CN220268070U

CN220268070U - Integrated pressure compensation valve

Info

Publication number: CN220268070U
Application number: CN202322194986.8U
Authority: CN
Inventors: 卢强; 卫冬; 戴岗云; 罗远飞; 李志强; 姜春兰
Original assignee: Lezhuo Bowei Hydraulic Technology Shanghai Co ltd
Current assignee: Lezhuo Bowei Hydraulic Technology Shanghai Co ltd
Priority date: 2023-08-15
Filing date: 2023-08-15
Publication date: 2023-12-29
Anticipated expiration: 2033-08-15

Abstract

An integrated pressure compensating valve comprising: the valve block is internally provided with an oil inlet cavity, an oil outlet cavity and an LS channel; a valve housing fixedly mounted in the valve block; a compensating spool disposed within the valve block and axially movably inserted into the valve housing to define a valve housing oil cavity therein facing the first end of the compensating spool, a switching valve being formed between the compensating spool and the valve block between the oil inlet cavity and the oil outlet cavity, the second end of the compensating spool facing the oil inlet cavity; the logic selection valve is arranged in the valve block and provided with a first oil inlet, a second oil inlet and an oil outlet, wherein the first oil inlet is communicated with the oil outlet cavity, the second oil inlet is communicated with the LS channel, the oil outlet is communicated with the valve sleeve oil cavity, and the logic selection valve is provided with a structure for establishing communication between one of the first oil inlet and the second oil inlet and the oil outlet based on the pressure in the first oil inlet and the second oil inlet. The integrated pressure compensation valve integrates a logic selection function, and simplifies the liquid path structure.

Description

Integrated pressure compensation valve

Technical Field

The present application relates to an integrated pressure compensating valve.

Background

In large-scale mechanical devices using hydraulic power, a single hydraulic pump is generally used to supply hydraulic oil to a plurality of actuators via a multi-path hydraulic system to achieve a plurality of simultaneous actions. In order to achieve a high degree of operability of the working device by means of the mutual engagement of the actuators, LUDV (load independent flow distribution) hydraulic systems are used. The use of pressure compensating valves in the LUDV hydraulic system allows each pressure compensating valve to raise the pressure at the flow control port of the low load actuator to the same level as the highest load when the multiple actuators are simultaneously actuated, despite the different load sizes at each path, to avoid preferential flow to the low load actuator, and to allow the flow to the loads at each path to pass substantially equally.

In the existing LUDV hydraulic system, besides a pressure compensation valve in each path, an anti-reflux valve and an LS (load sensing) selection valve are separately arranged. This independent distribution structure requires a large space and in order to avoid the problem that the pressure compensating valve is difficult to open, the logic selector valve requires a very accurate position set point.

Disclosure of Invention

The present application aims to provide an integrated pressure compensating valve that avoids the drawbacks of the prior art.

According to one aspect of the present application, there is provided an integrated pressure compensating valve comprising:

the valve block is internally provided with an oil inlet cavity, an oil outlet cavity and an LS channel;

a valve housing fixedly mounted in the valve block; and

a compensating spool disposed within the valve block and axially movably inserted into the valve housing to define a valve housing oil chamber within the valve housing axially facing the first end of the compensating spool, the compensating spool and the valve block defining a switching valve therebetween between the oil inlet chamber and the oil outlet chamber, the second end of the compensating spool axially facing the oil inlet chamber;

wherein, integrated pressure compensation valve still includes:

the logic selector valve is arranged in the valve block and is provided with a first oil inlet, a second oil inlet and an oil outlet, the first oil inlet is communicated with the oil outlet cavity, the second oil inlet is communicated with the LS channel, the oil outlet is communicated with the valve sleeve oil cavity, and the logic selector valve is provided with a structure for establishing communication between one of the first oil inlet and the second oil inlet and the oil outlet based on the pressure in the first oil inlet and the second oil inlet.

In one embodiment, the logic selector valve comprises:

a selector valve housing defining the first oil inlet, the second oil inlet, and the oil outlet; and

a selector valve ball movable in a selector valve housing between the first oil inlet and the second oil inlet.

In one embodiment, a selector valve cavity is formed in the valve block, the logic selector valve being disposed in the selector valve cavity and positioned in an orientation such that the first oil inlet communicates with the oil outlet cavity.

In one embodiment, the oil outlet communicates with the valve housing oil chamber through a first oil passage formed in the valve block, an intermediate oil chamber formed between the valve block and the valve housing and connected to the first oil passage, and an oil hole formed in the valve housing and connected to the intermediate oil chamber and the valve housing oil chamber.

In one embodiment, the second oil inlet communicates with the LS passage through a second oil passage formed in the valve block, an LS oil chamber formed between the valve block and the valve sleeve and connected to the second oil passage.

In one embodiment, the oil inlet chamber is connected to the LS oil chamber through a one-way passage provided with a one-way valve, the one-way passage including: an axial through hole formed in the compensating spool, a first radial through hole and a second radial through hole extending between the axial through hole and an outer periphery of the compensating spool, a groove formed on an inner wall of the valve housing and selectively facing one of the first radial through hole and the second radial through hole, and a valve housing radial through hole formed in the valve housing and communicating between the groove and the LS oil chamber.

In one embodiment, the check valve includes a tapered section defined in an axial through bore of the compensator spool and a check valve ball that mates with the tapered section.

In one embodiment, a throttle member is provided in the one-way passage, and an axial throttle passage and a radial throttle passage connected to the axial throttle passage are formed in the throttle member.

In one embodiment, a pressing spring is provided in the valve housing oil chamber, and presses the compensation valve element in a direction to close the on-off valve.

In one embodiment, a plug is mounted at an end of the compensating spool facing the valve sleeve oil chamber, the plug including a cylinder on a first axial side and a mounting portion on a second axial side, the cylinder being inserted into an end of the biasing spring, the mounting portion being sealingly secured in the compensating spool.

According to the integrated pressure compensation valve, at least a logic selection function is integrated in the integrated pressure compensation valve, the liquid path structure is simplified, and the occupied space is reduced. Furthermore, since the logic selector valve function is integrated in the pressure compensating valve, there is no need to select its setting position with additional precision.

Drawings

The foregoing and other aspects of the present application will be more fully understood from the following detailed description taken with reference to the accompanying drawings in which:

FIG. 1 is a schematic cross-sectional view of an integrated pressure compensating valve of an embodiment of the present application;

fig. 2-7 are schematic cross-sectional views of the main constituent elements in the integrated pressure compensating valve.

Detailed Description

The present application relates generally to an integrated pressure compensating valve that integrates anti-reflux, logic selection, and pressure relief functions. The pressure compensating valve is used in a hydraulic system having a plurality of hydraulic circuits, in particular in an LUDV hydraulic system. One pressure compensating valve and downstream flow control valve are provided in each hydraulic circuit.

An exemplary construction of the pressure compensating valve is shown in fig. 1, and the main constituent elements of the pressure compensating valve are shown in fig. 2 to 7.

As shown in fig. 1-7, the pressure compensating valve of the present application comprises a valve block 1, a valve sleeve 2 fixed in the valve block 1, and a compensating spool 3 axially movable relative to the valve sleeve 2. One end of the compensation valve core 3 is fixed with a plug 4, and a pushing spring 5 is arranged between the plug 4 and the end wall of the valve sleeve 2. The pressure compensation valve further comprises a throttle 6 integrated in the compensation spool 3, a check valve ball 7 arranged in the compensation spool 3, and a logic selector valve 8 integrated in the valve block 1.

The valve block 1 is formed with an axially penetrating through-hole. From the first side to the second side in the axial direction of the valve block 1, the through-hole is defined by the following wall sections: an internal thread section 11, a first cylindrical section 12, a second cylindrical section 13, a third cylindrical section 14, a concave cavity section 15, a conical surface section 16 and a fourth cylindrical section 17.

Between the thread segments 11 and the first cylindrical segment 12a first groove segment 11a is formed which is recessed in the material of the valve block 1 in a radially outward direction relative to the first cylindrical segment 12. A second groove section 12a is formed between the first cylindrical section 12 and the second cylindrical section 13, recessed in the material of the valve block 1 in a radially outward direction relative to both.

The LS channel 12b extends radially from the groove bottom of the second groove section 12a to the outer periphery of the valve block 1.

The first cylindrical section 12 is of equal diameter to the second cylindrical section 13. The third cylindrical section 14 has a smaller diameter than the first cylindrical section 12 and the second cylindrical section 13. The fourth cylindrical section 17 has a smaller diameter than the third cylindrical section 14. The pocket segment 15 is recessed in the material of the valve block 1 in a radially outward direction relative to the third cylindrical segment 14 as a whole. The tapered section 16 faces the first side.

Furthermore, an outlet channel 18 is formed in the valve block 1 leading from the space defined by the second cylindrical section 13 to the second end face of the valve block 1.

Further, a selective valve chamber 19 is formed in the valve block 1. One end of the selector valve chamber 19 opens into the passage 18, and the selector valve chamber 19 also opens into the bottoms of the first and second groove segments 11a, 12a through the first and second oil passages 19a, 19b, respectively.

The axial first end of the valve sleeve 2 is closed by an end wall. Further, the outer periphery of the valve sleeve 2 is formed with an external thread section 21 near the end wall, and an external cylindrical section 22 between the external thread section 21 and the axial second end. The externally threaded section 21 is adapted to be screwed with the internally threaded section 11 of the valve block 1.

The diameter of the outer cylindrical section 22 is smaller than the diameter of the outer threaded section 21 and is equal to the diameters of the first cylindrical section 12 and the second cylindrical section 13 of the valve block 1. An inclined step 23 is formed between the external thread section 21 and the external cylinder section 22 towards the axial second side.

The valve sleeve 2 has formed therein an inner bore extending from the end wall toward and opening at the axial second end, the inner bore being defined by a cylindrical inner wall 24. In the middle of the cylindrical inner wall 24 a recess 25 is formed which is recessed in the material towards the valve sleeve 2 in a radially outward direction with respect to the cylindrical inner wall 24.

One or more valve sleeve radial through holes 26 extend between the groove 25 and the outer cylindrical section 22. Further, one or more oil holes 27 in the form of inclined holes extend between the upper portion of the cylindrical inner wall 24 and the inclined stepped surface 23.

The compensating spool 3 has a cylindrical body section 31. The diameter of the outer periphery of the body section 31 is equal to the diameter of the cylindrical inner wall 24 of the valve sleeve 2.

The compensation spool 3 has a through hole formed therein to pass through in the axial direction. From the first side to the second side in the axial direction of the compensating spool 3, the through-hole is defined by the following wall sections: a first wall section 32, a second wall section 33, a third wall section 34, a fourth wall section 35, and a fifth wall section 36. The first wall section 32 has a smaller diameter than the second wall section 33. The third wall section 34 has a smaller diameter than the second wall section 33. The fourth wall section 35 has a smaller diameter than the third wall section 34. The fifth wall section 36 has a smaller diameter than the fourth wall section 35, and a tapered surface section 37 facing the first axial side is formed between the fourth wall section 35 and the fifth wall section 36.

A valve portion 38 protruding radially outward is formed at the axial second side end portion of the compensator spool 3. The axial second side of the valve portion 38 forms a conical surface 38a, which conical surface 38a is adapted to cooperate with the conical surface section 16 of the valve block 1.

A circular truncated cone 39 protruding radially outwards with respect to the body section 31 is formed between the valve portion 38 and the body section 31. The diameter of the outer periphery of the circular table 39 is equal to the diameter of the third cylindrical section 14 of the valve block 1.

The land 39 is spaced from the valve portion 38 by an annular recess 38 b. One or more axially extending grooves 39a are formed in the outer periphery of the boss 39. The lower end of the groove 39a communicates with the annular recess 38b, and the upper end is closed by the material of the circular truncated cone 39.

Further, one or more first radial through holes 33a and one or more second radial through holes 33b are formed in the compensating spool 3. The first radial through hole 33a and the second radial through hole 33b open from the second wall section 33 to the outer periphery of the body section 31. The second radial through hole 33b is located on the second axial side with respect to the first radial through hole 33 a.

The plug 4 includes a disk portion 41 in the axial middle, a cylinder 42 extending from the disk portion 41 toward the axial first side, and a mounting portion 43 extending from the disk portion toward the axial second side. The cylinder 42 is adapted to be inserted into the axial second end of the push spring 5. The diameter of the mounting portion 43 is equal to the diameter of the first wall section 32 of the compensator spool 3, and the mounting portion 43 is sealingly fixed in the first wall section 32 by means such as screwing, welding, or the like.

The throttle 6 includes a large diameter portion 51 and a small diameter portion 52 extending from the large diameter portion 51 toward the axial second side. The large diameter portion 51 has a groove 53 formed therein. The axial first end of the groove 53 faces away toward the axial first side end of the large diameter portion 51. The axial second end of the groove 53 is connected to an axial throttle passage 54 extending from the large diameter portion 51 into the small diameter portion 52. The axial throttle passage 54 is also connected to one or more radial throttle passages 55 formed in the small diameter portion 52.

The diameter of the large diameter portion 51 is equal to the diameter of the third wall section 34 of the compensator spool 3, and the large diameter portion 51 is sealingly fixed in the third wall section 34 by means such as screwing, welding, or the like. The check valve ball 7 is arranged in the compensation valve core 3 and cooperates with the conical surface section 37 to form a check valve. The small diameter portion 52 axially faces the check valve ball 7 in the compensator spool 3.

The logic selector valve 8 includes a selector valve housing 81. The selector valve housing 81 defines a cavity therein in which the selector valve ball 82 is disposed. The selector valve housing 81 has a first oil inlet 83, a second oil inlet 84, and an oil outlet 85 formed therein, which open to the outside from the cavity. Based on the magnitude of the oil pressure of the first oil inlet 83 and the second oil inlet 84, the selector valve ball 82 moves in the cavity to block one of the first oil inlet 83 and the second oil inlet 84, leaving the other oil inlet in communication with the oil outlet 85. The logic selector valve 8 is essentially a shuttle valve.

The selector valve housing 81 is fixedly mounted in the selector valve chamber 19 of the valve block 1 such that the first oil inlet 83 communicates with the selector valve chamber 19, the second oil inlet 84 communicates with the second oil passage 19b, and the oil outlet 85 communicates with the first oil passage 19 a.

In the assembled state of the pressure compensation valve, the axial first end of the compensation valve core 3 is fixed with a plug 4, and the compensation valve core 3 is internally provided with a throttling element 6 and a check valve ball 7. The compensating spool 3 is inserted into the valve housing 2 from an axial second end of the valve housing 2. The assembly of the compensating spool 3 and the valve sleeve 2 is inserted into the through-hole of the valve block 1 from the axial first side end face of the valve block 1. The axial second end of the push spring 5 is sleeved on the cylinder 42 of the plug 4, and the axial first end of the push spring 5 is pushed against the end wall of the valve sleeve 2. The cylindrical body section 31 of the compensating spool 3 is inserted into the cylindrical inner wall 24 from the axial second end of the valve sleeve 2 such that the cylindrical body section 31 is axially movable in the valve sleeve 2. Under the axial thrust of the pushing spring 5, the conical surface 38a of the compensating valve core 3 pushes against the conical surface section 16 of the valve block 1 to form a switching valve.

In the closed position of the on-off valve (i.e. the position shown in fig. 1), the first radial through hole 33a of the compensating spool 3 faces the recess 25 in the valve body 2 so as to communicate with the recess 25, and the second radial through hole 33 faces the cylindrical inner wall 24 of the valve housing 2 so as to be closed by the cylindrical inner wall 24. The fourth cylindrical section 17 defines an oil inlet chamber R1. The oil inlet cavity R1 is used for being connected with an output pipeline of a main pump of the hydraulic system.

A switching oil chamber R2 is formed on the first side in the axial direction with respect to the oil inlet chamber R1. The switching oil chamber R2 is defined by the valve portion 38 of the compensating spool 3, which is radially facing the recess portion 15, the land 39, and the corresponding portions of the annular recess 38 b.

The first groove segment 11a forms an intermediate oil chamber R3 with the outer cylindrical segment 22 and the ramp surface 23 of the valve sleeve 2. An LS oil chamber R4 is formed between the second groove section 12a and the outer cylindrical section 22 of the valve sleeve 2. The LS oil chamber R4 is connected to the LS line of the hydraulic system via a LS channel 12 b. The pressure in the LS oil chamber R4 is LS pressure.

Furthermore, in the valve body 2, a valve sleeve oil chamber R5 is defined between an end wall of the valve sleeve 2 and a first side end surface of the compensating spool 3. The intermediate oil chamber R3 communicates with the valve sleeve oil chamber R5 through the oil hole 27 in the valve sleeve 2.

Furthermore, the outlet channel 18 in the valve block 1 defines an outlet chamber R6, which outlet chamber R6 is adapted to be connected with an inlet of a flow control valve of a hydraulic circuit in which the pressure compensating valve is located. The outlet of the flow control valve is connected to the hydraulic actuator. The pressure in the oil outlet chamber R6 serves as the load pressure in the hydraulic circuit.

Furthermore, a spool oil chamber R7 is defined by the second wall section 33 in the compensation spool 3. In the open-close valve closing position shown in fig. 1, the spool oil chamber R7 communicates with the LS oil chamber R4 through the first radial through hole 33a, the groove 25, the valve housing radial through hole 26. At this time, the second radial through hole 33b is closed by the valve housing 2. When the pressure of the oil inlet chamber R1 is higher than the pressure of the switching oil chamber R2 to a certain extent, and the switching valve is opened, the first radial through hole 33a can leave the groove 25 and be closed by the valve sleeve 2, the second radial through hole 33b reaches a position communicated with the groove 25, and the valve core oil chamber R7 is communicated with the LS oil chamber R4 through the second radial through hole 33b, the groove 25 and the valve sleeve radial through hole 26. When the pressure of the oil inlet cavity R1 is higher than the pressure of the valve core oil cavity R7, the pressure of the oil inlet cavity R1 pushes away the check valve ball 7, so that the oil inlet cavity R1 can be communicated with the valve core oil cavity R7 through the axial through hole defined by the fifth wall section 36 in the compensation valve core 3, the radial throttling channel 55 and the axial throttling channel 54 in the throttling piece 6. The check valve ball 7 can prevent the hydraulic oil from flowing backward from the spool oil chamber R7 to the oil intake chamber R1. The middle oil cavity R3, the LS oil cavity R4 and the oil outlet cavity R6 are respectively communicated with an oil outlet 85, a second oil inlet 84 and a first oil inlet 83 of the logic selection valve 8 through a first oil way 19a, a second oil way 19b and the selection valve cavity 19 in the valve block 1. The first oil passage 19a, the intermediate oil chamber R3, and the oil hole 27 form a selector valve oil outlet passage. The axial through hole, the first radial through hole 33a or the second radial through hole 33b, the groove 25 and the valve sleeve radial through hole 26 in the compensation valve core 3 form a unidirectional channel which is communicated unidirectionally between the oil inlet cavity R1 and the LS oil cavity R4.

The area of the compensating spool 3 (including the plug 4) receiving the pressure of the oil inlet chamber R1 in the axial direction is substantially equal to the area of the compensating spool receiving the pressure of the valve housing chamber R5. The function of the pressure compensating valve is described below.

When the hydraulic system is not in operation, the main pump does not output pressure, the pressure compensating valve is in a closed state under the action of the pushing spring 5, and the oil inlet cavity R1 and the oil outlet cavity R6 are cut off through a switching valve formed between the conical surface 38a and the conical surface section 16.

When the hydraulic system works, the main pump outputs pressure, when the axial force generated by the pressure of the oil inlet cavity R1 received by the compensation valve core 3 overcomes the thrust of the pushing spring 5 and the axial force generated by the pressure of the valve sleeve oil cavity R5, the compensation valve core 3 moves towards the axial first side, the conical surface 38a leaves the conical surface section 16 to enable the oil inlet cavity R1 to be communicated with the oil outlet cavity R2, the round table 39 leaves the third cylindrical section 14 to enable the oil outlet cavity R2 to be communicated with the oil outlet cavity R6 through the groove 39a, namely, the switching valve is opened, so that communication is established between the oil inlet cavity R1 and the oil outlet cavity R6, and hydraulic oil output by the main pump can flow to the flow control valve through the pressure compensation valve. The decompression of the oil outlet chamber R6 with respect to the oil inlet chamber R1 is related to the opening degree of the on-off valve. Meanwhile, the hydraulic oil in the oil inlet cavity R1 also enters the valve core oil cavity R7 through a one-way valve formed by the one-way valve ball 7 and the throttling piece 6.

At this time, the second radial through hole 33b reaches a position communicating with the groove 25 in the valve body 2, the spool oil chamber R7 communicates with the LS oil chamber R4 through the second radial through hole 33b, the groove 25, the valve housing radial through hole 26, the LS oil chamber R4 communicates with the second oil inlet 84 of the logic selector valve 8 through the second oil passage 19b, and the oil outlet chamber R6 communicates with the first oil inlet 83 of the logic selector valve 8 through the selector valve chamber 19. Since the LS pressure in the LS line of the hydraulic system is the highest load pressure from the actuator, the LS pressure is transmitted via LS channel 12b into LS oil chamber R4.

The logic selector valve 8 supplies the higher of the LS pressure in the LS oil chamber R4 and the load pressure in the oil outlet chamber R6 as the selected pressure to the intermediate oil chamber R3 through the first oil passage 19a, and the intermediate oil chamber R3 in turn supplies the selected pressure to the valve housing oil chamber R5 through the oil hole 27. The valve position of the pressure compensating valve is thus dependent on the two-sided control oil pressure, wherein one-sided control oil pressure is the highest load pressure of the system and the other-sided control oil pressure is the inlet pressure, i.e. substantially equal to the main pump output pressure.

According to the integrated pressure compensation valve, at least a logic selection function (anti-backflow and decompression functions can also be integrated) is integrated, the liquid path structure is simplified, and the occupied space is reduced. In addition, since the logic selector valve function is integrated in the pressure compensating valve, there is no need to additionally precisely select its setting position.

Although the present application is described herein with reference to specific embodiments, the scope of the application is not intended to be limited to the details shown. Various modifications may be made to these details without departing from the underlying principles of the present application.

Claims

1. An integrated pressure compensating valve, comprising:

the valve block (1) is internally provided with an oil inlet cavity (R1), an oil outlet cavity (R6) and an LS channel (12 b);

a valve housing (2) fixedly mounted in the valve block (1); and

a compensating spool (3) disposed within the valve block (1) and axially movably inserted into the valve housing (2) to define a valve housing oil chamber (R5) within the valve housing (2) axially facing the first end of the compensating spool (3), the compensating spool (3) and the valve block (1) forming a switching valve therebetween between the oil inlet chamber (R1) and the oil outlet chamber (R6), a second end of the compensating spool (3) axially facing the oil inlet chamber (R1);

the integrated pressure compensation valve is characterized by further comprising:

the logic selection valve (8) is arranged in the valve block (1), the logic selection valve (8) is provided with a first oil inlet (83), a second oil inlet (84) and an oil outlet (85), the first oil inlet (83) is communicated with the oil outlet cavity (R6), the second oil inlet (84) is communicated with the LS channel (12 b), the oil outlet (85) is communicated with the valve sleeve oil cavity (R5), and the logic selection valve (8) is provided with a structure for establishing communication between one of the first oil inlet (83) and the second oil inlet (84) and the oil outlet (85) based on the pressure in the first oil inlet (83) and the second oil inlet (84).

2. An integrated pressure compensating valve according to claim 1, characterized in that the logic selection valve (8) comprises:

-a selector valve housing (81) defining said first oil inlet (83), second oil inlet (84) and oil outlet (85); and

a selector valve ball (82) movable in a selector valve housing (81) between the first oil inlet (83) and the second oil inlet (84).

3. An integrated pressure compensating valve according to claim 1, characterized in that a selection valve chamber (19) is formed in the valve block (1), said logic selection valve (8) being arranged in the selection valve chamber (19) and being positioned in such a way that the first oil inlet (83) communicates with the oil outlet chamber (R6).

4. An integrated pressure compensating valve as claimed in claim 3, characterized in that the oil outlet (85) communicates with the valve pocket oil pocket (R5) through a first oil passage (19 a) formed in the valve block (1), an intermediate oil pocket (R3) formed between the valve block (1) and the valve pocket (2) and connected to the first oil passage (19 a), and an oil hole (27) formed in the valve pocket (2) and connected to the intermediate oil pocket (R3) and the valve pocket oil pocket (R5).

5. An integrated pressure compensating valve as claimed in claim 3, characterized in that the second oil inlet (84) communicates with the LS channel (12 b) via a second oil channel (19 b) formed in the valve block (1), an LS oil chamber (R4) formed between the valve block (1) and the valve sleeve (2) and connected to the second oil channel (19 b).

6. The integrated pressure compensating valve according to claim 5, wherein said oil inlet chamber (R1) is connected to said LS oil chamber (R4) through a one-way passage provided with a one-way valve, said one-way passage comprising: -an axial through hole formed in the compensating spool (3), -a first radial through hole (33 a) and a second radial through hole (33 b) extending between said axial through hole and the outer periphery of the compensating spool (3), -a groove (25) formed on the inner wall (24) of the valve sleeve (2) and selectively facing one of the first radial through hole (33 a) and the second radial through hole (33 b), -a valve sleeve radial through hole (26) formed in the valve sleeve (2) and communicating between said groove (25) and the LS oil chamber (R4).

7. An integrated pressure compensating valve according to claim 6, characterized in that the non-return valve comprises a conical section (37) defined in the axial through-hole of the compensating spool (3) and a non-return valve ball (7) cooperating with the conical section (37).

8. An integrated pressure compensating valve according to claim 6, characterized in that a throttle element (6) is provided in the unidirectional passage, an axial throttle passage (54) and a radial throttle passage (55) connected to the axial throttle passage (54) being formed in the throttle element (6).

9. An integrated pressure compensating valve according to any of claims 1-8, characterized in that a push spring (5) is provided in the valve housing oil chamber (R5), which push spring (5) pushes against the compensating spool (3) in the direction of closing the on-off valve.

10. An integrated pressure compensating valve according to claim 9, characterized in that the end of the compensating spool (3) facing the valve housing oil chamber (R5) is provided with a plug (4), the plug (4) comprising a cylinder (42) on the first axial side and a mounting part (43) on the second axial side, the cylinder (42) being inserted into an end of the push spring (5), the mounting part (43) being sealingly fixed in the compensating spool (3).