JP2015155682A - Noncontact bearing pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noncontact bearing pump capable of suppressing occurrence of cogging.

SOLUTION: A noncontact bearing pump 1A comprises: a stationary body 10; an impeller 20 rotating about an axis Af with respect to the stationary body 10; a noncontact bearing 40 rotatably supporting the impeller 20 in a noncontact manner with respect to the stationary body 10; a drive magnet 31 integrally fixed to the impeller 20 about the axis Af; and a coreless coil 32 provided on the stationary body 10 and arranged on an outer circumference of the drive magnet 31 to be radially apart from the outer circumference of the drive magnet 31.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a non-contact bearing pump.

2. Description of the Related Art Conventionally, there is a pump device that transports a fluid, as disclosed in Patent Document 1, for example, including a housing, an impeller provided rotatably with respect to the housing, and a drive unit that rotationally drives the impeller.
In Patent Document 1, a plurality of permanent magnets provided on the impeller and arranged in the circumferential direction of the impeller, a plurality of magnetic bodies provided on the housing and arranged in the circumferential direction of the impeller, and a winding around each magnetic body, respectively. A drive unit comprising a plurality of rotated coils is disclosed.
Patent Document 1 discloses a configuration in which an impeller is rotatably supported by a hydrodynamic bearing in a non-contact manner with respect to a housing. The hydrodynamic bearing is constituted by a hydrodynamic groove formed on the opposing surfaces of the housing and the impeller facing each other.

JP 2012-205349 A

However, in the configuration in which the coil is wound around the magnetic material that is the core as in the conventional case, the magnetic force (magnetic attraction force) generated with the energization of each coil is concentrated on each part of the plurality of magnetic materials. Therefore, a phenomenon called cogging occurs during the rotation of the impeller. When cogging occurs, the impeller vibrates with respect to the housing and may not rotate smoothly. For this reason, the impeller cannot float stably due to the dynamic pressure effect of the dynamic pressure bearing. Further, there is a possibility that the opposed surfaces of the impeller and the housing come into contact with each other due to vibration due to the occurrence of cogging. If the impeller contacts the housing during rotation, for example, the rotation of the impeller becomes unstable, and it becomes impossible to supply fluid stably.
In particular, when the conventional pump device is applied to an artificial heart pump that transports blood, if the impeller contacts the housing during rotation, there is a risk of causing a thrombus due to friction between the impeller and the housing.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a non-contact bearing pump capable of suppressing the occurrence of cogging.

  In order to solve this problem, a non-contact bearing pump as one aspect according to the present invention includes a stationary body, an impeller that rotates about the axis with respect to the stationary body, and the impeller that is connected to the stationary body. A non-contact bearing that is rotatably supported in a non-contact manner, a drive magnet fixed integrally with the impeller around the axis, and provided on the fixed body, on the outer peripheral side of the drive magnet, And a coreless coil arranged at intervals in the radial direction.

  In the non-contact type bearing pump, the non-contact bearing has a circumferential surface of the stationary body and the impeller which are opposed to each other in the radial direction as a dynamic pressure bearing surface, and a fluid flows between the dynamic pressure bearing surfaces. It may be a dynamic pressure bearing that functions as a bearing by flowing.

According to the non-contact type bearing pump of the present invention, a coreless coil without a magnetic material serving as a core is adopted as a configuration for rotationally driving the impeller, so that the occurrence of cogging during rotation of the impeller can be suppressed. Thereby, the vibration of the impeller with respect to the fixed body can be suppressed, and the impeller and the fixed body can be prevented from contacting each other.
Moreover, since there is no magnetic body which winds a coil like the past, size reduction of a non-contact-type bearing pump can also be achieved easily.

It is sectional drawing which shows the non-contact-type bearing pump which concerns on 1st embodiment of this invention. It is a perspective view which shows the stationary body and impeller with which the non-contact-type bearing pump of FIG. 1 is equipped. FIG. 2 is a schematic diagram in which an example of a coreless coil provided in the non-contact bearing pump of FIG. 1 is developed in the circumferential direction of the casing. It is sectional drawing which shows the non-contact-type bearing pump which concerns on 2nd embodiment of this invention.

[First embodiment]
The first embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, a non-contact bearing pump 1A according to the present embodiment includes a fixed body 10, an impeller 20 that rotates about the axis (fixed body axis Af) with respect to the fixed body 10, and an impeller. And a drive mechanism 30 that rotationally drives 20 with respect to the fixed body 10. The fixed body 10 includes a fixed shaft 50 having a columnar fixed shaft main body 51, and a casing 60 that covers the outer periphery of the fixed shaft 50 and the impeller 20.

  In the following description, the central axis of the cylindrical fixed shaft main body 51 is referred to as a fixed body axis Af, and the direction in which the fixed body axis Af extends is referred to as a fixed body axis direction Df. One side of the fixed body axial direction Df is a suction side, and the other side is a discharge side. The cylindrical casing 60 is fixed to the fixed shaft 50 as described later, and the center axis of the casing 60 coincides with the fixed body axis Af of the fixed shaft main body 51.

  The fixed shaft 50 includes the above-described fixed shaft main body 51, a suction side cone 52 fixed to the suction side of the fixed shaft main body 51, a discharge side cone 53 fixed to the discharge side of the fixed shaft main body 51, and a discharge side cone. A plurality of guide vanes 54 fixed to the outer periphery of 53.

The discharge-side cone 53 is formed to increase in diameter from the discharge-side end toward the suction side with the fixed body axis Af as the center. Further, the suction side end of the discharge side cone 53 is formed in a columnar shape having a constant outer diameter.
The plurality of guide vanes 54 are fixed to the outer periphery of the suction side end of the discharge side cone 53. The guide blades 54 are spirally extended around the discharge-side cone 53 around the fixed body axis Af. Specifically, the guide vane 54 extends to the discharge side while extending in the clockwise direction from the front end on the most suction side when viewed from the suction side.

The suction side cone 52 is formed so as to increase in diameter from the end on the suction side toward the discharge side with the fixed body axis Af as the center. Further, the end of the suction side cone 52 on the discharge side is formed in a columnar shape having a constant outer diameter.
A first permanent magnet 55 having a magnetization direction facing the fixed body axis direction Df is provided inside the discharge-side end portion of the suction-side cone 52.

The impeller 20 is rotatably mounted on the fixed shaft main body 51 of the fixed shaft 50. The impeller 20 includes a cylindrical sleeve 21 that is rotatably mounted on the outer peripheral side of the fixed shaft main body 51, and a plurality of blades 22 that are fixed to the outer periphery of the sleeve 21.
The outer diameter dimension of the sleeve 21 is the same as the outer diameter dimension at the discharge side end of the suction side cone 52 and the suction side end of the discharge side cone 53 formed in a cylindrical shape.
A second permanent magnet 25 having a magnetization direction facing the fixed body axis direction Df is provided in the sleeve 21. The second permanent magnet 25 is disposed such that the magnetic pole having the same polarity as the one of the magnetic poles of the first permanent magnet 55 faces the one of the magnetic poles of the first permanent magnet 55.

  As shown in FIG. 2, the plurality of blades 22 are arranged at equal intervals in the circumferential direction of the sleeve 21. The blades 22 are spirally extended around the outer periphery of the sleeve 21 with the fixed body axis Af as the center. Specifically, when viewed from the suction side, the blade 22 extends to the discharge side while extending counterclockwise from the front end on the most suction side.

  As shown in FIG. 1, the non-contact bearing pump 1 </ b> A includes a non-contact bearing 40 that rotatably supports the impeller 20 with respect to the fixed shaft 50 in a non-contact manner. The non-contact bearing 40 of this embodiment uses the inner peripheral surface of the sleeve 21 of the impeller 20 and the outer peripheral surface of the fixed shaft main body 51 of the fixed shaft 50 that are opposed to each other in the radial direction as dynamic pressure bearing surfaces. This is a dynamic pressure bearing that functions as a bearing when fluid conveyed by the non-contact type bearing pump 1A flows between the pressure bearing surfaces.

The casing 60 is provided with a cylindrical casing body 63, a cylindrical suction pipe portion 64 that is provided on the suction side of the casing body 63 and forms the suction port 61 of the casing 60, and a casing that is provided on the discharge side of the casing body 63. And a cylindrical discharge pipe portion 65 having 60 discharge ports 62.
The inner peripheral surface of the casing main body 63 is spaced in the radial direction from the surfaces (outer peripheral surfaces) of the suction-side cone 52 and the discharge-side cone 53 of the fixed shaft 50 and the outer peripheral surface of the sleeve 21 of the impeller 20. It is formed so as to face each other. Specifically, the inner peripheral surface of the casing body 63 that faces the suction side cone 52 in the radial direction is formed so as to gradually increase toward the discharge side with the fixed body axis Af as the center. In addition, the inner peripheral surface of the casing body 63 that faces the discharge-side cone 53 in the radial direction is formed so as to gradually decrease toward the discharge side with the fixed body axis Af as the center. Further, the inner peripheral surface of the casing main body 63 that faces the sleeve 21 in the radial direction is set to have a substantially constant inner diameter.
The fixed shaft 50 described above is fixed in the casing body 63 by fixing the tip of the guide blade 54 extending radially outward from the discharge-side cone 53 to the inner peripheral surface of the casing body 63.

The suction pipe portion 64 is connected to the suction side end of the casing body 63. The discharge pipe portion 65 is connected to the discharge side end portion of the casing body 63.
The inner space of the suction pipe portion 64, the inner space between the casing body 63 and the suction side cone 52, the discharge side cone 53, and the sleeve 21, and the inner space of the discharge pipe portion 65 are connected to each other in the fixed body axial direction Df. Form a space. This space forms a flow path through which the fluid flows.

The drive mechanism 30 includes a drive magnet 31 that is integrally fixed to the impeller 20, and a coreless coil 32 that is provided on the fixed body 10.
The drive magnet 31 is disposed in the sleeve 21 of the impeller 20 so that the magnetization direction is in the radial direction with respect to the fixed body axis Af. Further, the drive magnet 31 is configured by alternately arranging magnetic poles in opposite directions in the circumferential direction of the impeller 20. As the drive magnet 31, a plurality of permanent magnets can be provided side by side in the circumferential direction of the impeller 20, or an annular polar anisotropic permanent magnet can be used. The drive magnet 31 is arranged on the discharge side in the sleeve 21 with respect to the second permanent magnet 25 described above.

The coreless coil 32 is fixedly provided in the casing 60 so as to be arranged on the outer peripheral side of the drive magnet 31 with an interval in the radial direction.
The coreless coil 32 is a coil that does not include a magnetic body serving as a core. For example, as shown in FIG. 3, the coreless coil 32 includes a plurality (three in the illustrated example) of coil portions 33 formed by connecting a plurality of annular portions 34 in which conductive wires are formed in a ring shape in series. Each coil part 33 is arranged in the casing 60 so that the axial direction of the annular part 34 is directed in the radial direction of the casing 60 and the plurality of annular parts 34 are arranged at intervals in the circumferential direction of the casing 60. Is provided.

In the coreless coil 32, the annular portions 34 of the plurality of coil portions 33 (the annular portion 34A of the first coil portion 33A, the annular portion 34B of the second coil portion 33B, and the annular portion 34C of the third coil portion 33C) are sequentially arranged. Arranged in the circumferential direction of the casing 60. In the coreless coil 32, two annular portions 34 (for example, the annular portion 34A of the first coil portion 33A and the annular portion 34B of the second coil portion 33B) adjacent in the circumferential direction of the casing 60 are, for example, one of these. The portions may be arranged so as to overlap in the radial direction of the casing body 63. Thereby, the coreless coil 32 generates a rotating magnetic field that rotates around the fixed body axis Af by sequentially energizing the first coil portion 33A, the second coil portion 33B, and the third coil portion 33C, for example.
In FIG. 3, each annular portion 34 of the coreless coil 32 is formed by winding the conductive wire only once, but may be formed by winding the conductive wire a plurality of times, for example.

  Moreover, the drive mechanism 30 of this embodiment is also provided with the cylindrical yoke 35 which consists of magnetic bodies, such as steel, as shown in FIG. The yoke 35 is provided adjacent to the outer peripheral side of the casing 60 with respect to the coreless coil 32. The yoke 35 serves to prevent the magnetic force generated in the coreless coil 32 from leaking outside the casing 60. The yoke 35 is configured by, for example, laminating a large number of ring-shaped plate materials formed in a ring shape in the fixed body axial direction Df.

Next, the operation of the non-contact bearing pump 1A in this embodiment will be described.
When a rotating magnetic field is generated inside the casing 60 by the coreless coil 32 provided in the casing 60, the drive magnet 31 in the impeller 20 follows this rotating magnetic field. As a result, the impeller 20 rotates in the casing 60 with the fixed body axis Af as the central axis. When the impeller 20 rotates, fluid is sucked into the casing 60 from the suction port 61 of the casing 60. Then, the rotation of the impeller 20 applies a force for turning the fluid in the casing 60 from the blades 22 while feeding it to the discharge side, and the flow velocity in the turning direction about the fixed body axis Af is increased. The guide blade 54 increases the static pressure by reducing the flow velocity in the swirling direction with respect to the fluid whose flow velocity in the swirling direction is increased by the blade 22. The fluid whose static pressure is increased is discharged from the discharge port 62 of the casing 60.

  A thrust force directed toward the suction side acts on the impeller 20 because a force for turning the fluid while feeding it to the discharge side is applied. Here, the suction side cone 52 is provided with a first permanent magnet 55, and the impeller 20 has a magnetic pole having the same polarity as one of the magnetic poles of the first permanent magnet 55. Are arranged so as to face each other. For this reason, the second permanent magnet 25 of the impeller 20 receives a repulsive force from the first permanent magnet 55 of the suction side cone 52 toward the discharge side. The aforementioned thrust force acting on the impeller 20 is received by this repulsive force.

  As described above, according to the non-contact type bearing pump 1A of the present embodiment, since the coreless coil 32 having no magnetic body (core) is adopted as a configuration for rotationally driving the impeller 20, the rotation of the impeller 20 is performed. The occurrence of cogging can be suppressed. Thereby, the vibration of the impeller 20 with respect to the fixed body 10 can be suppressed, and the impeller 20 and the fixed body 10 (in particular, the fixed shaft main body 51 of the fixed shaft 50) can be suppressed from contacting each other. Accordingly, it is possible to stably supply the fluid by stably rotating the impeller 20. Moreover, even if the non-contact type bearing pump 1A is applied to an artificial heart pump that transports blood, it is possible to suppress the occurrence of thrombus due to the contact between the impeller 20 and the fixed body 10.

  Further, by adopting the coreless coil 32, the casing 60 can be easily reduced in size and thickness without reducing the magnetic poles (for example, the number of the annular portions 34) of the coil as compared with the coil having the magnetic body (core). Can be aimed at. Therefore, it is possible to easily reduce the size of the non-contact bearing pump 1A. The downsizing of the non-contact bearing pump 1A is particularly effective when an artificial heart pump is implanted in the body.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 4, the non-contact bearing pump 1 </ b> B according to this embodiment includes a fixed body 110 and an impeller 120 that rotates around a rotation axis A with respect to the fixed body 110, as in the first embodiment. And a drive mechanism 130 that rotationally drives the impeller 120 with respect to the fixed body 110. The fixed body 110 of this embodiment includes a casing 160 that covers the outer peripheral side of the impeller 120.

  The casing 160 is formed with a discharge port 160B for discharging fluid and a suction port 160A for sucking fluid on an extension line of the rotation axis A. In the following description, in the axial direction Da in which the rotation axis A extends, the suction port 160A side of the casing 160 is the front side, and the opposite side is the rear side. Further, in the radial direction Dr perpendicular to the rotation axis A, the side closer to the rotation axis A is the radially inner side, and the direction away from the rotation axis A is the radially outer side.

  The impeller 120 provided in the casing 160 includes a plurality of blades 121 provided around the rotation axis A, a front shroud 122 covering the front side of the plurality of blades 121, and a rear shroud covering the rear side of the plurality of blades 121. 123. The impeller 120 forms a hermetic impeller by covering the front and rear of the plurality of blades 121 with the front shroud 122 and the rear shroud 123. The plurality of blades 121, the front shroud 122, and the rear shroud 123 of the impeller 120 are each an integrally molded product made of resin, and these are joined to each other by an adhesive.

  The front shroud 122 has a cylindrical shape centered on the rotation axis A, and an inlet cylinder 124 that forms an impeller inlet 120A whose front opening in the axial direction Da faces the suction port 160A of the casing 160, and an inlet cylinder 124 And a front side plate portion 125 that covers the front side of the plurality of blades 121. The rear shroud 123 includes a rear side plate portion 126 that covers the rear side of the plurality of blades 121, and a shaft portion 127 that is provided on the rear side of the rear side plate portion 126 and has a columnar shape with the rotation axis A as the center.

Each of the front side plate portion 125 of the front shroud 122 and the rear side plate portion 126 of the rear shroud 123 has a circular shape centered on the rotational axis A when viewed from the axial direction Da. The front plate portion 125 and the rear plate portion 126 are separated from each other in the axial direction Da, and a plurality of blades 121 are fixed between the front plate portion 125 and the rear plate portion 126. The outer edge in the radial direction Dr between the front side plate portion 125 and the rear side plate portion 126 forms an impeller outlet 120B. Between the front side plate portion 125 and the rear side plate portion 126 and between the plurality of blades 121 and the inside of the inlet tube portion 124 is an impeller internal flow passage Pr.
The shaft portion 127 of the rear shroud 123 passes through the rotation axis A in the axial direction Da, and communicates the space between the rear end surface 127a of the shaft portion 127 and the casing 160 and the aforementioned impeller flow path Pr. A hole 128 is formed.

  The casing 160 is connected to a suction hose (not shown) on the front end side, and has an inner peripheral surface 161a facing the outer peripheral surface 124a of the inlet cylinder portion 124 of the front shroud 122 with a gap therebetween. Forming portion 161 and a flat plate ring that extends radially outward from the rear end of the front bearing forming portion 161 and covers the front plate portion 125 so as to face the front surface 125a of the front plate portion 125 of the front shroud 122 with an interval in the axial direction Da. And a main body cylinder portion 163 that has a substantially cylindrical shape with the rotation axis A as the center and extends from the outer peripheral edge of the front facing portion 162 to the rear side. The front end of the front bearing forming portion 161 is open, and this opening forms a suction port 160 </ b> A of the casing 160. The inner peripheral surface 163a of the main body cylinder portion 163 is opposed to the outer peripheral edge of the front plate 125 of the front shroud 122 and the outer peripheral edge of the rear plate 126 of the rear shroud 123 with a gap.

  The casing 160 extends radially inward from the rear side of the front surface facing portion 162 of the main body cylinder portion 163, and faces the rear surface 126 a of the rear side plate portion 126 of the rear shroud 123 with an interval in the axial direction Da with the rear side plate portion 126. A flat plate ring-shaped rear surface facing portion 164 that covers the inner surface 165a and an inner peripheral surface 165a that extends rearward from the inner edge of the rear surface facing portion 164 and faces the outer peripheral surface 127b of the shaft portion 127 of the rear shroud 123 with a space therebetween. The rear bearing forming portion 165, the rear end of the main body cylinder portion 163 and the rear end of the rear bearing forming portion 165 are opposed to the rear end surface 127a of the shaft portion 127 of the rear shroud 123 with an interval in the axial direction Da. And a flat ring-shaped rear wall plate portion 166.

  The casing 160 includes a cylindrical portion 167 that extends from the inner peripheral edge on the radially inner side of the rear wall plate portion 166 around the rotation axis A and extends forward, and a front end portion of the cylindrical portion 167. And a closing portion 168 for closing. The cylindrical portion 167 is inserted into the hole portion 128 of the impeller 120, and the outer peripheral surface 167a faces the inner peripheral surface 128a of the hole portion 128 in the radial direction Dr with a gap. The cylindrical portion 167 has a cylindrical shape with the rotation axis A as the center. In other words, the front bearing formation portion 161 and the rear bearing formation portion 165 that support the impeller 120 in the radial direction Dr are aligned with the central axis. ing. The impeller 120 is provided in the casing 160 so as to be rotatable about the central axis. When the impeller 120 rotates, the hole 128 of the impeller 120 rotates around the cylindrical portion 167.

  The casing 160 has a substantially cylindrical discharge pipe portion 169 to which a discharge hose (not shown) is connected. The axis of the discharge pipe portion 169 is parallel to a plane perpendicular to the rotation axis A. The discharge pipe portion 169 is connected to the main body cylinder portion 163. The outer end of the discharge pipe portion 169 is opened, and this opening forms a discharge port 160B of the casing 160.

The non-contact bearing pump 1B includes a non-contact bearing 140 that supports the impeller 120 so as to be rotatable with respect to the casing 160 in a non-contact manner. The non-contact bearing 140 of the present embodiment uses the outer peripheral surface of the impeller 120 and the inner peripheral surface of the casing 160 that are opposed to each other in the radial direction as a dynamic pressure bearing surface, and a non-contact type between these dynamic pressure bearing surfaces. It is a hydrodynamic bearing that functions as a bearing when fluid conveyed by the bearing pump 1B flows.
In the non-contact bearing 140 of the present embodiment, the outer peripheral surface 124a of the inlet tube portion 124 of the impeller 120 and the inner peripheral surface 161a of the front bearing forming portion 161 of the casing 160 are used as dynamic pressure bearing surfaces. The front non-contact bearing 140A, the outer peripheral surface 127b of the shaft portion 127 of the impeller 120, and the rear non-contact bearing 140B having the inner peripheral surface 165a of the rear bearing forming portion 165 of the casing 160 as dynamic pressure bearing surfaces. There is one.

As in the first embodiment, the drive mechanism 130 includes a drive magnet 131 that is integrally fixed to the impeller 120 and a coreless coil 132 that is provided on the fixed body 110.
The drive magnet 131 is disposed in the shaft portion 127 of the impeller 120 so that the magnetization direction is directed to the radial direction Dr. Further, the drive magnet 131 is configured by alternately arranging magnetic poles in opposite directions in the circumferential direction of the impeller 120. As the drive magnet 131, a plurality of permanent magnets can be provided side by side in the circumferential direction of the impeller 120, or an annular polar anisotropic permanent magnet can be used.

The coreless coil 132 is configured similarly to the coreless coil 32 (see FIG. 3) of the first embodiment. The coreless coil 132 is fixedly provided in an annular internal space of the casing 160 surrounded by the main body cylinder portion 163, the rear surface facing portion 164, the rear bearing forming portion 165, and the rear wall plate portion 166. As a result, the coreless coil 132 is arranged on the outer peripheral side of the drive magnet 131 with an interval. The coreless coil 132 generates a rotating magnetic field that rotates about the rotation axis A, similarly to the coreless coil 32 of the first embodiment.
The drive mechanism 130 of this embodiment also includes a cylindrical yoke 135 similar to that of the first embodiment.

Next, operation | movement of the non-contact-type bearing pump 1B in this embodiment is demonstrated.
When a rotating magnetic field is generated inside the casing 160 by the coreless coil 132 provided in the casing 160, the drive magnet 131 in the impeller 120 follows this rotating magnetic field. As a result, the impeller 120 rotates around the rotation axis A in the casing 160. When the impeller 120 rotates, fluid is sucked into the casing 160 from the suction port 160 </ b> A of the casing 160. The fluid sucked into the casing 160 enters the impeller flow path Pr in the impeller 120 from the impeller inlet 120A. The fluid that has entered the flow path Pr in the impeller receives centrifugal force from the rotating plurality of blades 121, flows out of the impeller outlet 120 </ b> B, and is then discharged from the discharge port 160 </ b> B of the casing 160.

Part of the fluid that has flowed out of the impeller outlet 120B is between the inner surface 162a of the front facing portion 162 of the casing 160 and the front surface 125a of the front plate portion 125 of the impeller 120, and the hydrodynamic bearing surface of the front non-contact bearing 140A. It passes between the inner peripheral surface 161a of the front bearing forming portion 161 of the casing 160 and the outer peripheral surface 124a of the inlet tube portion 124 of the impeller 120. Thereby, the portion of the inlet cylinder portion 124 of the impeller 120 is supported by the casing 160 so as to be rotatable in the radial direction Dr without contact.
And the fluid which passed between the inner peripheral surface 161a of the front bearing formation part 161 and the outer peripheral surface 124a of the inlet cylinder part 124 returns to the front side rather than the inlet cylinder part 124 in the front bearing formation part 161, and again the blade It enters the impeller inner passage Pr from the vehicle entrance 120A.

  Further, another part of the fluid flowing out from the impeller outlet 120B is between the inner surface 164a of the rear surface facing portion 164 of the casing 160 and the rear surface 126a of the rear plate portion 126 of the impeller 120, and the rear non-contact bearing 140B. Passes through between the inner peripheral surface 165a of the rear bearing forming portion 165 of the casing 160 and the outer peripheral surface 127b of the shaft portion 127 of the impeller 120. Accordingly, the shaft 127 of the impeller 120 is supported by the casing 160 so as to be rotatable in the radial direction Dr without contact.

  Then, the fluid that has passed between the inner peripheral surface 165a of the rear bearing forming portion 165 and the outer peripheral surface 127b of the shaft portion 127 of the impeller 120 passes through the inner surface 166a of the rear wall plate portion 166 of the casing 160 and the shaft of the impeller 120. A cylindrical tube that passes between the rear end surface 127a of the portion 127 and extends along the axial direction Da between the inner peripheral surface 128a of the hole 128 of the impeller 120 and the outer peripheral surface 167a of the cylindrical portion 167 of the casing 160. The flow returns to the impeller internal flow path Pr via the flow path Pa. That is, between the hole 128 of the impeller 120 and the cylindrical portion 167 of the casing 160 is a cylindrical flow path Pa that returns the fluid to the flow path Pr in the impeller. When the fluid is caused to flow through the cylindrical tubular flow path Pa, the fluid can be flowed without stagnation as compared with the case where the fluid is caused to flow through the cylindrical flow path in the hole 128 without the tubular portion 167.

According to the non-contact type bearing pump 1B of this embodiment, there exists an effect similar to 1st embodiment.
That is, since the coreless coil 132 without a magnetic body (core) is employed as a configuration for rotationally driving the impeller 120, the occurrence of cogging during the rotation of the impeller 120 can be suppressed. Thereby, the vibration of the impeller 120 with respect to the fixed body 110 can be suppressed, and the impeller 120 and the fixed body 110 (particularly the front bearing forming portion 161 and the rear bearing forming portion 165 of the casing 160) can be prevented from contacting each other.
Further, by adopting the coreless coil 132, the casing 160 can be easily reduced in size and thickness without reducing the magnetic pole of the coil as compared with a coil having a magnetic body (core).

Although the details of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, a dynamic pressure bearing is employed as the non-contact bearing, but a magnetic bearing may be employed, for example.
Further, the non-contact bearing pump of the present invention is not limited to being applied to the pumps 1A and 1B of the above embodiment, but can be applied to a pump employing at least a non-contact bearing and a coreless coil.

DESCRIPTION OF SYMBOLS 1A, 1B ... Non-contact type bearing pump 10, 110 ... Fixed body, 20, 120 ... Impeller, 31, 131 ... Drive magnet, 32, 132 ... Coreless coil, 40, 140 ... Non-contact bearing

Claims (2)

A fixed body,
An impeller that rotates about an axis relative to the fixed body;
A non-contact bearing that rotatably supports the impeller with respect to the fixed body in a non-contact manner;
A drive magnet fixed integrally with the impeller around the axis;
A non-contact type bearing pump comprising: a coreless coil provided on the outer periphery of the driving magnet and disposed at a radial interval on the outer peripheral side of the driving magnet. The non-contact bearing has a hydrodynamic bearing surface that is a circumferential surface of the fixed body and the impeller that are opposed to each other in the radial direction, and a hydrodynamic bearing that functions as a bearing by fluid flowing between the hydrodynamic bearing surfaces. The non-contact bearing pump according to claim 1, wherein

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