Design of conveyor with chain traction member

Introduction

The logging industry belongs to the most important extractive industries of the national economy. The main products of the logging industry are round timber, as well as some types of products for their processing (sleepers, boards, rough blanks, technological chips, etc.).

The production of finished forest products is related to the implementation of a certain technological process of logging, including forestry, transportation of timber and forestry. The process of the logging plant is very complex and takes place under various conditions, which necessitates the creation of special equipment for the harvesting and transportation of timber, as well as for their processing.

There are several types of transporting machines. These are tape, scraper, plate, bucket, suspended, screw, roller and many, many other types.

In this course project, based on the initial data, the design of a sorting forestry vehicle with a chain traction organ of the TS7 type was developed for the longitudinal transportation of round timber.

Understanding the Designed Product

Transporters with a flexible traction member are used for moving operations with various cargoes, performing technological operations as part of flow lines and other works.

Designed timber transport with load-bearing working bodies, longitudinal movement (timber is located along the conveyor axis). The main elements of longitudinal sorting timber vehicles are a trestle, traction, drive and tensioning device.

The rack is the main bearing structure on which the traction member with working elements (crossarms), drive and tensioning devices are mounted. The trestle is made of wood, reinforced concrete or metal.

The traction device in this sorting forestry vehicle is a welded chain of round steel with crossarms fixed on it. Compared to steel ropes, the chain has several advantages: the chain is stronger than the ropes and it is more convenient to attach working elements to it.

Drive devices serve to move traction member and load. The drive includes an electric motor, a reduction gear and a drive sprocket.

The tensioning devices ensure normal operation of the traction member by tensioning it to the mounting value necessary for smooth travel and normal engagement with the driving sprocket. Screw tensioners are used for chain timber vehicles. In this case, the ends of the axis of the guide sprocket are fixed in the slides, which are moved by screws in the guides.

For further development, we will use the TC7 forest vehicle as a prototype, which is one of the most common for moving operations in lower warehouses.

Design of conveyor drive frame

The frames are used to install the drive units (engine, reduction gear box, etc.) and ensure their correct position during the entire service life.

Frame design shall meet the requirements of strength, stiffness, vibration resistance, shape stability during operation, etc.

Length and width of frame are determined in accordance with dimensions of units installed on it. Height of frame is determined depending on structural features of units and assemblies mounted on it.

When designing a frame, do not leave large free areas. For this purpose frame is made of L-or T-shape.

The dimensions of the frame in the plan are determined by the plates for placing the legs of the units. The platter should be longer than the paw by 3... 5 mm in each direction, but not reach the edge of the plate by about the thickness of its wall.

Conclusion

During the course project, an analysis of the structures of longitudinal forest vehicles was carried out, after which the prototype TS7 was chosen. The drive and tension stations are designed. The graphic part shows: the general view of the conveyor, the drive station, the tensioning station, as well as the working drawings of the parts.

In the structural part, the main parts of the forest vehicle were developed and calculated: calculation of the driving sprocket, selection of the traction element, design and verification calculations of the shaft, verification of the durability of the bearings and verification of the strength of the key joints.