WH Type Oldham Coupling: engineering overview
WH Type Oldham Coupling 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.
An Oldham coupling normally consists of two hubs with perpendicular drive slots and a center disc that engages both hubs. As the shafts rotate, the center member slides in the mating grooves, allowing parallel offset to be accommodated while torque is transmitted between the two hubs.
Key Features & Design Characteristics
Parallel offset compensation
The three-piece Oldham arrangement is commonly used to accommodate parallel shaft offset.
Compact three-part design
Two hubs and a center disc form a simple torque-transmission structure with easy visual inspection.
Low rotating mass
The compact architecture is useful in smaller motion and positioning systems.
Serviceable center element
The center disc can be inspected and replaced without replacing both metal hubs when the surrounding design permits.
How this version is configured
The design is especially useful where parallel misalignment is more significant than with many other compact coupling types. The center disc is a wearing and sliding component, so operating speed, surface condition, material pair, lubrication practice where applicable and the magnitude of offset all affect service life and generated heat.
- The configuration should be matched to the exact shaft connection, available space and duty shown in the model data below.
Selection sequence for a real machine
Confirm torque, speed, bore sizes, shaft fit, outside diameter, hub length and the parallel-offset requirement. The center-member material should suit the required wear resistance, damping and operating environment. Where setscrews or keys are used, verify that the shaft connection can transmit the required torque without slipping.
- 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.
| Type | Nominal Torque Tn (N·m) | Allowable Speed [n] (r/min) | Bore Dia. d (mm) | Hub Length L (mm) | Dimensions (mm) | Weight (kg) | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Y-Type L | J1-Type L | D (mm) | D1 (mm) | B (mm) | C (mm) | |||||
| WH1 | 16 | 10000 | 10–14 | 25–32 | 22–27 | 40 | 30 | 52 | 17 | 0.6 |
| WH2 | 31.5 | 8200 | 12–18 | 32–42 | 27–30 | 50 | 32 | 56 | 22 | 1.5 |
| WH3 | 63 | 7000 | 18–22 | 42–52 | 30–38 | 70 | 40 | 60 | 22 | 1.8 |
| WH4 | 160 | 5700 | 20–28 | 52–62 | 38–44 | 80 | 50 | 64 | 22 | 2.5 |
| WH5 | 280 | 4700 | 25–32 | 62–82 | 44–60 | 100 | 70 | 75 | 27 | 5.8 |
| WH6 | 500 | 3800 | 30–45 | 82–112 | 60–84 | 120 | 80 | 90 | 37 | 9.5 |
| WH7 | 900 | 3200 | 40–55 | 112 | 84 | 150 | 100 | 120 | 42 | 25 |
| WH8 | 1800 | 2400 | 50–70 | 112–140 | 84–107 | 190 | 120 | 150 | 52 | 55 |
| WH9 | 3550 | 1800 | 65–85 | 142–172 | 107–132 | 250 | 150 | 180 | 62 | 85 |
| WH10 | 5000 | 1500 | 80–100 | 172–212 | 132–167 | 330 | 190 | 180 | 62 | 120 |
| Type | Torque Tn (N·m) | Max Speed (r/min) | Bore Range (mm) | Typical Application Tier |
|---|---|---|---|---|
| WH1 | 16 | 10,000 | 10–14 | High-speed servo / encoder |
| WH2 | 31.5 | 8,200 | 12–18 | Servo & automation |
| WH3 | 63 | 7,000 | 18–22 | CNC & packaging |
| WH4 | 160 | 5,700 | 20–28 | Light industrial drives |
| WH5 | 280 | 4,700 | 25–32 | Pump & conveyor auxiliary |
| WH6 | 500 | 3,800 | 30–45 | Medium industrial |
| WH7 | 900 | 3,200 | 40–55 | Medium-heavy drives |
| WH8 | 1,800 | 2,400 | 50–70 | Heavy process drives |
| WH9 | 3,550 | 1,800 | 65–85 | Heavy industrial |
| WH10 | 5,000 | 1,500 | 80–100 | Heavy process & mill drives |
| Parameter | WH Oldham Coupling | Jaw Coupling | Bellows Coupling | Disc Coupling |
|---|---|---|---|---|
| Parallel Offset Compensation | Good (by sliding disc) | Limited (0.1–0.5 mm) | Low (0.1–0.3 mm) | |
| Angular Offset Compensation | Low | Moderate (1°–2°) | Good (1°–3°) | Low (0.5°–1°) |
| Backlash | Near Zero | Low–Moderate | Near Zero | Near Zero |
| Shock Absorption | Yes — disc material | Yes — spider element | Minimal | Minimal |
| Electrical Insulation | Yes (polymer disc) | Yes (spider) | No | No |
| Suitable Speed Range | Up to 10,000 r/min | Up to 6,000 r/min | Up to 10,000+ r/min | Up to 10,000+ r/min |
| Constant Velocity Ratio | Yes — true 1:1 CV | Yes | Yes | Yes |
| Installation & Maintenance | Simple — disc slides out radially | Simple — spider accessible | Moderate | More complex |
| Relative Cost | Moderate | Low | High | High |
Standards and designation references found in the source data
Where a standard or designation is shown below, treat it as a reference tied to the original product data and verify the applicable revision when placing an order.
Shaft fit, alignment and assembly checks
Align the shafts within the model limits, set the correct hub spacing and make sure the center disc enters both hub slots freely without binding. The coupling should rotate smoothly by hand before start-up. Excessive preload on the center member is a sign that shaft position or spacing needs correction.
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
Check the sliding faces and center member for wear, heat discoloration, deformation or debris. Increasing backlash or noise can indicate that the disc or grooves are worn. Replacement should restore the designed fit rather than compensating for wear by over-tightening hub fasteners.
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
Automation equipment
Used in compact motion systems where parallel offset and installation space must be managed.
Positioning mechanisms
Applicable to controlled motion assemblies that require a simple coupling between aligned shaft ends.
Small pumps & instruments
Suitable for lighter rotating equipment when torque and speed remain within the chosen model rating.
Packaging machinery
Considered for compact machine modules where maintenance access and shaft positioning are important.
Oldham couplings are widely used in positioning mechanisms, machine tools, packaging equipment, instrumentation and other compact drives where controlled parallel offset must be accommodated.
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.