Bearings: Types, Materials and Load Paths | Machinist Level 3

A replacement bearing fits the shaft and housing, yet the machine runs hot and loses accuracy. The missing information may be load direction, internal clearance, axial location, lubrication or the complete designation. This lesson follows the load through plain and rolling bearings, explains why their materials differ, and connects identification to a documented repair decision. Original calculations cover shaft reactions, sleeve clearance, projected pressure and a simplified rolling-bearing life comparison. The drawings explain mechanisms; they do not provide an interchangeable replacement specification. Begin with the machine documents and preserve the identity and position of the original components. Moving diagrams, worked examples and separate practice answers for Machinist learners. WHAT YOU WILL LEARN • Distinguish plain and rolling bearing families and resolve radial, axial and combined load paths. • Identify sleeve, split, flanged and mounted forms and explain installed clearance and axial location. • Compare bearing material systems and lubrication regimes using bounded pressure and surface-speed calculations. • Interpret bearing types, designations and basic life calculations while preserving refurbishment evidence. CHAPTERS 0:00 The outside dimensions do not identify the whole bearing 0:52 Plain and rolling describe the relative motion 2:22 Worked radial reactions: balance forces and moments 7:42 Worked sleeve clearance: distinguish diameter from radius 8:31 Worked nominal pressure: use projected area 9:16 Surface speed and PV provide a bounded screening calculation 21:53 Worked thermal growth: relative movement still needs analysis 24:17 Clearance suffixes are not precision grades 25:53 Worked life comparison: doubling load has a large effect 26:40 Preserve evidence before dismantling the bearing assembly 28:25 Check: identify the incorrect replacement assumptions 29:16 Practice: solve the reactions and installed clearance 30:12 Answer: use equilibrium and keep clearance quantities distinct 31:06 Recap: select and inspect a complete bearing system HOW TO STUDY Watch the mechanism. Explain the example aloud. Pause for practice. Recall the answers tomorrow. Next: BC G3 SOURCES AND SCOPE Mapped Machinist curriculum BC G3, PDF pages 122–122. Original teaching. Mapped coverage does not by itself establish certification equivalence. Complete references and detailed source notes are in the companion course file source-notes.txt. USEFUL LINKS SkilledTradesBC Machinist Program Outline: https://skilledtradesbc.ca/media/633/... Red Seal Occupational Standard: Machinist: https://www.red-seal.ca/eng/trades/ma... Audel Mechanical Trades Pocket Manual, All New Fourth Edition: Machinery’s Handbook, 30th edition (2016): Technology of Machine Tools, 9th edition (2024): JTEKT: basic bearing life and load rating: https://koyo.jtekt.co.jp/en/support/b... JTEKT: bearing numbers: https://koyo.jtekt.co.jp/en/support/b... JTEKT: bearing internal clearance: https://koyo.jtekt.co.jp/en/support/b... NTN-SNR: bearing lubrication: https://www.ntn-snr.com/lubrication-b... GGB: porous sintered BP25 bearing product: https://www.ggbearings.com/en/our-pro... SKF: rolling bearings catalogue: https://www.skf.com/binaries/pub12/Im... SKF: bearings and mounted products, 2018: https://www.skf.com/binaries/pub12/Im... Study principles. Plant work follows current law, applicable codes, manufacturer instructions, approved procedures and qualified supervision. Independent study material; no certification or institutional endorsement is implied. #Machinist #Bearings #BearingLoads #Machining #MachineShop #Metalworking #Manufacturing #SkilledTrades #Apprenticeship #TradeSchool #MachinistTraining #RedSealMachinist #PlainBearings #RollingBearings #RadialLoads #AxialLoads #BearingMaterials #BearingClearance #Lubrication #BearingLife #SleeveBearings #MountedBearings #BearingDesignation #SurfaceSpeed #LoadPaths