R4Z Series — UTEK-DELE Axial Fan Range

The R4Z Series takes a different approach to reversing: instead of changing blade pitch, the impeller is designed to work in both directions so the airflow follows the motor rotation. That removes the actuator, the hydraulic or pneumatic circuit and the pitch mechanism from the fan entirely.

The blades are die-cast aluminium in the 299-1011 mm range on a Z-3 hub. Aluminium gives the temperature headroom needed close to hot components, and the symmetrical profile keeps performance predictable in both directions, which suits smaller machines where a simple forward and reverse cycle is enough to clear the cooler.

Model Range and Specifications

Because no pitch mechanism is used, there is nothing to adjust in service; the reversing capability depends on the drive being able to run in both directions.

Blade Materials and Temperature Range

Blade material is selected from the working temperature and from the atmosphere around the impeller:

Hub Options

Blades are supplied with matched hub sets. The hub carries the blade loads and sets the shaft interface, so it is selected together with the blade count:

Typical Applications

This series is normally specified for the following duties:

• Simple forward and reverse cooling cycles

• Equipment without hydraulic or pneumatic supply

• High-temperature zones close to engine components

• Retrofit where an actuator cannot be fitted

Specification Support

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.

Quality Assurance and Dynamic Balancing

Metal impellers are assembled as a matched blade and hub set and balanced on a hand laser balancing machine before shipment, which keeps vibration low in both directions of rotation.

Customization and Series Overview

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 continuous pitch control or a self-cleaning cycle under load is required, the pneumatic and hydraulic reversible fans provide dedicated reversing mechanisms instead.

Related ranges: 4XR Series aluminium blades | S Series blades | P Series axial fan | H Series small impellers.