Overhead cranes are essential machines used in various industries for lifting and maneuvering heavy loads. The design and analysis of overhead cranes involve several critical calculations to ensure safe and efficient operation. This comprehensive guide will delve into the intricacies of calculating various aspects of overhead cranes, including wheel loads, deflection, and design considerations. We will explore different types of cranes, the significance of wheel load calculations, the measurement of deflection, and the importance of adhering to organizational specifications. So, let’s dive into the world of calculation overhead cranes and uncover the key principles and methodologies involved.
Types of Electric Overhead Cranes
Before delving into the calculations, let’s familiarize ourselves with the different types of electric overhead cranes commonly used in industries:
- Single Girder Cranes: These cranes consist of a single bridge girder supported on two end trucks. They are suitable for light to moderate lifting applications.
- Double Girder Cranes: Double girder cranes feature two bridge girders supported on two end trucks. They offer increased lifting capacity and are commonly used for heavy-duty applications.
- Gantry Cranes: Gantry cranes are characterized by their support on two or more legs running on fixed rails or runways. They provide versatility and can be used both indoors and outdoors.
The Significance of Wheel Load Calculations
Wheel load calculations play a crucial role in the design and analysis of overhead cranes. The wheel pressure load refers to the vertical pressure exerted by the crane’s wheels on the track or runway. It determines the strength and stability of the crane’s operating mechanism and metal structure. Additionally, wheel load calculations provide essential data for designing wheel devices and track support structures.
The calculation of wheel load is typically divided into two categories: the calculation of wheel load under moving loads and the calculation of wheel load under super static structures. The former considers the distribution of the supporting reaction force, while the latter takes into account factors such as structural rigidity, foundation rigidity, and track elasticity.
It is essential to accurately determine the wheel load to ensure the crane’s components can withstand the imposed forces and operate safely. Incorrect calculations can lead to structural failures, decreased performance, and potential hazards in the workplace.
Wheel Load Calculation Process
To calculate the wheel load of an overhead crane, a systematic approach is followed. Here is a step-by-step process for wheel load calculation:
- Identify Crane Parameters: Gather information on the crane’s rated lifting capacity, trolley weight, bridge weight, number of wheels, wheel spacing, and distance between the crane girders.
- Calculate Total Crane Load: Determine the total crane load by summing up the maximum lifting capacity, trolley weight, and bridge weight.
- Determine Load Distribution: Distribute the total crane load among the wheels by dividing it by the number of wheels.
- Calculate Wheel Loads on Girders: Allocate the load per wheel between the two crane girders, considering the distance between them.
- Consider Impact Factor: Take into account dynamic effects, such as impact, during crane operation. Apply an appropriate impact factor to the wheel loads on