Chris_Malcolm
Armdroid Wrist Differential Gears
In the human arm (and many other animal arms) it's convenient to have one set of joints (e.g. shoulder & elbow) primarily concerned with moving the hand to a location in 3D space, and another set in the wrist for changing the orientation of the hand. It's especially convenient if these wrist rotations take place about a common centre, as they do in the human arm.
This is a simple differential gear mechanism used in a number of robot arms for accomplishing two degrees of wrist rotation (pitch and roll) about a common centre. In the Armdroid robot they are exposed to view. The two side gears are rotated by the orange belts which run back down the forearm. The plate to the right is where the gripper is attached.
Rotating both the side gears in the same direction changes the pitch of the gripper. Rotating them in opposite directions accomplishes roll.
Armdroid Wrist Differential Gears
In the human arm (and many other animal arms) it's convenient to have one set of joints (e.g. shoulder & elbow) primarily concerned with moving the hand to a location in 3D space, and another set in the wrist for changing the orientation of the hand. It's especially convenient if these wrist rotations take place about a common centre, as they do in the human arm.
This is a simple differential gear mechanism used in a number of robot arms for accomplishing two degrees of wrist rotation (pitch and roll) about a common centre. In the Armdroid robot they are exposed to view. The two side gears are rotated by the orange belts which run back down the forearm. The plate to the right is where the gripper is attached.
Rotating both the side gears in the same direction changes the pitch of the gripper. Rotating them in opposite directions accomplishes roll.