I was the hydraulic engineering manager at Caterpillar before moving to BR. Yes, they could very well have changed the swash angle to limit the displacement.
Internals of the A10 motor are like this.
Swash plate is fixed at an angle to give the relevant displacement. Piston diameters are...
I used to work at Bosch Rexroth and now I work at a distributor for Bosch Rexroth. Try the link below.
https://www.boschrexroth.com/en/gb/search.html?q=R902495615&origin=header
You had said 5cc/rev for the motor displacement, I was just checking.
Yes, the motor could have an anti cavitation...
Are you confident on that number? The minimum displacement on those A10 motors is 10.6 cc/rev.
If this is the motor that is fitted, then the max speed is dictated by the mechanics of the swash plate and the reciprocal motion of the piston.
The statement on the data sheet is pretty clear:
▶...
A pump pushing oil through a motor will continue to do so until the pressure at the inlet of the motor goes above the max pressure. The motor will run at a speed that is proportional to input flow and the displacement.
A pump of the same displacement would be speed limited by it ability to...
If the load sense signal is draining across an orifice, the flow will vary depending on the pressure differential across the orifice. If you use a compensated flow control valve, you can set the total flow to 0.2 GPM and it will remain at that flow independent of the pressure in A and B.
Using...
Yes, that’s basically the right idea.
The check valve isn’t required as there will be no pressure from the LS port.
Is it safe to assume that the P,T and LS are on the back of the tractor?
You don’t need the solenoid valve. If you want to make sure your load sense drains down, you use a...
Hello Andy
Your load sense line needs to go on the A and B line, with shuttle valve between them so that the highest pressure is sent back to tractor to increase the flow.
With no signal back to the pump, via the LS port, it will stay at the standby pressure 250 - 290 PSI.
The pump will try...
The dash size refers to the bore of the hose and that is always given as nominal bore size as an approximate diameter.
The OD of the hose depends on the number of layers of wire and the outer sleeve thickness as per the application for the hose. A multi spiral hose with abrasion resistant outer...
It's not just a line relief, it's also a make up check valve to allow the cylinders to pull oil in if there are external loads acting on them. It does look like cavitation damage, which suggests that the cylinder has been subject to frequent external loads.
The damage to the external surface...
Aim for 0.008mm radial clearance.
Equation for leakage is
Q = [πR (R-r₀)3/ (6 µ L )] (1+ 3/2ε²) ∆p
where ε =e/ (R-r₀)
R is bore radius
rois spool radius
μ is oil viscosity
L is sealing length
Δp is pressure drop
e is eccentricity
The noise from the piston pump would be the first indication that the charge pump was struggling to fill the piston pump. Also, the charge pump is a gerotor type pump, centrifugal pumps don't lend themselves to applications where the speed varies.
We are looking for something that is related to the speed of the pump.
The servo piston on the pump is balanced between the pump outlet pressure + spring force versus the pilot pressure that is controlled by the proportional valve. The angular velocity of the pump will apply additional force on...
