Millwright Level 2 – Bearings Questions & Answers Correct 100%

What are the principle parts of a friction bearing housing? - ANSWER Base, Base bolt slots, cap and cap bolt holes. What are friction bearing housings made from adn what factors influence the choice of housing? - ANSWER Cast Iron, Cast Steel, Fabricated Steel. Choice depends on the Load, The Rotational Speed, the Direction of Pull and the Support Design How are friction bearing dimensions expressed? - ANSWER In a fraction of their nominal size. Do all new bearings of the same shaft size have the same base-to-eye measurement? - ANSWER If they are from the same manufacturer. What factors influence the choice of bearings? - ANSWER Load, Rotational Speed, Direction of the Pull and support Design What are the applications for the following bearings? a)Solid Bearings b)Split bearings c)Angle bearings d)Integrated Bearings - ANSWER a) Where Speed and Load are low. Where load is applied on the top part of the bearing. b) Where load is applied on the bottom portion of the bearing. Different bolt numbers for loads. c)When load is applied parallel to, or at a slight angle to, the horizontal. Or when the bearing is mounted on the vertical support d)Where the bearings are an integral part of the machine. How does friction bearing joint design affect its integrity? - ANSWER Position of the top half may affect the bearing tolerances and load positions. What qualities should a good bearing material have? (5 points) - ANSWER Softer than the shaft material, low coefficient of friction, wear-resistant, a good heat conductor and remain relatively stable with heat changes, readily available. List Metals generally used in bearing liners and their applications. (5 points) - ANSWER Babbitt - for general use Brass (copper zinc alloy) - for higher speeds and heavier load than babbit Bronze (coper tin alloy) - for higher speeds and heavier loading than babbitt Aluminum - hydraulic pumps Sintered Bronze - Porous bronze with a built in oil supply. 2:1 ratio. What characteristics of nylon polyurethanes and phenol laminates affect their applications? - ANSWER Heat, , water saturation. What is the hardest and toughest babbitt made from? - ANSWER Tin (90%) How does overheating affect babitt? - ANSWER Service life is greatly reduced How is babbitt held in bearing casting? - ANSWER Holes or slots. Describe the procedure for pouring a babbitt bearing using a mandrel. (6 Steps) - ANSWER 1. Gather Equipment ( oxyacetylene torch putt