JP2996558B2 - Rotating seal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal used for a rotating shaft.

[0002]

2. Description of the Related Art Conventionally, rubber lip seals and mechanical seals have been used as seals for rotating shafts of compressors and the like.

[0003]

However, the rubber lip seal has a problem of incompatibility between the rubber material and the refrigerant due to the change of the refrigerant from R12 to R134a due to environmental problems, and the pressure of the refrigerant dissolved in the rubber is high. -There was a problem of blisters that occurred due to insufficient tracking of temperature changes. In addition, since the sealing performance is limited, the pressure of the fluid will increase in the future use atmosphere (4 kgf /
cm Te is at the severe conditions associated with ² or more) and the rotation axis speed of (above 6000 rpm), it is impossible to obtain sufficient sealing property there is a problem to be unusable.

[0004] In addition, the mechanical seal has problems that the seal space is large because it is not compact, is expensive, has a lot of gas leaks, and has poor sealing performance against gas.

Accordingly, the present invention provides a rotary seal capable of obtaining sufficient sealing performance even when the pressure of the fluid is increased and the rotation speed of the rotating shaft is increased, and reliably sealing both gas and liquid fluids. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a flat annular sealing element for sealing a fluid to be sealed.
The seal element is bent in the axial direction toward the side , and the sealing element is brought into sliding contact with the outer peripheral surface of the rotating shaft member.
A rotary seal for sealing a fluid to be sealed , wherein two seal elements are provided side by side, and a plurality of concentric grooves are formed on a sliding surface side of one of the seal elements to form the fluid.
And a helical groove is formed on the sliding surface side of the other seal element, and the helical groove is formed on the gap side opposite to the fluid side.
It is arranged .

[0007]

In one seal element, the concentric grooves increase the contact surface pressure of the seal element with the rotating shaft member, and can seal not only liquid but also gas, and in the other seal element, The liquid that has entered can be pushed back to the fluid side by the rotational flow generated by the rotational force of the spiral groove and the shaft member, and the liquid can be sealed.

By arranging the two seal elements in parallel, the sealing performance is greatly improved, and the leakage of the fluid can be reliably prevented even when the pressure of the fluid is increased and the rotation speed of the rotating shaft is increased.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments.

FIG. 1 shows a rotary seal according to the present invention. The rotary seal 1 is a housing 2 such as a case.
Rotating shaft member 3 fitted on the inner peripheral surface of
Slidably in contact with the outer peripheral surface 4 to seal the liquid or gaseous fluid R.

The rotating seal 1 includes a rubber gasket 6,
Two sealing elements 8a, 8b via a spacer 7
And the press fitting 9 are installed side by side in the annular fitting 5.

Reference numeral 10 denotes the inner peripheral surface of the housing 2 and the annular metal fitting 5.
Is a rubber sealant interposed between the rubber sealant and the outer peripheral surface.

The sealing elements 8a and 8b are molded from a fluorine-based resin such as ethylene tetrafluoride resin, and have a thin flat annular shape after molding, as shown in FIG.

Therefore, the inner diameter sides of the seal elements 8a and 8b are pressed in the axial direction by a taper shank (not shown) or the like, and are bent from the gap S side to the fluid R side as shown in FIG.

Therefore, when the rotary seal 1 is mounted, the sliding contact surfaces 11a, 11b of the seal elements 8a, 8b are provided.
Presses against the outer peripheral surface 4 of the rotating shaft member 3.

As shown in FIGS. 2 and 3, a plurality of concentric grooves M ₁ , M around the axis O of the seal element 8a are formed on the sliding surface 11a of one seal element 8a.
₂ ... it is unequally spaced pitch P _1, P ₂ ... a, are formed by cuts or the like.

Each of the concentric grooves M ₁ , M ₂ ... Has a pitch P from the inner diameter side to the outer diameter side of the seal element 8a.
₁ , P ₂ ... Every predetermined length {for example, 0.3 to 0.4 mm
Each time it becomes shorter.

The inner circumferential edge concentric grooves M ₁ and the (spacing) pitch P of the sealing element 8a ₀ is set longer by the predetermined length amount than the pitch P _1.

Each of the concentric grooves M ₁ , M ₂ ... Has a minute constant width, reaches a depth of approximately half the thickness of the seal element 8a, and is inclined with respect to the sliding contact surface 11a (for example, 40 °).
The inclination angle θ _{1 is up} to 50 °.

When the sliding contact surface 11a of the seal element 8a is pressed against the outer peripheral surface 4 of the rotary shaft member 3 as shown in FIG. 4, the concentric grooves M ₁ , M ₂ . Are expanded in an acute triangle shape, and the bottoms of the concentric grooves M ₁ , M _2, ... Are inclined from the fluid R side to the gap S side.

At this time, the contact surface pressure of the seal element 8a on the rotary shaft member 3 increases sharply from the fluid R side to the gap S side as the contact surface decreases, as shown in FIG. The intrusion of the fluid R into the S side is reliably prevented.

As shown in FIGS. 2 and 5, a helical groove H centered on the axis O of the seal element 8b is formed on the sliding contact surface 11b side of the other seal element 8b at an equal pitch L. … Is formed.

The spiral groove H has a minute constant width and reaches a depth almost half of the thickness of the seal element 8b.
Inclined angle to, for example, an inclination angle θ ₂ of 40 ° to 50 °
───. The rotation direction of the spiral groove H is formed in the same direction as the rotation direction of the rotation shaft member 3.

Then, as shown in FIG.
When the sliding contact surface 11b of FIG. 3b is pressed against the outer peripheral surface 4 of the rotary shaft member 3, the spiral groove H expands into an acute triangular cross section (similar to the seal element 8a shown in FIG. 3). When opened, the spiral groove H is inclined from the fluid R side to the gap S side.

At this time, even if the fluid R enters the helical groove H, the rotational force of the rotating shaft member 3 generates a swirling rotating flow due to the viscosity of the fluid R from the gap S side to the fluid R side. Pushing back and intrusion of the fluid R into the gap S side can be reliably prevented.

Using the seal of the present invention, Table 1
Tables 2 and 4 show experimental results comparing the sealing performance of the conventional rubber lip seal with the conventional rubber lip seal at the time of shaft rotation under the conditions of Table 3 and Table 3.

Further, under the conditions shown in Table 5, the sealing performance of the conventional dual type (in which a plain type not shown is used as the sealing element 8a of the seal of the present invention) and the seal of the present invention when the shaft is stationary are compared. Table 6 shows the experimental results.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

[Table 4]

[0032]

[Table 5]

[0033]

[Table 6]

Thus, oil (liquid) and gas (gas)
Leakage did not occur at all, and it became clear that the sealing performance was greatly improved for both gas and liquid fluids as compared with the conventional rubber lip seal and dual type.

FIG. 6 shows the concentric groove M in the embodiment of FIG.
_1, M ₂ ... pitch P ₀ of, P _1, shows the case of P ₂ ... a regular intervals, also, Figures 7 and 8, At a embodiment of FIG. 3, the inner diameter of the sealing element 8a , The concentric grooves M ₁ , M _2, ... Are eccentric and pressed against the rotating shaft member 3.

It should be noted that the present invention is not limited to the above-described embodiment, and the design can be freely changed without departing from the gist of the present invention. In the embodiment shown in FIG. It is also preferable that the sealing element 8b is gradually shortened by a predetermined length from the inner diameter side to the outer diameter side (as in the embodiment of FIG. 3).

In each embodiment, the inclination angles θ ₁ , θ
₂ , pitches P ₀ , P ₁ ..., L, and concentric grooves M ₁ , M ₂
... can be freely increased or decreased .

[0038]

Since the present invention is configured as described above, the following significant effects can be obtained.

Even under severe conditions that cannot be used with conventional rubber lip seals and are accompanied by high pressure of the fluid and high speed of the rotating shaft, it is necessary to surely prevent fluid leakage and obtain sufficient sealing performance. Can be.

Since the sealing performance is greatly improved with respect to both gas and liquid fluids, a highly reliable and excellent rotary seal can be provided.

The sealing performance can be reliably exhibited over a long period of time.
Moreover, it can be made compact and inexpensive.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing one embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view before bending a seal element.

FIG. 3 is a front view of a seal element in which concentric grooves are formed.

FIG. 4 is an operation explanatory view of a seal element.

FIG. 5 is a front view of a seal element in which a spiral groove is formed.

FIG. 6 is a front view showing another embodiment.

FIG. 7 is a front view showing another embodiment.

FIG. 8 is an enlarged sectional view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation seal 3 Rotating shaft member 4 Outer peripheral surface 8a Seal element 8b Seal element 11a Sliding contact surface 11b Sliding contact surface M Concentric groove H Spiral groove

Claims (1)

(57) [Claims] A flat annular sealing element is sealed with a fluid to be sealed.
The seal element is bent in the axial direction toward the side , and the sealing element is brought into sliding contact with the outer peripheral surface of the rotating shaft member.
A rotary seal for sealing a fluid to be sealed , wherein two seal elements are arranged side by side, and a plurality of concentric grooves are formed on a sliding surface side of one of the seal elements to form the fluid.
And a helical groove is formed on the sliding surface side of the other seal element, and the helical groove is formed on the gap side opposite to the fluid side.
Rotating seal, characterized in that disposed.