A locking and anti-loosening device for connecting a valve stem to a control mechanism

Abstract

The present invention discloses an anti-loosening and anti-stop device for connecting a valve stem and a control mechanism, comprising: a valve stem, a transverse pin, a ball head, a lower clamping plate, an adjusting pad, an upper clamping plate, a locking block, a tenon block, a clamping groove and a pin hole; the lower clamping plate, the adjusting pad and the upper clamping plate are fixedly connected to form a cavity for accommodating the ball head, the lower clamping plate is sleeved on the valve stem, the ball head is connected to the valve stem, a horizontally penetrating transverse pin hole is provided in the upper part of the valve stem, a horizontally penetrating pin hole is provided at the inner center position of the ball head, the pin hole is matched with and aligned with the transverse pin hole; the transverse pin is arranged inside the pin hole and the transverse pin hole; a clamping groove communicating with a connecting hole is provided at the upper end center position of the ball head, and the locking block is arranged in the clamping groove; a vertically penetrating first tenon groove is provided at the center position of the locking block; the upper part of the tenon block is arranged in the first tenon groove of the locking block, and the lower part of the tenon block is connected to the top of the valve stem. The device of the present invention can effectively eliminate the disadvantages of poor anti-loosening and anti-stop reliability, poor maintenance economy, easy wear and fracture of the transverse pin, etc. of the traditional structure.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical connection structures, and in particular relates to an anti-loosening stop device used for connecting a valve stem with an operating mechanism. Background Art

[0002] The steam turbine high-pressure regulating valve (hereinafter referred to as the regulating valve) is an important part of the steam turbine regulating system. A steam turbine is usually composed of high and low pressure cylinders, which are equipped with high and low pressure regulating valves. The regulating valve is usually driven by an operating mechanism to control the amount of steam entering the steam turbine to adjust the turbine speed and power, so that the steam turbine can operate stably under the designed conditions, and can quickly shut down the steam inlet of the steam turbine in an emergency to put the unit in a safe state. It can be seen that the regulating valve is of great significance to the reliable operation of steam turbines and even power stations.

[0003] The traditional steam turbine high-pressure regulating valve stem is connected to the operating mechanism through a ball head, which is fixed to the stem through threads and prevented from loosening by a cross pin structure. In actual operation, the operating mechanism pull rod drives the ball head and the stem to move up and down, thereby achieving the function of adjusting the valve opening.

[0004] However, the traditional structure uses a cross pin to prevent the ball head thread from loosening. The torsional force generated between the valve stem and the ball head during operation is all borne by the cross pin. The cross-sectional area of ​​the cross pin is relatively small, and the reliability of the anti-loosening function is poor. In addition, high strength and toughness requirements are placed on the cross pin material. Special high-strength steel must be used, and ordinary materials cannot be used as a substitute.

[0005] In addition, the ball head is connected to the valve stem through a thread. There is a certain gap in the thread connection itself. After a period of use, the gap of the thread will increase due to wear due to vibration, resulting in a certain axial shake in the connection between the ball head and the valve stem. After the cross pin is installed, when the valve stem is under stress, due to the existence of the thread gap, the cross pin will inevitably bear the shear force along the axial direction of the valve stem. The shear force is concentrated on the thread connection between the ball head and the valve stem. The cross pin fits tightly with the valve stem pin hole and the ball head pin hole. The cross pin material is relatively hard. Under the shear force of the valve stem, it will cause great shear damage to the cross pin. The high-pressure regulating valve needs to be adjusted continuously during the operation of the unit. At the same time, the regulating valve and steam pipeline are disturbed by the high-speed steam flow to produce a certain intensity of excitation vibration. The frequent up and down movements of the valve stem cause the cross pin to be frequently stressed, which eventually leads to the cross pin breaking and the failure of the anti-loosening stop structure. In severe cases, the valve stem will fall off, which brings great risks to the safe and stable operation of the unit.

[0006] In addition, in order to ensure that the pin holes on the ball head and the valve stem are aligned both circumferentially and axially, and there is a strict matching relationship between them, when a defect occurs, only the valve stem and ball head assembly can be replaced as a whole, and damaged parts cannot be replaced individually, resulting in poor maintenance economy.

[0007] Therefore, it is urgent to develop a loosening prevention and stopping structure for the connection between the valve stem and the operating mechanism, which can effectively eliminate the disadvantages of poor reliability of loosening prevention and stopping, poor maintenance economy, high material requirements for the cross pin, easy wear and fracture of the cross pin, etc. of the traditional structure. Summary of the Invention

[0008] The purpose of the present invention is to provide a loosening prevention and stopping device for the connection between the valve stem and the operating mechanism, which can effectively eliminate the disadvantages of poor reliability of loosening prevention and stopping, poor maintenance economy, high material requirements for the cross pin, easy wear and fracture of the cross pin, etc. of the traditional structure.

[0009] The technical solution to achieve the purpose of the present invention: a loosening prevention and stopping device for the connection between the valve stem and the operating mechanism, the device includes: a valve stem, a cross pin, a ball head, a lower clamping plate, an adjusting pad, an upper clamping plate, a locking block, a tenon block, a clamping groove and a pin hole;

[0010] The upper clamping plate is located directly above the lower clamping plate, and the adjusting pad is located between the lower clamping plate and the upper clamping plate; the lower clamping plate, the adjusting pad and the upper clamping plate are fixedly connected to form a cavity; the lower clamping plate is sleeved on the lower part of the valve stem; the ball head is arranged in the cavity formed by the lower clamping plate, the adjusting pad and the upper clamping plate;

[0011] A vertically penetrating connection hole is arranged at the inner center position of the ball head, and the ball head is fixedly connected to the upper part of the valve stem through the connection hole; a horizontally penetrating cross pin hole is arranged at the upper part of the valve stem, a horizontally penetrating pin hole is arranged at the inner center position of the ball head, and the pin hole of the ball head is matched and aligned with the cross pin hole of the valve stem; the cross pin is arranged inside the aligned pin hole and cross pin hole;

[0012] A clamping groove communicating with the connection hole is arranged at the upper center position of the ball head, and the locking block is arranged in the clamping groove; a vertically penetrating first tenon groove is arranged at the center position of the locking block; the upper part of the tenon block is arranged in the first tenon groove of the locking block, and the lower part of the tenon block is connected to the top of the valve stem.

[0013] Further, a first hemispherical hole is arranged in the middle of the upper surface of the lower clamping plate, a second hemispherical hole is arranged in the middle of the lower surface of the upper clamping plate, a through circular hole is arranged in the middle of the adjusting pad, and the first hemispherical hole, the circular hole and the second hemispherical hole correspond to penetrate and form a cavity for accommodating the ball head.

[0014] Further, first bolt holes are uniformly arranged around the circumference of the first hemispherical hole in the lower clamping plate, second bolt holes vertically penetrating are uniformly arranged around the circumference of the second hemispherical hole in the upper clamping plate, third bolt holes are uniformly arranged around the circumference of the circular hole in the adjusting pad, and the first bolt holes, the second bolt holes and the third bolt holes correspond to penetrate; connection bolts are arranged in the first bolt holes, the second bolt holes and the third bolt holes, and the lower clamping plate, the adjusting pad and the upper clamping plate are fixedly connected through the connection bolts.

[0015] Furthermore, a vertical through hole is provided in the middle of the lower surface of the lower clamping plate, the through hole is connected to the first hemispherical hole, and the lower clamping plate is sleeved on the lower part of the valve stem through the through hole.

[0016] Furthermore, the pin hole is an elongated structure, and the length of the pin hole is greater than the diameter of the cross pin.

[0017] Furthermore, a second tenon groove is provided at the center position of the top of the valve stem, and the lower part of the tenon block is detachably connected to the second tenon groove.

[0018] Furthermore, the lower portion of the tenon block is connected to the tenon groove by interference fit.

[0019] Furthermore, the lower part of the tenon block is connected to the tenon groove via threads.

[0020] Furthermore, the tenon block and the valve stem are an integrally formed structure.

[0021] Furthermore, the locking block is polygonal, gear-shaped or spline-shaped.

[0022] Furthermore, the tenon block is polygonal, gear-shaped or spline-shaped.

[0023] Furthermore, the ball head is fixedly connected to the valve stem via threads.

[0024] The beneficial technical effects of the present invention are:

[0025] 1. The two structures of the cross pin and the lock block in the anti-loosening stop device for connecting the valve stem and the operating mechanism of the present invention both realize the anti-loosening stop function of the connecting thread of the ball head and the valve stem. The failure of a single structure will not cause the loss of the anti-loosening stop function of the connecting thread, thereby achieving a double protection effect and higher reliability;

[0026] 2. The torsional force of the ball head in the anti-loosening stop device for connecting the valve stem and the operating mechanism of the present invention is borne by the cross pin and the lock block, wherein the lock block is mainly subjected to the force and the cross pin is supplementary. This is because the lock block has a larger force bearing area and can bear a larger load. Therefore, there is no special requirement for the material of the cross pin and the lock block;

[0027] 3. The locking block in the anti-loosening stop device for connecting the valve stem and the operating mechanism of the present invention does not limit the axial shaking of the ball head and the valve stem. The pin hole on the ball head is processed into an elongated hole along the axial direction of the valve stem, which can allow a certain range of axial shaking of the cross pin. Therefore, the locking block and the cross pin are not affected by the axial shaking between the ball head and the valve stem, eliminating the risk of failure of the anti-loosening structure of the cross pin due to the axial shear force;

[0028] 4. The pin hole of the ball head in the anti-loosening stop device for connecting the valve stem and the operating mechanism of the present invention is an elongated hole, and there is no special matching requirement with the pin hole on the valve stem in the axial direction. The valve stem and the ball head can be replaced separately, which improves the maintenance economy;

[0029] 5. The pin hole of the ball head in the anti-loosening and anti-stopping device for connecting the valve stem and the operating mechanism of the present invention is an elongated hole, allowing the ball head to adjust its position relative to the valve stem within a certain axial range, realizing the adjustable overall length of the valve stem and the ball head, facilitating the adjustment of the valve zero position, and simplifying the maintenance process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 FIG. is a schematic structural diagram of an anti-loosening and anti-stopping device for connecting a valve stem and an operating mechanism provided by the present invention;

[0031] Figure 2 FIG. is a partial exploded view of an anti-loosening and anti-stopping device for connecting a valve stem and an operating mechanism provided by the present invention;

[0032] Figure 3 FIG. is a partial sectional view of an anti-loosening and anti-stopping device for connecting a valve stem and an operating mechanism provided by the present invention.

[0033] In the figure: 1. Valve stem; 2. Transverse pin; 3. Ball head; 4. Lower splint; 5. Adjusting pad; 6. Upper splint; 7. Locking block; 8. Tenon block; 9. Card slot; 10. Pin hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0035] As Figures 1 - 3 shown, an anti-loosening and anti-stopping device for connecting a valve stem and an operating mechanism provided by the present invention includes: a transverse pin 2, a ball head 3, a lower splint 4, an adjusting pad 5, an upper splint 6, a locking block 7, a tenon block 8, a card slot 9, and a pin hole 10.

[0036] As Figure 1 shown, the upper splint 6 is located directly above the lower splint 4, and the adjusting pad 5 is located between the lower splint 4 and the upper splint 6 for adjusting the clearance between the ball head 3 and the upper splint 6 and the lower splint 4. A first hemispherical hole is provided in the middle of the upper surface of the lower splint 4, and the aperture of the first hemispherical hole matches the outer diameter of the ball head 3; a second hemispherical hole is provided in the middle of the lower surface of the upper splint 6, and the aperture of the second hemispherical hole matches the outer diameter of the ball head 3; a through-round hole is provided in the middle of the adjusting pad 5, and the aperture of the round hole matches the outer diameter of the ball head 3; the first hemispherical hole, the round hole, and the second hemispherical hole are correspondingly penetrated to form a cavity.

[0037] As Figure 1As shown in the figure, first bolt holes are evenly arranged around the circumference of the first hemispherical hole in the lower clamping plate 4, second bolt holes that penetrate vertically are evenly arranged around the circumference of the second hemispherical hole in the upper clamping plate 6, and third bolt holes are evenly arranged around the circumference of the circular hole in the adjusting pad 5. The first bolt holes, the second bolt holes, and the third bolt holes are correspondingly penetrated and are matched with the connecting bolts. The connecting bolts are inserted into the second bolt holes, the third bolt holes, and the first bolt holes from top to bottom in sequence, and the lower clamping plate 4, the adjusting pad 5, and the upper clamping plate 4 are fixedly connected through the connecting bolts.

[0038] As Figure 1 shown, the upper clamping plate 6 is strip-shaped, and both ends of the upper clamping plate 6 are connected to the pull rod of the operating mechanism.

[0039] As Figures 1 - 3 shown, a through hole that penetrates up and down is provided in the middle of the lower surface of the lower clamping plate 4. The through hole is matched with the lower part of the valve stem 1, and the valve stem 1 can pass through. The lower clamping plate 4 is sleeved on the lower part of the valve stem 1 through the through hole. The ball head 3 is spherical and is located directly above the valve stem 1 and is arranged in the cavity formed by the first hemispherical hole, the circular hole, and the second hemispherical hole; a connecting hole that penetrates the ball head 3 up and down is provided at the inner center position of the ball head 3, and internal threads are provided in the connecting hole; the valve stem 1 is cylindrical, external threads are provided on the upper part of the valve stem 1, and the internal threads of the connecting hole are matched with the external threads of the valve stem 1, and the ball head 3 and the valve stem 1 are fixedly connected by threads.

[0040] As Figures 2 - 3 shown, a circular cross pin hole that penetrates the valve stem 1 horizontally is provided on the upper part of the valve stem 1. The diameter of the cross pin hole is matched with the diameter of the cross pin 2; a long pin hole 10 that penetrates the ball head 3 left and right is provided at the inner center position of the ball head 3. The width of the pin hole 10 is matched with the diameter of the cross pin 2, and the length of the pin hole 10 is greater than the diameter of the cross pin 2; the pin hole 10 of the ball head 3 is matched and aligned with the cross pin hole of the valve stem 1 for installing the cross pin 2. The cross pin 2 is matched with the aligned pin hole 10 and cross pin hole and is inserted into the interior of the aligned pin hole 10 and cross pin hole to prevent the ball head 3 from rotating relative to the valve stem 1, achieving the function of preventing loosening and stopping.

[0041] Since the pin hole 10 is machined into an elongated hole along the axial direction, allowing the cross pin 2 to shake or adjust its position along the axial direction, that is, the vertical direction, in the pin hole 10, the cross pin 2 is not affected by the axial shaking between the ball head 3 and the valve stem 1, eliminating the risk of the anti-loosening structure failing due to axial shear force on the cross pin 2.

[0042] As Figures 2 - 3 shown, a clamping groove 9 that penetrates through the connecting hole is provided at the upper center position of the ball head 3. The clamping groove 9 is an octagonal structure that is matched with the locking block 7 for accommodating the locking block 7. The locking block 7 is an octagonal structure corresponding to the clamping groove 9, and the upper part is spherical. The locking block 7 is installed in the clamping groove 9, and the upper surface of the locking block 7 and the upper surface of the ball head 3 form a complete spherical surface.

[0043] As shown Figures 2 - 3 in FIG. 1, a first mortise groove penetrating the lock block 7 vertically is provided at the central position of the lock block 7. The first mortise groove is a quadrilateral structure matching the tenon block 8 and is used for inserting the tenon block 8. A second mortise groove is provided at the central position of the top of the valve stem 1. The second mortise groove corresponds to the first mortise groove and is also a quadrilateral structure matching the tenon block 8. The tenon block 8 is in the shape of a slender rod, and its cross-section is a quadrilateral corresponding to the first mortise groove and the second mortise groove. The upper part of the tenon block 8 is inserted into the first mortise groove of the lock block 7 by interference fit, and the lower part of the tenon block 8 is inserted into the second mortise groove of the valve stem 1 by interference fit. The lock block 7 and the tenon block 8 cooperate to prevent the ball head 3 from rotating relative to the valve stem 1, achieving the function of anti-loosening and anti-rotation.

[0044] It should be noted that the tenon block 8 and the top of the valve stem 1 can also be connected by threads, and the tenon block 8 is adjusted circumferentially to match the first mortise groove on the lock block 7. In addition, according to needs, the tenon block 8 and the valve stem 1 can also be processed into one body to form an integral structure.

[0045] It should be noted that the lock block 7 and the matching card slot, the tenon block 8 and the matching mortise groove can be designed as polygons, gear shapes or spline shapes. The anti-loosening and anti-rotation functions and the principles of achieving anti-loosening and anti-rotation of different shapes are not different, so no further examples will be given.

[0046] The installation process of a kind of anti-loosening and anti-rotation device for connecting the valve stem and the operating mechanism of the present invention is specifically as follows:

[0047] Step (1): Fit the lower clamping plate 4 onto the valve stem 1 so that the valve stem 1 passes through the through hole of the lower clamping plate 4 and the upper thread of the valve stem 1 is exposed.

[0048] Step (2): Install the ball head 3 onto the upper part of the valve stem 1 by threaded connection, adjust the total length of the ball head 3 and the valve stem 1, and align the transverse pin hole on the valve stem 1 with the elongated pin hole 10 on the ball head 2.

[0049] Step (3): Insert the transverse pin 2 into the elongated pin hole on the ball head 3 and the transverse pin hole on the valve stem 1. Among them, there is a certain gap between the transverse pin 2 and the upper and lower cylindrical surfaces of the elongated pin hole 10 on the ball head 3, so that the transverse pin 2 has a certain free play gap along the axial direction in the elongated pin hole 10 of the ball head 3. This free gap is of appropriate size, preferably 0.5-2 mm.

[0050] Step (4): Install the tenon block 8 onto the top of the valve stem 1 through the mortise groove or thread on the top of the valve stem 1, or directly process the tenon block 8 into one body with the valve stem 1 to form an integral structure.

[0051] Step (5): Install the lock block 7 into the upper polygonal card slot of the ball head 3, and at the same time insert the tenon block 8 into the polygonal tenon slot inside the lock block 7. The lock block 7 can be repaired as needed. For example, if the tenon block 8 is threadedly connected to the valve stem 1, the tenon block 8 can also be finely adjusted in the circumferential direction to match the first tenon slot on the lock block 7. After the installation of the lock block 7 is completed, with the cooperation of the tenon block 8, the ball head 3 can be prevented from rotating relative to the valve stem 1, thus realizing the function of preventing loosening;

[0052] Step (6): Install the adjusting pad 5 between the upper clamping plate 6 and the lower clamping plate 4, and use the connecting bolts to connect the upper clamping plate 6, the lower clamping plate 4 and the adjusting pad 5 into a whole; at this time, the ball head 3, the lock block 7 and the valve stem 1 are installed in the spherical space formed by the upper clamping plate 6, the lower clamping plate 4 and the adjusting pad 5.

[0053] After the installation is completed, when the upper clamping plate 6 moves up and down following the operating mechanism, it will drive the lower clamping plate 4, the adjusting pad 5 and the ball head 3, the lock block 7, the valve stem 1 in the spherical space to move together, realizing the function of adjusting the opening degree of the regulating valve.

[0054] The present invention has been described in detail above in conjunction with the drawings and embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention. The content not described in detail in the present invention can all adopt the prior art.

Claims

1. A loosening prevention and stopping device for connecting a valve stem and a control mechanism, characterized in that, the device includes: a valve stem (1), a cross pin (2), a ball head (3), a lower clamping plate (4), an adjusting pad (5), an upper clamping plate (6), a locking block (7), a tenon block (8), a card slot (9) and a pin hole (10); The upper clamping plate (6) is located directly above the lower clamping plate (4), and the adjusting pad (5) is located between the lower clamping plate (4) and the upper clamping plate (6); the lower clamping plate (4), the adjusting pad (5) and the upper clamping plate (6) are fixedly connected to form a cavity; the lower clamping plate (4) is sleeved on the lower part of the valve stem (1); the ball head (3) is arranged in the cavity formed by the lower clamping plate (4), the adjusting pad (5) and the upper clamping plate (6); A vertically penetrating connecting hole is arranged at the inner center position of the ball head (3), and the ball head (3) is fixedly connected with the upper part of the valve stem (1) through the connecting hole; a horizontally penetrating cross pin hole is arranged in the upper part of the valve stem (1), and a horizontally penetrating pin hole (10) is arranged at the inner center position of the ball head (3), and the pin hole (10) of the ball head (3) is matched and aligned with the cross pin hole of the valve stem (1); the cross pin (2) is arranged inside the aligned pin hole (10) and the cross pin hole; A card slot (9) communicating with the connecting hole is arranged at the upper center position of the ball head (3), and the locking block (7) is arranged in the card slot (9); a vertically penetrating first tenon groove is arranged at the center position of the locking block (7); the upper part of the tenon block (8) is arranged in the first tenon groove of the locking block (7), and the lower part of the tenon block (8) is connected with the top of the valve stem (1); The locking block (7) is polygonal or gear-shaped; The tenon block (8) is polygonal or gear-shaped; The pin hole (10) is of an elongated structure, and the length of the pin hole (10) is greater than the diameter of the cross pin (2).

2. A loosening prevention and stopping device for connecting a valve stem and a control mechanism according to claim 1, characterized in that, A first hemispherical hole is arranged in the middle of the upper surface of the lower clamping plate (4), a second hemispherical hole is arranged in the middle of the lower surface of the upper clamping plate (6), a through hole is arranged in the middle of the adjusting pad (5), and the first hemispherical hole, the through hole and the second hemispherical hole correspond to be penetrated to form a cavity for accommodating the ball head (3).

3. A loosening prevention and stopping device for connecting a valve stem and a control mechanism according to claim 2, characterized in that, First bolt holes are uniformly arranged around the circumference of the first hemispherical hole in the lower clamping plate (4), second bolt holes vertically penetrating are uniformly arranged around the circumference of the second hemispherical hole in the upper clamping plate (6), third bolt holes are uniformly arranged around the circumference of the through hole in the adjusting pad (5), and the first bolt holes, the second bolt holes and the third bolt holes correspond to be penetrated; connecting bolts are arranged in the first bolt holes, the second bolt holes and the third bolt holes, and the lower clamping plate (4), the adjusting pad (5) and the upper clamping plate (6) are fixedly connected through the connecting bolts.

4. A loosening prevention and stopping device for connecting a valve stem and a control mechanism according to claim 2, characterized in that, A vertically penetrating through hole is arranged in the middle of the lower surface of the lower clamping plate (4), the through hole communicates with the first hemispherical hole, and the lower clamping plate (4) is sleeved on the lower part of the valve stem (1) through the through hole.

5. A loosening prevention and stopping device for connecting a valve stem and a control mechanism according to claim 1, characterized in that, a second mortise groove is provided at the center position of the top of the valve stem (1), and the lower part of the tenon block (8) is detachably connected to the second mortise groove.

6. A loosening prevention and stopping device for connecting a valve stem and a control mechanism according to claim 5, characterized in that, the lower part of the tenon block (8) is connected to the mortise groove in an interference fit manner.

7. A loosening prevention and stopping device for connecting a valve stem and a control mechanism according to claim 5, characterized in that, the lower part of the tenon block (8) is connected to the mortise groove by a threaded connection.

8. A loosening prevention and stopping device for connecting a valve stem and a control mechanism according to claim 1, characterized in that, the tenon block (8) and the valve stem (1) are of an integrally formed structure.

9. A loosening prevention and stopping device for connecting a valve stem and a control mechanism according to claim 1, characterized in that, the ball head (3) is fixedly connected to the valve stem (1) by a threaded connection.

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