Mechanical seal for pump

Abstract

The utility model provides a mechanical seal for a pump, and belongs to the technical field of machinery. The problem that an existing mechanical seal is poor in stability is solved. In the utility model, the pump comprises a rotor shaft, the mechanical seal comprises a spring seat, a rubber corrugated pipe and a static ring which are sequentially sleeved on the rotor shaft from front to back, the inner side and the outer side of the rubber corrugated pipe are respectively provided with a movable ring and a cylindrical lower seat, a telescopic spring is arranged between the spring seat and the lower seat, and the spring seat is fixedly connected with the rotor shaft. The spring seat is provided with at least two slots which are arranged in a penetrating manner along the axial direction of the rotor shaft and are uniformly distributed along the circumferential direction of the rotor shaft; each slot comprises two slot side walls distributed in the circumferential direction of the rotor shaft, insertion blocks are formed on the top wall of the lower seat, the insertion blocks and the slots are the same in number and are in one-to-one correspondence in position, the two insertion blocks are inserted into the two slots respectively, and the insertion blocks are located between the two corresponding slot side walls. The mechanical seal for the pump works stably.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology and relates to a mechanical seal, particularly a mechanical seal for pumps. Background Technology

[0002] A mechanical seal for a pump is a device used to seal the gap between the pump shaft and the pump casing to prevent media leakage and the entry of external impurities into the pump.

[0003] Existing mechanical seals, such as the bellows structure mechanical seal disclosed in the Chinese Patent Database (application number: 202021691606.1), include a rotating ring assembly that rotates with the shaft and a stationary ring assembly fixed to the pump body. The rotating ring assembly includes a spring seat, a rubber bellows, a fastening ring, a rotating ring seat, a rotating ring, and a spring arranged coaxially. The rubber bellows is interference-fitted onto the outside of the shaft, and the rotating ring seat is fitted onto the outside of the shaft. The rubber bellows and the rotating ring seat provide support for the rotating ring. The spring provides elastic force. An annular groove is formed on the outer wall of the end of the rubber bellows away from the moving ring. The fastening ring is embedded in the annular groove. A limiting block is provided on the side wall of the fastening ring away from the rubber bellows. A sliding groove is formed on the moving ring seat, and the limiting block is slidably installed in the sliding groove. The stationary ring assembly includes a cup and a stationary ring. The stationary ring is embedded in the cup. The moving ring contacts the stationary ring under the elastic force of the spring and the rubber bellows to form a sealing pair.

[0004] When the above-mentioned mechanical seal is in use, the rotating shaft drives the rotating ring to rotate through the rubber bellows. Since the rubber bellows is a soft material, when there is a large adhesion force between the rotating ring and the stationary ring, the rubber bellows will have difficulty driving the rotating ring to rotate, resulting in shaft seizure and affecting the normal use of the pump. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a stable mechanical seal for pumps.

[0006] The objective of this utility model can be achieved through the following technical solution: A mechanical seal for a pump, the pump including a rotor shaft, the mechanical seal including a spring seat, a rubber bellows and a stationary ring sequentially sleeved on the rotor shaft from front to back, a moving ring and a cylindrical lower seat respectively provided on the inner and outer sides of the rubber bellows, and a telescopic spring provided between the spring seat and the lower seat, the spring seat being fixedly connected to the rotor shaft, characterized in that the spring seat is provided with slots that are axially arranged along the rotor shaft, at least two slots being evenly distributed along the circumference of the rotor shaft; the slots include two groove sidewalls distributed along the circumference of the rotor shaft, and the top wall of the lower seat is formed with inserts, the number of inserts and slots being the same and their positions corresponding one-to-one, the two inserts being inserted into the two slots respectively, and the inserts being positioned between the corresponding two groove sidewalls.

[0007] In use, when there is a large adsorption between the stationary ring and the moving ring, the spring seat rotates with the rotor shaft and directly drives the lower seat to rotate by contacting at least one of the slot sidewalls through the slot. This causes the rubber bellows and the moving ring to rotate synchronously with the rotor shaft to release the adsorption braking.

[0008] With the cooperation of the insert and slot, a rigid circumferential fit is formed between the spring seat and the lower seat, ensuring that the rotor shaft can always stably drive the rotating ring to rotate, avoiding sticking and adsorption between the rotating ring and the stationary ring, and ensuring stable operation of the pump.

[0009] In the aforementioned mechanical seal for pumps, both the slot and the insert are coaxial with the rotor shaft in an arc shape. This design ensures that the central axes of the slot, insert, and rotor shaft are collinear, which facilitates machining and improves the circumferential fit strength between the insert and the slot sidewall. This ensures the rotor shaft stably drives the rotating ring, thereby enhancing the operational stability of the mechanical seal.

[0010] In the aforementioned mechanical seal for pumps, one side of the slot is open to allow the slot to connect with the inner hole of the spring seat. This facilitates the machining of the slot and reduces the stress on the spring seat during the machining of the slot.

[0011] In the aforementioned mechanical seal for pumps, the arc length of the insert is less than the width of the slot, which facilitates the assembly of the spring seat and the lower seat while ensuring circumferential fit.

[0012] In the aforementioned pump mechanical seal, a first flat surface in the shape of an elongated strip is formed on the inner wall of the spring seat, and the two ends of the first flat surface extend to the two end faces of the spring seat respectively; the outer wall of the rotor shaft has a second flat surface that matches the first flat surface, and the second flat surface is close to the first flat surface, so that a more stable and reliable circumferential fit is formed between the rotor shaft and the spring seat.

[0013] In the above-mentioned mechanical seal for pumps, there are two first planes arranged symmetrically along the center of the spring seat, and the number of second planes is the same as that of the first planes and their positions correspond one-to-one.

[0014] In the above-mentioned mechanical seal for pumps, there are two slots arranged symmetrically around the center of the spring seat, and the slots and the first plane are alternately distributed around the circumference of the spring seat.

[0015] Compared with existing technologies, the mechanical seal for this pump has the following advantages:

[0016] 1. With the cooperation of the insert block and slot, a rigid circumferential fit is formed between the spring seat and the lower seat, ensuring that the rotor shaft can always stably drive the rotating ring to rotate, avoiding the sticking and adsorption between the rotating ring and the stationary ring, and ensuring the stable operation of the pump.

[0017] 2. The arc length of the insert is less than the width of the slot, which facilitates the assembly of the spring seat and the lower seat while ensuring circumferential fit. Attached Figure Description

[0018] Figure 1 This is a front view schematic diagram of a mechanical seal for a pump.

[0019] Figure 2 yes Figure 1 Schematic diagram of cross-section at point AA.

[0020] In the figure, 1 is the rotor shaft; 2 is the spring seat; 2a is the slot; 2a1 is the slot sidewall; 2b is the first plane; 3 is the rubber bellows; 4 is the stationary ring; 5 is the moving ring; 6 is the lower seat; 6a is the insertion block; and 7 is the telescopic spring. Detailed Implementation

[0021] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0022] like Figure 2 As shown, in the mechanical seal for a pump, the pump includes a rotor shaft 1; the mechanical seal includes a spring seat 2, a rubber bellows 3 and a stationary ring 4, which are sequentially sleeved on the rotor shaft 1 from front to back, and the rotor shaft 1, spring seat 2, rubber bellows 3 and stationary ring 4 are coaxially arranged.

[0023] in,

[0024] The inner wall of the rubber bellows 3 is tightly fitted to the outer wall of the rotor shaft 1 to form a stable seal. A moving ring 5 and a cylindrical lower seat 6 are respectively provided on the inner and outer sides of the rubber bellows 3. The connection method of these three components is existing; for details, please refer to a mechanical seal with a bellows structure disclosed in the Chinese Patent Database (application number: 202021691606.1) or a mechanical seal structure of a rubber bellows 3 for a pump shaft (application number: 201310312680.6). Further details will not be provided here.

[0025] The spring seat 2 is fixedly connected to the rotor shaft 1. A telescopic spring 7 is provided between the spring seat 2 and the lower seat 6. The two ends of the telescopic spring 7 are respectively sleeved on the outside of the spring seat 2 and the lower seat 6. Annular limiting seats for the ends of the telescopic spring 7 to press against are formed on the outer side walls of the spring seat 2 and the lower seat 6.

[0026] like Figure 1 and Figure 2 As shown, the spring seat 2 is provided with slots 2a that extend through the rotor shaft 1 axially. There are at least two slots 2a and they are evenly distributed around the rotor shaft 1. Each slot 2a includes two slot sidewalls 2a1 distributed around the rotor shaft 1. Insert blocks 6a are formed on the top wall of the lower seat 6. The number of insert blocks 6a and slots 2a are the same and their positions correspond one-to-one. The two insert blocks 6a are inserted into the two slots 2a respectively, and the insert blocks 6a are located between the corresponding two slot sidewalls 2a1.

[0027] In use, when there is a large adsorption between the stationary ring 4 and the moving ring 5, the spring seat 2 rotates with the rotor shaft 1 and directly drives the lower seat 6 to rotate by contacting at least one of the slot sidewalls 2a1 through the slot 2a. This causes the rubber bellows 3 and the moving ring 5 to rotate synchronously with the rotor shaft 1, thereby releasing the above-mentioned adsorption braking.

[0028] With the cooperation of the insert 6a and the slot 2a, a rigid circumferential fit is formed between the spring seat 2 and the lower seat 6, ensuring that the rotor shaft 1 can always stably drive the rotating ring 5 to rotate, avoiding the sticking and adsorption between the rotating ring 5 and the stationary ring 4, and ensuring the stable operation of the pump.

[0029] To further explain, both the slot 2a and the insert 6a are coaxial with the rotor shaft 1 in an arc shape, so that the central axes of the slot 2a, insert 6a, and rotor shaft 1 are collinear. This facilitates machining and improves the circumferential fit strength between the insert 6a and the slot sidewall 2a1, ensuring that the rotor shaft 1 stably drives the rotating ring 5 to rotate, thus improving the working stability of the mechanical seal. Preferably, one side of the slot 2a is open so that the slot 2a connects to the inner hole of the spring seat 2. This facilitates the machining of the slot 2a and reduces the stress on the spring seat 2 during the machining of the slot 2a.

[0030] In the actual product, the arc length of the insert 6a is smaller than the width of the slot 2a, which facilitates the assembly of the spring seat 2 and the lower seat 6 while ensuring circumferential fit.

[0031] In this embodiment, the spring seat 2 and the rotor shaft 1 are tightly fitted and fixed. To further explain, the inner wall of the spring seat 2 is formed with a first plane 2b in the shape of an elongated strip, and the two ends of the first plane 2b extend to the two end faces of the spring seat 2 respectively; the outer wall of the rotor shaft 1 has a second plane that matches the first plane 2b, and the second plane is close to the first plane 2b, so that a more stable and reliable circumferential fit is formed between the rotor shaft 1 and the spring seat 2.

[0032] To further explain, there are two first planes 2b, which are symmetrically arranged around the center of the spring seat 2. The number of second planes is the same as that of first planes 2b, and their positions correspond one-to-one. There are two slots 2a, which are also symmetrically arranged around the center of the spring seat 2, and the slots 2a and the first planes 2b are alternately distributed around the circumference of the spring seat 2.

[0033] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A mechanical seal for a pump, the pump including a rotor shaft (1), the mechanical seal including a spring seat (2), a rubber bellows (3) and a stationary ring (4) sequentially sleeved on the rotor shaft (1) from front to back, a moving ring (5) and a cylindrical lower seat (6) respectively provided on the inner and outer sides of the rubber bellows (3), and a telescopic spring (7) provided between the spring seat (2) and the lower seat (6), the spring seat (2) being fixedly connected to the rotor shaft (1), characterized in that, The spring seat (2) is provided with slots (2a) that are axially arranged along the rotor shaft (1). There are at least two slots (2a) and they are evenly distributed along the circumference of the rotor shaft (1). The slots (2a) include two slot sidewalls (2a1) distributed along the circumference of the rotor shaft (1). The top wall of the lower seat (6) is formed with inserts (6a). The number of inserts (6a) and slots (2a) are the same and their positions correspond one-to-one. The two inserts (6a) are inserted into the two slots (2a) respectively, and the inserts (6a) are located between the corresponding two slot sidewalls (2a1).

2. The mechanical seal for pumps according to claim 1, characterized in that, The aforementioned slot (2a) and insert (6a) are both in the shape of an arc coaxial with the rotor shaft (1).

3. The mechanical seal for pumps according to claim 2, characterized in that, The slot (2a) is open on one side so that the slot (2a) connects to the inner hole of the spring seat (2).

4. The mechanical seal for pumps according to claim 2, characterized in that, The arc length of the insert (6a) is less than the width of the slot (2a).

5. The mechanical seal for pumps according to claim 1, characterized in that, The inner wall of the spring seat (2) is formed with a long strip-shaped first plane (2b), and the two ends of the first plane (2b) extend to the two end faces of the spring seat (2); the outer wall of the rotor shaft (1) has a second plane that matches the first plane (2b), and the second plane is attached to the first plane (2b).

6. The mechanical seal for pumps according to claim 5, characterized in that, There are two first planes (2b) and they are symmetrically arranged along the center of the spring seat (2). The number of second planes is the same as that of first planes (2b) and their positions correspond one-to-one.

7. The mechanical seal for pumps according to claim 6, characterized in that, The number of slots (2a) is two and they are arranged symmetrically along the center of the spring seat (2), and the slots (2a) and the first plane (2b) are alternately distributed along the circumference of the spring seat (2).

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