CN111188907B

CN111188907B - Exhaust joint

Info

Publication number: CN111188907B
Application number: CN202010073559.2A
Authority: CN
Inventors: 张三喜; 汤波
Original assignee: Wuhan Marine Machinery Plant Co Ltd
Current assignee: Wuhan Marine Machinery Plant Co Ltd
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2022-08-12
Anticipated expiration: 2040-01-22
Also published as: CN111188907A

Abstract

The disclosure provides an exhaust joint, and belongs to the technical field of hydraulic pressure. The exhaust joint comprises a shell, an end cover, a first valve core, a valve core limiting assembly and a first elastic connecting piece; the middle part of the shell is provided with a communicating hole which penetrates through the connecting end of the hydraulic device of the shell and the connecting end of the end cover of the shell; the end cover is movably sleeved outside the end cover connecting end along the axial direction of the communicating hole, and a thimble inserted in the communicating hole is arranged on the end cover; the first valve core is slidably arranged in the communicating hole, the valve core limiting assembly is positioned in the communicating hole, the valve core limiting assembly is sleeved on the ejector pin, the first valve core abuts against the valve core limiting assembly under the action of the first elastic connecting piece, the communicating hole is divided into a first cavity and a second cavity which are not communicated with each other by the first valve core and the valve core limiting assembly, and the ejector pin is configured to drive the first valve core to move back to the valve core limiting assembly; the housing further includes a plurality of vents communicating the first cavity with the atmosphere. The exhaust joint can fix the exhaust direction, so that the exhaust operation is more convenient.

Description

Exhaust joint

Technical Field

The disclosure relates to the technical field of hydraulic pressure, in particular to an exhaust joint.

Background

During the field debugging process of the hydraulic system, the internal gas of the hydraulic device is often required to be removed.

At present, the exhaust joint which is more applied in the hydraulic device comprises a pipe joint bolt and an air release plug, wherein the air release plug is connected with a hole of the hydraulic device, and the pipe joint bolt is connected with the air release plug through a thread. The fit clearance between the air release plug and the pipe joint bolt is controlled by adjusting the tightness of the pipe joint bolt and the pressure of a hydraulic device for jacking the air release plug, so that the air release function is realized.

However, the discharge of the gas and gas-liquid mixture discharged through the exhaust joint cannot be directed, and the gas and liquid mixture is easily sprayed to the periphery, thereby polluting the working environment. The movement of the air release plug depends on the tightness of the pipe joint bolt and the pressure from the hydraulic device, and the existence of the pressure can dissolve gas into liquid, so that the compression ratio of the liquid is changed, and the pressure of the hydraulic device is unstable.

Disclosure of Invention

The embodiment of the disclosure provides an exhaust joint, which can fix the exhaust direction, make the exhaust operation more convenient, and simultaneously can ensure the pressure of a hydraulic device to maintain stable. The technical scheme is as follows:

the embodiment of the disclosure provides an exhaust joint for exhausting gas in a hydraulic device, which comprises a shell, an end cover, a first valve core, a valve core limiting assembly and a first elastic connecting piece;

the shell comprises a hydraulic device connecting end and an end cover connecting end, a communication hole is formed in the middle of the shell and penetrates through the hydraulic device connecting end and the end cover connecting end;

the end cover is movably sleeved outside the end cover connecting end along the axial direction of the communicating hole, a thimble is arranged on the end cover, and the thimble is inserted in the communicating hole;

the first valve core is slidably arranged in the communicating hole, the valve core limiting assembly is positioned in the communicating hole, the valve core limiting assembly is sleeved on the thimble, one end of the first elastic connecting piece is connected with the first valve core, the other end of the first elastic connecting piece is connected with the shell, the first valve core is abutted against the valve core limiting assembly under the action of the first elastic connecting piece, the communicating hole is divided into a first cavity and a second cavity which are not communicated with each other by the first valve core and the valve core limiting assembly, the thimble is positioned in the first cavity, the first cavity is a sealed cavity, the second cavity is communicated with the gas outlet of the hydraulic device, and the thimble is configured to drive the first valve core to move back to the valve core limiting assembly;

the shell further comprises a plurality of air outlet holes which are arranged along the circumferential direction of the shell at intervals, and the air outlet holes are communicated with the first cavity and the atmosphere.

Optionally, the exhaust joint further comprises a plurality of air outlet sealing pieces which are arranged in one-to-one correspondence with the air outlets, and the air outlet sealing pieces are detachably mounted in the corresponding air outlets.

Optionally, the vent hole seal is a plug screw.

Optionally, the housing includes a first housing and a second housing that are coaxially disposed, the first housing and the second housing are detachably connected, the valve element limiting assembly is disposed in the first housing, and the other end of the first elastic connecting element is fixedly connected to the second housing.

Optionally, the exhaust joint further includes a clamping block and a first sealing element, the clamping block and the first sealing element are both disposed in the through hole, the clamping block and the first sealing element are both sleeved outside the thimble, the clamping block abuts against the housing, and the first sealing element is clamped between the valve core limiting assembly and the clamping block.

Optionally, the valve element limiting assembly comprises a second valve element, a second elastic connecting piece, a pressing plate and a clamping ring, and the second elastic connecting piece, the pressing plate and the clamping ring are all sleeved outside the thimble;

the second valve core is provided with a through hole for the thimble to pass through, the clamping ring is clamped in the through hole, the clamping ring is positioned between the second valve core and the pressing plate, one end of the second elastic connecting piece is connected with the second valve core, and the other end of the second elastic connecting piece is connected with the pressing plate.

Optionally, a chamfer is provided on an inner wall of the first sealing element close to the thimble.

Optionally, the exhaust fitting further comprises a shim plate configured such that the ejector pin is in a first position within the communication hole when the shim plate is positioned between the housing and the end cap.

Optionally, the exhaust joint further comprises a backing plate connecting piece, one end of the backing plate connecting piece is connected with the end cover, and the other end of the backing plate connecting piece is connected with the backing plate.

Optionally, the exhaust fitting further comprises a plurality of seals disposed between the poppet stop assembly and the sidewall of the communication bore, between the poppet stop assembly and the first poppet, between the end cap and the housing, and between the housing and the hydraulic device.

The technical scheme provided by the embodiment of the disclosure has the following beneficial effects:

through setting up an exhaust joint, when hydraulic means need not exhaust, first case offsets with the spacing subassembly of case under the effect of first elastic connection spare, and first case and the spacing subassembly of case divide into first cavity and the second cavity that communicates each other in with the communicating hole. The first cavity is a sealed cavity, and the second cavity is communicated with an air outlet of the hydraulic device. And a plurality of air outlets on the shell are communicated with the first cavity and the atmosphere, so that the gas exhausted from the hydraulic device cannot enter the first cavity and is exhausted from the air outlets after entering the second cavity, and the gas leakage in the hydraulic device can be prevented. When the hydraulic device needs to exhaust, the end cover can be moved, so that the ejector pin drives the first valve core to move back to the valve core limiting assembly, and the first valve core is separated from the valve core limiting assembly. At the moment, the first cavity is communicated with the second cavity, and exhausted gas in the hydraulic device can enter the first cavity after entering the second cavity and is discharged from the plurality of air outlets in a directional mode. Therefore, the exhaust joint can fix the exhaust direction, so that the exhaust operation is more convenient. Meanwhile, the size of the gap between the first valve core and the valve core limiting assembly is adjusted by manually adjusting the position of the end cover by an operator, and is irrelevant to the pressure of a hydraulic system, so that the pressure of the hydraulic device can be maintained stably.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a cross-sectional view of an exhaust fitting provided in accordance with an embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of an exhaust fitting provided in accordance with an embodiment of the present invention;

fig. 3 is a sectional view a-a of fig. 1.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

The disclosed embodiments provide an exhaust fitting for exhausting gas in a hydraulic device.

Fig. 1 is a cross-sectional view of a vent fitting provided by an embodiment of the present disclosure, as shown in fig. 1, including a housing 10, an end cap 20, a first valve spool 30, a valve spool limiting assembly 40, and a first resilient coupling 50.

The housing 10 includes a hydraulic device connection end 10a and an end cap connection end 10b, a communication hole 10c is formed in the middle of the housing 10, and the communication hole 10c penetrates through the hydraulic device connection end 10a and the end cap connection end 10 b.

The end cap 20 is movably sleeved outside the end cap connecting end 10b along the axial direction of the communicating hole 10c, the end cap 20 is provided with a thimble 21, and the thimble 21 is inserted in the communicating hole 10 c.

The first valve core 30 is slidably disposed in the communication hole 10c, the valve core limiting assembly 40 is disposed in the communication hole 10c, and the valve core limiting assembly 40 is sleeved on the thimble 21. One end of the first elastic coupling 50 is connected to the first valve spool 30, and the other end of the first elastic coupling 50 is connected to the housing 10. The first valve core 30 abuts against the valve core limiting assembly 40 under the action of the first elastic connecting piece 50, and the communicating hole 10c is divided into a first cavity S1 and a second cavity S2 by the first valve core 30 and the valve core limiting assembly 40, wherein the first cavity S1 and the second cavity S2 are not communicated with each other. The thimble 21 is located in the first cavity S1, the first cavity S1 is a sealed cavity, and the second cavity S2 is communicated with an air outlet of the hydraulic device. The needle 21 is configured to drive the first spool 30 to move away from the spool stop assembly 40.

The housing 10 further includes a plurality of air outlet holes 10d arranged at intervals in the circumferential direction of the housing 10, the air outlet holes 10d communicating the first cavity S1 with the atmosphere.

According to the exhaust joint, when the hydraulic device does not need to exhaust, the first valve core abuts against the valve core limiting assembly under the action of the first elastic connecting piece, and the communicating hole is divided into the first cavity and the second cavity which are not communicated with each other by the first valve core and the valve core limiting assembly. The first cavity is a sealed cavity, and the second cavity is communicated with an air outlet of the hydraulic device. And a plurality of air outlets on the shell are communicated with the first cavity and the atmosphere, so that the gas exhausted from the hydraulic device cannot enter the first cavity and is exhausted from the air outlets after entering the second cavity, and the gas leakage in the hydraulic device can be prevented. When the hydraulic device needs to exhaust, the end cover can be moved, so that the ejector pin drives the first valve core to move back to the valve core limiting assembly, and the first valve core is separated from the valve core limiting assembly. At the moment, the first cavity is communicated with the second cavity, and exhausted gas in the hydraulic device can enter the first cavity after entering the second cavity and is discharged from the plurality of air outlets in a directional mode. Therefore, the exhaust joint can fix the exhaust direction, so that the exhaust operation is more convenient. Meanwhile, the size of the gap between the first valve core and the valve core limiting assembly is adjusted by manually adjusting the position of the end cover by an operator, and is irrelevant to the pressure of a hydraulic system, so that the pressure of the hydraulic device can be maintained stably.

It should be noted that the hydraulic device discharges gas or gas with oil entrained therein.

In this embodiment, the hydraulic device connecting end 10a is provided with an external thread matching with the air outlet of the hydraulic device, and the housing 10 is connected with the hydraulic device through the thread.

Alternatively, the first elastic coupling 50 may be a spring.

In the present embodiment, as shown in fig. 1, when the exhaust joint does not require exhaust, the thimble 21 is in the first position, i.e. the thimble 21 is located in the first cavity S1 and is not in contact with the first valve element 30. The first resilient connector 50 is in a compressed state.

Fig. 2 is a cross-sectional view of another exhaust joint provided in the embodiment of the present disclosure, as shown in fig. 2, when the exhaust joint needs to exhaust, the thimble 21 is in a second position, that is, the thimble 21 abuts against the first valve core 30. At which time the first resilient coupling 50 is further compressed. When the thimble 21 moves from the second position shown in FIG. 2 to the first position shown in FIG. 1, the first elastic connector 50 is extended.

In the present embodiment, the end cap connection end 10b is screwed to the end cap 20 to achieve axial movement of the end cap 20 along the communication hole 10 c.

The thimble 21 is brought to the second position shown in figure 2 by tightening the end cap 20. The spike 21 is brought into the first position shown in fig. 1 by unscrewing the end cap 20.

Fig. 3 is a sectional view taken along line a-a of fig. 1, and as shown in fig. 3, in the present embodiment, the housing 10 includes four air outlet holes 10d arranged at intervals in the circumferential direction of the housing 10. The four air outlets 10d are arranged at intervals of 90 degrees in pairs. By providing four air outlet holes 10d, the air discharged from the hydraulic device can be discharged directionally from four directions.

Optionally, the exhaust joint further includes a plurality of outlet hole sealing members 60 disposed in one-to-one correspondence with the plurality of outlet holes 10d, and the outlet hole sealing members 60 are detachably mounted in the corresponding outlet holes 10 d. By providing the vent seal 60, a further sealing function can be achieved.

And when the exhaust joint needs to exhaust, the air outlet sealing element 60 can be taken out from the corresponding air outlet 10d, and the gas carrying with the oil can be sprayed out from the corresponding direction, so that the exhaust direction can be selected manually, and the exhaust operation is more convenient.

Optionally, the vent seal 60 is a plug screw. The inner wall of the air outlet hole 10d is provided with internal threads, and the screw plug is in threaded connection with the shell 10 so as to be convenient to assemble and disassemble.

Alternatively, the housing 10 includes a first housing 11 and a second housing 12 coaxially disposed, and the first housing 11 and the second housing 12 are detachably connected. The valve core limiting assembly 40 is arranged in the first housing 11, and the other end of the first elastic connecting piece 50 is fixedly connected with the second housing 12.

By providing the housing 10 in two parts, the installation of the exhaust fitting may be facilitated.

For example, the valve core limiting assembly 40 may be first installed in the first housing 11, and the other end of the first elastic connection element 50 is fixedly connected to the second housing 12, and then the first housing 11 and the second housing 12 are connected, so that the first valve core 30 abuts against the valve core limiting assembly 40.

In the present embodiment, the first housing 11 and the second housing 12 are screwed together.

Optionally, the exhaust joint further includes a fixture block 70 and a first sealing element 80, the fixture block 70 and the first sealing element 80 are both disposed in the communication hole 10c, the fixture block 70 and the first sealing element 80 are both sleeved outside the thimble 21, the fixture block 70 abuts against the housing 10, a surface of the fixture block 70 contacting the housing 10 is tapered, and the first sealing element 80 is sandwiched between the valve core limiting assembly 40 and the fixture block 70.

Since the contact surface between the latch 70 and the housing 10 is tapered, the coaxiality between the latch 70 and the housing 10 can be higher, and the sealing performance between the latch 70 and the housing 10 is better. The first seal 80 is provided to prevent gas from flowing out between the housing 10 and the spike 21.

Optionally, the inner wall of the first sealing element 80 close to the thimble 21 is provided with a chamfer. When the pressure applied to the first sealing element 80 is higher, the first sealing element 80 can tightly hold the thimble 21, and the sealing effect of the first sealing element 80 is better.

In one implementation of the present disclosure, the spool limit assembly 40 includes a second spool 41, a second resilient coupling 42, a pressure plate 43, and a snap ring 44. The second elastic connecting piece 42, the pressing plate 43 and the snap ring 44 are all sleeved outside the thimble 21.

The second valve core 41 is provided with a through hole 41a for passing the thimble 21 therethrough, and the retainer ring 44 is engaged with the communication hole 10c, and the retainer ring 44 is positioned between the second valve core 41 and the pressure plate 43. One end of the second elastic connection member 42 is connected to the second spool 41, and the other end of the second elastic connection member 42 is connected to the pressure plate 43. The second spool 41 can be made slidable in the communication hole 10c by providing the second elastic coupling member 42.

In this embodiment, the second elastic connection 42 is a spring. The first seal 80 is interposed between the pressure plate 43 and the latch 70, and the second valve body 41 abuts against the first valve body 30.

If gas leaks from the hydraulic device, the leaked gas flows from the hydraulic device connection end 10a to the communication hole 10c, and the gas cannot flow to the first chamber S1 due to the seal between the first valve element 30 and the second valve element 41, so that the leaked gas pushes the first valve element 30 and the second valve element 41 to move toward the head connection end 10 b. At this time, the second elastic coupling member 42 is compressed, and the second elastic coupling member 42 pushes the pressing plate 43 to move toward the end cap connection end 10b, thereby compressing the first sealing member 80. The first sealing element 80 is subjected to a larger pressure, which can further improve the sealing effect of the first sealing element 80 and prevent the gas from flowing out from between the housing 10 and the thimble 21.

In another implementation of the present disclosure, the spool restriction assembly 40 may include only the second spool 41, and the second spool 41 is fixedly disposed on a sidewall of the communication hole 10c to function to restrict movement of the first spool 30.

Optionally, the exhaust joint further includes a shim plate 90, the shim plate 90 being configured such that the ejector pin 21 is in the first position (shown in fig. 1) within the communication hole 10 when the shim plate 90 is positioned between the housing 10 and the end cap 20. At this time, the length of the thimble is not enough, and the first valve core 30 cannot be jacked open.

When the thimble 21 is required to be located at the second position, the end cap 20 may be removed, the pad 90 may be removed from the end cap connecting end 10b of the housing 10, and the end cap 20 may be screwed down, so that the thimble 21 is located at the second position as shown in fig. 2.

Optionally, the exhaust joint further comprises a pad connector 91, one end of the pad connector 91 is connected to the end cap 20, and the other end of the pad connector 91 is connected to the pad 90. By providing the tie plate connector 91, the tie plate 90 can be prevented from falling off easily after being taken out.

In this embodiment, the tie plate connector 91 may be an iron chain to ensure the service life of the tie plate connector 91. Alternatively, the mat attachment 91 may be a spring string to facilitate stretching for use while also reducing weight.

Optionally, the exhaust joint further includes a plurality of sealing members disposed between the spool limit assembly 40 and the sidewall of the communication hole 10c, between the spool limit assembly 40 and the first spool 30, between the head cover 20 and the housing 10, and between the housing 10 and the hydraulic device.

Optionally, the vent fitting includes an end cap seal 101 disposed between the end cap 20 and the housing 10 to prevent gas leakage from between the end cap 20 and the housing 10.

Alternatively, the exhaust joint includes a second seal member 102 provided between the second spool 41 in the spool restriction assembly 40 and the sidewall of the communication hole 10c to prevent gas from leaking between the second spool 41 and the sidewall of the communication hole 10 c.

Optionally, the vent fitting includes a third seal 103 disposed between the second spool 41 and the first spool 30 in the spool stop assembly 40 to prevent gas from leaking between the second spool 41 and the first spool 30.

Optionally, the exhaust fitting includes a fourth seal 104 disposed between the housing 10 and the hydraulic device to prevent gas from leaking between the housing 10 and the hydraulic device.

Optionally, the exhaust joint may further include a fifth seal 105 disposed between the first housing 11 and the second housing 12 to prevent gas from leaking between the first housing 11 and the second housing 12.

In this embodiment, each seal is an annular seal ring.

The following brief description discloses a method for installing and using an exhaust joint, which is provided by the present disclosure:

1. one end of the first elastic coupling 50 is coupled to the first valve spool 30, and the other end of the first elastic coupling 50 is coupled to the second housing 12.

2. The end cap 20 is fitted over the end cap connection end 10b of the first housing 11, so that the thimble 21 is located in the communication hole 10 c.

3. The fixture block 70, the first sealing element 80, the pressure plate 43, the snap ring 44, the second elastic connecting piece 42 and the second valve core 41 are sequentially arranged in the communication hole 10c and sleeved outside the thimble 21;

4. screwing the first housing 11 and the second housing 12;

5. and connecting the hydraulic device connecting end 10a on the second shell 12 with the air outlet of the hydraulic device through threads to complete the installation of the exhaust joint.

The above description is intended to be exemplary only and not to limit the present disclosure, and any modification, equivalent replacement, or improvement made without departing from the spirit and scope of the present disclosure is to be considered as the same as the present disclosure.

Claims

1. An exhaust fitting for exhausting gas from a hydraulic device, the exhaust fitting comprising a housing (10), an end cap (20), a first valve element (30), a valve element retainer assembly (40), and a first resilient connector (50);

the shell (10) comprises a hydraulic device connecting end (10a) and an end cover connecting end (10b), a communication hole (10c) is formed in the middle of the shell (10), and the communication hole (10c) penetrates through the hydraulic device connecting end (10a) and the end cover connecting end (10 b);

the end cover (20) is movably sleeved outside the end cover connecting end (10b) along the axial direction of the communicating hole (10c), a thimble (21) is arranged on the end cover (20), and the thimble (21) is inserted in the communicating hole (10 c);

the first valve core (30) is slidably arranged in the communicating hole (10c), the valve core limiting component (40) is positioned in the communicating hole (10c), the valve core limiting component (40) is sleeved on the thimble (21), one end of the first elastic connecting piece (50) is connected with the first valve core (30), the other end of the first elastic connecting piece (50) is connected with the shell (10), the first valve core (30) is abutted against the valve core limiting component (40) under the action of the first elastic connecting piece (50), the communicating hole (10c) is divided into a first cavity (S1) and a second cavity (S2) by the first valve core (30) and the valve core limiting component (40), the thimble (21) is positioned in the first cavity (S1), and the first cavity (S1) is a sealed cavity, the second cavity (S2) is communicated with an air outlet of the hydraulic device, and the thimble (21) is configured to drive the first valve core (30) to move back to the valve core limiting assembly (40);

the shell (10) further comprises a plurality of air outlet holes (10d) arranged at intervals along the circumferential direction of the shell (10), and the air outlet holes (10d) are communicated with the first cavity (S1) and the atmosphere;

the shell (10) comprises a first shell (11) and a second shell (12) which are coaxially arranged, the first shell (11) and the second shell (12) are detachably connected, the valve core limiting assembly (40) is arranged in the first shell (11), and the other end of the first elastic connecting piece (50) is fixedly connected with the second shell (12);

the exhaust joint further comprises a fixture block (70) and a first sealing element (80), the fixture block (70) and the first sealing element (80) are arranged in the communicating hole (10c), the fixture block (70) and the first sealing element (80) are sleeved outside the thimble (21), the fixture block (70) abuts against the shell (10), one surface, in contact with the shell (10), of the fixture block (70) is conical, the first sealing element (80) is clamped between the valve core limiting assembly (40) and the fixture block (70), the valve core limiting assembly (40) comprises a second valve core (41), a second elastic connecting element (42), a pressure plate (43) and a clamping ring (44), and the second elastic connecting element (42), the pressure plate (43) and the clamping ring (44) are sleeved outside the thimble (21); a through hole (41a) for the thimble (21) to pass through is formed in the second valve core (41), the snap ring (44) is clamped in the communicating hole (10c), the snap ring (44) is positioned between the second valve core (41) and the pressure plate (43), one end of the second elastic connecting piece (42) is connected with the second valve core (41), the other end of the second elastic connecting piece (42) is connected with the pressure plate (43), the first sealing piece (80) is clamped between the pressure plate (43) and the snap ring (70), the second valve core (41) is abutted against the first valve core (30), the inner wall surface of the through hole (41a) of the second valve core (41) facing the first valve core (30) is a conical surface, and the outer wall surface of the first valve core (30) facing one end of the second valve core (41) is a conical surface, the maximum diameter of the second spool (41) is not less than the maximum diameter of the first spool (30);

a chamfer is arranged on the inner wall, close to the thimble (21), of the first sealing element (80);

the exhaust joint further includes a shim plate (90), and the shim plate (90) is configured such that the ejector pin (21) is in a first position in the communication hole (10) when the shim plate (90) is positioned between the housing (10) and the end cap (20).

2. The exhaust fitting of claim 1 further comprising a plurality of outlet seals (60) disposed in one-to-one correspondence with said plurality of outlets (10d), said outlet seals (60) being removably mounted in corresponding said outlets (10 d).

3. The exhaust fitting of claim 2, wherein said vent seal (60) is a plug screw.

4. The exhaust fitting of claim 1 further comprising a shim plate connector (91), one end of the shim plate connector (91) being connected to the end cap (20) and the other end of the shim plate connector (91) being connected to the shim plate (90).

5. The exhaust fitting according to any one of claims 1 to 3, further comprising a plurality of sealing members disposed between the valve element retainer assembly (40) and a side wall of the communication hole (10c), between the valve element retainer assembly (40) and the first valve element (30), between the end cap (20) and the housing (10), and between the housing (10) and the hydraulic device.