By Steve Ormondroyd, Workshop Manager
January 2021 marks the start of the centenary year of Westin Drives, a company where quality has long been the hallmark of our work.
Take an electric motor repair. Where some repairers are content to slap on new bearings and send it on its way, we go the extra mile. For example, we have the best diagnostic and test equipment for motors – plus excellent balancing equipment and capacity.
Consider the attached pictures, above, of two bearing housings from the same motor. If the drive end bearing housing is examined closely, punch marks can be seen at 90° around the housing. They were made by a motor 'repairer' in Yorkshire.
The idea is by centre punching the housing, the resulting burr will stop the bearing moving in the housing. But this faulty technique will almost certainly put the rotor out of alignment, leading to premature bearing failure. When our engineers repair a bearing housing, it is bored, sleeved and machined to the correct tolerance according to SKF.
This motor came to us because of a bearing failure. Considering the previous attempt at a repair, that was inevitable – particularly as the rated speed for this type of motor is 10980 RPM.
We have now bored and bushed the housings, balanced the rotor, fitted the correct bearings and returned it to the customer. The correctly machined housings may be seen below.
By Steve Ormondroyd, workshop manager
This large pump built by the Dutch company Nijhuis Pompen comes from a ship and was sent to us for repair. In operation, it uses its maximum 635 kW power and 1500 M3/H capacity to dredge the sea bed.
It will be dismantled and meticulously inspected to identify any reclamation work required to return its performance to the level of when it was manufactured.
We will be looking out for:
As is routine with pump repairs of this nature, we will replace any seals, gaskets, O rings & bearings. We will also dynamically balance the whole rotating assembly to G6.3.
Meet our new balancing machine. Our previous model was ideal for balancing electric motor rotors and armatures, but more limited on pump and fan impellers.
We previously had to subcontract some impeller balancing, but a significant increase in our pump and fan repair work was enough to justify the investment in a new machine.
With a weight capacity of over two tonnes and a bed length of two metres, it comfortably covers all our workshop balancing requirements and the extra capacity allows us to confidently offer balancing as a service of its own.
Apprentice engineer Mika Everson works on a fan motor manufactured 61 years before he was born.
The motor, from a 1942 industrial extractor, was sent to us for repair by an large engineering firm in Huddersfield.
Inspection revealed that a bearing had collapsed, but the windings were found to be in good condition.
After thorough cleaning the rotor will be balanced to G2.5, new bearings fitted and the motor assembled. Then, after a successful test run, this piece of our industrial heritage will be returned to the customer.
Two control panel upgrades by our technical services department have doubled production on stone saws at a Huddersfield quarry.
The old system, built in 1969, was obsolete and needed constant operator input to maintain reliable production.
In collaboration with the site's maintenance manager, we developed a new PLC-controlled system which once setup would run the stone-cutting machines unmanned throughout the night.
Lenze Automation was chosen with WEG soft starts for the blade and pump motors. The system proved so reliable and efficient that the quarry quickly had a second saw retrofitted in the same way.
The customer was delighted: "It used to take 2-3 operators, including night shifts, to keep these two machines running. Now it takes just one day operator to run them, and they're getting twice as much production out in the same time."
The team at Westin Drives are pleased to have been appointed Yorkshire's WEG Authorised Repair Agent. The accreditation was awarded after rigorous inspection and auditing of our work.
We have been an Authorised Distributor for WEG for many years and are always looking to strengthen relationships and customer confidence.
WEG offer a high quality array of electric motors, variable speed drives and various other controls and we are proud to be working with them and promoting their products with our service to back them up.
It's a simple truth, but rewinding an electric motor can be cheaper than replacing it. Take for example this motor from a glass-cutting saw.
It is non-standard and to replace it like-for-like would involve a lead time of about 16 weeks and be very expensive. Our engineers, who are expert in rewinding electric motors, had it repaired within a couple of working days at a cost far cheaper than buying a replacement.
These were the problems they faced:
The stator was rewound, the bearing housing was repaired in our machine shop and the rotor balanced in-house to guarantee the motor will function as it should for years to come.
By Fraser Lynch, Technical Manager
Our engineers came up with an innovative solution when they were presented with a paint-stirring machine that could run at only one speed.
The machine's owners needed to diversify their paint offering, but the bespoke, single-phase agitator was not up to the job. A cost-effective way was required to upgrade the unit to run at variable speeds to reduce over-agitation of certain paints and to increase it for others.
Electrical engineer Adam Daffern, supported by our workshop manager Steve Ormondroyd, proposed an engineering solution, pictured above.
As single-phase motors have limited and expensive vsd controls, a progressive output three-phase motor and single to three-phase IP66 inverter from Invertek was offered. The existing gearbox was retained as it was perfectly serviceable.
The customer was delighted with this neat and effective solution and was able to adapt to present and future requirements with only 24 hours of down time.
By Steve Ormondroyd, Workshop Manager
This is the curious story of how we repaired an electric motor that ran on water. The motor, top left, from which water is pouring, was located in a pit under a machine in a dye house and hadn’t run for years.
The customer wanted to start using the machine again, so the motor was switched on and ran for around half an hour. The stop button was only pressed when someone reported water splashing out of the terminal box.
It turns out the motor had been flooded at some stage and nobody had noticed. How the windings didn’t blow amazed me.
When tested, the windings were in excellent condition, passing all our electrical tests as if the motor had just come out of the factory. We also balanced the rotor, fitted new bearings and ran a final test before giving the motor a fresh coat of paint and returning it to the customer.
This was the state of the motor (right) we received for repair from a Yorkshire textile dyeing company.
The corrosion was so severe that the nameplate had long since disintegrated, meaning further investigation was required.
But this was no simple stripping down. Our engineers needed to grind it apart in order to access the stator windings as all the nuts and bolts were seized.
One challenge was to establish the speed at which the motor operated. To do this, our rewinder had to look at the winding and use his years of experience to recognise the coil layout and certain other particulars.
He quickly established beyond doubt it was a four-pole motor (1500RPM). The completed job, with new motor and pulley, was then returned to a satisfied customer.