Shock valves
Description for setting of shock valves:
1. Connect T and EF port of VSPP to tank of pump station.
2. Plug P-port of VSPP.
3. Connect P port from pump supply to one servo port at a time (L and R), plug opposite servo port.
4. Connect pressure gauge to the servo port connected to P of pump station and to T of pump station.
5. The shock valves are to be set at an oil flow of 3 l/min applied to one of the servo ports L and R at a
time.
6. The shock valve (item 64, see
on page 5) is set according to specification:
Pressure (R-T/L-T), bar, for the code in question.
T pressure should not exceed ~5 bar. Max. allowed T pressure is 30 bar.
Pump supply circuit must be adjusted not to exceed 270 bar P-T at shock valve setting.
Steering tests
Description for system setup for steering tests:
1. Connect double rod cylinder to L and R ports of VSPP.
2. Connect T and EF port of VSPP to tank of pump station.
3. Connect P port of VSPP to P port from pump.
4. Connect pressure gauges to all ports of VSPP.
5. Connect steering column and steering wheel to VSPP surface for column.
Column must allow access to the adjusting screw for pilot relief valve by cut-out in the foot plate.
T pressure should not exceed ~5 bar. Max allowed T pressure is 30 bar.
Pump supply circuit must be adjusted not to exceed 190 bar P-T at steering test.
Start up test
During the testing, no disturbing vibrations, noise, or other irregularities must occur.
1. Start the pump.
The pump flow is adjusted to approximately 25 l/min and pump pressure control must be set to
approximately 70 bar.
2. Let the supplied oil flow through the steering unit for a few minutes.
3. Operate the steering wheel to move the steering cylinder from end stroke to end stroke for at least 5
cycles.
Make sure pressure P-T, 70 bar can be achieved, when steering against end stroke.
If this is not possible, the adjusting screw of the pilot relief valve (item 99, see
on
page 5) must be turned clockwise until P-T, 70 bar is achievable.
Pilot relief valve test
1. Adjust the pump flow to approximately 25 l/min and pressure to maximum 190 bar.
2. The steering wheel is actuated until the steering cylinder reaches one of its end strokes and the
steering wheel is actuated in this cylinder position with steering torque 25 ±5 Nm.
3. The pilot relief valve (item 99, see
on page 5) is set according to specification:
Maximum steering pressure (P-T), bar, for the code in question.
The setting pressure is the pressure on the P-port minus the T-port of VSPP.
Service Manual
VSPP Steering unit
Testing of VSPP
©
Danfoss | November 2019
AX319758618681en-000101 | 33
