TW201502399A - Shaft seal - Google Patents

Abstract

A shaft seal, attached to a ring groove of a female body, through which an insertion hole having the ring groove composed of a first side wall face on the pressure-receiving side, a second side wall face on a low pressure side, and a groove bottom face, sliding on the peripheral face of the shaft member inserted to the insertion hole as to freely reciprocate, and provided with a U-shaped seal portion on the pressure-receiving side composed of an inner peripheral lip and a peripheral lip, and a dust lip protruding to the low pressure side, is constructed as that a protruding portion is formed on a peripheral corner portion on low pressure side formed by a peripheral face portion which contacts the groove bottom face and a supporting face portion facing the second side wall face, and the protruding portion is pressed to a corner portion of the groove bottom face and the second side wall face and absorbed by the peripheral corner portion on low pressure side by elastic compressive deformation under a pressure-receiving state.

Description

Shaft seal

The present invention relates to a shaft seal.

Referring to Figures 10A and 10B, a conventional shaft seal (as a single seal) is used for an air pressure machine such as a cylinder or a valve, and integrally has a U-shaped seal portion 42 and a dust lip 47. It is attached to the ring groove 50 of the cylinder head or the valve body, and is connected to a reciprocating shaft member 41 (rod or mandrel, etc.).

However, in the conventional shaft seal shown in Figs. 10A and 10B, since the axial center positions of the inner peripheral lip 43 and the outer peripheral lip 44 (of the shaft member 41) are formed into a uniform shape (H ₄₃ = Fig. 10A). 0), therefore, as shown in Fig. 10B, the U-shaped groove portion 55 between the inner and outer peripheral lips 43, 44 is adsorbed on the side wall portion 51 of the ring groove 50, and the sealing property is lost, resulting from the high pressure side R The problem of the fluid leaking in the direction indicated by the arrow G.

As a countermeasure, as shown in Japanese Patent Publication No. Sho 60-14356, the size of the inner peripheral lip 43 is shortened, and the inner peripheral lip 43 and the outer peripheral lip 44 are formed with a size. The cross-sectional shape of the difference H ₄₃ .

In the conventional shaft seal 40, such as the above-mentioned Japanese Patent Publication No. Sho 60-14356, the integral shaft seal 40 is integrally formed in the direction of the arrow R (hereinafter referred to as the pressure receiving side R). The U-shaped seal portion 42 formed by the peripheral lip 43 and the outer peripheral lip 44, and the swinging dust lip 47 that protrudes in the arrow L direction (hereinafter referred to as the low pressure side L), and the protruding portion 45 are formed on the outer surface of the outer peripheral lip 44. As shown in Fig. 9, the shaft seal 40 is attached to a female body (in the cylinder head or the like) provided with an insertion hole. The ring groove 50 of the body B is inserted into the shaft member 41 so as to be reciprocally movable, and the shaft seal 40 is connected to the outer peripheral surface 41A of the shaft member 41. The annular groove 50 has a first side wall surface 51 on the pressure side R, a second side wall surface 52 on the low pressure side L, and a groove bottom surface 53. In a state in which the shaft seal 40 is mounted in the ring groove 50, the outer peripheral surface portion 49 of the shaft seal 40 abuts against the bottom surface 53 of the groove, and the support surface portion 46 and the second side wall surface formed on the low pressure side L of the shaft seal 40 are formed. 52 opposite.

In the pressed state shown in Fig. 9, the shaft seal 40 is pressed by the U-shaped seal portion 42, and is pressed by the pressure receiving side R toward the low pressure side L. At this time, the support surface 46 is pressed by the second side wall surface 52, and the dust lip 47 enters the gap between the female body B and the shaft member 41, and moves inside the shaft seal 40, and the corner portion P (the first The side of the two side wall faces 52) generates a rotational moment M as a fulcrum. Moreover, since the dimensional difference H _{43 is present} and the inner peripheral lip 43 has a short shape, the rotational moment M is increased. Due to the cause of the skew (elastic deformation) of the rotational moment M, the dust lip 47 is lifted by the shaft member 41. When the dust lip 47 is lifted, the contact surface pressure with the shaft member 41 becomes zero (refer to the diagram i in Fig. 9), or the dust lip 47 is separated from the shaft member 41 by a gap g. As described above, in the conventional shaft seal 40, the dust-proof lip 47 loses the sealing property and causes a problem that the lubricating oil retainability is lowered.

Further, due to the floating of the dust lip 47, the eccentric followability is lowered, and the dustproofness is lowered. Further, the abutting resistance of the inner peripheral lip 43 becomes excessively large, or the ventral surface 48 of the shaft seal 40 contacts the shaft member 41, causing a problem that the abutment resistance becomes excessive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shaft seal which can prevent blow-by of the aforementioned adsorption and prevent the floating of the dust lip in a pressurized state.

In order to achieve the foregoing object, the technical means applied by the present invention comprises: a shaft seal attached to a ring groove of a female body provided with an insertion hole, the ring groove being formed by the first side wall surface of the pressure side, and a low pressure a second side wall surface and a bottom surface of the groove are formed, and abuts against an outer peripheral surface of the shaft member that can be arbitrarily reciprocated and inserted into the insertion hole; the shaft seal includes the inner circumference a U-shaped sealing portion on the pressure side formed by the lip and the outer peripheral lip, and a dust lip protruding toward the low pressure side; wherein the peripheral surface abutting the bottom surface of the groove and facing the second side wall surface Supporting the low-pressure side outer peripheral corner portion formed by the face to form a protrusion portion; under pressure, receiving the corner portion of the groove bottom surface and the second side wall surface, the protrusion portion is elastically compressed and deformed, and The formation is absorbed by the crotch portion of the outer peripheral corner of the low pressure side.

In the shaft seal of the present invention, in the pressed state, the floating lip of the rotational moment generated by the second side wall surface and the corner portion of the insertion hole as a fulcrum is floated, and the protrusion is formed by the protrusion The elastic anti-addition force in the in-diameter direction generated by the elastic compression deformation is prevented.

According to the shaft seal of the present invention, the elastic anti-addition force generated by the elastic compression deformation of the projection portion under the pressed state can prevent the floating lip from the shaft member from floating. With this prevention of floating, the dust intrusion prevention performance (also referred to as dustproofness) can be improved, and the lubricant retainability can be improved. Moreover, it can be prevented from falling off by the ring groove. Further, in the air compressor in which the dimensional accuracy of the ring groove and the dimensional accuracy of the shaft member are lowered, and the axial center of the hole and the axis of the shaft member are eccentric, the eccentric followability of the dust lip of the present invention is better. It also ensures dust resistance, sealing and lubricant retention.

〔this invention〕

1‧‧‧Axis components

1A‧‧‧ outer perimeter

11‧‧‧ Inner Week Abdomen

12‧‧‧Second side wall

13‧‧‧First side wall

14‧‧‧Face bottom

15‧‧‧ peripheral face

16‧‧‧ Corner Department

17‧‧‧Lubricating chamber

2‧‧‧ Ring groove

3‧‧‧ inner lip

4‧‧‧peripheral lip

5‧‧‧Protruding

6‧‧‧Support for the face

7‧‧‧Dust lip

8‧‧‧ Low-pressure side peripheral angle

9‧‧‧Protruding

10‧‧‧U-shaped seal

20‧‧‧Insert hole

B‧‧‧Female ontology

C ₁ ‧‧‧ gap

C ₂ ‧‧‧ gap

D‧‧‧Deep size

D ₁₂ ‧‧‧Deep size

D ₁₃ ‧‧‧Deep size

F‧‧‧Flexible anti-addition

G‧‧‧ gap

H‧‧‧ Height size

L‧‧‧Low side

M‧‧‧Rotating torque

M ₇ ‧‧‧Floating

P‧‧‧Corner

P ₉ ‧ ‧ face pressure

Pmax‧‧‧ vertex

R‧‧‧ Pressure side

[study]

40‧‧‧ shaft seal

41‧‧‧Axis components

41A‧‧‧ outer perimeter

42‧‧‧U-shaped seal

43‧‧‧ inner lip

44‧‧‧peripheral lip

45‧‧‧Protruding

46‧‧‧Support for the face

47‧‧‧Dust lip

48‧‧‧ belly

49‧‧‧ peripheral face

50‧‧‧ Ring groove

51‧‧‧First side wall

52‧‧‧Second side wall

53‧‧‧Face bottom

55‧‧‧U-shaped groove

B‧‧‧Female ontology

G‧‧‧Fluid arrow

G‧‧‧ gap

H ₄₃ ‧‧‧Different size

L‧‧‧Low side

M‧‧‧Rotating torque

M ₇ ‧‧‧Floating

P‧‧‧Corner

R‧‧‧ Pressure side

Fig. 1 is a cross-sectional view showing an embodiment of the present invention in a free state.

Fig. 2 is a view showing the cross-sectional shape and the surface pressure distribution of the pressed state, the graph (i) reveals the surface pressure distribution of the shaft member and the dust lip, and the graph (ii) reveals the supporting face and the second side wall surface. The graph of the surface pressure distribution, and the graph (iii) show the surface pressure distribution of the outer peripheral surface and the bottom surface of the groove.

Figure 3 is a perspective view showing a partial section.

Fig. 4 is a cross-sectional view showing another embodiment of the present invention in a free state.

Fig. 5 is a view showing the cross-sectional shape and the surface pressure distribution of the pressed state, and the graph (i) reveals the surface pressure distribution of the shaft member and the dust lip, and the graph (ii) reveals the supporting surface and the second side wall surface. The graph of the surface pressure distribution, and the graph (iii) show the surface pressure distribution of the outer peripheral surface and the bottom surface of the groove.

Fig. 6 is a cross-sectional view showing still another embodiment of the present invention in a free state.

Figure 7 is a cross-sectional view showing an embodiment of a projection, (a) is a cross-sectional view of another embodiment, (b) is a cross-sectional view of still another embodiment, and (c) is a cross-sectional view of a further embodiment.

Figure 8 is a cross-sectional view showing the free state of a conventional shaft seal.

Fig. 9 is a view showing a cross-sectional shape and a surface pressure distribution of a pressure state of a conventional shaft seal, and Figure (i) is a view showing a surface pressure distribution of the shaft member and the dust lip, and Figure (ii) reveals a support surface. And a graph of the surface pressure distribution of the second side wall surface, and (iii) is a diagram showing the surface pressure distribution of the outer peripheral surface and the bottom surface of the groove.

Figure 10 is a cross-sectional view of a conventional shaft seal.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

The shaft seal of the present invention is used for a reciprocating portion of a cylinder or a valve of an air pressure machine. As shown in Figs. 1 to 3, the shaft seal is attached to the ring groove 2 of the female body B provided with the insertion hole 20, and the ring groove 2 is the first side wall surface 13 of the pressure side (high pressure side) R, and the low pressure. The second side wall surface 12 of the side L and the bottom surface 14 of the recess are formed to abut against the outer peripheral surface 1A of the shaft member 1 which is inserted into the insertion hole 20 so as to be reciprocally movable. In the present invention, the female body B refers to a cylinder head or a valve body or the like; the shaft member 1 is a finger or a mandrel. R 2 of the pressure side of the insertion hole 20 of the female body B, C ₁ and the ring groove void contrast, the low pressure side L of the ring groove 2 of C ₂ is set to be large voids. In the low pressure side L of the ring groove 2, the dust lip 7 is inserted between the female body B and the outer peripheral surface 1A of the shaft member 1 and abuts against the outer peripheral surface 1A of the shaft member 1. Further, the shaft seal of the present invention is not limited to a pneumatic device if it is used for low pressure, and may be used in a hydraulic device. The material of the shaft seal is made of rubber.

The shaft seal of the present invention includes a U-shaped seal portion 10 formed by the inner peripheral lip 3 and the outer peripheral lip 4 that protrudes toward the pressure receiving side R, and a dust lip 7 that protrudes toward the low pressure side L. In the pressed state shown in Fig. 2, the U-shaped seal portion 10 is pressed against the inner peripheral lip 3 and the outer peripheral lip 4, and the inner peripheral lip 3 abuts against the outer peripheral surface 1A of the shaft member 1, and the outer peripheral lip is made 4 (and the peripheral face 15) closely contact the groove bottom surface 14. On the outside of the peripheral lip 4 outside the free state, a projection 5 is provided. The inner peripheral surface between the inner peripheral lip 3 and the dust lip 7 forms a concave inner peripheral abdomen 11 which is formed between the inner peripheral lip 3, the dust lip 7 and the inner peripheral abdomen 11 and the shaft member 1. The lubricating oil seals the chamber 17.

Furthermore, as shown in FIGS. 1 and 3, the shaft seal of the present invention is attached to the outer peripheral surface portion 15 of the bottom surface 14 of the recess, and the low pressure side formed by the support surface portion 6 facing the second side wall surface 12. The outer peripheral corner portion 8 is formed with a projection 9. The protruding portion 9 is formed in a circular arc shape in cross section, and protrudes (expands) toward the outer peripheral surface portion 15 of the low-pressure side outer peripheral corner portion 8 .

In the pressed state shown in Fig. 2, the low-pressure side outer peripheral corner portion 8 is pressed by the groove bottom surface 14 and the corner portion 16 of the second side wall surface 12, and the projection portion 9 is elastically compressed and deformed. The low pressure side outer peripheral corner portion 8 is absorbed. In other words, the protruding portion 9 is compressed (elastically deformed) between the low-pressure side outer peripheral corner portion 8 and the corner portion 16 and the low-pressure side outer peripheral corner portion 8 and the corner portion 16 are brought into close contact.

In the pressed state, the U-shaped seal portion 10 is pressed, and the pressure receiving side R is pressed toward the low pressure side L, and the support surface portion 6 is pressed against the second side wall surface 12. At this time, since the low-pressure side of the L 2 ring groove clearance C ₂ is relatively large, and the low-pressure side of the second side wall surface 12 of the depth dimension D _{12 (13} on the pressure side than the first side wall surface of the depth dimension D 13) is small, and therefore The pressing moment M is generated by the pressing of the U-shaped seal portion 10 in the range of the large depth dimension D with the corner portion P as a fulcrum. In other words, a large gap C ₂ is set for the dust lip 7, and the fluid pressure acts on the left direction of the second figure from the depth dimension D as a whole. The second side wall surface to the fluid pressure, the second sidewall surfaces 12 system (by the presence of the clearance C of ₂₎ Partial positioned radial outward direction, and in that the deviation 12 is pressed. Therefore, the shaft seal as a whole receives the rotational moment M. The rotational torque generated by 1, the dust lip 7 lifting system M as shown by arrow _7, form the desired float.

However, in the pressed state shown in Fig. 2, the projection 9 of Fig. 1 is elastically compressed and deformed until it conforms to the shape of the groove bottom surface 14 of the ring groove 2, and is generated by the arrow F in Fig. 2 Shows the elastic anti-additional force in the direction of the inner diameter. By the elastic anti-addition force F, the floating M ₇ from the dust lip 7 of the shaft member 1 is prevented. That is, the additional elastic reaction force F not only want to eliminate dust lip 7 lifting force of the float ₇ direction of the arrow M, and further to the inside in the radial direction is pressed, and a chart of FIG. 2 (ii) as shown in the surface pressure Keep in touch.

As shown in the graph (ii) of Fig. 2, the highest point (vertex) of the surface pressure is generated between the second side wall surface 12 and the support surface portion 6 at the position of the corner portion P. On the other hand, as shown in the diagram (iii), in the groove bottom surface 14 and the outer peripheral surface portion 15, a high surface pressure P _{9 is} generated in the vicinity of the corner portion 16 by the repulsive force of the projection portion ₉ . The high surface pressure P ₉ is capable of generating the aforementioned elastic anti-addition force F. In this way, in the pressed state, the elastic backing force F can be used to prevent the floating M ₇ generated by the rotational moment M centered on the corner portion P. As a result, in the pressed state, it can be seen that the shaft member 1 and the dust lip 7 are abutted by a surface pressure distribution of a suitable mountain shape as shown in the diagram (i).

With respect to the depth dimension D of the ring groove 2 which is stopped by the shaft member 1 to the groove bottom surface 14, the height dimension H from the inner peripheral belly 11 to the front end of the projection 9 in the free state is set to be slightly smaller to form no It will be formed by the low pressure side L of the ring groove 2. In the pressed state, since the protruding portion 9 is absorbed by the low-pressure side outer peripheral corner portion 8 by elastic compression deformation, even if the difference in height dimension H with respect to the depth dimension D is only slightly small, the inner peripheral abdomen 11 can be avoided. The shaft member 1 is contacted and can be arbitrarily moved with low friction.

Next, another embodiment of the present invention will be described.

Referring to Fig. 4, the projection portion 9 formed on the low-pressure side outer peripheral corner portion 8 is projected (expanded) on the side of the support surface portion 6 of the low-pressure side outer peripheral corner portion 8. Due to other constructions Since it is the same as that of the above embodiment, the description thereof is omitted.

Referring to Fig. 5, in the pressed state, the U-shaped seal portion 10 is pressed, and the projection portion 9 is pressed against the second side wall surface 12, and the projection portion 9 is elastically compressed and deformed by the low pressure side outer circumference. The corner portion 8 is absorbed. As shown in the table (ii), the surface pressure increases in the vicinity of the corner portion 16 by the repulsive force of the projection 9, and is expressed by the vertex Pmax. The low-pressure side outer peripheral corner portion 8 is pressed against the corner bottom portion 14 of the groove bottom surface 14 and the second side wall surface 12, and is moved by the elastic compression deformation of the projection portion 9, as shown in the diagram (iii). , in the vicinity of the corner portion 16, the low pressure side of the outer peripheral corner portion of the bottom surface 8 based strong contact groove 14 to the surface pressure P ₉ represents, by an arrow and the direction to the inner diameter of the elastic force of the additional anti-F., can be shown The floating lip 7 is prevented from floating M ₇ and the appropriate surface pressure as shown in the diagram (iii) is maintained. In this way, it is possible to prevent the floating M ₇ from the dust lip 7 of the shaft member 1 caused by the rotational moment M around the corner portion P in the pressed state. As a result, in the pressed state, the shaft member 1 and the dust lip 7 are abutted by a surface pressure distribution of a suitable mountain shape as shown in the diagram (i).

Next, still another embodiment of the present invention will be described.

As shown in Fig. 6, in the low-pressure side outer peripheral corner portion 8, it is preferable to form the projection portion 9 in the oblique direction in which the outer peripheral surface portion 15 side and the support surface portion 6 are protruded (expanded). In the pressed state, the same angle as in Fig. 2 is pressed against the corner bottom portion 14 and the corner portion 16 of the second side wall surface 12, and the projection portion 9 is absorbed by the low pressure side outer peripheral corner portion 8 by elastic compression deformation. . Other configurations are the same as those of the above embodiment.

Further, the present invention can be modified in design. For example, as shown in Fig. 7(a), the projections 9 may have their end face shapes formed into a quadrangular shape. Further, a trapezoidal shape as shown in Fig. 7(b) may be formed, or a triangular shape as shown in Fig. 7(c) may be preferably formed.

In addition, in the third figure, the protrusions 9 are formed in a continuous shape on the circumference, but are not limited to the embodiment, and may be formed in an intermittent shape (not shown).

As described above, the shaft seal of the present invention is provided with a plug-in The ring groove 2 of the female body B of the hole 20 is formed by the first side wall surface 13 of the pressure receiving side R, the second side wall surface 12 of the low pressure side L, and the bottom surface 14 of the groove, and is abutted. The outer peripheral surface 1A of the shaft member 1 inserted into the insertion hole 20 is arbitrarily reciprocated; the shaft seal includes a U-shaped seal portion 10 of the pressure-receiving side R formed by the inner peripheral lip 3 and the outer peripheral lip 4, and protrudes toward the low-pressure side L. a dust-proof lip 7; wherein the outer peripheral surface portion 15 of the abutting groove bottom surface 14 and the low-pressure side outer peripheral corner portion 8 formed by the support surface portion 6 facing the second side wall surface 12 form a projection portion 9; Then, the protrusions 9 are elastically compressed and deformed by the elastic deformation of the bottom surface 14 of the groove bottom surface 14 and the second side wall surface 12, thereby forming a structure that is absorbed by the low-pressure side outer peripheral corner portion 8; In the state, the elastic anti-addition force F in the radial direction is generated by the elastic compression deformation of the projection 9, and the elastic back-adding force F prevents the floating lip 7 from the shaft member 1 from floating. Thereby, the lubricating oil retainability can be improved and the abutting resistance can be reduced. Furthermore, the eccentricity of the dust lip can be maintained, and the dust resistance and the lubricating oil retainability can be improved. Furthermore, it can be prevented from falling off by the ring groove.

Further, the dust lip of the rotation moment M due to the pressed state, the corner portion P to the second side wall surface 12 and the insertion hole 20 as a fulcrum of the float arising 7 M _7, line 9 is formed by a projection portion The elastic anti-addition force F generated in the in-diameter direction generated by the elastic compression deformation is prevented; therefore, the intended purpose can be achieved with a simple configuration, and the dust lip can be prevented from floating, and the eccentric followability is excellent. It also has excellent lubricant retention.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

1‧‧‧Axis components

1A‧‧‧ outer perimeter

11‧‧‧ Inner Week Abdomen

12‧‧‧Second side wall

13‧‧‧First side wall

14‧‧‧Face bottom

15‧‧‧ peripheral face

16‧‧‧ Corner Department

17‧‧‧Lubricating chamber

2‧‧‧ Ring groove

3‧‧‧ inner lip

4‧‧‧peripheral lip

6‧‧‧Support for the face

7‧‧‧Dust lip

8‧‧‧ Low-pressure side peripheral angle

10‧‧‧U-shaped seal

20‧‧‧Insert hole

B‧‧‧Female ontology

C ₁ ‧‧‧ gap

C ₂ ‧‧‧ gap

D‧‧‧Deep size

D ₁₂ ‧‧‧Deep size

D ₁₃ ‧‧‧Deep size

F‧‧‧Flexible anti-addition

L‧‧‧Low side

M‧‧‧Rotating torque

M ₇ ‧‧‧Floating

P‧‧‧Corner

P ₉ ‧ ‧ face pressure

R‧‧‧ Pressure side

Claims (2)

A shaft seal is provided with a ring groove of a female body having an insertion hole formed by a first side wall surface on a pressure receiving side, a second side wall surface on a low pressure side, and a bottom surface of the groove, and is fastened And an outer peripheral surface of the shaft member inserted into the insertion hole arbitrarily reciprocally movable; the shaft seal includes a U-shaped sealing portion formed on the pressure side by the inner peripheral lip and the outer peripheral lip, and a dust lip protruding toward the low pressure side Wherein the peripheral surface of the bottom surface of the recess is abutted against the bottom surface of the recess, and the bottom surface of the low-pressure side formed by the support surface facing the second side wall surface forms a protrusion; in the pressed state, the bottom surface of the recess is received. And pressing of the corner portion of the second side wall surface, the protrusion portion is elastically compressively deformed to form a structure that is absorbed by the low-pressure side outer peripheral corner portion. The shaft seal according to claim 1, wherein in the pressurized state, the dust lip of the rotation torque generated by the second side wall surface and the corner portion of the insertion hole is used as a fulcrum, The structure is formed by the elastic anti-addition force in the in-diameter direction generated by the elastic compression deformation of the protrusion.