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...
Your standby pressure at the pump should be 34.3 BAR (497 PSI). This set by the LS compensator on the pump. The actual load sense pressure should be 0 when nothing is moving.
Your pump pressure will always be 34.3 BAR above the LS pressure when a cylinder or motor is stalled, and perhaps a...
You can put an orifice in the outlet of the last motor to increase the decrease the pressure drop over the motors so that is barely enough torque to keep them turning. Then, when the motors need to do work, you can bypass the orifice with a valve, either manual or solenoid controlled.
The...
Yes, it does make sense.
The inertia in the discs is trying to drive the motors, so the system pulses as the work required to drive the motors goes up and down.
If you dampen the affect of the inertia by sticking the discs in the ground or by giving them some work to do, they will settle...
From a purely hydraulic point of view, you can go with a simple pump, a simple valve and just let the cylinder run to end of stroke or stop it with a mechanical end stop.
Alternatively, you could spend money on a proportional control system that will detect the cylinder position and stop it...
