A pressure balanced plunger pump

Abstract

The utility model discloses a kind of plunger pumps based on pressure balance, it is related to the technical field of plunger pump, the utility model aims to solve the problem that the higher wall thickness selection is selected, the smaller inner diameter is even smaller than the outer diameter of lead screw and cannot install sleeve rod under the condition that pump body outer diameter and load are invariable, the utility model includes rack, pump body, piston, reciprocating mechanism and drive mechanism, the pump body is installed above base frame, the piston is installed in pump body, the reciprocating mechanism is installed on rack, and reciprocating mechanism is connected with piston, drive mechanism is installed below the rack, and the output end of drive mechanism is connected with reciprocating mechanism.This scheme compact structure is with manufacturing and installation, by the part of sleeve rod and piston connection is set to the solid structure of smaller diameter, make sleeve rod can be installed inside pump body when working pressure is too large, and also can make larger diameter lower half install on the outer wall of lead screw, overcome the contradiction that the outer diameter of lead screw is too large and the inner diameter of pump body is too small.

Description

Technical Field

[0001] This utility model relates to the technical field of pressure-balanced plunger pumps, specifically a pressure-balanced plunger pump. Background Technology

[0002] In the application of plunger pumps, with the outer diameter and radial load of the pump body remaining constant, the greater the working pressure of the pump body, the greater the wall thickness required, resulting in a smaller inner diameter of the pump body. As the pressure increases, the outer diameter of the lead screw also increases. Even if the radial load is kept constant, the inner diameter of the pump body still cannot meet the requirements for the sleeve rod to pass through. Traditional plunger pump structures often cannot meet the requirements due to space limitations and material strength issues. Utility Model Content

[0003] To address the aforementioned problems, specifically those raised in the background section, this invention proposes a pressure-balanced plunger pump, comprising a frame, a pump body, a piston, a reciprocating mechanism, and a drive mechanism. The pump body is mounted above the frame, the piston is installed within the pump body, and the reciprocating mechanism is mounted on the frame and connected to the piston. A drive mechanism is mounted below the frame, and its output end is connected to the reciprocating mechanism. The reciprocating mechanism includes a lead screw, a lead nut, and a sleeve. The upper half of the sleeve is a solid structure with an outer diameter smaller than the lower half, extending into the pump body and connecting to the piston. The lead screw is rotatably mounted on the frame via bearings. The lower half of the lead nut and the sleeve are sequentially and movably sleeved on the outer wall of the lead screw, with the lead nut threadedly connected to the lead screw. The drive mechanism includes a stepper motor and a synchronous belt. The stepper motor is mounted below the frame and drives the lead screw via the synchronous belt.

[0004] A lifting platform is movably sleeved on the outer wall of the lead screw, and the lifting platform is connected to the sleeve and the lead screw nut respectively. Four telescopic rods are evenly distributed below the lifting platform, and the bottom end of the telescopic rods is connected to the frame.

[0005] A further feature of this invention is that a sliding groove is provided on the frame, and the lifting platform is slidably mounted on the sliding groove.

[0006] A further feature of this invention is that a cylinder is provided between the telescopic rod and the base, with the cylinder piston located in the middle inside the cylinder, the bottom end of the telescopic rod connected to the cylinder piston, and the inside of the cylinder being sealed.

[0007] A further feature of this invention is that a flexible connection is provided between the sleeve rod and the piston. The flexible connection includes a push rod installed below the piston, hydraulic oil filling the gap between the piston and the top of the sleeve rod, and a bolt for positioning. A countersunk hole for inserting the push rod is provided above the sleeve rod, and a through groove is provided below the push rod. The bolt passes through the sleeve rod and is inserted into the bottom of the through groove.

[0008] The beneficial technical effects of this utility model are as follows: This solution has a compact structure, which is easy to manufacture and install. By setting the part connecting the sleeve rod and the piston as a solid structure with a smaller diameter, the sleeve rod can be installed inside the pump body when the working pressure is too high, and the lower half with a larger diameter can also be installed on the outer wall of the lead screw. This overcomes the contradiction of the lead screw having an excessively large outer diameter and the pump body having an excessively small inner diameter. Over-positioning is achieved through a double limiting mechanism, namely the slide groove and the telescopic rod, to avoid fatigue bending of various components caused by high-frequency reciprocating motion, which would lead to changes in the load direction and cause greater losses. Rigid impact is avoided through the cylinder buffer mechanism and flexible connection design, which effectively reduces damage to components and lowers maintenance costs. Attached Figure Description

[0009] Figure 1 A schematic diagram of the overall structure of this solution is shown.

[0010] Figure 2 A schematic diagram of the flexible connection structure is shown.

[0011] Figure 3 A schematic diagram of the left-side structure of this scheme is shown.

[0012] The attached diagram includes the following reference numerals: 1. Frame, 2. Pump body, 3. Piston, 4. Sleeve rod, 5. Lead screw, 6. Stepper motor, 7. Synchronous belt, 8. Telescopic rod, 9. Lifting platform, 10. Slide groove, 11. Nut, 12. Top rod, 13. Through groove, 14. Countersunk hole, 15. Bolt, 16. Pressure sensor, 17. Cylinder. Detailed Implementation

[0013] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0014] This invention proposes a plunger pump based on pressure balance. In order to ensure pressure balance in the machining cavity, the plunger pump of this solution is installed on one side of the machining cavity. Since the required pressure is large, the maximum pressure needs to reach 200 MPa. However, the larger the required pressure, the thicker the pump body 2 needs to be. If the outer diameter of the pump body 2 remains unchanged, the inner diameter will be reduced accordingly. Even if the radial load is kept constant so that the outer diameter of the lead screw remains unchanged, the inner diameter of the pump body still cannot meet the requirements of the sleeve rod. Traditional plunger pump structures often cannot meet the requirements due to space limitations and material strength issues.

[0015] The radial load is controlled at 55KN. According to the conversion formula, the diameter of the lead screw 5 should be selected as 25mm. When the required pressure is 200mpa, the inner diameter of the pump body 2 is much smaller than the outer diameter of the lead screw 5. The upper half of the cylinder liner 4 is set as a solid structure that can pass through the inside of the pump body 2, so that the solid structure can withstand the pressure of 200mpa. The lower half of the sleeve 4 is set as a hollow structure with a diameter larger than the upper half of the solid structure, so that it can be fitted onto the outer wall of the lead screw 5.

[0016] Pump body 2 is installed above base frame 1, stepper motor 6 is installed below frame 1, lead screw 5 is installed on frame 1 through bearing, stepper motor 6 controls lead screw 5 to rotate through synchronous belt 7, lead screw 5 rotates through lead screw nut 11 to drive lifting platform 9 to move up and down, thereby lifting platform 9 drives piston 3 to reciprocate through sleeve 4, and outputs pressure through inlet, outlet and check valve on both sides of top of pump body 2.

[0017] The telescopic rods 8 set around the bottom of the lifting platform 9 are used to extend or retract as the lifting platform 9 moves, and to limit the lifting platform 9 to only reciprocating linear motion. A slide groove 10 is set on the base frame 1, and the lifting platform 9 is slidably installed in the slide groove 10. Through two sets of limit guide mechanisms, the limit mechanism is over-positioned to avoid fatigue bending of the limit mechanism after frequent reciprocating motion, which would cause the load direction to change and damage the equipment.

[0018] A cylinder 17 is installed between the telescopic rod 8 and the bracket 1. The cylinder piston is located in the middle section inside the cylinder 17. The bottom end of the telescopic rod 8 extends into the cylinder 17 and connects with the cylinder piston. The inside of the cylinder 17 is sealed. When the telescopic rod 8 extends or retracts to its limit, it will drive the cylinder piston to move up or down to compress the gas inside the cylinder 17, thereby offsetting the impact force and preventing the components involved in the reciprocating motion from being damaged by rigid impact.

[0019] The piston 3 and the sleeve rod 4 are flexibly connected, with a certain sealing space between them filled with hydraulic oil. A push rod 12 is installed below the piston 3, and the push rod 12 is inserted into a countersunk hole 14 on the upper part of the sleeve rod 4, leaving a telescopic space with a height greater than the height of the sealing space. A through groove 13 is opened in the push rod 12, and a bolt 15 is inserted into one side of the sleeve rod 4, passing through the through groove 13 to limit the stroke of the push rod 12. When the piston 3 is compressed to its limit, the hydraulic oil is compressed and pulse vibrations are absorbed to prevent the lead screw 5 from being rigidly damaged by pulse vibrations caused by collisions.

[0020] Although the present invention has been described with reference to preferred embodiments, various modifications can be made to it and components can be replaced with equivalents without departing from the scope of the present invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0021] In the description of this utility model, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to those processes, articles, or apparatus / devices.

[0024] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A pressure-balanced plunger pump, comprising a frame (1), a pump body (2), a piston (3), a reciprocating mechanism, and a drive mechanism, wherein the pump body (2) is mounted above the frame (1), the piston (3) is mounted in the pump body (2), the reciprocating mechanism is mounted on the frame (1) and connected to the piston (3), and a drive mechanism is mounted below the frame (1), the output end of the drive mechanism being connected to the reciprocating mechanism, characterized in that: The reciprocating mechanism includes a lead screw (5), a lead screw nut (11), and a sleeve rod (4). The upper half of the sleeve rod (4) is a solid structure with an outer diameter smaller than that of the lower half, and the solid structure extends into the pump body (2) and is connected to the piston (3). The lead screw (5) is rotatably mounted on the frame (1) through bearings. The lower half of the lead screw nut (11) and the sleeve rod (4) are sequentially movably sleeved on the outer wall of the lead screw (5), and the lead screw nut (11) is threadedly connected to the lead screw (5). The driving mechanism includes a stepper motor (6) and a synchronous belt (7). The stepper motor (6) is mounted below the frame (1), and the stepper motor (6) drives the lead screw (5) through the synchronous belt (7). The lifting platform (9) is movably sleeved on the outer wall of the lead screw (5), and the lifting platform (9) is connected to the sleeve rod (4) and the lead nut (11) respectively. Four telescopic rods (8) are evenly distributed below the lifting platform (9), and the bottom end of the telescopic rods (8) is connected to the frame (1).

2. A piston pump based on pressure balance according to claim 1, characterized in that: The frame (1) is provided with a slide groove (10), and the lifting platform (9) is slidably installed on the slide groove (10).

3. A pressure-balanced plunger pump according to claim 1 or 2, characterized in that: A cylinder (17) is also provided between the telescopic rod (8) and the base. The cylinder piston is located in the middle of the cylinder (17). The bottom end of the telescopic rod (8) is connected to the cylinder piston, and the cylinder (17) is in a sealed state.

4. A pressure-balanced plunger pump according to claim 1 or 2, characterized in that: A flexible connection is provided between the sleeve rod (4) and the piston (3). The flexible connection includes a push rod (12) installed below the piston (3), hydraulic oil filling the gap between the piston (3) and the top of the sleeve rod (4), and a bolt (15) for positioning. A countersunk hole (14) for inserting the push rod (12) is provided above the sleeve rod (4), and a through groove (13) is provided below the push rod (12). The bolt (15) passes through the sleeve rod (4) and is inserted into the bottom of the through groove (13).

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