Disclosure of Invention
The technical problem to be solved by the embodiments of the present specification is to overcome the defects of the prior art, and provide a position-controlled suspension centrifugal blood pump with small volume, light weight and simple structure.
In order to achieve the above purpose, the embodiments of the present specification adopt the following technical solutions:
a position-controlled suspended centrifugal blood pump comprising: the device comprises a pump shell, a rotor, an impeller, a servo motor, an inner magnetic core group, an outer magnetic ring group and a position control bearing; the rotor is connected with the impeller in a seamless mode, the rotor is arranged in an inner tube of the blood pump, and the rotor is driven by the servo motor to drive the impeller to do work;
the inner magnetic core group consists of a plurality of circular magnetic sheets and is internally arranged at the top end inside the rotor, and the outer magnetic ring group consists of a plurality of magnetic rings and is sleeved on the outer wall of the inner pipe;
the position control bearing is composed of a ceramic ball and a ceramic nest, the ceramic ball is embedded in the lower end of the rotor impeller and exposes out of the rotor, and the ceramic nest is arranged below the ceramic ball.
Optionally, the inner magnetic core group consists of three circular magnetic sheets, and the outer magnetic ring group consists of two magnetic rings; or
The inner magnetic core group consists of four round magnetic sheets, and the outer magnetic ring group consists of three magnetic rings; or
The inner magnetic core group consists of five circular magnetic sheets, and the outer magnetic ring group consists of four magnetic rings.
Optionally, the magnetic materials of the inner magnetic core group and the outer magnetic ring group are strong magnetic neodymium iron boron.
Optionally, the inclined surface at the middle part of the top of the impeller is of a hydraulic structure.
Optionally, the inclined surface has an inclination angle of 1-20 °
Optionally, the impeller is sheet-shaped and includes a plurality of blades, and the root of each blade is connected to the rotor.
Optionally, the impeller comprises 3-5 blades.
Optionally, the pump casing further comprises: an inlet conduit, a pump cavity cover and a pump cavity lower shell;
the inlet pipeline comprises an inlet bracket, an outer heat insulation sleeve, a middle sleeve and an inner pipe;
the outer heat insulation sleeve, the middle sleeve and the inner pipe are of a coaxial structure, one end of the outer heat insulation sleeve, the middle sleeve and the inner pipe is connected with the inlet support, and the other end of the outer heat insulation sleeve, the middle sleeve and the inner pipe is embedded in the pump cavity cover;
the pump cavity cover is annular and is concentrically connected with the inner pipe, and the excircle of the pump cavity cover is connected with the lower pump cavity shell;
the inner bottom of the pump cavity lower shell is provided with a convex round table, and the side edge of the pump cavity lower shell is provided with a pump outlet.
Optionally, the servo motor includes rotor magnetic steel, a stator core and a stator winding;
the rotor magnetic steel is arranged in the rotor, and the stator core and the stator winding are arranged on the inner wall of the inlet pipeline, namely, the stator core and the stator winding are arranged between the inner pipe and the middle sleeve;
the rotor magnetic steel and the rotor are integrated, and the stator core and the stator winding are integrated with the inlet pipeline.
Optionally, the servo motor further comprises a telecommunication transmission line, one end of the telecommunication transmission line is connected with the stator winding, and the other end of the telecommunication transmission line extends out of the body and is connected with the control system.
The embodiment of the specification adopts at least one technical scheme which can achieve the following beneficial effects:
the suspension bearing provided by the invention is a permanent magnet bearing, belongs to passive magnetic suspension, does not need a complex detection, feedback and control system, has a simpler structure and stable performance, and can greatly improve the technical reliability and the use safety of the blood pump; the volume and the weight of the blood pump are smaller, so that the operation invasion of the blood pump can be reduced, and the practicability is improved; the internal structure of the full-suspension blood pump is simple and smooth, has no dead space or dead angle, and can effectively prevent thrombosis.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be described in detail below. It is to be understood that the embodiments described are only some of the embodiments of the specification and not all of them. All other embodiments obtained by a person of ordinary skill in the art without any inventive work based on the examples in the present specification fall within the scope of protection of the examples in the present specification.
The following further describes the concrete implementation of the embodiment with reference to the attached drawings of the embodiment in the specification.
Referring to fig. 1 to 3, an embodiment of the present disclosure provides a position-controlled suspended centrifugal blood pump, including: pump unit, servo motor and accuse position system.
The pump device comprises a pump housing, arotor 11 and animpeller 12.
The pump housing comprises an inlet conduit, apump chamber cover 19 and a pump chamberlower shell 18.
The inlet duct comprises aninlet support 10, an outer insulating jacket 9, amiddle sleeve 8 and aninner pipe 7.
The outer heat insulation sleeve 9, themiddle sleeve 8 and theinner pipe 7 are of a coaxial structure, one end of the outer heat insulation sleeve, the middle sleeve and the inner pipe is connected with theinlet support 10, the other end of the outer heat insulation sleeve, the middle sleeve and the inner pipe is connected with thepump cavity cover 19, and the joint needs to be welded and is leakproof.
Theinlet support 10 is convex, and is used for preventing the pump from working failure and embolism caused by the negative pressure sucking the ventricular septum when the blood pump works.
A cavity is formed between the outer heat insulation sleeve 9 and themiddle sleeve 8, so that the heat-resistant and cooling effects can be achieved, and the blood pump and the motor can be guaranteed to work safely and effectively.
Asewing ring 22 is arranged on the outer heat insulation sleeve 9 near thepump cavity cover 19 and is used for fixing the blood pump and the apex of the heart.
Thepump cavity cover 19 is annular, the central opening is concentrically connected with theinner tube 7, the excircle is connected with the pump cavitylower shell 18, and the joint needs to be welded and is leak-proof.
The inner bottom of the pump cavitylower shell 18 is provided with a convex round table 16, the side edge is provided with apump outlet 20, and thepump cavity cover 19 is sealed and welded after being buckled on the pump cavitylower shell 18.
Therotor 11 and theimpeller 12 are seamlessly connected into a whole.
Therotor 11 is driven by the servo motor to drive theimpeller 12 to do work, so that blood continuously flows in from thepump inlet 21 and flows out from thepump outlet 20 after being centrifuged.
Theimpeller 12 is in the form of a blade, typically 4 blades, the root of which is connected to therotor 11, evenly distributed.
Optionally, theimpeller 12 has 3 blades or 5 blades.
The servo motor mainly comprises rotormagnetic steel 1, astator iron core 2, a stator winding 3 and atelecommunication transmission line 6.
The rotormagnetic steel 1 is arranged in therotor 11; thestator core 2 and the stator winding 3 are arranged in the interlayer of themiddle sleeve 8 and theinner tube 7.
Thetelecommunication transmission line 6 is used for transmitting electric energy and electric signals, one end of the telecommunication transmission line is connected with the stator winding 3, and the other end extends out of the body and is connected with the control system.
Because the servo motor and the pump device are integrated into a whole, the pump-motor integration is formed.
The position control system comprises a position control magnetic group, a position control bearing and a hydraulic structure.
The position control magnetic group comprises an inner magnetic core group 5 and an outer magnetic ring group 4. The inner magnetic core group 5 is formed by overlapping three round magnetic sheets with the same axle center and is internally arranged at the top end inside the rotor; the outer magnetic ring group 4 is formed by overlapping two magnetic rings together with the same axle center and is sleeved on the outer wall of the inner pipe, and the axial installation position of the outer magnetic ring group is close to the lower edge of the inner magnetic core group 5. The magnetic directions of the circular magnetic sheet and the magnetic ring are axial, and the stacking sequence is that the same poles are opposite and are bonded together forcibly.
Optionally, the inner magnetic core group 5 may be formed by combining four circular magnetic sheets, and the outer magnetic ring group 4 is formed by combining three magnetic rings; or the inner magnetic core group 5 is formed by combining five round magnetic sheets, the outer magnetic ring group 4 is formed by combining four magnetic rings, and the installation position is close to the lower edge.
Preferably, the magnetic material of the position control magnetic group is strong magnetic neodymium iron boron.
The position control bearing comprises aceramic ball 14 and aceramic nest 15, theceramic ball 14 is embedded at the lower end of therotor impeller 12 and is approximately half exposed, theceramic nest 15 is embedded at the top end of the convex circular table 16, the edges of the top end are flush, and under the action of axial pressure generated by the position control magnetic group, theceramic ball 14 abuts against theceramic nest 15 to form a group of sliding bearings, so that the starting of the position control blood pump can be well supported, as shown in figure 2.
The hydraulic structure is that the top middle part of theimpeller 12 is inclined, namely the top of the blade is inclined from the inlet flow side to the back flow side, theinclined surface 13 and the inner surface of thepump cavity cover 19 form a wedge-shaped space, and the two sides of the inclined surface are provided with edges parallel and level to the top surface, so that the liquid flow can be prevented from overflowing.
Optionally, theinclined surface 13 has an inclination angle of 1-20 °.
After the position-controlled suspension centrifugal blood pump provided by the embodiment of the specification is started smoothly, how the rotor impeller achieves suspension operation as shown in fig. 1 needs to be analyzed, and suspension can be decomposed into radial suspension and axial suspension.
The radial suspension is mainly realized by a position control magnetic group, the inner magnetic core group 5 and the outer magnetic ring group 4 are radially repelled by magnetic force, and the repulsive force can sufficiently overcome and balance various radial forces, so that the rotor impeller is always controlled to be positioned at the center of theinner tube 7, and a gyroscope dead axle effect is added when the rotor impeller rotates, thereby obtaining good radial suspension effect.
How to realize axial suspension needs to be analyzed, the blood pump can be influenced by a plurality of axial forces when working at high speed, wherein the axial forces can be divided into weak axial force and strong axial force, the weak axial force mainly comprises the axial component of the gravity of a rotor impeller and the axial force of other factors, and the weak axial force is a weak influence factor; the strong axial force mainly comprises four axial forces, which can be analyzed from the graph shown in fig. 3, F4 is a forward axial force (pointing to the pump inlet), F1, F2 and F3 are three backward axial forces (back to the pump inlet), F1 is generated by a position control magnetic group, because the inner magnetic core group 5 is more than the outer magnetic ring group 4 and is slightly higher, a backward axial pressure is generated to the rotor impeller, the force is smaller, but the magnitude is basically unchanged, and has no relation with the rotating speed of the pump; f2 is the axial component of the impulse force generated by the fluid momentum on the impeller, and the force is positively correlated with the rotating speed; f3 is the axial component of the pressure exerted by the hydraulic pressure on the inclined surface 13 of the impeller 12, the force magnitude is in positive geometric correlation with the rotation speed, but in negative correlation with the magnitude of the wedge-shaped space; f4 is generated by the pressure difference between the low hydraulic pressure of the inner surface and the suction inlet of the pump cavity cover 19 and the high hydraulic pressure of the lower cover surface when the pump works, the force is rapidly increased along with the increase of the pump rotating speed after the pump is started, when the rotating speed reaches a certain height and F4 is greater than the sum of F1, F2 and F3, F4 drives the rotor impeller and the ceramic ball 14 to separate from the ceramic socket 15 and axially move forwards, the wedge-shaped space is reduced along with the approach of the top end of the blade to the pump cavity cover 19, the generated hydraulic pressure axial component F3 is increased in geometric progression, the force can automatically resist F4, when the resultant force balance of the axial force is reached, the rotor impeller is forced to stop the axial displacement, F3 is not increased any more, that is, the axial stress of the rotor impeller can be automatically balanced in a certain rotating speed range, and the rotor impeller.
As mentioned above, the rotor impeller can realize omnibearing position control suspension by combining radial suspension and axial suspension, thereby stably operating.
The technical effects that can be achieved by the embodiments of the present description are as follows:
compared with the existing mechanical bearing blood pump, the blood pump disclosed by the embodiment of the specification has the advantages that in the suspension state when the blood pump works normally, the bearings have no friction, the hemolysis can be reduced, the service life of the blood pump is prolonged, and the thrombosis complications triggered by friction heating can be reduced.
Compared with the existing magnetic suspension blood pump, the suspension bearing in the embodiment of the specification is a permanent magnet bearing, belongs to passive magnetic suspension, does not need a complex detection, feedback and control system, has a simpler structure and stable performance, and can greatly improve the technical reliability and the use safety of the blood pump; the volume and the weight of the blood pump are smaller, so that the operation invasion of the blood pump can be reduced, and the practicability is improved; the internal structure of the full-suspension blood pump is simple and smooth, has no dead space or dead angle, and can effectively prevent thrombosis.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.