Liebherr develops and produces central components, such as rope drums, gearboxes, engines and control technology for lifting systems. The components are, therefore, perfectly matched together and can be used in a variety of combinations. Depending on requirements, the customer can flexibly select different degrees of integration. Liebherr offers components from the planetary plug-in gearbox through to a complete lifting system and every intermediate specification. Many options are also available, such as hardware switch-off, a secondary safety brake and either electric or hydraulic drives. All components have been approved in many years of application.
The new winch system DEW550/1916, which Liebherr exhibits at the Bauma, for instance, is designed as a complete lifting system and can be integrated into an application as a black box. A genuinely valuable feature is its reduced assembly time. Individual components, such as motor, brakes and gearboxes, are already pre-assembled. The DEW550/1916 consists of a rope winch with a high power density and a planetary plug-in gearbox integrated into the drum, electric motor, auxiliary engine, brake and switchgear. Its specific application area comprises ship-to-shore cranes, for which it ensures precise positioning of the derrick boom. Liebherr also offers similar lifting systems for many more applications, for instance tower cranes, deep-foundation and drilling equipment, lifting gear in the steel or extractive industries and in mining.
One principle – Many options
The winch systems are always designed according to the same principle: The rope pull force and lifting speed form the basis and provide the required performance and the rope diameter. Coaxial winch systems from Liebherr are designed for lifting speeds of up to 100 m/min and rope pull forces of between 30 kN and 700 kN, with rope pull forces of up to 2,700 kN also being implemented in a special case.
The gearbox is selected from the Liebherr product catalog for planetary plug-in gearboxes (PEGs). The gearbox size is determined by, among other things, the required torque, rotary unit group and the number of load lifts over the service life of the winch. Liebherr offers its customers great flexibility by the gearbox, winch frame and rope drum plus grooving being calculated, designed, and produced completely in-house.
Compact air-cooled asynchronous squirrel cage motors from Liebherr are used for electrically driven winches. These electric motors are available in the power range from 4 kW to 1,500 kW, and designed for use under toughest conditions. Thanks to decades of experience, with the switchgears developed in-house, Liebherr offers a broad product range for different application areas. The design can also be safety-related according to country specifications in line with EN ISO 13849. When requested by the customer, Liebherr performs acceptance tests with the established classification societies.
Skip winches in continuous operation
As well as winches for specific projects, Liebherr develops in cooperation with customers individual modular rope winch systems, so that they can assemble the winches flexibly to suit various needs without long development times. A modular rope winch system is already being operated successfully by Maerz Ofenbau AG, a manufacturer of lime kilns operating on a global basis. For this winch, which pulls the skip bucket upwards to fill the kiln, Liebherr as system supplier joined forces with the kiln manufacturer to develop a modular system solution with three electrical power categories. The winches differ not only in electrical power but also in their installed position, which can be at the bottom, center or top of the kiln. A 3x3 matrix, that is to say nine different winch systems, enables virtually all the company's lime kilns to be equipped efficiently. The modular winch system for Maerz Ofenbau incorporates just one control cabinet, one gearbox, one motor, and one rope diameter for each power category. The rope drums differ only in their length.