Design project 8 - N/a PDF

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Needle roller bearings A needle roller bearing is a bearing that uses small cylindrical rollers. These rollers are used to reduce friction of a rotating surface. Compared with ball bearings, needle roller bearings have a large surface area that is in contact with the bearing raceway journals. The typical structure of a needle roller bearing comprises an inner race, a needle cage which orientates and contains the needle rollers, the needle rollers themselves, and an outer raceway. There are many different designs of needle roller bearing, including drawn cup, precision race, caged roller, and thrust roller needle bearing havethe ability to handle relatively high loads in a compact design envelope. This technical advantage has made the needle roller bearing the preferred choice of bearing in a wide variety of industrial and automotive power transmission applications.

Task 4 There are many types of fastenings such as bolts, screws, nuts and washers. Machine screw

A screw is an externally threaded fastening. They are designed to put into a mating threaded hole or form its own thread. The diagram below shows a machine screw fixing and its purpose.

Bolts A bolt is an externally threaded fastening designed to be held by a nut after the bolt has been placed through the hole. The diagram below shows this application.

Screws and bolts can be identified by the pitch such as M8 x 1.5, length, head and also the shape.

1)Hex Head Screw Hex head screw can take a lot of torque and can be driven in or out with a socket. 2) Button Head Screw Button head screws are round on the top so they do not catch on anything. 3)Flat Head Screw Flat head screw are flat on top, they have tapers to guide. 4)Set Screws Set screws are also known as grommet screws; they are normally hardened and used to fasten pulleys and collars on a shaft. 5)Allen key bolts Allen key bolts tend to have more torque power and are used in counter bored holes. 6) Pan Head Screws PanHead screws have a small flat roundup which can be used in counter bored holes.

Nuts 1)Lock nuts Locking nuts or self locking nuts will not need a washer in their application....