The biggest potential safety hazard is the difference in material hardness between bolt steel and aluminum alloy materials, manufacturing process errors, and technical requirements for on-site installation.
First, the hardness of the bolt steel is about 35 degrees, and the hardness of the aluminum alloy is about 16 degrees. Once the two materials rub against each other, shift or even collide, the aluminum alloy must be cut, and the accumulated cutting damage may cause damage to the blade. ,fracture.
Secondly, with respect to the mounting method in which the hub petiole is inserted into the inner cavity of the aluminum alloy blade, the inner cavity of the aluminum alloy is difficult to process, and there are differences in manufacturing dimensions and errors, and it is difficult to form a close-fitting joint surface on the petiole surface and the blade cavity. When the solid bolt presses the blade shank and the blade, it is difficult for the joint surface to form enough contact friction force. At this time, in the event of violent mutual movement, the blade and the petiole may displace each other, which may cause the thread of the fastening bolt to cut the aluminum alloy blade.
Finally, the connection between the petiole and the blade needs to be completed at the installation site. Due to duration, responsibility, skills
It is difficult to ensure that the tightening force of the fastening bolts is of the same height as that of the installation equipment. If the pressing force is too large, the surface of the blade may collapse, and the too small pressing force may cause the thread to cut the blade.