DE2444792A1 - LIP SEAL RING, IN PARTICULAR FOR VALVE STEM GUIDES - Google Patents

Description

GOETZEWERKE Burscheid, d. September 9, 1974

Friedrich Goetze AG ZBT 329 / We / Mon. (1511)

Lip sealing ring, in particular for valve stem guides

The invention relates to a lip sealing ring made of rubber-elastic Material, in particular for sealing and metered lubrication of valve stem guides, consisting of one the end of the valve stem guide slide-on holding part with a vulcanized, one bent radially outward Mounting flange, metallic stiffening ring and a spring-loaded sealing lip integrally connected to the holding part.

For sealing valve stems in internal combustion engines are Sealing rings made of rubber-elastic material known, which according to the DT - utility model 1. 871. o39 from a on the End of a valve stem guide push-on holding part and an oil control ring resting on the valve stem surface. A metallic stiffening ring is in the holding part vulcanized with a mounting flange bent radially outwards. For the valve stem seal, see

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the DT utility model 6,600. 458 is instead of the oil control ring a spring-loaded sealing lip is provided and integrally connected to the holding part. In support of the A helical tension spring washer inserted into an outer circumferential groove of the sealing lip serves the radial force of the sealing lip.

Another type of valve stem is disclosed in US Pat. No. 3,625,525 Tab seal previously known, which consists essentially of a metallic holding part. For sealing the valve stem guide A relatively thin rubber washer is used, which is attached to the valve stem by means of resilient tongues of the metal part tguide is pressed. The resilient tongues are lengthened accordingly through axial incisions Holding part formed. Such a design of a valve stem seal has the disadvantage that special precautions must be taken on the metal part in order to ensure a sufficiently good adhesive fit on or in the valve guide end to ensure. In addition, the relatively thin rubber washer is in contact with the valve stem surface quickly worn out as a result of frictional stress.

In the case of spring elements acting on the sealing lip from the outside, malfunctions often occur after a long period of operation if there is a

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spring washer or the resilient tongues of a metal sleeve Deposit dirt particles from the medium to be sealed and thus hinder the mobility of the spring parts. It also happens that separate helical tension spring washers before assembly, during assembly or during the later Jump off the sealing lip of the valve stem seal during operation. Another problem is that lip sealing rings, in particular used as valve stem seals have to perform a double function with opposing effects. On the one hand, the oil space is to be sealed off from the gas space, and on the other hand, there must be sufficient lubrication of the valve stem which is reciprocated in the valve guide to be guaranteed. Various proposals have already become known for metered lubrication bring a defined leakage of the sealing ring with it.

The invention is based on the object of the function of the lip seal ring by fully embedding the To improve the spring element in the rubber material of the sealing lip and at the same time the production of such To simplify the sealing ring by using a different spring element without having to rely on the previous To have to do without assembly facilitation.

The object is achieved in that the

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axially extending into the sealing lip stiffening ring is divided in a known manner by axial incisions in individual, radially resilient tongues, of which distributed on the circumference several are shortened and bent radially outward. Due to the special design of the stiffening ring, the use of an additional helical tension spring washer for pressing the sealing lip can be dispensed with without losing the ability of an assembly tool to attack the seal. Another advantage is the position of the assembly tongues on the sealing lip side, so that the assembly tool does not have to be pushed over the entire axial length of the sealing ring. For the function of the sealing ring, the complete vulcanization of the stiffening ring with the resilient tongues that reinforce the sealing pressure is important, since no carbon or other dirt particles of the medium to be sealed are now deposited in the outwardly open spaces of the sealing lip - spring element and thus the suspension can affect. The production of the combined stiffening and spring ring proposed according to the invention is particularly simple in that the metal part can be made from a piece of pipe that has been cut to length .

By slightly plastic deformation of the resilient tongues

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the radial spring force of the sealing lip can also be changed after the sealing ring has been completed. In order to a targeted leak that can be individually tailored to the application in order to achieve the necessary lubricating effect is possible.

In the further embodiment of the subject matter of the invention, it is proposed that every second tongue is bent outwards, with a correspondingly high number of axial incisions, this results in a relatively even distribution of pressure in the sealing lip results. For this purpose, it is also conceivable for the width of the outwardly bent assembly tongues to be smaller than the width of the remaining resilient tongues to form around the circumferential points to be kept as small as possible with a lower radial pressure effect within the sealing lip. The scope of the Sealing lips with lower radial pressure can be used for a defined leak and thus for metered lubrication of the valve stem in the guide.

Another proposal consists in alternating the axial cuts in the stiffening ring which form the tongues to run differently obliquely to the seal axis, so that the tongues surfaces approximately trapezoidal circumference exhibit. In this case, those which become wider towards the end of the stiffening ring on the sealing lip side are preferably used Tongues for pressing the sealing lip while the

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between remaining, to be shortened and to be turned outwards Tongues in the bending area have their greatest width. For this purpose it is possible to move the resilient tongues at an angle as far as possible turn inside until the axial ends of the tongues almost touch. This is on the one hand a possible uniform pressure distribution achieved in the sealing lip and on the other hand the difference in the outer diameter between Valve stem guide and valve stem better balanced.

In addition, it is advantageous if the axial ends of the resilient tongues are also bent radially outwards, to counteract the cutting effect of the relatively sharp cutting edges of the tongue ends in the rubber material.

Finally, it is conceivable to curve the resilient tongues concavely or convexly in the axial direction and thus a certain one To exert an influence on the sealing and lubricating effect of the sealing lip.

Exemplary embodiments are shown in the drawing and are described in more detail below. Show it

Fig. 1 is a cross section through a

Valve stem guide with a mounted inventive

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moderate lip seal ring

2 and 3 each show a cross section of different ring profiles according to the invention Lip seals

Fig. 4 to 6 end-face parts - top views

on the stiffening rings of the sealing ring designs shown in FIGS. 1 to 3

In FIG. 1, the valve stem guide is denoted by 1 and the valve stem by 2. The end of the valve stem guide 1 has a paragraph 3, on which with the help of an assembly tool 4 indicated by dash-dotted lines, a lip seal ring 5 is postponed. The latter consists of a rubber body 6 with a vulcanized tubular Stiffening ring 7. While the lower half of the rubber body 6 is designated as the holding part 8, the upper half of the rubber body 6 forms the sealing lip 9. For radial The sealing lip 9 is pressed onto the valve stem surface, Io is the half of the stiffening ring 7 on the sealing lip side through several axial incisions 11 distributed around the circumference, cf. also FIG. 3, to individual resilient tongues 12 separated, with between two resilient tongues 12 one

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Tongue 13 shortened axially and radially outwards as an approach for the Assembly tool 4 is bent.

In the embodiment according to FIGS. 2 and 5, the resilient ones Tongues 14 angled inward so far that the front ends 15 of the tongues 14 almost touch.

In the embodiment according to FIGS. 3 and 6, the axial incisions 16 run in such a manner obliquely to the seal axis 17 that the peripheral surfaces 18, 19 of the resilient tongues 2o are trapezoidal with increasing width towards the end face 21. The resilient tongues 2o have a concave arched axial cross-section and are bent radially outward in the region of their front ends 22.

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Claims (6)

PATENT CLAIMS Lip sealing ring made of rubber-elastic material, especially for sealing and metered lubrication of valve stem guides, consisting of a holding part that can be pushed onto the end of the valve stem guide with a vulcanized metallic stiffening ring with a mounting flange bent radially outward and a spring-loaded sealing lip integrally connected to the holding part, characterized in that the stiffening ring (7) extended axially into the sealing lip (9) in a manner known per se by means of axial Incisions (11, 16) is divided into individual, radially resilient tongues (12, 14, 2o), of which distributed on the circumference several tongues (13) are shortened and bent radially outward. 2.) Lip sealing ring according to claim 1, characterized in that that the stiffening ring (7) consists of a piece of cut pipe. 609815/0523 -XQ ^ Page ji - Claims relating to "Lip seal ring, in particular for valve stem guides "(1511) 3.) Lip sealing ring according to claims 1 and 2, characterized in that every second tongue (13) is bent outwards. 4.) Lip sealing ring according to claims 1 to 3, characterized in that the width of the outwardly bent tongues (13) is less than the width of the resilient tongues (12, 14, 2o) is. 5.) Lip sealing ring according to claims 1 to 4, characterized in that the axial cuts (16) in the stiffening ring (7 ") run alternately at different angles to the sealing axis (17). 6.) Lip sealing ring according to claims 1 to 5, characterized in that the tongues (13), which are narrower at the end of the stiffening ring (7 "), are shortened and are bent outwards. 7.) Lip sealing ring according to claims 1 to 6, characterized in that the resilient tongues (14) are angled inwardly until the ends (15) of the tongues (14) almost touch. 6098 15/0523 -λ * Page 3 - Claims on "Lip sealing ring, especially for valve stem guides" (1511) 8.) Lip sealing ring according to claims 1 to 7, characterized in that the axial ends (22) of the resilient tongues (2o) are bent radially outwards are. 9.) Lip sealing ring according to claims 1 to 8, characterized in that the resilient tongues (2o) have a cross-section that is concave or convex in the axial direction. FRtEDF ICH GOETZE AKTIENGESELLSCHAFT 6 A No. 173/70 AV Vossieck 60981 5/0523