traction versus boat motor.

well i found what i thought was the perfect electric motor for a boat by reading lots and lots of car conversion forums. The number of people out there doing DIY conversions of cars to electric powered cars is amazing. Anyway I eventually found this blog where a person had reviewed stacks and stacks of motors for car conversions and decided a particular one was the best. I was given the direct contacts for the owner/inventor of this motor and asked him the question regarding a replacement for the specified diesel motor. To my amazement he told me that motors built for traction (which his one obviously was) were not usable in boats. It is not a corrosion issue as these motors are exposed to salty water coming into the engine bay after salt road de-icing. One of the factors that is different is the fact that the force in traction is torsion and shaft bearing. On a boat the shaft transfers push into the motor itself. Had not thought of that.
So can anyone else thing of what other properties would be required by a boat electric motor? Torque and shaft power are givens, along with corrosion resistance. Anyone else think of anything?

Mick

 

You need a double thrust bearing in the shaft so the thrust doesn't get transferred to the motor. They are standard equipment and you can get it from a bearing supply.

 

Gonzo has it right,you just need to transfer the thrust to the hull and let the motor shaft just rotate.

Steve.

 

Kws are kws

So apart form thrust bearings there is no other reason a traction motor is different to a boat motor...torque is torque, kws of power are kws of power!! A wheel spinning on a road is the same as a prop in the water! I think!!:?:

 

A wheel spinning on the road is not the same as a prop spinning on a boat, though you can probably make some modifications to your motor to make it serviceable in the marine environment. There are other considerations for a marine environment, besides the thrust bearing issue.

 

A motor on a boat is on full load all the time, there is no coasting. The power drain on your batteries will be much more than on a fork lift. You also need to worry about heat dissipation. But that is easy to solve, water cooling jacket.

Your batteries are your limiting factor. Big motors need a lot of juice. Don't spend a lot of money to fins out it will only run an hour before your drifting powerless.

 

Can you elaborate??

Actually, let me try to summaries...regarding purely the motor component. The key differences are...
- the motor is under torque load continuously while power operating;
- the motor requires a double thrust bearing to take the forward/aft loadings;
- the motor will require additional cooling due to the combination of continuos loading and lack of airflow compared to auto installation;

Anything else??

Thanks guys

Mick