JP4046986B2 - Pump device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pump device including a magnetic coupling as a constituent element, and more specifically to a structure of a magnetic coupling drive motor.
[0002]
[Prior art]
As shown in FIG. 3, in a water supply pump to which a magnet coupling method is applied, normally, a drive magnet 101 is directly connected to a motor output shaft 100 and a driven magnet 103 on the impeller 102 side is driven. The motor output shaft 100 always rotates in the state where it is pulled out from the motor 105 (arrow A) by the attractive force between the couplings 104 configured in cooperation with the magnetic force of the driven magnet 103. Therefore, the washer 107 provided in the axial stopper shown by the arrow A is a bearing inside the motor 105 in a state as shown in an enlarged view of a circled portion in FIG. The suction force that contacts the end face 106a of the metal 106 and acts in the thrust direction (arrow A) is supported.
[0003]
[Problems to be solved by the invention]
However, in the motor structure described above, although the bearing metal 106 of the output shaft 100 is basically a radial bearing, the end face 106a of the bearing metal 106 is in sliding contact with the retaining washer 107, so that the standard motor is provided. The thrust bearing 108 of the output shaft 100 is not used. When the limit of the life of the bearing metal 106 is taken into consideration, the specification application is limited. In addition, since the mounting position of the retaining washer 107 with respect to the output shaft 100 is unstable in the thrust direction, depending on the load, the rotation of the output shaft 100 may not be stable, and the characteristics may be distorted and noise may be generated. .
[0004]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the load applied to bearings and retainers by applying a force in the direction opposite to the attractive force of the magnet coupling to the rotor of the drive motor, thereby extending the life of the motor. Alternatively, it is to extend the life of the pump drive motor.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a pump device according to the present invention has an impeller in which a driving magnet coupled to a driving source and a driven magnet coupled with a partition through a partition are integrally formed of a synthetic resin. In the pump apparatus configured to rotate the impeller to transfer the fluid, the impeller is rotatably supported by a fixed shaft, and the driven magnet is spaced apart from the driving magnet in the axial direction. Using a motor as a drive source, which is opposed to each other in parallel, and has a motor output shaft fixed integrally with the rotor of the motor, the motor output shaft is mounted with the drive magnet at one end in the axial direction, The driving magnet of the magnet coupling acting on the rotor resists the attractive force attracted to the driven magnet side, and the front Magnetic means for applying a magnetic force in the direction opposite to the attractive force to the rotor, and other axial directions of the motor output shaft to prevent the thrust bearing receiving the thrust of the motor output shaft from being pulled out to the opposite side in the axial direction. A retaining ring inserted into an end, and the motor has an outer rotor structure, and a counter magnet, which is the magnetic means, is disposed inside the cup-shaped rotor yoke fixed to the motor output shaft. And the counter magnet reduces the retaining load applied to the retaining ring by the counter magnet.
[0007]
Moreover, the attraction force is canceled by the magnetic force acting in the opposite direction. Alternatively, a thrust bearing may be provided on the other end of the output shaft of the rotor in which the magnetic force acting in the opposite direction is made larger than the attractive force and the driving magnet is fixed to one end. That is, since the output shaft end face supports the thrust with an urging force exceeding the suction force, the contact angle is reduced, which is advantageous for improving the wear resistance.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a motor structure according to the present invention will be described below with reference to the drawings of one embodiment. FIG. 1 is a side view showing an entire pump device 10 according to the present invention, and is partially shown in cross section. The pump device 10 includes a drive unit 12 and a pump unit 14. The drive unit 12 includes a brushless DC motor 16 as a drive motor.
[0009]
A magnetic synthetic resin in which a fixed shaft 20 is fixed upright in the center of the pump case 18 in the pump portion 14 and a bearing portion 22 made of a wear-resistant resin having slipperiness is integrally provided by an insert mold. A molded impeller 24 is rotatably supported on the fixed shaft 20. The pump unit 14 is spatially separated from the drive unit 12 and is isolated by a non-magnetic bottom plate 18 a that defines the lower surface of the pump case 18.
[0010]
An impeller 24 that energizes the fluid 19 by rotating around the fixed shaft 20 in the fluid 19 filled in the pump case 18 and pressurizes and flows the fluid 19 is formed of a magnetic material, and an appropriate magnetic force is magnetized. Thus, it functions as a driven side coupling 26 a in the pair of magnet couplings 26. The drive unit 12 includes a motor 16 having a ring-shaped magnet that transmits rotation to the driven coupling 26 a as a drive side coupling 26 b fixed to the output shaft 30, a casing 17 that covers the drive motor 16, and a bottom surface 17 a of the casing 17. The substrate 33 is provided with a brushless DC motor drive circuit provided as the drive motor 16. 33a is a connector, and 33b is a flexible flat cable (FFC) that electrically connects the substrate 33 and the connector 33a. Reference numeral 33c denotes a connector terminal for electrical connection with a control panel (not shown).
[0011]
In both cases, the driven coupling 26a and the drive coupling 26b made of magnetized magnetic materials are opposed to each other in parallel on the common rotating shaft via the pump case bottom plate 18a while maintaining a separation distance d. The magnetic couplings 26 are provided with rotating magnetic surfaces that interact with each other, and there is no mechanical means such as a shaft for connecting the two. In the present embodiment, the driven coupling 26a is rotatably supported in the liquid 19 filling the pump case 18, and the drive coupling 26b is freely rotated by direct driving of the motor 16 in the air.
[0012]
FIG. 2 is a side view showing the structure of the drive motor 16 according to the present invention in an axial section. The drive motor 16 is an outer rotor type brushless DC motor, and a tubular bearing metal 42 is embedded and fixed in a bottomed cylindrical bearing case 40 fixed upright on a motor substrate 16a. A cup-shaped rotor yoke 44 formed of a magnetic material is integrally fixed to one end of the motor output shaft 30, and a drive coupling 26 b is attached to the outer end of the motor output shaft 30 so that the bearing metal 42 can be rotatably supported. Is done.
[0013]
The stator 46 is a laminated body of electromagnetic steel plates 46a, and a center hole 46c drilled in the base 46b is fitted and fixed to the outer surface of the bearing case 40. Windings (coils) 50 wound around the iron core 46d through the electrical insulating material 48 are accommodated in an appropriate number of slots formed by the iron core 46d extending radially from the base 46b of the stator 46. The annular magnet 54 fixed to the rotor yoke 44 of the rotor 52 has an inner surface 54a concentric with the outer peripheral surface (stator teeth) 46e of the iron core 46d, is opposed through a small fixed gap, and is driven to rotate around the output shaft 30. The The number of magnetic poles corresponding to the number of slots is set and magnetized in the annular magnet 54 according to the required motor output. A hall element 56 detects the position of the rotor 52 by the magnetic pole of the annular magnet 54 and controls the rotation.
[0014]
In the motor output shaft 30 that is rotatably supported by the tubular bearing metal 42, the end surface 30a opposite to the front end where the drive coupling 26b is mounted is formed in a spherical surface and faces the bottom inner surface 40a of the bottomed cylindrical bearing case 40. Therefore, the thrust bearing 58 is sandwiched between the output shaft end surface 30a and the bearing case bottom inner surface 40a. Further, an annular groove 30b is formed in the outer periphery near the output shaft end face 30a to forcibly insert the retaining ring 31, thereby preventing the output shaft 30 from being pulled upward in the figure by an unexpected external force.
[0015]
A ring-shaped counter magnet 60 is fixed to the open end 40 c side of the bearing case 40 that supports the stator 46 so as to face the rotor yoke 44, and a traction force that presses the rotor 52 toward the stator 46 more strongly than the attractive force between the magnet couplings 26. Set the magnetic field to be generated. For this reason, the magnetic force of the counter magnet 60 and the distance from the rotor yoke 44 are appropriately selected. In this way, the biasing force in the direction of the stator 46 acting on the rotor yoke 44 by the counter magnet 60 acts as a contact pressure that presses the output shaft end surface 30a integral with the rotor yoke 44 against the thrust bearing 58. Further, since the counter magnet 60 is set at a position covered with the rotor yoke 44 formed of a magnetic material, the leakage of magnetic flux is small, and the influence on other devices due to the mounting of the counter magnet 60 is small.
[0016]
The thrust bearing 58 of the output shaft 30 receives the thrust and is crimped to the bearing case bottom inner surface 40 a, and the bearing case 40 supports stress acting in the thrust direction of the entire rotor 52 including the motor output shaft 30. Accordingly, the thrust bearing 58 functions to support the sliding contact pressure in the thrust direction of the output shaft 30 to reduce friction and to ensure stable and smooth rotation. Further, since the output shaft end surface 30a formed in a spherical surface is always pressed against the thrust bearing 58 in a manner close to a point contact, stable characteristics that are not affected by the load can be obtained.
[0017]
Although the embodiments have been described above, the present invention is not limited to the illustrated embodiments. For example, the size and shape of the counter magnet can be used without departing from the configuration requirements of the present invention. It is anticipated that various changes regarding details, such as mounting positions, etc., and modifications such as reconfiguration of parts can be made.
[0018]
【The invention's effect】
As is apparent from the above description, according to the pump device of the present invention as set forth in claim 1, the driving magnet connected to the driving source and the driven magnet coupled with the partition across the partition are made of synthetic resin. In the pump device configured to transfer the fluid by rotating the impeller, the impeller is rotatably supported by a fixed shaft, and the driven magnet is connected to the driving magnet. A motor is used as the drive source, and the motor output shaft is fixed integrally with the rotor of the motor. The motor output shaft has one end in the axial direction. The drive magnet is attached, and the drive magnet of the magnet coupling acting on the rotor is attracted to the driven magnet side. In order to prevent the thrust of the thrust bearing receiving the thrust of the motor output shaft from being pulled out to the opposite side in the axial direction, the magnetic means for causing the rotor to exert a magnetic force in the direction opposite to the attractive force against the attractive force A retaining ring fitted to the other end of the motor output shaft in the axial direction, and the motor has an outer rotor structure, and the magnet is disposed inside a cup-shaped rotor yoke fixed to the motor output shaft. When the counter magnet, which is a central means, is installed so as to face the rotor yoke in the axial direction and the retaining load applied to the retaining ring is reduced by the counter magnet, the force in the reverse direction is not cancelled. Will extend the life of the retaining ring . When the magnetic force cancels, a standard thrust bearing that receives the shaft end face can be used. In addition, the motor has an outer rotor structure, and a counter magnet, which is the magnetic means, is provided inside the cup-shaped rotor yoke so as to face the rotor yoke. The effect can be suppressed, and it can be constructed compactly because it does not require a pedestal or space for mounting. In addition, it is not necessary to match performance between the pump device and the motor, and the pump device can be repaired, replaced, managed, etc. independently from the motor.
[0021]
Then, according to the pump equipment according to the present invention as set forth in claim 2, wherein the suction force because the offset by the magnetic force acting in the opposite direction, the contact angle is less wear resistant for a thrust in the motor shaft end face improves. In addition, the thrust load applied to the motor shaft is reduced and the bearing life is extended. That is, durability can be improved and the life can be extended. Ideally, the thrust load can be as close to zero as possible.
[0022]
Furthermore, according to the pump equipment according to the present invention as set forth in claim 3, wherein greater than the suction force of the magnetic force acting in the opposite direction, the output shaft of the rotor and fixing the driving magnet to one end Since a thrust bearing is provided at the other end, the output shaft end and the thrust bearing are always in sliding contact with a constant contact pressure in a constant direction, eliminating motor runout and backlash in the axial direction, enabling smooth operation. It becomes. Therefore, the characteristics do not vary depending on the load. Moreover, since the influence of gravity can be ignored, the installation posture can be freely selected, and the output shaft can be installed sideways or upside down.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing a pump device according to an embodiment of the present invention in a partial cross section.
FIG. 2 is a schematic side view showing a part of a motor structure according to the present invention in cross section.
FIG. 3 is a side view partially showing a cross section of an embodiment of a conventional pump device, and FIG. 3B is an enlarged view of a portion surrounded by a circle b in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Pump apparatus 12 Drive part 14 Pump part 16 Brushless DC motor 18 Pump case 20 Fixed shaft 24 Impeller 26 Magnet coupling 30 Motor output shaft 40 Cylindrical bearing case 42 Tubular bearing metal 44 Rotor yoke 46 Stator 50 Coil 52 Rotor 54 Annular magnet 58 Thrust Bearing 60 Counter magnet

Claims (3)

In a pump device having a structure in which a driving magnet connected to a driving source and a driven magnet magnet-coupled across a partition wall are integrally formed of a synthetic resin, and the impeller is rotated to transfer a fluid. ,
  The impeller is rotatably supported on a fixed shaft, and the driven magnet is opposed to the driving magnet in parallel with a distance in the axial direction, and a motor is used as the driving source. The motor output shaft is integrally fixed. The motor output shaft is mounted with the drive magnet at one end in the axial direction, and the drive magnet of the magnet coupling acting on the rotor is used for the follower. Magnetic means for causing the rotor to apply a magnetic force in a direction opposite to the attractive force against the attractive force attracted to the magnet side, and an axial direction opposite side of the thrust bearing that receives the thrust of the motor output shaft A retaining ring fitted to the other end in the axial direction of the motor output shaft to prevent pulling, the motor having an outer rotor structure, The counter magnet, which is the magnetic means, is installed inside the cup-shaped rotor yoke fixed to the rotor output shaft so as to face the rotor yoke in the axial direction, and the retaining load applied to the retaining ring by the counter magnet A pump device characterized by reducing the pressure. The pump device according to claim 1, wherein the attraction force is canceled by a magnetic force acting in the opposite direction. 3. The thrust bearing according to claim 2, wherein a thrust bearing is provided at the other end of the output shaft of the rotor in which the magnetic force acting in the opposite direction is made larger than the attractive force and the driving magnet is fixed to one end. Pump device.

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