LMZ-I Type Plum Blossom Coupling with Split Brake Wheel: engineering overview
LMZ-I Type Plum Blossom Coupling with Split Brake Wheel is presented here as an engineering selection page rather than a repetition of catalogue copy. The purpose is to make the operating logic, dimensional checks and ordering information easier to review while keeping the original technical values intact.
The coupling uses two metal hubs and an elastomeric spider positioned between interlocking jaws. Torque passes through compression of the elastomer, which adds damping and electrical isolation while avoiding the lubrication requirement of all-metal toothed couplings. The spider is also the normal wear element and can be replaced when its condition no longer meets service requirements.
Key Features & Design Characteristics
Elastomer damping
The resilient spider helps absorb shock and torsional vibration between the driving and driven hubs.
Lubrication-free element
The elastomeric transmission element does not require routine grease lubrication.
Compact hub arrangement
The jaw-style construction provides a short, practical connection for many motor-to-machine layouts.
Simple service access
Spider condition, hub fit and alignment can be checked during normal maintenance without complex disassembly procedures.
How this version is configured
Elastomer hardness and geometry influence torsional compliance, damping, allowable speed and how the coupling reacts to shock. A stiffer insert generally reduces twist while a softer insert can absorb more vibration. The coupling can tolerate limited installation error, but excessive angular, parallel or axial displacement still shortens spider life and can increase loads on connected bearings.
- An integrated brake drum / wheel allows the braking function to share the coupling assembly; brake diameter and caliper or shoe geometry must be coordinated with the machine.
- The split brake-wheel construction supports service access without the same degree of shaft movement required by an integral brake wheel.
Selection sequence for a real machine
Choose the size from design torque rather than motor power alone. Consider starting peaks, reversing duty, temperature, chemical exposure, bore diameter, hub outside diameter and the available installation envelope. For versions with flanges, brake wheels or brake discs, also verify service access and the brake component dimensions before ordering.
- Define continuous torque, starting torque and any short-duration peak load instead of selecting from motor power alone.
- Confirm rotational speed and check whether balance, centrifugal loading or critical-speed limits affect the chosen size.
- Match every shaft interface: bore diameter, key or locking method, hub length, flange pilot, bolt pattern and available assembly clearance.
- Review angular, axial and parallel displacement separately. A coupling that tolerates one form of movement may have a much lower limit for another.
- Check the surrounding equipment for guards, brakes, bearings, seals and maintenance access before freezing the final outside diameter and overall length.
- Use the exact model matrix for the final dimensional decision; do not interpolate a bore, torque or speed value that is not listed.
Technical Specifications & Dimensions
Use the tables below as the dimensional and model reference. Confirm bore, shaft fit, speed, torque and installation envelope before final selection.
| Feature | LMZ-I (Split Wheel) | LMZ-II (Integral Wheel) |
|---|---|---|
| Brake wheel construction | Two removable halves | Cast integrally with hub |
| Brake wheel replacement | Radial — no shaft movement | Requires hub removal |
| Axial length | Slightly longer (split ring) | Compact |
| Torque range | 250–25,000 N·m | 250–12,500 N·m |
| Brake wheel diameters | 160–800 mm | 160–800 mm |
| Best for | High brake-wear applications; tight axial access | Compact drives; lower brake wear frequency |
| Type | Nom. Torque N·m | Max Speed rpm | Shaft Bore d1,d2,dz mm | L mm | L0 mm | D0 Brake Wheel mm | B mm | D mm | Spider | |
|---|---|---|---|---|---|---|---|---|---|---|
| shA (a) | shD (b) | |||||||||
| LMZ5-1-160 | 250 | 400 | 4,750 | 25–45 | 50 | 127 | 160 | 70 | 105 | MT5 a/b |
| LMZ5-1-200 | 250 | 400 | 4,750 | 25–45 | 50 | 127 | 160 | 70 | 105 | MT5 a/b |
| LMZ6-1-200 | 400 | 710 | 3,800 | 30–48 | 55 | 143 | 200 | 85 | 125 | MT6 a/b |
| LMZ7-1-200 | 630 | 1,120 | 3,050 | 35–56 | 60 | 159 | — | — | 145 | MT7 a/b |
| LMZ7-1-250 | 630 | 1,120 | 3,050 | 35–56 | 60 | 159 | 250 | 105 | 145 | MT7 a/b |
| LMZ8-1-250 | 1,120 | 2,240 | 2,400 | 45–65 | 70 | 181 | 250 | 105 | 170 | MT8 a/b |
| LMZ8-1-315 | 1,120 | 2,240 | 2,400 | 45–65 | 70 | 181 | 315 | 135 | 170 | MT8 a/b |
| LMZ9-1-315 | 1,800 | 3,550 | 1,900 | 50–80 | 80 | 208 | 315 | 135 | 200 | MT9 a/b |
| LMZ9-1-400 | 1,800 | 3,550 | 1,900 | 50–80 | 80 | 208 | 400 | 170 | 200 | MT9 a/b |
| LMZ10-1-400 | 2,800 | 5,600 | 1,500 | 60–100 | 90 | 230 | 400 | 170 | 230 | MT10 a/b |
| LMZ10-1-500 | 2,800 | 5,600 | 1,500 | 60–100 | 90 | 230 | 500 | 210 | 230 | MT10 a/b |
| LMZ11-1-500 | 4,500 | 9,000 | — | 70–120 | 100 | 260 | 500 | 210 | 260 | MT11 a/b |
| LMZ12-1-630 | 6,300 | 12,500 | 1,200 | 80–130 | 115 | 297 | 630 | 265 | 300 | MT12 a/b |
| LMZ13-1-710 | 11,200 | 20,000 | 1,050 | 90–150 | 125 | 323 | 710 | 300 | 360 | MT13 a/b |
| LMZ14-1-800 | 12,500 | 25,000 | 950 | 100–160 | 135 | 343 | 800 | 340 | 400 | MT14 a/b |
| Symptom | Likely Cause | Action |
|---|---|---|
| Vibration after braking | Drum runout; uneven shoe wear; spider degradation | Check drum runout; replace spider; equalise shoes |
| Drum overheating | Excessive braking frequency; incorrect shoe clearance | Check duty cycle; reset shoe clearance |
| Coupling vibration (no braking) | Worn spider; shaft misalignment | Replace spider; realign shafts |
| Drum half-joint noise | Loose joining bolts; fretting at split faces | Re-torque bolts; inspect split faces |
| Criterion | LMZ-I (Split Wheel) | LMZ-II (Integral Wheel) | Separate Brake Wheel + LM Coupling |
|---|---|---|---|
| Drum replacement | Radial, in-situ | Hub removal required | Shaft removal required |
| Axial space required | L0 only | L0 (shorter) | L0 + brake wheel + spacers |
| Component count | 4 (2 hubs + drum halves + spider) | 3 (2 hubs + spider) | 5+ (coupling + wheel + key + spacers) |
| Vibration damping | ★★★★☆ | ★★★★☆ | ★★★★☆ |
| Max torque (standard) | 25,000 N·m | 12,500 N·m | Coupling-dependent |
Shaft fit, alignment and assembly checks
Set the hub spacing to the value specified for the selected model, align the shafts as closely as practical and verify the spider seats evenly between the jaws. Keys, setscrews or alternative locking features should be matched to the shaft design. Do not force an insert into a gap created by incorrect hub spacing; correct the mechanical position first.
Measure the actual shaft diameters and keyways before machining or confirming a finished bore. A drawing should identify shaft tolerances, key dimensions, required hub position and any shoulder, locknut or axial-retention feature. Alignment readings should be taken after the machine is in its normal installed condition because base distortion, pipe strain, belt pull or thermal growth can move the shaft centers after an initial bench alignment.
After assembly, turn the drive through at least one full revolution by hand where practical. Check for interference with guards, brake hardware and adjacent structures, then verify fastener security. On equipment that changes temperature significantly between start-up and steady operation, compare cold and hot alignment expectations before setting final offsets.
Operating behavior and service planning
These couplings normally require little routine attention because the elastomer works without grease. Inspection is still important. Look for cracking, permanent set, hardening, softening, heat damage, missing material and polished contact marks that indicate misalignment. Replace the insert before it fails completely so the metal jaws do not make unintended contact.
A coupling should not be used as a permanent correction for poor machine alignment. If vibration, temperature or noise changes after commissioning, compare the current condition with the initial baseline. Check connected bearings and shafts at the same time, because many coupling symptoms originate from looseness, soft foot, imbalance or movement elsewhere in the drivetrain.
For planned maintenance, record the installed model, actual bore sizes, fastener details, lubricant or flexible-element grade where applicable, and the measured alignment at return to service. That information makes later inspection more useful and helps distinguish normal wear from a change in machine condition.
Information to include with an RFQ or drawing review
- Required model or the closest model already identified from the specification data.
- Driving and driven shaft diameters, tolerances, keyways and available engagement length.
- Continuous torque, peak torque, starts per hour and whether the drive reverses.
- Normal and maximum rotational speed.
- Expected angular, axial and parallel movement during operation.
- Required overall length, shaft separation, flange or brake dimensions and surrounding clearance.
- Operating temperature, contamination, washdown, corrosion or other environmental conditions.
- Quantity, drawing revision and any material, coating, balance or inspection requirement.
Frequently asked engineering questions
Can I select this coupling only from the motor power?
No. Motor power is only a starting point. The selection should use actual torque, service factor, peak load, speed and the driven-machine characteristics.
Which dimension should be confirmed before ordering?
Confirm the shaft interface first, then the overall installation envelope. Bore, key or locking method, hub length, pilot or flange details and available removal clearance all affect whether a listed model will fit.
How much misalignment should be allowed in normal service?
Use the model-specific limit as a maximum capability, not as the target installation condition. Better initial alignment usually reduces cyclic load, heat and wear in both the coupling and connected bearings.
What information is needed for a custom bore or connection?
Provide a dimensioned shaft drawing or at minimum the shaft diameter and tolerance, keyway, engagement length, shoulder or axial-retention details and required hub position.
Should the coupling be inspected after commissioning?
Yes. A short follow-up inspection after the machine has run under real load can reveal fastener settlement, lubricant leakage, unexpected movement or alignment change before these develop into a larger problem.
How should I use the specification blocks on this page?
Treat the listed values as the model reference. Select a candidate from torque and speed, then verify every geometric field that affects your installation before issuing the final order drawing.
Applications
Pumps & fans
Used in motor-driven rotating equipment where compact size and vibration damping are useful.
Conveyors & packaging
Applicable to start-stop machinery where shock absorption and straightforward maintenance are valued.
HVAC & utilities
Suitable for auxiliary drives where shaft alignment and elastomer condition can be checked during service.
General automation
Considered for industrial motion systems when torque, bore size, speed and misalignment remain within the selected model limits.
They are commonly used with pumps, fans, compressors, conveyors, packaging machinery, general manufacturing equipment and other drives that benefit from vibration damping and straightforward maintenance. Brake-equipped variants combine the coupling function with a dedicated braking interface.
The same coupling family can behave very differently in a smooth continuous drive and in a reversing, impact-loaded or frequently started drive. For that reason, application name alone is not enough for selection. Supply the operating torque, peak load, speed, shaft dimensions, expected movement, ambient conditions and required service access so the configuration can be checked against the complete duty.