Flexible mechanical arm and robot
The present disclosure discloses a flexible mechanical arm and a robot. The flexible mechanical arm includes an arm joint, a flexible rotary module ( 2 ) and an end execution mechanism ( 3 ) which are connected with each other. The flexible rotary module ( 2 ) is driven by fluid, and includes a first end plate ( 23 ), a powered pusher plate ( 222 ), a first folding unit ( 21 ), a nut ( 221 ), and a lead screw ( 223 ) in threaded connection with the nut ( 221 ), wherein the first folding unit ( 21 ) is driven by fluid to be extended or compressed to push the powered pusher plate ( 222 ) to translate in an axial direction of the lead screw ( 223 ). The flexible mechanical arm can be deformed under drive of the fluid, thus causing no damage to surrounding objects or persons, and capable of being applied to special environments such as electric fields, magnetic fields, rays, etc.
1 . A flexible mechanical arm, comprising an arm joint, a flexible rotary module and an end execution mechanism connected with each other, wherein the flexible rotary module is connected between a fixed side which is a base or the arm joint of the flexible mechanical arm, and a rotary side which is the arm joint or the end execution mechanism; the flexible rotary module is driven by fluid, and comprises a first end plate, a powered pusher plate, a first folding unit connected between the first end plate and the powered pusher plate and driven by fluid to be extended or compressed, a nut fixed to the powered pusher plate, and a lead screw in threaded connection with the nut, wherein the lead screw rotates through the first end plate, and the first folding unit is driven by fluid to be extended or compressed to push the powered pusher plate to translate relative to the first end plate in an axial direction of the lead screw.
2 . The flexible mechanical arm according to claim 1 , wherein the first end plate is fixedly connected with one of the fixed side or the rotary side, and one or both ends of the lead screw is/are fixedly connected with the other of the fixed side or the rotary side.
3 . The flexible mechanical arm according to claim 2 , wherein both ends of the lead screw are fixedly connected with one of the fixed side or the rotary side through a connector; the connector comprises two connecting support arms and one connecting portion, two ends of the connecting portion are fixedly connected with the two connecting support arms respectively, the two connecting support arms are fixedly connected with the two ends of the lead screw respectively, and the connecting portion is fixedly connected with the fixed side or the rotary side.
4 . The flexible mechanical arm according to claim 1 , wherein the lead screw is configured to be hollow, an outer periphery of the lead screw is provided with an external thread in threaded connection with the nut, and the external thread is a multi-start trapezoidal thread.
5 . The flexible mechanical arm according to claim 1 , wherein that the arm joint is a flexible bending module, which comprises a first plate-shaped member, a second plate-shaped member, a folding unit group disposed between the first plate-shaped member and the second plate-shaped member, and a support structure connecting the first plate-shaped member with the second plate-shaped member, wherein the folding unit group comprises at least two second folding units which are driven to be deformed by fluid, with one end of the folding unit group being fastened to the first plate-shaped member, and the other end of the folding unit group being fastened to the second plate-shaped member; the support structure has one end fastened to the first plate-shaped member, and the other end fastened to the second plate-shaped member; and a hinge is provided on the support structure.
6 . The flexible mechanical arm according to claim 1 , wherein the flexible rotary module further comprises a second end plate and a booster, wherein the first end plate is fixedly connected with the second end plate, two ends of the booster are connected to the second end plate and the powered pusher plate respectively, and the lead screw rotates through the second end plate; the booster is an elastic member, or the booster is a third folding unit driven by fluid to be extended or compressed, wherein both ends of the third folding unit are fixed to the second end plate and the powered pusher plate respectively, and the third folding unit is driven by fluid to be extended or compressed to push the powered pusher plate to translate between the first end plate and the second end plate in the axial direction of the lead screw.
7 . The flexible mechanical arm according to claim 1 , wherein the flexible rotary module further comprises at least one group of guide assembly, and the guide assembly each comprises a first guide and a second guide, wherein the first guide is provided on the first end plate and the second guide is provided on the powered pusher plate; and the first guide and the second guide have fitted portions matching each other in shape, so as to enable the powered pusher plate to move relative to the first end plate in the axial direction parallel to the lead screw.
8 . The flexible mechanical arm according to claim 7 , wherein one of the first guide and the second guide is a rod parallel with the lead screw, and the other of the first guide and the second guide is a hole fitted over the rod; alternatively, one of the first guide and the second guide is a slot parallel with the lead screw, and the other of the first guide and the second guide is a lug embedded in the slot.
9 . The flexible mechanical arm according to claim 1 , wherein the first folding unit is a flexible side wall, and the flexible side wall, the first end plate and the powered pusher plate enclose to form a cylindrical cavity with a central axis;
the flexible side wall is designed to comprise multiple layers of folding structures, each layer of the folding structure has folding surfaces, a crease surface is formed at a connection of the folding surfaces on two adjacent layers, and an included angle between the folding surface and the crease surface adjacent to each other is defined as an intrusion angle θ;
the first folding unit has an initial intrusion angle θ p in an initial state, and the intrusion angle θ varies between 0° and a maximum intrusion angle θ max during compression or expansion of the folding structure, wherein the initial intrusion angle θ p and the maximum intrusion angle θ max of the first folding unit are configured to satisfy the following relationship: 0.60 max <θ p <0.8θ max ;
in the initial state, a distance between two adjacent layers of multiple layers of the crease surfaces is h, and a wall thickness of the flexible side wall is t, wherein h, t and θ p are configured to satisfy the following relationship: 0.05 h/sin θ p <t<0.2 h/sin θ p ;
openings are provided on the flexible side wall, the first end plate or the powered pusher plate to allow driving fluid to enter or leave the cavity to change an inside and outside pressure difference of the cavity and make the folding structure compressed or stretched thereby to drive the first end plate and the powered pusher plate to approach or depart from each other, and to shorten or extend the first folding unit.
10 . A robot, comprising the flexible mechanical arm according to claim 1 .