Arrangement for limiting rotation, and robot
An arrangement for limiting rotation, the arrangement including a base structure; a drive member rotatable relative to the base structure and having a drive feature; a stopping member having at least one driven feature, wherein the stopping member is arranged to be intermittently driven relative to the base structure between a plurality of discrete positions by a continuous rotation of the drive member and by cooperation between the drive feature and at least one driven feature, wherein the stopping member in a first end discrete position is arranged to limit rotation of the drive member in a first end position of a rotation range of the drive member; and a holding mechanism arranged to hold the stopping member in each discrete position, the holding mechanism being at least partly provided in the base structure.
1. An arrangement for limiting rotation, comprising:
a base structure;
a drive member rotatable relative to the base structure about a drive axis, the drive member having a drive feature offset from the drive axis;
a stopping member having at least one driven feature, wherein the stopping member is arranged to be intermittently driven relative to the base structure between a plurality of discrete positions by a continuous rotation of the drive member and by cooperation between the drive feature and the at least one driven feature, wherein the stopping member in a first end discrete position is arranged to limit rotation of the drive member in a first end position of a rotation range of the drive member, and in a second end discrete position is arranged to limit rotation of the drive member in a second end position of the rotation range; and
a holding mechanism arranged to hold the stopping member in each discrete position, the holding mechanism being at least partly provided in the base structure.
2. The arrangement according to claim 1 , wherein the holding mechanism includes at least one magnet arranged to hold the stopping member in each discrete position by magnetic force.
3. The arrangement according to claim 2 , wherein the stopping member is rotatable about a stopping axis.
4. The arrangement according to claim 2 , wherein the drive feature is positioned on a drive member surface of the drive member, and wherein a distance from the drive axis to the drive feature is at least 80% of a distance from the drive axis to a radially outermost position of the drive member surface with respect to the drive axis.
5. The arrangement according to claim 2 , wherein the drive feature includes a drive pin.
6. The arrangement according to claim 2 , wherein the stopping member is made of plastic.
7. The arrangement according to claim 2 , further comprising a cable fixed with respect to each of the base structure and the drive member.
8. The arrangement according to claim 2 , further comprising a drive motor arranged to drive the drive member about the drive axis, wherein the drive motor is positioned radially inside the drive feature with respect to the drive axis.
9. The arrangement according to claim 1 , wherein the stopping member is rotatable about a stopping axis.
10. The arrangement according to claim 9 , further comprising a plain bearing, wherein the stopping member is rotatably supported about the stopping axis by the plain bearing.
11. The arrangement according to claim 10 , wherein the stopping member includes a stopping feature, wherein the stopping feature and the stopping axis are substantially positioned on a line deviating at most 30°, such as at most 20° or at most 10°, from a tangential line at the drive feature with respect to the drive axis when the stopping member is in the first end discrete position and the drive member is in the first end position.
12. The arrangement according to claim 9 , wherein the stopping member includes a stopping feature, wherein the stopping feature and the stopping axis are substantially positioned on a line deviating at most 30°, such as at most 20° or at most 10°, from a tangential line at the drive feature with respect to the drive axis when the stopping member is in the first end discrete position and the drive member is in the first end position.
13. The arrangement according to claim 1 , wherein the drive feature is positioned on a drive member surface of the drive member, and wherein a distance from the drive axis to the drive feature is at least 80% of a distance from the drive axis to a radially outermost position of the drive member surface with respect to the drive axis.
14. The arrangement according to claim 1 , wherein the drive feature includes a drive pin.
15. The arrangement according to claim 1 , wherein the stopping member is made of plastic.
16. The arrangement according to claim 1 , further comprising a cable fixed with respect to each of the base structure and the drive member.
17. The arrangement according to claim 16 , further comprising a driven motor fixed with respect to the drive member, wherein the cable is fixedly connected to the driven motor.
18. The arrangement according to claim 1 , further comprising a drive motor arranged to drive the drive member about the drive axis, wherein the drive motor is positioned radially inside the drive feature with respect to the drive axis.
19. A robot comprising an arrangement for limiting rotation, including:
a base structure;
a drive member rotatable relative to the base structure about a drive axis, the drive member having a drive feature offset from the drive axis;
a stopping member having at least one driven feature, wherein the stopping member is arranged to be intermittently driven relative to the base structure between a plurality of discrete positions by a continuous rotation of the drive member and by cooperation between the drive feature and the at least one driven feature, wherein the stopping member in a first end discrete position is arranged to limit rotation of the drive member in a first end position of a rotation range of the drive member, and in a second end discrete position is arranged to limit rotation of the drive member in a second end position of the rotation range; and
a holding mechanism arranged to hold the stopping member in each discrete position, the holding mechanism being at least partly provided in the base structure.
20. The robot according to claim 19 , wherein the robot is an automated guided vehicle, AGV, having at least one wheel unit including a traction wheel rotatable about the drive axis and about a wheel axis perpendicular to the drive axis.