(19)
(11)EP 0 139 503 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
14.06.1989 Bulletin 1989/24

(21)Application number: 84306775.2

(22)Date of filing:  04.10.1984
(51)International Patent Classification (IPC)4F16J 15/32

(54)

Fluid sealing structure

Flüssigkeitsdichtung

Garniture pour fluide


(84)Designated Contracting States:
AT BE CH DE FR GB IT LI NL SE

(30)Priority: 06.10.1983 GB 8326706

(43)Date of publication of application:
02.05.1985 Bulletin 1985/18

(73)Proprietor: GEORGE ANGUS & COMPANY LIMITED
Newcastle upon Tyne NE99 1TG (GB)

(72)Inventors:
  • Johnston, David Ernest
    Gosforth Newcastle upon Tyne NE3 1PQ (GB)
  • Lopes, Rui de Jesus
    North Shields Tyne and Wear NE29 7NL (GB)

(74)Representative: Weston, Robert Dale et al
c/o PHILLIPS & LEIGH 7 Staple Inn High Holborn
London WC1V 7QF
London WC1V 7QF (GB)


(56)References cited: : 
DE-B- 2 736 207
US-A- 3 053 542
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] This invention relates to a fluid sealing structure for mechanism, such as an automobile engine, in which a relatively movable part, for example a main driving shaft or an auxiliary shaft, passes through a casing such as a crankcase end cover, and must be sealed against leakage of fluid, usually oil.

    [0002] Seals for this purpose, commonly called oil seals, are basically rings of elastomeric material which make a wiping seal contact, by an inner periphery, with the shaft or other member to be sealed and a static seal, by an outer periphery, in a housing recess or other seat in the component in which they are mounted.

    [0003] The static seal of an oil seal in its housing seat is usually an interference fit. Seals may be metal- cased, often with a coating of sealant, or may have an outer peripheral holding portion of elastomeric material; document DE-B-2 736 207 discloses an example of such a conventional oil seal. In either case, an oil seal must be very carefully installed so as to establish a static seal in its seat and a wiping seal with the sealed shaft or other member, without damage to any of the sealed or sealing surfaces. This requires experience, skill and care so as to establish simultaneously the wiping seal at the inner periphery and the static seal at the outer periphery of the sealing ring.

    [0004] It has been proposed, in United States Patent Specification No. 3053542, to provide a crankcase end cover for an internal combustion engine having a crankcase 10 and a crankshaft 14 therein, an end portion 17 of the crankshaft protruding through an aperture in the end of the crankcase, the aperture being covered by an end plate 11 that is bolted to the crankcase, wherein a shaft seal 20 sealing engages the crankshaft end portion and is replaceably housed in the end plate.

    [0005] In semi-skilled, and even automated, assembly of mechanisms, for example engines or motors, the positioning of such casing components as closing plates and covers, and securing them by such means as screws or nuts on studs, is a straight-forward operation which can be reliably performed.

    [0006] The present invention enables a corresponding, simple and reliable, operation to be employed in the installation of oil seals with consequent reliability as well as economy.

    [0007] We have realised that casing components which are substantially unstressed, so that they do not carry working loads and are therefore not liable to distortion on assembly or in use, and which are used for the housing of fluid seals, are suitable for pre-assembly with seals, prior to the casings of which they form part.

    [0008] To be of value, such pre-assembly must be reliable, in terms of accurate location in the casing component and avoidance of damage to the seal. The usual method of press-fitting seals in casing components, as a pre-assembly operation, would only transfer to a pre-assembly stage the problems of press-fitting seals in casing components already installed.

    [0009] Document EP-B-120 123, published 3rd October 1984 and therefore to be considered solely under the provisions of Article 54(3), discloses in claim 1 thereof:-

    [0010] "Sealing cover, especially for sealing the opening of a housing equipped with a shaft or rod, comprising a profiled body, if appropriate containing through bolt holes, with a dynamic sealing region running concentrically with the shaft or rod and at least one essentially planar region resting in another plane according to the contour of the housing, wherein both sealing regions possess sealing elements, characterised by the fact that the sealing elements consist of rubber profiles vulcanised to the cover body and connected together by means of additional partition elements."

    [0011] According to the present invention, a cover and seal unit for a machine, has an end portion of a rotary shaft protruding through an aperture in a casing, a cover for the casing aperture bolted or similarly attached to the casing and a shaft seal housed in the cover and sealingly engaging the shaft end portion, wherein the cover has an integral flange inwardly projecting around an aperture in the cover such that the inner rim of the flange surrounds the shaft end portion and the shaft seal an incorporated oil seal accurately on to the shaft or other member to be sealed.

    [0012] The invention is illustrated by way of example on the accompanying drawings, in which:-

    Fig. 1 is a half-plan, or axial, view of a simple circular casing end cover with an oil seal incorporated in accordance with the invention,

    Fig. 2 is an axial-radial section of the casing end cover of Fig. 1,

    Fig. 3 is an axial-radial section, on the line III-III of Fig. 4 which is an end elevation on a smaller scale, of an alternative construction of a crankcase end cover incorporating an oil seal.



    [0013] As shown by Figs. 1 and 2, a casing end cover consists of a moulded plastics ring 1 having an outer peripheral flange 2 with stud holes 3 for mounting on studs of a mechanism casing.

    [0014] In use, a shaft extends through the aperture of the casing end cover and, to provide an annular seat for an oil seal, the cover 1 at its inner periphery is moulded integrally with an inwardly directed peripheral radial flange 4. Moulded in situ on to the flange 4 is a holding portion 5 of an oil seal ring 6, moulded from an oil-resistant synthetic rubber or like elastomer, with a sealing lip 7, a garter spring 8 and a dust lip 9. The form of the oil seal ring as shown is only illustrative and any form of moulded oil seal ring can be used.

    [0015] In an alternative construction shown by Fig. 3, an engine crankcase end cover consists of a moulded plastics plate 10 with a central ring 11, buttressed by webs 12 is an elastomeric sealing ring moulded directly onto and around the inner rim of the flange with no other connection to the cover; the cover and sealing ring forming a single replaceable unit.

    [0016] Thus a cover and seal unit according to the present invention has no part corresponding to the "additional partition elements (18)" of Document EP-A-120 123; which elements are consistently described throughout Document EP-A-120 123 as being essential features of the claimed sealing cover.

    [0017] In a preferred construction, the cover is a preformed component itself moulded of plastics material.

    [0018] The invention thus provides, for the installation or replacement of oil seals, or other fluid seals, instead of an oil seal to be carefully fitted into a seat in a component, a composite seal and cover unit itself incorporating the oil seal, or seals, for relatively simple assembly with the mechanism to be sealed.

    [0019] Given the dimensional tolerance standards commonly achieved in quantity mechanical production, the positive location on installation of a cover, such as a crankcase end cover having marginal holes to fit on to mounting studs, can be relied upon to present at angularly spaced intervals, and stud-mounting holes 13.

    [0020] To provide for an annular seal seat around its central ring aperture, the plate 10 is formed with an inner circumferential recess 14 in which the axial flange 15 of an L-section metal ring 15,16 is set and moulded in place by an oil-resistant rubber filling 17. Although made as a sub-component, the metal ring 15,16 becomes an integral part ofthe plate 10.

    [0021] The flange 16 thus forms an integral part of the end cover plate 10 on to which is moulded the holding portion 5 of an oil seal ring otherwise corresponding to that of Figs. 1 and 2.

    [0022] The construction illustrated by Fig. 3 enables alternative production methods to be used.

    [0023] The plastics end cover plate 10 may be assembled with the L-section metal ring already moulded in the recess 14, by the rubber filling 17, and then the oil seal ring is moulded in situ.

    [0024] Alternatively the oil seal ring first may be moulded on to the flange 16 of the L-section metal ring and then the metal ring may be assembled with the end cover and moulded in place in the ring 10 by the rubber filling 17.

    [0025] In either case, the L-section metal ring eventually constitutes an integral part of the end cover and enables accurate and permanent assembly of the end cover and the oil seal ring to be effected before the end cover is installed on an engine.

    [0026] The rubber filling 17 may, according to its hardness, provide a resilient bed for the L-section metal ring and thus for the oil seal ring, permitting some yielding to accommodate for sealed shaft alignment or eccentricity.

    [0027] Also, the rubberfilling 17 is shown extending as a cushion facing 18 round the bend of the ring 11 and over the outer end surface of the cover plate 10. This provides for static sealing and, if desired, some degree of resilience in the fitting of the end cover on to the crankcase.

    [0028] Although the invention is particularly advantageous for use with a casing component moulded from plastics material, it could be used with other casing components, in particular pressed sheet metal components or die-cast metal components.


    Claims

    1. A cover and seal unit for a machine, having an end portion of a rotary shaft protruding through an aperture in a casing, a cover (1, 2 or 10,11) for the casing aperture being bolted or similarly attached to the casing and a shaft seal being housed in the cover and sealingly engaging the shaft end portion characterised in that the cover (1, 2 or 10, 11) has an integral flange (4 or 16) inwardly projecting around an aperture in the cover such that the inner rim of the flange surrounds the shaft end portion and the shaft seal is an elastomeric sealing ring (6) moulded directly onto and around the inner rim of the flange with no other connection to the cover; the cover and sealing ring forming a single replaceable unit.
     
    2. A unit as claimed in Claim 1 and further characterised in that the cover (1, 2 or 10, 11) itself is a preformed component moulded of plastics material.
     
    3. A unit as claimed in Claim 1 or Claim 2 and further characterised in that the flange (16) onto which the sealing ring (9) is directly moulded is part of a sub-component (15) of the cover and onto which the sealing ring is moulded before or after assembly and moulding of the sub-component with the cover so that the flange forms an integral part of the cover.
     
    4. A unit as claimed in Claim 3 and further characterised in that the sub-component (15) is an L-section metal ring.
     
    5. A unit as claimed in any of Claims 1 to 4 and further characterised in that the cover is a crankcase end cover.
     


    Ansprüche

    1. Eine Abdeck- und Dichteinheit für eine Maschine mit einem durch eine Öffnung in einem Gehäuse vorstehenden Endteil einer Drehwelle, wobei eine Abdeckung (1, 2 oder 10, 11) für die Gehäuseöffnung am Gehäuse angeschraubt oder auf ähnliche Weise angebracht ist, und eine Wellendichtung in der Abdeckung untergebracht ist und mit dem Wellenendteil in dichtendem Eingriff steht, dadurch gekennzeichnet, daß die Abdekkung (1, 2 oder 10, 11) einen damit integralen Flansch (4 oder 16) aufweist, der rund um die Öffnung in der Abdeckung nach innen vorspringt, so daß der innere Rand des Flansches den Wellenendteil umgibt, und die Wellendichtung ein elastomerer Dichtring (6) ist, der direkt, ohne eine andere Verbindung mit der Abdeckung, auf und um den inneren Rand des Flansches geformt ist; wobei die Abdeckung und der Dichtring eine einzige austauschbare Einheit bilden.
     
    2. Einheit nach Anspruch 1, dadurch gekennzeichnet, daß die Abdeckung (1, 2 oder 10, 11) selbst ein vorgeformter Bauteil ist, der aus Kunststoffmaterial geformt ist.
     
    3. Einheit nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Flansch (16), auf dem der Dichtring (9) direkt angeformt ist, Teil eines Unter-Bauteiles (15) der Abdeckung ist, an dem der Dichtring vor oder nach dem Zusammenbauen und Formen des Unter-Bauteiles mit der Abdeckung angeformt wird, so daß der Flansch einen integralen Teil der Abdeckung bildet.
     
    4. Einheit nach Anspruch 3, dadurch gekennzeichnet, daß der Unter-Bauteil (15) ein im Schnitt L-förmiger Metallring ist.
     
    5. Einheit nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß die Abdeckung ein Kurbelgehäuseschild ist.
     


    Revendications

    1. Ensemble de couvercle et de joint d'étanchéité pour une machine, ayant une portion terminale d'un arbre tournant dépassant à travers une ouverture dans un carter, un couvercle (1, 2 ou 10, 11) pour l'ouverture de carter boulonné ou fixé de façon similaire sur le carter, un joint d'étanchéité d'huile étant logé dans le couvercle et coopérant de façon étanche avec la portion terminale de l'arbre, caractérisé en ce que le couvercle (1, 2 ou 10, 11) a une collerette d'un seul tenant (4 ou 16) se projetant vers l'intérieur autour d'une ouverture dans le couvercle, de façon que le bord intérieur de la collerette entoure la portion terminale de l'arbre et en ce que le joint d'étanchéité d'arbre est un anneau d'étanchéité élastomère (6) moulé directement sur le bord intérieur de la collerette et autour de celui-ci sans autre liaison avec le couvercle, le couvercle et l'anneau d'étanchéité formant un seul ensemble amovible.
     
    2. Ensemble selon la revendication 1, caractérisé en ce que le couvercle (1, 2 ou 10, 11) est lui- même un composant pré-formé moulé en matière plastique.
     
    3. Ensemble selon la revendication 1 ou la revendication 2, caractérisé en ce que la collerette (10) sur laquelle est directement moulé l'anneau d'étanchéité (9) fait partie d'un sous-composant (15) du couvercle, l'anneau d'étanchéité étant moulé sur la collerette avant ou après assemblage et moulage du sous-composant avec le couvercle de façon que la collerette fasse partie intégrante du couvercle.
     
    4. Ensemble selon la revendication 3, caractérisé en ce que le sous-composant (15) est un anneau métallique à section en L.
     
    5. Ensemble selon l'une des revendications 1 à 4, caractérisé en ce que le couvercle est un couvercle terminal de carter moteur.
     




    Drawing