CN219888872U - A valve stem lifting structure that prevents rotation and falling off - Google Patents

Abstract

The utility model relates to the technical field of high-temperature high-pressure speed regulation main valves of steam turbines of thermal power plants, and discloses a valve rod lifting structure capable of preventing rotary falling, which comprises the following components: the anti-rotation lifting nut structure is arranged in the cross lifting sleeve, and the anti-rotation clamping block is arranged outside the cross lifting sleeve; the valve rod lifting structure capable of preventing the rotation and the falling is mainly in a threaded connection and cylindrical transverse pin connection mode; the valve rod lifting structure capable of preventing the valve rod from rotating and falling comprises a cross lifting sleeve, a valve rod, an anti-rotation transverse pin, a slotted lifting nut, a guide cylindrical pin, a round plug screw, an anti-rotation clamping block and a high-temperature bolt which are sequentially pressed and installed into a whole; according to the utility model, the self-locking principle of screw thread and cylindrical pin extrusion is utilized, so that the defect that the valve rod rotates and falls off due to irregular vibration generated by high-temperature high-pressure steam flow disturbance is effectively overcome, the reliability of a high-temperature high-pressure speed regulation main valve is ensured, and the running stability of a steam turbine generator set and a power grid is improved.

Description

A valve stem lifting structure that prevents rotation and falling off

Technical field

The utility model relates to the technical field of high-temperature and high-pressure speed regulating main valves in thermal power plants, and in particular to a valve stem lifting structure that prevents rotation and falling off.

Background technique

The load and speed of the steam turbine in a thermal power plant are realized by the steam distribution mechanism. The steam turbine is controlled by a digital electro-hydraulic control system. The high-pressure speed regulating main steam valve is not only an important regulating device, but also an important thermal equipment. Its equipment performance directly affects the unit's performance. Adjustment characteristics and economy, the high-pressure speed-regulating main steam valve changes the steam flow entering the cylinder according to the system instructions to adjust the load and speed. The high-pressure speed-regulating main steam valve is operated by a lever mechanism, which is closed by a spring on one side. Motor control requires about 11 MPa hydraulic oil to open through the servo valve. The servo valve receives instructions from the system to operate the valve switch. After reaching the operating speed, the speed control system will control the opening of the valve to meet the supply of steam under various loads. quantity. The valve stem of the high-pressure speed regulating main steam valve and the cross lifting sleeve in the control seat are directly connected in a threaded manner and are fixed with an anti-rotation pin. After the unit has been running for a period of time, the valve will be lifted when it is opened and closed and the power grid is peak-shaving. Force, as well as the disturbance excitation force of high-temperature and high-pressure steam flow, produce irregular vibrations on the valve stem, and the anti-rotation pin is subject to disturbance impact and shear fracture, causing the valve stem and the cross lifting sleeve to fall off, or the valve stem withdraws and the valve stem The thread connecting with the crosshead is seized, making the high-pressure speed-regulating main steam valve unable to operate, seriously affecting the operation of the steam turbine and the safety of the unit. The reliability of the high-pressure speed-regulating main steam valve directly affects the unit load and unit economy, and affects the stability of the power grid. operation, for this reason we propose a valve stem lifting structure that prevents rotation and falling off.

Utility model content

The utility model aims at the shortcomings of the existing technology and provides a valve stem lifting structure that prevents rotation and falling off.

7. In order to solve the above problems, the technical solution adopted by the present utility model is as follows: a valve stem lifting structure that prevents rotation and falling off, including a cross lifting sleeve (9), which is characterized in that: the cross lifting sleeve (9) is processed with internal The threaded hole of the cylindrical step, the valve stem (1), the screw plug (4), the lifting nut (5), the anti-rotation cross pin (6), the adjusting pad (8) are installed in the cross lifting sleeve (9), and the lifting nut (5) is used to connect the valve stem (1) and the cross lifting sleeve (9). The outer circle of the lifting nut (5) and the upper hole of the cross lifting sleeve (9) adopt a clearance fit, and an opening is opened on the outer circle of the lifting nut (5). A guide groove, a guide pin (7) is installed on the cross lifting sleeve (9) to prevent the lifting nut (5) from rotating, and ensure that the lifting nut (5) can move up and down; the positioning of the lifting nut is completed by the screw plug (4), The surface of the screw plug (4) is threaded and tightened in conjunction with the internal threads of the cross lifting sleeve (9); the end face of the cross lifting sleeve (9) is processed with threaded holes, and the valve stem (1) is processed with four flat surfaces on the cylindrical surface to prevent rotation jamming. The block (2) fits the four flat surfaces of the valve stem (1), and is fixed at the threaded hole on the end face of the cross lifting sleeve (9) with bolts (3). Adjust the pad (8) to transmit the impact force to the control seat ( 10), while reducing the difficulty of installation.

Furthermore, the lifting nut (5) is provided with a guide groove, the lifting nut (5) and the cross lifting sleeve (9) are used as pin holes, and the guide pin (7) is inserted to prevent the lifting nut (5) from rotating.

Further, the described valve stem lifting structure that prevents rotation and falling off is characterized in that: the valve stem (1) and the lifting nut (5) are threaded to prevent the valve stem (1) and the lifting nut (5) from being Relative rotation, the valve stem (1) and the lifting nut (5) are matched with the anti-rotation pin hole, and the anti-rotation pin (6) is inserted into the pin hole of the valve stem (1) and the lifting nut (5), and they are jointly installed on the cross lifting sleeve ( 9) into the cylindrical hole, and ensure that the lifting nut (5) and the valve stem (1) can move up and down.

Further, the described valve stem lifting structure that prevents rotation and falling off is characterized in that: the positioning of the lifting nut (5) is completed by the screw plug (4), the outer surface of the screw plug (4) is provided with threads, and the cross lifting sleeve ( 9) Screw the screw plug (4) tightly against the end face of the lifting nut (5). To prevent the screw plug (4) from withdrawing, the clamping block (2) is pressed against the screw plug (4).

Furthermore, the described valve stem lifting structure that prevents rotation and falling off is characterized by: the clamping block (2) has bolt holes, square holes and step planes, the clamping block (2) has a two-half structure, and the valve stem (1 ) The four flat surfaces of the cylindrical surface are processed to be the same size as the square hole of the clamping block (2). The two halves of the clamping block (2) are closed and fit on the four flat surfaces of the valve stem (1), and are fixed to the cross lifting sleeve (9) by bolts (3). ) end surface, and at the same time press the screw plug (4) on the step plane.

Furthermore, the described valve stem lifting structure that prevents rotation and falling off is characterized by: an adjustment pad (8) is provided on the top of the valve stem (1) to prevent installation difficulties, and the thread of the valve stem lifting nut (5) is directly If the valve is damaged due to force, adjust the pad (8) to fit closely with the top of the valve stem (1).

beneficial effects

The utility model provides a valve stem lifting structure that prevents rotation and falling off. It has the following beneficial effects:

1. This anti-rotation and fall-off valve stem lifting structure is set up with two halves of anti-rotation blocks positioned on all four sides and positioned closely with the processing plane of the valve stem. The four planes are evenly stressed, effectively suppressing the valve stem from being affected by high temperature and high pressure. The high-frequency flutter rotation caused by the excitation of the steam flow has eight bolt holes evenly distributed on the two halves of the anti-rotation blocks positioned on all four sides. The end face of the cross lifting sleeve is equipped with threaded holes. Eight high-temperature alloy bolts are used to connect the two halves of the anti-rotation blocks. It is very firmly fixed on the cross lifting sleeve. Torque pre-tightening is used when tightening the bolts to effectively prevent the loosening effect of high temperature thermal stress on the anti-rotation block.

2. This kind of valve stem lifting structure that prevents rotation and falling off is installed with two anti-rotation blocks positioned on all four sides to closely fit the lifting nut positioning screw plug. The lifting nut positioning screw plug is connected with a cross lifting sleeve through threads. It can be used at high temperatures. The lower pole is prone to thread loosening. The two halves and four-sided anti-rotation blocks prevent the valve stem from high-frequency flutter rotation and at the same time compress the positioning screw plug of the lifting nut, effectively preventing the positioning screw plug of the lifting nut from loosening and spinning. phenomenon.

3. This valve stem lifting structure prevents rotation and falling off. By setting an anti-rotation cross pin, the anti-rotation cross is passed through the pin hole of the lifting nut and the valve stem. The length of the pin is slightly lower than the outer surface of the lifting nut. , During assembly, the penetration of the lifting nut and the valve stem into the stepped threaded hole of the cross lifting sleeve must not be affected. The lifting nut and the valve stem are threaded, and the horizontal pin setting effectively prevents the thread from loosening and the valve stem spinning under high temperature conditions.

Description of the drawings

In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments recorded in this application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

Figure 1 is a cross-sectional view of a valve stem lifting structure that prevents rotation and falling off;

Figure 2 is a schematic diagram of the valve stem structure of the anti-rotation cross pin and lifting nut;

Figure 3 is a schematic diagram of the anti-rotation block structure.

Figure 4 is an overall schematic diagram of a valve stem lifting structure that prevents rotation and falling off.

Explanation of reference symbols:

1-valve stem, 2-anti-rotation block, 3-high temperature bolt, 4-screw plug, 5-lift nut, 6-anti-rotation cross pin, 7-guide pin, 8-adjustment pad, 9-cross lifting sleeve , 10-control seat.

Detailed ways

The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be construed as limiting the present application.

Please refer to Figures 1 to 4. The present utility model provides a valve stem lifting structure that prevents rotation and falling off, including a cross lifting sleeve (9), which is characterized in that: a cylindrical step threaded hole is processed inside the cross lifting sleeve (9), and The valve stem (1), screw plug (4), lifting nut (5), anti-rotation cross pin (6), and adjustment pad (8) are installed in the cross lifting sleeve (9), and the lifting nut (5) serves as the valve stem. (1) It is used to connect with the cross lifting sleeve (9). The outer circle of the lifting nut (5) adopts clearance fit with the hole in the upper part of the cross lifting sleeve. A guide groove is opened on the outer circle of the lifting nut (5), and a guide groove is opened on the outer circle of the cross lifting sleeve (5). 9) Install a guide pin (7) on the upper body to prevent the lifting nut (5) from rotating and ensure that the lifting nut (5) can move up and down during combined installation; the positioning of the lifting nut is completed by the screw plug (4), which is There are threads on the surface that match the internal threads of the cross lifting sleeve (9) for tightening; the cross lifting sleeve (9) has threaded holes on its end face, four flat surfaces are machined on the cylindrical surface of the valve stem (1), and the anti-rotation block (2) is The four flat surfaces of the valve stem (1) fit together and are fixed at the threaded hole on the end face of the cross lifting sleeve (9) with eight high-temperature bolts (3). The adjusting pad (8) can ensure that the valve stem (1) is closed when the valve is closed. ) thread is not stressed, and the impact force when the valve is closed is directly transmitted to the control seat (10), effectively extending the life of the high-temperature and high-pressure speed control main valve, and the gap between the end face of the valve stem (1) and the cross lifting sleeve (9) passes through Adjust the shim (8) to make the adjustment.

The working principle of this utility model:

A deep cylindrical step hole is processed into the cross lifting sleeve (9), and threads are opened at the larger hole diameter of the lower step. Four flat surfaces are processed into the cylindrical surface of the valve stem (1), and a longitudinal guide groove is opened on the outer surface of the lifting nut (5). , after the valve stem (1) is threaded with the lifting nut (5), use the pin hole to insert the anti-rotation cross pin (6). After installing the adjustment pad (8), insert the entire body into the cylindrical step of the cross lifting sleeve (9) In the hole, the screw plug (4) is tightened with the threads of the cross lifting sleeve (9), and the guide pin (7) is inserted into the pin hole according to the direction of the outer guide groove of the lifting nut (5), and the anti-rotation block (2) is integrated Four flat surfaces are processed to match the valve stem (1). The anti-rotation block (2) is processed into a step plane that matches the end face of the screw plug (4). The anti-rotation block (2) is divided into two halves. After the semi-anti-rotation block (2) is adjusted and positioned to make close contact with the valve stem (1) plug (4), it is used as a bolt hole with the cross lifting sleeve (9), and the high-temperature bolt (3) is screwed in. The high-temperature bolt ( 3) Perform torque preloading.

It is obvious to those skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the application is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of the equivalent elements are included in this application. Any reference signs in the claims shall not be construed as limiting the claim in question.

In addition, it should be understood that although this specification is described in terms of implementations, not each implementation only contains an independent technical solution. This description of the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole. , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (6)

1. A valve stem lifting structure that prevents rotation and falling off, including a cross lifting sleeve (9), which is characterized in that: a cylindrical step threaded hole is processed inside the cross lifting sleeve (9), and the valve stem (1) and screw plug (4) ), the lifting nut (5), the anti-rotation cross pin (6), the adjusting pad (8) are installed in the cross lifting sleeve (9), the lifting nut (5) serves as the valve stem (1) and the cross lifting sleeve (9) For connection, the outer circle of the lifting nut (5) and the upper hole of the cross lifting sleeve adopt a clearance fit. A guide groove is opened on the outer circle of the lifting nut (5), and a guide pin (7) is installed on the cross lifting sleeve (9). Prevent the lifting nut (5) from rotating and ensure that the lifting nut (5) can move up and down; the positioning of the lifting nut is completed by the screw plug (4), and the screw plug (4) has threads on its surface to match the internal threads of the cross lifting sleeve (9) Tighten; the end face of the cross lifting sleeve (9) is processed with threaded holes, and the cylindrical surface of the valve stem (1) is processed with four flat surfaces. The clamping block (2) is fitted with the four flat surfaces of the valve stem (1), and the bolts (3 ) is fixed at the threaded hole on the end face of the cross lifting sleeve (9), and the adjusting pad (8) fits the end face of the valve stem (1) to transmit the impact force to the control seat (10) and reduce the difficulty of installation. 2. A valve stem lifting structure that prevents rotation and falling off according to claim 1, characterized in that: the lifting nut (5) is provided with a guide groove, and the lifting nut (5) cooperates with the cross lifting sleeve (9) Pin hole, insert the guide pin (7) to prevent the lifting nut (5) from rotating. 3. A valve stem lifting structure that prevents rotation and falling off according to claim 1, characterized in that: the valve stem (1) and the lifting nut (5) are threaded to prevent the valve stem (1) from lifting. The nuts (5) rotate relatively, the valve stem (1) and the lifting nut (5) are used as anti-rotation pin holes, and the anti-rotation cross pin (6) is inserted into the pin holes of the valve stem (1) and the lifting nut (5), and they are installed together. in the cylindrical hole of the cross lifting sleeve (9), and ensure that the lifting nut (5) and the valve stem (1) can move up and down. 4. A valve stem lifting structure that prevents rotation and falling off according to claim 1, characterized in that: the positioning of the lifting nut (5) is completed by a screw plug (4), and the outer surface of the screw plug (4) is provided with threads. The screw plug (4) of the cross lifting sleeve (9) is tightened to fit the end face of the lifting nut (5). To prevent the screw plug (4) from withdrawing, the clamping block (2) is pressed against the screw plug (4). 5. A valve stem lifting structure that prevents rotation and falling off according to claim 1, characterized in that: the clamping block (2) is provided with bolt holes, square holes and step planes, and the clamping block (2) is a two-half structure. The cylindrical surface of the valve stem (1) is processed with four flat surfaces that are the same size as the square holes of the clamping block (2). The two halves of the clamping block (2) are closed and fit on the four flat surfaces of the valve stem (1), and are fixed on the cross by bolts (3). Lift the end surface of the sleeve (9), and at the same time press the screw plug (4) on the flat surface of the step. 6. A valve stem lifting structure that prevents rotation and falling off according to claim 1, characterized in that: an adjustment pad (8) is provided on the top of the valve stem (1) to prevent installation difficulties, and a valve stem lifting nut ( 5) The thread is damaged by direct force, and the adjustment pad (8) is in close contact with the top end surface of the valve stem (1).