HMEC - Products - Power Transmission - Slewing System Products - Applications
The Slewing System Products' Applications (put mouse on the picture for more information...)
Special purpose machinery
HMEC is professional in supplying Slewing Rings to the bottling industry. Our products ranging from 200 to 5,200 mm (7,8 to 204 in) externally toothed Slewing Rings, are used in machines for cleaning, filling, equipping and labelling. We supply manufacturers of blow moulders for the production of PET-plastic bottles. Because of the high circumferential speed, the Slewing Rings are equipped with closed cages.
Adjustment devices of take up and take off units of printing machines need high accuracy. Cross Roller Slewing Rings fulfill all required criteria perfectly and are perfectly adaptable for this application. In the picture you can see a Cross Roller Slewing Ring, partly assembled with a raceway diameter of about 1,300 mm (51 in).
In Cross Roller Slewing Rings, the rollers are arranged crosswise and run in a square sectioned raceway.

Conveyor systems
This is a facility to cover car facia panels with leather. It contains Slew Drive. Because of its operating condition, it is fitted with a spring energised multi-plate disk brake. Slewing Rings from our standard product line are used in automation systems for vehicle assembly and welding lines. Our standard product line is diverse and rapidly available. Some Ball Slewing Rings of the this series; from top to bottom: externally toothed, untoothed, internally toothed all with the same raceway diameter of 641 mm (25 in).  

Construction machinery
To protect the teeth of this demolition equipment from overload damages, a friction coupling is integrated in the spur gear driven Slew Drive. This kind of Slew Drive installed in a rotation and tilting device of an excavator shovel bucket. Tandem asphalt compaction roller uses untoothed Slewing Rings as a steering bearing (some designs are partly coated on the surface to prevent corrosion). In the split roller, Slewing Rings with special seals are used.
The vibratory roller of the refuse compactor in the picture uses untoothed Slewing Rings in the knuckle joint.
Slew Drive of this series in a special design for a foundation grab of a heavy construction machine. Cement mixer equipped with a conveyor belt with a length of 16.5 m, which is rotated with two Slew Drives; the considerable length of the belt leads to high tilting moments. Therefore a double row design with a reinforced housing is used.    

Mining and tunneling
  • Mining
  • Open-cast mining
  • Tunnel boring machines
Mining vehicle with special equipment and horizontal telescopic and rotating platform. Its boom is rotated with this kind Slew Drive.

This kind Slew Drive with hydrostatic gear for turning an excavator boom. Part of a cutter bar of a tunnel driving-machine.

To ensure that the blasthole drilling rig remains locked in place during the drilling process, this kind Slew Drive unit shown has an integrated locking system with a position holding gear

Bucket wheel excavators and stacker reclaimers use large diameter (over 5,000 mm – 196 in) Ball Roller Combination Slewing Rings as main bearings.Cross section of a typical main Slewing Ring. This unit is a combination type with external toothing and a diameter of 4,800 mm (189 in).

In this combination type Slewing Ring, heavy axial loading is carried by the roller raceway. The ball raceway provides support for light radial loads.

We design and manufacture high load Triple Row Roller Slewing Rings for tunnel boring machines. A multistage sealing system can be integrated if required.

Slewing Rings for cutting heads present large design challenges due to the heavy loading, adverse environmental conditions and life requirements.

The erector uses a Cross Roller Slewing Ring for lifting and positioning the concrete lining segments (Tubbing) which are used for strengthening the tunnel walls.
Specification:Raceway diameter 4,500 mm,Outside diameter 4,700 mm,Roller diameter 40 mm,Double lip seals with primary labyrinth


Drilling rigs      
This foundation drilling tool is equipped with a Ball Type Slewing Ring with hardened teeth.
It has an OD of around 1,000 mm (39 in).
This Ball Type Slewing Ring of special design contains wedgeshaped slots used by the drilling pipe clamps.    

Amusement park rides      
A ride in "zero g" guarantees thrills and alsozero gravity for a short time. The gondolas are rotatedwith our Slew Drive. "Tango" is one of the most breathtaking amusement park rides in its class. Each gondola is driven in its three rotational axes via five Slewing Rings which have internal hardened toothing. "Night Fly" - how would you feel if you could not rely on the engineering of an amusement park ride and its components. Everything revolves around HMEC!  
Foundries & steel works  
We manufacture Triple Row Roller Slewing Rings for cover swing gears of electric arc furnaces (so-called EAFs, picture above) as well as Triple Row Roller Slewing Rings for ladle turrets (picture below).

Manlift platforms      
  • Bridge inspection equipment
  • Big manlift platforms
  • Small and medium manlift platforms
This bridge inspection equipment uses Slew Drive in the boom joint. The unit is able to accommodate the suspended loads and is fitted with a worm drive and multi-plate disk brake. Here is one of the biggest manlift platforms. With a maximum platform height of 57 m (187 ft) it is the only platform in its class outreaching 43 m (141 ft) to the side - a world record! How this can be achieved? The solution is the patented turntable! And HMEC can supply the two vital Ball Slewing Rings and a Slew Drive as a drive unit!

Boom attached to gear ring Synchronous rotating turntable with HMEC Slew Drive Mounted to truck chassis.

The high capacity and low profile of the HMEC Slew Drives are perfectly suited for manlift platforms. The wide varity of sizes in this series enables their use in many different kinds of platforms (heights ranging between 7 and 27 meters). Design standardisation "at its best"!

The kind of Slew Drive is used for boom and basket rotation on this manlift system. HMEC Slew Drives: "One standard technology for your entire product offering!"


  • Railway slewing cranes
  • Harbour cranes
  • Industry cranes
  • Mobile cranes  
Railway slewing cranes are designed for multiple tasks such as bridge and railway construction as well as the utilisation as breakdown crane.
Due to the dimensional limitations of the loading gauge envelope and overhead power lines, only Triple Row Roller Slewing Rings are suitable for the loading encountered in railway cranes. Slewing Ring designs with internal toothing, or external toothing (as cross-section), are available.
Harbor mobile crane often use Triple Row Roller Slewing Rings with an external diameter up to 5,000 mm (196 in) to carry the high tilting moments.
This Harbour crane, operating with a Roller Slewing Ring with an inside diameter of about 2,800 mm.
Slewing Rings find diverse applications in steel works and foundries such as loading cranes, traversing-revolving cranes, wall slewing cranes, cover swing gears and ladle turrets. In the construction industry, Slewing Rings are used in gantry ceiling-boom cranes.
Gantry crane with rotable loading device in a concrete factory.
The special series Slew Drive with two direct hydraulic motors was developed for this special crane, used for roof top operations.
  • Ship cranes
  • Swim cranes
  • Service cranes
Large shipboard crane with a Triple Row external toothed Roller Slewing Ring. The high load capacity and compact proportions of this type of Slewing Ring are ideally matched to the mast and base block proportions of the crane.

Deep sea fishing vessels use Ball Slewing Rings for shipboard cranes and net handling equipment. Typical external diameters range between 600 to 1,500 mm (23,6 to 59

Harbour cranes, mobile harbour cranes Triple Row Roller Slewing Ring with an outside diameter of about 5,000 mm and root and flank hardened internal toothing.
Specifications: Outside diameter 5,000 mm; Support roller diameter 50 mm; Maximum permissible tilting moment 65,000 kNm; Module 24 mm; Weight 8,500 kg.
Light cranes - the standard equipment of service trucks, using Slew Drive.  

Agriculture & forestry      
Harvesters use our Ball Slewing Rings and Slew Drives for the axle swing arm, the crane boom, the harvester head (with a chain saw) and a rotatable cab. This work boat which is used in Dutch canals is fitted with a Slew Drive to move the boom of the excavator.    

Steering gears      
  • Crane undercarriage
  • Special vehicles
With the capacity to handle extreme tilting moments, high output torques, all in a compact design, the Slew Drives are especially suited as steering gears. In addition, integrated position feedback sensors support computer controlled steering systems.

Using Slew Drives, cranes and special vehicles achieve unique manoeuvring capabilities including turning on the spot.

Sixteen Slew Drives on each side of this 80 m (262 ft) long special vehicle forms its steering system. Such vehicles have been used to move and place the concrete tracks of Shanghai`s magnetic suspension railway.

In concrete factories, large movable gantry cranes displace heavy and bulky prefabricated concrete. With the Slew Drive, each axle can be turned individually. The steering torque required with the maximum load while turning on the spot is about 150,000 Nm (110,639 ft-lb).

Ship lifting device to lift and place ships up to a weight of 650 tons. Eight Slew Drives carry this load capacity.

Heavy load transporters present big technical challenges. Each single axle is steered by an Slew Drive requiring the maximum axial, radial and tilting moment capacity. The Slew Drive with steering torques of 27000 Nm is an excellent solution.

In May 2004 the world record for the heaviest load moved on wheels was claimed with this Self Propelled Modular Trailer (SPMT). The trailer was equipped with a total of 470 axle lines and 1880 wheels. The patented Slew drives, used as steering gear, took their share in reaching the world record.

Side loader with the steering gears of the Slew Drives; the high operating time requires the use of bronze worm gears.


Materials handling & bulk handling      
  • Materials handling
  • Bucket wheel stackers/reclaimers
This stacker on board of a ship is swivelled by means of an internal toothed, Triple Row Roller Slewing Ring. Specification: Outside diameter 3,250 mm; Maximum tilting moment 13,000 kNm. In bucketwheel-stacker/reclaimer the biggest range of our slewing rings is used: The gigantic bearings have an outside diameter of 5.2 m and every single slewing ring has a weight of more than 5000 kg. These bucketwheel-stacker/reclaimer with extension arms of up to 50 m are able to heap up or clear away more than 6000 m³ coal, iron ore or lime per hour.    

A unique application: On the masthead an untoothed Ball Slewing Ring enables the docked Zeppelin to orient in the direction of the wind.      

Medical technology      
Internal toothed Slewing Rings are used in linear accelerators in oncological investigations. They have to be highly precise with a minimum of running noise and friction torque. Slewing Rings with special surface coatings, lubricants and sealing systems are used in other critical medical applications.    

  • Cranes
  • Crude oil production systems FPSO
Depending on the required load carrying capacity, Single Row Ball or Triple Row Roller Slewing Rings (often with internal toothing) are used in offshore cranes.Slewing Rings for offshore applications have to meet special approval requirements regarding material characteristics and safety under catastrophic load cases. The arduous environmental conditions require high performance sealing systems. Inspection and approval by the certifying authorities is often required.

Slewing Rings for offshore applications are always subject to special approval requirements from the respective certifying authority. The rolled rings must demonstrate a notched bar impact strength of an average of 42 J at -20°C.The picture below shows the final assembly of a Triple Row, internal toothed Roller Slewing Ring for a large offshore crane.

Externally toothed Ball Slewing Rings with a diameter of 3,000 mm (118 in) are used in this oil spill barrier reel on an FSPO (Floating Production Storage Offloading) unit.

Buoys for transferring crude oil from the sea bed to an FPSO ship have a sviveling transfer system to allow for movement of the ship with wind direction changes (weather vaning).

Untoothed Triple Row Roller Slewing Rings, of diameter around 1,700 mm (67 in), are used in a so called “product swivel”.


Precision applications      
  • Antennas
  • Military technology
Cross Roller Slewing Rings are ideal where high precision, rigidity and smooth running are required. The picture below shows one partially assembled. This gun carriage is mounted on a Ball Slewing Ring. The bearing is given special raceway geometry to minimize the effects of distortion on its operation. The Slewing Ring includes a special seal and surface coating due to special environmental conditions.    

Renewable energies      
  • Tidal stream systems
  • Solar applications
  • Wind energy
A 3-row roller bearing with special sealing and an outside diameter of about 1.5 m is used in 15 m  water depth  to shift the blades of a – up to now – unique tidal stream power system in Great Britain.
With this way of generating energy  the whole system, therefore the blade bearings as well,  are continuously exposed to the tidal streams.
Slew Drives fitted with electric motors used for the yaw and pitch controls of this solar table.
Slewing Rings - approved for use in arctic conditions (operation down to -30°C, proof of structural integrity under load at -40°C)

We are our customers first contact to work on solutions for new or modified wind energy turbines. In the picture below you can see the graphic of a new large wind energy turbine with a power of 2.0 MW/Offshore.

Windpark at the Brazilian Atlantic Coast.


Ship building      
This functional but elegant twin worm Slew Drive, is ideally suited for the slewing gear of a yacht crane. A single row Ball Slewing Ring with root and flank hardened external toothing is used in this ship’s thruster. This unit is approved by certifying authorities such as Lloyds Register of Shipping.    

Special applications      
Imagine you need a special Slewing Ring that does not show any linear expansion with temperature increase and no shrinkage as it cools. Do you think this is impossible? Are you sure? Well here is a special bearing manufactured from a highly nickel rich material with a thermal expansion coefficient of practically zero. Such a bearing was developed and manufactured by HMEC! Eccentric bearing unit from a machine tool used for diesel engine crankshaft machining. The bearing unit contains two high precision cross roller raceways and one slide bearing. The integrated toothing makes it possible to adjust the eccentricity allowing machining of all of the crankshaft bearing surfaces in just one operation. The unit has an external diameter of around 1,200 mm (47 in).    

Public transportation systems      
Trams and subways use special design Ball Slewing Rings as hinge bearings between carriage sections and carriages and bogies. Difficult geometric conditions in the mounting structures of rail vehicles present real challenges for the design of Slewing Rings. High performance seals and long service lives are important requirements. Untoothed Ball Slewing Rings with a diameter of 400 mm (16 in) form the hinge of the air cargo luggage ramp as shown in the picture taken at Frankfurt airport.  
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