DE3326811A1 - Stem or shaft seal, in particular a valve-stem seal - Google Patents

Abstract

Valve-stem seal with an elastomeric seal sleeve comprising an adhering part and a sealing-lip part which has an inner sealing lip and with a metallic reinforcing sleeve which surrounds the adhering part secured on it, at its end facing the sealing-lip part has an end face which serves as a pressure surface and, at the other end, has an end face which serves as a stop surface. To achieve as small as possible a radial installation space, the reinforcing sleeve is bent inwards at its end facing away from the sealing-lip part to form an internal collar reaching under the seal sleeve and is otherwise of cylindrical design, and the internal collar forms the stop surface.

Description

HOEGERVSTELLRECHT & PARTNER

PATENT LAWYERS O 1 O Γ Ο 1

OO ΔΌΟ I!

UHLANDSTRASSe 14 c D 7000 STUTTGART 1

A 45 676 b Applicant: Elring Dichtungswerke GmbH b - 176 Höhenstraße 24

July 20, 1983 7012 Fellbach

Stem or shaft sealing, in particular valve stem sealing

The invention relates to a stem or shaft seal, in particular a valve stem seal an elastomer sealing sleeve made of an adhesive part and a sealing lip part having an inner sealing lip as well as with a metallic reinforcing sleeve that surrounds the adhesive part attached to it its end facing the sealing lip part has an end face serving as a pressing surface and at the other end has an end face serving as a stop surface.

Valve shaft seals of this type are known with its adhesive part surrounded by the reinforcing sleeve pushed onto the valve guide, the The inside diameter of the valve stem seal is matched to the outside diameter of the valve guide, that there is a press fit associated with a good seal. Sliding on the valve stem seal on the valve guide takes place with a tubular assembly stamp, which the metallic reinforcement sleeve overlaps and has an inner shoulder which is positioned against the end face serving as a pressing surface the reinforcement sleeve is applied. As a stop

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July 20, 1983

for the valve stem seal is provided by the valve guide an outer shoulder against which the other end face of the reinforcement sleeve, which serves as a stop surface, rests when the valve stem seal is finished is mounted.

A known valve stem seal of this type (DE-OS 32 22 356) has a reinforcing sleeve of graduated diameter, which is widened approximately in its central area so that the one facing the sealing lip The sleeve half has an inside or outside diameter that is approximately twice the wall thickness the sleeve is larger than the corresponding diameter of the sleeve half facing away from the sealing lip. Through this is intended to be an approach for the assembly stamp while taking up a relatively small radial installation space can be created without the risk of destroying the rubber-metal connection between the reinforcement sleeve and sealing sleeve when the valve stem seal is pressed onto the valve guide. This well-known However, the construction has two disadvantages: on the one hand, the expansion of the reinforcement sleeve leads to an increase in size the required radial installation space, and on the other hand, this valve shaft seal is for thin-walled Valve guides are not particularly suitable, since then the end face of the facing away from the sealing lip Reinforcement sleeve has a larger diameter than the valve guide and consequently no more than a stop surface can serve. The same applies to another known valve stem seal from the applicant, whose

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Reinforcement sleeve at its end facing the sealing lip to form one that interacts with the assembly punch The pressing surface is bent outwards, but otherwise has a strictly circular cylindrical design.

The invention was therefore based on the object of providing a shaft or shaft seal of the type mentioned at the beginning Kind of creating a smaller radial installation space than the known valve stem seals described above required and whose reinforcement sleeve also forms a reliable assembly stop, when the seal is pressed onto a thin-walled holder surrounding the shaft or shaft. This object can be achieved according to the invention in that the reinforcing sleeve on its part from the sealing lip opposite end bent inward to form an inner collar engaging under the elastomeric sealing sleeve and is otherwise cylindrical, the inner collar forming the stop surface. Such Sealing can therefore even then up to a stop on a seat in the form of an annular shoulder or the like having bracket can be pressed on like a valve guide, if the outer diameter of this Bracket is smaller than the outer diameter of the reinforcement sleeve, reduced by twice the wall thickness this reinforcement sleeve, so that neither a complicated control for the assembly punch when pressing The elastomeric sealing sleeve is still necessary to form the stop, as is the case in such a case the known valve stem described above

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A 45 676 b 3 3 2 6 8 1 Ί

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July 20, 1983

seals is the case, so that there is a high stress on the metal-rubber connection between elastomeric Sealing sleeve and metallic reinforcing sleeve can be avoided. When protruding from a cylindrical Training of the reinforcement sleeve is being discussed, this should not be understood to be exclusively circular-cylindrical because the cross-section of the reinforcement sleeve can also be oval or correspond to a polygon can. Appropriately, the reinforcement sleeve is on Transition of the adhesive part to the sealing lip part of the elastomer End of the sealing sleeve, as the outer diameter of the sealing lip part decreases from this point on, so that the assembly ram flawlessly against the sealing lip side End face of the reinforcing sleeve can be applied without the risk of damage to the elastomeric sealing sleeve.

Since the inside diameter of the elastomeric sealing sleeve when pressed onto the valve guide or a Another holder is expanded, a preferred embodiment of the seal according to the invention provides a approximately cylindrically shaped adhesive part of the elastomeric sealing sleeve, and the inner diameter of the The inner collar of the reinforcement sleeve is selected to be larger than the smallest inner diameter of the adhesive part, so that a collision between the inner collar and the circumferential surface of the valve guide cannot occur, and not even if the seal is not exactly aligned with the valve guide when it is pressed on.

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July 20, 1983

It is also recommended that the reinforcement sleeve have at least one, in particular bead-shaped, embossing and preferably to be provided with several, axially spaced annular beads, inwardly directed beads are particularly advantageous. These impressions act deformations of the Reinforcing sleeve during the injection or pressing in of the sealing sleeve forming the sealing sleeve under high pressure Elastomers counteract and also improve the connection between the reinforcement sleeve and the elastomer Sealing sleeve.

The invention preferably applied to valve stem seals with relatively small diameters is also advantageous for lip sealing rings of other types with similar dimensions and assembly problems with himself.

Further features, advantages and details of the invention emerge from the following description and the attached drawing of a preferred embodiment of an inventive Valve stem seal; the drawing shows an axial section through which is pressed onto a valve guide Valve stem seal with attached assembly stamp.

The drawing shows a valve stem 12 guided in a valve guide 10, one on the valve guide Pressed-on valve stem seal 14 made of an elastomer Sealing sleeve 16, a metallic reinforcement

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July 20, 1983

sleeve 18 and a conventional spring ring 20, as well as one assembly stones attached to the valve stem seal 14 22nd

The elastomer sealing sleeve 16 consists of an adhesive part 24 firmly connected to the reinforcing sleeve 18 and a sealing lip part 26 which is elastically deformable in the radial direction by the spring ring 20 and which has a has sealing lip 28 resting against the circumference of the valve stem 12 and causing the seal.

According to the invention: is the lower end area of the reinforcement sleeve 18 bent inwards to form an inner collar 30, while the reinforcement sleeve is otherwise is substantially cylindrical. In the cylindrical area 32 of the reinforcement sleeve are however, several circumferential beads 34 are embossed in such a way that there is also a certain form fit between elastomeric sealing sleeve 16 and metallic Reinforcement sleeve 18 results.

The sleeve-shaped or cap-shaped assembly punch 22 has an inner shoulder 40 with which it is applied against an upper end face 42 of the reinforcement sleeve 18 can be when the valve stem seal 14 is pushed onto the valve guide 10 and pressed on target. In order to obtain a good interference fit of the valve stem seal on the valve guide 10, the Inner diameter of the adhesive part 24 before assembly

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the valve stem seal is slightly smaller than the outer diameter the valve guide 10 above an outer shoulder of the valve guide which forms a seat 46, and so that the inner collar 30 is by no means involved when the valve stem seal is pushed onto the valve guide the latter can collide, the inner diameter of the inner collar 30 is larger than the outer diameter of the Valve guide 10 above seat 46.

As shown in the drawing, when the valve stem seal 14 is fully assembled, the inner collar is located 30 against the seat 46 of the valve guide.

Claims (4)

HOEGER, LAW & PARTNER PATENT LAWYERS Q Q O C Q 1 1 UHLANDSTRASSE 14 c D 7000 STUTTGART 1 \ J O £ - U I I A 45 676 b Applicant: Elring Dichtungswerke GmbH b - 176 Höhenstraße 24 July 20, 1983 7012 Fellbach Claims 1J stem or shaft seal, especially valve stem tab seal, with an elastomeric sealing sleeve made of an adhesive part and an inner sealing lip having sealing lip part and with a metallic reinforcing sleeve that is attached to it Haffteil surrounds, at its end facing the sealing lip part, a face serving as a pressing surface and on the the other end has an end face serving as a stop face, characterized in that that the reinforcing sleeve (18) at its end facing away from the sealing lip part (26) to form a the inner collar (30) engaging under the sealing sleeve (16) is bent inward and is otherwise cylindrical and that the inner collar (30) is the stop surface forms. 2. Seal according to claim 1, characterized in that the adhesive part (24) is approximately cylindrical and the inner diameter of the inner collar (30) is greater than the smallest inner diameter of the adhesive part (24). 3. Seal according to claim 1 or 2, characterized in that the reinforcing sleeve (18) with at least one in particular bead-shaped embossing (34) is provided. 4. Seal according to claim 3, characterized in that the reinforcing sleeve (18) at an axial distance from one another has a plurality of annular beads (34).