Piston structure and water hydraulic piston pump having the same

Abstract

The present invention provides a piston structure and a water hydraulic piston pump having the same. The piston structure includes a baffle piston, a hollow cylinder body with openings at both ends; a baffle, which is arranged in the hollow cylinder body and circumferentially connected to the inner wall of the hollow cylinder body along the inner wall of the hollow cylinder body. The baffle divides the inner cavity of the hollow cylinder body into a first cavity and a second cavity along its axial direction; a plunger shaft, the baffle is penetrated through the plunger shaft, the plunger shaft has an inner cavity, and the axes of the baffle, the hollow cylinder body and the plunger shaft coincide; wherein, a plurality of water distribution ports are evenly distributed in the circumferential direction of the part a of the hollow cylinder body corresponding to the first cavity; a plurality of water distribution ports are evenly distributed in the circumferential direction of the part b of the hollow cylinder body corresponding to the second cavity. It can solve the problems of relatively serious hydraulic flow loss in the existing pump, small structure flow distribution window, short flow distribution process time, too large working medium flow velocity, and easy occurrence of cavitation, etc.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluid machinery, and relates to a piston structure and a water hydraulic piston pump having the same, in particular to a baffle type piston structure, which is applicable to large flow rate working condition occasions with water as the working medium. Background Art

[0002] A pump is an energy conversion device that converts mechanical energy into fluid pressure energy and vice versa, and is usually used to output high-pressure fluid. In general, traditional pumps such as piston pumps, vane pumps, gear pumps, and screw pumps have sliding friction as the main motion pair in their mechanical structures during the working process, thus generating a large amount of frictional energy loss, and the parts have complex shapes and high processing costs.

[0003] The double-degree-of-freedom piston pump integrates the shaft and the piston, and uses the principle of "circumferential rotation + axial reciprocation" of the piston with two degrees of freedom to achieve continuous water suction and drainage, eliminating the distribution disc structure of the traditional piston pump. At the same time, a symmetric cam roller structure is used to replace the swash plate structure of the slipper, changing the original sliding friction pair to a rolling friction, and the symmetric force structure enables the piston to have no force in the radial direction, eliminating the two friction pairs of the piston and the cylinder block, and the cylinder block and the distribution disc. Therefore, the pump has higher efficiency and also breaks through the restrictions of the sliding friction pair on the pump performance and other aspects.

[0004] In the application occasions of large flow rate of water hydraulics, single-stage or multi-stage centrifugal pumps are generally used. The centrifugal pump converts mechanical energy into the potential energy of the working medium, and the potential energy is then converted into hydraulic energy, with a low energy conversion rate. When using the existing double-degree-of-freedom grooved piston pump, although most of the mechanical energy can be converted into hydraulic energy, since the piston is inside the cylinder, at high speed rotation, the piston has a large flow resistance, and the centrifugal potential energy of the liquid in the piston cavity hinders the suction process of the working medium, and a larger inlet pressure is required to realize the suction of the working medium, and the hydraulic flow loss in the pump is relatively serious; the existing structure has a small distribution window, a short distribution process time, and an excessive flow velocity of the working medium, which is prone to problems such as cavitation. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0006] To this end, the present invention provides a piston structure and a water hydraulic piston pump having the same.

[0007] The technical solution of the present invention is as follows:

[0008] According to one aspect, a piston structure is provided, and the piston structure includes a baffle type piston, and the baffle type piston includes:

[0009] A hollow cylinder with openings at both ends;

[0010] A baffle plate is arranged inside the hollow cylinder and is circumferentially connected to the inner wall of the hollow cylinder along the inner wall of the hollow cylinder. The baffle plate divides the inner cavity of the hollow cylinder into a first cavity and a second cavity along its axial direction.

[0011] A plunger shaft, the baffle plate is inserted through the plunger shaft, the plunger shaft has an inner cavity, and the axes of the baffle plate, the hollow cylinder and the plunger shaft coincide.

[0012] Wherein, a plurality of water distribution ports are evenly distributed in the circumferential direction of the part a of the hollow cylinder corresponding to the first cavity; a plurality of water distribution ports are evenly distributed in the circumferential direction of the part b of the hollow cylinder corresponding to the second cavity.

[0013] Further, the water distribution ports on the part a of the hollow cylinder extend from one end of the part a of the hollow cylinder to its free end; the water distribution ports on the part b of the hollow cylinder extend from one end of the part b of the hollow cylinder to its free end.

[0014] Further, 2 water distribution ports are provided on the part a of the hollow cylinder, and 2 water distribution ports are also provided on the part b of the hollow cylinder, and the two pairs of water distribution ports are orthogonally arranged.

[0015] Further, the end face of any of the water distribution ports is designed as an inclined cutting surface.

[0016] Further, the radius of the baffle plate is greater than the inner diameter of the plunger shaft.

[0017] Further, the baffle plate is a circular baffle plate, and the hollow cylinder is a hollow cylinder.

[0018] Further, the baffle plate, the hollow cylinder and the plunger shaft are of an integral structure.

[0019] Further, a plurality of straight ball grooves parallel to the axis are evenly distributed in the circumferential direction on the inner cavity wall of the plunger shaft.

[0020] Further, the piston structure further includes a cam guide rail, and the cam guide rail is arranged at one end of the plunger shaft.

[0021] According to another aspect, a water hydraulic piston pump is provided, and the piston pump includes the above-mentioned piston structure.

[0022] Advantages of the present invention compared with the prior art:

[0023] (1) The present invention adopts a baffle-type piston structure form, which is designed in a form of large outer diameter, small inner diameter and no inner wall surface (that is, a large outer diameter of the hollow cylinder and a small outer diameter of the plunger shaft, and the hollow cylinder and the plunger shaft do not contact). There is no longer a wall surface separating the high and low pressure chambers in the circumferential direction of the piston cavity, which can effectively reduce the hydraulic loss generated when the fluid in the piston cavity rotates along the piston wall surface.

[0024] (2) The end face of the water distribution port (inlet and outlet port) of the piston of the present invention has an inclined cutting surface design, which can effectively reduce the hydraulic loss caused by the outer diameter end face during the rotation of the piston, and can effectively improve the working efficiency of the large-flow double-degree-of-freedom water hydraulic piston pump;

[0025] (3) The present invention adopts a baffle-type piston structure, which can adapt to large-flow occasions, almost eliminates the rotational movement of the working medium during the flow distribution process, reduces the kinetic energy loss of the working medium, and improves the energy conversion rate and working efficiency of the piston pump;

[0026] (4) The present invention adopts a baffle-type piston structure, which enables the working medium to only generate low-speed flow along the radial and axial directions. The working medium can quickly and timely fill the piston cavity, avoiding cavitation and improving the cavitation resistance of the water hydraulic piston pump. Description of the Drawings

[0027] The accompanying drawings included are used to provide a further understanding of the embodiments of the present invention, which form a part of the specification, are used to illustrate the embodiments of the present invention, and together with the written description are used to explain the principles of the present invention. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 Shows a schematic structural diagram of a piston structure provided according to a specific embodiment of the present invention;

[0029] Figure 2 Shows a schematic diagram of an existing piston structure. Detailed Embodiments

[0030] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0031] It should be noted that the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0033] As Figure 2 shown, Figure 2 The piston structure in the existing piston pump is shown. When such a piston is used in a double-degree-of-freedom piston pump, it will cause a problem of relatively large plunger flow loss in a large-flow double-degree-of-freedom piston pump. For this reason, the solution of the embodiment of the present invention is proposed as follows:

[0034] As Figure 1 shown, in an embodiment of the present invention, a piston structure is provided. The piston structure includes a baffle-type piston. The baffle-type piston includes: a hollow cylinder 152 with openings at both ends, a baffle 154, and a plunger shaft 151. The baffle 154 is disposed inside the hollow cylinder 152 and is circumferentially connected to the inner wall of the hollow cylinder 152 along the inner wall of the hollow cylinder 152. The baffle 154 divides the inner cavity of the hollow cylinder 152 into a first cavity and a second cavity along its axial direction; the baffle 154 is inserted through the plunger shaft 151 (a part of the plunger shaft is located in the inner cavity of the hollow cylinder), the plunger shaft 151 has an inner cavity, and the axes of the baffle 154, the hollow cylinder 152, and the plunger shaft 151 coincide; a plurality of water distribution ports are evenly distributed in the circumferential direction of the part a of the hollow cylinder corresponding to the first cavity; a plurality of water distribution ports are evenly distributed in the circumferential direction of the part b of the hollow cylinder corresponding to the second cavity.

[0035] That is, the first cavity, i.e., the corresponding hollow column part, is the hollow column part a, and the hollow column part corresponding to the second cavity is the hollow column part b.

[0036] In the embodiment of the present invention, the multiple water distribution ports on the hollow column part a can be used as both water inlets and water outlets. Similarly, the multiple water distribution ports on the hollow column b can be used as both water inlets and water outlets. Therefore, in this embodiment, they are collectively referred to as water distribution ports.

[0037] It can be seen that different from the existing pistons, a new type of baffle piston structure is designed in this embodiment. The water distribution ports of the piston are arranged on the hollow column. Among them, those skilled in the art should understand that the water distribution ports communicate with the inner cavity of the hollow column. The hollow column does not contact the plunger shaft under the action of the baffle, and the plunger shaft directly penetrates the baffle inside the hollow column. Thus, there is no longer a wall surface separating the high-pressure and low-pressure chambers on the inner circumference of the piston cavity, which can effectively reduce the hydraulic loss generated when the fluid in the piston cavity rotates along the piston wall surface.

[0038] In the above embodiment, in order to better achieve flow distribution, the water distribution ports on the hollow column part a extend from one end of the hollow column part a to its free end; the water distribution ports on the hollow column part b extend from one end of the hollow column part b to its free end.

[0039] That is, the depth of the water distribution port is the same as the depth of the corresponding first cavity or second cavity.

[0040] Preferably, 2 water distribution ports are provided on the hollow column part a, and 2 water distribution ports are also provided on the hollow column part b, and the two pairs of water distribution ports are arranged orthogonally.

[0041] That is, the 2 water distribution ports on the hollow column part a form a pair of water distribution ports, and the 2 water distribution ports on the hollow column part b form another pair of water distribution ports. The two pairs of water distribution ports are arranged orthogonally to facilitate water suction and drainage during operation.

[0042] In the above embodiment, the end face of any of the water distribution ports is designed as an inclined section.

[0043] In the embodiment of the present invention, the end face of the piston inlet water distribution port has an inclined section design, which can effectively reduce the hydraulic loss caused by the outer diameter end face when the piston rotates, and can effectively improve the working efficiency of the large-flow double-degree-of-freedom water hydraulic piston pump.

[0044] In the above embodiment, in order to better reduce the hydraulic loss caused by the outer diameter end face, the radius of the baffle 154 is greater than the inner diameter of the plunger shaft 151.

[0045] Preferably, the baffle 154 is a circular baffle, and the hollow column 152 is a hollow cylinder.

[0046] Preferably, the baffle 154, the hollow cylinder 153 and the plunger shaft 151 are of an integral structure.

[0047] That is, the piston in the embodiment of the present invention has a design form with a large outer diameter, a small inner diameter, and no inner wall surface (i.e., a large outer diameter of the hollow cylinder and a small outer diameter of the plunger shaft, and the hollow cylinder and the plunger shaft do not contact). There is no longer a wall separating the high-pressure chamber and the low-pressure chamber on the inner circumference of the piston chamber. The middle cylindrical surface is a drainage surface, and two pairs of symmetrical water distribution ports are distributed on each side. The end surface of the water distribution port has an inclined cutting surface design, which can effectively reduce the hydraulic loss generated when the fluid in the piston chamber rotates along the piston wall surface, almost eliminate the rotational movement of the working medium during the flow distribution process, reduce the kinetic energy loss of the working medium, improve the energy conversion rate and working efficiency of the piston pump, and can adapt to large-flow occasions. In addition, the baffle piston structure of the present invention can enable the working medium to only generate low-speed flow along the radial and axial directions, and the working medium can quickly and timely fill the piston chamber, avoiding cavitation and improving the cavitation resistance of the water hydraulic piston pump.

[0048] In the above embodiment, in order to facilitate the coaxial cooperation with the transmission in the piston pump, a plurality of linear ball grooves 153 parallel to the axis are uniformly distributed along the circumferential direction of the inner cavity wall of the plunger shaft.

[0049] In the embodiment of the present invention, the coaxial cooperation between the piston and the transmission can adopt existing conventional technical means, which will not be elaborated here.

[0050] In addition, the piston structure may further include a cam guide rail 3, and the cam guide rail 3 is arranged at one end of the plunger shaft 151.

[0051] That is, by setting the cam guide rail, it can be ensured that the piston performs a reciprocating motion under the guidance of the end surface of the cam guide rail while rotating. The specific implementation principle is well-known in the art and will not be elaborated here in detail.

[0052] According to another embodiment, a water hydraulic piston pump is further provided, and the piston pump includes the above-mentioned piston structure.

[0053] That is, the main key point of the embodiment of the present invention lies in the design of the piston structure. As for the remaining structures of the piston pump, existing technologies can be adopted. By designing a special piston structure, the embodiment of the present invention can effectively reduce the hydraulic loss generated when the fluid in the piston chamber rotates along the piston wall surface, and thus effectively improve the working efficiency of the large-flow double-degree-of-freedom water hydraulic piston pump.

[0054] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0055] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above-mentioned", etc. can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation other than the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations for the spatial relative descriptions used here should be made.

[0056] In addition, it should be noted that the use of words such as "first", "second", etc. to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above words have no special meanings. Therefore, it should not be construed as a limitation on the protection scope of the present invention.

[0057] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A piston structure, characterized in that, The piston structure includes a baffle piston, and the baffle piston includes: A hollow cylinder with openings at both ends; A baffle, which is arranged inside the hollow cylinder and is connected to the inner wall of the hollow cylinder along the circumferential direction of the inner wall of the hollow cylinder. The baffle divides the inner cavity of the hollow cylinder into a first cavity and a second cavity along its axial direction; A plunger shaft, the baffle is inserted through the plunger shaft, the plunger shaft has an inner cavity, and the axes of the baffle, the hollow cylinder, and the plunger shaft coincide; Wherein, 2 water distribution ports are evenly distributed in the circumferential direction of the part a of the hollow cylinder corresponding to the first cavity; 2 water distribution ports are evenly distributed in the circumferential direction of the part b of the hollow cylinder corresponding to the second cavity, and the two pairs of water distribution ports are orthogonally arranged; the end face of any water distribution port is designed as an inclined section; The water distribution ports on the part a of the hollow cylinder extend from one end of the part a of the hollow cylinder to its free end; the water distribution ports on the part b of the hollow cylinder extend from one end of the part b of the hollow cylinder to its free end; The radius of the baffle is greater than the inner diameter of the plunger shaft; The piston structure further includes a cam guide rail, and the cam guide rail is arranged at one end of the plunger shaft; The baffle is a circular baffle, and the hollow cylinder is a hollow cylinder; The baffle, the hollow cylinder, and the plunger shaft are of an integral structure.

2. A piston structure according to claim 1, characterized in that, A plurality of linear ball grooves parallel to the axis are evenly distributed along the circumferential direction of the inner cavity wall of the plunger shaft.

3. A water hydraulic piston pump, characterized in that, The piston pump includes the piston structure according to any one of claims 1-2.

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