ACTUATOR FOR AN IMPROVED CONFIGURATION ROBOTIC ARM

Abstract

The present invention relates to an actuator (10) for a robotic arm comprising: - an input housing (12), - an output housing (15), - an electric motor (18) comprising a stator (19) and a rotor (20), - a mechanical speed reducer (23), - a hollow output shaft (25) being disposed inside the hollow rotor shaft (21), such that the hollow output shaft (25) and the hollow rotor shaft (21) are coaxial with respect to each other, - the hollow output shaft (25) being rotationally linked at one end with the output housing (15) carrying an electronic board (26) and rotationally linked at a second end with an element (27.1) of a rotating connector (29), and - at least one electrical wire (32) being disposed inside a hollow space passing through the hollow output shaft (15). Figure for abbreviation: Figure 2

Claims

Claims

1. Actuator (10) for a robotic arm characterized in that it comprises: - an input casing (12) provided with a fixing interface (13) capable of ensuring fixing of the input casing (12) with a first segment of the robotic arm, - an output casing (15) provided with a fixing interface (16) capable of ensuring fixing of the output casing (15) with a second segment of the robotic arm, - an electric motor (18) comprising a stator (19) fixed on the input casing (12) and a rotor (20) mounted on a hollow rotor shaft (21), - a mechanical speed reducer (23) comprising an input and an output, the hollow rotor shaft (21) being connected to the input of the mechanical speed reducer (23) and the output casing (15) being connected to the output of the mechanical speed reducer (23), - a hollow output shaft (25) being arranged inside the hollow rotor shaft (21),such that the hollow output shaft (25) and the hollow rotor shaft (21) are coaxial with each other, - the hollow output shaft (25) being rotatably connected at a first end to the output casing (15) carrying an electronic card (26) and rotatably connected at a second end to an element (27.1) of a rotating connector (29), and - at least one electrical wire (32) being arranged inside a hollow space passing through the hollow output shaft (15).,

2. Actuator according to claim 1, characterized in that at least one bearing (35) is interposed radially between an outer periphery of the hollow output shaft (15) and an inner periphery of the hollow rotor shaft (21).

3. Actuator according to claim 1 or 2, characterized in that if two end planes (PI, P2) of the stator (19) are considered perpendicular to an axis (X) of the actuator (10), the bearing (35) is arranged between the two end planes (PI, P2) or at one end of the stator (19) so that one end plane (PI, P2) intersects the bearing (35).

4. Actuator according to any one of claims 1 to 3, characterized in that there is an axial overlap along an axis of the actuator between the stator (19) of the electric motor (18), the input casing (12), and the output casing (15).

5. Actuator according to any one of claims 1 to 4, characterized in that the element (27.1) of the rotating connector (29) is fixed on a guide stud (38) mounted to slide while being linked in rotation relative to the hollow output shaft (25).

6. Actuator according to claim 5, characterized in that it comprises an elastic member (41) bearing on the one hand on a washer (42) carried by the guide stud (38) and on the other hand on the element (27.1) of the rotating connector (29) so as to urge brushes (28) against corresponding tracks (43) of the rotating connector (29).

7. Actuator according to claim 5 or 6, characterized in that the hollow output shaft (25) comprises longitudinal extension arms (44) each provided with at least one portion inserted inside a groove (47) of corresponding shape made in the guide stud (38).

8. Actuator according to any one of claims 5 to 7, characterized in that a screw (48) inserted inside a through opening made in the element (27.1) of the rotating connector (29) cooperates with a tapped hole made in the guide stud (38).

9. Actuator according to any one of claims 1 to 8, characterized in that it comprises at least one current-breaking brake (51) having an unlocked state when said current-breaking brake (51) is supplied with a current and a locked state when said current-breaking brake (51) is no longer supplied with a current.

10. Actuator according to claim 9, characterized in that, according to a first safety level of the current-breaking brake (51), the rotating connector (29) comprises at least one safety track (43') intended to cooperate with a corresponding brush (28), so that a break in contact between the safety track (43') and the corresponding brush (28) causes a reaction from a speed variator capable of cutting off a power supply to the current-breaking brake (51) to apply it.

11. Actuator according to claim 10, characterized in that, according to a second safety level of the current-failure brake (51), a cut-off of an electrical power supply to the speed variator is capable of causing a cut-off of a power supply to the current-failure brake (51) causing its activation.

12. Actuator according to claim 9 or 10, characterized in that the safety track (43') is a circular track located outside the rotating connector (29).

13. Actuator according to any one of claims 1 to 12, characterized in that the hollow output shaft (25) is made of steel and the output housing (15) is made of aluminum.

14. Actuator according to any one of claims 1 to 13, characterized in that the hollow output shaft (25) is mounted glued inside a receiving housing made in the output casing (15).

15. A robotic arm comprising a plurality of actuators (10) as defined in any preceding claim comprising hollow output shafts (15), and a plurality of segments extending between two consecutive actuators (10).

16. Robotic arm according to claim 15, characterized in that all the actuators (10) are powered by a single standby battery allowing a corresponding encoder (22) of an actuator (10) to keep its position in memory when said actuator (10) is powered off.

17. Robotic arm according to claim 16, characterized in that electrical wires connected to the single standby battery pass inside the hollow output shafts (15).

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