JP5961418B2 - Motor and pump device - Google Patents

Description

  The present invention relates to a pump device that sucks fluid, pressurizes and discharges the fluid, and a motor for driving the pump device.

  2. Description of the Related Art Conventionally, a pump device has been used in which impeller blades are arranged in an arc-shaped fluid passage provided in a pump case, and fluid is sucked into the fluid passage by rotating the impeller, and is pressurized and discharged. Patent Document 1 discloses this type of pump device.

  The pump device (electric pump) described in Patent Literature 1 includes a rotor configured to rotate integrally with a motor shaft, and a stator installed on the outer peripheral side thereof, and an impeller is provided at an end of the motor shaft. Rotating. Two bearings are fixed in the casing of the pump device, and the intermediate portion and one end of the motor shaft are rotatably supported by these bearings.

JP 2008-175090 A

  In Patent Document 1, the motor shaft has the thickest portion extending between two bearings, and step portions are formed on both sides thereof, and the bearing is mounted on a portion that is narrowed by the step portion. . The bearing is brought into contact with the step surface of the step portion facing the axial direction, thereby positioning the motor shaft in the axial direction. However, since it is difficult to process and assemble so that the axial interval between the two bearings and the axial interval between the two step portions formed on the motor shaft are completely coincident with each other, In the holding structure, axial backlash occurs on the motor shaft. Therefore, there is a problem that the positional accuracy of the motor shaft in the axial direction is low.

  When the impeller of the pump device is provided at the end of the motor shaft and rotated, the gap between the inner peripheral surface of the pump chamber and the impeller cannot be managed with high accuracy in a structure with low positional accuracy in the axial direction of the motor shaft. Therefore, there is a problem that the sealing performance of the pump chamber cannot be improved.

  In view of the above problems, an object of the present invention is to provide a motor capable of accurately positioning a motor shaft in the axial direction and a pump device having such a motor.

  In order to solve the above problems, a motor of the present invention includes a motor shaft, a rotor and a stator for rotating the motor shaft, a fixed bearing that rotatably supports the motor shaft, and the fixed bearing. A fixed reference member, a movable bearing that rotatably supports the motor shaft at a position different from the fixed bearing, and that is movable relative to the fixed bearing in the axial direction of the motor shaft, and the movable A biasing member that biases the bearing away from the fixed bearing, a first rotating member facing an end surface of the movable bearing facing away from the fixed bearing, and a reverse of the movable bearing in the fixed bearing A second rotating member facing an end surface facing the side, and the first rotating member and the second rotating member are attached so as not to rotate relative to the motor shaft, and are attached to the motor shaft. Is A first positioning portion that contacts the first rotating member from the same side as the movable bearing, and a second positioning portion that contacts the second rotating member from the same side as the fixed bearing, are provided on the fixed bearing. When the second rotating member abuts and the second positioning member abuts on the second rotating member, the motor shaft is positioned in the axial direction with respect to the reference member, and the first positioning portion The movable bearing is pressed against the first rotating member in contact with the first rotating member by the biasing force of the biasing member.

  In the present invention, the second rotating member is positioned with respect to the second positioning portion formed on the motor shaft as described above, and the fixed bearing is brought into contact with the second rotating member. Accordingly, the motor shaft can be positioned in the axial direction with respect to the reference member via the second rotating member and the fixed bearing. On the other hand, the movable bearing is positioned by being pressed by the urging force of the urging member against the first rotating member positioned on the motor shaft via the first positioning portion. With such a configuration, backlash in the axial direction of the motor shaft can be reduced, and the positional accuracy of the motor shaft with respect to the reference member can be improved.

  In the present invention, it is preferable that the first positioning portion and the second positioning portion are stepped portions formed on the motor shaft. Since the step portion has a surface facing the axial direction, the first and second rotating members can be brought into contact with the surface in the axial direction for positioning.

  In the present invention, each of the fixed bearing and the movable bearing includes an inner cylinder part and an outer cylinder part arranged coaxially, and each inner cylinder part holds the motor shaft in a relatively non-rotatable manner, The urging member applies an urging force to the outer cylindrical portion of the movable bearing, and the axial end surface of the inner cylindrical portion of the movable bearing is applied to the first rotating member by the urging member. It is desirable that the second rotating member is pressed by an urging force and abuts on an end surface in the axial direction of the inner cylindrical portion of the fixed bearing. If it does in this way, since it becomes the structure which contacted members (the 1st and 2nd rotating member and the inner side cylinder part of a bearing) which rotate integrally with a motor axis in the direction of an axis, the first, It is possible to suppress the second rotating member and the bearing portion in contact with the second rotating member from sliding in the rotational direction. Therefore, the torcross by friction between members can be controlled. Further, wear of the positioning portion for positioning the motor shaft in the axial direction can be suppressed. Therefore, it is possible to suppress a decrease in the position accuracy of the motor shaft due to wear.

  In this case, it is desirable that the reference member is provided with a contact portion that comes into contact with the outer cylindrical portion of the fixed bearing. Thus, by positioning the fixed bearing in contact with the contact portion, the fixed bearing can be attached at an accurate position as compared with the fixing method in which the fixed portion is fixed only by friction with the inner wall surface of the cylindrical portion. .

  In the present invention, it is desirable that the movable bearing is held by the reference member so as to be movable in the axial direction. Thus, by holding the movable bearing with the same member as the fixed bearing, the coaxiality of both bearings can be increased. Thereby, the inclination (falling) of the motor shaft with respect to the reference member can be reduced.

  In the present invention, it is desirable that the urging member is disposed between the fixed bearing and the movable bearing that are disposed apart in the axial direction. If it does in this way, the space between both bearings can be used effectively. Further, since the distance between both the bearings is increased, the inclination (falling) of the motor shaft due to the clearance between the inner peripheral surface of the bearing and the outer peripheral surface of the motor shaft can be reduced. Therefore, it is possible to reduce the force that supports the motor shaft against the force that the motor shaft tends to fall, and it is possible to reduce the force applied to the bearing.

  In the present invention, it is desirable that the rotor and the stator are disposed between the first rotating member and the second rotating member that are disposed apart from each other in the axial direction. If it does in this way, the space between the 1st rotation member and the 2nd rotation member can be used effectively, and it is advantageous to size reduction.

  In this case, the rotor and the stator are preferably arranged so as to overlap the urging member in the axial direction. If it does in this way, since the space of the outer peripheral side of an urging member can be used effectively, space can be used more effectively.

  In the present invention, the stator is preferably fixed to the reference member. In this way, since the position of the stator in the axial direction is accurately determined, there is an advantage that the magnetic centers of the rotor and the stator can be easily aligned.

  In order to solve the above problems, a pump device according to the present invention includes a pump case provided with the motor, an impeller that rotates integrally with the motor shaft of the motor, and a pump chamber for arranging the impeller. The reference member is a case member constituting the pump case, and an arc-shaped vortex chamber is provided in the outer peripheral portion of the pump chamber, and the pump is provided in the inner peripheral portion of the pump chamber. A seal portion for sealing a fluid flowing through the chamber is formed by an inner peripheral surface of the pump chamber and the impeller.

  As described above, the present invention can accurately position the motor shaft in the axial direction with respect to the case member (reference member) constituting the pump case, and thus can improve the positional accuracy of the impeller in the axial direction with respect to the pump case. Therefore, the sealing performance of the seal part in the pump chamber can be enhanced.

  In the present invention, the impeller is preferably provided at both ends of the motor shaft, and the pump case is preferably provided with two pump chambers for disposing the impellers at positions separated in the axial direction. If it does in this way, the position accuracy of the direction of an axis of two sets of impellers can be raised. Moreover, since two sets of pump chambers and impellers can be arranged apart in the axial direction, piping connected to each pump chamber can be arranged apart in the axial direction. Therefore, interference between the pipes can be avoided and the pipes can be easily connected.

  In this case, it is desirable that the fluid inlet and outlet in one of the two pump chambers and the fluid inlet and outlet in the other are provided at positions overlapping in the axial direction. A force is generated by the pressure difference of the fluid between the inlet (low pressure side) and the outlet (high pressure side). In such a configuration, the force due to the pressure difference is generated in the same direction in the two pump chambers. To do. Therefore, the force in the same direction is applied to each impeller provided at one end and the other end of the motor shaft, and the force applied to the motor shaft from the fluid in the upper and lower pump chambers does not work in the direction in which the motor shaft falls. . Therefore, it can suppress that an impeller inclines with the force from a fluid.

  Further, it is desirable that the flow path connected to the fluid outlet in one of the two pump chambers and the flow path connected to the fluid outlet in the other are independent of each other. In this way, even when a failure occurs in the flow path connected to one pump chamber, the fluid can be sent out from the other pump chamber. Therefore, it is possible to reduce the risk of the fluid supply completely stopping when a failure occurs.

In the present invention, a screw portion is formed at an end of the motor shaft on the side where the impeller is provided, and the impeller is attached to the screw portion in the axial direction of the first rotating member or the second rotating member. through the pre-Symbol impeller sandwiched between the end face, or to hold the first rotating member in a state of pressing the first positioning portion, or the second the second rotary member through said impeller It is desirable that the structure is held so as to be pressed against the positioning portion. If it does in this way, the play of an impeller can be controlled. In addition, since the impeller can be disposed at a position close to the bearing (position pressed against the bearing via the first and second rotating members), the positional accuracy of the impeller in the radial direction can be improved.

  Further, it is desirable that the rotation direction when the screw portion is tightened and the rotation direction when the motor shaft is forwardly rotated coincide with each other. If it does in this way, loosening of the fixing member at the time of motor drive can be controlled.

  In the present invention, the first rotating member or the second rotating member and the fixing member sandwich and hold the impeller in the axial direction at a position closer to the inner peripheral edge of the seal portion than the outer peripheral surface of the motor shaft. It is desirable that In this way, the impeller can be positioned in the axial direction near the seal portion. Therefore, the position accuracy of the impeller in the seal portion can be increased. Moreover, the deflection of the impeller can be suppressed.

  In the present invention, at least one of the first rotating member or the second rotating member, and the fixing member has a portion located on the inner peripheral side with respect to the portion in contact with the impeller in the axial direction. It is desirable to be spaced apart from the impeller in the axial direction. In this way, the impeller is positioned in the axial direction at a position away from the motor shaft, so that the inclination of the impeller can be reduced.

  In the present invention, the pump case includes a plurality of case members stacked in the axial direction, including the reference member, and a penetrating member that penetrates the plurality of case members in the axial direction. The penetrating portion by the penetrating member is in contact with another case member that is laminated adjacently, and the plurality of case members are clamped in the axial direction by the penetrating member and positioned with respect to each other. It is desirable. If it does in this way, since it becomes the structure which clamps and fixes the part which case members are contact | abutting to an axial direction, the bending of a case member and a penetration member (screw etc.) by clamping | tightening does not generate | occur | produce easily. Therefore, the accuracy in the axial direction of the pump case can be increased.

  According to the present invention, backlash in the axial direction of the motor shaft can be reduced, and the positional accuracy of the motor shaft with respect to the reference member can be improved.

It is a perspective view of a pump device to which the present invention is applied. It is the top view and front view of the pump apparatus to which this invention is applied. It is sectional drawing (XX sectional drawing of Fig.2 (a)) of the pump apparatus to which this invention is applied. It is a disassembled perspective view of the pump apparatus to which this invention is applied. It is explanatory drawing which shows the electromotive part and air supply system of a fuel cell using the pump apparatus to which this invention is applied.

  Hereinafter, a pump device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, for convenience of explanation, the upper and lower parts of the pump device will be described according to the upper and lower parts of the drawing.

(overall structure)
FIG. 1 is a perspective view of a pump apparatus to which the present invention is applied as viewed from the front obliquely from above, FIG. 2 (a) is a plan view of the pump apparatus, and FIG. 2 (b) is a front view of the pump apparatus. The pump device 1 of this example is a vortex pump that pumps fluid such as air. The pump device 1 is used for an application such as an air supply pump for supplying air to a cathode electrode of an electromotive cell provided in a fuel cell. A configuration example in this case will be described later.

  As shown in FIGS. 1 and 2, the pump device 1 includes a pump case 2 having a substantially quadrangular prism shape as a whole. The pump case 2 includes four case members, an upper case 3, an intermediate case 4, a reference case 5, and a lower case 6 that are stacked in the axial direction L (the vertical direction in FIGS. 1 and 2) of the pump device 1. The upper case 3, the intermediate case 4, the reference case 5, and the lower case 6 have through-holes 8 such as screws passed through fixing holes 7 formed at the four corners of each case member, and their tips are screwed onto the case member or nuts. By combining, it is assembled in the shape of the pump case 2. The part where the fixing hole 7 is formed in each case member is in contact with adjacent case members disposed on the upper side and the lower side. Therefore, by tightening with the penetrating member 8, the upper case 3, the intermediate case 4, the reference case 5, and the lower case 6 are positioned in contact with each other with respect to the case members adjacent in the vertical direction. Yes. Thus, in the structure in which the case members are brought into contact with each other at the tightening position by the penetrating member 8, the case member and the penetrating member 8 are unlikely to bend. Therefore, the pump case 2 can be formed with high accuracy.

  From the front surfaces of the upper case 3 and the intermediate case 4, an upper inflow pipe 9 and an upper outflow pipe 10 protrude in parallel toward the front. Further, the lower inflow pipe 11 and the lower outflow pipe 12 protrude in parallel from the front surfaces of the reference case 5 and the lower case 6 toward the front. These two sets of inflow pipe and outflow pipe are arranged so as to overlap in the vertical direction (that is, the axial direction L of the pump chamber). The pump device 1 discharges the fluid sucked from the opening at the front end of the upper inflow pipe 9 from the opening at the front end of the upper outflow pipe 10 and opens the fluid sucked from the opening at the front end of the lower inflow pipe 11 to the opening at the front end of the lower outflow pipe 12. It is discharged from.

  3 is a cross-sectional view of the pump device 1 (a cross-sectional view taken along the line XX of FIG. 2A), and FIG. 4 is an exploded perspective view of the pump device. An upper compartment 13 is provided between the upper case 3 and the intermediate case 4 at the upper part of the pump case 2. A motor chamber 14 is provided between the intermediate case 4 and the reference case 5 on the lower side of the intermediate case 4, that is, on the opposite side of the upper compartment 13. The motor chamber 14 and the upper compartment 13 communicate with each other in the vertical direction at the central portion thereof. A lower compartment 15 is provided between the reference case 5 and the lower case 6 on the lower side of the reference case 5, that is, on the side opposite to the motor chamber 14. The lower compartment 15 is provided in the lower part of the pump case 2 and is partitioned from the motor chamber 14. The upper compartment 13 and the lower compartment 15 are formed vertically symmetrically at the upper and lower parts of the pump case 2.

  At the center of the upper surface of the reference case 5, a cylindrical central protrusion 51 protrudes upward. An annular motor chamber bottom surface 52 is formed on the outer peripheral side of the central protruding portion 51, and a peripheral wall portion 53 protruding upward at a constant height along the outer periphery of the motor chamber bottom surface 52 is coaxial with the central protruding portion 51. Is formed. A cutout portion 53 a in which the peripheral wall portion 53 is partially cut out is provided at a portion of the peripheral wall portion 53 on the back side of the pump case 2. A substantially rectangular flange portion 54 is formed on the outer peripheral side of the peripheral wall portion 53.

  The intermediate case 4 is provided with a circular motor housing recess 42 that opens in the lower end surface 41 of the intermediate case 4. The motor housing recess 42 is formed coaxially with the central protrusion 51 and the peripheral wall 53 of the reference case 5. When the intermediate case 4 and the reference case 5 are assembled, the peripheral wall portion 53 is inscribed inside the opening edge of the motor housing recess 42, and the lower end surface 41 is in contact with the flange portion 54. Is configured. On the back side of the intermediate case 4, a notch 41 a is formed by notching upward the portion of the lower end surface 41 that faces the notch 53 a. The cutout portion 53a and the cutout portion 41a form a wiring extraction portion 43 that opens on the back surface of the pump case 2.

  The inner peripheral surface of the motor housing recess 42 is constituted by a lower cylindrical surface 42a extending upward from the opening edge of the motor housing recess 42 and an annular surface 42b connected to the upper end edge of the lower cylindrical surface 42a. A circular opening 44 is formed in the center of the annular surface 42b. The circular opening 44 is a through-hole formed coaxially with the central projecting portion 51, and the upper end thereof opens to the bottom surface of the upper compartment 13. The circular opening 44 is coaxial with the central protrusion 51, and the upper end portion of the central protrusion 51 extends into the circular opening 44.

(motor)
As shown in FIG. 3, a motor 1 </ b> A that is a drive source of the pump device 1 is disposed in the pump case 2. The motor 1A includes a motor shaft 16, a fixed bearing 17 and a movable bearing 18 that rotatably support the motor shaft 16, and a fixed bearing 17 that is fixed and that the movable bearing 18 is movable in the axial direction L. And a biasing member 19 that biases the movable bearing 18 toward the side away from the fixed bearing 17. In this example, a compression coil spring is used as the urging member 19. Note that another elastic member (for example, a leaf spring) can be used as the urging member 19. The motor 1 </ b> A includes a rotor 70 and a stator 60 for rotating the motor shaft 16, a first rotating member 20 </ b> A attached to the end of the motor shaft 16 on the movable bearing 18 side, and a fixed bearing 17 of the motor shaft 16. The 2nd rotation member 20B attached to the edge part of the side is provided.

  A motor shaft mounting hole 55 extending in the axial direction L (the vertical direction in FIGS. 3 and 4) of the pump device 1 is formed in the central protrusion 51 of the reference case 5. The motor shaft 16 is disposed in the motor shaft mounting hole 55. The upper end portion of the motor shaft 16 protrudes upward from the tip of the motor shaft mounting hole 55, and extends through the circular opening 44 into the upper compartment 13 disposed at the upper portion thereof. On the other hand, the lower end portion of the motor shaft 16 extends from the lower end of the motor shaft mounting hole 55 into the lower compartment 15 disposed on the lower side thereof.

  The fixed bearing 17 is disposed at the lower end of the motor shaft mounting hole 55, and the movable bearing 18 is disposed at the upper end. The fixed bearing 17 and the movable bearing 18 support the motor shaft 16 so as to be rotatable at two positions separated in the axial direction L. The fixed bearing 17 includes an inner cylindrical portion 17a and an outer cylindrical portion 17b arranged coaxially, and rolling elements 17c such as balls or rollers held between the two cylindrical portions. The movable bearing 18 includes an inner cylindrical portion 18a and an outer cylindrical portion 18b that are coaxially arranged, and a rolling element 18c that is held between the cylindrical portions. The motor shaft 16 is held on the inner cylindrical portions 17a and 18a of both bearings so as not to rotate relative to each other.

  The fixed bearing 17 is mounted on the lower end portion of the motor shaft mounting hole 55. An annular contact portion 56 that protrudes inward is formed on the inner peripheral surface of the motor shaft mounting hole 55. The fixed bearing 17 is positioned at the lower end portion of the motor shaft mounting hole 55 because the outer cylindrical portion 17b is in contact with the contact portion 56 from below. By such a positioning method, the fixed bearing 17 can be accurately positioned as compared with the case of positioning by friction with the inner peripheral surface of the motor shaft mounting hole 55 or the like. The contact portion 56 has a length (thickness) in the axial direction L smaller than the axial length of the outer cylindrical portion 17b.

  A compressed biasing member 19 (compression coil spring) is disposed between the contact portion 56 and the movable bearing 18. The urging member 19 has a lower end in contact with the contact portion 56 and an upper end in contact with the outer cylindrical portion 18b of the movable bearing 18 from below. Thus, in the motor shaft mounting hole 55, the outer cylindrical portion 17b of the fixed bearing 17, the contact portion 56, the biasing member 19, and the outer cylindrical portion 18b of the movable bearing 18 are arranged in this order in the vertical direction (that is, the axis line). They are arranged in the direction L). The movable bearing 18 is mounted in the motor shaft mounting hole 55 so as to be movable in the vertical direction. The movable bearing 18 can be moved up and down between the outer peripheral surface of the movable bearing 18 and the inner peripheral surface of the motor shaft mounting hole 55, and the movable bearing 18 is moved radially in the motor shaft mounting hole 55. Clearance is provided so that positioning can be performed without rattling. The movable bearing 18 is urged upward by the urging member 19 (that is, the side away from the fixed bearing 17).

  Here, in this example, the dimension of the urging member 19 (compression coil spring) is set as follows. First, the length in the axial direction L of the urging member 19 is H1, and the length in the axial direction L of the motor shaft mounting hole 55 (in this example, from the lower end surface 17d of the fixed bearing 17 to the upper end surface 18d of the movable bearing 18). H1 ≧ H2 / 2, where H2 is a dimension set to substantially match the above dimensions. Further, when the outer diameter of the urging member 19 is D, D <H1. Further, as described above, the urging member 19 is configured such that the upper end thereof is in contact with the outer cylindrical portion 18 b of the movable bearing 18, and its outer diameter D is the same as the inner peripheral surface of the motor shaft mounting hole 55. The clearance between the motor shaft 16 and the outer peripheral surface of the motor shaft 16 is set to be small. In other words, the urging member 19 is configured so as not to be greatly buckled during compression, and is unlikely to contact the rotating motor shaft 16 even if it is buckled and deformed.

  A stator 60 and a rotor 70 are disposed in the motor chamber 14. The stator 60 is fixed to the outer peripheral side of a central protrusion 51 provided at the center of the motor chamber 14. The stator 60 includes a drive coil 61 and a stator core 62 on which the drive coil 61 is mounted. The stator core 62 is an annular member provided with a plurality of salient poles projecting radially inward at equal angular intervals, and a drive coil 61 is wound around each salient pole via an insulating member. A wiring (not shown) drawn from the drive coil 61 of the stator 60 is drawn to the outside of the pump case 2 via the wiring extraction portion 43. The rotor 70 includes a rotor magnet 71 disposed on the outer peripheral side of the stator 60 and a holding member 72 that holds the rotor magnet 71. The rotor magnet 71 and the drive coil 61 constitute a magnetic drive mechanism for rotationally driving the motor shaft 16.

  The holding member 72 includes a cylindrical magnet holding portion 72a that opens downward, and the rotor magnet 71 is fixed to the inner peripheral surface of the magnet holding portion 72a. The holding member 72 includes an annular substrate holding portion 72b extending from the upper end of the magnet holding portion 72a to the inner peripheral side, and the substrate 73 is fixed to the lower surface of the substrate holding portion 72b. An upper cylindrical portion 72c that extends upward from the inner peripheral edge of the substrate holding portion 72b and a circular plate portion 72d that is bent inward from the upper end thereof are provided on the upper portion of the holding member 72. A circular fitting hole 72e is opened at the center of the circular plate portion 72d. The holding member 72 is arranged coaxially with the central protrusion 51. The stator 60 is fixed at a substantially central position in the axial direction L of the central protruding portion 51, and is disposed so as to overlap the urging member 19 in the central protruding portion 51 in the axial direction L. The holding member 72 holds the rotor magnet 71 at a position overlapping the stator 60 in the axial direction L.

  The holding member 72 is fixed to the first rotating member 20 </ b> A attached to the upper end side of the motor shaft 16. The first rotating member 20 </ b> A is not rotatable relative to the motor shaft 16. The first rotating member 20A includes a cylindrical motor shaft mounting portion 21A provided at the center thereof, a disk portion 22A provided near the lower end of the outer periphery of the motor shaft mounting portion 21A, and the disk portion 22A. An annular projecting portion 23A projecting upward at a constant height along the outer peripheral edge and a fitting projecting portion 24A projecting annularly downward from the lower surface of the disc portion 22A are provided. The holding member 72 is disposed such that the upper surface of the circular plate portion 72d, which is the upper end surface thereof, is in contact with the lower surface of the disc portion 22A, and the fitting protrusion 24A is press-fitted and fixed inside the fitting hole 72e. Yes. As a result, the rotor 70, the first rotating member 20A, and the motor shaft 16 rotate together.

  The upper portion of the motor shaft 16 protruding upward from the movable bearing 18 is inserted into the motor shaft mounting portion 21A of the first rotating member 20A. A step portion 25A is formed at the lower end portion of the inner peripheral surface of the motor shaft mounting portion 21A. The inner peripheral surface of the motor shaft mounting portion 21A is a cylindrical portion 26A1 having a constant inner diameter at the upper portion from the step portion 25A, and the lower portion from the step portion 25A has a larger diameter than the cylindrical portion 26A1. The large diameter portion 26A2. The step portion 25A is a downward annular surface perpendicular to the axial direction L, the inner peripheral edge thereof is connected to the lower end of the cylindrical portion 26A1, and the outer peripheral edge is connected to the upper end of the large diameter portion 26A2. On the other hand, the motor shaft 16 is formed with an upper end side step portion 16a on the outer peripheral surface of the portion inserted into the motor shaft mounting portion 21A. A small-diameter portion 16 c having a smaller diameter than the central portion 16 b of the motor shaft 16 is formed at the upper end portion of the motor shaft 16. The upper end side step portion 16 a is an upward annular surface perpendicular to the axial direction L, the inner peripheral edge thereof is connected to the lower end of the outer peripheral surface of the small diameter portion 16 c, and the outer peripheral edge is the center portion 16 b of the motor shaft 16. It is connected to the upper end of the outer peripheral surface. The step portion 25A of the first rotating member 20A and the upper end side step portion 16a of the motor shaft 16 are opposed to each other in the axial direction L, and the axial direction L of the first rotating member 20A and the motor shaft 16 is brought into contact with each other. The relative position of is determined. That is, the upper end side step portion 16a functions as a positioning portion (first positioning portion) for positioning the first rotating member 20A with respect to the motor shaft 16 in the axial direction L.

  Here, the lower end portion of the motor shaft mounting portion 21A protrudes downward from the inner peripheral edge of the disc portion 22A, and its lower end surface 27A faces the upper end surface 18d of the inner cylindrical portion 18a of the movable bearing 18. . As described above, since the movable bearing 18 is urged upward by the urging member 19, the movable bearing 18 has moved to a position where the upper end face 18d is pressed against the lower end face 27A. The movable bearing 18 is positioned at the contact position with the first rotating member 20 </ b> A by the biasing force of the biasing member 19.

  A second rotating member 20 </ b> B is attached to the lower end side of the motor shaft 16. The second rotating member 20 </ b> B is not rotatable relative to the motor shaft 16. The second rotating member 20B has the same shape as the first rotating member 20A, and is disposed upside down with respect to the first rotating member 20A. Below, the shape and attachment state of the 2nd rotation member 20B are demonstrated according to the upper and lower sides of FIG. The second rotating member 20B includes a cylindrical motor shaft mounting portion 21B provided at the center thereof, a disc portion 22B provided at a position near the upper end of the outer periphery of the motor shaft mounting portion 21B, and a disc portion 22B. An annular projecting portion 23B projecting downward at a constant height along the outer peripheral edge is provided. An annular protrusion having the same shape as the fitting protrusion 24A of the first rotating member 20A is provided on the upper surface of the disk portion 22B.

  The lower part of the motor shaft 16 protruding downward from the fixed bearing 17 is inserted into the motor shaft mounting portion 21B of the second rotating member 20B. A step portion 25B is formed at the upper end portion of the inner peripheral surface of the motor shaft mounting portion 21B. The inner peripheral surface of the motor shaft mounting part 21B is a cylindrical part 26B1 having a constant inner diameter at the lower part of the step part 25B, and the part above the step part 25B is larger in diameter than the cylindrical part 26B1. The large diameter portion 26B2. The step portion 25B is an upward annular surface perpendicular to the axial direction L, the inner peripheral edge thereof is connected to the upper end of the cylindrical portion 26B1, and the outer peripheral edge is connected to the lower end of the large diameter portion 26B2. On the other hand, the motor shaft 16 has a lower end side step portion 16d formed on the outer peripheral surface of the portion inserted into the motor shaft mounting portion 21B. At the lower end portion of the motor shaft 16, a small-diameter portion 16e having a smaller diameter than the central portion 16b in the axial direction of the motor shaft 16 is formed. The lower end side step portion 16d is a downward annular surface perpendicular to the axial direction L, the inner peripheral edge thereof is connected to the upper end of the outer peripheral surface of the small diameter portion 16e, and the outer peripheral edge is the lower end of the outer peripheral surface of the central portion 16b. It is connected to the. The step portion 25B of the second rotating member 20B and the lower end side step portion 16d of the motor shaft 16 are opposed to each other in the axial direction L, and both the step portions are in contact with each other to contact the axial direction L of the second rotating member 20B and the motor shaft 16. The relative position of is determined. That is, the lower end side step portion 16d functions as a positioning portion (second positioning portion) for positioning the second rotating member 20B in the axial direction L with respect to the motor shaft 16.

  The upper end portion of the motor shaft mounting portion 21B in the second rotating member 20B protrudes upward from the inner peripheral edge of the disc portion 22B, and its upper end surface 27B is on the lower end surface 17d of the inner cylindrical portion 17a of the fixed bearing 17. It is in contact. The motor shaft 16 and the fixed bearing 17 are positioned so that the lower end side step portion 16d of the motor shaft 16 contacts the step portion 25B and the upper end surface 27B contacts the lower end surface 17d of the fixed bearing 17. That is, on the lower end side of the motor shaft 16, the motor shaft 16 and the second rotating member 20 </ b> B are positioned in the axial direction L with respect to the fixed bearing 17 positioned by the contact portion 56 with respect to the reference case 5.

  With the above-described structure, the motor shaft 16 and the fixed bearing 17 that supports the lower end thereof are positioned in the axial direction L with respect to the reference case 5, and the lower end of the motor shaft 16 is connected to the lower end side step portion 16 d. The contacted second rotating member 20B is positioned. On the other hand, the movable bearing 18 that supports the upper end of the motor shaft 16 is pressed against the first rotating member 20 </ b> A in contact with the upper end side stepped portion 16 a by the biasing force of the biasing member 19. Therefore, the motor shaft 16 is attached to the reference case 5 so as not to rattle in the axial direction L, and the first rotating member 20A and the second rotating member 20B are spaced apart in the axial direction L from the upper end side. The positioning is performed so as to coincide with the interval between the stepped portion 16a and the lower end side stepped portion 16d.

(Impeller)
An upper impeller 80A disposed on the upper side of the first rotating member 20A and a fixing member 90A for sandwiching and holding the upper impeller 80A between the first rotating member 20A are attached to the upper end of the motor shaft 16. Yes. The upper impeller 80 </ b> A includes a disc portion 81 and an impeller 82 provided on the outer peripheral side of the disc portion 81. On the outer peripheral portion of the impeller 82, an upper concave portion 83a and a lower concave portion 83b formed in two upper and lower stages are formed at equal angular intervals in the circumferential direction. Between the upper recessed parts 83a adjacent in the circumferential direction are blades 84a extending in the radial direction, and between the lower recessed parts 83b adjacent in the circumferential direction are blades 84b extending in the radial direction. A rib 85 that extends in the circumferential direction and divides the blades 84a and 84b vertically is formed between the upper and lower recesses 83a and 83b adjacent in the vertical direction. The upper concave portion 83a and the lower concave portion 83b are concave portions having the same shape, and the same number is provided on the upper side and the lower side of the rib 85, respectively. Therefore, in the upper impeller 80A, the force received by the upper recess 83a from the fluid is the same as the force received by the lower recess 83b, and the force from the fluid may act as a force in the axial direction L on the upper impeller 80A. There is no shape. A through hole 86 is formed in the center of the disc part 81. When the upper impeller 80A is arranged on the upper portion of the first rotating member 20A, the motor shaft mounting portion 21A of the first rotating member 20A is inserted into the through hole 86, and the outer periphery of the motor shaft mounting portion 21A is inserted into the inner peripheral surface of the through hole 86. The surface is inscribed.

  The fixing member 90A has a disk shape, and a screw hole 91 extending in the axial direction L passes through the center of the fixing member 90A. A circular recess 93 having a certain depth is formed on the lower surface 92 of the fixing member 90 </ b> A so as to surround the screw hole 91. The lower surface 92 of the fixing member 90 </ b> A is a flat surface except for the portion where the circular recess 93 is formed. A male screw portion 94A for screwing the fixing member 90A is formed at the upper end of the motor shaft 16. The male threaded portion 94A is screwed into the screw hole 91 of the fixing member 90A, and the fixing member 90A is tightened, whereby the annular end surface 28A at the upper end of the annular protrusion 23A formed on the outer peripheral edge of the first rotating member 20A. And the disc part 81 of the upper impeller 80A is sandwiched between the lower surface 92 of the fixing member 90A, and the upper impeller 80A is fixed to the motor shaft 16. The male screw portion 94A and the screw hole 91 are formed with screw grooves such that the male screw portion 94A rotates in the screw tightening direction with respect to the fixing member 90A when the motor shaft 16 rotates forward.

  When the upper impeller 80A is sandwiched between the fixing member 90A and the first rotating member 20A, the upper end surface 29A of the motor shaft mounting portion 21A faces the bottom surface 93a of the circular recess 93 of the fixing member 90A. In this example, the depth of the circular recess 93 is set so that a gap is formed between the upper end surface 29A and the bottom surface 93a. Accordingly, the contact portion in the axial direction L between the first rotating member 20A and the upper impeller 80A is only the annular end surface 28A of the annular projecting portion 23A that is the outer peripheral portion away from the motor shaft 16, and A portion on the inner peripheral side of the protruding portion 23A is separated from the upper impeller 80A in the axial direction L. On the other hand, the entire lower surface 92 of the fixing member 90A excluding the circular recess 93 is a contact surface with the upper impeller 80A.

  On the other hand, at the lower end of the motor shaft 16, there is a lower impeller 80B disposed on the lower side of the second rotating member 20B and a fixing member 90B for sandwiching and holding the lower impeller 80B between the second rotating member 20B. It is attached. A male thread portion 94B for screwing the fixing member 90B is formed at the lower end of the motor shaft 16. Here, the lower impeller 80B and the fixing member 90B have the same configuration as the upper impeller 80A and the fixing member 90A, respectively, and are arranged upside down. Since the structure for attaching the lower impeller 80B to the lower end of the motor shaft 16 is the same as the structure for attaching the upper impeller 80A to the upper end of the motor shaft 16, the description thereof will be omitted.

(pump room)
The upper case 3 is provided with a recess 31 that opens to the lower surface of the upper case 3. The concave portion 31 includes a circular bottom surface 31a provided at the center thereof, an inner inner peripheral surface 31b extending downward from the outer peripheral edge of the circular bottom surface 31a, a seal surface 31c connected to the lower end edge of the inner inner peripheral surface 31b, An inner cylindrical surface 31d extending upward from the outer peripheral edge of the seal surface 31c, an annular bottom surface 31e connected to the upper end edge of the inner cylindrical surface 31d, and an outer cylindrical surface 31f extending downward from the outer peripheral edge of the annular bottom surface 31e are provided. ing. The inner inner peripheral surface 31b, the inner cylindrical surface 31d, and the outer cylindrical surface 31f are formed coaxially. The outer peripheral portion of the recess 31 has a groove shape with a constant width defined by the inner cylindrical surface 31d, the annular bottom surface 31e, and the outer cylindrical surface 31f, and the outer peripheral portion of the annular bottom surface 31e, which is the groove bottom surface, is semicircular. An arc groove 32 having a cross section is formed.

  On the other hand, a recess 45 facing the recess 31 is formed on the upper surface of the intermediate case 4 facing the upper case 3. A circular opening 44 communicating with the motor chamber 14 is opened at the center of the bottom surface of the recess 45. The recess 45 includes a circular bottom surface 45a connected to the upper end edge of the circular opening 44, an inner inner peripheral surface 45b extending upward from the outer peripheral edge of the circular bottom surface 45a, and a seal connected to the lower end edge of the inner inner peripheral surface 45b. A surface 45c, an inner cylindrical surface 45d extending upward from the outer peripheral edge of the seal surface 45c, an annular bottom surface 45e connected to the upper edge of the inner cylindrical surface 45d, and an outer cylinder extending downward from the outer peripheral edge of the annular bottom surface 45e A surface 45f is provided. The circular opening 44, the inner inner peripheral surface 45b, the inner cylindrical surface 45d, and the outer cylindrical surface 45f are formed coaxially. The outer peripheral portion of the recess 45 has a groove shape with a constant width defined by the inner cylindrical surface 45d, the annular bottom surface 45e, and the outer cylindrical surface 45f. An arc groove 46 having a semicircular cross section is formed on the outer peripheral portion of the annular bottom surface 45e that is the groove bottom surface so as to be vertically symmetrical with the arc groove 32 on the upper case 3 side.

  As shown in FIG. 4, one end and the other end of the arc groove 46 extend to the front side of the intermediate case 4 on the upper surface of the intermediate case 4, and the front surface of the intermediate case 4 where one end and the other end of the arc groove 46 are located. On the side portion, flow channel grooves 47a and 47b are formed in parallel for constituting the respective flow channels communicating with the tip openings of the upper inflow tube 9 and the upper outflow tube 10. Further, an arcuate fitting groove 48 is formed on the outer peripheral side of the recess 45 on the upper surface of the intermediate case 4 in a range excluding the front side portion where the flow path grooves 47a and 47b are formed. Similarly, on the lower surface of the upper case 3, a flow path groove (not shown) is formed in parallel on the front side portion of the upper case 3 where one end and the other end of the circular arc groove 32 are located, and a recess in the upper case 3 is formed. An arc-shaped rib 33 (see FIG. 3) is formed on the outer peripheral side of 31 so as to protrude downward. When the upper case 3 and the intermediate case 4 are assembled, the outer peripheral portions of both cases come into contact with each other, and the ribs 33 are fitted into the fitting grooves 48 to position both members. Thus, the upper compartment 13 is formed between the two cases, and a flow path passing through the upper inflow pipe 9 and the upper outflow pipe 10 is formed.

  An upper impeller 80A attached to the upper end of the motor shaft 16 is disposed in the upper compartment 13. The seal surface 31c of the concave portion 31 and the seal surface 45c of the concave portion 45 are opposed to each other with a small gap between the upper and lower surfaces of the disk portion 81 of the upper impeller 80A, and the seal portion 13c is formed in this portion. ing. The fixed member 90 </ b> A and the first rotating member 20 </ b> A sandwich the disk portion 81 of the upper impeller 80 </ b> A vertically at a position between the seal portion 13 c and the motor shaft 16. In the upper compartment 13, the annular protrusion 23 </ b> A of the first rotating member 20 </ b> A described above is disposed at a position closer to the inner peripheral edge of the seal portion 13 c than the outer peripheral surface of the motor shaft 16. Accordingly, the sandwiching position of the upper impeller 80A by the first rotating member 20A and the fixing member 90A is closer to the inner peripheral edge of the seal portion 13c than the outer peripheral surface of the motor shaft. The outer peripheral portion of the upper compartment 13 constitutes an annular pump chamber 13a whose inner peripheral side is sealed by a seal portion 13c. An arc-shaped vortex chamber 13b is formed in the angular range where the arc grooves 32 and 46 are formed in the outer peripheral portion of the pump chamber 13a. The impeller 82 of the upper impeller 80A is disposed coaxially with the pump chamber 13a and the vortex chamber 13b, and is inserted into the vortex chamber 13b.

  As described above, the lower compartment 15 is formed between the reference case 5 and the lower case 6, and is formed vertically symmetrical with the upper compartment 13 in the lower part of the pump case 2. In other words, the reference case 5 is provided with a recess 57 that opens to the lower surface of the reference case 5, and the recess 57 is formed in a shape that vertically inverts the recess 45 of the intermediate case 4. Further, a concave portion 63 that is the inverted shape of the concave portion 31 of the upper case 3 is formed on the upper surface of the lower case 6 facing the reference case 5 so as to face the concave portion 57. When the reference case 5 and the lower case 6 are assembled, the outer peripheral portions of both cases come into contact with each other, and the ribs 64 formed in the lower case 6 are fitted into the fitting grooves 58 formed in the reference case 5, so that both members Is positioned. As a result, a lower compartment 15 is formed between the two cases, and a flow path passing through the lower inflow pipe 11 and the lower outflow pipe 12 is formed.

  A lower impeller 80B attached to the lower end of the motor shaft 16 is disposed in the lower compartment 15. As with the upper compartment 13, the lower compartment 15 forms an annular pump chamber 15a, and an arc-shaped vortex chamber 15b is formed in the outer circumference of the pump chamber 15a. . Further, in the inner peripheral portion of the pump chamber 15a, a seal surface 57a provided on the inner peripheral surface of the concave portion 57 and a seal surface 63a provided on the inner peripheral surface of the concave portion 63 are very small between the lower impeller 80B. A seal portion 15c that is opposed to the gap is formed. The arrangement of the lower impeller 80B in the lower compartment 15 is the same as the arrangement of the upper impeller 80A in the upper compartment 13. In the lower compartment 15, the annular protrusion 23 </ b> B of the second rotating member 20 </ b> B is disposed at a position closer to the inner peripheral edge of the seal portion 15 c than the outer peripheral surface of the motor shaft 16. Therefore, the sandwiching position of the lower impeller 80B by the second rotating member 20B and the fixed member 90B is closer to the inner peripheral edge of the seal portion 15c than the outer peripheral surface of the motor shaft 16.

  Here, the pump chamber 13 a is connected to a flow path that passes through the upper inflow pipe 9 and the upper outflow pipe 10. A connection portion between the upper inflow pipe 9 and the pump chamber 13a is a fluid inlet 9a (see FIG. 2A) to the pump chamber 13a. Moreover, the connection part of the upper outflow pipe | tube 10 and the pump chamber 13a becomes the outflow port 10a (refer Fig.2 (a)) of the fluid from the pump chamber 13a. Similarly, the pump chamber 15a is connected to a flow path passing through the lower inflow pipe 11 and the lower outflow pipe 12, and an inflow port 11a (see FIG. 2A) that is a connection portion with the lower inflow pipe 11 and the lower An outlet 12a (see FIG. 2 (a)) that is a connecting portion with the outflow pipe 12 is provided. As described above, the pump chamber 13a and the pump chamber 15a are not in communication with each other, are connected to flow paths that pass through different inflow pipes and outflow pipes, and are connected to independent flow paths. As described above, the two flow paths of the upper inflow pipe 9 and the upper outflow pipe 10 and the lower inflow pipe 11 and the lower outflow pipe 12 are arranged so as to overlap in the vertical direction, that is, the axial direction L. Both inflow ports 9a and 11a in the pump chambers 13a and 15a are arranged so as to overlap in the axial direction L. Further, both outlets 10a, 12a are also arranged so as to overlap in the axial direction L.

  In the pump chambers 13a and 15a, a force is generated by the pressure difference of the fluid between the inlet (low pressure side) and the outlet (high pressure side). For this reason, as described above, by connecting the pipe connection portions (the inlet 9a and outlet 10a in the pump chamber 13a, the inlet 11a and outlet 12a in the pump chamber 15a) so as to overlap in the axial direction L. The force due to the pressure difference of the fluid is generated in the same direction in the pump chambers 13a and 15a. Therefore, a force in the same direction is applied to the upper impeller 80A and the lower impeller 80B provided at one end and the other end of the motor shaft 16, and this force does not work in the direction in which the motor shaft 16 is tilted. Therefore, it is possible to prevent the upper impeller 80A and the lower impeller 80B from being inclined by the force from the fluid. In addition, since the two sets of pump chambers 13a and 15a are arranged apart from each other in the axial direction, a pipe connected to the pump chamber 13a (upper inlet pipe 9 and upper outlet pipe 10) and a pipe connected to the pump chamber 15a (downstream) The inlet pipe 11 and the lower outlet pipe 12) can be separated in the axial direction L. Therefore, interference between the pipes can be avoided and the pipes can be easily connected.

(Assembly method of pump device)
When the pump device 1 is assembled, the fixed bearing 17 and the movable bearing 18 are disposed in the motor shaft mounting hole 55 of the reference case 5. After the motor shaft 16 is inserted into the inner cylindrical portions 17 a and 18 a of the fixed bearing 17 and the movable bearing 18, the stator 60 is fixed to the outer periphery of the central protrusion 51, and the rotor 70 and the first rotating member 20 </ b> A from the upper end of the motor shaft 16. And the rotor 70 is coaxially positioned on the outer peripheral side of the stator 60. On the other hand, the second rotating member 20 </ b> B is attached from the lower end of the motor shaft 16. After the intermediate case 4 is overlaid on the reference case 5, the upper impeller 80 </ b> A is attached on the first rotating member 20 </ b> A from the upper end of the motor shaft 16, and the fixing member 90 </ b> A is fastened to the male screw portion 94 </ b> A on the upper end of the motor shaft 16. Include. Similarly, the lower impeller 80B is attached on the second rotating member 20B from the lower end of the motor shaft 16, and the fixing member 90B is fastened to the male screw portion 94B at the lower end of the motor shaft 16. Then, the upper case 3 is disposed on the upper side of the intermediate case 4, the lower case 6 is disposed on the lower side of the reference case 5, and the four case members are fastened and fixed by the penetrating member 8.

  As a result, the impeller portions (upper impeller 80A and lower impeller 80B) are formed at both ends of the motor shaft 16, and the rotor 70 is disposed at the intermediate portion thereof so that they are integrally rotated. At this time, the distance between the two impeller portions in the axial direction L is an interval corresponding to the distance between the two step portions (the upper end side step portion 16a and the lower end side step portion 16d) formed on the motor shaft 16. Further, the interval between the movable bearing 18 and the fixed bearing 17 is adjusted to an interval corresponding to the interval between the two impeller portions by the urging force of the urging member 19. As a result, the pump device 1 is configured in which both impeller portions are accurately positioned in the upper compartment 13 and the lower compartment 15.

(Function and effect)
As described above, the pump device 1 of the present example includes the motor 1A, and the motor 1A moves the motor shaft 16 with respect to the reference case 5 in the axial direction L via the second rotating member 20B and the fixed bearing 17. Can be positioned. On the other hand, the movable bearing 18 is positioned by being pressed by the biasing force of the biasing member 19 against the first rotating member 20A positioned on the motor shaft 16 via the upper end side step portion 16a (first positioning portion). ing. With such a configuration, rattling in the axial direction L of the motor shaft 16 can be reduced, and the positional accuracy of the motor shaft 16 with respect to the reference case 5 can be improved.

  Further, in the motor 1A of this example, by forming step portions (upper end step portion 16a and lower end step portion 16d) as positioning portions on the motor shaft 16, both steps that are surfaces perpendicular to the axial direction L are formed. The first and second rotating members 20A and 20B can be brought into contact with each other and positioned. In such a positioning method, since the positional accuracy between the first and second rotating members 20A and 20B can be set to the processing accuracy of the motor shaft 16, both rotating members can be positioned with high accuracy.

  Further, in the motor 1A of this example, the first rotating member 20A and the inner cylindrical portion 18a of the movable bearing 18 are brought into contact with each other in the axial direction L, and the second rotating member 20B and the inner cylindrical portion 17a of the fixed bearing 17 are brought into the axial direction L. It is made to contact. Thus, by positioning the members that rotate together with the motor shaft 16 in contact with each other, it is possible to suppress the members that are in contact with each other during rotation of the motor shaft from sliding in the rotation direction. Therefore, the torcross by friction between members can be controlled. Further, it is possible to suppress wear of the contact portion for positioning the motor shaft 16 in the axial direction L. Therefore, it is possible to suppress a decrease in position accuracy of the motor shaft 16 due to wear.

  In addition, in the motor 1A of this example, not only the fixed bearing 17 but also the movable bearing 18 is held in the motor shaft mounting hole 55 of the reference case 5, and both bearings are held by the same member. For this reason, the coaxiality of both bearings can be increased, and the inclination (falling) of the motor shaft 16 with respect to the reference case 5 can be reduced.

  Moreover, in the motor 1A of this example, since the urging member 19 is disposed in a space sandwiched between the fixed bearing 17 and the movable bearing 18, the space between both bearings can be effectively utilized. Further, since the distance between the two bearings can be increased, the inclination (falling) of the motor shaft 16 caused by the clearance between the inner peripheral surfaces of the inner cylindrical portions 17a and 18a and the outer peripheral surface of the motor shaft 16 in each bearing can be reduced. Therefore, the force that supports the motor shaft 16 against the force that the motor shaft 16 tends to fall can be reduced, and the force applied to the bearing can be reduced.

  Further, in the motor 1A of this example, the rotor 70 and the stator 60 are arranged in a space sandwiched between the first and second rotating members 20A and 20B in the axial direction, and are arranged so as to overlap the urging member 19 in the axial direction L. ing. Therefore, the space on the outer peripheral side of the motor shaft 16 and the bearing can be used effectively, which is advantageous for downsizing. Further, the stator 60 is fixed to the outer peripheral side of the central projecting portion 51 by press-fitting the central projecting portion 51 of the reference case 5 into the stator core 62, and on the stepped portion 51 a provided on the outer peripheral surface of the central projecting portion 51. Positioning in the axial direction L is performed by bringing the stepped portion 62a of the stator core 62 into contact. With such a configuration, there is an advantage that the position of the stator 60 in the axial direction L is accurately determined and the magnetic centers of the rotor 70 and the stator 60 can be easily aligned.

  The pump device 1 of this example can accurately position the motor shaft 16 having the upper impeller 80A and the lower impeller 80B at both ends in the axial direction L, so the axial directions of the upper impeller 80A and the lower impeller 80B with respect to the pump case 2 The position accuracy of L can be increased. Further, since the positional accuracy of each impeller in the axial direction L is increased, the inclination of each impeller with respect to the motor shaft 16 can be reduced. Therefore, in the pump chamber 13a, the sealing performance of the seal portion 13c constituted by the pump chamber peripheral surfaces (seal surfaces 31c and 45c) and the upper impeller 80A can be improved, and similarly in the pump chamber 15a The sealing performance of the seal portion 15c constituted by the surfaces (seal surfaces 57a and 63a) and the lower impeller 80B can be enhanced.

  Further, in the pump device 1 of this example, the upper impeller 80A and the lower impeller 80B are sandwiched between the fixing members 90A and 90B screwed to the tip of the motor shaft 16 and the first and second rotating members 20A and 20B. Since it holds, each impeller can be attached without rattling. Moreover, since each impeller can be arrange | positioned in the position close | similar to the fixed bearing 17 and the movable bearing 18, the positional accuracy of the radial direction of each impeller can be improved. Further, one of the members sandwiching each impeller (first and second rotating members 20A and 20B) is configured to contact the impeller only at the outer peripheral portion thereof. In this way, by inserting each impeller at a position closer to the inner peripheral edge of the seal portions 13c and 15c than the outer peripheral surface of the motor shaft 16 in the pump chambers 13a and 15a, each impeller is axially positioned at a position near the seal portions 13c and 15c. Position in the direction L. Therefore, the position accuracy of each impeller in the seal portions 13c and 15c can be increased, and the deflection of the impeller can be suppressed. Moreover, the inclination of the impeller can be suppressed.

  Note that each impeller is positioned at a position closer to the seal portions 13c and 15c than the motor shaft 16, and the members (first and second rotating members 20A and 20B or The structure in which the fixing members 90 </ b> A and 90 </ b> B) are arranged apart from the impeller may be realized with a configuration different from the above embodiment. For example, a convex portion similar to the annular protrusion 23A is formed on the outer peripheral portion of the surface of the fixing members 90A and 90B facing each impeller, and only the outer peripheral portion of the fixing members 90A and 90B is in contact with each impeller. You may comprise. In this case, the surfaces facing the respective impellers in the first and second rotating members 20A and 20B may be flat surfaces, or on the first and second rotating members 20A and 20B side as in the above embodiment. Alternatively, an annular protrusion may be formed. Further, an annular protrusion is not formed on the first or second rotating member 20A, 20B or the fixing member 90A, 90B, but an annular protrusion is formed on the front or back surface of each impeller. You may comprise so that the end surface of a protrusion part may be contact | abutted to 1st, 2nd rotation member 20A, 20B or fixing member 90A, 90B.

  Further, in the pump device 1 of this example, since the motor shaft mounting portion 21A extending through the upper impeller 80A is formed on the first rotating member 20A, the contact length between the first rotating member 20A and the motor shaft 16 is increased. That is, the length of the motor shaft mounting portion 21A in the axial direction L is long. If it does in this way, since the inclination with respect to the motor shaft 16 of 20 A of 1st rotation members can be suppressed, the inclination with respect to the axial direction L of 80 A of upper impellers can be suppressed more effectively. Moreover, since the inclination with respect to the 2nd rotation member 20B and the motor shaft 16 can also be suppressed by the same structure, the inclination with respect to the axial direction L of the lower impeller 80B can be suppressed more effectively.

The configuration of this example can be changed as follows.
(1) In this example, step portions (upper end step portion 16a and lower end step portion 16d) are formed on the motor shaft 16 as positioning portions, and the first and second rotating members 20A and 20B are applied to the respective step portions. Although it is positioned in contact with each other, it is also possible to form a female screw portion at both ends of the motor shaft 16 instead of a stepped portion, and fix the first and second rotating members 20A, 20B to each female screw portion by screw tightening.
(2) As the movable bearing 18 and the fixed bearing 17, not a rolling bearing as in this example but a sliding bearing can be used. For example, a bearing in which the outer peripheral surface of the inner cylindrical portion and the inner peripheral surface of the outer cylindrical portion are slip surfaces can be used.
(3) In this example, the outer cylindrical portion 17b of the fixed bearing 17 is positioned in contact with the contact portion 56 formed on the inner peripheral surface of the motor shaft mounting hole 55, but the contact portion 56 is formed. Alternatively, the outer cylindrical portion 17b may be bonded and fixed to the inner peripheral surface of the motor shaft mounting hole 55.
(4) Centrifugal pump in which the pump device 1 of this example is connected to the pump chambers 13a, 15a in the axial direction L with the respective inflow tubes (upper inflow tube 9, lower inflow tube 11) supplying fluid to the pump chambers 13a, 15a. It is good.

(Application example of pump device to fuel cell)
FIG. 5 is an explanatory diagram showing an electromotive unit and an air supply system of a fuel cell using the pump device 1 of this example. The fuel cell 100 is a direct methanol fuel cell (DMFC) that uses an aqueous methanol solution as a liquid fuel and oxygen-containing air as an oxidizing agent for reaction. The fuel cell 100 is for electromotive use in which an electrolyte membrane 103 is provided between an anode electrode 101 to which an aqueous methanol solution (fuel fluid) is supplied and a cathode electrode 102 to which air (reaction gas containing oxygen) is supplied. A DMFC stack 105 in which a plurality of single cells 104 are arranged is provided. The fuel cell 100 also supplies a fuel supply system (not shown) for supplying fuel to each anode 101 of the DMFC stack 105, and discharges unreacted fuel fluid and reaction products from each anode 101. A fuel discharge system (not shown), an air supply system 106 for supplying air to each cathode electrode 102, and an exhaust system 107 for discharging reacted gas from each cathode electrode 102 of the DMFC stack 105. ing.

  The air supply system 106 includes a pump device 1, an intake passage 108 that takes in supply air to the pump device 1, and a supply passage 109 that sends air from the pump device 1 to each cathode 102 in the DMFC stack 105. ing. The intake flow path 108 includes two channels, a first intake flow path 108A and a second intake flow path 108B. The first intake flow path 108A is connected to the upper inflow pipe 9, and the second intake flow path 108B is connected to the lower inflow pipe 11. Further, the supply channel 109 includes two systems of channels, a first supply channel 109A and a second supply channel 109B. The first supply flow path 109 </ b> A is connected to the upper outflow pipe 10, and the second supply flow path 109 </ b> B is connected to the lower outflow pipe 12.

  The first intake passage 108A and the second intake passage 108B are connected to the intake port 108C. The pump device 1 sucks air flowing in from the inlet 108C into the inlet 9a of the pump chamber 13a via the first inlet passage 108A and the upper inlet pipe 9, and passes through the upper outlet pipe 10 from the outlet 10a. 1 It sends out to the supply flow path 109A. Further, air is sucked into the inlet 11a of the pump chamber 15a via the second intake passage 108B and the lower inflow pipe 11, and is sent from the outlet 12a to the second supply passage 109B via the lower outlet pipe 12.

  109 A of 1st supply flow paths and the 2nd supply flow path 109B are comprised by the mutually independent piping. Each downstream end of the first supply channel 109A and the second supply channel 109B is branched into a number of channels corresponding to the number of unit cells 104 to be connected, and a DMFC stack 105 is provided at the end of each branch channel. Single cells 104 are connected. Each single cell 104 is connected only to the branch channel from either the first supply channel 109A or the second supply channel 109B. Therefore, each cathode electrode 102 is supplied with air from only one of the first supply channel 109A and the second supply channel 109B. On the other hand, the exhaust system 107 includes a plurality of exhaust passages 107B connected to the exhaust port 107A. The number of exhaust passages 107 </ b> B is the same as the number of single cells 104, and the exhaust passage 107 </ b> B is connected to each single cell 104.

  In the air supply system 106 and the exhaust system 107 to the DMFC stack 105, troubles such as leakage of air from the pipe due to disconnection of the pipe constituting the flow path or clogging of the pipe for some reason. There was a risk of occurrence. Further, since water is generated as a reaction product at each cathode electrode 102, the generated water may be clogged in the air flow path or the exhaust flow path 107B in each single cell 104. In this example, the pump device 1 including two pump chambers 13a and 15a that are not in communication with each other is used as an air supply pump of the fuel cell 100, and an outlet (outlet 10a and outlet) from each pump chamber is used. 12a) is connected to independent pipes (first supply flow path 109A and second supply flow path 109B) to form two independent air supply paths. Each unit cell 104 is connected to only one system air supply path, and the exhaust passage 107B from each unit cell 104 is independent of each other.

  In such a configuration, even when a problem such as clogging or air leakage occurs in one air supply path or the flow path connected to this air supply path, the single cell 104 connected to the other air supply path. There is little influence on the air supply. In addition, since the pump device 1 of the present example has a configuration in which the backlash of the motor shaft 16 is reduced as described above, the malfunction of the flow path connected to one pump chamber is reduced from the other pump chamber. Little effect on fluid delivery. Therefore, the single cell 104 connected to the air supply path having no defect can be operated, and the operating rate of the single cell 104 can be increased even when a defect occurs. Therefore, the risk that the fuel cell 100 stops completely can be reduced.

  Note that the same effect can be obtained also when used as an air supply pump to devices other than the fuel cell 100. For example, when supply channels to different counterpart devices are connected to the outlets (the outlet 10a and the outlet 12a) from the pump chambers 13a and 15a, respectively, and these supply channels are independent from each other. In this case, a configuration can be obtained in which when the malfunction of one counterpart device occurs, the other counterpart device can continue to operate. Therefore, it is possible to reduce the risk that the fluid supply is completely stopped when the malfunction occurs and the apparatus completely stops functioning.

DESCRIPTION OF SYMBOLS 1 ... Pump apparatus 1A ... Motor 2 ... Pump case 3 ... Upper case 4 ... Intermediate case 5 ... Reference | standard case (reference | standard member)
6 ... lower case 7 ... fixing hole 8 ... penetrating member 9 ... upper inflow pipe 9a ... inlet 10 ... upper outflow pipe 10a / outlet 11 ... lower inflow pipe 11a / inlet 12 ... Lower outlet pipe 12a Outlet 13 Upper compartment 13a Pump chamber 13b Swirl chamber 13c Seal portion 14 Motor chamber 15 Lower compartment 15a Pump chamber 15b Swirl chamber 15c Seal portion 16 ..Motor shaft 16a and upper end side step portion (first positioning portion)
16b, central portion 16c, small diameter portion 16d, lower end side step portion (second positioning portion)
16e, small diameter part 17, fixed bearing 17a, inner cylinder part 17b, outer cylinder part 17c, rolling element 17d, lower end face 18, movable bearing 18a, inner cylinder part 18b, outer cylinder part 18c, rolling element 18d, upper part End face 19 .. biasing member 20A first rotating member 21A motor shaft mounting portion 22A disc portion 23A annular projection portion 24A fitting projection portion 25A step portion 26A1 cylindrical portion 26A2 large diameter portion 27A Lower end surface 28A, annular end surface 29A, upper end surface 20B, second rotating member 21B, motor shaft mounting portion 22B, disc portion 23B, annular projecting portion 25B, step portion 26B, annular step surface 26B1, cylindrical portion 26B2, large diameter portion 27B, upper end surface 31, concave portion 31a, circular bottom surface 31b, inner inner peripheral surface 31c, sealing surface 31d, inner cylindrical surface 31e, annular bottom surface 31f, outer cylindrical surface 32, arc groove 33, Re 41 ·· Lower end surface 41a · Notch portion · · Motor housing recess 42a · Lower cylindrical surface 42b · Ring surface 43 · · Wire extraction portion 44 · · Circular opening 45 · · Recess 45a · Circular bottom surface 45b · Inner inner peripheral surface 45c, sealing surface 45d, inner cylindrical surface 45e, annular bottom surface 45f, outer cylindrical surface 46, arc groove 47a, channel groove 47b, channel groove 48, fitting groove 51, central protrusion 51a, stepped portion 52, motor chamber bottom surface 53, peripheral wall portion 53a, notch portion 54, flange portion 55, motor shaft mounting hole 56, contact portion 57, recess 57a, seal surface 58, fitting Joint groove 60, stator 61, drive coil 62, stator core 62a, stepped portion 63, recess 63a, sealing surface 64, rib 70, rotor 71, rotor magnet 72, holding member 72a, magnet holding portion 2b, substrate holding portion 72c, upper cylindrical portion 72d, circular plate portion 72e, fitting hole 73, substrate 80A, upper impeller 80B, lower impeller 81, disc portion 82, impeller 83a, upper recessed portion 83b Lower recess 84a, blade 84b, blade 85, rib 86, through hole 90A, fixing member 90B, fixing member 91, screw hole 92, lower surface 93, circular recess 93a, bottom surface 94A, male screw portion 94B Male thread part 100, fuel cell 101, anode electrode 102, cathode electrode 103, electrolyte membrane 104, single cell 105, DMFC stack 106, air supply system 107, exhaust system 107A, exhaust port 107B, exhaust channel 108, intake channel 108A, first intake passage 108B, second intake passage 108C, intake port 109A, first supply passage 109B, second supply passage L, axial direction

Claims (18)

A motor shaft;
A rotor and a stator for rotating the motor shaft;
A fixed bearing that rotatably supports the motor shaft;
A reference member to which the fixed bearing is fixed;
A movable bearing that rotatably supports the motor shaft at a position different from the fixed bearing, and is movable relative to the fixed bearing in the axial direction of the motor shaft;
A biasing member that biases the movable bearing toward the side away from the fixed bearing;
A first rotating member facing an end surface facing the opposite side of the fixed bearing in the movable bearing;
A second rotating member facing an end face facing the opposite side of the movable bearing in the fixed bearing;
The first rotating member and the second rotating member are attached so as not to rotate relative to the motor shaft,
The motor shaft is provided with a first positioning portion that contacts the first rotating member from the same side as the movable bearing, and a second positioning portion that contacts the second rotating member from the same side as the fixed bearing. ,
The second rotating member is in contact with the fixed bearing, and the second positioning member is in contact with the second rotating member, whereby the motor shaft is positioned in the axial direction with respect to the reference member,
The motor, wherein the movable bearing is pressed against the first rotating member in contact with the first positioning portion by an urging force of the urging member. In claim 1,
The motor according to claim 1, wherein the first positioning portion and the second positioning portion are stepped portions formed on the motor shaft. In claim 1 or 2,
Each of the fixed bearing and the movable bearing includes an inner cylinder part and an outer cylinder part arranged coaxially, and each inner cylinder part holds the motor shaft in a relatively non-rotatable manner,
The biasing member applies a biasing force to the outer cylindrical portion of the movable bearing,
The axial end surface of the inner cylindrical portion of the movable bearing is pressed against the first rotating member by the urging force of the urging member,
The motor according to claim 1, wherein the second rotating member is in contact with an end face in the axial direction of the inner cylindrical portion of the fixed bearing. In claim 3,
The motor according to claim 1, wherein the reference member is provided with a contact portion that contacts the outer cylindrical portion of the fixed bearing. In any one of claims 1 to 4,
The motor is characterized in that the movable bearing is held by the reference member so as to be movable in the axial direction. In any one of claims 1 to 5,
The motor, wherein the biasing member is disposed between the fixed bearing and the movable bearing that are spaced apart in the axial direction. In claim 6,
The motor, wherein the rotor and the stator are disposed between the first rotating member and the second rotating member that are disposed apart from each other in the axial direction. In claim 7,
The rotor and the stator are disposed so as to overlap the biasing member in the axial direction. In any one of claims 1 to 8,
The motor is characterized in that the stator is fixed to the reference member. The motor according to any one of claims 1 to 9,
An impeller that rotates integrally with the motor shaft in the motor;
A pump case provided with a pump chamber for arranging the impeller,
The reference member is a case member constituting the pump case,
An arc-shaped vortex chamber is provided on the outer periphery of the pump chamber,
A pump device characterized in that a seal portion for sealing a fluid flowing through the pump chamber is formed on the inner peripheral portion of the pump chamber by the inner peripheral surface of the pump chamber and the impeller. In claim 10,
The impeller is provided at both ends of the motor shaft;
2. The pump device according to claim 1, wherein the pump case is provided with two pump chambers for disposing the impellers at positions separated from each other in the axial direction. In claim 11,
The pump apparatus according to claim 1, wherein the fluid inlet and outlet of one of the two pump chambers and the fluid inlet and outlet of the other of the two pump chambers are provided at positions overlapping in the axial direction. In claim 11 or 12,
The pumping apparatus according to claim 1, wherein the fluid outlet in one of the two pump chambers and the fluid outlet in the other are connected to mutually independent flow paths. In any one of claims 10 to 13,
A threaded portion is formed at the end of the motor shaft on the side where the impeller is provided,
The A threaded portion, said first positioning portion in front Symbol first rotating member through the front Symbol impeller sandwiched between the axial end faces of the said impeller first rotary member or said second rotary member held in a state pressed against the, or pump apparatus characterized by fixing member for holding the second rotary member pressed against the second positioning portion is screwed. In claim 14,
The pump device according to claim 1, wherein a rotation direction when the screw portion is tightened and a rotation direction when the motor shaft is forwardly rotated coincide with each other. In claim 14 or 15,
The first rotating member or the second rotating member and the fixing member hold the impeller sandwiched in the axial direction at a position closer to the inner peripheral edge of the seal portion than the outer peripheral surface of the motor shaft. A pump device characterized. In any one of claims 14 to 16,
At least one of the first rotating member or the second rotating member, and the fixing member has a portion located on the inner peripheral side with respect to the portion in contact with the impeller in the axial direction from the impeller to the axial line. A pump device characterized by being spaced apart in the direction. In any one of claims 10 to 17,
The pump case is
A plurality of case members including the reference member and stacked in the axial direction;
A penetrating member penetrating the plurality of case members in the axial direction,
The penetrating part by the penetrating member in each case member is in contact with another case member laminated adjacently,
The pump device, wherein the plurality of case members are clamped in the axial direction and positioned relative to each other by the penetrating member.

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