Article codes
1Couplings for power transmission
Oldham Style Flexible Coupling (MOL)
Three-piece Oldham coupling that compensates large parallel misalignment with small reaction forces: stable, easy to assemble and electrically insulating.
- Oldham type
- General purpose motor
- High allowable misalignment
- Small eccentric reaction force
Which coupling handles large parallel shaft misalignment?
An Oldham coupling like the NBK MOL is the right choice for large parallel and lateral shaft misalignment. Its classic three-piece mechanism (two slotted hubs and a central sliding spacer set perpendicular) transmits torque while the spacer slides to absorb eccentricity with small reaction forces on shafts and bearings. It offers identical CW/CCW behaviour, electrical insulation and easy assembly for stepping and general-purpose motors.
Features
- High allowable shaft misalignment
- Compensates for large eccentricity
- Small eccentric reaction force
- Identical clockwise and counter-clockwise characteristics
- Stable power transmission
- Easy to assemble
Overview
The MOL series Oldham coupling is a precision flexible shaft coupling that connects two shafts while compensating parallel and lateral misalignment. It uses a classic three-piece Oldham mechanism of two hubs and a central spacer: a blue spacer for OD 16–32 mm and a black spacer for OD 40–63 mm.
Working principle
The Oldham coupling connects two shafts while accommodating significant misalignment and minimising bearing load, using the classic Oldham mechanism suited to parallel or eccentric misalignment. It has three elements: two hubs fitted to each shaft and a central sliding spacer between them. Each hub has a tongue-shaped slot, and the spacer has matching slots oriented perpendicularly; as the coupling rotates the spacer slides in these slots, transmitting torque even when shafts are misaligned.
This sliding action absorbs angular and lateral misalignment without large reaction forces on shafts or bearings, reducing mechanical stress and improving system life. The coupling also provides electrical insulation, generates minimal eccentric reaction forces and gives identical clockwise and counter-clockwise performance.
Attachment types
The MOL is available as set-screw and clamping (C) types.
- Type
- Oldham type
- Outside Ø range
- Ø16 – 63 mm
- Bore diameter
- 3 – 25 mm
- Rated torque
- 0.7 – 36 Nm
- Hub material
- Aluminium
- Motor type
- For stepping and general-purpose motors
Ready to specify this coupling?
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