Hydraulics

[merle&louise]

How does a hydraulic system work?

I have a hydraulic radiator fan on my coach. When the thermostat opens indicating that the fan should turn what actually turns the fan?

[garyde]

How does a hydraulic system work?

I have a hydraulic radiator fan on my coach. When the thermostat opens indicating that the fan should turn what actually turns the fan?


Hi Tuga.
Squirrels. I base that on chasing two out of my engine compartment recently.

[JIM CHALOUPKA]

Tuga, I wish I could help you, NOW IF YOU ONLY HAD A BUS!;):D Too bad you have a COACH :eek:

:pJIM

[merle&louise]

Both great answers guys, but not what I am looking for. Maybe Google can help me. Thanks anyway!

[JIM CHALOUPKA]

Tuga, post a picture of the fan. Do you have a fan driven by a gear or belt but with a hydraulic clutch or do you have a fan driven by a hydraulic motor?

In either case you will need oil pressure to activate the clutch or run the motor.

There could be an engine driven pump and it would supply the oil pressure to activate the clutch or run the motor. There would be an electrical signal, probably thermostatically controlled that would call for the clutch to activate etc. Maybe your problem is the sensor or in the electricals and not the hydraulics (oil pressure) Also look for a solenoid bypass valve. Boy this is getting too complicated I sure am glad I have a plain old BUS.;)


JIM

[truk4u]

Tuga,

Hydraulic pressure created by the pump is what turns your fan..

[JIM CHALOUPKA]

Tuga, read this link. It may or may not be exactly what you have, but will be close and give you an understanding of the concept and what is going on in your COACH.


http://www.electricfanengineering.com/info_turbine_hyrdaulic_fans.html


JIM

[merle&louise]

Jim,

I am not having any problems.:D The radiator fan is working fine and has for 4 years! I am just trying to understand what turns the radiator fan because there are no belts. I think the series 60 turns a hydraulic pump that moves the fluid (like Truk said) is what's turning the fan. I see a hydraulic hose that goes to the area around the fan.

I understand it now. I Googled "What makes Hydraulics work?" and there is a good explanation and a video.

Thanks.

[travelite]

When the thermostat opens indicating that the fan should turn what actually turns the fan?

Hi Tuga,

I have a hydraulically driven fan too. On my bus there's a Chelsea PTO driven off the transmission. The PTO drives a Sauer Danfoss hydraulic pump which draws fluid from a large reservoir and pressurizes it. The fluid is than delivered to a PWM (Pulse Width Modulator) and then on to the hydraulic motor which spins the fan. The fluid is then routed back to the reservoir. Fan speed control is accomplished by the PWM taking queues from the DDEC ECU based on engine coolant temp, fan override, chassis AC, and probably more.

Under steadystate conditions, the S-60 fan should run at approximately 80% of engine rpm. When the dash AC is on, or when the fan override is on, or when the coolant temp is above 205 deg F, the fan should run at 1800 rpm.

David Brady
'02 Blue Bird, Wanderlodge, LXi,
Asheville, NC

[merle&louise]

David,

My system works directly off of the s60 thru a hydraulic pump and on to a hydraulic motor that spins the fan. I understand how it works now.

Thanks.

[sawdust_128]

Hi Tuga.
Squirrels. I base that on chasing two out of my engine compartment recently.


Nice smack there Gary.

[parksincpp]

Squirrels. I base that on chasing two out of my engine compartment recently.

We call those "little b......." at our house. They're very disructive. They ate the wire from our xmas lights. Just enough off of each strand we had to trash over a dozen. Not mention other stuff.