A disc coupling transmits torque between hubs through a thin flexible disc pack. Alternating bolt positions connect the pack to the driving and driven hubs. The animation shows the assembled hubs, shafts and disc pack, plus an isolated disc view that makes the alternating attachments visible.
Disc Coupling Interactive Calculator
Inspect rotating hubs and a thin disc pack. Compare the entered shaft angle with a stated limit; the separate angle diagram is magnified 30×.
Equation Used
- Intersecting shaft axes at the disc plane.
- Generic six-bolt disc with alternating hub attachments.
- Prescribed equal-phase rotation.
- Manufacturer-specific angular limit supplied by user.
Angle comparison only. The disc shape is illustrative and normalized; no stress, torque capacity or fatigue-life calculation.
Thin discs accommodate angular misalignment
The two shafts meet at the modeled disc plane with the selected angular misalignment. Each hub rotates about its own axis. Alternate bolt positions belong to opposite hubs; the flexible sheet between them bends out of plane during rotation.
The main assembly uses the actual entered angle. A separate diagram magnifies the angle 30 times so a fraction of a degree remains visible. The isolated disc face uses blue and gold bolt markers to distinguish the two hubs.
The six-bolt layout and normalized dimensions are illustrative. The interpolated sheet shape connects the attachment positions but is not a stress or fatigue solution. Rotation is prescribed at equal phase to illustrate the connection; no torsional dynamics are solved.
Compare angle with a stated limit
Enter measured angular misalignment and the applicable limit from the selected coupling’s documentation. The calculator reports utilization, remaining angular margin and any excess. Changing the limit alters the comparison, not the physical shaft angle.
The single-flex arrangement shown does not model parallel shaft offset. A double-flex assembly has different geometry and must be assessed using its own data.
Angular comparison
For entered angle θ and limit θlim, utilization is 100θ/θlim percent, angular margin is θlim−θ, and excess is max(0,θ−θlim). The limit-to-angle ratio is θlim/θ for nonzero θ.
At zero entered angle the ratio is undefined and the page reports “N/A (aligned)” instead of an arbitrary large value. This ratio is not a structural safety factor and does not account for torque, speed, axial motion or simultaneous misalignment.
Example: 0.40° against a 0.40° limit
The entered angle uses 100% of the stated angular limit, with zero angular margin and a limit-to-angle ratio of 1.00. At 0.60° with the same limit, use rises to 150%, margin is −0.20° and excess is 0.20°.
The assembly remains visible above the entered limit. Its warning indicates an exceeded comparison value, not a simulated crack or predicted failure time.
Manufacturer-specific limits matter
Disc-pack geometry, material, torque, speed and operating conditions affect permitted misalignment. The entered range is a comparison control, not a universal allowable angle.
Use the selected manufacturer’s complete ratings, disc-pack dimensions, fastener requirements and installation procedure for an actual coupling.
Disc-coupling questions
Why is the shaft angle barely visible in the main view?
The input is less than one degree. The main view preserves that angle; the separate 30× diagram makes it easier to compare.
Is the colored ring a rubber element?
No. It represents a thin metallic disc pack with alternating attachments. Colors identify the two hub connections.
Does the calculator predict fatigue life?
No. It compares an entered angle with an entered limit. The visible flexing is illustrative geometry.
Can this one-disc model absorb a parallel offset?
That condition is not modeled. The illustrated shaft axes intersect at the disc plane.
Manufacturer construction reference
Regal Rexnord Thomas flexible disc-coupling catalog, page 35, XTSRS single-flex construction and size-dependent angular data. The animation is a generic six-bolt illustration, not a reproduction of its product dimensions or ratings.
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