Sealing Ring and Pressure Measuring Transducer having at least one such Sealing Ring

Patent metadata

Field	Value
Publication number	US-2016290508-A1
Application number	US-201314442528-A
Country	US
Kind code	A1
Filing date	Oct 28, 2013
Priority date	Nov 15, 2012
Publication date	Oct 6, 2016
Grant date	—

Abstract

A ring arrangement with a synthetic material sealing ring between an outer radial guiding ring and an inner radial guiding ring, wherein the outer guiding ring has a greater coefficient of thermal expansion than the inner guiding ring, so that an effective volume expansion coefficient of an annular gap between the guiding rings is greater than the volume expansion coefficient of the synthetic material of the synthetic material sealing ring. Through a large effective coefficient of thermal expansion for the annular gap volume, as achieved via different coefficients of expansion of the outer and inner guiding rings, fluctuation of the axial clamping forces of the synthetic material sealing ring can be limited.

First claim

1 - 15 . (canceled)

16 . A sealing ring for sealing in an axially clamped state, comprising:
an annular sealing element of a first material having a first linear coefficient of thermal expansion; and an annular guiding arrangement, which defines at least one radial barrier for an equatorial annular surface of a volume consumable by said sealing element, wherein: said equatorial annular surface has an effective area thermal expansion coefficient, which amounts to more than twice, and not less than two and a half times, said first linear coefficient of thermal expansion, so that an effective axial coefficient of thermal expansion of said annular sealing element is less than said first linear coefficient of thermal expansion, and no more than half said first linear coefficient of expansion, preferably amounts to no more than 30 ppm/K, and still preferably no more than 20 ppm/K.

17 . The sealing ring as claimed in claim 16 , wherein:
said annular guiding arrangement has an inner radial guiding ring, which has an inner radial bounding surface for the sealing element; said inner guiding ring comprises a second material having a second linear coefficient of thermal expansion α 2 ; said annular guiding arrangement further includes an outer radial guiding ring, which has an outer radial bounding surface for said annular sealing element; said outer radial guiding ring comprises a third material having a third linear coefficient of thermal expansion α 3 ; and said second coefficient of thermal expansion α 2 is less than said third coefficient of thermal expansion α 3 .

18 . The sealing ring as claimed in claim 17 , wherein:
said third coefficient of thermal expansion α 3 is less than said first coefficient of thermal expansion α 1 ; and between an effective outer radius of the outer radius bounding surface and an effective inner radius of the inner radius bounding surface the following relationship holds:

R
o

R
i

-
1

=

K
·

[

α
1

-

2
3



α
2

-

1
3



α
3

α
1

-

α
3

-
1

]

wherein 0.67<K<1.5 especially 0.8<K<1.25, preferably 0.9<K<1.1 and especially preferably 0.95<K<1.05.

19 . The sealing ring as claimed in claim 17 , wherein:
said second material comprises a ceramic material or glass; and/or said second coefficient of thermal expansion α 2 amounts to no more than 8 ppm/K, especially no more than 5 ppm/K, and preferably no more than 3.5 ppm/K.

20 . The sealing ring as claimed in claim 17 , wherein:
said third material comprises a metal material, especially stainless steel; and/or said third coefficient of thermal expansion α 3 amounts to not less than 14 ppm/K, especially not less than 15 ppm/K, and preferably not less than 16 ppm/K.

21 . The sealing ring as claimed in claim 17 , wherein:
said first material comprises a polymer; and/or said first coefficient of thermal expansion α 1 amounts to not less than 80 ppm/K and no more than 200 ppm/K, especially no more than 150 ppm/K.

22 . The sealing ring as claimed in claim 21 , wherein:
said first material comprises a fluoropolymer, especially PTFE or PFA.

23 . The sealing ring as claimed in claim 16 , wherein:
said first material comprises an elastomer; said annular guiding arrangement has an inner radial guiding ring, which has an inner radial bounding surface for the sealing element; said inner guiding ring comprises a second material having a second linear coefficient of thermal expansion α 2 , which is less than the said linear coefficient of thermal expansion α 1 ; the sealing ring is specified for a temperature range up to a maximum temperature T max ; and said inner guiding ring prestresses said annular sealing element radially, such that said annular sealing element bears against a sealing surface at least up to a temperature of T max −20 K, preferably up to T max .

24 . A pressure measuring transducer, comprising:
a pressure sensor having a pressure body, which includes at least a first pressure receiving surface, which is contactable with a first pressure, and at least a first sealing surface, which annularly surrounds said at least a first receiving surface, and a transducer for providing a signal, which depends on a difference between said first pressure present on said at least a first pressure receiving surface and a reference pressure; at least a first connecting body, which includes a first pressure opening and a first opposing sealing surface, said first opposing sealing surface surrounds said first pressure opening annularly; and at least a first sealing ring, comprising: an annular sealing element of a first material having a first linear coefficient of thermal expansion; and an annular guiding arrangement, which defines at least one radial barrier for an equatorial annular surface of a volume consummable by said sealing element, wherein said equatorial annular surface has an effective area thermal expansion coefficient, which amounts to more than twice, and not less than two and a half times, said first linear coefficient of thermal expansion, so that an effective axial coefficient of thermal expansion of said annular sealing element is less than said first linear coefficient of thermal expansion, and no more than half said first linear coefficient of expansion, preferably amounts to no more than 30 ppm/K,and still preferably no more than 20 ppm/K, wherein said first sealing ring is axially clamped sealingly between said first sealing surface and said first opposing sealing surface, so that said first pressure receiving surface is contactable with a first pressure through said first pressure opening.

25 . The pressure measuring transducer as claimed in claim 24 , wherein:
said first connecting body and said pressure body each comprise a metal material, especially a material whose coefficient of thermal expansion deviates by no more th

Assignees

• Endress & Hauser Gmbh & Co Kg

Inventors

• Gugenberger Alexander

Classifications

• F16J15/121 Primary

  with metal reinforcement · CPC title

• G01L9/0072

  using variations in capacitance · CPC title

• F16J15/127 Primary

  the reinforcement being a compression stopper · CPC title

• G01L9/0075

  using a ceramic diaphragm, e.g. alumina, fused quartz, glass · CPC title