Nippondenso alternator rotation

tractorman414

Well Known and Active Forum User
VOC Member
Hi

I am enquiring on this subject for my friend and Dorset Section member, Mostyn Phelps.

Mostyn is in the process of fitting a Nippondenso alternator to his enclosed D twin. The label on the alternator reads AKD094 and the literature refers to it being for "forklift & other industrial application", the literature also uses the reference 1N254 Reg ND 12v. The control for the alternator is housed within the alternator casing. The data indicates an output of about 40 amps, but significantly 20 amps at 2000 revs, so a very desirable unit.

There is no problem with running this alternator via a belt off a counter shaft mounted in the original dynamo location, the alternator is located where the D battery would have been, and the alternator rotation is counter to the engine rotation. Mostyn is also considering using a similar alternator on his C twin and this is where the problem arises. With the C carburettor location, the alternator must be mounted on the left hand side and hence the rotation reversed to that of the D.

Advise so for is that the alternator cannot be made to work with a reversed rotation. We find this hard to understand and perhaps its more a case of they don’t know how to modify the unit for a reversed rotation.

Anybody out there who can help, please

Bernard
 

Ian Savage

VOC Vice President
VOC Member
I guessing but this sounds like a alternator with a field coil as opposed to a permanent magnet field.
In which case there will be slip ring pick up on the armature (like brushes on a dynamo) so it is probably the mechanical design of that prevent reverse rotation.
I did a bit of a search on the web and most of this type of alternator state a rotation direction.
 

shadhubh

Active Forum User
Non-VOC Member
I think ,generally, alternators can run in either direction, stated direction would be for cooling fan on front end.I could be wrong but it's a try..
Vic..
 

tractorman414

Well Known and Active Forum User
VOC Member
I guessing but this sounds like a alternator with a field coil as opposed to a permanent magnet field.
In which case there will be slip ring pick up on the armature (like brushes on a dynamo) so it is probably the mechanical design of that prevent reverse rotation.
I did a bit of a search on the web and most of this type of alternator state a rotation direction.

thanks Ian, yes it does have a field coil, and I believe, a slip ring. We shall have a look inside to see why the slip ring cannot rotate in the opposite direction, a dynamo can !

Bernard
 

timetraveller

Well Known and Active Forum User
VOC Member
Hi Guys, some of you will know that Dick Sherwin and I developed a car alternator kit to fit all models of post war Vincents. We now have over 40 of these out there with no problems so far. The alternator I use is intended to be used on a Citroen 2CV, Dyane etc. It has no cooling fan and can be rotated in either direction. I was loaned a 40 amp Nippon Denso alternator unit a few years ago to test out whether it would be suitable. I do not still have it so I cannot be sure it is the same model. However, when I set it up on a test rig, which is rotated with hand held electric drill which can be rotated in either direction, it ran fine in the correct direction and the drill really struggled when it was run in the wrong direction. I decided then that it might be suitable for a 'D' butdid not dare to use it on all the rest of the models as there was clearly some mechanical resistance which was likely to result in a reduced life for the unit. My guess at the time was the same as yours in that I assumed that there was probably an assymetrical slip ring system and the brushes were going to wear rapidly if used in the wrong direction. As it was not my alternator, and it was new, I could not justify taking it apart in case it would not go back together correctly so I did not investigate further. There was a further problem when compared with out 30 amp system in that the shaft which takes the drive into the alternator had a very small distance outside the alternator body. This meant that after taking off the original pressed steel 'v' belt pully we had to make a new input pulley to take our poly 'v' belt drive with most of the inside cut out to allow a nut to go onto the shaft to hold the new pulley on. Our normal input pullies are aluminium but so much of it had to be cut away to fit the Nippon Denso shaft and thread that I felt that these pullies would have to be made in either steel or stainless steel for longevity

If your friend would like to know more about our kit, which is absolutely complete, then he or you should ask around at various rallies to find someone who is using our kit or email me on enw07@btinternet.com and I can send out some information. Good luck.
 
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