Machine Parts

Mass balancing: Mass balancing means the balance of mass of turbine blades around the both sides of turbine shaft axis. Every object has a point called center of gravity through which the mass of that object acts. If this point of a turbine blade does not lie upon the center axis of shaft, an unbalanced condition will create which may cause the failure of turbine shaft as well as turbine. So it is very necessary to operate turbines with proper balancing. In case of single blade when its center of gravity does not lie upon the center axis of shaft, an unbalanced condition creates due to the variation of mass center and center axis.   For balancing, either welding or grinding is done on turbine blades. In which side the mass is less, welding is done there to increase mass in that side. Similarly in which side the mass is more, grinding is done to reduce mass from that side.   In case of multi-blade, it is very difficult to balance the mass center line through over the

                    Shaft alignment Shaft alignment is the process to align two or more shafts with each other to within a tolerated margin. It is an absolute requirement for machinery before the machinery is put in service. When a driver like an electric motor or a turbine is coupled to a pump, a generator, or any other piece of equipment, it is essential that the shafts of the two pieces are aligned. Any misalignment between the two increases the stress on the shafts and will almost certainly result in premature breakdown of the equipment. This can be very costly. When the equipment is down, production might be down. Also bearings or mechanical seals may be damaged and need to be replaced. A proper shaft alignment can prevent this. The resulting fault if alignment is not achieved within the demanded specifications is Shaft misalignment, which may be parallel, angular, or both.                                                                                           

Coupling means actually shaft coupling. A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. Couplings do not normally allow disconnection of shafts during operation, however there are torque limiting couplings which can slip or disconnect when some torque limit is exceeded. The primary purpose of couplings is to join two pieces of rotating equipment while permitting some degree of misalignment or end movement or both. By careful selection, installation and maintenance of couplings, substantial savings can be made in reduced maintenance costs and downtime. Types of coupling: Ø   Rigid coupling Ø   Flexible coupling Ø   Gear coupling Ø   Fluid coupling Ø   Diaphragm coupling Ø   Torque limiting coupling etc.                                                    Figure: Coupling joints. Applications: Shaft couplings are used in machinery for several purposes, the most common of which are the fo

Pumps:             Pumps are such a device, which transfer liquid from one place to another place by pressure difference. Types of pump: 1.       Centrifugal pump 2.         Reciprocating pump Centrifugal pump:                         The pump which raises water or a liquid from a lower level to a higher level by the action of centrifugal force is known as centrifugal pump. A centrifugal pump is a rotodynamic pump that uses a rotating impeller to increase the pressure of a fluid. Centrifugal pumps are commonly used to move liquids through a piping system. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward into a diffuser or volute chamber, from where it exits into the downstream piping system. Centrifugal pumps are used for large discharge through smaller heads.