Engine variable camshaft timing phaser with planetary gear set
AssigneeBorgWarner Inc.
InventorsDouglas W. Perry, Chad McCloy
Life of this patent
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Abstract
An engine variable camshaft timing (VCT) phaser assembly is equipped in an internal combustion engine (ICE) to adjust the rotation of the engine's camshaft relative to the engine's crankshaft. The adjustments advance and retard the opening and closing movements of the engine's intake and exhaust valves. An electric motor and a planetary gear set work together amid use of the VCT phaser assembly. The planetary gear set can include two or more ring gears, planet gears, and a sun gear. A backlash condition sometimes experienced in previous VCTs is minimized in the VCT phaser assembly by one or more springs that urge the planet gears into engagement with the ring gears.
Claims20
An engine variable camshaft timing (VCT) phaser assembly, comprising:
- a planetary gear set comprising:
- at least two ring gears;
- a plurality of planet gears engaged with the at least two ring gears and carried by a plurality of pins having a circular cross-sectional shape, a clearance residing between at least one of the plurality of planet gears and the plurality of pins;
- a sun gear engaged with the plurality of planet gears and rotatable about a central axis;
- at least one spring applying a force in a radial direction and urging the plurality of planet gears radially outboard and displacing the plurality of planet gears radially outboard via the clearance and into engagement with the at least two ring gears;
- and
- wherein the plurality of pins is fixed to the planetary gear set to prevent radial movement of the plurality of pins relative to the central axis.
An engine variable camshaft timing (VCT) phaser assembly, comprising:
- a planetary gear set comprising at least two ring gears, a plurality of planet gears engaged with the at least two ring gears, and a sun gear engaged with the plurality of planet gears, the planetary gear set further comprising a plurality of pins and a plurality of springs, the plurality of pins carrying the plurality of planet gears, the plurality of pins having a hollow section, the plurality of springs situated at least partly within the hollow section and exerting a biasing force against an inner wall of the plurality of planet gears.
An engine variable camshaft timing (VCT) phaser assembly, comprising:
- a planetary gear set comprising:
- at least two ring gears;
- a plurality of planet gears engaged with the at least two ring gears and carried by a plurality of pins having a circular cross-sectional shape, a clearance residing between the plurality of planet gears and the plurality of pins;
- a sun gear engaged with the plurality of planet gears and rotatable about a central axis;
- a plurality of springs held by the plurality of pins, the plurality of springs applying a force in a radial direction and biasing the clearance closed at a radially inboard side of a planet-gear-to-pin confrontation and biasing the clearance open at a radially outboard side of the planet-gear-to-pin confrontation;
- and
- wherein the plurality of pins is fixed to the planetary gear set to prevent radial movement of the plurality of pins relative to the central axis.
Dependencies are inferred from the claim text.