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Difference between belt drive and direct drive of CNC machining center

CNC machining center spindle according to the different transmission mode is divided into gear transmission spindle, belt transmission spindle, direct transmission spindle and electric spindle four types, the four types of spindle according to its own characteristics in different occasions.

Gear drive spindle: spindle speed is generally 6000r/min, more suitable for heavy cutting occasions.

Belt drive spindle (synchronous belt drive spindle) : mainly driven by the belt teeth on the spindle, the spindle speed is generally 8000r/min, this kind of spindle is more suitable for use in heavy cutting occasions.

Direct drive spindle: driven by the motor through the shaft coupling connected spindle, the speed of this kind of spindle is generally in 1000-18000r /min, direct spindle is not suitable for heavy cutting, only suitable for processing small workpiece, suitable for finishing machining occasions.

Motorized spindle: The spindle is integrated with the motor, the motor is the spindle, the spindle is the motor, the motor and the spindle are combined into one, this spindle is the world’s fastest spindle, its speed is more than 18000r/min, such as electric spindle adopts aerostatic bearing and magnetic floating bearing, its speed can reach 100000r/min, Such spindles are generally used in finishing applications, not in heavy cutting applications.

In actual use, we also need to consider more factors, such as whether routine maintenance and repair costs. Machining center belt transmission spindle, in the maintenance of the replacement of the belt cheap, but in the replacement of parts will not be accurate positioning, and debugging trouble, often heavy chip easy to damage the belt teeth;  Direct drive spindle, stronger power, not easy to break, but a bad maintenance is a big project, usually direct drive spindle is more expensive.  Customers can choose suitable spindle connection mode according to their actual use requirements.  Of course, our engineers can also provide you with more professional advice.

Can three axis CNC machining center process curves?

Three-axis CNC machining center can process curves and surfaces, but only simple curves and surfaces.  Such as mold cavity, vertical surface, due to the small number of controllable axes, after a clamping can only complete the processing of one of the six sides, the other several sides to be reclamped after processing, for some of the more complex continuous surface work efficiency is very low or can not be processed at all.

Therefore, when three axis CNC machining center of choose and buy, if it is to process complex curve surface products, military, aviation, aerospace, scientific research, precision machinery and other industries, products such as aircraft turbine engine blades, Marine propeller, large diesel engine crankshaft, guide wheel, CAM, etc. These will not be able to process the complex curved surface parts, can only choose five axis CNC machining center;  If it is a simple curve and surface, the number is not much, you can do a good job in the processing of coordinate accuracy, multiple clamping implementation.

In view of the simple curve and surface of the workpiece, in machining will encounter some special-shaped complex parts, some need four or five axis machining center to process.  The cost of four-axis CNC machining center is generally acceptable for enterprises, but the cost of five-axis CNC machining center is expensive.  So in the existing three axis CNC machining center, some simple surface parts or through the design of processing technology, parts clamping method and so on.

Using three axis CNC machining center production, reduce the production cost of enterprises.  Such as mold injection material turn round transition board, this part of the difficulty lies in the middle part of inner chamber is round transformation square surface structure, the length of a rectangle is more than the diameter of the circle, and the width of a rectangle is less than the diameter of the circle, eight upside down from a long side direction used to be a rectangle structure, but looking over the short edge direction is the structure of the eight.  Because the width of the rectangle is less than the diameter of the circle, if the three-axis vertical CNC machining center is used for processing, no matter from which side of the cutting tool and parts will cause interference.

This kind of part processing needs the spindle or workpiece to be able to rotate or swing the Angle of processing.  Usually, it is best to use five axis vertical CNC machining center for processing production.  Because there is no five-axis CNC machining center, it is limited by processing conditions.  Under the existing processing conditions, how to reasonably design the processing technology according to the characteristics of the product, and use the existing equipment to effectively process the product.

The operator can use the fixture to place the product at a certain Angle, and can process simple curves and surfaces on the three-axis vertical CNC machining center.

What are the auxiliary devices of CNC machining center?  What do they do?

Although the auxiliary equipment on the CNC machining center does not participate in the machining of the workpiece, it also plays a great role in the CNC machining center, especially the machining efficiency and machining accuracy of multiple machines play an important role.  CNC machining center auxiliary equipment mainly includes: lubrication, cooling, chip removal, protection, etc.  These are auxiliary equipment for the processing center.  Their main functions are:

Lubrication equipment is also a lubrication system, which can lubricate the moving parts of the CNC machining center, such as guide rail, spindle, screw and other moving parts.  If there is no lubrication system in the CNC machining center, it will cause wear of the guide rail, spindle and lead screw.  A long time will not only affect the machining accuracy of CNC machining center will also affect the service life.

The cooling system is mainly used to cool the high temperature produced by the CNC machining center. The main parts and tools are prone to high temperature.  So the cooling system is mainly for the workpiece and tool cooling.  If there is no cooling system in CNC machining center, high temperature and spark will lead to workpiece deformation, which directly affects the quality of workpiece and tool life.

When heavecutting, CNC machining center produces many metal scraps, if there is no chip removal device will happen then scrap metal scrap winding tool, or accumulation in artifacts and table surface, not only make the CNC machining center will not work and may cause safety accidents, so the chip removal device for heavy cutting CNC machining center is very important.

Protection is needed for each machining center, and protective cover needs to be installed on the guide rail, otherwise the scrap metal will enter the guide rail.  The guide rail is deformed or even damaged.

CNC machining center there are many auxiliary devices, when customers buy CNC machining center can choose according to their own needs.

What is a nitrogen balancing device?

Nitrogen balancing device is also called nitrogen balancing system, it eliminates the traditional counterweight in the vertical direction of rapid movement and reverse jitter and because of the counterweight block jitter caused by CNC machining center vibration.  More sensitive reaction, no impact, reduce the lag of servo response.  It can greatly improve the surface precision of the workpiece.  The working principle of the nitrogen balancing device is that when the spindle rises, the hydraulic oil in the accumulator enters the balance cylinder, and the compressed air from the upper part of the balance cylinder is discharged. Then the nitrogen expands and presses the oil into the balance cylinder.  An upward pressure is created to balance the weight of the headstock itself.  When the headstock is descending, it is shunt through the accumulator into the balance cylinders on both sides of the headstock.

CNC machining center nitrogen balance system includes nitrogen cylinder, control system and balance cylinder.  The nitrogen cylinder is usually arranged on one side of the column, and the top of the column is provided with a balancing cylinder.  Nitrogen cylinder filling control system.  The control system is connected with the balance cylinder through the air pipe.  Nitrogen balance weight system make up for the deficiency of the traditional method of balancing and present some, solve the problems existing in the method of balancing the other, so as to improve the processing speed and precision of the machine and the product surface quality and prolong the tool life and keep the precision of numerical control vertical CNC machining center spindle, it compared with the existing balance method is an innovation.

Differences between nitrogen balance cylinder counterweight system and other counterweight methods:

1. Counterweight of servo brake motor: the screw is enlarged and the screw pitch is enlarged.  This method is fast, but the temperature rise is fast and high, the power consumption is large, the screw loss is large, and the maintenance cost is high.
2. Weight block: this method is low cost, poor reaction characteristics, can not be applied to high speed cutting.  The need for large space, high-speed movement is easy to produce spindle unit vibration and affect the machining accuracy, the tool is easy to wear, shorten the life.
3. Oil pressure balancing weight (oil pressure cylinder + oil pressure control unit) : medium speed, reaction is not agile enough and accuracy is not high. It is must to deal with the oil temperature rise of the oil pressure loop.
4. Nitrogen balancing system: this method has small volume, low energy consumption, low maintenance cost, applied to CNC machines, can easily reach 48 m/min, high repetition accuracy, less product design change, energy saving and low maintenance cost.