Displacement control device of plunger pump

Abstract

The utility model discloses a displacement control device for a plunger pump, which comprises a pneumatic pressure reducing valve, a plunger pump, a displacement sensor and a controller, wherein the pneumatic pressure reducing valve is arranged vertical to the plunger pump; the displacement conversion mechanism comprises a thin film execution assembly, a moving part and a valve rod, the thin film execution assembly is communicated with an outlet of the pneumatic pressure reducing valve, the moving part is connected with the thin film execution assembly, and the valve rod is connected with a pump push rod of the plunger pump; wherein the valve rod is perpendicular to the moving part, and the valve rod is connected with the moving part through a 45-degree helical tooth structure. Proportional adjustment of the displacement of the plunger pump is achieved in a pneumatic mode, operation is convenient, precision is high, and the anti-explosion requirement can be met. Through the displacement conversion mechanism, conversion between vertical movement and horizontal movement can be achieved, so that the overall structure of the plunger pump displacement control device can be more compact, and the occupied space is smaller.

Description

Technical Field

[0001] The utility model relates to the technical field of plunger pumps, in particular to a plunger pump displacement control device. Background Art

[0002] The plunger pump is an important device in the hydraulic system. It relies on the reciprocating motion of the plunger in the cylinder to change the volume of the sealed working chamber to achieve oil suction and oil pressure. The plunger pump has the advantages of high rated pressure, compact structure, high efficiency and convenient flow regulation. For example, the swash plate axial piston pump consists of a swash plate, a plunger, a group, a valve plate and a drive shaft, and there is an inclination angle γ between the cylinder and the swash plate. The plungers are evenly distributed in the cylinder, and their heads are tightly pressed on the swash plate through the spring return mechanism and the oil pressure. The drive shaft drives the cylinder to rotate through the spline, and the swash plate and the valve plate are fixed. When the drive shaft can rotate counterclockwise (from left to right), the plunger rotates with the cylinder and makes reciprocating linear motion in the plunger hole of the cylinder. When the drive shaft and the cylinder rotate once, each plunger completes the suction and pressure of oil once. When the cylinder rotates continuously, the plunger continuously sucks and presses oil. If the inclination angle γ of the swash plate is changed, the reciprocating stroke of the plunger can be changed, that is, the displacement of the pump can be changed.

[0003] At present, the commonly used displacement adjustment methods of plunger pumps are manual adjustment method and electric adjustment method. The manual adjustment method has human errors and cannot meet the frequency requirements. Since the structure of the swash plate part of the plunger pump is set inside the oil tank, and the electric adjustment method is mainly regulated by a proportional solenoid valve, which cannot be installed in the oil tank and is inconvenient to wire. In addition, for some places with explosion-proof requirements such as chemical plants, the electric adjustment method must use electricity. If electric sparks occur, there is also a risk of explosion. Utility Model Content

[0004] The technical problem to be solved by the utility model is that the existing displacement adjustment method of the plunger pump is inconvenient to use.

[0005] To this end, the utility model provides a plunger pump displacement control device, which adopts a pneumatic adjustment method and cooperates with a position conversion mechanism, which is not only convenient for adjustment but also can meet the explosion-proof requirements.

[0006] The technical solution adopted by the utility model to solve the technical problem is: a plunger pump displacement control device, comprising: a pneumatic pressure reducing valve, the pneumatic pressure reducing valve is arranged perpendicular to the plunger pump; a displacement conversion mechanism, the displacement conversion mechanism comprises: a film actuator assembly, a moving part and a valve stem, the film actuator assembly is connected to the outlet of the pneumatic pressure reducing valve, the moving part is connected to the film actuator assembly, and the valve stem is connected to the pump push rod of the plunger pump;

[0007] Wherein, the valve stem and the moving part are arranged perpendicular to each other, and the valve stem and the moving part are connected via a 45° bevel gear structure.

[0008] Furthermore, the moving part includes a first push rod and a second push rod, the first push rod and the second push rod are threadedly connected, and the second push rod is provided with a first bevel tooth; the valve stem is provided with a second bevel tooth, and the first bevel tooth is meshed with the second bevel tooth.

[0009] Furthermore, the film actuator assembly includes: an upper film cover, a lower film cover, a diaphragm, a plurality of elastic parts and a supporting part. The upper film cover and the lower film cover are fixed by screws to form a cavity. The diaphragm, the plurality of elastic parts and the supporting part are all located in the cavity. The elastic part is located between the supporting part and the lower film cover. The diaphragm is in contact with the supporting part, and the upper end of the movable part is connected to the supporting part.

[0010] Furthermore, the edge of the diaphragm is clamped between the upper diaphragm cover and the lower diaphragm cover, an air pressure cavity is formed between the diaphragm and the upper diaphragm cover, an air inlet is opened on the upper diaphragm cover, and the air inlet is connected to the air pressure cavity.

[0011] Furthermore, the displacement conversion mechanism also includes: a bracket, the upper end of which is connected to the film actuator, and the first push rod is arranged inside the bracket and passes through the upper and lower ends of the bracket.

[0012] Furthermore, the displacement conversion mechanism also includes: a base, the upper end of the base is connected to the lower end of the bracket, the second push rod is arranged in the base, and a connecting flange is provided on the outer peripheral surface of the base.

[0013] Furthermore, an upper pressure cover and a first sealing ring are provided at the upper end of the base, the upper pressure cover is fixedly connected to the upper end of the base, the first sealing ring is located below the upper pressure cover, and the lower end of the first push rod penetrates the upper pressure cover and the first sealing ring and extends into the base.

[0014] Furthermore, the valve stem is arranged to penetrate the lower end of the base in a direction perpendicular to the length of the base, the left end of the base is connected to a left end cover, the right end of the base is connected to a right end cover, and the right end of the valve stem penetrates the right end cover.

[0015] Furthermore, a first shaft sleeve is provided between the left end of the valve stem and the base, and a second sealing ring is provided between the right end of the valve stem and the right end cover.

[0016] Furthermore, a lower pressure cover is connected to the lower end of the base.

[0017] The beneficial effect of the utility model is that the pneumatic pressure reducing valve can adjust the intake pressure, and the air pressure change enables the movable part to move up and down. The up and down movement of the movable part can be converted into the horizontal movement of the valve stem through the 45° bevel gear structure. When the valve stem moves horizontally, it drives the pump push rod to move together, thereby realizing the change of the displacement of the plunger pump. The proportional adjustment of the displacement of the plunger pump is achieved by pneumatic means, which is easy to operate and has high precision, and can also meet the explosion-proof requirements. The conversion between vertical movement and horizontal movement can be achieved through the displacement conversion mechanism, so that the overall structure of the plunger pump displacement control device can be more compact and occupy less space. The pneumatic pressure reducing valve is located outside the oil tank, which is also convenient for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0019] Figure 1 It is a three-dimensional schematic diagram of the plunger pump displacement control device of the utility model.

[0020] Figure 2 It is a cross-sectional view of the plunger pump displacement control device of the utility model.

[0021] Figure 3 It is a structural schematic diagram of the displacement conversion mechanism of the utility model.

[0022] Figure 4 It is a structural schematic diagram of the thin film execution component of the utility model.

[0023] In the figure: 1. pneumatic pressure reducing valve; 2. displacement conversion mechanism; 3. plunger pump; 201. diaphragm actuator; 202. moving part; 203. valve stem; 204. bracket; 205. base; 206. connecting flange; 207. upper pressure cover; 208. first sealing ring; 209. left end cover; 210. right end cover; 211. first bushing; 212. second sealing ring; 213. lower pressure cover; 2011. upper diaphragm cover; 2012. lower diaphragm cover; 2013. diaphragm; 2014. elastic part; 2015. supporting part; 20111. air inlet; 2021. first push rod; 2022. second push rod; 31. pump push rod; 32. inclined plate. DETAILED DESCRIPTION

[0024] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0025] In the description of the present utility model, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] like Figures 1 to 4 As shown, the plunger pump displacement control device of the utility model comprises: a pneumatic pressure reducing valve 1 and a displacement conversion mechanism 2, the pneumatic pressure reducing valve 1 is arranged perpendicular to the plunger pump 3, the displacement conversion mechanism 2 comprises: a diaphragm actuator assembly 201, a moving part 202 and a valve stem 203, the diaphragm actuator assembly 201 is connected to the outlet of the pneumatic pressure reducing valve 1, the moving part 202 is connected to the diaphragm actuator assembly 201, and the valve stem 203 is connected to the pump push rod 31 of the plunger pump 3; wherein the valve stem 203 and the moving part 202 are arranged perpendicular to each other, and the valve stem 203 and the moving part 202 are connected by a 45° bevel gear structure.

[0028] It should be noted that in the application scenario of this embodiment, the plunger pump 3 is placed on the ground, and the swash plate 32 and pump push rod 31 of the plunger pump 3 are partially located in the oil tank. Considering the problem of installation space, the pneumatic pressure reducing valve 1 is arranged perpendicular to the plunger pump 3 in this embodiment, and the pneumatic pressure reducing valve 1 is connected to the air source. The pneumatic pressure reducing valve 1 can adjust the swing angle of the swash plate 32 by adjusting the intake pressure, thereby realizing the change of the displacement of the plunger pump 3. Since the pump push rod 31 of the plunger pump 3 is parallel to the ground, and the pneumatic pressure reducing valve 1 is perpendicular to the ground, therefore, the displacement conversion mechanism 2 is set in this embodiment, and the air pressure of the pneumatic pressure reducing valve 1 acts on the film actuator 201 so that the moving part 202 can move downward, and the up and down movement of the moving part 202 can be converted into the horizontal movement of the valve stem 203 through the 45° bevel gear structure, and the valve stem 203 drives the pump push rod 31 to move together when it moves horizontally, thereby realizing the change of the displacement of the plunger pump 3.

[0029] The utility model improves the structure and uses pneumatic means to achieve proportional adjustment of the displacement of the plunger pump 3, which is easy to operate and has high precision, and can also meet explosion-proof requirements. The displacement conversion mechanism 2 can achieve conversion between vertical movement and horizontal movement, so that the overall structure of the plunger pump displacement control device can be more compact and occupy less space. The pneumatic pressure reducing valve 1 is located outside the oil tank, which is also convenient for maintenance.

[0030] Specifically, the film actuator assembly 201 includes: an upper film cover 2011, a lower film cover 2012, a diaphragm 2013, a plurality of elastic members 2014 and a supporting member 2015. The upper film cover 2011 and the lower film cover 2012 are fixed by screws to form a cavity. The diaphragm 2013, the plurality of elastic members 2014 and the supporting member 2015 are all located in the cavity. The elastic member 2014 is located between the supporting member 2015 and the lower film cover 2012. The diaphragm 2013 fits the supporting member 2015. The upper end of the moving member 202 is connected to the supporting member 2015. The edge of the diaphragm 2013 is clamped between the upper film cover 2011 and the lower film cover 2012. An air pressure cavity is formed between the diaphragm 2013 and the upper film cover 2011. An air inlet 20111 is provided on the upper film cover 2011, and the air inlet 20111 is connected to the air pressure cavity. The moving member 202 includes a first push rod 2021 and a second push rod 2022 . The first push rod 2021 and the second push rod 2022 are threadedly connected. The second push rod 2022 is provided with a first bevel gear. The valve stem 203 is provided with a second bevel gear. The first bevel gear meshes with the second bevel gear.

[0031] It should be noted that the air inlet 20111 is connected to the outlet of the pneumatic pressure reducing valve 1. When the pneumatic pressure reducing valve 1 discharges air, the air enters the air pressure chamber from the air inlet 20111. When the air pressure in the air pressure chamber exceeds the elastic force of the elastic member 2014, the air presses the diaphragm 2013 downward. At this time, the first push rod 2021 moves synchronously with the diaphragm 2013. When the first push rod 2021 moves, it drives the second push rod 2022 to move downward together. When the second push rod 2022 moves downward, the valve stem 203 is extended horizontally. The valve stem 203 pushes the pump push rod 31 to reduce the angle of the swash plate 32 and reduce the displacement. When the air pressure in the air pressure chamber becomes smaller and is not enough to overcome the elastic force of the elastic member 2014, the elastic member 2014 pushes the diaphragm 2013 upward. At this time, the first push rod 2021 and the second push rod 2022 move upward together, the valve stem 203 retracts, the swing angle of the swash plate 32 increases, and the displacement increases. When the diaphragm 2013 is at the uppermost position (the elastic member 2014 is not compressed at this time), the displacement is maximum.

[0032] For example, the displacement conversion mechanism 2 further includes: a bracket 204 and a base 205, the upper end of the bracket 204 is connected to the film actuator 201 (the upper end of the bracket 204 is connected to the lower membrane cover 2012 by screws), and the first push rod 2021 is arranged inside the bracket 204 and penetrates the upper and lower ends of the bracket 204. The upper end of the base 205 is connected to the lower end of the bracket 204, the second push rod 2022 is arranged in the base 205, and a connecting flange 206 is provided on the outer peripheral surface of the base 205. The connecting flange 206 is fixedly connected to the oil tank. In other words, the bracket 204 is located outside the oil tank, the base 205 is located inside the oil tank, and the second push rod 2022 and the valve stem 203 are located inside the oil tank.

[0033] For example, an upper gland 207 and a first sealing ring 208 are provided at the upper end of the base 205, the upper gland 207 is fixedly connected to the upper end of the base 205, the first sealing ring 208 is located below the upper gland 207, and the lower end of the first push rod 2021 penetrates the upper gland 207 and the first sealing ring 208 and extends into the base 205. The upper gland 207 and the first sealing ring 208 cooperate with each other to prevent dust or debris in the bracket 204 from falling into the base 205, thereby preventing the movement between the second push rod 2022 and the valve stem 203 from being affected.

[0034] For example, the lower end of the base 205 is connected with a lower pressure cover 213. Since the lower end of the base 205 is inside the oil tank, the lower pressure cover 213 can prevent the hydraulic oil from entering the base from the lower end of the base 205. The valve stem 203 is arranged at the lower end of the base 205 in a direction perpendicular to the length of the base 205. The left end of the base 205 is connected with a left end cover 209, the right end of the base 205 is connected with a right end cover 210, and the right end of the valve stem 203 passes through the right end cover 210. A first sleeve 211 is arranged between the left end of the valve stem 203 and the base 205, and a second sealing ring 212 is arranged between the right end of the valve stem 203 and the right end cover 210. The left end cover 209 can prevent the hydraulic oil from entering the base 205 from the left side of the base 205, and the right end cover 210 and the second sealing ring 212 can prevent the hydraulic oil from entering the base 205 from the oil side of the base 205.

[0035] Working principle:

[0036] When the outlet pressure of the pneumatic pressure reducing valve 1 increases, and the force exerted by the air pressure in the air pressure chamber on the diaphragm 2013 exceeds the elastic force of the elastic member 2014, the diaphragm 2013 moves downward. At this time, the movable member 202 moves downward, and the vertical movement of the movable member 202 is converted into the horizontal extension of the valve stem 203 through the 45° bevel gear structure. At this time, the valve stem 203 pushes the pump push rod 31 to reduce the angle of the inclined plate 32 and the displacement.

[0037] When the outlet pressure of the pneumatic pressure reducing valve 1 decreases, and the force exerted by the air pressure in the air pressure chamber on the diaphragm 2013 is less than the elastic force of the elastic member 2014, the diaphragm 2013 moves upward. At this time, the movable member 202 moves upward, and the vertical movement of the movable member 202 is converted into a horizontal retraction of the valve stem 203 through the 45° bevel gear structure. At this time, the valve stem 203 pulls the pump push rod 31 to increase the angle of the inclined plate 32 and the displacement.

[0038] When the elastic member 2014 is in an uncompressed state, the diaphragm 2013 is at the uppermost position and the displacement of the plunger pump is the largest.

[0039] In summary, the plunger pump displacement control device of the utility model uses pneumatic means to achieve proportional adjustment of the displacement of the plunger pump 3, which is easy to operate and has high precision, and can also meet explosion-proof requirements. The displacement conversion mechanism 2 can achieve conversion between vertical movement and horizontal movement, so that the overall structure of the plunger pump displacement control device can be more compact and occupy less space. The pneumatic pressure reducing valve 1 is located outside the oil tank, which is also convenient for maintenance.

[0040] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A plunger pump displacement control device, characterized in that: include: A pneumatic pressure reducing valve (1), wherein the pneumatic pressure reducing valve (1) is arranged perpendicular to the plunger pump (3); A displacement conversion mechanism (2), the displacement conversion mechanism (2) comprising: a film actuator assembly (201), a moving part (202) and a valve stem (203), the film actuator assembly (201) being connected to the outlet of the pneumatic pressure reducing valve (1), the moving part (202) being connected to the film actuator assembly (201), and the valve stem (203) being connected to a pump push rod (31) of the plunger pump (3); The valve stem (203) and the moving part (202) are arranged perpendicular to each other, and the valve stem (203) and the moving part (202) are connected via a 45° bevel gear structure.

2. The plunger pump displacement control device according to claim 1, characterized in that: The moving member (202) comprises a first push rod (2021) and a second push rod (2022), the first push rod (2021) and the second push rod (2022) are threadedly connected, and the second push rod (2022) is provided with a first bevel tooth; the valve stem (203) is provided with a second bevel tooth, and the first bevel tooth is meshed with the second bevel tooth.

3. The plunger pump displacement control device according to claim 1, characterized in that: The film actuator assembly (201) comprises: an upper film cover (2011), a lower film cover (2012), a diaphragm (2013), a plurality of elastic members (2014) and a supporting member (2015); the upper film cover (2011) and the lower film cover (2012) are fixed by screws to form a cavity; the diaphragm (2013), the plurality of elastic members (2014) and the supporting member (2015) are all located in the cavity; the elastic member (2014) is located between the supporting member (2015) and the lower film cover (2012); the diaphragm (2013) is in contact with the supporting member (2015); and the upper end of the movable member (202) is connected to the supporting member (2015).

4. The plunger pump displacement control device according to claim 3, characterized in that: The edge of the diaphragm (2013) is clamped between the upper diaphragm cover (2011) and the lower diaphragm cover (2012), and an air pressure chamber is formed between the diaphragm (2013) and the upper diaphragm cover (2011). An air inlet (20111) is provided on the upper diaphragm cover (2011), and the air inlet (20111) is connected to the air pressure chamber.

5. The plunger pump displacement control device according to claim 2, characterized in that: The displacement conversion mechanism (2) further comprises: a bracket (204), the upper end of the bracket (204) being connected to the film actuator assembly (201), and the first push rod (2021) being arranged inside the bracket (204) and penetrating the upper and lower ends of the bracket (204).

6. The plunger pump displacement control device according to claim 5, characterized in that: The displacement conversion mechanism (2) further comprises: a base (205), the upper end of the base (205) being connected to the lower end of the bracket (204), the second push rod (2022) being arranged in the base (205), and a connecting flange (206) being arranged on the outer peripheral surface of the base (205).

7. The plunger pump displacement control device according to claim 6, characterized in that: The upper end of the base (205) is provided with an upper pressure cover (207) and a first sealing ring (208), the upper pressure cover (207) is fixedly connected to the upper end of the base (205), the first sealing ring (208) is located below the upper pressure cover (207), and the lower end of the first push rod (2021) passes through the upper pressure cover (207) and the first sealing ring (208) and extends into the base (205).

8. The plunger pump displacement control device according to claim 6, characterized in that: The valve stem (203) is arranged to penetrate the lower end of the base (205) in a direction perpendicular to the length of the base (205); the left end of the base (205) is connected to a left end cover (209); the right end of the base (205) is connected to a right end cover (210); and the right end of the valve stem (203) penetrates the right end cover (210).

9. The plunger pump displacement control device according to claim 8, characterized in that: A first shaft sleeve (211) is provided between the left end of the valve stem (203) and the base (205), and a second sealing ring (212) is provided between the right end of the valve stem (203) and the right end cover (210).

10. The plunger pump displacement control device according to claim 6, characterized in that: The lower end of the base (205) is connected to a lower pressure cover (213).

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