JP2019143514A - Electric pump - Google Patents

Abstract

To inhibit foreign objects contained in water from entering into a slide surface between an impeller and a support shaft.SOLUTION: A part of water flowing in a flow passage 15 flows through a branch passage 45 to a slide surface between a radial bearing 56 of an impeller 50 and a support shaft 25. A part of the water flowing in the branch passage 45 flows on the slide surface between the radial bearing 56 of the impeller 50 and the support shaft 25 to lubricate the slide surface and then returns to the flow passage 15 through a circulation passage 55. Meanwhile, the rest of the water flows through a communication hole 27 and an opening hole 26 formed at the support shaft 25 and returns to the flow passage 15 through the circulation passage 55.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an electric pump.

  Conventionally, an electric pump including an impeller that sucks and discharges water by a rotating operation, a support shaft (rotation support bar) that rotatably supports the impeller, and a motor that rotates the impeller is known (for example, , See Patent Document 1).

  Here, in the electric pump of Patent Document 1, a gap is provided between the second housing recess of the second case portion and the rotor, and a part of the water flowing through the housing space passes through this gap to support shaft. And flows on the sliding surface of the impeller radial bearing. As a result, the sliding surfaces of the support shaft and the impeller radial bearing are lubricated with water.

JP 2017-166407 A

  However, since the gap between the support shaft and the radial bearing of the impeller is very small, if foreign matter is mixed in the water, the foreign matter is clogged in the gap and the impeller may not be able to rotate smoothly.

  The present invention has been made in view of such a point, and an object thereof is to prevent foreign matters contained in a fluid from entering a sliding surface between an impeller and a support shaft.

  The present invention includes a casing provided with a fluid flow passage, an impeller having a plurality of blades and disposed in the flow passage, a support shaft that rotatably supports the impeller, and a periphery of the support shaft. The following solution was taken for an electric pump provided with a motor for rotating the impeller.

That is, the first invention is a branch passage that branches a part of the fluid flowing through the flow passage so as to flow on a sliding surface between the impeller and the support shaft,
A circulation path for returning the fluid that has flowed through the sliding surface between the impeller and the support shaft to the flow path;
The support shaft is formed with an opening hole extending in the axial direction and opening toward the circulation path, and a communication hole communicating with the opening hole and the branch path.

  In 1st invention, a part of fluid which flows through a flow path flows through the branch path toward the sliding surface of an impeller and a support shaft. A part of the fluid flowing through the branch path flows through the sliding surface between the impeller and the support shaft and lubricates, and then returns to the flow path through the circulation path. On the other hand, the remaining fluid flows through the communication hole and the opening hole formed in the support shaft, and returns to the flow path through the circulation path.

  As described above, by forming the opening hole and the communication hole in the support shaft, another path is provided so that a part of the fluid flowing through the branch path can bypass the sliding surface between the impeller and the support shaft. Yes.

  As a result, even if the fluid contains foreign matter, the fluid containing the foreign matter flows not through the sliding surface between the impeller and the support shaft, but through the communication hole and the opening hole of the support shaft. It is possible to suppress clogging of foreign matter in the gap.

According to a second invention, in the first invention,
The impeller is provided with a bearing that is slidably fitted to the support shaft,
At the end of the bearing on the branch path side, a circumferential groove in which the peripheral edge of the shaft hole of the bearing is depressed over the entire circumference is formed,
The communication hole of the support shaft communicates with the branch passage through the entire circumferential groove.

  In the second invention, by forming a circumferential groove on the impeller bearing, the branch path and the communication hole of the support shaft always communicate with each other through the circumferential groove regardless of the rotation angle of the impeller. It will be in the state. That is, the communication hole is not blocked by the impeller, and the fluid that has entered the circumferential groove from the branch path can smoothly flow into the communication hole of the support shaft.

  According to the present invention, it is possible to prevent foreign matter contained in the fluid from entering the sliding surface between the impeller and the support shaft.

It is a top view which shows the structure of the electric pump which concerns on this embodiment. It is side surface sectional drawing which shows the structure of an electric pump. It is a top view which shows the structure of an impeller. It is a top view which shows the structure of a thrust bearing. It is side surface sectional drawing which shows the flow of the water inside an electric pump.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

  As shown in FIGS. 1 and 2, the electric pump 10 is for supplying water to various regions (for example, a radiator, a heater core, an oil cooler, etc.) of the vehicle, and has a substantially T shape in a side view. A resin casing 11 is provided.

  The casing 11 is configured to have an accommodation space inside by combining the first case portion 12 having a substantially circular panel shape and the second case portion 20 having a substantially rectangular plate shape.

  The first case portion 12 is formed with a first housing recess 12a that opens to the back surface side (the lower surface side in FIG. 2). A cylindrical inflow pipe portion 13 that communicates with the central portion of the first housing recess 12 a is provided on the surface of the first case portion 12 (upper surface in FIG. 2).

  The inflow pipe portion 13 is provided so as to be orthogonal to the surface of the first case portion 12, and allows water to flow into the first housing recess 12a. The first case portion 12 side of the inflow pipe portion 13 has a shape that is gradually expanded toward the first case portion 12.

  In addition, a cylindrical outflow pipe portion 14 that communicates with a side portion of the first housing recess 12 a is provided on the surface of the first case portion 12. The outflow pipe portion 14 is provided along the surface of the first case portion 12 and allows the water in the first accommodation recess 12a to flow out.

  Thus, the flow path 15 through which water flows from the inflow pipe portion 13 toward the outflow pipe portion 14 is formed in the casing 11.

  The second case portion 20 is provided on the back side of the first case portion 12. A half of one end side in the longitudinal direction of the second case portion 20 covers the entire back side of the first case portion 12.

  A protruding portion 20a is formed at a position corresponding to the first receiving recess 12a of the second case portion 20 so as to protrude toward the first case portion 12 and close the opening of the first receiving recess 12a at the tip portion. .

  A second receiving recess 20b that opens to the first receiving recess 12a is formed on the extending surface of the extending portion 20a, while an attachment recess 20c is provided on the opposite side of the extending receiving portion 20a from the second receiving recess 20b. Is formed.

  A support shaft 25 is attached to the center of the second case portion 20. The front end portion of the support shaft 25 protrudes from the surface side of the second case portion 20.

  A stator 31 constituting a so-called axial type motor 30 is provided in the mounting recess 20c.

  The stator 31 includes an iron stator core 32. A plurality of teeth portions 33 projecting toward the second case portion 20 are provided on the outer peripheral portion of the stator core 32. A coil 35 is wound around the teeth portion 33.

  Then, in a state where the coil 35 is wound around the tooth portion 33, the central portion of the stator core 32 is fixed to one end of the support shaft 25 by the fastening screw 36, and the gap between the second case portion 20 and the stator 31 is made of resin. The stator 31 is fixed to the second case portion 20 by being filled with a material.

  A resin impeller 50 is accommodated in the casing 11. A predetermined gap is formed between a rotor 40 (described later) provided on the impeller 50 and the second housing recess 20b. Specifically, gaps are formed between the outer peripheral surface of the rotor 40 and the inner peripheral surface of the second housing recess 20b, and between the back surface of the rotor 40 and the bottom surface of the second housing recess 20b. This gap serves as a branch path 45 where a part of the water discharged from the impeller 50 and going to the outflow pipe section 14 branches. The water branched into the branch path 45 flows toward the sliding surface between the impeller 50 and the support shaft 25.

  The impeller 50 is formed by injection molding, and has a boss portion 51 whose tip side is tapered. Inside the boss portion 51, a circulation path 55 is formed through which water flowing on the sliding surface between the impeller 50 and the support shaft 25 passes. A tip hole 51a communicating with the circulation path 55 is formed at the tip of the boss part 51, and the water flowing through the circulation path 55 is returned to the flow passage 15 through the tip hole 51a.

  As shown in FIG. 3, a plurality of blades 52 are provided on the base end side of the outer peripheral surface of the boss portion 51. The plurality of blades 52 are provided at equal intervals around the rotation axis of the boss portion 51. In the example shown in FIG. 3, eight blades 52 are provided, but other numbers may be used.

  An annular plate 53 that extends annularly around the boss portion 51 with a predetermined distance from the boss portion 51 is provided integrally with the blade 52 at the distal end side of the boss portion 51 of the plurality of blades 52.

  The inner peripheral side of the annular plate 53 is gently curved so as to be gradually positioned on the distal end side of the boss portion 51 toward the boss portion 51, and this portion serves as a suction port 53 a for sucking water.

  On the base end side of the boss portion 51, a radial bearing 56 made of carbon subjected to a firing process is provided. The radial bearing 56 is integrally formed when the impeller 50 is injection-molded.

  The radial bearing 56 is rotatably fitted to the distal end portion of the support shaft 25. At the end of the radial bearing 56 on the side of the branch path 45 (the lower end in FIG. 2), a circumferential groove 57 is formed in which the peripheral edge of the shaft hole of the radial bearing 56 is recessed over the entire circumference.

  A base end portion of the radial bearing 56 is supported by a thrust bearing 60. As shown in FIG. 4, the thrust bearing 60 is formed of a ring-shaped plate material, and the support shaft 25 is fitted into the hole in the center.

  Further, three radial grooves 61 extending radially are formed on the sliding surface of the thrust bearing 60 with the radial bearing 56. Here, when the water passes through the radial groove 61 as the impeller 50 rotates, the water is interposed between the base end portion of the radial bearing 56 and the thrust bearing 60, and the impeller 50 is subjected to a floating bearing. The number of the radial grooves 61 is not limited to three, but may be any other number.

  A rotor 40 constituting the motor 30 is attached to the base end side of the boss portion 51 in the impeller 50. The rotor 40 has a ring-shaped iron yoke 41 and a ring-shaped magnet 42. The rotor 40 is configured by superimposing a yoke 41 and a magnet 42 in a state where their axis centers coincide with each other.

  The magnet 42 is made of a plastic magnet material. The magnet 42 is integrally formed with the yoke 41 by insert molding. The magnet 42 is magnetized by performing a magnetizing operation after being integrally formed with the yoke 41. For example, four N-poles and four S-poles are alternately arranged around the central axis of the rotor 40 to form an 8-pole magnetized form on one side. In addition, the structure using the magnet 42 of another pole number may be sufficient.

  The stator 31 rotates the impeller 50 around the support shaft 25 together with the rotor 40 by the magnetic action of the stator core 32, the coil 35, and the magnet 42. Due to the rotating operation of the impeller 50 and the rotor 40, the impeller 50 periodically sucks and discharges water.

  Here, a part of the water discharged from the impeller 50 and directed to the outflow pipe portion 14 flows from the branch passage 45 through the radial groove 61 of the thrust bearing 60 to the sliding surface between the radial bearing 56 and the support shaft 25. . Thereby, the sliding surfaces of the radial bearing 56 and the support shaft 25 of the impeller 50 are lubricated with water. The water after flowing through the sliding surface between the radial bearing 56 and the support shaft 25 is returned from the circulation path 55 to the flow path 15 through the tip hole 51a.

  However, since the gap between the radial bearing 56 of the impeller 50 and the support shaft 25 is very small, if foreign matter is mixed in the water, the foreign matter is clogged in the gap, and the impeller 50 cannot be smoothly rotated. There is a fear.

  Therefore, in this embodiment, a path is provided so that the foreign matter mixed in the water can bypass the sliding surface.

  Specifically, as shown in FIG. 5, the support shaft 25 extends in the radial direction so as to communicate with the opening hole 26 that extends in the axial direction and opens toward the circulation path 55, and the opening hole 26 and the branch path 45. An extending communication hole 27 is formed. The communication hole 27 communicates with the branch path 45 through the entire circumferential groove 57 of the radial bearing 56 and the radial groove 61 of the thrust bearing 60.

  Here, part of the water flowing through the flow passage 15 of the casing 11 flows through the branch path 45 toward the sliding surface between the radial bearing 56 of the impeller 50 and the support shaft 25. A part of the water flowing through the branch passage 45 passes through the radial groove 61 and the circumferential groove 57, flows on the sliding surface between the radial bearing 56 of the impeller 50 and the support shaft 25, and is lubricated. And it returns to the flow path 15 through the tip hole 51a.

  On the other hand, the remaining water flowing through the branch passage 45 passes through the radial groove 61 and the entire circumferential groove 57, flows through the communication hole 27 and the opening hole 26 formed in the support shaft 25, passes through the circulation path 55 and the tip hole 51a. Return to the flow path 15.

  In this way, by forming the opening hole 26 and the communication hole 27 in the support shaft 25, the water flowing through the branch path 45 can be bypassed so as to bypass the sliding surface between the radial bearing 56 of the impeller 50 and the support shaft 25. The route is provided. Here, the passage diameters of the opening hole 26 and the communication hole 27, which are the other paths, are set to be larger than the clearance between the sliding surfaces of the radial bearing 56 of the impeller 50 and the support shaft 25. Therefore, most of the water flowing through the branch passage 45 passes through the opening hole 26 and the communication hole 27 of the support shaft 25.

  As a result, even when foreign matter is contained in the water, the water containing the foreign matter is not the sliding surface between the radial bearing 56 of the impeller 50 and the support shaft 25, but the communication hole 27 and the opening hole 26 of the support shaft 25. By flowing through, it is possible to suppress the clogging of foreign matter in the gap between the sliding surfaces.

  Further, by forming the circumferential groove 57 in the radial bearing 56 of the impeller 50, the branch path 45 and the communication hole 27 of the support shaft 25 are connected to the circumferential groove 57 regardless of the rotation angle of the impeller 50. It will be in the state always communicated through. That is, the communication hole 27 is not blocked by the impeller 50, and water that has entered the circumferential groove 57 from the branch path 45 through the radial groove 61 flows smoothly into the communication hole 27 of the support shaft 25. Can do.

<< Other Embodiments >>
About the said embodiment, it is good also as following structures.

  In the present embodiment, the magnet 42 is made of a plastic magnet material, but is not limited to this form. For example, you may comprise with other magnets, such as a sintered magnet.

  Moreover, in this embodiment, although the magnet 42 is integrally formed with the yoke 41 by insert molding, it is not limited to this form. For example, the magnet 42 may be attached to the yoke 41 by other methods such as adhesion, caulking, and bolt fastening.

  In this embodiment, the yoke 41 and the magnet 42 are integrally formed and then magnetized, and then the magnet 41 is magnetized and then the yoke 41 and magnet 42 are integrated. May be.

  In the present embodiment, the radial bearing 56 is formed of carbon that has been subjected to a firing process. However, the present invention is not limited thereto, and the radial bearing 56 may be formed of other materials such as resin.

  Moreover, although the electric pump 10 of this embodiment is performing suction and discharge of water, it can also perform suction and discharge of other fluids, for example, oil.

  Moreover, although the electric pump 10 of this embodiment is used to supply water to various areas of the vehicle, it can be used not only for automobiles and motorcycles but also for household appliances.

  As described above, the present invention is extremely useful and industrial because it can obtain a highly practical effect that foreign matter contained in the fluid can be prevented from entering the sliding surface between the impeller and the support shaft. The availability of is high.

DESCRIPTION OF SYMBOLS 10 Electric pump 11 Casing 15 Flow path 25 Support shaft 26 Opening hole 27 Communication hole 30 Motor 45 Branching path 50 Impeller 52 Blade 55 Circulation path 56 Radial bearing 57 Whole circumference groove

Claims (2)

A casing provided with a fluid flow passage, an impeller having a plurality of blades and disposed in the flow passage, a support shaft rotatably supporting the impeller, and the impeller rotating around the support shaft An electric pump having a motor to be driven,
A branch path for branching a part of the fluid flowing through the flow path so as to flow on a sliding surface between the impeller and the support shaft;
A circulation path for returning the fluid that has flowed through the sliding surface between the impeller and the support shaft to the flow path;
An electric pump characterized in that an opening hole extending in the axial direction and opening toward the circulation path and a communication hole communicating with the opening hole and the branch path are formed in the support shaft. In claim 1,
The impeller is provided with a bearing that is slidably fitted to the support shaft,
At the end of the bearing on the branch path side, a circumferential groove in which the peripheral edge of the shaft hole of the bearing is depressed over the entire circumference is formed,
The electric pump according to claim 1, wherein the communication hole of the support shaft communicates with the branch passage through the entire circumferential groove.

Images