Pump cavity of a positive displacement pump and positive displacement pump

Abstract

The present invention relates to a pump cavity of a displacement pump, the pump cavity comprising a medium inlet and a medium outlet on two sides for fluid inlet and outlet and a cavity for accommodating at least two rotors; the cavity is composed of a closed space defined by a first cavity rotation line and a second cavity rotation line and tangents thereto, the radius of the first cavity rotation line is R10, the radius of the second cavity rotation line is R20, R10>R20, and the pump cavity also comprises a fish mouth formed along the natural extension direction of the second cavity rotation line.

Description

Technical Field

[0001] The present invention relates to the field of pumps, and in particular to a pump cavity of a positive displacement pump and a positive displacement pump. Background Art

[0002] The cam pump is a type of rotor pump, a rotating positive displacement pump with the property of positive displacement. The flow rate does not change with the back pressure. The working volume is changed by the relative movement between the rotor and the pump chamber, thereby doing work on the medium.

[0003] The existing twin-rotor cam pump generally includes a pump cover, a pump chamber, a main rotor, a sub-rotor, a synchronous gear, a seal, a sleeve, a bearing and a bearing end cover. The main rotor and the sub-rotor are installed in the pump chamber, and the pump chamber is fixedly installed on the bearing cover. In the existing twin-rotor cam pump, the two rotors have the same rotation radius and low efficiency. When high-lift conveying medium is required, in order to increase the working pressure, the volume of the pump is generally increased as needed, but the volumetric efficiency is low, the performance is unstable, and it is difficult to carry. The pump chamber of the volumetric pump is a key component of the volumetric pump. How to design a pump chamber suitable for a new cam rotor pump with high lift, large flow, good stability and high efficiency is very important. Summary of the invention

[0004] In order to solve the shortcomings of the prior art mentioned in the background technology, the present invention provides the following technical solutions:

[0005] A pump cavity of a positive displacement pump, the pump cavity comprising a medium inlet and a medium outlet on both sides for fluid inlet and outlet and a cavity for accommodating at least two rotors; the cavity is composed of a closed space defined by a first cavity rotation line, a second cavity rotation line and tangents thereto, the radius of the first cavity rotation line is R10, the radius of the second cavity rotation line is R20, and R10>R20.

[0006] An optional embodiment, wherein the gap A is the gap between the first rotor and the first cavity rotation line, the gap B is the gap between the second rotor and the second cavity rotation line, R1 is the radius of the first rotor, and R2 is the radius of the second rotor; the formula R10=R1+A; R20=R2+B is satisfied, the gap A≤gap B, the gap A value range: 0.03-0.3mm, the gap B value range:

[0007] 0.03-0.5mm.

[0008] An optional embodiment, wherein the pump cavity further includes a fish mouth formed along the natural extension direction of the rotation line of the second cavity, wherein the fish mouth does not interfere with the first rotor, and the fish mouth increases the length of the matching area of ​​the gap B, thereby improving the dynamic sealing effect of the second rotor.

[0009] An optional embodiment, wherein the fish mouth is provided with at least one fish mouth adjustment section protruding in the gap B matching area, and the minimum gap formed by the fish mouth adjustment section and the second rotor working curve is smaller than the gap B.

[0010] An optional embodiment, wherein the fish mouth adjustment section is made of self-lubricating material, semi-rigid material or flexible material.

[0011] An optional embodiment, wherein the fish mouth further comprises a grease storage bag, wherein the grease storage bag stores grease, and the fish mouth adjustment section is provided with a plurality of grease discharge holes.

[0012] An optional embodiment, wherein the fish mouth adjustment section is movably connected to the fish mouth in the form of a slider, the fish mouth adjustment section includes an adjustment section slider section, a threaded adjustment rod and an adjustment section knob, the adjustment section slider section is movably connected to the threaded adjustment rod, the adjustment section knob is arranged outside the pump cavity, the pump cavity matches the internal threaded hole at the corresponding position of the threaded adjustment rod, and the adjustment section knob is rotated to adjust the gap between the fish mouth adjustment section and the second rotor.

[0013] An optional embodiment, wherein the fish mouth adjustment section is movably connected to the fish mouth by means of a slider, and the fish mouth adjustment section includes an adjustment slider, an elastic adjustment rod and a limit card, the adjustment slider is connected to the elastic adjustment rod, and the limit card is fixed to the pump cavity.

[0014] An optional embodiment, wherein the pump chamber also includes an adjustable fish mouth formed along the natural extension direction of the second chamber rotation line, the adjustable fish mouth includes a fish mouth body, a turbine shaft, a turbine and a worm gear matching therewith, and the handle of the rotating worm gear drives the fish mouth body to rotate, thereby adjusting the gap between the fish mouth arc body and the second rotor during the dynamic sealing process.

[0015] A positive displacement pump comprises the above-mentioned pump cavity, and also comprises a first rotor and a second rotor cooperating with the pump cavity, wherein the first rotor cooperates with the pump cavity to play a main working role, and the second rotor cooperates with the pump cavity to play an auxiliary working role and a dynamic sealing role. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an overall schematic diagram of the positive displacement pump of the present invention;

[0017] Figure 2 It is a specific schematic diagram of the pump of the present invention;

[0018] Figure 3 This is another specific schematic diagram of a pump of the present invention;

[0019] Figure 4 It is a specific schematic diagram of the pump cavity of the present invention;

[0020] Figure 5A schematic diagram of a first rotor and a second rotor of the present invention;

[0021] Figure 6 is a schematic diagram of the first rotor cam of the present invention;

[0022] Figure 7 is a schematic diagram of the second rotor cam of the present invention;

[0023] Figure 8 This is a schematic diagram of the cooperation between the first rotor and the second rotor of the present invention;

[0024] Fig. 9 It is another schematic diagram of the cooperation between the first rotor and the second rotor of the present invention;

[0025] Fig.10 It is another schematic diagram of the cooperation between the first rotor and the second rotor of the present invention;

[0026] Fig.11 It is a three-dimensional schematic diagram of the pump cavity of the present invention;

[0027] Fig.12 It is a partial three-dimensional schematic diagram of the pump cavity of the present invention;

[0028] Fig.13 It is a partial three-dimensional schematic diagram of the fish mouth of the pump cavity of the present invention;

[0029] Fig.14 It is another partial three-dimensional schematic diagram of a fish mouth of the present invention;

[0030] Figure 15-18 This is a schematic diagram of the working state of the pump of the present invention; DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0033] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features, can be combined in any manner.

[0034] The present invention is further described below with reference to the accompanying drawings and specific embodiments:

[0035] Embodiment 1:

[0036] In order to solve the related problems of the background technology, this embodiment is improved on the basis of the existing positive displacement pump, and the technical solution is as follows:

[0037] A displacement pump includes a pump body 1, wherein the pump body 1 includes a pump cavity 10 and a first pump cover 105 and a second pump cover 106, wherein the pump cavity 10 and the first pump cover 105 and the second pump cover 106 are connected and fixed, and the pump cavity 10 includes a medium inlet 101 and a medium outlet 102 arranged on both sides. For the convenience of understanding, the medium inlet 101 and the medium outlet 102 of this embodiment are used to discharge fluid from the right side to the left side by doing work, and at this time, the first rotor 40 rotates clockwise and the second rotor 50 rotates counterclockwise. The medium inlet connection area is defined as a low-pressure area, and the medium outlet connection area is defined as a high-pressure area. In an optional embodiment, the first rotor 40 rotates counterclockwise and the second rotor 50 rotates clockwise, and at this time, 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, high-pressure and low-pressure areas are periodically formed in the pump body 1. The fluid is sucked in at low pressure and squeezed out at high pressure. The fluid medium enters the pump cavity 10 from the medium inlet 101. Driven by the first rotor 40 and the second rotor 50, the fluid eventually flows from the medium outlet 102 to the external pipe outside the pump body 1, completing the normal operation of the pump. In an optional embodiment, the rotation centerline of the first rotor 40 in the pump cavity is higher than the highest point of the medium inlet and outlet, and its value range is 1mm--30mm.

[0038] The power input end of the first rotor 40 is provided with a fan blade, and the first rotor 40 and the second rotor 50 are both provided with two bearings and cooling sleeves, and the non-driving ends of the first rotor 40 and the second rotor 50 are both provided with a synchronous 139, and the two are connected by gear transmission. The bearings and high-pressure seals are both installed on the pump cover, and the first rotor 40 and the second rotor 50 are supported and rotated by the bearings at both ends, and the first rotor 40 and the second rotor 50 use a linkage mechanism to achieve synchronous rotation in opposite directions, and the linkage mechanism includes gear linkage, sprocket linkage, and synchronous belt linkage.

[0039] like Figure 1-8As shown, the first rotor 40 includes a first rotor shaft 401 and a first cam 402, and a section perpendicular to the axis of the first rotor shaft 401 is defined as a working section. The first cam 402 includes two first main rotation widths 421 and two second main rotation widths 422. In this embodiment, there are two cam units, which are symmetrically arranged along the axis. This embodiment can also be arranged to be composed of three or more cam units. A main rotation transition width 423 is also arranged between the first main rotation width 421 and the second main rotation width 422. As shown in FIG. Fig. 9 and Fig.10 As shown, the working curves corresponding to the first main rotation amplitude 421, the second main rotation amplitude 422 and the main rotation transition amplitude 423 are the first main rotation curve 421a and the second main rotation curve 422a and the main rotation transition curve 423a which is a direct transition between the two. The two groups of the first main rotation curve 421a and the second main rotation curve 422a connected end to end and the main rotation transition curve 423a therebetween form the first rotor working curve 402a in the working section.

[0040] Embodiment 2:

[0041] like Figure 6 and Figure 8 The first main turning curve 421a, the second main turning curve 422a and the main turning transition curve 423a are described to satisfy the following size and angle relationship.

[0042] The first main turning curve 421a satisfies the following curve equation:

[0043]

[0044] The second main rotation curve 422a satisfies the following cam equation:

[0045]

[0046] The main transition curve 423a satisfies the following transition arc equation:

[0047]

[0048] in:

[0049] r1 is the base circle radius, (r1>r2; r2<r m <r1+r2)

[0050] r2 is the convex radius,

[0051] r3 is the transition arc radius,

[0052] r m is the gyration radius of the first rotor (main rotor),

[0053] t is a parameter, ranging from 0 to 1;

[0054] θ1 is the base circle angle, and the range of θ1 is: 0-90°;

[0055] θ2 is the convex circle angle,

[0056] θ3 is the transition circle angle, θ3 = θ1 + θ2 - 90°;

[0057] like Figure 5-10 The second rotor 50 includes a second rotor shaft 501 and a second cam 502. The second rotor 50 includes a second rotor shaft 501 and a second cam 502. The second cam 502 includes two first auxiliary rotation width surfaces 521 and two second auxiliary rotation width surfaces 522. In this embodiment, there are two cam units, which are symmetrically arranged along the axis, and can also be arranged as three or more cam units. The first auxiliary rotation width surface 521 and the second auxiliary rotation width surface 522 are connected to the auxiliary rotation transition width surface 523 therebetween. The working curves corresponding to the first secondary rotation amplitude surface 521 and the second secondary rotation amplitude surface 522 and the secondary rotation transition amplitude surface 523 therebetween are the first secondary rotation curve 521a and the second secondary rotation curve 522a and the first secondary rotation transition curve 523a and the second secondary rotation transition curve 524a connected therebetween. The two groups of first secondary rotation curves 521a and second secondary rotation curves 522a connected end to end and the first secondary rotation transition curve 523a and the second secondary rotation transition curve 524a therebetween form the second rotor working curve 502a; the first rotor working curve 402a and the second rotor working curve 502a form a conjugate convex-concave curve. The first secondary rotation curve 521a and the second secondary rotation curve 522a and the first secondary rotation transition curve 523a and the second secondary rotation transition curve 524a satisfy the following size and angle relationship:

[0058] The first secondary turning curve 521a satisfies the following curve equation:

[0059]

[0060] The second rotor working curve 502a satisfies the following curve equation:

[0061]

[0062] The first secondary transition curve 523a satisfies the following curve equation:

[0063]

[0064] The second secondary transition curve 524a satisfies the following curve equation:

[0065]

[0066] Where: β1 is the angle between MO1 and O1P,

[0067] t is a parameter, ranging from 0 to 1;

[0068] θ4 is the angle between the start point and the end point of the second auxiliary turning curve segment of the first rotor (main rotor) in the coordinate system with the center O1 as the coordinate origin.

[0069] c is the distance from the starting point of the second secondary turning curve segment of the first rotor (main rotor) to the center O1,

[0070]

[0071] r m is the rotation radius of the first rotor (main rotor); r1 is the base circle radius; r2 is the convex circle radius;

[0072] η is the angle between PO2 and O1O2,

[0073] r3 is the transition arc radius,

[0074] θ1 is the base circle angle;

[0075] θ3 is the transition circle angle, θ3 = θ1 + θ2 - 90°;

[0076] θ2 is the convex circle angle,

[0077] O3P is the length between the center O3 and the conjugate instantaneous center point P,

[0078]

[0079] η5 is the angle between O3P and O1P,

[0080] O1M is the length between the center O1 and the conjugate point M,

[0081]

[0082] Those skilled in the art should understand that the first auxiliary rotation curve 521a and the second auxiliary rotation curve 522a extend to form a virtual intersection D1 (not shown), and the first auxiliary rotation curve 521a and the second auxiliary rotation curve 522a form an intersection D2 (not shown). When the first rotor 40 and the second rotor 50 are matched, a sudden change in the gap will occur at the intersection D1 and the intersection D2, causing pressure relief in the high-pressure area, thereby greatly affecting the efficiency of the positive displacement pump.

[0083] In this embodiment, the first main rotation curve 421a and the first auxiliary rotation curve 521a form a conjugate curve, the second main rotation curve 422a and the second auxiliary rotation curve 522a form a conjugate curve, and the main rotation transition curve 423a and the first auxiliary rotation transition curve 523a and the second auxiliary rotation transition curve 524a form a conjugate curve. The first rotor 40 and the second rotor 50 can maintain a stable and substantially the same gap as a whole, especially the transition section also maintains a stable gap, and there will be no gap mutation, thereby ensuring the stability of the high-pressure area and improving the overall efficiency of the product pump.

[0084] The rotation radius r of the first rotor 40 m is greater than the radius of gyration R2 of the second rotor 50. m The ratio of / R2 ranges from 1.1 to 2.8.

[0085] The source power is input from the first rotor 40 , which mainly performs the main work in the pump cavity 10 , while the second rotor 50 performs the auxiliary work and mainly performs the good dynamic sealing function.

[0086] Embodiment 3:

[0087] Figure 1-4 As shown, the pump cavity 10 is a cavity 120 of a closed cavity space defined by a first rotation line segment 124 of a first cavity rotation line 121, a second rotation line segment 125 of a second cavity rotation line 122, and a tangent 123 thereof. The radius of the first cavity rotation line 121 is R10, the radius of the second cavity rotation line 122 is R20, the gap A is the minimum gap between the first rotor 40 and the first cavity rotation line 121, and the gap B is the minimum gap between the second rotor 50 and the second cavity rotation line 122, satisfying the formula R10=r m +A; R20 = R2 + B; the gap A ≤ gap B, the gap A value range is: 0.03-0.3mm, the gap B value range is: 0.03-0.5mm.

[0088] The first rotor 40 and the second rotor 50 are both equipped with matching bearings at both ends. The second rotor 50 is driven by synchronous gears to achieve synchronous rotation of the first rotor 40 and the second rotor 50 in opposite directions. The first cam 402 and the second cam 502 are conjugate curves of each other and maintain a certain gap. The first rotor working curve 402a and the second rotor working curve 502a form a conjugate convex-concave curve. The gap is C. The gap C has a value range of 0.03-0.3mm. In a preferred embodiment, the conjugate convex-concave curves maintain approximately the same gap.

[0089] In this embodiment, by setting the main transition curve 423a and the auxiliary transition curve 523a to form a meshing fit, the overall gap between the first rotor working curve 402a and the second rotor working curve 502a is kept basically consistent, no obvious pressure release point occurs, and the pressure in the high pressure area is maintained.

[0090] Those skilled in the art should understand that there is also a certain gap between the first rotor 40 and the second rotor 50 and the pump cover to ensure that the first rotor 40 and the second rotor 50 do not frictionally interfere with each other when moving. The gap between the rotor and the pump cover ensures that the rotor does not frictionally interfere with the pump cover when moving.

[0091] Those skilled in the art should understand that when the medium to be extracted contains a large amount of impurities or debris, it is easy to cause the displacement pump to be blocked. For ease of understanding, the gap A and gap B are set to 0 for explanation. When the first rotor 40 used in the present invention rotates, the position of the vertex of the convex first main rotation amplitude surface 421 is in line contact with the first rotation line segment 124 of the pump cavity 10, and when the second rotor 50 used in the present invention rotates, the area where the convex first secondary rotation amplitude surface 521 is located forms a surface contact with the second rotation line segment 125 of the pump cavity 10. Those skilled in the art should understand that when the gap A and gap B are greater than 0, when the first rotor 40 rotates, the vertex of the first main rotation amplitude surface 421 and the first rotation line segment 124 are the minimum gap position of the rotor, and the minimum gap is only the area corresponding to the vertex of the first main rotation amplitude surface 421. When the second rotor 50 rotates, the minimum gap position between the first secondary rotation amplitude surface 521 and the second rotation line segment 125 is the area corresponding to the first secondary rotation amplitude surface 521. When the pump of this embodiment needs to work at a high head, the cavity pressure can be increased by increasing the rotation speed of the first rotor. Since the second rotor 50 and the second rotating line segment 125 form a dynamic seal, sudden pressure release can be effectively avoided to keep the pressure in the high-pressure area stable.

[0092] The first rotor 40 plays the role of actively doing work. Compared with a dual-rotor displacement pump of basically the same size, if a multi-cam unit method is adopted, in order to ensure the coordination between the cams, the main rotor diameter is usually not designed to be too thick. In this embodiment, due to the use of an asymmetric rotor, the rotation radius of the first rotor 40 is greater than the rotation radius of the second rotor 50, and the first rotor shaft 401 has space to increase the diameter. The diameter of the first rotor shaft 401 can be thickened to ensure that the first rotor shaft 401 does not break or fail under high torque requirements under the high pressure requirements of the displacement 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 to 2.

[0093] Embodiment 4:

[0094] like Figure 11-14As shown, this embodiment is based on the embodiment 1 and describes the pump cavity 10 in detail. The pump cavity 10 also includes a fish mouth 103, which is arranged along the tangent point position of the second cavity turning line 122 and the tangent line 123 along the extension direction of the second cavity turning line 122, and the fish mouth 103 includes a fish mouth matching section 131 and a fish mouth water dividing section 132 and a fish mouth top 133 where the two extend and intersect. The fish mouth matching section 131 of the fish mouth 103 increases the matching area of ​​the gap B between the second turning line segment 125 and the first secondary rotating width surface 521, which can effectively improve the dynamic sealing effect. The fish mouth 103 and the pump cavity 10 can be fixed by an integral molding connection.

[0095] An optional technical solution is that the distance between the fish mouth water dividing 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.

[0096] like Fig.11 As shown, another optional technical solution, the gap during the dynamic sealing process between the fish mouth matching section 131 and the first secondary rotation surface 521 is gap B, and a gradual gap can also be used. The material of the fish mouth matching section 131 includes: 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 bonded, welded or otherwise fixedly connected. An optional technical solution is that the top 133 of the fish mouth is protruding to set the first fish mouth adjustment section 134 to form a minimum gap with the first secondary rotation surface 521, and the gap is B1. When extending from the first fish mouth adjustment section 134 to the position of the second cavity rotation line 122, the gap between the fish mouth matching section 131 and the first secondary rotation surface 521 gradually increases, and the gap B1 is less than the gap B. Since there is a gap B1 between the fishmouths on both sides of the symmetry, the length of the first secondary rotation amplitude surface 521 corresponding to the first secondary rotation curve 521a must meet the following requirements: at any position of the second rotor 50, the first secondary rotation amplitude surface 521 at least cooperates with the fishmouth on one side to achieve the gap B1, and the gaps at other positions can be larger than the gap B1.

[0097] Another optional 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 are made of metal material, the first cam 402 is made of metal material, and the second cam 502 is made of self-lubricating plastic such as POM, PTFE, PA, etc., which can further reduce the fitting clearance between the second rotor 50 and the second cavity rotation line 122 and the fish mouth fitting section 131.

[0098] The positive displacement pump under this implementation can achieve a high head of more than 200 meters. Compared with the positive displacement pump of the prior art under the same working conditions, the volume is reduced by 40%, and compared with the centrifugal pump of the prior art under the same head flow, the efficiency is improved by more than 20%.

[0099] When gap B1 is less than gap B, those skilled in the art should understand that in order to achieve the same dynamic sealing effect, when a gradient gap is used, the gap B can adopt a larger value range. This technical solution not only satisfies the motion sealing performance of the second rotor 50, but also reduces the difficulty of assembly and the processing difficulty of the pump cavity 10 (the processing accuracy requirement of the first secondary rotating surface 521 can be reduced). In particular, when it is necessary to extract a large amount of debris, the fish mouth 103 of the POM material can achieve self-lubrication in the gap B1 area, and at the gap B position, due to the use of a larger gap value range, the second rotor 50 can be avoided from being blocked, and the dynamic sealing sliding friction of the first secondary rotating surface 521 can be effectively reduced.

[0100] like Fig.12 As shown, another optional technical solution is that the fish mouth matching section 131 is set as a rotatable roller, and during the dynamic sealing process with the first secondary amplitude rotating surface 521, the fish mouth matching section 131 forms rolling friction with the first secondary amplitude rotating surface 521. Since the friction force of the rolling friction is small, the gap B1 is smaller, thereby further improving the dynamic sealing performance.

[0101] In another embodiment, the fish mouth matching section 131 is further provided with a second fish mouth adjustment section 135, and the gap during the dynamic sealing process between the second fish mouth adjustment section 135 and the first secondary width rotation surface 521 is B2, and the gap B1 < gap B2 < gap B. The first fish mouth adjustment section 134 and the second fish mouth adjustment section 135 can be provided simultaneously or separately, and the matching gap between the fish mouth 103 and the first secondary width rotation surface 521 forms a high pressure area and gradually reduces the pressure. More fish mouth adjustment sections can also be provided on the fish mouth matching section 131. The use of multiple fish mouth adjustment sections can further increase the dynamic sealing of the first secondary width rotation surface 521.

[0102] In another embodiment, the fish mouth 103 is made of a rigid material, and the first fish mouth adjustment section 134 and the second fish mouth adjustment section 135 are made of a flexible material. This setting can further reduce the value range of the gap B1 and the gap B2, and further increase the dynamic sealing performance of the first secondary rotating amplitude surface 521 without increasing the dynamic sealing sliding friction of the first secondary rotating amplitude surface 521. The fish mouth adjustment section is generally arranged along the axial direction of the second rotor 50, and can also be S-shaped or other other shapes that run through the axial direction of the fish mouth.

[0103] like Fig.12As shown, another optional technical solution, the fish mouth 103 also includes a grease storage bag (not shown), the grease storage bag stores grease, and a plurality of grease discharge holes 136 are set in the first fish mouth adjustment section 134. The first fish mouth adjustment section 134 is made of flexible material. Under this solution, the gap B1 between the first fish mouth adjustment section 134 and the first secondary rotation width surface 521 can be 0, and the first fish mouth adjustment section 134 and the first secondary rotation width surface 521 can also form an interference fit. When the second rotor 50 rotates, the first secondary rotation width surface 521 squeezes the first fish mouth adjustment section 134, and the grease automatically overflows from the grease discharge holes 136, which plays a role in lubricating the first secondary rotation width surface 521 and the first fish mouth adjustment section 134. This solution achieves good dynamic sealing of the first secondary rotation width surface 521 without increasing the dynamic sealing sliding friction of the first secondary rotation width surface 521.

[0104] When it is necessary to adapt to the transportation of different media, especially for the case where there are more impurities, the second rotor 50, which mainly plays a sealing role, may be blocked. In another optional embodiment, the first fish mouth adjustment section 134 is movably connected to the fish mouth 103 in the form of a slider, and the first fish mouth adjustment section 134 includes an adjustment section slider section 139, a threaded adjustment rod 137 and an adjustment section knob 138. The adjustment section slider section 139 is movably connected to the threaded adjustment rod 137, and the adjustment section knob 138 is arranged outside the pump cavity 10, and the pump cavity 10 matches the internal threaded hole at the corresponding position of the threaded adjustment rod 137. Rotate the adjustment section knob 138, the threaded adjustment rod 137 feeds or withdraws in the pump cavity 10, and the threaded adjustment rod 137 pushes the adjustment section slider section 139 to protrude or retract into the pump cavity 10 to adjust the gap between the first fish mouth adjustment section 134 and the first secondary rotation surface 521. During use, the gap B1 between the first fish mouth adjustment section 134 and the first auxiliary rotating surface 521 on the fish mouth 103 can be adjusted. When a problem requiring blocking occurs, the gap B1 can be increased to achieve a slag discharge effect. After the slag discharge is completed, the gap B1 can be reduced to solve the dynamic sealing problem.

[0105] Embodiment 5:

[0106] like Fig.13As shown, another optional embodiment, the first fish mouth adjustment section 134 is movably connected to the fish mouth 103 as a slider, and the first fish mouth adjustment section 134 includes an adjustment slider 139a, an elastic adjustment rod 137a and a limit card 138a, the adjustment slider 139a is connected to the elastic adjustment rod 137a, and the limit card 138a is fixed on the pump chamber 10. The first fish mouth adjustment section 134 contacts with the first secondary rotation surface 521 or maintains a very small gap. When the second rotor 50 rotates, the first fish mouth adjustment section 134 is compressed by the first secondary rotation surface 521, and the first fish mouth adjustment section 134 is continuously in contact with the first secondary rotation surface 521. Since the elastic adjustment rod 137a is compressed, the contact pressure of the first fish mouth adjustment section 134 is small, but it can achieve a good sealing effect.

[0107] Embodiment 6:

[0108] like Fig.11 as well as Fig.14 As shown, the pump cavity 10 replaces the fish mouth 103 with Fig.14 The adjustable fish mouth 103a that can achieve angle adjustment is set from the tangent point of the second cavity rotation line 122 and the tangent line 123 along the second cavity rotation line 122 extending downward. The adjustable fish mouth 103a includes a fish mouth body 168, a turbine shaft 163, a turbine 161 and a worm 162 matched therewith. The fish mouth body 168 is provided with a fish mouth arc body 165, and the fish mouth body 168 is provided with a sealing groove 166 and a U-shaped mounting groove 169. The sealing groove 166 is provided with a sealing strip to form a seal with the pump cavity 10. The turbine shaft 163 is fixed to the turbine 161 and the fish mouth body 168, and the pump cavity 10 is provided with a mounting platform 167 for assembling the U-shaped mounting groove 169. The mounting platform 167 and the U-shaped mounting groove 169 are rotatably connected through the turbine shaft 163. The worm 162 extends outside the pump cavity 10 to provide a handle 164. The handle 164 of the rotating worm 162 drives the fish mouth body 168 to rotate, thereby adjusting the gap size during the dynamic sealing process between the fish mouth arc body 165 and the first secondary rotating surface 521. On the one hand, since the sealing strip or sealing film of the sealing groove 166 needs to be compressed during the angle adjustment process, a certain compression reaction force will be generated after the sealing strip is compressed. In particular, the fish mouth body 168 will also be subjected to a large force during the high-speed rotation of the second rotor 50, and there is a risk of failure caused by the automatic rotation of the adjustable fish mouth 103a. However, the turbine 161 and the worm 162 cooperate to form a self-locking effect, ensuring that the adjustable fish mouth 103a does not rotate after the angle is adjusted, thereby achieving angle fixation. This implementation can adjust the angle of the adjustable angle fish mouth 103a according to actual needs, thereby improving the dynamic sealing performance and slag removal effect of the second rotor 50.

[0109] like Figure 15-18 As shown, this embodiment describes in detail that when the first rotor 40 and the second rotor 50 rotate in the pump body 1, high-pressure areas and low-pressure areas are periodically formed in the pump body 1. The pump uses low pressure to suck in fluid and uses high pressure to squeeze out fluid. The fluid medium enters the pump cavity 10 from the medium inlet 101. Driven by the first rotor 40 and the second rotor 50, the fluid finally flows from the medium outlet 102 to the external pipeline outside the pump body 1, completing the normal operation of the pump.

[0110] The above description is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, shall be covered by the protection scope of the present invention by equivalently replacing or changing the technical solution and the inventive concept of the present invention. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "top", "bottom", "one side", "the other side", "front", "back", "middle part", "inside", "top", "bottom" and the like is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or a movable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A pump chamber of a positive displacement pump, characterized in that: The pump cavity includes a medium inlet and a medium outlet on both sides for fluid inlet and outlet, and a cavity for accommodating at least two rotors; the cavity is composed of a closed space defined by a first cavity rotation line, a second cavity rotation line and tangents thereto, the radius of the first cavity rotation line is R10, the radius of the second cavity rotation line is R20, R10>R20, the pump cavity also includes a fish mouth formed along the natural extension direction of the second cavity rotation line, and the fish mouth is provided with at least one fish mouth adjustment section.

2. The pump chamber according to claim 1, characterized in that: Gap A is the clearance between the first rotor and the first cavity, gap B is the clearance between the second rotor and the second cavity, r m is the first rotor gyration radius, R2 is the second rotor gyration radius; satisfying the formula R10 = r m +A; R20 = R2 + B, the gap A ≤ gap B, the gap A value range is: 0.03-0.3mm, the gap B value range is: 0.03-0.5mm.

3. The pump chamber according to claim 2, characterized in that: The fish mouth does not interfere with the first rotor, and the fish mouth increases the length of the matching area of ​​the gap B, thereby improving the dynamic sealing effect of the second rotor.

4. The pump chamber according to claim 2, characterized in that: The minimum gap formed by the fish mouth adjustment section and the second rotor working curve is smaller than the gap B.

5. The pump chamber according to claim 1, characterized in that: The fish mouth adjustment section is made of self-lubricating material, semi-rigid material or flexible material.

6. The pump chamber according to claim 1, characterized in that: The fish mouth also includes a grease storage bag, which stores grease, and the fish mouth adjustment section is provided with a plurality of grease discharge holes.

7. The pump chamber according to claim 1, characterized in that: The fish mouth adjustment section is movably connected to the fish mouth in the form of a slider. The fish mouth adjustment section includes an adjustment section slider section, a threaded adjustment rod and an adjustment section knob. The adjustment section slider section is movably connected to the threaded adjustment rod. The adjustment section knob is arranged outside the pump cavity. The pump cavity matches the internal threaded hole at the corresponding position of the threaded adjustment rod. The adjustment section knob is rotated to adjust the gap between the fish mouth adjustment section and the second rotor.

8. The pump chamber according to claim 1, characterized in that: The fish mouth adjustment section is movably connected to the fish mouth in the form of a slider. The fish mouth adjustment section includes an adjustment slider, an elastic adjustment rod and a limit card. The adjustment slider is connected to the elastic adjustment rod, and the limit card is fixed to the pump cavity.

9. The pump chamber according to claim 1, characterized in that: The pump cavity also includes an adjustable fish mouth formed along the natural extension direction of the second cavity rotation line. The adjustable fish mouth includes a fish mouth body, a turbine shaft, a turbine and a worm gear matching therewith. The handle of the rotating worm gear drives the fish mouth body to rotate, thereby adjusting the gap between the fish mouth arc body and the second rotor during the dynamic sealing process.

10. A volumetric pump, comprising a pump chamber as described in any one of claims 1 to 9, and further comprising a first rotor and a second rotor cooperating with the pump chamber, wherein the first rotor cooperates with the pump chamber to perform a main work function, and the second rotor cooperates with the pump chamber to perform an auxiliary work function and a dynamic sealing function.

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