A locking and limiting device for a valve actuator

Abstract

This utility model provides a locking and limiting device for a valve actuator, belonging to the technical field of valve actuators. It includes a housing, a drive shaft, and a limiting assembly. The drive shaft is rotatably disposed inside the housing, and a limiting gear ring is provided on the drive shaft. The limiting assembly includes a support bar, an operating bar, a support frame, and a floating bar. The support bar is slidably disposed inside the housing, and the operating bar is disposed outside the housing, connected to the support bar via two pull rods. The support frame is disposed between the support bar and the drive shaft, with its two ends slidably connected to the two pull rods respectively. The floating bar is slidably disposed on the support frame, and multiple limiting teeth are provided on the side wall of the floating bar near the drive shaft for meshing with the limiting gear ring. The locking and limiting device for a valve actuator described in this utility model can lock and limit the rotation of the valve stem, preventing any impact on the valve opening.

Description

Technical Field

[0001] This utility model belongs to the field of valve actuator technology, and in particular relates to a locking and limiting device for valve actuators. Background Technology

[0002] A valve actuator is an automated device that drives a valve. During operation, the valve actuator receives signals from the control system and converts these signals into corresponding mechanical motions, thereby driving the internal moving parts of the valve to achieve precise control over the flow, pressure, or direction of the medium. In existing technology, valve actuators can be broadly classified into three types: electric valve actuators, pneumatic valve actuators, and hydraulic valve actuators. Among these, electric valve actuators are widely used due to their high control accuracy and good safety and reliability.

[0003] In practical applications, power outages are unavoidable in production environments. After a power outage, the valve actuator loses its power source. If the valve is in a critical throttling or shut-off position at this time, its stem can easily rotate abnormally under the influence of the internal medium, causing a change in the valve opening. To solve this problem, those skilled in the art typically use a toothed protrusion to restrain and limit the gear on the valve actuator's output shaft, thereby preventing abnormal rotation of the valve stem during power failure. However, in existing technologies, the relative position between the toothed protrusion and the gear cannot be adaptively adjusted, thus failing to ensure that the toothed protrusion is perfectly aligned with the gear's teeth at the moment of power failure. This necessitates first rotating the output shaft before locking and limiting, which is not only inefficient but also causes a change in the valve opening, affecting the accuracy of medium control. Utility Model Content

[0004] In view of this, the present invention aims to provide a locking and limiting device for valve actuators to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A locking and limiting device for a valve actuator includes: a housing, a drive shaft, and a limiting assembly; the drive shaft is rotatably disposed inside the housing, its top end is connected to the output shaft of the valve actuator, its bottom end is connected to the valve stem, and a limiting gear ring is provided on the drive shaft; the limiting assembly includes: a support bar, an operating bar, a support frame, and a floating bar; the support bar is slidably disposed inside the housing, and the sliding direction of the support bar is perpendicular to the axial direction of the drive shaft; the operating bar is disposed outside the housing, with the operating bar and the support bar located on opposite sides of the drive shaft, and the operating bar is connected to the support bar. The operating bar is connected to the support bar via two parallel tie rods; a threaded hole is provided on the operating bar, and a locking screw is provided inside the threaded hole, with the end of the locking screw abutting against the side wall of the housing; the support frame is disposed between the support bar and the drive shaft, and the two ends of the support frame are slidably connected to the two tie rods respectively; the floating bar is slidably disposed on the support frame, and multiple limiting teeth are provided on the side wall of the floating bar near the drive shaft for meshing with the limiting tooth ring. The sliding direction of the floating bar is perpendicular to the sliding direction of the support bar, and the sliding direction of the floating bar is perpendicular to the axial direction of the drive shaft.

[0007] Furthermore, the support frame includes a guide rod and two connecting seats. The floating bar is provided with a guide hole for accommodating the guide rod. The two connecting seats are respectively disposed at both ends of the guide rod, and the two connecting seats are slidably sleeved on the two pull rods.

[0008] Furthermore, two floating springs are sleeved on the guide rod, and the two floating springs are located on both sides of the floating bar.

[0009] Furthermore, the guide rod is provided with a limiting strip, the length direction of which is parallel to the length direction of the guide rod, and a limiting groove for accommodating the limiting strip is provided inside the guide hole.

[0010] Furthermore, a first friction plate is provided on the side wall of the floating bar near the support bar, and a second friction plate is provided on the side wall of the support bar near the floating bar, which is opposite to the first friction plate, and the area of ​​the second friction plate is larger than the area of ​​the first friction plate.

[0011] Furthermore, the pull rod is equipped with a return spring, and the return spring is located between the support bar and the bearing frame.

[0012] Furthermore, the top end of the drive shaft is provided with a first spline sleeve, and the top surface of the housing is provided with a first connecting pipe for accommodating the first spline sleeve, and the top end of the first connecting pipe is provided with a first flange; the bottom end of the drive shaft is provided with a second spline sleeve, and the bottom surface of the housing is provided with a second connecting pipe for accommodating the second spline sleeve, and the top end of the second connecting pipe is provided with a second flange.

[0013] Furthermore, the side wall of the housing is provided with a receiving groove for accommodating the end of the locking screw.

[0014] Compared with the prior art, the locking and limiting device for valve actuators described in this utility model has the following advantages:

[0015] (1) The locking and limiting device for a valve actuator described in this utility model has a limiting toothed ring on the transmission shaft and multiple limiting teeth on the floating bar. When it is necessary to lock and limit the valve stem, the operator can pull the operating bar so that the limiting teeth on the floating bar can be embedded into the tooth gaps on the limiting toothed ring, thereby limiting the rotation of the transmission shaft. Since the output shaft of the valve actuator is connected to the valve stem through the transmission shaft, the valve stem will also be limited to rotation after the transmission shaft is limited to rotation, thus preventing abnormal rotation of the valve stem. Secondly, the floating bar in this device can slide on the support frame. Therefore, when there is a misalignment between the limiting teeth and the tooth gaps on the limiting toothed ring, the floating bar can adjust the position of the limiting teeth by sliding, thereby achieving locking and limiting without changing the valve opening, and preventing the accuracy of media control from being affected. In addition, the device is equipped with a locking screw on the operating bar. After the limiting teeth are inserted into the gap on the limiting tooth ring, the operator can tighten the locking screw so that the support bar and the limiting tooth ring can tightly and reliably clamp the floating bar, thereby preventing abnormal slippage of the floating bar and improving the locking and limiting effect of the valve stem.

[0016] (2) The locking and limiting device for a valve actuator described in this utility model has a limiting strip on the guide rod and a limiting groove in the guide hole. Therefore, when the floating strip slides, it can prevent the floating strip from rotating and ensure that the limiting teeth always face the limiting tooth ring. At the same time, the device has a first friction plate and a second friction plate on the floating strip and the support strip respectively, which can increase the frictional resistance between the floating strip and the support strip and further improve the locking and limiting effect of the device. Attached Figure Description

[0017] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0018] Figure 1 This is a schematic diagram of the locking and limiting device for the valve actuator according to an embodiment of the present invention;

[0019] Figure 2 This is a cross-sectional view of the locking and limiting device for the valve actuator described in an embodiment of the present invention;

[0020] Figure 3This is a cross-sectional view of the locking and limiting device for the valve actuator described in this embodiment of the present invention from another angle;

[0021] Figure 4 This is an exploded view of the locking and limiting device for the valve actuator described in this embodiment of the utility model;

[0022] Figure 5 This is an exploded view of the limiting component described in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1-Housing; 11-First connecting pipe; 111-First flange; 12-Second connecting pipe; 121-Second flange; 13-Receiving groove; 2-Drive shaft; 21-Limiting toothed ring; 22-First spline sleeve; 23-Second spline sleeve; 31-Support bar; 311-Second friction plate; 32-Operating bar; 321-Threaded hole; 33-Pull rod; 331-Reset spring; 41-Connecting seat; 42-Guide rod; 421-Limiting bar; 43-Floating spring; 5-Floating bar; 51-Limiting tooth; 52-Guide hole; 521-Limiting groove; 53-First friction plate; 6-Locking screw. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0026] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] A locking and limiting device for a valve actuator, the structure of which can be made of Figures 1-5 The following is an illustration. In this embodiment, the locking and limiting device for the valve actuator includes: a housing 1, a drive shaft 2, and a limiting assembly. The housing 1 provides installation space for other components in the device, the drive shaft 2 connects the output shaft of the valve actuator to the valve stem, and the limiting assembly limits the drive shaft 2 when power is off, thereby preventing abnormal rotation of the valve stem after the valve controller fails and ensuring that the valve opening is not affected by abnormal media flow.

[0030] Specifically, such as Figure 2 , Figure 3 and Figure 4 As shown, the drive shaft 2 is rotatably mounted inside the housing 1, and a limiting gear ring 21 is provided on the drive shaft 2. In use, the top end of the drive shaft 2 is connected to the output shaft of the valve actuator, and the bottom end of the drive shaft 2 is connected to the valve stem, so that the torque in the output shaft of the valve actuator can be input into the valve stem through the drive shaft 2, thereby controlling the rotation of the valve stem and adjusting the valve opening.

[0031] Optionally, to facilitate the assembly of this device with the valve actuator and valve stem, a first spline sleeve 22 can be provided at the top of the drive shaft 2, and a second spline sleeve 23 can be provided at the bottom of the drive shaft 2. Correspondingly, a first connecting pipe 11 for accommodating the first spline sleeve 22 should be provided on the top surface of the housing 1, with a first flange 111 at the top of the first connecting pipe 11. A second connecting pipe 12 for accommodating the second spline sleeve 23 should be provided on the bottom surface of the housing 1, with a second flange 121 at the top of the second connecting pipe 12. During assembly, spline shafts should be provided at the bottom of the valve actuator output shaft and the top of the valve stem. After the spline shafts at the bottom of the valve actuator output shaft and the top of the valve stem are respectively inserted into the first spline sleeve 22 and the second spline sleeve 23, the operator can fix the housing 1 to the valve actuator using the first flange 111 and fix the housing 1 to the valve body using the second flange 121, thus achieving effective assembly between the valve actuator, this device, and the valve.

[0032] It should be noted that in this embodiment, the first spline sleeve 22 and the second spline sleeve 23 should be assembled with the drive shaft 2 in a detachable manner, and the housing 1 can also adopt a split structure, thereby reducing the assembly difficulty of each component in this device.

[0033] like Figure 3 and Figure 5 As shown, in this embodiment, the limiting component includes: a support bar 31, an operating bar 32, a support frame, and a floating bar 5. The support bar 31 is slidably disposed inside the housing 1, and its sliding direction is perpendicular to the axial direction of the transmission shaft 2. The operating bar 32 is disposed outside the housing 1, located on both sides of the transmission shaft 2, and connected to the support bar 31 via two parallel tie rods 33. The support frame is disposed between the support bar 31 and the transmission shaft 2, and its two ends are slidably connected to the two tie rods 33. The floating bar 5 is slidably disposed on the support frame. Multiple limiting teeth 51 for meshing with the limiting toothed ring 21 are provided on the side wall of the floating bar 5 near the transmission shaft 2. The sliding direction of the floating bar 5 is perpendicular to the sliding direction of the support bar 31 and also perpendicular to the axial direction of the transmission shaft 2.

[0034] When the valve stem needs to be locked and limited, the operator can pull the operating bar 32 outward (away from the drive shaft 2) to move the support bar 31 and the carrier frame closer to the drive shaft 2. When the limiting tooth 51 contacts the limiting tooth ring 21, if there is a misalignment between the limiting tooth 51 on the floating bar 5 and the tooth gap on the limiting tooth ring 21, the floating bar 5 will slide on the carrier frame to align the limiting tooth 51 with the tooth gap on the limiting tooth ring 21, preventing the valve opening from changing due to the rotation of the drive shaft 2 and the valve stem. Next, continuing to pull the operating bar 32 outward will cause the limiting tooth 51 to insert into the tooth gap on the limiting tooth ring 21, and the support bar 31 and the limiting tooth ring 21 will tightly clamp the floating bar 5, thereby limiting the rotation of the drive shaft 2 and preventing abnormal sliding of the floating bar 5. After the transmission shaft 2 is limited to a certain position, the valve stem will be unable to rotate. This prevents the valve opening from being affected by the flow of the medium and ensures that the valve still has good medium control accuracy after the valve actuator is de-energized.

[0035] In addition, to prevent the limiting teeth 51 from disengaging from the teeth on the limiting ring 21 during the locking and limiting process, the operating bar 32 should also be provided with a threaded hole 321. A locking screw 6 is provided inside the threaded hole 321, and the end of the locking screw 6 abuts against the side wall of the housing 1. After the locking and limiting is completed, the operator can tighten the locking screw 6, thereby strengthening the locking and limiting effect of the device by using the abutment of the locking screw 6 against the housing 1.

[0036] Optionally, to improve the abutting effect of the locking screw 6 on the housing 1, a receiving groove 13 for accommodating the end of the locking screw 6 may be provided on the side wall of the housing 1, thereby improving the stability of the locking screw 6 abutting on the housing 1 by means of the receiving groove 13.

[0037] In addition, to increase the frictional resistance between the floating strip 5 and the support strip 31, a first friction plate 53 can be provided on the side wall of the floating strip 5 near the support strip 31, and a second friction plate 311, opposite to the first friction plate 53, can be provided on the side wall of the support strip 31 near the floating strip 5, with the area of ​​the second friction plate 311 being larger than that of the first friction plate 53. When the support strip 31 and the limiting toothed ring 21 tightly clamp the floating strip 5, the first friction plate 53 will come into contact with the second friction plate 311, thereby increasing the frictional resistance between the floating strip 5 and the support strip 31 and preventing abnormal movement of the floating strip 5. At the same time, since the area of ​​the second friction plate 311 is larger than that of the first friction plate 53, it can be ensured that even after the floating strip 5 slides, the first friction plate 53 can still come into contact with the second friction plate 311, so that the device can achieve a good limiting effect for the floating strip 5 under different working conditions.

[0038] To achieve a sliding connection between the support frame and the tie rod 33, the support frame in this embodiment may include a guide rod 42 and two connecting seats 41. The two connecting seats 41 are respectively disposed at both ends of the guide rod 42, and are slidably sleeved on the two tie rods 33. Furthermore, to achieve a sliding connection between the floating bar 5 and the support frame, the floating bar 5 should also be provided with guide holes 52 for accommodating the guide rod 42, thereby guiding the floating bar 5 to slide by means of the cooperation between the guide holes 52 and the guide rod 42.

[0039] Optionally, to prevent abnormal rotation of the floating bar 5 during sliding, a limiting bar 421 parallel to the length direction of the guide rod 42 can be provided on the guide rod 42, and a limiting groove 521 for accommodating the limiting bar 421 can be provided inside the guide hole 52. The cooperation of the limiting bar 421 and the limiting groove 521 can circumferentially limit the floating bar 5 to ensure that the limiting teeth 51 always face the limiting tooth ring 21.

[0040] As an optional implementation of this embodiment, to improve the ease of operation of the device, the limiting component may further include a floating spring 43 and a return spring 331. Specifically, two floating springs 43 may be sleeved on the guide rod 42, and the two floating springs 43 should be located on both sides of the floating bar 5 respectively. By setting the floating springs 43, the floating bar 5 can be reset to the central position of the guide rod 42 after the limiting tooth 51 disengages from the limiting tooth ring 21, which facilitates the floating bar 5 to slide and adjust according to the position of the tooth gap of the limiting tooth ring 21 during the next locking and limiting. The return spring 331 is sleeved on the pull rod 33, and the return spring 331 should be located between the support bar 31 and the bearing frame. By setting the return spring 331, a gap can be formed between the bearing frame and the support bar 31 when the device is not locked and limited, so that the floating bar 5 can slide flexibly during the next locking and limiting.

[0041] The effects of the above solution are explained below:

[0042] This embodiment provides a locking and limiting device for a valve actuator. It can limit the rotation of the drive shaft through the engagement of limiting teeth and a limiting ring, thereby preventing changes in the valve opening after power failure. Secondly, the floating bar in this device can slide on the support frame. Therefore, when there is misalignment between the teeth on the limiting teeth and the limiting ring, the position of the limiting teeth can be adjusted by sliding the floating bar, thus achieving locking and limiting without changing the valve opening and preventing any impact on the accuracy of media control. Furthermore, this device can securely and reliably clamp the floating bar to the support bar and the limiting ring through a locking screw, and can increase the frictional resistance between the floating bar and the support bar through the first and second friction plates, preventing abnormal slippage of the floating bar in the locked and limited state.

[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A locking and limiting device for valve actuators, characterized in that, include: The housing (1), drive shaft (2), and limiting assembly are provided. The drive shaft (2) is rotatably disposed inside the housing (1). The top end of the drive shaft (2) is connected to the output shaft of the valve actuator, and the bottom end of the drive shaft (2) is connected to the valve stem. A limiting gear ring (21) is provided on the drive shaft (2). The limiting assembly includes a support bar (31), an operating bar (32), a support frame, and a floating bar (5). The support bar (31) is slidably disposed inside the housing (1), and the sliding direction of the support bar (31) is perpendicular to the axial direction of the transmission shaft (2); the operating bar (32) is disposed outside the housing (1), and the operating bar (32) and the support bar (31) are respectively located on both sides of the transmission shaft (2), and the operating bar (32) is connected to the support bar (31) through two parallel tie rods (33); a threaded hole (321) is also provided on the operating bar (32), and a locking screw (6) is provided inside the threaded hole (321), and the locking screw (6) The end of the support bar (31) abuts against the side wall of the housing (1); the support frame is set between the support bar (31) and the drive shaft (2), and the two ends of the support frame are slidably connected to the two pull rods (33); the floating bar (5) is slidably set on the support frame, and multiple limiting teeth (51) for meshing with the limiting tooth ring (21) are provided on the side wall of the floating bar (5) near the drive shaft (2). The sliding direction of the floating bar (5) is perpendicular to the sliding direction of the support bar (31), and the sliding direction of the floating bar (5) is perpendicular to the axial direction of the drive shaft (2).

2. The locking and limiting device for valve actuators according to claim 1, characterized in that: The support frame includes a guide rod (42) and two connecting seats (41). The floating bar (5) is provided with a guide hole (52) for accommodating the guide rod (42). The two connecting seats (41) are respectively disposed at both ends of the guide rod (42) and are respectively slidably sleeved on the two pull rods (33).

3. The locking and limiting device for valve actuators according to claim 2, characterized in that: Two floating springs (43) are fitted on the guide rod (42), and the two floating springs (43) are located on both sides of the floating bar (5).

4. The locking and limiting device for valve actuators according to claim 2, characterized in that: The guide rod (42) is provided with a limiting strip (421), the length direction of the limiting strip (421) is parallel to the length direction of the guide rod (42), and a limiting groove (521) for accommodating the limiting strip (421) is provided inside the guide hole (52).

5. The locking and limiting device for valve actuators according to claim 1, characterized in that: The floating bar (5) has a first friction plate (53) on the side wall near the support bar (31), and a second friction plate (311) is provided on the side wall near the floating bar (5) of the support bar (31) opposite to the first friction plate (53), and the area of ​​the second friction plate (311) is larger than the area of ​​the first friction plate (53).

6. The locking and limiting device for valve actuators according to claim 1, characterized in that: The pull rod (33) is provided with a return spring (331), and the return spring (331) is located between the support bar (31) and the bearing frame.

7. The locking and limiting device for valve actuators according to claim 1, characterized in that: The top end of the drive shaft (2) is provided with a first spline sleeve (22), and the top surface of the housing (1) is provided with a first connecting pipe (11) for accommodating the first spline sleeve (22), and the top end of the first connecting pipe (11) is provided with a first flange (111); the bottom end of the drive shaft (2) is provided with a second spline sleeve (23), and the bottom surface of the housing (1) is provided with a second connecting pipe (12) for accommodating the second spline sleeve (23), and the top end of the second connecting pipe (12) is provided with a second flange (121).

8. The locking and limiting device for valve actuators according to claim 1, characterized in that: The side wall of the housing (1) is provided with a receiving groove (13) for accommodating the end of the locking screw (6).

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