Clutch, industrial robot and the use thereof

A clutch comprising:

• a hub extending in an axial direction and a cam connected to the hub, said cam comprising a ring-shaped part having grooves formed on a bottom surface of the ring-shaped part, said grooves being arranged in the angular direction and each groove being configured to accommodate a top part of a transmission element;
• a spring plate having recesses formed on a top surface of the spring plate, said recesses being arranged in the angular direction and each recess being configured to accommodate a bottom part of the transmission element;
• an output flange comprising a ring-shaped part configured to accommodate the spring plate;
• a plurality of transmission elements arranged in the angular direction between the spring plate and the cam;
• a plurality of springs arranged in the angular direction between the spring plate and the output flange, allowing the spring plate to move axially with respect to the output flange;
• one or more sliders configured to allow the spring plate to be displaced in the axial direction;
• and
• a sliding bearing provided at an interface between the hub and the output flange, wherein the clutch is configured to be changed between:
• a first state in which the springs push the spring plate against the cam in the axial direction to engage the cam at a predetermined position and in which the transmission elements are provided in spaces defined by the recesses of the spring plate and the grooves of the cam such that, during use, torque is transmitted from the hub to the output flange via the cam and the transmission elements, and
• a second state in which the transmission elements are provided in the recesses of the spring plate and engage the ring-shaped part of the cam between subsequent grooves and in which the cam and spring plate are separated from each other,
• wherein the clutch is configured to be moved from the first state to the second state upon the torque exceeding a clutch threshold torque during use, and to provide in the second state a predetermined friction torque between the hub and the output flange resulting from friction between the transmission elements and the surface of the cam and/or between the sliding bearing and the output flange such that the predetermined friction torque prevents the output flange and the hub to rotate freely from each other,
• wherein the predetermined friction torque is at least 1% of the clutch threshold torque.