New washing machine to clean stators, rotors and armatures developed By - Jessica Hannah Published - 20 May 11

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Thermal processing equipment company Tulip Technique has developed a stator, rotor and armature washing and drying machine for use by industries using large electric motors.

Design work on the machine started in May last year, following a request from electrical and mechanical engineer LH Marthinusen for this type of equipment. The washing machine was completed by August 2010.

The machine has two phases – washing and drying.

An armature assembly, which can measure up to 1 m in diameter and 3 m in length, is placed inside the washing machine on rubber pads. The bath is filled with water and detergent and is heated to 70 ºC.

Air bubbles are blown into the water from the base of the machine to circulate the water and penetrate the pores of the motor where there may be contamination.

With many large motors, carbon and other dust-exposure contamination is the main cause of windings and commutator failure. “The rewinding of large electric motors is expensive and costs companies in downtime,” says Tulip Technique technical director Wim van Dijk.

He adds this machine loosens and removes carbon contaminants that build up between segments of the commutator and on the coils of the armature windings, which can lead to windings failure or burnt-out motors.

Cleanliness of the static and rotating parts improves ventilation and prevents machines from running hot.

Motor contaminants are loosened over a 12-hour washing period. Once complete, the bath is drained and the water is disposed of. The armature is taken out of the washing machine and put into a powerspray station where the contaminants are blasted off at high pressure with water. The armature is then put back into the washing machine to dry.

The drying phase, which takes about a further 12 hours, involves heated air being circulated by fan to ensure even movement.

Van Dijk believes that a number of mines, power stations and other grassroot industries will benefit from using the armature washing machine.

The company has had a lot of interest from local and international companies and has installed the unit in two of precious metal producer Gold Fields’ operations.

The machine runs off a three-phase 380 VAC, 63 A electrical supply cable linked to a control panel.

Tulip Technique plans to adapt the machine to make it more environment-friendly by treating and recycling the washing water and detergent, as opposed to dumping it. It further hopes to incorporate a power-spray station in the machine to make it a complete wash, power spray and drying unit, Van Dijk concludes.