Xinfeng magnet Company found and summarized in the experience of common design with customers for many years: there are many factors of permanent magnet synchronous rotor motor magnet bonding failure, and mostly for the process, for permanent magnet synchronous motor rotor magnet bonding, need to focus on the following points:
1. Selection of binder. According to the specification of temperature range of products in “Basic Technical Conditions of Automotive Electrical Equipment”, the operating temperature range of double pinion and rack assisted motor installed in the engine compartment is -40°~200°. Therefore, it is necessary to pay attention to the shear strength of the binder at 200° and calculate the corresponding allowable shear force. Ensure that the allowable shear force is much greater than the force applied to the magnet.
2. Control the surface cleanliness of motor parts. The cleanliness of the rotor core surface, magnet surface and glue coating equipment is very important, which directly affects the bonding effect and the fatigue life of the rotor magnet after bonding. The root cause of Toyota’s recall is that the surface cleanliness of the iron core is not up to standard, resulting in unstable bonding of magnets.
3. The amount of binder. This is related to the surface area of the magnet, the basic requirement is that the adhesive layer should be distributed in more than 2/3 of the magnet area, too little binder will lead to unstable bonding.
4. Baking and heat preservation time control. Strictly in accordance with the selection of adhesive instructions to control the baking and insulation time, need to pay attention to the baking and insulation equipment temperature is evenly distributed.
5. Product online testing. All rotors should be tested for bonding strength after permanent magnet bonding and baking and cooling to room temperature to ensure its safety. It is generally recommended to use fixed rotor core and apply its large force force of about 20 times to the magnet.
Post time: Apr-06-2022