Locking anti-loosening device for cantilever type impeller

Abstract

The invention provides a locking anti-loosening device for a cantilever type impeller, and relates to the technical field of centrifugal fans, pumps and other equipment. The device adopts a'static-dynamic 'dual anti-loosening mechanism: in a static state, an anti-rotation pin on the end face of a locking nut is inserted into a blind hole of an impeller to realize rigid mechanical locking; dynamic, through the anti-rotation gasket which is arranged outside the nut in a sleeving mode and is provided with an asymmetric structure, continuous auxiliary torque tending to be tightened is generated through rotating fluid. The double mechanisms have a synergistic effect, and the elastic check ring ensures that the pin does not exit. The structure is highly integrated and compact in space, the anti-loosening performance is far better than that of a traditional method, disassembly, assembly and maintenance are convenient, all parts can be repeatedly used, the cantilever impeller locking device is particularly suitable for cantilever impeller locking of high-speed, heavy-load and strong-vibration centrifugal fans, pumps and other equipment, and the operation safety and reliability of the equipment are greatly improved.

Description

Technical Field

[0001] This invention relates to the technical field of centrifugal fans, pumps and other equipment, and in particular to a locking and anti-loosening device for cantilever impellers. Background Technology

[0002] Cantilevered impellers (such as centrifugal fan impellers) are typically axially clamped and fixed to the end of the main shaft using lock nuts. During high-speed rotation, the impeller often endures complex vibrations and alternating loads. Traditional lock nuts rely solely on the pre-tightening friction between the threads for anti-loosening. However, under prolonged impeller operation, frequent start-ups and shutdowns, or harsh conditions, this pre-tightening friction can easily diminish due to vibration, leading to nut loosening. Loosening of the nut can cause impeller axial movement and intensified vibration, potentially resulting in serious equipment accidents such as impeller-casing scraping and main shaft wear.

[0003] Existing anti-loosening measures, such as using locking washers, applying thread-locking agents, using flow guide caps, or adopting a double nut structure, have drawbacks such as decreased locking effect with disassembly and assembly, poor resistance to high temperatures or difficulty in disassembly, and increased axial dimensions.

[0004] Therefore, for compact cantilever impellers, there is an urgent need for a locking and anti-loosening device that does not take up extra space, is reliable, durable, and easy to maintain. Summary of the Invention

[0005] The purpose of this invention is to provide a locking and anti-loosening device for cantilever impellers, which can achieve dual anti-loosening protection by combining rigid mechanical stop with hydrodynamic assistance.

[0006] This invention provides a locking and anti-loosening device for a cantilever impeller, comprising: an impeller, a main shaft, and a locking nut. One end of the main shaft is fitted with a tie rod bolt, and the end of the tie rod bolt away from the main shaft passes through the central hole of the impeller and is tightened in conjunction with the locking nut. The locking nut is fastened to the end face of the impeller by an anti-rotation pin. An anti-rotation washer is fitted on the outside of the locking nut, and the outer edge of the anti-rotation washer is provided with a guide structure whose inclination direction is opposite to that of the blade inclination direction of the impeller.

[0007] Preferably, the outer circumferential surface of the locking nut is provided with splines or teeth at intervals, and the inner hole surface of the anti-rotation washer is provided with a keyway or tooth groove that is adapted to the splines or teeth for anti-rotation installation.

[0008] Preferably, the locking nut has a threaded through hole parallel to its axis, the impeller has a positioning hole on its end face, and the anti-rotation pin is screwed into the threaded through hole with its head extending into the positioning hole.

[0009] Preferably, the positioning hole is a blind hole or process hole opened on the end face of the impeller, and the head of the anti-rotation pin is clearance fit or transition fit with the positioning hole.

[0010] Preferably, an annular groove is provided at the opening of the threaded through hole, and an elastic retaining ring for the hole is installed in the annular groove.

[0011] Preferably, the number of anti-rotation pins is two sets.

[0012] Preferably, the positioning hole is a round hole or a non-round hole.

[0013] Preferably, the flow guiding structure is a series of flow guiding plates arranged at intervals on the outer ring plate of the anti-rotation washer. One side of the flow guiding plate is perpendicularly connected to the outer ring plate, and the other side is inclinedly connected to the outer peripheral surface of the anti-rotation washer.

[0014] Preferably, a plurality of locating pins are provided between the contact surfaces of the main shaft and the impeller, and the two ends of the locating pins are respectively inserted into the main shaft and the impeller.

[0015] Preferably, the elastic retaining ring for the hole is an elastic open washer, with locking holes provided at both ends of its open side.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. "Static-Dynamic" Dual-Synergistic Anti-Loosening Mechanism: Combining static rigid stop (anti-rotation pin inserted into impeller positioning hole) with dynamic fluid dynamic assistance (anti-rotation washer generates tightening torque) to form a composite anti-loosening system that combines active and passive mechanisms. Its anti-loosening capability far exceeds that of traditional methods based on a single principle, fundamentally eliminating the possibility of the nut loosening under vibration. It is especially suitable for harsh working conditions such as high-frequency vibration and frequent start-stop. 2. Integrated dual-function structure: The anti-rotation washer is not only a fluid torque generator, but its coupling structure with the lock nut also forms an external reinforcing sleeve, which improves the overall rigidity of the lock nut. The anti-rotation pin integrated on the end face of the lock nut forms an independent and reliable mechanical locking module. 3. Space Adaptation and Energy Utilization: The entire system makes full use of the inherent rotating flow field energy during equipment operation, converting the fluid energy in the harmful vibration environment into beneficial anti-loosening force. No external energy input is required, and all new functions are integrated within the contour space of the original parts, with almost no increase in axial installation dimensions. The structure is compact, which solves the contradiction between the limited space of the cantilever design and the high reliability requirements. 4. Reliability under all operating conditions and convenient maintenance: The dual mechanism ensures the reliability of anti-loosening throughout the entire cycle from start-up, operation to shutdown. The modular design makes the disassembly process clear (remove the retaining ring first, then remove the pin), and maintenance is simple. The pure mechanical structure has strong weather resistance and no problems such as aging or hardening. Standardized parts are easy to replace. The reusable characteristics greatly reduce the maintenance cost throughout the entire life cycle. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional schematic diagram of the assembly state of the device of the present invention; Figure 2 This is an exploded schematic diagram of the device of the present invention; Figure 3 for Figure 1 A magnified view of a portion of region A in the middle; Figure 4 This is a schematic diagram of the structure of the elastic retaining ring for the hole in the device of the present invention; Figure 5 This is a left view of the device of the present invention in its assembled state; Figure 6 This is a schematic diagram of the anti-rotation washer in the device of the present invention; Explanation of reference numerals in the attached figures: 1: Locking nut; 11: Threaded through hole; 2: Anti-rotation pin; 3: Hole elastic retaining ring; 4: Tie rod bolt; 5: Impeller; 51: Positioning hole; 6: Positioning pin; 7: Main shaft; 8: Anti-rotation washer; 801: Flow guide structure. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] like Figures 1-6 As shown, the present invention provides a locking and anti-loosening device for a cantilever impeller, comprising: an impeller 5, a main shaft 7, and a locking nut 1. The impeller 5 is installed at one end of the main shaft 7 and can rotate with it. A tie rod bolt 4 is embedded at one end of the main shaft 7. The end of the tie rod bolt 4 away from the main shaft 7 passes through the central hole of the impeller 5, and its end is provided with an external thread to cooperate with the locking nut 1 and be tightened on the end face of the impeller 5. The locking nut 1 is fastened to the end face of the impeller 5 by an anti-rotation pin 2. An anti-rotation washer 8 is sleeved on the outside of the locking nut 1. A flow guide structure 801 with an inclined direction opposite to the inclined direction of the blades of the impeller 5 is provided on the outer edge of the anti-rotation washer 8. The flow guide structure 801 is an asymmetrical blade or a force-bearing protrusion structure. The anti-rotation pin 2 is fastened to the end face of the impeller 5 to form the first rigid mechanical anti-loosening. When the impeller 5 rotates, the fluid acts on the structure, causing the anti-rotation washer 8 to generate a continuous torque that tends to tighten the locking nut 1. This torque is then transmitted to the locking nut 1 through the coupling structure, forming the second fluid dynamic assisted anti-loosening.

[0023] In this embodiment, splines or teeth are spaced apart on the outer circumferential surface of the locking nut 1, and a keyway or groove adapted to the splines or teeth for anti-rotation is formed on the inner hole surface of the anti-rotation washer 8. Alternatively, the anti-rotation washer 8 can be circumferentially coupled to the outer contour of the locking nut 1 through a high-friction coupling surface to transmit torque. The fluid rotating in the impeller 5 acts on the flow guiding structure 801 of the anti-rotation washer 8, generating a continuous torque in the opposite direction to the loosening of the locking nut 1. This torque is transmitted to the locking nut 1 through the coupling structure, providing dynamic "tightening" compensation.

[0024] In this embodiment, the locking nut 1 has a threaded through hole 11 parallel to its axis, and the impeller 5 has a positioning hole 51 on its end face. The anti-rotation pin 2 can be screwed into the threaded through hole 11 under the action of a tool, and its head extends into the positioning hole 51. The positioning hole 51 is a blind hole or an existing process hole on the end face of the impeller 5. The head of the anti-rotation pin 2 and the positioning hole 51 are clearance fit or transition fit. The positioning hole 51 is a round hole or a non-round hole such as a rectangle or D-shape. When it is a non-round hole, it can enhance the anti-torsion ability. There are two sets of threaded through holes 11, positioning holes 51 and anti-rotation pins 2, or multiple sets arranged on the same circumference, which can adapt to different final locking angles of the locking nut 1.

[0025] In this embodiment, an annular groove is provided at the opening of the threaded through hole 11, and a hole elastic retaining ring 3 is installed in the annular groove. The hole elastic retaining ring 3 is an elastic open washer, and locking holes are provided at both ends of its open side for easy installation and locking. The hole elastic retaining ring 3 ensures that the anti-rotation pin 2 will not be dislodged due to vibration, ensuring a rigid mechanical anti-loosening effect. The anti-rotation pin 2 has a shoulder. When disassembling, it is rotated outward to make its head exit the positioning hole 51, and then the locking nut 1 can be removed. At this time, the anti-rotation pin 2 is still confined within the locking nut 1.

[0026] In this embodiment, the flow guiding structure 801 is a series of flow guiding plates arranged at intervals on the outer ring plate of the anti-rotation washer 8. One side of the flow guiding plate is perpendicularly connected to the outer ring plate, and the other side is inclinedly connected to the outer peripheral surface of the anti-rotation washer 8. In other embodiments, inclined surfaces at specific angles, eccentrically arranged protrusions, etc., can also be used, as long as they can generate a unidirectional net torque in the flow field.

[0027] In this embodiment, multiple sets of positioning pins 6 are provided between the contact surfaces of the main shaft 7 and the impeller 5. The two ends of the positioning pins 6 are respectively inserted into the main shaft 7 and the impeller 5 to ensure the connection effect between the main shaft 7 and the impeller 5 and to prevent relative rotation between the two.

[0028] The usage procedure of the device of the present invention is as follows: During assembly, first tighten the tie rod bolt 4 onto the main shaft 7, then put the impeller 5 onto the tie rod bolt 4, and use the locating pin 6 to achieve circumferential positioning of the impeller 5 and the main shaft 7. Put the anti-rotation washer 8 onto the locking nut 1, ensuring that its internal part and the external contour of the locking nut 1 are tightly fitted through the keyway and other structures. Then screw the assembly into the end of the tie rod bolt 4 and tighten it to the specified torque to press and fix the impeller 5. After tightening the lock nut 1 to its final position, drill a positioning hole 51 on the end face of the impeller 5 through the threaded through hole 11 on the lock nut 1. Then, unscrew the lock nut 1 and the anti-rotation washer 8, and screw the anti-rotation pin 2 into the threaded through hole 11 of the lock nut 1 to an appropriate depth (usually when its shoulder contacts the bottom of the hole). Next, tighten the lock nut 1 and the anti-rotation washer 8 with the anti-rotation pin 2 to the specified torque. At this time, the protruding end of the anti-rotation pin 2 can be inserted into the positioning hole 51 of the impeller 5. Finally, install the elastic retaining ring 3 for the hole in the annular groove on the end face of the lock nut 1 to cover the end of the anti-rotation pin 2, and complete the assembly.

[0029] When the equipment is running, the impeller 5 rotates at high speed. If the locking nut 1 shows any tendency to loosen, it will be doubly prevented: First, its slight rotation will be immediately blocked by the anti-rotation pin 2 inserted into the positioning hole 51 of the impeller 5, achieving rigid mechanical locking; Second, the rotating fluid acts on the flow guiding structure 801 on the outer edge of the anti-rotation washer 8, generating a continuous torque in the opposite direction to the loosening of the locking nut 1. This torque is transmitted to the locking nut 1 through the coupling structure, dynamically "tightening" it. The elastic retaining ring 3 in the hole ensures that the anti-rotation pin 2 itself will not come out due to vibration.

[0030] During disassembly and maintenance, first use snap ring pliers to remove the retaining ring 3 for the hole, then use a tool to unscrew the anti-rotation pin 2 to disengage it from the positioning hole 51. After that, the locking nut 1 and the anti-rotation washer 8 can be disassembled normally. All parts are undamaged and can be reused.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A locking and anti-loosening device for a cantilever impeller, characterized in that, include: Impeller (5), main shaft (7) and locking nut (1), one end of the main shaft (7) is fitted with a tie rod bolt (4), the end of the tie rod bolt (4) away from the main shaft (7) passes through the center hole of the impeller (5) and is tightened with the locking nut (1), the locking nut (1) is fastened to the end face of the impeller (5) by an anti-rotation pin (2), an anti-rotation washer (8) is sleeved on the outside of the locking nut (1), and a guide structure (801) with an inclined direction opposite to the inclined direction of the blades of the impeller (5) is provided on the outer edge of the anti-rotation washer (8).

2. The locking and anti-loosening device for a cantilever impeller according to claim 1, characterized in that, The outer circumferential surface of the locking nut (1) is provided with splines or teeth at intervals, and the inner hole surface of the anti-rotation washer (8) is provided with a keyway or tooth groove that is adapted to the splines or teeth for anti-rotation installation.

3. The locking and anti-loosening device for a cantilever impeller according to claim 1, characterized in that, The locking nut (1) has a threaded through hole (11) parallel to its axis, and the impeller (5) has a positioning hole (51) on its end face. The anti-rotation pin (2) is screwed into the threaded through hole (11) and its head extends into the positioning hole (51).

4. The locking and anti-loosening device for a cantilever impeller according to claim 3, characterized in that, The positioning hole (51) is a blind hole or process hole opened on the end face of the impeller (5), and the head of the anti-rotation pin (2) is clearance fit or transition fit with the positioning hole (51).

5. The locking and anti-loosening device for a cantilever impeller according to claim 4, characterized in that, An annular groove is provided at the opening of the threaded through hole (11), and an elastic retaining ring (3) for the hole is installed in the annular groove.

6. The locking and anti-loosening device for a cantilever impeller according to claim 1, characterized in that, The number of anti-rotation pins (2) is two sets.

7. The locking and anti-loosening device for a cantilever impeller according to claim 3, characterized in that, The positioning hole (51) can be a round hole or a non-round hole.

8. The locking and anti-loosening device for a cantilever impeller according to claim 1, characterized in that, The flow guiding structure (801) is a flow guiding plate arranged in a ring on the outer ring plate of the anti-rotation washer (8). One side of the flow guiding plate is perpendicularly connected to the outer ring plate, and the other side is inclinedly connected to the outer peripheral surface of the anti-rotation washer (8).

9. The locking and anti-loosening device for a cantilever impeller according to claim 1, characterized in that, Multiple sets of positioning pins (6) are provided between the contact surfaces of the main shaft (7) and the impeller (5), and the two ends of the positioning pins (6) are respectively inserted into the main shaft (7) and the impeller (5).

10. The locking and anti-loosening device for a cantilever impeller according to claim 5, characterized in that, The elastic retaining ring (3) for the hole is an elastic open washer with locking holes at both ends of its open side.

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