An adjustable stroke fluid power actuator

Abstract

The utility model discloses a kind of fluid transmission execution elements of adjustable stroke, belong to hydraulic cylinder or cylinder transmission technical field, it includes cylinder barrel, piston cavity, front end seal, rear end seal, piston rod, piston seal and opening;The front end of cylinder barrel is connected with screw rod seat, screw rod seat inside is coaxially installed with the adjusting screw that is penetrated front end seal and extends into piston cavity by thread, the rear half section of adjusting screw is non-thread section, the non-thread section of adjusting screw is equipped with the adjusting plug that is axially moved in piston cavity following adjusting screw from rear to front, by changing the position of adjusting plug and further changing the stroke of piston rod axially moving in piston cavity.Adjusting plug is axially moved by the thread rotation of adjusting screw, without complex transmission mechanism, and adjusting precision is high and stability is strong;And adjusting plug is not connected with piston rod, only by position limit piston rod stroke, avoid the length redundancy caused by traditional adjusting mechanism and piston rod direct linkage.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder or pneumatic cylinder transmission technology, specifically to a fluid transmission actuator with adjustable stroke. Background Technology

[0002] Fluid-driven actuators (such as hydraulic cylinders and pneumatic cylinders) are mechanical components that use fluid pressure to drive a piston rod in linear reciprocating motion. They are widely used in industrial automation, engineering machinery, and other fields. The stroke of traditional actuators is usually fixed by the cylinder length or adjusted by a mechanism within the cylinder, but this presents the following problems: Fixed stroke design cannot meet the needs of diverse working conditions, and multiple cylinder models are required to adapt to different strokes, which increases costs. Some adjustable stroke designs use a direct connection between the piston rod and the adjustment mechanism (such as an adjusting screw), resulting in an excessively long overall length that is difficult to adapt to compact spaces. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a fluid transmission actuator with adjustable stroke, wherein the adjusting plug and adjusting screw are not directly connected to the piston rod, which not only realizes the adjustment of the actuator stroke, but also shortens the length of the adjusting screw, thus solving the problems of fixed stroke and excessive overall length of traditional actuators.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: An adjustable stroke fluid transmission actuator, which is a hydraulic cylinder or a pneumatic cylinder, includes a cylinder barrel, a piston chamber opened inside the cylinder barrel, a front seal fixed to the front end of the piston chamber, a rear seal fixed to the rear end of the piston chamber, a piston rod axially slidably mounted in the piston chamber and extending from the rear seal to the outside of the cylinder barrel, a piston seal fixed to the front end of the piston rod and located in the piston chamber, and an opening opened on the side wall of the cylinder barrel and communicating with the piston chamber; the piston seal divides the piston chamber into a front piston chamber and a rear piston chamber that are not interconnected, and the opening includes a front opening and a rear opening, wherein the front opening is connected to the front piston chamber, and the rear opening is connected to the rear piston chamber; The core improvement is that the front end of the cylinder is connected to a screw seat, and an adjusting screw is installed coaxially inside the screw seat through the front end seal and into the piston cavity. The rear half of the adjusting screw is a non-threaded section. An adjusting plug that moves axially in the piston cavity with the adjusting screw is fitted from back to front on the non-threaded section of the adjusting screw. By changing the position of the adjusting plug, the stroke of the piston rod moving axially in the piston cavity is changed.

[0005] By adopting the above solution, the adjusting plug is driven to move axially by the rotation of the screw thread, eliminating the need for a complex transmission mechanism. This results in high adjustment accuracy and strong stability. Furthermore, the adjusting plug is not connected to the piston rod, and the piston rod stroke is limited only by its position. This avoids the length redundancy caused by the direct linkage between the traditional adjusting mechanism and the piston rod, allowing the entire system to be used in a compact space.

[0006] In a preferred embodiment of an adjustable stroke fluid transmission actuator, the assembly relationship between the non-threaded section of the adjusting screw and the adjusting plug is a clearance fit, and lubricating oil is applied to the gap between the non-threaded section of the adjusting screw and the adjusting plug. In addition, a bearing can be coaxially assembled in the gap between the non-threaded section of the adjusting screw and the adjusting plug. Both the "gap lubrication method" and the "bearing lubrication method" can reduce the frictional resistance of the adjusting screw during rotation and reduce the situation where the adjusting plug rotates synchronously with the adjusting screw, thereby avoiding excessive wear of the front seal due to the rotation of the adjusting plug.

[0007] In a preferred embodiment of an adjustable stroke fluid transmission actuator, the rear end of the adjusting screw is a flat head, and the contact between the flat head and the adjusting plug is a surface contact. Alternatively, the rear end of the adjusting screw can be a round head, and the contact between the round head and the adjusting plug is a point contact. In practical applications, the round head has a smaller force-bearing area than the flat head, making it easier to rotate the adjusting screw. This also reduces the likelihood of the adjusting plug rotating synchronously with the adjusting screw, thereby avoiding excessive wear of the front seal due to the rotation of the adjusting plug.

[0008] In a preferred embodiment of an adjustable stroke fluid transmission actuator, the inner side of the front seal is provided with at least one axially extending guide groove, and the outer side of the adjusting plug is fixed with a guide post that extends into the guide groove and always slides along the guide groove. Under the cooperation of the guide post and the guide groove, the adjusting plug moves only along the piston cavity axially, which can completely ensure that the adjusting plug does not rotate synchronously with the adjusting screw, and can completely avoid the situation of excessive wear of the front seal caused by the rotation of the adjusting plug.

[0009] The beneficial effects of this utility model are: 1. Threaded adjustment, simple and reliable structure: The adjusting plug is driven to move axially by the rotation of the adjusting screw thread, without the need for a complex transmission mechanism, and the adjustment accuracy is high and the stability is strong. 2. Independent adjusting plug, shortening the overall length: The adjusting plug is not connected to the piston rod, and the piston rod stroke is limited only by its position. This avoids the length redundancy caused by the direct linkage between the traditional adjusting mechanism and the piston rod, allowing the whole unit to be used in a compact space. 3. Anti-pollution: The regulating plug is not exposed, preventing the intrusion of foreign matter; 4. Extend service life: Through clearance fit, bearing, guide structure and other design, the synchronous rotation of the adjusting plug with the adjusting screw can be reduced, thereby avoiding excessive wear of the front seal due to the rotation of the adjusting plug; 5. Multi-scenario adaptation: It can be compatible with both hydraulic cylinders and pneumatic cylinders. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a top view of a fluid transmission actuator with adjustable stroke. Figure 2 These are cross-sectional views of Embodiment 1 and Embodiment 2 along the location of Figure AA; Figure 3 for Figure 2 A magnified view of a section at point B in the middle; Figure 4 These are cross-sectional views of Embodiments 3 and 4 along the location of Figure AA; Figure 5 These are cross-sectional views of Examples 5 and 6 along the location of Figure AA; Figure 6 These are cross-sectional views of Examples 7 and 8 along the location of Figure AA; Reference numerals: 1-Cylinder; 2-Piston chamber; 2a-Front piston chamber; 2b-Rear piston chamber; 3-Front end seal; 4-Rear end seal; 5-Piston rod; 6-Piston seal; 7-Opening; 7a-Front opening; 7b-Rear opening; 8-Screw seat; 9-Adjusting screw; 10-Adjusting plug; 11-Bearing; 12-Guide groove; 13-Guide post. Detailed Implementation

[0012] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0013] Example 1, as Figures 1 to 2As shown, an adjustable stroke fluid transmission actuator is a hydraulic cylinder, which includes a cylinder barrel 1, a piston chamber 2 opened inside the cylinder barrel 1, a front seal 3 (O-ring) fixed to the front end of the piston chamber 2, a rear seal 4 (O-ring) fixed to the rear end of the piston chamber 2, a piston rod 5 axially slidably installed in the piston chamber 2 and extending from the rear seal 4 to the outside of the cylinder barrel 1, a piston seal 6 (O-ring) fixed to the front end of the piston rod 5 and located in the piston chamber 2, and an opening 7 opened on the side wall of the cylinder barrel 1 and communicating with the piston chamber 2.

[0014] Continue as Figures 1 to 2 As shown, the piston seal 6 divides the piston chamber 2 into a front piston chamber 2a and a rear piston chamber 2b that are not connected to each other. The opening 7 includes a front opening 7a and a rear opening 7b, wherein the front opening 7a is connected to the front piston chamber 2a, and the rear opening 7b is connected to the rear piston chamber 2b. like Figure 2 As shown, the front end of the cylinder 1 is connected to a screw seat. Inside the screw seat, an adjusting screw is coaxially installed through the front end seal 3 and extends into the piston chamber 2. The rear half of the adjusting screw is a non-threaded section. An adjusting plug 10 is fitted from back to front on the non-threaded section of the adjusting screw, which moves axially in the piston chamber 2 along with the adjusting screw. By changing the position of the adjusting plug 10, the stroke of the piston rod 5 moving axially in the piston chamber 2 is changed.

[0015] Continue as Figure 2 As shown, the assembly relationship between the non-threaded section of the adjusting screw and the adjusting plug 10 is a clearance fit, and lubricating oil is applied to the gap between the non-threaded section of the adjusting screw and the adjusting plug 10; the above "gap lubrication method" can reduce the frictional resistance of the adjusting screw when rotating.

[0016] Continue as Figure 2 As shown, the rear end of the adjusting screw is a flat head, and the contact between the flat head and the adjusting plug 10 is a surface contact.

[0017] like Figure 3 As shown, the inner side of the front seal 3 is provided with two axially extending guide grooves 12. The outer side of the adjusting plug 10 is fixed with a guide post 13 that extends into the guide groove 12 and always slides along the guide groove 12. Under the cooperation of the guide post 13 and the guide groove 12, the adjusting plug 10 moves only along the axial direction of the piston cavity 2, which can completely ensure that the adjusting plug 10 does not rotate synchronously with the adjusting screw, and can completely avoid the situation of excessive wear of the front seal 3 caused by the rotation of the adjusting plug 10.

[0018] Working principle: When the stroke of piston rod 5 needs to be adjusted, the adjusting screw 9 is rotated using a tool (such as an Allen wrench): Clockwise rotation moves the adjusting screw 9 backward along the thread, pushing the adjusting plug 10 backward simultaneously, thus reducing the effective stroke of piston rod 5 within piston chamber 2; counterclockwise rotation moves the adjusting screw 9 forward along the thread, pushing the adjusting plug 10 forward simultaneously, thus expanding the effective stroke of piston rod 5 within piston chamber 2. Injecting oil into the front piston chamber 2a through the forward opening 7a drives piston rod 5 to extend outward; injecting oil into the rear piston chamber 2b through the rear opening 7b drives piston rod 5 to retract inward. The axial movement of adjusting plug 10 is driven by the rotation of the adjusting screw 9's thread, eliminating the need for a complex transmission mechanism, resulting in high adjustment accuracy and stability. Furthermore, adjusting plug 10 is not connected to piston rod 5; its position only limits the stroke of piston rod 5, avoiding the length redundancy caused by direct linkage between the traditional adjusting mechanism and piston rod 5, allowing the entire system to be used in a compact space.

[0019] Example 2, as Figures 1 to 3 As shown, the only difference between this embodiment and Embodiment 1 is that the fluid transmission actuator is replaced by a pneumatic cylinder instead of a hydraulic cylinder.

[0020] Working principle: When the stroke of piston rod 5 needs to be adjusted, the adjusting screw 9 is rotated using a tool (such as an Allen wrench): Clockwise rotation moves the adjusting screw 9 backward along the thread, pushing the adjusting plug 10 backward simultaneously, thus reducing the effective stroke of piston rod 5 within piston chamber 2; counterclockwise rotation moves the adjusting screw 9 forward along the thread, pushing the adjusting plug 10 forward simultaneously, thus expanding the effective stroke of piston rod 5 within piston chamber 2. Air is injected into the front piston chamber 2a through the forward opening 7a, driving piston rod 5 to extend outward; air is injected into the rear piston chamber 2b through the rear opening 7b, driving piston rod 5 to retract inward. The axial movement of adjusting plug 10 is driven by the rotation of the adjusting screw 9's thread, eliminating the need for a complex transmission mechanism, resulting in high adjustment accuracy and stability. Furthermore, adjusting plug 10 is not connected to piston rod 5, only limiting the stroke of piston rod 5 through its position, avoiding the length redundancy caused by direct linkage between the traditional adjusting mechanism and piston rod 5, allowing the entire system to be used in a compact space.

[0021] Example 3, as Figure 1 , Figure 4As shown, the difference between this embodiment and Embodiment 1 is only that the assembly relationship between the non-threaded section of the adjusting screw and the adjusting plug 10 is a clearance fit, and the gap between the non-threaded section of the adjusting screw and the adjusting plug 10 is also coated with lubricating oil; instead, a bearing 11 is coaxially assembled in the gap between the non-threaded section of the adjusting screw and the adjusting plug 10. The above "bearing 11 lubrication method" can reduce the frictional resistance of the adjusting screw when rotating, and can reduce the situation where the adjusting plug 10 rotates synchronously with the adjusting screw, thereby avoiding excessive wear of the front end seal 3 caused by the rotation of the adjusting plug 10.

[0022] Example 4, as Figure 1 , Figure 4 As shown, the only difference between this embodiment and Embodiment 3 is that the fluid transmission actuator is replaced by a pneumatic cylinder instead of a hydraulic cylinder.

[0023] Example 5, as Figure 1 , Figure 5 As shown, the difference between this embodiment and Embodiment 1 is only that the rear end of the adjusting screw is a flat head, and the contact between the flat head and the adjusting plug 10 is a surface contact; instead, the rear end of the adjusting screw is a round head, and the contact between the round head and the adjusting plug 10 is a point contact. In practical applications, the round head has a smaller force-bearing area than the flat head, making it easier to rotate the adjusting screw. This can also reduce the situation where the adjusting plug 10 rotates synchronously with the adjusting screw, thereby avoiding excessive wear of the front end seal 3 caused by the rotation of the adjusting plug 10.

[0024] Example 6, as Figure 1 , Figure 5 As shown, the only difference between this embodiment and embodiment five is that the fluid transmission actuator is replaced by a pneumatic cylinder instead of a hydraulic cylinder.

[0025] Example 7, as Figure 1 , Figure 6 As shown, the difference between this embodiment and Embodiment 3 is only that the rear end of the adjusting screw is a flat head, and the contact between the flat head and the adjusting plug 10 is a surface contact; instead, the rear end of the adjusting screw is a round head, and the contact between the round head and the adjusting plug 10 is a point contact. In practical applications, the round head has a smaller force-bearing area than the flat head, making it easier to rotate the adjusting screw. This can also reduce the situation where the adjusting plug 10 rotates synchronously with the adjusting screw, thereby avoiding excessive wear of the front end seal 3 caused by the rotation of the adjusting plug 10.

[0026] Example 8, as Figure 1 , Figure 6 As shown, the only difference between this embodiment and embodiment seven is that the fluid transmission actuator is replaced by a pneumatic cylinder instead of a hydraulic cylinder.

[0027] The above are merely preferred embodiments of the present utility model and are 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 shall be included within the protection scope of the present utility model.

Claims

1. An adjustable stroke fluid transmission actuator, comprising a cylinder, a piston chamber formed inside the cylinder, a front seal fixed to the front end of the piston chamber, a rear seal fixed to the rear end of the piston chamber, a piston rod axially slidably mounted in the piston chamber and extending from the rear seal to the outside of the cylinder, a piston seal fixed to the front end of the piston rod and located in the piston chamber, and an opening formed in the side wall of the cylinder and communicating with the piston chamber; Its features are: The front end of the cylinder is connected to a screw seat. Inside the screw seat, an adjusting screw is coaxially installed through the front end seal and extends into the piston cavity. The rear half of the adjusting screw is a non-threaded section. An adjusting plug that moves axially within the piston cavity following the adjusting screw is fitted from back to front on the non-threaded section of the adjusting screw. By changing the position of the adjusting plug, the stroke of the piston rod moving axially within the piston cavity is changed.

2. The adjustable stroke fluid transmission actuator according to claim 1, characterized in that: The assembly relationship between the non-threaded section of the adjusting screw and the adjusting plug is a clearance fit.

3. The adjustable stroke fluid transmission actuator according to claim 2, characterized in that: The gap between the non-threaded section of the adjusting screw and the adjusting plug is also coated with lubricating oil.

4. The adjustable stroke fluid transmission actuator according to claim 1, characterized in that: The non-threaded section of the adjusting screw is coaxially fitted with a bearing within the gap between it and the adjusting plug.

5. The adjustable stroke fluid transmission actuator according to claim 1, characterized in that: The rear end of the adjusting screw is a flat head, and the contact between the flat head and the adjusting plug is a surface contact.

6. The adjustable stroke fluid transmission actuator according to claim 1, characterized in that: The rear end of the adjusting screw is round, and the contact between the round end and the adjusting plug is a point contact.

7. The adjustable stroke fluid transmission actuator according to claim 1, characterized in that: The inner side of the front sealing element is provided with at least one axially extending guide groove, and the outer side of the adjusting plug is fixed with a guide post that extends into the guide groove and always slides along the guide groove.

8. The adjustable stroke fluid transmission actuator according to claim 1, characterized in that: The piston seal divides the piston chamber into a front piston chamber and a rear piston chamber that are not connected to each other. The opening includes a front opening and a rear opening, wherein the front opening is connected to the front piston chamber and the rear opening is connected to the rear piston chamber.

9. The adjustable stroke fluid transmission actuator according to claim 1, characterized in that: The fluid transmission actuator is a hydraulic cylinder.

10. The adjustable stroke fluid transmission actuator according to claim 1, characterized in that: The fluid transmission actuator is a cylinder.

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