KR100941373B1 - Hydraulic actuator and maintenance method for use in generator equipment - Google Patents

Abstract

PURPOSE: A hydraulic actuator for a power plant and a maintenance method thereof are provided to minimize the electric power production setback of a generating station by improving the accuracy of the hydraulic actuator and reducing maintenance time. CONSTITUTION: A piston assembly comprises a piston rod, a piston, a disc and a piston nut. A cylinder assembly comprises a guide bush(124) and a backup ring(122). The guide bush is inserted into the lower part of the cylinder and a cylinder cover, passes the piston rod through the inner circumference, and comprises an oil ring, the piston rod, and the guide ring. The oil ring prevents the outflow of the oil. The backup ring is fixed by the guide bush and the fastening unit. A scraper ring and a guide ring are inserted to control the amount of the oil.

Description

Hydraulic actuator and maintenance method for power generation equipment

The present invention relates to a hydraulic actuator for a power plant and a maintenance method thereof. More particularly, the present invention relates to a hydraulic actuator for a power plant and a method of maintaining the same, which shortens the maintenance time of the hydraulic actuator, improves the accuracy of the hydraulic actuator, and improves the reliability of the hydraulic actuator that minimizes power generation disruptions of the power plant.

In general, a steam turbine installed in a nuclear power plant or a thermal power plant includes a high pressure turbine and a plurality of low pressure turbines, and steam flowing through the high pressure turbine and the low pressure turbines and the steam discharged through the turbine are installed in the turbine governor control system. Controlled by

That is, the steam pressure and the flow rate are controlled by the high pressure side turbine valves and the low pressure side turbine valves, which are essential elements of the turbine governor control system, and the rotation speed of the steam turbine is controlled by the steam control.

These turbine valves are each controlled by a hydraulic actuator.

Therefore, if there is a problem in the governor control system, especially in the hydraulic actuator, the steam pressure and flow rate will not be properly adjusted, and the power system frequency of the generator will not be kept constant. Excessive steam pressure and flow rate will act on the steam turbine. Trip of the turbine is caused.

As such, when a hydraulic actuator malfunctions, the operation of the power plant is inevitably shut down, so excessive maintenance time is required and a large disruption in power generation is required. Therefore, the hydraulic actuator is required to have high reliability.

In particular, in order to perform maintenance on the hydraulic actuators, the power plant should be shut down and the hydraulic actuators are dismantled from the turbine while the turbine temperature is lowered. The operation was performed in order to check whether the turbine valve is smoothly adjusted by the hydraulic actuator while supplying steam to the turbine.

However, such conventional hydraulic actuators fail to shut down power plants and turbines, cool down turbines, cool down hydraulic actuators, refurbish, if the hydraulic actuators do not meet the required accuracy for power plant operation or are not suitable for turbine operation. The hydraulic actuators should be tested by taking the steps of assembling and restarting the power plant in turn.

However, the maintenance work for the hydraulic actuator takes at least two days, so considering the fact that the adjustment of the hydraulic actuator is usually repeated many times, it was inevitably a big obstacle in power generation.

In particular, when servicing hydraulic actuators, there is no fixed order, so all maintenance workers who perform the maintenance work in different ways. There was a problem that the cost required for maintenance, such as to increase, and the time required for the maintenance work is also different during each maintenance, there was a difficult problem of predicting the operation of the generator.

In order to solve this problem, the present invention unifies the maintenance method of the hydraulic actuator to shorten the maintenance time, as well as to improve the accuracy of the hydraulic actuator, to minimize the power production disruption of the power plant, and to improve the reliability of the hydraulic actuator Its purpose is to.

In order to achieve the above object, the present invention is a hydraulic actuator, the space is formed inside the supply and discharge of the oil having a predetermined pressure, the top is opened and the bottom is formed through; A piston rod penetrating the cylinder vertically and reciprocating upward and downward; a piston provided on an outer circumferential surface of the piston rod and reciprocating the piston rod by hydraulic pressure; A piston assembly coupled to the piston rod and including a piston nut to secure the piston to the piston rod; A cylinder cover inserted into and installed in an upper opening of the cylinder to seal the inside of the cylinder, through which the piston rod penetrates, and an eye bolt formed on an upper surface thereof; And a piston rod is inserted into and installed in the lower part of the cylinder and the cylinder cover, respectively, and a piston rod penetrates the inner circumferential surface, and an oil ring for preventing the outflow of oil on the outer circumferential surface and a piston rod and guide ring for supporting the reciprocating motion of the piston rod. And a cylinder assembly including a guide bush which is fastened by the guide bush and a fastening means, and a scraper ring for adjusting the amount of oil on the inner circumferential surface and a backup ring into which the guide ring is inserted. do.

Further, in the present invention, a screw hole is formed on one outer circumferential surface of the piston nut, a disk inserted into the screw hole and in contact with the outer circumferential surface of the piston rod and a locking bolt fastened to the screw hole to press the disk are added. It is provided with a hydraulic actuator, characterized in that for strengthening the fastening force of the piston nut and the piston rod.

In addition, in the present invention, the piston assembly is provided with a hydraulic actuator, characterized in that the retaining ring is further provided on the upper and lower portions of the piston and is fixed to the piston by the fastening means to limit the movement of the piston. To provide.

In addition, in the present invention, a piston assembly, which is installed on the upper portion of the cylinder, the cylinder cover having an eye bolt formed on one surface, a piston and a piston rod provided inside the cylinder, the upper and lower portions of the cylinder A maintenance method of a hydraulic actuator including a cylinder assembly consisting of a guide bush and a backup ring respectively installed, the method comprising: (a) disassembling the hydraulic actuator; (b) replacing the sealing member of the disassembled hydraulic actuator; (c) checking the wear state of the inner surface of the cylinder and the contact state of the piston; (d) washing the decomposed hydraulic actuator to reduce the pollution degree, and removing various foreign substances, rust and various harmful components caused by corrosion; (e) assembling the disassembled hydraulic actuator in the reverse order of step (a); And (f) performing a hydraulic test, an operation state abnormality check, oil filling and an oil leakage state check on the assembled hydraulic actuator.

In addition, in the present invention, the step (a) may include (a1) disassembling the backup ring of the cylinder assembly and the guide ring and the scraper ring inserted into the backup ring; (a2) disassembling the guide bush, the oil ring, the piston rod seal, and the guide ring inserted into the guide bush; (a3) releasing the fastening means fastened to the cylinder cover installed on the upper portion of the cylinder; (a4) disassembling the cylinder cover and the piston assembly from the cylinder using a shackle, a crane, etc. through the eye bolts of the cylinder cover; (a5) disassembling the retaining ring and the piston nut of the piston assembly; And (a6) disassembling the piston of the piston assembly from the piston rod, providing a maintenance method of the hydraulic actuator.

In addition, in the present invention, the sealing member may include an oil ring inserted into the guide bush, a piston rod seal and a guide ring, a guide ring and a scraper ring inserted into the backup ring, and an oil ring inserted into the cylinder cover. It provides a maintenance method of a hydraulic actuator comprising a piston chamber provided in the piston.

According to the present invention, it is possible to shorten the maintenance time of the hydraulic actuator, improve the accuracy of the hydraulic actuator, it is possible to minimize the power generation disruption of the power plant.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the elements of each drawing, it should be noted that the same reference numerals are used to refer to the same elements even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is an exploded perspective view showing a hydraulic actuator according to a preferred embodiment of the present invention, Figure 2 is a cross-sectional view showing a hydraulic actuator according to a preferred embodiment of the present invention.

As shown, the hydraulic actuator of the present invention is provided with a cylinder 110, which is supplied and discharged the oil given a predetermined pressure therein, the cylinder 110 and the upper and lower, respectively, are installed on the piston rod 126 The cylinder cover (120) and the cylinder assembly (120) which support the reciprocating motion of the piston rod (126) at the same time as being fixed, are coupled to the cylinder cover (130) and the cylinder fixed to the upper portion of the cylinder (110). It is formed to surround the outer circumferential surface of the assembly 120 is configured to include a piston assembly (Piston Assembly: 140) reciprocating upward and downward depending on whether the oil is supplied and discharged into the cylinder (110).

The cylinder 110 has an opening 114 having an upper opening, and a through hole 116 through which the piston rod 126 of the cylinder assembly 120 to be described later is formed at the lower center portion. The inner diameter of the cylinder 110 is precision machining is made so that the piston 142 of the piston assembly 130 can be moved to the upper or lower side of the piston rod 126 with the piston rod 126, the cylinder 110 It is formed to maintain the airtight with the piston 142 so that oil does not flow between the inner diameter of the cylinder, that is, the inner surface of the cylinder 110 and the piston assembly 130.

The cylinder cover 130 is inserted into the upper opening 114 of the cylinder 110 and is fixed by a fastening means 150 such as a fixing bolt to seal a space formed inside the cylinder 110. The guide bush 124 of the cylinder assembly 120 is penetrated to be coupled to each other, and an eye bolt 132 is formed on an upper surface thereof so that the separation coupling is easily performed.

Here, the eye bolt (Eye Bolt 132) is a bolt having a ring on the head portion, is a fastener for use when lifting or moving a large heavy object such as a mechanical equipment mainly, such eye bolt 132 When used, using a tool such as a shackle (not shown) to connect the wire rope with the eye bolt 132 to use.

The cylinder assembly 120 is fixed to the cylinder 110 and the cylinder cover 130, and its inner circumferential surface supports the piston rod 126 to allow reciprocating movement of the piston rod 126, and the outer circumferential surface thereof is a cylinder ( The guide bush 124 fixedly inserted into the 110 and the cylinder cover 130, the guide bush 124 is fixedly coupled, and comprises a backup ring 122 for supporting the reciprocating motion of the piston rod 126.

The guide bush 124 is inserted into the cylinder cover 130 fixedly coupled to the upper opening 114 of the cylinder 110 and the lower through hole 116 of the cylinder 110, respectively, and has a piston rod 126 on the inner circumferential surface thereof. ) Is provided to pass through.

An oil ring 228 is inserted into an outer circumferential surface of the guide bush 124 to prevent oil from flowing out and to adjust the thickness of the oil film formed on the inner wall of the cylinder 110 to perform lubrication. A piston rod chamber 224 and a guide ring 222a for supporting the reciprocating motion of 126 are provided.

The backup ring 122 is located at the rear of the guide bush 124 provided at the upper and lower portions of the cylinder 110, respectively, and is inserted into the guide bush 124 to support the vertical reciprocating motion of the piston rod 126. Play a role.

The backup ring 122 is fixedly coupled by the fastening means 150 such as the guide bush 124 and the fixing bolt, the inner peripheral surface of the amount of oil flowing in the inner wall of the cylinder 110 at every stroke of the piston rod 126 The scraper ring 226 for adjusting the insertion is inserted, and the guide ring 222b for supporting the vertical reciprocating motion of the piston rod 126 is inserted.

The piston assembly 140 is provided to penetrate the cylinder 110 vertically to penetrate the upper opening 114 and the lower through hole 116 of the cylinder 110 to reciprocate upward and downward. Piston rod 126, piston 142 reciprocating by hydraulic pressure, piston nut 144 for fixing the piston 142 to the piston rod 126, retaining ring for limiting the movement of the piston 142 ( 146).

The piston 142 is configured to surround the outer circumferential surface of the piston rod 126, and is provided to be in close contact with the inner wall of the cylinder 110 to move the piston rod 126 up and down by reciprocating motion by the pressure of the supplied oil. It serves to move up or down.

The piston 142 is provided with a groove on its outer circumferential surface, so that the piston chamber which prevents the mixture gas or the soot gas from leaking between the piston 142 and the inner wall of the cylinder 110 when the piston 142 is reciprocating ( 242 is inserted.

The piston nut 144 is installed on the upper and lower portions of the piston 142, respectively, and is fastened to the piston rod 126 by screwing, so that the piston 142 is fixed to the piston rod 126. A disk 244 which forms a threaded screw hole and contacts the outer circumferential surface of the piston rod 126 is accommodated in the screw hole, and presses the disk 244 by a locking bolt 246 or the like and is fastened to the screw hole. By doing so, it may be possible to strengthen the fastening force between the piston nut 144 and the piston rod 126.

The retaining ring 146, also known as a stop ring or snap ring, is a component that can be attached to a relatively small place, which is beneficial for miniaturization or simplification of the device, and restricts the movement of the piston 142. It is provided at the top and bottom of each is fixed by the fastening means 150 and the like.

3 is a flowchart illustrating a maintenance process of a hydraulic actuator according to a preferred embodiment of the present invention, and FIG. 4 is a flowchart illustrating a process of disassembling a hydraulic actuator according to a preferred embodiment of the present invention.

As shown, the hydraulic actuator of the present invention disassembles the hydraulic actuator in a predetermined order in order to complete maintenance with a minimum maintenance time (S310).

This, as shown in Figure 4, the maintenance order of the hydraulic valve fluid actuator disassembles the backup ring 122 of the cylinder assembly 120 (S410), the guide ring is inserted into the disassembled backup ring 122 222b and scraper ring 226 are disassembled.

When the disassembly of the backup ring 122 is completed, the cylinder cover 130 and the guide bush 124 fixed to the lower part of the cylinder 110 are disassembled (S420), and the oil ring 228 inserted into the guide bush 124. ), The piston rod chamber 224, the guide ring 222a, and the like are disassembled from the guide bush 124.

Then, disassemble the cylinder cover 130 fixed to the upper portion of the cylinder 110, but release only the fastening of the fastening means 150 fastened to the cylinder cover 130, (S430) wire rope to the eye bolt 132 To completely disassemble the cylinder cover 130 from the cylinder 110, at which time the piston assembly 140 accommodated in the cylinder cover 130 is separated from the cylinder 110 together. (S440)

That is, the piston assembly 140 is separated from the cylinder 110 together with the cylinder cover 130, and is separated from the cylinder 110 by a shackle and a crane.

The piston assembly 140 separated from the cylinder 110 disassembles the retaining ring 146 holding the piston 142 and (S450) the piston nut 144 fixed to the upper and lower portions of the piston 142, respectively. Disassemble).

Here, the piston chamber 242 inserted into the outer peripheral surface of the piston 142, the disk 244 and the locking bolt provided on one surface of the piston nut 144 to disassemble the piston nut 144 from the piston rod 126 Of course, the decomposition of (246) must be made.

When disassembly of the piston nut 144 is completed, the piston 142 and the piston rod 126 are finally disassembled to complete disassembly of the hydraulic actuator. (S460)

In addition, when the disassembly of the hydraulic actuator is completed, the entire disassembly of the various sealing members are replaced (S320).

Here, the sealing member refers to the guide rings 222a and 222b, the piston rod chamber 224, the scraper ring 226, the oil ring 228, the piston chamber 242, and the retaining ring 146. .

In addition, when an abnormality occurs by checking the wear state of the inner surface of the cylinder 110 and the contact state of the piston 142, processing for normal operation is performed.

In addition, cleaning is performed to reduce the pollution of all the decomposed components, and various foreign substances, rust generated by corrosion, and other harmful components remaining in each component are removed.

Thereafter, the hydraulic valve assembly is assembled in the reverse order of disassembly.

That is, the piston 142 and the piston nut 144 are coupled to the piston rod 126, the piston chamber 242 is inserted into the piston 142, and the piston 142 is piston by the retaining ring 146. When the assembly of the piston assembly 140 is completed by fixing to the rod 126, the piston assembly 140 is inserted into the cylinder 110, and the cylinder cover 130 is coupled with the cylinder 110 to connect the cylinder 110. The upper opening 114 of the seal is sealed.

Thereafter, the guide bush 124 and the backup ring 122 into which the oil ring 228, the piston rod chamber 224, the guide ring 222a, and the like are inserted are inserted into the cylinder cover 130 and the lower through hole of the cylinder 110. 116, respectively fixed to the piston assembly 140 is fixed to the cylinder 110 to complete the assembly of the hydraulic actuator.

When the assembly is completed, the hydraulic test is performed, the operation state of the hydraulic actuator is checked to determine whether there is an abnormality, and the oil leakage state after the oil filling is checked.

Through such a maintenance method, the hydraulic actuator of the present invention is normally disassembled, inspected, and assembled in a predetermined order of two days, thereby reducing maintenance time and improving product accuracy. Minimizing disruptions in power generation at the power plant can be minimized, improving product reliability.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

1 is an exploded perspective view showing a hydraulic actuator according to a preferred embodiment of the present invention,

2 is a cross-sectional view showing a hydraulic actuator according to a preferred embodiment of the present invention;

3 is a flow chart showing a maintenance process of the hydraulic actuator according to a preferred embodiment of the present invention;

4 is a flowchart illustrating a process of disassembling the hydraulic actuator according to the preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: cylinder 112: space

114L opening 116: through hole

120: cylinder assembly 122: backup ring

124: guide bush 126: piston rod

130: cover 132: eye bolt

140: piston assembly 142: piston

144: piston nut 146: retaining ring

150: fastening means 222a, 222b: guide ring

224: piston rod seal 226: scraper ring

228: oil ring 242: piston seal

244: disk 246: locking bolt

Claims (6)

In the hydraulic actuator, A space is formed therein to supply and discharge oil having a predetermined pressure, the cylinder having an upper opening and a lower opening therethrough; A piston rod penetrating the cylinder vertically and reciprocating upward and downward; a piston provided on an outer circumferential surface of the piston rod and reciprocating the piston rod by hydraulic pressure; A screw hole is formed on one outer circumference of the piston rod to secure the piston to the piston rod, and a disk is inserted into the screw hole to contact the outer circumferential surface of the piston rod and a locking bolt fastened to the screw hole to pressurize the disk. A piston assembly further comprising a piston nut to provide a tightening force with the piston rod; A cylinder cover inserted into and installed in an upper opening of the cylinder to seal the inside of the cylinder, through which the piston rod penetrates, and an eye bolt formed on an upper surface thereof; And The piston rod penetrates the inner circumferential surface and is inserted and installed in the lower part of the cylinder and the cylinder cover, respectively, and an oil ring for preventing the outflow of oil and a piston rod and guide ring for supporting the reciprocating motion of the piston rod are installed on the outer circumferential surface. A cylinder assembly including a guide bush and a back ring which is fastened by the guide bush and the fastening means, and which has a scraper ring for adjusting the amount of oil on the inner circumferential surface and a guide ring inserted therein. Hydraulic actuator comprising a. delete The method of claim 1, The piston assembly is provided with a hydraulic actuator, characterized in that the retaining ring is further provided on the upper and lower portions of the piston and is fixed to the piston by the fastening means to limit the movement of the piston. A cylinder, a cylinder cover installed at an upper portion of the cylinder and having an eye bolt formed on one surface thereof, a piston assembly including a piston and a piston rod provided inside the cylinder, a guide bush and a backup installed at the upper and lower portions of the cylinder, respectively. In the maintenance method of a hydraulic actuator comprising a cylinder assembly consisting of a ring, (a) disassembling the backup ring of the cylinder assembly, the guide ring and the scraper ring inserted in the backup ring, disassembling the guide bush, the oil ring, the piston rod seal, the guide ring inserted into the guide bush, Release the fastening means fastened to the cylinder cover installed on the upper portion of the cylinder, and disassemble the cylinder cover and the piston assembly from the cylinder by using a shackle, a crane, etc. through the eye bolt of the cylinder cover, Disassembling the retaining ring and the piston nut and disassembling the hydraulic actuator disassembling the piston of the piston assembly from the piston rod; (b) replacing the sealing member of the disassembled hydraulic actuator; (c) checking the wear state of the inner surface of the cylinder and the contact state of the piston; (d) washing the decomposed hydraulic actuator to reduce the pollution degree, and removing various foreign substances, rust and various harmful components caused by corrosion; (e) assembling the disassembled hydraulic actuator in the reverse order of step (a); And (f) performing a hydraulic test, an operation status check, an oil filling and a leak condition check on the assembled hydraulic actuator; Maintenance method of the hydraulic actuator comprising a. delete The method of claim 4, wherein The sealing member includes an oil ring inserted into the guide bush, a piston rod seal and a guide ring, a guide ring and a scraper ring inserted into the backup ring, an oil ring inserted into the cylinder cover, and a piston provided in the piston. A maintenance method of a hydraulic actuator comprising a seal.

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