Motor spindle
The motorized spindle is one of the most important technical innovations of the last century - if not the entire last millennium. Because without motorized spindles, as they are used everywhere in production today, life as we know it today would not exist.
What exactly is a motorized spindle?
When we talk about a motorized spindle, we mean a shaft that is directly driven and precisely supported. This usually includes a tool interface - at least in the case of tool-carrying spindles. The counterpart to this are workpiece-carrying machines. Here there is an interface for the workpiece. However, these devices are clearly in the minority.
The motor spindle plays an important role in the machines used today in the automated manufacture of many products.
What applications are there for a motorized spindle?
As already mentioned, the motorized spindle is used in many areas of automated production. There is a simple reason for this. Hardly any other type of machine can guarantee such precise and fast machining of workpieces as a motorized spindle. With speeds of 30,000 per minute, motor spindles achieve a considerable speed and thus offer a level of production that seemed unattainable just a few decades ago.
It is therefore not surprising that the motor spindle is generally used in CNC machine tools. Whether in milling, turning or grinding machines. The motor spindle also plays an important role in the HPC and HSC sectors.Modern aviation would not be possible without the motor spindle. Automotive production is also dependent on the high reliability on the one hand and the equally high speed of the work on the other. Even mold and tool making in Germany can no longer do without the motor spindle.
Nice to know - when was the motor spindle developed?
It is a child of the late twentieth century. In the 1980s, the demands on manufacturing machines in terms of speed and precision were growing in equal measure. However, it quickly became clear that faster production was simply not possible with conventional machines and technologies.
New approaches therefore had to be developed. In fact, it was back in the 1980s that the first manufacturers came up with the idea of driving the tool-supporting spindle directly and no longer using an intermediate step. This increased the achievable speed and, at the same time, the quality of the machines many times over.
In the 1990s, a crisis emerged in the machine tool manufacturing industry. Companies took advantage of this to outsource a whole range of areas. Even back then, the production of motor spindles was an area that was ideal for outsourcing. This is because the motor spindle is a component of a large machine that is self-contained and therefore relatively self-sufficient.
The work on the machine itself can therefore be carried out by the machine tool manufacturer, while suppliers specializing in the manufacture of machine components for their customers can produce the motor spindle in parallel. This already reduces the production and delivery time for tool-carrying machines.
However, the advantage of this development was also that new companies were now focusing on motorized spindles and continuously developing the models available on the market.
What is the significance of the motor spindle in today's automated production?
In fact, it is impossible to imagine today's automated production without the motorized spindle. As mentioned, it is primarily CNC machine tools in which the motorized spindle is used. The motor spindle itself has revolutionized manufacturing processes all over the world. Significantly higher speeds - sometimes up to 30,000 revolutions per minute and more - with enormous working accuracy and the possibility of automated tool changing as a separate work step.
These few points alone make older production systems appear old and, above all, very slow and impractical next to the motorized spindle. Quite rightly so, because the success and capabilities of the modern manufacturing industry would be inconceivable without the motorized spindle.
How is a typical motor spindle constructed?
With some machines, the design differs from manufacturer to manufacturer. However, this is not a real factor for a motor spindle. Only the respective field of application and the type of machine itself can lead to differences in the design of the motor spindle. Nevertheless, the design itself is often similar and the different motor spindles are at least somewhat comparable.
The motor spindle consists of the following elements:
- The housing with the built-in cooling
- The wave
- A tool or workpiece interface
- The drive itself
- The bearing or bearings - there are usually two that are installed here
- Stator
- Rotor
- The release unit
- The tool clamp
- One mounting flange
The housing of a tool spindle is generally compact and space-saving in its design. The small space inside the spindle naturally increases the need for cooling. Oil, air or water with the appropriate coolant can be used here. Water cooling of the stator is the most common type of cooling.
The shaft is the central element of the entire spindle. The tool interface or workpiece interface is also integrated here. It is important that the shaft is rigid enough to correctly assess the enormous forces acting on it and to be able to withstand them in the end.
The tool or workpiece interface is something like the heart of the motor spindle. Without the ability to clamp a tool or workpiece and - especially in the case of tool-guiding spindles - to change the tool during operation, there can be no automated processes. For this reason, this interface must function absolutely faultlessly
The motor spindle is usually driven by an electric motor. The motor spindle is a direct drive, which can be seen at first glance on closer inspection. This is because in this case there is no gearbox between the drive or motor and the spindle or shaft that is being driven. The motor power is transferred directly to the spindle and must therefore match the motor spindle 100 percent.
The spindle bearing is another essential component of a motor spindle. It ensures that the enormous forces acting inside the machine do not fall back onto the tool or the shaft. The bearing itself must ensure that the tools in the interface continue to perform their work reliably and correctly.
The stator and rotor are the heart of the machine and represent the stationary and moving parts of the spindle. They surround the tool clamp into which the tools to be used are clamped. The release unit is responsible for opening or "releasing" the tool clamp when the tool needs to be changed.
The tool interface itself is located at the end of the motor spindle and represents the point at which the clamped tool protrudes from the machine itself.
Conclusion: The motorized spindle is one of the most important developments of the last century
It has significantly changed the manufacturing process and the lives of people around the world. This requires absolute sound judgment when manufacturing and selecting the right motor spindle for your company. Because the quality of your production stands and falls with the quality of your motor spindlesand your tool-guiding machines.