where can i get ; brush motor pulley for Bosch Extraxx 17?

I have a Bosch Extraxx 17 vacuum cleaner (buc 11700gb/01) i need a brush drive motor pulley to drive the belt drive. It is a push fit onto the motor shaft. It is shown on the model diagram in the area 41 7322.
I dont want a complete motor. Everyone wants to sell me the whole motor to get a 50 pence piece of plastic. Where can i get one please, otherwise the whole thing goes in the bin and I DONT buy another Bosch.

bert Kennedy
August 2010