Description
WH7 WH Type Oldham Coupling – 40–55mm Bore Shock-Absorbing Sliding-Block Flexible Drive Coupling
The WH7 WH Type Oldham coupling is a sliding-block flexible drive coupling designed for applications transmitting 900 N·m at up to 3200 rpm where a certain degree of shaft relative offset compensation, shock absorption, and vibration damping capability are all simultaneously required. With a 150 mm outer diameter and bore range of 40–55 mm, it suits the full range of industrial shaft connections in this torque class — from compact instrument drives at the WH1 end of the series to large pump and processing equipment drives at the WH10 level. The coupling’s working temperature range of -20°C to +70°C covers standard industrial and outdoor service environments. The WH7 at 900 N·m serves 40–55 mm shaft connections in the 22–75 kW industrial drive class. Its shock absorption capability is particularly suited to reciprocating compressor drives and heavy-duty conveyor connections where peak torque loads significantly exceed the continuous operating torque.
The WH Type coupling is a three-component sliding-block Oldham design: two identical metal hubs, each mounted on one shaft, and a central polymer slider block that simultaneously engages the tongue-groove features on each hub face. Torque is transmitted through the sliding contact between the polymer block tongues and the metal hub grooves. Relative radial displacement between the two shafts is absorbed by translational sliding of the block within the hub grooves during rotation. The polymer block material provides inherent shock absorption by deflecting elastically under peak torque loads, attenuating transient torque spikes before they are transmitted to the connected shaft and its bearings. This shock absorption characteristic distinguishes the WH Type from rigid Oldham couplings and makes it particularly valuable in drive applications with variable or intermittent loading.
Y-type (standard length) and J-type (short hub) bore configurations are both available for the WH7, with bore length dimensions of 112 mm (Y-type) and 84 mm (J-type). The full WH series documentation and selection guidance is available on our product catalog page.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | WH7 |
| Type | WH Type Oldham (Sliding-Block) Coupling |
| Bore Range (d) | 40–55 mm |
| Outer Diameter (D) | 150 mm |
| Inner Hub Diameter (D₁) | 100 mm |
| Slider Block Width (B) | 120 mm |
| Tongue Depth (C) | 42 mm |
| Y-Type Bore Length (L) | 112 mm |
| J-Type Bore Length (L) | 84 mm |
| Nominal Torque (Tn) | 900 N·m |
| Maximum Speed [n] | 3200 rpm |
| Working Temperature | -20°C to +70°C |
| Mass | 25 kg |
Dimension Reference
Hub and Slider Block Assembly
The WH7’s intermediate slider block is the functional core of the coupling. Machined from engineering polymer to precise tongue and groove dimensions, the block simultaneously engages the drive faces on both hub ends. The tongue width and groove dimensions on the WH7 are sized to provide adequate compressive contact area for reliable 900 N·m torque transmission while maintaining the sliding clearance needed for radial compensation movement during rotation. The tongue depth dimension C = 42 mm determines the shear plane geometry of the engagement and is a key parameter in the coupling’s shock absorption capacity.
Shock Absorption
The polymer slider block deflects elastically under peak torque loads, attenuating drive transients and protecting both motor and driven equipment bearings from shock loading. This is the primary functional differentiator of the WH Type over rigid Oldham couplings.
Shaft Offset Compensation
Radial shaft offset between the two connected shaft centrelines is absorbed by the sliding mechanism, preventing transmission of radial forces to motor or driven equipment bearings — reducing bearing overload and extending equipment service life.
Vibration Damping
The polymer block’s internal damping dissipates vibrational energy transmitted through the drive shaft, reducing vibration levels in both the motor and driven equipment — beneficial in applications where vibration affects product quality or equipment fatigue life.
Y and J Bore Options
Both standard-length Y-type and short-hub J-type bore configurations are available, accommodating applications with different axial space constraints between bearing supports.
Manufacturing
Typical Applications
- Compressor drive connections — reciprocating compressor peak torque absorption and motor protection
- Large conveyor drive shaft connections — belt conveyor head drum drive couplings with sustained high torque
- Processing industry pump drives — large centrifugal pump motor connections with thermal offset accommodation
- Wood and paper industry process drives — chipper, roll, and agitator drive connections with shock loading
For application enquiries and volume supply, please visit our contact page.
Customer Reviews and Case Studies
★★★★★
Germany — Industrial Compressor OEM
The WH7 Oldham coupling is specified for drive connections on our reciprocating compressor product range. At 900 N·m rated torque, it handles the peak drive loads of our compressor range, and the shock absorption reduces the cyclic torque impulse transmitted from the piston drive to the motor.
— Senior Engineer, Mannheim
★★★★★
Malaysia — Palm Oil Milling
Used on fruit bunch conveyor drive connections at our palm oil mill. The WH7 handles the variable torque loading of the harvest conveyor and its shock absorption protects the drive motor from the impact loading when bunches drop onto the conveyor.
— Maintenance Supervisor, Johor Bahru
★★★★☆
Mexico — Sugar Processing
Fitted on cane elevator drive connections. The WH7 Oldham coupling has operated reliably through two full cane crushing seasons without coupling maintenance, handling the variable torque of the cane elevator drive.
— Plant Engineer, Veracruz
Frequently Asked Questions
How is the WH Type coupling assembled?
The WH Type coupling is assembled in three steps: (1) mount and secure each hub on its respective shaft using the keyway and setscrew or clamping arrangement; (2) bring the shafts into approximate alignment with the coupling gap between hub faces; (3) insert the intermediate slider block tongue-and-groove features into engagement with both hub faces simultaneously. No special tools are required.
What bore types are available for WH Type couplings?
Both Y-type (standard cylindrical) and J-type (short hub) bore configurations are available. Y-type is the standard configuration; J-type uses a shorter hub length suitable for applications with limited axial space. Both bore types are offered for each model. Specify Y or J type when placing your order.
Is the intermediate slider block replaceable without removing hubs from shafts?
Yes. In most WH Type installations, the slider block can be removed and replaced without removing either hub from its shaft. Slide the hubs apart axially (if axial clearance allows) or, where axial movement is limited, partially loosen one hub and move it axially to release the block. Replacement blocks are available as spare parts for all WH Type models.
Can the WH Type coupling be used in outdoor applications?
Yes, within its rated temperature range of -20°C to +70°C. The metal hubs are not affected by outdoor exposure. The polymer slider block should be protected from prolonged UV exposure and from immersion in oils, solvents, or strong chemicals unless the specific block material has been verified for compatibility with the operating environment.
What is the maximum shaft bore for WH10?
The WH10 accepts shaft bore diameters from 80 to 100 mm. This covers the output shaft sizes of large industrial motors and gearboxes in the 100–500 kW power range.
Enquire About the WH7 WH Type Oldham Coupling
Ever Power manufactures the WH7 and the complete WH Type coupling range — 10 models from WH1 to WH10 covering 16 N·m to 5,000 N·m — direct from our factory. Specify your bore diameter, bore type (Y or J), operating torque, and speed for a prompt technical and commercial response.
