Horizontal multistage centrifugal pump inner core locking tool

Abstract

The application discloses a horizontal multi-stage centrifugal pump inner core locking tool and relates to the field of centrifugal pump assembly. The tool comprises a constant-torque wrench, an upper-and-lower-through fixed sleeve and an upper-and-lower-through connecting sleeve. The connecting sleeve is sleeved on the constant-torque wrench, one end of the fixed sleeve is installed in the connecting sleeve and slides axially along the inner wall of the connecting sleeve, the other end of the fixed sleeve extends from the lower stop of the connecting sleeve and is used for being sleeved on the outer periphery of a hexagonal gland of the centrifugal pump and being relatively locked, and the hexagonal gland is locked on a pump shaft, so that the pump shaft is locked relative to the fixed sleeve and does not rotate relatively. The head of the constant-torque wrench extends into the fixed sleeve and is used for screwing a nut to lock the inner core of the centrifugal pump with the pump shaft. The hexagonal gland is fixed by the fixed sleeve, the fixed sleeve is connected by the connecting sleeve, and both are kept in contact with hexagonal surfaces, so that the pump shaft is not rotated during the locking of the inner core and the pump shaft obtains an accurate and stable locking torque.

Description

Technical Field

[0001] This invention relates to the field of centrifugal pump assembly, and more specifically to a locking fixture for the inner core of a horizontal multistage centrifugal pump. Background Technology

[0002] like Figure 1 , 2 As shown, centrifugal pumps require locking their inner core during assembly. This locking process typically involves using a torque wrench (6) to axially lock components such as the nut (5), washer (4), hexagonal cap (3), and impeller (1) relative to the pump shaft (2). However, currently, during the inner core locking process, the pump shaft cannot be fixed, causing it to rotate, the torque wrench to fail, and the locking torque to become unstable. Unstable locking torque can also lead to the inner core loosening or even damage, and in severe cases, there is a risk of pump shaft breakage. The locking process requires only slight hand pressure on the impeller, posing a safety hazard. Because the pump shaft rotates, it is impossible to confirm whether the inner core is locked, resulting in low assembly efficiency and poor quality of the assembled centrifugal pump.

[0003] Chinese patent document (CN214055063U) discloses a valve core plug locking fixture, including a base, a conical sleeve, a threaded clamping head, and an upper protective sleeve. The base includes a hollow cavity comprising a cylindrical cavity and a conical cavity that are interconnected. The conical cavity is adapted to the conical sleeve, and the base has fastening threads on its outer periphery. The conical sleeve is fitted inside the conical cavity of the base and includes a clamping end and a fastening end. The clamping end is elastic. The fastening end abuts against the inner side of the threaded clamping head. The threaded clamping head is connected to the base via fastening threads. The upper protective sleeve is fitted inside the conical sleeve. The surface of the base has a base clamping surface. In this technical solution, the valve core plug locking fixture clamps and fixes the outer cylindrical surface of the valve core before inserting the valve plug. Because the outer cylindrical surface is uniformly pressed for fixation, the contact area is large, which can minimize damage to the valve core. However, since the conical jacket and the base use a conical surface seal, the upper sleeve and the conical jacket use a cylindrical surface contact, and the valve core and the upper sleeve also use a cylindrical surface contact, and the valve core surface is very smooth, the above contact surfaces will inevitably rotate relative to each other during the tightening of the valve plug, which cannot completely solve the problem of preventing rotation during assembly. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a locking fixture for the inner core of a horizontal multistage centrifugal pump, which ensures that the pump shaft does not rotate during the inner core locking process, thereby obtaining an accurate and stable locking torque.

[0005] The objective of this invention is achieved through the following technical solution: This horizontal multistage centrifugal pump inner core locking fixture includes a torque wrench, a vertically penetrating fixed sleeve, and a vertically penetrating connecting sleeve. The connecting sleeve is fitted onto the torque wrench. One end of the fixed sleeve is installed inside the connecting sleeve and slides axially along the inner wall of the connecting sleeve. The other end of the fixed sleeve extends from the lower stop of the connecting sleeve and is used to fit around the hexagonal cap of the centrifugal pump and lock it relative to the cap. The hexagonal cap is locked onto the pump shaft, thereby locking the pump shaft relative to the fixed sleeve and preventing relative rotation. The head of the torque wrench extends into the fixed sleeve and is used to tighten the nut to lock the centrifugal pump inner core to the pump shaft.

[0006] As a further technical solution, a step is provided on the outer wall of the fixing sleeve, and the step stops the fixing sleeve on the lower stop.

[0007] As a further technical solution, the fixing sleeve is installed inside the connecting sleeve by a spring. One end of the spring presses against the fixing sleeve to apply downward pressure to the fixing sleeve, and the other end of the spring presses against the torque wrench, which locks the connecting sleeve together.

[0008] As a further technical solution, an impeller is sleeved on the pump shaft. When the torque wrench turns the nut, the fixing sleeve presses on the impeller and applies a clamping force to the impeller.

[0009] As a further technical solution, the spring is supported on the torque wrench by a spring seat, and spring grooves are provided on both the fixing sleeve and the spring seat for installing the spring.

[0010] As a further technical solution, a hexagonal hole matching the shape of the hexagonal cap is opened at the bottom of the fixing sleeve.

[0011] As a further technical solution, the outer wall of the fixing sleeve is hexagonal, and the lower stop is also hexagonal, matching the outer wall of the fixing sleeve so that the fixing sleeve and the connecting sleeve do not rotate relative to each other.

[0012] As a further technical solution, the pump shaft includes a locking section extending from the centrifugal pump and a threaded section connected to the locking section. The threaded section is used to install a nut. The hexagonal gland has an anti-rotation inner hole for fitting and locking onto the locking section.

[0013] As a further technical solution, the anti-rotation inner hole is an oblong hole, and the cross-section of the locking section is oblong, matching the oblong hole.

[0014] As a further technical solution, the anti-rotation inner hole is an internal spline hole, and an external spline is provided on the outer wall of the locking section, so that the hexagonal gland and the pump shaft are engaged by the spline.

[0015] The beneficial effects of this invention are as follows:

[0016] 1. Use a fixing sleeve to fix the hexagonal cap, and then use a connecting sleeve to connect the fixing sleeve. Both should be in contact with the hexagonal surfaces to ensure that the pump shaft will not rotate during the inner core locking process, so that the pump shaft can obtain accurate and stable locking torque.

[0017] 2. A spring is added between the fixed sleeve and the torque wrench. One function is to apply downward pressure to fix the impeller and ensure stability during the locking process. The other function is to ensure that the fixed sleeve automatically resets after locking, so that the next locking can be performed.

[0018] 3. The fixing sleeve is stopped by a step on the lower stop to prevent it from coming out of the connecting sleeve;

[0019] 4. Spring grooves are provided on both the fixed sleeve and the spring seat to prevent the spring from coming out of the corresponding part when it moves, thus ensuring the stability and reliability of the tooling during use.

[0020] 5. The hexagonal gland and the pump shaft can be fitted with a slotted hole or spline to ensure that they are locked together and will not rotate. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the existing technology.

[0022] Figure 2 for Figure 1 A magnified view of a portion of region B in the middle.

[0023] Figure 3 This is a schematic diagram of the structure of the present invention when locked with a centrifugal pump.

[0024] Figure 4 for Figure 3 A magnified view of a portion of region A in the middle.

[0025] Figure 5 This is a schematic diagram of the pump shaft in this invention.

[0026] Figure 6 for Figure 5 CC section view.

[0027] Figure 7 This is a schematic diagram of the hexagonal cap structure in this invention.

[0028] Figure 8 This is a cross-sectional view of the fixed sleeve in this invention.

[0029] Figure 9 for Figure 8 DD sectional view.

[0030] Figure 10 This is a three-dimensional structural diagram of the fixing sleeve in this invention.

[0031] Figure 11This is a top view of the connecting sleeve in this invention.

[0032] Figure 12 for Figure 11 EE sectional view.

[0033] Explanation of reference numerals in the attached drawings: Impeller 1, Pump shaft 2, Threaded section 21, Locking section 22, Hexagonal gland 3, Anti-rotation inner hole 31, Washer 4, Nut 5, Torque wrench 6, Head 61, Fixing sleeve 7, Step 71, Connecting sleeve 8, Lower stop 81, Spring 9, Spring seat 10, Locking screw 11, Hexagonal hole 12, Spring groove 13. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings:

[0035] Example: As attached Figures 1-12 As shown, this horizontal multistage centrifugal pump core locking fixture includes an impeller 1, a pump shaft 2, a threaded section 21, a locking section 22, a hexagonal gland 3, an anti-rotation inner hole 31, a gasket 4, a nut 5, a torque wrench 6, a head 61, a fixing sleeve 7, a step 71, a connecting sleeve 8, a lower stop 81, a spring 9, a spring seat 10, a locking screw 11, a hexagonal hole 12, and a spring groove 13.

[0036] Reference Appendix Figure 3 , 4 Both the fixed sleeve 7 and the connecting sleeve 8 are through-hole structures. The connecting sleeve 8 is fitted onto the torque wrench 6, and the two sides of the connecting sleeve 8 are radially locked relative to the torque wrench 6 with locking screws 11. The upper end of the fixed sleeve 7 is installed inside the connecting sleeve 8. A step 71 is provided on the outer wall of the top of the fixed sleeve 7. The step 71 stops the fixed sleeve 7 on the lower stop 81 to prevent it from coming out of the connecting sleeve 8. One end of the spring 9 presses against the upper end of the fixed sleeve 7, applying downward pressure to the fixed sleeve 7. The other end of the spring 9 presses against the torque wrench 6, allowing the fixed sleeve 7 to slide axially up and down along the inner wall of the connecting sleeve 8.

[0037] The lower end of the fixed sleeve 7 extends from the lower stop 81 of the connecting sleeve 8 and can be fitted onto the outer periphery of the hexagonal gland 3 of the centrifugal pump, so that the hexagonal gland 3 and the fixed sleeve 7 are locked relative to each other. In addition, the hexagonal gland 3 is also locked onto the pump shaft 2, so the pump shaft 2 is locked relative to the fixed sleeve 7 and does not rotate relative to each other. The head 61 of the torque wrench 6 passes through the lower stop 81 and extends into the fixed sleeve 7. The impeller 1 is fitted onto the pump shaft 2. After the hexagonal gland 3 is locked with the pump shaft 2 (locking section 22), it presses against the impeller 1. The washer 4 is fitted into the pump shaft 2 (threaded section 21) and presses against the hexagonal gland 3. When the torque wrench 6 (head 61) turns the nut 5, since the lower end face of the fixed sleeve 7 is closer to the impeller 1 than the end face of the head 61, the fixed sleeve 7 will press against the impeller 1 first, applying a clamping force to the impeller 1, which plays a role in pressing down and fixing, ensuring stability during the locking process. Then, the nut 5 is tightened onto the threaded section 21 of the pump shaft 2 by the torque wrench 6, which locks the inner core of the centrifugal pump. At this time, the pump shaft 2 is locked by the hexagonal cap 3, the fixing sleeve 7 and the connecting sleeve 8, and cannot rotate, thus obtaining an accurate and stable locking torque.

[0038] Preferably, such as Figure 4 As shown, the spring 9 rests on the torque wrench 6 via the spring seat 10. Both the fixed sleeve 7 and the spring seat 10 have spring grooves 13. The upper and lower ends of the spring 9 are placed in the spring grooves 13, which can prevent the spring from coming out of the corresponding parts when it moves, and keep the tooling stable and reliable when in use.

[0039] Reference Appendix Figure 8 , 9 The bottom of the fixing sleeve 7 has a hexagonal hole 12 that matches the shape of the hexagonal pressure cap 3, preventing relative rotation between the fixing sleeve 7 and the hexagonal pressure cap 3. The outer wall of the fixing sleeve 7 is hexagonal, and the lower stop 81 is also hexagonal (e.g., Figure 11 , 12 As shown in the figure, it matches the outer wall of the fixed sleeve 7 so that the fixed sleeve 7 and the connecting sleeve 8 do not rotate relative to each other.

[0040] like Figure 4 , 5 As shown in Figure 6, the pump shaft 2 includes a locking section 22 extending from the centrifugal pump and a threaded section 21 connected to the locking section 22. The threaded section 21 is used to engage with the nut 5 for threaded connection. Figure 7 As shown, the hexagonal cap 3 has an anti-rotation inner hole 31, which is preferably an oblong hole. Correspondingly, the cross-section of the locking section 22 is preferably oblong and matches the oblong hole, so that the hexagonal cap 3 fits and locks onto the locking section 22 of the pump shaft 2. Alternatively, the anti-rotation inner hole 31 can also be an internal spline hole. Correspondingly, the cross-section of the locking section 22 is no longer oblong, but an external spline is provided on the outer wall of the locking section 22, so that the hexagonal cap 3 and the pump shaft 2 are engaged by the spline.

[0041] The working process of this invention is as follows: Before use, first place the fixing sleeve 7 into the connecting sleeve 8, and then place the spring 9 and spring seat 10 on the fixing sleeve 7 in sequence, so that the spring 9 is embedded in the corresponding spring groove 13; use the locking screw 11 to lock and fix the connecting sleeve 8 to the torque wrench 6, and then the centrifugal pump inner core can be locked. When locking the inner core, place (sleeve) the impeller 1, hexagonal pressure cap 3 and gasket 4 on the pump shaft 2 in sequence, wherein the hexagonal pressure cap 3 cooperates with the locking section 22 of the pump shaft 2 to prevent rotation, and then pre-tighten the nut 5 into the threaded section 21 of the pump shaft 2, tightening it three to five threads. Next, the entire fixture is pressed down. First, the hexagonal cap 3 is fixed through the hexagonal hole 12 of the fixing sleeve 7. Then, the torque wrench 6 is also pressed down. Through the force transmitted by the spring 9, the fixing sleeve 7 presses down to tighten the impeller 1, which activates the torque wrench 6 and drives the nut 5 to tighten downwards until the preset torque is reached. The torque wrench 6 then stops working, ensuring that the inner core tightening torque meets the preset requirements, accurately and stably. After tightening is completed, the fixture is pulled up. The fixing sleeve 7 automatically returns to its original position under the action of the spring 9 and is stopped at the lower stop 81 by the step 71.

[0042] Terminology Explanation:

[0043] Impeller: A rotating body with blades that transfers energy to a liquid;

[0044] Pump shaft: The core component of the centrifugal pump rotor assembly. The centrifugal pump impeller, shaft sleeve, etc. are mounted on the pump shaft and rotate on the bearings via the pump shaft;

[0045] Hexagonal cap: A special part for axially pressing the inner core;

[0046] Fixing sleeve: Fixes the hexagonal pressure cap, which mates with the connecting sleeve for connection;

[0047] Connecting sleeve: A part that connects the torque wrench to the fixed sleeve;

[0048] Torque: A special type of torque that causes an object to rotate;

[0049] Spring: A mechanical part that works by utilizing elasticity;

[0050] Spring seat: A part used to support and position a spring.

[0051] It is understood that, for those skilled in the art, any equivalent substitutions or modifications to the technical solutions and inventive concepts of this invention should fall within the scope of protection of the appended claims.

Claims

1. A locking fixture for the inner core of a horizontal multistage centrifugal pump, characterized in that: The device includes a torque wrench (6), a vertically extending fixed sleeve (7), and a vertically extending connecting sleeve (8). The connecting sleeve (8) is fitted onto the torque wrench (6). One end of the fixed sleeve (7) is installed inside the connecting sleeve (8) and slides axially along the inner wall of the connecting sleeve (8). The other end of the fixed sleeve (7) extends out from the lower stop (81) of the connecting sleeve (8) and is used to fit around the hexagonal cap (3) of the centrifugal pump and lock it relative to the cap. The hexagonal cap (3) is locked onto the pump shaft (2), thereby locking the pump shaft (2) relative to the fixed sleeve (7) and preventing relative rotation. The head (61) of the torque wrench (6) extends into the fixed sleeve (7) and is used to turn the nut (5) to lock the centrifugal pump core with the pump shaft (2). The fixed sleeve (7) is installed inside the connecting sleeve (8) by a spring (9). One end of the spring (9) presses against the fixed sleeve (7) to apply downward pressure to the fixed sleeve (7), and the other end of the spring (9) presses against the torque wrench (6) to lock the torque wrench (6) with the connecting sleeve (8). The outer wall of the fixed sleeve (7) is hexagonal, and the lower stop (81) is also hexagonal in shape, matching the outer wall of the fixed sleeve (7) so that the fixed sleeve (7) and the connecting sleeve (8) do not rotate relative to each other.

2. The locking fixture for the inner core of the horizontal multistage centrifugal pump according to claim 1, characterized in that: A step (71) is provided on the outer wall of the fixed sleeve (7), and the step (71) stops the fixed sleeve (7) on the lower stop (81).

3. The locking fixture for the inner core of the horizontal multistage centrifugal pump according to claim 2, characterized in that: The spring (9) rests on the torque wrench (6) through the spring seat (10). Spring grooves (13) are provided on both the fixing sleeve (7) and the spring seat (10) for installing the spring (9).

4. The locking fixture for the inner core of a horizontal multistage centrifugal pump according to any one of claims 1 to 3, characterized in that: An impeller (1) is fitted onto the pump shaft (2). When the torque wrench (6) turns the nut (5), the fixing sleeve (7) presses onto the impeller (1) and applies a clamping force to the impeller (1).

5. The locking fixture for the inner core of the horizontal multistage centrifugal pump according to claim 4, characterized in that: The bottom of the fixing sleeve (7) has a hexagonal hole (12) that matches the shape of the hexagonal cap (3).

6. The locking fixture for the inner core of a horizontal multistage centrifugal pump according to claim 5, characterized in that: The pump shaft (2) includes a locking section (22) extending from the centrifugal pump and a threaded section (21) connected to the locking section (22). The threaded section (21) is used to install a nut (5). The hexagonal cap (3) has an anti-rotation inner hole (31) for fitting and locking onto the locking section (22).

7. The locking fixture for the inner core of a horizontal multistage centrifugal pump according to claim 6, characterized in that: The anti-rotation inner hole (31) is a waist-shaped hole, and the locking section (22) has a waist-shaped cross section that matches the waist-shaped hole.

8. The locking fixture for the inner core of a horizontal multistage centrifugal pump according to claim 6, characterized in that: The anti-rotation inner hole (31) is an internal spline hole, and an external spline is provided on the outer wall of the locking section (22) so that the hexagonal cover (3) and the pump shaft (2) are engaged by the spline.

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