CN117028195A - Plunger pump device with fine adjustment flow rate and fine adjustment flow rate method thereof - Google Patents

Abstract

The invention provides a plunger pump device with a fine-tuning flow, which comprises a valve plate and a miniature variable pump, wherein the second miniature variable pump and the first miniature variable pump are symmetrically distributed at two ends of the valve plate, and a first one-way valve and a second one-way valve are respectively arranged on one side surface of the valve plate. In the miniature variable pump, a coil is arranged in the middle of a stator, and a permanent magnet is arranged outside a rotor bracket. The piston head is connected with the fixed end of the piston head adapter, the driving bevel gear is connected with the first fixed end of the interior of the rotor bracket, the driving bevel gear is meshed with the driven bevel gear through a pinion, the middle mounting end of the pinion is connected with the first end of the connecting shaft through a rotating shaft respectively, and the third end of the connecting shaft is connected with the second end of the transmission connecting rod respectively. The invention also discloses a flow fine adjustment method of the plunger pump device, which adopts a mode of electromagnetically controlling the initial phases of the two micro variable pumps by using the coil and the permanent magnet integrated in the micro variable pump, thereby carrying out fine adjustment on the output flow.

Description

Plunger pump device with fine adjustment flow rate and fine adjustment flow rate method thereof

Technical Field

The invention relates to the field of axial plunger type hydraulic pumps, in particular to a plunger pump device with fine adjustment flow and a flow adjustment method.

Background

In the hydraulic field, plunger pumps have been widely used, and variable mechanisms, such as an axial plunger pump with the grant number of CN202211430245.9, are added on the basis of a quantitative plunger pump in order to realize the adjustment of the output displacement, and these variable mechanisms are mainly swash plate mechanisms, and the variable mechanisms are complicated and have poor reliability, so that the weight and volume of the unit power are large. Great research is currently being conducted on the displacement adjustment of plunger pumps. In the structure for driving the piston to move, a through-shaft type axial plunger pump is mainly used, for example, an axial flow distribution and rolling support axial plunger pump with an authorized bulletin No. CN202310047331 is mainly used, a transmission shaft is driven by a motor and drives a cylinder body to rotate, and the structure has the following defects that the structure is complex in structure and large in external dimension due to the through-shaft and the driving structure.

Therefore, the invention provides the plunger pump device with the fine adjustment flow and the fine adjustment flow method thereof, the fine adjustment means that the diameter of the inner cavity of the miniature variable pump reaches millimeter level, the flow adjustment range of zero to twice the volume of a single variable pump can be realized, and the accuracy of flow adjustment can reach milliliter level.

Disclosure of Invention

Aiming at the problems existing in the prior art, the invention provides a plunger pump device with fine adjustment flow and a fine adjustment flow method thereof, wherein a magnetic field generated by a coil drives a permanent magnet on a rotor bracket connected with a driving bevel gear to rotate through external current, and further, the reciprocating movement of a piston head is realized through a transmission connecting rod connected with a connecting shaft in a rotation center assembly, so that the micro adjustment of a micro variable pump is realized; meanwhile, fluid medium enters the cavity through the valve plate, and as the first micro variable pump and the second micro variable pump use the same cavity, the control of the mass flow of the plunger pump and the reduction of the pulsation of the medium are realized by changing the phase difference of the two micro variable pumps.

The invention provides a plunger pump device with a fine-tuning flow, which comprises a valve plate, a second micro variable pump and a first micro variable pump, wherein the second micro variable pump and the first micro variable pump are symmetrically distributed at two ends of the valve plate, and a first one-way valve and a second one-way valve are respectively arranged on one side surface of the valve plate. The second miniature variable pump and the first miniature variable pump have the same structure, and comprise a piston head rotating piece, a first transmission connecting rod, a second transmission connecting rod, a driving bevel gear, a driven bevel gear, a first connecting shaft, a first rotating shaft, a second connecting shaft, a second rotating shaft, a rotor support, an outer shell, a stator, a piston head, a first motor end cover, a second motor end cover, a permanent magnet, a coil, a first pinion and a second pinion, wherein a first mounting end and a second mounting end of the rotor support are respectively connected with middle mounting ends of the first motor end cover and the second motor end cover through a first lip seal ring and a second lip seal ring, a third mounting end of the rotor support is connected with middle mounting ends of the outer shell through tapered roller bearings, the stator is positioned between the first motor end cover and the second motor end cover, one side surface of the outer shell is connected with the first end of the first motor end cover through a gasket, the middle of the stator is provided with the coil, and the outer part of the rotor support is provided with the permanent magnet. The piston head is located the inside first end of rotor support, the installation end of piston head with the stiff end of piston head adaptor is connected, the first installation end and the second installation end of piston head adaptor respectively with first transmission connecting rod with the first end of second transmission connecting rod, initiative helical gear with the inside first stiff end of rotor support is connected, driven helical gear with the second end of first motor end cover is connected, initiative helical gear loops through first pinion and second pinion with driven helical gear meshing, the mid-mounting end of first pinion with the mid-mounting end of second pinion respectively with first pivot with the first end of second pivot, first pivot with the second end of second pivot respectively with first connecting axle with the first end of second connecting axle, the second end of first connecting axle passes through slide bearing with the second end of second connecting axle is connected, first connecting axle with the second end of second connecting axle respectively with first transmission connecting rod. The structure of the first one-way valve is the same as that of the second one-way valve, the first one-way valve comprises a push rod, a valve shell, a valve body and a vortex spring, the lower end of the valve shell is in contact connection with an inner round hole of the valve body, the upper end of the valve shell is connected with the first end of the push rod, and the second end of the push rod is connected with the vortex spring.

Preferably, the first connecting shaft, the first rotating shaft, the second connecting shaft, the second rotating shaft, the sliding bearing, the first pinion and the second pinion form a rotation center assembly; the first connecting shaft, the first rotating shaft, the second connecting shaft, the second rotating shaft, the first pinion and the second pinion are symmetrically distributed relative to the central plane of the sliding bearing respectively.

Preferably, the axes of the first connecting shaft, the first rotating shaft, the second connecting shaft, the second rotating shaft, the first pinion and the second pinion are on the same straight line.

Preferably, the axes of the piston head rotating member, the driving bevel gear, the driven bevel gear, the rotor bracket, the outer housing, the stator, the piston head, the first motor end cover and the second motor end cover are on the same straight line.

Preferably, the axis of the rotation center assembly and the axis of the driving bevel gear are perpendicular to each other.

Preferably, the motor end cover of the second micro variable pump and the motor end cover of the first micro variable pump are respectively and fixedly connected with two ends of the valve plate.

In another aspect of the present invention, there is provided a method for fine tuning a flow rate for the aforementioned plunger pump device having a fine tuning flow rate, comprising the steps of:

s1, connecting a first miniature variable pump with the outside in a current way, wherein a coil wound on a stator in the first miniature variable pump generates a magnetic field, and a rotor bracket provided with a permanent magnet rotates under the action of the magnetic field, so that a driving helical gear rotates;

s2, under the transmission of a first pinion and a second pinion which are respectively meshed with the driving bevel gear and the driven bevel gear, power is transmitted to a piston head connected with a first transmission connecting rod and a second transmission connecting rod through a first connecting shaft, a first rotating shaft, a second connecting shaft and a second rotating shaft, so that the piston head reciprocates to reach an initial phase;

and S3, connecting the second micro variable pump with external current at a time interval when the external current of the first micro variable pump and the second micro variable pump is ensured, so that the first micro variable pump and the second micro variable pump generate phase differences, namely different output flow is generated, and the fine adjustment of the flow is completed.

Preferably, the flow curves output by the first micro variable pump and the second micro variable pump are sinusoidal.

Compared with the prior art, the invention has the following advantages:

1. according to the invention, the stator, the rotor support, the coil and the permanent magnet are integrated in the miniature variable pump to realize electromagnetic control, and the output flow of the miniature variable pump is accurately controlled by controlling the current in the coil, so that the whole control is more reliable and accurate.

2. The invention utilizes the first micro variable pump and the second micro variable pump which share the cavity, and simultaneously uses the motor structure to arrange the magnetic field for driving the micro variable pump outside the first micro variable pump, so that the structure is more compact, and the miniaturization, microminiaturization and integration of the variable pump can be realized.

3. The invention uses the mode of electromagnetic control of the initial phases of the two micro variable pumps to finely adjust the output flow, so that the flow adjustment precision is higher, and the invention can be used in occasions with high requirements on the flow precision.

4. The mode of combining the miniature variable pump through the valve plate has low noise, no external leakage and lower manufacturing and maintenance cost.

5. The combination mode of the miniature variable pump provided by the invention can be used for combining more miniature variable pumps by changing the structure of the valve plate, and can greatly improve the efficiency of a hydraulic system.

Drawings

FIG. 1 is a full cross-sectional view of a plunger pump apparatus with fine flow control according to the present invention;

FIG. 2 is a semi-sectional view of a plunger pump device with fine tuning of flow rate according to the present invention;

FIG. 3 is a block diagram of a first micro variable displacement pump in a plunger pump apparatus with fine flow adjustment according to the present invention;

FIG. 4 is a block diagram of a port plate in a plunger pump apparatus with fine tuning of flow in accordance with the present invention;

FIG. 5 is a block diagram of a stator of a permanent magnet rotor holder wound coil in a plunger pump apparatus with fine tuning of flow rate according to the present invention;

fig. 6 is a block diagram of a check valve in the plunger pump apparatus with fine adjustment of flow rate according to the present invention.

The main reference numerals:

the piston head rotor 1, the first transmission connecting rod 2, the driving bevel gear 3, the driven bevel gear 4, the sliding bearing 5, the first connecting shaft 6, the first rotating shaft 7, the rotor bracket 8, the tapered roller bearing 9, the outer shell 10, the gasket 11, the valve plate 12, the stator 13, the piston head 14, the first motor end cover 15, the first lip seal 16, the second lip seal 17, the second motor end cover 18, the permanent magnet 19, the second transmission connecting rod 20, the second connecting shaft 21, the second rotating shaft 22, the first pinion 23, the second pinion 24, the second miniature variable pump 25, the first miniature variable pump 26, the first check valve 27, the second check valve 28, the ejector pin 29, the valve housing 30, the valve disc 31 and the vortex spring 32.

Detailed Description

In order to make the technical content, the structural features, the achieved objects and the effects of the present invention more detailed, the following description will be taken in conjunction with the accompanying drawings.

The plunger pump device with the flow fine adjustment function comprises a valve plate 12, a second micro variable pump 25 and a first micro variable pump 26, wherein the second micro variable pump 25 and the first micro variable pump 26 are symmetrically distributed at two ends of the valve plate 12, two ends of a first outer shell 10 in the second micro variable pump 25 and the first micro variable pump 26 are fixedly connected with the two ends of the valve plate 12 through screws, the first micro variable pump 26 and the second micro variable pump 25 share a cavity, the end faces of the first micro variable pump 26 and the second micro variable pump 25 are matched to form a flow channel, so that a medium flowing in through the valve plate 12 can enter the cavity, the input medium and the output medium are controlled through the valve plate 12, one side face of the valve plate 12 is respectively provided with a first check valve 27 and a second check valve 28, and the inner side of the valve plate 12 is matched with a rotor bracket 8 as shown in fig. 4.

Further, as shown in fig. 1, by changing the initial positions of the piston heads 14 in the first micro variable pump 26 and the second micro variable pump 25, the two micro variable pumps generate different phases, so as to realize control of the pumped medium flow and reduction of flow pulsation, when the piston heads 14 in the first micro variable pump 26 and the second micro variable pump 25 are positioned at the same position relative to the inner sides of the respective permanent magnet rotor brackets 8, the first micro variable pump 26 and the second micro variable pump 25 simultaneously suck medium and discharge medium, the common cavity volume of the quantitative single-plunger type micro variable pump is maximum, and the output displacement is maximum; when the piston heads 14 of the first and second micro variable pumps 26, 25 are in different positions inside the respective permanent magnet rotor supports 8, one of the micro variable pumps is outputting medium and the other micro variable pump is inputting medium, the volume of the common cavity becomes smaller and the total displacement of the pumps decreases.

The second micro variable displacement pump 25 has the same structure as the first micro variable displacement pump 26, and as shown in fig. 1, 2 and 3, includes a stator 13 around which a coil is wound, a rotor bracket 8 to which a driving bevel gear 3 is mounted, tapered roller bearings 9 to which the rotor bracket 8 is fixed, first and second lip seal rings 16 and 17 to which the rotor bracket 8 is fixed, a piston head rotating member 1 mounted on a piston head 14 and connected to rotate the piston head 14, a driven bevel gear 4 mounted inside a first motor end cover 15, first and second pinion gears 23 and 24 engaged with the driving bevel gear 3 and the driven bevel gear 4, a first rotary shaft 7 for mounting the first pinion gear 23, a second rotary shaft 22 for mounting the second pinion gear 24, first and second connecting shafts 6 and 21 for respectively connecting the first and second rotary shafts 7 and 22, a rotary shaft sliding bearing 5 engaged with the first and second connecting shafts 6 and 21, and first and second transmission links 2 and 20 for transmitting power.

The first mounting end and the second mounting end of the rotor support 8 are respectively connected with the middle mounting ends of the first motor end cover 15 and the second motor end cover 18 through a first lip seal ring 16 and a second lip seal ring 17, the circumference of the first motor end cover 15 is matched with the rotor support 8 to realize circumferential fixation, the first lip seal ring 16 and the second lip seal ring 17 are mounted on the rotor support in an interference fit manner), the axial directions of the first lip seal ring 16 and the second lip seal ring 17 are respectively fixed by a tapered roller bearing 21 and the motor end cover, the third mounting end of the rotor support 8 is connected with the middle mounting end of the outer shell 10 through the tapered roller bearing 9, the stator 13 is positioned between the first motor end cover 15 and the second motor end cover 18, one side surface of the outer shell 10 is connected with the first end of the first motor end cover 15 through a gasket 11, the outer shell 10 is matched with the outer side of the first motor end cover 15 to realize axial fixation of the first motor end cover 15, the middle part of the stator 13 is provided with a coil, the outer part of the rotor support 8 is provided with a permanent magnet 19, and the stator 13 is connected and fixed at the third end of the first motor end cover 15 through a screw.

As shown in fig. 5, the piston head 14 is located at a first end inside the rotor bracket 8, the inner side of the rotor bracket 8 is a cavity for the piston head 14 to move, the mounting end of the piston head 14 is connected with the fixed end of the piston head adapter 1 through threads, the piston head rotating part 1 is matched with the circumference of the piston head 14 and the inner side of the rotor bracket 8, the first mounting end and the second mounting end of the piston head adapter 1 are respectively connected with the first end of the first transmission connecting rod 2 and the first end of the second transmission connecting rod 20 through short shafts and shaft holes, the driving bevel gear 3 is connected with the first fixed end inside the rotor bracket 8 through screws, the driven bevel gear 4 is connected with the second end of the first motor end cover 15 through screws, the driven bevel gear 4 is mounted on the outer shell 10 through threaded connection, the driving bevel gear 3 is meshed with the driven bevel gear 4 through a first pinion 23 and a second pinion 24 sequentially, the middle mounting end of the first pinion 23 and the middle mounting end of the second pinion 24 are respectively connected with the first end of the first rotating shaft 7 and the first rotating shaft 22, the second end of the second rotating shaft 22 is respectively connected with the first end of the first rotating shaft 7 and the second rotating shaft 22 through matching, the second end of the first rotating shaft 7 is respectively connected with the first end of the first rotating shaft 21 through the first connecting shaft 6 and the second connecting shaft 21, the first end of the first connecting rod 6 is connected with the first end of the first connecting rod 2 through the first connecting shaft 21 and the second connecting shaft 21 through the first end of the first connecting shaft 21, and the first end of the first connecting shaft 4 is connected with the first end of the first connecting shaft 2 through the first connecting shaft and the first end 21 through the first connecting shaft.

Specifically, the working principle of a single micro variable pump is as follows: the external current controls a coil wound by a stator 13 in the micro variable pump to generate a magnetic field, and the rotor bracket 8 rotates under the action of the magnetic field, so that the driving bevel gear 3 installed on the rotor bracket 8 through screw connection rotates. Because the first pinion 23 and the second pinion 24 are respectively meshed with the driving bevel gear 3 and the driven bevel gear 4, the power of the driving bevel gear 3 is transmitted to drive the first rotating shaft 7 and the first connecting shaft 6 to rotate, the first transmission connecting rod 2 and the second transmission connecting rod 20 are connected with the piston head rotating member 1 through shaft holes to be matched, and the power is transmitted to the piston head rotating member 1 through the transmission connecting rods to realize the reciprocating motion of the piston head 14.

The first check valve 27 and the second check valve 28 have the same structure, and as shown in fig. 6, the check valve comprises a push rod 29, a valve housing 30, a valve body 31 and a vortex spring 32, wherein the lower end of the valve housing 30 is in contact connection with an inner circular hole of the valve body 31, the upper end of the valve housing 30 is connected with the first end of the push rod 29, and the second end of the push rod 29 is connected with the vortex spring 32.

Specifically, in the device of the present invention, the first connecting shaft 6, the first rotating shaft 7, the second connecting shaft 21, the second rotating shaft 22, the sliding bearing 5, the first pinion 23, and the second pinion 24 constitute a rotation center assembly; the axis of the rotation center assembly and the axis of the driving bevel gear 4 are perpendicular to each other.

The first connecting shaft 6, the first rotating shaft 7, the second connecting shaft 21, the second rotating shaft 22, the first pinion 23 and the second pinion 24 are respectively symmetrically distributed about the center plane of the slide bearing 5. The axes of the first connecting shaft 6, the first rotating shaft 7, the second connecting shaft 21, the second rotating shaft 22, the first pinion 23 and the second pinion 24 are on the same straight line. The axes of the piston head rotor 1, the driving bevel gear 3, the driven bevel gear 4, the rotor support 8, the outer housing 10, the stator 13, the piston head 14, the first motor end cover 15 and the second motor end cover 18 are collinear.

The first motor end cover 15 of the second micro variable pump 25 and the first motor end cover 15 of the first micro variable pump 26 are fixedly connected with two ends of the valve plate 12 respectively.

The following describes a plunger pump device with a fine adjustment flow rate and a method for fine adjustment flow rate according to the embodiments:

in this embodiment, the method for fine adjustment of the flow rate of the plunger pump apparatus having the fine adjustment of the flow rate is implemented as follows:

s1, the first micro variable pump 26 is connected with the outside in a current way, at the moment, a magnetic field is generated by a coil wound on the stator 13 in the first micro variable pump 26, and the rotor bracket 8 provided with the permanent magnet 19 rotates under the action of the magnetic field, so that the driving bevel gear 3 connected with the rotor bracket 8 through a screw is rotated.

S2, under the transmission of a first pinion 23 and a second pinion 24 which are meshed with the driving bevel gear 3 and the driven bevel gear 4 respectively, the power of the driving bevel gear 3 is transmitted to drive the rotating shaft and the connecting shaft to perform periodic motion, the telescopic motion of the piston head 14 is realized through the action of the rotating shaft and the connecting shaft, further, the fluid medium is sucked and pumped out, and the power is transmitted to the piston head 14 connected with the first transmission connecting rod 2 and the second transmission connecting rod 20 through the first connecting shaft 6, the first rotating shaft 7, the second connecting shaft 21 and the second rotating shaft 22, so that the piston head 14 performs reciprocating motion to reach an initial phase.

S3, under the condition that the time interval of externally connecting the first micro variable pump 26 and the second micro variable pump 25 with current is ensured, the second micro variable pump 25 is connected with external current, so that the first micro variable pump 26 and the second micro variable pump 25 generate phase difference, the flow control is realized, when the initial phases of the first micro variable pump 26 and the second micro variable pump 25 are consistent, the volume of the public cavity is maximum, the displacement is maximum at the moment, when the phases of the first micro variable pump 26 and the second micro variable pump 25 are different by half period, the volume of the public cavity is minimum, the displacement is minimum at the moment, and the displacement of the whole device can be controlled by controlling the initial phase.

Because the first micro variable pump 26 and the second micro variable pump 25 share a cavity, the flow curves output by the first micro variable pump 26 and the second micro variable pump 25 are sinusoidal, the sum of the output flows is the superposition of curve values at the same moment, the phase difference leads to different time of suction and discharge of the two pumps, and at the moment, the phase difference is reflected on the output flows, namely different output flows are generated, so that the fine adjustment of the flow is completed.

The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the present invention.

Claims (8)

1. The plunger pump device with the flow fine adjustment comprises a valve plate, a second micro variable pump and a first micro variable pump, wherein the second micro variable pump and the first micro variable pump are symmetrically distributed at two ends of the valve plate, one side surface of the valve plate is respectively provided with a first one-way valve and a second one-way valve,

the second micro variable pump has the same structure as the first micro variable pump, and comprises a piston head rotating piece, a first transmission connecting rod, a second transmission connecting rod, a driving bevel gear, a driven bevel gear, a first connecting shaft, a first rotating shaft, a second connecting shaft, a second rotating shaft, a rotor support, an outer shell, a stator, a piston head, a first motor end cover, a second motor end cover, a permanent magnet, a coil, a first pinion and a second pinion, wherein a first mounting end and a second mounting end of the rotor support are respectively connected with middle mounting ends of the first motor end cover and the second motor end cover through a first lip seal ring and a second lip seal ring, a third mounting end of the rotor support is connected with middle mounting ends of the outer shell through tapered roller bearings, the stator is positioned between the first motor end cover and the second motor end cover, one side surface of the outer shell is connected with the first end of the first motor end cover through a gasket, the coil is arranged in the middle of the stator, and the permanent magnet is arranged outside the rotor support;

the piston head is positioned at a first end in the rotor bracket, the mounting end of the piston head is connected with the fixed end of the piston head switching piece, the first mounting end and the second mounting end of the piston head switching piece are respectively connected with the first ends of the first transmission connecting rod and the second transmission connecting rod, the driving bevel gear is connected with the first fixed end in the rotor bracket, the driven bevel gear is connected with the second end of the first motor end cover, the driving bevel gear is meshed with the driven bevel gear sequentially through a first pinion and a second pinion, the middle mounting end of the first pinion and the middle mounting end of the second pinion are respectively connected with the first ends of the first rotating shaft and the second rotating shaft, the second ends of the first rotating shaft and the second rotating shaft are respectively connected with the first ends of the first connecting shaft and the second connecting shaft, the second ends of the first connecting shaft are connected with the second ends of the second connecting shaft through sliding bearings, and the first connecting shaft and the second connecting shaft are respectively connected with the first ends of the first transmission connecting rod and the second connecting shaft;

the structure of the first one-way valve is the same as that of the second one-way valve, the first one-way valve comprises a push rod, a valve shell, a valve body and a vortex spring, the lower end of the valve shell is in contact connection with an inner round hole of the valve body, the upper end of the valve shell is connected with the first end of the push rod, and the second end of the push rod is connected with the vortex spring.

2. The plunger pump apparatus with fine tuning flow according to claim 1, wherein the first connecting shaft, the first rotating shaft, the second connecting shaft, the second rotating shaft, the sliding bearing, the first pinion and the second pinion constitute a rotation center assembly; the first connecting shaft, the first rotating shaft, the second connecting shaft, the second rotating shaft, the first pinion and the second pinion are symmetrically distributed relative to the central plane of the sliding bearing respectively.

3. The plunger pump apparatus with fine adjustment of flow rate according to claim 1, wherein axes of the first connecting shaft, the first rotating shaft, the second connecting shaft, the second rotating shaft, the first pinion and the second pinion are on the same straight line.

4. The plunger pump apparatus with fine tuning flow of claim 1, wherein the axes of the piston head rotating member, the driving bevel gear, the driven bevel gear, the rotor support, the outer housing, the stator, the piston head, the first motor end cap and the second motor end cap are collinear.

5. The plunger pump apparatus with fine tuning flow of claim 1, wherein the axis of the rotational center assembly and the axis of the driving bevel gear are perpendicular to each other.

6. The plunger pump apparatus with fine-tuning flow according to claim 1, wherein the motor end cover of the second micro-variable pump and the motor end cover of the first micro-variable pump are fixedly connected with both ends of the valve plate, respectively.

7. A method of trimming a flow of a plunger pump device having a trimming flow according to one of claims 1 to 6, characterized in that it comprises the steps of:

s1, connecting a first miniature variable pump with the outside in a current way, wherein a coil wound on a stator in the first miniature variable pump generates a magnetic field, and a rotor bracket provided with a permanent magnet rotates under the action of the magnetic field, so that a driving helical gear rotates;

s2, under the transmission of a first pinion and a second pinion which are respectively meshed with the driving bevel gear and the driven bevel gear, power is transmitted to a piston head connected with a first transmission connecting rod and a second transmission connecting rod through a first connecting shaft, a first rotating shaft, a second connecting shaft and a second rotating shaft, so that the piston head reciprocates to reach an initial phase;

and S3, connecting the second micro variable pump with external current at a time interval when the external current of the first micro variable pump and the second micro variable pump is ensured, so that the first micro variable pump and the second micro variable pump generate phase differences, namely different output flow is generated, and the fine adjustment of the flow is completed.

8. The method of trimming a flow rate of a plunger pump apparatus having a trimming flow rate according to claim 7, wherein the flow rate curves outputted from the first micro variable displacement pump and the second micro variable displacement pump are both sinusoidal.