Mesh Mounting Concept for a Mechanical Rock Excavation Machine

Sammanfattning: This report is the result of a Master’s Thesis done at the Machine Design Department at the Royal Institute of Technology. The project was carried out at Svea Teknik AB in cooperation with Atlas Copco Rock Drills AB and the Mining and Rock Excavation division in Örebro. Atlas Copco is currently developing a new TBM for mechanical rock excavation, which have been named the RVM (Remote Vein Miner. When doing the excavation, stresses and cracks are induced in the tunnel walls and roof, why it is necessary to reinforce the tunnel so that is does not collapse. In this case this is done by drilling holes and inserting rock bolts into the tunnel walls, and at the same time clothe the walls with a chain link mesh. The operators that are doing this are working in an unsecured part of the tunnel and are hence exposed to a safety risk. It is therefore of interest to make this mesh mounting procedure automated. The project’s purpose was to develop a design concept for the mesh handling and mounting for the RVM that require less manual hands-on work by the operators, i.e. replacing the existing semi-manual mesh handling to a solution that instead can be automatized and remote controlled. Brainstorming was used to generate 6 different concepts, 4 for the mesh handling and 2 for the bolt handling, which were evaluated in two separate Pugh’s evaluation matrices. The two concepts that was deemed most promising, the bolt carrousel and an arm handling solution for mesh rolls, were further developed. CAD models of the included components and systems were made and used to verify the arm’s range and that it fulfilled all of the constraints related to the spatial limitations on the machine. The hydraulic cylinders were dimensioned with forces obtained from an ADAMS simulation. The final conceptual design did fulfil the requirements, but was considered to be very complex and concerns were made regarding how it would handle the harsh environment in the tunnel.