Need help on rotary broom hydraulic conversion

[oldnslo]

Page 4 of the data sheet on your link discusses Inlet condition.
Pumps are rated for a given RPM with a given inlet pressure. This inlet pressure is sometimes shown in inches of mercury for vacuum or PSIA for PSI Absolute. In the case of this vane pump it states inlet vacuum should never exceed 5 in Hg. Running at 2000 + RPM you may need to upsize the suction hose one size larger than the pump port. I.e. Keep velocity under 3 ft / sec if possibly. Vane pumps self destruct rather rapidly when they cavitate. The cam ring typically gets scalloped causing the vanes to wear excessively and break over time. If you can mount the reservoir higher than the pump this will help since each foot of height above the pump inlet is approx 1/2 PSI head pressure.

 

[locknut]

Page 4 of the data sheet on your link discusses Inlet condition.
Pumps are rated for a given RPM with a given inlet pressure. This inlet pressure is sometimes shown in inches of mercury for vacuum or PSIA for PSI Absolute. In the case of this vane pump it states inlet vacuum should never exceed 5 in Hg. Running at 2000 + RPM you may need to upsize the suction hose one size larger than the pump port. I.e. Keep velocity under 3 ft / sec if possibly. Vane pumps self destruct rather rapidly when they cavitate. The cam ring typically gets scalloped causing the vanes to wear excessively and break over time. If you can mount the reservoir higher than the pump this will help since each foot of height above the pump inlet is approx 1/2 PSI head pressure.

Now you got me worried.How does one figure the flow velocity in this proposed configuration?

 

[MossRoad]

I'd be surprised if you need a cooler. The reservior tank sides should act like a cooler. Remember, its winter, too. Our log splitter has no cooler, just a 2 gallon tank. The fluid is constantly moving through the pump and valve, so it heats up. It heats up more under load, of course. Just more things to consider, like you need that!!! :laughing:

 

[oldnslo]

Now you got me worried.How does one figure the flow velocity in this proposed configuration?

The way I remember figuring velocity is Flow = velocity x area

example: flow of 13 GPM target velocity of 3 FPS (feet per second)

To make everything common factors of inches per second

take the GPM x 3.85 = 50.05 cubic inches per second flow

3 FPS x 12 = 36 IPS

50.05 / 36 =1.39 square inch area which = a diameter of 1.33 inches.

 

[locknut]

Haven't posted for a while.Been busy redesigning the broom for the hydraulic drive.Had to move the lift over to the left side from center to open up an area for the tank and pump.Also reworked the float/spring mechanism.Went with a gear pump instead of the vane pump.The tank will hold up to 7 gal of fluid.Planned to use a motor spool valve mounted back by the seat on the right side but my hydraulic experts decided the simplest way to control the broom motor circuit was to use a flow control valve up front,which I like,as everything is simplified and self contained forward of the front hitch.I'm really pleased how it come together and it's so quiet,unlike the clackety-clack racket of the gearbox drive.

Also decided not to run a heater off the front PTO.Been wanting to get a Gen anyway,so I got me a little Honda that powers the 1500 watt heater for the cab.Just sits back there and purrs along.

Checked the speed on the motor and it's running a little over design speed @ 621 rpm,and the broom head runs @ 155 rpm.When I lower the broom on concrete to a four inch pattern it only drops 4 rpm and the tractor doesn't know it's there.Of course,the real test will be when I put some load on it when we get some snow,so we'll see. As far as cost on this project.....don't ask....but I'm happy and glad it's done.Longest project I've worked on to date.

Pics;

 

[MossRoad]

Tractor- check.
Cab - check.
Snow broom - check.
Portable generator to power heater in cab.... priceless!!! :laughing:

Nice job. Hope you get snow in small increments to test it out.

 

[locknut]

Follow up with a short action video.Changed the motor out for a little more speed.Went from a 4.5 to a 3.95.Speed upped to 178 rpm. After working it fairly hard for about an hour the temp was 100 deg w/20 deg ambient.Works great so far.

https://www.youtube.com/watch?v=qom5CW9vjkM

 

[oldnslo]

Nice job locknut.

I presume that you put a shield over the chain and sprockets. Only reason I say this is I watched my sons mitten go round and round on a sprocket once due to a gaurd missing. That took a couple years off the ole pacemaker...

 

[MossRoad]

Very nice job!

Now I'm curious as to the bristle wear on the brush. You might want to measure the length of the bristles, then try to log the hours on the broom, to get some idea of how long the bristles will last. It won't be scientific, but I've hear stories about folks putting too much pressure on a brush and wearing it out quicker than expected.

 

[locknut]

Very nice job!

Now I'm curious as to the bristle wear on the brush. You might want to measure the length of the bristles, then try to log the hours on the broom, to get some idea of how long the bristles will last. It won't be scientific, but I've hear stories about folks putting too much pressure on a brush and wearing it out quicker than expected.

I hope they last a long time@ $250 a set.They are 24" new.The float pattern on this one calls for 2-3" across the contact area.They say that's the life of the broom-just the right amount of down pressure.The way I have it set up,I just turn the locknuts on the eye bolts that hold the extension springs.