A chemical process pump with impeller blade timing progression

Abstract

The present application relates to the technical field of centrifugal pump, in particular to a chemical process pump with gradually changing impeller blade timing, comprising a pump shell, an impeller assembly rotatably installed in the pump shell, and a pump shaft for providing power for the rotation of the impeller assembly, wherein the impeller assembly comprises movable blades; further comprising: a transmission mechanism arranged on the pump shell for transmitting power between the pump shaft and the impeller assembly; and a centrifugal connecting mechanism arranged on the pump shaft for realizing the power connection between the pump shaft and the transmission mechanism. In the initial state, the pump shaft and the impeller assembly are disconnected, and as the rotation speed of the pump shaft increases, the blades are gradually adjusted from the initial gathering state to the open working state through the transmission of the transmission mechanism, the centrifugal connecting mechanism and the adjusting mechanism; when the impeller assembly is initially rotated, the blades are in the gathering state, which can reduce the effective flow area of the outlet of the impeller assembly, reduce the work done by the blades on the fluid, and reduce the initial torque and the peak value of the motor current.

Description

Technical Field

[0001] This invention relates to the field of centrifugal pump technology, specifically to a chemical process pump with gradually changing impeller blades. Background Technology

[0002] Chemical process pumps are key equipment used to transport high-temperature, high-pressure, and corrosive liquids, and are widely used in the production processes of the petrochemical industry. The main function of petrochemical process pumps is to transport crude oil, natural gas, chemical products, etc., through pipelines to different processing units or production equipment, ensuring the smooth operation of the production process. Process pumps are typically non-variable displacement centrifugal pumps, mainly utilizing the impeller to generate centrifugal force to pressurize and transport the liquid. Centrifugal process pumps share the same characteristics as common process pumps; they must be primed with liquid materials before startup to completely expel air from the pump, thereby ensuring smooth liquid transport.

[0003] For example, invention patent CN110848174B discloses a chemical process pump with high cavitation resistance, including a pump body assembly and a flow guiding assembly. The pump body assembly includes an impeller, a pump shaft, and a pump casing. One end of the pump shaft is drivenly connected to the impeller, and the pump shaft is located inside the pump casing and rotatably connected to the pump casing. The outer wall of the pump casing has an inlet and an outlet, which are interconnected. The flow guiding assembly includes a connecting block and a guide plate. The guide plate is integrally formed with the connecting block, and both ends of the connecting block are fixedly connected to the pump casing, forming a flow guide between the connecting block and the pump casing. The pump shaft drives the impeller to rotate, thus achieving the transportation of the medium.

[0004] In the prior art of the aforementioned patent, the blades on the impeller are fixed. At the moment the process pump starts, the blades do work on the fluid at full load. However, as the impeller accelerates from a standstill to its rated speed, the blades need to overcome the static friction and inertial resistance of the fluid. Since the fluid inside the pump has not yet formed a stable flow, the torque required for the impeller to start is large, which will cause a surge in power consumption at the moment of startup. Therefore, there is an urgent need for a chemical process pump with a gradually changing impeller blade sequence to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a chemical process pump with impeller blades that change in time sequence, in order to overcome the above-mentioned shortcomings of the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a chemical process pump with progressively changing impeller blades, comprising a pump casing, an impeller assembly rotatably mounted inside the pump casing, and a pump shaft for providing power for the rotation of the impeller assembly, wherein the impeller assembly includes movable blades;

[0007] It also includes: a transmission mechanism, which is mounted on the pump casing and is used to transmit power between the pump shaft and the impeller assembly; a centrifugal connection mechanism, which is mounted on the pump shaft and is used to realize the power connection between the pump shaft and the transmission mechanism; and an adjustment mechanism, which is mounted on the impeller assembly and is used to adjust the opening and closing of the blades.

[0008] After the pump shaft is driven to reach the rated speed, the centrifugal connection mechanism opens under the action of centrifugal force and achieves power connection with the transmission mechanism. After the centrifugal connection mechanism is connected to the transmission mechanism, under the drive of the pump shaft rotation, the centrifugal connection mechanism pushes the transmission mechanism to press against the adjustment mechanism, and the adjustment mechanism unfolds the blades to the working state.

[0009] Preferably, the impeller assembly further includes a rear cover plate, and the blades are movably mounted on the front end of the rear cover plate. In the initial state, the blades are in a converged state at the front end of the rear cover plate.

[0010] Preferably, the transmission mechanism includes a retractable outer transmission sleeve, an inner transmission sleeve, and an auxiliary drive sleeve. The auxiliary drive sleeve is disposed on the pump housing, and the inner wall of the auxiliary drive sleeve is provided with threads that cooperate with the centrifugal connection mechanism.

[0011] Preferably, the centrifugal connection mechanism includes a mounting bracket, which is snapped onto one end of the pump shaft near the impeller assembly. A centrifugal top arm is movably mounted on the periphery of the mounting bracket. When the pump shaft drives the mounting bracket to rotate, the centrifugal top arm extends out along the outside of the mounting bracket under the action of centrifugal force and snaps onto the inner transmission sleeve.

[0012] Preferably, the centrifugal connection mechanism further includes a threaded connection assembly, which is disposed on the inner transmission sleeve and corresponds to the position of the centrifugal top arm. When the centrifugal top arm is engaged with the inner transmission sleeve, it presses against the threaded connection assembly, which can connect the threaded connection assembly with the thread on the inner wall of the auxiliary drive sleeve.

[0013] Preferably, after the threaded connection assembly is threadedly connected to the inner wall of the auxiliary drive sleeve, when the pump shaft drives the centrifugal connection mechanism and the inner drive sleeve to rotate, it can simultaneously drive the inner drive sleeve to move closer to the outer drive sleeve.

[0014] Preferably, the adjusting mechanism includes an adjusting sleeve rotatably mounted on the rear end of the rear cover plate; an adjusting rod disposed inside the adjusting sleeve and spirally connected to the adjusting sleeve; the adjusting rod can drive the adjusting sleeve to rotate axially when subjected to top pressure.

[0015] Preferably, the adjustment mechanism further includes a positioning rod disposed inside the adjustment sleeve to limit the axial rotation of the adjustment rod; and a return spring four disposed outside the positioning rod to drive the adjustment rod to return to its original position.

[0016] Preferably, the adjustment mechanism further includes a gear set disposed at the rear end of the rear cover plate for transmission between the blade and the adjustment sleeve.

[0017] Preferably, the pump casing is provided with an annular slide rail inside, and the outer transmission sleeve is provided with a roller bracket on its periphery, and the roller bracket is slidably disposed in the annular slide rail. The outer transmission sleeve is rotatably mounted on the pump casing through the annular slide rail and the roller bracket.

[0018] In the above technical solution, the beneficial effects of the present invention are as follows: In the initial state, the pump shaft and impeller assembly are disconnected. As the pump shaft speed increases, the blades are gradually adjusted from the initial converged state to the open working state through the transmission mechanism, centrifugal connection mechanism, and adjustment mechanism. When the impeller assembly initially rotates, the blades are in the converged state, which can reduce the effective flow area of ​​the impeller assembly outlet, reduce the blades' work capacity on the fluid, reduce the initial torque and motor current peak, thereby reducing the starting energy consumption. The blades are gradually adjusted with time to gradually match the system requirements, which can greatly avoid the energy waste caused by full-load start-up.

[0019] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative only, and are not intended to limit this disclosure.

[0020] This application provides an overview of various implementations or examples of the technology described in this disclosure, and is not a full disclosure of the entire scope or all features of the disclosed technology. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 This is a schematic diagram of one side of the overall structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure on the other side of the entire invention;

[0024] Figure 3 This is a schematic diagram of the connection position between the pump casing and the bearing seat of the present invention;

[0025] Figure 4 This is a schematic diagram of the cross-sectional structure of the pump casing of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of one side of the rear cover plate of the present invention;

[0027] Figure 6This is a schematic diagram of the structure of the other side of the rear cover plate of the present invention;

[0028] Figure 7 This is a schematic diagram of the connection position between the adjusting sleeve and the adjusting rod of the present invention;

[0029] Figure 8 This is a schematic diagram of the structure after the inner and outer transmission sleeves of the present invention are connected;

[0030] Figure 9 This is a structural schematic diagram of the mounting bracket installation position of the present invention;

[0031] Figure 10 This is a schematic diagram of the installation position of the centrifugal connection mechanism of the present invention;

[0032] Figure 11 This is a schematic diagram of the centrifugal connection mechanism of the present invention during operation;

[0033] Figure 12 This is a schematic diagram of the structure of the threaded connection assembly of the present invention after it has been moved into place during operation.

[0034] Figure 13 This is a schematic diagram of the threaded connection assembly of the present invention.

[0035] Explanation of reference numerals in the attached figures:

[0036] In the diagram: 1. Mounting base; 2. Drive motor; 3. Pump casing; 4. Bearing housing; 5. Pump shaft; 6. Impeller assembly; 61. Rear cover plate; 62. Blade; 7. Transmission mechanism; 71. Outer transmission sleeve; 72. Inner transmission sleeve; 73. Auxiliary drive sleeve; 74. Transmission slide groove; 8. Centrifugal connection mechanism; 81. Mounting bracket; 82. Centrifugal top arm; 83. Return spring one; 84. Threaded connection assembly; 841. Transmission plate; 842. Connecting quick; 843. Return spring two; 85. Return spring three; 9. Adjustment mechanism; 91. Adjustment sleeve; 92. Adjustment rod; 93. Positioning rod; 94. Return spring four; 95. Transmission gear; 96. Arc rack; 97. Transmission bracket; 10. Circular slide rail; 11. Roller bracket. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0038] Please see Figure 1-13The present invention provides a technical solution: a chemical process pump with progressively changing impeller blades, including a pump casing 3, an impeller assembly 6 rotatably installed inside the pump casing 3, and a pump shaft 5 for providing power for the rotation of the impeller assembly 6. The impeller assembly 6 includes movable blades 62.

[0039] It also includes: a transmission mechanism 7, which is mounted on the pump casing 3 and is used to transmit power between the pump shaft 5 and the impeller assembly 6; a centrifugal connection mechanism 8, which is mounted on the pump shaft 5 and is used to realize the power connection between the pump shaft 5 and the transmission mechanism 7; and an adjustment mechanism 9, which is mounted on the impeller assembly 6 and is used to adjust the opening and closing of the blades 62.

[0040] After the pump shaft 5 is driven to reach the rated speed, the centrifugal connection mechanism 8 opens under the action of centrifugal force and is connected to the transmission mechanism 7. After the centrifugal connection mechanism 8 is connected to the transmission mechanism 7, under the rotation of the pump shaft 5, the centrifugal connection mechanism 8 pushes the transmission mechanism 7 to press against the adjustment mechanism 9, and the adjustment mechanism 9 unfolds the blade 62 to the working state.

[0041] The chemical process pump with gradually changing impeller blades also includes: a bearing housing 4, which is fixedly installed at the end of the pump casing 3 away from the inlet; a drive motor 2, which provides power for the rotation of the pump shaft 5; a mounting base 1, which supports the pump casing 3 and the drive motor 2; the pump shaft 5 is movably installed on the bearing housing 4, one end of the pump shaft 5 extends into the interior of the pump casing 3, and the other end is connected to the output shaft of the drive motor 2 through a coupling.

[0042] Specifically, in the initial state, several blades 62 in the impeller assembly 6 are in a clustered state, and the pump shaft 5 is disconnected from the impeller assembly 6. The drive motor 2, controlled by the control system, drives the pump shaft 5 to rotate, and the pump shaft 5 synchronously drives the centrifugal connecting mechanism 8 to rotate. As the speed of the pump shaft 5 increases, the centrifugal connecting mechanism 8 opens under the action of centrifugal force and engages with the transmission mechanism 7, thus achieving a power connection between the centrifugal connecting mechanism 8 and the transmission mechanism 7. At this time, the pump shaft 5 can drive the impeller assembly 6 to rotate through the centrifugal connecting mechanism 8 and the transmission mechanism 7, and the blades 62 are in a clustered state when the impeller assembly 6 initially rotates. The centrifugal connecting mechanism 8 drives the transmission mechanism 7 to start rotating. Simultaneously, the transmission mechanism 7 is driven to retract, which in turn presses against the adjustment mechanism 9. The adjustment mechanism 9 then unfolds the blades 62 to the working state, allowing the blades 62 to operate continuously. During the retraction of the transmission mechanism 7, the blades 62 are gradually adjusted from the converged state to the working state. The impeller assembly 6 is initially in the converged state, which reduces the effective flow area at the outlet of the impeller assembly 6, decreases the work capacity of the blades 62 on the fluid, reduces the initial torque and motor current peak, and reduces starting energy consumption. The blades 62 are gradually adjusted over time to match the system requirements, which can significantly avoid energy waste caused by full-load startup.

[0043] Compared with the prior art, in the initial state of the present invention, the pump shaft 5 and the impeller assembly 6 are disconnected. As the speed of the pump shaft 5 increases, the blades 62 are gradually adjusted from the initial closed state to the open working state through the transmission mechanism 7, the centrifugal connection mechanism 8, and the adjustment mechanism 9. When the impeller assembly 6 initially rotates, the blades 62 are in the closed state, which can reduce the effective flow area of ​​the outlet of the impeller assembly 6, reduce the work capacity of the blades 62 on the fluid, reduce the initial torque and the peak motor current, thereby reducing the starting energy consumption. The blades 62 are gradually adjusted with time to gradually match the system requirements, which can greatly avoid the energy waste caused by full-load start-up.

[0044] As a preferred technical solution in this embodiment, the impeller assembly 6 also includes a rear cover plate 61, and the blades 62 are movably installed at the front end of the rear cover plate 61. In the initial state, the blades 62 are in a converged state at the front end of the rear cover plate 61. Specifically, the blades 62 are in a converged state when they initially rotate, which can reduce the effective flow area of ​​the outlet of the impeller assembly 6 and reduce the work capacity of the blades 62 on the fluid. The blades 62 are gradually adjusted to the working state over time to gradually match the system requirements, which can greatly avoid the energy waste caused by full-load start-up.

[0045] As a preferred technical solution of this embodiment, the transmission mechanism 7 includes a retractable outer transmission sleeve 71, an inner transmission sleeve 72, and an auxiliary drive sleeve 73. The auxiliary drive sleeve 73 is disposed on the pump housing 3, and the inner wall of the auxiliary drive sleeve 73 is provided with a thread that cooperates with the centrifugal connection mechanism 8. Specifically, one end of the outer transmission sleeve 71 is fixedly connected to the rear cover plate 61, and the other end is rotatably installed inside the pump housing 3. The position of the impeller assembly 6 can be restricted by the outer transmission sleeve 71 to ensure the stability of the impeller assembly 6 when it rotates. The inner transmission sleeve 72 is snapped into the inside of the outer transmission sleeve 71. The inner wall of the outer transmission sleeve 71 is provided with a transmission groove 74, and the outer wall of the inner transmission sleeve 72 is provided with a transmission slide bar that cooperates with the transmission groove 74. Through the restriction of the transmission groove 74 and the transmission slide bar, power can be transmitted between the outer transmission sleeve 71 and the inner transmission sleeve 72, and the inner transmission sleeve 72 can move axially inside the outer transmission sleeve 71.

[0046] As a preferred embodiment, the centrifugal connection mechanism 8 includes a mounting bracket 81, which is snapped onto one end of the pump shaft 5 near the impeller assembly 6. A centrifugal top arm 82 is movably mounted on the periphery of the mounting bracket 81. When the pump shaft 5 drives the mounting bracket 81 to rotate, the centrifugal top arm 82 extends outward along the outside of the mounting bracket 81 under the action of centrifugal force and snaps onto the inner transmission sleeve 72. Specifically, the inner ring of the mounting bracket 81 and the pump shaft 5 are provided with mutually cooperating slide bars and slide grooves, so that power can be transmitted between the pump shaft 5 and the mounting bracket 81, and at the same time, the mounting bracket 81 can slide outside the pump shaft 5; the outer side of the mounting bracket 81 is movably fitted with a centrifugal top arm 82. The return spring 83 located inside the mounting bracket 81 is used to drive the centrifugal top arm 82 to return to its original position. The cross-sectional shape of the part of the centrifugal top arm 82 that mates with the mounting bracket 81 is polygonal to prevent the centrifugal top arm 82 from rotating axially and to ensure that the centrifugal top arm 82 can be precisely matched with the inner transmission sleeve 72. The inner transmission sleeve 72 has a snap-fit ​​cavity that mates with the centrifugal top arm 82. When the centrifugal top arm 82 opens under the action of centrifugal force, it can be snapped into the snap-fit ​​cavity to realize the power connection between the centrifugal top arm 82 and the inner transmission sleeve 72. This allows the pump shaft 5 to drive the transmission mechanism 7 and the impeller assembly 6 to rotate simultaneously when it drives the centrifugal connection mechanism 8 to rotate.

[0047] It should be noted that before starting a centrifugal pump, the pump casing must be filled with liquid. Otherwise, the pump will not be able to pump water normally due to air binding. Therefore, it is necessary to fill the pump casing with priming water before starting the centrifugal pump. However, in the existing technology, the pump shaft 5 and the impeller assembly 6 are fixedly connected, and the pump shaft 5 is locked when the pump is stopped. This causes the impeller assembly 6 to be unable to rotate when filling with priming water, resulting in a dead zone in the pump casing. This causes a small amount of air to remain in the inlet pipe or pump body, making it impossible for the process pump to start smoothly.

[0048] When the chemical process pump of this application is stopped, the centrifugal top arm 82 loses its centrifugal force and is reset by the return spring 83, disconnecting the centrifugal connection mechanism 8 from the transmission mechanism 7, and then disconnecting the pump shaft 5 from the impeller assembly 6, so that the impeller assembly 6 can rotate freely when the pump is stopped, which facilitates the liquid to drive the impeller assembly 6 to rotate during priming and avoids the existence of priming dead zones.

[0049] As a preferred embodiment, the centrifugal connection mechanism 8 further includes a threaded connection assembly 84, which is disposed on the inner transmission sleeve 72 and corresponds to the position of the centrifugal top arm 82. When the centrifugal top arm 82 is engaged with the inner transmission sleeve 72, it presses against the threaded connection assembly 84, allowing the threaded connection assembly 84 to connect with the threads on the inner wall of the auxiliary drive sleeve 73. After the threaded connection assembly 84 is connected to the threads on the inner wall of the auxiliary drive sleeve 73, when the pump shaft 5 drives the centrifugal connection mechanism 8 and the inner transmission sleeve 72 to rotate, it can simultaneously drive the inner transmission sleeve 72 to move towards the side closer to the outer transmission sleeve 71. Specifically, the threaded connection assembly 84 includes... The transmission plate 841 is movably installed in the engagement cavity of the inner transmission sleeve 72. A mating block 842 is fixedly connected to the side of the transmission plate 841 near the outer side of the inner transmission sleeve 72. The mating block 842 has an engagement groove that engages with the threaded inner wall of the auxiliary drive sleeve 73. A return spring 843 is movably fitted on the transmission plate 841, located inside the engagement cavity, to drive the transmission plate 841 and the mating block 842 to return to their original positions. When the pump shaft 5 drives the mounting bracket 81 and the centrifugal top arm 82 to rotate, the centrifugal top arm 82 is engaged in the engagement cavity by centrifugal force and presses against the transmission plate 841. The transmission plate 841 then drives the mating block 73 to rotate. The connecting fastener 842 moves outward from the inner drive sleeve 72, engaging with the threads on the inner wall of the auxiliary drive sleeve 73. This allows the inner drive sleeve 72 to move synchronously towards the outer drive sleeve 71 as the pump shaft 5 rotates, driving the mounting bracket 81, centrifugal top arm 82, and the inner drive sleeve 72. The inner drive sleeve 72 then compresses and adjusts the adjusting mechanism 9. Once the adjusting mechanism 9 has adjusted the blade 62 to its position, the threaded connection assembly 84 moves to the front end of the threads on the inner wall of the auxiliary drive sleeve 73, disconnecting the threaded connection assembly 84 from the threads on the inner wall of the auxiliary drive sleeve 73. The impeller assembly 6 then continues to operate. During the continuous rotation, the threaded connection assembly 84 rotates at this position; when the process pump stops, the centrifugal top arm 82 retracts under the elastic force of the return spring 83, releasing the centrifugal top arm 82 from the inner transmission sleeve 72 and releasing the centrifugal top arm 82 from the threaded connection assembly 84. The transmission plate 841 and the docking fastener 842 are reset under the elastic force of the return spring 843. In this state, the docking fastener 842 is not connected to the thread inside the auxiliary drive sleeve 73. The inner transmission sleeve 72 and the threaded connection assembly 84 are reset by the adjustment mechanism 9, and the mounting bracket 81 and the centrifugal top arm 82 are reset by the return spring 85.

[0050] As a preferred technical solution of this embodiment, the adjustment mechanism 9 includes an adjustment sleeve 91, which is rotatably mounted on the rear end of the rear cover plate 61; and an adjustment rod 92, which is disposed inside the adjustment sleeve 91 and is spirally connected to the adjustment sleeve 91. When the adjustment rod 92 is subjected to top pressure, it can drive the adjustment sleeve 91 to rotate axially. Specifically, the adjustment mechanism 9 also includes a transmission bracket 97, which is fixedly installed inside the inner transmission sleeve 72 and is fixedly fitted outside the adjustment rod 92. When the inner transmission sleeve 72 is driven to move, it can drive the adjustment rod 92 to move, thereby driving the adjustment sleeve 91 to rotate, providing power for the adjustment of the blade 62.

[0051] As a preferred embodiment, the adjusting mechanism 9 further includes a positioning rod 93, which is disposed inside the adjusting sleeve 91 to restrict the axial rotation of the adjusting rod 92; and a return spring 94, which is fitted outside the positioning rod 93 to drive the adjusting rod 92 to return to its original position. Specifically, the positioning rod 93 restricts the adjusting rod 92 so that it can only move axially. Since the adjusting sleeve 91 and the adjusting rod 92 are connected by a screw, the adjusting sleeve 91 can be driven to rotate when the adjusting rod 92 moves axially. When the process pump stops, the positioning rod 93 applies a spring force to the adjusting rod 92 to return it to its original position, and the inner transmission sleeve 72 can be driven to return to its original position through the transmission bracket 97.

[0052] As a preferred technical solution of this embodiment, the adjustment mechanism 9 also includes a gear set, which is disposed at the rear end of the rear cover plate 61 and is used for transmission between the blade 62 and the adjustment sleeve 91. Specifically, the gear set includes a transmission gear 95, which is fixedly fitted on the outside of the adjustment sleeve 91; a rotating shaft is fixedly connected to one end of the blade 62 near the center of the rear cover plate 61, and the blade 62 is movably mounted on the rear cover plate 61 through the rotating shaft. An arc-shaped rack 96 is fixedly fitted on the rear end of the rotating shaft, and the arc-shaped rack 96 meshes with the transmission gear 95 to realize the transmission connection between the adjustment sleeve 91 and the blade 62; in order to avoid interference when several arc-shaped racks 96 rotate, several arc-shaped racks 96 are arranged in multiple layers in parallel. For example, when there are six sets of arc-shaped racks 96, they are set in groups of three and three, and arranged in double layers.

[0053] As a preferred technical solution in this embodiment, an annular slide rail 10 is provided inside the pump casing 3, and a roller bracket 11 is provided on the periphery of the outer transmission sleeve 71. The roller bracket 11 is slidably disposed in the annular slide rail 10. The outer transmission sleeve 71 is rotatably mounted on the pump casing 3 through the annular slide rail 10 and the roller bracket 11. Specifically, the annular slide rail 10 and the roller bracket 11 restrict and ensure that the outer transmission sleeve 71 and the impeller assembly 6 can rotate stably inside the pump casing 3. At the same time, the roller bracket 11 cooperates with the annular slide rail 10 to prevent the axial force on the impeller assembly 6 during operation from being transmitted to the connection between the pump shaft 5 and the pump casing. It should be noted that in order to improve the sealing performance of the connection position between the annular slide rail 10 and the outer transmission sleeve 71, a rotary sealing structure, such as a rotary sealing ring, is required at the connection position between the annular slide rail 10 and the outer transmission sleeve 71.

[0054] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A chemical process pump with progressively changing impeller blades, comprising a pump casing (3), an impeller assembly (6) rotatably mounted inside the pump casing (3), and a pump shaft (5) for providing power for the rotation of the impeller assembly (6), characterized in that, The impeller assembly (6) includes movable blades (62); It also includes: a transmission mechanism (7), which is disposed on the pump casing (3) for transmitting power between the pump shaft (5) and the impeller assembly (6); a centrifugal connection mechanism (8), which is disposed on the pump shaft (5) for realizing the power connection between the pump shaft (5) and the transmission mechanism (7); and an adjustment mechanism (9), which is disposed on the impeller assembly (6) for adjusting the opening and closing of the blades (62). After the pump shaft (5) is driven to reach the rated speed, the centrifugal connection mechanism (8) opens under the action of centrifugal force and achieves power connection with the transmission mechanism (7); after the centrifugal connection mechanism (8) is connected to the transmission mechanism (7), under the rotation of the pump shaft (5), the centrifugal connection mechanism (8) pushes the transmission mechanism (7) to press against the adjustment mechanism (9), and the blade (62) is unfolded to the working state through the adjustment mechanism (9); The transmission mechanism (7) includes a retractable outer transmission sleeve (71), an inner transmission sleeve (72) and an auxiliary drive sleeve (73). The auxiliary drive sleeve (73) is mounted on the pump housing (3), and the inner wall of the auxiliary drive sleeve (73) is provided with a thread that cooperates with the centrifugal connection mechanism (8). The centrifugal connection mechanism (8) includes a threaded connection assembly (84), which is disposed on the inner transmission sleeve (72) and corresponds to the position of the centrifugal top arm (82). When the centrifugal top arm (82) is engaged on the inner transmission sleeve (72), it presses against the threaded connection assembly (84), which can connect the threaded connection assembly (84) with the thread on the inner wall of the auxiliary drive sleeve (73). After the threaded connection assembly (84) is threadedly connected to the inner wall of the auxiliary drive sleeve (73), when the pump shaft (5) drives the centrifugal connection mechanism (8) and the inner drive sleeve (72) to rotate, the inner drive sleeve (72) can be driven to move towards the side closer to the outer drive sleeve (71) in sync. The adjustment mechanism (9) includes an adjustment sleeve (91); an adjustment rod (92), which is located inside the adjustment sleeve (91) and is spirally connected to the adjustment sleeve (91); the adjustment rod (92) can drive the adjustment sleeve (91) to rotate axially when it is pressed; and a transmission bracket (97), which is fixedly installed inside the inner transmission sleeve (72) and fixedly fitted on the outside of the adjustment rod (92). When the inner transmission sleeve (72) is driven to move, it can drive the adjustment rod (92) to move, thereby driving the adjustment sleeve (91) to rotate, providing power for the adjustment of the blade (62).

2. A chemical process pump with progressively changing impeller blades according to claim 1, characterized in that, The impeller assembly (6) also includes a rear cover plate (61), and the blades (62) are movably installed at the front end of the rear cover plate (61). In the initial state, the blades (62) are in a converged state at the front end of the rear cover plate (61).

3. A chemical process pump with progressively changing impeller blades according to claim 1, characterized in that, The centrifugal connection mechanism (8) includes a mounting bracket (81), which is snapped onto one end of the pump shaft (5) near the impeller assembly (6). A centrifugal top arm (82) is movably mounted on the periphery of the mounting bracket (81). When the pump shaft (5) drives the mounting bracket (81) to rotate, the centrifugal top arm (82) is subjected to centrifugal force and extends out along the outside of the mounting bracket (81) and snaps onto the inner transmission sleeve (72).

4. A chemical process pump with progressively changing impeller blades according to claim 2, characterized in that, The adjusting sleeve (91) is rotatably mounted on the rear end of the rear cover plate (61).

5. A chemical process pump with progressively changing impeller blades according to claim 1, characterized in that, The adjustment mechanism (9) also includes a positioning rod (93), which is located inside the adjustment sleeve (91) and is used to limit the axial rotation of the adjustment rod (92); and a reset spring (94), which is fitted outside the positioning rod (93) and is used to drive the adjustment rod (92) to reset.

6. A chemical process pump with progressively changing impeller blades according to claim 5, characterized in that, The adjustment mechanism (9) also includes a gear set located at the rear end of the rear cover plate (61) for transmission between the blade (62) and the adjustment sleeve (91).

7. A chemical process pump with progressively changing impeller blades according to claim 1, characterized in that, The pump casing (3) is provided with an annular slide rail (10) inside, and the outer transmission sleeve (71) is provided with a roller bracket (11) on its periphery. The roller bracket (11) is slidably disposed in the annular slide rail (10). The outer transmission sleeve (71) is rotatably mounted on the pump casing (3) through the annular slide rail (10) and the roller bracket (11).

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