Balanced low-vibration reciprocating pump

Abstract

The invention relates to the field of reciprocating pumps, in particular to a balanced low-vibration reciprocating pump which comprises plunger assemblies which are arranged in a transmission case and arranged around the rotation axis of a cam in a circumferential array mode, one end of a plunger of each plunger assembly is in transmission with the cam, and the other end of the plunger linearly moves in a reciprocating mode in the corresponding fluid end to convey media. An included angle is formed between the arrangement direction of each plunger and the radial direction of the transmission case; a plunger roller is installed at the end, matched with the cam, of the plunger, the rotation axis of the plunger roller is parallel to a cam shaft of the cam, an elastic assembly is arranged in the transmission box in the axial direction of the plunger, the elastic assembly exerts elastic force towards the direction of the cam on the plunger, and the plunger roller abuts against the wheel face of the cam to form rolling type contact. The working noise of the reciprocating pump is greatly reduced.

Description

Technical Field

[0001] The invention relates to the field of reciprocating pumps, in particular to a balanced low-vibration reciprocating pump. Background Art

[0002] A reciprocating pump is a positive displacement pump that transports liquids through the reciprocating motion of a piston or plunger. It is widely used in the fields of petroleum, chemical industry, electric power, metallurgy, etc. During the suction stroke of a reciprocating pump, the plunger moves backward, increasing the volume of the cavity in the hydraulic end, creating negative pressure, and the medium is drawn into the hydraulic end through the suction valve. During the discharge stroke of a reciprocating pump, the piston moves forward, decreasing the volume of the cavity in the hydraulic end, increasing pressure, and forcing the liquid out through the discharge valve. This reciprocating switching between the suction and discharge strokes achieves the transport of the medium.

[0003] The reciprocating linear drive mechanism of the piston or plunger in the existing reciprocating pump, as described in the publication number "CN117108471A", adopts a crank-connecting rod transmission mechanism, in which the crank-connecting rod drives the plunger or piston to move back and forth in a straight line. During this working process, the connecting rod and crosshead and other components of the crank-connecting rod transmission mechanism periodically move to generate unbalanced force, which will cause flow pulsation and generate large noise. It cannot meet the design requirements of the medium conveying system and therefore needs to be solved urgently. Summary of the Invention

[0004] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a balanced low-vibration reciprocating pump, which significantly reduces the operating noise of the reciprocating pump.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A balanced, low-vibration reciprocating pump comprises plunger assemblies arranged in a circular array around the axis of rotation of a cam within a transmission housing. One end of each plunger assembly is engaged with the cam, while the other end reciprocates linearly within the corresponding hydraulic end to convey a medium. The arrangement direction of each plunger forms an angle with the radial direction of the transmission housing.

[0007] The matching ends of the plunger and the cam are equipped with plunger rollers. The rotation axis of the plunger roller is arranged parallel to the camshaft of the cam. An elastic component is arranged along the axial direction of the plunger in the transmission box. The elastic component applies an elastic force to the plunger toward the cam direction. The plunger roller abuts against the wheel surface of the cam to form rolling contact.

[0008] As a further solution of the present invention: the base circle radius of the cam is r0:

[0009]

[0010] α=D / s0;

[0011]

[0012] β=b / s0;

[0013] Where: P is the medium discharge pressure at the hydraulic end;

[0014] α is the cam's diameter ratio coefficient;

[0015] Q is the pump flow rate;

[0016] z is the number of pump heads;

[0017] η0 is the dynamic viscosity of the lubricating oil of the cam;

[0018] n is the cam speed;

[0019] β is the width-to-path ratio of the cam;

[0020] s0 is the stroke length of the plunger;

[0021] D is the cross-sectional diameter of the plunger;

[0022] b is the load-bearing width of the contact area of ​​the cam.

[0023] As a further solution of the present invention: a plane rectangular coordinate system is established with the center of the cam as the coordinate origin, and a line connecting the base circle of the cam and the intersection of the cam is used as the Y axis of the plane rectangular coordinate system. The contour curve of the cam in the second quadrant and the contour curve in the first quadrant of the plane rectangular coordinate system are arranged symmetrically about the Y axis, the contour curve of the cam in the second quadrant and the contour curve in the third quadrant of the plane rectangular coordinate system are arranged symmetrically about the X axis, and the contour curve of the cam in the first quadrant and the contour curve in the fourth quadrant of the plane rectangular coordinate system are arranged symmetrically about the X axis.

[0024] Along the direction away from the Y axis, the profile curve of the cam in the second quadrant of the plane rectangular coordinate system includes a first curve, a second curve and a third curve connected in sequence;

[0025] The polar coordinate equation of the first curve is:

[0026]

[0027] The polar coordinate equation of the second curve is:

[0028]

[0029] The polar coordinate equation of the third curve is:

[0030]

[0031] Where: r is the radius of the plunger roller;

[0032] δ is the rotation angle of the cam;

[0033] θ is the pressure angle of the cam;

[0034] s is the lift of the cam.

[0035] As a further solution of the present invention: the motor shaft of the driving motor drives the cam to rotate through the reducer, the driving motor is connected and fixed to the transmission box through the support flange, and a damping block with a buffering effect is provided between the support flange and the transmission box.

[0036] As a further solution of the present invention: the transmission box has an axial opening for the cam to pass through, and bearings are provided on the shoulders at both ends of the camshaft. The camshaft rotates with the transmission box through the bearings, and the two bearings are tightened and fixed by bearing covers. One group of bearing covers has an axial opening for the rotating power source to pass through and then connect with the camshaft.

[0037] As a further solution of the present invention: a medium channel is opened in the hydraulic end along the direction perpendicular to the plunger, the end of the plunger is inserted into the medium channel and moves back and forth in a straight line; one-way valves are installed at intervals in the medium channel along the direction of medium flow, and a liquid inlet and a liquid outlet are provided on the transmission box so as to be connected to the inlet and outlet of the medium channel respectively.

[0038] As a further solution of the present invention: a roller groove is formed at one end of the plunger adjacent to the cam, the plunger pin is installed in the roller groove and rotates with the plunger, and the plunger roller and the plunger pin are coaxially fixed.

[0039] As a further solution of the present invention: the plunger assembly includes a plunger sleeve and a plunger coaxially slidably arranged in the plunger sleeve, the plunger sleeve is radially provided with an installation step, the plunger is a two-stage stepped columnar structure, the plunger roller is arranged in the large diameter section of the plunger, the small diameter section of the plunger is inserted into the hydraulic end, the elastic component is a return spring sleeved on the outer ring of the plunger, and the two ends of the return spring are respectively in contact with the large diameter section of the plunger and the installation step.

[0040] As a further solution of the present invention: a sealing assembly is provided between the mounting step of the plunger and the hydraulic end, the sealing assembly includes a spring seat coaxially sleeved on the plunger and arranged symmetrically on the left and right, a sealing spring is provided between the two spring seats, and the spring seat, packing seal and guide sleeve are arranged in sequence in the direction away from the sealing spring, one group of guide sleeves abuts the mounting step, and the other group of guide sleeves abuts the hydraulic end.

[0041] As a further solution of the present invention, a reflux hole located between the two spring seats is opened on the plunger sleeve, and the reflux hole is communicated with the liquid inlet of the transmission box.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. In the present invention, the medium entering the hydraulic end of the reciprocating pump passes through the hydraulic end using the positive and negative pressure differences formed by the reciprocating linear motion of the plunger as the driving force. The cam is used as the power source. The cam and the roller at the end of the plunger contact each other after abutment, thereby converting the rotational motion of the cam into the linear motion of the plunger. This greatly reduces the operating noise of the plunger reciprocating pump. By setting the plunger offset, the friction force is reduced, and the service life of the plunger and cam is increased.

[0044] 2. The present invention can obtain the minimum base circle radius of the cam to meet the cam force through calculation, providing technical support for the design of reciprocating pumps; and by designing the cam profile curve, the operating noise of the pump is minimized.

[0045] 3. The cam of the present invention is symmetrically designed, so that the movement states of the symmetrical plungers in the pump body are exactly the same and the movement directions are opposite, so that the movement inertia force of the plunger is balanced; the plunger seal adopts a spring pre-tightening design, so that the pre-tightening force of the seal is controlled, and the friction force between the plunger seal and the plunger is consistently controlled to avoid the generation of unbalanced force.

[0046] 4. The present invention sets up a double-stage sealing structure, and the middle spring pre-tightening space also serves as a lubrication chamber. The high-pressure sealing auxiliary medium will leak into the lubrication chamber, which has the function of lubricating and cooling the plunger. At the same time, the excess leakage medium returns to the liquid inlet of the transmission box through the reflux hole to avoid leakage to the outside; under the action of the sealing spring, the packing seal can always maintain the abutment state of the sealing surface under the action of the elastic force, maintaining a long-life continuous sealing function. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a structural schematic diagram of the present invention.

[0048] Figure 2 It is a schematic diagram of the cooperation relationship between the plunger assembly and the cam in the present invention.

[0049] Figure 3 It is a structural schematic diagram of the plunger assembly in the present invention.

[0050] Figure 4 for Figure 2 sectional view of .

[0051] Figure 5 Schematic diagram of the profile curve of the cam in the present invention.

[0052] Figure 6 This is a flow curve simulation diagram of the present invention.

[0053] In the picture:

[0054] 1. Transmission box; 11. Installation cavity; 12. Liquid inlet; 13. Liquid outlet;

[0055] 2. Plunger assembly; 21. Plunger sleeve; 211. Installation step;

[0056] 22. Plunger; 221. Plunger pin; 222. Plunger roller;

[0057] 23. Sealing assembly; 231. Spring seat; 232. Sealing spring;

[0058] 233. Packing seal; 234. Guide sleeve;

[0059] 24. Reflux hole; 25. Return spring;

[0060] 3. Cam; 31. Camshaft; 32. Bearing; 33. Bearing gland;

[0061] 4. Hydraulic end; 41. Medium channel; 42. One-way valve;

[0062] 5. Drive motor; 51. Support flange; 52. Damping block; 53. Reducer;

[0063] 6. Medium inlet pipe. DETAILED DESCRIPTION

[0064] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0065] See also Figures 1 to 4 In an embodiment of the present invention, a balanced, low-vibration reciprocating pump includes a transmission case 1 and a drive motor 5. The motor shaft of the drive motor 5 is coaxially fixed to the camshaft 31 of the cam 3 via a reducer 53 to drive the cam 3 to rotate. The motor housing of the drive motor 5 is connected and fixed to the housing of the transmission case 1 via a support flange 51. A damping block 52 is disposed within the flange hole of the support flange 51 to provide a cushioning effect.

[0066] The camshaft 31 of cam 3 is coaxially arranged with the transmission case 1. The housing of the transmission case 1 has an axial opening for the cam 3 to be inserted. Bearings 32 are provided at the openings on either side of the transmission case 1. The outer rings of the two bearings 32 abut against the transmission case 1, while the inner rings of the two bearings 32 abut against the shoulders of the camshaft 31. The camshaft 31 is clamped and positioned by the two bearings 32, thereby rotating in conjunction with the transmission case 1. After the cam 3 is installed, the openings on both sides of the transmission case 1 are tightened and positioned by bearing glands 33. One set of bearing glands 33 has an axial opening to allow the reducer to connect to the camshaft 31.

[0067] The transmission case 1 is provided with mounting cavities 11 arranged in a circumferential array around the camshaft 31. A plunger assembly 2 is installed in each mounting cavity 11. There are two arrangements of the mounting cavities 11:

[0068] In the first arrangement, the mounting cavity 11 is arranged radially along the camshaft 31 .

[0069] In the second arrangement, the mounting cavities 11 are arranged at an angle to the radial direction of the camshaft 31, forming an offset arrangement. As the cam 3 rotates counterclockwise, each mounting cavity 11 rotates clockwise around the direction away from the camshaft 31 as a base point, and then becomes offset.

[0070] The transmission case 1 is circumferentially arranged with a hydraulic end 4 for medium passage. This hydraulic end 4 includes a medium channel 41 arranged parallel to the camshaft 31. Check valves 42 are interspersed within the channel 41 to ensure one-way flow of the medium. The media channel 41 has a medium inlet and outlet at its ends, respectively. The center of the hydraulic end 4 has an opening for the plunger 22. The transmission case 1 is equipped with a corresponding number of liquid inlets 12 and outlets 13, corresponding to the number of liquid ends 4. The medium in the inlet pipe is evenly distributed to each of the inlets 12 after being split.

[0071] The plunger assembly 2 includes a plunger sleeve 21 and a plunger 22 coaxially slidably disposed within the plunger sleeve 21. A roller groove is defined between the mating surface of the plunger 22 and the cam 3. A plunger pin 221 is mounted within the roller groove and rotatably engages with the plunger 22. A plunger roller 222 is coaxially fixed to the plunger pin 221. The plunger 22 abuts the wheel surface of the cam 3 via the plunger roller 222, thereby forming rolling contact. The axis of rotation of the plunger roller 222 is arranged parallel to the camshaft 31 of the cam 3.

[0072] The plunger 22 has a two-stage stepped columnar structure, with its diameter increasing as it moves away from the cam 3. The plunger roller 22 is located in the large-diameter section of the plunger 22, while the small-diameter section of the plunger 22 is used to mate with the hydraulic end 4. A return spring 25 is coaxially sleeved on the outer ring of the plunger 22. A mounting step 211 is radially provided on the inner ring of the plunger sleeve 21. The two ends of the return spring 25 abut the large-diameter section of the plunger 22 and the mounting step 211, respectively.

[0073] A sealing assembly 23 is provided between the mounting step 211 of the plunger 22 and the hydraulic end 4. This sealing assembly 23 includes a spring seat 231 coaxially sleeved on the plunger 22 and arranged symmetrically. A sealing spring 232 is provided between the two spring seats 231. The spring seat 231, packing seal 233, and guide sleeve 234 are arranged in sequence, moving away from the sealing spring 232. One set of guide sleeves 234 abuts the mounting step 211, while the other set of guide sleeves 234 abuts the hydraulic end 4. The packing seal 233 on the side adjacent to the cam 3 is a high-pressure seal, while the packing seal 233 on the side away from the cam 3 is a low-pressure seal. A reflux hole 24 is provided on the plunger sleeve 21, located between the two spring seats 231. The reflux hole 24 is connected to the corresponding liquid inlet 12 on the transmission case 1.

[0074] In order to satisfy the force of cam 3, the base circle radius r0 of cam 3 must meet the following conditions:

[0075]

[0076] α=D / s0;

[0077]

[0078] β=b / s0;

[0079] Where: P is the medium discharge pressure of the liquid end 4;

[0080] α is the diameter ratio coefficient of the cam 3; preferably it is 1.5 to 2.5.

[0081] Q is the pump flow rate;

[0082] z is the number of pump heads, preferably a symmetrical even number.

[0083] η0 is the dynamic viscosity of the lubricating oil of cam 3;

[0084] n is the rotation speed of the cam 3, preferably 100-400 rpm.

[0085] β is the width ratio of the cam 3 and is preferably 1.7 to 2.3.

[0086] s0 is the stroke length of the plunger 22;

[0087] D is the cross-sectional diameter of the plunger 22;

[0088] b is the load-bearing width of the contact area of ​​cam 3.

[0089] A plane rectangular coordinate system is established with the center of the cam 3 as the coordinate origin, and the line connecting the base circle of the cam 3 and the intersection of the cam 3 is used as the Y axis of the plane rectangular coordinate system. The contour curve of the cam 3 in the second quadrant and the contour curve in the first quadrant in the plane rectangular coordinate system are symmetrically arranged about the Y axis, the contour curve of the cam 3 in the second quadrant and the contour curve in the third quadrant in the plane rectangular coordinate system are symmetrically arranged about the X axis, and the contour curve of the cam 3 in the first quadrant and the contour curve in the fourth quadrant in the plane rectangular coordinate system are symmetrically arranged about the X axis.

[0090] Along the direction away from the Y-axis, the contour curve of the cam 3 in the second quadrant of the plane rectangular coordinate system includes a first curve, a second curve and a third curve connected in sequence; the angles between the end points of the first curve, the second curve and the third curve and the origin of the plane rectangular coordinate system are all thirty degrees.

[0091] The first curve corresponds to the sinusoidal acceleration process, and its polar coordinate equation is:

[0092]

[0093] The second curve corresponds to a uniform speed process, and its polar coordinate equation is:

[0094]

[0095] The third curve corresponds to the sinusoidal deceleration process, and its polar coordinate equation is:

[0096]

[0097] Wherein: r is the radius of the plunger roller 222, preferably 0.1r0~0.5r0.

[0098] δ is the rotation angle of cam 3;

[0099] θ is the pressure angle of cam 3;

[0100] s is the lift of cam 3.

[0101] Since the contour curves in the remaining quadrants are symmetrical to each other, the polar coordinate equations of the contour curves in the remaining quadrants are not described in detail.

[0102] Each stroke of the cam 3 pushing the plunger 22 adopts a three-stage curve to ensure that the plunger 22 has neither rigid impact nor flexible impact. The uniform speed process in the middle makes the plunger acceleration 0 within this range, further optimizing the vibration. The output flow of the pump is theoretically close to a straight line, which greatly reduces fluid impact and reduces the generation of flow-induced vibration.

[0103] The flow curve simulation of the reciprocating pump of this application is carried out, such as Figure 5As shown in the figure, with the passage of time on the horizontal axis, the maximum flow rate is 44.800494L / h, the minimum is 44.8L / h, and the average is 44.800157L / h. The pulsation rate of the reciprocating pump during the whole process does not exceed 0.0001%, and the pulsation rate is negligible. The flow-induced vibration caused by the fluid pulsation of the conventional plunger reciprocating pump is basically eliminated, and the vibration condition of the hydraulic end of the pump is greatly optimized.

[0104] In this embodiment, the flow rate requirement of the pump body is 40 L / h, the discharge pressure is 5.7 MPa, the diameter ratio coefficient a is 1.6, the number of pump heads is 6, and the rotation speed is 120 rpm.

[0105] Substituting in:

[0106]

[0107] Plunger diameter D = αs0 = 1.6 × 8 = 12.8 mm.

[0108] The contact area load width of the cam 3 is b=βs0=2×8=16 mm.

[0109] The lubricating oil used in the pump prototype is 85W-140GL-5 heavy-duty gear oil, with an operating temperature of about 40°C and a kinematic viscosity range of 315 (mm 2 / s)~<689(mm 2 / s), density is usually 850kg / m 3 , dynamic viscosity (Pa·s) and kinematic viscosity (m 2 / s) is:

[0110] Dynamic viscosity (Pa·s) = kinematic viscosity (m 2 / s)×density (kg / m 3 );

[0111] Calculation shows that the dynamic viscosity range of 85W-140GL-5 heavy-duty gear oil is 0.26 (Pa·s) to 0.58 (Pa·s). Taking 0.45 Pa·s, then:

[0112]

[0113] After the reciprocating pump of the present application is fixed, the vibration values ​​of its four footing points are shown in Table 1 below.

[0114] Table 1

[0115]

[0116] After the conventional crank-connecting rod driven plunger pump is fixed, the vibration values ​​of its four footing points are shown in Table 2 below.

[0117] Table 2

[0118]

[0119] As shown in Tables 1 and 2, the vibration acceleration value of the conventional crank-connecting rod driven plunger pump in the low frequency range (10Hz-315Hz) is 13.6 times that of the present invention, and the vibration acceleration value in the full frequency range (10Hz-8000Hz) is 57.9 times that of the present invention. The present invention has a significant vibration reduction effect.

[0120] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0121] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

Claims

1. A balanced low-vibration reciprocating pump, characterized in that: The invention comprises plunger assemblies (2) arranged in a circumferential array around the rotation axis of a cam (3) in a transmission case (1); one end of a plunger (22) of each plunger assembly (2) is in transmission with the cam (3), and the other end reciprocates linearly in a corresponding hydraulic end (4) to convey a medium; an angle is formed between the arrangement direction of each plunger (22) and the radial direction of the transmission case (1); A plunger roller (222) is installed at the mating end of the plunger (22) and the cam (3), and the rotation axis of the plunger roller (222) is arranged in parallel with the cam shaft (31) of the cam (3). An elastic component is arranged along the axial direction of the plunger (22) in the transmission box (1), and the elastic component applies an elastic force to the plunger (22) in the direction of the cam (3). The plunger roller (222) abuts against the wheel surface of the cam (3) to form rolling contact.

2. A balanced low-vibration reciprocating pump according to claim 1, characterized in that: The base circle radius of cam (3) is r0: α=D / s0; β=b / s0; Where: P is the medium discharge pressure of the hydraulic end (4); α is the diameter ratio coefficient of cam (3); Q is the pump flow rate; z is the number of pump heads; η0 is the dynamic viscosity of the lubricating oil of the cam (3); n is the cam (3) speed; β is the width-to-path ratio of the cam (3); s0 is the stroke length of the plunger (22); D is the cross-sectional diameter of the plunger (22); b is the load-bearing width of the contact area of ​​the cam (3).

3. A balanced low-vibration reciprocating pump according to claim 2, characterized in that: A plane rectangular coordinate system is constructed with the center of the cam (3) as the coordinate origin, a line connecting the base circle of the cam (3) and the intersection of the cam (3) as the Y axis of the plane rectangular coordinate system, a contour curve of the cam (3) in the second quadrant and a contour curve in the first quadrant in the plane rectangular coordinate system are arranged symmetrically about the Y axis, a contour curve of the cam (3) in the second quadrant and a contour curve in the third quadrant in the plane rectangular coordinate system are arranged symmetrically about the X axis, and a contour curve of the cam (3) in the first quadrant and a contour curve in the fourth quadrant in the plane rectangular coordinate system are arranged symmetrically about the X axis; Along the direction away from the Y axis, the profile curve of the cam (3) in the second quadrant of the plane rectangular coordinate system includes a first curve, a second curve and a third curve connected in sequence; The polar coordinate equation of the first curve is: The polar coordinate equation of the second curve is: The polar coordinate equation of the third curve is: Wherein: r is the radius of the plunger roller (222); δ is the rotation angle of cam (3); θ is the pressure angle of cam (3); s is the lift of the cam (3).

4. A balanced low-vibration reciprocating pump according to claim 1, characterized in that: The motor shaft of the driving motor (5) drives the cam (3) to rotate via a speed reducer (53). The driving motor (5) is connected and fixed to the transmission box (1) via a supporting flange (51). A damping block (52) having a buffering effect is provided between the supporting flange (51) and the transmission box (1).

5. A balanced low-vibration reciprocating pump according to claim 1, characterized in that: The transmission box (1) is opened in the axial direction for the cam (3) to pass through, and bearings (32) are provided on the shaft shoulders at both ends of the camshaft (31). The camshaft (31) is rotatably matched with the transmission box (1) through the bearings (32). The two bearings (32) are pressed and fixed by bearing pressure covers (33), and one group of bearing pressure covers (33) has an axial opening for the rotation power source to pass through and then be connected to the camshaft (31).

6. A balanced low-vibration reciprocating pump according to claim 1, characterized in that: A medium channel (41) is provided in the hydraulic end (4) along a direction perpendicular to the plunger (22), and the end of the plunger (22) is inserted into the medium channel (41) and moves back and forth in a straight line; one-way valves (42) are installed in the medium channel (41) at intervals along the medium flow direction, and a liquid inlet (12) and a liquid outlet (13) are provided on the transmission box (1) so as to be connected to the inlet and outlet of the medium channel (41) respectively.

7. A balanced low-vibration reciprocating pump according to claim 1, characterized in that: A roller groove is provided at one end of the plunger (22) adjacent to the cam (3). The plunger pin (221) is installed in the roller groove and rotates with the plunger (22). The plunger roller (222) and the plunger pin (221) are coaxially fixed.

8. A balanced low-vibration reciprocating pump according to claim 1, characterized in that: The plunger assembly (2) comprises a plunger sleeve (21) and a plunger (22) coaxially slidably arranged in the plunger sleeve (21); the plunger sleeve (21) is provided with a mounting step (211) in the radial direction; the plunger (22) is a two-stage stepped columnar structure; the plunger roller (222) is arranged in the large diameter section of the plunger (22); the small diameter section of the plunger (22) is inserted into the hydraulic end (4); the elastic component is a return spring (25) sleeved on the outer ring of the plunger (22); the two ends of the return spring (25) are respectively in contact with the large diameter section of the plunger (22) and the mounting step (211).

9. A balanced low-vibration reciprocating pump according to claim 1, characterized in that: A sealing assembly (23) is provided between the mounting step (211) of the plunger (22) and the hydraulic end (4). The sealing assembly (23) comprises a spring seat (231) coaxially sleeved on the plunger (22) and arranged symmetrically on both sides. A sealing spring (232) is provided between the two spring seats (231). In a direction away from the sealing spring (232), the spring seat (231), the packing seal (233) and the guide sleeve (234) are arranged in sequence. One group of the guide sleeves (234) abuts against the mounting step (211), and the other group of the guide sleeves (234) abuts against the hydraulic end (4).

10. A balanced low-vibration reciprocating pump according to claim 1, characterized in that: A reflux hole (24) located between two spring seats (231) is provided on the plunger sleeve (21), and the reflux hole (24) is communicated with the liquid inlet (12) of the transmission box (1).

Images