تصنيف وخصائص الرافعات الجسرية

According to the structure of the door frame, it is divided into gantry crane and cantilever gantry crane

رافعة جسرية
1. Full gantry crane: the main girder has no overhang, and the trolley is carried within the main span.
2. Semi-gantry crane: The outriggers have a height difference, which can be determined according to the civil engineering requirements of the site.

Cantilever Gantry Crane
1. Double cantilever gantry crane: The most common structural form, the force of the structure and the effective use of the site area are reasonable.
2. Single cantilever gantry crane: This structural form is often selected due to site constraints.

According to the main beam form
1. Single girder gantry crane
The single main girder gantry crane is simple in structure, easy to manufacture and install, and its own weight is small. Most of the main girder is a partial rail box frame structure. Compared with the double girder gantry crane, the overall rigidity is weaker. Therefore, this form can be used when the lifting capacity Q≤50t and the span S≤35m. There are two types of L-shaped and C-shaped gantry legs for single girder gantry cranes. The L-type is easy to manufacture and install, has a good stress condition, and its own mass is small, but the space for hoisting goods through the outriggers is relatively small. The C-shaped leg is made into an inclined or curved shape, and the purpose is to have a larger lateral space so that the goods can pass through the leg smoothly.

2. Double girder gantry crane
The double main girder gantry crane has strong bearing capacity, large span, good overall stability and many varieties, but its own quality is larger than that of the single main girder gantry crane with the same lifting capacity, and the cost is also higher. According to the structure of the main girder, it can be divided into two forms: box girder and truss. At present, box-shaped structures are generally used.

According to the main beam structure

1. شعاع الجمالون
يتميز الشكل الهيكلي الملحوم بالفولاذ الزاوي أو العارضة I بمزايا التكلفة المنخفضة والوزن الخفيف والمقاومة الجيدة للرياح. ومع ذلك، نظرًا لنقاط اللحام العديدة وعيوب الجمالون نفسه، فإن شعاع الجمالون له أيضًا عيوب الانحراف الكبير والصلابة المنخفضة والموثوقية المنخفضة نسبيًا والفحص المتكرر لنقاط اللحام. إنها مناسبة للمواقع ذات متطلبات السلامة المنخفضة وقدرة الرفع المنخفضة.

2. العارضة الصندوقية
يتم لحام اللوحة الفولاذية في هيكل صندوقي، والذي يتميز بخصائص السلامة العالية والصلابة العالية. يتم استخدامه بشكل عام للرافعات الجسرية ذات الحمولة الكبيرة والحمولة الكبيرة جدًا. كما هو موضح في الصورة على اليمين، فإن MGhz1200 هي أكبر رافعة جسرية في الصين بقدرة رفع تصل إلى 1200 طن. العارضة الرئيسية تتبنى هيكل العارضة الصندوقية. تتميز العارضة الصندوقية أيضًا بعيوب التكلفة العالية والوزن الثقيل وضعف مقاومة الرياح.

3. شعاع قرص العسل
يشير بشكل عام إلى "شعاع العسل الثلاثي متساوي الساقين"، والوجه النهائي للشعاع الرئيسي مثلث، وهناك فتحات قرص العسل على البطن المائل على كلا الجانبين، وهناك أوتار في الأجزاء العلوية والسفلية. تمتص العارضة على شكل قرص العسل خصائص العارضة الجمالونية والعارضة الصندوقية، وتتميز بصلابة أكبر وانحراف أصغر وموثوقية أعلى من العارضة الجمالونية. ومع ذلك، بسبب لحام الألواح الفولاذية، فإن الوزن الذاتي والتكلفة أعلى قليلاً من تلك الخاصة بعوارض الجمالون. إنها مناسبة للمواقع أو ساحات العوارض التي يتم استخدامها بشكل متكرر أو ذات قدرة رفع ثقيلة. نظرًا لأن هذا النوع من الشعاع هو منتج حاصل على براءة اختراع، فهناك عدد أقل من الشركات المصنعة.

by purpose
1. الرافعة الجسرية العادية
This kind of crane mostly adopts box type and truss type structure, which is the most widely used. It can carry various pieces and bulk materials, with a lifting capacity of less than 100 tons and a span of 4 to 39 meters. Ordinary gantry cranes with grabs have a higher level of work. Ordinary gantry cranes mainly refer to hook, grab, electromagnetic, hoist gantry cranes, and also include semi-gantry cranes.

2. Gantry cranes for hydropower stations
It is mainly used for lifting and opening and closing gates, and can also be used for installation operations. The lifting capacity is 80-500 tons, the span is small, 8-16 meters; the lifting speed is low, 1-5 meters per minute. Although this kind of crane is not frequently lifted, once it is used, the work is very heavy, so the work level should be raised appropriately.

3. Shipbuilding gantry cranes
It is used to assemble the hull on the berth, and there are always two lifting trolleys: one has two main hooks, running on the track of the upper flange of the bridge; the other has a main hook and an auxiliary hook, which is on the lower flange of the bridge run on rails for flipping and hoisting large hull sections. The lifting capacity is generally 100-1500 tons; the span is up to 185 meters; the lifting speed is 2-15 meters per minute, and there is also a fretting speed of 0.1-0.5 meters per minute.

4. الرافعة الجسرية للحاويات
For container terminals. After the trailers transport the containers unloaded from the ship by the quay wall container carrier bridge to the yard or rear, they are stacked by the container gantry crane or directly loaded and transported away, which can speed up the turnover of the container carrier bridge or other cranes. The yard that can stack containers with a height of 3 to 4 layers and a width of 6 rows is generally of the tire type, but also of the rail type. Compared with the container straddle truck, the container gantry crane has a larger span and height on both sides of the portal frame. In order to meet the transportation needs of the port terminal, this kind of crane has a higher working level. The lifting speed is 8-10 meters per minute; the span is determined by the number of rows of containers that need to be crossed, and the maximum is about 60 meters, corresponding to the lifting capacity of 20 feet, 30 feet, and 40 feet long containers, which are about 20 tons and 25 tons respectively. and 30 tons.