Valve stem seal

Patent metadata

Field	Value
Publication number	US-9284863-B2
Application number	US-201213628271-A
Country	US
Kind code	B2
Filing date	Sep 27, 2012
Priority date	Sep 29, 2011
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

A valve stem seal ( 1 ) seals a valve stem ( 4 ) that is reciprocally movable in an axial direction. The valve stem seal includes a base body ( 8 ) that is connectable with a valve stem guide ( 6 ). A first seal lip ( 10 ) is resiliently positioned relative to the base body via an elastic connection ( 16 ) and seals the valve stem relative to an oil chamber ( 24 ). A second seal lip ( 12 ) is spaced in the axial direction ( 2 ) from the first seal lip and seals the valve stem relative to a gas chamber. The second seal lip is also resiliently positioned relative to the base body via the elastic connection.

First claim

The invention claimed is:

1. A valve stem seal for sealing a valve stem that is movable in an axial direction, the valve stem seal comprising:
a base body configured to be connected to a valve stem guide that receives and guides the valve stem,
a first seal lip configured to seal the valve stem relative to an oil chamber such that the first seal lip is oil-tight,
a second seal lip spaced in the axial direction from the first seal lip in the direction of the base body and configured to seal the valve stem relative to a gas chamber, wherein a first portion of the second seal lip that is configured to contact the valve stem has a radial cross section that is more rounded than a second portion of the first seal lip that is configured to contact the valve stem,
an elastic connection resiliently connecting the first and second seal lips to the base body, wherein no material is interjected into the elastic connection of the valve stem seal between the base body and the second seal lip, and wherein a radial cross section of the elastic connection defines only a single concave section between the base body and the second seal lip, and
a support element substantially surrounding the base body of the valve stem seal wherein one of the group of the base body and the combination of the base body and the elastic connection contacts the entire inner surface of the support element, an axial end of the support element proximate to the first seal lip and the second seal lip does not have a radially extending portion that protrudes into another part of the valve stem seal,
the valve stem seal being configured to receive an elastic spring element radially therearound, the valve stem seal being configured to support the elastic spring element such that it is axially located between the first seal lip and the second seal lip.

2. The valve stem seal according to claim 1 , wherein the elastic connection enables movement of the first and second seal lips in a radial direction that is perpendicular to the axial direction.

3. The valve stem seal according to claim 2 , wherein the base body and the first and second seal lips are all integrally made as one piece from the same seal material, and
wherein the elastic connection is formed from the same seal material and is configured as a connecting bridge that connects the first and second seal lips with the base body.

4. The valve stem seal according to claim 3 , wherein the second seal lip is disposed on an arm extending away from the elastic connection in the axial direction.

5. The valve stem seal according to claim 4 , wherein the base body includes at least one third seal lip configured to sealingly contact the valve stem guide, a second axial end of the support element that is proximate to the at least one third seal lip has a radial portion extending therefrom towards the valve stem.

6. The valve stem seal according to claim 5 , wherein:
the elastic spring element is configured to exert an elastic spring force on the first seal lip and/or second seal lip in a radially inward direction, wherein the second axial end of the support element is free of seal material.

7. The valve stem seal according to claim 6 , wherein the elastic spring element is a garter spring.

8. The valve stem seal according to claim 7 , wherein the support element is made of an inelastic material that is different from the material of the first and second seal lips and is configured to rigidly affix the base body on the valve stem guide so that the base body is not axially moveable during operation of the valve stem seal.

9. The valve stem seal according to claim 8 , wherein the elastic connection extends at least partially beyond a terminal end of the support element in the axial direction.

10. The valve stem seal according to claim 1 , wherein the base body and the first and second seal lips are all integrally made as one piece from the same seal material, and
wherein the elastic connection is formed from the same seal material and is configured as a connecting bridge that connects the first and second seal lips with the base body.

11. The valve stem seal according to claim 1 , wherein the second seal lip is disposed on an arm extending away from the elastic connection in the axial direction.

12. The valve stem seal according to claim 1 , wherein the base body includes at least one third seal lip configured to sealingly contact the valve stem guide.

13. The valve stem seal according to claim 1 , further comprising:
at least one spring element configured to exert an elastic spring force on the first seal lip and/or second seal lip in a radially inward direction.

14. The valve stem seal according to claim 13 , wherein the at least one spring element is a garter spring.

15. The valve stem seal according to claim 1 , wherein the support element is made of an inelastic material that is different from the material of the first and second seal lips and is configured to rigidly affix the base body on the valve stem guide so that the base body is not axially moveable during operation of the valve stem seal.

16. The valve stem seal according to claim 15 , wherein the elastic connections extends at least partially beyond a terminal end of the support element in the axial direction.

17. A valve assembly comprising:
a valve stem reciprocally linearly movable in an axial direction and having a first outer diameter,
an annular valve stem guide having an inner diameter matched to the first outer diameter and including a seal seat having a second outer diameter, and
the valve stem seal according to claim 1 ,
wherein the base body is fixedly connected to the seal seat of the annular valve stem guide and
the first and second seal lips resiliently elastically contact the valve stem in its radial direction.

18. The valve assembly according to claim 17 , wherein a ratio of the second outer diameter to the first outer diameter falls within the range of 1.05-2.0:1.

19. A valve stem seal comprising:
an annular base portion configured to be disposed around and fixedly connected with a seal seat of a stationary valve stem guide that guides reciprocal linear movement of a valve stem therein,
an annular first seal lip configured to sealingly contact the valve stem around its entire circumference such that the first seal lip is oil-tight,
an annular second seal lip spaced in an axial direction from the first seal lip in the direction of the base body and configured to sealingly contact the valve stem around its entire circumference, wherein a first portion of the second seal lip that is configured to contact the valve stem has a radial cross section that is more rounded than a second portion of the first seal lip that is configured to contact the valve stem,
an annular elastic bridge resiliently connecting the first and second seal lips to the base body, the elastic bridge being configured to enable radial movement of the first and second seal lips so as to follow radial movements of the valve stem relative to the valve stem guide without breaking the sealing contact of the first and second seal lips with the valve stem, wherein no material is interjected into the annular elastic bridge of the valve stem seal between the base body and the second seal lip, and wherein a radial cross section of the annular elastic bridge defines only a single concave section between the base body and the second seal lip, and
a support element substantially surrounding the base body of the valve stem seal wherein one of the group of the base body and the combination of th

Assignees

• Kurth Juergen
• Netzer Juergen
• Skf Ab

Inventors

• Kurth Juergen
• Netzer Juergen

Classifications

• F01L3/08 Primary

  Valves guides; Sealing of valve stem, e.g. sealing by lubricant · CPC title

• F16K1/32

  Details (details of more general applicability F16K25/00 - F16K51/00) · CPC title

• F16K41/04

  with at least one ring of rubber or like material between spindle and housing · CPC title