A pressure relief protection keyway structure for spindle mechanical seals

Abstract

This invention discloses a pressure relief protection keyway structure for a spindle mechanical seal, comprising a spindle with a keyway fixedly provided on its side; one end of the spindle is driven by a drive mechanism, and the other end of the spindle is detachably installed inside a pump housing; a mechanical seal is provided between the drive mechanism and the pump housing, the mechanical seal is fixedly connected to the pump housing, and the mechanical seal is rotatably connected to the spindle. By milling a pressure relief keyway on the pump spindle, high-pressure water near the mechanical seal at the pump end and low-pressure water at the inlet are connected, effectively relieving pressure and protecting the mechanical seal, thus extending the pump's service life. Practical experience has proven that this structure is effective and feasible. Furthermore, the control board of this invention can adjust the effective depth of the keyway based on the spindle speed using the reaction force of the water flow, avoiding problems such as insufficient head due to excessively slow spindle speed, and insufficient pressure relief due to excessively fast spindle speed.

Description

Technical Field

[0001] This invention belongs to the field of mechanical seal technology for pumps, specifically relating to a pressure relief protection keyway structure for a spindle mechanical seal. Background Technology

[0002] A mechanical seal is a device that prevents fluid leakage. It consists of at least one pair of end faces perpendicular to the axis of rotation, which remain in contact and slide relative to each other under the action of fluid pressure, the elastic force (or magnetic force) of the compensation mechanism, and the cooperation of auxiliary seals. A mechanical seal is a shaft sealing device for rotating machinery, such as centrifugal pumps, centrifuges, reactors, and compressors. Because the drive shaft runs through both the inside and outside of the equipment, there is a circumferential gap between the shaft and the equipment. The medium in the equipment leaks outward through this gap. If the pressure inside the equipment is lower than atmospheric pressure, air leaks into the equipment. Therefore, a shaft sealing device is necessary to prevent leakage.

[0003] Down-suction multistage mining pumps, where multistage pumps refer to pumps with two or more impellers, are characterized by having more impellers, higher head, and wider applicability; however, the mechanical seal stationary ring near the pump end is subjected to very high pressure, which can easily cause mechanical seal failure and pump malfunction. Summary of the Invention

[0004] In order to solve the above-mentioned problems in the prior art, the present invention aims to provide a pressure relief protection keyway structure for spindle mechanical seals.

[0005] The technical solution adopted in this invention is as follows:

[0006] A pressure relief protection keyway structure for a spindle mechanical seal includes a spindle with a keyway fixedly provided on its side; one end of the spindle is driven by a drive mechanism, and the other end of the spindle is detachably installed inside a pump housing; a mechanical seal is provided between the drive mechanism and the pump housing, the mechanical seal is fixedly connected to the pump housing, and the mechanical seal is rotatably connected to the spindle.

[0007] As a preferred embodiment of the present invention, the main shaft is provided with a plurality of impellers, the impellers are located inside the pump casing, the plurality of impellers are evenly distributed along the axial direction of the main shaft, the pump casing is provided with an inlet at one end away from the drive mechanism, and an outlet is provided on the side of the pump casing, the inlet being perpendicular to the outlet.

[0008] As a preferred embodiment of the present invention, the inner wall of the pump casing and one of the impellers near the mechanical seal form a high-pressure chamber; two adjacent impellers and the inner wall of the pump casing form a transition chamber; and the keyway hole communicates with the high-pressure chamber.

[0009] As a preferred embodiment of the present invention, the side of the spindle is provided with two keyway holes, both of which are distributed along one of the diameters of the cross-section of the spindle, and a control plate is detachably installed in each keyway hole.

[0010] As a preferred embodiment of the present invention, a control groove is provided at one end of the main shaft near the water inlet, and a control plate is installed in the control groove. The control plate is rotatably mounted on the drive shaft.

[0011] As a preferred embodiment of the present invention, there are two control slots, each control slot is provided with a control plate, each control plate is rotatably mounted on a drive shaft, the two control slots are located on both sides of the main shaft, and the control slots are perpendicular to the keyway hole.

[0012] As a preferred embodiment of the present invention, each of the top plates of the control tank is fixedly provided with a driven shaft at one end near the water inlet; a transmission rod is provided between the two driving shafts and the two driven shafts, the transmission rod is located on one side of the control plate, and the two ends of each transmission rod are respectively hinged to one driving shaft and one driven shaft; the two transmission rods are parallel to each other.

[0013] As a preferred embodiment of the present invention, the top plate of the control groove is slidably connected to the keyway hole, and the top plate of the control groove slides radially along the main shaft; the height of the top plate of the control groove is less than the depth of the keyway hole.

[0014] As a preferred embodiment of the present invention, a mounting groove is provided at one end of the main shaft near the water inlet, a mounting block is fixedly provided in the mounting groove, and a telescopic column is slidably provided at both ends of the mounting block, and the drive shaft is fixedly mounted on the telescopic column.

[0015] As a preferred embodiment of the present invention, a control spring is disposed within the mounting block, and the two ends of the control spring are respectively fixed to the two telescopic columns.

[0016] The beneficial effects of this invention are as follows: As a pressure relief protection keyway structure for a main shaft mechanical seal, this invention connects the high-pressure water near the mechanical seal at the pump end and the low-pressure water at the inlet by milling a pressure relief keyway hole on the pump's main shaft, effectively relieving pressure and protecting the mechanical seal, thus extending the pump's service life. Practical experience has proven that this structure is effective and feasible. Furthermore, the control board of this invention can adjust the effective depth of the keyway hole according to the main shaft speed using the reaction force of the water flow, avoiding problems such as insufficient head due to excessively slow main shaft speed, and insufficient pressure relief due to excessively fast main shaft speed. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0018] Figure 1 This is a schematic diagram of the structure of the present invention;

[0019] Figure 2 This is the present invention. Figure 1 A schematic diagram of the main shaft structure;

[0020] Figure 3 This is the present invention. Figure 2 A schematic diagram of the control panel structure;

[0021] Figure 4 This is the present invention. Figure 3 A schematic diagram of the installation block structure;

[0022] Figure 5 This is the present invention. Figure 2 A front view structural diagram;

[0023] Figure 6 This is the present invention. Figure 2 A top-view structural diagram;

[0024] Figure 7 This is the present invention. Figure 6 A schematic diagram of the CC-direction structure. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0027] The following is combined Figure 1-7This invention describes a keyway structure for pressure relief protection of a main shaft mechanical seal. The structure includes a main shaft 11 with a keyway hole 18 fixedly provided on its side. By milling a pressure relief keyway hole 18 on the pump's main shaft 11, high-pressure water near the mechanical seal 14 at the pump end and low-pressure water at the inlet 19 are connected, effectively relieving pressure and protecting the mechanical seal while extending the pump's service life. Practical experience has proven that this structure is effective and feasible. One end of the main shaft 11 is driven by a drive mechanism 13 (a conventional pump motor), and the other end of the main shaft 11 is detachably installed inside the pump housing 17. A mechanical seal 14 is provided between the drive mechanism 13 and the pump housing 17. The mechanical seal 14 is fixedly connected to the pump housing 17 and rotatably connected to the main shaft 11. The mechanical seal 14 mainly consists of a rotating ring, a stationary ring, a cooling device, and a compression spring.

[0028] Advantageously, for a down-draft multi-stage mining pump, the main shaft 11 is provided with multiple impellers 12. The impellers 12 are professional pump impellers, which drive water to flow unidirectionally and pressurize by rotating. The impellers 12 are located inside the pump casing 17, and the multiple impellers 12 are evenly distributed along the axial direction of the main shaft 11. The multiple impellers realize the staged pressurization of water flow. The pump casing 17 is provided with an inlet 19 at the end away from the drive mechanism 13, and an outlet is provided on the side of the pump casing 17. The inlet 19 is perpendicular to the outlet.

[0029] Advantageously, the inner wall of the pump casing 17 and one of the impellers 12 near the mechanical seal 14 form a high-pressure chamber 15; two adjacent impellers 12 and the inner wall of the pump casing 17 form a transition chamber 16; the keyway 18 communicates with the high-pressure chamber 15; the pressure relief water flow will only flow from the high-pressure chamber 15 to the inlet 19, avoiding the water flow to the transition chamber 16, ensuring normal pressure relief (because the pressure difference between adjacent chambers is small, the directional flow of water may be affected by the pressure relief keyway 18).

[0030] Advantageously, the main spindle 11 has two keyway holes 18 on its side, and the two keyway holes 18 are distributed along one of the diameters of the cross-section of the main spindle 11. A control plate 20 is detachably installed in each keyway hole 18. The two keyway holes 18 on the side of the main spindle 11 share the pressure relief and do not significantly affect the strength of the spindle 11. The control plate 20 is controlled by a control device and can be flexibly adjusted to change the depth of the keyway hole 18 (specifically the effective depth, i.e., the depth of the keyway hole 18 minus the depth of the portion covered by the control plate 20).

[0031] Advantageously, a control groove 22 is provided at one end of the main shaft 11 near the water inlet 19, and a control plate 21 is installed in the control groove 22. The control plate 21 is rotatably mounted on the drive shaft 23. The control groove 22 and the control plate 21 can change their posture according to the speed of the water flow, thereby controlling the movement of the top plate 20 of the control groove. The width of the control groove 22 is greater than the thickness of the control plate 21, and the control plate 21 can change its posture within a small range within the control groove 22.

[0032] Advantageously, there are two control slots 22, and each control slot 22 is provided with a control plate 21. Each control plate 21 is rotatably mounted on a drive shaft 23. The two control slots 22 are located on both sides of the main shaft 11. The control slots 22 are perpendicular to the keyway hole 18. The control slots 22 and control plates 21 are arranged symmetrically.

[0033] Advantageously, each of the control tank top plates 20 is fixed with a driven shaft 25 at one end near the water inlet 19; a transmission rod 24 is provided between the two drive shafts 23 and the two driven shafts 25, the transmission rod 24 is located on one side of the control plate 21, and the two ends of each transmission rod 24 are respectively hinged to one drive shaft 23 and one driven shaft 25; the two transmission rods 24 are parallel to each other; on a plane, the two drive shafts 23 and the two driven shafts 25 are respectively located at the four vertices of a certain parallelogram, and the two transmission rods 24 are respectively located on two sides of this parallelogram, and the two transmission rods 24 are parallel to each other.

[0034] Advantageously, the top plate 20 of the control groove is slidably connected to the keyway hole 18, and the top plate 20 of the control groove slides radially along the main shaft 11; the height of the top plate 20 of the control groove is less than the depth of the keyway hole 18; the top plate 20 of the control groove and the inner wall of the keyway hole 18 are completely fitted together, and the movement of the top plate 20 of the control groove can quickly change the effective depth of the keyway hole 18 to adapt to changes in water flow.

[0035] Advantageously, the main shaft 11 is provided with a mounting groove at one end near the water inlet 19, and a mounting block 27 is fixedly provided in the mounting groove. A telescopic column 26 is slidably provided at both ends of the mounting block 27. The drive shaft 23 is fixedly mounted on the telescopic column 26. The movement of the telescopic column 26 will drive the drive shaft 23 to move together. Under the action of the transmission rod 24, a connecting rod is formed to realize the change of force transmission.

[0036] Advantageously, a control spring 28 is installed inside the mounting block 27. The two ends of the control spring 28 are respectively fixed on the two telescopic columns 26. The control spring 28 provides a reset function. After installation, the control spring 28 is in a stretched state. The control spring 28 keeps the two control plates 21 horizontal when they are not under force.

[0037] Working principle of this invention:

[0038] This invention addresses the characteristics of down-draft multistage mining pumps, which have multiple impellers and high head. By milling a keyway hole 18 for pressure relief on the pump's main shaft 11, the high-pressure water near the mechanical seal 14 at the pump end and the low-pressure water at the inlet 19 are connected, effectively relieving pressure, protecting the mechanical seal, and extending the pump's service life.

[0039] Specifically, when the water pump is working, the water flows from the inlet 19 to the impeller 12, and then flows through one or more pump casings 17 to the transition chamber 16. During this process, the water flow gradually accelerates and pressurizes, reaching its highest pressure in the high-pressure chamber 15. Therefore, the pressure exerted on the stationary ring of the high-pressure chamber 15 near the pump end is high, which can easily cause mechanical seal failure and pump malfunction. Now, a keyway hole 18 for pressure relief is milled on the side of the main shaft 11. The keyway hole 18 is connected to the high-pressure chamber 15. The water flow in the high-pressure chamber 15 near the mechanical seal 14 flows out along the keyway hole 18. Since the two ends of the keyway hole 18 are the inlet 19 of the high-pressure chamber 15, the water flow will always flow from the high-pressure area to the low-pressure area.

[0040] Specifically, when the water pump is working, the speed of the impeller 12 controlled by the drive mechanism 13 (pump motor) varies due to environmental and other factors. The control plate 21 rotates together with the main shaft 11. Affected by the reaction force, the faster the main shaft 11 rotates, the greater the deflection of the control plate 21, and vice versa. The two control plates 21 deflect in opposite directions along the rotation of the main shaft 11. Since the end of the control plate 21 abuts against the mounting block 27 (forced to make surface contact under the action of the control spring 28), after the control plate 21 deflects (the control plate 21 rotates around the drive shaft 23 as the axis), the end of the control plate 21 and the mounting block 27 become in line contact, the two telescopic columns 26 move away from each other, and the control spring 28 is stretched.

[0041] In short: Under the action of water flow, the control plate 21 overcomes the elastic force of the control spring 28 and deflects around the drive shaft 23. The faster the water flow, the greater the deflection angle of the control plate 21.

[0042] After the control plate 21 deflects, the telescopic column 26 moves along its axial direction, while the drive shaft 23 moves horizontally along with the telescopic column 26. Through the transmission rod 24, a connecting rod is formed, which drives the driven shaft 25 and the control tank top plate 20 to move (the control tank top plate 20 is constrained by the keyway hole 18, and the movement direction of the driven shaft 25 is perpendicular to the movement direction of the drive shaft 23). That is, the faster the water flow, the closer the two control tank top plates 20 are to each other, and the deeper the effective depth of the main shaft 11. By controlling the rotational speed of the main shaft 11, the depth of the main shaft 11 can be controlled, so as to flexibly control the pressure relief protection degree.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A pressure relief protection keyway structure for a spindle mechanical seal, characterized in that: The system includes a main shaft with a keyway hole fixedly provided on its side; one end of the main shaft is driven by a drive mechanism, and the other end of the main shaft is detachably installed inside the pump housing; a mechanical seal is provided between the drive mechanism and the pump housing, the mechanical seal is fixedly connected to the pump housing, and the mechanical seal is rotatably connected to the main shaft; the inner wall of the pump housing and an impeller near the mechanical seal form a high-pressure chamber; the keyway hole communicates with the high-pressure chamber. The side of the spindle is provided with two keyway holes, and the two keyway holes are distributed along one of the diameters of the cross-section of the spindle. A control slot top plate is detachably installed in each keyway hole. The pump housing has a water inlet at the end away from the drive mechanism, and the main shaft has a control slot at the end near the water inlet. There are two control slots, and each control slot contains a control plate. Each control plate is rotatably mounted on a drive shaft. The two control slots are located on opposite sides of the main shaft, and the control slots are perpendicular to the keyway hole. Each of the top plates of the control tank is fixed with a driven shaft at one end near the water inlet; a transmission rod is provided between the two driving shafts and the two driven shafts, the transmission rod is located on one side of the control plate, and the two ends of each transmission rod are respectively hinged to one driving shaft and one driven shaft; the two transmission rods are parallel to each other.

2. The pressure relief protection keyway structure for a spindle mechanical seal according to claim 1, characterized in that: The main shaft is provided with multiple impellers, which are located inside the pump casing. The multiple impellers are evenly distributed along the axial direction of the main shaft. The pump casing has an outlet on its side, and the inlet is perpendicular to the outlet.

3. The pressure relief protection keyway structure for a spindle mechanical seal according to claim 2, characterized in that: The two adjacent impellers and the inner wall of the pump casing form a transition chamber.

4. The pressure relief protection keyway structure for a spindle mechanical seal according to claim 2, characterized in that: The top plate of the control groove is slidably connected to the keyway hole, and the top plate of the control groove slides radially along the main shaft; the height of the top plate of the control groove is less than the depth of the keyway hole.

5. The pressure relief protection keyway structure for a spindle mechanical seal according to claim 4, characterized in that: The main shaft is provided with a mounting groove at one end near the water inlet. A mounting block is fixedly installed in the mounting groove. A telescopic column is slidably installed at each end of the mounting block. The drive shaft is fixedly installed on the telescopic column.

6. The pressure relief protection keyway structure for a spindle mechanical seal according to claim 5, characterized in that: A control spring is installed inside the mounting block, and the two ends of the control spring are respectively fixed to the two telescopic columns.

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