🔍 Key Concepts

• Electric motor bearing lubrication practices for anti-friction (ball/roller) bearings • Effect of over-greasing vs. under-greasing on bearing temperature and seal pressure • Typical procedure for flushing old grease from a running motor using the drain/opening shown in figure B

💭 Think About

• Look closely at figure B: what is the purpose of the grease fitting and drain/opening arrangement, and how does that relate to flushing old grease? • For a high‑speed electric motor, what happens inside the bearing housing if you pack the entire cavity solid with grease? Think about heat generation and grease churning. • When, if ever, is solvent normally used on an in‑service, sealed or shielded motor bearing without disassembly?

✅ Before You Answer

• Identify which choice would lead to excess heat and pressure in the bearing housing at normal operating speed. • Decide which options are normal maintenance procedures versus something you would only do after the bearing is disassembled in a shop. • Confirm which practice prevents old grease from being trapped and allows new grease to flow through and out the drain, as suggested by the illustration.