Magnetic Material in Voice Coil Motor (VCM)

The Voice coil motor (VCM) is a special kind of direct drive motor, which can convert electric energy into linear mechanical energy. The principle is that a cylinder winding is placed in a uniform air gap magnetic field. The winding is energized to generate a magnetic field, which drives the load equipment to move in a straight line to change the strength and direction of the current. The size and direction of the magnetic field can be changed, so that the linear motion frequency and distance of the load equipment can be changed.

VCM has the advantages of high response, high speed, high acceleration, simple structure, small size and easy control. VCM is a core component in Hard disk drive (HDD). HDDS are the most common peripheral devices used to store information in computer systems. HDDS include a Spindle motor and a spindle positioning device. The main shaft motor has two functions: one is to drive the disk to provide enough air buoyancy, so that the magnetic head flies on the disk surface; The second is to rotate the magnetic fan (Sector) to be accessed to the head so that the head reads and writes information recorded on the disk surface. Magnetic Head positioning devices include the VCM, Arm Arm actuator and the Head assy itself. The role of voice coil motor is head positioning, so it is also called "head positioning motor".

Voice coil motor is mainly used in small stroke, high speed, high acceleration movement, suitable for small space. In addition to HDDS, common applications include autofocus drivers in mobile phone cameras. VCM magnets mainly use sintered NdFeb and bonded NdFeb, mainly 42M, 45M, 45H, 48M and other brands of products, 50M, 52M, 48H also occupy a certain market share.