Demag new product launch
One rope hoist. Two designs. Many possibilities.
Demag new product launch ceremony was successfully conducted in Shanghai, on Jan. 12, 2017.
Whoever needs a new rope hoist is spoilt for choice. With the new DMR modular rope hoist, Demag has developed a rope hoist that can be precisely configured to meet specific customer needs – with one basic technology.
The search for a rope hoist is often like a puzzle. Companies not only have to compare many individual rope hoists with their specifications. Ultimately, they often have to make a compromise, because one rope hoist has the required motor, while a different one is available in exactly the right size, for example.
“We solve this problem and offer our customers more flexibility in their choice of a rope hoist”, explains Dr. Thomas Bönker, Senior Director of the Components Business Line at Terex Material Handling. This is how the Demag DMR modular rope hoist evolved. “Thanks to its modular design, DMR makes it possible to achieve an unparalleled variety of rope hoists with one basic technology”, explains Bönker. “The rope hoist exactly meets our customers’ requirements and offers the perfect solution for their specific applications.” Depending on the specifications, the customer can select the basic design, hoist or crab type, electric equipment, drive method, size and load capacity, for example.
Crane and stationary applications
DMR is the first rope hoist that can be built in both C-design and in co-axial design. Both designs have the same rope reeving components and have identical interfaces for covers and other fittings. The compact C-design is particularly suitable for crane manufacturers: the approach dimensions can be reduced since the motor is located beneath the rope drum. This means that the crane can approach closer to the building walls. The co-axial design offers a high level of flexibility for stationary applications, for example. In this configuration, the rope drum, gearbox and motor are arranged virtually in one axis, which enables the DMR rope hoist to be easily integrated into virtually any construction. DMR is available as a foot-mounted hoist unit and a low-headroom travelling hoist and, from 2016, as a double-rail crab and standard-headroom travelling hoist.
On the way to the industry of the future
According to a recent study by consultants IWL, 61 per cent of intralogistics experts consider “Industry 4.0” to be the top innovation topic. The smart Demag SafeControl system is already prepared to meet this challenge. “Thanks to its system architecture, it ensures a high level of operating reliability and system transparency. Furthermore, SafeControl satisfies the requirements for efficient production processes”, states Dr. Thomas Bönker. The integrated Demag SmartCheck sensor system continuously detects all of the rope hoist’s operating parameters – from information on speed to brake wear. Many safety and operating functions can be individually activated, such as slack-rope monitoring or load-dependent lifting speeds. Two rope hoists can be coupled for tandem operation at the press of a button. In addition, the Demag StatusControl remote access system makes all relevant operating data available anywhere and in real time. The smart control system features a redundant design and works with a high-performance double processor.
As an alternative to the smart control system, Demag also offers DMR with the proven contactor control system. It can be easily maintained and is available with various control voltages. If required, customers can also use their own control systems. For this purpose, the DMR has two prepared mounting positions where the electric equipment housing can be installed.
Improved precision with variable-speed hoist motor
Customers can decide on the hoist drive regardless of their choice of control system. A pole-changing motor that has two and 12 pairs of poles can lift loads at two speeds. The lower speed is one sixth of the higher speed. The motor is operated with a line frequency of 50 Hertz (60 Hertz in the USA). “However, our customers can position their loads even more precisely with a variable-speed hoist motor”, states Bönker. “The four-pole drive is equipped with a frequency inverter, which variably adjusts the motor speed. This enables the crane operator to accelerate fast and, at the same time, set the load down carefully.” For loads that weigh up to 30 per cent of the rated load capacity, the variable-speed drive can lift and lower at higher speeds thanks to its “ProHub” function.
Demag equips its DMR modular rope hoists with an asynchronous cylindrical-rotor motor fitted with a disc brake as standard. It features a high motor output of up to 45 kilowatts.
However, customers who opt for the co-axial design receive a second option: the motor with an F10 mechanical microspeed unit.
The drive consists of two separate conical-rotor motors for the main and creep lifting motions. The microspeed unit works with one tenth of the speed of the main hoist motor and can position loads more precisely. Conical-rotor motors have excellent braking characteristics. In addition, they automatically brake if the power drops or the motor is switched off. The F10 motor is primarily used for rugged applications with a high number of starts and stops.
Extend as required
The “modular” part of the DMR name also means that the rope hoist can be extended by the addition of many accessories. For this reason, the rope hoist has cable connections and the opportunity to add fittings at many positions. For example, a second geared limit switch can be simply fitted on the foot flange and a cover added above the rope drum, or a limit switch to the electric equipment housing.
The low-headroom travelling hoist can be easily converted by the addition of the two-wheel “DualDrive” to increase traction for outdoor applications, for example. With this arrangement, the cross-travel motor simultaneously drives two wheels via a belt. Thanks to its predefined mounting position, a second travel drive (“DualDrive Plus”) can also be simply installed.
Any downtime in production costs industry a lot of money. For this reason, the engineers at Demag also took a close look at the component parts of the DMR rope hoist and optimised them in comparison with previous models. “We have also put a lot of work into the technical details of the DMR rope hoist to improve the reliability of our rope hoists even further”, states Dr. Thomas Bönker. “This resulted in many innovations that provide for even more cost-effective operation.” One example of this is the coupling between the motor and gearbox, which absorbs sudden forces from the motor, thus extending the service life of the rope hoist. Furthermore, the motor can be removed without the need to drain the gearbox of oil.
Various other components also help to ensure a longer service life. The oil lubrication of the gearbox will last for ten years and is also kinder to the environment thanks to the oil quantity, which is reduced by 30 per cent. The top and bottom blocks feature larger rope sheaves than the previous rope hoist models. In this way, rope wear is also minimised even over longer periods of service. In addition, the rope guide offers reduced wear: it is made of tough, acid-resistant plastic. If, however, it is necessary to replace wearing parts, this can be accomplished quickly by means of the standardised interfaces between the various modules. The rope lead-in guard is particularly easy to replace. It consists of two parts and can be replaced without the need for the service technician to remove the rope.
The most important facts about the DMR
- Designs: C-design and co-axial design
- Application types: foot-mounted hoist, low-headroom monorail hoist, double-rail crab, standard-headroom monorail hoist
- Sizes: 3, 5, 10, 16 and 20
- Load capacities: 3, 5, 12.5, 16, 20 and 50 tons
- Electric equipment: smart SafeControl system, contactor control or control system provided by the customer
- Reeving: 2/1, 4/1, 6/1, 8/1, 4/2, 8/2, 12/2
- Lifting speeds (for sizes 3, 5 and 10; similar for 16 and 20):
- Two-stage: 4, 6 and 8 m/min (1:6 control ratio)
- Variable: 3.2–4.5/6.4–9.6/12.5–19 m/min (1:50 control ratio)
- Control: DRC D3 radio control, DSE 10R control pendant (for SafeControl), DST control pendant (for contactor control)