Air motors up to 4.4 kW by Mannesmann Demag without integrated brake

Pneumatic Motors up to 4.4 kW without Holding Brake from Mannesmann Demag

Pneumatic motors up to 4.4 kW without a holding brake from Mannesmann Demag are robust drive solutions for industrial applications requiring high torques at variable speeds. These motors are designed with steel housings and cover power classes from **2.2 kW to 4.4 kW**. They offer various no-load speeds and nominal torques, are designed for harsh environments, and do not require an electrical supply, making them particularly suitable for applications with explosion risks or where simple, low-maintenance drives are needed.

Construction, Materials, and Sealing Systems

The housings are made of coated or blued steel, which increases mechanical strength and resistance to shocks and vibrations. Shafts and bearing supports are made of hardened steel, often with precision machining to ensure consistent concentricity. Piston, vane, or rotor designs (depending on the type) utilize wear-resistant materials and surface coatings; typical seals are NBR, FKM, or PTFE-coated materials, depending on temperature and media requirements. Seal designs are dimensioned to allow low leakage and long service life, even under intermittent load and variable speeds.

Connections, Air Preparation, and Accessories

The motors are available with standardized compressed air connections, typically G or NPT threads, partly with quick-connect options. For reliable operation, air preparation (filter, pressure regulator, oil mist lubricator) is required: **Clean, filtered, and condensate-free compressed air** significantly extends seal and bearing life and reduces power losses. Silencers at the outlets minimize exhaust noise; optional check valves and vent lines enable safe standstill positions despite the lack of a holding brake. For rotary further use, standardized shaft ends (cylindrical, keyway, feather key) are available; custom flanges or intermediate gears are offered for adaptation to existing machine layouts.

Designs, Performance Data, and Characteristic Curves

Pneumatic motors up to 4.4 kW are available in several designs, differing in housing length, shaft dimension, and speed range. Typical no-load speeds range from 1,500 to 6,000 min⁻¹, with nominal torque distributed depending on the gear ratio and operating pressure. Manufacturer characteristic curves provide actual power as a function of operating pressure (e.g., 4, 6, 8 bar) and volumetric flow; for design purposes, information on maximum torque, permissible continuous torque, and thermal load capacity is important. When selecting, the match between required starting torque, continuous load, and thermal performance is crucial, as air motors can overheat in continuous operation if the exhaust gas is not sufficiently cooled or the motor housing does not have enough air flow.

Operating Requirements, Control, and Service Life

Optimal power delivery requires a regulated compressed air supply with **constant pressure maintenance** and low pressure drop between the regulator and the motor. For speed control, pressure regulators are often used in combination with throttle valves; if necessary, proportional valves offer finer controllability. For lubrication, manufacturers usually recommend targeted mist lubrication with specified oils; alternatively, motor-side lubrication points are available. Regular inspections include seal checks, bearing preload, throttle and control valves, and cleaning of silencers and filters. With proper maintenance, these motors achieve long operating times; typical wear parts are seals and silencers, which should be replaced as scheduled.

Connection to Drivetrains and Gear Ratios

Pneumatic motors are designed for direct coupling to pumps, belt or toothed belt drives, as well as planetary or spur gears. The coupling design should accommodate axial and radial tolerances, as air motors can exhibit slight shaft deflections during load changes. For high power requirements, a reduction gear is recommended to increase the output torque and bring the motor speed into an economical range. Flexible couplings with compensating elements and suitable shaft seals at the gearbox input are ideal to prevent lubricant migration into the air motor area.

Applications and Industries

Pneumatic motors of this power class are used in assembly/conveyor technology, in hazardous areas, in food and chemical production, and in mobile and stationary machine drive technology. Their advantages lie in simple integration, high starting torque capability at low pressure, and operational safety in dusty or humid environments.

Practical Examples: Structured Application Cases

Conveyor belt drive in a harsh environment: A feeding system in a foundry uses a 4.4 kW air motor directly on a toothed belt drive to move hot castings. Due to sparks and high ambient temperatures, an electric drive is not permitted. The air motor operates with 6 bar regulated pressure; an oil mist lubricator ensures continuous lubrication, and silencers are thermally insulated. Control valves allow speed modulation for dosing phases. Mixer drive with reduction gear: A chemical process requires variable stirring speed with high starting torque. A 2.2 kW air motor drives the stirrer via a planetary gear. The combination of air pressure regulation and mechanical reduction achieves both smooth starts and high torques for operation in viscous media. The shaft seals are double-designed to keep out process media. Mobile crane or hoist drive: In a maintenance vehicle, a pneumatic motor replaces electric drives for hydraulic pumps because the vehicle's compressed air supply is always available. The compact design and lack of a holding brake are supplemented by external locking devices that ensure loads can be held at a standstill. Explosion-protected torque requirement: In an explosive environment, an air-powered swivel drive is used, which is required due to the absence of electrical ignition sources. The motor is made of steel, with antistatic surface treatment and suitable sealing materials to prevent contamination and spark formation. The control concept relies on pneumatic valve technology and position switches with safe switching. Further technical information, data sheets, and specific application examples can be found on our technical pages and in the practical section: Technology and Application Examples.

Installation Instructions and Safety Aspects

During installation, ensure exact alignment and adherence to the recommended tightening torques for flange and shaft connections. Bearing preload and shaft play must be checked according to manufacturer specifications. Since these models do not have a holding brake, additional mechanical interlocks or external brakes must be planned if safe rest positions are required. For the compressed air supply, pay attention to condensate separation and frost protection (for outdoor use). Shut-off and vent valves are part of the standard safety equipment so that pressure can be reliably relieved before maintenance work.

Selection Criteria and Dimensioning

Select the motor based on the required parameters: nominal power, required starting and continuous torque, available operating pressure, desired no-load speed, and environmental influences (temperature, humidity, explosion protection). Consider volumetric flow losses due to long pipe runs and pipe cross-sections. For final design, a combination of characteristic curve comparison and practical load measurement is recommended, if necessary with simulation of thermal load absorption.

Maintenance Recommendations

Schedule regular intervals for seal and silencer inspection, checking lubrication points and air filters, as well as checking control valves and connection flanges. Document operating hours, pressure curves, and maintenance measures to enable wear trend analysis and avoid unplanned downtimes.

FAQs

• What air preparation is necessary for pneumatic motors up to 4.4 kW? Install filters for particle and water separation, pressure regulators for stable pressure maintenance, and an oil mist lubricator if the manufacturer prescribes lubrication; for critical applications, additionally use condensate drains and dryers.
• How is the speed controlled if there is no electrical control? Speed control is performed pneumatically via pressure regulators and throttle valves; for finer control, proportional valves or pneumatically controlled servo valves are suitable.
• What safety aspects must be considered when operating without a holding brake? Integrate mechanical locking devices, hydraulic or drum brakes, or interlocking couplings for load securing; additionally, plan locking and venting devices for maintenance work.