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US 2017/0254371 A1Published application
Position force controlled actuator
AssigneeBorgWarner Inc.
InventorsBrett PEGLOWSKI, Chris BLAIR, Calahan CAMPTON
Life of this patent
Estimating the term…
Abstract
An actuator device for a selectable clutch having three or more clutch modes may include a dual rate piston with a stable middle position. A positive stop provides very accurate control when shifting from an end position to a middle position without overshoot. Precision position control of the actuator device facilitates consistent, stable control of the current mode of the selectable clutch.
Claims20
An actuator device for a selectable clutch having a plurality of mode positions for controlling relative rotation between two components connected by the selectable clutch, the actuator device comprising:
- a piston housing having an exterior surface, a piston housing longitudinal bore extending longitudinally there through, a first fluid passage extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore proximate a first bore end, and a second fluid passage extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore proximate a second bore end;
- a main piston disposed within the piston housing longitudinal bore for longitudinal motion therein, the main piston comprising:
- a main piston main portion having a main piston main portion outer diameter and being disposed between the first fluid passage and the second fluid passage, and
- a main piston secondary portion having a main piston secondary portion outer diameter that is less than the main piston main portion outer diameter and extending longitudinally from the main piston main portion toward the second fluid passage;
- a secondary piston having a secondary piston longitudinal bore such that the secondary piston is disposed and slidable on the main piston secondary portion, the secondary piston comprising:
- a secondary piston main portion having a secondary piston main portion outer diameter that is less than the main piston main portion outer diameter, and
- a secondary piston secondary portion having a secondary piston secondary portion outer diameter that is less than the secondary piston main portion outer diameter and being disposed between the main piston main portion and the secondary piston main portion;
- and
- a stop snap ring having an annular shape and a stop snap ring inner diameter that is less than the secondary piston main portion outer diameter and greater than the secondary piston secondary portion outer diameter, wherein the stop snap ring is fixed within the piston housing longitudinal bore between the main piston main portion and the secondary piston main portion and with the secondary piston secondary portion extending there through,
- wherein a first pressure force acting on the main piston toward the second bore end is equal to a first pressure supplied at the first fluid passage multiplied by a first area equal to a main piston cross-sectional area of the main piston main portion,
- wherein a second pressure force acting on the main piston toward the first bore end when the secondary piston main portion is not engaged by the stop snap ring is equal to a second pressure supplied at the second fluid passage multiplied by a second area equal to a combined cross-sectional area of a main piston secondary portion cross-sectional area and a secondary piston main portion cross-sectional area;
- and
- wherein a third pressure force acting on the main piston toward the first bore end when the secondary piston main portion is engaged by the stop snap ring is equal to the second pressure supplied at the second fluid passage multiplied by a third area equal to the main piston secondary portion cross-sectional area.
10 more elements
An actuator device for a selectable clutch having a plurality of mode positions for controlling relative rotation between two components connected by the selectable clutch, the actuator device comprising:
- a piston housing having an exterior surface, a piston housing longitudinal bore extending longitudinally there through, a first fluid passage extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore proximate a first bore end, and a second fluid passage extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore proximate a second bore end;
- a main piston disposed within the piston housing longitudinal bore for longitudinal motion therein, the main piston comprising:
- a main piston main portion having a main piston main portion outer diameter and being disposed between the first fluid passage and the second fluid passage, and
- a main piston secondary portion having a main piston secondary portion outer diameter that is less than the main piston main portion outer diameter and extending longitudinally from the main piston main portion toward the second fluid passage;
- a secondary piston having a secondary piston outer diameter and a secondary piston longitudinal bore such that the secondary piston is disposed and slidable on the main piston secondary portion within the piston housing longitudinal bore;
- and
- a stop snap ring fixed within the piston housing longitudinal bore between the main piston main portion and the second bore end and having an annular shape and a stop snap ring inner diameter that allow at least a portion of the secondary piston to pass through the stop snap ring,
- wherein a first pressure force acting on the main piston toward the second bore end is equal to a first pressure supplied at the first fluid passage multiplied by a first area equal to a main piston cross-sectional area of the main piston main portion,
- wherein a second pressure force acting on the main piston toward the first bore end when the secondary piston is not engaged by the stop snap ring is equal to a second pressure supplied at the second fluid passage multiplied by a second area equal to a combined cross-sectional area of a main piston secondary portion cross-sectional area and a secondary piston main portion cross-sectional area, and
- wherein the second pressure force acting on the main piston when the secondary piston is engaged by the stop snap ring is equal to the second pressure supplied at the second fluid passage multiplied by a third area equal to the main piston secondary portion cross-sectional area.
7 more elements
Dependencies are inferred from the claim text.