Active learning ideas
The Footstep Bearing (or Pivot Bearing) is a specialized assembly used to support the bottom end of a vertical rotating shaft. This topic introduces students to a multi-part assembly including the body, a brass bush, and a steel disc (or pad) that takes the vertical thrust. Drawing this requires a deep understanding of how vertical loads are managed and how parts are nested within each other.
Activity 01
Students use a vertical stick (shaft) and try to spin it on different surfaces (sand, wood, a metal coin). They observe which 'pad' allows the best rotation, simulating the function of the steel disc in a footstep bearing.
What is the function of the disc in a footstep bearing?
Activity 02
Students display their sectional front views of the footstep bearing. Peers check if the 'pin' or 'key' that prevents the bush from rotating is correctly drawn and if the hatching directions for the body, bush, and disc are distinct.
How is the vertical shaft represented?
Activity 03
Why is the top of the steel disc sometimes made slightly concave? Students discuss how this helps in centering the shaft and holding oil, then share their ideas with the class.
What are the critical dimensions for the body and bush?
A few notes on teaching this unit
Watch Out for These Misconceptions
Forgetting to draw the clearance at the bottom of the shaft.
Students often draw the shaft touching the very bottom of the housing. It is important to show that the shaft rests on the disc, and there is often a small gap or oil space. Peer-checking against a standard 'clearance' diagram helps correct this.
Incorrectly sectioning the 'snug' fit parts.
Because the parts fit so tightly, students often miss the double lines. Using a 'magnified view' exercise where students draw just the junction of the body, bush, and disc at a 5:1 scale helps them see the individual boundaries.
Methods used in this brief
Open Bearing and Bushed Bearing
Drafting the assembly of open and bushed bearings showing all internal and external features.
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Cotter Joint and Knuckle Joint
Drafting the assembly of socket and spigot cotter joints and knuckle joints.
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Flange Pipe Joint
Creating assembly drawings of standard flange pipe joints.
8 methodologies