Thrust bearing for propeller shaft

Hi
I'm designing the integration of EV motors inside our Cat and I have few questions.

What to use as thrust bearing now the transmission of the diesel is out?
The motor will be direct drive and inline with the prop shaft.
The ball bearings inside the EV motor can take some thrust load, but not much and I would like to add a proper bearing.
Very affordable solution to me seem to use hub from a car as they cost 40-50$ and last thousand miles even in salty snow/water.
Any thought?
Thanks

 

Yes it's good idea .And you need to fix hub into the hull.

 

How much thrust are you expecting? How much unbalance? Shaft speed? These things trade off in bearing type selection (i.e. tapered roller, cylinderical roller, or shoe). Additionally, the tapered roller bearings used in vehicles are used in pairs and require a pre-load to be maintained to prevent unloading and damage, something difficult to obtain with a simple through shaft.

 

https://www.autozone.com/suspension...l-bearing-and-hub-assembly-dl512175/95504_0_0
choose correct load direction.

 

The car hub solution is only cost competitive if you have access to free (or very low cost) machining services. In addition to the brackets to fix it to the hull, it needs a custom flange on the wheel side of the hub and a splined connector on the other (usually made using parts from the cars driveshaft instead of manufacturing a custom splined shaft). It's not actually difficult to do, but if you have to pay commercial rates for the work it isn't cheaper then a off the shelf solution. To make it work the minimum equipment is a lathe, welder and the usual electric hand tools.

The funny part is that if you do have access to free machining the car hub route doesn't offer any significant labor savings or other advantages over adapting other types of industrial thrust blocks.

 

Not much. I'm designing for max 15-20 kW motor so the thrust is limited.

Nothing on motor side and, I hope, very little on the shaft/prop side.

1000-1500 rpm max.

 

it's my case as I'm designing entirely new motor bracket/thrust bearing support.

I'm really open to suggestion. What kind of industrial blocks can take high load in both direction, are sealed and cost almost nothing?

 

If you don't know the thrust, I suggest you check the bearing dimensions in the lower gear for an outboard with the power corresponding to what you have. Part numbers/dimensions available on the net. Wheel cartridge bearings are nice, but overkill for your purpose.

 

It's exacly what I have hard time to find.
Wheel bearing are maybe overkill, but available everywhere for few $$.
Where can I find a ''boat'' bearing for a 1.375'' prop shaft?

 

If machining is free it's easy, on one side a flange with the wheel lugs hole pattern (4x100, etc.), on the other side the driveshaft wheel end with the cv joint housing modified to accept another shaft (how exactly depends on the exact cv joint size, if it's big enough you can just turn the housing into a flange).

The typical small power thrust block consists of a spherical roller bearing with tapered bore, adapter sleeve with locknut, housing.
Every major bearing manufacturer will have a combination to fit your needs, you just have to go trough the catalogs.

There are more fancy blocks that use expansion sleeves to retain the shaft.

 

Hi yabert, I second Rumars on the bearing taper lock.
1.375" = 1 3/8" = a very common shaft size.
Look for a bearing set with a taper locking sleeve setup, so it can be placed at a convenient place on the shaft, or aligned on your hull frames. Try a double row tapered roller bearing, or a double row angular contact ball bearing, or a curved/toroidal roller bearing. Spherical bearings are ok, and probably adequate for your low thrust, low speed, low temp application. Also look for a set with a self aligning housing, and a grease nipple, then that's one less thing to worry about when mounting. It won't be extremely cheap, but self aligning taper locks will make the installation and replacement much easier, with common off the shelf items.
Avoid bearings from the land of instant land fill.
You will likely also need shims when bolting the bearing housing down to your mounting block, and when bolting the motor down, so the shaft stays in alignment when secured, with no sideways/up/down loadings.
An internet search of bearing types will help you explain your needs, and a visit to a couple of bearing suppliers may have informative counter staff to help, and maybe give a cheap(ish) solution.
Adapting car parts will cost you time, and risk failure; small industrial bearings and housings will be much simpler. Don't bother with stainless steel components, unless you are loaded with dough.

Show us photos of your progress; many will be interested.

 

Taper lock bushing, tapered roller bearing/angular contact ball bearing... all this is know and easy to understand form me.
BUT, can someone put a pictures or links of what is a typical boat thrust bearing please.
I'm struggle to find anything seashing google ending to find thing like this at 15k$

 

Here is ThunderStruck Motors, LLC motor mounting solution with a gear reduction
You can custom the shaft size and reduction ratio

Home :: Gear Reduction & Motor Plates :: 12-24KW Gear Reduction https://www.thunderstruck-ev.com/12-24kw-gear-reduction.html

 

Yes, I know those one... and I have hard time to understand how the prop shaft can put all the thrust in the set screw of the chain coupling
Imagine in reverse...

 

Here a rough 3D of the idea with a nissan leaf motor. Yanmar 3 cylinders is there for scale idea.
The wheel bearing is fix to the motor via a flange (not represented). This flange fix the motor to the boat and take the thrust.
Then, a taperlock bushing can be the link between 1-3/8'' shaft and the wheel bearing via a hub (not represented).

The ''magical'' part here is the spline in/out part who link the male spline of the motor shaft to the female spline of the hub (last pic).
Maybe 3D print stainless steel?