Heat dissipation structure of multiphase pump and multiphase pump

Abstract

The utility model relates to the technical field of oil-gas mixed transportation equipment, in particular to a heat dissipation structure of a mixed transportation pump and the mixed transportation pump, the heat dissipation structure comprises a first sleeve and a second sleeve which are located in a pump shell of the mixed transportation pump and have the same structure, the first sleeve is sleeved on a driving shaft, and the first sleeve is close to but not in contact with a main rotor on the driving shaft; the driven shaft is sleeved with the second sleeve, the second sleeve is close to but not in contact with the auxiliary rotor on the driven shaft, the driving shaft and the driven shaft are arranged in parallel, and the first sleeve corresponds to the second sleeve in position; the first sleeve is provided with a first fluid channel, the second sleeve is provided with a second fluid channel, a third fluid channel is arranged in the pump shell, and the first fluid channel, the second fluid channel and the third fluid channel are communicated to form a cooling liquid channel. When the multiphase pump works, cooling liquid can be injected into the cooling liquid channel, the injected cooling liquid can take away heat generated by sealing on the first sleeve and the second sleeve, and the sealing effect is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas mixed transportation equipment, in particular to a heat dissipation structure of a mixed transportation pump and the mixed transportation pump. Background Art

[0002] Mixed transportation technology is a key technology in the process of oil and natural gas extraction and transportation. Compared with the traditional separation and transportation technology, mixed transportation technology does not require oil, gas and water separation to complete the transportation of oil and gas, reducing the number of transfer stations and transportation pipelines, and greatly reducing production costs. The oil, gas and sand multiphase mixed transportation pump is the core equipment of the entire mixed transportation technology, and its performance greatly affects the economic benefits of the oil and natural gas transportation process.

[0003] Seals are an important part of mechanical equipment. If the seal design cannot meet the equipment requirements, the equipment's working efficiency will be reduced, and oil and gas leakage will lead to resource waste and environmental pollution, and even safety accidents in serious cases. As my country's economy enters a stage of high-quality development, the reliability requirements for mechanical systems are getting higher and higher. The oil and gas mixed transmission pump is related to the safety of resource transportation and is also a reflection of the level of industrial manufacturing. Therefore, it is necessary to design a high-quality sealing structure.

[0004] In order to achieve the reliability of the seal, the seal is usually pressed against certain parts, so during the use of the petroleum mixed rotor pump, a large amount of heat is often generated due to friction. If the heat cannot be dissipated in time, the temperature of the pump body and the seal will rise, affecting the sealing performance, and further even causing the seal to fail and cause safety accidents. Therefore, for the petroleum mixed rotor pump, it is crucial to carry out effective heat dissipation design for its sealing structure. It can not only improve the operating efficiency and sealing reliability of the pump, but also extend the service life of the pump, reduce maintenance costs, and ensure the safety and stability of production. In the prior art, the research on the sealing ring is mainly on the sealing performance, and there is little research on the cooling and heat dissipation of the sealing ring. Utility Model Content

[0005] In view of this, the purpose of the utility model is to provide a heat dissipation structure and a mixed pump for a mixed pump, so as to at least solve the problems that when the existing petroleum mixed pump runs at high speed, high pressure and large displacement, the sealing ring temperature rises too quickly and cannot dissipate heat in time, affecting the sealing performance and even causing sealing failure.

[0006] The utility model solves the above technical problems through the following technical means:

[0007] In a first aspect, the utility model provides a heat dissipation structure of a mixed flow pump, comprising a first sleeve and a second sleeve of the same structure located inside a pump casing of the mixed flow pump, wherein the first sleeve is sleeved on a driving shaft, and the first sleeve is close to but does not contact a main rotor on the driving shaft, the second sleeve is sleeved on a driven shaft, and the second sleeve is close to but does not contact a secondary rotor on the driven shaft, the driving shaft and the driven shaft are placed in parallel, and the positions of the first sleeve and the second sleeve correspond; the first sleeve has a first fluid channel, the second sleeve has a second fluid channel, and the pump casing has a third fluid channel, and the first fluid channel, the second fluid channel and the third fluid channel are connected to form a coolant channel.

[0008] In combination with the first aspect, in some embodiments, the interiors of the first sleeve and the second sleeve are both hollow structures, the outer walls of the first sleeve and the second sleeve both have a first annular groove, the first sleeve and the second sleeve both have at least one through hole connected to the internal hollow, the through hole is located in the first annular groove and connected to the first annular groove, the first annular groove, the through hole and the internal hollow on the first sleeve are connected to form a first fluid channel, and the first annular groove, the through hole and the internal hollow on the second sleeve are connected to form a second fluid channel.

[0009] In combination with the first aspect, in some embodiments, the first sleeve and the second sleeve have tightening rings at opposite ends, the tightening ring on the first sleeve is sleeved on the driving shaft, and a gap communicating with the through hole is left between the inner cylinder wall between the two tightening rings on the first sleeve and the driving shaft, and the tightening ring on the second sleeve is sleeved on the driven shaft, and a gap communicating with the through hole is left between the inner cylinder wall between the two tightening rings on the second sleeve and the driven shaft.

[0010] In combination with the first aspect, in some embodiments, a second annular groove is provided inside the pump casing at a position corresponding to the first annular groove, and the second annular groove is communicated with the first annular groove. The pump casing also has an inlet channel and an outlet channel, and the inlet channel and the outlet channel are respectively communicated with the corresponding second annular groove to form a third fluid channel.

[0011] In combination with the first aspect, in some embodiments, one end of the first sleeve and the second sleeve are both provided with a retaining ring, and the other end is both provided with a main sealing structure, wherein the main seal is used to enhance the sealing performance inside the coolant channel, and the second annular groove corresponding to the first sleeve is sealed by the retaining ring, the outer tube wall of the first sleeve and the main sealing structure to form a first annular cavity, and the second annular groove corresponding to the second sleeve is sealed by the retaining ring, the outer tube wall of the second sleeve and the main sealing structure to form a second annular cavity, the inlet channel is connected to the first annular cavity, and the outlet channel is connected to the second annular cavity, and the inlet channel, the first annular cavity, the second annular cavity and the outlet channel constitute a third fluid channel.

[0012] In combination with the first aspect, in some embodiments, the main sealing structure includes an O-ring and a wear-resistant ring, and the O-ring and the wear-resistant ring are both mounted on the first sleeve and the second sleeve, and a cover plate is installed between the O-ring and the second annular groove, and the cover plate is fixed to the pump casing by countersunk screws.

[0013] In combination with the first aspect, in some embodiments, tapered roller bearings are installed on the driving shaft between the first sleeve and the pump cover of the mixed pump, and on the driven shaft between the second sleeve and the pump cover, and the outer ring of the tapered roller bearing is matched with the pump cover as J7, and the inner ring of the tapered roller bearing is matched with the driving shaft as K6.

[0014] The heat dissipation structure of the mixed pump of the utility model is formed by sleeved a first sleeve on the driving shaft and a second sleeve on the driven shaft, and the first fluid channel on the first sleeve, the second fluid channel on the second sleeve and the third fluid channel inside the pump housing are connected to form a coolant channel. When the mixed pump is working, coolant can be injected into the coolant channel, and the injected coolant can take away the heat generated by the seals on the first sleeve and the second sleeve to ensure the sealing effect. The heat dissipation structure of the mixed pump of the utility model can effectively dissipate the heat of the seals on the first sleeve and the second sleeve, and store coolant to ensure the sealing effect through the gap between the first sleeve and the driving shaft, and the gap between the second sleeve and the driven shaft.

[0015] In a second aspect, the utility model provides a mixed flow pump, wherein the mixed flow pump comprises the heat dissipation structure described in the first aspect.

[0016] In combination with the second aspect, in some embodiments, a driving gear is installed on the driving shaft, a driven gear is installed on the driven shaft, a expansion sleeve is provided between the driving gear and the driving shaft, a retaining ring is installed at one end of the expansion sleeve, and an expansion cover is installed at the other end, and the expansion cover is fixed to the driving gear by screws.

[0017] In combination with the second aspect, in some embodiments, a shaft end cover is installed at one end of the driven shaft away from the auxiliary rotor, and the shaft end cover is fixed to the driven shaft by screws and cylindrical pins. The shaft end cover covers part of the driven gear to achieve axial positioning of the driven gear.

[0018] In the mixed flow pump of the utility model, the coolant enters from the inlet channel opened at the bottom. Due to the gravity of the coolant itself, the third fluid channel opened in the mixed flow pump and the cavity formed by the first fluid channel and the second fluid channel can be filled, and then flow out from the outlet channel above the pump housing, so that the heat dissipation structure in the mixed flow pump can better cool the sealing components and reduce the bubbles in the flow channel, and the circulating cooling is more stable. The mixed flow pump of the utility model uses an expansion sleeve to position the driving gear, and at the same time ensures the accuracy of the matching between the main rotor and the auxiliary rotor, which increases the flexibility of the mixed flow pump when working. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a mixed flow pump and a heat dissipation structure inside the mixed flow pump;

[0020] Figure 2 yes Figure 1 The enlarged view of point A in the middle;

[0021] Figure 3 It is a schematic diagram of the structure of the driving shaft and the driven shaft;

[0022] Figure 4 is a schematic diagram of the structure of the first sleeve;

[0023] Figure 5 is a cross-sectional view of the first sleeve;

[0024] Figure 6 It is a partial structural diagram of the pump casing;

[0025] Figure 7 This is the coolant flow diagram Figure 1 ;

[0026] Figure 8 This is the coolant flow diagram Figure 2 ;

[0027] Fig. 9 yes Figure 1 The enlarged view of point B in the middle;

[0028] Among them, the driving shaft 001, the main rotor 011, the first section 0011, the second section 0012, the third section 0013, the fourth section 0014, the fifth section 0015, the sixth section 0016, the driven shaft 002, the first part 0021, the second part 0022, the third part 0023, the fourth part 0024, the fifth part 0025, the auxiliary rotor 022, the first annular cavity 003, the second annular cavity 004, the first sleeve 110, the second sleeve 12 0, first annular groove 130, through hole 140, clamping ring 150, retaining ring 160, pump housing 200, second annular groove 210, inlet channel 220, outlet channel 230, intermediate channel 240, tapered roller bearing 300, O-ring 410, wear-resistant ring 420, cover plate 430, pump cover 500, driving gear 610, driven gear 620, expansion sleeve 700, retaining ring 710, expansion cover 720, shaft end cover 800, cylindrical pin 810. DETAILED DESCRIPTION

[0029] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the illustrations provided in the following embodiments are only for exemplary descriptions, and they are only schematic diagrams, not physical diagrams, and cannot be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts in the figures may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the figures may be omitted.

[0030] The same or similar numbers in the figures of the embodiments of the present invention correspond to the same or similar parts. In the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "back", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the figures, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the figures are only used for illustrative purposes and cannot be understood as limitations on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] Example 1

[0032] This embodiment describes a heat dissipation structure of a mixed flow pump, including a first sleeve 110 and a second sleeve 120 of the same structure located inside a pump housing 200 of the mixed flow pump, wherein the first sleeve 110 is sleeved on the driving shaft 001, and the first sleeve 110 is close to but not in contact with a main rotor 011 on the driving shaft 001, and the second sleeve 120 is sleeved on the driven shaft 002, and the second sleeve 120 is close to but not in contact with a secondary rotor 022 on the driven shaft 002, the driving shaft 001 and the driven shaft 002 are placed in parallel, and the positions of the first sleeve 110 and the second sleeve 120 correspond to each other; the first sleeve 110 has a first fluid channel, the second sleeve 120 has a second fluid channel, and the pump housing 200 has a third fluid channel inside, and the first fluid channel, the second fluid channel and the third fluid channel are connected to form a coolant channel.

[0033] In order to dissipate heat from the sealing structure more effectively, two first sleeves 110 and two second sleeves 120 are provided. The two first sleeves 110 are respectively sleeved on the driving shaft 001 at the opposite ends of the main rotor 011, and the two first sleeves 110 are arranged axially symmetrically with the center line of the main rotor 011. The two second sleeves 120 are respectively sleeved on the driven shaft 002 at the opposite ends of the auxiliary rotor 022, and the two second sleeves 120 are arranged axially symmetrically with the center line of the auxiliary rotor 022. In addition, sufficient space should be reserved at both ends of the main rotor 011 and the auxiliary rotor 022. The longer the length of the first sleeve 110 and the second sleeve 120, the more significant the heat dissipation effect of the seal.

[0034] The first sleeve 110 and the second sleeve 120 are both hollow in structure. The outer walls of the first sleeve 110 and the second sleeve 120 are both provided with a first annular groove 130. The first sleeve 110 and the second sleeve 120 are both provided with at least one through hole 140 connected to the internal hollow. The through hole 140 is located in the first annular groove 130 and is connected to the first annular groove 130. Preferably, four through holes 140 are evenly spaced on the first sleeve 110 and the second sleeve 120. The first annular groove 130, the through hole 140 and the internal hollow on the first sleeve 110 are connected to form a first fluid channel, and the first annular groove 130, the through hole 140 and the internal hollow on the second sleeve 120 are connected to form a second fluid channel.

[0035] In order to ensure sufficient heat dissipation area, the length of the internal hollow of the first sleeve 110 and the second sleeve 120 must be long enough. And to ensure the use effect of the tapered roller bearing 300, it is necessary to avoid the first sleeve 110 and the shoulder of the active shaft 001 being on the same plane, and to avoid the second sleeve 120 and the shoulder of the driven shaft 002 being on the same plane. The other end of the first sleeve 110 needs to keep a distance from the impeller of the main rotor 011 without contact. The other end of the second sleeve 120 needs to keep a distance from the impeller of the auxiliary rotor 022 without contact. The length of the first sleeve 110 is designed to be the length of the shaft section where it is located minus the length of the gap between the main rotor 011 and the pump housing 200, and the length of the second sleeve 120 is designed to be the length of the shaft section where it is located minus the length of the gap between the auxiliary rotor 022 and the pump housing 200.

[0036] The first sleeve 110 is interference fit with the driving shaft 001, and the second sleeve 120 is interference fit with the driven shaft 002. Specifically, the first sleeve 110 and the second sleeve 120 have a clamping ring 150 at opposite ends. The clamping ring on the first sleeve 110 is sleeved on the driving shaft 001, and a gap communicating with the through hole 140 is left between the inner cylinder wall between the two clamping rings on the first sleeve 110 and the driving shaft 001. The clamping ring on the second sleeve 120 is sleeved on the driven shaft 002, and a gap communicating with the through hole 140 is left between the inner cylinder wall between the two clamping rings on the second sleeve 120 and the driven shaft 002.

[0037] A second annular groove 210 is provided inside the pump housing 200 at a position corresponding to the first annular groove 130, and the second annular groove 210 is communicated with the first annular groove 130. The pump housing 200 also has an inlet channel 220 and an outlet channel 230, which are respectively communicated with the corresponding second annular groove 210 to form a third fluid channel. Specifically, one end of the first sleeve 110 and the second sleeve 120 are both provided with a retaining ring 160, and the other end is both provided with a main sealing structure, the main seal is used to enhance the sealing performance inside the coolant channel, the second annular groove 210 corresponding to the first sleeve 110 is sealed by the retaining ring 160, the outer tube wall of the first sleeve 110 and the main sealing structure to form a first annular cavity 003, the second annular groove 210 corresponding to the second sleeve 120 is sealed by the retaining ring 160, the outer tube wall of the second sleeve 120 and the main sealing structure to form a second annular cavity 004, the inlet channel 220 is communicated with the first annular cavity 003, the outlet channel 230 is communicated with the second annular cavity 004, the inlet channel 220, the first annular cavity 003, the second annular cavity 004, and the outlet channel 230 constitute a third fluid channel. An intermediate passage 240 is provided inside the pump housing 200 between the first annular cavity 003 and the second annular cavity 004. The intermediate passage 240 is used to connect the first annular cavity 003 and the second annular cavity 004 to ensure smooth flow of the coolant.

[0038] Specifically, the main sealing structure includes an O-ring 410 and a wear ring 420. The O-ring 410 is made of nitrile rubber O-ring. The O-ring 410 and the wear ring 420 are both sleeved on the first sleeve 110 and the second sleeve 120. A cover plate 430 is installed between the O-ring 410 and the second annular groove 210. The cover plate 430 is fixed to the pump housing 200 by countersunk screws. When the wear ring 420 contacts and rubs with the first sleeve 110 and the second sleeve 120, the O-ring 410 is in a stationary state.

[0039] Tapered roller bearings 300 are installed on the driving shaft 001 between the first sleeve 110 and the pump cover 500 of the mixed pump, and on the driven shaft 002 between the second sleeve 120 and the pump cover 500. In order to leave enough space for the pump cover 500 and avoid the contact between the coupling and the pump cover 500, the outer ring of the tapered roller bearing 300 and the pump cover 500 are matched as J7, the inner ring of the tapered roller bearing 300 and the driving shaft 001 are matched as K6, and the inner ring of the tapered roller bearing 300 and the driven shaft 002 are also matched as K6.

[0040] The driving shaft 001 of this embodiment is divided into six sections. The diameter length of the first section 0011 is slightly shorter than the length of the hub hole so that the shaft end retaining ring is only pressed on the coupling, and a flat key is provided for connecting the coupling; the second section 0012 is used for installing the tapered roller bearing 300 and the pump cover; the third section 0013 and the fourth section 0014 are both where the sealing and heat dissipation structures are installed, and are located on opposite sides of the main rotor 011 respectively; the fifth section 0015 has the same function as the second section 0012 due to the symmetry of the rotor pump; the sixth section 0016 is used for installing the driving gear 610. Correspondingly, the driven shaft 002 is also divided into five parts. The first part 0021 corresponds to the second section 0012, which is used to install the tapered roller bearing 300 and the pump cover 500; the second part 0022 and the third part 0023 correspond to the third section 0013 and the fourth section 0014 respectively, which are used to install the sealing and heat dissipation structure, the fourth part 0024 corresponds to the fifth section 0015, which is used to install the tapered roller bearing 300 and the pump cover 500, and the fifth part 0025 corresponds to the sixth section 0016, which is used to install the driven gear 620.

[0041] When the mixed pump is working, the heat dissipation structure of this embodiment drives the driving shaft 001 to rotate driven by the coupling, the main rotor 011 drives the auxiliary rotor 022 to start rotating, and the oil, gas and sand flow accordingly, and the external cooling circulation system is started. The external cooling box allows the coolant to flow in from the lower inlet channel 220 as the inlet, and flows into the first annular cavity through the inlet channel 220. Due to the coolant's own gravity, the coolant will fill the first annular cavity 003, and the coolant in the first annular groove 130 of the first sleeve 110 rotates with the driving shaft 001. When the coolant moves to the through hole 140, it will enter and exit the gap formed between the first sleeve 110 and the driving shaft 001, and take away the heat generated by the seal on the first sleeve 110, and then enter the second annular cavity 004 through the middle channel. Similarly, the heat generated by the seal on the second sleeve 120 is taken away, and finally, it flows out from the outlet channel 230 as the outlet.

[0042] Example 2

[0043] This embodiment describes a mixed flow pump, which includes the heat dissipation structure described in the above embodiment 1.

[0044] A driving gear 610 is installed on the driving shaft 001 of the mixed pump, and a driven gear 620 is installed on the driven shaft 002. In order to ensure the accuracy of the matching between the main rotor 011 and the auxiliary rotor 022, at least one place of the gear meshing must be flexible. For this reason, a tightening sleeve 700 is sleeved between the driving gear 610 and the driving shaft 001. The tightening sleeve 700 is used to position the driving gear 610. A retaining ring 710 is installed at one end of the tightening sleeve 700, and an tightening cover 720 is installed at the other end. The tightening cover 720 is fixed to the driving gear 610 by screws.

[0045] According to the symmetry of the rotor pump, the driven shaft 002 corresponds to the driving shaft 001 almost everywhere. A shaft end cover 800 is installed at the end of the driven shaft 002 away from the auxiliary rotor 022. The shaft end cover 800 is fixed to the driven shaft 002 by screws and cylindrical pins 810. The shaft end cover 800 covers part of the driven gear 620 to achieve axial positioning of the driven gear 620.

[0046] The above embodiments are only used to illustrate the technical solution of the utility model and are not intended to limit it. Although the utility model is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model. The technology, shape, and structure that are not described in detail in the utility model are all well-known technologies.

Claims

1. A heat dissipation structure of a mixed flow pump, characterized in that: It includes a first sleeve and a second sleeve with the same structure which are located inside the pump housing of the mixed pump, the first sleeve is sleeved on the driving shaft, and the first sleeve is close to but not in contact with the main rotor on the driving shaft, the second sleeve is sleeved on the driven shaft, and the second sleeve is close to but not in contact with the secondary rotor on the driven shaft, the driving shaft and the driven shaft are placed in parallel, and the positions of the first sleeve and the second sleeve correspond; the first sleeve has a first fluid channel, the second sleeve has a second fluid channel, and the pump housing has a third fluid channel, and the first fluid channel, the second fluid channel and the third fluid channel are connected to form a coolant channel.

2. The heat dissipation structure of a mixed flow pump according to claim 1, characterized in that: The interiors of the first sleeve and the second sleeve are both hollow structures, and the outer walls of the first sleeve and the second sleeve are both provided with a first annular groove. The first sleeve and the second sleeve are both provided with at least one through hole connected to the internal hollow space, and the through hole is located in the first annular groove and connected to the first annular groove. The first annular groove, the through hole and the internal hollow space on the first sleeve are connected to form a first fluid channel, and the first annular groove, the through hole and the internal hollow space on the second sleeve are connected to form a second fluid channel.

3. The heat dissipation structure of a mixed flow pump according to claim 2, characterized in that: The first sleeve and the second sleeve have tightening rings at opposite ends. The tightening ring on the first sleeve is sleeved on the driving shaft, and a gap communicating with the through hole is left between the inner cylinder wall between the two tightening rings on the first sleeve and the driving shaft. The tightening ring on the second sleeve is sleeved on the driven shaft, and a gap communicating with the through hole is left between the inner cylinder wall between the two tightening rings on the second sleeve and the driven shaft.

4. The heat dissipation structure of a mixed flow pump according to claim 3, characterized in that: A second annular groove is provided inside the pump housing at a position corresponding to the first annular groove, and the second annular groove is communicated with the first annular groove. The pump housing also has an inlet channel and an outlet channel, and the inlet channel and the outlet channel are respectively communicated with the corresponding second annular groove to form a third fluid channel.

5. The heat dissipation structure of a mixed flow pump according to claim 4, characterized in that: One end of the first sleeve and the second sleeve are both provided with a retaining ring, and the other end is both provided with a main sealing structure, wherein the main seal is used to enhance the sealing performance inside the coolant channel, the second annular groove corresponding to the first sleeve is sealed by the retaining ring, the outer tube wall of the first sleeve and the main sealing structure to form a first annular cavity, the second annular groove corresponding to the second sleeve is sealed by the retaining ring, the outer tube wall of the second sleeve and the main sealing structure to form a second annular cavity, the inlet channel is communicated with the first annular cavity, the outlet channel is communicated with the second annular cavity, and the inlet channel, the first annular cavity, the second annular cavity and the outlet channel constitute a third fluid channel.

6. The heat dissipation structure of a mixed flow pump according to claim 5, characterized in that: The main sealing structure includes an O-ring and a wear-resistant ring, both of which are sleeved on the first sleeve and the second sleeve. A cover plate is installed between the O-ring and the second annular groove, and the cover plate is fixed to the pump housing by countersunk screws.

7. The heat dissipation structure of a mixed flow pump according to claim 1, characterized in that: Tapered roller bearings are installed on the driving shaft between the first sleeve and the pump cover of the mixed pump, and on the driven shaft between the second sleeve and the pump cover. The outer ring of the tapered roller bearing is matched with the pump cover as J7, and the inner ring of the tapered roller bearing is matched with the driving shaft as K6.

8. A mixed flow pump, characterized in that: The mixed flow pump comprises the heat dissipation structure as described in any one of claims 1-7.

9. A mixed flow pump according to claim 8, characterized in that: A driving gear is installed on the driving shaft, a driven gear is installed on the driven shaft, a tightening sleeve is sleeved between the driving gear and the driving shaft, a retaining ring is installed on one end of the tightening sleeve, and a tightening cover is installed on the other end, and the tightening cover is fixed to the driving gear by screws.

10. A mixed flow pump according to claim 8, characterized in that: A shaft end cover is installed at one end of the driven shaft away from the auxiliary rotor. The shaft end cover is fixed to the driven shaft by screws and cylindrical pins. The shaft end cover covers part of the driven gear to achieve axial positioning of the driven gear.

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