Assignment Submitted by: 2014-CH-03 ( M. Kaleem Asif )
Maintenance Engineering Submitted to: Dr. Hassan Javed Naqvi
TYPICAL ANSI (or DIN) PROCESS PUMP
Small diameter of shaft with excessive overhang An increased length from 4 to 10 times the bar diameter will give a 16 times larger deflection for a bar taking a constant cutting force. A further extension from 10 to 12 times the bar diameter, gives another 70% increase in deflection from the same cutting force. Holding the bar length constant while changing the bar diameter from 25 to 32 mm, reduces deflection with 62% for equal cutting forces. It is important to cut with sharp edges to minimize the cutting force required to perform the machining operation - a positive cutting cutting geometry geometry reduces reduces cutting forces. Stuffing box designed for packing A stuffing box is an assembly which is used to house a gland seal. It is used to prevent leakage of fluid, such as water or steam, between sliding or turning parts of machine elements. A stuffing box of a sailboat will have a stern tube that's slightly bigger than the prop shaft. It will also have packing nut threads or a gland nut. The packing is inside the gland nut and creates the seal. The shaft is wrapped by the packing and put in the gland nut. Through tightening it onto the stern tube, the packing is compressed, creating creating a seal against the shaft. Creating a proper plunger alignment is critical for correct flow and a long wear life. Stuffing box components are of stainless steel, brass or other application-specific materials. Shaft sleeve A shaft sleeve is a cylindrical hollow metal tube placed over the shaft to protect as it passes through the packing. Pump shafts are often protected protected from erosion, corrosion, and and wear at at leakage leakage joints, seal chambers, internal bearings and in the waterways by renewable sleeves. The most common shaft sleeve function is that of protecting the shaft from packing wear at the stuffing box. A shaft sleeve used between two multistage pump impellers in conjunction with the inter-stage bushing to form an inter-stage leakage joint is called called an inter-stage or distance sleeve. Light to medium duty bearings While the basic internal design and load capacity of BF Series bearings are fixed by the internal design, the bore size, front extension (“G”) and the rear extension, (“H”) can be modified to fit individual applications in most cases. A minimum of 25,000 pieces are required for custom revisions. Rubber lip seals protecting the bearings The lip oil seal, while selected mainly for sealing the shaft to housing gap, is typically an unsatisfactory sealing device. Over time, the lip causes fretting corrosion of the shaft (the gouge seen under the lip when it slides off the shaft). Moisture on the shaft capillaries is drawn past the lip, and water sprayed directly at the lip seal blows past the seal and into the bearing. Oil seals are rarely replaced in installed equipment even though the seal is a perishable component and should be replaced routinely. Snap ring retains thrust bearing in housing A retaining ring is a fastener that holds components or assemblies onto a shaft or in a housing/bore when installed in a groove. Once installed, the exposed portion acts as a shoulder which retains the specific component or assembly. Circlips are a type of retaining ring. Self-locking retaining rings may be installed in applications where there is no groove. Retaining rings are typically made from carbon steel, stainless steel or beryllium copper and may feature a variety of finishes for corrosion protection depending on the type of environment in which they are used.
Shaft adjustment requires dial indicator Shaft misalignment is one the major causes of premature coupling, bearing, and seal failures in a power transmission system. Even while staying within the misalignment limits of a flexible coupling, it is still advisable to keep misalignment to a minimum. While dial indicators offer an excellent shaft alignment solution for many applications, for those looking for a best in class solution, laser shaft alignment tools are available. Double row thrust bearing Double Row Angular Contact ball bearings have two rows of balls arranged back-to-back. The lines of action of the load at the contact between balls and raceways (load lines) diverge at the bearing axis and form an angle of 30° to the radial plane. In essence, they work similarly to having a matched pair of Single Row Angular Contact ball bearings either face-to-face or back-to-back. The difference is that Double Row Angular Contact ball bearings can take a bi-directional axial load in one bearing where it takes a matched pair otherwise. This means the bearings are particularly suitable for accommodating simultaneously acting radial load and axial load in both directions. Cast jacket on bearing frame for cooling The water jacket cooled WGM motors were designed to meet the increasing demand for compact and reduced noise level machines, where high output power versus frame size ratio is required. Small oil reservoir
The oil pump in an internal combustion engine circulates engine oil under pressure to the rotating bearings, the sliding pistons and the camshaft of the engine. This lubricates the bearings, allows the use of higher-capacity fluid bearings and also assists in cooling the engine. As well as its primary purpose for lubrication, pressurized oil is increasingly used as a hydraulic fluid to power small actuators. One of the first notable uses in this way was for hydraulic tappets in camshaft and valve actuation. Increasingly common recent uses may include the tensioner for a timing belt or variations for variable valve timing systems.
