This size motor was very common in washing machines. Many had capacitor start as grumpy said. Some then switched out that extra field but some had cap start, cap run, effectively making them work like two phase motors. Given the high current rating of 4 amps at 230 volts I'd guess this one is a cap run unit, especially as it seems to have an ability to reverse the rotation by repositioning the brushes, which wouldn't be something I'd expect to see on a cap start motor.
