A taper bush adapts the fan hub to the drive shaft: the tapered surfaces clamp the hub onto the shaft and keep the impeller concentric with the drive.
The taper bush is the part that turns a hub into a mounted impeller. Two tapered surfaces are drawn together by the clamping screws, so the hub grips the shaft as a friction connection rather than relying on a keyway alone, and the impeller stays concentric with the drive.
Because the connection is a taper, removing the impeller is a matter of releasing the screws instead of pulling a seized hub off a shaft. On equipment that is serviced in the field, that difference is often the reason a fan change takes an hour rather than a day.
| Property | Effect on the fan assembly |
|---|---|
| Tapered clamping | Friction grip on the shaft without relying on a keyway |
| Concentric fit | Keeps the impeller centred on the drive axis |
| Releasable joint | Impeller can be removed without a puller |
| Hub family match | Supplied against the H, Z or W hub it serves |
Taper bushes are quoted with the hub family they belong to, so a replacement bush keeps the same shaft interface and clamping behaviour.
Blade material is selected from the working temperature and from the atmosphere around the impeller:
| Material | Composition | Temperature range | Typical duty |
|---|
This series is normally specified for the following duties:
Mounting a fan hub onto a drive shaft
Field replacement of an impeller without a puller
Service kits where hub, bush and blades are renewed together
Any fan assembly where shaft concentricity matters
When a fan is being specified or replaced, the following points are confirmed before a blade set is released. They are the same checks used for OEM programs and for retrofit projects.
Duty point: airflow and static pressure required at the working speed, taken from the cooling pack or ventilation requirement
Installation: available diameter, shroud clearance, mounting pattern and the shaft interface of the existing hub
Environment: maximum air temperature, dust or gas atmosphere, and whether static discharge has to be avoided
Drive: available power, belt or direct drive, and whether the fan has to reverse in service
Service: blade weight for handling during maintenance and spare-part availability across the machine fleet
Blade count, profile and material are then matched to those conditions in a fixed order: material first, then blade count, then hub family, with diameter confirmed against the shroud. Working in that sequence keeps the mechanical interface stable when the duty requirement changes later in the project, and it is why the same blade family can often stay in production while the cooling pack is revised.
Taper bushes are supplied as part of the matched hub set: the bush, hub and blade assembly is balanced together on a hand laser balancing machine before shipment.
Blade count, blade profile, hub family and material can be customized for OEM programs, and existing fans can be reviewed when airflow, noise or durability has to be improved on a running machine. Where the hub is being reused, only the bush is replaced, provided the shaft diameter and the hub family stay unchanged.
Related ranges: Air cooling system parts | Equipment and balancing | P Series axial fans | S Series blades.
