Double-head liquid injection pump

Abstract

The application provides a double-head liquid injection pump, which comprises a double-head motor, a shaft coupling assembly connected with the output shaft of the double-head motor, and a pump head assembly connected with the shaft coupling assembly; the pump head assembly is a piston pump; the output shaft of the double-head motor is connected with the shaft coupling assembly through a key groove gap; the shaft coupling assembly is connected with the pump head assembly through a universal ball head connecting rod; the shaft center of the output shaft of the double-head motor and the shaft coupling assembly is distributed in a straight line; the shaft center of the pump head assembly and the shaft center of the shaft coupling assembly are distributed at a certain angle; the double-head motor drives the shaft coupling assembly to rotate; and the shaft coupling assembly drives the piston of the piston pump to reciprocate through the universal ball head connecting rod. The double-head liquid injection pump has the advantages of compact structure, safety and reliability, and can improve the liquid injection precision. When the double-head liquid injection pump is applied to the electrolyte injection of the lithium battery industry, the electrolyte injection precision and efficiency can be improved, the injection amount can be adjusted, and the service life of the driving motor can be prolonged.

Description

Technical Field

[0001] The present invention relates to the field of mechanical automation technology, in particular to a double-head liquid filling pump used in liquid filling industries such as battery filling, liquid medicine filling, oral liquid filling, etc. Background Art

[0002] With the continuous development of society and the continuous advancement of science and technology, the application of mechanical automation production is becoming more and more extensive. Double-head injection pumps are used in the perfusion equipment of many industries such as battery production, pharmaceutical production, biological reagents, and chemical industry.

[0003] A double-head injection pump generally consists of three main components: a drive motor, a transmission connection assembly, and a hydraulic end. Common double-head injection pumps include vane pumps, piston pumps, diaphragm pumps, gear pumps, and screw pumps. In battery and pharmaceutical production, where high-precision injection processes are required, piston-type double-head injection pumps are often used.

[0004] Existing piston double-head injection pumps usually have the following disadvantages:

[0005] 1. During the reciprocating motion, the piston at the hydraulic end will exert an axial reaction force on the drive motor through the transmission connection assembly, which will reduce the service life of the drive motor.

[0006] Second, the hydraulic end piston has an axial reaction force on the drive motor, which may usually cause the drive motor to jump. In turn, the jumping of the drive motor will cause the hydraulic end piston stroke to be inaccurate, which in turn causes errors in the hydraulic end injection and inaccurate injection.

[0007] 3. During the injection process, the piston stroke needs to be adjusted according to the injection volume of different specifications; the existing adjustment methods are either inconvenient to adjust or have insufficient adjustment accuracy.

[0008] If a double-head liquid injection pump can be developed in which the hydraulic load end does not exert axial reaction force on the driving motor, and can ensure the accuracy of the axial stroke of the piston of the hydraulic end of the double-head liquid injection pump, and is not affected by inaccurate injection caused by problems such as the driving motor vibration, it will have great market value. Summary of the Invention

[0009] To address the problems of the prior art, the present invention provides a compact, safe, and reliable dual-head injection pump that improves injection accuracy and efficiency. When applied to electrolyte injection in the lithium battery industry, the dual-head injection pump improves electrolyte injection accuracy and extends the service life of the drive motor.

[0010] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a double-headed liquid injection pump, comprising a double-headed motor, a coupling assembly connected to the output shaft of the double-headed motor, and a pump head assembly connected to the coupling assembly; the output shaft of the double-headed motor is symmetrically distributed; the pump head assembly is a piston pump; the output shaft of the double-headed motor and the coupling assembly are connected by a keyway clearance; the coupling assembly and the pump head assembly are connected by a universal ball joint connecting rod; the output shaft of the double-headed motor and the axis of the coupling assembly are colinearly distributed; the axis of the pump head assembly and the axis of the coupling assembly are distributed at a certain angle; the double-headed motor drives the coupling assembly to rotate; the coupling assembly drives the piston of the piston pump to reciprocate through the universal ball joint connecting rod.

[0011] According to the preferred technical solution, the coupling assembly includes a stepped shaft that is overall "T"-shaped, a coupling bearing sleeved on the stepped shaft (the coupling bearing can adopt a variety of 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 double-headed motor through a keyway fitting clearance; 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] According to a preferred technical solution, the coupling assembly further includes an annular first locking member and an annular second locking member, wherein the first locking member is fixedly connected to the coupling fixing seat and abuts against the outer ring of the coupling bearing, thereby limiting the outer ring of the coupling bearing from moving in the axial direction; the second locking member is fixedly connected to the stepped shaft and abuts against the inner ring of the coupling bearing, thereby limiting the inner ring of the coupling bearing from moving in the axial direction.

[0013] The preferred technical solution is that the annular first locking piece is provided with an external thread, and the annular second locking piece is provided with an internal thread; the stepped shaft has an outer flange protruding outward, and the smaller end of the stepped shaft is also provided with an external thread that cooperates with the internal thread of the second locking piece; one end of the coupling fixing seat has an inner flange protruding inward, and the other end of the coupling fixing seat has an internal thread that cooperates with the external thread of the first locking piece; one end of the inner ring of the coupling bearing is abutted against the outer flange of the stepped shaft, and the other end of the inner ring of the coupling bearing is abutted against the second locking piece; one end of the outer ring of the coupling bearing is abutted against the inner flange of the coupling fixing seat, and the other end of the outer ring of the coupling bearing is abutted against the first locking piece.

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

[0015] According to the preferred technical solution, the universal ball joint connecting rod includes a universal ball and a connecting rod that can be inserted into the universal ball and moved; the universal ball of the universal ball joint connecting rod can be steered and embedded in the piston of the piston pump, one end of the connecting rod of the universal ball joint 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 double-headed motor rotates to drive the coupling assembly to rotate, driving the connecting rod of the universal ball joint connecting rod to move in the universal ball, driving the piston of the piston pump to perform reciprocating motion.

[0016] According to the preferred technical solution, the universal ball joint connecting rod includes a universal ball and a connecting rod that can be inserted into the universal ball and moved; the universal ball of the universal ball joint connecting rod is rotatably embedded in the stepped shaft of the coupling assembly, one end of the connecting rod of the universal ball joint 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 double-headed motor drives the stepped shaft of the coupling assembly to rotate, drives the connecting rod to move in the universal ball, and drives the piston of the piston pump to perform reciprocating motion.

[0017] According to the preferred technical solution, the double-head liquid injection pump also 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 the installation angle of the pump head assembly is adjusted by driving the rotating plate assembly to rotate.

[0018] According to a 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 mounted 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 which can be 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 which is that the connecting 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 plate of the rotating plate, and the double-ear plate of the rotating plate is connected to the single-ear plate of the sliding fork shaft by a pin.

[0019] In a preferred technical solution, a rotating plate is provided on the base; the rotating plate is rotatably mounted on the base via a pin and has an internally threaded through-hole. The internally threaded through-hole of the rotating plate engages with the threads of the larger threaded section of the differential bolt. A spring is also sleeved on the sliding fork shaft and the differential bolt. This spring prevents the differential bolt from slipping and loosening. Using a rotating plate to bridge the direct connection between the differential bolt and the base prevents the differential bolt from getting stuck during angle adjustment, significantly increasing the adjustment angle. Specifically, the rotating plate can rotate a certain angle as the differential bolt advances, allowing the differential bolt to adapt to potential sticking caused by the rotating plate's angular changes.

[0020] The threaded connection between the yoke shaft and the differential bolt can be: the yoke shaft has external threads, while the smaller threaded section of the differential bolt has internal threads. This can be achieved by providing an axial blind hole at the end of the differential bolt connected to the yoke shaft, and then tapping an internal thread into the blind hole that mates with the external thread on the yoke shaft. Alternatively, the yoke shaft can have internal threads, while the smaller threaded section of the differential bolt has external threads. This can be achieved by providing an axial blind hole at the end of the yoke shaft connected to the differential bolt, and then tapping an internal thread into the blind hole of the yoke shaft to mate the internal thread of the yoke shaft with the smaller threaded section of the differential bolt.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The dual-headed liquid injection pump's dual-headed motor and coupling assembly are connected by a keyway with a clearance fit. Therefore, there is no axial force transmission between the dual-headed motor and the coupling assembly, only radial rotational force transmission. At the same time, the axis distribution between the coupling assembly and the pump head assembly has a certain angle, and the coupling assembly and the pump head assembly are connected by a universal connecting rod. Due to the certain angle between the axis centers and the universal connecting rod connection, the rotational motion transmitted by the dual-headed motor received by the coupling assembly can be converted into the reciprocating motion of the piston of the pump head assembly's piston pump. The entire mechanism operates reliably, without axial force transmission, which helps to increase the service life of the dual-headed motor.

[0023] 2. The coupling assembly of the dual-head injection pump of the present invention utilizes a stepped shaft in the overall "T" shape, and the coupling bearing, coupling holder, first locking member, and second locking member cooperate with each other, so that the coupling blocks the axial reaction force at the load end of the pump head assembly. By independently limiting 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 isolated, so that the axial force is not transmitted to the dual-head motor, which is beneficial to improving the service life of the dual-head motor. At the same time, because the outer flange on the stepped shaft and the second locking member limit the axial movement of the inner ring of the coupling bearing, the inner flange of the coupling holder and the first locking member limit the axial movement of the outer ring of the coupling bearing. At the same time, the force on the outer ring of the coupling is transmitted to the coupling holder via the set screw, thereby no longer transmitting axial force to the driving end of the dual-head motor. Moreover, the axial movement of the inner and outer rings of the coupling bearings is independently limited by separate structures, which is also conducive to the stable and reliable output power of the coupling assembly, especially the safe and reliable axial output, thereby making the reciprocating motion of the piston of the pump head assembly accurate and reliable, so that the injection of the double-head injection pump is more accurate.

[0024] 3. The pump head assembly of the dual-head infusion pump of the present invention is rotatably fixed to the base and is equipped with an angle adjustment assembly, allowing the angle between the pump head assembly and the axis of the coupling assembly to be adjusted. This in turn allows the piston of the pump head assembly to be adjusted during reciprocating motion, thereby achieving the purpose of adjusting the injection volume of the dual-head infusion pump.

[0025] 4. The angle adjustment component adopts a structure in which a differential bolt and a sliding fork shaft cooperate with each other, which can achieve precise adjustment of the rotation angle of the rotating component.

[0026] 5. The present invention adopts a double-head motor with two output shafts and two pump head assemblies. Under the same conditions, compared with a single-head motor and a single-head injection pump, the double-head injection pump of the present invention has a faster injection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the three-dimensional structure of the double-head liquid injection pump of the present invention.

[0028] Figure 2 This is a front view structural diagram of the double-head liquid injection pump of the present invention.

[0029] Figure 3 This is a schematic top view of the double-head liquid injection pump of the present invention.

[0030] Figure 4 It is a right side structural schematic diagram of the double-head liquid injection pump of the present invention.

[0031] Figure 5 It is a schematic diagram of the three-dimensional structure of the coupling assembly.

[0032] Figure 6 It is a schematic diagram of the front view of the coupling assembly.

[0033] Figure 7 Schematic diagram of the cross-sectional structure of the coupling assembly.

[0034] Figure 8 Schematic diagram of the top view of the coupling assembly.

[0035] Figure 9 Schematic diagram of the three-dimensional structure of the stepped shaft.

[0036] Figure 10 This is a schematic diagram of the front view structure of the stepped shaft.

[0037] Figure 11 This is a schematic diagram of the right view structure of the stepped shaft.

[0038] Figure 12 Schematic diagram of the top view of the stepped shaft.

[0039] Figure 13 It is a schematic diagram of the front view structure of the coupling fixed seat.

[0040] Figure 14 It is a schematic diagram of the right side structure of the coupling fixed seat.

[0041] Figure 15 for Figure 14 Schematic diagram of the cross-sectional structure along the AA direction.

[0042] Figure 16 It is a three-dimensional schematic diagram of the connection structure between the base, rotating plate assembly, and angle adjustment assembly.

[0043] Figure 17 This is a front view schematic diagram of the connection structure between the base, rotating plate assembly, and angle adjustment assembly.

[0044] Figure 18 This is a left-side schematic diagram of the connection structure between the base, rotating plate assembly, and angle adjustment assembly.

[0045] Figure 19 This is a right view schematic diagram of the connection structure between the base, rotating plate assembly, and angle adjustment assembly.

[0046] Figure 20 It is a three-dimensional schematic diagram of the connection structure between the rotating plate assembly and the sliding fork shaft.

[0047] Figure 21 It is a three-dimensional schematic diagram of the connection structure between the rotating plate, sliding fork shaft and differential bolt.

[0048] Figure 22 Schematic diagram of the structure of the differential bolt.

[0049] Figure 23 It is a structural diagram of the sliding fork shaft.

[0050] Figure 24 Schematic diagram of the connection structure between the differential bolt and the sliding fork shaft.

[0051] Figure 25 It is a schematic diagram of the three-dimensional structure of the universal ball joint connecting rod.

[0052] The following are marked in the figure:

[0053] 1-Double-head motor; 2-Coupling assembly; 21-Stepped shaft; 211-Outer flange; 22-Coupling bearing; 23-Coupling fixing seat; 231-Inner flange; 232-Threaded hole; 24-First locking piece; 25-Second locking piece; 26-Set screw; 3-Pump head assembly; 4-Universal ball joint 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 segment; 712-Larger threaded segment; 713-Spring; 72-Sliding fork shaft; 721-Single ear plate. DETAILED DESCRIPTION

[0054] Reference Figures 1 to 25 An embodiment of a double-head liquid injection pump of the present invention is further described.

[0055] A double-head liquid injection pump comprises a double-head motor 1, a coupling assembly 2 connected to the output shaft of the double-head motor 1, and a pump head assembly 3 connected to the coupling assembly 2; the output shaft of the double-head motor 1 is symmetrically distributed, and the pump head assembly 3 is also symmetrically distributed; the pump head assembly 3 is a piston pump; the output shaft of the double-head motor 1 is connected to the coupling assembly 2 through a keyway clearance; the coupling assembly 2 and the pump head assembly 3 are connected through a universal ball joint 4; the output shaft of the double-head motor 1 and the axis of the coupling assembly 2 are colinearly distributed; the axis of the pump head assembly 3 and the axis of the coupling assembly 2 are distributed at a certain angle; the double-head motor 1 drives the coupling assembly 2 to perform rotational motion; the coupling assembly 2 drives the piston of the piston pump 3 to perform reciprocating motion through the universal ball joint 4.

[0056] The coupling assembly 2 includes a stepped shaft 21 in a T-shape, a coupling bearing 22 sleeved on the stepped shaft 21 (the coupling bearing can be a variety of conventional bearings, such as deep groove ball bearings), and a coupling fixing seat 23; the larger end of the stepped shaft is connected to the piston of the piston pump 3 via a universal ball joint connecting rod 4;

[0057] The universal ball joint connecting rod 4 includes a universal ball 41 and a connecting rod 42 that can be inserted and moved within the universal ball 41. In this embodiment, the universal ball 41 of the universal ball joint connecting rod 4 is rotatably embedded in the piston of the piston pump 3. One end of the connecting rod 42 of the universal ball joint connecting rod 4 is fixed to 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 rotation of the double-headed motor 1 drives the coupling assembly 2 to rotate, driving the connecting rod 42 of the universal ball joint connecting rod 4 to move within the universal ball 41, driving the piston of the piston pump 3 to reciprocate. Of course, in other embodiments, the universal ball 41 of the universal ball joint connecting rod 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 joint connecting rod 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 double-headed motor 1 drives the stepped shaft 21 of the coupling assembly 2 to rotate, drives the connecting rod 42 to slide in the universal ball 41, and drives the piston of the piston pump 3 to reciprocate.

[0058] The smaller end of the stepped shaft 21 is connected to the output shaft of the double-headed motor 1 through a keyway clearance; 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.

[0059] The coupling assembly 2 also 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, limiting the outer ring of the coupling bearing 22 from moving in the axial direction; the second locking member 25 is fixedly connected to the stepped shaft 21 and abuts against the inner ring of the coupling bearing 22, limiting the inner ring of the coupling bearing 22 from moving in the axial direction.

[0060] The annular first locking piece 24 is provided with an external thread, and the annular second locking piece 25 is provided with an internal thread; the stepped shaft 21 has an outwardly protruding outer flange 211, and the smaller end of the stepped shaft 21 is also provided with an external thread that cooperates with the internal thread of the second locking piece 25; one end of the coupling fixing seat 23 has an inwardly protruding inner flange 231, and the other end of the coupling fixing seat 23 is provided with an internal thread that cooperates with the external thread of the first locking piece 24; one end of the inner ring of the coupling bearing 22 is abutted against the outer flange 211 of the stepped shaft 21, and the other end of the inner ring of the coupling bearing 22 is abutted against the second locking piece 25; one end of the outer ring of the coupling bearing 22 is abutted against the inner flange 231 of the coupling fixing seat 23, and the other end of the outer ring of the coupling bearing 22 is abutted against the first locking piece 24. In a preferred embodiment, the inner diameter of the first locking member 24 is larger 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 .

[0061] The coupling fixing seat 23 further has a threaded hole 232 , which is threadedly engaged with the threaded hole 232 by a set screw 26 , and the set screw 26 abuts against the first locking member 24 , thereby limiting the movement of the first locking member 24 relative to the coupling fixing seat 23 .

[0062] The double-head injection pump also 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 the installation angle of the pump head assembly 3 is adjusted by driving the rotating plate assembly 6 to rotate.

[0063] 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 vary, and one embodiment of the sliding fork shaft 72 can have a single ear plate 721 at one end and threads at the other end. The connection method between the rotating plate 61 and the sliding fork shaft 72 can also be diverse. One of them is that the connecting end of the rotating plate 61 and the sliding fork shaft 72 is a double-ear plate 611 structure, and 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 through a pin shaft.

[0064] The base 5 is provided with a rotating plate 51, which is rotatably mounted on the base 5 via a pin and has an internally threaded through-hole. The internally threaded through-hole of the rotating plate 51 engages 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 prevents the differential bolt 71 from slipping or loosening. Using the rotating plate 51 to bridge the direct connection between the differential bolt 71 and the base 5 prevents the differential bolt 71 from getting stuck during angle adjustment, significantly increasing the adjustable angle. Specifically, the rotating plate 51 can rotate a certain angle as the differential bolt 71 advances, allowing the differential bolt 71 to adapt to potential sticking caused by the rotating plate's angular changes.

[0065] The threaded connection between the sliding fork shaft 72 and the differential bolt 71 can be: if the sliding fork shaft 72 is externally threaded, the smaller threaded section 711 of the differential bolt 71 is internally threaded. Specifically, an axial blind hole can be formed at the end of the differential bolt 71 connected to the sliding fork shaft 72, and then an internal thread can be tapped into the blind hole to mate with the external thread on the sliding fork shaft 72. Alternatively, the sliding fork shaft 72 can be internally threaded, and the smaller threaded section 711 of the differential bolt 71 can be externally threaded. Specifically, an axial blind hole can be formed at the end of the sliding fork shaft 72 connected to the differential bolt 71, and an internal thread can be tapped into the blind hole of the sliding fork shaft 72 to mate the internal thread of the sliding fork shaft 72 with the smaller thread section 711 of the differential bolt 71.

[0066] The double-head liquid injection pump of the present invention works as follows:

[0067] The dual-headed liquid injection pump utilizes a keyway connection with a clearance fit between the dual-headed motor and the coupling assembly. Therefore, no axial force is transmitted between the dual-headed motor and the coupling assembly, only radial rotational force is transmitted. Furthermore, the axis centers of the coupling assembly and the pump head assembly are arranged at a predetermined angle, and the coupling assembly and the pump head assembly are connected by a universal connecting rod. Due to the predetermined angle between the axis centers and the universal connecting rod connection, the rotational motion transmitted by the dual-headed motor received by the coupling assembly is converted into reciprocating motion of the piston pump of the pump head assembly. The coupling assembly of the dual-headed liquid injection pump of the present invention utilizes a stepped shaft shaped like a T, a coupling bearing, a coupling mount, a first locking member, and a second locking member. This allows the coupling to block the axial reaction force at the load end of the pump head assembly. By independently limiting the axial movement of the inner and outer rings of the coupling bearing, the coupling assembly isolates the axial force transmitted from the load end of the coupling assembly, preventing this axial force from being transmitted to the dual-headed motor, thereby improving the service life of the dual-headed motor. At the same time, the outer flange of the stepped shaft and the second locking member restrict axial movement of the inner ring of the coupling bearing, while the inner flange of the coupling holder and the first locking member restrict axial movement of the outer ring of the coupling bearing. The force on the outer ring of the coupling is transmitted to the coupling holder via the set screw, thereby preventing axial force from being transmitted to the driving end of the dual-head motor. Furthermore, by independently restricting the axial movement of the inner and outer rings of the coupling bearing through separate structures, the output power of the coupling assembly is stable and reliable, especially its axial output is safe and reliable, thereby ensuring precise and reliable reciprocating motion of the piston of the pump head assembly, thereby achieving more accurate injection of the dual-head injection pump. The pump head assembly of the dual-head injection pump of the present invention is rotatably fixed to the base and is equipped with an angle adjustment assembly. When different injection volumes are required, the stroke of the piston pump of the pump head assembly during reciprocating motion can be changed by simply adjusting the angle between the pump head assembly and the axis of the coupling assembly, thereby achieving the purpose of adjustable injection volume of the dual-head injection pump. The angle adjustment component adopts a structure in which a differential bolt and a sliding fork shaft cooperate with each other, which can achieve precise adjustment of the rotation angle of the rotating component.

[0068] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A double-head injection pump, characterized in that: It comprises a double-headed motor, a coupling assembly connected to the output shaft of the double-headed motor, and a pump head assembly connected to the coupling assembly; the output shaft of the double-headed motor is symmetrically distributed; the pump head assembly is a piston pump; the output shaft of the double-headed motor and the coupling assembly are connected through a keyway clearance; the coupling assembly and the pump head assembly are connected through a universal ball joint connecting rod; the output shaft of the double-headed motor and the axis of the coupling assembly are colinearly distributed; the axis of the pump head assembly and the axis of the coupling assembly are distributed at a certain angle; the double-headed motor drives the coupling assembly to rotate; the coupling assembly drives the piston of the piston pump to reciprocate through the universal ball joint connecting rod; It also 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 the installation angle of the pump head assembly is adjusted 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 mounted on the rotating plate, and the rotating shaft rotatably mounts the rotating plate on the base; the differential bolt has a smaller thread section and a larger thread 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 thread section of the differential bolt; the larger thread section of the differential bolt is threadedly connected to the base; 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 has an internal threaded through hole; the internal threaded through hole of the rotating plate cooperates with the thread of the larger threaded section of the differential bolt; a spring is also sleeved on the sliding fork shaft and the differential bolt.

2. A double-head liquid injection pump according to claim 1, characterized in that: The coupling assembly includes a stepped shaft that is overall "T"-shaped, 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 joint connecting rod; the smaller end of the stepped shaft is connected to the output shaft of the double-headed motor through a keyway fitting clearance; 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. A double-head liquid injection pump according to claim 2, characterized in that: The coupling assembly also 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, limiting the outer ring of the coupling bearing from moving in the axial direction; the second locking member is fixedly connected to the stepped shaft and abuts against the inner ring of the coupling bearing, limiting the inner ring of the coupling bearing from moving in the axial direction.

4. A double-head liquid injection pump according to claim 3, characterized in that: The annular first locking piece is provided with an external thread, and the annular second locking piece is provided with an internal thread; the stepped shaft has an external flange protruding outward, and the smaller end of the stepped shaft is also provided with an external thread that cooperates with the internal thread of the second locking piece; one end of the coupling fixing seat has an internal flange protruding inward, and the other end of the coupling fixing seat has an internal thread that cooperates with the external thread of the first locking piece; one end of the inner ring of the coupling bearing is abutted against the outer flange of the stepped shaft, and the other end of the inner ring of the coupling bearing is abutted against the second locking piece; one end of the outer ring of the coupling bearing is abutted against the inner flange of the coupling fixing seat, and the other end of the outer ring of the coupling bearing is abutted against the first locking piece.

5. A double-head liquid injection pump according to claim 4, characterized in that: The coupling fixing seat is also provided with a threaded hole, which is threadedly matched with the threaded hole by a set screw, and the set screw abuts against the first locking member to limit the movement of the first locking member relative to the coupling fixing seat.

6. The double-head liquid injection pump according to claim 1, characterized in that: The universal ball joint connecting rod includes a universal ball and a connecting rod that can be inserted into the universal ball and moved; the universal ball of the universal ball joint connecting rod can be steered and embedded in the piston of the piston pump, one end of the connecting rod of the universal ball joint 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 double-headed motor rotates to drive the coupling assembly to rotate, driving the connecting rod of the universal ball joint connecting rod to move in the universal ball, driving the piston of the piston pump to perform reciprocating motion.

7. A double-head liquid injection pump according to claim 2, characterized in that: The universal ball joint connecting rod includes a universal ball and a connecting rod that can be inserted into the universal ball and moved; the universal ball of the universal ball joint connecting rod can be steered and embedded in the stepped shaft of the coupling assembly, one end of the connecting rod of the universal ball joint 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 double-headed motor drives the stepped shaft of the coupling assembly to rotate, drives the connecting rod to move in the universal ball, and drives the piston of the piston pump to perform reciprocating motion.

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