Cooling of The Spindle of Turning And Milling Machine Toolsl

In milling and turning composite machining, the spindle serves as the core component, and its temperature stability directly affects machining accuracy and tool life. With the continuous increase of speed and load, spindle cooling has evolved from a simple auxiliary function to a key technology to ensure machining quality.

Liquid cooling systems are still the preferred solution for most application scenarios. Through the spiral cooling channel inside the spindle, the constant temperature cutting fluid circulates and carries away heat from the bearings and motor windings. The advantage of this method lies in its high cooling efficiency, which can stably maintain the spindle temperature fluctuating within ± 1 ℃, providing a guarantee for the continuous high load operation of the machine. It should be noted that the temperature of the coolant is best controlled between 20-25 ℃. If it is too low, it will cause spindle shrinkage and affect accuracy. If it is too high, it will reduce the cooling effect.

The composite system of oil mist lubrication and cooling exhibits unique value in high-speed machining. When the spindle speed exceeds 12000rpm, traditional grease lubrication is no longer sufficient to meet the demand. The oil mist system mixes a small amount of lubricating oil (5-15ml/h) with compressed air and delivers it to the bearing position, which not only provides lubrication but also takes away heat. The advantage of this solution is its low friction loss, making it particularly suitable for ceramic bearing spindles. But it must be equipped with a sophisticated oil mist recovery device, otherwise it may pollute the working environment.

Circulating water cooling of the spindle housing is another effective auxiliary means. Process a cooling water jacket on the spindle housing and perform secondary cooling through an external circulating water system. Although this method cannot directly cool the internal bearings, it can effectively control the overall temperature rise of the spindle, especially suitable for long-term continuous machining conditions.

The concept of thermal symmetry design is changing the approach to spindle cooling. By optimizing the spindle structure to present a symmetrical distribution of thermal deformation, coupled with real-time monitoring and compensation by temperature sensors, accuracy can be improved without increasing the burden on the cooling system. This is like high-precision measuring instruments eliminating temperature effects through material matching, reflecting the advanced concept of "design for process".

The intelligent temperature management system represents the future development direction. By arranging multiple temperature sensors at key positions and combining the spindle load and speed information, the system can predict the temperature change trend and adjust the cooling parameters in advance. This preventive control is more precise than traditional feedback regulation, just like the intelligent temperature control system in modern buildings, which can achieve smoother temperature control.

The maintenance of the cooling system is equally important. The coolant needs to be regularly tested for pH value and concentration to prevent corrosion and bacterial growth. The pipeline system must ensure that there are no air bubbles trapped, otherwise it will affect the cooling efficiency. Just like a car needs regular oil changes, the maintenance of the cooling system directly affects the lifespan and performance of the spindle.

The selection of cooling strategy ultimately depends on specific processing requirements. For conventional processing, a mature liquid cooling system is sufficient; For high-speed precision machining, the addition of oil mist cooling or phase change cooling may be required; For ultra long continuous processing, a combination of multi-stage cooling systems may be more suitable. Just as doctors choose treatment plans based on the condition, engineers also need to select the most suitable cooling method according to the processing characteristics.

Spindle cooling may seem like an auxiliary function, but it is actually a key link in ensuring the optimal performance of the milling and turning machine tool. From traditional water cooling to cutting-edge phase change cooling, from passive temperature compensation to active intelligent control, the advancement of cooling technology is constantly expanding the boundaries of precision machining. In this field, innovation is always on the road, and every breakthrough in temperature control may lead to a leap in machining accuracy.