Volvo Alternator

Bondy111,

Alternators by and large do not make good motors and if you can get one to motor it will be pretty inefficient. You would be better off using the cooling fan motor (assuming it has one). That would also probably not be your best choice. There are numerous bicycle motors available out there. You might also consider an electric trolling motor. You can probably find a used one pretty readily and the controller is already there.

I don't think you could use the alternator as a motor because:

1. It would be too bulky to attach to the bike.

2.You'd need a very high rpm to get the the current flowing and...

3.even if you do bring the rpm high enough with a velocity increasing gear system for example, i doubt the voltage would be sufficient to accelerate 200-300 lbs (passenger + bike)

You could definately incorporate a smaller version of the alternator w/ a permanent magnet as a dynamo to power a headlamp or horn!!

Bett4haze

Does the car have power windows? these motors are designed to pull fairly heavy loads. If you group pairs of them together you could have a cheap solution.

The car will run without an alternator, as long as the voltage in the battery is high enough to supply the ignition system sufficient power to fire the plugs, and fuel pump and fire the injectors.

A more serious problem is weather or not you will be able to keep the water pump spinning. The car will run for about 2 hours on the battery alone if it was fully charged when starting. The car will overheat inside of five min. if the fan belt that runs the alternator is removed, causing the water pump to stop turning.

By power windows, do you mean electric windows (no winder), and how would you group them together

Typically these electric motors come in left hand, and right hand. If you have four electric windows, stack the two rights, and the two lefts. I would look to weld a small sprocket to the window gear. The four sprockets to a short idler shaft with five additional sprockets on it. The fifth sprocket would run to drive the sprocket on the bike wheel. If you used another rear wheel-sprocket combination on the front, you could leave the original pedal power system intact, only running the motors when desired.

For spacing convenience, it might be better to face a right hand and left hand motor to each other so as to keep the two window gears next to each other. You probably need to get the motors out and look at them to see what you are comfortable with.

Each window motor has two leads on it. They will reverse rotation by reversing the two wires. This will allow you to get each motor to spin in the direction you need no matter how you mount them. Good luck.

Bondy,

Most window motors have a worm-drive gear reduction drive head. You need a gear with matching teeth to mount to your bicycle wheel hub and an apparatus to attach the motor to the bicycle frame in a position to mesh the gears. You will also need a method of disengaging the gears because that worm drive doesn't work well in reverse (when spun by the driven gear rather than the motor).

To determine the size of gear to put on the wheel hub you need to know two things 1) the RPMs and diameter or # of teeth of the drive gear and 2) the maximum speed you wish to travel. For most bicycles 25 MPH is pushing the limits of braking potential. Find the circumference of the wheel/tire in question. No need for math yet. Use a soft tape measure (sewing style). Divide the number of inches in a mile by the number of inches in the tire circumference. This will tell you how many times that tire has to revolve to cover that mile.

If this is a standard bicycle (2 wheels) you can put one motor on each wheel and wire them in parallel. The motors should automatically synchronize themselves.

You will still have a need to control the speed. Again I will tell you an electric boat trolling motor will have the cheapest, most reliable unit for that. Find one with a twist grip and you are all set.

By using the rear wheel-sprocket on the front the worm gear problem should be solved. You are probably right about the trolling motor. If he was to remove the motors, and alternator and sell on ebay, or even a scrap metal yard, he would get a good start on the money required for a trolling motor setup.

The only trolling motor I ever played with was 24 volt. Are they out there with 12 volt?

Hi Bob,

24 volts is not a big problem. All it takes is a little more money. Get a couple of those cheap booster packs they sell at most auto supply stores. The gel cell batteries are best for his purposes anyway. They are reasonably light weight and come with built in chargers. Some come with built in lights, air compressors and even small inverters.

The Starter Motor will work, but heavy & overkill,:).

Old Tech

As Long As You Faithfully Plug in an 115 A.C. to 12vd.c. charger connected to your battery every day when you get home.

1) An automotive alternator should work as a motor if you can supply the rotor with 12V DC and the stator with 3-phase AC. You will need to bypass the rectifier diodes.

2) The car will function well without the alternator so long as you keep the battery charged.

The starter motor would do better than the generator.

In a Word-NO

As you have probably surmised from the other posts, it is really not a good idea.

yes u can but still you have to go with the speed control technique of the synchronous motor to achive speed range that will vary according to your driving And for most simplisity in driving ur car u mast use an engine which can drive the generator with rated speed to generate the power with which u will able to drive a induction motor(squirrel cage/ wound rotor), u can also use adc genset with universal, steeper or brushless dc motor as it has varying speed torque charaatristic, still u want some more information contact me on "drool_parimal@rediffmail.com" Also send me some information about ur 12 v electric bike if u can ALL D BEST

Suppose your generator's 500W then if you (by passing the diodes) apply 12V 3phase to it with max current of 500/12=41.66A and at the same time also apply some dc power to its rotor, via its regulator, then you can start ending-up with a similar sort of motor that apparently drives the hybrid-cars.

By varying the current (A) to the rotor you can vary its torque and to some extent its speed however, its is not the right way of doing it.

The question is where do you get the complex 3 phase power supply from (that does the speed control also) at a reasonable cost, have you thought about it?

Can an alternator generate that much power functioning as a motor with the small thin brushes and commutator rings that are in it?

The alternator generates its power in the stator nd not in the rotor. The brushes only supply the induction current to the rotor to make it magnetic according to the given power demand on board in order to maintain the nominal voltage of the vehicle to charge the battery @14-15V.

The max rotor current requirement isn't much for a car or even for a average truck generator, around 5A.

I knew generators could become motors. I never heard of alternators being able to act that way. Thank you.

Would a starter motor be able to run continuously, not just in bursts for starting the engine, and what sort of weight would the motor support to move the bike along?

The starter motor can run continuously as long as the load on it is low. But you will want to get a good load on the motor to get some speed out of the bike. You will need larger battery cables than on the car, as well as all other current carrying accessories.

The motor should drag along 250 pounds. The question is how fast do you want to drag that 250 pounds.

I must admit to you when I said earlier that the starter would be a better driving force for your proposed bike I meant it in a jest and slightly sarcastically because, I knew how the others will react.

To be honest with you, a starter motor is designed to deliver high torques at short bursts therefore, it would, literary, reap a push bike to pieces. And to quench its thirst would be impossible without having a power-station nearby. It is the type of motor they use in electric-winches that you can retro-fit on 4x4 for being so powerful.

Further, its slip bearings would be unable to withstand long continuous operations due to lack of constant forced lubrication.

Forget the wiper and fan motors!!! They're neither powerful nor suitable due to lack of proper gearbox.

You must look for better alternatives like hub-motors with planetary gear. Some manufacturers offer motors and gear boxes that you can taylor and re-taylor according to your needs.