Electric Spindle

Electric spindle is a new technology that has appeared in the field of CNC machine tools in recent years. It integrates the machine tool spindle and the spindle motor. Together with linear motor technology and high-speed tool technology, it will push high-speed machining into a new era. The electric spindle is a set of components, which includes the electric spindle itself and its accessories: electric spindle, high-frequency frequency conversion device, oil mist lubricator, cooling device, built-in encoder, tool changer.

 

 

Technology integrated by the electric spindle:

• High-speed bearing technology: Electric spindles usually use composite ceramic bearings, which are wear-resistant and heat-resistant, and their lifespan is several times that of traditional bearings; sometimes electromagnetic suspension bearings or static pressure bearings are also used, and the inner and outer rings do not contact, and the lifespan is theoretically unlimited;
• High-speed motor technology: The electric spindle is the product of the fusion of the motor and the spindle. The rotor of the motor is the rotating part of the spindle. In theory, the electric spindle can be regarded as a high-speed motor. The key technology is dynamic balancing at high speed;

 

Lubrication: The lubrication of the electric spindle generally adopts timed and quantitative oil and gas lubrication; grease lubrication can also be used, but the corresponding speed will be discounted. The so-called timing means injecting oil once at a certain time interval. The so-called quantitative means that the amount of lubricating oil is accurately controlled each time through a device called a quantitative valve. Oil-gas lubrication means that the lubricating oil is blown into the ceramic bearing under the carrier of compressed air. Oil quantity control is very important. Too little oil will not play a lubricating role; too much oil will cause heat due to the resistance of the oil when the bearing rotates at high speed.

 

Cooling device: In order to dissipate the heat of the high-speed electric spindle as soon as possible, the outer wall of the electric spindle is usually circulated with coolant. The function of the cooling device is to maintain the temperature of the coolant.

Built-in pulse encoder: In order to achieve automatic tool change and rigid tapping, the electric spindle has a built-in pulse encoder to achieve accurate phase angle control and coordination with feed.
 

Automatic tool changer: In order to be used in machining centers, the electric spindle is equipped with an automatic tool changer, including disc springs, broaching cylinders, etc.;
 

High-speed tool clamping method: The well-known BT and ISO tools have been proven in practice to be unsuitable for high-speed machining. In this case, high-speed tools such as HSK and SKI appear.
 

High-frequency frequency conversion device: To achieve a spindle speed of tens of thousands or even hundreds of thousands of revolutions per minute, a high-frequency frequency conversion device must be used to drive the built-in high-speed motor of the spindle. The output frequency of the frequency converter must reach thousands or several kilohertz.