About a month ago, I disassembled a Rainbow D3.  I ordered all the parts to service the motor but the bearing plate was on back order for an unspecified period of time.  Being the impatient person that I am, I scouted around until I found a seller with the part in stock.  When it shipped, the seller sent a tracking number and I followed its progress through the postal system, anxiously awaiting its arrival today.  I was careful not to put anything on my schedule tonight so I could work on reassembling the motor and vacuum.  I went home at lunch, and there was the package!  YES!  But when I opened it, I discovered that I'd been sent the WRONG bearing plate.  Ahhhhhhhh!!!!!!!!!!!!

But I decided to post a photo for anyone interested in seeing the change in Rainbow motor design.  The bearing I received (see photo) is for a D2 model ("Chrome Dome").  Notice the four vents directly around the bearing.  They are designed to direct airflow as the fans suck air through the motor.  In the D2 motor setup, the motor itself is actually sitting on the water basin with the fans on top.  The D3 still uses that same basic arrangement, but the motor uses a peripheral airflow design.  Rather than having large vents in the center through which air can flow, the vents are around the periphery of the bearing plate.  A plastic shroud surrounds the motor housing, thus creating an air path around the motor.  The air is then directed around the motor and through the holes around the periphery of the bearing plate. 

With the D3, I think Rainbow made an important design change.  In the D2 arrangement with air flowing directly through the motor (around the armature and motor field where electric current is also flowing), I can see how a motor would easily get fried if the separator is left off accidentally and water is sucked directly into the motor.  But the D3 directs air around the periphery of the motor.  It never flows through it.  In fact, the motor is more effectively sealed off from the accidental intrusion of water since air flows around the motor.  (see photo of D3 bearing plate that I took from a seller's website)

I've been gone on a family vacation.  When I arrived home today, the bearing plate in question was in the mail.  But when I opened the package, I discovered that it was bent on the edge!!!  It might be usable, but I'm concerned that it won't create a good seal.  So it's back to the vendor one more time.  I can't imagine that it was sent that way, but it was mailed in an envelope with no padding.  Still, I can't imagine that the past office would cause that.  Very frustrating. 

The inside gasket doesn't seem to be affected.  It sits on on the plastic motor housing, which directs air around the outside of the motor.  However, an air guide sits on top of it, which is the first part of the fan assembly.  I'm afraid it will lead air, resulting in a loss of suction.  This has been a month long odyssey!