Spindles for brushing without compliance by Mannesmann Demag for your robot

Rigid Spindles for Brushing by Mannesmann Demag for Your Robot

**Rigid spindles** from Mannesmann Demag are specifically designed for robotic workstations that require constant positioning, high running smoothness, and reliable power transmission during brushing. These spindles combine a fixed housing with precise bearings, coordinated drive parameters, and robust connection details to enable abrasive, intermittent, or continuous brushing operations under industrial conditions. Typical applications include deburring and cleaning processes on body, forged, and welded parts, as well as pre-treatments before painting processes.

Construction and Designs

The rigid designs are characterized by a torsionally stiff housing made of high-strength aluminum or hardened steel, which minimizes thermal distortion and ensures the positioning accuracy of the brushing tool. Internally, the spindles are equipped with precision-ground shafts and double-ball or roller bearings to absorb both axial and radial loads. Shaft materials are typically hardened tempered steel or corrosion-resistant stainless steel alloys (e.g., 1.4112, 1.4305) for increased service life in aggressive environments. The bearing clearance is factory-calibrated to reduce vibrations at high speeds.

Drive, Power, and Control

Rigid robot spindles from Mannesmann Demag are optimized for constant torque transmission: motor flanges allow direct mounting of brushless synchronous motors or servo-driven actuators. The spindle housings are prepared for various connection options such as belt, coupling, or direct drive. Electrical interfaces support speed control via PWM or Field-Oriented Control (FOC) to enable precise speeds from a few hundred to >20,000 min‑1. For brushing applications, selecting the correct torque and characteristic curve is crucial: soft-spring brushes and flexible build-up tools require higher starting currents, while rigid wire brushes require constant speed and increased holding torque.

Seals, Cooling, and Protection

The housing design takes into account the stresses caused by abrasion and moisture. Applications with dirt and particle contamination require labyrinth sealing systems combined with axial O-ring seals or dynamic shaft seals (e.g., Viton, NBR) at the drive inputs. Optionally, spindles with integrated labyrinth seals and dust protection covers are available. For processes with high thermal loads or continuous operation, Mannesmann Demag offers spindles with internal water cooling or external cooling channels that can be integrated via standardized connections (G1/8, G1/4). Electrical connections are routed in protected connectors (M12, Harting, IP67); if required, additional protective housings for fieldbus technology are available.

Brush Mounting, Tools, and Interfaces

Brushes are mounted using standardized clamping systems: taper connections (HSK, Morse), mounting flanges, or cylindrical clamping sleeves with set screws. For rotating wire brushes, planned balancing bores and defined distances to the bearings are provided to keep unbalance low. For filament brushes, adapters with hold-down rings and defined press fits are used to ensure repeatable positioning. The spindles offer optional torque sensing and speed sensing (Hall, encoder) for process monitoring and automatic shutdown in case of tool failure.

Integration into the Robot Process

The rigid spindle design is engineered for fixed tool geometries and facilitates robot path planning through constant tool length reference and minimal vibration amplitudes. Mounting flanges comply with common robot manufacturer standards, reducing the need for mechanical adapters. Cable and air lines are designed not to impede the robot's freedom of movement; optional drag chain compatibility is recommended. In terms of control technology, the spindle can be easily integrated into robot controllers via industrial fieldbuses (Profinet, EtherCAT) or digital I/O. In combination with force/torque sensing, the machine can execute adaptive feed profiles during brushing to ensure constant surface energy.

Brush Materials and Service Life

Brush materials vary depending on the application: unalloyed steel wire for coarse deburring, stainless steel for corrosive environments, brass or bronze alloys for gentle deburring, and synthetic filaments for finishing and cleaning processes. The choice influences the spindle's service life due to different effects on bearings and shaft; aggressive metal particles require reinforced sealing concepts and regular maintenance intervals. Mannesmann Demag offers spindles with interchangeable protective rings and easily accessible service openings, allowing wear parts to be replaced without disassembling large assemblies.

Maintenance, Inspection, and Spare Parts

Maintenance concepts are designed for minimal downtime: regular lubrication intervals for the bearings, inspection of sealing elements, and cleaning of cooling channels are sufficient to ensure continuous operational reliability. For tested applications, maintenance kits with bearings, O-rings, dirt deflectors, and lubricant are available. Condition monitoring via integrated sensors reduces unplanned downtimes, as increasing vibrations or temperature rises are detected early. Spare parts such as shafts, bearing packages, and mounting adapters are available as modular components to enable quick repairs.

Practical Application Examples

Example 1: In sheet metal production, a rigid Mannesmann Demag spindle with direct drive is installed on a six-axis robot. The spindle drives a stainless steel wire brush at 2,800 min‑1 for weld seam post-processing. The fixed housing design reduces vibrations, allowing consistent seam exposure without damaging the substrate. Integrated speed monitoring detects load peaks, and the robot path is automatically adjusted. Example 2: In a forging process, a rigid spindle with water cooling is used to remove black oxide layers before painting. The spindle is equipped with a brass filament that gently degreases. The cooling keeps the tool temperature below 60 °C and prevents temperature-sensitive deformation of the sheets. The spindle is connected to the production control system to synchronize cycle times. Example 3: In an assembly line for gearbox housings, deburring takes place in a robot cell. Here, a rigid spindle with torque monitoring is used; upon contact with protruding burr edges, the torque is briefly registered as increased, and the path is corrected by a few millimeters, preventing component damage. Easy mounting and standardized interfaces allow quick tool changes between different brush types.

Technical Selection Criteria

The correct spindle selection is based on these core parameters: * Speed range, nominal torque, and starting behavior * Size and weight for robot kinematics * Mounting and connection technology (taper, flange, direct) * Sealing and protection concept (IP class, labyrinth, cooling) * Sensor technology and interfaces (encoder, torque, fieldbus) Further technical details, material information, and application notes can be found on our technology page https://maku-industrie.de/technik and in the documented practical examples at https://maku-industrie.de/anwendungsbeispiele. Specific data sheets and CAD models for Mannesmann Demag robot spindles are available in the shop profile for the category: https://maku-industrie.de/shop/de/mannesmann-demag/roboterspindeln/buersten/starre-ausfuehrung/

Selection Aid and Integration

For system design, load capacity calculations for bearings and shaft, thermal load considerations, and frequency analyses for vibration decoupling are required. The coordination between robot kinematics, spindle weight, and tool inertia is crucial for path accuracy. For retrofit projects, we offer mounting kits and electrical connection kits that facilitate integration into existing control systems. Upon request, we provide test reports for unbalance measurement, thermal images under load, and service life estimates based on your operating parameters.

Conformity and Safety Aspects

Mannesmann Demag spindles comply with relevant standards for industrial drives and machine safety. Protection classes, CE marking, and, upon request, customer-specific test certificates (e.g., EN ISO, RoHS) are available. For brushing processes, full enclosures and extraction concepts should be considered to prevent particle migration into the robot cell. Interfaces for emergency shutdown and monitoring of protective covers are recommended.

FAQs

**1. What are typical speed ranges for rigid brushing spindles and how do I choose the right one?** Typical speeds range from 500 to >20,000 min‑1. The choice depends on the brush type: wire brushes often operate at 1,000–5,000 min‑1 for effective deburring, while filament brushes often require higher speeds for fine surfaces. Material, feed rate, and desired surface energy are crucial. **2. Which sealing concepts are recommended in dusty environments?** Labyrinth seals combined with axial O-ring seals and optional dust protection covers are proven. In particularly abrasive conditions, a pressure-differential housing or air purging at the shaft seal is also recommended. **3. How do I integrate a Mannesmann Demag rigid spindle into my robot controller?** Spindles provide standardized flanges and connection panels. Electrically, encoders or Hall sensor technology, as well as digital inputs/outputs or fieldbus modules (Profinet, EtherCAT), are used. For integration, motor control, speed control system, and safety shutdowns must be connected to the robot controller; we offer connection kits and integration support.