A kind of axial-flow pump impeller structure of leaking without leaf top
Technical field
The present invention relates to a kind of axial-flow pump impeller structure of leaking without leaf top, the impeller that relates in particular to axial-flow pump is arranged and driving mechanism layout, belongs to pump technology field, is applicable to the pipeline delivery pump of small axial flow pump and pipe with small pipe diameter.
Background technique
The axial-flow pump of design is because blade is fixed on wheel hub at present, and blade is done work to water by wheel hub driven rotary, and shell is static, blade rotary, and shell is static, quiet one unavoidably there is rim clearance between moving in this, pressure difference between relative movement between impeller clearance and shell and impeller clearance pressure side and suction surface has produced leaf top leakage flow, the main flow of itself and blade suction surface interacts and has formed leaf top leakage vortex, leakage vortex is disturbed main flow motion, and nearly 20% region in runner is exerted an influence, and has significantly reduced axial-flow pump efficiency and cavitation performance, although so impeller leaf top zone radius is larger, fluid acting ability and fluid passing capacity are all stronger, Lang Jixing " pre-test of axial-flow pump wheel axis plane velocity and circular rector best distribution rule " (fluid engineering, 1990,12:31-36) known in a literary composition, owing to there is gap between wheel rim and shell, unavoidably can cause leakage, in order to make impeller obtain higher efficiency, people have to greatest axis face velocity radially to move to wheel hub direction, but defect is, this kind of arrangement cannot make full use of acting ability and the fluid passing capacity near rim area, and because existing, rim clearance leaks, can cause leakage loss, leaf top leakage flow has not only reduced volumetric efficiency, also can produce serious problem of cavitation, document " impact of different blade tip clearances on axial-flow pump cavitation performance and flow field " (Central China University of Science and Technology's journal: natural science edition, 2013 (4): 21-25) and " axial-flow pump blade tip clearance cavitation stream visualized experiment research " (Engineering Thermophysics journal, 2011, 32 (8): 1315-1318) all proved this problem, therefore traditional axial flow pump structure becomes the bottleneck that current restriction axial-flow pump hydraulic performance further improves, axial-flow pump impeller structure innovation is to address this problem inevitable approach.
Through retrieval, the patented technology that publication number is CN102116316A at present, makes rim clearance dwindle 20 ~ 30% by tip being set on leaf top, but thoroughly do not eliminate rim clearance, and in running, the upper outstanding part in leaf top is easy to collide with shell, causes scraping damage; Publication number is the patented technology of CN202732374U, by split type mechanism is made into direct-connected, though simplified to a certain extent maintenance service difficulty, but its maintenance time is still longer, can not meet the needs of long-time continuous running, there is change by a relatively large margin in water (flow) direction in addition in water pump, affects the efficiency of water pump.
Summary of the invention
The object of the present invention is to provide a kind of simple in structurely, with low cost, reveal without blade tip clearance, efficiency is high, blade strength and the large axial-flow pump impeller structure of rigidity.
To achieve these goals, the technological scheme adopting is: change impeller means of fixation and the kind of drive, be specially: impeller, shell and the wheel hub formation impeller body that is fixed as one, impeller, shell and wheel hub are rotated with entirety, described housing exterior is fixed a circle gear ring, described gear ring and motor engagement driving, arrange motive sealing between described shell and stator section and shell and inlet segment.
Described impeller, shell and wheel hub are fixed as one and form impeller body and refer to: impeller two ends are fixed, and blade root and wheel hub are fixed, and leaf top and shell are fixed; Between described impeller and shell, impeller and wheel hub, do not stay gap.
Described gear ring and shell are for together casting or welding or be fixed on shell by interference fit or key.
Described gear ring is belt pulley.
Described motor can configure one in axial-flow pump one side, or respectively configures one in axial-flow pump both sides, so that redundancy to be provided, strengthens reliability.
Described motive sealing is mechanical seal.
The present invention by by impeller and wheel hub and shell is fixed and as a whole rotation, guarantee impeller leaf top gapless from structure, fundamentally solve the leakage flow problem of blade tip clearance, make axial-flow pump can distribute and design according to the best axis plane velocity of impeller loss reduction in the time of the Hydraulic Design, to make full use of Ye Ding region, to flow ability by liquid strong, the advantage that acting ability is large; And, because each blade has been taked the fixing mode in two ends, compared with traditional cantilever type means of fixation, structural strength strengthens greatly, and blade can do thinlyyer, thereby can reduce blade excretion coefficient, improve axial-flow pump conveyance capacity, and contribute to further to improve hydraulic efficiency; Motor engages drives impeller body case by gear, drive blade rotary to do work by shell, drive blade rotary to compare with traditional by axle, the moment of motor is required to reduce, can use pot motor, thereby the cost volume of motor is reduced, save user's investment and space; In addition, because blade is by shell driven rotary, therefore, axle no longer needs to stretch out outside pump case, thereby makes water (flow) direction without change, has also reduced thus because water (flow) direction changes the hydraulic loss causing; Compared with tubular axial-flow pump, also reduce motor to put into the complexity of pump and expensive.
Brief description of the drawings
Below in conjunction with drawings and Examples, the present invention is further described.
Fig. 1 is impeller body schematic diagram.
In Fig. 1: 1, wheel hub; 2, leaf is followed with wheel hub and is fixed, gapless; 3, impeller, 4, wheel rim and shell fix, gapless; 5, shell.
Fig. 2 is the schematic diagram of fixing a circle gear on impeller body shell.
Fig. 3 is that motor engages the schematic diagram that drives whole impeller body rotation by gear.
Fig. 4 schematic diagram that to be impeller body link together by motive sealing and stator section and feed-water end.
In figure: the 6th, inlet segment, the 7th, fair water cone, the 8th, the motive sealing between inlet segment and impeller body shell, the 9th, a circle gear of fixing on impeller, the 10th, the motive sealing between impeller body shell and stator section, the 11st, stator section, the 12nd, dunnage, the 13rd, water exit end, the 14th, motor, the 15th, gear, the 5th, shell, the 3rd, impeller, the 1st, wheel hub.
Embodiment
As shown in Figure 4, the invention discloses a kind of axial-flow pump impeller structure of revealing without leaf top, comprise shell 5, impeller 3, wheel hub 1, gear ring 9 and motive sealing 8 (10), motor 14.
Further, described impeller 3 is fixing with shell 5, and gap is not stayed in centre, thereby has stopped leaf top leakage flow from structure; Impeller 3 is fixing with wheel hub 1, and gap is not stayed in centre yet, thereby stops blade root leakage flow, and X-Y scheme as shown in Figure 1.
The described impeller being fixed together 3, wheel hub 1, shell 5 are done as a whole being rotated.
Between the impeller body of described rotation as a whole and static stator section shell, motive sealing 10 is set; Between the impeller body of described rotation as a whole and static inlet segment shell, motive sealing 8 is also set.
Described motive sealing 8,10 is mechanical seal.
The described impeller body of rotation as a whole, fixes a circle gear ring 9 on shell 5.
Fixing gear ring 9 on described impeller body shell, can be casting together with shell 5, or is fixed on impeller body shell 5 by means such as welding, interference fit, key cooperations after manufacturing separately.
On described impeller body shell 5, fixing gear ring 9 can be belt pulley.
Described gear ring 9 engages by gear or belt transmission is driven by motor 14.
Except motor 14, also can adopt other dynamic power machine.
Current are entered by inlet segment 6, through by motor 14 by gear 15 be fixed on gear ring 9 engagement driving on impeller body shell 5, thereby make the impeller body integral-rotation that is fixed as one by wheel hub 1, blade 3, shell 5 and to the waterflow boosting passing through from it, integrally rotated impeller body and inlet segment 6 seal by motive sealing 8, same and the stator section 11 of integrally rotated impeller body seals by motive sealing 10, current after supercharging carry out rectification after entering stator section 11, finally flow out from water exit end 13.