Rotating Assembly Callout Map¶
Run the Rotating Assembly Callout Map MicroSim Fullscreen
About This MicroSim¶
This MicroSim is a schematic side cross-section of an overhung (Arrangement 1 style) centrifugal fan: the impeller inside the housing at the left, the shaft passing through the housing's drive-side wall, two pillow block bearings on a pedestal, and a drive sheave on the right-hand shaft end. Ten parts of the rotating assembly carry callouts:
| # | Callout | What it does |
|---|---|---|
| 1 | Shaft keyway | A groove cut into the shaft that accepts keystock so torque passes to the hub or sheave. |
| 2 | Shaft turndown | A length of shaft machined to a smaller diameter to fit a bearing, seal, hub or coupling. |
| 3 | Shaft sleeve | A tube over the shaft inside the housing that shields the shaft from the airstream when materials differ. |
| 4 | Shaft locking collar | A ring clamped to the shaft that keeps the shaft from sliding axially into another part. |
| 5 | Shaft seal | A seal mounted on the housing wall where the shaft passes through, limiting air leakage in or out. |
| 6 | Non-drive end bearing (inboard) | The bearing nearer the impeller, farther from the sheave. |
| 7 | Drive end bearing (outboard) | The bearing nearer the sheave or coupling. |
| 8 | Bearing seal | A seal built into the bearing that keeps dirt out of the bearing. |
| 9 | Bearing positioner | A threaded bolt on a bracket beside the bearing, used for fine adjustment of bearing location. |
| 10 | Vibration sensor tap | A drilled and tapped hole in the bearing housing where a vibration sensor is mounted. |
The quiz shows the ten descriptions once each in shuffled order. You get two attempts per description. A first wrong click names the part you clicked and its job; a second wrong click highlights the correct part with an "Answer" badge and the description counts as missed. The running line reads "Correct on first try: n of 10", and mastery is 8 of 10 correct on the first attempt. Explore mode is never scored.
The drawing is schematic and not to scale. It is based on FanPedia pp. 79-81 (shaft, keyways and turndowns), p. 91 (drive end and inboard bearings), pp. 100-102 (bearing seals, vibration sensor tap, bearing positioner) and p. 129 (shaft collar and shaft sleeve).
How to Use¶
- Explore mode (the starting mode). Click any part to read what it does. Each part you have opened gets a ✓ mark and a shaded label, and the counter shows how many of the 10 you have visited.
- Quiz mode. Press Quiz. The labels are hidden and a description
appears above the drawing. Click the part it describes.
- Correct: "✓ Correct:" and the part name; its label appears.
- Wrong on the first attempt: "✗ Not quite. That callout is the" part you clicked, with what that part does. Try again.
- Wrong on the second attempt: the correct part is highlighted and marked "Answer", and the description counts as missed.
- Clicking an empty area of the drawing does nothing and uses no attempt.
- Press Next description after each answer. After the tenth, the summary shows your first-attempt score, whether you reached mastery (8 of 10), and the parts you missed. All labels return. Press Start over to retake the quiz with a new shuffle, or Back to explore to review.
- Start over in the toolbar clears your visited parts and the quiz at any time and returns to explore mode.
Keyboard: Tab moves between the parts (from the shaft sleeve at the housing to the keyway at the shaft end) and the buttons; Enter or Space selects a part. After an answer, focus moves to Next description, so Enter goes on.
Narrow screens: when the drawing is narrower than about 650 px, the callouts become numbers with a key list below the drawing.
Data label: "Schematic, not to scale · Overhung (Arrangement 1 style) fan · Based on FanPedia pp. 79-81, 91, 100-102 and 129", shown below the drawing.
Iframe Embed Code¶
You can add this MicroSim to any web page by adding this to your HTML:
<iframe src="https://moroshek.github.io/FanTASTIC-textbook/sims/ch16-rotating-assembly-callout-map/main.html"
height="792px"
width="100%"
scrolling="no"></iframe>
Lesson Plan¶
Learning Objective¶
The learner will identify ten parts of an overhung fan's rotating assembly, given a one-sentence description of each part's job (Bloom: Remember, verb: identify).
Audience¶
Adult professional development: new application engineers, sales staff, representatives and facilities staff.
Duration¶
10-15 minutes
Prerequisites¶
- Rotating assembly and overhung impeller (Chapter 16, "The Rotating Assembly"; Chapter 3)
- Shaft keyway, turndown, sleeve and locking collar (Chapter 16, "Shaft Features")
- Pillow block bearings, bearing seals, bearing positioners and vibration sensors (Chapter 16, "Bearings" and "Monitoring the Bearings")
- Shaft seal (Chapter 16, "Shaft Seals")
Activities¶
- Explore (4 min): Open all ten callouts. Sort them aloud into three groups: on the shaft, on the bearings, on the housing.
- Compare (2 min): Open the shaft seal and the bearing seal one after the other. Say what each one keeps in or out. Do the same for the shaft locking collar and the shaft sleeve.
- Quiz (5 min): Switch to quiz mode and answer the ten descriptions.
- Review (3 min): Read the missed list, return to explore mode for those parts, then press Start over for a new shuffle.
Common Misconceptions Addressed¶
- The shaft sleeve is a bearing part. The sleeve sits inside the housing, over the shaft in the airstream, far from both bearings.
- The shaft locking collar and a bearing's locking collar are the same part. The shaft collar is drawn on its own on the shaft between the shaft seal and the inboard bearing.
- The shaft seal keeps grease in the bearing. The shaft seal sits on the housing wall and limits air leakage; the bearing seal is built into the bearing. A wrong click on either one names the clicked part's job.
Assessment¶
- First-attempt score shown in the summary as "First-attempt score: n of 10"; mastery is 8 of 10 on the first attempt. The running line reads "Correct on first try: n of 10".
- Follow-up question: a nominally leak-tight fan is ordered for a stainless airstream with a steel shaft. Which callout on this drawing is left off, and why? (The shaft sleeve and cap: FanPedia's leak-tight construction does not use them.)
References¶
- FanPedia: The Fan & Blower Encyclopedia (PDF) - Twin City Fan & Blower; shaft p. 79, keyways and turndowns pp. 80-81, drive end and inboard bearings p. 91, bearing seals p. 100, vibration sensor tap p. 101, bearing positioner p. 102, shaft collar and sleeve p. 129.
- FanPedia online - Twin City Fan & Blower's online version of the encyclopedia.
- Chapter 16: Bearings, Shafts and Shaft Seals - the sections "Shaft Features", "Bearings", "Monitoring the Bearings" and "Shaft Seals".
- Chapter 3: Basic Fan Anatomy - overhung and center hung bearing layouts.