[Electric spindle talk] What technologies are integrated with the electric spindle?

The electric spindle is a new technology that integrates the machine tool spindle and the spindle motor in the field of CNC machine tools in recent years. Together with linear motor technology and high-speed tool technology, it will push high-speed machining to a new era.

The picture shows an outline drawing of the electric spindle.

The picture shows the electric spindle used for milling

    The electric spindle is a set of components, including the electric spindle itself and its accessories: electric spindle, high frequency inverter, oil mist lubricator, cooling device, built-in spindle encoder, tool changer.

    The technology integrated by the electric spindle:

    High-speed bearing technology: The electric spindle usually adopts composite ceramic bearing, which is wear-resistant and heat-resistant. The service life is several times that of the traditional bearing; sometimes the electromagnetic suspension bearing or the static pressure bearing is used, the inner and outer rings are not in contact, and the theoretical life is unlimited;

    High-speed motor technology: The electric spindle is the product of the motor and the main shaft. The rotor of the motor is the rotating part of the main shaft. In theory, the electric spindle can be regarded as a high-speed motor. The key technology is the dynamic balance at high speeds;

    Lubrication technology: Lubrication of electric spindles is generally based on timed quantitative spindle oil and gas lubrication; grease lubrication can also be used, but the corresponding speed should be discounted. The so-called timing is to inject oil at regular intervals. The so-called quantification is to precisely control the amount of oil per lubricant through a device called a dosing valve. Oil and gas lubrication means that the lubricating oil is blown into the ceramic bearing under the carrying of compressed air. Oil quantity control is very important, too little, and does not provide lubrication; too much, when the bearing rotates at high speed, it will heat up due to oil resistance.

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

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

   Automatic tool changer: In order to be applied to the machining center, the electric spindle is equipped with an automatic tool changer, including a disc spring, a broach cylinder, etc.;

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