Detachable impeller pump body maintenance device

Abstract

The utility model provides a detachable impeller pump body maintenance device, which belongs to the technical field of impeller pump bodies and comprises a motor and a connecting support fixed at one end of the motor. A pump body is detachably installed on the side, away from the motor, of the connecting support and provided with a water inlet end and a water drainage end, an end plate fixedly connected to the connecting support is conveniently and detachably installed on the side, facing the motor, of the pump body, and a detachable structure is adopted between the connecting support and the pump body. A sealing gasket attached to the pump body is fixedly arranged on one side of the end plate, a motor rotating shaft of the motor penetrates through one end of the end plate, extends into the pump body and is fixedly provided with impeller blades, and a shaft sealing sleeve fixed in the end plate is installed on the motor rotating shaft of the motor. A sealing unit installed in the end plate is fixedly arranged on the outer edge face of the shaft sealing sleeve. The defect that a traditional structure is low in maintenance convenience is overcome.

Description

Technical Field

[0001] The utility model belongs to the technical field of impeller pump bodies, and in particular relates to a detachable impeller pump body maintenance device. Background Art

[0002] Impeller pumps are widely used in a wide range of fields, including industry, agriculture, and construction, and their importance is self-evident. The impeller pump maintenance device is designed to ensure the stability, reliability, and efficiency of the impeller pump during operation. It also allows for convenient and quick inspection, replacement, or maintenance of key components within the pump body, such as the impeller, shaft seal, and bearings, when equipment malfunctions or requires scheduled maintenance.

[0003] The Chinese utility model patent with publication number CN220566285U (application number CN202322179149.8) discloses a dynamic sealing structure for the shaft end of a centrifugal pump, comprising a motor and a connecting seat fixed to one end of the motor, wherein a pump body is detachably mounted on a side of the connecting seat away from the motor, the pump body having a water outlet and a water inlet, and an end cover fixedly connected to the connecting seat is detachably mounted on the side of the pump body facing the motor. The utility model maintains a sealing effect with a static sealing ring by pushing a rubber dynamic sealing ring with a guiding function through a composite spring, thereby avoiding the occurrence of increased wear due to the combination of granular matter and sediment in sewage, reducing leakage, and reducing the maintenance frequency and cost of the centrifugal pump.

[0004] Traditional impeller pump maintenance devices typically use a relatively fixed and complex connection structure. For example, the connection between the pump body and the motor is often fastened with a large number of bolts. Although this connection method ensures the firmness of the connection to a certain extent, it brings a lot of inconvenience when the pump body needs to be maintained. When disassembling the pump body, maintenance personnel need to spend a lot of time and energy to remove the numerous bolts one by one. When reinstalling, they also need to carefully adjust the position of the pump body to ensure that key parameters such as the coaxiality of the impeller and the motor shaft meet the requirements. Failure to do so can easily lead to problems such as increased vibration of the pump body during operation, seal failure, and accelerated bearing wear, seriously affecting the service life and working performance of the pump body. Utility Model Content

[0005] In view of this, the present invention provides a detachable impeller pump body maintenance device, which solves the disadvantages of the traditional impeller pump body maintenance device, such as the complex connection structure and low maintenance convenience.

[0006] The utility model is achieved in this way:

[0007] The utility model provides a detachable impeller pump body maintenance device, comprising an electric motor and a connecting bracket fixed to one end of the electric motor; the pump body is detachably mounted on the side of the connecting bracket away from the electric motor, the pump body has a water inlet end and a discharge end, and the end plate fixedly connected to the connecting bracket is conveniently and detachably mounted on the side of the pump body facing the electric motor, wherein a disassembly structure is adopted between the connecting bracket and the pump body, a sealing gasket that fits the pump body is fixedly arranged on one side of the end plate, the motor shaft of the electric motor passes through one end of the end plate and extends into the pump body and is fixedly mounted with an impeller blade, and a shaft sealing sleeve fixed in the end plate is mounted on the motor shaft of the electric motor, and a sealing unit installed in the end plate is fixedly arranged on the outer edge surface of the shaft sealing sleeve.

[0008] The technical benefits of the detachable impeller pump maintenance device provided by this utility model are as follows: The quick-detachable structure connecting the bracket and the pump housing greatly improves maintenance convenience, shortens repair time, reduces equipment downtime, and improves production efficiency. The auxiliary positioning of the locating pin and locating hole ensures connection accuracy, reduces the risk of failure due to improper installation, and improves equipment operational stability. The power motor drives the impeller component to achieve liquid delivery, while the shaft seal sleeve and seal assembly ensure the internal seal of the pump body, preventing liquid leakage, extending the equipment's service life, and ensuring a safe working environment.

[0009] On the basis of the above technical solution, the detachable impeller pump body maintenance device of the present invention can also be improved as follows:

[0010] In which, the disassembly structure includes a connecting card seat arranged on the connecting bracket and a connecting buckle seat arranged on the pump body shell. The connecting card seat and the connecting buckle seat are connected, locked or unlocked and separated by a rotatable locking device. The cross-sectional shape of the connecting card seat is an inverted "L" shape, and the connecting buckle seat is in a shape that matches the connecting card seat, which is an "L"-shaped structure.

[0011] The cross-section of the connecting bracket is an inverted "L" shape, with a horizontal mounting plate and a vertical clamping plate. The mounting plate is fixed to the connecting bracket by welding or bolting, while the clamping plate is used to mate with the connecting bracket.

[0012] The connector base is located on the edge of the pump housing corresponding to the connecting bracket. It's an L-shaped structure that matches the connector base. Its horizontal portion is fixedly connected to the outer wall of the pump housing, while its vertical portion is designed to interlock with the connector base's snap plate. The vertical portion of the connector base features a semicircular slot near the top and bottom, respectively. These slots engage the two locking heads of the rotatable locking mechanism when the connector base and connector base are engaged.

[0013] The locking mechanism consists of a rotating shaft, two locking heads, and an operating handle. The rotating shaft is mounted horizontally on the connecting bracket, a certain distance above or below the connecting base. Its ends are fixed to the connecting bracket via bearing seats to ensure smooth rotation.

[0014] Two locking heads, each fixed to either end of the rotating shaft, are curved, hook-shaped structures that match the semicircular slots on the connector base. To lock the connection, the operating handle rotates the rotating shaft, causing the two locking heads to rotate downward into the slots of the connector base, thereby firmly locking the connector base and the connector base together. To unlock, the operating handle is rotated in the opposite direction, causing the locking heads to rotate upward and out of the slots, effectively releasing the connection.

[0015] Furthermore, the connecting bracket and the end plate are assisted in positioning by using a positioning pin and a positioning hole. The head of the positioning pin is conical, and a positioning hole is provided on the end plate at a position corresponding to the positioning pin. The positioning hole is circular in shape, and its diameter is slightly larger than the diameter of the positioning pin.

[0016] The locating pin can be fixed to the connecting bracket by means of an interference fit, or can be threaded and fastened using a nut.

[0017] Furthermore, the sealing unit includes a base seat connected to the shaft sealing sleeve and a static seal fixed in the end plate. A composite spring is installed on the side of the base seat close to the motor, and a dynamic sealing component installed on the base seat is connected to the side of the composite spring facing away from the base seat.

[0018] Furthermore, the dynamic sealing component includes a bearing base, and a first limiting protrusion ring and a second limiting protrusion ring are integrally formed on both sides of the bearing base. The bearing base is made of rubber, and the outer side of the bearing base is provided with a positioning sleeve that abuts against the first limiting protrusion ring.

[0019] Furthermore, a contact structure that abuts against the second limiting protrusion is sleeved on one side of the outer surface of the bearing base, and the composite spring is fixedly connected to one side of the contact structure. The side of the contact structure away from the composite spring is in close contact with one side of the static seal, and the static seal includes a static sealing ring fixed in the end plate.

[0020] Furthermore, the contact structure includes a mounting base that is sleeved on the bearing base and abuts against the second limiting protrusion ring. A rubber dynamic sealing ring that is in close contact with the second limiting protrusion ring is installed in the mounting base, and a sealing mating surface is formed between the rubber dynamic sealing ring and the static sealing ring body.

[0021] Further, a plurality of positioning inserts are arranged in an annular array on the side of the mounting base body away from the rubber dynamic sealing ring, and a plurality of positioning clamping grooves for the positioning inserts to be inserted are arranged in an annular array on the outer circumferential surface of the positioning sleeve, and the cooperation of the positioning inserts and the positioning clamping grooves is used for the circumferential positioning of the mounting base body and the positioning sleeve.

[0022] Further, a plurality of anti-rotation protrusions are arranged in an annular array on the outer circumferential surface of the mounting base body away from the second limiting protrusion ring, and a plurality of anti-rotation recesses for the anti-rotation protrusions to be embedded are arranged in an annular array on the outer circumferential surface of the rubber dynamic sealing ring, so as to prevent the rubber dynamic sealing ring from rotating circumferentially relative to the mounting base body.

[0023] Further, the anti-rotation protrusion is arranged on the outer circumferential surface of the mounting base body away from the second limiting protrusion ring, and has a cuboid shape, and the length direction of the anti-rotation protrusion extends by a certain angle along the circumferential direction of the mounting base body, and the arc length of the angle ranges from 30° to 60°, and the anti-rotation recess is arranged on the outer circumferential surface of the rubber dynamic sealing ring, and has a cuboid recess shape matched with the anti-rotation protrusion.

[0024] The anti-rotation protrusion is arranged on the outer circumferential surface of the mounting base body away from the limiting protrusion ring two, and has a cuboid shape, and the length direction of the anti-rotation protrusion extends by a certain angle along the circumferential direction of the mounting base body, for example, extends by an arc length ranging from 30° to 60°. The height of the anti-rotation protrusion is 1 / 3-1 / 2 of the thickness of the rubber dynamic sealing ring, and the width of the anti-rotation protrusion is determined according to the size and strength requirement of the mounting base body, and is generally between 2-5 millimeters. The top and both side edges of the anti-rotation protrusion are chamfered to avoid scratching the rubber dynamic sealing ring during installation.

[0025] The depth of the anti-rotation recess is slightly greater than the height of the anti-rotation protrusion, and the width of the anti-rotation recess is slightly greater than the width of the anti-rotation protrusion, so as to ensure that the anti-rotation protrusion can be smoothly embedded in the anti-rotation recess with a certain gap, facilitate installation, and effectively prevent the rubber dynamic sealing ring from rotating circumferentially relative to the mounting base body. The inner wall of the recess is also chamfered to reduce stress concentration and improve the service life of the rubber dynamic sealing ring.

[0026] Compared with the prior art, the beneficial effects of the detachable impeller pump body maintenance device provided by the utility model are:

[0027] The quick disassembly structure has the following advantages:

[0028] The quick dismounting structure between the connecting support and the pump body shell greatly simplifies the dismounting and mounting process of the pump body shell.

[0029] Component connection and positioning optimization:

[0030] The positioning pin and the positioning hole are matched for auxiliary positioning between the connecting support and the end plate, which improves the installation accuracy and also provides convenience for subsequent maintenance work.

[0031] Function of the anti-rotation structure:

[0032] The cooperation of the positioning insert, the positioning clamping groove, the anti-rotation protruding key and the anti-rotation recess groove effectively prevents the circumferential rotation of the sealing component during operation. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0034] Figure 1 It is a detachable impeller pump body maintenance device example drawing;

[0035] Figure 2 It is a detachable impeller pump body maintenance device side view;

[0036] Figure 3 It is a detachable impeller pump body maintenance device sealing unit example drawing;

[0037] Figure 4 It is a detachable impeller pump body maintenance device sealing unit exploded view;

[0038] Figure 5 It is a detachable impeller pump body maintenance device disassembly structure example drawing;

[0039] In the drawings, the components represented by each reference numeral are listed as follows:

[0040] 10, motor; 20, connecting support; 21, disassembly structure; 22, connecting clamping seat; 23, connecting buckle; 30, pump body; 31, water inlet end; 32, water outlet end; 40, end plate; 41, positioning pin; 50, sealing unit; 51, bearing base; 52, mounting base; 521, rubber dynamic sealing ring; 522, anti-rotation key; 523, anti-rotation groove; 53, positioning insert; 54, positioning clamping groove. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical scheme in the embodiments of the present application.

[0042] As Figure 1-Figure 5The figure shows a first embodiment of a detachable impeller pump body maintenance device provided by the utility model. In this embodiment, it includes a motor 10 and a connecting bracket 20 fixed to one end of the motor 10; a pump body 30 is detachably installed on the side of the connecting bracket 20 away from the motor 10, and the pump body 30 has a water inlet end 31 and a discharge end 32, and the pump body 30 is conveniently and detachably installed on the side facing the motor 10. An end plate 40 fixedly connected to the connecting bracket 20 is provided, wherein a disassembly structure 21 is adopted between the connecting bracket 20 and the pump body 30, and a sealing gasket that fits the pump body 30 is fixedly provided on one side of the end plate 40, and the motor shaft of the motor 10 extends through one end of the end plate 40 into the pump body 30 and is fixedly installed with an impeller blade, and a shaft seal sleeve fixed in the end plate 40 is installed on the motor shaft of the motor 10, and a sealing unit 50 installed in the end plate 40 is fixedly provided on the outer edge surface of the shaft seal sleeve.

[0043] like Figure 5 As shown, in the above technical solution, the disassembly structure 21 includes a connecting card seat 22 arranged on the connecting bracket 20 and a connecting buckle seat 23 arranged on the outer shell of the pump body 30. The connecting card seat 22 and the connecting buckle seat 23 are connected, locked or unlocked and separated by a rotatable locking device. The cross-sectional shape of the connecting card seat 22 is an inverted "L" shape, and the connecting buckle seat 23 is a shape that matches the connecting card seat 22, which is an "L"-shaped structure.

[0044] like Figure 2 As shown, further, in the above technical solution, the connecting bracket 20 and the end plate 40 are assisted in positioning by using a positioning pin 41 and a positioning hole. The head of the positioning pin 41 is conical, and a positioning hole is provided on the end plate 40 at a position corresponding to the positioning pin 41. The positioning hole is circular in shape, and its diameter is slightly larger than the diameter of the positioning pin 41.

[0045] Furthermore, in the above technical solution, the sealing unit 50 includes a base seat connected to the shaft sealing sleeve and a static seal fixed in the end plate 40, a composite spring is installed on the side of the base seat close to the motor 10, and a dynamic sealing component installed on the base seat is connected to the side of the composite spring facing away from the base seat.

[0046] like Figure 3 、 Figure 4 As shown, the dynamic sealing component includes a rubber bearing base, and a limiting convex ring 1 and a limiting convex ring 2 are integrally formed on both sides of the rubber bearing base. A positioning sleeve is provided on the outer side of the rubber bearing base and abuts against the limiting convex ring 1. A plurality of guide through holes are evenly distributed on one side of the positioning sleeve, and guide column rods are slidably assembled in the plurality of guide through holes. A blocking end is fixedly provided at one end of the guide column rod, and a plurality of positioning sockets for fixing the guide column rod are correspondingly provided on one side of the base seat.

[0047] The rubber bearing base is mounted on the shaft seal sleeve, with its axis aligning with the motor output shaft. It is flanked by integrally formed stop collars 1 and 2, which restrict its axial position. The mounting base is mounted on the rubber bearing base and abuts against stop collar 2. Its primary function is to mount the rubber dynamic seal ring and coordinate with other components to provide sealing and prevent rotation.

[0048] The rubber dynamic seal ring is installed inside the mounting base, with its outer circumference tightly fitting the inner wall of the mounting base. An annular sealing protrusion is constructed on the side of the rubber dynamic seal ring away from the second stopper protrusion. This protrusion tightly abuts the static seal ring body, forming the primary sealing contact surface to prevent liquid leakage from the shaft end during pump operation.

[0049] The anti-rotation key is located on the outer circumference of the mounting base, away from the second retaining ring. It is rectangular in shape, with its length extending at a predetermined angle along the circumference of the mounting base. An anti-rotation groove is provided on the outer circumference of the rubber dynamic sealing ring, its shape matching the anti-rotation key. During installation, the anti-rotation key engages within the groove, preventing the rubber dynamic sealing ring from rotating circumferentially relative to the mounting base, ensuring uniform contact pressure on the sealing surface and a stable sealing effect.

[0050] The positioning inserts are arranged on a side of the mounting base away from the rubber dynamic sealing ring and are in an annular array structure.

[0051] Furthermore, in the above technical solution, a contact structure that abuts against the second limiting convex ring is sleeved on one side of the outer surface of the supporting base 51, and the composite spring is fixedly connected to one side of the contact structure, and the side of the contact structure away from the composite spring is in close contact with one side of the static seal, and the static seal includes a static sealing ring body fixed in the end plate 40.

[0052] Furthermore, in the above technical solution, the contact structure includes a mounting base 52 which is mounted on the supporting base 51 and abuts against the second limiting protrusion ring. A rubber dynamic sealing ring 521 which is in close contact with the second limiting protrusion ring is installed in the mounting base 52, and a sealing mating surface is formed between the rubber dynamic sealing ring 521 and the static sealing ring body.

[0053] Furthermore, in the above technical solution, a plurality of positioning inserts 53 are provided in a ring array on the side of the mounting base 52 away from the rubber dynamic sealing ring 521, and a plurality of positioning slots 54 for inserting the positioning inserts 53 are provided in a ring array on the outer circumferential surface of the positioning sleeve. The cooperation between the positioning inserts 53 and the positioning slots 54 is used for circumferential positioning of the mounting base 52 and the positioning sleeve.

[0054] Furthermore, in the above technical solution, a plurality of anti-rotation keys 522 are distributed in a circular array on the side of the outer circumferential surface of the mounting base 52 away from the second limiting convex ring, and a plurality of anti-rotation grooves 523 for the anti-rotation keys 522 to be embedded in a circular array on the outer circumferential surface of the rubber dynamic sealing ring 521 are provided to prevent the rubber dynamic sealing ring 521 from rotating circumferentially relative to the mounting base 52.

[0055] Furthermore, in the above technical solution, the anti-rotation key 522 is arranged on the side of the outer circumferential surface of the mounting base 52 away from the second limiting convex ring, and is in the shape of a rectangular parallelepiped. Its length direction extends along the circumferential direction of the mounting base 52 at a certain angle, and the arc length of the angle ranges from 30° to 60°. The anti-rotation groove 523 is opened on the outer circumferential surface of the rubber dynamic sealing ring 521, and its shape matches the anti-rotation key 522, and is a rectangular parallelepiped groove.

[0056] Specifically, the principle of the present utility model is:

[0057] Quick disassembly principle:

[0058] The quick-disassembly structure is based on the ingenious design of the connecting base, connecting buckle base, and locking device. The connecting base is fixed to the connecting bracket, and the connecting buckle base is fixed to the pump body shell. When the two are docked, the operating handle of the locking device is operated to drive the rotating shaft to rotate the locking head into the slot of the connecting buckle base, thereby locking the connecting bracket and the pump body shell together. When disassembly is required, the handle is operated in the reverse direction, and the locking head rotates out of the slot, and the connection between the connecting bracket and the pump body shell is released. This structure utilizes the principle of mechanical locking, achieving connection and disassembly through a simple rotation action, eliminating the need for complicated bolt disassembly and installation processes, greatly improving disassembly speed;

[0059] Positioning principle:

[0060] The coordination of the locating pins and locating holes between the connecting bracket and the end plate is based on the principle of mechanical positioning. The head of the locating pin is conical, making it easier to insert into the locating hole. During installation, the locating pin is first inserted into the locating hole to preliminarily locate the position of the end plate. Then, during the connection between the connecting bracket and the pump casing, the end plate is constrained by the locating pins to maintain its accurate position, ensuring the correct relative position relationship between the various components within the pump body. This positioning method can effectively improve installation accuracy and reduce equipment operational failures caused by installation errors. For example, in terms of ensuring the coaxiality of the impeller and the motor shaft, the coordination of the locating pin and the locating hole can control the coaxiality error to a very small range, generally within 0.05-0.1mm, thereby ensuring the smooth operation of the pump body and good sealing performance.

Claims

1. A detachable impeller pump body maintenance device, comprising a motor (10) and a connecting bracket (20) fixed to one end of the motor (10); a pump body (30) is detachably mounted on a side of the connecting bracket (20) away from the motor (10), the pump body (30) having a water inlet end (31) and a water outlet end (32), and an end plate (40) fixedly connected to the connecting bracket (20) is conveniently and detachably mounted on a side of the pump body (30) facing the motor (10), characterized in that: A disassembly structure (21) is used between the connecting bracket (20) and the pump body (30), a sealing gasket that is attached to the pump body (30) is fixedly provided on one side of the end plate (40), a motor shaft of the motor (10) passes through one end of the end plate (40) and extends into the pump body (30) and is fixedly installed with an impeller blade, and a shaft seal sleeve fixed in the end plate (40) is installed on the motor shaft of the motor (10), and a sealing unit (50) installed in the end plate (40) is fixedly provided on the outer edge surface of the shaft seal sleeve.

2. A detachable impeller pump body maintenance device according to claim 1, characterized in that: The disassembly structure (21) comprises a connection card seat (22) arranged on the connection bracket (20) and a connection buckle seat (23) arranged on the outer shell of the pump body (30); the connection card seat (22) and the connection buckle seat (23) are connected, locked, unlocked, and separated by a rotatable locking device; the cross-section of the connection card seat (22) is an inverted "L" shape; the connection buckle seat (23) is in a shape matching the connection card seat (22), and is an "L"-shaped structure.

3. A detachable impeller pump body maintenance device according to claim 2, characterized in that: The connecting bracket (20) and the end plate (40) are assisted in positioning by the cooperation of a positioning pin (41) and a positioning hole. The head of the positioning pin (41) is conical. A positioning hole is provided on the end plate (40) at a position corresponding to the positioning pin (41). The positioning hole is circular in shape, and its diameter is larger than the diameter of the positioning pin (41).

4. A detachable impeller pump body maintenance device according to claim 3, characterized in that: The sealing unit (50) includes a base seat connected to the shaft seal sleeve and a static seal fixed in the end plate (40); a composite spring is installed on a side of the base seat close to the motor (10), and a dynamic sealing component installed on the base seat is connected to a side of the composite spring facing away from the base seat.

5. A detachable impeller pump body maintenance device according to claim 4, characterized in that: The dynamic sealing component comprises a bearing base (51), a first limiting convex ring and a second limiting convex ring are integrally formed on both sides of the bearing base (51), the bearing base (51) is made of rubber, and a positioning sleeve is sleeved on the outer side of the bearing base (51) and abuts against the first limiting convex ring.

6. A detachable impeller pump body maintenance device according to claim 5, characterized in that: A contact structure that abuts against the second limiting convex ring is sleeved on one side of the outer surface of the bearing base (51), and the composite spring is fixedly connected to one side of the contact structure. The side of the contact structure away from the composite spring is in close contact with one side of a static seal, and the static seal includes a static sealing ring body fixed in the end plate (40).

7. A detachable impeller pump body maintenance device according to claim 6, characterized in that: The contact structure comprises a mounting base (52) which is sleeved on the bearing base (51) and abuts against the second limiting convex ring; a rubber dynamic sealing ring (521) which is in close contact with the second limiting convex ring is mounted in the mounting base (52); a sealing mating surface is formed between the rubber dynamic sealing ring (521) and the static sealing ring body.

8. A detachable impeller pump body maintenance device according to claim 7, characterized in that: A plurality of positioning inserts (53) are provided in an annular array on one side of the mounting base (52) away from the rubber dynamic sealing ring (521); a plurality of positioning slots (54) for inserting the positioning inserts (53) are provided in an annular array on the outer circumferential surface of the positioning sleeve; the positioning inserts (53) cooperate with the positioning slots (54) for circumferential positioning of the mounting base (52) and the positioning sleeve.

9. A detachable impeller pump body maintenance device according to claim 8, characterized in that: A plurality of anti-rotation cams (522) are distributed in an annular array on the side of the outer circumferential surface of the mounting base (52) away from the second limiting cam ring, and a plurality of anti-rotation grooves (523) are provided in an annular array on the outer circumferential surface of the rubber dynamic sealing ring (521) for embedding the anti-rotation cams (522), so as to prevent the rubber dynamic sealing ring (521) from rotating circumferentially relative to the mounting base (52).

10. A detachable impeller pump body maintenance device according to claim 9, characterized in that: The anti-rotation convex key (522) is arranged on a side of the outer circumferential surface of the mounting base (52) away from the second limiting convex ring, and is in the shape of a rectangular parallelepiped. Its length direction extends along the circumferential direction of the mounting base (52) at a certain angle, and the arc length range of the angle is 30°-60°. The anti-rotation groove (523) is opened on the outer circumferential surface of the rubber dynamic sealing ring (521), and its shape matches the anti-rotation convex key (522), and is a rectangular parallelepiped groove.

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