Double Flap Clamshell Grab Bucket

Product Introduction

Clamshell Grab Bucket for Bridge Crane

The clamshell grab bucket is unique in its construction with two vertically articulated housings that can be opened and closed like a clam, and is designed for fast and efficient loading/unloading of bulk materials such as sand, gravel, coal, and agricultural products. The capacity of a clamshell grab varies greatly, from a few cubic meters to several cubic meters, depending on the size and type of equipment. It is typically mounted on cranes, excavators, or other material handling equipment, and the shells are hydraulically operated with a strong gripping force to accurately grab and release materials. It is widely used in construction projects, shipyards, ports, and other industrial scenarios involving the transportation of large quantities of loose materials.

Clamshell grabs manufactured by Weyerhaeuser are rugged, smooth-running, and efficient for long-term use in demanding environments. Products are available in a wide range of sizes and configurations to meet the specific needs of different customers, including shell thickness, lining materials, and connection systems. For detailed product specifications or application support, please feel free to contact our team.

Clamshell Grab Types

There are three main types of clamshell grab buckets depending on the construction, application scenario, and requirement:

Mechanical Grab Buckets

Adopting a wire rope or chain drive mechanism, the opening and closing action is controlled by winches or hoists, with a simple and reliable structure. It is mainly suitable for medium-sized material conveying operations of bridge cranes, gantry cranes, and general cargo loading/unloading scenarios, with the advantages of easy maintenance and economical cost.

Hydraulic Grab Bucket

Directly driven by a hydraulic cylinder, equipped with a proportional valve system to realize precise control. Its powerful driving force and fast response characteristics make it an ideal attachment for excavators, backhoes, and other construction machinery, especially suitable for heavy-duty material handling and high-frequency work environments.

Electro-hydraulic Grab Bucket

Combining the dual advantages of electric power and hydraulic systems, they are equipped with intelligent functions such as remote control, load monitoring, and automatic circulation. These grab buckets are mainly used in port terminals, ship loading and unloading, and other occasions with high requirements for operational precision, which can realize precise material placement and automated operation, and are the core equipment of modern large-scale material handling systems.

Working Principle

The clamshell grab bucket completes the grabbing and releasing of material through the telescoping action of the hydraulic cylinder. When the hydraulic cylinder extends, the bucket opens and prepares to drop to the target material. During the descent, the bucket remains open, allowing the material to enter the interior. When the hydraulic cylinder is retracted, the bucket closes, holding the material firmly in place. The grab is then lifted with the material to the designated position by the lifting equipment, and the bucket is opened at the target area to complete the unloading of the material. The whole process is efficient and precise, and is suitable for loading and unloading all kinds of bulk materials.

Clamshell Grab Bucket Structure

Clamshell grab bucket is mainly composed of the main frame, articulation mechanism, drive system, and functional components, adopting a modular design concept. The main components include:

• The main frame: a combination of box beam and reinforcement structure, Q690 high-strength steel plate welded molding, the key bearing parts inlaid with Hardox wear-resistant plate.
• Double-flap shell: composed of left and right symmetrical arc-shaped bucket flaps, connected by a high-strength alloy steel hinge, the opening and closing angle is usually 90°-110°, and the bucket flaps are lined with replaceable manganese steel liners;
• Driving system: There are three kinds of driving systems, including mechanical, hydraulic, and electro-hydraulic.
• Cutting device: Bucket arrangement of segmented edge plate, optional flat edge, serrated edge, or composite edge design;
• Rotating mechanism: some models are equipped with a slewing bearing + planetary reducer to realize 360° stepless rotation;
• Safety system: Including overload protection valve, mechanical locking pin, and anti-collision sensor.

Clamshell Grab Bucket Specifications

Features

• Double/multiple flap articulation structure: High-strength articulation mechanism realizes precise opening and closing, suitable for bulk materials, lump materials, and waste materials, etc., and the opening and closing angle is adjustable.
• Capacity and size design: Various sizes and capacities are available to suit different equipment and applications, ranging from several hundred liters to several cubic meters.
• Material options: made of high-strength steel, aluminum alloy, or wear-resistant Hardox steel, for flexibility in selecting materials for specific applications and durability requirements.
• Shell design: Semi-closed and fully closed shell designs. Semi-enclosed housings have a spill-proof design and are suitable for handling coarse flowable materials, while fully enclosed housings have a sealing strip and are suitable for fine-grained materials or underwater operations.
• Edge design: Straight edge or serrated edge design to meet the needs of different hardness materials for efficient processing. Serrated edge is especially suitable for digging and processing hard materials, straight edge is suitable for softer materials or loose soil.
• Connections: Conveniently connects to cranes, excavators, and other equipment via hooks, chains, or quick couplings, making it compatible with ancillary equipment.
• Rotation capability: Some models are equipped with a 360-degree swivel mechanism to enhance operational flexibility, which is usually suitable for complex or changing working environments.
• Power parameters: For hydraulic and electro-hydraulic grabs, specific working pressures and oil flow rates need to be matched and harmonized with the technical specifications of the connected equipment.

Application of Hydraulic Flap Clamshell Grab Bucket

Double Flap Clamshell Grab Bucket comes with a hydraulic system and is widely used in ports, steel mills, power stations, ships, garbage treatment plants, and other scenes. It is usually used with portal cranes, bridge cranes, gantry cranes, tower cranes, marine cranes, ship unloaders, excavators, and other cranes. Customized configurations can be provided according to special operational requirements. The following are specific industries and application scenarios:

Clamshell Grab Bucket for Bridge Crane

Clamshell Grab Bucket for Bridge Crane

Clamshell Grab Bucket for Bridge Crane

Clamshell Grab Bucket for Bridge Crane

Clamshell Grab Bucket for Bridge Crane

Clamshell Grab Bucket for Gantry Crane

Clamshell Grab Bucket for Portal Crane

1. Port operations

Bulk handling: efficient loading and unloading of coal, iron ore, and grain; Stockyard management: material stacking and recycling; Barge loading and unloading: rapid transfer between ships and terminals;

2. Iron and steel, and metallurgy

Raw material handling: scrap metal, iron ore, limestone; Slag handling: hot slag collection and transportation; Coke handling: loading/unloading of coke plants;

3. Power generation

Coal yard: fuel handling in thermal power plants; Ash removal: fly ash and bottom ash collection; Biomass processing: renewable fuel processing;

4. Ocean and offshore

Ship loading and unloading: bulk carrier operations; Dredging support: seabed material recovery; Barge operations: river and coastal logistics;

5. Waste management

MSW processing: municipal solid waste transfer; Recycling plants: waste sorting and processing; Incinerator facilities: waste feed systems;

6. Construction and infrastructure

Aggregate handling: sand, gravel, crushed stone; Dredging projects: channel maintenance; Demolition sites: debris removal

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