hub motor question

[nogelt123]

This may sound like a stupid question but do some brushless motors come with only 2 wires going into the hub? I know that brushless motors require 3 wires,but do some have the controller built into the hub as well?
There doesn't appear to be any controller on the bike other than the large bottom bracket pedelec unit.This bike was sold to me as having a brushless motor.
Could I add a throttle without too much problems?

Thanks,Jan

 

[flecc]

It seems like it's a brush motor Jan, not necessarily a bad thing.

Can you tell us anything about the bike, the make and model, which might help us to answer more accurately?
.

 

[nogelt123]

It is called an ebiko,2007,it is pretty much like the 2009 model.I have seen may other similar chinese bikes with a different name..The hub is quite large and very quiet.
I assumed the controller was in the hub as well as it is not on the bike.
36 volt lithium ion 8 ah battery,no throttle just the large bottom bracket with the pedelec.
Here is the website where I bought it Motion Urbaine | Motocyclettes, vélos, scooters, trottinettes électriques look under inventaire for fb250. And it is a bad thing if I was told it was absolutly brushless.
Thanks ,Jan

 

[flecc]

I don't know that motor and it is quite large and looks like most brushless types. It's difficult for me to make any judgement without knowing the wiring of battery and pedelec, and the pedelec unit type. Bikes of this type often have the controller under the battery platform at the rear of the bottom bracket.

Are you sure that it is only two wires into the hub and not more than one wire in each sleeving? Is the wiring from the battery going via the pedelec unit to the hub?

The battery platform in the Inventaire photo looks like it might have multiple connections into the battery rather than the usual two. Has it in fact?
.

 

[nogelt123]

There are only 2 wires going into the motor,I know because I put a small trailer plug to make the wheel removable.The battery has only 2 contacts on the bottom,
and the platform has 2 corresponding spring contacts.
Definately no controller.
I saw an expoded view of a similar hub on another forum with 3 fets and hall sensors built into the hub.
As to the pedelec it is a sealed unit with wires going into
the motor.
Thanks,Jan

 

[flecc]

I can't really tell from this then Jan. I don't know if you mean the pedelec wires are going into the motor in addition to the two wires you first mentioned.

Together with not knowing what that sealed pedelec unit is, I don't think it's possible to be sure. The motor could either have an internal controller or it could be a brush motor. It certainly seems an unusual setup from what you say, and I'd be surprised if they claimed it was brushless if it wasn't.
.

 

[rog_london]

I can't really tell from this then Jan. I don't know if you mean the pedelec wires are going into the motor in addition to the two wires you first mentioned.

Together with not knowing what that sealed pedelec unit is, I don't think it's possible to be sure. The motor could either have an internal controller or it could be a brush motor. It certainly seems an unusual setup from what you say, and I'd be surprised if they claimed it was brushless if it wasn't.
.

If the motor contains hall sensors and FETs it's certainly a brushless motor, with at least some of the controller functions built in.

There should also be some electronics in there somewhere, to read the HE sensors and drive the FETs.

There would then be no need for the usual three-wire coil drive system or the hall sensor wires to ever leave the motor, and a two core cable may well be all that's needed.

Of course I haven't seen inside the actual motor nogel123 is dealing with, but if it's similar then it would make sense.

Rog.

 

[john]

If there are only two wires going to the motor then there must be an external controller, otherwise there would be no way to turn the power down or off.

This means it is almost certainly brushed, the only other possibility being that there is an additional controller in the motor, something I have never come across.

 

[flecc]

If there are only two wires going to the motor then there must be an external controller, otherwise there would be no way to turn the power down or off.

This means it is almost certainly brushed, the only other possibility being that there is an additional controller in the motor, something I have never come across.

One other possibility John, since the Chinese seem to like to revive old ideas on their motors like the band brake now re-appearing.

Some early hub motors had integral torque sensors from the chain drive, so that could control a motor via an internal controller. nogelt123 has said the pedelec unit wires go into the motor, presumably in addition to the power pair, so these together could provide a complete control set.

Similarly, in another odd arrangement Giant are now using a pressure sensor in the rear dropout to detect minute movements of the rear spindle on the r/h side. Reports are that it works extremely well to provide a full power control range from very slight to full.
.