KR101314821B1 - Hydraulic cylinder - Google Patents

Abstract

Hydraulic cylinders are provided. According to an exemplary embodiment of the present invention, a hydraulic cylinder includes a cylinder body having a first area into which a working fluid flows in and a piston head and a piston head reciprocally moved forward and backward with respect to the first area in the cylinder body. A piston rod assembly including a rod coupled to the piston rod assembly, the piston rod assembly comprising: a main sealing member installed at an outer circumference of the piston head; An auxiliary sealing member provided on an outer circumferential portion of the piston head so as to be adjacent to the first region rather than the main sealing member; A fluid flow path formed inside the piston head to fluidly connect the second region and the first region between the auxiliary sealing member and the main sealing member and inside the piston head to block the fluid flow path. And a plug movably installed.

Description

Hydraulic cylinder

The present invention relates to a hydraulic cylinder.

Hydraulic drives used for pitch control of wind generators are generally used for two purposes.

The first is to continuously adjust the pitch angle of the blades to limit the wind generator's power production in harsh environments such as storms. The second is to drive the blades in a wind and horizontal position to stop the machinery in the wind generator. It is to let.

Since this function must be safe, malfunction of the hydraulic pitch drive is not permitted and the mechanical device must be stopped until such a problem is solved. However, all the time the wind generator is stopped in this way is undesirable because it leads to a loss of energy.

Hydraulic drives require fast repair if the sealing member is worn and damaged. At this time, since the rod-side sealing member of the hydraulic cylinder in the hydraulic drive device can be easily replaced as compared with the piston-side sealing member, a major problem in the sealing occurs in the piston-side sealing member.

At this time, it is not easy to replace the piston side sealing member because the working fluid must be completely discharged when the operator wants to approach the piston of the hydraulic cylinder.

One embodiment of the present invention is to provide a hydraulic cylinder that can easily replace the main sealing member of the hydraulic cylinder.

One embodiment of the present invention is to provide a hydraulic cylinder that can be replaced of the main sealing member without spilling oil.

According to an aspect of the present invention, a cylinder body having a first region into which a working fluid flows in and out, and a piston head reciprocating in a forward and backward direction with respect to the first region within the cylinder body, and a rod coupled to the piston head. Including a piston rod assembly including a, wherein the piston rod assembly, the main sealing member is installed on the outer peripheral portion of the piston head; An auxiliary sealing member provided on an outer circumferential portion of the piston head so as to be adjacent to the first region rather than the main sealing member; A fluid flow path formed inside the piston head to fluidly connect the second region and the first region between the auxiliary sealing member and the main sealing member and inside the piston head to block the fluid flow path. A hydraulic cylinder is provided that includes a plug that is movably installed.

At this time, the hydraulic cylinder includes a plug guide installed inside the piston head, wherein the plug moves from the first position not blocking the fluid flow path along the plug guide to a second position that blocks the fluid flow path. It is possible.

At this time, the first region is sealed by the main sealing member in the state where the plug is located in the first position, and the first region is the auxiliary sealing member in the state where the plug is located in the second position. Can be sealed by.

In this case, a thread is formed on an outer circumferential surface of the plug, and a corresponding thread is formed on an inner circumferential surface of the plug guide, and the plug is rotated relative to the plug guide as the plug rotates relative to the plug guide. It may be movable from one position to the second position.

In this case, the plug guide may be formed at the front end of the piston, one end of which may be opened toward the first region, and the other end of which may be opened toward the fluid flow path.

At this time, a projection formed on one surface of the cylinder body facing the front end of the piston head and a receiving groove formed on the front end surface of the plug and the projection is fitted, the piston head is adjacent to the one surface The protrusion may be fit and coupled to the receiving groove in a state where it is disposed.

At this time, the plug guide may be arranged in the movement direction of the piston on the central axis of the piston.

At this time, the piston rod may be rotatably formed about the central axis.

At this time, the fluid flow path is arranged on the central axis of the cylinder, the first flow path extending from the front side of the cylinder to the rear side of the cylinder, one end is connected to the first fluid flow path and the rear of the cylinder The second flow path extending to the side and one end may be connected to the other end of the second fluid flow path, the other end may include a third flow path connected to the second region.

In this case, the plug may be formed to block between the first flow path and the second flow path.

In this case, the first flow path and the third flow path may each be formed in plural, and the plurality of first flow paths and the third flow path may be arranged in a radial direction about the central axis.

At this time, the rear end surface of the plug is formed in a wedge shape, the maximum diameter of the rear end surface of the plug may be formed larger than the diameter of the second flow path.

On the other hand, the outer peripheral portion of the piston head may further include a pair of gaskets provided in front of the auxiliary sealing member and the rear of the main sealing member.

According to an embodiment of the present invention, when the main sealing member is worn, the auxiliary sealing member may be used to maintain the sealing of the piston so that the main sealing member can be replaced without oil leakage.

In addition, when the main sealing member is worn, the auxiliary sealing member may be used to maintain the sealing of the piston, thereby extending the life of the piston.

1 is a cross-sectional view of a hydraulic cylinder according to an embodiment of the present invention.
FIG. 2 is an enlarged view of a portion A in FIG. 1.
3 is a view illustrating a state in which the hydraulic cylinder operates while the main sealing member maintains the sealing of the hydraulic cylinder.
4 is a view showing a state in which a plug installed in a piston head of a hydraulic cylinder according to an embodiment of the present invention is coupled to a protrusion inside the hydraulic cylinder.
5 is a view illustrating a state in which a plug installed in a piston head of a hydraulic cylinder according to an embodiment of the present invention closes a fluid flow path formed in the piston head.
6 is a view showing a state in which the hydraulic cylinder operates while the auxiliary sealing member maintains the sealing of the hydraulic cylinder.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

1 is a cross-sectional view of a hydraulic cylinder according to an embodiment of the present invention. FIG. 2 is an enlarged view of a portion A in FIG. 1.

1 and 2, the hydraulic cylinder 10 according to an embodiment of the present invention includes a cylinder body 20 and a piston rod assembly 30. The piston rod assembly 30 includes a piston head 32 and a rod 34. At this time, according to an embodiment of the present invention, the main sealing member 40 and the auxiliary sealing member 50 is provided on the outer peripheral portion of the piston head 32.

In the following description of the hydraulic cylinder according to an embodiment of the present invention with reference to the drawings as shown in Figure 1, the direction toward the left end of the cylinder body is defined as the front of the cylinder body, the opposite direction is defined as the rear Explain.

In more detail, referring to FIG. 1, the cylinder body 20 of the hydraulic cylinder 10 according to the exemplary embodiment of the present invention is formed in a tubular shape, and as shown in FIG. 1, the front end 21 is blocked.

The projection 22 is formed in the center on the inner side 21a of the front end 21 side of the cylinder body 20. The protrusion 22 may have an elliptical, rectangular or polygonal cross section and may be formed as an extension member protruding to the rear side.

The projection part 22 is coupled to one side of the plug 70 in the piston head 32 to be described later to allow the plug 70 to move in the piston head 32 to the hydraulic cylinder according to an embodiment of the present invention ( It is a component for making the auxiliary sealing member 50 usable when the main sealing member 40 of 10) is broken. A more detailed description of the coupling and operation of the protrusion 22 and the plug 70 will be described later.

On the other hand, inside the tubular cylinder body 20, the piston rod assembly 30 is installed to be able to move in the front and rear direction as seen in FIG. The piston rod assembly 30 includes a piston head 32 and a rod 34.

At this time, a first region 24 is formed between the piston head 32 and the front end 21 of the cylinder body 20 in which a working fluid for moving the piston head 32 is located.

The first region 24 is formed to allow the working fluid to flow into or out of the first region 24 through a working fluid inlet and a working fluid outlet, not shown. .

The piston head 32 may be formed in a cylindrical shape and includes a main sealing member 40, an auxiliary sealing member 50, and a gasket 60 at an outer circumference thereof.

1 and 2, the main sealing member 40 is formed in a ring shape, and is installed in the rear portion of the piston head 32 that is cylindrical in FIG. 1.

The auxiliary sealing member 50 is formed in a ring shape similarly to the main sealing member 40, but is installed in the front portion of the piston head 32 as shown in FIG.

The primary sealing member 40 and the secondary sealing member 50 are components for sealing the working fluid located in the first region 24.

According to an embodiment of the present invention, a second region 26 is formed in the space between the main sealing member 40 and the auxiliary sealing member 50 and between the outer circumferential surface of the piston head 32 and the inner surface of the piston body 20. do.

At this time, according to an embodiment of the present invention, the piston head 32 is configured to allow the second region 26 of the outside of the piston head 32 to be in fluid communication with the first region 24 inside the cylinder body 20. In order to achieve this, a fluid flow path 80 is formed.

1 and 2, the fluid flow path 80 includes a first flow path 82, a second flow path 84, and a third flow path 86.

The first flow path 82 is formed to extend from the front edge of the piston head 32 to the rear center portion of the piston head 32.

A plurality of first flow paths 82 may be formed in the piston head 32, and the plurality of first flow paths 82 may be arranged in a radial direction about the central axis C in the extending direction of the piston head 32. Can be.

The rear end portion of the first flow passage 82 is connected to the second flow passage 84. The second flow path 84 is arranged in the extension direction of the central axis C on the extension axis central axis of the piston head 32.

The third flow path 86 is connected to the rear end portion of the second flow path 84. The third flow path 86 extends in the direction of the second region 26 from the rear end of the second flow path 84. In this embodiment, the third flow path 86 is formed to extend in a direction perpendicular to the central axis C of the piston head 32.

In this case, the third flow path 86 may be formed in plural, and the plurality of third flow paths 86 may be arranged in a radial direction about the central axis C of the piston head 32.

Accordingly, the first region 24 inside the cylinder may be connected to the second region 26 through the first flow passage 82, the second flow passage 84, and the third flow passage 86 of the fluid flow passage 80. Can be.

At this time, according to one embodiment of the present invention, a plug 70 is provided inside the piston head 32 to selectively block the first region 24 from being in fluid communication with the second region 26. Is installed.

The plug 70 is formed to be movable in the front-rear direction on the central axis C of the piston head 32, and the plug 70 is movable in the front-rear direction on the central axis C of the piston head 32. A tubular plug guide 76 is installed inside the piston head 32 for positioning.

At this time, the plug guide 76 moves in the direction of movement of the piston head 32 on the central axis C of the piston head 32, that is, in an extension direction of the central axis C of the piston head 32. Can be arranged.

Referring to FIG. 2, the plug guide 76 is formed such that the front end is opened to the front side of the piston head 32, and the rear end is formed to protrude in the direction of the first flow path 82.

At this time, a corresponding thread 76a is formed on the inner circumferential surface of the plug guide 76, and the corresponding thread 76a is formed to be screwed with the thread 70a formed on the outer circumferential surface of the plug 70.

The plug 70 installed inside the plug guide 76 is formed in a cylindrical shape. A receiving groove 73 is formed in the center portion of the front end surface 72 of the plug 70.

The receiving groove 73 has a cross-sectional shape corresponding to the protrusion 22 so as to fit with the protrusion 22 formed on the front side of the cylinder body 20, and has a depth corresponding to the protruding length of the protrusion 22. It is formed to have.

On the other hand, the rear end surface 74 of the plug 70 is formed in a wedge shape, and is formed to protrude rearward from the rear end of the plug guide 76. The rear end face 74 of the cylindrical plug 70 has a maximum diameter larger than that of the second flow path 84.

Accordingly, according to one embodiment of the present invention, when the cylindrical plug 70 moves to the rear side, the rear end face 74 of the wedge-shaped plug 70 has a second flow path inside the piston head 32. It is formed so that the front end side of 84 may be closed. Detailed description of the operation of the plug 70 in the piston head 32 will be described later.

On the other hand, the piston rod 34 is provided on the rear side of the piston head 32 of the piston rod assembly 30. The piston rod 34 is formed to extend from the inside of the cylinder body 20 to the outside of the cylinder body 20, not shown, and when the piston head 32 moves forward and backward inside the cylinder body 20, 32) to move forward and backward together.

On the other hand, a gasket 60 is provided on the outer circumferential portion of the piston head 32 at the front side of the auxiliary sealing member 50 and the rear side of the main sealing member 40.

Hereinafter, the operation of the hydraulic cylinder according to an embodiment of the present invention will be described with reference to the drawings.

3 is a view illustrating a state in which the hydraulic cylinder operates while the main sealing member maintains the sealing of the hydraulic cylinder. 4 is a view showing a state in which a plug installed in a piston head of a hydraulic cylinder according to an embodiment of the present invention is coupled to a protrusion inside the hydraulic cylinder. 5 is a view illustrating a state in which a plug installed in a piston head of a hydraulic cylinder according to an embodiment of the present invention closes a fluid flow path formed in the piston head. 6 is a view showing a state in which the hydraulic cylinder operates while the auxiliary sealing member maintains the sealing of the hydraulic cylinder.

Referring to FIG. 3, the hydraulic cylinder 10 according to the exemplary embodiment of the present invention normally seals the first region 24 inside the cylinder by the main sealing member 40.

At this time, the plug 70 inside the piston head 32 has a front end face 72 positioned adjacent to the front end face 32a of the piston head 32, and the rear end face 74 has a first flow path. 82 is formed to protrude to the inner side.

At this time, the rear end surface 74 of the plug 70 protrudes to the inner side of the first flow path 82 but does not block the first flow path 82 and the second flow path 84. Hereinafter, the front end face 72 of the plug 70 is adjacent to the front end face 32a of the piston head 32 without the plug 70 blocking the first flow path 82 and the second flow path 84. The position to be positioned is defined as the first position.

When the hydraulic cylinder 10 is operated with the plug 70 positioned in the first position, the piston head 32 moves forward and backward while the working fluid flows into and out of the first region 24 inside the cylinder body 20. Move.

Accordingly, the piston rod assembly 30 is formed to move in the front-back direction. Such movement of the piston rod assembly 30 causes the components connected to the piston rod assembly 30 to operate.

As such, when the plug 70 is positioned at the first position, the first region 24 and the second region 26 remain in fluid communication with each other, and the piston head 32 moves forward and backward. The working fluid is also present inside the second region 26 during this time.

According to one embodiment of the invention, the main sealing member 40 is worn while the hydraulic cylinder 10 is operating in the normal operating state as described above, so that the sealing of the first region 24 inside the cylinder body 20. If this is not done completely, the secondary sealing member 50 causes the first region 24 to be sealed.

In order to seal the first region 24 using the auxiliary sealing member 50 as described above, first, the piston head 32 is moved as far as possible from the inside of the cylinder body 20 to the front side.

When the piston head 32 is moved to the front side from the inside of the cylinder body 20 as much as possible, the protrusion 22 is fitted into the receiving groove 73 formed in the front end surface 72 of the plug 70 of the piston head 32. do.

When the protrusion 34 is fitted into the receiving groove of the plug 70, as shown in FIG. 4, when the rod 34 of the piston rod assembly 30 is rotated, the piston head 32 is rotated in place.

When the piston head 32 is rotated in place, the plug 70 screwed into the plug guide 76 rotates relative to the plug guide 76, thereby allowing the plug 70 to plug into the plug guide 76. It moves to the rear side with respect to.

When the plug 70 is moved rearward with respect to the plug guide 76, the plug 70 has a rear end face 74 of the plug 70 having a first flow path 82 and a second as shown in FIG. After the movement to the second position that blocks the flow path 84, the movement is stopped.

The plug 70 closes the front end of the second flow path 84 in the state of being positioned in the second position, passing the first flow path 82 and the second flow path 84 from the first region 24 to the second. Region 26 prevents the working fluid from fluidly connecting.

In the state where the plug 70 is located in the second position, the piston rod assembly 30 is moved to the rear side to separate the protrusion 22 from the receiving groove 73 of the plug 70.

After the protrusion 22 is separated from the receiving groove 73, the hydraulic cylinder 10 is sealed in the first region 24 inside the cylinder body 20 by the auxiliary sealing member 50 as shown in FIG. 6. The piston head 32 may be moved in the cylinder body 20 while being maintained.

Accordingly, when the sealing force of the main sealing member 40 is weakened, the auxiliary sealing member 50 is used to maintain the sealing of the first region 24 inside the cylinder body 20 of the hydraulic cylinder 10. Activate the hydraulic cylinder (10).

Then, after replacing the main sealing member 40 at the maintenance of the hydraulic cylinder 10, the main sealing member again by positioning the plug 70 inside the piston head 32 from the second position to the first position. The 40 may be used to seal the first region 24 inside the cylinder body 20.

As described above, the hydraulic cylinder according to an embodiment of the present invention is used period of the hydraulic cylinder by auxiliary sealing the working fluid receiving space inside the cylinder body by using the auxiliary sealing member when the sealing force of the main sealing member is weakened Can be increased.

In addition, when the sealing in the hydraulic cylinder is performed using the auxiliary sealing member of the hydraulic cylinder according to an embodiment of the present invention, the main sealing member may be replaced while the auxiliary sealing member seals the hydraulic cylinder. During the replacement of the main sealing member, the main sealing member can be replaced simply without discharging the working fluid from the inside of the hydraulic cylinder to the outside.

In one embodiment of the present invention has been illustrated a hydraulic cylinder for adjusting the pitch of the wind generator, the hydraulic cylinder according to the present invention can be used as a hydraulic cylinder for various other purposes, of course.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

10 hydraulic cylinders 20 cylinder bodies
22 protrusion 24 first area
26 Second Zone 30 Piston Rod Assembly
32 piston head 34 rod
40 Primary sealing member 50 Secondary sealing member
60 gasket 70 plug
76 Plug guide 80 Fluid flow path
82 1st Euro 84 2nd Euro
86 3rd Euro

Claims (13)

A cylinder body having a first region into which the working fluid can flow in and out;
A piston rod assembly including a piston head reciprocally movable in the front and rear direction with respect to the first region within the cylinder body and a rod coupled to the piston head,
The piston rod assembly,
A main sealing member installed at an outer circumference of the piston head;
An auxiliary sealing member provided on an outer circumferential portion of the piston head so as to be adjacent to the first region rather than the main sealing member;
A fluid flow path formed inside the piston head to fluidly connect the second region and the first region between the auxiliary sealing member and the main sealing member;
A plug movably installed inside the piston head to block the fluid flow path
Hydraulic cylinder comprising a.
The method of claim 1,
Including a plug guide installed inside the piston head,
And the plug is movable along the plug guide from a first position that does not block the fluid flow path to a second position that blocks the fluid flow path.
3. The method of claim 2,
In the state where the plug is located in the first position, the first region is sealed by the main sealing member,
And the first region is sealed by the auxiliary sealing member when the plug is located in the second position.
The method of claim 3, wherein
A thread is formed on the outer circumferential surface of the plug,
Corresponding threads corresponding to the outer circumferential surface of the plug are formed on the inner circumferential surface of the plug guide,
A hydraulic cylinder movable from the first position to the second position as the plug rotates relative to the plug guide.
5. The method of claim 4,
The plug guide is formed at the front end of the piston, one end is open to the side of the first region, the other end is a hydraulic cylinder is opened to the fluid flow path side.
6. The method of claim 5,
A protrusion formed on one surface of the cylinder body opposite to the front end surface of the piston head;
A receiving groove is formed at the front end of the plug and the protrusion is fitable,
The protrusion may be fitted into the receiving groove in a state where the front end surface of the piston head is disposed adjacent to the one surface, the hydraulic cylinder.
The method of claim 5, wherein
And the plug guide is arranged in the direction of movement of the piston on the central axis of the piston head.
The method of claim 7, wherein
The rod is a hydraulic cylinder is formed rotatably about the central axis.
The method of claim 8,
The fluid flow path
A first flow passage extending from the front side of the piston head to the rear side of the cylinder,
A second flow path arranged on a central axis of the piston head, one end of which is connected to the first fluid flow path and extending to the rear side of the cylinder;
And a third flow path, one end of which is connected to the other end of the second fluid flow path and the other end of which is connected to the second region.
The method of claim 9,
The plug is formed to be able to block between the first flow path and the second flow path, the hydraulic cylinder.
11. The method of claim 10,
The first flow path and the third flow path are each formed in plural, the plurality of first flow path and the third flow path is arranged in the radial direction about the central axis, the hydraulic cylinder.
The method of claim 11,
The rear end face of the plug is formed in a wedge shape,
A maximum diameter of the rear end surface of the plug is formed larger than the diameter of the second flow path.
The method of claim 1,
And a pair of gaskets installed at the outer circumferential portion of the piston head in front of the auxiliary sealing member and behind the main sealing member.

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