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US 11,530,740 B2Granted
Ball-screw nut with over-molded shell
AssigneeSchaeffler Technologies AG & Co. KG
InventorsRenato de Paula, Mario Kreutzer, Dieter Adler, Michael Zinnecker
Life of this patent
Estimating the term…
Abstract
A ball-screw actuator includes a screw nut having a metal core and an over-molded plastic outer shell. The plastic outer shell includes features which would be expensive to manufacture in a single piece metal screw nut, such as an anti-rotation feature, an axial position control feature, and a lateral position control feature. The anti-rotation feature may take the form of an axial groove or of an axial ridge.
Claims13
An actuator comprising:
- a screw nut having a metal core and a plastic over-molded outer shell, the metal core having internal threads, and the outer shell having an anti-rotation feature configured to engage a mating feature of a housing to prevent relative rotation therebetween;
- a spindle extending through the screw nut, the spindle having external threads;
- a plurality of rolling elements disposed between the external threads and the internal threads;
- and
- a locating feature configured to orient the metal core for a molding process of the screw nut, the locating feature configured as a cavity that extends axially from an end of the metal core.
2 more elements
An actuator comprising:
- a screw nut having a metal core and a plastic over-molded outer shell, the metal core having internal threads, and the outer shell having an anti-rotation feature configured to engage a mating feature of a housing to prevent relative rotation therebetween;
- a spindle extending through the screw nut, the spindle having external threads;
- a plurality of rolling elements disposed between the external threads and the internal threads;
- and
- a locating feature configured to orient the metal core for a molding process of the screw nut;
- and
- the internal threads define recirculation paths arranged radially inwardly of an outer surface of the metal core.
4 more elements
A screw nut for a ball-screw actuator, the screw nut comprising:
- a metal core having:
- internal threads;
- and
- a plurality of insertable recirculation units configured to redirect rolling elements from a first internal thread to a second internal thread adjacent to the first internal thread, the plurality of insertable recirculation units and internal threads defining recirculation paths configured for the railing elements;
- a plastic over-molded outer shell having an anti-rotation feature configured to engage a mating feature of a housing to prevent relative rotation therebetween;
- and
- the recirculation paths arranged radially inwardly of an outer surface of the metal core.
4 more elements
Dependencies are inferred from the claim text.