Hollow speed reduction executing mechanism of stop valve

Abstract

The invention relates to a hollow speed reduction executing mechanism of a stop valve. The hollow speed reduction executing mechanism comprises a shell, a sun wheel assembly, a planet carrier assembly a and an inner gear ring assembly. The sun gear assembly, the planet carrier assembly a and the inner gear ring assembly are used for achieving screwing-in and screwing-out actions of the threaded rod of the stop valve, then the opening and closing actions of the stop valve are achieved, the total reduction ratio is greatly smaller than the reduction ratio of an electric executing mechanism, and the opening and closing time of the stop valve can be effectively shortened. Meanwhile, the axis of the input end and the axis of a screw in the stop valve assembly are coaxially arranged, and the requirement for convenience of underground valve operation is met.

Description

Technical Field

[0001] The invention relates to a hollow deceleration actuator for a stop valve. Background Art

[0002] The stop valve on the steam pipeline of the steam turbine is equipped with a worm gear electric actuator. Each stop valve electric actuator operates twice a year on average. Due to the high temperature of the steam pipeline ≥500°C, the power cord and data cable are repeatedly damaged by heat. Therefore, when the valve needs to be opened and closed on site, the personnel can only turn the worm gear by hand-cranking the handwheel to realize the valve opening and closing action. The worm gear reduction output ratio is 25:1, and it takes about 2-3 hours to manually open or close once, which is time-consuming and labor-intensive.

[0003] Some steam pipeline stop valves are equipped with manual bevel gear reducers. However, due to the structural limitations of the bevel gear transmission, the handwheel at the input end is arranged laterally, and the output end is arranged vertically coaxially with the stop valve screw, with the two ends crossing at 90°. For the stop valves arranged underground, the lateral handwheel rotation operation is extremely difficult, which wastes on-site operation time.

[0004] At present, the stop valves on the steam pipeline of steam turbines, especially the stop valves under the ground, often have their actuators hidden under the ground. Because they are close to the steam pipeline and the surrounding temperature is high, it is very easy to damage the internal and external circuits of the electric actuators, resulting in failure and inability to be used. In addition, the worm gear reduction ratio of the electric actuator is too large, resulting in a long rotation time and low rotation efficiency for the operator's handwheel. In order to avoid the screw-in and screw-out action of the stop valve screw, the handwheel of the other matching reduction devices can only be arranged sideways, which also makes it difficult for personnel to operate the handwheel smoothly. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a hollow deceleration actuator for a stop valve, which can realize the screwing-in and screwing-out action of the stop valve screw and effectively shorten the switch time of the stop valve.

[0006] The technical solution adopted by the present invention is: A hollow deceleration actuator for a stop valve, comprising a housing, a sun gear assembly, a planet carrier assembly and an inner gear ring assembly; The sun gear assembly includes a sun gear m; The planet carrier assembly a comprises a planet carrier a, a planet gear a and a shaft a, wherein the shaft a is arranged on the planet carrier a, and the number of the shafts a is three and they are evenly arranged around the planet carrier a, the planet gear a is mounted on the corresponding shaft a through a bearing c, and the planet gear a is meshed with the sun gear m; The inner gear ring assembly is arranged on the outer side of the planet carrier assembly a, and the planetary gear a is meshed with the inner teeth of the inner gear ring assembly; The stop valve assembly is installed on the steam pipeline of the steam turbine, and a connecting plate, a connecting nut and a screw are provided at its input end. The connecting plate is fixedly connected to the bottom surface of the shell, and is drivingly connected to the planet carrier a at the top surface of the connecting nut. The screw is installed in the connecting nut through a thread.

[0007] Furthermore, a handwheel assembly is connected above the sun gear assembly, and the handwheel assembly is transmission-connected to the sun gear assembly to drive the sun gear m to rotate.

[0008] Furthermore, an upper cover is provided on the top of the housing, a bearing a is provided between the outer ring of the sun gear assembly and the inner ring of the planet carrier a, and a bearing b is provided between the planet carrier a and the upper cover.

[0009] Furthermore, a blocking cover is provided above bearing a and bearing b, the lower part of bearing a cooperates with the sun gear assembly and planet carrier a, the lower part of bearing b cooperates with the upper cover and planet carrier a, and the blocking cover is fixedly connected to the upper cover.

[0010] Furthermore, the planet carrier a is a hollow structure, and the sun gear m is provided with a corresponding hollow structure.

[0011] Furthermore, a planet carrier assembly b is provided below the planet carrier assembly a, and the planet carrier assembly b includes a planet carrier b, a planet gear b and a shaft b. The shafts b are provided on the planet carrier b, and there are three of them and they are evenly arranged around the planet carrier b. The planet gears b are installed on the corresponding shafts b through bearings d. A sun gear n is provided at the lower end of the planet carrier a. The planet gears b are located between the sun gear n and the inner gear ring assembly and are respectively meshed with them. The connecting nut is transmission connected to the planet carrier b.

[0012] Furthermore, the planet carrier b is a hollow structure.

[0013] Furthermore, a connecting cylinder is fixedly installed on the bottom surface of the planet carrier b, the lower end of the connecting cylinder is drivingly connected to the connecting nut, and bearings e are provided between the upper and lower ends of the outer side of the connecting cylinder and the outer shell.

[0014] Furthermore, the handwheel assembly includes an inner ring and an outer ring connected to the inner ring via reinforcing ribs, and the inner ring is drivingly connected to the sun gear m.

[0015] Furthermore, an extension rod is provided between the handwheel assembly and the sun gear m.

[0016] The positive effects of the present invention are: The present invention utilizes the sun gear assembly, the planetary carrier assembly a and the inner gear ring assembly to realize the screwing in and out action of the stop valve threaded rod, thereby realizing the switch action of the stop valve. Its total reduction ratio is significantly smaller than the reduction ratio of the electric actuator, which can effectively shorten the switch time of the stop valve. At the same time, the axis of the input end of the present invention is coaxially arranged with the axis of the screw in the stop valve assembly, which meets the convenience of valve operation under the ground. In addition, the electric components are removed, and the external dimensions are designed to be compact, which has obvious advantages over the existing worm gear reduction structure and bevel gear reduction structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an outline diagram of the deceleration actuator of the present invention; Figure 2 For the present invention Figure 1 Middle AA section view; Figure 3 For the present invention Figure 1 Middle BB section view; Figure 4 For the present invention Figure 1 Middle CC section view; Figure 5 For the present invention Figure 2 Middle DD section view; Figure 6 This is a schematic diagram of underground installation and underground operation of the stop valve of the present invention; Figure 7 This is a schematic diagram of the underground installation and above-ground operation of the stop valve of the present invention. DETAILED DESCRIPTION

[0018] As attached Figure 1-7 As shown, the present invention discloses a hollow deceleration actuator for a stop valve, comprising a handwheel assembly 1, a sun gear assembly 2, a planet carrier assembly a5 and an inner gear ring assembly 6.

[0019] The handwheel assembly 1 is an input port, comprising an inner ring 11 and an outer ring connected to the inner ring 11 via reinforcing ribs, and an inner keyway a111 is provided on the inner side of the inner ring 11 .

[0020] The sun gear assembly 2 includes a sun gear m21 and a bearing a23. An outer keyway d22 is provided on the top of the sun gear m21, and the outer keyway d22 is connected to the inner keyway a111 for torque and rotation transmission. Preferably, when the handwheel assembly 1 is far from the ground, an extension rod 12 (such as the attached one) is quickly connected between the handwheel assembly 1 and the sun gear m21. Figure 7As shown), the hand wheel assembly 1 is extended out of the ground for easy operation. The upper end of the extension rod 12 is provided with an outer key groove c121 for quick plug connection with the inner key groove a111, and the lower end is provided with an inner key groove b122 for quick plug connection with the outer key groove d22, thereby realizing torque and rotation transmission. The inner key groove a111, the outer key groove c121, the inner key groove b122, and the outer key groove d22 can all be changed into features such as a square quick plug connection or a hexagonal quick plug connection through design, thereby realizing the realization of torque and rotation transmission action.

[0021] The sun gear m21 is arranged at the lower position of the sun gear assembly 2 and is the primary torque input end.

[0022] The planet carrier assembly a5 includes a planet carrier a51, a planetary gear a52 and a shaft a53. Three rectangular grooves are arranged on the upper end of the planet carrier a51 for mounting and positioning the planetary gear a52. The planetary gear a52 is sleeved with a shaft a53 set through the center and a bearing c55 for radial support, thereby satisfying the planetary gear a52's rotation around the axis. Preferably, inner and outer retaining rings are arranged at both the upper and lower ends of the bearing c55 to prevent its axial movement.

[0023] The inner gear ring assembly 6 is located outside the planet carrier assembly a5, and the planetary gear a52 is located between the inner gear ring assembly 6 and the sun gear m21, and meshes with the sun gear m21 and the inner gear 61. The planetary gear a52 can rotate around its own axis a53, and mesh with the inner gear 61 provided in the inner gear ring assembly 6, thereby realizing the planetary carrier assembly a5 to revolve around the axis to meet the primary reduction.

[0024] The bearing a23 is mounted between the outer ring of the sun gear assembly 2 and the inner ring of the planetary carrier assembly a5, thereby ensuring radial support and positioning of the sun gear assembly 2 when it revolves around the axis. To prevent the axial movement of the bearing a23, a cover 3 is provided at the upper end and is fixed by bolts. The bearing b41 is mounted between the planetary carrier assembly a5 and the upper cover 4, and is used to meet the radial support and positioning of the planetary carrier assembly a5 when it revolves around the axis. At the same time, a cover 3 is provided at the upper end of the bearing b41 and is fixed by bolts to prevent its axial movement.

[0025] When the planet carrier assembly a5 revolves around the axis, it drives the three evenly distributed planetary gears a52 to revolve and rotate in mesh with the internal gear 61. A sun gear n54 is provided at the lower end of the planet carrier a51 as a secondary torque input end. Preferably, the planet carrier a51 is a hollow structure, and the sun gear m21 is provided with an equivalent hollow structure, which can meet the lifting and insertion of the screw 91 in the stop valve assembly 9.

[0026] The planet carrier assembly B7 includes a planet carrier B71, a planetary gear B72 and a shaft B73. Three rectangular grooves are arranged at the upper end of the planet carrier B71 for installing and positioning the planetary gear B72. The inner sleeve of the planetary gear B72 is provided with a shaft B73 set through the center and a bearing D75 for radial support, thereby satisfying the planetary gear B72's rotation around the axis. Preferably, both the upper and lower ends of the bearing D75 are provided with inner and outer retaining rings to prevent its axial movement. When the planet carrier assembly B7 revolves around the axis, it then drives the three evenly distributed planetary gears B72 to revolve and rotate in mesh with the inner teeth 61. A connecting tube 10 is provided at the lower end of the planet carrier B71, and a spline X74 is provided at the lower end of the connecting tube 10 as a secondary torque output end. Preferably, the planet carrier B71 is provided with a hollow structure with the same characteristics as the sun gear M21, which can meet the lifting and insertion of the screw 91 in the stop valve assembly 9. Bearings e83 are respectively mounted on the upper and lower outer rings of the planet carrier b71 to achieve radial positioning support when it revolves around the axis.

[0027] The upper end of the housing 8 is provided with an upper flange 84 fastened to the inner gear ring assembly 6 by bolts, and the lower end of the housing 8 is provided with a lower flange 81 fastened to the connecting plate 92 in the stop valve assembly 9 by bolts. Two bearings e83 are installed on the upper and lower inner diameters of the housing 8 to meet the revolution of the planet carrier b71. Preferably, the lower end of the bearing e83 is provided with an inner nut 82 and an inner retaining ring that are threadedly connected to the inner diameter of the housing 8 to prevent axial movement.

[0028] The connecting plate 92 in the stop valve 9 assembly is fixed and does not rotate, and then the lower flange 81 connected thereto and the outer shell 8 are fixed and do not rotate, thereby achieving the fixation of the inner ring gear assembly 6 connected by bolts, and can withstand the two-level counter-torque force transmitted by the meshing transmission of the sun gear M21 and the sun gear N54 through the planetary carrier assembly A5 and the planetary carrier assembly B7.

[0029] The stop valve assembly 9 is installed on the steam pipe of the steam turbine and is set under the ground. The input end is provided with a connecting plate 92, a connecting nut 94, a screw 91 and other components. The connecting plate 92 is fastened to the lower flange 81 by bolts to form an external positioning. The connecting nut 94 is pressed into the center of the connecting plate 92. The upper end of the connecting nut 94 is provided with a spline y that can transmit torque and speed to each other with the spline x74. The number of spline teeth is preferably 3 teeth. According to the design experience of engineers, 4 teeth or other number of teeth can be selected to design the transmission of torque and speed. The center of the connecting nut 94 is provided with a screw 91 connected by threaded engagement. The rotation action of the connecting nut 94 is converted into the lifting action of the screw 91 along the middle hole of the sun gear assembly 2, the middle hole of the planetary carrier assembly a5, and the middle hole of the planetary carrier assembly b7.

[0030] The operator operates the handwheel assembly 1, which in turn drives the sun gear assembly 2 and the planetary carrier assembly a5 to form a first-stage deceleration rotation of the planetary system. Then the planetary carrier assembly a5 again drives the planetary carrier assembly b7 to form a second-stage deceleration rotation of the planetary system, and transmits the torque and speed to the spline y set on the stop valve assembly 9 through the spline X74, thereby driving the screw 91 to rise and fall by the thread, and finally realizing the switching action of the stop valve assembly 9.

[0031] This embodiment is a two-stage planetary reduction. According to the torque value required for the stop valve switch, the designer can select a single-stage planetary reduction. At this time, the upper end of the connecting tube 10 is connected to the planet carrier a51.

[0032] In the present invention, the handwheel assembly 1 is the input port, the housing 8 is connected to the stop valve assembly 9, which is the output port. The sun gear assembly 2 is the primary torque input port, the planet carrier assembly a5 is the primary torque output port and the secondary torque input port, and the planet carrier assembly b7 is the secondary torque output port.

[0033] The two-stage planetary reduction is adopted to make full use of the height space of the underground stop valve. It has a compact structure and a small appearance. It also realizes the coaxial arrangement of the input handwheel and the output stop valve screw, which meets the convenience of underground valve operation by underground personnel. The existing worm gear arrangement, 90° bevel gear arrangement, and cylindrical gear transmission arrangement have been abandoned, which have the disadvantages of large volume, large space occupation, and different axes. The sun gear and planet carrier are designed as hollow structures to meet the lifting and insertion of the stop valve screw. At the same time, the two-stage planetary reduction design has a more balanced force than the traditional bevel gear transmission and cylindrical gear transmission, a smaller reduction ratio than the traditional worm gear, and a more compact volume and diameter setting.

[0034] The total reduction ratio of the present invention is significantly smaller than that of the electric actuator, which can effectively shorten the switching time of the stop valve; at the same time, the two-stage planetary gear reduction structure can meet the coaxial input and output, and realize the arrangement of the handwheel just above the stop valve, which solves the difficulty of on-site operation; three planetary gears and the inner ring gear are arranged in each level of the reduction structure to rotate, which meets the requirement of balanced force of the gear system; at the same time, the electric components are cut off, and the external dimensions are designed to be compact, which has obvious advantages over the existing worm gear reduction structure and bevel gear reduction structure.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hollow deceleration actuator for a stop valve, characterized in that It comprises a housing (8), a sun gear assembly (2), a planet carrier assembly a (5) and an inner gear ring assembly (6); The sun gear assembly (2) comprises a hollow sun gear m (21); The planet carrier assembly a (5) comprises a hollow planet carrier a (51), a planet gear a (52) and a shaft a (53), wherein the shafts a (53) are arranged on the planet carrier a (51), the number of the shafts a (53) is three and the shafts a (53) are evenly arranged around the planet carrier a (51), the planet gear a (52) is mounted on the corresponding shaft a (53) via a bearing c (55), and the planet gear a (52) is meshed with a sun gear m (21); The inner gear ring assembly (6) is arranged on the outer side of the planet carrier assembly a (5), and the planet gear a (52) is meshed with the inner teeth (61) of the inner gear ring assembly (6); The stop valve assembly (9) is installed on the steam pipeline of the steam turbine, and is provided with a connecting plate (92), a connecting nut (94) and a screw (91) at its input end. The connecting plate (92) is fixedly connected to the bottom surface of the housing (8), and is drivingly connected to the planet carrier a (51) at the top surface of the connecting nut (94). The screw (91) is installed in the connecting nut (94) through a thread.

2. A hollow deceleration actuator for a stop valve according to claim 1, characterized in that A handwheel assembly (1) is connected above the sun gear assembly (2), and the handwheel assembly (1) is transmission-connected to the sun gear assembly (2) to drive the sun gear m (21) to rotate.

3. A hollow deceleration actuator for a stop valve according to claim 1, characterized in that An upper cover (4) is provided on the top of the housing (8), a bearing a (23) is provided between the outer ring of the sun gear assembly (2) and the inner ring of the planet carrier a (51), and a bearing b (41) is provided between the planet carrier a (51) and the upper cover (4).

4. A hollow deceleration actuator for a stop valve according to claim 3, characterized in that A blocking cover (3) is provided above the bearing a (23) and the bearing b (41); the lower part of the bearing a (23) cooperates with the sun gear assembly (2) and the planet carrier a (51); the lower part of the bearing b (41) cooperates with the upper cover (4) and the planet carrier a (51); and the blocking cover (3) is fixedly connected to the upper cover (4).

5. The hollow deceleration actuator for a stop valve according to claim 1, characterized in that A planet carrier assembly b (7) is provided below the planet carrier assembly a (5), the planet carrier assembly b (7) comprising a hollow planet carrier b (71), a planet gear b (72) and a shaft b (73), three shafts b (73) are provided on the planet carrier b (71) and are evenly arranged around the planet carrier b (71), the planet gear b (72) is mounted on the corresponding shaft b (73) via a bearing d (75), a sun gear n (54) is provided at the lower end of the planet carrier a (51), the planet gear b (72) is located between the sun gear n (54) and the inner gear ring assembly (6) and is respectively meshed with the sun gear n (54) and the connecting nut (94) is drivingly connected to the planet carrier b (71).

6. A hollow deceleration actuator for a stop valve according to claim 5, characterized in that A connecting tube (10) is fixedly mounted on the bottom surface of the planet carrier b (71), the lower end of the connecting tube (10) is drivingly connected to a connecting nut (94), and a bearing e (83) is provided between the upper and lower ends of the outer side of the connecting tube (10) and the housing (8).

7. The hollow deceleration actuator for a stop valve according to claim 2, characterized in that The handwheel assembly (1) comprises an inner ring (11) and an outer ring connected to the inner ring (11) via reinforcing ribs, and the inner ring (11) is drivingly connected to a sun gear m (21).

8. The hollow deceleration actuator for a stop valve according to claim 2, characterized in that An extension rod (12) is provided between the hand wheel assembly (1) and the sun wheel m (21).

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