Spindles for brushing with compliance by Mannesmann Demag for your robot

Spindles with Deflection for Brushing by Mannesmann Demag for Your Robot

Spindles with deflection from Mannesmann Demag are specifically designed for robotic workstations that require precise, repeatable brushing processes on various workpiece geometries. These spindles combine encapsulated drive technology with a mechanical deflection mechanism that allows defined lateral and axial movements. Typical applications include deburring, surface preparation before painting, weld seam post-processing, and the removal of oxide layers on steel and stainless steel components.

Construction and Materials

Housing and Shaft: Mannesmann Demag spindle housings and shafts are usually made of high-strength steel (1.4301/1.4307 for stainless steel options) or hardened tool steel for wear-intensive applications. For corrosive environments, versions with surface-treated housings (nitriding, zinc-nickel plating) or entirely made of stainless steel are available. The shafts are often ground and laser-balanced to minimize vibrations at high speeds.

Bearings: Double-row precision ball bearings or ceramic bearings ensure axial and radial stiffness; combined axial-radial bearing arrangements are used when high side forces occur due to brush contact. For high-speed variants, hybrid ceramic bearings are employed, which improve temperature and lubricant resistance.

Sealing and Protection: Spindles with deflection are often equipped with multiple sealing systems: external labyrinth seals against coarse particles, combined radial shaft seals (NBR, FKM), and optional protective sleeves made of polyurethane or PTFE for additional sealing against abrasive materials. For wet conditions or the use of cooling lubricants, hermetically encapsulated variants with special lubrication are available.

Drive, Connections, and Control

Motor Integration: The spindles are supplied as direct drives or with angular gears. Direct drive spindles use brushless DC or synchronous servo motors with encoders for speed and position control. Angular gear solutions utilize planetary or spur gear stages when the robot arm is positioned laterally. Motor mounting complies with common industry standards (IEC, NEMA) to ensure easy replacement and assembly.

Electrical Connections: Plug connections are available in protection classes up to IP67 and IP69K; optional M12 or M23 connectors for signals and power enable quick robot changes. Control cabinet interfaces support standard protocols such as EtherCAT, PROFINET, or CANopen for integration into existing control architectures.

Sensor Technology: Integrated speed and torque monitoring provides real-time data for process monitoring. Many models also offer position detection of the deflection mechanism via magnetic or optical sensors to ensure exact repeatability.

Deflection Mechanics and Adjustability

Deflection Principles: Deflection occurs mechanically via eccentric bearings, controlled fork arms, or hydraulically/pneumatically actuated tilting mechanisms. Mechanical eccentrics are particularly compact and robust; hydraulic systems allow fine force control at high contact pressure. Selectable options include free deflection systems for automatic force feedback or fixed, defined angular positions for reproducible grinding and brushing processes.

Adjustment Ranges: Typical deflection ranges are between ±3° and ±15° or laterally up to 10 mm for specialized models. Fine adjustment is performed via scaling on the housing or digitally via the robot control in combination with position feedback.

Brush Holder, Clamping Systems, and Interfaces

Holders: Standard holders include HSK, ISO, or custom clamping systems for cylindrical shank brushes, cup brushes, and filament brushes with shank diameters from 6–32 mm. Quick-clamping systems enable tool changes in seconds, which is important for cycle-time-critical processes. For abrasive brushes, reinforced flange adapters and ceramic inserts are available to minimize wear.

Torque and Speed Profiles: Brushing processes often require moderate speeds with high torque. Mannesmann Demag spindles cover ranges from 500 to 12,000 rpm, with configurable torque limits and ramp-up profiles to prevent workpiece distortion. Torque sensing enables automatic braking in case of increased resistance, protecting the motor and brush.

Thermal Management and Lubrication

Heat Dissipation: Highly dynamic brushing processes generate thermal load; spindles are available with cooling fins, internal oil circulation systems, or optional liquid cooling (water/glycol). Temperature monitoring via thermistor or PT100 can be used for process control and condition monitoring.

Lubrication Systems: Permanent grease filling with high-temperature grease is standard for low-maintenance applications. For high load changes, central or external lube options with dosing pumps are available, which automatically regulate lubrication intervals.

Integration and Safety Aspects

Mechanical Interface to the Robot: Mounting adapters are matched to robot flange dimensions, including centering dowel pins and torque-resistant screw connections. Vibration-damped intermediate plates reduce vibration transmission to the robot arm.

Process Safety: Overload protection, torque thresholds, and electronic monitoring enable automatic fault detection and safe shutdown. Protective covers and draft-proof seals minimize particle ingress into processing cells. For explosion-proof areas, versions with ATEX certification are available.

Maintenance, Service Life, and Replacement Parts

Maintenance Concepts: Inspection recommendations include bearing inspection, seal testing, and brush wear measurement at defined intervals depending on operating hours and load. Replacement kits with bearing and seal sets reduce downtime. Spare part numbers and maintenance plans are documented and support site-specific maintenance.

Practical Examples

Example 1 — Seam Processing on a Welded Assembly: A seven-axis robot uses a Mannesmann Demag spindle with ±8° deflection along the weld seam. The spindle operates with a filament brush (shank 12 mm), speed 1,800 rpm, and constant contact pressure of 15 N, measured via integrated torque feedback. Automatic correction of deflection through sensor feedback compensates for slight variations in weld seam guidance, resulting in uniform edge deburring without material removal beyond tolerance.

Example 2 — Deburring of Stamped Parts at High Cycle Rates: In a line integration, a spindle with hydraulic deflection is installed to compensate for different workpiece thicknesses. The hydraulic control adjusts the contact pressure in real-time, while an M12 signal synchronizes the start/stop sequence with the robot control. Result: consistent deburring quality with cycle times under 25 seconds per component.

Example 3 — Surface Preparation Before Paint Application: A stainless steel component is processed with a cup brush. The spindle features water-resistant seals and robust stainless steel housings. Temperature monitoring ensures consistent surface energy, which improves paint adhesion. Process data is transmitted via EtherCAT to the MES and documented.

Why Choose Mannesmann Demag Spindles

Mannesmann Demag offers modular spindle concepts with variable deflection systems, robust material options, and comprehensive control integration. For industrial robot cells, these spindles are optimized for maximum process stability, easy assembly, and low downtime. Detailed technical specifications and application reports can be found at https://maku-industrie.de/technik and specific use cases at https://maku-industrie.de/anwendungsbeispiele.

• Key parameters for selection: material and protection class, bearing design, deflection range, connection types, torque and speed requirements

FAQs

1. Which deflection is ideal for deburring processes?
For deburring applications, mechanical deflection values between ±3° and ±10° or lateral deflections up to 5–8 mm are recommended, combined with torque monitoring to prevent overload. The specific choice depends on workpiece geometry and brush format.

2. How are connection and integration into the robot control performed?
Spindles offer standardized flange dimensions and M12/M23 connectors; control integration is done via EtherCAT, PROFINET, or CANopen. Encoder and torque signals are connected directly to the robot control to ensure synchronization and process monitoring.

3. What are typical maintenance intervals?
Maintenance intervals depend on operating hours and abrasiveness: visual inspection and brush check every 250–500 operating hours, bearing and seal inspection every 1,000–2,000 hours. Shorter intervals are necessary for heavily abrasive media; replacement kits reduce downtime.