Small Engines (Lawn Mowers, etc.): washing machine motor problem, motor brushes, machine manufacturers

Question
I bought a washing machine from the UK (230 volts 50hz) to the Caribbean (230 volts 60hz) and it worked ok for a year. Then the motor brushes burnt out and so I replaced them, they worked for 6 months before it happened again. Then I replaced them again this week, they lasted one wash before burning out again. The washing machine manufacturers (Hotpoint) make a 60 hz pump for export but the pump is working perfectly well, the only problem I have is the motor and Hotpoint for obvious reasons do not want to give advice except buy another motor which will be exactly the same unless this one is faulty which I am sure it is not as long as the brushes continue to work.
Although it is fairly simple & cheap to replace the brushes from the UK I need a permanent solution as I am far away from there. Is there an adapter I can buy to alter the electric supply or can I bodge up the motor to get it to work better without burning out.
What do you think? I am not a technical person and we have limited resources on this island so maybe you can help. Thanks.  

Answer
Hi Claire,

Here is the consensus:
We don't think a 50 Hz motor on 60 Hz, is the problem.  Weak brush springs,  rough commutator (It might be by now if not cleaned between brush changes) rotor winding failure i.e.: partial short are possible causes. If the brush holders and springs are OK, replace the motor.

Let me know how you make out.

Good Luck,
Michael