Hydraulic arrangement for a vehicle transmission
A hydraulic arrangement for a vehicle transmission includes a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit. The arrangement also includes a control valve connected between a pump outlet of the pump and the two hydraulic circuits and has two different switching positions. The control valve, depending on its switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit.
1. A hydraulic arrangement for a vehicle transmission, comprising:
a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit;
a control valve connected between a pump outlet of the pump and the two hydraulic circuits and having two different switching positions; and
a holding valve unit including a mechanical locking mechanism for releasably locking the control valve in the second switching position;
wherein the control valve, depending on its switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit.
2. The arrangement as claimed in claim 1 , further comprising a storage unit hydraulically connected to the system circuit.
3. The arrangement as claimed in claim 1 , wherein the control valve changes its switching position if the system pressure reaches or drops below a predetermined minimum system pressure, or if the system pressure reaches or exceeds a predetermined maximum system pressure.
4. The arrangement as claimed in claim 3 , wherein, based on a falling system pressure after the system pressure reaches or drops below the minimum system pressure, the control valve moves to the first switching position for a hydraulic connection of the pump to the system circuit.
5. The arrangement as claimed in claim 3 , wherein, based on a rising system pressure after the system pressure reaches or exceeds the maximum system pressure, the control valve moves to the second switching position for a hydraulic connection of the pump to the lubrication circuit.
6. The arrangement as claimed in claim 1 , wherein the control valve comprises a 3/2-way valve.
7. The arrangement as claimed in claim 1 , wherein the holding valve unit is actuable depending on the system pressure.
8. The arrangement as claimed in claim 1 , wherein the holding unit includes a control input connected to the system pressure and a restoring spring having a spring pressure set approximately to a minimum system pressure.
9. The arrangement as claimed in claim 1 , wherein the mechanical locking mechanism has a locking protrusion which engages with a cutout in a locking arm of the control valve for releasably locking the control valve in the second switching position.
10. The arrangement as claimed in claim 1 , wherein the holding unit includes a control input connected to the system pressure and a restoring spring having a spring pressure set approximately to a minimum system pressure, and the mechanical locking mechanism has a locking protrusion which engages with a cutout in a locking arm of the control valve for releasably locking the control valve in the second switching position.
11. A hydraulic arrangement for a vehicle transmission, comprising:
a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit;
a control valve connected between a pump outlet of the pump and the two hydraulic circuits and having two different switching positions;
a holding valve unit including a mechanical locking mechanism for releasably locking the control valve in the second switching position; and
a storage unit hydraulically connected to the system circuit;
wherein the control valve, depending on its switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit;
wherein the control valve changes its switching position if the system pressure reaches or drops below a predetermined minimum system pressure, or if the system pressure reaches or exceeds a predetermined maximum system pressure.
12. The arrangement as claimed in claim 11 , wherein:
based on a falling system pressure after the system pressure reaches or drops below the minimum system pressure, the control valve moves to the first switching position for a hydraulic connection of the pump to the system circuit; and
based on a rising system pressure after the system pressure reaches or exceeds the maximum system pressure, the control valve moves to the second switching position for a hydraulic connection of the pump to the lubrication circuit.
13. The arrangement as claimed in claim 11 , wherein the control valve comprises a 3/2-way valve.
14. The arrangement as claimed in claim 11 , wherein the holding valve unit is actuable depending on the system pressure.
15. The arrangement as claimed in claim 11 , wherein the holding unit includes a control input connected to the system pressure and a restoring spring having a spring pressure set approximately to a minimum system pressure, and the mechanical locking mechanism has a locking protrusion which engages with a cutout in a locking arm of the control valve for releasably locking the control valve in the second switching position.
16. A hydraulic arrangement for a vehicle transmission, comprising:
a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit;
a control valve connected between a pump outlet of the pump and the two hydraulic circuits and having a first and a second switching position; and
a holding valve unit including a mechanical locking mechanism for releasably locking the control valve in the second switching position;
wherein the control valve, depending on its switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit.
17. The arrangement as claimed in claim 16 , further comprising a storage unit hydraulically connected to the system circuit.
18. The arrangement as claimed in claim 16 , wherein the control valve changes its switching position if the system pressure reaches or drops below a predetermined minimum system pressure, or if the system pressure reaches or exceeds a predetermined maximum system pressure.
19. The arrangement as claimed in claim 16 , wherein:
when the system pressure reaches or drops below the minimum system pressure, the control valve moves to the first switching position for a hydraulic connection of the pump to the system circuit; and
when the system pressure reaches or exceeds the maximum system pressure, the control valve moves to the second switching position for a hydraulic connection of the pump to the lubrication circuit.
20. The arrangement as claimed in claim 19 , wherein the holding unit includes a control input connected to the system pressure and a restoring spring having a spring pressure set approximately to a minimum system pressure, and the mechanical locking mechanism has a locking protrusion which engages with a cutout in a locking arm of the control valve for releasably locking the control valve in the second switching position.