Global Patent Index - EP 0990797 A1

EP 0990797 A1 2000-04-05 - Hydraulic gear pump

Title (en)

Hydraulic gear pump

Title (de)

Hydraulische Zahnradpumpe

Title (fr)

Pompe à engrenages hydraulique

Publication

EP 0990797 A1 (DE)

Application

EP 99119406 A

Priority

DE 19845383 A

Abstract (en)

The gear pump (10) has a housing (12) with chamber (21) containing a drive with meshing gears (24,26) to convey a pressure medium from a suction channel to a pressure channel. A sleeve is fitted pre-tensioned into the pressure channel, to cover at least the opening part of the channel facing away from the drive chamber. The sleeve is at least partially conical, and may have a conical outer thread for screwing into the pressure channel. It consists of a material with an elasticity module higher than that of the housing material. Housing and sleeve are of materials with similar heat expansion characteristics.

Abstract (de)

Es wird eine hydraulische Zahnradpumpe (10) vorgeschlagen, deren Zeitstandsfestigkeit ihres Gehäuses (12) durch eine in den Druckanschluß (38) eingesetzte, konische Buchse (40) erhöht ist. Die Buchse (40) kann eingepreßt oder eingeschraubt sein und erzeugt im Gehäuse (12) eine Vorspannung. Unter Betriebsbedingungen der Zahnradpumpe (10) wird der Vorspannung ein von den Einsatzverhältnissen her bedingte, schwellende Druckbelastung überlagert. Die von dieser Druckbelastung hervorgerufenen Zugspannungen im Gehäuse (12) werden wenigstens teilweise von den in der Buchse (40) herrschenden Druckspannungen ausgeglichen. Auf das Gehäuse (12) wirkt daher nur eine Schwellbelastung geringerer Amplitude ein. Eine Materialermüdung im Gehäuse (12) wird dadurch vermieden oder tritt allenfalls zeitlich verzögert ein. <IMAGE>

IPC 1-7 (main, further and additional classification)

F04C 2/08; F04C 2/18; F04C 15/00; F04C 15/02

IPC 8 full level (invention and additional information)

F04C 2/08 (2006.01); F04C 15/00 (2006.01); F04C 15/06 (2006.01)

CPC (invention and additional information)

F04C 15/06 (2013.01); F04C 2/086 (2013.01); F04C 15/0049 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE FR GB IT

EPO simple patent family

EP 0990797 A1 20000405; EP 0990797 B1 20040922; DE 19845383 A1 20000420; DE 19845383 C2 20001012

INPADOC legal status


2009-08-31 [PG25 IT] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

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2005-09-14 [26N] NO OPPOSITION FILED

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2005-06-24 [ET] FR: TRANSLATION FILED

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2004-10-28 [REF] CORRESPONDS TO:

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2000-04-05 [AK] DESIGNATED CONTRACTING STATES:

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