Goat crane drawings

Contents

Contents

1. Job for Course Project

2. Introduction

2.1. Project Relevance

2.2. Project Objective

2.3. Main tasks of the project

3. Technical Analysis and Technical Proposal

3.1. Technical analysis

3.2. Technical Proposal

4. Calculation of load lifting mechanism

4.1 Hook Suspension Selection

4.2 Rope Selection

4.3 Determination of drum length and main dimensions of drum installation

4.4 Power calculation and motor selection

4.5. Gearbox selection

4.6 Coupling Selection

4.7 Determination of brake torque and selection of brake

4.8 Calculation of rope attachment to drum

4.9 Calculation of drum axis

4.10 Calculation of rolling bearings of lifting mechanism for durability

4.11 Check of electric motor of lifting mechanism by start-up time

4.12 Check of braking time

4.13.Check the drum wall for strength and stability

4.14 Calculation of bolts connecting the gear rim to the drum

5. Calculation of trolley movement mechanism

5.1. Determination of static loads on drive wheels

5.2. Selection of wheel units

5.3. Determination of crane movement resistance

5.4. Electric motor selection

5.5. Gearbox selection

5.6. Brake selection

5.7. Selection of couplings

5.8. Engine check during acceleration

5.9. Engine check during braking

5.10. Check of traction margin of wheels with rails

6. Conclusion

List of used literature

Job for Course Project

Task: calculate and design the gantry crane according to the following specified parameters:

Q = 5 t - load capacity;

H = 8 m - required lifting height;

L = 32 m - crane span;

- cargo lifting speed;

- trolley travel speed

Operating mode: A3

Introduction

2.1. Project Relevance

Lifting and transportation machines and mechanisms (including goat crane) are the main means of mechanization and automation of loading and unloading operations in all industries and agriculture.

Gantry lifting cranes are the main means for loading and moving various materials, as well as for performing heavy installation work, which is currently relevant.

2.2. Project Objective

The main goal of the project is to obtain a practical skill in designing crane structures.

2.3. Main tasks of the project

a) perform technical analysis of gantry cranes mechanisms

b) calculate and design the mechanism for lifting (lowering) the cargo of the goat crane;

-select rope and hook suspension

-compute drum parameters

-assemble motor, gearbox, clutch, brake, bearings

-Process design and verification calculations

c) calculate and design the movement mechanism of the goat crane trolley;

-define static loads on drive wheels and trolley movement resistance

-select wheel unit

-select electric motor, gearbox, couplings, brake

-provide verification calculations

Technical Analysis and Technical Proposal

3.1. Technical analysis

Goat cranes are one of the main means of mechanization of transshipment and warehouse work in various sectors of the national economy.

By purpose, goat cranes are divided into three main groups: general purpose, or reloading, construction and installation and special purpose.

Transshipment cranes are operated in open warehouses and loading areas serviced by means of ground rail and rail-free transport; their carrying capacity is usually 3.2... 50 t, spans 10... 40 m, lifting height depending on the conditions for loading and unloading vehicles or stabilizing goods 7... 16 m.

Construction and installation cranes are intended mainly for the installation of equipment of industrial enterprises, power plants and prefabricated transport facilities. Lifting capacity of these cranes 300... 400 t, spans 60... 80 m and lifting height 20... 30 m. Cranes are designed for light operation; their design often provides quick relocation, assembly in various versions with varying load capacity, span, lifting height, etc.

Special-purpose cranes serving hydraulic structures that provide sectional assembly of ships, etc., are extremely diverse in design and working equipment; their parameters are varied within the widest limits [1].

Regardless of the type, goat cranes have a bridge (span) resting on two supports equipped with rail-wheel undercarriages. Trolley moves along the bridge.

Depending on the design scheme of the bridge, cantilever and non-cantilever cranes are distinguished. The possibility of the cargo trolley entering the console allows the transport rail and rail-free tracks to be located under it, and the platform under the span of the bridge can be used for the construction of a warehouse or technological facility. In addition, the total storage area is increased.

Unconsolidated cranes are somewhat simpler in design, but placement in the span of transport routes often prevents the rational organization of warehouses; the safety of persons working in such warehouses is also reduced.

The cranes may have two rigid or one rigid and the other flexible supports. Struts of rigid supports are made with dimensions of struts section increasing in height. Such cranes have a smoother stroke and their supporting structures are much less susceptible to oscillation. However, they are very sensitive to the deviations of crane rails and the accuracy of mounting the running wheels in the horizontal plane. Exceeding these deviations in excess of the values prescribed by the standards leads to rapid wear of the ridges of the running wheels.

For cranes with one rigid and the other flexible supports, the posts of the latter have very significant compliance compared to the posts of the rigid support, sometimes they are attached to the bridge using hinges. Such

cranes can usually move along tracks whose rail deviations in the horizontal plane are 2540% higher than the maximum permissible, they are also less sensitive to deviations in the accuracy of installation of running wheels in the horizontal plane. However, both the running wheels and the rigid support rail track experience axial loads that are two to three times higher than the corresponding loads of cranes with two rigid supports.

Cranes with one rigid and the other flexible supports often experience slowly attenuating low-frequency longitudinal vibrations. This adversely affects the accuracy of the crane and worsens the working conditions of the crane operator.

For most cranes, the bridge rests on two-post supports, through the openings of which the load is transported from the cantilevers to the span, while the maximum length of the load is determined by the distance between the posts of the supports.

For cranes with cantilever freight trolley and single-rack supports, long-length loads supplied under cantilevers are turned by 90 ° on weight and, regardless of their length, they are freely moved past the support of the span part. If necessary, the cargo can be deployed again by 90 °.

Depending on the location of the lifting mechanism relative to the lift tracks, cranes with suspended, support and cantilever cargo carts are distinguished. Cranes with suspended monorail freight trolleys are the most simple in design. However, when working with increased, as well as medium intensity, the lower riding shelves of the monorail bend. In addition, monorail trolleys are not protected from transverse swinging.

These disadvantages are devoid of cranes with suspended two-rail trolleys, which, however, are characterized by a more complex design.

Support freight trolleys are most convenient to use. However, they can only be used on relatively high mass double-beam cranes or on non-horseless cranes that are ineffective in some cases.

Cranes are made with control from floor by means of suspended push-button panel or from cockpit. Cranes with control from the floor usually have spans of no more than 16 m and are equipped with electric steel. When spans up to 1625 m, the cab is usually installed on one of the supports or on a bridge near the support.

Calculation of load lifting mechanism

The load lifting mechanism is designed to move the load in the vertical direction. It is selected depending on the carrying capacity.

The load lifting and lowering mechanism drive includes a hoist of the lifting mechanism. The torque generated by the electric motor is transmitted to the reduction gear through the clutch. The reduction gear is designed to reduce the number of revolutions and increase the torque on the drum.

Drum is intended for conversion of rotary motion of drive into translational motion of rope.

Conclusion

As a result of the course project, a goat crane with a carrying capacity of 5 tons and a mode of operation (A3) was designed.

The design part consists of two parts: the lifting mechanism and the movement mechanism of the trolley.

The following calculation was made in the lifting mechanism:

- a double rope of the LCR type with a diameter of 9.9 mm and having 1578 MPa at the marking group of wires is selected;

- hook suspension is selected;

- the dimensions of the drum, its diameter and total length are determined taking into account the multiplicity of the polyspast;

- rational material of the drum is selected and checked for strength by compressive stresses;

- couplings selected;

- electric motor is selected considering that the mechanism operates with different loads;

- check with permissible values of starting and braking characteristics in unfavourable operating modes of the mechanism.

The central drive is calculated in the trolley movement mechanism, for which:

- running wheels are selected taking into account their quantity, crane lifting capacity, trolley weight and its speed of movement;

- electric motor is selected and checked;

- gearbox is selected;

- check was made with permissible values of starting characteristics at unfavorable operation mode of the crane.

On the basis of the calculation part, a graphic is made, in which it is displayed on sheets in A1 formats:

- general view of the crane; load lifting (lowering) mechanism; trolley movement mechanism; drum.