripheral surface of the crankshaft. To prevent this, an oil seal may be installed between the crankshaft and the crankcase. The oil seal can prevent oil inside the crankcase from leaking to the outside by maintaining airtightness between the crankshaft and the crankcase.

An object of the present invention is to provide an oil seal for preventing oil from leaking to the outside along an outer circumferential surface of a crankshaft.

In order to achieve the above object of the present invention, the oil seal according to exemplary embodiments of the present invention is installed between the crankshaft and the crankcase to form a space for accommodating oil therein, and is A first sealing member for maintaining airtightness inside the crankcase by being in close contact with the crankshaft and the crankcase, one end is fixed to the inside of the first sealing member and the other end is in contact so as to be slidable on the outer circumferential surface of the crankshaft and a second sealing member having a spiral groove for returning oil flowing out along an outer circumferential surface of the crankshaft to the inside of the crankcase as the crankshaft rotates, and the second sealing member in contact with the crankshaft. It may include a pressing member surrounding the side surface for pressing the second sealing member in the direction of the crankshaft. In this case, the second sealing member may be polytetrafluoroethylene (PTFE).

In example embodiments, the first sealing member may further include a dust lip protruding in the crankshaft direction to contact the crankshaft to prevent foreign substances from flowing into the crankcase. .

In example embodiments, the first sealing member may further include at least one outer circumferential sealing portion protruding annularly on the outer surface to contact the crankcase.

In example embodiments, the oil seal may further include a reinforcing member coupled to an inner side of the first sealing member and supporting the oil seal to maintain a constant external shape.

In exemplary embodiments, the second sealing member protrudes from the helical groove to contact the crankshaft, and interrupts the continuity of the helical groove so that oil inside the crankcase is transferred to the helical groove when the crankshaft is stopped. It may further include at least one oil leakage preventing unit for preventing leakage to the outside along the.

In exemplary embodiments, the pressing member may press the oil leakage preventing part in the crankshaft direction.

In exemplary embodiments, the pressing member may be installed at the other end of the second sealing member in contact with the crankshaft.

In exemplary embodiments, the pressing member may be a spring.

The oil seal according to exemplary embodiments may be installed between the crankcase and the crankshaft to maintain airtightness inside the crankcase. In particular, it is possible to prevent the oil inside the crankcase from flowing out along the outer circumferential surface of the crankshaft.

In addition, the pressing member installed on the outer surface of the oil seal may press one end of the oil seal to be in close contact with the crankshaft. Accordingly, it is possible to improve the tightening force and followability of the oil seal to the crankshaft.

However, the effects of the present invention are not limited to the above-mentioned effects, and may be variously expanded without departing from the spirit and scope of the present invention.

1 is a cross-sectional view illustrating an oil seal according to exemplary embodiments.
FIG. 2 is a partial cross-sectional view illustrating the second sealing member of FIG. 1 .
FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2 .
FIG. 4 is a front view showing the pressing member of FIG. 1 .

With respect to the embodiments of the present invention disclosed in the text, specific structural or functional descriptions are only exemplified for the purpose of describing the embodiments of the present invention, and the embodiments of the present invention may be embodied in various forms and the text It should not be construed as being limited to the embodiments described in .

Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms may be used for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle. Other expressions describing the relationship between elements, such as "between" and "immediately between" or "neighboring to" and "directly adjacent to", etc., should be interpreted similarly.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate that the specified feature, number, step, operation, component, part, or a combination thereof exists, and includes one or more other features or numbers. , it is to be understood that it does not preclude the possibility of the existence or addition of steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted to have meanings consistent with the context of the related art, and are not to be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. .

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and repeated descriptions of the same components are omitted.

1 is a cross-sectional view illustrating an oil seal according to exemplary embodiments. FIG. 2 is a partial cross-sectional view illustrating the second sealing member of FIG. 1 . FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2 . Figure 4 is a front view showing the pressing member of Figure 1;

1 to 4 , the oil seal 100 according to exemplary embodiments is installed between the crankshaft 200 and the crankcase 300 to form a space 10 in which oil is accommodated. The first sealing member 110 , the reinforcing member 120 coupled to the inside of the first sealing member 110 , one end is fixed to the inside of the first sealing member 110 , and the other end is sliding on the crankshaft 200 . It may include a second sealing member 130 that makes possible contact, and a pressing member 140 surrounding the outer surface of the second sealing member 130 in contact with the crankshaft 200 .

An engine (not shown) of an internal combustion engine may burn fuel in a cylinder (not shown) and move a piston (not shown) using explosive force generated during combustion. The piston reciprocates within the cylinder, and kinetic energy of the piston may be transmitted to the crankshaft 200 through a connecting rod (not shown). The crankshaft 200 converts the reciprocating kinetic energy of the piston into rotational kinetic energy, and the converted rotational kinetic energy may be transmitted to the drive shaft of the wheel through a flywheel (not shown) and a transmission (not shown), etc. .

The crankcase 300 is installed under the cylinder block (not shown) and can accommodate a part of the crankshaft 200 . One end of the crankshaft 200 may be accommodated in the crankcase 300 , and the other end may extend to the outside of the crankcase 300 and be connected to the flywheel.

Oil may be accommodated in the inner space 10 of the crankcase 300 . The oil acts as a lubricating oil for the connecting rod and the crankshaft 200 to prevent wear and seizure of internal parts of the crankcase 300 . At this time, the oil seal 100 may be installed between the crankshaft 200 and the crankcase 300 to prevent the oil in the crankcase 300 from flowing out to the outside 20 .

In example embodiments, the oil seal 100 may include first and second sealing members 110 and 130 , a reinforcing member 120 , and a pressing member 140 .

The first sealing member 110 is installed between the crankshaft 200 and the crankcase 300 , and may have an internal space 10 for accommodating oil therein. The inner space 10 may be isolated from the outer space 20 by the first sealing member 110 . The crankshaft 200 passes through the center of the first sealing member 110 , and the outer surface of the first sealing member 110 may contact the crankcase 300 .

For example, the first sealing member may include an elastic member such as rubber. Accordingly, the first sealing member 110 can maintain the airtightness of the inner space 10 by closely contacting the crankshaft 200 and the crankcase 300 by the elastic restoring force, respectively.

In example embodiments, the first sealing member 110 may further include at least one outer circumferential sealing part 112 protruding annularly on the outer surface to contact the crankcase 300 .

Since the outer peripheral sealing part 112 is in contact with the crankcase 300 , the airtightness of the inner space 10 may be maintained even if the entire outer surface of the first sealing member 110 does not come into contact with the crankcase 300 . In addition, since the radius of the outer surface of the first sealing member 110 may be reduced, it may be easier to couple the oil seal 100 between the crankcase 300 and the crankshaft 200 .

In example embodiments, the first sealing member 110 may further include a dust lip 114 protruding inward toward the crankshaft 200 . The dust lip 114 has a ring shape and comes in contact with the crankshaft 200 to prevent foreign substances from the external space 20 from flowing into the internal space 10 .

The reinforcing member 120 is coupled to the inside of the first sealing member 110 , and in some cases, a part of the reinforcing member 120 may be inserted into the first sealing member 110 . The reinforcing member 120 may support the first sealing member 110 to maintain a constant shape. In addition, since the reinforcing member 120 supports the first sealing member 110 , contact between the outer surface of the first sealing member 110 and the crankcase 300 may be improved. For example, the reinforcing member may include a metal member such as steel.

In exemplary embodiments, the second sealing member 130 includes a fixing part 132 fixedly installed on the first sealing member 110 and an oil lip 134 slidably in contact with the crankshaft 200 . may include In this case, the fixing part 132 and the oil lip 134 may be integrally formed.

The fixing part 132 is coupled to the inner surface of the first sealing member 110 , and may fix the second sealing member 120 to the first sealing member 110 . In FIG. 1 , the fixing part 132 is illustrated as not in contact with the reinforcing member 120 , but in some cases, the fixing part 132 may be extended to contact the reinforcing member 120 .

The oil lip 134 is formed to extend from the fixing part 132 toward the crankshaft 200 and may have a ring shape. The crankshaft 200 may be inserted into the oil lip 134 . In this case, one surface of the oil lip 134 in the direction in contact with the crankshaft 200 is defined as the inner surface 135a, and the other surface opposite to the inner space 10 is defined as the outer surface 135b. to define

The oil lip 134 extending from the fixing part 132 toward the crankshaft 200 may be bent so that the inner surface 135a contacts the crankshaft 200 . The crankshaft 200 is not a perfect circle, and the rotation center of the crankshaft 200 may not be constant either. Accordingly, the degree to which the oil lip 134 is bent and the area of the oil lip 134 in contact with the crankshaft 200 may be variously changed according to the rotation of the crankshaft 200 .

For example, the oil lip 134 may include polytetrafluoroethylene (PTFE) or rubber. The PTFE is elastically deformable, has a small coefficient of friction, and has excellent wear resistance. Accordingly, the oil lip 134 may be in close contact with the crankshaft 200 by the elastic restoring force to maintain the airtightness of the inner space 10 , and when the crankshaft 200 rotates, it may slide on the outer peripheral surface of the crankshaft 200 . can

In exemplary embodiments, the oil lip 134 is a spiral groove 136 for preventing the oil filled in the inner space 10 from flowing out to the outer space 20 along the surface of the crankshaft 200 . and an oil leakage preventing unit 138 . In this case, both the spiral groove 136 and the oil leakage preventing part 138 may be formed on the inner surface 135a of the oil lip 134 .

As shown in FIG. 2 , the spiral groove 136 is formed on the inner surface 135a of the oil lip 134 , and may form a spiral flow path between the oil lip 134 and the crankshaft 200 . . In this case, the rotational direction of the spiral groove 136 may be opposite to the rotational direction of the crankshaft 200 . Accordingly, when the crankshaft 200 rotates, the oil on the surface of the crankshaft 200 may return to the inner space 10 along the spiral groove 136 .

For example, the spiral groove may have a triangular cross section. Alternatively, the cross section of the spiral groove may have various shapes as needed, such as a square or a semicircle.

2 and 3, the oil leakage preventing part 138 is formed on the inner surface 135a of the oil lip 134, and can protrude from the spiral groove 136 to contact the crankshaft 200. there is. For example, the oil leakage preventing part may have substantially the same height as the inner surface 135a of the oil lip 134 and may be integrally formed with the inner surface 135a.

While the crankshaft 200 rotates, the oil in the inner space 10 can be prevented from flowing into the outer space 20 by the spiral groove 136 formed in the direction opposite to the rotation direction of the crankshaft 200 . there is. However, since the spiral groove 136 forms one continuous flow path on the surface of the crankshaft 200 , when the rotation of the crankshaft 200 is stopped, the oil in the inner space 10 is transferred to the spiral groove 136 by the pressure gradient. ) may flow out to the external space 20 along the. The oil leakage preventing unit 138 may prevent oil leakage of the internal space 10 even when the crankshaft 200 does not rotate by stopping the continuity of the spiral groove 136 .

That is, while the crankshaft 200 rotates, it is possible to prevent the oil in the inner space 10 from flowing into the outer space 20 by the spiral groove 136 . When the rotation of the crankshaft 200 is stopped, the oil leakage preventing unit 138 separates the inner space 10 and the outer space 20 to prevent oil from leaking.

In addition, although the oil lip 134 is illustrated as having three oil leakage preventing units 138 in FIG. 3 , the number of the oil leakage preventing units 138 is not limited thereto, and the oil lip 134 may have various numbers as needed. may have leakage preventing parts of

The pressing member 140 is installed to surround the outer surface 135b of the oil lip 134 in contact with the crankshaft 200, and by pressing the oil lip 134 in the crankshaft 200 direction, the oil lip 134 ) can be prevented from being spaced apart from the crankshaft 200 . For example, the pressing member may include an elastic member such as a spring or rubber. Tightness and followability of the oil lip 134 with respect to the crankshaft 200 may be improved by the elastic restoring force of the pressing member 140 .

Since the rotation center of the crankshaft 200 is not constant, the stress acting on the oil lip 134 as the crankshaft 200 rotates may not be constant. In particular, the stress may be concentrated on a bent portion of the oil lip 134 . Accordingly, the distal end of the oil lip 134 opposite the bent portion may be spaced apart from the crankshaft 200 , and the tension force of the oil lip 134 on the crankshaft 200 may be reduced. In this case, the pressing member 140 may be installed at the distal end of the oil lip 134, and by pressing the distal end of the oil lip 134 in the direction of the crankshaft 200, the oil lip 134 is moved to the crankshaft ( 200) can be prevented.

In exemplary embodiments, the pressing member 140 may be installed to surround the outer surface 135b of the oil lip 134 on which the oil leakage preventing part 138 is located. In this case, the pressing member 140 may press the oil leakage preventing unit 138 in the crankshaft 200 direction to bring the oil leakage preventing unit 138 into close contact with the crankshaft 200 . Accordingly, while the crankshaft 200 does not rotate, it is possible to more effectively prevent the oil in the inner space 10 from flowing into the outer space 20 along the spiral groove 136 .

In exemplary embodiments, in order to prevent the pressing member 140 from being separated from the oil lip 134 , a groove is formed on the outer surface 135b of the oil lip 134 , and the pressing member is formed in the groove. (140) can be installed. In addition, although not shown, a plurality of pressing members 140 may be installed as needed.

As described above, the oil seal 100 according to exemplary embodiments is installed between the crankshaft 200 and the crankcase 300 so that the oil filled in the inner space 10 leaks into the outer space 20 . can be prevented from becoming In particular, the spiral groove 136 and the oil leakage preventing part 138 formed on the inner surface 135a of the oil lip 134 operate when the crankshaft 200 rotates and stops, respectively, so that the crankshaft ( 200), it is possible to prevent oil leakage regardless of the rotation.

In addition, the pressing member 140 presses the distal end of the oil lip 134, which is easy to lift, toward the crankshaft 200, thereby improving the tension and followability of the oil seal 100 with respect to the crankshaft 200. .

Although the above has been described with reference to the embodiments of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. You will understand that you can.

10: inner space 20: outer space
100: oil seal 110: first sealing member
112: outer peripheral sealing portion 114: dust lip
120: reinforcing member 130: second sealing member
132: fixed portion 134: oil lip
135a: inner surface 135b: outer surface
136: spiral groove 138: oil leakage prevention part
140: pressing member 200: crankshaft
300: crankcase

Claims (8)

a first sealing member installed between the crankshaft and the crankcase to form a space for accommodating the oil therein, and for maintaining airtightness inside the crankcase by closely contacting the crankshaft and the crankcase by an elastic restoring force;
One end is fixed to the inner side of the first sealing member and the other end is slidably in contact with the outer circumferential surface of the crankshaft, and as the crankshaft rotates, oil flowing out along the outer circumferential surface of the crankshaft is discharged into the crankcase a second sealing member having a spiral groove for returning to the furnace; and
and a pressing member surrounding the outer surface of the second sealing member in contact with the crankshaft and for pressing the second sealing member in the direction of the crankshaft,
The second sealing member is PTFE (Polytetrafluoroethylene),
The second sealing member protrudes from the spiral groove to contact the crankshaft, and stops the continuity of the spiral groove so that the oil inside the crankcase flows out along the spiral groove when the crankshaft is stopped. It further comprises at least one oil leakage preventing part for preventing,
The pressing member is installed so as to surround the outer surface of the oil lip where the oil leakage preventing portion is located at the other end of the second sealing member in contact with the crankshaft to press the oil leakage preventing portion in the direction of the crankshaft,
The oil seal, characterized in that the rotation direction of the spiral groove is opposite to the rotation direction of the crankshaft. The method according to claim 1, wherein the first sealing member further comprises a dust lip protruding in the direction of the crankshaft to contact the crankshaft to prevent foreign substances from flowing into the crankcase. oil seal. The oil seal according to claim 1, wherein the first sealing member further comprises at least one outer circumferential sealing portion protruding annularly on an outer surface to contact the crankcase. The oil seal according to claim 1, further comprising a reinforcing member coupled to an inner side of the first sealing member and supporting the oil seal to maintain a constant external shape. delete delete delete The oil seal according to claim 1, wherein the pressing member is a spring.

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