The design of the bearing housings are based upon nature of lubrication process. The forced-feed lubrication system contains pressurised oil inside the housing, thus bearing housing is exposed to stresses and flow variance. The pressure-filled oil system contains consistent oil level, and the bearing housing is exposed to high temperature of the oil, whereas the pressure of the oil inside the housing remains normal. The manufacturing process of the material has been discussed, and the pre and post machining quality checks have bee elaborated.
The Computerised Numerical Control machines have offered smart way of machining the mechanical parts. The CNC machines ensure dimensional accuracy, and have prevented human and machining error. The different between machining process conducted by human and machine is that the human error i.e. the positioning of tool, and handling of tool during machining are extremely crucial, and therefore the human technicians are vulnerable to off-set certain dimensional measurements, which will eventually develop shortcomings inside the machined object. The CNC machines have controlled the dimensional accuracy and geometrical requirements.
Prior to the machining process, the solid block shall be tested and dimensionally verified. The part shall undergo non-destructive testing. The part should be tested against crack generation, which is possible through dye penetrant test; the hardness of the part shall be verified through hardness check. The job piece shall undergo ultra-sonic flaw detection; this exercise will verify the presence of internal cracks inside the block. Any detection of external and inside cracks, variance of the hardness within the prescribed limit shall be concluded at rejection of the solid piece. The roughness of the block shall be verified, and surface imperfection can be handled by application of emery-paste of the surface to ensure smooth surface.
The manufacturing of the bearing housing is simple process. A huge solid block 65mm x 40mm x 25mm, is initially machined. The machining can be conducted on simple jig. The cutting tools shall be essential to proceed with the machining process. The excessive parts of the machines shall be chopped off. The object shall be then placed in lathe machine, and cutting tool shall be operated on the job piece to make two holes. The holes are of two different measurements; therefore the size of cutting tool shall be changed. Once the external geometrical configuration is achieved, and holes are drilled. It ends of the external parts shall be chamfered; this is possible by operating a cutting tool on the edges of the job piece. In the last step, two holes are drilled on end sides of the job piece, this job can be executed on drilling machine.
The entire machining process has been summarised in the given figure. The process initially starts from the casting of the solid piece. Another smart approach for the manufacturing of such shape will be the design of the jig, the jig will then hold the molten material, and after quenching the required shape and dimensional characteristics of the object can be attained.
The machining program for this job is as discussed,
N10 G00 G20
N12 T3 M06
N14 S10000 M03
N16 G00 X0.5 Y0.5 Z5. H03 M08
N22 X2 Y2
N24 X2 Y2
N26 X2 Y2
N28 X3 Y4
N30 G80 M09
N32 T4 M06
N36 S3761 M03
N38 G00 G54 X0.25 Y0.1 Z1. H04 M08
N42 G99 G73 Z-1. R.05 Q.1 F18.
N44 X1.5 Y1.1