The spindle part of CNC milling machine is the main component

Update:30-08-2019
Summary:

The spindle part of CNC milling machine is the main com […]

The spindle part of CNC milling machine is the main component that affects the machining precision of the machine. Its rotation precision affects the machining accuracy of the workpiece; its power and rotation speed affect the machining efficiency; its automatic shifting, quasi-stop and tool change affect the automation of the machine tool. Therefore, the spindle components are required to have high rotation accuracy, stiffness, vibration resistance, wear resistance and low temperature rise in accordance with the working performance of the machine. In terms of structure, the clamping of the tool and the workpiece, the configuration of the bearing, the adjustment of the bearing clearance, and the lubrication and sealing must be well solved.

The spindle should adopt different spindle bearings according to the specifications and precision of the CNC milling machine. Generally, the spindle components of medium and small-sized CNC milling machines adopt grouped high-precision rolling bearings, heavy-duty CNC milling machines use hydrostatic bearings, high-precision CNC milling machines use hydrostatic bearings, and spindles with a rotational speed of 20000r/min use magnetic bearings or nitride. Ceramic ball bearing of silicon material.

Lubrication of the spindle. In order to ensure that the spindle has good lubrication, reduce friction and heat, and at the same time take away the heat of the spindle assembly, a circulating lubrication system is usually used. The oil is lubricated with a hydraulic pump, and the oil temperature controller is used to control the temperature of the oil in the fuel tank. Nowadays, the spindles of many CNC milling machines are lubricated with high-grade lithium-based grease sealing. The grease can be used for 710 years, which simplifies the structure, reduces the cost, and is easy to maintain. However, it is necessary to prevent the mixing of lubricating oil and grease. Sealing method. In order to meet the needs of higher speed development of the spindle speed, new lubrication cooling methods have been developed. These new lubrication cooling methods not only reduce the bearing temperature rise, but also reduce the temperature difference between the inner and outer rings of the bearing to ensure that the thermal deformation of the main shaft is small.