Spring protection type mechanical sealing structure

Abstract

The utility model belongs to the technical field of sealing, and particularly relates to a spring protection type mechanical sealing structure which comprises a check ring, a clamping spring, a transmission sleeve, a push ring, a spring, a movable ring assembly, a static ring and an anti-rotating pin. The moving ring assembly comprises a moving ring and a moving ring seat, and the moving ring is embedded in a matching hole of the moving ring seat in an interference manner; counter bores for positioning the spring are formed in the circumference of the movable ring seat; large semicircular arc grooves are evenly distributed in the circumference of the movable ring seat, the anti-rotating pin is embedded in the arc grooves in an interference mode, the clamping spring and the check ring are installed at the tail end of the movable ring seat, and the movable ring O-shaped ring is arranged between the transmission sleeve and the movable ring seat and limited by the check ring and the clamping spring. A first shoulder is arranged on the outer circle of the transmission sleeve and is used for placing the limiting push ring; arc-shaped grooves which are uniformly distributed are formed in the outer circle of the transmission sleeve for mounting the push ring; one end of the spring is mounted in the counter bore of the movable ring seat, and the other end of the spring abuts against the end face of the push ring; and the static ring is mounted in the gland, the O-shaped ring is used for auxiliary sealing, and the end surfaces of the dynamic ring friction pair and the static ring friction pair are rotationally matched.

Description

Technical Field

[0001] The utility model belongs to the technical field of sealing, and particularly relates to a spring protection type mechanical sealing structure. Background Art

[0002] For media containing impurities, spring-protected seals are widely used. The seal before the modification of the utility model is a commonly used seal. The existing seal dynamic ring anti-rotation pin is radially installed on the dynamic ring seat. Due to the thin wall thickness of the dynamic ring seat, the interference fit position is prone to static sealing problems, resulting in sealing leakage, which limits the wide application of the seal. How to change the structural type of the anti-rotation pin and improve the stability of the seal is the key to solving the problem of whether this seal can be stably applied. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides a spring protection type mechanical seal structure, including a retaining ring, a retaining spring, a transmission sleeve, a push ring, a spring, a dynamic ring assembly, a static ring and an anti-rotation pin;

[0004] The dynamic ring assembly includes a dynamic ring and a dynamic ring seat. The dynamic ring is inserted in the matching hole of the dynamic ring seat through interference fit. The dynamic ring seat is arranged with countersunk holes for positioning the spring on its circumference. The countersunk holes are matched with the outer diameter clearance of the spring. The dynamic ring seat is evenly distributed with large semicircular arc grooves for inserting the anti-rotation pin on its circumference. The anti-rotation pin is inserted in the arc groove through interference fit. The inner diameter surface of the tail end of the dynamic ring seat is provided with grooves and steps for installing the retaining ring and the retaining ring. The dynamic ring O-ring is arranged between the transmission sleeve and the dynamic ring seat and is limited by the retaining ring and the retaining ring.

[0005] The transmission sleeve is provided with a first shoulder on the outer circle of the transmission sleeve for placing a limit push ring; the outer circle of the transmission sleeve for installing the push ring is provided with evenly distributed arc-shaped grooves, and the arc-shaped grooves and the semicircular arc grooves cooperate with each other to form an installation space for installing the anti-rotation pin, and the arc-shaped grooves and the anti-rotation pin are floatingly matched to transmit the rotation torque of the dynamic ring;

[0006] A spring, one end of which is installed in the countersunk hole of the moving ring seat and the other end of which abuts against the end surface of the push ring. The spring provides elastic compensation for the moving ring assembly;

[0007] The stationary ring is installed in the gland and assisted in sealing by an O-ring. The end faces of the friction pair of the dynamic ring and the friction pair of the stationary ring rotate in cooperation.

[0008] Furthermore, a second shoulder is provided at the rear end of the transmission sleeve, and threaded holes are evenly arranged in the circumference. The threaded holes are provided with hexagon socket head set screws fixed on the shaft, and a transmission sleeve O-ring is provided between the inner diameter surface of the transmission sleeve and the shaft sleeve.

[0009] The advantages of the utility model are:

[0010] 1. The utility model is a mechanical seal generally applicable to media containing impurities. In this solution, the spring does not contact the media, the circumference of the seal in contact is smooth and flat, and the impurity media is not likely to cause seal failure.

[0011] 2. The utility model makes full use of the integrated design of the radial space of the drive sleeve and the moving ring seat. Seals of the same specification conform to the radial dimensions of conventional seals (the spring of the conventional seal contacts the media, and the spring and the transmission parts are arranged in series), and the spring and the transmission components are in a parallel space, reducing the axial space.

[0012] 3. In this solution, the anti-rotation pin does not leak, and at the same time, the spring protection does not get stuck. Moreover, the anti-rotation of the anti-rotation pin is more stable, making the seal effect of the utility model good and the service life long. Brief Description of the Drawings

[0013] Figure 1 is the structural schematic diagram of the utility model;

[0014] Figure 2 is the structural schematic diagram of the drive sleeve;

[0015] Figure 3 is the structural schematic diagram of the moving ring seat;

[0016] Figure 4 is the structural schematic diagram of the transmission component;

[0017] Description of the part numbers in the drawings: 1 - hexagon socket countersunk head set screw; 2 - drive sleeve O-ring; 3 - moving ring O-ring; 4 - retaining ring; 5 - circlip; 6 - drive sleeve; 7 - push ring; 8 - spring; 9 - moving ring assembly; 901 - moving ring; 902 - moving ring seat; 10 - stationary ring O-ring; 11 - stationary ring; 12 - anti-rotation pin; 13 - large semi-circular arc groove; 14 - arc groove. Detailed Implementation Manner

[0018] The principles and features of the utility model are described below with reference to the drawings. The examples given are only used to explain the utility model and are not intended to limit the scope of the utility model.

[0019] As Figures 1-4 shown, the utility model provides a spring-protected mechanical seal structure applicable to the flushing scheme of Plan11, including: hexagon socket countersunk head set screw, drive sleeve O-ring 2; auxiliary O-ring 3 of the moving ring assembly, retaining ring 4, circlip 5 (two pieces), drive sleeve 6, push ring 7, spring 8 (multiple), moving ring assembly 9, stationary ring O-ring 10, stationary ring 11, anti-rotation pin 12.

[0020] The moving ring assembly 9 is composed of a moving ring 901 and a moving ring seat 902. The moving ring 901 is press-fitted into the mating hole of the moving ring seat 902. The moving ring seat 902 is circumferentially provided with counterbores for positioning the spring 8, and the counterbores are in clearance fit with the outer diameter of the spring 8. The moving ring seat 902 is circumferentially evenly provided with large semi-circular arc grooves 13 for press-fitting the anti-rotation pins 12. The anti-rotation pins 12 are press-fitted into the large semi-circular arc grooves 13. The inner hole of the moving ring seat 902 is provided with grooves and steps for installing the snap ring 5 and the retaining ring 4. The O-ring 3 of the moving ring is limited by the retaining ring 4 and the snap ring 5 and is installed on the moving ring assembly 9.

[0021] The drive sleeve 6 is provided with grooves in its inner hole for installing the O-ring 2 of the drive sleeve. The outer circle of the drive sleeve 6 is provided with two shoulders. One shoulder is used to limit the push ring 7, and the other shoulder is provided with evenly distributed threaded holes for installing the socket head cap screws 1. The outer circle of the drive sleeve 6 where the push ring 7 is installed is provided with evenly distributed circular arc grooves 14, which are in floating fit with the anti-rotation pins 12 to transmit the rotational torque of the moving ring 901.

[0022] One end of the spring 8 is installed in the counterbore of the moving ring seat 902, and the other end abuts against the end face of the push ring 7. The spring 8 provides elastic compensation for the moving ring assembly 9. The socket head cap screws 1 fasten the drive sleeve 6 to the shaft sleeve to rotate with the pump shaft. The moving ring friction pair rotates in cooperation with the static ring friction pair. The static ring 11 is installed in the gland and is assisted by an O-ring for sealing.

[0023] During operation, the moving ring assembly 9 rotates with the drive sleeve. The static ring 11 is fixed to the pump body by the gland. The friction pair realizes dynamic sealing, and the auxiliary O-ring realizes static sealing to ensure that the medium does not leak.

[0024] The installation sequence of the present utility model is as follows: clean the pump shaft, install the assembled seal in the sealing cavity, tighten the socket head cap screws, remove the positioning block, connect the flushing pipeline, evacuate the gas in the pipeline, and after checking by turning the shaft by hand, the equipment can be operated.

[0025] As Figure 1 shown, the moving ring assembly is designed as a balanced structure, making full use of the radial dimension of the moving ring seat. Steps are provided for arranging the anti-rotation pins, springs, snap rings, and retaining rings. After the anti-rotation pins are assembled with the moving ring seat, the anti-rotation pins are installed in the large semi-circular arc grooves 13, and the protruding parts of the anti-rotation pins 12 form multiple arc-shaped convex platforms along the circumference. The cooperation between this convex platform and the circular arc groove 14 of the drive sleeve to prevent rotation is the key to this solution. The auxiliary sealing ring of the moving ring assembly is limited by the retaining ring and the snap ring. This structure seal is suitable for working conditions containing impurities that require spring protection. If the anti-rotation pin structure is not adopted and the anti-rotation convex platform is integrally machined on the moving ring seat, the processing technology is complex, the processing equipment requirements are high, and the personnel quality requirements are high, making it difficult to complete high-quality products. By using the anti-rotation pins to form convex platforms, the processing technology is simplified, the anti-rotation pins can be finely processed, so that the cooperation between the anti-rotation pins and the grooves of the drive sleeve is smoother and the transmission is more stable.

[0026] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A spring-protected mechanical seal structure, characterized in that, It includes a retaining ring, a snap ring, a transmission sleeve, a push ring, a spring, a moving ring assembly, a stationary ring and an anti-rotation pin; The moving ring assembly consists of a moving ring and a moving ring seat. The moving ring is press-fitted into the mating hole of the moving ring seat; counterbores for positioning the spring are circumferentially arranged on the moving ring seat, and the counterbores are in clearance fit with the outer diameter of the spring; semi-circular arc grooves for press-fitting the anti-rotation pin are evenly distributed circumferentially on the moving ring seat, and the anti-rotation pin is press-fitted into the arc grooves; a groove and a step are provided on the inner diameter surface at the tail end of the moving ring seat for installing the snap ring and the retaining ring. The moving ring O-ring is arranged between the transmission sleeve and the moving ring seat and is limited by the retaining ring and the snap ring; For the transmission sleeve, a first shoulder is provided on the outer circle of the transmission sleeve for placing the limiting push ring; evenly distributed circular arc grooves are provided on the outer circle of the transmission sleeve for installing the push ring. The circular arc grooves cooperate with the semi-circular arc grooves to form an installation space for installing the anti-rotation pin, and the circular arc grooves are in floating fit with the anti-rotation pin to transmit the rotation torque of the moving ring; One end of the spring is installed in the counterbore of the moving ring seat, and the other end abuts against the end face of the push ring. The spring provides elastic compensation for the moving ring assembly; The stationary ring is installed in the gland and is assisted in sealing with an O-ring. The end faces of the moving ring friction pair and the stationary ring friction pair rotate in cooperation.

2. The spring protection type mechanical seal structure according to claim 1, characterized in that, A second shoulder is further provided at the tail end of the transmission sleeve, and threaded holes are evenly provided in the circumferential direction. Inner hexagon socket set screws are provided at the threaded holes and are fixed on the shaft. A transmission sleeve O-ring is arranged between the inner diameter surface of the transmission sleeve and the shaft sleeve.

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