The numerical control machine generates high heat when it is working, which makes the temperature of the machine tool spindle rise and is easily damaged. The machine tool spindle component is an important component of the mechanical part of the numerical control machine, which is mainly composed of the spindle, bearing, spindle stop device, automatic clamping and chip removal device. The cooling and maintenance of machine tool spindle components are issues worthy of attention during the use of numerical control machine. The maintenance of machine tool spindle components mainly lies in lubrication and sealing.
The cooling of machine tool spindle components is mainly to reduce bearing heating and effectively control the heat source.
The maintenance of machine tool spindle components mainly lies in lubrication and sealing.
First, a good lubrication effect can reduce the operating temperature of the bearing and prolong the service life of the machine tool spindle components.
Pay attention to the operation and use: at low speed, use grease and oil circulating lubrication; at high speed, use oil mist and oil-air lubrication. However, when grease is used for lubrication, the enclosed amount of the machine tool spindle bearing is usually 10% of the bearing space volume. Do not fill it up at will, because too much grease will increase the spindle heat. For oil circulating lubrication, check the lubrication constant temperature oil tank of the main shaft of the machine tool every day during operation and use to see if the oil quantity is sufficient. If the oil quantity is insufficient, add lubricating oil in time; at the same time, pay attention to check whether the lubricating oil temperature range is appropriate .
In order to ensure that the main shaft has good lubrication, reduce friction and heat, and at the same time take away the heat of the machine tool spindle components, a circulating lubrication system is usually used, with a hydraulic pump for strong oil lubrication, and an oil temperature controller to control the temperature of the oil in the tank. The spindle bearings of high-end CNC machine tools are lubricated by high-grade grease sealing, and each time the grease is added, it can be used for 7-10 years. The new lubrication cooling method not only reduces the temperature rise of the bearing, but also reduces the temperature difference between the inner and outer rings of the bearing to ensure that the thermal deformation of the machine tool spindle components is small.
There are two common lubrication methods for machine tool spindle components.
The oil-air lubrication method is similar to the oil-mist lubrication method, but the oil-mist lubrication method is to supply oil mist continuously, while the oil-air lubrication method sends the oil mist into the bearing gap regularly and quantitatively, which not only realizes oil mist lubrication, but also avoids oil Too much fog pollutes the surrounding air. The injection lubrication method is to inject a larger flow of constant temperature oil into the spindle bearing to achieve the purpose of lubrication and cooling. Here, the oil injected with a larger flow rate must be forced to drain by the drain pump instead of returning naturally. At the same time, a dedicated large-capacity, high-precision constant temperature oil tank is also used, and the oil temperature variation is controlled at ±0.5°C.
Second, the sealing of the machine tool spindle components not only prevents dust, chips and cutting fluid from entering the spindle parts, but also prevents the leakage of lubricating oil.
The seals of machine tool spindle components have contact and non-contact seals. For contact seals using linoleum rings and oil-resistant rubber seals, pay attention to checking for aging and damage; for non-contact seals, in order to prevent leakage, it is important to ensure that the oil return can be drained as soon as possible, and the oil return hole should be unobstructed .
To sum up, in the use and maintenance of numerical control machine, we must attach great importance to the cooling and maintenance of machine tool spindle components, and carefully do this work.