JP2006071058A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device 10 capable of preventing slide of an elastic ring 2 and a bottom face 112a of an annular channel 112 to provide stable sealing property for a long time. <P>SOLUTION: This sealing device 10 is stored in the annular channel 112 formed on an inner peripheral face of a shaft hole of a housing 110. This sealing device is provided with a seal ring 1 coming into close-contact with an outer peripheral face 121 of a rotary shaft 120 inserted into the inner periphery of the housing 110 concentrically and rotatably so as to slide and made of low friction resin and the elastic ring 2 made of a rubber-like elastic material fitted in the seal ring 1 in a condition in which it is polymerized in the radial direction. A seal protruding bar 22 extending in the circumferential direction and many projections 23 formed at a predetermined interval in the circumferential direction are provided on an outer peripheral face of the elastic ring 2. These seal protruding bar 22 and projections 23 are brought into pressure-contact with the bottom face 112a of the annular channel 112 with proper crushing allowance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sealing device for sealing a rotating part of an apparatus, and more particularly to a sealing device in which a seal ring made of a low friction resin material is supported by an elastic ring made of a rubber-like elastic material.

2. Description of the Related Art Conventionally, as a sealing device that seals a rotating shaft that rotates at a low speed, for example, at a bearing portion of a continuous casting machine, a device disclosed in Patent Document 1 below is known.
JP 60-84478 A

  FIG. 3 is a cross-sectional view of the conventional sealing device described in Patent Document 1 in a mounted state by cutting along a plane passing through the axis thereof. Reference numeral 110 denotes a housing, and 120 denotes a shaft hole 111 of the housing 110. The rotating shaft is inserted and supported concentrically and rotatably by a bearing (not shown). On the inner peripheral surface of the shaft hole of the housing 110, an annular groove 112 having a rectangular cross section cut by a plane passing through the shaft center is formed, and the sealing device 100 is attached to the annular groove 112.

  The sealing device 100 includes a seal ring 101 made of a low friction synthetic resin material such as PTFE (polytetrafluoroethylene) and an elastic ring 102 made of a rubber-like elastic material. The seal ring 101 is in close contact with the outer peripheral surface 121 of the rotating shaft 120 so that the inner peripheral surface 101a is slidable, and the elastic ring 102 is in a state where the inner peripheral surface 102a is overlapped with the outer peripheral surface 101b of the seal ring 101 in the radial direction. A plurality of seal ridges 102 b that are closely fitted and circumferentially continuous are formed on the outer peripheral surface, and these seal ridges 102 b are appropriately crushed on the bottom surface 112 a of the annular groove 112 of the housing 110. It is pressed with a generation. With such a configuration, the shaft circumferential gap G between the housing 110 and the rotating shaft 120 is sealed, and leakage of fluid on the bearing side and intrusion of dust from the outside to the bearing are prevented.

  However, according to the conventional sealing device 100, the inner peripheral surface 101a of the seal ring 101 is originally slidably contacted with the outer peripheral surface 121 of the rotating shaft 120, but is formed on the outer peripheral surface of the elastic ring 102. Since the seal protrusion 102b extends in the circumferential direction, in other words, extends in the direction of the rotational force transmitted from the seal ring 101 as it slides on the rotation shaft 120, it is formed in the housing 110. The frictional force of the elastic ring 102 against the bottom surface 112a of the annular groove 112 is relatively small. For this reason, the elastic ring 102 may slide with the bottom surface 112a of the annular groove 112 due to the rotational force, particularly under the condition of low speed rotation such as in a continuous casting machine. In this case, the seal ridge 102b is worn. Therefore, there is a concern that the pressing force in the radial direction against the seal ring 101 is reduced and the sealing performance is deteriorated at an early stage.

  The present invention has been made in view of the above points, and its technical problem is that sliding between the elastic ring and the bottom surface of the annular groove can be prevented, and stable sealing performance can be achieved over a long period of time. It is to provide a sealing device.

  As a means for effectively solving the technical problem described above, the sealing device according to the invention of claim 1 includes a circumferential member and an inner circumferential member, which are arranged concentrically and relatively rotatably with each other. A sealing device housed in an annular groove formed in one of the seal rings, and a seal ring made of a low friction resin slidably in contact with the other of the opposed peripheral surfaces, and a radial direction in the seal ring An elastic ring made of a rubber-like elastic material fitted in a polymerized state, and a seal protrusion extending in the circumferential direction on a surface opposite to the seal ring in the elastic ring, and a predetermined interval in the circumferential direction The seal protrusions and protrusions are pressed against the bottom surface of the annular groove with an appropriate crushing allowance.

  In this configuration, the elastic ring is pressed against the bottom surface of the annular groove formed in one of the outer peripheral member and the inner peripheral member, and the seal ring is slidably contacted with the other peripheral surface of the outer peripheral member and the inner peripheral member. The seal ring performs a sealing sliding function with the other peripheral surface. The seal ridges extending in the circumferential direction formed on the surface of the elastic ring opposite to the seal ring improve the sealing performance with the bottom surface of the annular groove, and are formed at predetermined intervals in the circumferential direction. The large number of protrusions increases the friction torque with the bottom surface of the annular groove to prevent relative rotation of the elastic ring with respect to the annular groove.

  According to the sealing device of the present invention, since the frictional force of the elastic ring against the bottom surface of the annular groove increases, it is possible to effectively prevent the elastic ring from sliding on the bottom surface of the annular groove by the rotational force transmitted from the seal ring. In addition, stable sealing performance can be achieved over a long period of time.

  Hereinafter, preferred embodiments of a sealing device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a preferred embodiment of a sealing device according to the present invention cut along a plane passing through the axis thereof, and FIG. 2 is a sectional view taken along the line II-II ′ in FIG. FIG.

  1 and 2, reference numeral 110 is a housing in the vicinity of a bearing in a continuous casting machine, for example, 120 is a rotating shaft that is inserted through a shaft hole 111 of the housing 110 and is supported concentrically and rotatably by a bearing (not shown). is there. An annular groove 112 having a rectangular cross section cut by a plane passing through the shaft center is formed on the inner peripheral surface of the shaft hole of the housing 110, and the sealing device 10 according to the present invention is attached to the annular groove 112. ing. The housing 110 corresponds to the outer peripheral member described in claim 1, and the rotating shaft 120 corresponds to the inner peripheral member described in claim 1.

  The sealing device 10 according to this embodiment includes a seal ring 1 made of a low friction synthetic resin material such as PTFE (polytetrafluoroethylene) having a low friction coefficient and excellent wear resistance, and an elastic ring 2 made of a rubber-like elastic material. It consists of. The seal ring 1 has a cylindrical inner peripheral surface 11 having a smaller diameter than the shaft hole 111 of the housing 110 and is slidably in close contact with the outer peripheral surface 121 of the rotating shaft 120. In a state where the peripheral surface 21 is overlapped with the outer peripheral surface 12 of the seal ring 1 in the radial direction, the peripheral surface 21 is closely fitted with an appropriate surface pressure.

  On the outer peripheral surface of the elastic ring 2, a pair of seal protrusions 22 are formed in the vicinity of both ends in the axial direction and continuous in the circumferential direction. The outer diameter of the seal protrusion 22 is appropriately larger than the bottom surface 112a of the annular groove 112 of the housing 110 in a free state (unmounted state).

  Further, a large number of protrusions 23 extending in the axial direction, that is, in a direction orthogonal to the circumferential direction, are formed between the seal protrusions 22 and 22 at a constant pitch in the circumferential direction. The outer peripheral surface of the elastic ring 2 corresponds to the “surface opposite to the seal ring” described in claim 1. As shown in FIG. 2, each of the protrusions 23 has a mountain shape and is formed at the same height as the seal protrusion 22.

  Since the sealing device 10 according to this embodiment has the above-described configuration, in the illustrated mounting state, the elastic ring 2 made of a rubber-like elastic material has a diameter between the seal ring 1 and the bottom surface 112a of the annular groove 112. The outer peripheral seal protrusions 22 and 22 and the multiple protrusions 23 are brought into close contact with the bottom surface 112a of the annular groove 112 of the housing 110 while being appropriately crushed by the reaction force. A sealing force is applied to the seal ring 1, and the inner peripheral surface 11 of the seal ring 1 is slidably brought into close contact with the outer peripheral surface 121 of the rotating shaft 120. Accordingly, the shaft circumferential gap G between the housing 110 and the rotating shaft 120 is sealed, and leakage of fluid on the bearing side and intrusion of dust from the outside to the bearing are prevented.

  Although the seal ring 1 is made of a low friction synthetic resin material, the rotational force applied to the seal ring 1 due to sliding resistance may increase depending on the rotation conditions of the rotary shaft 120 and the like. However, according to this sealing device 10, a large number of chevron projections 23 formed on the outer peripheral surface of the elastic ring 2 at equal pitches in the circumferential direction are in pressure contact with the bottom surface 112 a of the annular groove 112 with an appropriate crushing margin. The friction torque with respect to the bottom surface 112a is sufficiently large. Therefore, it is possible to effectively prevent the elastic ring 2 from rotating relative to the housing 110 due to the rotational force transmitted from the seal ring 1. can do. Accordingly, the outer peripheral surface of the elastic ring 2 does not slide and wear with the bottom surface 112a of the annular groove 112, and the radial pressing force on the seal ring 1 is reduced, resulting in early deterioration of the sealing performance. Can be prevented.

  It should be noted that the above-described embodiment is opposite to the inner and outer circumferences, that is, an elastic ring on the inner circumferential side and a seal ring on the outer circumferential side are arranged in an annular groove formed on the outer circumferential surface of the rotating shaft (inner circumferential member). As a positional relationship, the present invention can also be applied to a sealing device that slidably contacts the outer peripheral surface of the seal ring with the inner peripheral surface of the housing. In this case, the seal protrusion and the protrusion are formed on the inner peripheral surface of the elastic ring.

It is sectional drawing of the mounting state which cut | disconnects and shows preferable embodiment of the sealing device which concerns on this invention by the plane which passes the axial center. FIG. 2 is a half cross-sectional view cut along a plane orthogonal to the axis at the position II-II ′ in FIG. 1. It is sectional drawing of the mounting state which shows the conventional sealing device cut | disconnected and shown by the plane which passes along the axial center.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seal ring 11, 21 Inner peripheral surface 12, 121 Outer peripheral surface 2 Elastic ring 22 Seal protrusion 23 Protrusion 10 Sealing device 110 Housing (outer peripheral member)
111 Shaft hole 112 Annular groove 112a Bottom surface 120 Rotating shaft (inner peripheral member)

Claims (1)

  The sealing device is housed in an annular groove (112) formed on one of the opposing peripheral surfaces of the outer peripheral member (110) and the inner peripheral member (120) arranged concentrically and relatively rotatably. A seal ring (1) made of a low friction resin that is slidably brought into close contact with the other of the opposed peripheral surfaces, and a rubber-like shape fitted to the seal ring (1) in a state of being polymerized in the radial direction An elastic ring (2) made of an elastic material, a seal protrusion (22) extending in a circumferential direction on a surface of the elastic ring (2) opposite to the seal ring (1), and a predetermined circumferential direction It has a number of protrusions (23) formed at intervals, and these seal protrusions (22) and protrusions (23) are pressed against the bottom surface (112a) of the annular groove (112) with an appropriate crushing allowance. Sealing device characterized.

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