CN215461412U - Hydrodynamic bearing and rotary blood pump - Google Patents

Abstract

The utility model relates to a fluid dynamic pressure bearing and a rotary blood pump, which comprise a first shell, a thrust disc and a second shell, wherein the shaft end of the first shell facing the thrust disc is a first shell end, the shaft end of the thrust disc facing the first shell end is a first thrust end, the shaft end of the second shell facing the thrust disc is a second shell end, the shaft end of the thrust disc facing the second shell end is a second thrust end, one of the first shell end and the first thrust end is provided with a first spiral groove, and one of the second shell end and the second thrust end is provided with a second spiral groove; first helicla flute is asymmetric with the second helicla flute, and the thrust dish can stabilize the suspension in the axial position of difference under different rotational speed operating mode, can extrude the liquid in the liquid dynamic pressure bearing through the rotational speed that changes the thrust dish, avoids partial liquid to be detained in the liquid dynamic pressure bearing for a long time, when being applied to the rotation type blood pump, can improve the blood compatibility of liquid dynamic pressure bearing clearance department, prevents the thrombus.

Description

Hydrodynamic bearing and rotary blood pump

Technical Field

The utility model belongs to the field of bearings, and particularly relates to a hydrodynamic bearing and a rotary blood pump.

Background

Hydrodynamic lubrication is based on the relative motion between a pair of lubricated solid friction surfaces, so that pressure is generated in a lubricating fluid film between the solids to bear external load and avoid the solids from contacting with each other, thereby reducing frictional resistance and protecting the solid surfaces. The elements of hydrodynamic lubrication are: a wedge-shaped gap is formed between the two solid surfaces; the gap is filled with fluid with proper viscosity; the fluid can be adsorbed on the surfaces of two solids; the relative motion of the two solid surfaces drives the fluid from the large gap to the small gap.

Hydrodynamic bearings are a type of hydrodynamic bearing applying the hydrodynamic lubrication principle and can be classified into radial bearings and thrust bearings according to the bearing direction. Hydrodynamic bearings generally have a wedge-shaped lubricating film, and in addition, a step-shaped and a spiral groove-shaped lubricating film, both of which can be considered as a special type of wedge gap.

The method is characterized in that a solid friction surface of the hydrodynamic bearing is provided with spiral shallow grooves which are usually made into rectangular sections, and during operation, the relative motion of the solid surface drives lubricating fluid to flow along each spiral groove; the bearing principle can be applied to a thrust bearing and a radial bearing.

The hydrodynamic bearing with the spiral groove has simple structure and small volume, and is suitable for occasions with high-speed rotary motion and ultra-clean occasions such as a rotary blood pump and the like. However, two solid surfaces of the existing hydrodynamic bearing are provided with symmetrical spiral grooves, so that a thrust disc of the hydrodynamic bearing is suspended in the middle all the time, and part of liquid is easy to be retained in the hydrodynamic bearing, so that the conveying of the liquid is influenced, and the bearing is applied to a rotary blood pump and has the risk of thrombus.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is as follows: the hydrodynamic bearing and the rotary blood pump are provided for solving the problem that the existing thrust disk always hovers in the middle position and easily causes part of liquid to be retained in the hydrodynamic bearing.

In order to solve the above technical problem, an embodiment of the present invention provides a hydrodynamic bearing, including a first housing, a thrust disc, and a second housing, where the first housing is fixedly connected to the second housing, and the thrust disc is disposed between the first housing and the second housing and can rotate relative to the first housing and the second housing;

the shaft end of the first shell facing the thrust disc is a first shell end, the shaft end of the thrust disc facing the first shell end is a first thrust end, the shaft end of the second shell facing the thrust disc is a second shell end, the shaft end of the thrust disc facing the second shell end is a second thrust end, one of the first shell end and the first thrust end is provided with a first spiral groove, and one of the second shell end and the second thrust end is provided with a second spiral groove;

the first spiral groove and the second spiral groove are asymmetric, so that the suspension axial position of the thrust disk correspondingly changes when the rotation speed of the thrust disk changes.

Optionally, one of the first spiral groove and the second spiral groove is an equal groove depth spiral groove, and the other is a variable groove depth spiral groove, and the groove depth gradually decreases or increases from outside to inside.

Optionally, the groove depth of the first spiral groove is 0.005-0.5 mm, and the groove depth of the second spiral groove is 0.005-0.5 mm.

Optionally, one of the first spiral groove and the second spiral groove is an equal-groove-width spiral groove, the other is a variable-groove-width spiral groove, and the groove width gradually decreases or increases from outside to inside.

Optionally, the width of the first spiral groove is 0.2-5 mm, and the width of the second spiral groove is 0.2-5 mm.

Optionally, the number of the first spiral grooves is 4 to 36, and the number of the second spiral grooves is 4 to 36.

Optionally, the groove length ratio of the first spiral groove is 0-1, and the spiral angle ranges from 0-85 degrees; the groove length ratio of the second spiral groove is 0-1, and the spiral angle range is 0-85 degrees.

Optionally, a gap between the first thrust end and the first shell end is 0.005-0.5 mm, and a gap between the second thrust end and the second shell end is 0.005-0.5 mm.

Optionally, the shape of any one of the first spiral grooves is double-arc, logarithmic spiral, oblique straight line or parabolic, and the shape of any one of the second spiral grooves is double-arc, logarithmic spiral, oblique straight line or parabolic.

The embodiment of the utility model also provides a rotary blood pump which comprises the hydrodynamic bearing.

According to the hydrodynamic bearing and the rotary blood pump provided by the embodiment of the utility model, the first shell and the second shell provide a certain axial net bearing force for the thrust plate, the first spiral groove and the second spiral groove of the hydrodynamic bearing are asymmetrically arranged, when the rotating speed of the thrust plate is changed, the two axial sides of the thrust plate are subjected to thrust forces with different magnitudes, the thrust plate can move along the axial direction of the hydrodynamic bearing, the axial clearance between the thrust plate and the first shell or the second shell is changed, and finally the stress balance position under the corresponding rotating speed is stabilized, so that the thrust plate can be stably suspended at different axial positions under different rotating speed working conditions through the arrangement of the first spiral groove and the second spiral groove, and further, the liquid in the hydrodynamic bearing can be extruded through changing the rotating speed of the thrust plate, so that part of the liquid is prevented from being retained in the hydrodynamic bearing for a long time, and when the rotary blood pump is applied, the blood compatibility at the gap of the hydrodynamic bearing can be improved, and thrombus can be prevented.

Drawings

Fig. 1 is a schematic structural view of a hydrodynamic bearing according to an embodiment of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1 after rotation;

FIG. 3 is an enlarged view of portion B of FIG. 1 after rotation;

the reference numerals in the specification are as follows:

1. a first housing; 11. a first shell end; 12. a first helical groove;

2. a thrust plate; 21. a first thrust end; 22. a second thrust end;

3. a second housing; 31. a second shell end; 32. a second helical groove.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

As shown in fig. 1 to 3, a hydrodynamic bearing provided by an embodiment of the present invention includes a first housing 1, a thrust disk 2, and a second housing 3, where the first housing 1 is fixedly connected to the second housing 3, and the thrust disk 2 is disposed between the first housing 1 and the second housing 3 and can rotate relative to the first housing 1 and the second housing 3;

the shaft end of the first shell 1 facing the thrust disc 2 is a first shell end 11, the shaft end of the thrust disc 2 facing the first shell end 11 is a first thrust end 21, the shaft end of the second shell 3 facing the thrust disc 2 is a second shell end 31, and the shaft end of the thrust disc 2 facing the second shell end 31 is a second thrust end 22; one of the first shell end 11 and the first thrust end 21 is provided with a first spiral groove 12, in fig. 1, the first spiral groove 12 is arranged at the first shell end 11, and the first thrust end 21 is set to be a smooth axial plane; one of the second shell end 31 and the second thrust end 22 is provided with a second spiral groove 32, in fig. 1, the second spiral groove 32 is arranged at the second shell end 31, and the second thrust end 22 is arranged as a smooth axial plane; for convenience of description, the first spiral groove 12 and the second spiral groove 32 are collectively referred to as a spiral groove in the present application;

the first helical grooves 12 are asymmetric with the second helical grooves 32 (meaning that the groove structure formed by all the first helical grooves 12 is asymmetric with the groove structure formed by all the second helical grooves 32), so that the axial position at which the thrust disk 2 floats when the rotation speed of the thrust disk 2 changes correspondingly.

When the thrust disc 2 is used, the thrust disc rotates clockwise relative to one of the first shell 1 and the second shell 3 and rotates counterclockwise relative to the other, so that liquid is driven to flow along the first spiral groove 12 and the second spiral groove 32 by means of relative movement of the solid surface, specifically, a scheme that the liquid flows from the periphery to the center of the hydrodynamic bearing is a pump-in bearing, or a scheme that the liquid flows from the center to the periphery of the hydrodynamic bearing is a pump-out bearing, the rotation direction of the thrust disc can be determined according to actual needs, and the rotation direction of the spiral grooves can be changed correspondingly. Since the ends of the first spiral groove 12 and the second spiral groove 32 are not conducted, the gap between the friction surfaces (i.e. between the first thrust end 21 and the first shell end 11, and between the second thrust end 22 and the second shell end 31) at the non-grooved position is small, and the liquid is blocked at the ends of the spiral grooves, so that pressure distribution is established to bear load. In addition, when the thrust disk 2 rotates to drive the liquid to flow from the groove to the non-groove, dynamic pressure is also generated.

In the hydrodynamic bearing provided by the embodiment of the utility model, the first housing 1 and the second housing 3 provide a certain axial net bearing force to the thrust disc 2, the first spiral groove 12 and the second spiral groove 32 of the hydrodynamic bearing are asymmetrically arranged, when the rotating speed of the thrust disc 2 is changed, the two axial sides of the thrust disc 2 are subjected to thrust forces with different magnitudes, the thrust disc 2 can move along the axial direction of the hydrodynamic bearing, the axial clearance between the thrust disc 2 and the first housing 1 or the second housing 3 is changed, and finally the thrust balance position at the corresponding rotating speed is stabilized, so that the thrust disc 2 can be stably suspended at different axial positions under different rotating speed working conditions through the arrangement of the asymmetric first spiral groove 12 and the second spiral groove 32, further, the liquid in the hydrodynamic bearing can be extruded through changing the rotating speed of the thrust disc 2, and a part of the liquid is prevented from being retained in the hydrodynamic bearing for a long time, when being applied to the rotary blood pump, the utility model can improve the blood compatibility in the gap of the hydrodynamic bearing and prevent the thrombus.

In an embodiment, one of the first spiral groove 12 and the second spiral groove 32 is an equal-groove-depth spiral groove (the first spiral groove 12 shown in fig. 2 is an equal-groove-depth spiral groove), and the other is a variable-groove-depth spiral groove (the second spiral groove 32 shown in fig. 3 is a variable-groove-depth spiral groove), and the groove depth gradually decreases or increases from outside to inside, so that the structure is simple, in addition to that the liquid is blocked at the end of the spiral groove to establish pressure distribution, the pressure distribution is established through a wedge-shaped gap formed between the first shell 1 or the second shell 3 and the thrust plate 2 at the variable-groove-depth spiral groove, and the bearing capacity of the hydrodynamic bearing is greatly improved by conveying the fluid to the wedge-shaped gap at the spiral groove of the hydrodynamic bearing through relative rotation;

the first spiral groove 12 and the second spiral groove 32 can be arranged in opposite positions, other parameters (such as groove width, groove length ratio, groove shape, spiral angle and groove number) are correspondingly the same, and only one spiral groove is arranged to be a variable-groove-depth spiral groove, so that the groove depth of one spiral groove is finely adjusted on the basis of the conventional hydrodynamic bearing, the first spiral groove 12 and the second spiral groove 32 are asymmetrically arranged, the structure is further simplified, and the improvement cost is low. Of course, the groove depths of the first spiral groove 12 and the second spiral groove 32 may be both different or both different.

In one embodiment, as shown in fig. 2 and 3, the groove depth 1a of the first spiral groove 12 is 0.005-0.5 mm, and the groove depth 3a of the second spiral groove 32 is 0.005-0.5 mm, so that when the thrust disk 2 rotates, the first housing 1 and the second housing 3 can provide a proper thrust to the thrust disk 2 through the liquid, and the influence of the spiral grooves on the service life of the corresponding structure (the first housing 1, the thrust disk 2 or the second housing 3) on the hydrodynamic bearing is avoided.

In one embodiment, one of the first spiral groove 12 and the second spiral groove 32 is an equal-groove-width spiral groove, and the other is a variable-groove-width spiral groove, and the groove width gradually decreases or increases from outside to inside, so that the structure is simple; the first spiral groove 12 and the second spiral groove 32 can be arranged in opposite positions, other parameters (such as groove depth, groove length ratio, groove shape, spiral angle and groove number) are correspondingly the same, and only one spiral groove is arranged to be a variable-groove-width spiral groove, so that the groove width of one spiral groove is finely adjusted on the basis of the conventional hydrodynamic bearing, the first spiral groove 12 and the second spiral groove 32 are asymmetrically arranged, the structure is further simplified, and the improvement cost is low. Of course, the groove widths of the first spiral groove 12 and the second spiral groove 32 may be both different or both different.

In one embodiment, as shown in fig. 1, the groove width 1b of the first spiral groove 12 is 0.2-5 mm, and the groove width 3b of the second spiral groove 32 is 0.2-5 mm, so that when the thrust disk 2 rotates, the first housing 1 and the second housing 3 can provide a proper thrust to the thrust disk 2 through the liquid, and the influence of the spiral grooves on the service life of the corresponding structure (the first housing 1, the thrust disk 2, or the second housing 3) on the hydrodynamic bearing is avoided.

In one embodiment, the number of the first spiral grooves 12 is 4 to 36, and the number of the second spiral grooves 32 is 4 to 36, so that when the thrust disk 2 rotates, the first housing 1 and the second housing 3 can provide a proper thrust to the thrust disk 2 through the liquid. Other parameters (such as groove width, groove depth, groove length ratio, groove shape and spiral angle) of the first spiral groove 12 and the second spiral groove 32 can be set to be correspondingly the same, and the number of the two spiral grooves is different, so that the number of the spiral grooves is finely adjusted on the basis of the existing hydrodynamic bearing, and the asymmetric arrangement of the first spiral groove 12 and the second spiral groove 32 is realized.

In an embodiment, the ratio of the groove lengths of the first spiral groove 12 is 0 to 1, and the ratio of the groove lengths of the second spiral groove 32 is 0 to 1, which is specifically selected according to actual needs, so that when the thrust disk 2 rotates, the first housing 1 and the second housing 3 can provide a proper thrust to the thrust disk 2 through the liquid. The groove length ratio of the first helical groove 12 and the groove length ratio of the second helical groove 32 may be equal or unequal.

Preferably, as shown in fig. 1, the end surfaces of the first shell end 11, the first thrust end 21, the second thrust end 22 and the second shell end 31 are circular surfaces, the outer ends of the first spiral grooves 12 are located on a first outer circle, the inner ends of all the first spiral grooves 12 are located on a first inner circle, the first outer circle and the second inner circle are overlapped with the central point of the circular surface of the structure where the first spiral grooves 12 are located, the radius of the first outer circle is 1e, the radius of the first inner circle is 1d, the inner diameter of the first shell end 11 is 1r, and the ratio of the groove length of the first spiral grooves 12 is (1e-1 d)/1 r; the outer ends of the second spiral grooves 32 are located on a second outer circle, the inner ends of all the second spiral grooves 32 are located on a second inner circle, the second outer circle and the second inner circle are overlapped with the central point of the circular surface of the structure where the second spiral grooves 32 are located, the radius of the second outer circle is 3e, the radius of the second inner circle is 3d, the inner diameter of the second shell end 31 is 3r, and the groove length ratio of the second spiral grooves 32 is (3e-3d)/3 r.

In one embodiment, as shown in FIG. 1, the first spiral groove 12 has a spiral angle 1c ranging from 0 to 85 °; the spiral angle 3c of the second spiral groove 32 is in the range of 0-85 degrees, and is specifically selected according to actual needs, so that when the thrust disc 2 rotates, the first shell 1 and the second shell 3 can provide proper thrust to the thrust disc 2 through liquid. The helix angle of the first helical flute 12 and the helix angle of the second helical flute 32 may be equal or unequal. The helix angle 1c of the first helical groove 12 is the angle between the direction of extension of the outer end of the inner curved side of the first helical groove 12 and the radial line of the outer end of the inner curved side of the first helical groove 12 at the first shell end 11.

In one embodiment, as shown in fig. 2 and 3, the gap 1f between the first thrust end 21 and the first shell end 11 is 0.005-0.5 mm, and the gap 3f between the second thrust end 22 and the second shell end 31 is 0.005-0.5 mm, so that when the thrust disk 2 rotates, the first shell 1 and the second shell 3 can provide a proper thrust force to the thrust disk 2 through the liquid.

In an embodiment, any one of the first spiral grooves 12 is shaped as a double-arc, a logarithmic spiral, a diagonal straight line or a parabola, and any one of the second spiral grooves 32 is shaped as a double-arc, a logarithmic spiral, a diagonal straight line or a parabola, which all can enable the first shell 1 and the second shell 3 to indirectly provide axial thrust to the thrust plate 2 through liquid flowing along the spiral grooves when the thrust plate 2 rotates. Other parameters (such as groove width, groove depth and groove length ratio) of the first spiral groove 12 and the second spiral groove 32 can be set to be correspondingly the same, and the groove shape of part of at least one spiral groove is different from that of another spiral groove, so that the groove shape of part of the spiral grooves is finely adjusted on the basis of the existing hydrodynamic bearing, and the asymmetric arrangement of the first spiral groove 12 and the second spiral groove 32 is realized.

Specifically, the first helical groove 12 and the second helical groove 32 may be set to have different parameters (e.g., groove width, groove depth, groove length ratio, groove shape) to increase the dynamic pressure.

The embodiment of the utility model also provides a rotary blood pump which comprises the hydrodynamic bearing mentioned in any one of the embodiments.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A kind of hydrodynamic bearing, including the first body, thrust disc and second body, said first body and said second body are fixedly connected, the said thrust disc locates between said first body and said second body, and can rotate relative to said first body and said second body;

the shaft end of the first shell facing the thrust disc is a first shell end, the shaft end of the thrust disc facing the first shell end is a first thrust end, the shaft end of the second shell facing the thrust disc is a second shell end, the shaft end of the thrust disc facing the second shell end is a second thrust end, one of the first shell end and the first thrust end is provided with a first spiral groove, and one of the second shell end and the second thrust end is provided with a second spiral groove;

it is characterized in that the preparation method is characterized in that,

the first spiral groove and the second spiral groove are asymmetric, so that the suspension axial position of the thrust disk correspondingly changes when the rotation speed of the thrust disk changes.

2. The hydrodynamic bearing of claim 1, wherein one of the first spiral groove and the second spiral groove is an equal groove depth spiral groove, and the other is a variable groove depth spiral groove, and the groove depth gradually decreases or increases from outside to inside.

3. The hydrodynamic bearing as claimed in claim 1, wherein the first spiral groove has a groove depth of 0.005 to 0.5mm, and the second spiral groove has a groove depth of 0.005 to 0.5 mm.

4. The hydrodynamic bearing of claim 1, wherein one of the first spiral groove and the second spiral groove is a constant groove width spiral groove, the other is a variable groove width spiral groove, and the groove width gradually decreases or increases from the outside to the inside.

5. The hydrodynamic bearing as claimed in claim 1, wherein the first helical groove has a groove width of 0.2 to 5mm, and the second helical groove has a groove width of 0.2 to 5 mm.

6. The hydrodynamic bearing as claimed in claim 1, wherein the number of the first helical grooves is 4 to 36, and the number of the second helical grooves is 4 to 36.

7. The hydrodynamic bearing of claim 1, wherein the first helical groove has a groove length ratio of 0 to 1 and a helix angle in the range of 0 to 85 °; the groove length ratio of the second spiral groove is 0-1, and the spiral angle range is 0-85 degrees.

8. The hydrodynamic bearing of claim 1, wherein a gap between the first thrust end and the first shell end is 0.005 to 0.5mm, and a gap between the second thrust end and the second shell end is 0.005 to 0.5 mm.

9. The hydrodynamic bearing of claim 1, wherein the shape of any of the first helical grooves is double-circular-arc, logarithmic-spiral, oblique-straight-line, or parabolic, and the shape of any of the second helical grooves is double-circular-arc, logarithmic-spiral, oblique-straight-line, or parabolic.

10. A rotary blood pump comprising a hydrodynamic bearing as claimed in any one of claims 1 to 9.

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