Main Parameters of Hoisting Machinery

1. Lifting Capacity G

Lifting capacity G (formerly often represented by the letter Q) refers to the mass of the load being lifted, measured in kilograms (kg) or tons (t). It is generally divided into rated lifting capacity, maximum lifting capacity, total lifting capacity, and effective lifting capacity.

(I) Rated lifting capacity Gn (excluding the mass of the lifting wire rope, hook, and pulley block) refers to the total mass of the load or material that the crane can lift, along with any separable lifting tools or attachments (such as grab buckets, electromagnetic chucks, balance beams, etc.). For cranes with variable radius, the rated lifting capacity varies with the radius.

(II) Maximum lifting capacity Gmax refers to the maximum rated lifting capacity that the crane is allowed to lift under normal operating conditions. For cranes with variable radius, the maximum rated lifting capacity that the crane is allowed to lift under safe operating conditions at its minimum radius is also called the nominal rated lifting capacity.

(III) Gross lifting capacity (Gt) refers to the total mass of the load or material that the crane can lift, including detachable lifting attachments and attachments or accessories permanently fixed to the crane (including hooks, pulley blocks, lifting wire ropes, and other lifting items below the boom or trolley).

(IV)Effective lifting capacity (Gp) refers to the net mass of the load or material that the crane can lift. For cranes equipped with detachable grab buckets, the mass of material allowed to be grabbed by the grab bucket is the effective lifting capacity; the sum of the grab bucket's mass and the material's mass is the rated lifting capacity.

2.Span S: The horizontal distance between the center lines of the supports of a bridge-type crane is called the span, represented by the letter "S", and the unit is meters (m).

3. Track Gauge k: For a trolley, it is the distance between the center lines of the trolley tracks.

4. Base Distance B: Base distance, also known as wheelbase, refers to the distance between the center lines of the crane or trolley supports along the longitudinal direction of movement. 5.Amplitude L: When a crane is placed on a horizontal site, the horizontal distance between the vertical center line of the unloaded lifting device and the center line of rotation is called the amplitude L. Amplitude has a maximum amplitude and a minimum amplitude.

6.Lifting Moment M: Lifting moment is the product of amplitude L and the weight G of the corresponding lifted item, M=G·L.

7. Lifting Overturning Moment MA: Lifting overturning moment is the product of the weight G of the lifted item and the distance A to the overturning line.

8.Wheel Pressure P: Wheel pressure refers to the maximum vertical load transmitted by a wheel to the track or ground. The unit is N.

9.Lifting Height H and Lowering Depth h: Lifting height refers to the vertical distance from the crane's horizontal stopping surface or running track to the allowable position of the lifting device, in meters (m).

10.Lifting Speed Vn: Lifting (lowering) speed Vn refers to the vertical displacement speed (m/min) of the rated load under stable motion conditions.

11.Trolley Running Speed Vt refers to the speed (m/min) of the trolley carrying the rated load running on the horizontal track under stable motion conditions.

12.Crane Working Class: The crane working class is a working characteristic that considers the utilization of lifting capacity and time, as well as the number of work cycles. It is divided according to the crane utilization level (total number of work cycles over the entire design life) and load status. The crane load status is divided into four levels: light, medium, heavy, and special, according to the nominal load spectrum; the crane utilization level is divided into ten levels from U0 to U9. The crane working class, that is, the working class of the metal structure, is determined by the main hoisting mechanism and is divided into levels A1 to A8 (work busyness and full load).