Fluid drive device

Abstract

The application provides a fluid driving device, comprising a cylinder, a flexible body, a flexible body sealing end cover; wherein the cylinder has a cavity; the flexible body is arranged in the cavity; the flexible body sealing end cover is arranged in the cavity and is fixedly connected with one end of the flexible body; and a gap exists between the flexible body sealing end cover and the cylinder. The application uses the flexible body and other components as a fluid driving piston device, superimposes the surface tension of the flexible body and the thrust generated by the pressure difference inside and outside the flexible body, effectively increases the thrust on the push rod, and further avoids the loss of the thrust on the push rod by arranging a gap between the flexible body sealing end cover and the cylinder, thereby reducing the friction generated by the movement of the push rod. Therefore, the driving device does not need to start energy when starting, and solves the "hysteresis" described in the background art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pistons, in particular to a fluid driving device. BACKGROUND

[0002] A piston is a device that converts fluid pressure into force and displacement, which can well meet the application requirements of various scenes. However, in a traditional piston system, in order to ensure good sealing performance, the piston will slide in close contact with the inner wall of the cylinder, thus causing serious friction loss and also bringing the risk of sealing failure.

[0003] In addition, the ideal state of the piston device, such as a cylinder, has a thrust F 推力 = ΔP × S 缸径 , wherein F 推力 is the ideal thrust of the cylinder; ΔP is the relative pressure difference between the inside of the cylinder and the outside environment; S 缸径 is the inner diameter of the cylinder, which is approximately equal to the diameter of the piston. It can be seen that the thrust of the cylinder is affected by ΔP and S 缸径 , but ΔP has an upper limit due to the sliding sealing factor; it is also difficult to increase the inner diameter of the cylinder due to space and cost constraints. Therefore, it is difficult to increase the thrust of the existing piston device. Of course, in actual application, the piston device is also affected by the frictional resistance between the piston and the inner wall of the cylinder, as well as the internal energy loss and other parameters. In order to balance various friction losses and internal energy losses in the piston device, a certain starting energy is required at startup, that is, a ΔP 启动 is required. If the value of ΔP 启动 is too small, the piston device cannot be started, that is, the existing piston device has a certain hysteresis.

[0004] In summary, the present application introduces flexible material technology into the design of the piston device to overcome the problems of frictional resistance, sealing failure, hysteresis and other problems in the prior art, and to improve the thrust of the piston device. SUMMARY

[0005] The present application provides a fluid driving device to solve or partially solve the above problems in the background art or at least one other deficiency in the prior art.

[0006] The present application provides a fluid driving device, which comprises a cylinder body, a flexible body, a flexible body sealing end cover, wherein the cylinder body has a cavity; the flexible body is arranged in the cavity; the flexible body sealing end cover is arranged in the cavity and fixedly connected with one end of the flexible body; and there is a gap between the flexible body sealing end cover and the cylinder body.

[0007] In some embodiments, the flexible body is a bellows having a plurality of convex portions and a plurality of concave portions, and the end of the bellows fixedly connected with the flexible sealing end cover is a convex portion.

[0008] In some embodiments, the device further comprises: a first sealing cover located at an end of the flexible body away from the flexible sealing end cover; and a push rod penetrating through the first sealing cover and the flexible body and fixedly connected with the flexible sealing end cover.

[0009] In some embodiments, the first sealing cover is fixedly connected with the end of the flexible body away from the flexible sealing end cover.

[0010] In some embodiments, the device further comprises: a flexible body fixing support located between the first sealing cover and the cylinder body and fixedly connected with the end of the flexible body away from the flexible sealing end cover.

[0011] In some embodiments, the push force on the push rod is:

[0012] F 推 = F1 + F2; wherein,

[0013] F1 is the push force generated by the pressure difference between the flexible body and the cavity, and F2 is the push force generated by the surface tension of the flexible body.

[0014] In some embodiments, the push force generated by the pressure difference between the flexible body and the cavity is:

[0015] F1 = ΔP × S1; wherein

[0016] ΔP is the pressure difference between the flexible body and the cavity, and S1 is the effective area of the end of the flexible body in contact with the flexible sealing end cover.

[0017] In some embodiments, the push force generated by the surface tension of the flexible body is:

[0018] F2 = ΔP × S2; wherein,

[0019] ΔP is the pressure difference between the flexible body and the cavity, and S2 is the effective area of the flexible body.

[0020] In some embodiments, the device further comprises:

[0021] a second sealing cover located at an end of the cylinder body opposite the first sealing cover.

[0022] In some embodiments, the device further comprises:

[0023] a power joint in communication with the second sealing cover for injecting fluid into the cavity.

[0024] The technical solutions of the above-mentioned embodiments can at least obtain at least one of the following beneficial effects.

[0025] According to the fluid driving device of the embodiment of the present application, the surface tension of the flexible body is superimposed with the thrust generated by the pressure difference between the inside and outside of the flexible body, and other components are used as the fluid driving piston device, so that the thrust on the push rod is effectively increased. In addition, the gap is arranged between the flexible body sealing end cover and the cylinder, so that the friction generated by the movement of the push rod is reduced, and the loss of the thrust on the push rod is avoided, so that the driving device of the present application does not need to start the energy when starting, and the "hysteresis" in the background art is solved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments thereof as read in conjunction with the accompanying drawings:

[0027] Figure 1 is a structural schematic diagram of a fluid driving device according to an exemplary embodiment of the present application;

[0028] Figure 2 is a structural schematic diagram of a bellows according to an exemplary embodiment of the present application; and

[0029] Figure 3 is a connection schematic diagram of the convex part of the bellows and the flexible body sealing end cover according to an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0030] In the following detailed description of the application, numerous specific details are set forth in order to provide a thorough understanding of the relevant teachings. However, it will be apparent to one of ordinary skill in the art that the present application can be practiced without these details. In other instances, well-known methods, procedures, components, and network architectures have not been described in detail so as not to unnecessarily obscure aspects of the related disclosure. It will be understood that the terms "system," "device," "unit," and / or "module" as used herein are used in their broadest context to mean different components, elements, parts, or assemblies at different levels in a sequential arrangement. However, these terms can be replaced by other expressions if they can achieve the same purpose.

[0031] It should be understood that when a device, unit, or module is referred to as being "on", "connected to", or "coupled to" another device, unit, or module, it can be directly on, connected or coupled to, or in communication with other devices, units, or modules, or there can be intervening devices, units, or modules, unless the context clearly indicates otherwise. For example, the term "and / or" as used herein includes any one and all combinations of one or more of the associated listed items.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the articles "a", "an" and "the" are intended to include one or more items, unless the context clearly indicates otherwise. Generally, the terms "comprise", "comprising", "including", "including", "containing", "contain" and / or "have" are intended to be open-ended terms that do not exclude additional elements, steps, operations, elements and / or components.

[0033] These and other features and characteristics of the present application, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the present application. As such, the

[0034] Various structural diagrams are used in the present application to illustrate various modifications of embodiments according to the present application. It should be understood that the foregoing or following structures are not intended to limit the present application. The scope of protection of the present application is subject to the claims.

[0035] It should be noted that in the present specification, the expressions first, second, etc. are used only to distinguish one feature from another feature, and do not indicate any limitation on the features. Thus, for example, the first sealing cap discussed below can also be referred to as the second sealing cap without departing from the teachings of the present application. The converse is also true.

[0036] Figure 1 is a structural schematic diagram of a fluid driving device according to an exemplary embodiment of the present application.

[0037] As Figure 1 shown, the present application provides a fluid driving device, which can include: a cylinder body 1, a flexible body 2, a flexible body sealing end cap 3; wherein the cylinder body 1 can have a cavity 11; the flexible body 2 can be arranged in the cavity 11; the flexible body sealing end cap 3 can be arranged in the cavity 11 and fixedly connected with one end of the flexible body 2; and there is a gap between the flexible body sealing end cap 3 and the cylinder body 2.

[0038] The fluid described in the present application can be gas, liquid, etc., and the specific form of the fluid is not limited. In the present embodiment, gas will be taken as the specific form of the fluid.

[0039] In some embodiments, the cylinder 1 can be a cylinder, and both ends of the cylinder are not sealed. It should be noted that the shape of the cylinder 1 is not limited to the cylinder in the present embodiment. Specifically, the cylinder 1 is a cylindrical structure, and a cavity 11 can be arranged inside. The cavity 11 can be used to place the flexible body 2 and the flexible body sealing end cover 3, and can be filled with a fluid, such as a gas in the present embodiment. Of course, the material of the cylinder 1 can be any rigid material with sealing properties, such as metal or glass, which is not limited herein.

[0040] Figure 2 is a structural schematic diagram of a bellows according to an exemplary embodiment of the present application.

[0041] In some embodiments, the flexible body 2 is arranged in the cavity 11 of the cylinder 1. Specifically, the flexible body 2 extends along one end of the cylinder 1 to the middle of the cylinder 1, and the specific position is not limited as long as the flexible body 2 has a stretching space.

[0042] Specifically, due to the pushing force of the piston device

[0043] F = ΔP x S, (1)

[0044] where F is the ideal pushing force of the push rod, ΔP is the pressure difference between the inside and outside of the flexible body, and S is the inner diameter of the flexible body. According to formula (1), the pushing force of the fluid driving device is mainly affected by the pressure difference between the inside and outside of the flexible body 2 and the inner diameter of the flexible body 2. However, due to sealing factors, the pressure difference between the inside and outside of the flexible body 2 is difficult to increase; due to space and cost, the inner diameter of the flexible body 2 cannot be increased at will. In the present application, the inner diameter of the flexible body 2 is extended to another concept, i.e. the effective working area. In the present embodiment, as shown in Figure 2 , the bellows is used as the flexible body 2, and the effective area of the flexible body 2 is increased by the depth of the flexible body 2. Specifically, the flexible body 2 includes a plurality of alternating convex portions A and concave portions B, and there is a certain link area between the convex portions A and the concave portions B, thereby increasing the effective area in a small space.

[0045] In some embodiments, the flexible body sealing end cover 3 is arranged in the cavity 11 and fixedly connected to one end of the flexible body 2 located in the middle of the cylinder 1. The flexible body sealing end cover 3 and the flexible body 2 can be used as a piston of the present application to apply a certain pushing force to the push rod 5.

[0046] Figure 3 is a connection schematic diagram of the convex portion of the bellows and the flexible body sealing end cover according to an exemplary embodiment of the present application.

[0047] In some embodiments, the diameter of the flexible body sealing end cover 3 is slightly smaller than the inner diameter of the cylinder body 1, so that there is a gap between the flexible body sealing end cover 3 and the cylinder body 1 to avoid friction with the cylinder body 1 when the piston moves, thus avoiding the increased starting energy due to overcoming friction in the prior art, and thus solving the problem of "hysteresis". In addition, the diameter of the flexible body sealing end cover 3 is the same as or similar to the diameter of the convex portion A of the flexible body 2 to ensure its sealing performance. As shown in Figure 3 According to formula (1), in order to increase the effective contact area between the end of the flexible body 2 and the flexible body sealing end cover 3, the flexible body sealing end cover 3 is fixedly connected with the convex portion A in this embodiment. Of course, if a larger thrust is not required, any part of the flexible body 2 can be connected and fixed with the flexible body sealing end cover 3, and adjustments can be made according to requirements.

[0048] In some embodiments, a first sealing cover 4 and a push rod 5 are also provided. The first sealing cover 4 is provided with an exhaust hole (not shown), and the diameter of the exhaust hole is slightly larger than the diameter of the push rod 5, so that the push rod 5 penetrates through the first sealing cover 4 and can move along the pushing direction of the thrust, while reducing the energy loss due to friction.

[0049] Specifically, the first sealing cover 4 is arranged at one end of the cylinder body 1 and is fixedly connected with the end of the flexible body 2 away from the flexible body sealing end cover 3. The diameter of the first sealing cover 4 is the same as or similar to the diameter of the cylinder body 1 to ensure the sealing performance of the cylinder body 1.

[0050] Specifically, the push rod 5 penetrates through the first sealing cover 4 and the flexible body 2 and is fixedly connected with the flexible body sealing end cover 3, so that the thrust generated by the piston movement can be fully applied to the push rod 5.

[0051] In some embodiments, if the first sealing cover 4 cannot fix the flexible body 2, a flexible body fixing support 6 can also be provided to fix the flexible body 2. The flexible body fixing support 6 is located between the first sealing cover 4 and the cylinder body 1 and is fixedly connected with them, and the connection manner is not limited herein, and the shape of the flexible body fixing support 6 is also not limited herein, as long as it can ensure the sealing performance of the cylinder body 1. It should be noted that whether to additionally provide the flexible body fixing support 6 or to integrally form the flexible body fixing support 6 with the first sealing cover 4 can be selected according to the process difficulty and processing capacity, and the selection is not limited herein.

[0052] In some embodiments, a second sealing cover 7 is also provided. The second sealing cover 7 is provided with an air inlet hole (not shown) opposite to the exhaust hole of the first sealing cover 4. The second sealing cover 7 is arranged opposite to the first sealing cover 4 at the other end of the cylinder body, and the diameter of the second sealing cover 7 is the same as or similar to the diameter of the cylinder body 1 to ensure the sealing performance of the cylinder body 1.

[0053] In some embodiments, a power joint 8 is further provided. The power joint 8 is in communication with the air inlet hole of the second sealing cover 7 to fill the cavity 11 with gas so that a certain air pressure exists in the cavity 11. The specific material and shape of the power joint 8 are not limited as long as the sealing of the cylinder body 1 can be ensured and the function of filling fluid can be achieved.

[0054] According to the fluid pushing device of the present embodiment, the internal air pressure of the flexible body 2 and the air pressure in the cavity 11 have a pressure difference: ΔP=P1-P2, wherein P1 is the air pressure in the cavity and P2 is the air pressure in the flexible body. Influenced by the pressure difference, the flexible body 2 and the flexible body sealing end cover 3 will drive the push rod 5 to move in the direction of low pressure. When the air pressure P1 in the cavity 11 is less than the air pressure P2 in the flexible body, the flexible body 2 will generate a certain tension, and the flexible body 2 and the flexible body sealing end cover 3 will drive the push rod 5 to move in the direction of the second sealing cover 7. At this time, the push rod 5 will generate a pushing force F towards the second sealing cover 7. 推 .

[0055] Specifically, based on the above device, the pushing force on the push rod 5 is:

[0056] F 推 =F1+F2, (2)

[0057] wherein F1 is the pushing force generated by the pressure difference between the flexible body and the cavity, and F2 is the pushing force generated by the surface tension of the flexible body. According to formula (2), in the present application, the pushing force on the push rod 5 includes the pushing force generated by the pressure difference between the flexible body and the cavity, and the pushing force generated by the surface tension of the flexible body.

[0058] Further, the pushing force on the push rod 5 includes the pushing force generated by the pressure difference between the flexible body and the cavity:

[0059] F1=ΔP×S1, (3)

[0060] In formula (3), ΔP is the pressure difference between the flexible body and the cavity, and S1 is the effective area of the end of the flexible body in contact with the flexible body sealing end cover.

[0061] Further, the pushing force on the push rod 5 generated by the surface tension of the flexible body is:

[0062] F2=ΔP×S2, (4)

[0063] In formula (4), ΔP is the pressure difference between the flexible body and the cavity, and S2 is the effective area of the flexible body.

[0064] In some embodiments, the pressure difference between the inside and outside of the flexible body 2 can be adjusted by changing the air inlet speed of the power joint 8, and the moving direction of the push rod 5 can be changed. That is, when the air pressure P1 in the cavity 11 is greater than the air pressure P2 in the flexible body, the flexible body 2 and the flexible body sealing end cover 3 will drive the push rod 5 to move towards the first sealing cover 4, that is, away from the above, which will not be repeated here.

[0065] It should be noted that, since the application does not set a sliding sealing ring, the pressure difference ΔP between the internal air pressure of the flexible body 2 and the air pressure in the cavity 11 can break through the limit of the applied pressure and atmospheric pressure (about 100 kpa).

[0066] In the present embodiment, the effective area of the bellows is fully utilized to generate tension, and the effective area of the bellows end and the flexible body sealing end cover is fully utilized to generate thrust, and the superposition of the two forces increases the thrust of the device described in the application; in addition, the flexible body sealing end cover of the application acts as a piston, avoiding contact friction with the cylinder, which solves the "hysteresis" problem of the prior art. Of course, since the application does not set a sealing ring for sliding sealing, it avoids the limitation of the material and structure of the sealing ring, allowing a larger pressure difference between the inside and outside of the flexible body, and thus increasing the thrust.

[0067] It should be understood that the above specific embodiments of the application are only used for illustrative or explanatory purposes, and do not constitute a limitation of the application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the application shall be included in the protection scope of the application. In addition, the claims attached to the application are intended to cover all changes and modifications falling within the scope and boundary of the appended claims, or the equivalent forms of such scope and boundary.

Claims

1. A fluid drive device, characterized in that, include: Cylinder block, flexible body, flexible body sealing end cap, first sealing cover, second sealing cover, power connector, push rod; among which, The cylinder body has a cavity; The flexible body is disposed within the cavity; The flexible sealing end cap is disposed within the cavity and is fixedly connected to one end of the flexible body; and There is a gap between the flexible sealing end cap and the cylinder body; The second sealing cap is located at the end of the cylinder body opposite to the first sealing cap; The power connector is connected to the second sealing cover and is used to inject fluid into the cavity; The fluid is a gas or a liquid; The flexible body is a corrugated tube with several protrusions and several concave parts, and the end of the corrugated tube that is fixedly connected to the sealing end cap of the flexible body is a protrusion. The first sealing cap is located at the end of the flexible body away from the sealing end cap of the flexible body; and The push rod passes through the first sealing cover and the flexible body, and is fixedly connected to the sealing end cap of the flexible body; The thrust force on the push rod is: ;in, The thrust is generated by the pressure difference between the flexible body and the cavity. The thrust generated by the surface tension of the flexible body; The thrust generated by the pressure difference between the flexible body and the cavity is: ;in The pressure difference between the flexible body and the cavity. The effective area of ​​the end of the flexible body that contacts the sealing end cap of the flexible body; The thrust generated by the surface tension of the flexible body is: ;in, The pressure difference between the flexible body and the cavity. The effective area of ​​the flexible body; The first sealing cover has an exhaust hole with a diameter slightly larger than that of the push rod, so that the push rod can pass through the first sealing cover and move along the direction of the pushing force. The diameter of the first sealing cap is the same as the diameter of the cylinder body to ensure the cylinder body's sealing performance.

2. The fluid drive device according to claim 1, characterized in that, The first sealing cap is fixedly connected to the end of the flexible body away from the sealing end cap of the flexible body.

3. The fluid drive device according to claim 2, characterized in that, Also includes: A flexible body fixing bracket is located between the first sealing cover and the cylinder body, and is fixedly connected to the end of the flexible body away from the flexible body sealing end cover.

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