Assembly in 3D
The whole project in one 3D view: every shaft where its gear pairs and drives put it, the gears in mesh, the bearings at their supports and the housing walls, coloured by their checks.
The assembly view shows the open project as one machine. Every shaft stands where its gear pairs and belt or chain drives put it, the gears mesh, the bearings sit at their supports and housing walls stand round their seats. The parts are coloured by their checks or by the shafts' stress, so you see at a glance where the design is closest to its limits, and a click opens a part in its module.
The view has no inputs of its own. It reads the same model and results as the modules and changes as soon as a solve finishes.
Opening the assembly
- Choose Assembly in the Project group of the navigation, under Overview.
- The Two-stage helical gearbox example opens here.
- To open every project here, open File › Settings and set Open projects in to Assembly in 3D. A project without a shaft opens in its module instead.
Where the shafts stand
All shafts of a project are parallel: x runs along each shaft from its left end, y and z are the same directions for every shaft, y up in the view. The first shaft's left end is the origin; the others are placed from it along the couplings:
- A mounted gear pair puts the wheel's axis at the pair's working centre distance a from the pinion's, in the pair's Wheel direction (its mesh angle): 0° puts the wheel shaft in +y (above), 90° in +z (beside it), from +y towards +z about +x. A ring wheel (an internal pair) stands the same way. Set it in the gear module under Gearbox mounting.
- The pinion and the wheel sit in one plane across the shafts, so the wheel shaft is shifted along x until the wheel's position on it meets the pinion's.
- A belt or chain drive places the driven shaft at its centre distance in its Direction to driven shaft. A drive without a centre distance is drawn at 1.5 times the sum of the pitch radii, as its drawing is.
These are the directions the mesh and belt forces act in, so the view shows the geometry the shaft loads assume.
When the geometry does not close
Three shafts coupled in a ring, or two pairs between the same two shafts, fix a shaft's place twice. The view places each shaft once, breadth first from the first shaft in the order of the project (gear pairs, then drives), and checks every coupling against the places: one that would put its shaft more than 0.01 mm from where it stands does not close its loop. The view then lists it under Not shown as the project says, with how far off it is and which coupling placed the shaft, and draws the shafts where that one puts them. Shafts coupled to nothing are set beside the others.
What else is drawn
| Part | Where |
|---|---|
| Bearings | At the shaft supports they are linked to, from their own geometry, the rolling elements coloured by their load. A bearing on no support is listed in the notes. |
| Housing walls | Across the shafts at the first support seated in them, the seat's bore on that shaft's axis, see-through with their edges. Imported housing models are not drawn. |
| Electric machine rotors | On their shafts at their position, with their stack length and diameter. |
| Gear pairs not mounted, planetary sets, bevel and worm pairs, plastic gear pairs | Beside the assembly, each as its own module's 3D model: they sit on no shaft of the project. |
Colours
Choose what the colours show with the switch above the view:
| Choice | Colour |
|---|---|
| Checks (the default) | Every part by its governing check: the share of its limit it uses, steel at none, through amber and orange to red at the limit. A part past its limit stays red. The same governing check as in the overview. |
| Stress | The shafts by their von Mises stress along their length, on one scale for all of them: up to the largest of their stress limits (or of their stresses, without limits). The other parts stay steel. |
| Plain | Steel, without results. |
The legend in the corner gives the scale. The choice is remembered in this browser.
Looking round
- Drag to orbit, scroll to zoom, right-drag to pan. Reset view frames the whole assembly again.
- Point at a part: a box marks it and a label names it with its status and its governing check.
- Click a part to open it in its module: a shaft in the shaft module, a bearing in the bearing module, a gear pair in the gear module, a drive, housing or gear set in its own module.
- Turn the gears turns every shaft at its ratio with the gears in mesh, and the belts round their pulleys. It stays off when your system asks for reduced motion, and pauses while the window is hidden.
- The Parts in the view table lists every part with its status and the utilisation of its governing check; each name opens the part, also from the keyboard.
Without WebGL the view says so and still lists the parts.
Example: the two-stage helical gearbox
Open the example. A motor drives the input shaft at 1450 rpm with 60 N·m; two helical stages turn the output at 139.8 rpm with about 613 N·m.
| Stage | Teeth | Module | Helix | Face width | Centre distance | Mesh angle |
|---|---|---|---|---|---|---|
| First (G1) | 19/67 | 2.5 mm | 15° | 35 mm | 111.29 mm | 90°: the intermediate shaft beside the input |
| Second (G2) | 17/50 | 4 mm | 12°, left-hand | 50 mm | 136.99 mm | 60°: the output shaft above and beside it |
The six bearings are two 6207 on the input shaft, an NU 210 and a 6310 on the intermediate shaft and two 6212 on the output shaft, each on a seat of its bore. The second pinion gets what the first wheel delivers (60 N·m · 67/19 · η), so the intermediate shaft balances.
The engine gives:
| Item | Value |
|---|---|
| Checks | 42, all passing |
| Highest utilisation | pitting safety of the pinion of G2, SH 1.60 against 1.0 (62.5 %) |
| First stage, pitting and root safety | 1.74 and 7.39 (pinion) |
| System life of the six bearings | 261 155 h modified, 15 187 h basic (in the gears' VG 220 oil) |
| Power loss | 178.7 W, efficiency 98.04 % |
The output shaft's bearings turn at 140 rpm: even in the VG 220 oil their film is thin (κ 0.64), which the bearing module's What drives life points out; their lives still clear the 20 000 h they are checked against many times over.
In Checks the shafts and bearings read close to steel; the gears, at 57 % to 63 % of their pitting limit, are the warmest, the second stage most.
Limits
- All shafts are parallel. Bevel and worm pairs and planetary sets are not mounted on the project's shafts, so they stand beside the assembly rather than in it.
- The view draws the parts as the modules size them; it is not a CAD model. Housings are drawn as their walls, without the rest of a casing.
- Shaft deflections are not shown here; the shaft module's 3D view shows them, exaggerated.
From the command line
The mesh angle is the gear pair's mounting.direction; set it like any other field.
axm new box.axm.json --template gearbox-two-stage
axm set box.axm.json gears.G2.mounting.direction 45
axm solve box.axm.json