A plunger-type metering pump with adjustable displacement

Abstract

The present invention discloses a plunger-type metering pump with adjustable displacement, including a pump head, a fluid channel longitudinally arranged in the pump head, one-way valves symmetrically arranged at the upper and lower ends of the fluid channel, a piston channel arranged on one side of the fluid channel, a plunger rod slidably and sealedly connected to the piston channel, the outer end of the plunger rod connected to the plunger reciprocating mechanism, a plunger sleeve sealedly connected between the plunger rod and the piston channel, and an adjusting screw threadedly connected to the pump head, the plunger sleeve and the plunger rod. The present invention can fix the pump head and the plunger sleeve or the plunger sleeve and the plunger rod by rotating the adjusting screw, and change the diameter of the plunger to adjust the single displacement, which is more convenient, does not need to adjust the stroke of the transmission mechanism, and the viscous medium is easily discharged.

Description

Technical Field

[0001] The invention relates to the technical field of plunger type metering pumps, in particular to a plunger type metering pump with adjustable displacement. Background Art

[0002] The plunger metering pump directly inhales and discharges the working medium through the reciprocating motion of the plunger. The plunger metering pump generally includes a worm gear drive mechanism, an eccentric rotary mechanism and a plunger reciprocating mechanism. The worm gear drive mechanism drives the eccentric rotary mechanism to move, and the eccentric wheel of the eccentric rotary mechanism drives the plunger in the plunger reciprocating mechanism to reciprocate. The plunger of the plunger pump head contacts the conveying liquid. The plunger metering pump is widely used in the fields of petrochemical, pharmaceutical and food due to its simple structure and high temperature and high pressure resistance. The plunger pump of the prior art has the following defects: (1) It is troublesome to adjust the single displacement by changing the stroke of the eccentric rotary mechanism, and the viscous medium is not easy to discharge when the stroke is too large; (2) When the packing and plunger are severely worn, liquid leakage is likely to occur, which greatly shortens the service life of the product and the cost of replacing the plunger is relatively high. Summary of the invention

[0003] The present invention aims to solve the above problems existing in the prior art and provides a plunger-type metering pump with adjustable displacement, which can adjust the single displacement without changing the stroke.

[0004] The present invention solves the technical problem by adopting the following technical solution: a plunger-type metering pump with adjustable displacement, comprising a pump head, a fluid channel longitudinally arranged in the pump head, one-way valves symmetrically arranged at the upper and lower ends of the fluid channel, a piston channel arranged on one side of the fluid channel, a plunger rod slidingly and sealingly connected to the piston channel, the outer end of the plunger rod being connected to a plunger reciprocating mechanism, a plunger sleeve sealingly connected between the plunger rod and the piston channel, an adjusting screw being threadedly connected to the pump head, the plunger sleeve and the plunger rod, and the pump head and the plunger sleeve or the plunger sleeve and the plunger rod can be fixedly connected by rotating the adjusting screw.

[0005] Further improvement, the adjusting screw includes a first screw segment and a second screw segment, and the first screw segment and the second screw segment are circumferentially fixed and axially slidably connected. By rotating the adjusting screw, the first screw segment can be fixedly connected to the pump head and the plunger sleeve, or the second screw segment can be fixedly connected to the plunger sleeve and the plunger rod.

[0006] For further improvement, the first screw segment and the second screw segment are both provided with a hexagonal hole, a hexagonal rod is installed on the hexagonal hole, one end of the hexagonal rod is connected to the adjusting motor, and the adjusting motor is fixedly connected to the pump head.

[0007] For further improvement, the piston channel and the plunger sleeve are respectively threadedly connected with a first stuffing gland and a second stuffing gland, and the first stuffing gland and the second stuffing gland are both provided with through holes, and a linkage rod is movably and slidably connected to the through holes.

[0008] For further improvement, an anti-loosening spring is provided between the linkage rod and the pump head.

[0009] For further improvement, a rotary valve barrel is provided in the pump head, the right end of the rotary valve barrel is connected to the piston channel, the left end of the rotary valve barrel is connected to the flip motor, and a guide hole connected to the fluid channel is provided on the side wall of the rotary valve barrel.

[0010] For further improvement, a limit shaft shoulder is provided on the rotary valve barrel, a bearing is provided between the limit shaft shoulder and the piston channel, and a sealing ring is provided at the right end of the rotary valve barrel.

[0011] For further improvement, a flow guide bend is provided between the flow guide hole and the piston channel.

[0012] The beneficial effects of the present invention are: (1) the present invention can fix the connection between the pump head and the plunger sleeve or the plunger sleeve and the plunger rod by rotating the adjusting screw, and change the diameter of the plunger to adjust the single displacement, which is relatively convenient and does not require adjustment of the stroke of the transmission mechanism, and the viscous medium is easy to discharge; (2) when the adjusting screw is a multi-stage structure, multiple plunger sleeves can be arranged, and when a single plunger sleeve is worn, it does not need to be replaced, and the maintenance cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the present invention when the plunger sleeve is fixedly connected to the plunger rod;

[0014] Figure 2 It is a schematic diagram of the structure of the present invention when the pump head and the plunger sleeve are fixedly connected;

[0015] Explanation of the accompanying drawings: 1. Pump head, 2. Check valve, 3. Plunger rod, 4. Plunger sleeve, 5. Adjusting screw, 6. Hexagonal hole, 7. Hexagonal rod, 8. Adjusting motor, 9. First stuffing gland, 10. Second stuffing gland, 11. Linking rod, 12. Anti-loosening spring, 13. Rotary valve barrel, 14. Flip motor, 15. Diversion hole, 16. Limiting shoulder, 17. Bearing, 18. Sealing ring, 19. Diversion bend. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings:

[0017] A plunger-type metering pump with adjustable displacement in this embodiment 1 includes a pump head 1, a fluid channel is longitudinally arranged in the pump head 1, and one-way valves 2 are symmetrically arranged at the upper and lower ends of the fluid channel. A piston channel is arranged on one side of the fluid channel, and a plunger rod 3 is slidably and sealedly connected to the piston channel. The outer end of the plunger rod 3 is connected to a plunger reciprocating mechanism, and a plunger sleeve 4 is sealedly connected between the plunger rod 3 and the piston channel. An adjusting screw 5 is threadedly connected to the pump head 1, the plunger sleeve 4 and the plunger rod 3, and the pump head 1 and the plunger sleeve 4 or the plunger sleeve 4 and the plunger rod 3 can be fixedly connected by rotating the adjusting screw 5.

[0018] Working principle: The motor drives the eccentric rotary mechanism through the worm gear drive mechanism, and the eccentric wheel of the eccentric rotary mechanism drives the plunger rod 3 in the plunger reciprocating mechanism to reciprocate. The adjusting screw 5 is rotated forward to move the adjusting screw 5 to the left to fix the connection between the pump head 1 and the plunger sleeve 4. At this time, the plunger sleeve 4 does not move, and the plunger rod 3 reciprocates alone. When the displacement of the single displacement pump needs to be increased, the adjusting screw 5 is rotated in the opposite direction to move right to fix the connection between the plunger sleeve 4 and the plunger rod 3. At this time, the plunger sleeve 4 reciprocates with the plunger rod 3, which increases the diameter of the plunger and improves the single displacement. It is more convenient and does not need to adjust the stroke of the transmission mechanism. The viscous medium is easy to discharge. The plunger sleeve 4 can move with the plunger rod 3 or the plunger rod 3 can move alone. In this way, when one of the sealing surfaces is worn, another sealing surface can be quickly used, which reduces the maintenance cost without replacing the plunger rod 3.

[0019] Example 2, refer to the attached Figure 1-2 On the basis of Example 1, in order to improve the switching efficiency when a single plunger sleeve 4 is used or to be able to use more than two plunger sleeves 4, the adjusting screw 5 includes a first screw segment and a second screw segment, and the first screw segment and the second screw segment are circumferentially fixed and axially slidably connected. By rotating the adjusting screw 5, the first screw segment can be fixedly connected to the pump head 1 and the plunger sleeve 4, or the second screw segment can be fixedly connected to the plunger sleeve 4 and the plunger rod 3. The adjusting screw 5 is a two-section separable structure, which can achieve switching at the separation point when a single plunger sleeve 4 is used, or when more than two plunger sleeves 4 are used, it can avoid the problem of separation of the plunger sleeve 4 from the pump head 1 when the plunger rod 3 reciprocates.

[0020] The first screw segment and the second screw segment are both provided with a hexagonal hole 6, a hexagonal rod 7 is installed on the hexagonal hole 6, one end of the hexagonal rod 7 is connected to the adjustment motor 8, and the adjustment motor 8 is fixedly connected to the pump head 1. When the adjustment motor 8 drives the hexagonal rod 7 to rotate, the hexagonal rod 7 drives the first screw segment and the second screw segment to rotate synchronously, and the axial movement is performed simultaneously under the action of the thread to complete the switching operation. The hexagonal hole 6 is slidably connected to the hexagonal rod 7, which can enhance the stability of the axial movement of the plunger.

[0021] Embodiment 3, on the basis of embodiment 1, the piston channel and the plunger sleeve 4 are respectively threadedly connected with a first packing gland 9 and a second packing gland 10, and the first packing gland 9 and the second packing gland 10 are both provided with through holes, and the through holes are movably and slidably connected with a linkage rod 11. The linkage rod 11 can simultaneously drive the first packing gland 9 and the second packing gland 10 to rotate, compress the packing to achieve sealing, ensure that the first packing gland 9 and the second packing gland 10 generate approximately equal pressing forces, and avoid the sliding resistance generated when switching to use the plunger sleeve 4 within a reasonable range.

[0022] An anti-loosening spring 12 is arranged between the linkage rod 11 and the pump head 1. The anti-loosening spring 12 can provide elastic torsion for the linkage rod 11, realize elastic pre-tightening, keep the first packing gland 9 and the second packing gland 10 from loosening easily, and enhance the sealing performance.

[0023] In order to adjust the elastic force of the anti-loosening spring 12, a fixed bracket can be further fixedly installed on the pump head 1, an arc-shaped guide rail is fixedly installed on the fixed bracket, a slider is slidably installed on the arc-shaped guide rail, and the slider is fixedly connected to the linkage rod 11. The arc-shaped guide rail is provided with a plurality of gear holes, and the gear holes are provided with pins, and the anti-loosening spring 12 is fixedly installed between the pins and the slider. By selecting different gear holes, the anti-loosening spring 12 can generate elastic forces of different gear sizes.

[0024] Embodiment 4, on the basis of embodiment 1, in order to improve the working efficiency of the plunger pump, a rotary valve barrel 13 is provided in the pump head 1, the right end of the rotary valve barrel 13 is connected to the piston channel, the left end of the rotary valve barrel 13 is connected to the flip motor 14, and a guide hole 15 connected to the fluid channel is provided on the side wall of the rotary valve barrel 13. The flip motor 14 can drive the rotary valve barrel 13 to rotate 180 degrees. In the process of the plunger moving to the right, the guide hole 15 is downwardly connected to the inlet check valve to facilitate the inhalation of the medium. After it is in place, it is rotated and switched so that in the process of the plunger moving to the left, the guide hole 15 is upwardly connected to the outlet check valve to facilitate the extrusion of the medium.

[0025] The rotary valve barrel 13 is provided with a limit shoulder 16, and a bearing 17 is provided between the limit shoulder 16 and the piston channel. The bearing 17 can reduce the friction of the rotary valve barrel 13, and a sealing ring 18 is provided at the right end of the rotary valve barrel 13. The sealing ring 18 can improve the sealing performance between the rotary valve barrel 13 and the piston channel, so that the medium in the piston channel can flow through the inside of the rotary valve barrel 13 as much as possible. A diversion bend 19 is provided between the diversion hole 15 and the piston channel to reduce the resistance of the medium flow.

[0026] Although the present invention has been shown and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein within the scope of the claims.

Claims

1. A plunger-type metering pump with adjustable displacement, comprising a pump head (1), a fluid channel longitudinally arranged in the pump head (1), one-way valves (2) symmetrically arranged at the upper and lower ends of the fluid channel, a piston channel arranged on one side of the fluid channel, a plunger rod (3) slidably and sealably connected to the piston channel, the outer end of the plunger rod (3) being connected to a plunger reciprocating mechanism, characterized in that: A plunger sleeve (4) is sealedly connected between the plunger rod (3) and the piston passage; an adjusting screw (5) is threadedly connected to the pump head (1), the plunger sleeve (4) and the plunger rod (3); the pump head (1) and the plunger sleeve (4) or the plunger sleeve (4) and the plunger rod (3) can be fixedly connected by rotating the adjusting screw (5); a rotary valve barrel (13) is provided in the pump head (1); the right end of the rotary valve barrel (13) is connected to the piston passage; the left end of the rotary valve barrel (13) is connected to a turnover motor (14); a flow guide hole (15) connected to the fluid passage is provided on the side wall of the rotary valve barrel (13); a limit shaft shoulder (16) is provided on the rotary valve barrel (13); a bearing (17) is provided between the limit shaft shoulder (16) and the piston passage; a sealing ring (18) is provided at the right end of the rotary valve barrel (13); and a flow guide bend (19) is provided between the flow guide hole (15) and the piston passage.

2. A plunger-type metering pump with adjustable displacement according to claim 1, characterized in that: The adjusting screw (5) comprises a first screw segment and a second screw segment, the first screw segment and the second screw segment being circumferentially fixed and axially slidably connected, and by rotating the adjusting screw (5), the first screw segment can be fixedly connected to the pump head (1) and the plunger sleeve (4), or the second screw segment can be fixedly connected to the plunger sleeve (4) and the plunger rod (3).

3. A plunger-type metering pump with adjustable displacement according to claim 2, characterized in that: The first screw segment and the second screw segment are both provided with a hexagonal hole (6), a hexagonal rod (7) is mounted on the hexagonal hole (6), one end of the hexagonal rod (7) is connected to an adjusting motor (8), and the adjusting motor (8) is fixedly connected to the pump head (1).

4. The plunger-type metering pump with adjustable displacement according to claim 1, characterized in that: The piston channel and the plunger sleeve (4) are respectively threadedly connected to a first stuffing gland (9) and a second stuffing gland (10); the first stuffing gland (9) and the second stuffing gland (10) are both provided with through holes, and a linkage rod (11) is movably and slidably connected to the through holes.

5. The plunger-type metering pump with adjustable displacement according to claim 4, characterized in that: An anti-loosening spring (12) is provided between the linkage rod (11) and the pump head (1).

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