CN211117899U

CN211117899U - Shifting fork actuator

Info

Publication number: CN211117899U
Application number: CN201921438431.0U
Authority: CN
Inventors: 约瑟夫·孙; 李塔; 李克芹; 埃德温·施勒德
Original assignee: Emerson Process Management Valve Automation Tianjin Co Ltd
Current assignee: Emerson Process Management Tianjin Valves Co Ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2020-07-28
Anticipated expiration: 2029-08-30

Abstract

The utility model relates to a shift fork executor. Wherein, this shift fork executor includes drive module and cylinder body. The driving module is provided with a sliding block and a shifting fork, so that the sliding block can be translated to drive the shifting fork to swing. The cylinder body is arranged on the side part of the driving module. The cylinder body includes a piston, a first piston rod and a second piston rod. The piston is slidably disposed within the cylinder. The first piston rod and the second piston rod are fixedly connected to the piston and the slider respectively. Therefore, the piston drives the sliding block to translate through the first piston rod and the second piston rod. The two piston rods are connected with the piston in a symmetrical mode, so that the load of the piston rods acting on the piston can be more uniformly distributed on the piston, the stress concentration on the piston is reduced, the generation of bending moment is reduced, and the friction between parts sliding relatively and the abrasion of a sealing element are reduced.

Description

Shifting fork actuator

Technical Field

The utility model relates to a shift fork executor specifically relates to a pneumatic shift fork executor with double piston rod.

Background

The shifting fork actuator is a piston type actuating mechanism, which is generally used in the oil and gas industry for controlling the opening and closing of a valve of a pipeline. As shown in fig. 5, prior art fork actuators generally have a cylinder 701, a drive module 702, and a spring cylinder 703. The air cylinder and the spring cylinder are respectively positioned on two sides of the driving module. A piston rod 704 connects a piston 705 in a cylinder and a slider 706 in a drive module. Spring rod 709 connects spring plate 707 and slide block 706 in the spring cylinder. The shifting fork actuator utilizes a piston rod and a spring rod to transfer the translational movement of a piston and a spring plate to a slide block in a driving module. The slider is associated with a fork 708 in the drive module, so that translation of the slider is converted into oscillating movement of the fork 708 for controlling the opening and closing of the valve. Specifically, when the cylinder 701 is inflated, as the gas pressure is continuously increased, the gas pressure pushes the piston to translate in the cylinder along a first direction, so as to drive the slider to translate, and push the spring to store elastic potential energy; when the cylinder 701 is deflated, the spring, through the spring rod, drives the slider and thus the piston in translation in the direction opposite to the first direction, as the gas pressure decreases.

Prior art fork actuators typically connect the piston to the slide via a single piston rod 704. A guide bar 730 extending through the slider guides the movement of the slider. In this prior art arrangement, the piston is moved under the combined action of the gas pressure and the reaction force of the piston rod. Since the piston rod is attached to the center of the piston, the gas pressure creates bending stresses on the piston. And as the diameter and the air pressure of the piston increase, the bending stress becomes large. In the case of an increase in bending stress, the thickness of the piston needs to be increased accordingly. Moreover, when the slider is driven to move on the guide rod via a single piston rod, the slider is stressed asymmetrically, so that a certain friction force exists between the guide rod and the slider, a bending moment is easily generated in the piston rod system, and the piston rod is deformed.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems of the prior art that the bending stress generated on the piston of the shifting fork actuator is large and the bending moment generated in the system is asymmetric due to stress, the utility model provides a shifting fork actuator with double piston rods.

According to the utility model discloses a shift fork executor includes drive module and cylinder body. Wherein, drive module is provided with slider and shift fork for the translation of slider drives the swing of shift fork. The cylinder body is arranged on the side part of the driving module. Wherein, the cylinder body includes: a piston disposed within the cylinder and slidably translatable within the cylinder; a first piston rod fixedly connected to the piston and fixedly connected to the slider; and a second piston rod fixedly connected to the piston and fixedly connected to the slider. Thereby, the piston drives the slider to translate through the first piston rod and the second piston rod.

The first piston rod and the second piston rod are arranged in parallel, and the positions connected with the pistons are symmetrically arranged relative to the centers of the pistons. And wherein the positions at which the first piston rod and the second piston rod are connected to the slider are symmetrically arranged with respect to the center of the slider.

Wherein the drive module has a guide bar. The guide bar is provided to extend through the center of the slider so that the slider can be supported on and slid along the guide bar. Wherein the first piston rod, the second piston rod and the guide rod are arranged parallel to each other.

Wherein the slider has first and second piston rod bores and a guide rod bore. The first and second piston rods extend through the first and second piston rod bores, respectively. The guide rod extends through the guide rod aperture.

Wherein, the slider has a slider pinhole. And a slide block pin is arranged in the slide block pin hole. The shifting fork is provided with a shifting fork groove. The slider pin can slide in the fork groove.

The first piston rod and the second piston rod are provided with clamping ring grooves, and clamping rings can be arranged in the clamping ring grooves to realize the fixed connection of the first piston rod and the second piston rod with the sliding block and the piston.

Wherein the first piston rod and the second piston rod are fixedly connected to the piston through a threaded connection.

Wherein the fork actuator further comprises a first tie rod and a second tie rod. End covers are arranged at two ends of the cylinder body. The first and second tie rods extend through the entire cylinder and through tie rod bores in the piston, ultimately supporting and being secured to the end caps.

Wherein the first and second tie bars are symmetrically disposed with respect to the center of the piston, and the plane in which the first and second tie bars lie is orthogonal to the plane in which the first and second piston rods lie.

The shifting fork actuator is provided with two cylinder bodies, and the two cylinder bodies are a first cylinder body and a second cylinder body. The first cylinder body and the second cylinder body are respectively arranged on two sides of the driving module. The first piston rod and the second piston rod are fixedly connected with the first piston of the first cylinder body and the second piston of the second cylinder body in a sealing mode. The first piston and the second piston simultaneously drive the sliding block to translate through the first piston rod and the second piston rod. Wherein the first and second cylinders can be spring-piston cylinders integrating a spring cylinder with a cylinder in one cylinder. Wherein the first and second cylinders can be cylinders.

Wherein the fork actuator has a cylinder body provided at a side of the driving module. The first piston rod and the second piston rod are fixedly connected with the piston of the cylinder body in a sealing mode. Wherein the cylinder body can be a spring-piston cylinder integrating a spring cylinder with a cylinder in one cylinder body. Wherein the cylinder block can be a cylinder.

The shifting fork actuator is provided with two cylinder bodies, and the two cylinder bodies are a first cylinder body and a second cylinder body. The first cylinder body and the second cylinder body are respectively arranged on two sides of the driving module. Wherein, the first cylinder body is a cylinder; the second cylinder body is a spring cylinder.

The two piston rods are connected with the piston in a symmetrical mode, so that the load of the piston rods acting on the piston can be more uniformly distributed on the piston, the bending stress generated on the piston due to the action of air pressure is reduced, the thickness of the piston can be reduced, and materials are saved. Meanwhile, the piston rods on the sliding blocks are symmetrically arranged on two sides of the guide rod, so that the stress of the sliding blocks is symmetrical, the friction force between the guide rod and the sliding blocks can be reduced, and the bending stress of the sliding blocks acting on the guide rod is reduced.

Drawings

Fig. 1 is a cross-sectional view illustrating an exemplary shift fork actuator according to the present invention.

Fig. 2 is a sectional view showing a driving module of a shift fork actuator according to the present invention.

Fig. 3a to 3d are perspective views of a slider and front views of three exemplary embodiments of a slider, respectively.

Fig. 4a, 4b and 4c are a perspective view, a front view and a cross-sectional view H-H of the piston, respectively.

Fig. 5 shows a prior art fork actuator.

Detailed Description

As described above, in the prior art fork actuator, the slider connected to the fork is driven by a single piston rod and guided by the guide rod. In this structure, since the piston rod is connected to the center of the piston, the piston generates a large bending stress by the gas pressure. Meanwhile, as the guide rod does not penetrate through the center of the sliding block, the bending stress generated by the guide rod is increased by the friction force generated on the sliding block, so that the sealing ring on the piston is seriously abraded. It is sometimes necessary to add wear-resistant bearing washers, which in turn requires an increase in piston thickness. In order to solve the problem, the utility model provides a shift fork executor with double-piston rod. The two piston rods can be fixedly connected with the piston and the sliding block in a symmetrical mode. Compared with the structure of a single piston rod, the two piston rods are connected with the piston in a symmetrical mode, so that the load of the piston rods acting on the piston can be more evenly distributed on the piston, the stress concentration on the piston is reduced, and the thickness of the piston can be reduced. Due to the symmetrical structural design, bending stress on the piston and the guide rod is reduced, so that the thickness of the piston and the abrasion of a sealing ring on the piston can be reduced.

The overall structure of the shift fork actuator according to the present invention will be described in detail below with reference to the accompanying drawings. As shown in fig. 1 and 2, the fork actuator 1 has a drive module 10 and spring-

piston cylinders

20, 30. In the exemplary embodiment shown, the fork actuator 1 has a drive module 10 and two spring-

piston cylinders

20, 30 arranged on both sides of the drive module 10. In other embodiments, the fork actuator may have only one spring-piston cylinder. According to this exemplary embodiment, the drive module 10 has a slide 11, a fork 12,

piston rods

13 and 14, a guide rod 15 and a drive housing 16. Wherein the slider 11 and the fork 12 are arranged in the drive housing 16. The guide rod 15 is fixedly supported at both ends thereof on the end caps 25, 35. The slider 11 is supported by and slidable along a guide rod 15. The

piston rods

13, 14 are fixedly connected to the slide 11 and extend through the slide 11 into the spring-

piston cylinders

20, 30 and are supported on the

pistons

21, 31.

The structure of the integrated spring-piston cylinder 20 according to the invention is described in detail below with reference to fig. 1. The spring-piston cylinder 20 has a piston 21, a spring 22, spring seats 26, 27, a housing 23, and end

caps

24, 25. The piston 21, the spring 22, and the spring seats 26, 27 are provided in the housing 23. End caps 24, 25 are attached to both ends of the housing 23 to form an airtight chamber with the housing 23. The piston 21 is in airtight contact with the inner surface of the housing 23 and is capable of sliding translation along the inner surface of the housing. The piston 21 has a first side 211 and a second side 212. The first side 211, the end cap 25 and the housing 23 enclose a cylinder chamber 201. Second side 212, end cap 24, and housing 23 form spring chamber 202. Spring seats 26, 27 are fixed to the end cap 24 and the piston 21, respectively. The spring seats 26, 27 have guide rod holes 261, 271 at the bottom centers thereof. The guide rod 267 extends through the guide rod aperture. Stoppers are provided at both ends of the guide bar 267 to prevent the guide bar 267 from slipping out of the guide bar holes 261, 271. The spring 22 is disposed in the spring chamber 202 and on the two cylindrical spring seats 26, 27. Spring seats 26, 27 are used to support and guide spring 22. The spring-piston cylinder 20 is provided with two tie rods, only the tie rod 28 being shown in fig. 1, symmetrically arranged about the centre of the piston. A tie rod 28 extends through the entire spring-piston cylinder 20 and through a tie rod bore of the piston 21 to ultimately support and secure the end caps at both ends of the spring-piston cylinder to the combined

end caps

24, 25.

The end caps 34, 35 of the spring-piston cylinder 30 are connected to both ends of the housing 33 to form an airtight chamber together with the housing 33. The chambers include a cylinder chamber 301 and a spring chamber 302. The spring-piston cylinder 30 is substantially identical in construction to the spring-piston cylinder 20, except that the cylinder chambers are oriented differently from the spring chambers within the spring-piston cylinder, and will not be described in further detail herein.

Fig. 2 shows a drive module of a fork actuator according to the invention. As shown in fig. 2, the slider pin 111 is fixedly disposed in a slider pin hole 112 provided on the slider 11. The shift fork 12 has a fork groove 121 and a shaft hole 124. A fork shaft 122 supported on the drive section housing 16 extends through the shaft hole 124 to support the fork 12. A pin 125 disposed between fork 12 and fork shaft 122 limits relative rotation between fork shaft 122 and fork 12. The slider pin 111 provided on the slider 11 is provided in the fork groove 121 and can slide in the fork groove 121. When the slide 11 is translated by the piston rod, the slide pin 111 translates with the slide 11 and pushes the wall of the fork slot 121, thereby oscillating the fork 12 about the central axis of the fork shaft 122.

Fig. 3a-3c show exemplary perspective and front views of a slider. But the slider shape is not limited to the shape shown. The slider 11 has a slider pin hole 112, a guide rod hole 113 and piston rod holes 114, 115 extending through the slider. The guide rod hole 113 is provided in the center of the slider. The piston rod bores 114, 115 are arranged symmetrically with respect to the guide rod bore 113. The central axes of the piston rod bores 114, 115 and the guide rod bore 113 are parallel to each other. The slider pin 111 is disposed in the slider pin hole 112.

The first piston rod 13 and the second piston rod 14 extend through the piston rod bores 114, 115, respectively, and are fixedly connected to the slide 11, so that a movement of the piston rods causes the slide to move. As shown in fig. 1, the connection between the

piston rods

13 and 14 and the slider 11 is as follows: the

piston rods

13, 14 may be provided with snap ring grooves in which snap rings are provided to limit the relative movement between the slider and the piston rod. However, the connection manner of the piston rod and the slider is not limited thereto. The piston rod and the slider can be fixedly connected by means of, for example, a threaded connection. The

piston rods

13, 14 extend through holes in the end caps 25, 35 and into the two spring-piston cylinders. The piston rod is fitted in a sealing manner with a hole in the

end cap

25, 35.

As shown in fig. 4a-4c, the piston 21 in the spring-piston cylinder 20 has two piston rod bores 213, 214 and two tie rod bores 215, 216. In this case, the two piston rod bores 213, 214 are arranged symmetrically with respect to the center of the piston. Two tie rod holes 215, 216 are also symmetrically disposed about the center of the piston. The line connecting the piston rod holes 213, 214 and the line connecting the tie rod holes 215, 216 are perpendicular to each other.

Annular sealing grooves

2131 and 2141 for receiving seals are provided in the two piston rod bores 213, 214. The piston is provided with a sealing groove 217 on its outer periphery for receiving a sealing member. Referring to fig. 1, the piston 21 is fitted in a sealed manner with the inner surface of the housing 23 when the piston 21 is fitted in the housing 23. The piston 31 in the spring-piston cylinder 30 has a similar structure and will not be described in detail.

One end of the first and

second piston rods

13, 14 extends through the two piston rod bores 213, 214 of the piston 21 and is fixedly connected in a sealing manner to the piston 21. A first piston rod 13 and

the other end of the second piston rod 14 extends through two piston rod bores of a piston 31 in the spring-piston cylinder 30 and is fixedly connected in a sealing manner to the piston 31. As shown in fig. 1 by way of example, the

piston rods

13, 14 are connected to the

pistons

21, 31 in such a way that: two snap ring grooves are provided near both ends of the

piston rods

13, 14, respectively, and a snap ring is provided in the snap ring grooves to restrict relative movement between the piston and the piston rods. This manner of connection is merely exemplary. The

piston rods

13, 14 and the

pistons

21, 31 can also be fixedly connected, for example by screwing. The first piston rod 13 and the second piston rod 14 are arranged in parallel. And a sealing element is arranged in the groove of the piston rod hole of the piston, so that the sealing between the piston and the piston rod is realized. With this connection, when the piston is pushed, it carries the

piston rods

13, 14 and therefore the slide 11 in translation.

The operation of an exemplary pneumatic fork actuator according to the present invention will now be described with reference to the accompanying drawings.

When pressurized gas is simultaneously introduced into the

cylinder chambers

201, 301 of the spring-

piston cylinders

20, 30, the

pistons

21, 31 are moved in the direction in which the springs are pressurized, pushed by the gas pressure. The direction in which the spring is compressed is referred to as the first direction of movement. Since the

piston rods

13, 14 are fixedly connected to the

pistons

21, 31 and the slide 11, the movement of the

pistons

21, 31 moves the slide 11 in the first movement direction. The movement of the slider drives the slider pin 111 coupled thereto to translate in the same direction, the slider pin 111 cooperating with the fork slot 121 further pushing the fork 12 to oscillate in a first oscillation direction about the central axis of the fork shaft 122. The fork 12 rotates the fork shaft 122.

When the gas in the spring-

piston cylinder

20, 30 is released, the

piston

21, 31 is moved in a second direction of movement opposite to the first direction of movement, which brings the slide 11 in the second direction of movement, when the spring force applied to the second side 212 of the piston 21 is greater than the force exerted by the gas on the first side 211 of the piston 21 due to the decrease in gas pressure in the cylinder chamber. The movement of the slide 11 in the second direction of movement causes the fork 12 to oscillate in the second direction of oscillation. The first swing direction is opposite to the second swing direction.

Through the process, the swing motion of the shifting fork shaft 122 along different directions can be realized, so that the valve connected with the shifting fork shaft 122 can be driven, and the opening and closing of the valve are controlled.

According to the utility model discloses a shift fork executor is owing to adopted two piston rods for when the piston drives the slider and removes, the load on the piston is more dispersed, has reduced the stress concentration on the piston. In addition, because two piston rods are symmetrically arranged on two sides of the guide rod, the stress of the sliding block is symmetrical, the friction force between the guide rod and the sliding block can be reduced, and the bending stress of the sliding block acting on the guide rod is reduced. Meanwhile, the abrasion of a sealing element on the piston is reduced by the supporting action of the double piston rods on the piston, so that a bearing gasket on the piston can be omitted, the thickness of the piston is reduced, and materials are saved. According to the utility model discloses a spring-piston cylinder body is integrated into a cylinder body with cylinder and spring cylinder and has set up two spring-piston cylinder bodies that the structure is roughly the same at drive module's both ends. The two symmetrically arranged cylinder bodies drive the driving module, so that the structure symmetry is realized, and the whole size of the cylinder bodies is reduced

As described above, two integrated spring-piston cylinders are symmetrically disposed at both ends of the drive module of the exemplary fork actuator with dual piston rods. However, a fork actuator with a double piston rod according to the invention is not limited to this exemplary embodiment.

According to a further exemplary embodiment of the present invention, the fork actuator with a double piston rod can be a fork actuator with a drive module and an integrated spring-piston cylinder arranged on one side of the drive module. In this fork actuator, the spring-piston cylinder has the same structure as the spring-piston cylinder described above. One end of each of the two piston rods is fixedly connected with a piston arranged in the spring-piston cylinder, and the other end of the piston rod is fixedly connected with a slide block in the drive module and is positioned in a drive housing of the drive module.

According to a further exemplary embodiment of the present invention, the shift fork actuator with a double piston rod can be a shift fork actuator with a drive module and two cylinders arranged on both sides of the drive module. That is, the two integrated spring-piston cylinders of the fork actuator according to fig. 1 are replaced by two cylinders, and the structure of the drive module and the piston rod is unchanged. Two parallel piston rods fixedly connected with the slide block in the drive module as shown in fig. 1 are fixedly connected with the pistons in the two cylinders.

According to a further exemplary embodiment of the present invention, the shift fork actuator with a double piston rod can be a shift fork actuator with a drive module and a single cylinder arranged on one side of the drive module. That is, one integrated spring-piston cylinder of the fork actuator according to fig. 1 is replaced by a cylinder, the other side of the drive module being closed. Two piston rods arranged in parallel as shown in fig. 1 are fixedly connected at one end to a slide in the drive module and at the other end to a piston in a single cylinder.

According to a further exemplary embodiment of the present invention, the fork actuator with a double piston rod can be a fork actuator with a drive module, a single cylinder arranged on one side of the drive module and a spring cylinder arranged on the other side of the drive module. That is, one integrated spring-piston cylinder of the fork actuator according to fig. 1 is replaced by a cylinder and the other spring-piston cylinder is replaced by a spring cylinder. Two parallel piston rods fixedly connected with the slide block as shown in fig. 1 are fixedly connected with the piston in the cylinder.

Exemplary structures and/or couplings are disclosed for purposes of describing the present invention in detail. However, it will be apparent to those of ordinary skill in the art that these exemplary structures and/or couplings may be embodied in many different forms and that the specific details and exemplary configurations should not be construed as limiting the scope of the invention.

Reference numerals

1 Shifting fork actuator

10 drive module

11 slide block

12 shifting fork

13 piston rod

14 piston rod

15 guide bar

111 slide block pin

121 shift fork groove

122 fork shaft

124 axle hole

125 Pin

20 spring-piston cylinder

21 piston

22 spring

23 casing

24. 25 end cap

201 cylinder chamber

202 spring chamber

211 first side of

212 second side surface

26. 27 spring seat

261. 271 guide rod hole

215. 216 tie bar hole

30 spring-piston cylinder

31 piston

32 spring

33 casing

34 end cap

35 end cap

301 cylinder chamber

302 spring chamber

Claims

1. A fork actuator, comprising:

the driving module is provided with a sliding block and a shifting fork, so that the sliding block is translated to drive the shifting fork to swing;

a cylinder disposed at a side of the driving module, the cylinder including:

a piston disposed within the cylinder and slidably translatable within the cylinder;

a first piston rod fixedly connected to the piston and fixedly connected to the slider; and

a second piston rod fixedly connected to the piston and fixedly connected to the slider;

thereby, the piston drives the slider to translate through the first piston rod and the second piston rod.

2. A fork actuator according to claim 1, wherein the first and second piston rods are arranged in parallel and the position of connection to the piston is arranged symmetrically with respect to the centre of the piston.

3. A fork actuator according to claim 1, wherein the first and second piston rods are arranged in parallel and the position of connection with the slide block is arranged symmetrically with respect to the centre of the slide block.

4. A fork actuator according to claim 1, wherein the drive module has a guide rod arranged to extend through the centre of the slide block so that the slide block can be supported on and slid along the guide rod, wherein the first piston rod, the second piston rod and the guide rod are arranged parallel to each other.

5. A fork actuator as claimed in claim 4, wherein the slide block has first and second piston rod bores extending therethrough, respectively, and a guide rod bore extending therethrough.

6. A fork actuator as claimed in claim 5, wherein the slide has a slide pin bore in which a slide pin is disposed, and the fork has a fork slot in which the slide pin can slide.

7. A fork actuator as claimed in claim 5, wherein the first and second piston rods are provided with snap ring grooves in which snap rings can be provided to effect a fixed connection of the first and second piston rods to the slide and the piston.

8. A fork actuator according to claim 5, wherein the first and second piston rods are fixedly connected to the piston by a threaded connection.

9. A fork actuator as claimed in claim 1, further comprising first and second tie rods, end caps being provided at both ends of the cylinder, the first and second tie rods extending through the entire cylinder and through tie rod holes in the piston, ultimately being supported and secured on the end caps.

10. A fork actuator according to claim 9, wherein the first and second tie rods are symmetrically disposed with respect to the centre of the piston and lie in a plane orthogonal to the plane in which the first and second piston rods lie.

11. A fork actuator according to any of claims 1 to 10, wherein the fork actuator has two cylinders, a first cylinder and a second cylinder,

the first cylinder body and the second cylinder body are respectively arranged at two sides of the driving module,

the first piston rod and the second piston rod are fixedly connected with the first piston of the first cylinder and the second piston of the second cylinder in a sealing mode,

the first piston and the second piston simultaneously drive the sliding block to translate through the first piston rod and the second piston rod.

12. A fork actuator as claimed in claim 11, wherein the first and second cylinders are spring-piston cylinders integrating a spring cylinder with a cylinder in one cylinder.

13. A fork actuator as claimed in claim 11, wherein the first and second cylinders are both air cylinders.

14. A fork actuator as claimed in claim 11, wherein the first cylinder is a cylinder and the second cylinder is a spring cylinder.

15. A fork actuator according to any of claims 1-10, wherein the fork actuator has one of the cylinders disposed to the side of the drive module,

the first piston rod and the second piston rod are fixedly connected with the piston of the cylinder body in a sealing mode.

16. A fork actuator as claimed in claim 15, wherein the cylinder is a spring-piston cylinder integrating a spring cylinder with a cylinder in one cylinder.

17. A fork actuator as claimed in claim 15, wherein the cylinder is a pneumatic cylinder.