1. Loosening of anchor bolts

　　This is one of the main failure cause vibration motor burned, due to the particularity of structure vibration motor itself, both ends of the vibration force produced by the eccentric block impact anchor bolt to thousands of times per minute, again due to the vibration motor itself is concluded, pastly bolt is very easy to loose, once a bolt looseness, will be in a relatively short period of time to cause other bolt looseness, even fracture, thus burning motor.

　　Preventive measures: 1) frequently strengthen anchor bolts 2) add anti-loose devices