Propeller mother and child transmission assembly with dual protection

A propeller mother and child transmission assembly with dual protection, comprising a child transmission shaft sleeve and a mother transmission shaft sleeve,

• wherein an outer peripheral surface of the child transmission shaft sleeve is fixedly provided with a plurality of first transmission protrusions and a plurality of second transmission protrusions, each of the first transmission protrusions and each of the second transmission protrusions are alternately arranged;
• the mother transmission shaft sleeve is provided with a plurality of first transmission recesses and a plurality of second transmission recesses, each of the first transmission recesses and each of the second transmission recesses are arranged alternately;
• when the child transmission shaft sleeve is rotatably provided in a middle position of the mother transmission shaft sleeve, each of the first transmission protrusions is threaded through each of the first transmission recesses, and each of the second transmission protrusions is threaded through each of the second transmission recesses;
• when the child transmission shaft sleeve is rotated in any direction, each of the first transmission protrusions is rotated to an angle A where it abuts against each of the first transmission recesses, each of the second transmission protrusions is rotated to an angle B where it abuts against each of the second transmission recesses, and the angle A is smaller than the angle B.