A liquid injection pump

Abstract

The present invention provides a liquid injection pump, which includes a motor, a coupling component connected to the output shaft of the motor, and a pump head component connected to the coupling component; the pump head component is a piston pump; the output shaft of the motor is connected to the coupling component through a clearance fit with a keyway; the coupling component is connected to the pump head component through a universal ball head connecting rod; the output shaft of the motor and the coupling component are distributed collinearly; the axis of the pump head component and the axis of the coupling component are distributed at a certain angle; the motor drives the coupling component to perform a rotational motion; the coupling component drives the piston of the piston pump to perform a reciprocating motion through the universal ball head connecting rod. The liquid injection pump of the present invention has a compact structure, is safe and reliable, and can improve the liquid injection accuracy. When the liquid injection pump of the present invention is applied to the liquid injection of electrolytes in the lithium battery industry, it can improve the liquid injection accuracy of the electrolytes, and at the same time, the liquid injection volume can be adjusted, and the service life of the driving motor can also be extended.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical automation, and particularly to a liquid injection pump used in liquid filling industries such as battery liquid injection, liquid medicine injection, and oral liquid filling. Background Art

[0002] With the continuous development of society and the continuous progress of technology, the application of mechanical automation production is becoming more and more extensive. In the perfusion equipment in multiple industrial fields such as battery production, pharmaceutical production, biological reagents, and petrochemical industry, a liquid injection pump is used.

[0003] The liquid injection pump generally includes three main parts: a driving motor end, a transmission connection component, and a hydraulic end. The common liquid injection pumps include vane pumps, piston pumps, diaphragm pumps, gear pumps, and screw pumps. In the perfusion processes of battery production or pharmaceutical production with relatively high precision requirements, a piston pump type liquid injection pump is generally used for perfusion.

[0004] The existing piston type liquid injection pumps usually have the following disadvantages:

[0005] First, during the reciprocating motion of the piston at the hydraulic end, an axial reaction force will be given to the driving motor through the transmission connection component, which is harmful to the service life of the driving motor.

[0006] Second, due to the axial reaction force of the piston at the hydraulic end on the driving motor, the driving motor usually may jump, and in turn, the jump of the driving motor will cause the piston stroke at the hydraulic end to be misaligned, resulting in inaccurate liquid injection at the hydraulic end and inaccurate liquid injection.

[0007] Third, during the liquid injection process, for different specifications of liquid injection volumes, the stroke of the piston needs to be adjusted; the existing adjustment methods either have inconvenient adjustment or insufficient adjustment accuracy.

[0008] If a liquid injection pump can be developed in which the hydraulic load end does not give an axial reaction force to the driving motor and can ensure the accurate axial stroke of the piston at the hydraulic end of the liquid injection pump, and is not affected by problems such as the jump of the driving motor resulting in inaccurate liquid injection, it will have great market value. Summary of the Invention

[0009] To solve the problems in the prior art, the present invention provides a liquid injection pump with a compact structure, safe and reliable, and can improve the liquid injection accuracy. When the liquid injection pump of the present invention is applied to the electrolyte injection in the lithium battery industry, it can improve the liquid injection accuracy of the electrolyte and at the same time improve the service life of the driving motor.

[0010] To achieve the above object, the present invention provides the following technical solutions: A liquid injection pump includes a motor, a coupling assembly connected to the output shaft of the motor, and a pump head assembly connected to the coupling assembly; the pump head assembly is a piston pump; the output shaft of the motor is connected to the coupling assembly through a keyway with a clearance connection; the coupling assembly is connected to the pump head assembly through a universal ball head connecting rod; the axes of the output shaft of the motor and the coupling assembly are distributed in a straight line; there is a certain angle between the axis of the pump head assembly and the axis of the coupling assembly; the motor drives the coupling assembly to perform a rotational motion; the coupling assembly drives the piston of the piston pump to perform a reciprocating motion through the universal ball head connecting rod.

[0011] In a preferred technical solution, the coupling assembly includes a stepped shaft integrally shaped like a "T", a coupling bearing sleeved on the stepped shaft (this coupling bearing can adopt various conventional bearings, such as deep groove ball bearings), and a coupling fixing seat; the larger end of the stepped shaft is connected to the piston of the piston pump through a universal ball head connecting rod; the smaller end of the stepped shaft is connected to the output shaft of the motor through a keyway with a clearance connection; the coupling bearing is sleeved on the smaller end of the stepped shaft; the coupling fixing seat is sleeved on the coupling bearing, and the coupling fixing seat presses and fixes the outer ring of the coupling bearing.

[0012] In a preferred technical solution, the coupling assembly further includes an annular first locking member and an annular second locking member. The first locking member is fixedly connected to the coupling fixing seat and abuts against the outer ring of the coupling bearing to limit the axial movement of the outer ring of the coupling bearing; the second locking member is fixedly connected to the stepped shaft and abuts against the inner ring of the coupling bearing to limit the axial movement of the inner ring of the coupling bearing.

[0013] In a preferred technical solution, the annular first locking member has an external thread, and the annular second locking member has an internal thread; the stepped shaft has an outwardly protruding outer flange, and the smaller end of the stepped shaft also has an external thread that is threadedly engaged with the internal thread of the second locking member; one end of the coupling fixing seat has an inwardly protruding inner flange, and the other end of the coupling fixing seat has an internal thread that is threadedly engaged with the external thread of the first locking member; one end of the inner ring of the coupling bearing abuts against the outer flange of the stepped shaft, and the other end of the inner ring of the coupling bearing abuts against the second locking member; one end of the outer ring of the coupling bearing abuts against the inner flange of the coupling fixing seat, and the other end of the outer ring of the coupling bearing abuts against the first locking member.

[0014] In a preferred technical solution, the coupling fixing seat is also provided with a threaded hole, and a set screw is threadedly engaged with the threaded hole, and the set screw abuts against the first locking member to limit the relative movement of the first locking member with respect to the coupling fixing seat.

[0015] Preferred technical solution: The universal ball head connecting rod includes a universal ball and a connecting rod that can move by inserting into the universal ball. The universal ball of the universal ball head connecting rod is rotatably embedded in the piston of the piston pump. One end of the connecting rod of the universal ball head connecting rod is fixed on the coupling assembly, and the other end of the connecting rod is inserted into the universal ball located in the piston. The motor rotates to drive the coupling assembly to rotate, driving the connecting rod of the universal ball head connecting rod to move within the universal ball, and driving the piston of the piston pump to reciprocate.

[0016] Preferred technical solution: The universal ball head connecting rod includes a universal ball and a connecting rod that can move by inserting into the universal ball. The universal ball of the universal ball head connecting rod is rotatably embedded in the stepped shaft of the coupling assembly. One end of the connecting rod of the universal ball head connecting rod is fixed on the piston of the piston pump, and the other end of the connecting rod is inserted into the universal ball located in the stepped shaft. The motor drives the stepped shaft of the coupling assembly to rotate, driving the connecting rod to move within the universal ball, and driving the piston of the piston pump to reciprocate.

[0017] Preferred technical solution: The liquid injection pump further includes a base, a rotating plate assembly, and an angle adjustment assembly. The rotating plate assembly rotatably mounts the pump head assembly on the base. The angle adjustment assembly is connected to the rotating plate assembly and adjusts the installation angle of the pump head assembly by driving the rotating plate assembly to rotate.

[0018] Preferred technical solution: The rotating plate assembly includes a rotating plate and a rotating shaft. The angle adjustment assembly includes a differential bolt and a sliding fork shaft. The pump head assembly is fixedly installed on the rotating plate, and the rotating shaft rotatably mounts the rotating plate on the base. The differential bolt has a smaller threaded section and a larger threaded section. One end of the sliding fork shaft is connected to the rotating plate, and the other end of the sliding fork shaft is threadedly connected to the smaller threaded section of the differential bolt. The larger threaded section of the differential bolt is threadedly connected to the base. The shape of the sliding fork shaft can be various. One of the sliding fork shafts can have a single ear plate at one end and a thread at the other end. The connection method between the rotating plate and the sliding fork shaft can also be various. One of them is that the connection end of the rotating plate and the sliding fork shaft is a double ear plate structure. The single ear plate end of the sliding fork shaft is inserted into the double ear plates of the rotating plate, and the double ear plates of the rotating plate and the single ear plate of the sliding fork shaft are connected by a pin shaft.

[0019] Preferred technical solution: A rotating plate is provided on the base; the rotating plate is rotatably mounted on the base through a pin shaft, and the rotating plate is provided with an internally threaded through hole; the internally threaded through hole of the rotating plate is in threaded fit with the larger threaded section of the differential bolt; a spring is also sleeved on the sliding fork shaft and the differential bolt. This spring can prevent the differential bolt from slipping and loosening. Using a rotating plate to transition the direct connection between the differential bolt and the base can ensure that there is no jamming phenomenon during the process of adjusting the angle of the differential bolt, greatly increasing its adjustable angle. That is, when the differential bolt feeds, the rotating plate can rotate by a certain angle to enable the differential bolt to adapt to the possible jamming phenomenon caused by the angle change of the rotating plate.

[0020] The threaded connection method between the sliding fork shaft and the differential bolt can be: the sliding fork shaft has external threads, and the smaller threaded section of the differential bolt has internal threads. The specific implementation method can be to open an axial blind hole at one end of the differential bolt connected to the sliding fork shaft, and then tap internal threads in this blind hole that match the external threads on the sliding fork shaft. Of course, it can also be that the sliding fork shaft has internal threads and the smaller threaded section of the differential bolt has external threads. The specific implementation method is to open an axial blind hole at one end of the sliding fork shaft connected to the differential bolt, and tap internal threads in the blind hole of the sliding fork shaft to achieve the threaded fit between the internal threads of the sliding fork shaft and the smaller threaded section of the differential bolt.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The motor of the liquid injection pump is connected to the coupling assembly by a keyway and is in clearance fit. Therefore, there is no axial force transmission between the motor and the coupling assembly, only radial rotational force transmission. At the same time, there is a certain included angle in the axial center distribution between the coupling assembly and the pump head assembly, and the coupling assembly and the pump head assembly are connected by a universal link. Due to the existence of a certain included angle between the axial centers and the use of a universal link connection, the rotational motion transmitted from the motor received by the coupling assembly can be converted into the reciprocating motion of the piston of the piston pump of the pump head assembly. The entire mechanism operates reliably and there is no axial force transmission, so it is beneficial to extend the service life of the motor.

[0023] 2. The coupling assembly of the liquid injection pump of the present invention adopts the mutual cooperation among a stepped shaft integrally in the shape of "T", a coupling bearing, a coupling fixing seat, a first locking member, and a second locking member, so that the coupling blocks the axial reaction force at the load end of the pump head assembly. By separately and independently restricting the axial movement of the inner and outer rings of the coupling bearing, the axial force transmitted from the load end of the coupling assembly is blocked, so that the axial force will not be transmitted to the motor, which is beneficial to improving the service life of the motor. At the same time, since the outer flange on the stepped shaft and the second locking member restrict the axial movement of the inner ring of the coupling bearing, and the inner flange of the coupling fixing seat and the first locking member restrict the axial movement of the outer ring of the coupling bearing, and at the same time, the force on the outer ring of the coupling is transmitted to the coupling fixing seat through the set screw, thus no longer transmitting the axial force to the driving motor end. Moreover, by separately and independently structured to independently restrict the axial movement of the inner and outer rings of the coupling bearing, it is also beneficial to make the output power of the coupling assembly stable and reliable, especially its axial output is safe and reliable, and further makes the reciprocating movement of the piston of the pump head assembly accurate and reliable. Therefore, the liquid injection of this liquid injection pump is more accurate.

[0024] 3. The pump head assembly of the liquid injection pump of the present invention is rotatably fixed on the base and is equipped with an angle adjustment assembly, so that the distribution angle between it and the axis of the coupling assembly can be adjusted. Furthermore, the stroke of the piston of the piston pump of the pump head assembly can be adjusted during the reciprocating movement, thereby achieving the purpose that the liquid injection volume of the liquid injection pump can be adjusted.

[0025] 4. The angle adjustment assembly adopts a structure of mutual cooperation between a differential bolt and a sliding fork shaft, which can achieve precise adjustment of the rotation angle of the rotating assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a three-dimensional structural schematic diagram of the liquid injection pump of the present invention.

[0027] Figure 2 It is a front view structural schematic diagram of the liquid injection pump of the present invention.

[0028] Figure 3 It is a top view structural schematic diagram of the liquid injection pump of the present invention.

[0029] Figure 4 It is a right view structural schematic diagram of the liquid injection pump of the present invention.

[0030] Figure 5 It is a three-dimensional structural schematic diagram of the coupling assembly.

[0031] Figure 6 It is a front view structural schematic diagram of the coupling assembly.

[0032] Figure 7 It is a sectional view structural schematic diagram of the coupling assembly.

[0033] Figure 8 It is a schematic top view structure diagram of the coupling assembly.

[0034] Figure 9 It is a schematic three-dimensional structure diagram of the stepped shaft.

[0035] Figure 10 It is a schematic front view structure diagram of the stepped shaft.

[0036] Figure 11 It is a schematic right view structure diagram of the stepped shaft.

[0037] Figure 12 It is a schematic top view structure diagram of the stepped shaft.

[0038] Figure 13 It is a schematic front view structure diagram of the coupling fixing seat.

[0039] Figure 14 It is a schematic right view structure diagram of the coupling fixing seat.

[0040] Figure 15 For Figure 14 It is a schematic sectional view structure diagram in the A-A direction in

[0041] Figure 16 It is a schematic three-dimensional connection structure diagram among the base, the rotating plate assembly, and the angle adjustment assembly.

[0042] Figure 17 It is a schematic front view connection structure diagram among the base, the rotating plate assembly, and the angle adjustment assembly.

[0043] Figure 18 It is a schematic left view connection structure diagram among the base, the rotating plate assembly, and the angle adjustment assembly.

[0044] Figure 19 It is a schematic right view connection structure diagram among the base, the rotating plate assembly, and the angle adjustment assembly.

[0045] Figure 20 It is a schematic three-dimensional connection structure diagram between the rotating plate assembly and the sliding fork shaft.

[0046] Figure 21 It is a schematic three-dimensional connection structure diagram among the rotating plate, the sliding fork shaft, and the differential bolt.

[0047] Figure 22 It is a schematic structure diagram of the differential bolt.

[0048] Figure 23 It is a schematic structure diagram of the sliding fork shaft.

[0049] Figure 24 It is a schematic connection structure diagram between the differential bolt and the sliding fork shaft.

[0050] Figure 25 It is a schematic three-dimensional structure diagram of a universal ball head connecting rod.

[0051] The markings in the figure are:

[0052] 1 - Motor; 2 - Coupling assembly; 21 - Step shaft; 211 - Outer flange; 22 - Coupling bearing; 23 - Coupling fixing seat; 231 - Inner flange; 232 - Threaded hole; 24 - First locking member; 25 - Second locking member; 26 - Set screw; 3 - Pump head assembly; 4 - Universal ball head connecting rod; 41 - Universal ball; 42 - Connecting rod; 5 - Base; 51 - Rotating plate; 6 - Rotating plate assembly; 61 - Rotating plate; 611 - Double ear plate; 62 - Rotating shaft; 7 - Angle adjustment assembly; 71 - Differential bolt; 711 - Smaller threaded section; 712 - Larger threaded section; 713 - Spring; 72 - Slide fork shaft; 721 - Single ear plate. Specific implementation manner

[0053] Refer to Figures 1 to 25 To further illustrate an embodiment of an injection pump of the present invention.

[0054] An injection pump includes a motor 1, a coupling assembly 2 connected to the output shaft of the motor 1, and a pump head assembly 3 connected to the coupling assembly 2; the pump head assembly 3 is a piston pump; the output shaft of the motor 1 and the coupling assembly 2 are connected by a clearance fit through a keyway; the coupling assembly 2 and the pump head assembly 3 are connected by a universal ball head connecting rod 4; the output shaft of the motor 1 and the axis of the coupling assembly 2 are distributed collinearly; the axis of the pump head assembly 3 and the axis of the coupling assembly 2 are distributed at a certain angle; the motor 1 drives the coupling assembly 2 to perform a rotational motion; the coupling assembly 2 drives the piston of the piston pump to perform a reciprocating motion through the universal ball head connecting rod 4.

[0055] The coupling assembly 2 includes a step shaft 21 integrally in a "T" shape, a coupling bearing 22 sleeved on the step shaft 21 (this coupling bearing can adopt a variety of conventional bearings, such as deep groove ball bearings), and a coupling fixing seat 23; the larger end of the step shaft is connected to the piston of the piston pump 3 through a universal ball head connecting rod 4;

[0056] The universal ball head link 4 includes a universal ball 41 and a connecting rod 42 that can move by being inserted into the universal ball 41. In this embodiment, the universal ball 41 of the universal ball head link 4 is rotatably embedded in the piston of the piston pump 3. One end of the connecting rod 42 of the universal ball head link 4 is fixed on the stepped shaft 21 of the coupling assembly 2, and the other end of the connecting rod 42 is inserted into the universal ball 41 located in the piston; and the connecting rod 42 can slide within the universal ball 41. The motor 1 rotates to drive the coupling assembly 2 to rotate, driving the connecting rod 42 of the universal ball head link 4 to move within the universal ball 41, and driving the piston of the piston pump 3 to reciprocate. Of course, in other embodiments, the universal ball 41 of the universal ball head link 4 can also be embedded in the stepped shaft 21 of the coupling assembly 2. One end of the connecting rod 42 of the universal ball head link 4 is fixed on the piston of the piston pump 3, and the other end of the connecting rod 42 is inserted into the universal ball 41 located in the stepped shaft 21; the motor 1 drives the stepped shaft 21 of the coupling assembly 2 to rotate, driving the connecting rod 42 to slide within the universal ball 41, and driving the piston of the piston pump 3 to reciprocate.

[0057] The smaller end of the stepped shaft 21 is connected to the output shaft of the motor 1 with a clearance fit through a keyway; the coupling bearing 22 is sleeved on the smaller end of the stepped shaft 21; the coupling fixing seat 23 is sleeved on the coupling bearing 22, and the coupling fixing seat 23 presses and fixes the outer ring of the coupling bearing 22.

[0058] The coupling assembly 2 further includes an annular first locking member 24 and an annular second locking member 25. The first locking member 24 is fixedly connected to the coupling fixing seat 23 and abuts against the outer ring of the coupling bearing 22 to restrict the axial movement of the outer ring of the coupling bearing 22; the second locking member 25 is fixedly connected to the stepped shaft 21 and abuts against the inner ring of the coupling bearing 22 to restrict the axial movement of the inner ring of the coupling bearing 22.

[0059] The annular first locking member 24 is provided with an external thread, and the annular second locking member 25 is provided with an internal thread; the stepped shaft 21 has an outwardly protruding external flange 211, and the smaller end of the stepped shaft 21 is also provided with an external thread that is threadedly engaged with the internal thread of the second locking member 25; one end of the coupling fixing seat 23 has an inwardly protruding internal flange 231, and the other end of the coupling fixing seat 23 is provided with an internal thread that is threadedly engaged with the external thread of the first locking member 24; one end of the inner ring of the coupling bearing 22 abuts against the external flange 211 of the stepped shaft 21, and the other end of the inner ring of the coupling bearing 22 abuts against the second locking member 25; one end of the outer ring of the coupling bearing 22 abuts against the internal flange 231 of the coupling fixing seat 23, and the other end of the outer ring of the coupling bearing 22 abuts against the first locking member 24. In a preferred embodiment, the inner diameter of the first locking member 24 is greater than the outer diameter of the second locking member 25, and the second locking member 25 passes through the inner diameter of the first locking member 24 and abuts against the inner ring of the coupling bearing 22.

[0060] The coupling fixing seat 23 is further provided with a threaded hole 232, and a set screw 26 is threadedly engaged with the threaded hole 232, and the set screw 26 abuts against the first locking member 24 to restrict the movement of the first locking member 24 relative to the coupling fixing seat 23.

[0061] The liquid injection pump further includes a base 5, a rotating plate assembly 6, and an angle adjustment assembly 7; the rotating plate assembly 6 rotatably mounts the pump head assembly 3 on the base 5; the angle adjustment assembly 7 is connected to the rotating plate assembly 6, and adjusts the mounting angle of the pump head assembly 3 by driving the rotating plate assembly 6 to rotate.

[0062] The rotating plate assembly 6 includes a rotating plate 61 and a rotating shaft 62; the angle adjustment assembly 7 includes a differential bolt 71 and a sliding fork shaft 72; the pump head assembly 3 is fixedly mounted on the rotating plate 61, and the rotating shaft 62 rotatably mounts the rotating plate 61 on the base 5; the differential bolt 71 has a smaller threaded section 711 and a larger threaded section 712; one end of the sliding fork shaft 72 is connected to the rotating plate 61, and the other end of the sliding fork shaft 72 is threadedly connected to the smaller threaded section 711 of the differential bolt 71; the larger threaded section 712 of the differential bolt 71 is threadedly connected to the base 5. The shape of the sliding fork shaft 72 can be various. One of the shapes of the sliding fork shaft 72 can be that one end is a single ear plate 721 and the other end has a thread. The connection manner between the rotating plate 61 and the sliding fork shaft 72 can also be diverse. One of them is that the connection end of the rotating plate 61 and the sliding fork shaft 72 is a double ear plate 611 structure. The single ear plate 721 of the sliding fork shaft 72 is inserted into the double ear plate 611 of the rotating plate 61, and the double ear plate 611 of the rotating plate 61 and the single ear plate 721 of the sliding fork shaft 72 are connected by a pin shaft.

[0063] A rotating plate 51 is provided on the base 5; the rotating plate 51 is rotatably mounted on the base 5 through a pin shaft, and the rotating plate 51 is provided with an internally threaded through hole; the internally threaded through hole of the rotating plate 51 is in threaded engagement with the larger threaded section 712 of the differential bolt 71; a spring 713 is also sleeved on the sliding fork shaft 72 and the differential bolt 71. The spring 713 can prevent the differential bolt 71 from slipping and loosening. Using the rotating plate 51 to transition the direct connection between the differential bolt 71 and the base 5 can ensure that the differential bolt 71 does not get stuck during the angle adjustment process, greatly increasing its adjustment angle. That is, when the differential bolt 71 feeds, the rotating plate 51 can rotate by a certain angle to enable the differential bolt 71 to adapt to the possible jamming phenomenon caused by the angle change of the rotating plate.

[0064] The threaded connection mode between the sliding fork shaft 72 and the differential bolt 71 can be as follows: if the sliding fork shaft 72 has external threads, then the smaller threaded section 711 of the differential bolt 71 has internal threads. The specific implementation method can be to open an axial blind hole at one end of the differential bolt 71 connected to the sliding fork shaft 72, and then tap internal threads in the blind hole that match the external threads on the sliding fork shaft 72. Of course, it is also possible that the sliding fork shaft 72 has internal threads and the smaller threaded section 711 of the differential bolt 71 has external threads. The specific implementation method is to open an axial blind hole at one end of the sliding fork shaft 72 connected to the differential bolt 71, and tap internal threads in the blind hole of the sliding fork shaft 72 to achieve the cooperation between the internal threads of the sliding fork shaft 72 and the smaller threaded section 711 of the differential bolt 71.

[0065] The working principle of the liquid injection pump of the present invention is as follows:

[0066] The motor of the liquid injection pump is connected to the coupling assembly by a keyway and has a clearance fit. Therefore, there is no axial force transmission between the motor and the coupling assembly, and only radial rotational force transmission exists. At the same time, there is a certain included angle in the axial center distribution between the coupling assembly and the pump head assembly, and the coupling assembly and the pump head assembly are connected by a universal connecting rod. Due to the existence of a certain included angle between the axial centers and the use of a universal connecting rod, the rotational motion transmitted from the motor received by the coupling assembly can be converted into the reciprocating motion of the piston of the piston pump of the pump head assembly. The coupling assembly of the liquid injection pump of the present invention adopts the mutual cooperation between a stepped shaft integrally shaped like a "T", a coupling bearing, a coupling fixing seat, a first locking member, and a second locking member, so that the coupling blocks the axial reaction force at the load end of the pump head assembly. By separately and independently restricting the axial movement of the inner and outer rings of the coupling bearing, the axial force transmitted from the load end of the coupling assembly is blocked, so that the axial force will not be transmitted to the motor, which is beneficial to improving the service life of the motor. At the same time, since the outer flange on the stepped shaft and the second locking member restrict the axial movement of the inner ring of the coupling bearing, and the inner flange of the coupling fixing seat and the first locking member restrict the axial movement of the outer ring of the coupling bearing, and at the same time, the force on the outer ring of the coupling is transmitted to the coupling fixing seat through a set screw, so that the axial force is no longer transmitted to the driving motor end. Moreover, by separately and independently structured to independently restrict the axial movement of the inner and outer rings of the coupling bearing, it is also beneficial for the output power of the coupling assembly to be stable and reliable, especially its axial output is safe and reliable, and further makes the reciprocating movement of the piston of the pump head assembly accurate and reliable. Therefore, the liquid injection of the liquid injection pump is more accurate. The pump head assembly of the liquid injection pump of the present invention is rotatably fixed on the base and is equipped with an angle adjustment assembly. When different liquid injection amounts are required, only by adjusting the distribution angle between the axial centers of the pump head assembly and the coupling assembly, the stroke of the piston of the piston pump of the pump head assembly during reciprocating operation can be changed, so as to achieve the purpose that the liquid injection amount of the liquid injection pump can be adjusted. The angle adjustment assembly adopts a structure in which a differential bolt and a sliding fork shaft cooperate with each other, and can achieve precise adjustment of the rotation angle of the rotating assembly.

[0067] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. It should be noted that any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A liquid injection pump, comprising a motor, a coupling assembly connected to the output shaft of the motor, and a pump head assembly connected to the coupling assembly; characterized in that: The pump head assembly is a piston pump; the motor output shaft is connected to the coupling assembly with a clearance fit through a keyway; the coupling assembly is connected to the pump head assembly through a universal ball head connecting rod; the axes of the motor output shaft and the coupling assembly are distributed collinearly; the axis of the pump head assembly and the axis of the coupling assembly are distributed at a certain angle; the motor drives the coupling assembly to make a rotational motion; the coupling assembly drives the piston of the piston pump to make a reciprocating motion through the universal ball head connecting rod; It further includes a base, a rotating plate assembly, and an angle adjustment assembly; the rotating plate assembly rotatably mounts the pump head assembly on the base; the angle adjustment assembly is connected to the rotating plate assembly and adjusts the installation angle of the pump head assembly by driving the rotating plate assembly to rotate; The rotating plate assembly includes a rotating plate and a rotating shaft; the angle adjustment assembly includes a differential bolt and a sliding fork shaft; the pump head assembly is fixedly installed on the rotating plate, and the rotating shaft rotatably mounts the rotating plate on the base; the differential bolt has a smaller threaded section and a larger threaded section; one end of the sliding fork shaft is connected to the rotating plate, and the other end of the sliding fork shaft is threadedly connected to the smaller threaded section of the differential bolt; the larger threaded section of the differential bolt is threadedly connected to the base; A rotating plate is provided on the base; the rotating plate is rotatably installed on the base through a pin shaft, and the rotating plate is provided with an internally threaded through hole; the internally threaded through hole of the rotating plate is in threaded fit with the larger threaded section of the differential bolt; a spring is also sleeved on the sliding fork shaft and the differential bolt.

2. The liquid injection pump according to claim 1, characterized in that: The coupling assembly includes a stepped shaft integrally shaped like a "T", a coupling bearing sleeved on the stepped shaft, and a coupling fixing seat; the larger end of the stepped shaft is connected to the piston of the piston pump through a universal ball head connecting rod; the smaller end of the stepped shaft is connected to the motor output shaft with a clearance fit through a keyway; the coupling bearing is sleeved on the smaller end of the stepped shaft; the coupling fixing seat is sleeved on the coupling bearing, and the coupling fixing seat presses and fixes the outer ring of the coupling bearing.

3. The liquid injection pump according to claim 2, wherein: The coupling assembly further includes an annular first locking member and an annular second locking member. The first locking member is fixedly connected to the coupling fixing seat and abuts against the outer ring of the coupling bearing to limit the axial movement of the outer ring of the coupling bearing; the second locking member is fixedly connected to the stepped shaft and abuts against the inner ring of the coupling bearing to limit the axial movement of the inner ring of the coupling bearing.

4. The liquid injection pump according to claim 3, characterized in that: The annular first locking member is provided with an external thread, and the annular second locking member is provided with an internal thread; the stepped shaft has an outwardly protruding external flange, and the smaller end of the stepped shaft is also provided with an external thread that is in threaded fit with the internal thread of the second locking member; one end of the coupling fixing seat has an inwardly protruding internal flange, and the other end of the coupling fixing seat is provided with an internal thread that is in threaded fit with the external thread of the first locking member; one end of the inner ring of the coupling bearing abuts against the external flange of the stepped shaft, and the other end of the inner ring of the coupling bearing abuts against the second locking member; one end of the outer ring of the coupling bearing abuts against the internal flange of the coupling fixing seat, and the other end of the outer ring of the coupling bearing abuts against the first locking member.

5. The liquid injection pump according to claim 4, wherein: The coupling fixing seat is also provided with a threaded hole, which is in threaded cooperation with the threaded hole through a set screw, and the set screw abuts against the first locking member to restrict the movement of the first locking member relative to the coupling fixing seat.

6. The liquid injection pump according to claim 1, wherein: The universal ball head connecting rod includes a universal ball and a connecting rod that can move by inserting into the universal ball; the universal ball of the universal ball head connecting rod is rotatably embedded in the piston of the piston pump, one end of the connecting rod of the universal ball head connecting rod is fixed on the coupling assembly, and the other end of the connecting rod is inserted into the universal ball located in the piston; the motor rotates to drive the coupling assembly to rotate, driving the connecting rod of the universal ball head connecting rod to move in the universal ball, and driving the piston of the piston pump to reciprocate.

7. The liquid injection pump according to claim 2, wherein: The universal ball head connecting rod includes a universal ball and a connecting rod that can move by inserting into the universal ball; the universal ball of the universal ball head connecting rod is rotatably embedded in the stepped shaft of the coupling assembly, one end of the connecting rod of the universal ball head connecting rod is fixed on the piston of the piston pump, and the other end of the connecting rod is inserted into the universal ball located in the stepped shaft; the motor drives the stepped shaft of the coupling assembly to rotate, driving the connecting rod to move in the universal ball, and driving the piston of the piston pump to reciprocate.

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