Semi-connecting shaft of single-stage centrifugal coaxial pump

Abstract

The utility model discloses a single-stage centrifugal coaxial pump semi-connecting shaft which comprises a shaft head, a first shaft section, a second shaft section and a shaft sleeve, the shaft head is coaxially and fixedly connected with one end of the first shaft section, the other end of the first shaft section is coaxially and fixedly connected with one end of the second shaft section, and the other end of the second shaft section is coaxially and fixedly connected with the shaft sleeve. A first key groove used for installing an impeller is formed in the outer wall of the first shaft section, a center hole used for being connected with a motor output shaft is formed in the outer end face of the shaft sleeve in the axis direction, the shaft head, the first shaft section, the second shaft section and the shaft sleeve are preferably made of 3Cr13, and the diameters of the shaft head, the first shaft section, the second shaft section and the shaft sleeve are sequentially increased. Two radial through holes communicated with the center hole are formed in the side wall of the shaft sleeve in the circumferential direction; according to the utility model, the motor and the impeller of the centrifugal coaxial pump can be stably connected and transmitted, the motor shaft is prevented from being damaged, the service life is long, and the maintenance cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of single-stage centrifugal coaxial pumps, in particular to a semi-connecting shaft of a single-stage centrifugal coaxial pump. Background Art

[0002] The output shaft of the single-stage centrifugal coaxial pump is connected to the impeller by a key connection. When the operating system is switched, the pump flow fluctuates greatly. The booster pump shaft is subjected to a large shear force, causing the single-stage centrifugal coaxial pump shaft to break frequently. Since the booster pump shaft has a uniform shaft diameter, stress concentration is prone to occur during rotation, increasing the risk of single-stage centrifugal coaxial pump shaft breaking. In addition, the motor coaxial pump requires a long maintenance cycle when outsourcing the replacement of the motor rotor shaft, and the maintenance cost is high. Utility Model Content

[0003] The utility model provides a single-stage centrifugal coaxial pump semi-connected shaft, which solves the problem that the direct connection between the output shaft and the impeller of the traditional single-stage centrifugal coaxial pump easily leads to frequent breakage of the motor rotor shaft, high maintenance cost and short service life of the motor shaft.

[0004] The utility model provides a single-stage centrifugal coaxial pump semi-connecting shaft, comprising a shaft head, a first shaft section, a second shaft section, and a shaft sleeve, wherein the shaft head is coaxially fixedly connected to one end of the first shaft section, the other end of the first shaft section is coaxially fixedly connected to one end of the second shaft section, the other end of the second shaft section is coaxially fixedly connected to the shaft sleeve, a first keyway for installing an impeller is arranged on the outer wall of the first shaft section, a center hole is arranged on the outer end surface of the shaft sleeve along the axial direction, the shaft sleeve is detachably fixedly connected to the output shaft of the motor through the center hole, and an external thread is arranged on the outer wall of the shaft head.

[0005] In the above technical solution, further, the material of the shaft head, the first shaft section, the second shaft section and the shaft sleeve is preferably 3Cr13; the diameters of the shaft head, the first shaft section, the second shaft section and the shaft sleeve increase sequentially.

[0006] In the above technical solution, preferably, a plurality of radial threaded holes penetrating the center hole are evenly distributed on the side wall of the sleeve along the circumferential direction, and the sleeve is interference fit with the motor output shaft and is fastened by screws arranged in the radial threaded holes.

[0007] In the above technical solution, preferably, at least two second keyways are arranged on the inner wall of the center hole along the circumferential direction, and the sleeve is connected to the motor output shaft with a flat key.

[0008] In the above technical solution, preferably, a plurality of axial screw holes are arranged on the inner end surface of the sleeve along the circumferential direction, and disassembly screws are arranged in the axial screw holes.

[0009] In the above technical solution, preferably, two radial through holes penetrating the center hole are arranged on the side wall of the sleeve along the circumferential direction, the center hole is an internal spline hole, the motor output shaft is arranged as a spline shaft, the sleeve is spline-connected to the motor output shaft, a stepped hole is radially arranged in the center hole of the sleeve, an oil seal is nested in the stepped hole and is outer-mounted on the motor output shaft.

[0010] In the above technical solution, preferably, a connecting disk is coaxially arranged in the center hole, two arc-shaped bosses are evenly arranged on the side of the connecting disk along the circumferential direction, an annular groove is arranged on the bottom surface of the center hole along the circumferential direction, the two arc-shaped bosses are embedded in the annular groove for rotational cooperation, a compression spring is arranged between two adjacent arc-shaped bosses, and a plurality of axial through holes are arranged in the circumferential direction of the connecting disk, and a top screw is arranged in each axial through hole to be connected and fixed with a threaded hole corresponding to the end face of the motor output shaft.

[0011] It can be seen from the above technical solutions that the utility model provides a single-stage centrifugal coaxial pump semi-connecting shaft.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] The utility model realizes that the motor output shaft is inserted into the shaft sleeve and fixedly connected with the shaft sleeve, and the motor output shaft drives the semi-connecting shaft to drive the impeller to rotate. The semi-shaft transmission has good mechanical stability, and the motor output shaft, the impeller and the semi-connecting shaft are easy to install and disassemble, and the output shear stress of the motor is dispersed to the first shaft section, the second shaft section and the shaft sleeve, thereby overcoming the problem that the existing impeller is directly installed on the motor output shaft to transmit torque, and effectively transferring the maximum stress position to the semi-connecting shaft, so as to prevent the frequent starting of the booster pump from causing wear and breakage of the motor output shaft, reduce the number of motor overhauls, increase the service life of the booster pump motor, and reduce the repair and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solution of the utility model, the following is a brief introduction to the drawings required for use in the implementation cases. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] Figure 1 This is a schematic diagram of the overall structure of a semi-connected shaft of a single-stage centrifugal coaxial pump proposed by the utility model;

[0016] Figure 2 The utility model provides a single-stage centrifugal coaxial pump half-connection shaft attachment Figure 1 AA cross-sectional view of ;

[0017] Figure 3 The utility model provides a single-stage centrifugal coaxial pump half-connection shaft attachment Figure 1BB cross-sectional view;

[0018] Figure 4 This is a schematic structural diagram of a first embodiment of a single-stage centrifugal coaxial pump half-connecting shaft proposed by the utility model;

[0019] Figure 5 This is a structural schematic diagram of a second embodiment of a single-stage centrifugal coaxial pump half-connecting shaft proposed by the utility model;

[0020] Figure 6 It is a partial structural cross-sectional structural schematic diagram of a second embodiment of a half-connecting shaft of a single-stage centrifugal coaxial pump proposed by the utility model;

[0021] Figure 7 The utility model provides a schematic diagram of the connecting plate structure of a half-connecting shaft of a single-stage centrifugal coaxial pump.

[0022] In the figure:

[0023] 1-shaft head; 11-external thread;

[0024] 2-first shaft section; 21-first keyway;

[0025] 3- Second shaft section;

[0026] 4-shaft sleeve; 40-radial through hole; 41-center hole; 42-second keyway; 43-radial threaded hole; 44-step hole; 45-oil seal; 46-axial screw hole; 47-disassembly screw; 48-radial threaded hole; 49-guide screw;

[0027] 5-motor output shaft; 51-annular guide groove;

[0028] 6-connecting plate; 61-arc boss; 62-annular groove; 63-compression spring; 64-axial through hole; 65-top screw. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0030] See also Figure 1-7A single-stage centrifugal coaxial pump semi-connecting shaft comprises a shaft head 1, a first shaft section 2, a second shaft section 3, and a shaft sleeve 4. The shaft head 1, the first shaft section 2, the second shaft section 3, and the shaft sleeve 4 are an integrated connection structure. The shaft head 1 is coaxially fixedly connected to one end of the first shaft section 2, the other end of the first shaft section 2 is coaxially fixedly connected to one end of the second shaft section 3, and the other end of the second shaft section 3 is coaxially fixedly connected to the shaft sleeve 4. A first keyway 21 for installing an impeller is provided on the outer wall of the first shaft section 2, a center hole 41 is provided on the outer end surface of the shaft sleeve 4 along the axial direction, and the shaft sleeve 4 is detachably fixedly mounted on the motor output shaft 5 through the center hole 41. Fixed connection, the impeller is installed on the first shaft section 2, the motor output shaft is fixedly connected with the shaft sleeve 4 by being inserted into the shaft sleeve 4, and the semi-connecting shaft is driven by the motor output shaft 5 to drive the impeller to rotate, the mechanical stability is good, the motor output shaft and the impeller are easy to install and disassemble, and the output torque of the motor is dispersed to the first shaft section 2, the second shaft section 3, and the shaft sleeve 4, which overcomes the existing impeller directly installed on the motor output shaft to transmit torque, effectively transfers the maximum force position to the semi-connecting shaft, prevents frequent starting of the booster pump from causing wear and breakage of the motor output shaft, reduces the number of motor maintenance times, and increases the service life of the booster pump motor.

[0031] In this embodiment, see Figure 1 The material of the shaft head 1, the first shaft section 2, the second shaft section 3, and the shaft sleeve 4 is preferably 3Cr13. 3Cr13 is martensitic stainless steel. The components of the steel mainly include carbon, chromium and other elements. It can withstand higher loads and has higher wear resistance. The diameters of the shaft head 1, the first shaft section 2, the second shaft section 3, and the shaft sleeve 4 increase successively. Specifically, the diameter of the first shaft section 2 is 54mm, the diameter of the second shaft section 3 is 60mm, and the diameter of the shaft sleeve 4 is 120mm. An external thread 11 is arranged on the outer wall of the shaft head 1, and the specification of the external thread 11 is M30X1.5mm. By increasing the shaft diameters of the shaft head 1, the first shaft section 2, and the second shaft section 3 successively, the stress on the half shaft is prevented from being concentrated together, the shear stress is dispersed, the service life of the shaft is increased, and the stability of the stress transfer of the shaft is increased.

[0032] In this embodiment, see Figure 1 An external thread 11 is arranged on the outer wall of the shaft head 1. By installing a nut on the shaft head 1, the impeller is fastened to the semi-connected shaft along the axial direction of the shaft head 1 to prevent the impeller from axially separating from the semi-connected shaft, which has good safety.

[0033] In this embodiment, see Figure 3 Eight radial threaded holes 43 are evenly distributed on the side wall of the sleeve 4 along the circumferential direction and penetrate the center hole 41. The size of the radial threaded holes 43 is M8. The sleeve 4 and the motor output shaft 5 are interference fit and fastened by screws arranged in the radial threaded holes 43, so that the sleeve 4 and the motor output shaft 5 can be positioned and fixed in the axial direction and in the circumferential direction to prevent the relative position of the sleeve 4 and the motor output shaft 5 from changing.

[0034] In this embodiment, see Figure 3 Two second key grooves 42 are arranged on the inner wall of the center hole 41 along the circumferential direction. The width of the two second key grooves 42 is 22 mm. The shaft sleeve 4 is connected to the motor output shaft 5 with a flat key.

[0035] As a first improved implementation of the above embodiment, see Figure 4 Two radial through holes 40 penetrating the center hole 41 are arranged on the side wall of the sleeve 4 along the circumferential direction. The center hole 41 is an inner spline hole. The motor output shaft 5 is arranged as a spline shaft. The sleeve 4 is spline-connected with the motor output shaft 5. A stepped hole 44 is arranged radially in the center hole 41 of the sleeve 4. An oil seal 45 is nested in the stepped hole 44 and is outer-mounted on the motor output shaft 5. Lubricating oil is added to the center hole 41 through the radial through holes 40. At the same time, a sealing plug is arranged in the radial through hole 40. The oil seal 45 can prevent the lubricating oil in the center hole 41 from leaking out, so as to prevent the outer spline of the motor output shaft 5 and the inner spline arranged in the center hole 41 from wearing and rusting due to long-term mechanical cooperation.

[0036] Preferably, see Figure 4 A plurality of axial screw holes 46 are arranged along the circumferential direction on the inner end surface of the sleeve 4, and a disassembly screw 47 is arranged in the axial screw hole 46. When it is necessary to separate the sleeve 4 and the motor output shaft 5, the disassembly screw 47 is screwed with a wrench to push the motor output shaft 5 axially out of the center hole 41 of the sleeve 4, so that the sleeve 4 and the motor output shaft 5 can be quickly separated, and the disassembly efficiency is high.

[0037] As a second improved implementation of the above embodiment, see Figure 5 , 6 7. A connecting plate 6 is coaxially arranged in the center hole 41. Two arc-shaped bosses 61 are evenly arranged on the side of the connecting plate 6 along the circumferential direction. An annular groove 62 is arranged on the bottom surface of the center hole 41 along the circumferential direction. The two arc-shaped bosses 61 are embedded in the annular groove 62 for rotational cooperation. A compression spring 63 is arranged between two adjacent arc-shaped bosses 61. A plurality of axial through holes 64 are arranged in the circumferential direction of the connecting plate 6. A top screw 65 is arranged in each axial through hole 64 to be threadedly connected and fixed with the end face of the motor output shaft 5. The sleeve 4 is connected to the motor through the connecting plate 6. The output shafts 5 are connected together. During the frequent start and stop of the system, the arc-shaped boss 61 acts on the spring 63 to achieve a buffer between the motor output shaft 5 and the sleeve 4 to prevent the motor output shaft 5 and the sleeve 4 from being rigidly matched. An annular guide groove 51 is provided on the outer wall of the motor output shaft 5, and a radial threaded hole 48 is provided on the outer wall of the sleeve 4. A guide screw 49 is installed in the radial threaded hole 48, and the threaded head of the guide screw 49 extends into the annular guide groove 51 to prevent the sleeve 4 and the motor output shaft 5 from relative movement in the axial direction.

[0038] It can be seen from the above technical scheme that when in use, the impeller is sleeved on the first shaft section 2, and a flat key is installed in the first keyway 21 to fix the impeller and the first shaft section 2 together, and the impeller lock nut is used to fasten the impeller and the first shaft section 2 together, and the sleeve 4 is sleeved on the output shaft of the booster pump motor through the center hole 41, so that the motor output shaft and the center hole 41 of the sleeve 4 are installed with interference fit, and at the same time, 8 M12 high-strength top screws are inserted into the radial threaded holes 43 to fasten the sleeve 4 and the motor output shaft in the radial direction, and the sleeve 4 and the motor output shaft 5 can also be fixedly connected by the flat keys by inserting the flat keys into the two second keyways 42. When the center hole 4 When the inner spline hole 1 is a spline hole, lubricating oil can be added into the center hole 41 through the radial through hole 40, and a sealing plug is arranged in the radial through hole 40, and the oil seal 45 can prevent the lubricating oil in the center hole 41 from leaking out, so as to prevent the outer spline of the motor output shaft 5 and the inner spline arranged in the center hole 41 from wearing due to long-term mechanical cooperation. When the connecting disk 6 is used to connect the sleeve 4 with the motor output shaft 5, the sleeve 4 and the motor output shaft 5 are connected together through the connecting disk 6. During the frequent start and stop of the system, the arc boss 61 acts on the spring 63 to realize the buffer connection between the motor output shaft 5 and the sleeve 4.

[0039] After the machine pump was modified by adopting the structure of the utility model, the operation cycle of the machine pump was significantly increased, from an average of one maintenance every 6 months to 2 years; an average of 2 shafts of a booster pump were replaced each year, and the outsourcing cost of each unit was 9,300 yuan each time. After the modification, the annual cost savings were 9,300×7×2=130,200 yuan. The average annual maintenance frequency of 7 booster pumps was 14 times, which was reduced to 0 times after the modification, greatly saving the outsourcing maintenance cost and reducing the maintenance frequency of the maintenance unit and the electrical workshop. It ensures the long-term operation of the device and avoids the unstable effects caused by the maintenance of the machine pump. This method can also be extended to other coaxial pumps, and has a wide range of applications.

[0040] Those skilled in the art will readily come up with other embodiments of the present invention after considering the specification and practicing the utility model disclosed herein. The present invention is intended to cover any variation, use or adaptation of the present invention, which follows the general principles of the present invention and includes common knowledge or customary technical means in the art that are not disclosed in the present invention. The specification and examples are to be regarded as exemplary only, and the true scope of the present invention is indicated by the claims.

[0041] It should be understood that the present invention is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The above-described embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention.

Claims

1. A single-stage centrifugal coaxial pump semi-connecting shaft, characterized in that: The invention comprises a shaft head (1), a first shaft section (2), a second shaft section (3), and a shaft sleeve (4), wherein the shaft head (1) is coaxially fixedly connected to one end of the first shaft section (2), the other end of the first shaft section (2) is coaxially fixedly connected to one end of the second shaft section (3), the other end of the second shaft section (3) is coaxially fixedly connected to the shaft sleeve (4), a first keyway (21) for mounting an impeller is arranged on the outer wall of the first shaft section (2), a center hole (41) is arranged on the outer end surface of the shaft sleeve (4) along the axial direction, the shaft sleeve (4) is detachably fixedly connected to the motor output shaft (5) by being sleeved through the center hole (41), and an external thread (11) is arranged on the outer wall of the shaft head (1).

2. A single-stage centrifugal coaxial pump semi-connecting shaft according to claim 1, characterized in that: The shaft head (1), the first shaft section (2), the second shaft section (3), and the shaft sleeve (4) are all made of 3Cr13; and the diameters of the shaft head (1), the first shaft section (2), the second shaft section (3), and the shaft sleeve (4) increase in sequence.

3. A single-stage centrifugal coaxial pump half-connecting shaft according to claim 2, characterized in that: A plurality of radial threaded holes (43) intersecting the center hole (41) are evenly distributed on the side wall of the shaft sleeve (4) in the circumferential direction; the shaft sleeve (4) and the motor output shaft (5) are interference fit and are fastened together by screws arranged in the radial threaded holes (43).

4. A single-stage centrifugal coaxial pump half-connecting shaft according to claim 1, characterized in that: At least two second key grooves (42) are arranged on the inner wall of the central hole (41) along the circumferential direction, and the shaft sleeve (4) is key-connected to the motor output shaft (5).

5. A single-stage centrifugal coaxial pump semi-connecting shaft according to claim 1, characterized in that: The inner end surface of the shaft sleeve (4) is provided with a plurality of axial screw holes (46) along the circumferential direction, and disassembly screws (47) are provided in the axial screw holes (46).

6. A single-stage centrifugal coaxial pump semi-connecting shaft according to claim 1, characterized in that: Two radial through holes (40) are arranged on the side wall of the sleeve (4) along the circumferential direction and are connected with the center hole (41); the center hole (41) is an internal spline hole; the motor output shaft (5) is arranged as a spline shaft; the sleeve (4) is spline-connected with the motor output shaft (5); a stepped hole (44) is arranged radially inside the center hole (41) of the sleeve (4); an oil seal (45) is embedded in the stepped hole (44) and is externally mounted on the motor output shaft (5).

7. A single-stage centrifugal coaxial pump half-connecting shaft according to claim 1, characterized in that: A connecting disk (6) is coaxially arranged in the center hole (41), two arc-shaped bosses (61) are evenly arranged on the side surface of the connecting disk (6) along the circumferential direction, an annular groove (62) is arranged on the bottom surface of the center hole (41) along the circumferential direction, the two arc-shaped bosses (61) are embedded in the annular groove (62) for rotational cooperation, a compression spring (63) is arranged between two adjacent arc-shaped bosses (61), a plurality of axial through holes (64) are arranged on the connecting disk (6) along the circumferential direction, and a top screw (65) is arranged in each of the axial through holes (64) to be connected and fixed with a threaded hole correspondingly arranged on the end surface of the motor output shaft (5).

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