Machine Tools & Rotary Tables
Direct Drive Applications
Machine Tools & Rotary Tables — Direct Drive Applications
The rotary and feed axes of machine tools demand the highest levels of torque density, stiffness, positioning accuracy and dynamic response. Direct-drive motors eliminate intermediate elements such as gears, belts and couplings, driving the load directly with zero backlash and maintenance-free operation: torque motors for rotary tables, swivel axes, indexing tables and workpiece spindles, and iron-core linear motors for high-dynamic feed axes.
Key Drive Challenges in Machine ToolsKey drive challenges in machine tools
From grinding and milling machines to machining centers and rotary tables, machine tools require drive systems that combine high torque, high stiffness, high precision and high dynamics.
High Torque Density & StiffnessHigh Torque Density & Stiffness
Rotary tables, swivel axes and workpiece spindles must output high torque and maintain high stiffness within limited installation space. RKI provides the maximum torque in the available space — up to +30% torque compared to the RI series; segmented motors make the high-torque requirements of large-diameter rotary tables economically viable.
Zero Backlash & Positioning AccuracyZero Backlash & Positioning Accuracy
Direct drive eliminates the backlash, elasticity and hysteresis caused by gears and couplings; positioning accuracy and repeatability depend on the measuring system rather than the drive train. SRV motors run exceptionally smoothly and can machine top-grade surfaces with extremely high form and dimensional accuracy, free of optical defects.
High Dynamics & SpeedHigh Dynamics & Speed
HSC high-speed cutting and fast CNC axes require high acceleration/deceleration and high speed. The redesigned laminated magnet carrier of RKI reduces eddy-current losses for higher speed; the L7 water-cooled iron-core linear motor delivers high-dynamic feed, purpose-built for machine tools and handling systems.
Maintenance-Free & CoolingMaintenance-Free & Cooling
Machine tools run continuously and require long-term drive stability. Direct-drive motors are contactless, wear-free and near maintenance-free; the RIB / RKI stator is fully potted with external liquid cooling, the RE external-rotor offers efficient cooling, and the L7 mover comes standard with water cooling, reducing power loss by up to 50% at the same thrust.
Direct Drive Solutions for Machine ToolsDirect drive solutions for machine tools
Select the corresponding torque motor or linear motor based on the torque, speed, accuracy and installation-space requirements of the rotary or feed axis.
High-Performance Internal-Rotor Torque MotorHigh-Performance Internal-Rotor Torque Motor
Slotted high-performance internal-rotor motor with a laminated magnet carrier that reduces eddy-current losses. Available in 7 fixed outer diameters with a 25 mm stator increment and R10 / R12 / R22 magnet versions (high-speed / balanced / high-torque). Ideal for fast rotary axes, CNC axes and workpiece spindles.
- Peak torque 88 – 17,670 Nm
- Outer diameter 230 – 1030 mm
- Vs. RI: +30% torque, +400% speed, −40% thermal loss
- Fully potted stator, external liquid cooling, maintenance-free
External-Rotor High-Power-Density Torque MotorExternal-Rotor Torque Motor
Slotted permanent-magnet external-rotor AC synchronous motor that integrates well into rotary systems, achieving maximum power density in minimum installation space. Usable as a direct-drive rotary table or for swivel axes, with efficient cooling, compact design and near maintenance-free operation. Ideal for machining centers, HSC, tool changers and milling heads.
- Peak torque 114 – 8,162 Nm
- Outer diameter 230 – 734 mm
- Synchronism and torque consistency superior to the RI series
- Usable as a direct-drive rotary table or for swivel axes
Ultra-Precision Internal-Rotor Torque MotorPrecision Internal-Rotor Torque Motor
Slotted permanent-magnet internal-rotor direct-drive motor running exceptionally smoothly with no pulsating axial and radial forces, delivering full torque even at low speed. Capable of machining top-grade surfaces with extremely high form and dimensional accuracy and free of optical defects, reducing post-machining time and cost. Ideal for grinding machines, gear machining machines and indexing tables.
- Air-gap diameter 89 – 384 mm
- Kit height 25 – 200 mm, up to 14,000 rpm
- Electrical time constant just 1/10, for fast response
- Highest running smoothness, excellent synchronism
Segmented Torque MotorSegmented Torque Motor
Primary / secondary parts designed as segments rather than continuous rings, scaling torque via the number of segments to make very large diameters (such as large rotary tables) economically viable. Redundant design, reduced maintenance needs and lower mass — ideal for large rotary tables and indexing axes.
- Segment tangential force 560 – 4500 N
- Peak torque up to 182,575 Nm (135,739 Nm with cooling)
- Ideal for large-diameter rotary tables (> 1260 mm)
- Magnet height 25 – 200 mm (25 mm increments)
Iron-Core Linear Motors (Feed Axes)Iron-Core Linear Motors
L7 is a new-generation water-cooled iron-core linear motor with peak force up to 24,313 N, purpose-built for machine tools and handling systems, reducing power loss by up to 50% at the same thrust. The L1 series is optimized for ultimate efficiency, providing maximum force in limited space. Drives the feed motion of milling, turning, grinding and HSC axes.
- L7 peak force 4,052 – 24,313 N (4 widths × 3 lengths = 12 models)
- L1 peak force 169 – 5,171 N
- Applications: milling, turning, grinding, HSC axes, PCB drilling machines
- Maintenance-free, zero backlash, compliant with Ecodesign 2009/125/EC (L7)
Typical Direct-Drive Applications in Machine ToolsTypical direct-drive applications in machine tools
The following correspond to the machine-tool application scope listed for each torque motor series on the Schaeffler Industrial Drives website.
Explore Related ApplicationsExplore related applications
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