Engineering Operations and Maintenance - Types of Lubricants - Assignment Example

Engineering Operations and Maintenance Task 1a (P1) A lubricant refers to a substance that is specifically used to minimize friction existing between surfaces; this in turn minimizes the heat that is generated due to the movement of the surfaces. The key purpose of lubricants is to reduce wear and tear on the surfaces that are in relative motion. However, wear and tear cannot be totally eliminated but they can be cut or reduced to some levels that are deemed to be acceptable. Moreover, lubricants have other secondary purposes such as minimizing oxidation in order to prevent rust, provide insulation in all transformer applications, transmission of the mechanical power in the hydraulic fluids and sealing surfaces dust, dirt and moisture (Mortier, 1997). Lubricants have a number of applications. To start with are used to keep the moving parts of a machine apart so as to reduce the possibility of surface fatigue and friction. This is achieved by forming a layer between the surfaces that acts as a barrier. Secondly, lubricants are used to transfer heat. Liquid lubricants are effective in this application due to their ability to hold heat (heat capacity). Finally, lubricants are used to prevent corrosion; such lubricants have additives which chemically form bonds with metallic surfaces in order to exclude air and moisture from reaching the surface. Types of lubricants Mineral oil: - This is a type of lubricant that is made from crude oil and it is used in combustion engines to prevent oxidation. Vegetable oil: - This is a type of lubricant that is made from organic plant substances. In most cases, they form the base oil. Grease: - This is a lubricant with the highest level of viscosity. It is made from either mineral or vegetable oils; it is a corrosion inhibitor. Synthetic oil: - This is a type of lubricant that is artificially made from chemical compounds, mostly petroleum products instead of the entire crude oil. They are used in metal stamping. Cutting fluid: - This is a type of lubricant that is made from either petroleum products or organic substances. It is specifically made for machines and metal work (Caines & Haycock, 2004). Task 1b (P2) Gravity feed is a lubrication system that uses gravity to move liquid substances from one point to another. This is a relatively simple method of moving fluids without necessarily using a pump. This is commonly applied in fuel supply to internal combustion engines by simply placing the fuel tanks above the engines (mostly in motorcycles). Such systems are made up of a loosely covered manifold which is placed on top of the bearing that regulates the amount of oil supply at certain intervals. This supply is controlled by a conical valve that is adjustable when necessary and is connected to a reservoir which is often refilled when the oil level drops (Rudnick, 2005). Forced feed Lubrication System In this system of lubrication, the lubricant (oil) is pressurized to move from one point to another. It is mostly used in machines that operate at relatively high speed and those associated with movement of heavy loads. A high and fast flow of oil is required to protect such machines from overheating caused by friction. Gear boxes and turbine generators are major examples of machines that use this system of lubrication. Thus, to maintain the flow of oil in such systems, the pump often takes the lubricant from the reservoir, clean it up and return it back to the reservoir. Grease cups and nipples lubricating system This is a system which is made up of smaller containers that are filled with grease and fitted to a bearing. The main aim of this system is to force grease to enter the bearing by rotating and turning the cap which is covering the grease container. Thus, its operations are accomplished through replacement of screw piston, in the compression cups, with a spring plunger. When pressure is applied on the plunger, grease is slowly forced into the bearing. Task 1c (D1) Compressors handle the flow of fluids at a relatively high speed. Thus, they need a gear that increases speed. High speed is associated with overheating which is caused by high frictional force between surfaces. The mineral oil lubricant’s function is to minimize friction and prevent wear in the gears and bearings. Moreover, it reduces overheating, contamination and corrosion. Thus, the mineral oil is the appropriate lubricant since it is recommended for combustion engines where oxidation is most likely to occur (Gupta, 2006). Task 2a (P3) Circular oil seals are round seals which are used to keep fluids within their respective places and keep dirt and other contaminants out. Such seals are always placed between parts that are in relative motion like the pistons of hydraulic cylinder and rotate g pumps. Moreover, they are relatively cheap, reliable and easy to make (Dresel & Mang, 2007). Packing: - Gaskets Gaskets are mechanical seals that fill the spaces between surfaces to prevent any kind of leakage; whether into or out of the joined surfaces under compression. Thus, they are used in systems such as the high-pressure steam whereby they function appropriately with the application of a sealant. Bearings: - Ball bearings Ball bearings refer to the type of rolling bearings that use balls to separate the bearing surfaces. Thus, they are mainly applied in rotational machines so as to minimize friction and to support the radial load whereby two races are used to contain balls where the loads are transmitted through; one race is always stationary. Task 3a (P4) Screwed fastenings: - metric bolts and self-tapping screws Metric bolts are those bolts that are fully or partially threaded and they are used alongside washers and nuts. Self-tapping screws are screws that have the ability to create tap of their own holes as they drive into any surface. They are used on hard materials like metals, hard plastics and soft woods whereby the self-tapping ability is crated through cutting gaps in continuity of threads on screw-generating tap. Rivets A rivet refers to a permanent mechanical fastener which has a head and a tail. It is used to join metallic plates; mostly steel. Thus, a snap head rivet is one which has a button head or snap. It is used in general plate works that require a lot of strength. Pop Rivets are those that are tubular with a mandrel through their centers. Thus, a pop rivet assembly is placed inside a drilled hole through the parts or plates to be joined and the mandrel is drawn down into the rivet. Task 3b (D2) Milling Machine This is a machine used in cutting processes and uses the mill cutter to remove materials from workplace surfaces. The mill cutter has several cutting points which make it a rotary cutter; the tool is advanced in a way that it moves perpendicularly along a circular or rotational axis. Thus, as the cutter enters the workplace surfaces, the teeth of the cutter cuts into the exit repeatedly and shave off the chips from working surface (Youssef & El-HOFY, 2008). The machine has a number of engineering components that enable it to perform effectively. To start with, the machine has a gray Iron Base which is casted accurately on the top and bottom surfaces of the machine. Its key role is to support other parts of the machine; forms a foundation. Column is a vertical frame which is mounted on the bag. Its role is to support the entire machine from the middle. Knee is a gray-iron which moves up and down by sliding parallel to the column. Saddle is placed or rather it sits on the knee and thus it allows access to the worktable. Table sits on the saddle in a position that can allow it to move longitudinally. Longitudinal and traverse wheel move the worktable from left to right and up and down respectively. Therefore, the above named components are designed using engineering knowledge of joints and lubricating systems which make them a better choice. References list CAINES, J. A. & HAYCOCK, R. F. (2004). Automotive Lubricants Reference Book. New York: John Wiley & Sons DRESEL, W. & MANG, T. (2007). Lubricants and Lubrication. New York: John Wiley & Sons. GUPTA, H. N. (2006). Fundamentals of Internal Combustion Engines. Mumbai: PHI Learning Pvt. Ltd. MORTIER, R. M. (1997). Chemistry and technology of lubricants. Berlin: Springer Science & Business Media. RUDNICK, L. R. (2005). Synthetics, Mineral Oils, and Bio-Based Lubricants: Chemistry and Technology. New York: CRC Press. YOUSSEF, H. A. & EL-HOFY, H. (2008). Machining Technology: Machine Tools and Operations. New York: CRC Press. Read More