JP4936258B2 - Submersible bearing pump - Google Patents

Description

  The present invention relates to an underwater sliding bearing pump in which an impeller is rotatably supported through a bearing fixed in the center around a shaft, and slides using lubrication of circulating water.

  A pump called a submerged slide bearing pump has a sliding portion, and generates a pump action by rotational sliding of a bearing and a bearing plate.

  As an example of this submersible slide bearing pump, for example, ones having structures disclosed in Japanese Patent No. 3099434 and Japanese Patent Application Laid-Open No. 2006-200197 have been proposed.

  This type of pump is typically a pump called a magnet pump disclosed in Patent Document 1 or a DC brushless pump disclosed in Patent Document 2.

  A conventional pump will be described with reference to FIG. 12, which is a DC brushless pump. In the pump 2, the motor 1 has a winding 3 having a coil disposed thereon, thereby generating a magnetic field, and the control unit 4 controls the generation of the magnetic field. In order to follow this generated magnetic field, an impeller 7 to which a permanent magnet 6 is fixed via a separation plate 5 is rotatably supported by a shaft 8. Thereby, circulating water is absorbed and drained by the impeller 7 following the rotating magnetic field rotating.

  The shaft 8 is fixed by a separation plate shaft support 5 a provided at the center of the separation plate 5 and a casing shaft support 9 a provided at the center of the casing 9. A bearing 10 is fixed to the center of the impeller 7 so that the impeller 7 is rotatably supported with respect to the shaft 8, and the shaft 8 and the bearing 10 rotate and slide. Further, between the both end faces of the bearing 10 and the casing shaft support 9a and the separation plate shaft support 5a, the first bearing plate 11 and the second bearing plate 12 are interposed, respectively, so that rotational sliding in the thrust direction is achieved. Do. The first bearing plate 11 and the second bearing plate 12 are prevented from rotating by forming a D shape only on the end face portions on both sides of the shaft 8.

  In this pump, the gap f between the casing shaft support 9a and the shaft support 5a of the separation plate is slightly smaller than the total length of the bearing 10 and the sum of the thicknesses of the first bearing plate 11 and the second bearing plate 12. By providing this, consideration is given to preventing the impeller 7 from locking due to variations in assembly.

  A gap g is also provided between the end face of the shaft 8 and the casing shaft support bottom portion 9d in order to absorb variations in assembly. Since the accumulation of component dimensional variations is concentrated in this gap g, some dimensional variations occur.

  In this pump, a thrust force is applied to the shaft 8 as the impeller 7 stops rotating. For this reason, the shaft 8 tends to gradually move toward the casing 9 by the gap g. As a result, the second bearing plate 12 is not pressed down, and the second bearing plate 12 is in a free state, and abnormal noise may be generated due to dancing caused by water flow. In order to prevent this, the cushion 8 formed of an elastic body such as silicon rubber is inserted into the gap g and compressed to suppress the shaft 8 from floating.

  The casing 9 and the separation plate 5 are sealed through an O-ring or packing 14 to prevent the circulating water in the pump chamber from leaking. The casing 9 and the separation plate 5 are generally fixed with screws 15.

  Next, the operation of the pump configured as described above will be described. With the rotating magnetic field generated from the winding 3, the impeller 7 follows and rotates by the attractive repulsion of the fixed permanent magnet 6. As a result, a pumping action is generated, the circulating water is sucked in from the arrow A, and the circulating water is discharged in the arrow B direction. At this time, the impeller 7 is pressed against the casing 9 by the pressure difference between A and B, and the first bearing plate 11 and the end face of the bearing 10 are rotated and slid.

  There is almost no sliding between the bearing 10 and the second bearing plate 12, and it is limited to a moment when starting and stopping or an abnormal operation such as an idling operation in which the pump is operated without circulating water. For this reason, in general, the material of the first bearing plate 11 is often ceramic, and the material of the second bearing plate 12 is often SUS (stainless steel). A water film of circulating water is formed on the sliding portion between the shaft 8 and the bearing 10 and on the sliding portion between both end faces of the bearing 10 and the first bearing plate 11 and the second bearing plate 12. In addition, good sliding of both is performed through this water film.

  As described above, the casing 9 and the separation plate 5 are generally screw-fixed via an O-ring or packing. For example, when the rubber cannot be used due to use conditions and environmental conditions, or when the cost is reduced, the O-ring or packing When it is desired to eliminate the screw, fixing by welding is performed.

  FIG. 13 shows a cross-sectional view at the time of welding when the casing 9 and the separation plate 5 are joined by welding. 14 is a cross-sectional view of the welded portion 16 before welding, and FIG. 15 is a cross-sectional view of the welded portion 16 after welding.

  At the time of welding, the pump 2 is installed on the receiving jig 21 with its upper surface facing, and the horn 20 is lowered. The horn 20 is pressed against the upper surface of the welded portion 16, and ultrasonic waves and vibrations are generated by the horn 20, whereby kinetic energy is propagated to the casing welded portion 9b and the separation plate welded portion 5b. At this time, the kinetic energy concentrates on the welded portion, so that it is converted into thermal energy, and the welded portion 16 formed of resin is melted to join and seal both. The part to be melted ensures a shape that is easy to melt by providing small protrusions and edges.

  The vibration of the horn 20 is basically propagated and welded to the portion where the horn 20 is pressed, but the vibration is partially propagated as a whole. For this reason, when the horn 20 is pressed against the casing 9, the vibration is transmitted to the casing shaft support 9a disposed near the center of the casing 9, and the casing shaft support 9a tends to vibrate up and down. Although the cushioning material 13 is disposed between the end surfaces of the casing shaft support bottom 9d and the shaft 8, the vertical vibration of the casing shaft support 9a cannot be suppressed because it is an elastic body. For this reason, the first bearing plate 11 is intermittently impacted by the casing shaft support 9a and may be broken or broken.

  Therefore, the present invention can prevent the first bearing plate from cracking even when vibration caused by the horn propagates to the casing shaft support and vibrates up and down, and also eliminates the use of a cushioning material that suppresses shaft floating. An object is to provide a bearing pump.

One aspect of the present invention includes an impeller for sucking and discharging circulating water, a shaft for fixing the impeller, and an impeller for rotatably supporting the impeller with respect to the shaft. Installed in the center of the separation plate, a casing and a separation plate for housing the impeller and forming a pump chamber, a casing shaft support for fixing one end side of the shaft installed in the center of the casing, A separation plate shaft support for fixing the other end side portion of the shaft, and the casing and the separation plate are sealed and fixed by welding to form the pump chamber, and at the bottom of the casing shaft support projections to weld the end face of the shaft is provided, characterized in that pressed end portion of said shaft at said protrusion.

FIG. 1 is a cross-sectional view of the pump according to the first embodiment. FIG. 2 is a perspective view illustrating an example of a casing shaft support in the first embodiment. FIG. 3 is a perspective view showing another example of the casing shaft support in the first embodiment. FIG. 4 is a cross-sectional view of the casing shaft support portion after welding in the first embodiment. FIG. 5A is a perspective view illustrating an example of a casing shaft support in the second embodiment, and FIG. 5B is a perspective view illustrating another example of the casing shaft support. FIG. 6 is a cross-sectional view in a pump welding state of an example in which a casing and a separation plate are sealed and fixed by spin welding. FIG. 7 is an enlarged cross-sectional view of a main part showing a welded portion between the casing and the separation plate before spin welding. FIG. 8 is an enlarged cross-sectional view of a main part showing a welded portion between the casing and the separation plate after spin welding. FIG. 9A is a perspective view illustrating an example of a casing shaft support in which the tip of the protrusion is a flat surface, and FIG. 9B is a perspective view illustrating an example of a casing shaft support in which the protrusion is cylindrical. FIG. 10 is a perspective view showing an example of a casing shaft support in which the tip of the protrusion is hemispherical. FIG. 11A is an enlarged cross-sectional view of the main part when a concave shape is formed on the end face of the shaft corresponding to the tip shape of the hemispherical projection, and FIG. 11B is the tip of the projection. It is a principal part expanded sectional view when the convex shape fitted to this is formed in the end surface of a shaft corresponding to the formed concave shape. FIG. 12 is a cross-sectional view of a conventional pump. FIG. 13 is a cross-sectional view of a conventional pump having a welding structure in a welding state. FIG. 14 is a cross-sectional view of the welded portion in a state before welding. FIG. 15 is a cross-sectional view of the welded portion in a state after welding.

An embodiment of the present invention is fixed to an impeller for sucking and discharging circulating water, a shaft for fixing the impeller, and the impeller for rotatably supporting the impeller with respect to the shaft. Installed in the center of the separation plate, a casing and a separation plate for housing the impeller and forming a pump chamber, a casing shaft support for fixing one end side of the shaft installed in the center of the casing, A separation plate shaft support for fixing the other end side portion of the shaft, and the casing and the separation plate are sealed and fixed by welding to form the pump chamber, and at the bottom of the casing shaft support A protrusion welded to the end surface of the shaft is provided , and the end of the shaft is pressed by the protrusion.

  As a result, even when welding vibration due to the horn propagates and vibrates to the casing shaft support, vibration energy is absorbed by melting a part of the protrusion and welding to the tip of the shaft, and the impact from the casing shaft support The crack of the first bearing plate can be prevented. Furthermore, since the projections are melted along the gaps with variations, the shaft can be pressed with zero fitting, so that it is possible to eliminate the cushioning material that suppresses the shaft lift that has been conventionally required.

  In the embodiment of the present invention, the protrusion is arranged at a center of the casing shaft support or a symmetrical position with respect to the center.

  In this way, the protrusions are arranged at the center of the casing shaft support or at a symmetrical position with respect to the center, so that the protrusions can be balanced and melted (welded) to the shaft, leaving stress on the casing shaft support. There is no adverse effect on the welded part which is not necessary or originally required.

  Further, according to the embodiment of the present invention, the end surface of the shaft has a concave shape or a convex shape that fits the tip shape of the protrusion, corresponding to the tip shape of the protrusion formed on the bottom of the casing shaft support. It is provided.

  In this manner, corresponding to the tip shape of the protrusion formed on the bottom portion of the casing shaft support, a concave shape or a convex shape that fits with the tip shape of the protrusion is provided on the end surface of the shaft so that they are fitted. A larger surface area can be secured, and the protrusions can be effectively melted. As a result, the shaft can be pressed with zero fitting, and the cushioning material can be deleted.

  Further, in the embodiment of the present invention, the pump chamber is formed by sealing and fixing the casing and the separation plate by spin welding.

  In this way, by performing spin welding, the horn at the time of welding does not move up and down, but moves in the rotational direction, so the casing and separation plate are sealed and fixed without affecting the first bearing plate. The

  Furthermore, if the glass content of the resin is large and the glass fiber has an effect on ultrasonic welding and sufficient strength cannot be expected at the welded part, the casing and the separator plate can be melted together by performing spin welding. Thus, a desired strength can be realized.

[Example]
Hereinafter, the best mode for carrying out the present invention will be described in Examples, and will be described more specifically with reference to the drawings.

  Here, in the accompanying drawings, the same members as those of the conventional pump are denoted by the same reference numerals, and redundant description will be omitted. In addition, since description here is the best form by which this invention is implemented, this invention is not limited to the said form (Example).

Example 1
1 is a cross-sectional view of a pump according to a first embodiment of the present invention, FIGS. 2 and 3 are perspective views of a casing shaft support in the first embodiment of the present invention, and FIG. 4 is a casing after welding in the first embodiment of the present invention. It is a cross-sectional view of a shaft support part.

  The pump of the present embodiment is a submerged slide bearing pump that is rotatably supported through a bearing in which an impeller is fixed in the center about a shaft, and slides using lubrication of circulating water. This pump is used in, for example, a fuel cell device, a heat pump device, or various cooling systems.

  The motor 1 in this pump is provided with a winding 3 provided with a coil. In the motor 1, a rotating magnetic field is generated by energizing the winding 3, and the rotating magnetic field is controlled by the control unit 4 in response to a signal from a position detection unit (not shown). The outer shell of the pump unit 2 is composed of a casing 9 and a separation plate 5, and is fixed and sealed by the welded portion 16.

  The motor 1 and the pump unit 2 are partitioned and sealed by a separation plate 5. At the center of the separation plate 5 and the center of the casing 9, a separation plate shaft support 5 a that fixes the other end side portion of the shaft 8 and a casing shaft support 9 a that fixes one end side portion of the shaft 8 are provided. Both ends of the shaft 8 are substantially D-shaped in cross section. Among them, one end of the shaft 8 is fixed to the separation plate shaft support 5a through a second bearing plate 12 having a center hole 12a having a D shape, thereby preventing the shaft 8 from rotating. The second bearing plate 12 is lifted and prevented from rotating.

  Further, the other end (the other end) of the shaft 8 is fixed to the casing shaft support 9a through a first bearing plate 11 having a center hole 11a having a D shape. Is preventing.

  The impeller 7 is rotatably supported with respect to the shaft 8, and a bearing 10 is disposed between the first bearing plate 11 and the second bearing plate 12. At this time, in order to prevent the bearing 10 from locking due to assembly variations, the casing shaft support 9a and the separation plate shaft support are provided for the total length of the bearing 10 and the sum of the thicknesses of the first bearing plate 11 and the second bearing plate 12. A slight gap f is provided between 5a. In addition, a slight gap g is formed between one end of the shaft 8 and the casing shaft support bottom portion 9d in consideration of assembly variations.

  In the submerged slide bearing pump of the present embodiment, the impeller 7 rotates the shaft 8 by attracting and repelling the permanent magnet 6 fixed to the impeller 7 with the rotating magnetic field generated by energizing the winding 3. Rotate to center. Since the bearing 10 is fixed at the center of the impeller 7, the bearing 10 and the shaft 8 rotate and slide. Generally, the material of the shaft 8 is made of SUS (stainless steel) or ceramic. On the other hand, the bearing 10 is often formed of carbon or a resin having slidability. Similar to the shaft 8, the first bearing plate 11 and the second bearing plate 12 are made of SUS or ceramic.

  In this submerged sliding bearing pump, a pump action is generated as the impeller 7 rotates, and the circulating water is sucked from the suction port A and discharged from the discharge port B. At this time, the impeller 7 is pressed against the casing 9 by the pressure difference between the suction and discharge, and rotates and slides. In other words, the impeller 7 rotates and slides in a state where the end face of the bearing 10 and the first bearing plate 11 are in contact in the thrust direction (the axial direction of the shaft 8). The higher the pump performance, the greater the pressure applied, and the higher the sliding resistance.

  Therefore, in many cases, the first bearing plate 11 is made of ceramic in order to reduce sliding resistance and realize good sliding. For this reason, the first bearing plate 11 may be cracked when a strong impact or the like from the impeller 7 is applied. Circulating water is provided in the sliding portion between the outer diameter portion of the shaft 8 and the inner diameter portion of the bearing 10 and in the sliding portion between both end faces of the bearing 10 and the first bearing plate 11 or the second bearing plate 12, respectively. A water film is formed by this, and both of them can slide well through this water film.

  FIG. 2 shows the casing shaft support 9a before assembly. At the center of the bottom 9d of the casing shaft support 9a, a conical protrusion 9c is provided at one location so as to protrude upward. A plurality of such protrusions 9c may be installed at positions symmetrical with respect to the center as shown in FIG. However, since the end surface of the shaft 8 is partially missing with the cross-sectional shape being D-shaped as described above, a symmetrical arrangement is necessary in consideration of the missing portion. By arranging the projections 9c symmetrically with respect to the center, no stress is left on the casing shaft support 9a during and after welding, and the projections 9c are evenly melted, so that the original separation plate 5 and the casing 9 The vibration is evenly propagated to the welded portion 16 to achieve good welding.

  In such a submerged plain bearing pump in which the projection 9c welded to the end surface of the shaft 8 is provided on the casing shaft support 9a, when the welded portion 16 between the separation plate 5 and the casing 9 is welded, vibration energy is applied to the welded portion 16. As shown in FIGS. 14 and 15, the casing welded portion 9b and the separation plate welded portion 5b are melted and joined.

  At this time, a part of the vibration energy is also propagated to the casing shaft support 9a. The casing shaft support 9a tends to vibrate up and down by vibration energy. At this time, the vibration energy is converted into thermal energy by concentrating on the tip of the projection 9c, and the tip of the projection 9c is welded to the end surface of the shaft 8 as shown in FIG. As a result, the casing shaft support 9a is welded to the end surface of the shaft 8 so that vertical vibrations are suppressed, that is, the first bearing plate 11 is not damaged by an impact and can be welded satisfactorily.

  Furthermore, as shown in FIG. 4, a part of the protrusion 9 c remains in the gap g between the casing shaft support bottom 9 d and the end surface of the shaft 8, and the end surface of the shaft 8 can be pressed by zero fitting. No need to hold down with cushioning material. Therefore, even if the gap g dimension changes slightly due to variations, it can be adjusted by the melt length of the protrusion 9c, and the shaft 8 can be pressed down with certainty.

(Example 2)
In the first embodiment, the shape of the protrusion 9c formed on the casing shaft support bottom portion 9d is conical, but the shape of the protrusion 9c is not necessarily limited to the conical shape, and is shown in FIGS. 5 (a) and 5 (b). Such a rib having a substantially triangular cross section may be used. One or a plurality of ribs may be provided, and in the case of a plurality of ribs, the ribs may be arranged at symmetrical positions in consideration of the missing portion of the shaft 8.

(Example 3)
In Example 1 or Example 2, the projection shape is particularly suitable for ultrasonic welding, and the purpose is to melt the projection end surface by concentrating energy at one point. Has a shape that makes point contact or line contact.

  In recent years, a glass reinforced grade resin in which glass fiber is contained in a resin material to increase the strength of the resin has been used due to the demand for improvement in the water pressure resistance of the pump.

  Since the welding time at the time of ultrasonic welding is as short as about 1 second and the size of the welded part 16 is limited, the casing 9 and the separating plate 5 are not kneaded when the glass fiber content is large, and sufficient welding strength is obtained. It is difficult to obtain. In such a case, spin welding is an effective welding method.

  Spin welding is a method in which a resin is melt-bonded by frictional heat by fixing one and rotating the other around an axis.

  FIG. 6 shows a cross-sectional view at the time of spin welding, FIG. 7 shows a cross-sectional view of the welded portion in a state before spin welding, and FIG. 8 shows a cross-sectional view of the welded portion in a state after spin welding.

  In FIG. 6, the horn 20 is formed with a partial notch 20 a corresponding to the uneven shape on the surface of the casing 9. The notch 20a is shaped to fit the concave-convex shape portion of the casing 9 so that the casing 9 rotates integrally with the horn 20 when the horn 20 is rotated. Thereby, when the horn 20 is rotated together with the casing 9, even if the resistance of the welded portion 16 increases, the horn 20 and the casing 9 do not slip, and the casing 9 can follow the horn 20. The separation plate 5 side is fixed to the receiving jig 21 via the motor 1 and is securely fixed so that it does not rotate as the casing 9 rotates.

  The horn 20 is rotated in the direction of arrow C in FIG. 6 and the casing 9 is rotated together with the horn 20, and at the same time, pressure is applied in the direction of arrow D in FIG. As a result, friction heat is generated in the casing welded portion 9b and the separator plate welded portion 5b as shown in FIG. 7, and both are melted and kneaded to perform sealing and fixing as shown in FIG. Since the welding part 16 has a large melting allowance, the glass fibers are sufficiently kneaded together to achieve a sufficient welding strength.

  In spin welding, unlike ultrasonic welding, the horn 20 is not vibrated up and down in the D direction, but is pressed and stopped at a predetermined height while rotating around the shaft 8. 11 is not affected. Therefore, the casing 9 and the separation plate 5 can be sealed and fixed without causing problems such as cracking of the first bearing plate 11.

  In spin welding, since the welding is performed by frictional heat due to rotation, the protrusion 9c has a shape different from that of ultrasonic welding. If it is the shape as shown in FIG. 2, FIG. 3, FIG. 5 as shown by ultrasonic welding, since the welded portion is point contact or line contact, the contact area is small and sufficient frictional heat is not generated. The protrusion 9c is difficult to melt.

  FIG. 9 shows the shape of the protrusion 9c suitable for spin welding. In order to secure the contact area, the protrusion 9c may simply form the flat surface 22 at the tip of the protrusion 9 as shown in FIG. However, if the contact area is too large, it is necessary to have an appropriate size in order to affect the welding of the casing welding portion 9b and the separation plate welding portion 5b, which are originally welded portions. The area of the flat surface 22 at the tip of the protrusion 9 varies depending on the size of the welding allowance of the casing welded part 9b and the separation plate welded part 5b.

  In addition, as shown in FIG. 9B, welding can be performed even with a hollow cylindrical projection 9c.

  In addition, when sufficient frictional heat cannot be obtained, means for increasing the surface roughness of the flat surface portion of the end surface 8a of the shaft 8 corresponding to the protrusion 9c can be considered.

Example 4
In the case of a small pump, the diameter of the shaft 8 is small, and even if it is intended to increase the contact area of the protrusion 9c, the size may not be large. In such a case, as shown in FIG. 10, the tip of the protrusion 9c is made hemispherical.

  Further, as shown in FIG. 11 (a), the end surface 8a of the shaft 8 corresponding thereto is also provided with a concave hemispherical portion 8b that fits in correspondence with the tip shape of the projection 9c. Since the concavo-convex shapes are in contact with each other, the contact area between the two can be made larger than the plane. The hemispherical portion 8b may be provided with unevenness on either the protrusion 9c or the end surface 8a of the shaft 8. FIG. 11B shows an example in which a concave portion 9e having a concave shape is formed on the tip of the projection 9c so as to be fitted in correspondence with the convex portion 8c having a convex shape formed on the end surface 8a of the shaft 8.

  In the fourth embodiment, in addition to the fitting of the concavo-convex shape, it may be combined with means for increasing the surface roughness of the shaft end surface 8a of the shaft 8.

  According to the present invention, by providing the protrusion in the vicinity of the center of the casing shaft support, even when vibration due to the horn propagates to the casing shaft support and vibrates up and down, a part of the protrusion is melted and welded to the tip of the shaft. As a result, vibration energy is absorbed, and cracking of the first bearing plate can be prevented by an impact from the casing shaft support.

Claims (4)

An impeller for sucking and discharging circulating water;
A shaft for fixing the impeller,
A bearing fixed to the impeller for rotatably supporting the impeller relative to the shaft;
A casing and a separating plate for housing the impeller and forming a pump chamber;
A casing shaft support that fixes one end side portion of the shaft installed in the center of the casing;
A separation plate shaft support for fixing the other end side portion of the shaft installed at the center of the separation plate,
The casing and the separation plate are sealed and fixed by welding to form the pump chamber, and a protrusion that is welded to the end surface of the shaft is provided at the bottom of the casing shaft support, and the end of the shaft is formed by the protrusion. Submerged slide bearing pump characterized by pressing the part . The submersible bearing pump according to claim 1,
The submerged plain bearing pump, wherein the protrusion is disposed at a center of the casing shaft support or a symmetrical position with respect to the center. The submersible bearing pump according to claim 1,
An underwater sliding bearing characterized in that a concave shape or a convex shape is provided on the end surface of the shaft so as to fit the shape of the tip of the protrusion, corresponding to the shape of the tip of the protrusion formed on the bottom of the casing shaft support. pump. The submersible bearing pump according to claim 1,
The submerged slide bearing pump, wherein the pump chamber is formed by sealing and fixing the casing and the separation plate by spin welding.

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