Electromechanical actuator for generating an axial actuating force

Patent metadata

Field	Value
Publication number	US-11852237-B2
Application number	US-202017613336-A
Country	US
Kind code	B2
Filing date	Mar 6, 2020
Priority date	May 23, 2019
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

An electro-mechanical actuator for generating an axial actuation force is provided. The electro-mechanical actuator includes an electric machine having a stator ( 1 ) and a rotor ( 2 ). The electro-mechanical actuator also includes a spindle drive with a rotary element ( 6 ) and with an element that is movable in a translatory manner. A rotation of the rotary element ( 6 ) may result in a translatory motion of the element that is movable in a translatory manner. The rotor ( 2 ) and the rotary element ( 6 ) of the spindle drive are coupled to each other in a circumferential direction (U) such that a rotation of the rotor ( 2 ) results in a rotation of the rotary element ( 6 ) of the spindle drive ( 5 ). A rotational play ( 8 ) is formed between the rotor ( 2 ) and the rotary element ( 6 ) of the spindle drive in the circumferential direction (U).

First claim

The invention claimed is:

1. An electro-mechanical actuator ( 23 ) for generating an axial actuation force, comprising:
an electric machine ( 24 ) with a stator ( 1 ) and a rotor ( 2 );
a spindle drive ( 5 ) with a rotary element ( 6 / 7 ) and a translatable element ( 7 / 6 ), the spindle drive ( 5 ) configured such that rotation of the rotary element ( 6 / 7 ) drives translation of the translatable element ( 7 / 6 ), the rotor ( 2 ) and the rotary element ( 6 / 7 ) of the spindle drive ( 5 ) being coupled to each other in a circumferential direction (U) such that rotation of the rotor ( 2 ) drives rotation of the rotary element ( 6 / 7 ) of the spindle drive ( 5 ), a rotational play ( 8 ) being formed between the rotor ( 2 ) and the rotary element ( 6 / 7 ) of the spindle drive ( 5 ) in the circumferential direction (U); and
a control unit ( 17 ), the control unit ( 17 ) being configured for:
driving the rotor ( 2 ) in a forward direction of rotation (U 1 );
resetting the rotor ( 2 ) by driving the rotor ( 2 ) in a reverse direction of rotation (U 2 ) within the rotational play ( 8 ) when the rotor ( 2 ) is at a standstill due to an excessive counter-torque of the rotary element ( 6 / 7 ) of the spindle drive ( 5 ), the reverse direction of rotation (U 2 ) being opposite the forward direction of rotation (U 1 ); and
driving the rotor ( 2 ) in the forward direction of rotation (U 1 ) once again after the rotor ( 2 ) has been reset in the reverse direction of rotation (U 2 ) such that the rotor ( 2 ) turns freely with respect to the rotary element ( 6 / 7 ) of the spindle drive ( 5 ) in the forward direction of rotation (U 1 ) within the rotational play ( 8 ) and drives the rotary element ( 6 / 7 ) with momentum upon engagement of a driving toothing ( 9 ).

2. The electro-mechanical actuator ( 23 ) of claim 1 , wherein:
the rotor ( 2 ) and the rotary element ( 6 / 7 ) of the spindle drive ( 5 ) are coupled to each other by the driving toothing ( 9 ); and
the driving toothing ( 9 ) forms the rotational play ( 8 ) in the circumferential direction (U).

3. The electro-mechanical actuator ( 23 ) of claim 1 , further comprising a return travel interlock configured for holding the spindle drive ( 5 ) in place while the rotor is reset in the reverse direction of rotation (U 2 ).

4. The electro-mechanical actuator ( 23 ) of claim 1 , wherein:
the rotary element ( 6 ) of the spindle drive ( 5 ) comprises a spindle ( 6 );
the translatable element ( 7 ) of the spindle drive ( 5 ) comprises a spindle nut ( 7 );
the spindle ( 6 ) and the spindle nut ( 7 ) are coupled to each other such that rotation of the spindle ( 6 ) drives translation of the spindle nut ( 7 );
the driving toothing ( 9 ) comprises an internal toothing ( 25 ) of the rotor ( 2 ) and an external toothing ( 26 ) of the spindle ( 6 );
the external toothing ( 26 ) engages into the internal toothing ( 25 ) such that rotation of the rotor ( 2 ) drives rotation of the spindle drive ( 5 ); and
the rotational play ( 8 ) is formed between the internal toothing ( 25 ) and the external toothing ( 26 ).

5. The electro-mechanical actuator ( 23 ) of claim 1 , wherein:
the rotary element ( 6 ) of the spindle drive ( 5 ) comprises a spindle nut ( 7 );
the translatable element ( 7 ) of the spindle drive ( 5 ) comprises a spindle ( 6 );
the spindle ( 6 ) and the spindle nut ( 7 ) are coupled to each other such that rotation of the spindle nut ( 7 ) drives translation of the spindle ( 6 );
the driving toothing ( 9 ) comprises an internal toothing ( 25 ) of the rotor ( 2 ) and an external toothing ( 26 ) of the spindle nut ( 7 ); and
the rotational play ( 8 ) is formed between the internal toothing ( 25 ) and the external toothing ( 26 ).

6. The electro-mechanical actuator ( 23 ) of claim 1 , wherein a rotating mass of the rotor ( 2 ) and a rotating mass of the rotating element ( 6 ) of the spindle drive ( 5 ) are decoupled from one other by a torsional elasticity unit ( 10 ).

7. The electro-mechanical actuator ( 23 ) of claim 1 , wherein the electro-mechanical actuator ( 23 ) is at least partially arranged in an interior of a shaft ( 35 ).

8. The electro-mechanical actuator ( 23 ) of claim 1 , further comprising:
an axial guide bearing ( 30 ); and
a preloaded spring ( 12 ),
wherein the rotor ( 2 ) is pressed against the axial guide bearing ( 30 ) via the preloaded spring ( 12 ) in a play-free manner.

9. The electro-mechanical actuator ( 23 ) of claim 1 , wherein the rotor ( 2 ) is mounted on the rotary element ( 6 ) of the spindle drive ( 5 ).

10. The electro-mechanical actuator ( 23 ) of claim 9 , further comprising:
a housing ( 18 ); and
a radial bearing ( 15 ) arranged between the rotor ( 2 ) and the housing ( 18 ),
wherein the rotor ( 2 ) is mounted on the rotary element ( 6 ) of the spindle drive ( 5 ) and in the radial bearing ( 15 ).

11. The electro-mechanical actuator ( 23 ) of claim 1 , further comprising a housing ( 18 ),
wherein the rotary element ( 6 ) of the spindle drive ( 5 ) is mounted to the housing ( 18 ) in an axial direction (x) and in a radial direction (r).

12. The electro-mechanical actuator ( 23 ) of claim 1 , further comprising a sensor ( 21 ) configured for detecting a rotation (φ 1 ) of the rotor ( 2 ).

13. A motor vehicle transmission ( 32 ), comprising the electro-mechanical actuator ( 23 ) of claim 1 .

14. A motor vehicle ( 33 ), comprising the motor vehicle transmission ( 32 ) of claim 13 .

15. An electro-mechanical actuator ( 23 ) for generating an axial actuation force, comprising:
an electric machine ( 24 ) with a stator ( 1 ) and a rotor ( 2 );
a spindle drive ( 5 ) with a rotary element ( 6 / 7 ) and a translatable element ( 7 / 6 ), the spindle drive ( 5 ) configured such that rotation of the rotary element ( 6 / 7 ) drives translation of the translatable element ( 7 / 6 ), the rotor ( 2 ) and the rotary element ( 6 / 7 ) of the spindle drive ( 5 ) being coupled to each other in a circumferential direction (U) such that rotation of the rotor ( 2 ) drives rotation of the rotary element ( 6 / 7 ) of the spindle drive ( 5 ), a rotational play ( 8 ) is formed between the rotor ( 2 ) and the rotary element ( 6 / 7 ) of the spindle drive ( 5 ) in the circumferential direction (U); and
a return travel interlock configured for holding the spindle drive ( 5 ) in place while the rotor ( 2 ) is reset in a reverse direction of rotation (U 2 ).

16. A motor vehicle transmission ( 32 ), comprising the electro-mechanical actuator ( 23 ) of claim 15 .

17. A motor vehicle ( 33 ), comprising the motor vehicle transmission ( 32 ) of claim 16 .

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Reisch Matthias
• Füssl Andreas
• WAFZIG JüRGEN
• Wendzel Andreas
• Fischer Lorenz
• Gohmert Holger
• Fehr Uwe
• Arnegger Michael

Classifications

• F16H63/304 Primary

  the final output mechanisms comprising elements moved by electrical or magnetic force (band brake actuating mechanisms F16H63/3003) · CPC title

• F16H25/20

  Screw mechanisms (with automatic reversal F16H25/12) · CPC title

• H02K7/06

  Means for converting reciprocating motion into rotary motion or vice versa · CPC title

• H02K11/215

  Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements · CPC title

• F16H2025/2075

  Coaxial drive motors · CPC title