The SWP-B Short Flexible Universal Joint Coupling is a compact-body, split axletree spider-type cardan shaft with full telescoping sleeve capability (Ls 50–230 mm). With gyration diameters of 160–640 mm and nominal torques of 16–1 250 kN·m at axes fold angle ≤10°, SWP-B delivers the same compensation performance as SWP-A in a shorter overall length — the preferred choice for mining conveyors, crusher drives, and compact industrial drivetrains where axial space is restricted.
The SWP-B Short Flexible Universal Joint Coupling is a split axletree, spider-type cardan joint built for installations where axial space is constrained yet axial displacement compensation remains necessary. Its distinguishing characteristic versus the SWP-A is a shorter overall body length (Lmin 585–2780 mm compared to 660–2685 mm for SWP-A at comparable diameters), achieved through a reduced-length intermediate tube while retaining the full-range telescoping sleeve with stroke Ls of 50–230 mm.
Like all SWP-series couplings, the SWP-B operates on the Hooke's joint (universal joint) mechanism: two flanged yokes linked through a precision-ground cross-spider transmit high torque across shaft angular offsets of ≤10°. The split axletree bearing housing is the signature feature — the two-piece housing separates radially, allowing spider replacement with connected shafts still in position. In mining and mineral processing environments, where mechanical access space is often severely restricted, this translates directly into faster maintenance and reduced confined-space work.
Torque coverage spans 16 kN·m (SWP160B) through 1 250 kN·m (SWP640B), with corresponding fatigue torques from 8 to 630 kN·m — the same capacity envelope as SWP-A, packaged in a more compact form. Gyration diameters run from 160 to 640 mm across 14 standard sizes.
Specifying the longer SWP-A where only SWP-B installation space is available forces costly relocation of connected equipment. SWP-B resolves this directly, offering identical torque ratings with no compromise on axial or angular compensation performance.
| Type | D (mm) | Tn (kN·m) | Tf (kN·m) | Ls (mm) | β | Lmin (mm) | D1 js11 | D2 H7 | E | E1 | b×h | h1 | L1 | n–d | I Lmin (kg·m²) | G Lmin (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SWP160B | 160 | 16 | 8 | 50 | ≤10 | 585 | 140 | 95 | 15 | 4 | 20×12 | 6 | 85 | 6–13 | 0.14 | 44 |
| SWP180B | 180 | 20 | 10 | 60 | ≤10 | 640 | 155 | 105 | 15 | 4 | 24×14 | 7 | 95 | 6–15 | 0.23 | 56 |
| SWP200B | 200 | 31.5 | 16 | 70 | ≤10 | 730 | 175 | 125 | 17 | 5 | 28×16 | 8 | 110 | 8–15 | 0.36 | 75 |
| SWP225B | 225 | 40 | 20 | 76 | ≤10 | 830 | 196 | 135 | 20 | 5 | 32×18 | 9 | 130 | 8–17 | 0.61 | 108 |
| SWP250B | 250 | 63 | 31.5 | 80 | ≤10 | 860 | 218 | 150 | 25 | 5 | 40×25 | 12.5 | 135 | 8–19 | 0.98 | 138 |
| SWP285B | 285 | 90 | 45 | 100 | ≤10 | 1000 | 245 | 170 | 27 | 7 | 40×30 | 15 | 150 | 8–21 | 2.12 | 229 |
| SWP315B | 315 | 140 | 63 | 110 | ≤10 | 1120 | 280 | 185 | 32 | 7 | 40×30 | 15 | 170 | 10–23 | 3.8 | 309 |
| SWP350B | 350 | 180 | 90 | 120 | ≤10 | 1230 | 310 | 210 | 35 | 8 | 50×32 | 16 | 185 | 10–23 | 6.6 | 408 |
| SWP390B | 390 | 250 | 112 | 120 | ≤10 | 1310 | 345 | 235 | 40 | 8 | 70×36 | 18 | 205 | 10–25 | 10.5 | 539 |
| SWP435B | 435 | 355 | 160 | 150 | ≤10 | 1555 | 385 | 255 | 42 | 10 | 80×40 | 20 | 235 | 16–28 | 22.39 | 903 |
| SWP480B | 480 | 450 | 224 | 170 | ≤10 | 1740 | 425 | 275 | 47 | 12 | 90×45 | 22.5 | 265 | 16–31 | 38.21 | 1243 |
| SWP550B | 550 | 710 | 315 | 190 | ≤10 | 1905 | 492 | 320 | 50 | 12 | 100×45 | 22.5 | 290 | 16–31 | 61.0 | 1643 |
| SWP600B | 600 | 1000 | 500 | 210 | ≤10 | 2600 | 544 | 380 | 55 | 15 | 90×55 | 27.5 | 360 | 22–34 | 99.13 | 2335 |
| SWP640B | 640 | 1250 | 630 | 230 | ≤10 | 2780 | 575 | 380 | 60 | 15 | 100×60 | 30 | 385 | 18–38 | 170.21 | 2720 |
Note: Gyration diameter D=315mm, installation length L=1120mm → SWP315B×1120. SWP-B omits the D3 column present in SWP-A; all other parameters are equivalent. I and G values are for the Lmin configuration.
⛏️ Underground Mining Conveyor & Feeder Drives
Working condition: Severely constrained axial space in underground drives, frequent shock loads from rock fall onto conveyors, high ambient dust and moisture.
Why SWP-B: The shorter overall length fits within the standard motor-to-gearbox spacing of underground conveyor drives without requiring custom shaft extensions. Telescoping stroke absorbs coupling misalignment caused by conveyor frame flexure under load.
Customer benefit: Standard frame designs maintained; no custom fabrication needed. Spider replacement achievable within a single maintenance shift in confined drives.
️ Aggregate Crushing & Screening Plants
Working condition: High intermittent torque spikes during crusher cavity clearance, outdoor operation with dust and water ingress, restricted maintenance access.
Why SWP-B: The compact body accommodates the tight gearbox-to-crusher shaft spacing typical in jaw and cone crusher configurations. Torque capacity to 1 250 kN·m covers even the largest primary crusher drives.
Customer benefit: Lower total installed cost compared to custom long-shaft arrangements; quicker spider change during scheduled maintenance windows.
Steel Mill Auxiliary Drive Decks
Working condition: Multiple drives positioned closely on narrow roll table decks, moderate speeds, oil mist environment.
Why SWP-B: Where roll table drive spacing does not permit SWP-A length, SWP-B maintains the same torque and compensation capability in a smaller footprint.
Customer benefit: Standardised coupling across both mill floor and auxiliary positions, reducing spare parts inventory to a single spider cross size per diameter.
Rail Ballast Processing & Track Maintenance Equipment
Working condition: Mobile equipment with variable shaft alignment as vehicle frame flexes, high vibration, constant exposure to ballast dust and moisture.
Why SWP-B: Compact length suits the tight drivetrain packaging of self-propelled rail equipment. Axial flexibility prevents frame-induced shaft preloads from damaging gearbox bearings.
Customer benefit: Drivetrain protection under dynamic frame loading; fewer gearbox warranty claims for equipment builders.
The most frequent error when specifying SWP-B is confusing it with SWP-C — both are short-body types, but SWP-C has no telescoping sleeve. If your installation involves any axial shaft movement (thermal, mechanical, or assembly-related), only SWP-B or SWP-A are appropriate.
| Parameter | SWP-B (This Type) | SWP-A | SWP-C | SWP-E | SWP-G |
|---|---|---|---|---|---|
| Body Length Class | Short | Long | Short | Long | Super Short |
| Axial Telescoping | ✅ Yes | ✅ Yes | ❌ No | ✅ Yes | ✅ Yes |
| Max Fold Angle | ≤10° | ≤10° | ≤10° | ≤10° | ≤5° |
| Flange Configuration | Single yoke each end | Single yoke each end | Single yoke each end | Double flange | Single yoke each end |
| Ideal Application | Compact flex drive | Long span flex | Fixed axial spacing | Dual flange machines | Ultra-compact spaces |
Step 1 — Determine peak torque: T_peak = (P × 9550) / n × KA, where P is power in kW, n is speed in rpm, KA is service factor (1.5 for mining conveyors, 2.0–2.5 for crusher direct drives).
Step 2 — Verify fatigue rating: If the application involves fully reversed torque cycles (e.g., hoists, reversing mills), T_peak must not exceed Tf (fatigue torque). For uni-directional loading, Tn is the governing limit.
Step 3 — Check installation length: verify Lmin for your selected size fits within your frame. SWP-B Lmin values (585–2780 mm) are 5–15% shorter than equivalent SWP-A sizes.
⚠️ Three Critical Errors to Avoid with SWP-B
Unsure which sub-type suits your drivetrain layout? Contact Our Engineers for a no-obligation technical review.
We have supplied SWP-B couplings to mining equipment OEMs, steel plant operators, and MRO distributors across four continents for over two decades. Our production facility is equipped with CNC gear hobbing, precision grinding, and automated heat treatment lines dedicated to universal joint components.
Material & Heat Treatment
Yoke bodies: 42CrMo4 alloy steel, quenched and tempered to tensile strength ≥ 900 MPa. Cross-spider pins: carburised 20CrMnTi, case hardness 58–62 HRC, core toughness ≥ 60 J. Telescoping sleeve splines: induction hardened 45# steel. All critical surfaces receive manganese phosphate anti-corrosion treatment.
Inspection & Testing Protocol
Magnetic particle inspection (MPI) of all yoke welds and critical radii. Spider needle bearing assemblies: load-tested at 110% rated radial load. Final assembly torque test: 1.5× Tn for 30 seconds. Dimensional report issued per ISO 2768 tolerance class. Each batch includes hardness verification certificates.
Packaging & Logistics
Export-grade wooden crating with VCI anti-corrosion film for sea freight. Couplings pre-greased and protective end-caps fitted. All fasteners individually bagged with torque specifications.
Credentials
ISO 9001:2015 certified.
We switched our conveyor tail-end drive couplings from a competitor brand to SWP-B units. The compact body resolved our clearance issue between the gearbox and the conveyor frame. Eight months in, running 24/7 — no issues. Spider greasing is now part of our 500-hour PM schedule.
South Africa — Coal Wash Plant Drive, Mpumalanga ★★★★★
We ordered SWP285B and SWP315B couplings for a coal wash plant refurbishment. Dimensional accuracy was excellent and the split housing proved its value during the first unplanned jam event — spider replaced in under two hours without removing the motor. Highly recommended.
— Project Engineer, South African Coal Processing Plant
Canada — Aggregate Crusher Drive, Ontario ★★★★☆
We replaced our primary jaw crusher coupling with SWP390B. The nominal torque of 250 kN·m with K factor of 1.5 gave us ample margin for shock loading. Installation was straightforward. Minor feedback: grease nipple location could be improved for our guarding configuration.
— Plant Manager, Ontario Aggregate Producer
Singapore — Port Handling Equipment Retrofit ★★★★★
We used SWP250B on a stacker/reclaimer slewing drive retrofit. The short flex type fitted within the existing coupling guard envelope without modification. Angular compensation up to 10° was essential for this application. Delivery to Singapore in three weeks — faster than local alternatives.
— Mechanical Engineer, Singapore Port Equipment Supplier
For the same gyration diameter (D), SWP-A and SWP-B share identical flange bolt patterns (n–d) and all mating dimensions (D1, D2, E, E1, bXh). The only difference is the overall installed length Lmin. This means that if your frame can accommodate the SWP-A length, either type will bolt directly to the same connected equipment. If replacing an existing SWP-A with SWP-B, verify that the shorter body does not produce interference with intermediate structure or require a spacer.
Maximum permissible speed depends on gyration diameter and dynamic balance grade. As a general guide: D160–D225: up to 1500 rpm; D250–D315: up to 1000 rpm; D350–D435: up to 750 rpm; D480–D640: up to 500 rpm. For higher speeds, verify the balance grade and dynamic analysis with our engineering team. Operating at elevated speeds with significant angular offset reduces bearing life — keep fold angle below 5° for continuous high-speed operation.
In typical mining duty (KA=1.5–2.0 service factor, moderate contamination), spider cross service life is 8,000–15,000 operating hours. In heavily contaminated underground environments or where the coupling runs near maximum fold angle continuously, shorten inspection intervals to every 4,000 hours. The split axletree housing of SWP-B means spider inspection requires only unbolting the bearing housing halves — typically a 2–3 hour task — without any shaft disassembly.
Yes. While standard sizes follow the D1 js11 and D2 H7 bore pattern shown in the specification table, custom bore diameters and keyway profiles are available for retrofit applications. For non-standard bores, please provide: required bore diameter and tolerance, keyway width and depth (to DIN 6885 or equivalent), shaft material and surface hardness if an interference fit is required. Lead time for custom-bore units is typically 3–5 business days in addition to standard production time.
We offer a 12-month warranty from date of shipment against manufacturing defects in materials and workmanship under normal operating conditions within the rated parameters. The warranty covers the spider cross, needle bearing, yoke casting, and sleeve assembly. It does not cover failure resulting from: operation beyond rated torque or fold angle, inadequate lubrication, contamination ingress due to damaged seals not reported at commissioning, or user modification. Warranty claims are supported by our technical team with replacement parts dispatched within 5 business days of claim verification.
Whether you need a single replacement unit or a full plant supply contract, we scale to your procurement model. Provide your required gyration diameter, torque load, installation length, and quantity — our team responds within one business day with a full technical and commercial proposal.
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ISO 9001:2015 · Mining Industry Supply Experience
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