CN215109306U

CN215109306U - Pump head and pump body structure of liquid chromatography infusion pump

Info

Publication number: CN215109306U
Application number: CN202120600611.5U
Authority: CN
Inventors: 李乃杰; 杜福新; 封娇; 杨三东; 于德秀; 唐涛; 李彤
Original assignee: Dalian Elite Analytical Instruments Co ltd
Current assignee: Dalian Elite Analytical Instruments Co ltd
Priority date: 2021-03-24
Filing date: 2021-03-24
Publication date: 2021-12-10
Anticipated expiration: 2031-03-24

Abstract

The utility model provides a pump head pump body structure of liquid chromatography transfer pump belongs to liquid chromatography transfer pump technical field. The utility model provides a pump head pump body structure has the pulsation damping function, the pump head is the series structure pump head, the pump head cavity that has the check valve is the main pump chamber, the pump chamber that does not take the check valve is vice pump chamber, plunger rear end and the contact of elasticity post in the vice pump chamber, because the pulsation of liquid chromatography transfer pump is the change of pressure, when the pulsation produces, the plunger in the vice pump chamber receives the pressure variation in the pump chamber, compression or release elasticity post, make the push rod have extra removal, reduce the pressure variation in the vice pump chamber, thereby reduce the pulsation. The pulsation damping structure has no extra cavity, so that the delay volume is reduced; no circulation dead angle exists, and the mixing and solvent replacement effects are improved; the structure is simple, no additional high-pressure sealing structure is provided, and the reliability is improved; the chemical resistance of the material does not need to be considered additionally, the elastic material can be freely selected according to the pressure range of the infusion pump, and the cost is low.

Description

Pump head and pump body structure of liquid chromatography infusion pump

Technical Field

The utility model relates to a liquid chromatogram transfer pump technical field especially relates to a pump head pump body structure of liquid chromatogram transfer pump.

Background

The liquid chromatography infusion pump is used for conveying liquid at a constant flow rate, and a high-pressure liquid chromatography infusion pump usually adopts a structure that a double-pump-head serial plunger is connected with the high-pressure liquid chromatography infusion pump. The inlet and outlet of the main pump head of the series pump are provided with one-way valves for active liquid suction, the auxiliary pump head is used for active liquid suction and transfusion, the main pump head and the auxiliary pump head alternately suck liquid and send liquid, and stable transfusion is realized through coordination work. The operating characteristics of reciprocating plunger pumps make it inevitable to produce large infusion pulses.

Generally, a cavity or a valve body with a damping effect is arranged in a liquid conveying pump pipeline, such as an elastic material pipeline damping device, a diaphragm cavity damper, a compressed fluid damper and the like, when liquid pressure increases when the liquid flows through the damping device, an elastic object is compressed and deformed, when the liquid pressure decreases, the elastic object recovers and deforms, the liquid path pressure is increased, and therefore the system pressure of the liquid conveying pump is stabilized through accumulation and release of elastic potential energy.

In chinese patent application CN110425102A, the applicant of the present invention discloses an adjustable infusion pump pulsation damper, which comprises an upper cover, an elastic diaphragm, a body and an adjusting device, wherein the upper cover and the body are cylindrical and are coaxially and fixedly connected; the end surface of one side, away from the body, of the upper cover is axially provided with two flow path interfaces towards the body, and the two flow path interfaces are positioned on the same circumference; a first inner cavity is arranged in the center of the end face of one side, close to the upper cover, of the body, the first inner cavity is cylindrical, the diameter of the first inner cavity is larger than the outer diameter of the circular groove, a second inner cavity is arranged between the center of the end face of one side, far away from the upper cover, of the body and the first inner cavity, the second inner cavity is cylindrical and is overlapped with the axis of the first inner cavity, and the diameter of the second inner cavity is smaller than that of the first inner cavity; the first inner cavity is provided with an upper positioning pad, the second inner cavity is provided with a lower positioning pad, an elastic piece is fixedly arranged between the upper positioning pad and the lower positioning pad, the upper positioning pad is in a spherical crown shape, the circular end surface of the upper positioning pad is fixedly connected with the elastic piece, and the diameter of the circular surface of the upper positioning pad is equal to that of the first inner cavity; the elastic diaphragm is circular, the diameter of the elastic diaphragm is larger than that of the first inner cavity, and the elastic diaphragm is fixedly arranged in the center between the opposite end faces of the upper cover and the body; the adjusting device is arranged in contact with the lower positioning pad and used for adjusting the deformation amount of the elastic piece. The pulsation damper is an independent structure cavity, is large in size, is easy to generate circulation dead angles, needs a high-pressure sealing structure design, and is easy to leak.

In chinese patent application CN111336078A, the applicant of the present invention discloses a double-plunger liquid chromatography infusion pump, wherein the pump head is composed of a main pump head and an auxiliary pump head connected in series, the lower end of the main pump head main body of the main pump head is provided with a fluid inlet and is provided with an inlet check valve, the upper end of the main pump head main body is provided with a fluid outlet and is provided with an outlet check valve, the rear end of the pump head main body is connected with a positioning plate through screws, a cylindrical liquid inlet tank is arranged inside the pump head main body, the cylindrical liquid inlet tank is close to the upper and lower inner surfaces of the bottom and is provided with an open pore channel, and is respectively communicated with the fluid outlet and the fluid inlet; a plunger rod is slidably mounted in a cylindrical liquid inlet groove of the pump head main body, the rear end of the plunger rod is inserted and fixed in a plunger rod sleeve, and the front end of the plunger rod is inserted and penetrates through a plunger rod positioning sleeve; the rear end of the pump head main body is provided with a groove, and a plunger rod positioning sleeve is embedded and installed in the groove; a primary sealing ring is arranged between the front end surface of the plunger rod positioning sleeve and the pump head main body, a secondary sealing component is arranged on the rear end surface of the plunger rod positioning sleeve, and the plunger rod, the primary sealing ring and the secondary sealing component form a double-sealing floating plunger structure; the plunger rod is sleeved with a plunger spring, and the plunger spring is positioned between the plunger rod sleeve and the secondary sealing component; the plunger rod sleeve is embedded in the guide sleeve, one end of the guide sleeve is arranged between the pump head main body and the positioning plate, the other end face of the guide sleeve is provided with a through hole, and the tail end of the plunger rod sleeve is exposed through the through hole of the guide sleeve; the upper end and the lower end of the auxiliary pump head are respectively provided with a fluid inlet and a fluid outlet, and the auxiliary pump head is not provided with a one-way valve, and the rest structures are consistent with the main pump head; the main pump head and the auxiliary pump head are arranged in parallel and fixedly connected; the fluid outlet of the main pump head is communicated with the fluid inlet of the auxiliary pump head; the push rod assembly is two sections of independent movable optical axes, the top ends of plunger rod sleeves of the main pump head and the auxiliary pump head are respectively contacted with one ends of the two sections of optical axes of the push rod assembly, the other end of the push rod assembly is in close contact with the cam, the push rod assembly is supported by two groups of self-lubricating linear bearings, the cam is supported by two groups of bearings, the cam is connected with a cam shaft belt wheel, the cam shaft belt wheel is connected with a motor shaft belt wheel through a rubber synchronous belt, and the motor shaft belt wheel is driven by a stepping motor. The scheme adopts a plunger with a rigid structure and reciprocating motion to realize constant-flow pumping of high-pressure liquid, but still needs an additional pulsation damper to suppress flow pulsation.

The prior art has at least the following disadvantages:

1. the pulsation damping device adopts a cavity or valve body pulsation damping device with an independent structure, has larger volume, increases the infusion delay volume and leads the gradient response time of the liquid chromatography system to be longer;

2. the pulsation damping device adopts a cavity body or a pulsation damping device of a valve body with an independent structure, so that a circulation dead angle is easily generated, and the gradient mixing and solvent replacement effects of a mobile phase are influenced;

3. the pulsation damping device adopts a cavity body or a pulsation damping device of a valve body with an independent structure, needs an additional high-pressure sealing structure design and a high-pressure connection design, and is easy to generate leakage fault points;

4. the pulsation damping device adopts a cavity body or a valve body with an independent structure, needs to adopt a material with strong chemical resistance, often cannot use the best material suitable for the pressure range of the pump, and has high manufacturing cost;

5. the infusion pump adopting the cam to drive the push rod assembly to move and then the push rod assembly to drive the plunger rod to move can pump high-pressure fluid, but the fluid pulsation cannot be avoided and weakened, so that an additional pulsation damper is needed to weaken the flow pulsation.

SUMMERY OF THE UTILITY MODEL

For solving the problem that exists among the prior art, the utility model provides a pump head pump body structure of liquid chromatography transfer pump, including pump head subassembly and pump body subassembly, the pump head is the series structure pump head, the pump head cavity that has the check valve is the main pump chamber, the pump chamber that does not take the check valve is vice pump chamber, plunger rear end and the contact of elasticity post in the vice pump chamber, because the pulsation of liquid chromatography transfer pump is the change of pressure, when the pulsation produces, the plunger in the vice pump chamber receives the pressure variation in the pump chamber, compression or release elasticity post, make the push rod have extra removal, reduce the pressure variation in the vice pump chamber, thereby reduce the pulsation. The pulsation damping structure has no extra cavity, so that the delay volume is reduced; no circulation dead angle exists, and the mixing and solvent replacement effects are improved; the structure is simple, no additional high-pressure sealing structure is provided, and the reliability is improved; the chemical resistance of the material does not need to be considered additionally, the elastic material can be freely selected according to the pressure range of the infusion pump, and the cost is low.

The utility model provides a pump head pump body structure of liquid chromatography transfer pump, include:

the infusion pump is a reciprocating plunger pump; the pump head and pump body structure of the infusion pump comprises a pump head component and a pump body component;

the pump head assembly includes: the pump head body, the outlet one-way valve, the positioning sleeve, the spring positioning sleeve, the plunger, the guide sleeve and the inlet one-way valve;

the pump head body comprises two pump cavities, namely a main pump cavity and an auxiliary pump cavity, an outlet one-way valve and an inlet one-way valve are respectively arranged at the upper end and the lower end of the main pump cavity, and the auxiliary pump cavity is communicated with the liquid chromatography system;

the pump body assembly includes: the damping device comprises a front pump body, an elastic column, a positioning column, a damping push rod, a push rod bearing and a push rod;

one end of the plunger penetrates through the spring positioning sleeve and the positioning sleeve and extends into the auxiliary pump cavity, and the other end of the plunger penetrates through the guide sleeve and is respectively contacted with the elastic column and the push rod;

the elastic column is arranged at the foremost end of the damping push rod and is supported by the positioning column;

the damping push rod and the push rod are both connected with the front pump body.

Preferably, the pump head assembly further comprises: the upper connecting pipe of the pump head, the outlet pressing cap, the sealing ring seat, the pressing plate, the spring, the secondary sealing ring, the primary sealing ring, the inlet pressing cap and the lower connecting pipe of the pump head.

Preferably, the guide sleeve is sleeved outside the plunger, the plunger extends out of a hole at the tail part of the guide sleeve, and the other end of the guide sleeve is fixed on the positioning sleeve by the pressing plate; the pressure plate is fixed on the pump head body through screws to fix the pump head assembly together.

Preferably, the outlet one-way valve and the inlet one-way valve are respectively fixed on the pump head body through an outlet pressure cap and an inlet pressure cap; one end of the spring is fixedly arranged on the sealing ring seat, the other end of the spring is provided with a spring positioning sleeve in a pressing mode, and the elastic positioning sleeve is clamped on the plunger.

Preferably, the pump body assembly further comprises: the device comprises a motor, a synchronous belt, a cam, a long support plate, a short support plate, a bottom plate, a push rod guide sleeve and a push rod shaft.

Preferably, the motor is connected with the synchronous belt, the synchronous belt is connected with the cam, the cam is connected with the push rod bearing, and the push rod bearing is connected with the damping push rod.

Preferably, the damping push rod and the tail end of the push rod are both provided with push rod bearings, the push rod bearings are fixed by push rod shafts, the other ends of the push rod shafts are provided with push rod guide sleeves, and the front pump body is fixed with the long supporting plate and the short supporting plate through screws; the bottom plate is fixed with the long supporting plate and the short supporting plate through screws.

Preferably, the pump body assembly further comprises: a camshaft pulley and a motor shaft pulley.

Preferably, the motor is installed on the long support plate, a motor shaft belt wheel is installed on the motor shaft, a cam shaft belt wheel is installed on the same side of the cam and the motor shaft belt wheel, and the motor shaft belt wheel is connected with the cam shaft belt wheel through a synchronous belt.

Preferably, the pump body assembly further comprises: the self-lubricating bearing is pressed in the front pump body, the cam bearings are pressed at two ends of the cam, and the cam bearings are respectively pressed in the corresponding bearing mounting holes in the long support plate and the short support plate.

Compared with the prior art, the beneficial effects of the utility model are as follows:

(1) the utility model discloses a pump head pulsation damping elastic column does not contact with liquid, does not increase the liquid pipeline volume, and no pulsation damping delays the volume.

(2) The elastic column of the utility model is arranged at the rear end of the plunger of the auxiliary pump cavity, and simultaneously generates deformation along with the pressure change of the pump head, thereby reducing the gradient mixing delay volume;

(3) the utility model discloses an elasticity post and plunger rear end direct contact, the auxiliary pump chamber flow path links to each other all the time with the liquid route export of transfer pump, and no circulation dead angle promotes and mixes and solvent replacement effect.

(4) The utility model has simple structure, no extra high pressure sealing structure, and improved reliability;

(5) the utility model discloses well elastic column contactless transfer pump interior liquid, consequently need not additionally to consider material chemistry tolerance, can freely choose for use elastic material and low cost according to the pressure range of pump.

Drawings

Fig. 1 is a perspective view of a pump head pump body according to an embodiment of the present invention;

fig. 2 is a split view of a pump head and pump body of an embodiment of the present invention;

fig. 3 is a front view of a pump head of an embodiment of the present invention;

FIG. 4 is a top view of a pump head of one embodiment of the present invention;

fig. 5 is an exploded view of a pump head of an embodiment of the present invention;

fig. 6 is a left side view of the pump body of an embodiment of the present invention;

FIG. 7 is a right side view of the pump body of one embodiment of the present invention;

FIG. 8 is a top view of the pump body of one embodiment of the present invention;

fig. 9 is an exploded view of the pump body of one embodiment of the present invention;

FIG. 10 is a top cross-sectional view of a pump head and pump body structure of an embodiment of the present invention;

fig. 11 is a schematic view of a fluid flow path according to an embodiment of the present invention;

the device comprises a pump head assembly 1, a pump body assembly 2, a pump body assembly 3, a pump head body 4, a pump head upper connecting pipe 5, an outlet pressure cap 6, an outlet one-way valve 7, a positioning sleeve 8, a sealing ring seat 9, a spring positioning sleeve 10, a guide sleeve 11, a pressure plate 12, a plunger 13, a spring 14, a secondary sealing ring 15, a primary sealing ring 16, an inlet pressure cap 17, a pump head lower connecting pipe 18, an inlet one-way valve 19, a front pump body 20, a self-lubricating bearing 21, an elastic column 22, a positioning column 23, a damping push rod 24, a cam shaft belt wheel 25, a synchronous belt 26, a motor shaft belt wheel 27, a long supporting plate 28, a cam 29, a felt 30, a lubricating oil box 31, a cam bearing 32, a motor 33, a short supporting plate 34, a bottom plate 35, a push rod bearing 36, a push rod guide sleeve 37, a push rod shaft 38, a push rod 39, a main pump cavity 40, an auxiliary pump cavity 41, a liquid storage bottle 42 and a liquid chromatography system.

Detailed Description

The following description of the present invention will be made in detail with reference to the accompanying drawings 1 to 11.

the infusion pump is a reciprocating plunger pump; the pump head and pump body structure of the infusion pump comprises a pump head component 1 and a pump body component 2;

the pump head assembly includes: the pump head body 3, the outlet one-way valve 6, the positioning sleeve 7, the spring positioning sleeve 9, the plunger 12, the guide sleeve 10 and the inlet one-way valve 18;

the pump head body 3 comprises two pump cavities, namely a main pump cavity 39 and an auxiliary pump cavity 40, an outlet one-way valve 6 and an inlet one-way valve 18 are respectively arranged at the upper end and the lower end of the main pump cavity 39, and the auxiliary pump cavity 40 is communicated with a liquid chromatography system 42;

the pump body assembly includes: the front pump body 19, the elastic column 21, the positioning column 22, the damping push rod 23, the push rod bearing 35 and the push rod 38;

one end of the plunger 12 penetrates through the spring positioning sleeve 9 and the positioning sleeve 7 to extend into the auxiliary pump cavity 40, and the other end of the plunger 12 penetrates through the guide sleeve 10 to be respectively contacted with the elastic column 21 and the push rod 38;

the elastic column 21 is arranged at the foremost end of the damping push rod 23 and is supported by the positioning column 22;

the pulsation damping is realized by the cooperation of the plunger 12, the elastic column 21, the positioning column 22 and the damping push rod 23 in the auxiliary pump cavity 40;

as shown in FIG. 11, the liquid chromatography system 42 is always connected to the secondary pump chamber 40 in the liquid path, and the liquid chromatography system 42 is a relatively stable high-pressure system, that is, the secondary pump chamber 40 is always in a high-pressure state, assuming that the pressure is about 10MPa, and if the flow rate of the pump is unstable, assuming that the pressure is in the range of 9.5-10.5MPa, the pressure fluctuation can be counteracted by adding the pulsation damping function, so that the pressure is still maintained at 10 MPa. However, the main pump chamber 39 is not pressurized when sucking liquid from the liquid storage bottle, and is in a high-pressure state when discharging liquid, and the pressure range of the main pump chamber 39 is from normal pressure to 10MPa, so that the main pump head 39 itself has great pressure fluctuation, but the pressure fluctuation is in a normal state and does not need to be eliminated. When the pressure of the main pump cavity 39 is less than 10MPa, the auxiliary pump cavity 40 and the liquid chromatography system are separated by a one-way valve, and the pressure change of the main pump cavity 39 does not influence the liquid chromatography system 42, so that pulsation damping is not needed.

In the invention, only the plunger 12 of the auxiliary pump cavity 40 of the two plungers contacts with the elastic column 21, the elastic column 21 is arranged at the front end of the damping push rod 23, and the other plunger 12 contacts with the push rod 38, so the design is that the liquid chromatography system 42 is a high-pressure system, the auxiliary pump cavity is always connected with the liquid chromatography system, the pressure keeps consistent, the pressure pulsation in the auxiliary pump cavity 40 can be restrained by restraining the pressure pulsation in the liquid chromatography system 42, the main pump cavity 39 has huge pressure variation in the process of liquid suction and liquid discharge because one end is connected with a liquid storage bottle with normal pressure and the other end is connected with the high-pressure auxiliary pump cavity 40, and a one-way valve is arranged between the main pump cavity 39 and the auxiliary pump cavity 40 for isolation, the pressure variation of the main pump cavity 39 can not influence the pressure of the auxiliary pump cavity 40, so the pressure variation in the liquid chromatography system 42 can be restrained only by adding the elastic column 21 behind the push rod of the auxiliary pump cavity 40, and a good pulsation damping effect is achieved.

The damping push rod 23 and the push rod 38 are both connected to the front pump body 19.

As a preferred embodiment, the pump head assembly 1 further comprises: the pump head comprises an upper pump head connecting pipe 4, an outlet pressing cap 5, a sealing ring seat 8, a pressing plate 11, a spring 13, a secondary sealing ring 14, a primary sealing ring 15, an inlet pressing cap 16 and a lower pump head connecting pipe 17.

In a preferred embodiment, the guide sleeve 10 is sleeved outside the plunger 12, the plunger 12 extends out of a hole at the tail part of the guide sleeve 10, and the other end of the guide sleeve 10 is fixed on the positioning sleeve 10 by the pressing plate 11; the pressure plate 11 is fixed on the pump head body 3 through screws to fix the pump head assembly 1 together.

In a preferred embodiment, the outlet check valve 6 and the inlet check valve 18 are respectively fixed on the pump head body 3 through an outlet pressure cap 5 and an inlet pressure cap 16; one end of the spring 13 is fixedly arranged on the sealing ring seat 8, the other end of the spring 13 is provided with a spring positioning sleeve 9 in a pressing mode, and the elastic positioning sleeve 9 is clamped on the plunger 12.

As a preferred embodiment, the pump body assembly further comprises: motor 32, timing belt 25, cam 28, long support plate 27, short support plate 33, bottom plate 34, push rod guide sleeve 36 and push rod shaft 37.

In a preferred embodiment, the motor 32 is connected to a timing belt 25, the timing belt 25 is connected to a cam 28, the cam 28 is connected to a push rod bearing 35, and the push rod bearing 35 is connected to the damping push rod 23.

In a preferred embodiment, the damping push rod 23 and the push rod 38 have both tail ends provided with a push rod bearing 35, the push rod bearing 35 is fixed by a push rod shaft 37, the other end of the push rod shaft 37 is provided with a push rod guide sleeve 36, and the front pump body 19 is fixed with the long support plate 27 and the short support plate 33 through screws; the bottom plate 34 is fixed to the long stay 27 and the short stay 33 by screws.

As a preferred embodiment, the pump body assembly 2 further comprises: a camshaft pulley 24 and a motor shaft pulley 26.

In a preferred embodiment, the motor 32 is mounted on the long support plate 27, the motor shaft pulley 26 is mounted on the motor shaft, the camshaft pulley 24 is mounted on the same side of the cam 28 as the motor shaft pulley 26, and the motor shaft pulley 26 and the camshaft pulley 24 are connected through the timing belt 25.

As a preferred embodiment, the pump body assembly 2 further comprises: the self-lubricating bearing 20 and the cam bearing 31 are pressed and mounted in the front pump body 19, the cam bearings 31 are pressed and mounted at two ends of the cam 28, and the cam bearings 31 are respectively pressed and mounted in corresponding bearing mounting holes in the long support plate 27 and the short support plate 33.

In a preferred embodiment, a lubricant box 30 is further mounted on the bottom plate 34, a felt 29 is placed in the lubricant box 30, and the felt 29 contacts the cam 28 to provide lubricant for the cam 28.

In a preferred embodiment, the plunger 12 is a rigid material; the positioning column 22 is made of rigid materials, when the elastic column 21 deforms to the front end position of the positioning column 22, the damping push rod 23 is in rigid contact with the positioning column 22 and does not extrude the elastic column 21 any more, so that the elastic column 21 is prevented from being extruded beyond the elastic deformation range.

When the pressure of the liquid chromatography system 42 is increased, the elastic column 21 is compressed, the plunger 12 in the sub-pump chamber 40 is retreated relative to the pump head body 3, and the volume in the sub-pump chamber 40 is increased for reducing the pressure in the liquid chromatography system 42;

when the pressure in the liquid chromatography system 42 is reduced, the elastic column 21 is released, the plunger 12 in the sub-pumping chamber 40 is advanced relative to the pumping head body 3, and the volume in the sub-pumping chamber 40 is reduced to supplement the pressure in the liquid chromatography system 42.

Example 1

The present invention will be described in detail with reference to the accompanying drawings 1-11 according to an embodiment of the present invention.

the infusion pump is a reciprocating plunger pump;

the infusion pump head and pump body structure comprises a pump head component 1 and a pump body component 2;

the pump head assembly 1 comprises: the device comprises a pump head body 3, a pump head upper connecting pipe 4, an outlet pressure cap 5, an outlet one-way valve 6, a positioning sleeve 7, a sealing ring seat 8, a spring positioning sleeve 9, a guide sleeve 10, a pressure plate 11, a plunger 12, a spring 13, a secondary sealing ring 14, a primary sealing ring 15, an inlet pressure cap 16, a pump head lower connecting pipe 17 and an inlet one-way valve 18;

the positioning sleeve, the sealing ring seat, the spring positioning sleeve, the guide sleeve, the plunger, the spring, the secondary sealing ring and the primary sealing ring are all two.

The pump head body 3 comprises two pump cavities, namely a main pump cavity 39 and an auxiliary pump cavity 40, the difference between the two pump cavities is that an outlet one-way valve 6 and an inlet one-way valve 18 are respectively arranged above and below the main pump cavity 39, and the auxiliary pump cavity 40 is directly communicated with a liquid chromatography system 42;

the outlet one-way valve 7 and the inlet one-way valve 18 are respectively fixed on the pump head body 3 through an outlet pressure cap 5 and an inlet pressure cap 16;

the primary sealing ring 15 is pressed on the pump head body 3 by the positioning sleeve 7, and the secondary sealing ring 14 is fixed on the other surface of the positioning sleeve 7 by the sealing ring seat 8.

The spring 13 is arranged on the sealing ring seat 8, and the other end of the spring 13 is provided with the spring positioning sleeve 9 in a pressing mode.

The plunger 12 penetrates through the spring positioning sleeve 9, the spring 13, the sealing ring seat 8, the secondary sealing ring 14 and the primary sealing ring 15 and extends into the pump head body 3.

The guide sleeve 10 is sleeved on a plunger 12, the plunger 12 extends out of a hole in the tail of the guide sleeve 10, and the other end of the guide sleeve 10 is fixed on the positioning sleeve 7 by a pressing plate 11;

the pressure plate 11 is fixed on the pump head body 3 through screws to fix the whole pump head assembly 1;

the pump body assembly 2 includes: the device comprises a front pump body 19, a self-lubricating bearing 20, an elastic column 21, a positioning column 22, a damping push rod 23, a camshaft belt pulley 24, a synchronous belt 25, a motor shaft belt pulley 26, a long supporting plate 27, a cam 28, a felt 29, a lubricating oil box 30, a cam bearing 31, a motor 32, a short supporting plate 33, a bottom plate 34, a push rod bearing 35, a push rod guide sleeve 36, a push rod shaft 37 and a push rod 38;

the rear end of one plunger 12 in the sub-pump chamber 40 is in contact with the elastic column 21, and the other plunger 12 in the main pump chamber 39 is in contact with the push rod 38; the other plunger 12 in the main pump chamber 39 passes through the guide sleeve 10 and contacts with a push rod 38, and the push rod 38 is connected with the front pump body 19; the push rod 38 is connected with the push rod bearing 35, and the other end of the push rod shaft 37 is provided with a push rod guide sleeve 36;

the self-lubricating bearing 20 is pressed into the front pump body 19;

the front pump body 19 is fixed with the long support plate 27 and the short support plate 33 through screws;

the bottom plate 34 is fixed with the long support plate 27 and the short support plate 33 through screws;

cam bearings 31 are pressed at two ends of the cam 28, and the cam bearings 31 are respectively pressed in corresponding bearing mounting holes in the long support plate 27 and the short support plate 33;

a lubricating oil box 30 is arranged on the bottom plate 34, a felt 29 is placed in the lubricating oil box 30, and the felt 28 is in contact with the cam 28 to provide lubricating oil for the cam;

the long support plate 27 is provided with a motor 32, and a motor shaft belt wheel 26 is arranged on the motor shaft;

a cam shaft belt wheel 24 is arranged on the same side of the cam 28 and the motor shaft belt wheel 26, and the motor shaft belt wheel 26 and the cam shaft belt wheel 24 are connected through a synchronous belt 25;

the tail ends of the damping push rod 23 and the push rod 38 are both provided with push rod bearings 35, the push rod bearings 35 are fixed by push rod shafts 37, and the other ends of the push rod shafts 37 are provided with push rod guide sleeves 36;

when the pressure of the liquid chromatography system is increased, the elastic column 21 is compressed, the plunger 12 in the secondary pump cavity 40 is retreated relative to the pump head body 3, and the volume of the secondary pump 40 is increased for reducing the pressure in the liquid chromatography system;

when the pressure of the liquid chromatography system is reduced, the elastic column 21 is released, the plunger 12 in the secondary pump cavity 40 is extended forwards relative to the pump head body 3, and the volume in the secondary pump 40 is reduced to supplement the pressure in the liquid chromatography system 42;

the positioning column 22 is made of a rigid material, and when the elastic column 21 deforms to the front end position of the positioning column 22, the damping push rod 23 is in rigid contact with the positioning column 22 and does not press the elastic column 51 any more, so that the elastic column 51 is prevented from being pressed beyond the elastic deformation range.

The working principle is as follows:

when the motor 32 moves, the cam 28 is driven to rotate through the synchronous belt 25, the cam 28 pushes the push rod 38 and the damping push rod 23 to move,

the push rod 38 and the damping push rod 23 transmit pushing forces to the two plungers 12 in the main pumping chamber 39 and the sub-pumping chamber 40, respectively, and the plungers reciprocate under the combined action of the pushing force of the push rod and the elastic force of the spring 13.

The main pump chamber 39 has an outlet check valve 6 and an inlet check valve 18 at the upper and lower sides thereof, and the reciprocating motion of the plunger 12 can suck the liquid in the liquid storage bottle 41 into the main pump chamber and discharge the liquid. A portion of the liquid displaced from the main pump chamber 39 is directed into the liquid chromatography system 42 and a portion is drawn into the sub-pump chamber 40, and the sub-pump chamber 40 displaces the liquid when the main pump chamber 39 is primed, preventing flow interruption.

The secondary pump chamber 40 is always connected to the liquid chromatography system 42 and is maintained at a consistent pressure. The plunger 12 in the secondary pumping chamber 40 contacts the elastomeric post 21 during operation of the infusion pump. When the system pressure changes, the elastic column 21 deforms, so that the position of the plunger 12 in the auxiliary pump cavity 40 is changed, the volume of the auxiliary pump cavity 40 is adjusted, the system pressure change is restrained, and the effect of pulsation damping is achieved.

The elastic column 21 is sleeved on the positioning column 22, and the positioning column 22 is made of a rigid material, so that when the pressure abnormally increases and exceeds a limit value, and the elastic column 21 deforms to the front end position of the positioning column 22, the push rod 13 is in rigid contact with the positioning column 22 and does not extrude the elastic column 21 any more, and the elastic column 21 is prevented from being extruded beyond an elastic range and generating unrecoverable deformation.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention is included in the protection scope of the present invention.

Claims

1. The utility model provides a pump head pump body structure of liquid chromatogram transfer pump which characterized in that includes:

2. A pump head pump body structure for a liquid chromatography infusion pump according to claim 1, wherein the pump head assembly further comprises: the upper connecting pipe of the pump head, the outlet pressing cap, the sealing ring seat, the pressing plate, the spring, the secondary sealing ring, the primary sealing ring, the inlet pressing cap and the lower connecting pipe of the pump head.

3. A pump head and pump body structure for a liquid chromatography infusion pump according to claim 2, wherein the guide sleeve is sleeved outside the plunger, the plunger extends from a hole at the tail of the guide sleeve, and the other end of the guide sleeve is fixed to the positioning sleeve by a pressing plate; the pressure plate is fixed on the pump head body through screws to fix the pump head assembly together.

4. A pump head and pump body structure for a liquid chromatography infusion pump according to claim 2, wherein the outlet check valve and the inlet check valve are fixed to the pump head body by an outlet pressure cap and an inlet pressure cap, respectively; one end of the spring is fixedly arranged on the sealing ring seat, the other end of the spring is provided with a spring positioning sleeve in a pressing mode, and the elastic positioning sleeve is clamped on the plunger.

5. A pump head and pump body structure for a liquid chromatography infusion pump according to claim 1, wherein the pump body assembly further comprises: the device comprises a motor, a synchronous belt, a cam, a long support plate, a short support plate, a bottom plate, a push rod guide sleeve and a push rod shaft.

6. A pump head and pump body structure for a liquid chromatography infusion pump according to claim 5, wherein the motor is connected to a timing belt, the timing belt is connected to a cam, the cam is connected to a push rod bearing, and the push rod bearing is connected to the damping push rod.

7. A pump head and pump body structure of a liquid chromatography infusion pump according to claim 5, wherein the damping push rod and the tail end of the push rod are provided with push rod bearings, the push rod bearings are fixed by the push rod shaft, the other end of the push rod shaft is provided with a push rod guide sleeve, and the front pump body is fixed with the long support plate and the short support plate through screws; the bottom plate is fixed with the long supporting plate and the short supporting plate through screws.

8. A pump head and pump body structure for a liquid chromatography infusion pump according to claim 5, wherein the pump body assembly further comprises: a camshaft pulley and a motor shaft pulley.

9. A pump head and pump body structure for a liquid chromatography infusion pump according to claim 8, wherein the long support plate is provided with a motor, a motor shaft pulley is provided on the motor shaft, a cam shaft pulley is provided on the same side of the cam as the motor shaft pulley, and the motor shaft pulley and the cam shaft pulley are connected through a synchronous belt.

10. A pump head and pump body structure for a liquid chromatography infusion pump according to claim 8, wherein the pump body assembly further comprises: the self-lubricating bearing is pressed in the front pump body, the cam bearings are pressed at two ends of the cam, and the cam bearings are respectively pressed in the corresponding bearing mounting holes in the long support plate and the short support plate.