Water pump capable of preventing dry grinding of mechanical seal

Abstract

The utility model relates to a water pump capable of preventing dry grinding of a mechanical seal. A mechanical seal of an existing water pump is prone to dry grinding. The pump body comprises a pump shell and an impeller, a rotating shaft of the motor forwards penetrates through a mechanical seal and is connected with the impeller, a water inlet is formed in the middle of the front wall of the impeller, a water outlet is formed in the periphery of the impeller, the impeller rotates and drives a medium to form main water flow conveyed from the water inlet to the water outlet, and an overflowing hole is formed in the middle of the rear wall of the impeller; main water flow in the impeller is divided through the overflowing holes to form branch flow sprayed towards the mechanical seal, so that the mechanical seal is immersed in the branch flow, and dry grinding is prevented. The overflow hole is formed in the rear wall of the impeller, water flowing in through the water inlet can be discharged through the water outlet and the overflow hole, branch flow sprayed by the overflow hole is used for immersing the mechanical seal, dry grinding of the mechanical seal is prevented, immersion lubrication is conducted on the mechanical seal, abrasion of the mechanical seal is effectively reduced, the service life of the mechanical seal is prolonged, and the use experience is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of water pump, concretely relates to a water pump of anti machine seal dry grinding. BACKGROUND

[0002] The existing water pump includes a motor and a pump body, the pump body includes a pump shell with an assembly cavity and an impeller arranged in the assembly cavity, the rotating shaft of the motor penetrates a machine seal arranged on the rear end wall of the assembly cavity and is connected with the impeller, so as to ensure that the impeller rotates under the drive of the motor and drives the water flow to flow along a preset path. The inlet and outlet are arranged on the front end wall and the side wall of the pump shell respectively, the rear wall of the impeller is a flat sealing surface, the front wall and the rear wall of the impeller are arranged separately to form a channel for guiding the water flow, the middle part of the front wall of the impeller is provided with a water inlet, and the periphery of the front wall and the rear wall is enclosed to form an annular water outlet. The water flow entering the pump shell through the inlet is sucked into the channel by the water inlet of the impeller and is output through the water outlet after being pressurized, and then is discharged through the outlet. The rear end wall of the pump shell is provided with a machine seal, the rotating shaft of the motor penetrates the machine seal and is inserted into the pump shell and connected with the impeller, and the machine seal ensures better sealing between the rotating shaft and the pump shell by arranging the static ring and the dynamic ring.

[0003] In use, a large amount of air will be sucked into the inlet when the inlet sucks in the water source, and due to the smaller density of air than that of water, the water source is centrifugally transported from the water inlet in the middle to the water outlet at the outer edge due to the centrifugal force when the impeller rotates, and the air with smaller density is squeezed and remains in the middle of the pump shell and wraps the machine seal, resulting in damage of the friction surface between the static ring and the dynamic ring in the machine seal due to dry grinding, shortening the service life of the machine seal and causing the joint between the pump shell and the rotating shaft to easily leak, affecting the use experience. UTILITY MODEL CONTENTS

[0004] In order to solve the problems in the prior art, the utility model provides a water pump capable of preventing dry grinding of the machine seal, a flow hole is arranged on the rear wall of the impeller, the flow hole divides the main water flow passing through the impeller and obtains a branch flow directed to the machine seal, the machine seal is submerged in the water source by expelling air, dry grinding is prevented, the service life of the machine seal is effectively prolonged, and the use experience is improved.

[0005] The utility model discloses a kind of water pumps of anti-mechanical seal dry grinding, including motor and pump body, the pump body includes the pump shell of inner set assembly cavity and the impeller being arranged in assembly cavity, the rotating shaft of motor is forward and passes through mechanical seal and is connected with impeller, the front wall middle part of impeller is provided with water inlet, the periphery of impeller is provided with water outlet, impeller rotates and drives medium to form the main water flow conveyed by water inlet to water outlet, the rear wall middle part of impeller is provided with overflow hole, and main water flow in impeller is shunted to form the branch stream towards mechanical seal injection by the overflow hole, to make mechanical seal immerse in branch stream and prevent dry grinding.The overflow hole is arranged on the rear wall of impeller, and the water flow flowing in through water inlet can be discharged through water outlet and overflow hole respectively, and the branch stream injected by overflow hole is used to immerse mechanical seal, which not only effectively removes the air accumulated at mechanical seal to prevent dry grinding, but also lubricates mechanical seal to effectively reduce mechanical seal wear, prolong the service life of mechanical seal and improve the use experience.

[0006] Preferably, the rear wall of the impeller is annular, with a hub in the middle, and the overflow holes are four and equally spaced along the inner edge of the rear wall.The overflow holes are arranged around the hub, which not only ensures that the jet flow output by the overflow holes can effectively avoid the rotating shaft, but also ensures that the jet flow can cover the mechanical seal arranged around the rotating shaft, ensuring that the mechanical seal is effectively immersed.By increasing the number of overflow holes to increase the number of branch streams, the mechanical seal can be immersed in each section of the circumference.

[0007] Preferably, the front-to-back projection of the overflow hole is located outside the front-to-back projection of the mechanical seal, so that the branch stream is delivered to the outside of the mechanical seal and completely wraps the mechanical seal by converging towards the center.The front-to-back projection of the overflow hole is arranged around the front-to-back projection of the mechanical seal, and the radial distance between the overflow hole and the axis of the impeller is greater than the radius of the mechanical seal, ensuring that the water source delivered by the branch stream can completely wrap the mechanical seal.

[0008] Preferably, the front-to-back projections of the overflow hole and the water inlet at least partially overlap, and the ratio of the overlapping area to the cross-sectional area of the corresponding overflow hole is B, B≥0.7.The front-to-back projections of the overflow hole and the water inlet at least partially overlap, and B≥0.7, which ensures that the main water flow input along the axis of the water inlet can pass through the overflow hole in the direction of the overflow hole axis before turning and form a branch stream, effectively improving the injection speed and increasing the flow of the branch stream to improve the air exhaust effect.

[0009] Preferably, the ratio of the sum of the cross-sectional areas of the overflow holes to the area of the front-to-back projection of the water inlet is A, 0.02≤A≤0.08.By controlling parameter A to adjust the flow ratio between the branch stream and the main water flow, not only the flow of the main water flow is reduced to ensure the operating efficiency of the water pump, but also the flow of the branch stream meets the requirement of immersing the mechanical seal, improving the dry grinding prevention effect of the mechanical seal.

[0010] As preferred, the hub is provided with a transmission hole penetrating in front-rear direction, the rotating shaft penetrates the mechanical seal along the shell axis and is inserted into the transmission hole, so that the rotating shaft and the impeller are linked in circumferential direction. The rolling circumferential edge of the linkage wheel is fixedly connected with the inner edge of the rear wall of the impeller, the transmission hole is non-circular and matches the cross-sectional profile of the corresponding section of the rotating shaft, the circumferential force applied by the rotating shaft can be transmitted to the rear wall through the hub, thereby ensuring the continuous rotation of the impeller under the driving of the rotating shaft, and playing a role in driving the water source to flow.

[0011] As preferred, the pump shell comprises a tubular shell and a pump cover sealing the port of the shell, the mechanical seal is arranged in the middle of the pump cover, and the rotating shaft penetrates the mechanical seal along the shell axis and is fixedly connected with the impeller. The shell and the pump cover are independently processed and assembled to form the pump shell, which effectively reduces the processing difficulty and facilitates assembly and maintenance. The mechanical seal is installed in the middle of the pump cover, which ensures that the rotating shaft can penetrate the mechanical seal along the axis of the pump shell and be connected with the middle of the impeller, and guarantees that the impeller can rotate in the assembly cavity with the rotating shaft as the center.

[0012] As preferred, the mechanical seal comprises a static ring fixedly connected with the pump cover and a dynamic ring connected with the rotating shaft, and the branch flow is sprayed towards the friction surface between the static ring and the dynamic ring. The static ring is installed in the middle of the pump cover, and the dynamic ring is sleeved on the rotating shaft, the inner edge of the dynamic ring is tightly fitted with the outer side wall of the rotating shaft, and the facing surfaces of the dynamic ring and the static ring form the friction surfaces that resist each other, which not only ensures that the dynamic ring can rotate relative to the static ring, but also ensures that the static ring and the dynamic ring realize rotary sealing through the friction surface, preventing the water source in the assembly cavity from leaking out through the mechanical seal.

[0013] As preferred, an annular flow guide shell is arranged between the impeller and the shell, the impeller comprises a final stage wheel arranged at the rear end of the assembly cavity and close to the mechanical seal, and the flow passage is arranged on the final stage wheel close to the mechanical seal, so that the branch flow is directly sprayed towards the mechanical seal. The flow passage is arranged on the final stage wheel at the rear end of the assembly cavity, which ensures that the flow passage on the final stage wheel has a space for the branch flow to be sprayed linearly between the flow passage and the mechanical seal, thereby ensuring that the mechanical seal is completely wrapped and immersed by the branch flow. The impellers are axially connected in sequence by the rotating shaft, which ensures that the impellers can be driven to operate by the same motor.

[0014] As preferred, the inlet is arranged in the middle of the end surface of the pump shell away from the pump cover. The water inlet of the impeller is arranged corresponding to the inlet of the pump shell, which effectively reduces the flow resistance of the water source, facilitates the water inlet to extract the water source at the inlet, and thereby improves the operating efficiency of the water pump.

[0015] As preferred, the outlet is arranged on the side wall of the pump shell close to the motor, and a through hole is arranged on the flow guide shell corresponding to the final stage wheel. The main water flow output by the final stage wheel and the branch flow can be output through the through hole and then discharged through the outlet. The main water flow output through the outlet of the final stage wheel and the branch flow used to wrap and immerse the mechanical seal can be output through the through hole and then discharged through the outlet. The air impacted and squeezed by the branch flow is also discharged synchronously with the branch flow.

[0016] The utility model discloses beneficial effect: set up overflow hole on the back wall of impeller, the water flow that through water inlet can respectively through water outlet and overflow hole and export, utilize the branch of overflow hole and spray to carry out the immersion to machine seal, effectively remove the air that is accumulated at machine seal, prevent machine seal dry grinding, still carry out the immersion lubrication to machine seal, effectively reduce machine seal wear and tear, prolong the service life of machine seal, promote the use experience. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is cross section structure schematic diagram of water pump;

[0018] Figure 2 It is structure schematic diagram of last stage wheel;

[0019] Figure 3 It is main view structure schematic diagram of last stage wheel;

[0020] In the drawing: 1, motor, 2, shell, 3, water inlet, 4, water outlet, 5, overflow hole, 6, machine seal, 7, wheel hub, 8, transmission hole, 9, shaft, 10, pump cover, 11, flow guide shell, 12, through -hole, 13, outlet, 14, import, 15, primary wheel, 16, last stage wheel, 17, intermediate wheel. DETAILED DESCRIPTION

[0021] The essence of the utility model is further explained below in conjunction with the drawings and specific embodiments.

[0022] As Figure 1 And 2 The utility model discloses a kind of water pumps for preventing machine seal dry grinding, comprising motor 1 and pump body, the pump body includes the pump shell of inner set assembly cavity and the impeller being arranged in assembly cavity, the shaft 9 of motor 1 is forward and passes through machine seal 6 and is connected with impeller, the middle part of the front wall of the impeller is provided with water inlet 3, the periphery of the impeller is provided with water outlet 4, impeller rotates and drives medium to form the main water flow conveyed by water inlet 3 to water outlet 4, the middle part of the back wall of the impeller is provided with overflow hole 5, main water flow in impeller is shunted to form the branch stream that is sprayed towards machine seal 6 by overflow hole 5, so that machine seal 6 is immersed in branch stream and prevents dry grinding. Overflow hole 5 is arranged on the back wall of impeller, the water flow that through water inlet 3 can be respectively exported by water outlet 4 and overflow hole 5, utilize the branch of overflow hole 5 and spray to carry out the immersion to machine seal 6, effectively remove the air that is accumulated at machine seal 6, prevent machine seal 6 dry grinding, still carry out the immersion lubrication to machine seal 6, effectively reduce machine seal 6 wear and tear, prolong the service life of machine seal 6, promote the use experience.

[0023] In actual operation, the motor 1 is arranged at the rear of the pump body, the rotating shaft 9 of the motor 1 is inserted into the pump shell along the pump body axis from the rear to the front and is fixedly connected with the impeller, the impeller is sleeved on the rotating shaft 9 through the hub 7 with the belt transmission hole 8, so that the motor 1 can drive the impeller to rotate through the rotating shaft 9, and then the impeller drives the liquid to flow along the preset path, so as to achieve the purpose of conveying the water source. The pump shell comprises a tubular shell 2 and a pump cover 10 sealing the port of the shell 2, the mechanical seal 6 is arranged in the middle of the pump cover 10, the rotating shaft 9 penetrates the mechanical seal 6 along the axis of the shell 2 and is fixedly connected with the impeller to drive linkage. When the water pump is running, the inlet 14 will extract the water source and air from the outside, the rotating impeller drives the water and air to rotate circumferentially in the assembly cavity, because the density of water is greater than that of air, the water will move to the peripheral edge of the assembly cavity under the centrifugal force, and the air will gather in the middle area of the assembly cavity under the extrusion of the water, causing the mechanical seal 6 located in the middle of the pump cover 10 to be exposed to the air, the mechanical seal 6 will be dry ground due to the lack of liquid lubrication, causing the mechanical seal 6 to wear and tear, shortening the service life of the mechanical seal 6. Therefore, the overflow hole 5 is arranged on the rear wall of the impeller, in use, the water flow flows into the impeller along the axis direction of the water inlet 3, part of the water flow will flow straight along the axis direction of the impeller and form a branch flow that sprays towards the mechanical seal 6 through the overflow hole 5, and the remaining water flow will form a main water flow that flows towards the water outlet 4 through the diversion under the action of the centrifugal force. The branch flow sprays towards the mechanical seal 6, drives the air accumulated at the mechanical seal 6, so that the mechanical seal 6 can be completely immersed in water, the water plays a lubricating role on the mechanical seal 6, thereby effectively avoiding the wear and tear of the mechanical seal 6 during operation, and protecting the mechanical seal 6.

[0024] In actual operation, the pump shell is provided with the inlet 14 in the middle of the end surface away from the pump cover 10, the pump shell side wall is provided with the outlet 13 close to the end of the motor 1, the annular flow guide shell 11 is arranged between the impeller and the shell 2, the through hole 12 is arranged on the flow guide shell 11 corresponding to the last stage wheel 16, and the main water flow and the branch flow output by the last stage wheel 16 can be discharged outside through the outlet 13 after penetrating the through hole 12. The impeller rotates and extracts the water source from the outside through the inlet 14 corresponding to the water inlet 3, part of the water source forms the main water flow and is pressurized and conveyed to the water outlet 4, and the other part forms the branch flow that penetrates the overflow hole 5 and sprays towards the mechanical seal 6, and the main water flow and the branch flow carrying air penetrate the through hole 12 and are discharged outside through the outlet 13.

[0025] In actual operation, the impeller comprises a front wall and a rear wall, the front wall and the rear wall are connected through guide vanes, the rear wall of the impeller is annular, the middle part is provided with the hub 7, the middle part of the front wall of the impeller is provided with the water inlet 3, the front wall and the rear wall are fixedly connected and surrounded to form a channel for the main water flow to flow, the outer edges of the front wall and the rear wall are surrounded to form an annular water outlet 4, the impeller rotates to extract the water source through the water inlet 3 and discharge the water source outside through the water outlet 4 after flowing through the channel, so as to pressurize and convey the water source.

[0026] In actual operation, the flow holes 5 are preferably four and equidistantly arranged along the inner edge of the rear wall, and preferably six, which is convenient for processing and can ensure that the seal 6 is completely covered and wrapped by the branch flow by increasing the number of flow holes 5, thereby improving the air removal effect. The number of flow holes 5 can also be one, three, five, seven, etc., which should all be considered as specific embodiments of the utility model. When the number of flow holes 5 is small, the flow of the branch flow is increased to ensure that the water source can completely wrap the seal 6, which is convenient for processing and effectively prevents the seal 6 from being dry ground.

[0027] In actual operation, the front-to-back projection of the flow hole 5 is located outside the front-to-back projection of the seal 6, so that the branch flow is delivered to the outside of the seal 6 and completely wraps the seal by converging to the center. The branch flow is sprayed to the circumference of the seal, and the multiple branch flows converge to the center to achieve the purpose of completely wrapping and immersing the seal. The radial distance between the edge of the flow hole 5 and the impeller axis is greater than the radius of the seal 6, which ensures that the branch flow sprayed by the flow hole 5 can be delivered to the outer edge of the seal 6, and then multiple branch flows are sprayed to ensure that the seal 6 is completely wrapped and immersed in the water source, thereby achieving good lubrication for each section of the circumference of the seal 6.

[0028] In actual operation, the front-to-back projection of the flow hole 5 and the water inlet 3 at least partially overlaps, and the ratio of the overlapping area to the cross-sectional area of the corresponding flow hole 5 is B, B≥0.7. The front-to-back projection of the flow hole 5 and the water inlet 3 at least partially overlaps, and the preferred B=0.8, which ensures that the water flow flowing along the axis of the water inlet 3 into the impeller can directly pass through the flow hole 5 without changing direction and form a sprayed branch flow, effectively reducing the resistance when the water source at the water inlet 3 changes to the branch flow, increasing the flow rate of the branch flow to improve the delivery water volume, and effectively driving the air gathered around the seal 6. In addition, the parameter B can also be set to 0.7, 0.9, 1, etc. according to the needs, which should all be considered as specific embodiments of the utility model. When B=1, the front-to-back projection of the flow hole 5 completely falls into the water inlet 3 (as shown in FIG. 6B), so that the flow hole 5 obtains the maximum flow rate and flow of the branch flow. Figure 3

[0029] In actual operation, the ratio of the sum of the cross-sectional areas of the flow holes 5 to the front-to-back projection area of the water inlet 3 is A, 0.02≤A≤0.08. The cross-sectional area of the flow hole 5 is controlled by adjusting the diameter of the flow hole 5, and then the water volume ratio between the main flow and the branch flow is adjusted by adjusting the parameter A, which not only reduces the influence on the flow of the main flow, but also ensures that the flow of the branch flow meets the requirements of immersing the seal 6. The sum of the cross-sectional areas of the flow holes 5 refers to the data obtained by adding the cross-sectional areas of all flow holes 5, which is used to control the total flow of each branch flow.

[0030] ​In actual operation, the hub 7 is provided with a transmission hole 8 penetrating in front and back directions, the rotating shaft 9 penetrates the machine seal 6 along the axis of the shell 2 and is inserted into the transmission hole 8, so that the rotating shaft 9 and the impeller are circumferentially linked. The cross-sectional profile of the corresponding section of the rotating shaft 9 and the transmission hole 8 matches, so that they are matched and connected in a sleeve connection and are circumferentially linked, ensuring that the driving force generated by the motor 1 can effectively drive the impeller to rotate. The front and back projections of the cross section of the rotating shaft 9 at the transmission hole 8 completely fall into the front and back projections of the cross section of the rotating shaft 9 at the machine seal 6, ensuring that the rotating shaft 9 can smoothly penetrate the machine seal 6 and be connected with the transmission hole 8. Preferably, the transmission hole 8 is non-circular, ensuring that the transmission hole can effectively transmit the circumferential force from the rotating shaft, and in turn ensuring that the impeller can reliably operate. In addition, a transmission flat square and a key can also be used between the hub 7 and the rotating shaft 9 to achieve linkage, which should also be considered as a specific embodiment of the utility model.

[0031] In actual operation, the machine seal 6 includes a static ring fixedly connected with the pump cover 10 and a dynamic ring connected with the rotating shaft 9, and the branch flow is sprayed towards the friction surface between the static ring and the dynamic ring. The friction surface not only achieves a sealing effect by closely fitting, but also ensures the free rotation of the rotating shaft 9 by relative friction, ensuring that the rotating shaft 9 and the pump cover 10 remain sealed and can move relative to each other.

[0032] In actual operation, by setting different numbers of impellers, water pumps with different stages are obtained, including but not limited to two-stage water pumps, three-stage water pumps, four-stage water pumps, five-stage water pumps, etc. The water source is gradually pressurized by the synchronous rotation of multiple impellers, thereby increasing the pump head, which should all be considered as specific embodiments of the utility model. When the water pump is a two-stage water pump, it includes a primary wheel 15 and a final wheel 16 which are sequentially stacked along the axis of the pump shell from front to back and are connected in series by the rotating shaft 9. When the water pump is three-stage, four-stage or five-stage, a corresponding number of intermediate wheels 17 are provided between the primary wheel 15 and the final wheel 16, and the primary wheel 15, the intermediate wheel 17 and the final wheel 16 are sequentially connected in series by the rotating shaft 9.

[0033] In actual operation, on water pumps with different stages, the flow hole 5 is arranged on the final wheel 16 close to the machine seal 6, ensuring that there is no obstruction between the flow hole 5 and the machine seal 6, facilitating the direct injection of the branch flow to the machine seal 6, and effectively improving the anti-wear effect.

Claims

1. A water pump with anti-mechanical seal dry grinding, comprising a motor (1) and a pump body, the pump body comprising a pump shell with an assembly cavity and an impeller arranged in the assembly cavity, a rotating shaft (9) of the motor (1) penetrating through a mechanical seal (6) and being connected with the impeller, a water inlet (3) being arranged in the middle of a front wall of the impeller, a water outlet (4) being arranged on a periphery of the impeller, the impeller rotating and driving the medium to form a main water flow conveyed from the water inlet (3) to the water outlet (4), characterized in that, The rear wall of the impeller is annular, and a hub (7) is arranged in the middle part of the rear wall.

2. A canned dry pump according to claim 1, characterized in that The front-to-rear projection of the through-flow hole (5) is located outside the front-to-rear projection of the mechanical seal (6), so that the branch flow is delivered to the outside of the mechanical seal (6) and completely wraps the mechanical seal (6) by converging towards the middle.

3. A canned dry pump according to claim 2, characterized in that The front-to-rear projection of the through-flow hole (5) and the water inlet (3) at least partially overlaps, and the ratio of the overlapping area to the cross-sectional area of the corresponding through-flow hole (5) is B, B≥0.

7.

4. A canned dry pump according to claim 2, characterized in that The ratio of the sum of the cross-sectional areas of the through-flow holes (5) to the front-to-rear projection area of the water inlet (3) is A, 0.02≤A≤0.

08.

5. A canned dry pump according to claim 2, characterized in that The hub (7) is provided with a transmission hole (8) passing through the front-to-rear direction in the middle part, and the rotating shaft (9) passes through the mechanical seal (6) along the axis of the shell (2) and is inserted into the transmission hole (8), so that the rotating shaft (9) and the impeller are connected in the circumferential direction.

6. A canned dry pump according to claim 2, characterized in that The pump shell includes a tubular shell (2) and a pump cover (10) blocking the port of the shell (2), and the mechanical seal (6) is arranged in the middle part of the pump cover (10), and the rotating shaft (9) passes through the mechanical seal (6) along the axis of the shell (2) and is connected to the impeller.

7. A canned dry pump according to any one of claims 1 to 6, characterized in that The mechanical seal (6) includes a static ring fixed to the pump cover (10) and a dynamic ring connected to the rotating shaft (9), and the branch flow is sprayed towards the mechanical seal (6) and infiltrates the friction surface between the static ring and the dynamic ring.

8. A canned dry pump according to claim 7, characterized in that The impeller and the shell (2) are provided with an annular flow guide shell (11), and the impeller includes a final stage wheel (16) arranged at the rear end of the assembly cavity and close to the mechanical seal (6), and the through-flow hole (5) is arranged on the final stage wheel (16), so that the branch flow is directly sprayed towards the mechanical seal (6).

9. A canned dry pump according to claim 7, characterized in that The pump shell is provided with an inlet (14) in the middle part of the end surface away from the pump cover (10); or the pump shell is provided with an outlet (13) on the side wall close to the motor (1), and a through hole (12) is arranged on the flow guide shell (11) corresponding to the final stage wheel (16), and the main water flow and the branch flow output by the final stage wheel (16) can be discharged through the outlet (13) after passing through the through hole (12).

10. A canned dry pump according to claim 9, characterized in that ​

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