Demag DR-Pro Wire Rope Hoist, up to 50 t

Overview

The Demag DR-Pro is a wire rope hoist range for load capacities up to 50 t, and up to 100 t with twin hoist units, designed to meet the requirements of modern overhead cranes and lifting installations. Demag highlights a particularly long service life, comprehensive standard features and a lifting speed of at least 6 m/min with 4/1 reeving on most models. The rope drive mechanism meets FEM specifications while the gearbox service life is 20 percent longer, giving more time before the general overhaul is due at the end of the safe working period.

Seven Star LLC supplies the Demag DR-Pro to crane builders, plant owners and EPC contractors in Oman and across the GCC, with engineering support in Muscat. Rope hoist selection depends on load spectrum, operating time, reeving and mounting design, and our engineers work with clients to translate those requirements into the correct DR-Pro size and configuration using the Demag selection method.

Operating Principle

As general engineering background, a rope hoist lifts the load by winding a steel wire rope onto a grooved drum driven by a motor through a reduction gearbox. Reeving the rope through sheaves in the bottom block (for example 2/1 or 4/1) multiplies the lifting capacity and reduces the speed in proportion. In the Demag DR-Pro the hoist motor is a 12/2-pole or 4-pole squirrel-cage motor with cylindrical rotor, optionally inverter-fed for even more precise lifting and lowering, driving a three-stage helical gearbox with high-endurance gearing and oil lubrication for life.

Safety functions are integrated throughout the Demag DR-Pro. A Demag DC disc brake with brake release monitoring and integrated electronic modules provides fast-acting, highly reliable braking. Electro-mechanical overload protection is built into the rope-retaining crosshead and evaluated by the central electronic unit, with optional electronic overload protection offering load summation for several hoists, a load display and slack rope cut-off. A precision geared limit switch cuts off lifting and lowering in the limit positions, with four contacts set for emergency cut-off and a fast-to-slow cut-off as standard.

Engineering Design of the Demag DR-Pro

Demag offers the DR-Pro in four basic designs: the GDR basic hoist for plant engineering, the FDR foot-mounted hoist for integration into prepared steel structures or special crabs, the EKDR monorail hoist for single-girder cranes up to 12.5 t, and the double-rail crab for double-girder cranes up to 50 t with standard track gauges of 1,400, 2,240 and 2,800 mm. The travelling versions use a compact C-shaped design with a thrust rocker arrangement for a very good C dimension and maximum hook path, and a cross-travel inverter gives variable travel speeds up to 30 m/min for low-sway positioning.

The Demag DR-Pro protective rope guide is made of tough plastic with hardened pressure rollers on anti-friction bearings, allowing inclined pull of up to 4° without touching the guide. The motor has thermal contacts against overheating, an IP 55 enclosure, an integrated pulse encoder to monitor speed and direction of rotation, and a duty factor higher than the FEM classification. Customers can choose processor control, contactor control or a parallel control arrangement; processor control adds monitoring of operating speed and brake wear, load evaluation, an integrated load spectrum recorder and communication with higher-level control systems via an open interface.

Key Features

Demag lists the following characteristics for the Demag DR-Pro rope hoist.

• Load capacities extend up to 50 t, and up to 100 t with twin hoist units.
• Most models lift at a minimum of 6 m/min with 4/1 reeving as standard.
• A 20 percent longer gearbox service life extends the time to general overhaul.
• Four basic designs, GDR, FDR, EKDR and double-rail crab, cover plant engineering and crane duties.
• The DC disc brake with brake release monitoring gives fast, reliable braking.
• Electro-mechanical overload protection in the crosshead is standard, with electronic options.
• A precision geared limit switch with emergency and fast-to-slow cut-off protects the limit positions.
• Processor control with load spectrum recorder supports condition-based service planning.

Industrial Applications

Rope hoists such as the Demag DR-Pro are the core of overhead travelling cranes in fabrication shops, power plant turbine halls, pump and compressor stations, warehouses, steel stockyards and port maintenance buildings. In Oman, the Demag DR-Pro suits crane installations in the Sohar and Duqm industrial zones, workshop cranes at oil and gas service bases, maintenance cranes over pumps at water transmission and desalination plants, and turbine and generator halls at independent power plants. Double-rail crabs give the maximum hook height in tall buildings, while EKDR monorail hoists keep approach dimensions small in single-girder cranes.

Seven Star LLC supplies the Demag DR-Pro together with the electrical components that crane projects need. For chain hoist duties at lower capacities, customers can consider the Demag DC-Com electric chain hoist; for crane long-travel and other large drives, Demag hoists are often combined with inverters such as the ABB ACS880-01 industrial drive or the Schneider Electric Altivar Process 630. Our Muscat team helps coordinate the hoist, controls and crane electrics within one supply scope.

Technical Specifications

The Demag DR-Pro data below is taken from the Demag DR-Pro rope hoist brochure 213 133 44.

How to Order

Request a quotation for the Demag DR-Pro by sending Seven Star LLC an RFQ with load capacity, hook path, lifting speed, reeving, design (basic, foot-mounted, monorail or crab), span or track gauge and supply voltage. Our engineering team in Muscat will help select the hoist size and share the Demag brochure attached to this page. Seven Star LLC supplies Demag rope hoists for crane projects in Oman and the GCC.