JP2006037918A - Axial-flow pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and highly efficient axial-flow pump suitable for in-line installation into a small diameter pipe. <P>SOLUTION: A cylindrical motor rotor 1 disposed in a housing 20 and rotating in the circumferential direction is supported by a plain bearing formed of the inner peripheral surface 20b of the housing 20 and the outer peripheral surface 1a of the motor rotor 1. Thrust support members 3A and 3B are disposed on the motor rotor 1 near the upstream side end face 1c and the downstream side end face 1d. By this configuration, the motor rotor 1 rotating in the circumferential direction and a load in the thrust direction by the reaction of a force-fed fluid can be supported on the rotating axis of an impeller 13 forming the center of the flow of the fluid without disposing members obstructing the flow of the fluid. Also, the axial-flow pump is so formed that the impeller 13 force-feeding the fluid is formed integrally with the inside of the motor rotor 1 so that the overall device can be reduced in weight and size. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-line axial flow pump that can be mounted linearly in piping constituting a fluid passage.

  An axial-flow pump has a propeller-type impeller disposed in a pipe line serving as a fluid passage, and does not have a spiral shell, and can send fluid in the axial direction at a relatively high rotational speed. . Further, compared with the spiral pump, the volume is about ½, and the structure is simple and highly efficient.

  However, in order to drive the main shaft provided with the impeller, the conventional axial flow pump has to extend the main shaft to the outside of the pipe body serving as the pump housing, and the seal structure of the extension portion becomes complicated. There was a problem.

  Therefore, as a means for accommodating all the main shafts in the housing, there has been proposed a method in which the rotor portion of the motor is formed integrally with the main shaft, and the main shaft is driven by the stator portion of the motor disposed outside the tubular body. (See, for example, Patent Document 1).

  In addition, a method has been proposed in which the main shaft is rotated in both forward and reverse directions by coupling an inner magnet that rotates integrally with the main shaft and an outer magnet that rotates outside the tube (see Patent Document 2).

JP 11-37079 A JP-A-6-307377

  By the way, the axial flow pump having the structure in which the main shaft is housed in the housing as described above supports the circumferential rotation of the motor rotor and the main shaft connected to the motor rotor, and loads in the thrust direction of the rotor and the main shaft (longitudinal direction of the housing). It is necessary to dispose support members that load the shaft in the vicinity of both ends in the axial direction of the main shaft.

  However, this conventional main shaft support member obstructs the flow of fluid because a relatively large component must be disposed at the substantially central portion in the radial direction of the housing (i.e., the central portion of the fluid flow). This was a factor that reduced pump efficiency.

  In addition, the smaller the inner diameter of the straight tube housing that constitutes the axial flow pump, the more the loss due to the main shaft support member tends to increase, and there is a need for in-line and further miniaturization and weight reduction. In pumps used in related equipment and the like, this reduction in pump efficiency becomes a serious problem.

  The present invention has been made to address the above-described problems, and has an object to provide an axial flow pump that is compact and highly efficient and suitable for in-line incorporation into a small-diameter pipe.

  In order to achieve the above-mentioned object, the invention according to claim 1 comprises a straight tubular housing, a cylindrical motor rotor disposed with a gap in the inner periphery of the housing, and an inner side of the motor rotor. An axial-flow rotor formed, and a motor stator disposed on the outer periphery of the housing opposite to the motor rotor, the motor rotor being disposed in the longitudinal direction of the housing by thrust support members disposed in the vicinity of both end faces of the motor rotor. The movement of the motor is restricted, and the rotation in the circumferential direction is supported by a plain bearing constituted by the inner peripheral surface of the housing and the outer peripheral surface of the motor rotor facing each other.

  The present invention supports an in-line axial flow pump that can be mounted linearly in a pipe, and supports the circumferential rotation of a cylindrical motor rotor disposed in the housing by a slip between the inner peripheral surface of the housing. By doing so, it is intended to achieve the intended purpose.

  In other words, according to the first aspect of the present invention, the circumferential rotation of the cylindrical motor rotor disposed in the housing is supported by the slide bearing configured by the inner peripheral surface of the housing and the outer peripheral surface of the motor rotor. Thus, it becomes possible to omit the main shaft, which is essential in the conventional configuration. In addition, since the main shaft can be omitted, there is no need to provide a main shaft support member that is arranged to support the main shaft. Therefore, in the axial flow pump of the present invention, the member that obstructs the flow of the fluid is not disposed on the substantially central portion in the radial direction of the housing, that is, on the rotational axis of the axial flow rotary blade that is the center of the fluid flow. There is no reduction in efficiency.

  Further, in the axial flow pump of the present invention, the axial flow rotor blade for extruding the fluid is integrally formed inside the motor rotor, and the longitudinal dimension of the pump can be shortened. Combined with the fact that the device is not used, the entire apparatus can be configured to be lightweight and compact.

  Note that the configuration of the axial flow pump according to the present invention also has advantages such as cost reduction by reducing the number of parts and response improvement by lowering inertia of the rotating body including the rotor and the rotor blades.

  Here, in the axial flow pump for sending the fluid filled in the housing in a predetermined direction by the rotation of the motor rotor and the axial flow rotor blade, the inner peripheral surface of the housing constituting the slide bearing and the outer periphery of the motor rotor It is preferable to adopt a configuration in which a groove is formed on at least one of the surfaces so that the fluid existing between the two surfaces of the motor rotor flows in the direction opposite to the fluid delivery direction as the motor rotor rotates. (Claim 2).

  According to the present invention, the fluid in the housing is forcibly circulated between the inner peripheral surface of the housing, which is poorly lubricated by the rotation of the motor rotor, and the outer peripheral surface of the motor rotor, and the lubrication of the slide bearing constituted by these surfaces is excellent. I want to keep it. Also, with this configuration, a fluid that provides a lubricating action is also fed between the motor rotor end surface on the upstream side in the fluid delivery direction and the upstream thrust support member, which are in contact with each other by the reaction force of fluid delivery caused by the rotation of the axial flow rotor blades. It is. Therefore, in the axial flow pump of the present invention, the lubrication between the motor rotor and the housing and between the motor rotor and the support member is well maintained, and the life thereof is improved.

  Next, according to a third aspect of the present invention, the thrust support member is formed in a disc shape having a hole having a diameter larger than the inner diameter of the motor rotor and smaller than the outer diameter of the motor rotor at the center. It is characterized by.

  The thrust support members respectively disposed in the vicinity of both end faces of the motor rotor are required not only to receive the force in the thrust direction caused by the delivery of the fluid but also to not disturb the flow of the fluid as described above. Therefore, the shape that does not hinder the flow of fluid while reliably restricting the movement of the motor rotor in the longitudinal direction of the housing is centered on a hole having a diameter larger than the inner diameter of the motor rotor and smaller than the outer diameter of the motor rotor. A disk shape is preferable. Further, the disk-like thrust support member is easy to process and low in cost, and has an advantage that the longitudinal dimension of the entire apparatus can be shortened as compared with the conventional spindle support member having a complicated shape.

  Further, in the axial flow pump that sends the fluid filled in the housing in a predetermined direction by the rotation of the motor rotor and the axial flow rotor blade, the end face of the motor rotor located downstream in the fluid delivery direction; A groove is formed in at least one of the end faces of the disk-like thrust support member facing the end face of the motor rotor to allow fluid existing therebetween to flow radially outward as the motor rotor rotates. This configuration can be suitably employed (claim 4).

  With this configuration, the fluid in the housing circulates between the inner peripheral surface of the housing that becomes poorly lubricated by the rotation of the motor rotor and the outer peripheral surface of the motor rotor, as in the invention described in claim 2, and the axial flow rotor blade A fluid that gives a lubricating action is also fed between the motor rotor end face on the upstream side in the fluid delivery direction and the upstream disk-like thrust support member, which are in contact with each other by the reaction force of fluid delivery caused by the rotation of. Therefore, in the axial flow pump of the present invention, the lubrication between the motor rotor and the housing and between the motor rotor and the support member is well maintained, and the life thereof is improved.

  As described above, according to the axial flow pump of the present invention, no member that obstructs the flow of the fluid is disposed on the rotation axis of the axial flow rotor that is the center of the flow of the fluid, and the pump efficiency is reduced. Absent. In addition, the axial rotor blade for extruding the fluid is integrally formed on the inner side of the motor rotor, the longitudinal dimension of the pump is shortened, and the main shaft and the main shaft support member used in the conventional axial flow pump are required. In combination with this, the entire apparatus can be configured to be lightweight and compact. Therefore, the axial flow pump of the present invention can be a compact and highly efficient axial flow pump suitable for in-line incorporation into a small-diameter pipe.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is an axial sectional view showing a configuration of an axial flow pump according to an embodiment of the present invention, and FIG. 2 is an end view taken along arrow A in FIG. When the direction of fluid flow by the rotation of the motor rotor 1 of this axial flow pump (in the direction of arrow B) is the direction of arrow C, the left side in the figure (thrust support member 3A side) is the upstream side and the right side in the figure (thrust). The support member 3B side) is expressed as the downstream side.

  The axial flow pump in this embodiment is used, for example, to pump water, coolant or the like, and is incorporated in-line in the fluid piping 21. A housing 20 of this axial flow pump is a straight tube having substantially the same diameter as the pipe, and a motor stator 2 for driving a motor rotor 1 described later is disposed on the outer peripheral surface 20a.

  The motor rotor 1 has a substantially cylindrical shape, a metallic cylindrical body 12, a magnet 11 fitted to the outer periphery thereof, and an axial flow rotary blade (impeller 13) fitted and fixed to the inner periphery of the cylindrical body 12. ). The outer peripheral surface 1a of the motor rotor 1 is formed to have a diameter slightly smaller than the diameter of the housing inner peripheral surface 20b, and a clearance S1 is formed between the housing inner peripheral surface 20b and the motor rotor outer peripheral surface 1a. ing.

  A feature of the axial flow pump in the present embodiment is that the circumferential rotation of the cylindrical motor rotor 1 disposed in the housing 20 is caused by a slide bearing constituted by the housing inner peripheral surface 20b and the motor rotor 1 outer peripheral surface 1a. It is a point that is supported.

  Further, a hole having a diameter larger than the inner diameter (1b) of the motor rotor 1 and smaller than the outer diameter (1a) of the motor rotor 1 is provided in the vicinity of the upstream end face 1c and the downstream end face 1d of the motor rotor 1. The disc-shaped thrust support members 3A and 3B are disposed on the end surface 3y of the thrust support member 3B on the downstream side facing the motor rotor 1, as shown in FIG. A groove 3z is formed to allow the fluid to flow outward in the radial direction.

  With the above configuration, this axial flow pump can be arranged in a substantially central portion in the radial direction of the housing 20, that is, on the rotation axis of the impeller 13 that is the center of the fluid flow without disposing a member that obstructs the fluid flow. The circumferential rotation of the motor rotor 1 and the thrust load due to the reaction force of fluid delivery can be supported. Therefore, the axial flow pump in this embodiment can improve the pump efficiency compared with the conventional axial flow pump which arrange | positioned the main axis | shaft, the shaft support member, etc. in the radial direction approximate center part of the housing.

  Further, due to the action of the groove 3z (pump-out groove) formed in the end surface 3y facing the motor rotor 1 of the downstream thrust support member 3B, the clearance S1 between the housing inner peripheral surface 20b and the motor rotor outer peripheral surface 1a, and the upstream The fluid which gives the lubricating action is also fed into the clearance S2 between the motor rotor end surface 1c on the side and the end surface 3x of the upstream disk-shaped thrust support member facing this. Therefore, in the axial flow pump according to the present embodiment, friction between the motor rotor 1 and the housing 20 and friction / wear between the motor rotor 1 and the thrust support members 3A and 3B are reduced, and the life and pump efficiency are improved.

  In the present embodiment, the groove 3z having a pump-out action is formed on one end surface 3y of the downstream thrust support member 3B. However, the shape of the groove in the present invention is limited to the above example. is not. The groove may be formed on the downstream end surface 1d of the motor rotor 1 facing the end surface 3y of the thrust support member, or may be formed on both surfaces.

  Further, instead of forming a groove 3y having a pump-out action on the end surface 3y of the thrust support member 3B facing the end surface 1d of the motor rotor 1, as shown in FIG. You may form the groove | channel 20v which makes the fluid which exists in clearance gap S1 between the surface 20b and the motor rotor outer peripheral surface 1a flow toward an upstream direction. Similarly to the groove 3z, the groove 20v may be formed on the outer peripheral surface 1a of the motor rotor 1 facing the inner peripheral surface 20b of the housing, and the groove shape is not limited.

It is an axial direction sectional view showing the composition of the axial flow pump in the embodiment of the present invention. FIG. 2 is an end view taken along arrow A in FIG. 1. It is an axial sectional view showing another composition of an axial flow pump in an embodiment of the present invention.

Explanation of symbols

1 Motor rotor 1a Outer peripheral surface 1b Inner peripheral surface 1c End surface (upstream side)
1d End face (downstream side)
2 Motor stator 3A Thrust support member (upstream side)
3x End face 3B Thrust support member (downstream)
3y end face 3z groove 11 magnet 12 cylindrical body 13 impeller 20 housing 20a outer peripheral surface 20b inner peripheral surface 20v groove 21 piping

Claims (4)

A straight tubular housing, a cylindrical motor rotor disposed with a gap in the inner periphery of the housing, an axial flow rotor integrally formed on the inner side of the motor rotor, and an outer periphery of the housing facing the motor rotor A motor stator arranged,
The motor rotor is restricted in movement in the longitudinal direction of the housing by thrust support members disposed in the vicinity of both end faces of the motor rotor, and the circumferential rotation of the motor rotor and the inner peripheral surface of the housing facing each other. An axial pump characterized in that it is supported by a plain bearing formed on the outer peripheral surface of a motor rotor. In the axial flow pump that sends out the fluid filled in the housing in a predetermined direction by the rotation of the motor rotor and the axial flow rotor blades,
The fluid existing between at least one of the inner peripheral surface of the housing and the outer peripheral surface of the motor rotor constituting the slide bearing flows in the direction opposite to the fluid delivery direction as the motor rotor rotates. The axial flow pump according to claim 1, wherein a groove is formed.   The said thrust support member is formed in the disk shape which has a hole larger in diameter than the internal diameter of the said motor rotor, and smaller than the outer diameter of this motor rotor in the center part. Axial flow pump. In the axial flow pump that sends out the fluid filled in the housing in a predetermined direction by the rotation of the motor rotor and the axial flow rotor blades,
At least one of the end face of the motor rotor positioned downstream in the fluid delivery direction and the end face of the disc-like thrust support member facing the end face of the motor rotor, with the rotation of the motor rotor, between them The axial flow pump according to claim 3, wherein a groove for flowing an existing fluid radially outward is formed.

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