阅读说明：本技术 一种阀门执行器的直行程传动装置 (Straight stroke transmission device of valve actuator ) 是由 顾荣玉 高越 于 2021-08-06 设计创作，主要内容包括：本发明公开了一种阀门执行器的直行程传动装置,属于阀门执行器技术领域。主要包括基座、传动轴、旋转件、滑动件、直线驱动杆、第一齿条以及第二齿条,基座上设有用于驱动直线驱动杆转动的驱动器以及齿轮,直线驱动杆的圆柱面上开设有缺口,缺口中形成有两个相对的侧壁,两侧的侧壁上分别设有多个均匀分布的第一卡合部以及第二卡合部,第一齿条上对应第一卡合部设有第一卡合件,第二齿条邻近第一齿条,第二齿条上对应第二卡合部设有第二卡合件,齿轮位于第一齿条与第二齿条之间并分别与第一齿条与第二齿条相啮合。本发明的一种阀门执行器的直行程传动装置,适用于采用非整圈蜗轮的阀门执行器,提高阀门执行器以及直行程传动装置的适配性。(The invention discloses a straight stroke transmission device of a valve actuator, and belongs to the technical field of valve actuators. The base is provided with a driver and a gear for driving the linear driving rod to rotate, a notch is formed in the cylindrical surface of the linear driving rod, two opposite side walls are formed in the notch, a plurality of first clamping portions and second clamping portions which are uniformly distributed are arranged on the side walls of the two sides respectively, a first clamping piece is arranged on the first rack corresponding to the first clamping portions, the second rack is adjacent to the first rack, a second clamping piece is arranged on the second rack corresponding to the second clamping portions, and the gear is located between the first rack and the second rack and meshed with the first rack and the second rack respectively. The straight stroke transmission device of the valve actuator is suitable for the valve actuator adopting a non-full-circle worm wheel, and improves the adaptability of the valve actuator and the straight stroke transmission device.)

1. A straight stroke transmission device of a valve actuator is characterized in that: the valve actuator comprises a base, a transmission shaft, a rotating part, a sliding part, a linear driving rod, a first rack and a second rack, wherein the transmission shaft is arranged on the base and used for being connected with an output shaft of a valve actuator, the rotating part is rotatably arranged on the base and is in transmission connection with the transmission shaft, the sliding part is axially and slidably arranged on the base and is in threaded fit with the rotating part, the linear driving rod is axially and slidably arranged on the base along the rotating part, the first rack is fixedly arranged on the sliding part, the second rack is slidably arranged on the base, the base is provided with a driver for driving the linear driving rod to rotate and a gear which is rotatably arranged on the base, the cylindrical surface of the linear driving rod is provided with a notch, two opposite side walls are formed in the notch, and the side walls on two sides are respectively provided with a plurality of first clamping parts and second clamping parts which are uniformly distributed along the axial direction of the linear driving rod, the first rack is provided with a first clamping piece corresponding to a first clamping part on the linear driving rod, the second rack is adjacent to the first rack, the second rack is provided with a second clamping piece corresponding to a second clamping part on the linear driving rod, and the gear is positioned between the first rack and the second rack and is respectively meshed with the first rack and the second rack.

2. A valve actuator linear actuator assembly as defined in claim 1 wherein: the first clamping piece is used for enabling a first clamping portion on the linear driving rod to be axially limited with a first clamping piece on the first rack when the linear driving rod rotates in the circumferential direction, and the second clamping piece is used for enabling a second clamping portion on the linear driving rod to be axially limited with a second clamping piece on the second rack when the linear driving rod rotates.

3. A valve actuator linear actuator as defined in claim 2, wherein: the first clamping part and the second clamping part are cylindrical holes arranged on the linear driving rod, and the corresponding first clamping piece on the first rack and the corresponding second clamping piece on the second rack are cylindrical lugs respectively arranged on the first rack and the second rack.

4. A valve actuator linear actuator assembly as defined in claim 1 wherein: the base is provided with a bottom plate and a guide rod, the center of the bottom plate is provided with a sliding hole along the axial direction of the bottom plate, and the sliding hole is used for being matched with the linear driving rod to be connected to the base in a sliding mode along the axial direction of the rotating piece.

5. A valve actuator linear actuator assembly as defined in claim 1 wherein: the guide rod is fixedly installed on the base and extends along the axial direction of the base, and the sliding piece is installed on the guide rod in a sliding mode.

6. A valve actuator linear actuator assembly as defined in claim 1 wherein: the straight stroke transmission device of the valve actuator further comprises a deflection gear, the deflection gear is hollow inside, a convex block is arranged on the inner side wall of the deflection gear corresponding to the sliding groove on the straight line driving rod, the deflection gear is rotatably arranged on the base and is in transmission connection with the driver, and the sliding groove on the straight line driving rod is slidably matched and arranged on the convex block on the deflection gear.

7. A valve actuator linear actuator assembly as defined in claim 1 wherein: the base is further provided with a sliding rod, the sliding rod extends along the axial direction of the linear driving rod and is fixedly connected to the base, and the second rack is connected to the sliding rod in a sliding mode.

8. A valve actuator linear actuator assembly as defined in claim 1 wherein: and a clutch claw used for being connected with an output shaft of the valve actuator is arranged at the end part of one end of the transmission shaft, which is far away from the base.

9. A valve actuator linear actuator assembly as defined in claim 1 wherein: the base is also fixedly provided with a connecting frame, and the connecting frame is used for connecting the straight stroke transmission device of the valve actuator with the valve when in use.

10. A valve actuator linear actuator assembly as defined in claim 1 wherein: and a coupler is rotatably arranged at one end of the linear driving rod, which is used for being matched and connected with the valve rod of the valve.

Technical Field

The invention relates to the technical field of valve actuators, in particular to a straight-stroke transmission device of a valve actuator.

Background

The straight stroke transmission device of the valve actuator is a device for converting the circular motion of the rotary valve actuator into the linear motion, so that the rotary valve actuator can control a straight stroke valve (such as a gate valve), and the application range of the rotary valve actuator is enlarged. The conventional rotary valve actuator realizes power output through a worm gear and a worm, but a part of the rotary valve actuator does not adopt a full-circle worm gear, so that the rotation range of an output shaft of the valve actuator is limited, while the conventional straight stroke transmission device realizes circular motion to straight line motion simply through a screw-nut structure, cannot adapt to the valve actuator adopting the non-full-circle worm gear, or has short stroke and poor adaptability due to the limited rotation range of the output shaft of the valve actuator.

It is therefore desirable to provide a linear actuator for a valve actuator that addresses the above-mentioned problems.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the straight stroke transmission device of the valve actuator is suitable for the valve actuator adopting a non-full-circle worm wheel, and the adaptability of the valve actuator and the straight stroke transmission device of the valve actuator is improved.

The technical scheme adopted by the invention for solving the technical problems is as follows: a straight stroke transmission device of a valve actuator; the valve actuator comprises a base, a transmission shaft, a rotating part, a sliding part, a linear driving rod, a first rack and a second rack, wherein the transmission shaft is arranged on the base and used for being connected with an output shaft of a valve actuator, the rotating part is rotatably arranged on the base and is in transmission connection with the transmission shaft, the sliding part is axially and slidably arranged on the base and is in threaded fit with the rotating part, the linear driving rod is axially and slidably arranged on the base along the rotating part, the first rack is fixedly arranged on the sliding part, the second rack is slidably arranged on the base, the base is provided with a driver for driving the linear driving rod to rotate and a gear which is rotatably arranged on the base, the cylindrical surface of the linear driving rod is provided with a notch, two opposite side walls are formed in the notch, and the side walls on two sides are respectively provided with a plurality of first clamping parts and second clamping parts which are uniformly distributed along the axial direction of the linear driving rod, the first rack is provided with a first clamping piece corresponding to a first clamping part on the linear driving rod, the second rack is adjacent to the first rack, the second rack is provided with a second clamping piece corresponding to a second clamping part on the linear driving rod, and the gear is positioned between the first rack and the second rack and is respectively meshed with the first rack and the second rack.

Further, the first engaging member is configured to axially limit the first engaging portion of the linear driving rod and the first engaging member of the first rack when the linear driving rod rotates in the circumferential direction, and the second engaging member is configured to axially limit the second engaging portion of the linear driving rod and the second engaging member of the second rack when the linear driving rod rotates.

Further, the first engaging portion and the second engaging portion are cylindrical holes disposed on the linear driving rod, and the corresponding first engaging member on the first rack and the corresponding second engaging member on the second rack are cylindrical protrusions disposed on the first rack and the second rack, respectively.

Furthermore, a bottom plate and a guide rod are arranged on the base, a sliding hole is formed in the center of the bottom plate along the axial direction of the bottom plate, and the sliding hole is used for being matched with the linear driving rod to be connected to the base in a sliding mode along the axial direction of the rotating piece.

Further, the guide rod is fixedly installed on the base and extends in the axial direction of the base, and the sliding member is slidably installed on the guide rod.

Furthermore, a sliding groove extending along the axial direction of the linear driving rod is further formed in the cylindrical surface of the linear driving rod, the linear stroke transmission device of the valve actuator further comprises a deflection gear, the inside of the deflection gear is hollow, a convex block is arranged on the inner side wall of the deflection gear corresponding to the sliding groove in the linear driving rod, the deflection gear is rotatably mounted on the base and is in transmission connection with the driver, and the sliding groove in the linear driving rod is slidably mounted on the convex block in a matched mode.

Furthermore, a sliding rod is further arranged on the base, the sliding rod extends along the axial direction of the linear driving rod and is fixedly connected to the base, and the second rack is connected to the sliding rod in a sliding mode.

Furthermore, a clutch claw used for being connected with an output shaft of the valve actuator is arranged at the end part of one end, far away from the base, of the transmission shaft.

Furthermore, a connecting frame is fixedly installed on the base and used for connecting the straight stroke transmission device of the valve actuator with the valve when in use.

Furthermore, a coupler is rotatably mounted at one end of the linear driving rod, which is used for being matched and connected with the valve rod of the valve.

The invention has the beneficial effects that: the invention relates to a straight stroke transmission device of a valve actuator, which comprises a base, a transmission shaft arranged on the base and used for being connected with an output shaft of the valve actuator, a rotating piece rotationally arranged on the base and in transmission connection with the transmission shaft, a sliding piece which is slidably arranged on the base along the axial direction of the base and is in threaded fit with the rotating piece, a straight line driving rod which is slidably arranged on the base along the axial direction of the rotating piece, a first rack fixedly arranged on the sliding piece and a second rack slidably arranged on the base, wherein the base is provided with a driver used for driving the straight line driving rod to rotate and a gear rotationally arranged on the base, the cylindrical surface of the straight line driving rod is provided with a notch, two opposite side walls are formed in the notch, the side walls at two sides are respectively provided with a plurality of first clamping parts and second clamping parts which are uniformly distributed along the axial direction of the straight line driving rod, and the first clamping parts on the first rack corresponding to the straight line driving rod are provided with first clamping pieces, the second rack is adjacent to the first rack, a second clamping piece is arranged on the second rack corresponding to a second clamping part on the linear driving rod, the gear is positioned between the first rack and the second rack and is respectively meshed with the first rack and the second rack, therefore, the linear driving rod can be alternatively connected with the first rack and the second rack which move in opposite directions through the switching of the driver, therefore, no matter how the output shaft of the valve actuator rotates, the motion direction of the linear driving rod can be controlled at will by the driver, so that the output shaft of the valve actuator can rotate positively and negatively, and the linear driving rod can move towards the same direction all the time, therefore, the stroke of the straight stroke transmission device of the valve actuator is not limited by the rotation angle of the output shaft of the valve actuator, and the straight stroke transmission device can be suitable for the valve actuator adopting non-full-circle worm wheels, thereby improving the adaptability of the valve actuator.

Drawings

The invention is further illustrated by the following figures and examples.

In the figure: FIG. 1 is a perspective view of a linear actuator of the valve actuator of the present invention;

FIG. 2 is a cross-sectional view of a linear actuator of the valve actuator shown in FIG. 1;

FIG. 3 is an enlarged view of area A of FIG. 2;

FIG. 4 is a schematic structural diagram of a linear actuator rod of the linear actuator device of the valve actuator of the present invention;

FIG. 5 is a schematic diagram of the linear actuator rod and the deflection gear of the linear actuator device of the valve actuator according to the present invention;

FIG. 6 is a schematic view of the mounting plate cooperating with the first and second racks in the linear actuator of the valve actuator of the present invention;

FIG. 7 is a schematic view of the position relationship between the linear actuator rod and the first and second racks in the linear actuator of the valve actuator of the present invention;

fig. 8 is a schematic view of a bottom plate of the linear actuator of the valve actuator of the present invention.

100. A base; 110. a base plate; 111. a slide hole; 120. a guide bar; 130. a driver; 131. a drive gear; 140. mounting a plate; 150. a slide bar; 160. a gear; 170. a connecting frame; 200. a drive shaft; 300. a rotating member; 400. a slider; 500. a linear drive rod; 510. a chute; 520. a notch; 530. a first engaging portion; 540. a second engaging portion; 550. a coupling; 600. a deflection gear; 610. a bump; 700. a first rack; 710. a first engaging member; 800. a second rack; 810. a second engaging member; 820. a through hole; 900. a gear set.

Detailed Description

The present invention will now be described in detail with reference to the accompanying drawings. This figure is a simplified schematic diagram, and merely illustrates the basic structure of the present invention in a schematic manner, and therefore it shows only the constitution related to the present invention.

As shown in fig. 1, the present invention provides a linear motion actuator of a valve actuator, which includes a base 100, and a transmission shaft 200 and a linear driving rod 500 mounted on the base 100, wherein the linear motion actuator of the valve actuator is mounted between the valve actuator and a valve in use, the transmission shaft 200 is connected to an output shaft of the valve actuator, and the linear driving rod 500 is connected to a valve stem of the valve, so as to convert a circular motion of the valve actuator into a linear motion through the linear motion actuator of the valve actuator, so as to drive the valve to move.

In a specific embodiment, the base 100 is provided with a bottom plate 110, a guide rod 120 and a driver 130, the bottom plate 110 is spaced from the base 100 and is fixedly disposed at one end of the base 100, and as shown in fig. 8, a sliding hole 111 corresponding to the linear driving rod 500 is formed in the center of the bottom plate 110 along the axial direction of the bottom plate 110, and the sliding hole 111 is used for being matched with the linear driving rod 500 to be slidably connected to the base 100 along the axial direction of the base 100; the guide rods 120 are fixedly installed on the base 100 and extend along the axial direction of the base 100, and more specifically, the guide rods 120 are fixedly disposed between the base 100 and the bottom plate 110, and in the present embodiment, the guide rods 120 are provided in plurality, and the plurality of guide rods 120 are distributed on the base 100 along the circumferential direction of the base 100.

The driver 130 is mounted on the base 100, the driver 130 is a device for outputting circular motion power, in a specific embodiment, the driving gear 131 is fixedly mounted on the output shaft of the driver 130 corresponding to the linear driving rod 500, in this embodiment, the driver 130 is a motor.

Referring to fig. 2, the transmission shaft 200 is a hollow cylindrical structure, the transmission shaft 200 is rotatably mounted on the base 100 and extends in the axial direction of the base 100, in this embodiment, a clutch claw for connecting with an output shaft of a valve actuator is provided at an end of the transmission shaft 200 away from the base 100, it can be understood that the structure of the transmission shaft 200 for connecting with the output shaft of the valve actuator can be adjusted according to actual conditions, for example, a flange coupling, a connection key, and the like provided at the end of the transmission shaft 200 can also be connected with the shaft.

In one specific embodiment, the linear actuator of the valve actuator further comprises a rotary member 300, a slider 400, a deflection gear 600, a first rack 700, and a second rack 800.

The rotary member 300 is rotatably mounted on the base 100, and the rotary member 300 is in transmission connection with the transmission shaft 200, and referring to fig. 1, in a specific embodiment, the linear stroke transmission device of the valve actuator further comprises a gear set 900 for connecting the rotary member 300 with the transmission shaft 200 so as to make the rotary member 300 rotate along with the transmission shaft 200, and more specifically, the gear set 900 comprises a plurality of gears which are arranged on the transmission shaft 200, the rotary member 300 and rotatably mounted on the base 100 and are meshed with each other, and the rotary member 300 is in transmission connection with the transmission shaft 200 through meshing fit among the gears; and the rotary member 300 extends in the axial direction of the base 100, more precisely, the rotary member 300 is rotatably disposed between the base 100 and the base plate 110.

The sliding member 400 is slidably mounted on the base 100 along the axial direction of the base 100, and more specifically, the sliding member 400 is slidably mounted on the guide rod 120 on the base 100, and the sliding member 400 is in threaded engagement with the rotating member 300, so that when the rotating member 300 rotates along with the transmission shaft 200, a thrust force is generated on the sliding member 400 along the axial direction, and the sliding member 400 is driven to linearly reciprocate on the guide rod 120 on the base 100.

Referring to fig. 4, a notch 520 with a sector-shaped cross section is formed on the cylindrical surface of the linear driving rod 500 along the axial direction of the linear driving rod 500, so that two opposite side walls 521 are formed in the notch 520 along the radial direction of the linear driving rod 500; in addition, a sliding groove 510 extending along the axial direction of the linear driving rod 500 is further formed on the cylindrical surface of the linear driving rod 500.

In order to avoid affecting the stroke of the linear driving rod 500 when the rotation angle of the transmission shaft 200 is limited, in addition, a plurality of first engaging portions 530 are disposed on the side wall 521 on one side of the notch 520 on the linear driving rod 500, a plurality of second engaging portions 540 are disposed on the side wall 521 on the other side, the plurality of first engaging portions 530 and the plurality of second engaging portions 540 are uniformly distributed on the side wall 521 of the linear driving rod 500 along the axial direction of the linear driving rod 500, in this embodiment, the distance from the first engaging portions 530 to the axial line of the linear driving rod 500 is different from the distance from the second engaging portions 540 to the axial line of the linear driving rod 500, and the linear driving rod 500 passes through the sliding hole 111 of the upper bottom plate 110 of the base 100 and is in sliding fit with the sliding hole 111.

Referring to fig. 5, the deflection gear 600 is hollow, the inner sidewall of the deflection gear 600 is provided with a protrusion 610 corresponding to the sliding slot 510 of the linear driving rod 500, and referring to fig. 2, the deflection gear 600 is rotatably mounted on the base 100, the deflection gear 600 is in transmission connection with the driver 130, more precisely, the deflection gear 600 is engaged with the driving gear 131 of the driver 130, and the sliding slot 510 of the linear driving rod 500 is slidably fitted on the protrusion 610 of the deflection gear 600, so that not only the linear driving rod 500 can linearly reciprocate along the axial direction relative to the base 100, but also the linear driving rod 500 can circumferentially rotate along with the deflection gear 600.

Referring to fig. 6 and 7, the first rack 700 is fixedly installed on the slider 400 and is received in the notch 520 of the linear driving rod 500, a first engaging member 710 is fixedly disposed on the first rack 700 corresponding to the first engaging portion 530 on the linear driving rod 500, and the first engaging member 710 is configured to axially limit the first engaging portion 530 on the linear driving rod 500 and the first engaging member 710 on the first rack 700 when the linear driving rod 500 rotates circumferentially, so that the linear driving rod 500 moves linearly with the slider 400; the second rack 800 is slidably mounted on the base 100 along the axial direction of the linear driving rod 500, and the second rack 800 is accommodated in the notch 520 of the linear driving rod 500 and is adjacent to the first rack 700, the second rack 800 is parallel to the first rack 700, a second engaging member 810 is fixedly disposed on the second rack 800 corresponding to the second engaging portion 540 on the linear driving rod 500, and the second engaging member 810 is configured to axially limit the second engaging portion 540 on the linear driving rod 500 and the second engaging member 810 on the second rack 800 when the linear driving rod 500 rotates, so that the linear driving rod 500 linearly moves along with the slider 400.

Referring to fig. 3 and 6, in a specific embodiment, a mounting plate 140 and a sliding rod 150 are further disposed on the base 100, the mounting plate 140 is fixedly mounted on the base 100, the sliding rod 150 is used to cooperate with the second rack 800 to make a linear reciprocating motion on the base 100 along an axial direction of the linear driving rod 500, the sliding rod 150 extends along the axial direction of the linear driving rod 500 and is fixedly connected to the base 100, more precisely, two ends of the sliding rod 150 are respectively fixedly connected to the mounting plate 140 and the bottom plate 110, a through hole 820 is axially formed in the second rack 800 corresponding to the sliding rod 150, and the second rack 800 is slidably connected to the sliding rod 150 through the through hole 820.

Referring to fig. 3, in a specific embodiment, the base 100 is further rotatably mounted with the gear 160, and more specifically, the gear 160 is rotatably mounted on the mounting plate 140 of the base 100, and the gear 160 is located between the first rack 700 and the second rack 800, and the gear 160 is engaged with the first rack 700 and the second rack 800, respectively, so that when the first rack 700 moves linearly with the slider 400, the second rack 800 and the first rack 700 move linearly in opposite directions through the gear 160.

In the present embodiment, the first engaging portion 530 and the second engaging portion 540 are cylindrical holes disposed on the linear driving rod 500, and the corresponding first engaging piece 710 on the first rack 700 and the corresponding second engaging piece 810 on the second rack 800 are cylindrical protrusions disposed on the first rack 700 and the second rack 800, respectively.

Therefore, when the linear stroke transmission device of the valve actuator is used, when the transmission shaft 200 is connected with the output shaft of the valve actuator and the linear driving rod 500 is connected with the valve rod of the valve, even if the rotation angle of the output shaft of the valve actuator is limited, after the sliding part 400 matched with the rotating part 300 is driven to move towards one direction for a certain distance, the linear driving rod 500 can be driven to rotate circumferentially by the driver 130, so that the linear driving rod 500 is alternatively connected with the first rack 710 and the second rack 800 which move in the opposite direction, and the stroke of the linear stroke transmission device of the valve actuator can not be limited by the rotation angle of the valve actuator.

Referring to fig. 1, in order to enable the linear driving rod 500 to rotate circumferentially and connect to the valve stem, a coupling 550 is rotatably mounted on one end of the linear driving rod 500 for being coupled to the valve stem of the valve.

In one embodiment, a connecting bracket 170 is also fixedly mounted to the base 100, and the linear actuator for the valve actuator of the present invention is coupled to the valve during use.

For example, when the linear driving rod 500 needs to be driven to move in a downward direction in fig. 2, the driver 130 drives the deflection gear 600 to drive the linear driving rod 500 to rotate a certain angle towards the first engaging member 710 on the first rack 700 until the first engaging member 710 on the first rack 700 is connected to one of the first engaging portions 530 on the linear driving rod 500, and then the valve actuator drives the transmission shaft 200 and the connected rotating member 300 to rotate in one direction to drive the sliding member 400 to drive the first rack 700 and the linear driving rod 500 to move linearly downward, when the rotational angle of the output shaft of the valve actuator is limited, and the distance that the linear driving rod 500 moves downward is not enough, at this time, the control driver 130 drives the linear driving rod 500 to rotate in the opposite direction, so that the first engaging member 710 on the first rack 700 is disconnected from the first engaging portion 530 on the linear driving rod 500, and the second engaging portion 810 of the second rack 800 is connected with the second engaging portion 540 of one of the linear driving rods 500, and then the output shaft of the valve actuator rotates in the opposite direction to drive the transmission shaft 200 to rotate reversely, so that the sliding member 400 which has previously moved downwards moves back upwards, because the second rack 800 and the first rack 700 move in the opposite direction, that is, the second rack 800 moves downwards at this time, and the linear driving rod 500 is driven to continue moving downwards, therefore, when the rotation angle of the output shaft of the valve actuator is limited, the linear driving rod 500 can be switched and connected with the first rack 700 and the second rack 800 which move in the opposite direction by the driver 130, so that the movement direction of the linear driving rod 500 can be controlled at will no matter the rotation direction of the output shaft of the valve actuator, and further, the output shaft of the valve actuator can move in the same direction all the time by the forward and reverse rotation, the stroke of the straight stroke transmission device of the valve actuator is not limited by the rotation angle of the output shaft of the valve actuator, and the straight stroke transmission device can be suitable for the valve actuator adopting non-full-circle worm wheels, so that the adaptability of the valve actuator is improved.

Therefore, the straight stroke transmission device of the valve actuator has at least the following beneficial effects:

the straight stroke transmission device of the valve actuator of the invention comprises a base 100, a transmission shaft 200 which is arranged on the base 100 and is used for being connected with an output shaft of the valve actuator, a rotating member 300 which is rotatably arranged on the base 100 and is in transmission connection with the transmission shaft 200, a sliding member 400 which is arranged on the base 100 in an axial sliding way and is in threaded fit with the rotating member 300, a straight line driving rod 500 which is arranged on the base 100 in an axial sliding way along the rotating member 300, a first rack 700 which is fixedly arranged on the sliding member 300 and a second rack 800 which is arranged on the base 100 in a sliding way, wherein the base 100 is provided with a driver 130 which is used for driving the straight line driving rod 500 to rotate and a gear 160 which is rotatably arranged on the base 100, a notch 520 is arranged on the cylindrical surface of the straight line driving rod 500, two opposite side walls 521 are formed in the notch 520, a plurality of first clamping parts 530 and a plurality of second clamping parts 540 which are uniformly distributed along the axial direction of the straight line driving rod 500 are respectively arranged on the side walls 521 at two sides, the first rack 700 is provided with a first engaging member 710 corresponding to the first engaging portion 530 on the linear driving rod 500, the second rack 800 is adjacent to the first rack 700, the second rack 800 is provided with a second engaging member 810 corresponding to the second engaging portion 540 on the linear driving rod 500, the gear 160 is located between the first rack 700 and the second rack 800 and is engaged with the first rack 700 and the second rack 800 respectively, so that the linear driving rod 500 can be switched by the driver 130 to be selectively connected between the first rack 700 and the second rack 800 which move in opposite directions, so that the driver 130 can control the moving direction of the linear driving rod 500 at will no matter the rotating direction of the output shaft of the valve actuator, and the output shaft of the valve actuator can rotate in the forward and reverse directions and simultaneously the linear driving rod 500 can always move in the same direction, thereby the stroke of the linear stroke transmission device of the valve actuator of the present invention is not limited by the rotating angle of the output shaft of the valve actuator, the valve actuator can be suitable for a valve actuator adopting a non-full-circle worm wheel, so that the adaptability of the valve actuator is improved.

In light of the foregoing description of preferred embodiments in accordance with the invention, it is to be understood that numerous changes and modifications may be made by those skilled in the art without departing from the scope of the invention. The technical scope of the present invention is not limited to the contents of the specification, and must be determined according to the scope of the claims.