JP2022145151A - Pump, pump design method, and pump manufacturing method - Google Patents

Abstract

To attain an effect for reducing a friction loss over a long time.SOLUTION: A pump includes: an impeller 12 rotatably provided; and a pump case having an inflow part in which the impeller 12 is housed and where a liquid flows into the pump case toward the impeller 12 side, and an outflow part from which the liquid that has passed through the impeller 12 flows. At a portion, which faces the pump case in a rotation axis direction, of the impeller 12, a groove 32 is formed along a rotation diameter direction.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to pumps, methods of designing pumps, and methods of manufacturing pumps.

Patent Literature 1 listed below discloses a pump in which a film is formed on the main plate of the impeller to reduce friction loss during rotation of the impeller. In the configuration described in this document, a water-repellent film having a contact angle with water of 120° or more is formed on the main plate of the impeller to reduce friction loss during rotation of the impeller.

JP-A-9-195983

However, in the configuration described in Patent Document 1, it is conceivable that the water-repellent coating may be detached from the main plate of the impeller due to deterioration of the water-repellent coating. As a result, it is conceivable that the effect of reducing friction loss during rotation of the impeller cannot be obtained over a long period of time.

In view of the above facts, an object of the present disclosure is to obtain a pump, a method for designing a pump, and a method for manufacturing a pump that can obtain the effect of reducing friction loss over a long period of time.

A pump (10) for solving the above problems comprises a rotatably provided impeller (12) and an inflow part (40) in which the impeller is accommodated and liquid flows in toward the impeller. a pump case (16) having an outflow portion (54) from which the liquid that has passed through the impeller flows out; and grooves (32, 36) formed in at least one of the portions facing each other in the direction and formed along the radial direction of rotation.

By configuring in this way, the effect of reducing friction loss can be obtained over a long period of time.

It is a sectional side view which shows typically the pump of this embodiment. It is a side view which shows an impeller. It is the bottom view which looked at the impeller from the axial direction other side. It is the top view which looked at the impeller from one axial direction side. 4 is an enlarged cross-sectional view showing an enlarged cross-section of the first disk portion cut along line 5-5 shown in FIG. 3; FIG. FIG. 6 is a cross-sectional view corresponding to FIG. 5 and schematically showing the flow of liquid around the groove; FIG. 10 illustrates liquid flow around a groove simulated by computational fluid dynamics; It is a graph which shows the relationship between the inclination-angle of a 1st inclined surface and a 2nd inclined surface, and pump efficiency ratio. FIG. 6 is a cross-sectional view corresponding to FIG. 5 showing another form of groove; FIG. 6 is a cross-sectional view corresponding to FIG. 5 showing another form of groove;

A pump 10 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 8. FIG. The arrow Z direction, arrow R direction, and arrow C direction appropriately shown in the drawings indicate one side in the rotation axis direction, the outside in the rotation radial direction, and the one side in the rotation circumferential direction of the impeller 12, which will be described later. Further, hereinafter, when simply indicating an axial direction, a radial direction, and a circumferential direction, unless otherwise specified, it indicates a rotating shaft direction, a rotating radial direction, and a rotating circumferential direction of the impeller 12 .

As shown in FIG. 1, the pump 10 of this embodiment is used as a vehicle water pump as an example. The pump 10 includes a motor section 14 whose rotation is controlled by a control section (not shown), an impeller 12 rotated by the motor section 14, and a pump case 16 in which the impeller 12 is arranged. there is

The motor unit 14 includes a stator 18 that generates a rotating magnetic field when energization is controlled by a control unit (not shown), and a rotor 20 that rotates when the stator 18 generates the rotating magnetic field. An impeller 12 , which will be described later, is fixed to one axial end of the rotating shaft 22 of the rotor 20 .

As shown in FIG. 2 , the impeller 12 includes a first disk portion 24 as a disk portion having a thickness direction in the axial direction, and a first disk portion 24 with a thickness direction extending in the axial direction. A second disk portion 26 as a disk portion arranged on one side and formed in a disk shape is provided. The impeller 12 is arranged between the first disc portion 24 and the second disc portion 26 and has a plurality of blades that axially connect the first disc portion 24 and the second disc portion 26 . 28. Note that the impeller 12 of this embodiment rotates on one side in the rotational circumferential direction.

As shown in FIGS. 2 and 3, the surface 30 on the other side in the axial direction of the first disc portion 24 is formed in a planar shape substantially parallel to the radial direction and the circumferential direction. In addition, a plurality of grooves 32 that are open on the other axial side are formed along the radial direction on the side of the surface 30 on the other axial side of the first disc portion 24 . In this embodiment, 16 grooves 32 are formed on the side of the surface 30 on the other side in the axial direction of the first disc portion 24 . In addition, the plurality of grooves 32 are radially arranged when viewed from the other side in the axial direction and are arranged at regular intervals along the circumferential direction.

As shown in FIGS. 2 and 4, the surface 34 on one side in the axial direction of the second disk portion 26 is inclined toward the other side in the axial direction toward the radially outer side and is planar along the circumferential direction. is formed in A plurality of grooves 36 that are open on one axial side are formed along the radial direction on the side of the surface 34 on the one axial side of the second disc portion 26 . In this embodiment, 16 grooves 36 are formed on the surface 34 side of the second disk portion 26 on one side in the axial direction. In addition, the plurality of grooves 36 are radially arranged when viewed from one side in the axial direction and are arranged at regular intervals along the circumferential direction. The basic configuration of the groove 36 formed on the surface 34 on one axial side of the second disk portion 26 is similar to the groove formed on the surface 30 on the other axial side of the first disk portion 24. 32 has almost the same configuration. Therefore, in the following description, the groove 32 formed on the surface 30 on the other axial side of the first disc portion 24 will be described, and the groove 32 formed on the surface 34 on the one axial side of the second disc portion 26 will be described. A description of the grooves 36 that are formed is omitted. A flange portion 38 that is bent toward one side in the axial direction is formed at the radially inner end portion of the second disk portion 26 .

As shown in FIG. 1 , the pump case 16 includes a tubular inflow portion 40 arranged axially facing the impeller 12 on one axial side of the impeller 12 . Liquid flows into the pump case 16 from the inflow portion 40 . The pump case 16 also includes a second facing portion 42 extending radially outward from the other axial end of the inflow portion 40 . A surface 44 of the second opposing portion 42 on the impeller 12 side is substantially parallel to a surface 34 of the second disk portion 26 of the impeller 12 on the one side in the axial direction. Further, the pump case 16 has a first facing portion 46 extending radially on the other side in the axial direction with respect to the second facing portion 42 . A surface 48 of the first facing portion 46 on the impeller 12 side is substantially parallel to the surface 30 of the first disk portion 24 of the impeller 12 on the other side in the axial direction. The pump case 16 is arranged radially outwardly of the impeller 12 and is an outer annular portion connecting the radially outer end of the first facing portion 46 and the radially outer end of the second facing portion 42 . It has 50. A space inside the outer annular portion 50 forms a spiral chamber 52 in which the flow path gradually increases toward one side in the circumferential direction. The pump case 16 also includes an outflow portion 54 that is connected to the outer annular portion 50 and formed in a cylindrical shape. The liquid that has flowed into the pump case 16 from the inflow portion 40 passes through the impeller 12 and the spiral chamber 52 and flows out from the outflow portion 54 .

Next, the configuration of the grooves 32 and 36, which is the configuration of the main part of this embodiment, will be described.

FIG. 5 shows a cross section obtained by cutting the portion of the first disk portion 24 of the impeller 12 in which the grooves 32 are formed along the circumferential direction and the axial direction. The shape of the bottom surface of the groove 32 in this cross-sectional view is a V-shape that is most recessed at the center position in the circumferential direction, which is the width direction of the groove 32 . Here, a portion of the bottom surface of the groove 32 on one side in the circumferential direction with respect to the center position of the groove 32 in the circumferential direction is referred to as a first inclined surface 32A. A portion of the bottom surface of the groove 32 on the other side in the circumferential direction with respect to the center position of the groove 32 in the circumferential direction is referred to as a second inclined surface 32B.

32 A of 1st inclined surfaces are formed in planar shape which inclines to the axial direction other side as it goes to the circumferential direction one side. Accordingly, the depth dimension d of the groove 32 at the portion corresponding to the first inclined surface 32A gradually decreases from the center position of the groove 32 in the circumferential direction toward one side in the circumferential direction. Further, the depth dimension d is 0 at one end 32C of the groove 32 in the circumferential direction.

The second inclined surface 32B is formed in a planar shape that is inclined toward the other side in the axial direction toward the other side in the circumferential direction. As a result, the depth dimension d of the groove 32 at the portion corresponding to the second inclined surface 32B gradually decreases from the center position of the groove 32 in the circumferential direction toward the other side in the circumferential direction. Further, the depth dimension d is 0 at the end 32D of the groove 32 on the other side in the circumferential direction.

As shown in FIG. 6, in this embodiment, the grooves 32 are shaped and dimensioned so that a vortex Y around the radial direction of rotation is generated inside the grooves 32 when the impeller 12 rotates at a constant speed. is set. Specifically, the width dimension W, depth dimension d, and length dimension L (see FIG. 3) of the groove 32, and the first circles of the first inclined surface 32A and the second inclined surface 32B are arranged so that the vortex Y is generated. An inclination angle θ and the like with respect to the surface 30 on the other side in the axial direction of the plate portion 24 are set. When the impeller 12 rotates at a constant speed, a vortex Y is generated inside the groove 32 in the radial direction of rotation, so that the surface 30 on the other side in the axial direction of the first disc portion 24 and the pump case The velocity gradient of the flow velocity of the liquid between the impeller 12 side surface 48 and the first facing portion 46 of 16 can be moderated. In FIG. 6, the direction and length of the arrow V indicate the direction and flow velocity of the liquid at each position in the axial direction.

Whether or not the vortex Y is generated and how much the pump efficiency can be improved by generating this vortex Y are determined by a computer capable of simulating the flow of liquid in the pump case 16 by computational fluid dynamics. is parsed using FIG. 7 shows the results of this analysis under one condition. In FIG. 7, the direction and flow velocity of the liquid at each position between the surface 30 of the first disk portion 24 on the other axial side and the surface 48 of the first facing portion 46 of the pump case 16 on the impeller 12 side. is indicated by the direction and length of arrow V.

Here, in the process of performing the above analysis, the inventors found that the inclination angle θ of the first inclined surface 32A and the second inclined surface 32B with respect to the surface 30 on the other side in the axial direction of the first disk portion 24 is large for the pump efficiency. found to affect.

The graph of FIG. 8 shows the relationship between the inclination angle θ of the first inclined surface 32A and the second inclined surface 32B and the pump efficiency ratio P. As shown in FIG. Here, the pump efficiency ratio P is defined as the pump efficiency of the pump 10 of the present embodiment, where η1 is the pump efficiency. It is a value calculated by (η1/η2), where η2 is the pump efficiency of the pump according to the example. The fact that this pump efficiency ratio exceeds 1 means that the pump efficiency η1 of the pump 10 of this embodiment exceeds the pump efficiency η2 of the pump according to the comparative example. Then, as shown in FIG. 8, the inventors set the inclination angle θ of the first inclined surface 32A and the second inclined surface 32B to an angle between 10° and 50°, thereby improving the pump efficiency of the pump 10. It was found that η1 can be greatly improved with respect to the pump efficiency η2 of the pump according to the comparative example. Then, in the step of forming the impeller 12 , which is one step of the manufacturing process of the pump, the grooves 32 and 36 set as described above are formed in the first disk portion 24 and the second disk portion 24 of the impeller 12 .

(Action and effect of this embodiment)
Next, the operation and effects of this embodiment will be described.

As shown in FIGS. 1, 3, 4, and 5, in the pump 10 of the present embodiment described above, the impeller 12 is provided with the grooves 32 and 36 so that the first disk portion 24 is moved in the other axial direction. The velocity gradient of the flow velocity of the liquid between the side surface 30 and the impeller 12 side surface 48 of the first facing portion 46 of the pump case 16 can be moderated, The velocity gradient of the liquid flow velocity between the side surface 34 and the impeller 12 side surface 44 of the second facing portion 42 of the pump case 16 can be made gentle. As a result, the friction loss between the impeller 12 and the fluid can be reduced compared to the case where the grooves 32 and 36 are not provided, and the pump efficiency η1 of the pump 10 can be improved compared to the case where the grooves 32 and 36 are not provided. can be done. In addition, in the pump 10 of the present embodiment, the effect of reducing the friction loss can be obtained over a long period of time due to the simple configuration in which the grooves 32 and 36 are provided.

Further, in this embodiment, by setting the inclination angle θ of the first inclined surface 32A and the second inclined surface 32B to an angle between 10° and 50°, the pump efficiency η1 of the pump 10 can be greatly improved. can.

In the pump 10 of the present embodiment, an example in which the grooves 32 and 36 are formed in both the first disc portion 24 and the second disc portion 26 of the impeller 12 has been described, but the present invention is not limited to this. For example, the grooves 32 may be formed only in the first disk portion 24 of the impeller 12 or the grooves 36 may be formed only in the second disk portion 26 of the impeller 12 . Also, the number and arrangement of the grooves 32 and 36 may be appropriately set in consideration of the efficiency η1 of the pump 10, the noise level of the pump 10 during rotation of the impeller 12, and the like.

Also, in the pump 10 of the present embodiment, an example in which the inclination angles θ of the first inclined surface 32A and the second inclined surface 32B of the groove 32 are set to the same angle has been described, but the present invention is not limited to this. For example, the inclination angle θ of the first inclined surface 32A and the inclination angle θ of the second inclined surface 32B may be set to different angles. Alternatively, as shown in FIG. 9, the groove 32 may be configured such that only the surface corresponding to the second inclined surface 32B is the bottom surface. In this manner, the depth d of the groove 32 gradually decreases toward the side opposite to the rotational direction of the impeller 12, whereby the efficiency η1 of the pump 10 can be significantly improved. Furthermore, as shown in FIG. 10, the bottom surface of the groove 32 may be curved.

Further, grooves similar to the grooves 32 formed in the first disk portion 24 of the impeller 12 are formed on the surface 48 side of the impeller 12 side of the first facing portion 46 of the pump case 16, and the second circular portion of the impeller 12 is formed. A groove similar to the groove 36 formed in the plate portion 26 may be formed on the impeller 12 side surface 44 side of the second facing portion 42 of the pump case 16 . With this configuration as well, the efficiency η1 of the pump 10 can be improved. Also, a configuration in which grooves are provided in both the impeller 12 and the pump case 16 may be adopted.

An embodiment of the present disclosure has been described above, but the present disclosure is not limited to the above, and can be implemented in various modifications other than the above without departing from the scope of the present disclosure. is of course.

10 pump, 12 impeller, 16 pump case, 24 first disc portion (disc portion), 26 second disc portion (disc portion), 28 blades, 32 groove, 32B second inclined surface (inclined surface), 36 groove, 40 inlet, 54 outlet, d depth of groove

Claims (7)

a rotatably mounted impeller (12);
A pump case (16) in which the impeller is accommodated and which has an inflow portion (40) into which liquid flows toward the impeller side and an outflow portion (54) into which the liquid that has passed through the impeller flows out. )When,
Grooves (32, 36) formed in at least one of a portion of the impeller facing the pump case in the direction of the rotation axis and a portion of the pump case facing the impeller in the direction of the rotation axis, and formed along the radial direction of rotation. )When,
A pump (10) comprising: A plurality of grooves are formed in at least one of a portion of the impeller facing the pump case in the direction of the rotation axis and a portion of the pump case facing the impeller in the direction of the rotation axis,
2. The pump of claim 1, wherein a plurality of said grooves are spaced apart in the circumferential direction of rotation. The impeller includes disc portions (24, 26) formed in a disc shape, and a plurality of blades (28) integrally provided with the disc portion and arranged at intervals in the circumferential direction of rotation. , consisting of
3. The pump according to claim 1, wherein the groove is formed on a side of the disk portion opposite to the side on which the plurality of blades are provided. 4. A pump according to claim 3, wherein the depth (d) of said grooves becomes shallower toward the side opposite to the direction of rotation of said impeller. In a cross-sectional view cut along the rotation circumferential direction and the rotation axis direction, the groove is an inclined surface (32B) that is inclined toward the opening direction side of the groove toward the side opposite to the rotation direction of the impeller. has
5. The pump according to claim 4, wherein the angle formed by said inclined surface and the rotation circumferential direction is set to an angle between 10° and 50°. A pump design method according to any one of claims 1 to 5,
Using a computer capable of simulating the flow of liquid in the pump case by computational fluid dynamics,
A method of designing a pump in which the shape and dimensions of the groove are set so that a vortex around the radial direction of rotation is generated inside the groove while the impeller is rotating. A method for manufacturing a pump according to any one of claims 1 to 5,
Using a computer capable of simulating the flow of liquid in the pump case by means of numerical fluid dynamics, the groove is adjusted so that a vortex is generated inside the groove in the radial direction of rotation while the impeller is rotating. and forming said grooves of this setting in said impeller.

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