Plunger sealing structure with long service life

Abstract

The utility model relates to the technical field of plunger pumps, plunger pipettes and plunger injectors, in particular to a long-service-life plunger sealing structure which comprises a stepping motor, a pump support is installed on the surface of the stepping motor through bolts, a plunger sliding block capable of moving up and down is arranged in the pump support, and a plunger is installed at the top end of the plunger sliding block. An upper blocking cover is installed in the center of the top of the pump support, and a lower elastic compensation piece, a lower sealing ring, an upper sealing ring and an upper elastic compensation piece are sequentially placed on the surface of the upper blocking cover from bottom to top. According to the utility model, crystals or particulate matters on the surface of the plunger can be scraped cleanly, so that the crystals or particulate matters are prevented from damaging the upper sealing ring, and the plunger is effectively protected; when the lower sealing ring is abraded, elastic force generated by the lower elastic compensation piece enables the lower sealing ring to be still tightly attached to the plunger, the upper sealing ring can still be effectively protected, and therefore the sealing life of reciprocating motion of the plunger is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical fields of plunger pumps, plunger pipettes, and plunger syringes, and particularly relates to a plunger sealing structure with high service life. Background Technique

[0002] The existing plunger sealing technology uses a one-way sealing ring. Since the plunger sealing technology cannot achieve absolute sealing, that is, the oil film or water film sealing in the industry, when the plunger makes a reciprocating motion, liquid molecules will be adsorbed on the surface of the plunger. The liquid molecules adsorbed on the surface of the plunger will move outside the sealing ring along with the movement of the plunger. This sealing technology has no problem when used in pure water or an environment without crystallization or dust. However, once it is used in an environment with crystallization or dust, the plunger seal will fail very quickly. Because the liquid molecule crystals brought out by the surface of the plunger or the plunger will adsorb particles on the surface of the plunger in a dusty environment. When the plunger moves towards the sealing ring again, the harder crystals or particles will damage the sealing ring, resulting in seal failure and the failure of the product function. Content of the Utility Model

[0003] The purpose of the utility model is to provide a plunger sealing structure with high service life to solve the problem that the existing plunger sealing technology is prone to damage the sealing ring and cause seal failure when used in an environment with crystallization or dust as mentioned in the above background technique.

[0004] To achieve the above purpose, the utility model provides the following technical solution: A plunger sealing structure with high service life, including a stepper motor. The surface of the stepper motor is installed with a pump bracket through bolts, and one side inside the pump bracket is fixed with a photoelectric switch through screws; the output shaft end of the stepper motor is fixed with a hollow lead screw, and the hollow lead screw is located inside the pump bracket. A plunger slider that can move up and down is arranged inside the pump bracket, and a plunger is installed at the top of the plunger slider; the central part of the top of the pump bracket is installed with an upper cover, and a lower elastic compensator, a lower sealing ring, an upper sealing ring, and an upper elastic compensator are sequentially placed on the surface of the upper cover from bottom to top. Moreover, the upper cover, the lower elastic compensator, the lower sealing ring, the upper sealing ring, and the upper elastic compensator are sleeved on the plunger, and at the same time, both the lower sealing ring and the upper sealing ring are in close contact with the surface of the plunger.

[0005] Preferably, a pump mounting plate is fixed to the surface of the bottom of the pump bracket through bolts, and the pump mounting plate facilitates the installation and fixation of the pump bracket.

[0006] Preferably, a nut is threadedly connected to the surface of the hollow lead screw, and the surface of the nut is fixedly connected to the bottom of the plunger slider.

[0007] Preferably, an origin pin is installed on one side of the surface of the plunger slider. After being sensed by the photoelectric switch, the origin pin makes the plunger stop moving.

[0008] Preferably, a guide pin is fixedly installed on the surface of the plunger slider and above the origin pin. The guide pin is used for the limiting and guiding work when the plunger slider moves up and down.

[0009] Preferably, the top end of the pump bracket is fixed with a pump cavity through bolts. The top end of the plunger sequentially penetrates through the upper cover, lower elastic compensator, lower sealing ring, upper sealing ring, and upper elastic compensator and extends into the interior of the pump cavity. After the pump cavity is fixed to the pump bracket, the pump cavity is in close contact and sealed with the upper elastic compensator.

[0010] Compared with the prior art, the beneficial effects of the present utility model are as follows: The high-life plunger sealing structure includes an upper sealing ring, an upper elastic compensator, a lower sealing ring, and a lower elastic compensator for the plunger, and is mainly applied to the application technical field of the reciprocating motion of the plunger, mainly for the accurate transfer and quantitative sampling of liquids by pump instruments in the medical, pharmaceutical, and laboratory technical fields; the specific technical effects produced by the present utility model are as follows: The lower sealing ring is in close fit with the plunger under the action of the lower elastic compensator. When the plunger moves into the plunger cavity, the lower sealing ring scrapes off the crystals or particulate matters on the surface of the plunger, avoiding the damage of the upper sealing ring by the crystals or particulate matters, and effectively protecting the plunger. Since the long-term reciprocating motion of the lower sealing ring and the plunger will cause wear of the lower sealing ring, at this time, the elastic force generated by the lower elastic compensator will keep the lower sealing ring in close fit with the plunger, and still can effectively protect the upper sealing ring. This new sealing structure technology effectively improves the sealing life of the reciprocating motion of the plunger. Description of the Drawings

[0011] Figure 1 is a three-dimensional external structure schematic diagram of the present utility model;

[0012] Figure 2 is a three-dimensional cross-sectional structure schematic diagram of the present utility model;

[0013] Figure 3 is a front cross-sectional structure schematic diagram of the present utility model;

[0014] Figure 4 is a partial enlarged structure schematic diagram of the present utility model;

[0015] Figure 5 is a schematic diagram of the plunger sealing structure of the prior art.

[0016] In the figure: 1, stepping motor; 2, pump mounting plate; 3, pump bracket; 4, hollow lead screw; 5, nut; 6, plunger slider; 7, photoelectric switch; 8, origin pin; 9, guide pin; 10, upper cover; 11, lower elastic compensator; 12, lower sealing ring; 13, upper sealing ring; 14, upper elastic compensator; 15, plunger; 16, pump cavity. Detailed implementation mode

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. In addition, the terms "first", "second", "third", "upper, lower, left, right", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. At the same time, in the description of the present invention, unless otherwise clearly specified and limited, the terms "connected" and "connected" 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 directly connected or indirectly connected through an intermediate medium. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0018] The structure of a high-life plunger seal structure provided by the present invention is as shown in Figure 1 and Figure 3 shown, including a stepping motor 1. A pump bracket 3 is installed on the surface of the stepping motor 1 through bolts. A pump mounting plate 2 is fixed on the bottom surface of the pump bracket 3 through bolts. This pump mounting plate 2 facilitates the installation and fixation work of the pump bracket 3. One side inside the pump bracket 3 is fixed with a photoelectric switch 7 through screws; the output shaft end of the stepping motor 1 is fixed with a hollow lead screw 4. This hollow lead screw 4 is located inside the pump bracket 3. A plunger slider 6 that can move up and down is arranged inside the pump bracket 3. A nut 5 is threadedly connected to the surface of the hollow lead screw 4, and the surface of the nut 5 is fixedly connected to the bottom of the plunger slider 6. An origin pin 8 is installed on one side of the surface of the plunger slider 6. After this origin pin 8 is sensed by the photoelectric switch 7, the plunger 15 stops moving. A guide pin 9 is fixedly installed on the surface of the plunger slider 6 and above the origin pin 8. This guide pin 9 is used for the limit guiding work when the plunger slider 6 moves up and down.

[0019] During implementation, the stepping motor 1 rotates clockwise to drive the hollow lead screw 4 to rotate. The nut 5 and the plunger slider 6 are tightly connected by screws. Under the combined action of the nut 5 and the guide pin 9, the plunger 15 installed on the plunger slider 6 will move downward, and the plunger 15 installed on the plunger slider 6 will move downward by a set rated stroke.

[0020] Furthermore, as shown in Figure 2 and Figure 4As shown, a plunger 15 is installed at the top of the plunger slider 6; an upper retaining cover 10 is installed at the central part of the top of the pump bracket 3, and a lower elastic compensator 11, a lower sealing ring 12, an upper sealing ring 13 and an upper elastic compensator 14 are sequentially placed on the surface of the upper retaining cover 10 from bottom to top. Moreover, the upper retaining cover 10, the lower elastic compensator 11, the lower sealing ring 12, the upper sealing ring 13 and the upper elastic compensator 14 are sleeved on the plunger 15. At the same time, both the lower sealing ring 12 and the upper sealing ring 13 are in close contact with the surface of the plunger 15. The top of the pump bracket 3 is fixed with a pump cavity 16 by bolts. The top of the plunger 15 sequentially penetrates through the upper retaining cover 10, the lower elastic compensator 11, the lower sealing ring 12, the upper sealing ring 13 and the upper elastic compensator 14 and extends into the interior of the pump cavity 16. After the pump cavity 16 and the pump bracket 3 are fixed, the pump cavity 16 is in close contact and sealed with the upper elastic compensator 14.

[0021] In the prior art, as Figure 5 shown, where in the figure: 81. pump cavity; 82. elastic compensator; 83. sealing ring; 84. plunger; 811. inside the cavity; 812. outside the cavity; Specifically, when the 84 plunger moves downward, the solution inside the 811 cavity will move along with the 84 plunger. When it moves to the outside of the 812 cavity, since there are liquid molecules on the surface of the 84 plunger, if the liquid molecules belong to reagents that are prone to crystallization, the liquid molecules on the surface of the 84 plunger exposed outside the 812 cavity will crystallize or adsorb air particles. At this time, when the 84 plunger moves into the 81 pump cavity, the crystals or particles on the surface of the 84 plunger will damage the 83 sealing ring, resulting in the failure of the plunger seal, and then liquid leakage will occur, and further the product will be damaged.

[0022] The plunger sealing structure of the present utility model includes: an upper sealing ring 13 for the plunger, an upper elastic compensator 14, a lower sealing ring 12, and a lower elastic compensator 11. The elastic compensator is not limited to rubber rings, springs, spring washers, etc., and is mainly applied to the technical field of reciprocating motion of the plunger, mainly used for precise transfer and quantitative sampling of liquids by pump instruments in the medical, pharmaceutical, and laboratory technology fields; the specific technical effects are as follows: under the action of the lower elastic compensator 11, the lower sealing ring 12 is in close contact with the plunger 15. When the plunger 15 moves into the pump cavity 16, the lower sealing ring 12 scrapes off the crystals or particulate matters on the surface of the plunger 15, avoiding damage to the upper sealing ring 13 by the crystals or particulate matters, and effectively ensuring the sealing of the plunger 15; due to the long-term reciprocating motion of the lower sealing ring 12 and the plunger 15, the lower sealing ring 12 will be worn. At this time, the elastic force generated by the lower elastic compensator 11 will keep the lower sealing ring 12 in close contact with the plunger 15, still effectively protecting the upper sealing ring 13; due to the long-term reciprocating motion of the upper sealing ring 13 and the plunger 15, the upper sealing ring 13 will be worn. At this time, the elastic force generated by the upper elastic compensator 14 will keep the upper sealing ring 13 in close contact with the plunger 15, still enabling the upper sealing ring 13 and the plunger 15 to complete the sealing. This new sealing structure technology effectively improves the sealing life of the reciprocating motion of the plunger.

[0023] Working principle: Absorbing liquid: The stepping motor 1 rotates clockwise to drive the hollow lead screw 4 to rotate. The nut 5 and the plunger slider 6 are tightly connected by screws. Under the common action of the nut 5 and the guide pin 9, the plunger 15 installed on the plunger slider 6 will move downward for a set rated stroke; the upper elastic compensator 14 makes the upper sealing ring 13 in close contact with the plunger 15 to complete the internal sealing of the plunger 15, and the upper sealing ring 13 is tightly pressed and fitted between the upper cover 10 and the pump cavity 16 to complete the external sealing. Then the plunger 15 completes the liquid absorption action.

[0024] Discharging liquid: The stepping motor 1 rotates counterclockwise to drive the hollow lead screw 4 to rotate. The nut 5 and the plunger slider 6 are tightly connected by screws. Under the common action of the nut 5 and the guide pin 9, the plunger 15 installed on the plunger slider 6 will move upward until the photoelectric switch 7 senses the origin pin 8 and then stops moving. Then the plunger 15 completes the liquid discharge action.

[0025] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above exemplary embodiments, and the present utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present utility model. Any reference signs in the claims should not be construed as limiting the claimed rights.

Claims

1. A plunger seal structure with a long service life, comprising a stepper motor (1), characterized in that: The surface of the stepper motor (1) is mounted with a pump bracket (3) by means of bolts, and a photoelectric switch (7) is fixed to one side of the pump bracket (3) by means of screws; a hollow screw rod (4) is fixed to the output shaft end of the stepper motor (1), and the hollow screw rod (4) is located inside the pump bracket (3); a plunger slider (6) movable up and down is provided inside the pump bracket (3), and a plunger (15) is installed at the top end of the plunger slider (6); a photoelectric switch (7) is installed at the center of the top of the pump bracket (3); An upper stopper (10) is provided, and a lower elastic compensating member (11), a lower sealing ring (12), an upper sealing ring (13) and an upper elastic compensating member (14) are sequentially placed on the surface of the upper stopper (10) from bottom to top, and the upper stopper (10), the lower elastic compensating member (11), the lower sealing ring (12), the upper sealing ring (13) and the upper elastic compensating member (14) are sleeved on the plunger (15), and the upper sealing ring (13) and the upper sealing ring (13) are both in close contact with the surface of the plunger (15).

2. A plunger seal structure with a long service life according to claim 1, characterized in that: A pump mounting plate (2) is fixed to the surface of the bottom of the pump bracket (3) by means of bolts, and the pump mounting plate (2) facilitates the installation and fixing of the pump bracket (3).

3. A plunger seal structure with a long service life according to claim 1, characterized in that: The surface of the hollow screw rod (4) is threadedly connected to a nut (5), and the surface of the nut (5) is fixedly connected to the bottom of the plunger slider (6).

4. A plunger seal structure with a long service life according to claim 1, characterized in that: An origin pin (8) is installed on one side of the surface of the plunger slider (6). After the origin pin (8) is sensed by the photoelectric switch (7), the plunger (15) stops moving.

5. A plunger seal structure with a long service life according to claim 1, characterized in that: A guide pin (9) is fixedly mounted on the surface of the plunger slider (6) and located above the origin pin (8). The guide pin (9) is used for position limiting and guiding work when the plunger slider (6) moves up and down.

6. A plunger seal structure with a long service life according to claim 1, characterized in that: The top end of the pump bracket (3) is fixed with a pump cavity (16) by means of bolts, and the top end of the plunger (15) sequentially passes through the upper baffle (10), the lower elastic compensating member (11), the lower sealing ring (12), the upper sealing ring (13) and the upper elastic compensating member (14) and extends into the interior of the pump cavity (16), and after the pump cavity (16) and the pump bracket (3) are fixed, the pump cavity (16) and the upper elastic compensating member (14) are tightly sealed.

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