CN114483575B - Twin screw pump for transporting fluids of high specific gravity - Google Patents
Twin screw pump for transporting fluids of high specific gravity Download PDFInfo
- Publication number
- CN114483575B CN114483575B CN202210133007.5A CN202210133007A CN114483575B CN 114483575 B CN114483575 B CN 114483575B CN 202210133007 A CN202210133007 A CN 202210133007A CN 114483575 B CN114483575 B CN 114483575B
- Authority
- CN
- China
- Prior art keywords
- screw
- pump
- thread
- pump body
- external
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000012530 fluid Substances 0.000 title claims abstract description 66
- 230000005484 gravity Effects 0.000 title claims abstract description 46
- 230000000149 penetrating effect Effects 0.000 claims abstract description 4
- 230000002146 bilateral effect Effects 0.000 claims description 3
- 108700041286 delta Proteins 0.000 abstract description 3
- 238000010992 reflux Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- 238000005299 abrasion Methods 0.000 description 3
- 230000010006 flight Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000008676 import Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2/00—Rotary-piston machines or pumps
- F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C2/12—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
- F04C2/14—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
- F04C2/16—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2240/00—Components
- F04C2240/20—Rotors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2240/00—Components
- F04C2240/30—Casings or housings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2240/00—Components
- F04C2240/50—Bearings
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Rotary Pumps (AREA)
- Details And Applications Of Rotary Liquid Pumps (AREA)
Abstract
The invention discloses a twin-screw pump for delivering a fluid of high specific gravity, comprising: the device comprises a pump body, a driving screw, a driven screw, a front bearing seat, a rear bearing seat and a gear box, wherein two sides of the pump body are provided with pump body inner holes penetrating through the pump body, the driving screw is in meshed connection with the driven screw, the driving screw and the driven screw are arranged on the pump body inner holes, and two sections of first external threads with the same screw pitch and opposite rotation directions are symmetrically arranged on two sides of the central position of the driving screw; two sections of second external threads with the same size as the first external threads are symmetrically arranged on two sides of the central position of the driven screw, and the meshing gaps delta 1 between the first external threads and the second external threads and the corresponding tooth surfaces meet the following formula: δ1= (1.2-2) T/[ (d+de) x pi ], the clearances δ2 between the first external thread and the second external thread and the inner bore of the pump body satisfy the following formula: δ2=0.5×10 ‑3 ×d. The double-screw pump for conveying the fluid with large specific gravity, disclosed by the invention, can be used for conveying the fluid with large specific gravity at a low rotating speed efficiently, so that the problems of low efficiency and short service life of the conventional screw pump are fundamentally solved.
Description
Technical Field
The invention relates to the technical field of chemical equipment, in particular to a double-screw pump for conveying fluid with large specific gravity.
Background
Screw pumps are adopted in China at present in the chemical industry field for conveying large specific gravity fluid, but the screw pumps are low in efficiency and short in service life at present.
The screw tooth surfaces are not contacted when the screw rod is meshed with the screw rod, and a larger gap is formed between the screw rod and the pump body, and the gap is as high as 0.2mm-0.5mm, so that the double-screw pump can be used for conveying low-viscosity fluid with poor lubricity. However, when a medium with low viscosity and poor lubricity is conveyed, a stable lubricating oil film cannot be formed on the spiral tooth surface and the inner surface of the pump body, so that the efficiency of the medium conveying pump is very low. The large specific gravity fluid has low viscosity, no lubricity and stronger permeability, so that the return flow of the pumping medium from a larger gap is more, and the pump efficiency is lower. Increasing the rotational speed of the pump can greatly increase the efficiency of the pump. The rotating speed of the double-screw pump for conveying low-viscosity medium is generally 1500r/min, if the rotating speed of the pump is continuously increased to 3000r/min, the turbulence can be definitely increased when the high-specific-gravity medium is conveyed by the faster rotating speed, the suction energy of the pump can be rapidly increased, and meanwhile, the abrasion of the pump is accelerated, so that the instability of the pump is increased, the failure rate of the pump is increased, and the service life of the high-specific-gravity fluid conveying pump is further shortened.
Accordingly, there is a need for a twin screw pump for delivering fluids of high specific gravity.
Disclosure of Invention
The invention aims to provide a double-screw pump for conveying fluid with large specific gravity, which solves the problems in the prior art, can efficiently convey the fluid with large specific gravity at a lower rotating speed, and fundamentally solves the problems of low efficiency and short service life of the traditional screw pump.
The present invention provides a twin screw pump for delivering a fluid of high specific gravity, comprising:
The pump comprises a pump body, a driving screw, a driven screw, a front bearing seat, a rear bearing seat and a gear box, wherein two sides of the pump body are provided with pump body inner holes penetrating through the pump body, the driving screw is in meshed connection with the driven screw, the driving screw and the driven screw are arranged on the pump body inner holes, two sections of first external threads with the same screw pitch and opposite rotation directions are symmetrically arranged on two sides of the central position of the driving screw, the first external threads close to the pump shaft extending side are left-handed threads, and the first external threads far away from the pump shaft extending side are right-handed threads; the center position bilateral symmetry of driven screw is provided with two sections with the second external screw thread that the size of first external screw thread is the same, and the second external screw thread that is close to the pump shaft side of stretching is right-handed screw, and the second external screw thread that keeps away from the pump shaft side of stretching is left-handed screw, the front bearing frame with the back bearing frame sets up respectively the front and back both ends of the pump body, the gear box with the back bearing frame is connected, wherein:
The engagement gap δ1 between the first external thread corresponding to the drive screw and the second external thread corresponding to the driven screw and the corresponding tooth face satisfies the following equation:
δ1＝(1.2～2)T/[(D+de)×π] (1)
The clearance delta 2 between the first external thread corresponding to the driving screw and the second external thread corresponding to the driven screw and the inner hole of the pump body satisfies the following formula:
δ2＝0.5×10-3×D (2)
Wherein D represents the thread outer diameters of the first external thread and the second external thread, de represents the thread minor diameters of the first external thread and the second external thread, and T represents the thread lead lengths of the first external thread and the second external thread.
The twin-screw pump for transporting a fluid having a large specific gravity as described above, wherein the left-hand thread and the right-hand thread of the first external thread corresponding to the driving screw are preferably equal in length to the left-hand thread and the right-hand thread of the second external thread corresponding to the driven screw.
The twin screw pump for transporting a fluid of a large specific gravity as described above, wherein it is preferable that the side of the pump body is provided with an independent fluid inlet at the front and rear, and a fluid outlet is provided at the upper middle of the pump body.
The twin-screw pump for conveying a fluid with a high specific gravity as described above, wherein it is preferable that the driving screw is provided with a first bearing and a second bearing at the front and rear, the driven screw is provided with a second bearing at the front and rear, the first bearing is an axial positioning bearing for axially limiting and radially supporting the driving screw, and the second bearing is a radial positioning bearing for radially supporting the driving screw and the driven screw.
The twin-screw pump for transporting a fluid of a large specific gravity as described above, wherein it is preferable that one side of the front bearing housing is fixed to the pump body, and a first front cover corresponding to the driving screw and a second front cover corresponding to the driven screw are connected to the other side of the front bearing housing.
The twin-screw pump for transporting a fluid of a large specific gravity as described above, wherein it is preferable that the front bearing housing is connected with a mechanical seal on the side close to the pump body, the front bearing housing is mounted with the first bearing in the pump body inner hole on the side close to the first front cover, and the front bearing housing is mounted with the second bearing in the pump body inner hole on the side close to the second front cover.
The twin-screw pump for transporting a fluid of a large specific gravity as described above, wherein preferably, one side of the rear bearing housing is fixed on the pump body, a gear box is connected on the other side of the rear bearing housing, the rear bearing housing is connected with a mechanical seal on the side close to the pump body, and the rear bearing housing is respectively provided with the second bearings in the inner holes of the pump body close to the gear box, which correspond to the driving screw and the driven screw.
The twin-screw pump for transporting a fluid of a large specific gravity as described above, wherein it is preferable that a driving gear and a driven gear are provided in the rear bearing housing, wherein the driving gear is mounted on the driving screw, and the driven gear is mounted on the driven screw.
The twin-screw pump for transporting a fluid of a large specific gravity as described above, wherein it is preferable that the front bearing housing and the rear bearing housing are positioned with two positioning cylindrical pins, respectively, between the pump body and the rear bearing housing.
The twin-screw pump for transporting a fluid having a large specific gravity as described above, wherein it is preferable that a ratio of a thread outer diameter D to a thread minor diameter de of the first external thread corresponding to the driving screw and the second external thread corresponding to the driven screw is 1.3 to 1.5;
The equivalent diameter of the span length L section between the front bearing and the rear bearing of the driving screw and the driven screw meets the following formula:
da＝[L0×de+L2×(D+de)+2×L1×d0]÷L (3)
Wherein L2 represents the thread length of the left-hand thread and the right-hand thread of the first external thread and the left-hand thread and the right-hand thread of the second external thread, L0 represents the distance between the left-hand thread and the right-hand thread of the first external thread and the second external thread, L1 represents the wheel base between the thread section and the front and rear bearings, d0 represents the diameter of the shaft between the thread section and the front and rear bearings,
The larger the equivalent diameter da, the more robust the L-section comprehensive performance is represented, the equivalent diameter da is not smaller than the minor diameter de of the thread,
L0 is 1.2-1.4 times of the tool withdrawal distance required by processing the threads on the screw,
The length of L2 is selected based on the inlet-outlet pressure differential, at a thread lead length T of 4-6 times,
L1 and d0 are selected on the premise of meeting the formula (3) by combining the size of the mechanical seal, so that the distance of the span length L section between the front bearing and the rear bearing of the screw is reduced while the equivalent diameter da is larger than the small diameter de of the screw.
The invention provides a double-screw pump for conveying fluid with large specific gravity, which reduces the clearance between a screw and a pump body by reducing the meshing clearance between screw threads and tooth surfaces, so that the reflux amount of a medium from the clearance when conveying fluid with large density can be reduced, and the pump can efficiently and stably convey the fluid with large specific gravity at a lower rotating speed; meanwhile, the lower rotating speed greatly reduces the suction energy of the pump, greatly reduces the noise of the pump, reduces the vibration of the pump, and improves the stability and the service life of the pump; the meshing clearance of the tooth surface of the screw thread can be reduced through the formula (1), the positioning cylindrical pin, the first bearing, the second bearing, the driving gear and the driven gear; the clearance between the screw and the pump body can be reduced by designing two independent fluid inlets and one fluid outlet through the formula (2) to cancel the complex flow passage of the pump inlet cavity and positioning the cylindrical pin; through designing the ratio of the thread external diameter D of first external thread and second external thread to the thread minor diameter de and the size of da, cancel the complicated runner of pump import chamber and connect front bearing frame and rear bearing frame with the pump body directly in order to simplify the pump structure, increase screw rod intensity, the medium is from the reflux volume in clearance when further greatly reducing and carrying high density fluid.
Drawings
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described with reference to the accompanying drawings, in which:
FIG. 1 is a cross-sectional view of an embodiment of a twin screw pump for delivering a fluid of high specific gravity provided by the present invention;
FIG. 2 is a front view of an embodiment of a twin screw pump for delivering a fluid of high specific gravity provided by the present invention;
FIG. 3 is a schematic illustration of the outside diameter, minor diameter, and lead length of the screw flights of an embodiment of a twin screw pump for delivering high specific gravity fluids provided by the present invention;
FIG. 4 is a schematic view of the meshing gap between the screw flights and the flanks of the flights of an embodiment of a twin screw pump for delivering high specific gravity fluids provided by the present invention;
FIG. 5 is a schematic illustration of the clearance between the screw flight section and the pump body bore of an embodiment of a twin screw pump for delivering a fluid of high specific gravity provided by the present invention;
fig. 6 is an external view schematically showing an embodiment of a twin-screw pump for transporting a fluid having a large specific gravity according to the present invention.
Reference numerals illustrate: the pump body 1, the driving screw 2, the driven screw 3, the mechanical seal 4, the positioning cylindrical pin 5, the first bearing 6, the first front cover 7, the second front cover 8, the fluid inlet 9, the second bearing 10, the driving gear 11, the driven gear 12, the fluid outlet 13, the front bearing seat 14, the rear bearing seat 15, the gear box 16 and the pump body inner hole 17.
Detailed Description
Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative, and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments should be construed as exemplary only and not limiting unless otherwise specifically stated.
"First", "second", as used in this disclosure: and similar words are not to be interpreted in any order, quantity, or importance, but rather are used to distinguish between different sections. The word "comprising" or "comprises" and the like means that elements preceding the word encompass the elements recited after the word, and not exclude the possibility of also encompassing other elements. "upper", "lower", etc. are used merely to denote relative positional relationships, which may also change accordingly when the absolute position of the object to be described changes.
In this disclosure, when a particular element is described as being located between a first element and a second element, there may or may not be intervening elements between the particular element and the first element or the second element. When it is described that a specific component is connected to other components, the specific component may be directly connected to the other components without intervening components, or may be directly connected to the other components without intervening components.
All terms (including technical or scientific terms) used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs, unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods, and apparatus should be considered part of the specification.
As shown in fig. 1 and 2, an embodiment of the present invention provides a twin screw pump for delivering a fluid having a large specific gravity, comprising: the novel pump comprises a pump body 1, a driving screw 2, a driven screw 3, a front bearing seat 14, a rear bearing seat 15 and a gear box 16, wherein a pump body inner hole 17 penetrating through the pump body 1 is formed in two sides of the pump body 1, the driving screw 2 and the driven screw 3 are in meshed connection, the driving screw 2 and the driven screw 3 are arranged on the pump body inner hole 17, two sections of first external threads with the same screw pitch and opposite screw directions are symmetrically formed in two sides of the central position of the driving screw 2, the first external threads close to the pump shaft extending side (shown in a box in fig. 1) are left-handed threads, and the first external threads far away from the pump shaft extending side are right-handed threads; the center position bilateral symmetry of driven screw 3 be provided with two sections with the second external screw thread that the size of first external screw thread is the same, and the second external screw thread that is close to the pump shaft side of stretching is right-handed screw, and the second external screw thread that keeps away from the pump shaft side of stretching is left-handed screw, front bearing frame 14 with rear bearing frame 15 sets up respectively the front and back both ends of pump body 1, gear box 16 with rear bearing frame 15 is connected, wherein:
as shown in fig. 4, the engagement gap δ1 between the first external thread corresponding to the drive screw 2 and the second external thread corresponding to the driven screw 3 and the corresponding tooth surface satisfies the following equation:
δ1＝(1.2～2)T/[(D+de)×π] (1)
As shown in fig. 5, the clearance δ2 between the first external thread corresponding to the drive screw 2 and the second external thread corresponding to the driven screw 3 and the pump body inner bore 17 satisfies the following equation:
δ2＝0.5×10-3×D (2)
As shown in fig. 3, D represents the outer diameters of the first and second external threads, de represents the minor diameters of the first and second external threads, and T represents the lead lengths of the first and second external threads.
In the invention, the delta 1 and the delta 2 adopt smaller design gaps, so that the meshing gap between screw threads and tooth surfaces can be reduced, and the gap between the screw and the pump body can be reduced, thereby reducing the reflux amount of medium from the gap when conveying high-density fluid and ensuring that the pump can efficiently and stably convey high-specific gravity fluid at lower rotating speed; meanwhile, the lower rotating speed reduces the suction energy of the pump to a great extent, greatly reduces the noise of the pump, reduces the vibration of the pump, and improves the stability and the service life of the pump.
In the present invention, the rotational speed of the pump is 800r/min to 1000r/min, for example 900r/min.
The left-handed threads and the right-handed threads of the first external threads corresponding to the driving screw 2 are equal to the left-handed threads and the right-handed threads of the second external threads corresponding to the driven screw 3 in terms of thread length.
Further, a first bearing 6 and a second bearing 10 are respectively installed in the front and the rear of the driving screw 2, the second bearings 10 are installed in the front and the rear of the driven screw 3, the first bearing 6 is an axial positioning bearing for axially limiting and radially supporting the driving screw 2, and the second bearing 10 is a radial positioning bearing for radially supporting the driving screw 2 and the driven screw 3.
Further, one side of the front bearing block 14 is fixed on the pump body 1, and a first front cover 7 corresponding to the driving screw 2 and a second front cover 8 corresponding to the driven screw 3 are connected to the other side of the front bearing block 14.
Further, the front bearing block 14 is connected to the mechanical seal 4 near the pump body 1, the first bearing 6 is mounted in the pump body inner hole 17 near the first front cover 7, and the second bearing 10 is mounted in the pump body inner hole 17 near the second front cover 8, and the front bearing block 14 is connected to the mechanical seal 4 near the pump body 1.
Further, one side of the rear bearing block 15 is fixed on the pump body 1, a gear box 16 is connected to the other side of the rear bearing block 15, the rear bearing block 15 is connected to the mechanical seal 4 near the pump body 1, and the second bearings 10 are respectively installed in the inner holes 17 of the pump body near the gear box 16, corresponding to the driving screw 2 and the driven screw 3.
The prior double-screw pump bearing seat and the pump body are connected by adopting a plurality of parts in a combined way, and the parts comprise the pump body bearing seat, a positioning ring, a mechanical seal seat, an end cover and the like, the parts are matched in a way of opening matching, the positioning gap is quite large (more than or equal to 0.05 mm), the bridging of a plurality of parts and the larger spigot fit gap between the bearing seat and the pump body seriously influence the positioning precision between the bearing seat and the pump body, so that the design gap of the pump cannot be ensured. Therefore, the front bearing seat 14 and the rear bearing seat 15 are directly connected with the pump body 1, so that a plurality of parts such as a positioning ring, an end cover, a mechanical seal seat and the like on the existing pump are eliminated, the pump structure is simplified, and the assembly precision of the pump is improved; the elimination of multiple parts also shortens the axial installation space of the pump, so that a shorter span length L is ensured.
Further, a driving gear 11 and a driven gear 12 are arranged in the rear bearing block 15, wherein the driving gear 11 is mounted on the driving screw 2, and the driven gear 12 is mounted on the driven screw 3. In the concrete implementation of the invention, the driving gear 11 and the driven gear 12 are precisely machined herringbone gears, and the positioning effect on the driven screw 3 is realized by the self-locking effect generated by the fact that the herringbone gears are respectively arranged on the driving screw 2 and the driven screw 3 after being meshed, so that the relative positions of the driving screw 2 and the driven screw 3 are fixed, and the meshing gap delta 1 between screw threads and each tooth of the threads is ensured.
Further, two positioning cylindrical pins 5 are respectively adopted for positioning between the front bearing seat 14 and the rear bearing seat 15 and the pump body 1. On the basis of reducing parts, the positioning mode is changed by positioning the cylindrical pin 5, and the positioning precision between the front bearing seat 14 and the rear bearing seat 15 and the pump body 1 is further improved, so that smaller meshing gaps between screw threads and smaller gaps between the screw and the pump body are ensured.
Further, as shown in fig. 6, the front and rear sides of the pump body 1 are respectively provided with an independent fluid inlet 9, and the middle position of the upper part of the pump body 1 is provided with a fluid outlet 13. The inlet cavity of the existing double-screw pump is provided with a complex inlet flow channel design, the flow division of liquid is carried out in the pump body, the unstable turbulence of large specific gravity fluid is aggravated by the change of medium flow velocity and impact in the inlet cavity of the pump body, the suction energy of the inlet of the pump is increased, the pump generates larger noise and vibration, the stability of the pump is reduced, and the service life of the pump is shortened. Therefore, the invention adopts two independent through inlets (namely the fluid inlet 9), eliminates the complex flow passage of the pump inlet cavity, leads the split flow of the large specific gravity fluid to be carried out on the pipeline outside the pump body, and leads the split flow to directly enter the suction inlet of the screw in the pump body, thereby reducing the pump suction energy, reducing the pump noise and low vibration and improving the overall stability.
Further, the ratio of the thread outer diameter D to the thread minor diameter de of the first external thread corresponding to the driving screw 2 and the second external thread corresponding to the driven screw 3 is 1.3 to 1.5;
As a whole, the equivalent diameter of the span length L section between the front and rear bearings of the drive screw 2 and the driven screw 3 satisfies the following formula as shown in fig. 3:
da＝[L0×de+L2×(D+de)+2×L1×d0]÷L (3)
Wherein, as shown in fig. 3, L2 represents the thread length of the left-hand thread and the right-hand thread of the first external thread and the left-hand thread and the right-hand thread of the second external thread, L0 represents the pitch of the left-hand thread and the right-hand thread of the first external thread and the second external thread, L1 represents the wheelbase between the thread segments and the front and rear bearings, d0 represents the diameter of the shaft between the thread segments and the front and rear bearings,
The larger the equivalent diameter da, the more robust the L-section comprehensive performance is represented, the equivalent diameter da is not smaller than the minor diameter de of the thread,
L0 is 1.2-1.4 times of the tool withdrawal distance required by processing the threads on the screw,
The length of L2 is selected based on the inlet-outlet pressure differential, at a thread lead length T of 4-6 times,
L1 and d0 are optimally designed in combination with the dimensions of the mechanical seal 4 on the premise of satisfying the formula (3), in order to ensure that the distance of the span length L segment between the front and rear bearings of the screw is reduced while the equivalent diameter da is larger than the minor diameter de of the screw.
The existing double-screw pump has low screw strength, and when the screw is subjected to pressure difference between an inlet and an outlet, larger deflection is generated, so that the screw and the pump body generate direct metal contact hard abrasion. On the structure of the existing double-screw pump, the structural design of the slender screw rod cannot be changed, which is also an important reason that the service life of the existing large specific gravity fluid delivery pump is very short. Therefore, the invention improves the intensity of the screw to the greatest extent by designing the ratio of the outer diameter D of the first external thread and the second external thread to the minor diameter de of the thread and the size da, reduces the deflection of the screw under the action of the pressure difference of an inlet and an outlet, ensures that the deflection of the screw under the action of the pressure difference of the inlet and the outlet is not larger than the fit clearance delta 2 between the thread section of the screw and the inner hole of the pump body, ensures that the screw is not contacted with the pump body, and ensures the smaller design clearance between the screw and the pump body, the screw and the meshing tooth surface of the screw, thereby fundamentally solving the problem of metal contact hard abrasion caused by direct contact of the screw and the pump body.
Further, as shown in fig. 6, the invention eliminates the complicated runner of the pump inlet cavity, the whole pump body can be processed and molded by adopting a round bar without being limited by a pump body die and a runner space, so that the length of the pump body can be adaptively designed according to the span length L between the front bearing and the rear bearing of the screw rod, thereby realizing the shorter span length L and further improving the strength of the driving screw rod 2 and the driven screw rod 3.
According to the double-screw pump for conveying the fluid with the large specific gravity, provided by the embodiment of the invention, the clearance between the screw and the pump body is reduced by reducing the meshing clearance between the screw threads and the tooth surfaces, so that the reflux amount of a medium from the clearance when conveying the fluid with the large density can be reduced, and the pump can be ensured to efficiently and stably convey the fluid with the large specific gravity at a lower rotating speed; meanwhile, the lower rotating speed greatly reduces the suction energy of the pump, greatly reduces the noise of the pump, reduces the vibration of the pump, and improves the stability and the service life of the pump; the meshing clearance of the tooth surface of the screw thread can be reduced through the formula (1), the positioning cylindrical pin, the first bearing, the second bearing, the driving gear and the driven gear; the clearance between the screw and the pump body can be reduced by designing two independent fluid inlets and one fluid outlet through the formula (2) to cancel the complex flow passage of the pump inlet cavity and positioning the cylindrical pin; through designing the ratio of the thread external diameter D of first external thread and second external thread to the thread minor diameter de and the size of da, cancel the complicated runner of pump import chamber and connect front bearing frame and rear bearing frame with the pump body directly in order to simplify the pump structure, increase screw rod intensity, the medium is from the reflux volume in clearance when further greatly reducing and carrying high density fluid.
Thus, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concepts of the present disclosure, some details known in the art are not described. How to implement the solutions disclosed herein will be fully apparent to those skilled in the art from the above description.
Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that the foregoing embodiments may be modified and equivalents substituted for elements thereof without departing from the scope and spirit of the disclosure. The scope of the present disclosure is defined by the appended claims.
Claims (10)
1. A twin screw pump for delivering a fluid of high specific gravity, comprising:
The pump comprises a pump body, a driving screw, a driven screw, a front bearing seat, a rear bearing seat and a gear box, wherein two sides of the pump body are provided with pump body inner holes penetrating through the pump body, the driving screw is in meshed connection with the driven screw, the driving screw and the driven screw are arranged on the pump body inner holes, two sections of first external threads with the same screw pitch and opposite rotation directions are symmetrically arranged on two sides of the central position of the driving screw, the first external threads close to the pump shaft extending side are left-handed threads, and the first external threads far away from the pump shaft extending side are right-handed threads; the center position bilateral symmetry of driven screw is provided with two sections with the second external screw thread that the size of first external screw thread is the same, and the second external screw thread that is close to the pump shaft side of stretching is right-handed screw, and the second external screw thread that keeps away from the pump shaft side of stretching is left-handed screw, the front bearing frame with the back bearing frame sets up respectively the front and back both ends of the pump body, the gear box with the back bearing frame is connected, wherein:
the engagement gap δ1 between the first external thread corresponding to the drive screw and the second external thread corresponding to the driven screw satisfies the following equation:
δ1＝(1.2～2)T/[(D+de)×π] (1)
The clearance delta 2 between the first external thread corresponding to the driving screw and the second external thread corresponding to the driven screw and the inner hole of the pump body satisfies the following formula:
δ2＝0.5×10-3×D (2)
Wherein D represents the thread outer diameters of the first external thread and the second external thread, de represents the thread minor diameters of the first external thread and the second external thread, and T represents the thread lead lengths of the first external thread and the second external thread.
2. The twin-screw pump for transporting fluids of high specific gravity according to claim 1, wherein the left-hand threads and the right-hand threads of the first external thread corresponding to the driving screw are equal in length to the left-hand threads and the right-hand threads of the second external thread corresponding to the driven screw.
3. The twin-screw pump for transporting fluids of high specific gravity according to claim 1, wherein each of the side edges of the pump body is provided with an independent fluid inlet and each of the side edges of the pump body is provided with a fluid outlet at a middle position of an upper portion of the pump body.
4. The twin-screw pump for transporting fluids of high specific gravity according to claim 2, wherein a first bearing and a second bearing are mounted on the front and rear of the driving screw, respectively, the second bearings are mounted on the front and rear of the driven screw, the first bearings are axial positioning bearings for axially limiting and radially supporting the driving screw, and the second bearings are radial positioning bearings for radially supporting the driving screw and the driven screw.
5. The twin screw pump for transporting a fluid of high specific gravity according to claim 4, wherein one side of the front bearing housing is fixed to the pump body, and a first front cover corresponding to the driving screw and a second front cover corresponding to the driven screw are connected to the other side of the front bearing housing.
6. The twin screw pump for transporting a fluid of high specific gravity according to claim 5, wherein the front bearing housing is connected with a mechanical seal on a side close to the pump body.
7. The twin screw pump for transporting fluids of high specific gravity according to claim 6, wherein one side of the rear bearing housing is fixed to the pump body, a gear box is connected to the other side of the rear bearing housing, and a mechanical seal is connected to the rear bearing housing at the side close to the pump body.
8. The twin screw pump for transporting a high gravity fluid according to claim 7, wherein a driving gear and a driven gear are provided in the gear box, wherein the driving gear is mounted on the driving screw, and the driven gear is mounted on the driven screw.
9. The twin screw pump for transporting fluids of high specific gravity according to claim 7, wherein two locating cylindrical pins are used for locating each of the front and rear bearing blocks and the pump body.
10. The twin-screw pump for transporting a fluid of a large specific gravity according to claim 7, wherein a ratio of a thread outer diameter D to a thread minor diameter de of the first external thread corresponding to the driving screw and the second external thread corresponding to the driven screw is 1.3 to 1.5;
The equivalent diameter of the span length L section between the front bearing and the rear bearing of the driving screw and the driven screw meets the following formula:
da＝[L0×de+L2×(D+de)+2×L1×d0]÷L (3)
Wherein L2 represents the thread length of the left-hand thread and the right-hand thread of the first external thread and the left-hand thread and the right-hand thread of the second external thread, L0 represents the distance between the left-hand thread and the right-hand thread of the first external thread and the second external thread, L1 represents the wheel base between the thread section and the front and rear bearings, d0 represents the diameter of the shaft between the thread section and the front and rear bearings,
The larger the equivalent diameter da, the more robust the L-section comprehensive performance is represented, the equivalent diameter da is not smaller than the minor diameter de of the thread,
L0 is 1.2-1.4 times of the tool withdrawal distance required by processing the threads on the screw,
The length of L2 is selected based on the inlet-outlet pressure differential, at a thread lead length T of 4-6 times,
L1 and d0 are selected on the premise of meeting the formula (3) by combining the size of the mechanical seal, so that the distance of the span length L section between the front bearing and the rear bearing of the screw is reduced while the equivalent diameter da is larger than the small diameter de of the screw.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210133007.5A CN114483575B (en) | 2022-02-08 | 2022-02-08 | Twin screw pump for transporting fluids of high specific gravity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210133007.5A CN114483575B (en) | 2022-02-08 | 2022-02-08 | Twin screw pump for transporting fluids of high specific gravity |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114483575A CN114483575A (en) | 2022-05-13 |
| CN114483575B true CN114483575B (en) | 2024-05-03 |
Family
ID=81481236
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210133007.5A Active CN114483575B (en) | 2022-02-08 | 2022-02-08 | Twin screw pump for transporting fluids of high specific gravity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114483575B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117404041B (en) * | 2023-12-14 | 2024-02-23 | 中国石油集团渤海钻探工程有限公司 | Injection and production wellhead device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0496170A2 (en) * | 1990-12-24 | 1992-07-29 | James River Corporation Of Virginia | Positive displacement pumps |
| CN1088666A (en) * | 1992-07-29 | 1994-06-29 | 海因里希·莫勒 | Be used to rotate the conveying screw pair of compressor pump |
| CN2408276Y (en) * | 2000-03-03 | 2000-11-29 | 天津螺杆机械实业有限公司 | Two screw transport pump for high thickness medium |
| CN2641326Y (en) * | 2003-07-31 | 2004-09-15 | 黄工机械有限公司 | Novel double screw stem pump |
| CN205937097U (en) * | 2016-08-18 | 2017-02-08 | 黄山工业泵制造有限公司 | Simplify double suction double -screw pump of structure |
| CN206054285U (en) * | 2016-07-08 | 2017-03-29 | 天津君宇科技股份有限公司 | High-pressure large-displacement Quimby pump |
| CN107387401A (en) * | 2017-08-10 | 2017-11-24 | 黄山市威格狮泵业有限公司 | A kind of high pressure Quimby pump |
| CN110397588A (en) * | 2019-07-29 | 2019-11-01 | 山东劳伦斯流体科技有限公司 | A kind of high-pressure heavy-load Quimby pump |
-
2022
- 2022-02-08 CN CN202210133007.5A patent/CN114483575B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0496170A2 (en) * | 1990-12-24 | 1992-07-29 | James River Corporation Of Virginia | Positive displacement pumps |
| CN1088666A (en) * | 1992-07-29 | 1994-06-29 | 海因里希·莫勒 | Be used to rotate the conveying screw pair of compressor pump |
| CN2408276Y (en) * | 2000-03-03 | 2000-11-29 | 天津螺杆机械实业有限公司 | Two screw transport pump for high thickness medium |
| CN2641326Y (en) * | 2003-07-31 | 2004-09-15 | 黄工机械有限公司 | Novel double screw stem pump |
| CN206054285U (en) * | 2016-07-08 | 2017-03-29 | 天津君宇科技股份有限公司 | High-pressure large-displacement Quimby pump |
| CN205937097U (en) * | 2016-08-18 | 2017-02-08 | 黄山工业泵制造有限公司 | Simplify double suction double -screw pump of structure |
| CN107387401A (en) * | 2017-08-10 | 2017-11-24 | 黄山市威格狮泵业有限公司 | A kind of high pressure Quimby pump |
| CN110397588A (en) * | 2019-07-29 | 2019-11-01 | 山东劳伦斯流体科技有限公司 | A kind of high-pressure heavy-load Quimby pump |
Non-Patent Citations (1)
| Title |
|---|
| 螺杆泵;筑比地仁;管洪;;机电设备;19831215(第12期);10-14 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114483575A (en) | 2022-05-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114483575B (en) | Twin screw pump for transporting fluids of high specific gravity | |
| US20090311120A1 (en) | Gear pump | |
| CN101384821A (en) | Uni-axial screw pump | |
| US10323636B2 (en) | Gear pump with end plates or bearings having spiral grooves | |
| CN201306277Y (en) | Highly viscous three-screw pump | |
| US8496456B2 (en) | Progressive cavity pump including inner and outer rotors and a wheel gear maintaining an interrelated speed ratio | |
| CN102606517A (en) | Inner and outer combined double-spiral seal | |
| US2588888A (en) | Pump | |
| CN101251107A (en) | Multilevel inner series dual supercharging double-circular-arc gear pump | |
| CN110594150B (en) | Spiral tooth double-arc tooth-shaped hydraulic gear pump with axial and radial static pressure support | |
| CN206530480U (en) | A kind of Quimby pump | |
| CN105952636B (en) | The capacity new-type double screw pump of self-lubricating supporting | |
| CN101532490A (en) | Ball bearing screw pump | |
| CN106337806A (en) | High-temperature molten aluminum conveying pump | |
| CN102597522A (en) | Helical gear pump | |
| CN205446430U (en) | Antifriction bearing structure and gear pump and crescent gear pump of gear pump | |
| CN207364244U (en) | A kind of power takeoff being lubricated using helicoidal pump, gearbox or Retarder | |
| CN114320910B (en) | Screw compressor and air conditioning system | |
| CN219888258U (en) | Gear pump shaft and gear pump for conveying liquid medium | |
| CN218863241U (en) | Lubricating structure for electric drive input shaft spline | |
| CN2378553Y (en) | Efficient small displacement high pressure gear oil pump | |
| CN2890422Y (en) | Anti-corrosion wearable single-screw pump | |
| US3519375A (en) | Screw pumps | |
| CN109869310A (en) | A kind of high viscosity medium lubricating gear pump | |
| CN108302035B (en) | Packaging mechanical seal elastomer double-screw pump |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |