High-pressure heavy-load type double-screw pump

Abstract

The utility model provides a high-pressure heavy-load type double-screw pump which comprises a pump body, a lining, a driving screw, a driven screw, a front bearing seat, a rear bearing seat, a bearing box and a gear box, the lining is arranged in the pump body, and a spiral section of the driving screw and a spiral section of the driven screw are meshed with each other and are arranged in the lining in parallel; the left and right polished rod sections of the driving screw and the driven screw penetrate through the bushings and then are respectively supported by the front bearing seat and the rear bearing seat; a driving gear is arranged on the left polished rod section of the driving screw rod, and a driven gear meshed with the driving gear is arranged on the left polished rod section of the driven screw rod; the driving gear and the driven gear are both located in the gearbox. An inner hole of the lining comprises a left conical hole and a right conical hole which are coaxial, and the left conical hole and the right conical hole are symmetrically arranged relative to the axial center line of the lining. The diameter of the left conical hole is gradually increased from left to right, and the diameter of the right conical hole is gradually decreased from left to right. The double-screw pump disclosed by the utility model can be better suitable for high-pressure and heavy-load working conditions.

Description

Technical Field

[0001] The utility model belongs to the technical field of twin-screw pumps, and in particular relates to a high-pressure and heavy-load twin-screw pump. Background Art

[0002] In the field of petrochemicals, twin-screw pumps are increasingly used to transport chemical materials. In long-distance transportation or device feeding, the required head is large (generally ≥2.5MPa), and continuous transportation is required, so the pressure-boosting capacity and stable operation capacity of the twin-screw pump are extremely high. Existing twin-screw pumps can basically meet the working conditions below 1.6MPa, but their stability is generally poor in working situations with pressures above ≥2.5MPa, which is mainly manifested in vibration and noise that cannot meet the requirements, flow rates that do not meet the design requirements, and even screw breakage accidents, resulting in their inability to meet the use requirements of high-pressure and heavy-load conditions. Therefore, how to design a twin-screw pump that can better meet the use requirements of high-pressure and heavy-load conditions has become a technical problem that technicians in this field urgently need to solve. Utility Model Content

[0003] The utility model aims to provide a high-pressure heavy-load twin-screw pump to solve the above technical problems in the prior art.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A high-pressure, heavy-load twin-screw pump, comprising a pump body, a bushing, a driving screw, a driven screw, a front bearing seat, a rear bearing seat, a bearing box and a gear box, wherein the bushing is arranged in the pump body, the spiral section of the driving screw and the spiral section of the driven screw are meshed and arranged in parallel in the bushing; the front bearing seat is arranged on the right side of the pump body, and the rear bearing seat is arranged on the left side of the pump body, and the left and right bare rod sections of the driving screw and the driven screw pass through the bushing and are supported by the front bearing seat and the rear bearing seat respectively; the bearing box is arranged at the front The gear box is arranged on the left side of the rear bearing seat; a driving gear is arranged on the left smooth rod section of the driving screw, and a driven gear for meshing with the driving gear is arranged on the left smooth rod section of the driven screw; the driving gear and the driven gear are both located in the gear box; the inner hole of the bushing includes a coaxial left conical hole and a right conical hole, and the left conical hole and the right conical hole are symmetrically arranged about the axial center line of the bushing; the diameter of the left conical hole gradually increases from left to right, and the diameter of the right conical hole gradually decreases from left to right.

[0006] Preferably, a first through hole provided on the right end of the bushing for allowing the right polished rod segment of the driving screw to pass through and a second through hole provided on the right end of the bushing for allowing the right polished rod segment of the driven screw to pass through are both provided with mechanical sealing structures; a third through hole provided on the left end of the bushing for allowing the left polished rod segment of the driving screw to pass through and a fourth through hole provided on the left end of the bushing for allowing the left polished rod segment of the driven screw to pass through are both provided with mechanical sealing structures.

[0007] Preferably, right-side bearings are provided in the fifth through hole provided on the right end of the front bearing seat for rotationally cooperating with the right polished rod segment of the driving screw and the sixth through hole provided for rotationally cooperating with the right polished rod segment of the driven screw.

[0008] Preferably, a left-side bearing is provided in the seventh through hole provided on the left end of the rear bearing seat for rotationally cooperating with the left polished rod segment of the driving screw and in the eighth through hole provided for rotationally cooperating with the left polished rod segment of the driven screw.

[0009] Preferably, a tail end bearing is provided in the ninth through hole provided on the left end of the gear box for rotationally cooperating with the left polished rod segment of the driving screw and the tenth through hole provided for rotationally cooperating with the left polished rod segment of the driven screw.

[0010] Preferably, it also includes a drive shaft pressure cover, and the drive shaft pressure cover is arranged outside the ninth through hole.

[0011] Preferably, it further comprises a driven shaft pressure cover, and the driven shaft pressure cover is arranged outside the tenth through hole.

[0012] Preferably, the radial clearance between different parts of the spiral segment of the driving screw and the inner wall of the inner hole of the bushing is equal to the sum of the flexible deformation of the corresponding parts on the spiral segment of the driving screw and the safety margin value; the radial clearance between different parts of the spiral segment of the driven screw and the inner wall of the inner hole of the bushing is equal to the sum of the flexible deformation of the corresponding parts on the spiral segment of the driven screw and the safety margin value.

[0013] The beneficial effects of the utility model are:

[0014] The high-pressure, heavy-load twin-screw pump of the utility model supports the driving screw and the driven screw by means of the front bearing seat, the rear bearing seat and the gear box, thereby reducing the deflection of the two screws, making the meshing of the driving gear and the driven gear more stable, and making the operation of the twin-screw pump more reliable, thereby better meeting the use requirements of high-pressure, heavy-load conditions; at the same time, the inner hole of the bushing is designed according to the flexible deformation of the driving screw and the driven screw, so that the inner hole of the bushing includes coaxial left and right conical holes, the diameter of the left conical hole gradually increases from left to right, and the diameter of the right conical hole gradually decreases from left to right, thereby effectively reducing the radial clearance between the spiral section of the screw and the inner wall of the inner hole of the bushing, so that it can not only improve the boosting capacity of the pump, but also has better reliability, thereby making the twin-screw pump better suitable for high-pressure, heavy-load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present utility model in detail in conjunction with the drawings, wherein

[0016] Figure 1 A schematic diagram of a high-pressure, heavy-duty twin-screw pump provided in an embodiment of the utility model;

[0017] Figure 2 A schematic diagram of the flexible deformation of the screw provided in the embodiment of the utility model;

[0018] Figure 3 A front view of a bushing provided in an embodiment of the utility model;

[0019] Figure 4 The left side view of the bushing provided in the embodiment of the utility model.

[0020] Markings in the accompanying drawings:

[0021] 1. Pump body, 2. Bushing, 3. Driving screw, 4. Driven screw, 5. Front bearing seat,

[0022] 6. Rear bearing seat, 7. Bearing box, 8. Gear box, 9. Drive shaft gland,

[0023] 10. Driven shaft gland, 11. Mechanical seal structure, 12. Right bearing, 13. Left bearing,

[0024] 14. Tail end bearing, 15. Driving gear, 16. Driven gear, 17. Left tapered hole of bushing,

[0025] 18. Right tapered hole of bushing, 19. Axial centerline, 20. Left polished section of screw,

[0026] 21. The right smooth rod section of the screw, 22. The left spiral section of the screw, 23. The right spiral section of the screw. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the utility model, the solution will be further described in detail below in conjunction with specific embodiments.

[0028] like Figures 1 to 4 As shown, the utility model embodiment provides a high-pressure heavy-duty twin-screw pump, which includes a pump body 1, a bushing 2, a driving screw 3, a driven screw 4, a front bearing seat 5, a rear bearing seat 6, a bearing box 7 and a gear box 8. The bushing 2 is arranged in the pump body 1, and the spiral section of the driving screw and the spiral section of the driven screw are meshed and arranged in parallel in the bushing 2; the front bearing seat 5 is arranged on the right side of the pump body 1, and the rear bearing seat 6 is arranged on the left side of the pump body 1. The left and right bare rod sections of the driving screw and the driven screw pass through the bushing 2 and are supported by the front bearing seat and the rear bearing seat respectively; the bearing box 7 It is arranged on the right side of the front bearing seat 5, and the gear box 8 is arranged on the left side of the rear bearing seat 6; a driving gear 15 is arranged on the left smooth rod section of the driving screw, and a driven gear 16 for meshing with the driving gear is arranged on the left smooth rod section of the driven screw; the driving gear and the driven gear are both located in the gear box 8; the inner hole of the bushing includes a coaxial left conical hole 17 and a right conical hole 18, and the left conical hole and the right conical hole are symmetrically arranged about the axial center line 19 of the bushing 2; the diameter of the left conical hole 17 gradually increases from left to right, and the diameter of the right conical hole 18 gradually decreases from left to right.

[0029] The high-pressure and heavy-load twin-screw pump provided by the embodiment of the utility model supports the driving screw and the driven screw through the front bearing seat 5, the rear bearing seat 6 and the gear box 8, thereby reducing the deflection of the above-mentioned two screws, making the meshing of the driving gear and the driven gear more stable, and the operation of the twin-screw pump more reliable, thereby better meeting the use requirements of high-pressure and heavy-load conditions; at the same time, the inner hole of the bushing is designed according to the flexible deformation of the driving screw and the driven screw, so that the inner hole of the bushing includes a coaxial left tapered hole 17 and a right tapered hole 18, and the diameter of the left tapered hole gradually increases from left to right, and the diameter of the right tapered hole gradually decreases from left to right, thereby effectively reducing the radial gap between the spiral section of the above-mentioned screw and the inner wall of the inner hole of the bushing, so that it can not only improve the boosting capacity of the pump, but also have good reliability, thereby making the twin-screw pump better suitable for high-pressure and heavy-load conditions.

[0030] Furthermore, a mechanical seal structure 11 is provided in the first through hole for the right polished rod section of the driving screw to pass through and the second through hole for the right polished rod section of the driven screw to pass through, which are provided on the right end of the bushing 2; a mechanical seal structure 11 is provided in the third through hole for the left polished rod section of the driving screw to pass through and the fourth through hole for the left polished rod section of the driven screw to pass through, which are provided on the left end of the bushing 2. With this solution, the pump body can be better sealed by the mechanical seal structure.

[0031] Specifically, the right side bearing 12 is arranged in the fifth through hole for rotationally cooperating with the right polished rod section of the driving screw and the sixth through hole for rotationally cooperating with the right polished rod section of the driven screw, which is provided on the right end of the front bearing seat 5, so that the driving screw and the driven screw can be conveniently arranged in the fifth through hole and the sixth through hole. It can be understood that the right end of the driving screw is connected to the driving member after passing through the bearing box 7, so that the driving member is used to drive the driving screw to rotate.

[0032] Preferably, the seventh through hole provided on the left end of the rear bearing seat 6 for rotationally cooperating with the left smooth rod section of the driving screw and the eighth through hole provided for rotationally cooperating with the left smooth rod section of the driven screw are both provided with a left-side bearing 13, thereby conveniently realizing the rotation setting of the driving screw and the driven screw in the seventh through hole and the eighth through hole.

[0033] Furthermore, a ninth through hole on the left end of the gear box 8 for rotationally cooperating with the left smooth rod section of the driving screw and a tenth through hole for rotationally cooperating with the left smooth rod section of the driven screw are both provided with tail end bearings 14, thereby conveniently realizing the rotation setting of the driving screw and the driven screw in the ninth through hole and the tenth through hole.

[0034] It is understandable that under low-pressure conditions, since the driving gear and the driven gear do not need to transmit a large torque, the support method of the above two gears adopts a cantilever type, but it is not suitable for high-pressure and heavy-load conditions. Under high-pressure and heavy-load conditions, the driving gear 15 and the driven gear 16 need to transmit a large torque. Generally, the load-bearing and transmission capacity of the two gears are guaranteed by increasing the tooth width. However, the increase in tooth width will also increase the weight of the gears. Under the action of the gravity bending moment of the gears and the transmission torque of the gears, it is very likely that the stiffness of the two screws will be insufficient and fail; the increase in bending moment and torque will also increase the load on the left and right side bearings, especially the life of the left side bearing will be greatly affected. The utility model adopts two tail-end bearings 14 to support the tail ends of the driving screw and the driven screw respectively, and changes the supporting mode of the two gears, so that the two ends of the gears are supported by the left-side bearing 13 and the tail-end bearing 14 respectively, thereby reducing the deflection of the two screws, making the meshing of the two gears more stable, and the operation of the twin-screw pump more reliable; at the same time, the tail-end bearing can share the torque load of the gear, thereby reducing the load of the left-side bearing and increasing the service life of the left-side bearing.

[0035] Specifically, the twin-screw pump also includes a drive shaft cover 9, which is arranged outside the ninth through-hole, so that the drive shaft cover 9 can protect the left end of the drive screw and the tail end bearing 14 located in the ninth through-hole, thereby ensuring the service life of the tail end bearing 14.

[0036] Furthermore, the twin-screw pump also includes a driven shaft pressure cover 10, which is arranged outside the tenth through hole, so that the driven shaft pressure cover 10 can protect the left end of the driven screw and the tail end bearing 14 located in the fourth through hole, thereby ensuring the service life of the tail end bearing 14.

[0037] Specifically, the radial clearance between different parts of the spiral section of the driving screw and the inner wall of the inner hole of the bushing is equal to the sum of the flexible deformation of the corresponding parts of the spiral section of the driving screw and the safety margin value; the radial clearance between different parts of the spiral section of the driven screw and the inner wall of the inner hole of the bushing is equal to the sum of the flexible deformation of the corresponding parts of the spiral section of the driven screw and the safety margin value. This solution can effectively reduce the radial clearance between the spiral sections of the two screws and the inner wall of the inner hole of the bushing, so that it can not only improve the boosting capacity of the pump, but also have better reliability, so that the twin-screw pump can better meet the use requirements of high-pressure and heavy-load conditions.

[0038] It should be noted that the fluid pressure increase is achieved by gradually increasing the pressure in multiple sealed chambers formed between the screw (i.e., the driving screw and the driven screw) and the bushing. Under high-pressure and heavy-load conditions, more sealed chambers are required to complete the entire pressure increase process, which will cause the screw length to increase.

[0039] According to the bending deformation equation y max =5×q×L 4 / (384×E×I), where y max is the maximum flexural deformation of the screw, q is the load, E is the elastic modulus of the material, and I is the moment of inertia. When the distance L between the left bearing and the right bearing increases, the maximum flexural deformation of the screw y max Under low pressure conditions, the maximum flexural deformation of the screw is usually max The sum of the safety margin value is set as the radial clearance between the spiral section of the screw and the inner wall of the bushing. However, under high-pressure and heavy-load conditions, if the clearance between the screw and the inner wall of the bushing is too large, it will make it difficult for the twin-screw pump to increase the pressure, and the volumetric efficiency is extremely low, which cannot meet the use requirements of high-pressure and heavy-load conditions.

[0040] According to the deflection curve equation y = q × x × (L 3 -2×L×x 2 +x 3 ) / (24×E×I), where x is the distance from a point on the screw (i.e., the driving screw and the driven screw) to the left bearing, and y is the flexural deformation of the point. a That is, the distance between the left end point a on the left spiral section 22 of the screw and the left bearing, see Figure 2 , the flexural deformation y of the left end point a of the left spiral section of the screw can be calculated respectively a =q×x a ×(L 3 -2×L×x a 2 +x a 3 ) / (24×E×I), the flexural deformation y of the right end point d of the right spiral section 23 of the screw d =q×x d ×(L 3 -2×L×x d 2 +x d 3 ) / (24×E×I), the flexible deformation y of the right end point b of the left helical section of the screw b =q×x b ×(L 3 -2×L×x b 2 +x b 3 ) / (24×E×I) and the flexural deformation y of the left end point c of its right spiral segment c =q×x c ×(L 3 -2×L×x c 2 +xc 3 ) / (24×E×I), where a and d are symmetrical about the axial center point of the screw, and b and c are symmetrical about the axial center point of the screw, and y is obtained. a =y d ,y b =y c .

[0041] The utility model arranges the inner walls of the left and right sides of the inner hole of the bushing (i.e. the left tapered hole and the right tapered hole) according to the surface equation Y=q×x×[L 3 -2×L×x 2 +x 3 ) / (24×E×I)]+k=y+k, where Y is the radial clearance between the bushing and the screw at a distance x from the support point (i.e., the left bearing or the right bearing) on ​​the screw, and k is the safety margin value, see Figure 3 , the radial clearance Y between the inner wall of the left end of the left conical hole and the outer surface of the spiral segment at point a on the driving screw a =y a +k, radial clearance Y between the outer surface of the spiral segment at point b on the driving screw and the inner wall of the right end of the left tapered hole b =y b +k, at this time, the radial clearance Y between the outer surface of the spiral segment at point d of the driving screw and the inner wall of the right end of the right conical hole d =y d + k = y a +k, radial clearance Y between the outer surface of the spiral segment at point c of the driving screw and the inner wall of the right conical hole near its left end c =y c + k = y b +k;

[0042] Similarly, at the corresponding position of the driven screw, the radial clearance Y between the left end outer surface of the left spiral section of the driven screw and the left end inner wall of the left tapered hole is a =y a +k, radial clearance Y between the outer surface of the right end of the left spiral section of the driven screw and the inner wall of the left tapered hole near its right end b =y b +k, radial clearance Y between the right end outer surface of the right spiral segment of the driven screw and the right end inner wall of the right tapered hole d =Y a =y a +k, radial clearance Y between the left end outer surface of the right spiral section of the driven screw and the inner wall of the right tapered hole near its left end (i.e., near the axial center line of the bushing) c =Y b =y b +k;

[0043] It can be seen that the radial clearance between the outer surface of the left spiral section of the driving screw and the inner wall of the left tapered hole gradually increases from left to right, that is, the radial clearance increases as the distance between different parts of the left spiral section of the driving screw and the left end bearing increases, and the radial clearance between the outer surface of the right spiral section of the driving screw and the inner wall of the right tapered hole gradually decreases from left to right, that is, the radial clearance decreases as the distance between different parts of the right spiral section of the driving screw and the left end bearing increases; the radial clearance between the outer surface of the left spiral section of the driven screw and the inner wall of the left tapered hole gradually increases from left to right, and the radial clearance between the outer surface of the right spiral section of the driven screw and the inner wall of the right tapered hole gradually decreases from left to right, which makes the diameter of the left tapered hole 17 gradually increase from left to right, and the diameter of the right tapered hole 18 gradually decrease from left to right. The utility model ensures the safety margin value, and makes the radial clearance between different parts of the spiral section of the screw and the bushing different, instead of making the radial clearance always have the same large value, thereby effectively reducing the radial clearance between the spiral section of the screw and the bushing, and better solving the problem that high pressure and high reliability are difficult to coexist, and at the same time greatly improves the volumetric efficiency of the twin-screw pump, so that the twin-screw pump can be better applied to high-pressure and heavy-load conditions.

[0044] The above are only preferred implementation modes of the present invention. It should be pointed out that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, after reading the contents of the present invention, relevant technical personnel in the field can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A high pressure heavy load twin screw pump, characterized in that: It includes a pump body, a bushing, a driving screw, a driven screw, a front bearing seat, a rear bearing seat, a bearing box and a gear box. The bushing is arranged in the pump body, and the spiral section of the driving screw and the spiral section of the driven screw are meshed and arranged in parallel in the bushing; the front bearing seat is arranged on the right side of the pump body, and the rear bearing seat is arranged on the left side of the pump body. The left and right bare rod sections of the driving screw and the driven screw pass through the bushing and are supported by the front bearing seat and the rear bearing seat respectively; the bearing box is arranged on the right side of the front bearing seat , the gear box is arranged on the left side of the rear bearing seat; a driving gear is arranged on the left polished rod section of the driving screw, and a driven gear for meshing with the driving gear is arranged on the left polished rod section of the driven screw; the driving gear and the driven gear are both located in the gear box; the inner hole of the bushing includes a coaxial left conical hole and a right conical hole, and the left conical hole and the right conical hole are symmetrically arranged about the axial center line of the bushing; the diameter of the left conical hole gradually increases from left to right, and the diameter of the right conical hole gradually decreases from left to right.

2. The high-pressure, heavy-duty twin-screw pump according to claim 1, characterized in that: A first through hole provided on the right end of the bushing for allowing the right polished rod segment of the driving screw to pass through and a second through hole provided on the right end of the bushing for allowing the right polished rod segment of the driven screw to pass through are both provided with mechanical sealing structures; a third through hole provided on the left end of the bushing for allowing the left polished rod segment of the driving screw to pass through and a fourth through hole provided on the left end of the bushing for allowing the left polished rod segment of the driven screw to pass through are both provided with mechanical sealing structures.

3. The high-pressure, heavy-duty twin-screw pump according to claim 1, characterized in that: The right side bearing is arranged in the fifth through hole arranged on the right end of the front bearing seat for rotationally cooperating with the right polished rod section of the driving screw and the sixth through hole arranged for rotationally cooperating with the right polished rod section of the driven screw.

4. The high-pressure, heavy-load twin-screw pump according to claim 1, characterized in that: The left side bearing is arranged in the seventh through hole arranged on the left end of the rear bearing seat for rotationally cooperating with the left polished rod section of the driving screw and the eighth through hole arranged for rotationally cooperating with the left polished rod section of the driven screw.

5. The high-pressure, heavy-load twin-screw pump according to claim 1, characterized in that: Tail end bearings are provided in the ninth through hole provided on the left end of the gear box for rotationally cooperating with the left polished rod section of the driving screw and the tenth through hole provided for rotationally cooperating with the left polished rod section of the driven screw.

6. The high-pressure, heavy-load twin-screw pump according to claim 5, characterized in that: It also includes a drive shaft pressure cover, and the drive shaft pressure cover is arranged outside the ninth through hole.

7. The high-pressure, heavy-load twin-screw pump according to claim 5, characterized in that: It also includes a driven shaft pressure cover, and the driven shaft pressure cover is arranged outside the tenth through hole.

8. The high-pressure, heavy-duty twin-screw pump according to any one of claims 1 to 7, characterized in that: The radial clearance between different parts of the spiral segment of the driving screw and the inner wall of the inner hole of the bushing is equal to the sum of the flexible deformation of the corresponding parts on the spiral segment of the driving screw and the safety margin value; the radial clearance between different parts of the spiral segment of the driven screw and the inner wall of the inner hole of the bushing is equal to the sum of the flexible deformation of the corresponding parts on the spiral segment of the driven screw and the safety margin value.

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