CN215370243U - Centrifugal pump and dish washing machine - Google Patents

Abstract

A centrifugal pump, comprising: the pump shell comprises a pump seat and a pump cover which is surrounded with the pump seat to form a pump cavity, the impeller is arranged in the pump cavity, and a first protruding part is formed on the inner wall of the pump seat in a protruding mode from the inner wall to the impeller so as to reduce a gap between the inner wall of the pump seat and the impeller; the inner wall of the pump cover protrudes and extends towards the impeller from the inner wall to form a second protruding portion so as to reduce a gap between the inner wall of the pump cover and the impeller, and the first protruding portion and the second protruding portion are basically arranged on two sides of the impeller oppositely, so that backflow of high-pressure liquid is reduced, the efficiency of the centrifugal pump is improved, in addition, the phenomenon that the high-pressure liquid enters a sealing cavity formed by the impeller and a pump seat is reduced, the safety performance of the centrifugal pump is improved, the preparation cost is low, and the structure is simple. A dishwasher including a centrifugal pump.

Description

Centrifugal pump and dish washing machine

[ technical field ] A method for producing a semiconductor device

The utility model relates to a centrifugal pump and a dish washing machine.

[ background of the utility model ]

Dishwashers have been increasingly used for household washing, which has many advantages such as saving labor and having good washing effect. The pump is used as a core component of the dish washing machine, the good performance of the pump is the basis for ensuring the efficiency of the dish washing machine, a gap is formed between the impeller inside the pump and the pump shell, and high-pressure liquid in the pump shell can flow back to the water inlet of the pump along the gap, so that the efficiency is reduced. Be provided with the recess on the pump case on the present market, be provided with the arch on the impeller, the recess forms a little clearance with protruding cooperation, reduces to reveal, prevents the liquid backward flow of high pressure district or gets into sealed cavity, however, such structure is complicated, and the cost of manufacture is higher, and the effect is not obvious.

Accordingly, there is a need for improvements in the art that overcome the deficiencies in the prior art.

[ Utility model ] content

The utility model aims to provide a centrifugal pump which is simple in structure and can effectively reduce backflow of high-pressure liquid and entry of the high-pressure liquid into a sealed chamber.

The purpose of the utility model is realized by the following technical scheme: a centrifugal pump, comprising:

an impeller;

the pump shell comprises a pump seat and a pump cover which is arranged around the pump seat to form a pump cavity, the impeller is arranged in the pump cavity,

a first protruding part is formed on the inner wall of the pump seat in a protruding mode from the inner wall to the impeller so as to reduce a gap between the inner wall of the pump seat and the impeller; a second protruding part is formed on the inner wall of the pump cover in a protruding mode from the inner wall to the impeller so as to reduce a gap between the inner wall of the pump cover and the impeller; wherein the first protrusion and the second protrusion are substantially oppositely disposed at both sides of the impeller.

In one embodiment, the first protrusion and the second protrusion are arranged in a ring shape centering on an axis of the pump case.

In one embodiment, the first protrusion and the second protrusion are disposed near the impeller edge.

In one embodiment, the minimum distance between the first and second protrusions and the impeller is 0.5-2.0 mm.

In one embodiment, the first protrusions are radially spaced on the inner wall of the pump base.

In one embodiment, the pump housing is provided with a water outlet, and a fluid passage is formed between the first protrusion and the second protrusion and the inner wall of the pump cavity to guide the liquid to flow to the water outlet.

In one embodiment, the centrifugal pump further comprises a motor with a rotating shaft, and a machine cover which is used for sealing the motor and is arranged close to the pump base, wherein the machine cover and the pump base are arranged away from each other.

In one embodiment, the impeller is a shrouded impeller with a balancing hole having a diameter of 2.0 mm.

In one embodiment, a plurality of second protruding portions are radially arranged on the inner wall of the pump cover at intervals.

The utility model also provides a dishwasher comprising a centrifugal pump as described above.

Compared with the prior art, the utility model has the following beneficial effects: the first protruding part is formed on the inner wall of the pump seat to reduce the gap between the inner wall of the pump seat and the impeller; the second protruding portion is formed on the inner wall of the pump cover so as to reduce a gap between the inner wall of the pump seat and the impeller, and the first protruding portion and the second protruding portion are basically oppositely arranged on two sides of the impeller, so that backflow of high-pressure liquid is reduced, the efficiency of the centrifugal pump is improved, in addition, the phenomenon that the high-pressure liquid enters a sealing cavity formed by the impeller and the pump seat is reduced, the safety performance of the centrifugal pump is improved, the manufacturing cost is low, and the structure is simple.

[ description of the drawings ]

Fig. 1 is a perspective view of a centrifugal pump of the present invention.

Fig. 2 is an exploded perspective view of the centrifugal pump of the present invention.

Fig. 3 is a partial exploded view of the centrifugal pump of the present invention.

Fig. 4 is a sectional view of a partial structure of the centrifugal pump of the present invention.

Fig. 5 is a sectional view of the centrifugal pump of the present invention.

Fig. 6 is a partially enlarged view of fig. 5.

Fig. 7 is another partial enlarged view of fig. 5.

Fig. 8 is a cross-sectional view of the mechanical seal of the present invention.

Fig. 9 is a schematic structural view of the impeller of the present invention.

Fig. 10 is a schematic view of the structure of the seal of the present invention.

Among them, the pump head assembly-100; motor assembly-200; a pump base-1; a second seal ring-11; a first projecting portion-12; a pump cover-2; a water inlet-21; a water outlet-22; a second projecting portion-23; a pump cavity-3; an impeller-4; balance hole-41; a guide vane-42; an impeller shaft-43; a motor-5; a rotating shaft-51; a rotor assembly-52; rotor injection molding assembly-521; a bearing-522; rotor injection molding-523; round bar-5231; a long pole-5232; baffle-5233; magnetic steel-524; silicon steel sheet-525; an annular portion-5251; an extension-5252; fixing strip-5253; a through hole-5254; a housing portion-5255; a clearance hole-526; stator assembly-53; a machine seal cover-6; a first seal ring-61; a motor rear cover-7; mechanical seal-8; a seal ring-81; mechanical seal stationary ring-82; mechanical seal rotating ring-83; an elastic member-84; a third seal ring-85; a seal-9; a first seal-91; a second seal portion-92; a blade-93.

[ detailed description ] embodiments

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting of the utility model. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "comprising" and "having," as well as any variations thereof, in the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the utility model. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

Referring to fig. 1 to 5, a centrifugal pump according to an embodiment of the present application includes a pump head assembly 100 and a motor assembly 200, where the pump head assembly 100 includes an impeller 4 and a pump casing, the pump casing includes a pump base 1 and a pump cover 2 enclosing with the pump base 1 to form a pump cavity 3, and the impeller 4 is disposed in the pump cavity 3; the motor assembly 200 includes a motor 5 having a rotation shaft 51, a motor cover 6 for sealing the motor 5 and disposed close to the pump mount 1, and a motor back cover 7 for sealing the motor 5 and disposed far from the pump mount 1. One end of the rotating shaft 51 sequentially penetrates through the machine cover 6 and the pump base 1 and is fixedly connected with the impeller 4, the centrifugal pump is a pump which conveys liquid by means of centrifugal force generated when the impeller 4 rotates, when the centrifugal pump works, the rotating shaft 51 of the motor 5 drives the impeller 4 to rotate, and the liquid generates centrifugal motion by means of rotation of the impeller 4, so that the liquid is thrown to the outer edge of the impeller 4 and flows out, wherein the liquid can be tap water, oil and the like, which are not listed.

Wherein, motor 5 is brushless motor 5, and brushless motor 5 is small, compact structure, light in weight, energy consumption are low and the rotational speed is high, and centrifugal pump's efficiency has been guaranteed to high rotational speed, and little volume has reduced centrifugal pump's volume. The motor 5 is located between the machine cover 6 and the motor rear cover 7, the machine cover 6 is fixedly connected with the motor 5, the motor 5 is fixedly connected with the motor rear cover 7 to form a sealing structure, and external steam is prevented from permeating into the motor 5, so that the motor 5 is protected from being corroded. In this embodiment, the machine cover 6 and the motor 5, and the motor 5 and the motor rear cover 7 are fixedly connected by screw sealing, but the connection method is not limited to this, and may be a bonding method, which is not listed here.

The brushless motor 5 includes a rotor assembly 52 and a stator assembly 53, the rotor assembly 52 being connected to a rotating shaft 51 provided at the center thereof and rotating in synchronization, the rotor assembly 52 being rotatably received in the stator assembly 53. In this embodiment, the size of the air gap between the rotor assembly 52 and the stator assembly 53 is 0.5mm, the magnetic resistance between the rotor assembly 52 and the stator assembly 53 can be reduced by the design of the small-size air gap, the effective power is improved, the high efficiency of the motor 5 is ensured, the specific size of the air gap can be set according to actual needs, and no specific limitation is made here.

The rotor assembly 52 includes a rotor injection molding assembly 521 fixedly sleeved on the rotating shaft 51 and a bearing 522 disposed between the machine cover 6 and the rotating shaft 51 and sleeved on the rotating shaft 51, and when the motor 5 works, the rotating shaft 51 drives the bearing 522 and the rotor injection molding assembly 521 to rotate synchronously. The bearing 522 is disposed between the mechanical cover 6 and the rotating shaft 51, and is used for supporting the rotating shaft 51 to rotate relative to the mechanical cover 6, reducing the friction coefficient of the rotating shaft 51 during the rotation process and ensuring the rotation precision thereof.

The rotor injection molding assembly 521 comprises a rotor injection molding piece 523, and magnetic steel 524 and silicon steel sheets 525 arranged in the rotor injection molding piece 523, wherein the magnetic steel 524 is split and embedded into a containing part 5255 formed by the silicon steel sheets 525 and is injected and molded into a whole through the rotor injection molding piece 523. The silicon steel sheet 525 includes an annular portion 5251 and a plurality of extension portions 5252 integrally formed with the annular portion 5251, the annular portion 5251 is a hollow cylindrical structure, and the annular portion 5251 is positioned at the center of the silicon steel sheet 525 to accommodate the rotating shaft 51 therein. Specifically, the rotating shaft 51 passes through the annular portion 5251 and is fixedly connected with the annular portion 5251, and the inner surface of the annular portion 5251 protrudes outwards from the surface and is provided with a plurality of fixing strips 5253, wherein the fixing strips 5253 are used for fixing the rotating shaft 51 so as to increase the connection stability between the rotating shaft 51 and the annular portion 5251. The plurality of extension portions 5252 are arranged at equal intervals along the annular portion 5251, the extension portions 5252 are formed by extending outwards from the radial direction of the annular portion 5251, the cross section of each extension portion 5252 is of a triangle-like structure, each extension portion 5252 is provided with a through hole 5254 penetrating along the extending direction of the rotating shaft 51, a receiving portion 5255 is formed between adjacent extension portions 5252, and the cross section of each receiving portion 5255 is of a rectangular structure. In this embodiment, the number of the extension portions 5252 is eight, and the number of the receiving portions 5255 formed is eight, but the number of the extension portions 5252 and the number of the receiving portions 5255 may be set as needed. The eight split magnetic steels 524 are respectively embedded into one accommodating portion 5255, a clearance hole 526 is formed between the magnetic steels 524 and the annular portion 5251, and the magnetic steels 524 and the silicon steel sheets 525 form a structure similar to a cylinder.

In order to improve the stability of the structure formed by the silicon steel sheets 525 and the magnetic steel 524 and prevent the magnetic steel 524 from moving when the rotor assembly 52 rotates, the rotor injection molding piece 523 is arranged on the periphery of the silicon steel sheets 525 and the magnetic steel 524. The rotor injection molding piece 523 is of a cylindrical-like structure, the rotor injection molding piece 523 comprises a top part and a bottom part which are arranged at the outer sides of the two ends of the magnetic steel 524 and the silicon steel sheet 525, and is provided with a round rod 5231 capable of passing through the through hole 5254 and a long rod 5232 capable of passing through the clearance hole 526, and the two ends of the round rod 5231 and the two ends of the long rod 5232 are respectively connected with the top part and the bottom part. It is clear that the number of round rods 5231, through holes 5254 and extensions 5252 are the same, and that the number of long rods 5232 and clearance holes 526 are the same. In addition, rotor injection molding 523 still includes baffle 5233 for fixed magnet steel 524, when forming rotor injection molding subassembly 521, round bar 5231 inserts perforating hole 5254, and stock 5232 inserts clearance hole 526, and at this moment, baffle 5233 is located the outside of magnet steel 524 to inject magnet steel 524 and silicon steel sheet 525 in rotor injection molding 523, thereby mould plastics into an organic whole, compact structure, convenient integral erection and improved the stability of rotor injection molding subassembly 521.

The pump cover 2 is hermetically installed on the pump base 1, in the embodiment, the peripheries of the pump base 1 and the pump cover 2 are provided with a plurality of screw holes, and the pump base 1 and the pump cover 2 are relatively fixed through screws, in other embodiments, the fixing mode between the pump cover 2 and the pump base 1 can be other, and no specific limitation is made here. A pump chamber 3 defined between the pump base 1 and the pump cover 2 is used for receiving liquid, and an impeller 4 is installed in the pump chamber 3.

The pump cover 2 is provided with a water inlet 21 on the side wall far away from the pump base 1, the water inlet 21 is used for being externally connected with a water pipe, a water outlet 22 is arranged above the water pipe, and the water inlet 21 and the water outlet 22 are communicated with the pump cavity 3. The water inlet 21 is of a hollow circular truncated cone structure, the inclination angle of the side wall of the hollow circular truncated cone structure is 2 degrees, the diameter of one end, connected with the water pipe, of the water inlet 21 is smaller than that of one end, communicated with the pump cavity 3, of the water inlet, so that the water pumping efficiency of the impeller 4 is improved, the cavitation erosion and noise of the impeller 4 are reduced, specific numerical values of the inclination angle of the side wall of the water inlet are not specifically limited, and the specific numerical values can be set according to actual needs.

Referring to fig. 9, in the present embodiment, the impeller 4 is a closed impeller 4, the closed impeller 4 is provided with a balancing hole 41 for balancing a part of the axial force, and the diameter of the balancing hole 41 is 2.0mm, so as to reduce the leakage loss and improve the efficiency of the centrifugal pump. The impeller 4 is provided with a plurality of guide vanes 42, the thickness of each guide vane 42 is 1.2-1.5mm, and the thickness of each guide vane 42 is gradually increased along the direction far away from the rotating shaft 51, namely the thickness of each guide vane 42 is linearly changed, so that cavitation erosion is reduced, and the working efficiency of the impeller 4 is improved. The present embodiment optimizes the structure of the impeller 4 to improve the efficiency of the centrifugal pump.

Referring to fig. 6, a first protruding portion 12 is formed on the inner wall of the pump holder 1 protruding from the inner wall toward the impeller 4 to reduce the gap between the inner wall of the pump holder 1 and the impeller 4, thereby increasing the flow resistance in the gap, reducing the backflow of the high-pressure liquid to the water inlet 21, reducing the leakage of the centrifugal pump, improving the efficiency of the centrifugal pump, and reducing the energy consumption. And a second protruding part 23 is formed on the inner wall of the pump cover 2 in a protruding way from the inner wall to the impeller 4 so as to reduce the gap between the inner wall of the pump cover 2 and the impeller 4, further increase the flow resistance in the gap, reduce the high-pressure liquid entering a sealing cavity formed between the impeller 4 and the pump seat 1 and increase the safety performance of the centrifugal pump. The first protruding portion 12 and the second protruding portion 23 are substantially oppositely arranged on two sides of the impeller 4, and the structure can effectively reduce the gap between the pump cavity 3 and the impeller 4 and increase the gap flow resistance by forming protruding extension on the inner walls of the pump cover 2 and the pump seat 1 under the condition of not increasing the processing and assembling difficulty, thereby improving the performance of the pump, and the structure is simple and the preparation is simple and easy to obtain.

Specifically, the first projecting portion 12 and the second projecting portion 23 are arranged in a ring shape centering on the axis of the pump case. The cross sections of the first protruding portion 12 and the second protruding portion 23 along the axial direction are similar to a semicircular shape, but are not limited to this, and the cross sections of the first protruding portion 12 and the second protruding portion 23 may also be rectangular, trapezoidal, inverted trapezoidal, triangular, circular arc-shaped, and the like. The pump casing and the impeller 4 are provided coaxially with the rotating shaft 51, and the rotating direction of the rotating shaft 51 may be an axial direction and the radial direction around the rotating shaft 51 may be a radial direction.

In the present embodiment, the first protruding portion 12 and the pump base 1 are integrally formed, and the second protruding portion 23 and the pump cover 2 are integrally formed, for example, by integrally injection molding using a plastic material, so as to facilitate the preparation of the pump base 1 and the pump cover 2 and enhance the overall strength of the pump base 1 and the pump cover 2.

A fluid passage is formed between the first protrusion 12, the second protrusion 23 and the inner wall of the pump chamber 3 to guide the liquid toward the outlet 22. The water inlet 21, the fluid channel and the water outlet 22 are sequentially communicated, when the rotating shaft 51 drives the impeller 4 to rotate at a high speed, water flow is continuously sucked from the water inlet 21, then passes through the fluid channel, and is quickly discharged from the water outlet 22 under the action of the high-speed centrifugal force of the impeller 4, and a continuous circulating process of active water suction and water discharge is formed.

The first and second protrusions 12 and 23 are located close to the edge of the impeller 4 so that the fluid passage is away from the water inlet 21 and the sealed chamber formed between the impeller 4 and the pump block 1, preventing backflow and improving the safety of the sealed chamber. A plurality of first protruding parts 12 are arranged on the inner wall of the pump seat 1 at intervals along the radial direction; the inner wall of the pump cover 2 is provided with a plurality of second protruding parts 23 at intervals along the radial direction, so that the sealing effect is further enhanced, and the specific number of the first protruding parts 12 and the second protruding parts 23 can be set according to actual needs.

The minimum distance between the first protruding part 12 and the second protruding part 23 and the impeller 4 is 0.5-2.0mm, the gap width is preferably 1mm, and the design minimizes the distance between the impeller 4 and the pump seat 1 and the pump cover 2, so that the liquid flowing at the outer ring of the impeller 4 is prevented from flowing back to the water inlet 21 and flowing to the pump seat 1, and the efficiency and the safety performance of the centrifugal pump are improved. The existence of these clearances is, on the one hand, a reason for limitation in terms of machining and assembly accuracy, and on the other hand, the existence of these clearances effectively reduces friction between the impeller 4 and the pump base and the pump cover 2 when rotating, preventing an increase in leakage due to wear of the impeller 4.

Because the rotating shaft 51 sequentially penetrates through the machine cover 6 and the pump base 1 and extends into the pump head assembly 100 and rotates relative to the machine cover 6 and the pump base 1, the contact part of the rotating shaft 51 and the pump base 1 and the contact part of the rotating shaft 51 and the machine cover 6 have poor sealing performance, in order to reduce the phenomenon that liquid in the pump cavity 3 volatilizes from between the rotating shaft 51 and the pump base 1 and flows to the motor assembly 200, the safety performance and the service life of the motor assembly 200 are reduced. Referring to fig. 1, 3 and 7, in the embodiment, the mechanical cover 6 and the pump base 1 are disposed apart from each other, and the distance L between the mechanical cover 6 and the pump base 1 is 2-10mm, that is, an open environment is formed between the mechanical cover 6 and the pump base 1, so that steam volatilized from the pump base 1 can flow to the outside, thereby reducing the steam entering the motor assembly 200 and improving the safety performance of the centrifugal pump. The specific distance between the cover 6 and the pump base 1 is not limited in detail, and may be set according to actual needs.

Referring to fig. 7 and 8, in order to improve the sealing between the pump base 1 and the rotating shaft 51, a mechanical seal 8 is provided between the impeller 4 and the pump base 1, so that the liquid in the pump chamber 3 is prevented from flowing out from the gap between the rotating shaft 51 and the pump base 1. The impeller 4 is provided with an impeller shaft 43 sleeved on the rotating shaft 51, and the mechanical seal 8 comprises a sealing ring 81 sleeved on the impeller shaft 43, a mechanical seal movable ring 83 fixedly connected with the sealing ring 81 and a mechanical seal static ring 82 fixedly connected with the pump base 1.

The sealing ring 81 and the impeller shaft 43 are in interference fit, so that the sealing performance between the pump base 1 and the rotating shaft 51 is improved, and particularly, the sealing ring 81 is a rubber sealing ring. The end face of the mechanical seal dynamic ring 83 abuts against the end face of the mechanical seal static ring 82, and sealing is achieved. When the centrifugal pump works, the sealing ring 81, the mechanical seal rotating ring 83 and the impeller 4 synchronously rotate, the mechanical seal rotating ring 83 rotates relative to the mechanical seal static ring 82, in order to enable the end faces of the sealing ring 81 and the mechanical seal static ring 82 to always keep a butt joint state, and the sealing performance of the butt joint of the end faces is improved, the sealing ring 81 is provided with the elastic piece 84, the elastic piece 84 has a driving force for driving the mechanical seal rotating ring 83 to move towards the mechanical seal static ring 82 and enable the end faces to be attached, and in the embodiment, the elastic piece 84 is a spring. When the centrifugal pump works, abutting end faces of the mechanical seal movable ring 83 and the mechanical seal static ring 82 mutually rub and move, and therefore the purpose of leakage resistance is achieved. In addition, the outer surface of the mechanical seal static ring 82 is also connected with the pump base 1 in a sealing way through a third seal ring 85, so that the sealing performance of the pump head assembly 100 is ensured. In addition, in order to improve the connection sealing performance between the pump base 1 and the pump cover 2, a second sealing ring 11 for sealing is arranged between the pump base 1 and the pump cover 2, and the arrangement of the second sealing ring 11 prevents the liquid in the pump cavity 3 from volatilizing or flowing out from the connection position of the pump base 1 and the pump cover 2.

However, when the centrifugal pump is operated, the mechanical seal 8 moves to generate heat, so that the liquid in the pump cavity 3 leaks from the mechanical seal 8 in the form of steam and permeates into the motor 5 to damage the motor 5. In order to solve the problem, a sealing element 9 is arranged between the machine cover 6 and the rotating shaft 51, and the sealing element 9 is sleeved on the rotating shaft 51 and rotates synchronously with the rotating shaft 51. Referring to fig. 10, the sealing element 9 includes a first sealing portion 91 disposed on the rotating shaft 51 and a second sealing portion 92 formed by extending outward from the outer periphery of the first sealing portion 91. First sealing 91 is hollow cylindrical structure, and the internal diameter of first sealing 91 is the same with the diameter of pivot 51, second sealing 92 is the loop configuration, and the height of second sealing 92 is greater than between machine closing cap 6 and the pivot 51 apart from, when sealing 9 cover was established on pivot 51, second sealing 92 was located the motor element 200 outside and was close to machine closing cap 6, because of the height of second sealing 92 is greater than the distance between machine closing cap 6 and the pivot 51, thereby can shelter from the gap that forms between machine closing cap 6 and the pivot 51, prevent that steam from locating inside entering motor 5.

The sealing member 9 is provided with a plurality of blades 93 for generating air flow, the blades 93 are arranged between the first sealing portion 91 and the second sealing portion 92, specifically, the blades 93 are in a right-angled triangle structure, a right-angled side of each blade 93 is fixed on the first sealing portion 91, and the other right-angled side is fixed on the second sealing portion 92. In order to allow one surface of the second seal portion 92 to be in close proximity to the machine cover 6, a vane 93 is provided on one side of the second seal portion 92. In this embodiment, the number of the blades 93 is eight, and the eight blades 93 are arranged at equal intervals along the outer periphery of the first sealing portion 91, but not limited thereto, and the number of the blades 93 may be other, and is not specifically limited herein. Blade 93, first sealing 91 and second sealing 92 integrated into one piece set up, and simple structure is compact, and motor 5 during operation, pivot 51 drive sealing member 9 and rotate, and the steam that the blade 93 rotated the production volatilizees here also can be accelerated to the mobile air, further prevents inside steam flow direction motor element 200.

The motor 5 generates heat during operation, which causes the bearing 522 and the mechanical cover 6 to generate heat, the bearing 522 is generally made of stainless steel, the mechanical cover 6 is generally made of plastic material, and the gap between the bearing 522 and the mechanical cover 6 is increased due to the different corresponding expansion coefficients of the two materials. Referring to fig. 7, in order to prevent steam from entering the motor 5 due to the increase of the gap, a first sealing ring 61 for sealing is disposed between the bearing 522 and the cover 6, and the first sealing ring and the sealing member 9 achieve the dual protection purpose, so as to prevent steam from entering the motor 5, and improve the safety and the service life of the motor 5.

In addition, when the centrifugal pump is not in operation, liquid is always stored in the pump cavity 3, and the liquid can enter the inner cavity of the motor 5 along the rotating shaft 51 due to long-time liquid storage. The presence of the seal 9 avoids the possibility of liquid entering the interior of the motor 5, thereby improving the safety and longevity of the motor 5.

The application also provides a dishwasher, which comprises the centrifugal pump as shown above, and the dishwasher realizes the purpose of cleaning the objects to be cleaned by spraying water or sprinkling water through the centrifugal pump, and the application target or the application scene of the dishwasher is not specifically limited by the application.

In summary, the first protruding part is formed on the inner wall of the pump seat to reduce the gap between the inner wall of the pump seat and the impeller; the second protruding portion is formed on the inner wall of the pump cover so as to reduce a gap between the inner wall of the pump seat and the impeller, and the first protruding portion and the second protruding portion are basically oppositely arranged on two sides of the impeller, so that backflow of high-pressure liquid is reduced, the efficiency of the centrifugal pump is improved, in addition, the phenomenon that the high-pressure liquid enters a sealing cavity formed by the impeller and the pump seat is reduced, the safety performance of the centrifugal pump is improved, the manufacturing cost is low, and the structure is simple.

The above is only one embodiment of the present invention, and any other modifications based on the concept of the present invention are considered as the protection scope of the present invention.

Claims (10)

1. A centrifugal pump, comprising:

an impeller;

the pump shell comprises a pump seat and a pump cover which is arranged around the pump seat to form a pump cavity, the impeller is arranged in the pump cavity,

a first protruding part is formed on the inner wall of the pump seat in a protruding mode from the inner wall to the impeller so as to reduce a gap between the inner wall of the pump seat and the impeller; a second protruding part is formed on the inner wall of the pump cover in a protruding mode from the inner wall to the impeller so as to reduce a gap between the inner wall of the pump cover and the impeller; wherein the first protrusion and the second protrusion are substantially oppositely disposed at both sides of the impeller.

2. The centrifugal pump according to claim 1, wherein said first protrusion and said second protrusion are annularly arranged centering on an axis of said pump case.

3. The centrifugal pump of claim 1, wherein said first protrusion and said second protrusion are disposed proximate to said impeller rim.

4. The centrifugal pump of claim 1, wherein the minimum distance between said first and second protrusions and said impeller is 0.5-2.0 mm.

5. The centrifugal pump of claim 1, wherein said first protrusions are radially spaced on the inner wall of said pump block.

6. The centrifugal pump of claim 1, wherein said pump casing defines a water outlet, and wherein a fluid passage is defined between said first projection, said second projection and an inner wall of said pump chamber for directing fluid toward said water outlet.

7. The centrifugal pump of claim 1 further comprising a motor having a shaft, and a mechanical cover disposed adjacent said pump base for sealing said motor, said mechanical cover being spaced from said pump base.

8. The centrifugal pump of claim 1 wherein said impeller is a shrouded impeller with a balancing hole of 2.0mm diameter.

9. The centrifugal pump of claim 1, wherein a plurality of said second protrusions are radially spaced on the inner wall of said pump cover.

10. A dishwasher, characterized by comprising a centrifugal pump as claimed in any one of claims 1 to 9.

Images