Background
My mother was using a handheld food blender which she had for over 25 years, probably longer. After a minute or so of use it stopped working. When i checked it i could hear the motor trying to start rotating but it was seized.
As the blender only had one screw securing the two halves of the case i decided to try to open it up and see if the unit could be repaired.
As soon as the case was opened it was clear that the motor shaft was seized. The rotor could only be turned with some considerable pressure on the vanes of the cooling fan.
As the blender only had one screw securing the two halves of the case i decided to try to open it up and see if the unit could be repaired.
As soon as the case was opened it was clear that the motor shaft was seized. The rotor could only be turned with some considerable pressure on the vanes of the cooling fan.
The blade and drive shaft of the blender was unscrewed from the drive end of the hand unit.
The securing screw was removed and the two halves of the case separated quite easily.
Inside there were no signs of heat damage to the rotor nor stator windings. There was some dirt and marking on the inside of the casings from the carbon dust from the motor brushes.
The motor was removed from the case and the two electrical connections were removed from the motor assembly.
The plastic sub-assembly holding the on/off switch, noise suppression capacitor and the mains connections was carefully removed from the case after releasing the hidden securing catch.
The frame the motor was mounted in was stamped, "Moulinex Made in France".
Some light machine oil was carefully applied to the bearings at both ends of the motor ensuring that it did not get onto the commutator. The oil was left to soak into the bearings for a couple of hours.
The motor was carefully turned and almost immediately the rotor moved. With a few more turns the rotor was turning quite freely.
The excess oil that had run out of the bearings was carefully wiped from the area around the bearings.
The motor was left for 24hrs to allow the oil to continue to soak around the bearings.
To try to ensure that the bearings would not dry out again, some Lithium Grease was spayed onto both bearings again ensuring it did not get onto the commutator.
The motor was carefully turned and almost immediately the rotor moved. With a few more turns the rotor was turning quite freely.
The excess oil that had run out of the bearings was carefully wiped from the area around the bearings.
The motor was left for 24hrs to allow the oil to continue to soak around the bearings.
To try to ensure that the bearings would not dry out again, some Lithium Grease was spayed onto both bearings again ensuring it did not get onto the commutator.
While the grease was soaking into the motor bearings all the plastic parts were cleaned and dried.
The motor was then partially re-assembled in the case and tested by connecting to the mains.
The motor turned freely with no noise coming from the bearings.
The case was closed up and the blender tested with the drive shaft and blades connected. The motor worked as expected.
The total time to repair the unit was well under 2 hours, that of course excludes the time allowed to let the oil soak into the bearings.
With a little bit of luck this well made unit will give many more years of service. The recycling yard will have to wait a little longer to see this blender!
The motor was then partially re-assembled in the case and tested by connecting to the mains.
The motor turned freely with no noise coming from the bearings.
The case was closed up and the blender tested with the drive shaft and blades connected. The motor worked as expected.
The total time to repair the unit was well under 2 hours, that of course excludes the time allowed to let the oil soak into the bearings.
With a little bit of luck this well made unit will give many more years of service. The recycling yard will have to wait a little longer to see this blender!