Principle of Equilibrium

The E-Crane Concept

Click here for preferred language(s) / Cliquez pour la langue

To a large extent, the working principle of the crane is already explained by its name. It is indeed the case that the counterweight compensates a consederable part of the tipping moment of the crane. What is unique about this concept is the fact that this counterweight continuously balances the total weight of the steel structure increased by half of the operational load and it does this for all possible positions of the main boom and front arm.

A Special Design

The connection with the aid of the push-pull rod (connecting rod) between the back end of the front arm and the counterweight is of essential importance here since this part results in the synchronization of the front arm movements and movements of the counterweight. The fact that here a rigid, direct connection is opted for should be no surprise. It is namely so that an equilibrated crane can also exert pressure on the grab in all front arm positions.

Advantages

The advantages of this type of construction, or better of this unique concept, are readily apparent:

Lower stress on the support structure, due to a decreased tipping moment
Mechanically rigid connection between the grab and the crane structure, even at the maximum operating radius
A continuous operating load (payload) over the total working area
It is possible to exert a pressure (by means of the main boom and the counterweight cylinder)
A smoother operation of the whole machine, due to the lower level of operating power required Energy Savings

In these times of energy conservation, it is also important to say something about the energy consumption. With the more traditional hoisting machinery, not only the payload (contents of the grab) has to be raised, but also the working tool (grab) and the steel construction. By contrast, with the E-crane only the payload needs to be raised. It goes without saying that this results in energy savings.

Upperstructure

The upper structure is everything above the swing gear. In other words: everything that swings around (including the swing gear).

Stick

Stick or ‘Front Arm’ is the connecting part between the crane tool (grapple, magnet, bucket,...) and the outer part of the main boom. At the end of the stick there is a fork-shaped part, the grab suspension, to connect all kinds of grabs more easily to your E-Crane.

Boom
The boom (also ‘main boom’) is the biggest arm where all cylinders are connected with. These hydraulic cylinders can be devided into a main cylinder (lifting cylinder) and a counterweight cylinder (luffing cylinder). The lifting cylinder moves the boom, while the counterweight cylinder moves the counterweight and, through the use of the connecting rod, the stick or front arm.

Connecting Rod
The connecting rod, or the push-pull bar, is the link between the back of the front arm and the upper part of the counterweight. This essential part synchronizes movements of the stick and the counterweight.

Upper Chassis

The chassis is the central, triangular shaped, steel structure, supporting the boom on top and having the swing gear at the bottom. This way, chassis and column are connected to each other by the the swing gear.

Machine deck
The machine deck, also operators’ platform or upper platform, is the assembly of gangways, stairs, engine room, and cab platform on the upper structure.

E-Crane Components

Undercarriage

To help the reader better understand names and expressions used throughout this manual we hereby add a list of the most important parts of an E-Crane.

Everything below the swing gear (swing bearing) belongs to the undercarriage.

Column

The tube supporting the swing bearing.

•1 frontarm (Stick)
• 2 Connecting Link
• 3 Main Boom
• 4 Counterweight (-concrete)
• 5 Chassis + Inspection Platform
• 6 Gangways + Platform
• 7 Grab Suspension
• 8 Cylinder Group
• 9 Hydraulic (Clamshell) Grab
• 10 Lubrication Superstructure
• 11 Hydraulics
• 12 Electricity
• 13 Pedestal / Undercarriage / Gantry