A high-lift volumetric pump

Abstract

The present application relates to a kind of high-lift volume pumps, including pump body, still at least including first rotor and second rotor 2 rotors, the first rotor and second rotor are supported in pump body by bearing and carry out synchronous opposite direction rotation movement, the pump body includes pump cavity and the pump cover connected with it, the pump cavity includes two sides for fluid inlet and outlet medium inlet and medium outlet;First rotor cam shape is defined by first rotor working curve, second rotor cam shape is defined by second rotor working curve, first rotor working curve and second rotor working curve are each other's conjugate curve;The rotary radius of the first rotor is greater than the rotary radius of the second rotor, source power is input by first rotor, and first rotor plays the main role of doing work, and second rotor plays the role of auxiliary doing work and dynamic sealing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pump, in particular to a high-lift volumetric pump. BACKGROUND

[0002] The cam pump belongs to a kind of rotor pump, it is a kind of rotary volumetric pump, with the property of positive displacement, flow does not change with back pressure, the relative movement between rotor and pump cavity is changed to work volume size, to medium work in turn.

[0003] The existing double-rotor cam pump generally includes pump cover, pump cavity, main rotor, secondary rotor, synchronous gear, seal, shaft sleeve, bearing and bearing end cover, the main rotor and secondary rotor are installed in pump cavity, and pump cavity is fixedly installed on bearing cover.The existing double-rotor cam pump, the turning radius of two rotors is consistent, and the efficiency is low.When high-lift medium needs to be transported, in order to improve working pressure, the volume of pump is generally increased, and the volumetric efficiency is low, the performance is unstable, and the transportation is difficult.Therefore, how to design a new type of cam rotor pump with high-lift, large flow, good stability and high efficiency has very important role. SUMMARY

[0004] In order to solve the technical problems in the background art, the present application provides the following technical scheme: a high-lift volumetric pump, comprising a pump body, further comprising at least two rotors, i.e., a first rotor and a second rotor, the first rotor and the second rotor are supported by bearings in the pump body to rotate in opposite directions synchronously, the pump body comprises a pump cavity and a pump cover connected thereto, the pump cavity comprises a medium inlet and a medium outlet on both sides for fluid inlet and outlet; the cam shape of the first rotor is defined by a first rotor working curve, and the cam shape of the second rotor is defined by a second rotor working curve, the first rotor working curve and the second rotor working curve are conjugate curves; the turning radius of the first rotor is greater than that of the second rotor, the source power is input by the first rotor, the first rotor plays a major role in doing work, and the second rotor plays an auxiliary role in doing work and dynamic sealing.

[0005] Optionally, the turning radius of the first rotor is r m , the turning radius of the second rotor is R2, and the ratio of r m / R2 is in the range of 1.1-2.8, the first rotor and the second rotor maintain a gap C, and the value of the gap C is in the range of 0.03-0.3 mm.

[0006] Optionally, the first rotor and the second rotor are composed of at least two cam units. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 It is a whole schematic view of the volumetric pump of the present application;

[0008] Figure 2 A specific diagram of a pump of the present application;

[0009] Figure 3 A specific diagram of another pump of the present application;

[0010] Figure 4 A specific diagram of a pump cavity of the present application;

[0011] Figure 5 A specific diagram of a first rotor and a second rotor of the present application;

[0012] Figure 6 A specific diagram of a first rotor cam of the present application;

[0013] Figure 7 A specific diagram of a second rotor cam of the present application;

[0014] Figure 8 A specific diagram of a first rotor and a second rotor of the present application;

[0015] Figure 9 A specific diagram of another first rotor and a second rotor of the present application;

[0016] Figure 10 A specific diagram of another first rotor and a second rotor of the present application;

[0017] Figure 11 A specific diagram of a pump cavity of the present application;

[0018] Figure 12 A specific diagram of a pump cavity of the present application; DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application, i.e., the described embodiments are only some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0020] Therefore, the detailed description of the embodiments of the present application provided below in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0021] All features disclosed in this specification, and / or all steps of any methods or processes disclosed in this specification, can be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive.

[0022] The application will be further described below with reference to the drawings and specific embodiments:

[0023] Embodiment 1:

[0024] In order to solve the problems in the background art, the present embodiment improves the existing volumetric pump, and the technical scheme is as follows:

[0025] As shown in Figures 1-6 A volumetric pump includes a pump body 1, the pump body 1 includes a pump cavity 10 and a first pump cover 105 and a second pump cover 106, the pump cavity 10 and the first pump cover 105 and the second pump cover 106 are connected and fixed, the pump cavity 10 includes a medium inlet 101 and a medium outlet 102 arranged on both sides, in order to facilitate understanding of the medium inlet 101 and the medium outlet 102 of the present embodiment, the fluid is discharged from the right side to the left side, at this time the first rotor 40 rotates clockwise and the second rotor 50 rotates counterclockwise. Define the medium inlet connection area as a low pressure area, and the medium outlet connection area as a high pressure area. An alternative embodiment is that the first rotor 40 rotates counterclockwise and the second rotor 50 rotates clockwise, at this time the positions of the medium inlet 101 and the medium outlet 102 are interchanged. The first rotor 40 is the main rotor, and the first rotor 50 is the auxiliary rotor. When the first rotor 40 and the second rotor 50 rotate in the pump body 1, a high pressure area and a low pressure area are periodically formed in the pump body 1, fluid is sucked by the low pressure and is extruded by the high pressure, the fluid medium enters the pump cavity 10 from the medium inlet 101, is driven by the first rotor 40 and the second rotor 50, and finally flows to the outside of the pump body 1 from the medium outlet 102, completing the normal work of the pump. In an alternative embodiment, the first rotor 40 in the pump cavity has a return center line higher than the maximum point of the medium inlet and outlet, and the value range is 1mm-30mm.

[0026] The power input end of the first rotor 40 has fan blades, the first rotor 40 and the second rotor 50 are both provided with two bearings and a cooling shaft sleeve, the non-driving end of the first rotor 40 and the second rotor 50 is provided with a synchronous gear, and the two are connected through gear transmission. The bearings and high pressure seals are installed on the pump cover, the first rotor 40 and the second rotor 50 are supported and rotated through the bearings at both ends, the first rotor 40 and the second rotor 50 realize synchronous rotation in opposite directions through a linkage mechanism, and the linkage mechanism includes gear linkage, sprocket linkage and synchronous belt linkage.

[0027] As shown in Figures 1-8As shown, the first rotor 40 includes a first rotor shaft 401 and a first cam 402, defining a working section perpendicular to the axis of the first rotor shaft 401. The first cam 402 includes two first main cam surfaces 421 and two second main cam surfaces 422. In this embodiment, there are two cam units, which are symmetrically arranged along the axis. In this embodiment, the cam unit can also be arranged in three or more than three cam units. Figure 9 and Figure 10 As shown, the first main cam surface 421 and the second main cam surface 422 and the main cam transition surface 423 correspond to the working curve of the first main cam curve 421a and the second main cam curve 422a and the main cam transition curve 423a. The two groups of first main cam curve 421a and second main cam curve 422a and the main cam transition curve 423a connected at the end form the first rotor working curve 402a in the working section.

[0028] Embodiment 2

[0029] As shown, Figure 6 and Figure 8 The first main cam curve 421a, the second main cam curve 422a and the main cam transition curve 423a satisfy the following size and angle relationship.

[0030] The first main cam curve 421a satisfies the following curve equation:

[0031]

[0032] The second main cam curve 422a satisfies the following cam equation:

[0033]

[0034] The main cam transition curve 423a satisfies the following transition arc equation:

[0035]

[0036] Wherein:

[0037] r1 is the base circle radius, (r1 > r2; r2 < r m <r1+r2)

[0038] r2 is the convex circle radius,

[0039] r3 is the transition arc radius,

[0040] r m is the first rotor (main rotor) revolution radius,

[0041] t is a parameter, ranging from 0 to 1;

[0042] θ1 is a base circle included angle, θ1 ranging from 0 to 90°;

[0043] θ2 is a convex circle included angle,

[0044] θ3 is a transition circle included angle, θ3 = θ1 + θ2 - 90°;

[0045] As Figures 5-10 , the second rotor 50 includes a second rotor shaft 501 and a second cam 502, the second cam 502 including 2 first sub-rotation surfaces 521 and 2 second sub-rotation surfaces 522, in the embodiment, the cam unit is 2, the two cam units are symmetrically arranged along the axis, and the cam unit can also be arranged as 3 or more than 3. The first sub-rotation surface 521 and the second sub-rotation surface 522 are connected by a sub-rotation transition surface 523. The first sub-rotation surface 521 and the second sub-rotation surface 522 and the sub-rotation transition surface 523 therebetween correspond to a first sub-rotation curve 521a and a second sub-rotation curve 522a and a first sub-rotation transition curve 523a and a second sub-rotation transition curve 524a connected therebetween, the two groups of first sub-rotation curve 521a and second sub-rotation curve 522a connected end to end and the first sub-rotation transition curve 523a and the second sub-rotation transition curve 524a therebetween form a second rotor working curve 502a; the first rotor working curve 402a and the second rotor working curve 502a form a conjugate convex-concave type curve. The first sub-rotation curve 521a and the second sub-rotation curve 522a and the first sub-rotation transition curve 523a and the second sub-rotation transition curve 524a satisfy the following size and angle relationship:

[0046] The first sub-rotation curve 521a satisfies the following curve equation:

[0047]

[0048] The second rotor working curve 502a satisfies the following curve equation:

[0049]

[0050] The first sub-rotation transition curve 523a satisfies the following curve equation:

[0051]

[0052] The second sub-rotation transition curve 524a satisfies the following curve equation:

[0053]

[0054] wherein: β1 is the angle between MO1 and O1P,

[0055] t is a parameter, ranging from 0 to 1;

[0056] θ4 is the angle between the start point and the end point of the second sub-rotor curve segment of the first rotor (main rotor) in the coordinate system with the center O1 as the coordinate origin,

[0057] c is the distance from the start point of the second sub-rotor curve segment of the first rotor (main rotor) to the center O1,

[0058]

[0059] r m r is the first rotor (main rotor) rotation radius; r1 is the base circle radius; r2 is the convex circle radius;

[0060] η is the angle between PO2 and O1O2,

[0061] r3 is the transition arc radius,

[0062] θ1 is the base circle angle;

[0063] θ3 is the transition angle, θ3 = θ1 + θ2 - 90°;

[0064] θ2 is the convex circle angle,

[0065] O3P is the length of the center O3 and the conjugate instant point P,

[0066]

[0067] η5 is the angle between O3P and O1P,

[0068] O1M is the length of the center O1 and the conjugate point M,

[0069]

[0070] Those skilled in the art should understand that the first sub-rotor curve 521a and the second sub-rotor curve 522a extend to form a virtual intersection point D1 (not shown), the first sub-rotor curve 521a and the second sub-rotor curve 522a form an intersection point D2 (not shown), when the first rotor 40 and the second rotor 50 are matched, a gap mutation occurs at the intersection point D1 and the intersection point D2, causing the high pressure area to be decompressed, thereby greatly affecting the efficiency of the volumetric pump.

[0071] The first main cam curve 421a and the first auxiliary cam curve 521a form conjugate curves in this embodiment

[0072] The second main cam curve 422a and the second auxiliary cam curve 522a form conjugate curves, and the main cam transition curve 423a and the first auxiliary cam transition curve 523a and the second auxiliary cam transition curve 524a form conjugate curves. The first rotor 40 and the second rotor 50 can keep a stable and substantially same gap, especially the transition section also keeps a stable gap, and no gap mutation occurs, thereby ensuring the stability of the high-pressure zone and improving the overall efficiency of the pump.

[0073] The turning radius r m of the first rotor 40 is greater than the turning radius R2 of the second rotor 50, and the ratio of r m to R2 ranges from 1.1 to 2.8.

[0074] The source power is input from the first rotor 40, which mainly plays a main working role in the pump cavity 10, while the second rotor 50 plays an auxiliary working role and mainly plays a good dynamic sealing role.

[0075] Embodiment 3:

[0076] Figures 1-4 As shown, the pump cavity 10 is a cavity 120 defined by a first turning line segment 124 of a first cavity turning line 121, a second turning line segment 125 of a second cavity turning line 122, and a tangent line 123 of the two, the first cavity turning line 121 has a radius R10, the second cavity turning line 122 has a radius R20, the gap A is the minimum gap between the first rotor 40 and the first cavity turning line 121 region, and the gap B is the minimum gap between the second rotor 50 and the second cavity turning line 122 region, which satisfies the formula R10 = r m +A; R20 = R2 + B; the gap A is less than the gap B, the gap A ranges from 0.03 to 0.3 mm, and the gap B ranges from 0.03 to 0.5 mm.

[0077] The first rotor 40 and the second rotor 50 are both installed with matching bearings at both ends, the second rotor 50 is driven by a synchronous gear to realize synchronous and opposite direction rotation of the first rotor 40 and the second rotor 50, and the first cam 402 and the second cam 502 are conjugate curves and keep a certain gap, the first rotor working curve 402a and the second rotor working curve 502a form conjugate convex-concave curves, and the gap C ranges from 0.03 to 0.3 mm. In the preferred embodiment, the conjugate convex-concave curves keep a substantially same gap.

[0078] In this embodiment, the primary rotation transition curve 423a and the secondary rotation transition curve 523a are set to form a meshing fit, the overall gap of the first rotor working curve 402a and the second rotor working curve 502a is kept substantially consistent, and there is no obvious pressure relief point, thereby maintaining the pressure in the high pressure area.

[0079] Those skilled in the art should understand that the first rotor 40 and the second rotor 50 also have a certain gap with the pump cover, which ensures that the first rotor 40 and the second rotor 50 do not interfere with each other when moving, and the gap between the rotor and the pump cover ensures that the rotor does not interfere with the pump cover when moving.

[0080] Those skilled in the art should understand that when the medium to be extracted contains a large amount of impurities or residues, it is easy to cause the volumetric pump to be blocked. For the convenience of understanding, the gap A and the gap B are set to 0, and the first rotor 40 rotates, the vertex of the first primary rotation amplitude surface 421 is in line contact with the first rotary line segment 124 of the pump cavity 10, and the second rotor 50 rotates, the first secondary rotation amplitude surface 521 is in surface contact with the second rotary line segment 125 of the pump cavity 10. Those skilled in the art should understand that when the gap A and the gap B are greater than 0, the first rotor 40 rotates, the vertex of the first primary rotation amplitude surface 421 is in the minimum gap position of the rotor, and the minimum gap is only the corresponding area of the vertex of the first primary rotation amplitude surface 421. The second rotor 50 rotates, and the minimum gap position of the first secondary rotation amplitude surface 521 and the second rotary line segment 125 is the corresponding area of the first secondary rotation amplitude surface 521. When the pump needs to work at high lift in this embodiment, the cavity pressure can be increased by increasing the rotation speed of the first rotor. Since the second rotor 50 forms a dynamic seal with the second rotary line segment 125, sudden pressure relief can be effectively avoided, and the pressure in the high pressure area is stable.

[0081] The first rotor 40 plays a role in active work, and compared with a double-rotor volumetric pump of substantially the same size, if a multi-cam unit is used, the diameter of the primary rotor cannot be designed too thick to ensure the cooperation between the cams. In this embodiment, since an asymmetric rotor is used, the rotation radius of the first rotor 40 is greater than that of the second rotor 50, and the first rotor shaft 401 has space to increase the diameter, so that the diameter of the first rotor shaft 401 can be increased to ensure that the first rotor shaft 401 does not break or fail under the condition of bearing large torque under the requirement of high pressure of the volumetric pump. The ratio of the rotation radius of the first rotor to the radius of the first rotor shaft is in the range of 1.3-2.

[0082] Embodiment 3

[0083] As Figures 11-12As shown, the embodiment is based on the above embodiments, and is described in detail for the pump cavity 10. The pump cavity 10 further comprises a fish mouth 103, which is arranged along the extension direction of the second cavity rotation line 122 at the intersection position of the second cavity rotation line 122 and the tangent line 123. The fish mouth 103 comprises a fish mouth matching section 131, a fish mouth water distribution section 132, and a fish mouth top end 133 extending and intersecting the two sections. The fish mouth matching section 131 of the fish mouth 103 increases the gap B matching area between the second rotation line section 125 and the first secondary rotation amplitude surface 521, which can effectively improve the dynamic sealing effect. The fish mouth 103 and the pump cavity 10 can be fixed by an integrated molding connection mode.

[0084] An alternative technical solution is that the distance between the fish mouth water distribution section 132 and the first cavity rotation line 121 is greater than 10 mm, and the fish mouth 103 does not interfere with the first rotor 40.

[0085] Embodiment 4

[0086] As Figure 11 As shown, another alternative technical solution is that the gap between the fish mouth matching section 131 and the first secondary rotation amplitude surface 521 during dynamic sealing is gap B, which can also adopt a gradually changing gap. The material of the fish mouth matching section 131 comprises self-lubricating plastics such as POM, PTFE, PA, or other self-lubricating materials and semi-rigid materials. The fish mouth 103 and the pump cavity 10 can be fixed by bonding, welding, or other fixed connection modes. In an alternative technical solution, the fish mouth top end 133 protrudes to form a first fish mouth adjusting section 134 and a first secondary rotation amplitude surface 521 with a minimum gap, which is gap B1. When the first fish mouth adjusting section 134 extends to the position of the second cavity rotation line 122, the gap between the fish mouth matching section 131 and the first secondary rotation amplitude surface 521 gradually increases, and gap B1 < gap B. Due to the existence of gap B1 on the symmetric two sides of the fish mouth, the length of the first secondary rotation amplitude surface 521 corresponding to the first secondary rotation curve 521a needs to meet the following condition: at any position of the second rotor 50, the first secondary rotation amplitude surface 521 at least realizes the gap B1 matching with one side of the fish mouth, and the gap at the remaining positions can be greater than gap B1.

[0087] Another alternative technical solution is that the first rotor shaft 401 of the first rotor 40 and the second rotor shaft 501 of the second rotor 50 adopt metal materials, the first cam 402 adopts a metal material, and the second cam 502 adopts self-lubricating plastics such as POM, PTFE, and PA, which can further reduce the matching gap between the second rotor 50 and the second cavity rotation line 122 and the fish mouth matching section 131.

[0088] The volumetric pump of the embodiment can realize a high lift of 200 meters or more. Compared with the volumetric pump of the prior art under the same working condition, the volume is reduced by 40%, and compared with the centrifugal pump of the prior art under the same lift and flow, the efficiency is increased by more than 20%.

[0089] When the gap B1 is less than the gap B, those skilled in the art should understand that, in order to achieve the same dynamic sealing effect, in the case of using a gradually changing gap, the gap B can use a larger range of values. Using this technical solution can not only meet the dynamic sealing performance of the second rotor 50, but also reduce the assembly difficulty and the processing difficulty of the pump cavity 10 (the processing precision requirement of the first secondary rotor surface 521 can be reduced), especially in the case of needing to extract a large amount of debris, the fish mouth 103 of the POM material can realize self-lubrication at the gap B1 position, and at the gap B position, due to the use of a larger gap value range, the second rotor 50 can be prevented from being blocked, and the dynamic sealing sliding friction of the first secondary rotor surface 521 can be effectively reduced.

[0090] Embodiment 5

[0091] As Figure 12 shown, yet another alternative technical solution is that the fish mouth matching section 131 is arranged as a rotatable roller, and during the dynamic sealing process with the first secondary rotor surface 521, the fish mouth matching section 131 forms rolling friction with the first secondary rotor surface 521. Since the friction of rolling friction is smaller, the gap B1 is smaller, thereby further improving the dynamic sealing performance.

[0092] In yet another embodiment, the fish mouth matching section 131 is further provided with a second fish mouth adjusting section 135, and during the dynamic sealing process with the first secondary rotor surface 521, the gap is B2, and the gap B1 is less than the gap B2, which is less than the gap B. The first fish mouth adjusting section 134 and the second fish mouth adjusting section 135 can be arranged simultaneously or separately, and during the process of gradually reducing the pressure in the high-pressure area formed by the matching gap between the fish mouth 103 and the first secondary rotor surface 521. More fish mouth adjusting sections can also be arranged on the fish mouth matching section 131. By using multiple fish mouth adjusting sections, the dynamic sealing performance of the first secondary rotor surface 521 can be further improved.

[0093] In yet another embodiment, the fish mouth 103 is made of a rigid material, and the first fish mouth adjusting section 134 and the second fish mouth adjusting section 135 are made of a flexible material. By this arrangement, the range of values of the gap B1 and the gap B2 can be further reduced, and under the condition of not increasing the dynamic sealing sliding friction of the first secondary rotor surface 521, the dynamic sealing performance of the first secondary rotor surface 521 can be further improved. The fish mouth adjusting section is arranged along the axial direction of the second rotor 50, and can also be S-shaped or other shapes that penetrate the axial direction of the fish mouth.

[0094] As Figure 12As shown, in another alternative technical solution, the fish mouth 103 further comprises a grease storage bag (not shown) for storing lubricating grease, and a plurality of grease discharge holes 136 are arranged on the first fish mouth adjusting segment 134, and the first fish mouth adjusting segment 134 is made of flexible material. In this solution, the gap B1 between the first fish mouth adjusting segment 134 and the first secondary rotor blade surface 521 can be 0, and the first fish mouth adjusting segment 134 and the first secondary rotor blade surface 521 can also form an interference fit. When the second rotor 50 rotates, the first secondary rotor blade surface 521 extrudes the first fish mouth adjusting segment 134, and the lubricating grease automatically overflows from the grease discharge holes 136, thereby lubricating the first secondary rotor blade surface 521 and the first fish mouth adjusting segment 134. This solution can achieve good dynamic sealing of the first secondary rotor blade surface 521 without increasing the dynamic sealing sliding friction of the first secondary rotor blade surface 521.

[0095] In the case of needing to adapt to different medium delivery, especially for cases with more impurities, the second rotor 50, which mainly plays a sealing role, may be blocked. In another alternative embodiment, the first fish mouth adjusting segment 134 is movably connected to the fish mouth 103 in a slider mode, and the first fish mouth adjusting segment 134 comprises an adjusting segment slider segment 139, a threaded adjusting rod 137, and an adjusting segment knob 138. The adjusting segment slider segment 139 is movably connected to the threaded adjusting rod 137, and the adjusting segment knob 138 is arranged outside the pump cavity 10 and matches an internal threaded hole in the pump cavity 10 at the corresponding position of the threaded adjusting rod 137. Rotating the adjusting segment knob 138, the threaded adjusting rod 137 is fed or withdrawn in the pump cavity 10, and the threaded adjusting rod 137 pushes the adjusting segment slider segment 139 to protrude into the pump cavity 10 or retract, thereby adjusting the gap between the first fish mouth adjusting segment 134 and the first secondary rotor blade surface 521. During use, the gap B1 between the first fish mouth adjusting segment 134 on the fish mouth 103 and the first secondary rotor blade surface 521 can be adjusted, the gap B1 is increased when the problem of blockage occurs, thereby achieving the effect of discharging slag, and after discharging the slag, the gap B1 is reduced to achieve dynamic sealing.

[0096] The above merely describes a preferred embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacements or changes to the technical scheme and inventive concept of the present application within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. In the description of the present application, it should be noted that the orientation or position relationship indicated by the terms "top", "bottom", "one side", "the other side", "front", "back", "intermediate position", "interior", "top end", "bottom end" and the like is based on the orientation or position relationship shown in the drawings, and is merely for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application; the terms "first", "second", "third" are merely for the purpose of description, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood broadly, for example, can be fixed connection, can also be detachable connection or movable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be the communication inside two elements. For the person skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

Claims

1. A high head positive displacement pump characterized by: The pump body comprises at least two rotors, i.e. a first rotor and a second rotor, which are supported by bearings in the pump body and rotate in opposite directions synchronously, the pump body comprises a pump cavity and a pump cover connected thereto, the pump cavity comprises medium inlets and outlets on two sides for fluid in and out, the cam shape of the first rotor is defined by a first rotor working curve, the cam shape of the second rotor is defined by a second rotor working curve, the first rotor working curve and the second rotor working curve are conjugate curves, the rotation radius of the first rotor is greater than that of the second rotor, the source power is input by the first rotor, the first rotor plays a major role in doing work, and the second rotor plays a role in assisting work and dynamic sealing, the pump cavity further comprises a fish mouth formed in the natural extension direction of the second cavity rotation line, and the fish mouth protrudes at least one fish mouth adjusting section in the gap B matching area.

2. The high-lift volumetric pump of claim 1, wherein The first rotor has a radius of revolution r m The second rotor has a radius of revolution R2, r m The ratio r / R2 is in the range 1.1-2.8, the first rotor and the second rotor maintain a gap C, the value of which is in the range 0.03-0.3 mm.

3. The high-lift volumetric pump of claim 1, wherein The first rotor and the second rotor are composed of at least two cam units.

4. The high-lift volumetric pump of claim 3, wherein, The first rotor is composed of two cam units, and the working curve comprises a first main rotation curve, a second main rotation curve and a main rotation transition curve, The first main rotation curve satisfies the following curve equation: The second main rotation curve satisfies the following cam equation: The main rotation transition curve satisfies the following transition arc equation: Wherein: r1 is the base circle radius, r1 > r2; r2 < r m r1 + r2; r2 is the convex circle radius, r3 is a transition arc radius, r m R is the working revolution radius of the first rotor, t is a parameter, ranging from 0 to 1; θ1 is a base circle included angle, θ1 ranging from 0 to 90°; θ2 is the included angle of the convex circle, θ3 is a transition circle included angle, θ3 = θ1 + θ2 - 90°.

5. The high-lift volumetric pump of claim 3, wherein, The second rotor has two cam units, and the second rotor working curve comprises a first secondary rotation curve, a second secondary rotation curve and a first secondary rotation transition curve; The first secondary rotation curve satisfies the following curve equation: The second rotor working curve satisfies the following curve equation: The first secondary rotation transition curve satisfies the following curve equation: The second secondary rotation transition curve satisfies the following curve equation: wherein: β1 is the angle between MO1 and O1P, t is a parameter, ranging from 0 to 1; θ4 is an included angle of the starting point to the terminal point of the second secondary rotation curve of the first rotor in the coordinate system with the center O1 as the coordinate origin, c is the distance from the starting point of the second secondary rotation curve of the first rotor to the center O1, r m r is the working revolution radius of the first rotor; r1 is the base circle radius; r2 is the convex circle radius; η is the angle between PO2 and O1O2, r3 is a transition arc radius, θ1 is a base circle included angle; θ3 is a transition circle included angle, θ3 = θ1 + θ2 - 90°; θ2 is the included angle of the convex circle, O3P is the length of the center O3 and the conjugate instant center point P, η5 is the angle between O3P and O1P, O1M is the length of the center O1 and the conjugate point M, 6. The high-lift volumetric pump of claim 2, wherein The pump cavity is defined by the first cavity rotation line and the second cavity rotation line and the tangent lines thereof to form a cavity space, which satisfies the following formula: R10= r m + A; R20= R2+ B; A < B; R10 is the first cavity rotation line radius; R20 is the second cavity rotation line radius; The gap A is the minimum gap between the first cavity rotation line and the first rotor working curve; The gap B is the minimum gap between the second cavity rotation line and the second rotor working curve.

7. The high-lift volumetric pump of claim 6, wherein, The gap A has a value range of 0.03-0.3mm, and the gap B has a value range of 0.03-0.5mm:

8. The high-lift volumetric pump of claim 6, wherein, The fish mouth does not interfere with the first rotor, the fish mouth increases the length of the gap B matching area, and improves the dynamic sealing effect of the second rotor.

9. The high-lift volumetric pump of claim 6, wherein, The minimum gap formed between the fish mouth adjusting section and the second rotor working curve is smaller than the gap B, and the fish mouth adjusting section is made of self-lubricating material, semi-steel material or flexible material.

10. The high-lift volumetric pump of claim 8, wherein, The fish mouth further comprises a fat storage sac which stores lubricating grease, and the fish mouth adjusting section is provided with a plurality of fat holes.

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