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...
Does the same thing happen when you stall the lift cylinders in both directions and also when you rack back and tilt forward?
The 10% reduction in the pump displacement is a big clue about what's going on here.
If you see the same pressure reduction on all implement movements, then it suggests...
Could be an electronic issue.
The pump displacement is controlled by a proportional solenoid. The spools for the implements are all electro hydraulic too.
Might seem like a strange question, but are you sure that it’s not meant to back the pump displacement off at high idle to limit the power...
It’s valve 1 that’s too small to handle the flow from P1, not the highlighted valve as I said before.
The pilot flow is very small. There is a control orifice in the highlighted valve to make sure there is a good pressure differential. Otherwise the valve will be unstable when the P2 pressure...
As a former employee of Bosch Rexroth I can confirm the following.
The highlighted valve is not big enough to handle the flow. It’s a small pilot valve that vents the main stage at the required pressure, as set on the spring in valve 1.
The issue here is the load differential across the cylinders. The flow divider will do its best to compensate for the pressure differential, but one leg of the flow divider will see higher leakage around the gears and it may also be spilling oil across the relief valve and that is why the...
It depends on the application and the aspect of the design that you are considering.
Basic force and velocity are straightforward. Beyond that, there is the fluid dynamics for getting the fluid in and out when the cylinder is moving quickly. There is mechanics, when the cylinder has side...
It really depends on how fast you want to the system to work.
The smaller the accumulator, the faster it will operate, without using flow controls to slow it down.
The pressure of the gas will double when you halve the volume of the gas.
Calculate the volume of the cylinder at full...
It’s not a pressure switch. It’s solenoid valve that is most likely normally closed to lock the arm in position / isolate the accumulator and stop the break back function. The 12V DC supply is there to turn the valve on/off.
I’ve looked at the video and the operation looks quite slow, so the...
This is commonly known a breakback. It's used on agricultural machines to allow booms to yield if they hit something and then spring back to the normal position when the obstacle has passed.
Contrary to the comment above, the hydraulic solution is the preferred method as it's more reliable and...
