Design of bridge electric crane lifting mechanism

Contents

Contents

Introduction

1. Source Data

2. Load lifting mechanism

2.1. Hook suspension selection

2.2. Rope Selection

2.3. Definition of drum, upper blocks and equalizer

2.4. Electric motor selection

2.5. Gearbox selection

2.6. Selection of couplings

2.7. Brake selection

2.8. Kinematic diagram

3. Check of engine starting reliability of lifting mechanism

4. Steel Structure Calculation

4.1 Initial data

4.2. Structural materials

4.2.1.Selection of structural material

4.2.2. Welding materials

4.3. Estimated loading cases. Normative and design loads, their combinations

4.3.1. Design loads

4.3.2. Design diagrams of vertical loads application

4.4. Determine optimal cross-sectional dimensions of the span beam

4.4.1. Calculation of dimensions in the middle part of the span based on the condition of strength

4.4.2. Calculation of dimensions in the middle part of the span based on static stiffness

4.4.3. Sizing a Span Beam Cross Section

4.5. Bridge Layout Diagram

4.5.1. Beams

4.5.2. Arrangement of crane movement mechanism

4.5.3. Mating of span beams with end beams

4.6. Place Stiffness Edges

4.7. Construction lifting of span beams

4.8. Strength of span beam at its total bending in two planes

4.9. Weld joint connecting strap to end beam

4.10. Weld joint connecting belt to wall

Conclusion

List of literature

Introduction

Lifting machines are a highly efficient means of complex mechanization and automation of lifting, loading and unloading and storage operations. The use of such machines reduces the use of heavy manual operations and contributes to a sharp increase in productivity. Automation of lifting machines allows you to include it in the production line, and the versatility of use - to make it a component of flexible automated production.

One of the points of the huge list of the nomenclature of lifting machines is a bridge crane. A bridge crane is a lifting machine that moves along rails at a distance from the ground (floor) and provides for the movement of the load in three mutually perpendicular directions. Bridge cranes are one of the most common means of mechanization of various industries. Moving along the above-ground tracks, they do not occupy the useful area of ​ ​ the workshop or warehouse, while providing service to almost any of their points.

The main goal of this course project is to teach the basics of designing a complex assembly as a whole, to consolidate, deepen and generalize the knowledge acquired by the student during the study of the "Basics of Design of PTM" discipline.

Estimated loading cases. Normative and design loads, their combinations

4.3.1. Design loads

When determining the strength of steel structures, design loads are considered in combination II A, while the trolley is in the middle of the bridge span and the load is lifted.

Bridge Layout Diagram

Crane bridge layout is determined to a large extent by layout of junction units of span beams with end beams and crane undercarriage structure. Cranes with a lifting capacity of up to 50 tons are installed on four running wheels, of which two are driven. Connection of span beams with end beams is made in joint as beams of equal height.

Conclusion

During this course project, the mechanism for lifting the bridge crane was calculated.

The project has been completed according to the task. The difference in the lifting speeds of the load in comparison with the nominal ones does not exceed the permissible 15%.

The course design contains elements of preliminary and technical design, as well as development of detailed documentation. The method of technical design implementation is mastered in the development of drawings of complex assembly units, performance of check calculations, technical description of the machine, determination of its most important technical and economic indicators.

The assembly drawing solves another important task: it is the basis for the development of smaller assemblies and parts. Therefore, the assembly drawing contains reference dimensions and other necessary information.