Mechanical seal arrangement having sliding surfaces of different hardness

Patent metadata

Field	Value
Publication number	US-9841107-B2
Application number	US-201414780662-A
Country	US
Kind code	B2
Filing date	Mar 11, 2014
Priority date	Apr 4, 2013
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

The invention relates to a mechanical seal arrangement comprising: a rotating slide ring ( 2 ) having a first slide surface and a stationary slide ring ( 3 ) with a second slide surface which between them define a sealing gap 4 , wherein the first and second slide surfaces have different hardnesses, wherein the harder slide surface has a diamond coating ( 20 ) and the softer slide surface is produced from carbon composite material, and wherein an average initial roughness R a 1 (of the diamond coating 20 ) is less than an average initial roughness R a 2 of the slide surface made from carbon composite material.

First claim

The invention claimed is:

1. Mechanical seal arrangement comprising:
a rotating slide ring having a first slide surface and a stationary slide ring having a second slide surface which define a sealing gap between them;
wherein the first and second slide surfaces have different hardnesses;
wherein the harder slide surface has a diamond coating and the softer slide surface is produced from carbon composite material, wherein the carbon composite material is a silicon carbide graphite composite material comprising silicon carbide, graphite and free silicon; and
wherein an average initial roughness (Ra 1 ) of the first slide surface of the diamond coating is smaller than an average initial roughness (Ra 2 ) of the second slide surface made from carbon composite material, wherein the diamond coating of the slide ring is additionally provided on a non-sliding surface on an outer peripheral region of the slide ring.

2. Mechanical seal arrangement as claimed in claim 1 , wherein the average initial roughness (Ra 1 ) of the slide ring with the diamond coating is 50% less than the average initial roughness (Ra 2 ) of the slide ring made from carbon composite material.

3. Mechanical seal arrangement as claimed in claim 2 , wherein the average initial roughness (Ra 1 ) of the diamond coating is in a range of 0.01 μm to 0.06 μm and/or that the average initial roughness (Ra 2 ) of the slide surface made from carbon composite material is in a range of 0.1 μm to 0.2 μm.

4. Mechanical seal arrangement as claimed in claim 1 , wherein the diamond coating has doping such that the diamond coating is electrically conductive.

5. Mechanical seal arrangement as claimed in claim 4 , wherein the doping is boron doping.

6. Mechanical seal arrangement as claimed in claim 1 , wherein the diamond coating is provided only partially on the outer peripheral region of the slide ring and in particular the diamond coating on the outer peripheral region has a tapering region.

7. Mechanical seal arrangement as claimed in claim 1 , wherein a support ring at least partially covers the diamond coating provided on the outer peripheral region of the slide ring.

8. Mechanical seal arrangement as claimed in claim 1 , wherein the diamond coating of the slide ring is additionally provided on an inner peripheral region of the slide ring.

9. Mechanical seal arrangement as claimed in claim 1 , wherein the first slide surface of the diamond coating is polished.

10. Mechanical seal arrangement as claimed in claim 1 , wherein the rotating slide ring comprises the diamond coating.

11. Mechanical seal arrangement as claimed in claim 1 , wherein the first slide surface of the diamond coating has a support portion of ≧50%.

12. Mechanical seal arrangement as claimed in claim 1 , wherein the carbon composite material comprises 60 to 75% by weight silicon carbide, 15 to 40% by weight carbon and 0.5 to 10% by weight free silicon.

13. Mechanical seal arrangement as claimed in claim 1 , wherein on the second slide surface made from carbon composite material are formed graphite-containing regions, in particular with a Rockwell hardness of 50 to 100 HR15T, which are arranged to receive free particles.

14. Power station feed pump comprising a mechanical seal arrangement as claimed in claim 1 .

15. Mechanical seal arrangement comprising:
a rotating slide ring having a first slide surface and a stationary slide ring having a second slide surface which define a sealing gap between them;
wherein the first and second slide surfaces have different hardnesses;
wherein the harder slide surface has a diamond coating and the softer slide surface is produced from carbon composite material, wherein the carbon composite material is a silicon carbide graphite composite material comprising silicon carbide, graphite and free silicon; and
wherein an average initial roughness (Ra 1 ) of the first slide surface of the diamond coating is smaller than an average initial roughness (Ra 2 ) of the second slide surface made from carbon composite material.

16. Mechanical seal arrangement as claimed in claim 15 , wherein the average initial roughness (Ra 1 ) of the slide ring with the diamond coating is 50% less than the average initial roughness (Ra 2 ) of the slide ring made from carbon composite material.

17. Mechanical seal arrangement as claimed in claim 15 , wherein the diamond coating has doping such that the diamond coating is electrically conductive.

18. Mechanical seal arrangement as claimed in claim 15 , wherein the rotating slide ring comprises the diamond coating.

19. Mechanical seal arrangement as claimed in claim 15 , wherein the first slide surface of the diamond coating has a support portion of ≧50%.

20. Mechanical seal arrangement comprising:
a rotating slide ring having a first slide surface and a stationary slide ring having a second slide surface which define a sealing gap between them;
wherein the first and second slide surfaces have different hardnesses;
wherein the harder slide surface has a diamond coating and the softer slide surface is produced from carbon composite material, wherein the carbon composite material is a silicon carbide graphite composite material comprising silicon carbide, graphite and free silicon; and
wherein an average initial roughness (Ra 1 ) of the first slide surface of the diamond coating is smaller than an average initial roughness (Ra 2 ) of the second slide surface made from carbon composite material, wherein the diamond coating of the slide ring is additionally provided on an outer peripheral region of the slide ring.

Assignees

• Eagleburgmann Germany Gmbh

Inventors

• Otschik Joachim
• Kretschmer Andreas
• Scholz Carsten
• Schicktanz Rudolf
• Schrufer Andreas

Classifications

• F16J15/3496 Primary

  use of special materials · CPC title

• F16J15/162

  Special parts or details relating to lubrication or cooling of the sealing itself (F16J15/324, F16J15/3404, F16J15/40 take precedence) · CPC title

• F04D29/126

  especially adapted for liquid pumps · CPC title

• F04D29/026

  especially adapted for liquid pumps · CPC title