FR2512913A1 - ROTATING SEAL - Google Patents

Abstract

THIS ROTARY GASKET INCLUDES INTERNAL AND EXTERNAL SHELLS12, 13 WHICH HAVE IN SECTION A SHAPE ABOUT L-SHAPED AND WHICH FIX BETWEEN THEIR LEGS17,19 A WATERPROOFING ELEMENT20 IN P.T.F.E. AND A FRICTION WASHER 15. ON THE EXTERNAL SURFACE OF THE EXTERNAL SHELL12 IS DEPOSITED A LAYER11 OF AN ELASTIC MATERIAL WHICH MAY EXTEND RADIALLY INTO THE INTERIOR ON THE TONGUE EXTENDING RADIALLY FROM THE SHELL12 AND MAY END WITH A SECONDARY SEALING LEVER21.

Description

The present invention relates to seals

  rotary which include uti element of sealing in poly-

  tetrafluoroethylene (which will be designated hereinafter by

the abbreviation P T F E).

  Rotary seals comprising a PTPE sealing element are well known and usually comprise a metal shell having an external diameter which is either finished by grinding to a predetermined size or has a sealing agent applied to it These forms of finish

  are acceptable for those applications in the-

  which boxes are used, in which the seal is pressed, and whose construction is bulky or robust. Problems arise when seals need to be fitted in thin-walled enclosures, especially in aluminum or aluminum alloy enclosures or when the enclosure is divided

  in two parts so that it can be assembled and disassembled.

  The subject of the invention is a seal

  rotary tee comprising an outer shell, an inner shell, a PTFE sealing member having a radially extending portion which is fixed between portions of the radially extending inner and outer shells, and a layer of elastic material linked

  to the outer surface of the outer shell.

  Other features and benefits of

  the invention will appear during the description which

  will follow made with reference to the accompanying drawings in which the five Figs each show a sectional view

  radial of a rotary seal according to the invention

  tion. The seal shown in FIG. 1 comprises an external annular shell 12 having roughly

  near in section an L shape and on a leg extends

  radially 17 of which are mounted a friction element or washer 15: and a portion 18 extending radially of a sealing element 14 made of PTP E. The washer 15 and the sealing element 14 are fixed in place by means of an internal annular shell 13 having an L-shaped cross section and a tab 19

  extending radially covers the portion 18 of the element

  seal and is applied towards the tab 17 of the external shell by the upper part of a radial tab of the external element 12, which is bent the function of the friction washer 15 is simply to prevent the element seal to rotate in the shell, and prevent leakage through the parts

internal joints.

  The sealing element 14 is in itself conventional and comprises a sealing lip 20 which is adapted to come into contact and ensure sealing

  with a rotating shaft passing through the joint.

  On the outer surface of the outer shell

  12 is deposited a layer of an elastic material 11 which is linked to the shell 12 and which can be compressed and thus absorb the misalignments which can occur in the divided housings, thus protecting

  the shells against any deformation.

  Suitable characteristic materials are well known elastomer rubbers such as nitrile, polyacrylic rubbers and elastomers,

  silicones or fluorocarbon rubber.

  The embodiment represented in lig 2 is similar to that of FIG. 1, the same references being used to designate the similar elements, but in this example the elastic layer is also deposited on the external surface of the tab 17 of the shell. external and extends radially inward

  so as to form a secondary sealing lip 21.

  The embodiment of Pig 3 is very similar to

  that of Fig 2 except that the sealing lip is

  condaire 21 has a different shape.

  The difference between the embodiment of Fig 4 and that of Fig l is that a secondary sealing lip 22 is formed by a second sealing element 26 made of PTFE which also has a portion 24 extending radially which is fixed between the tabs 17 and 19 of the shells In a particular way, the portion 24 is sandwiched between the portion 18 of the sealing element 14 and the

washer 15.

  In the embodiments of Fig l to 4,

  the elastic layer 11 has a ribbed external surface, but these layers can also have

  a smooth outer surface as shown in Fig 5.

  The embodiment of Fig 5 also differs

  of previous embodiments in that the cost of

  che ll is provided with a collar 30 extending radially-

  outwardly, and also in that the friction washer is integral with the layer il and its

  secondary sealing lip 21.

Claims (5)

REVENIDI CATI ONS   1 rotary seal characterized   in that it comprises an outer shell 12, a co-   internal part 13, a sealing element 14 in P T P E. comprising a portion 18 extending radially fixed between parts of the internal and external shells   which extend radially, and a layer 11 of a ma-   elastic third linked to the outer surface of the shell external 12.   2 rotary seal according to claim 1, characterized in that it comprises a   friction member 15 which is also fixed between the   said parts 17, 19 extending radially from the shells internal and external 12, 13.   3 Rotary seal according to one   any of claims 1 or 2, characterized in   that the layer of elastic material 11 extends radially   inwardly on the surface of part 17   extending radially from the outer shell 12.   4 Rotary seal according to   claim 3, characterized in that the layer of ma-   elastic face 11 has a sealing lip 21 coming of matter.   Rotary seal according to   claim 3 when dependent on the claim   cation 2, characterized in that the friction member 15   is integral with the layer 11 of elastic material.   6 Rotary seal according to one   The one of claims 1 to 3, characterized in that   that it comprises a second sealing element 26 fixed between the parts 17, 19 extending radially from the shells.