Air motors up to 4.4 kW by Mannesmann Demag with integrated brake

Pneumatic Motors up to 4.4 kW with Holding Brake from Mannesmann Demag – Technical Characteristics and Practical Applications

This category includes robust steel pneumatic motors from Mannesmann Demag with rated outputs of 2.2 to 4.4 kW, integrated holding brakes, and variable no-load speeds. These motors are designed for demanding industrial applications requiring high starting torques, operational tolerance to compressed air contaminants, and secure positioning under load. The focus is on long-term mechanical strength, precise braking force, and easy integration into existing systems with standardized connections.

Construction, Materials, and Sealing Technology

Housings and critical components are predominantly made of alloyed steel with surface treatment against corrosion and abrasion to ensure long service life even in harsh industrial environments. Shafts and bearing surfaces are hardened or coated to minimize flank wear and settling. High-quality NBR or FKM seals are used for sealing, depending on temperature and media requirements; FKM seals increase resistance to oils and higher temperatures, while NBR offers a balanced cost-benefit ratio for standard air applications. The sealing systems used are dimensioned for operating pressures up to 10 bar, allowing the motors to be operated in common compressed air networks without special adaptations.

Mechanics and Brake Design

The integrated holding brake is designed as a dry-acting disc brake or a multi-disc spring-applied brake package, depending on the model and torque requirements. The brakes are designed to handle both static holding tasks and dynamic braking. Typical braking forces are matched to the motor's maximum output torque to enable secure positioning without additional clamping or lashing. The brake can be mechanically, pneumatically, or spring-actuated with a pneumatic release function; the choice influences response time, maintenance effort, and fail-safe behavior.

Performance and Torque Characteristics

The series covers rated outputs of 2.2 kW, 3.0 kW, and up to 4.4 kW. The motors offer variable no-load speeds, typically in the range of 2,000 to 10,000 min-1 depending on the gear ratio and model. The instantaneous power output is directly dependent on operating pressure and volumetric flow; characteristic curves show the specific relationship between pressure, speed, and torque. For applications with high starting torque, models with reduced no-load speed or an additional gear stage are available to increase the available starting torque.

Connections, Mounting, and Interfaces

The motors feature standardized compressed air connections with BSP or NPT threads, optionally with quick couplings for easy maintenance. Mechanical outputs are available with round shafts, square shafts, or toothed flanges. Mounting is done via standardized flange dimensions or foot flanges, allowing direct installation on aggregate frames or machine frames. Electrical or pneumatic control connections for the brake are clearly marked and can be ordered in redundant versions to enable safe control logics. The housings offer threaded bushings for sensor mounting, e.g., speed sensors or temperature sensors for condition monitoring.

Maintenance, Service Life, and Spare Parts

Maintenance intervals follow the application profile; longer intervals are possible in clean, dry-operated systems. Replaceable wear parts include seal kits, bearings, brake linings, and filter elements. Mannesmann Demag supplies coordinated maintenance kits and exploded drawings for quick part identification. Regular compressed air treatment with a filter-regulator-lubricator (F-R-L) extends the life of the seals and reduces dirt accumulation in the motor chamber.

Typical Applications and Requirements

Pneumatic motors with holding brakes are preferred in areas where electric drives are unsuitable due to explosion protection requirements, spark-free operation, or high ambient humidity levels. Typical industries include metal processing, packaging technology, conveyor systems, swivel and positioning units in assembly cells, as well as planing and grinding units in harsh manufacturing environments. Requirements for the holding function arise in end-position holding, safety shutdowns, and intermittent load absorption, such as when feeding workpieces or holding fixtures during manual interventions.

Practical Examples (Structured Application Scenarios)

Practical Example 1 – Positioning Swivel of a Robot Cell: In an assembly cell, a pneumatic motor with a holding brake replaces an electric rotary encoder drive for swiveling a feed carrier. The motor is installed via a gear stage to increase the starting torque. The spring-actuated holding brake ensures fail-safe holding in case of pressure loss; the pneumatic control of the brake is redundantly designed. After installation, torque and angle limit switches were integrated via existing threaded bushings to demonstrate end-position safety.

Practical Example 2 – Conveyor Unit with Intermittent Load: In a piece goods conveying system, a 3.0 kW pneumatic motor takes on the drive task for a speed range with variable loads. The holding brake is used for precise stopping of the conveyor belts to reduce cycle times. An inline air filter and a fine regulator provide clean, conditioned operating compressed air, minimizing seal wear and maintaining stable brake performance.

Practical Example 3 – Tool Spindle in Clamping Device: In a device for manual clamping of large workpieces, a pneumatic motor with a holding brake performs the rotation task for pre-tensioning. The motor is connected to a square shaft, and the braking force is designed so that the spindle remains securely in position when the compressed air is switched off. The use-case requirements for temperature resistance were met by FKM seals, as the application is located close to heat-emitting machines.

Selection Criteria and Configuration Recommendations

When selecting, the required net torque in the working range is primarily decisive; the rated torque must be designed for both continuous and peak loads. Furthermore, operating pressure, available air volumetric flows, and desired no-load speed must be considered. If frequent braking and releasing are planned, a motor-integrated multi-disc brake design with replaceable linings is recommended to minimize maintenance times. For hygienically sensitive environments, surface coatings and special sealing materials are available. In potentially explosive areas, ATEX-compliant variants must be chosen; manufacturer specifications in the technical data sheets provide guidance on this.

• Recommended checkpoints before ordering: desired starting/operating torque, operating pressure, air flow rate, connection type, brake design (mechanical/pneumatic/spring-actuated), sealing material, mounting flange.

Further Information and Documentation

Technical data sheets, exploded drawings, and maintenance instructions for individual models are essential for engineering and commissioning. Detailed information on general pneumatic technology and practical examples can be found on our technology page https://maku-industrie.de/technik, as well as specific application cases under https://maku-industrie.de/anwendungsbeispiele. For project-specific designs, we provide characteristic curves, sectional dimensions, and 3D mounting data upon request.

FAQ

1. What advantages does a holding brake on pneumatic motors offer compared to purely pneumatic standstill?
A holding brake enables secure, mechanical fixation in end positions regardless of active air pressure. This provides fail-safe security in case of pressure loss, reduces mechanical slippage, and increases process stability with intermittent loads.

2. Which sealing materials are recommended for high temperatures and oily environments?
For increased temperature and oil resistance, FKM seals are recommended. NBR is suitable for standard compressed air applications at moderate temperatures. The final material choice depends on the medium, temperature profile, and cost requirements.

3. How are braking force and motor power matched to each other?
Braking force is dimensioned according to maximum output torque and safety factors. During selection, designers consider peak loads, desired stopping times, and thermal stress on the brake linings. Manufacturer specifications and characteristic curves define permissible load cycles and required maintenance intervals.