IP Library Granted Patent US 6,865,886
Granted Patent B2
US 6,865,886 · App. 10/405,174 · Granted Mar 15, 2005

Hydraulic control system

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Quick Facts
Patent No.
US 6,865,886
App. No.
10/405,174
Granted
Mar 15, 2005
Kind
B2
Abstract

A hydraulic control system ( 1 ) has a hydraulic motor ( 10 ), which is connected with a control valve ( 2 ) via two working lines ( 8, 9 ), the control valve ( 2 ) being connected with a low-pressure connection (T) and, via a compensation valve ( 4 ), with a high-pressure connection (P), to ensure that a return compensation valve ( 14, 15 ) is arranged in each working line, each return compensation valve ( 14, 15 ) having a nominal flow line ( 29 ), which extends unintersectedly in relation to the nominal flow line ( 28 ) of the compensation valve ( 4 ).

Claims (11)

1. A hydraulic control system with a hydraulic motor, which is connected with a control valve via two Working lines, the control valve being connected with a low-pressure connection and, via a compensation valve, with a high-pressure connection, wherein the improvement comprises:

a return compensation valve ( 14 , 15 ) is arranged in each working line, each return compensation valve ( 14 , 15 ) having means for a nominal flow line ( 29 ), which extends unintersectedly in relation to a nominal flow line ( 28 ) of the compensation valve ( 4 ).

2. A hydraulic control system according to claim 1 , wherein the nominal flow lines ( 29 ) of the two return compensation valves ( 14 , 15 ) are equal.

3. A hydraulic control system according to claim 1 , wherein the nominal flow lines ( 28 , 29 ) of the return compensation valves ( 14 , 15 ) and of the compensation valve ( 4 ) are parallel to each other.

4. A hydraulic control system according to claim 1 , wherein the return compensation valves have a larger flow than the compensation valve.

5. A hydraulic control system according to claim 1 , wherein an anti-cavitation valve arrangement ( 20 ) ends between the motor ( 10 ) and the return compensation valves ( 14 , 15 ).

6. A hydraulic control system according to claim 5 , wherein the anti-cavitation valve arrangement ( 20 , 25 , 26 ) has a shiftable non-return valve ( 26 ).

7. A hydraulic control system according to claim 6 , wherein the shiftable non-return valve ( 26 ) closes automatically in connection with negative loads.

8. A hydraulic control system according to claim 1 , wherein the compensation valve ( 4 ) has a smaller spring tension than the return compensation valves ( 14 , 15 ).

9. A hydraulic control system according to claim 1 , wherein in the flow direction from the high-pressure connection (P) to the motor ( 10 ) the control valve ( 2 ) has a larger flow resistance than in the flow direction from the motor ( 10 ) to the low-pressure connection (T).

10. A hydraulic control system according to claim 1 , wherein each return compensation valve ( 14 , 15 ) is provided with a load sensing connection (LSA, LSB) acting in the opening direction and with a control connection acting in the closing direction and being connected with a section of the working line ( 8 , 9 ) leading to the control valve ( 2 ), and that the return compensation valve ( 14 , 15 ) in the working line ( 8 , 9 ), through which hydraulic fluid flows to the motor ( 10 ), is acted upon through the load sensing connection (LSA, LSB) by the pressure also ruling in the working line ( 8 , 9 ).

Assignments (2)
CHANGE OF NAME Recorded Apr 7, 2014
From: SAUER-DANFOSS APS
To: DANFOSS POWER SOLUTIONS APS
Reel/Frame 032612/0709 →
CHANGE OF NAME Recorded May 21, 2004
From: SAUER-DANFOSS (NORDBORG) A/S
To: SAUER-DANFOSS APS
Reel/Frame 015349/0498 →