Description
SL210 SL Type Oldham Coupling – 85–90mm Bore 210mm OD Radial Misalignment Compensating Drive Shaft Coupling
The SL210 SL Type Oldham coupling is a three-component sliding-block coupling designed for connecting two coaxial drive shaft lines where significant radial displacement between shaft centrelines must be accommodated without transmitting radial load to the connected equipment bearings. With a nominal torque rating of 5000 N·m at 250 rpm maximum speed, 210 mm outer diameter, and a bore range of 85–90 mm, the SL210 serves drive connections in the full range of industrial machinery — from medium-duty pump and fan drives to large-scale industrial processing equipment. The radial displacement compensation of 3.4 mm, angular compensation of 0.5°, and axial accommodation of 2.6 mm make the SL Type one of the most flexible misalignment-compensating couplings available at this torque level.
The SL Type coupling operates through a three-piece sliding-block mechanism: two identical cast iron flanged hubs, each mounted on one shaft, and a central polymer (or metal) slider block that engages with both hubs simultaneously through tongue-and-groove interfaces positioned at 90° to each other. Torque is transmitted from the driving hub through the tongue-groove contact to the slider block, and from the slider block to the driven hub through the second pair of tongue-groove faces. Radial misalignment between the shaft centrelines is absorbed by sliding movement of the block within the hub grooves — the block translates in the plane perpendicular to the shaft axis as the coupling rotates, compensating for the offset continuously during operation. This mechanism produces a uniform angular velocity transmission — unlike some other misalignment-compensating coupling types that introduce cyclic velocity variation.
The slider block is a replaceable wear element. At planned maintenance intervals, the block can be inspected for wear and replaced without removing either hub from its shaft, minimising maintenance downtime. Full series documentation and application guidance are available on our product catalog page.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | SL210 |
| Type | SL Type Oldham (Sliding-Block) Coupling |
| Bore Range (d) | 85–90 mm |
| Outer Diameter (D) | 210 mm |
| Inner Diameter (D₁) | 130 mm |
| Overall Length (L) | 160 mm |
| Hub Width (H) | 33 mm |
| Slider Width (S) | 0.5 mm |
| Nominal Torque (Tn) | 5000 N·m |
| Maximum Speed [n] | 250 rpm |
| Radial Compensation (Δy) | 3.4 mm |
| Angular Compensation (Δa) | 0.5° |
| Axial Compensation (Δx) | 2.6 mm |
| Rotational Inertia | 0.9 kg·m² |
| Mass | 45 kg |
Dimension Reference
Coupling Assembly and Slider Block
The SL210 slider block engages the two hub faces through precision-machined tongue-and-groove features. The tongue dimensions and groove clearances are controlled to minimise backlash while providing the sliding freedom needed for misalignment compensation. The standard slider block material is an engineering polymer selected for low friction, adequate compressive strength at the operating torque, and dimensional stability across the rated temperature range of -20°C to +70°C. For higher-load or elevated-temperature applications, a metal slider block is available.
Large Radial Compensation
3.4 mm radial offset compensation eliminates the need for precision motor-to-driven equipment alignment on most plant installations, significantly reducing commissioning time and equipment cost.
Constant Velocity Transmission
The Oldham mechanism maintains constant angular velocity ratio between input and output shafts at all rotational positions — unlike universal joint couplings which produce cyclic velocity variation proportional to operating angle.
Replaceable Wear Element
The slider block is the only wear element in the coupling. It can be inspected and replaced without removing either hub from its shaft, minimising maintenance downtime and hub replacement cost.
No Radial Force Transmission
The sliding mechanism absorbs shaft offset without transmitting significant radial forces to the connected shaft bearings — protecting motor bearings and driven equipment bearings from misalignment-induced overload.
Manufacturing and Quality
Typical Applications
- Large ball mill and grinding mill drive connections — highest-torque motor coupling with maximum radial compensation
- Primary crusher and conveyor drive connections — variable load, high-shock mining industry applications
- Offshore platform drive connections — structural movement compensation in marine environments
- Large agitator drive connections — high-torque motor shaft coupling for dense slurry mixing equipment
For enquiries about large volume supply or custom bore configurations, visit our contact page.
Customer Reviews and Case Studies
★★★★★
Germany — Large Industrial Pump Manufacturing
The SL210 Oldham coupling is our standard for large centrifugal pump drive connections. At 5,000 N·m rated torque, it covers our full pump product range, and the 3.4 mm radial compensation eliminates the need for precision motor alignment in most field installations.
— Chief Engineer, Hamburg
★★★★★
Malaysia — Petrochemical Plant
Installed on product transfer pump drive connections. The SL210 handles our operating torque reliably and the replaceable slider block is available as a spare part through our maintenance stores.
— Plant Engineer, Kuala Lumpur
★★★★☆
Chile — Copper Processing Plant
Used on concentrate pump drive connections. The SL210 accommodates the shaft offset that develops in our process pumps from thermal cycling of the process fluid.
— Maintenance Superintendent, Antofagasta
Frequently Asked Questions
What is the rotational inertia of the SL Type coupling?
Rotational inertia values are specified in the technical table for each model, ranging from 0.002 kg·m² for SL70 to 62.9 kg·m² for SL460. These values should be reflected into the motor shaft inertia calculation when evaluating servo or variable-speed drive systems.
Can the SL Type coupling be supplied with a keyway bore?
Yes. Keyway bores to DIN 6885 standard dimensions can be machined in the hubs at the time of manufacture. Specify the required keyway dimensions when placing your order. Keyway and setscrew combinations are also available.
How is the intermediate slider block installed or replaced?
To install: place one hub on each shaft and secure. Slide the intermediate block tongue-and-groove features into engagement with one hub, then bring the second hub into axial alignment and engage the remaining pair of tongue-groove faces. No special tools are required. To replace: remove one hub from its shaft (or slide it back), remove the worn block, and insert the new one. Hub bores do not need to be removed from the shafts in most cases.
What is the maximum bore diameter for each SL Type model?
Bore ranges are specified for each model in the dimension table: from 15–18 mm for SL70 to 200 mm for SL460. For bores near or at the maximum for a given model, confirm wall thickness adequacy with Ever Power if keyway machining is also required.
Is the SL Type Oldham coupling interchangeable with other manufacturers’ Oldham couplings?
Major external dimensions (D, L, H, S) are based on the GB/T standard for SL Type couplings. Interchangeability with other manufacturers’ SL Type products depends on the dimensional standard each manufacturer follows. Provide your existing coupling’s dimensional data when enquiring about replacement supply.
Enquire About the SL210 SL Type Oldham Coupling
Ever Power manufactures the SL210 and the complete SL Type coupling range — 17 sizes from SL70 to SL460 — direct from our production facility. Provide your bore diameter, operating torque, shaft speed, and misalignment data for a prompt technical and commercial response.