Useful information about mechatron

We aim to give additional information to every customer and technologically enthusiastic person in terms of technology, design and construction of prospective and existing spindle systems.

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Hybrid bearings

Hybrid bearings are rolling bearings including ceramic (such as Silicon Nitride Si3N4) steel rings (such as 100Cr6). Hybrid bearings provide the following benefits compared to rolling elements made of steel: 

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  • Ceramic material is a significantly more durable material, providing better protection against seizures and wear and tear, increasing the lifespan disproportionately
  • The decreased centrifugal forces help to reduce friction at high RPM, a result of a decreased rolling element density
  • Steel bearings can easily be damaged due to spark erosion, hybrid bearings are never affected likewise because of its insulated rolling element
  • These insulating properties are useful when processing conductive work pieces (Spindle shaft and body close the electric circuit only when touching the work piece)
We provide professional Series spindles with hybrid bearings (additional charge) if requested.

Corner frequency & Field weakening range

Operating HF Motors within the field weakening range is a method to achieve a wide RPM range, combining high torque at low RPM as well as high RPM's when needed.

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The corner frequency describes the specific motor frequence when reaching its performance peak - usually describing the nominal motor point.

The average output voltage will reach its peak at the corner frequency. The motor has a constant torque level when constantly increasing the voltage level, in addition it is possible to "boost" the system to increase the torque level in case your motor is designed likewise.

Field weakening can appear when exceeding the corner frequency. The operating frequency - including RPM - will increase, magnetic motor flow decrease on a constant voltage level.

This effect causes a reciprocal behaviour of torque and RPM, the power output remains constant. Please note: Non-linear friction and iron losses reduce the shaft power including a performance factor change (cos&phi) due to increased slack.

Many spindles within the professional series are designed to be operated within the field weakening range. We have the knowledge and technical possibilities to use this process through different frequency inverter settings - enabling to use the full spindle potential.

Feel free to contact us.

Spindle bearings

The predominant motor spindle bearings are preloaded springs with solid and floating bearings.

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The bearing pair A-Side is predominantly fix-mounted to the housing via the outer ring. The connection to the shaft is guaranteed via the inner ring. Spindle bearing layouts can be characterized as follows:

  • Tandem layout: High axial load capacity on one side only, high radial stiffnes, precise spring preload through adjusted B-Side bearings
  • O-layout: Improved support base resulting in high radial stiffness, axial durability during high load on both sides, bearing-pairs are self-preloaded when having fixed outer rings
  • X-layout: Reduced support base resulting in less radial stiffnes, high radial load capacity ion both sides, less-used bearing layout when designing motor spindles

B-Side bearings (bearing-pairs) are usually directly mounted to the shaft. These bearings "float" on the bearing seat to compensate linear expansions between shaft and housing. It is crucial to define the springs' preload via the spring package onto the outher ring. The number of bearings and pairing can vary upon different layouts.

If you are interested in additional information about the use of layout variations depending on the spindle type and whether these types result in different advantages for your specific use, please don't hesitate to contact us.

Support Base

The support base of a bearing pair is defined as the distance from the middle shaft line including the extended lines of force from the inner to the outer bearing rings.

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A high-valued support base helps to increase the radial bearing stiffness - this is a desired effect when working with high feeding forces. It can be achieved with the following layouts:
  • Use of precisive-grinded spacer rings
  • Bearing set mounted in O-layout
  • Additional use of bearings with higher contact angle 0
  • Use of three or more paired bearings

High Speed Cutting (HSC)

High Speed Cutting is a ultra-modern machine cutting process when talking about CNC-milling.

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Characteristic features are a significant increase in RPM and feed-rate while reducing chip thickness compared to conventional maching operations.

In theory, this process is based on the thermal inertia between used materials: When cutting, a heat quantity is created through deformation and frictional work. Heat conduction distributes energy to both, tool and work piece. The contact time can be reduced when increasing RPM and therefore cutting speeds.

When exceeding a certain cutting speed cutting temperatures can even be reduced. This can be explained when comparing cutting and heat conduction time - meaning that it takes more time to transfer the heat than to cut the work piece with the corresponding increased cutting speed.

HSC-Processing offers the following advantages:

  •   Reduced cutting forces (up to 30 times)

o   The machine can be mounted with a much lower stability factor

o   Improved thin-walled work piece processing

o   Lowered technical demands to solid clamping devices impoving the vacuum clamping technology

  • Increased chip volume per time unit and increased feeding speeds - up to 10 times
  • Significant suface quality improvement, renouncement of mechanical post processing - up to the dismiss of downstream grinding/polishing processes.
  • Hard processing of tool steels possible

If you are interested in High Speed Cutting and our HSC-Spindles, do not hesitate to contact us.

We are continuously working on additional information for our "Did you know...?"-Section. Our drive is to provide valuable suggestions and on-hand advices to bring this cutting-edge technology to our spindles and your personal use.

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