When the Cassini-Huygens spacecraft enters Saturn's orbit in July 2004, it will have endured - for the first time in history - not only the vibration, shock, and temperature extremes of a Titan IV rocket launch, but also a seven-year journey from Earth across more than 750 million miles of space. Later, the Huygens probe will dive into the murky atmosphere of Titan, Saturn's largest moon, measuring atmospheric composition down to Titan's frigid surface. For accurate atmospheric measurement of both Saturn from the Cassini orbiter and of Titan from the Huygens probe, several hundred bolts must maintain vacuum-tight sealed cavities for the duration of their mission, with no thread loosening or stripping. The design and size tolerances of standard thread forms also must allow for a variety of unavoidable problems such as drill, tap, and die wear with resultant hole size variation, as well as errors in placement, machine setup, thread finish, etc. The result, falling within these manufacturing tolerance parameters, is engaged threads with clearance between the male and female members at the crest and root of each. The secret to Spiralock's thread form is a 30 deg. 'wedge' ramp cut at the root of the female thread. Under clamp load, the crests of the threads on any standard bolt are drawn tightly against the wedge ramp. This causes thread contact forces to be applied at approximately 60 deg. from the bolt axis, rather than 30 deg. away, as in a standard thread form. The mechanical advantage - the angular relationship between the wedge ramp and the male thread - restricts bolt or screw movement. The wedge ramp allows the fastener to spin freely until clamp load is applied. In laboratory tests, Spiralock threads have demonstrated superior resistance to vibration loosening. These tests compared three types of female thread forms: a standard nut; a prevailing torque locknut; and a Spiralock nut, under comparable, controlled conditions. NASA was one of the first to recognize the advantages of the new thread when designing the main engines of the Shuttle orbiter.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Innovations: travelling to Saturn? Get some new threads


    Erschienen in:

    Erscheinungsdatum :

    2004


    Format / Umfang :

    3 Seiten, 2 Bilder



    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Print


    Sprache :

    Englisch





    Saturn

    Engineering Index Backfile | 1945


    2007 Saturn Sky - Saturn Aura Concept

    Lassa,T. / Saturn,US | Kraftfahrwesen | 2005


    SATURN

    Online Contents | 1996


    Saturn

    Engineering Index Backfile | 1945