Spindles for brushing with compliance by Mannesmann Demag for your robot

Spindles with Deflection for Brushing by Mannesmann Demag for Your Robot

Robot spindles with deflection from Mannesmann Demag are specifically designed for automated brushing processes at manufacturing and assembly stations. They combine a compact design with precise eccentric movement, allowing for controlled paths and reproducible contact forces. For use in robot cells, the **shaft form, bearing, mounting flange**, and connection variants are crucial to ensure the spindle can be securely integrated into the robot's kinematics and that the brush heads are guided effectively.

Core Function and Operating Principle

The deflection in these spindles is achieved via eccentrically mounted spindle heads or integrated connecting rods, which move the brush laterally or radially within a defined stroke. This enables both linear brushing movements and rotating overlays for complex surface treatments. By combining the winding arrangement, bearing pressure, and deflection mechanism, the contact force per brush fiber can be precisely specified, which is particularly relevant for coatings, deburring, or surface finishing.

Materials, Seals, and Protection Classes

Mannesmann Demag offers spindles in various material designs: die-cast aluminum housings for low weight and good heat dissipation, steel housings for maximum rigidity, and stainless steel variants for corrosion resistance in wet or chemically aggressive environments. Bearing components are typically made of hardened rolling bearing steel; special bearings with ceramic coating reduce wear and extend service life during high operating times. Sealing is achieved through multi-stage sealing concepts: labyrinth seals in conjunction with radial shaft seals (NBR or FKM) and optional protective covers for abrasive environments. Spindles with IP classification up to IP67 are available, which is important for wet processes or splash water. For applications with coolants or emulsions, the stainless steel version with FKM seals and additional overpressure valves is recommended to reliably prevent the ingress of particles and liquids.

Designs, Connections, and Interfaces

Mannesmann Demag spindles offer various connection options: standardized HSK or ISO interfaces for tool changes, customer-specific quick couplings for electrical and pneumatic lines, and integrated rotary unions for media supply to rotating brush heads. Electrical variants are available with brushless motors (BLDC) or collision-resistant commutator motors; control signals are transmitted via SSI, EnDat, or simple PWM control. Mechanical mounting surfaces are available in versions with and without a flat flange for direct mounting on robot wrists or intermediate flanges.

Performance, Torque, and Deflection Frequency

For brushing tasks, frequency, stroke, and contact force are the decisive parameters. Mannesmann Demag offers spindles with deflection strokes from a few 0.1 mm to several millimeters and oscillation frequencies from a few Hertz up to the kilohertz range. Higher frequencies are suitable for fine surface treatment and smooth finishes, while larger strokes are required for heavy deburring or the removal of solder residues. Torque specifications and power consumption must be considered in the robot kinematics, as deflection forces can act on axis moments. The spindle characteristics (power, nominal torque, max. load) are specified in the technical documentation and must be coordinated with the robot controller and power supply.

Integration into Robot Cells and Control

Integration includes mechanical fastening, power supply (electrical, pneumatic, possibly hydraulic), and signal networking. For reproducible brushing paths, close interlocking between spindle control and robot control is necessary: force measurement, path compensation, and real-time control of the deflection increase process stability. Mannesmann Demag spindles can be connected to robot controllers via standardized fieldbuses or digital IOs and support real-time parameters such as target speed, stroke width, and phase position. For collaborative applications, force limitations and software-side collision detection parameters must be configured.

Economic Efficiency, Service Life, and Maintenance

Operating costs depend on bearing quality, sealing system, and maintenance cycles. Spindles with higher-quality bearings and additional dirt protection measures show longer interval-free operating times. Service-friendly designs with interchangeable bearing cartridges and modular brush adapters reduce downtime. Maintenance measures include regular lubrication intervals, checking the seals, and controlling axial play; documented inspection intervals based on operating hours and load cycles are part of the technical specification.

Customization Options and Special Designs

Customer adaptations include modified flange dimensions, special materials for high-temperature or cleanroom environments, integrated sensors for position and force monitoring, and modified brush holders for various brush types (wire, filament, Scotch-Brite® equivalents). For potentially explosive areas (ATEX), suitable configurations are possible, including antistatic materials and certified motors. If required, a hybrid solution with combined rotation and deflection can be implemented to efficiently process complex surface geometries.

Practical Examples

**Practical Example 1 – Deburring of CNC Milled Parts:** Robot guides workpiece into spindle zone, spindle activates eccentric deflection with 0.8 mm stroke at 50 Hz; stainless steel monofilament brush removes burrs from edges, contact force limited to 10 N via force sensor, action time 1.2 s per component, HSK spindle connection for quick assembly changes. **Practical Example 2 – Surface Finish on Cable Holders:** In a transfer line, the robot handles component feeding, stainless steel housing spindle with FKM seals operates in a wet process; stroke 0.2 mm at 500 Hz, nylon brushes to prevent scratches, media supply via integrated rotary union, with automatic brush cleaning by flushing cycle after 2000 parts. **Practical Example 3 – Pre-treatment before Bonding Process:** Robot processes contact surfaces with rotating overlay deflection, controlled roughness increase through combined rotation and lateral stroke, parameter set transferred to the robot controller via EnDat, quality assurance through inline roughness measurement and feedback of measurement data to the process control system. * Selection criteria: Stroke & frequency, material & seal type, connection & controllability, protection class & maintainability, special equipment (sensors, ATEX, media transfer)

Safety and Quality Aspects

When integrating into robot cells, safety measures such as safety shutdowns, associated emergency stop functions, and collision safety checks are mandatory. Quality testing includes measurement protocols for concentricity, deflection precision, and force constancy. Series measurements during production ensure process parameters and enable trend analyses for early detection of wear. For documented supply chains and traceability, Mannesmann Demag provides material certificates and test data upon request. Further technical information on interfaces and robot integration, as well as practical examples, can be found under [Technik](https://maku-industrie.de/technik) and [Anwendungsbeispiele](https://maku-industrie.de/anwendungsbeispiele).

Frequently Asked Questions (FAQ)

**Q: What protection class should my spindle have for wet processes?**
A: For splash water and occasional cleaning cycles, at least IP65 is recommended; for continuous immersion or heavily contaminated environments, IP67 or an additional protective cover with a stainless steel housing and FKM seals is preferable. **Q: How do I choose the stroke and frequency for my brushing process?**
A: The choice depends on the desired roughness level and the material: fine finishes require small strokes (<0.5 mm) and high frequencies (>200 Hz), coarse deburring requires larger strokes (>0.5 mm) at lower frequencies. Test series with roughness measurement (Ra/Rz) are useful for parameterization. **Q: Which interfaces do Mannesmann Demag spindles support for robot integration?**
A: Common interfaces include HSK/ISO mounts, electrical connections with EnDat/SSI or PWM, digital IOs, and fieldbuses. Rotary unions are available for media supply to rotating heads. The exact configuration is coordinated project-specifically.