Description
SL190 SL Type Oldham Coupling – 75–80mm Bore 190mm OD Radial Misalignment Compensating Drive Shaft Coupling
The SL190 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 3200 N·m at 250 rpm maximum speed, 190 mm outer diameter, and a bore range of 75–80 mm, the SL190 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 3.0 mm, angular compensation of 0.5°, and axial accommodation of 2.2 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 | SL190 |
| Type | SL Type Oldham (Sliding-Block) Coupling |
| Bore Range (d) | 75–80 mm |
| Outer Diameter (D) | 190 mm |
| Inner Diameter (D₁) | 110 mm |
| Overall Length (L) | 140 mm |
| Hub Width (H) | 29 mm |
| Slider Width (S) | 0.5 mm |
| Nominal Torque (Tn) | 3200 N·m |
| Maximum Speed [n] | 250 rpm |
| Radial Compensation (Δy) | 3.0 mm |
| Angular Compensation (Δa) | 0.5° |
| Axial Compensation (Δx) | 2.2 mm |
| Rotational Inertia | 0.5 kg·m² |
| Mass | 31.5 kg |
Dimension Reference
Coupling Assembly and Slider Block
The SL190 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
3.0 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 industrial pump drive couplings — motor connections where precision alignment is impractical on process plant baseplates
- Power station auxiliary drive connections — boiler feed pump, induced draft fan, and cooling water pump motor couplings
- Steel mill auxiliary drive connections — high-vibration environment motor couplings with misalignment compensation
- Sugar and pulp mill process drive connections — large sustained-torque motor shaft couplings
For enquiries about large volume supply or custom bore configurations, visit our contact page.
Customer Reviews and Case Studies
★★★★★
United States — Industrial Mixer OEM
We use the SL190 on large mixing equipment motor connections. The 3.0 mm radial compensation allows our motors to be mounted on standard frames without precision-aligned baseplates, reducing installation cost for our customers.
— Applications Director, Chicago
★★★★★
Norway — Marine Equipment
Installed on deck equipment drive connections on our patrol vessels. The Oldham coupling compensates for the shaft misalignment that results from vessel hull flexure under sea state loading.
— Marine Engineer, Bergen
★★★★☆
Vietnam — Plastic Extrusion
Used on extruder drive shaft connections. The SL190 handles the sustained high torque of our plastic extrusion process and accommodates the thermal expansion offset of the extruder barrel.
— Production Engineer, Hanoi
Frequently Asked Questions
Is the SL Type coupling suitable for frequent start-stop and reversing duty?
Yes. The tongue-and-groove engagement between the slider block and hub faces provides positive torque transmission in both rotational directions and under both acceleration and deceleration loads. For frequent reversing duty, the slider block should be inspected more frequently as reversing impacts the contact faces at the tongue-groove engagement.
What temperature range is the SL Type coupling rated for?
Standard polymer slider block versions are rated for operating temperatures of approximately -20°C to +70°C. For elevated temperature applications, a metal slider block version may be required. Consult Ever Power with your operating temperature for appropriate material selection.
Can the SL Type coupling be used in wet or outdoor environments?
Yes. The SL Type coupling is a metal-bodied coupling with no elastomeric elements — the cast iron or steel hubs are not affected by water exposure. For outdoor installations, a protective cover is recommended to prevent debris entry into the tongue-groove contact. The polymer slider block should be protected from UV exposure in long-term outdoor installations.
What happens if the intermediate slider block fails?
If the slider block fractures or wears excessively, the coupling will lose its torque transmission capability. Metal slider block failure may also cause hub-to-hub contact. In most applications, slider block condition can be inspected visually during planned maintenance by removing the coupling guard. Replacement slider blocks are available as spare parts.
Does the SL Type Oldham coupling transmit axial forces between shafts?
The axial compensation provided by the sliding interface between the slider block and hub faces means that small axial forces can be transmitted, but the coupling does not fully isolate axial loads. For applications where axial force isolation is critical, a flexible coupling with dedicated axial isolation capacity should be specified instead.
Enquire About the SL190 SL Type Oldham Coupling
Ever Power manufactures the SL190 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.
