CN113202772A - Pump device - Google Patents

Abstract

A pump device is provided, which can restrain the damage of the casing and restrain the reduction of the pump performance even if the fluid is frozen in the pump chamber. A pump device (1) is provided with: a rotor (2) that includes an impeller (11), a shaft (12) extending coaxially with the impeller, and a magnet (13) fixed to the shaft and separated from the impeller in an axial direction (L) of the shaft; a casing (4) provided with a casing (15) provided with a recess (41) for accommodating the impeller, and a partition member (16) that covers the casing from the axial direction and that partitions a pump chamber (3) for accommodating the rotor (2) together with the casing; an elastic member (25) disposed on the bottom surface (41a) of the recess (41); and a partition member (26) which is disposed between the elastic member and the impeller and is fixed to the housing. The partition member (26) has an opening (260) that overlaps a portion of the elastic member (25) when viewed from the axial direction.

Description

Pump device

Technical Field

The present invention relates to a pump device in which an impeller rotates in a pump chamber provided in a housing.

Background

Patent document 1 describes a pump device in which an impeller rotates in a pump chamber provided in a housing. The pump device of patent document 1 includes: the magnetic pump includes a rotor including an impeller and a magnet, a pump chamber for accommodating the rotor, a housing for partitioning the pump chamber, and a coil facing the magnet with the housing interposed therebetween. The magnet is fixed at a position apart from the impeller in the axial direction of the impeller. In addition, in order to prevent the casing from being damaged when frozen, the pump device includes an elastic member disposed in the pump chamber. The elastic member is disposed on the opposite side of the impeller with respect to the magnet in the axial direction.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2002-227791

Disclosure of Invention

Technical problem to be solved by the invention

The pump chamber is divided by a housing having a recess for accommodating the impeller, and a partition member disposed between the rotor and the stator and covering the housing from the axial direction. In the pump device of patent document 1, the elastic member is disposed on the bottom surface of the recess for accommodating the impeller in the pump chamber, and therefore the capacity of the pump chamber can be increased around the impeller to suppress damage to the casing.

However, when the elastic member is disposed on the bottom surface of the recess for accommodating the impeller, the elastic member is deformed by the pressure during the operation of the pump device, and the gap between the elastic member and the impeller is enlarged. When the gap between the elastic member and the impeller is changed, the size of the gap through which the fluid flows is changed. Therefore, the head may be lowered, and the pump performance may be lowered.

In view of these points, an object of the present invention is to provide a pump device capable of suppressing damage to a housing and suppressing a reduction in pump performance even when a fluid freezes in a pump chamber.

Technical scheme for solving technical problem

In order to solve the above-described problems, a pump device according to the present invention includes: a rotor including an impeller, a shaft portion extending coaxially with the impeller, and a magnet fixed to the shaft portion and separated from the impeller in an axial direction of the shaft portion; a casing including a housing having a recess for accommodating the impeller, and a partition member covering the housing from the axial direction and defining a pump chamber for accommodating the rotor together with the housing; an elastic member disposed on a bottom surface of the recess; and a partition member that is disposed between the elastic member and the impeller, is fixed to the housing, and has an opening that overlaps a part of the elastic member when viewed in the axial direction.

According to the present invention, the casing that defines the pump chamber includes the recess that accommodates the impeller, and the elastic member is disposed on the bottom surface of the recess. The partition member disposed between the elastic member and the impeller includes an opening portion that overlaps a part of the elastic member. Therefore, since a part of the elastic member is exposed in the pump chamber through the opening portion, when the volume of the fluid remaining in the pump chamber increases due to freezing, the elastic member is compressed around the impeller having a large space in which the fluid exists in the pump chamber, and the capacity of the pump chamber is increased. This can reduce the pressure applied to the inner wall surface of the pump chamber when the fluid freezes, and therefore can suppress damage to the housing. In addition, since the elastic member can be positioned by the partition member, it is possible to suppress the elastic member from being deformed by the pressure of the fluid when the pump device is operated and to expand the gap between the impeller and the elastic member. Therefore, since the pump chamber is provided with the elastic member to reduce the head, the casing can be prevented from being damaged when the fluid freezes, and the pump performance can be prevented from being reduced.

In the present invention, it is preferable that a sheet member is provided between the partition member and the elastic member, and the sheet member overlaps with a part of the opening when viewed in the axial direction. In this way, by covering a part of the elastic member disposed in the opening with the sheet member, which is a member different from the partition member fixed to the housing, the effect of suppressing the damage of the housing when the fluid is frozen is maintained, and the deformation of the elastic member can be appropriately suppressed when the pump device is operated. Therefore, the pump chamber can be prevented from being provided with the elastic member to reduce the head, and therefore, the pump performance can be prevented from being reduced.

In the present invention, it is preferable that the elastic member is annular, and the partition member includes: the opening portion is provided between the connection portions adjacent in the circumferential direction. Accordingly, the inner peripheral edge and the outer peripheral edge of the elastic member can be positioned by the partition member, and therefore, the expansion of the gap between the impeller and the elastic member due to the deformation of the elastic member can be suppressed.

In the present invention, it is preferable that the housing includes a protruding portion protruding in the axial direction from a center of a bottom surface of the recess, and the inner annular portion is positioned in the axial direction by a metal positioning ring fitted into the protruding portion. Thus, the partition member can be easily fixed by using the positioning ring. In addition, the inner annular portion can be easily positioned.

In the present invention, it is preferable that a protrusion portion protruding from an outer peripheral surface of the protrusion portion is provided, and the positioning ring overlaps with the protrusion portion as viewed in the axial direction. Thus, the inner annular portion can be held between the positioning ring and the projecting portion. Therefore, the positional accuracy of the inner annular portion can be improved. In addition, since the positioning ring and the protrusion overlap in the axial direction, the overlapping area of the positioning ring and the elastic member can be reduced. Therefore, deformation of the elastic member can be appropriately suppressed.

In the present invention, it is preferable that the positioning ring is a snap ring having a toothed portion formed on an inner peripheral edge thereof. Accordingly, the fixation of the positioning ring is easy. In addition, the positioning ring can be inhibited from falling off after installation.

In the present invention, it is preferable that the outer annular portion is welded to a welding portion provided on an inner peripheral surface of the recessed portion. This can improve the fixing strength of the outer annular portion. In addition, no fixing member is required.

In the present invention, it is preferable that the elastic member is a closed cell foam. By using closed cell foam, the resilient member is compressed when frozen, thereby allowing the volume of the pump chamber to expand.

In the present invention, it is preferable that the elastic member is disposed on the entire bottom surface. Accordingly, the volume of the elastic member can be increased, and therefore, the capacity of the pump chamber can be greatly increased by the compression deformation of the elastic member. Therefore, the pressure applied to the inner wall surface of the pump chamber when the fluid freezes can be greatly reduced.

In the present invention, it is preferable that the welded portion is a convex portion protruding from an end surface of a second protruding portion extending in an axial direction from an outer peripheral edge of a bottom surface of the concave portion, the outer peripheral annular portion is in contact with the end surface, the welded portion is disposed in a welding cutout portion provided in an outer peripheral edge of the outer annular portion, and the outer annular portion is heat-welded to the case by heating and pressing the welded portion.

In the present invention, it is preferable that the welding notches are formed on the outer peripheral side of each of the plurality of connection portions.

In the present invention, it is preferable that the protruding portion includes an annular stepped portion at a distal end portion thereof and a small diameter portion protruding in an axial direction on an inner peripheral side of the stepped portion, and the stepped portion is a position regulating portion for regulating the partition member to move by a certain amount or more toward the bottom surface side of the recessed portion.

In the present invention, it is preferable that the opening portion of the partition member has a first region radially inward of the sheet member and radially outward of an outer peripheral edge of the positioning ring, the first region not overlapping the sheet member, a second region radially outward of an inner peripheral edge of the sheet member overlapping the sheet member, and a portion of the elastic member overlapping the first region of the opening portion is exposed to the pump chamber.

Effects of the invention

According to the present invention, since a part of the elastic member is exposed in the pump chamber through the opening portion of the partition member, when the volume of the fluid remaining in the pump chamber increases due to freezing, the elastic member is compressed around the impeller having a large space for the fluid in the pump chamber, and the capacity of the pump chamber is increased. This can reduce the pressure applied to the inner wall surface of the pump chamber when the fluid freezes, and therefore can suppress damage to the housing. In addition, since the elastic member can be positioned by the partition member, it is possible to suppress the elastic member from being deformed by the pressure of the fluid when the pump device is operated and to expand the gap between the impeller and the elastic member. Therefore, since a reduction in the head due to the arrangement of the elastic member in the pump chamber can be suppressed, damage to the housing when the fluid freezes can be suppressed, and a reduction in the pump performance can be suppressed.

Drawings

Fig. 1 is an external perspective view of a pump device to which the present invention is applied.

Fig. 2 is a cross-sectional view of the pump apparatus of fig. 1.

Fig. 3 is an exploded perspective view of the pump device of fig. 1 as viewed from one side in the axial direction.

Fig. 4 is an exploded perspective view of the pump device of fig. 1 as viewed from the other side in the axial direction.

Fig. 5 is a perspective view of the housing as viewed from the other side in the axial direction.

Fig. 6 is a perspective view of the housing and the frost damage prevention portion as viewed from the other side in the axial direction.

Fig. 7 is a perspective view of the elastic member, the partition member, the sheet member, and the positioning ring.

Fig. 8 is a partial sectional view of the frost damage prevention portion (partial sectional view of the area a of fig. 2).

Fig. 9 is a graph showing the influence of the freeze damage preventive portion on the pump characteristics.

Description of the reference numerals

1 … pump device; 2 … rotor; 3 … pump chamber; 4 … outer shell; 5 … motor mechanism part; 11 … impeller; 12a … axle hole; 12 … a shaft portion; 13 … a magnet; 15 … a housing; 15a … case-side through-hole; 16 … partition members; 16a … partition member side through-hole; 17 … stator; 18 … a stator core; 19 … coil; 21 … circuit substrate; 22 … resin sealing member; 22a … resin seal member side through-hole; 23 … base member; 23a … threaded holes; 25 … an elastic member; 26 … a partition member; 27 … sheet member; 28 … a retaining ring; 29 … frost damage prevention; 31 … a first annular plate portion; 31a … annular projection; 32 … second annular plate portion; 33 … leaf blades; 35 … axle sleeve; 36 … jaw portions; 40 … fulcrum; 41 … recess; 41a … bottom surface; 41b … inner peripheral surface; 42 … a housing body; 43 … water supply pipes; 43a … pump chamber side opening; 44 … discharge pipe; 44a … pump chamber side opening; a 45 … projection; 47 … case-side rotor support; 48 … legs; 49 … weld; 49a … protrusions; end faces of the 49b … protrusions; a 50 … shim; 51 … opposite part; 52 … a cylindrical part; a 53 … closure; 54 … outer tubular portion; 55 … flange portion; 57 … step portion; 58 … O-ring; 62 … partition member side rotor support portion; 63 … supporting shaft fixing concave part; 66 … salient poles; 67 … an insulator; a 68 … connector; 69 … screw; 260 … opening part; 260a … first region; 260b … second area; 261 … outer ring portion; 262 … inner annular portion; 263 … connection; 264 … notch for welding; 281 … ring portion; 282 … teeth; 451 … outer peripheral surface; 452 … a step; 453, 453 … small diameter section; 454 … a projection; l … axial direction; one side of L1 …; the other side of L2 …; r … direction of rotation.

Detailed Description

An embodiment of a pump device to which the present invention is applied will be described below with reference to the drawings.

(Overall Structure)

Fig. 1 is an external perspective view of a pump device 1 to which the present invention is applied. Fig. 2 is a sectional view of the pump device 1 of fig. 1. Fig. 3 is an exploded perspective view of the pump device 1 in fig. 1 as viewed from one side L1 in the axial direction L, and fig. 4 is an exploded perspective view of the pump device 1 in fig. 1 as viewed from the other side L2 in the axial direction L. The pump device 1 of the present embodiment is mounted in a water heater, a washing machine, a dishwasher, or the like. The pump device 1 supplies fluid such as tap water to the device.

As shown in fig. 2, the pump device 1 includes a rotor 2 and a pump chamber 3 that accommodates the rotor 2. The pump device 1 further includes a housing 4 that partitions the pump chamber 3. The pump device 1 further includes a motor mechanism 5 for rotating the rotor 2. In the present specification, a direction along the rotation axis of the rotor 2 is referred to as an axial direction L. One side of the axial direction L is L1, and the other side of the axial direction L is L2.

As shown in fig. 2 to 4, the rotor 2 includes an impeller 11, a shaft portion 12 extending coaxially from the impeller 11, and a ring magnet 13 fixed to the shaft portion 12. The impeller 11 and the magnet 13 are provided at positions separated in the axial direction L. The impeller 11 is positioned on one side L1 in the axial direction L, and the magnet 13 is positioned on the other side L2 in the axial direction L.

As shown in fig. 2, the housing 4 includes a case 15 and a partition member 16. The case 15 and the partition member 16 overlap in the axial direction L. The pump chamber 3 is formed between the housing 15 and the partition member 16. The housing 15 includes a water supply pipe 43 and a discharge pipe 44 communicating with the pump chamber 3. The water supply pipe 43 projects toward one side L1 in the axial direction L, and the discharge pipe 44 extends toward the outer peripheral side of the housing 15. The pump device 1 sends out the fluid drawn into the pump chamber 3 from the water supply pipe 43 from the discharge pipe 44.

As shown in fig. 2, the motor mechanism 5 includes a stator 17 surrounding the magnet 13 from the radially outer side on the side opposite to the pump chamber 3 with respect to the partition member 16. The stator 17 includes a stator core 18 and a plurality of coils 19. The stator core 18 and the coil 19 constitute the motor mechanism portion 5 together with the magnet 13 of the rotor 2.

The pump device 1 includes a circuit board 21 to which an end of the winding of the coil 19 is connected, a resin sealing member 22 covering the stator 17 and the circuit board 21, and a metal base member 23 fixed to the resin sealing member 22. The resin sealing member 22 constitutes a part of the exterior of the pump device 1.

The pump device 1 further includes an elastic member 25 disposed in the pump chamber 3, a partition member 26 for positioning the elastic member 25, a sheet member 27 disposed between the elastic member 25 and the partition member 26, and a positioning ring 28 for fixing the partition member 26. The elastic member 25 is compressed to increase the volume of the pump chamber 3 when the fluid remaining in the pump chamber 3 freezes. Thus, when the fluid remaining in the pump chamber 3 is frozen, the pressure applied to the casing 4 and the impeller 11 is reduced. Therefore, the elastic member 25, the partition member 26, and the sheet member 27 constitute a frost damage prevention portion 29 for preventing damage to the casing 4 and the impeller 11.

(rotor)

As shown in fig. 2 to 4, the impeller 11 includes a first annular plate portion 31 having an annular shape when viewed from the axial direction L, an annular second annular plate portion 32 positioned on the other side L2 of the first annular plate portion 31 in the axial direction L, and a plurality of blades 33 provided between the first annular plate portion 31 and the second annular plate portion 32. The first annular plate 31 is slightly inclined from the inner periphery side to the outer periphery side toward the other side L2 in the axial direction L. The first annular plate portion 31 includes an annular protrusion 31a protruding from the inner peripheral edge toward one side L1 in the axial direction L. The second annular plate portion 32 overlaps the first annular plate portion 31 when viewed in the axial direction L. The plurality of blades 33 extend between the first annular plate portion 31 and the second annular plate portion 32 from the inner circumferential side to the outer circumferential side in a curved manner toward the front in the rotational direction R. In the present embodiment, each of the vanes 33 is a rib protruding from the first annular plate portion 31 to the other side L2 in the axial direction L. The second annular plate portion 32 is connected to the end of the other side L2 in the axial direction L of each blade 33 by ultrasonic welding.

The shaft portion 12 is cylindrical and includes a shaft hole 12a penetrating in the axial direction L. The shaft portion 12 extends from an inner peripheral edge of the second annular plate portion 32 of the impeller 11 to the other side L2 in the axial direction L. As shown in fig. 2, a sleeve 35 as a slide bearing is fixed inside the shaft hole 12 a. A fulcrum shaft 40 that rotatably supports the rotor 2 is inserted into a center hole of the boss 35. The support shaft 40 is made of stainless steel and extends in the axial direction L. An end portion of one side L1 of the support shaft 40 in the axial direction L is supported by the case 15, and an end portion of the other side L2 in the axial direction L is supported by the partition member 16.

The shaft portion 12 includes a collar portion 36 protruding from a middle portion in the axial direction L toward an outer peripheral side. As shown in fig. 2 to 4, the magnet 13 is fixed to the outer peripheral surface of the shaft portion 12 in a region on the other side L2 in the axial direction L of the collar portion 36. The magnet 13 is annular and has S poles and N poles alternately magnetized in the circumferential direction.

(outer cover)

Fig. 5 is a perspective view of the housing 15 as viewed from the other side L2 in the axial direction L. As shown in fig. 2 and 5, the housing 15 includes: the impeller includes a casing body 42 having a recess 41 for accommodating the impeller 11, a water supply pipe 43 having a water supply passage communicating with the recess 41, and a discharge pipe 44 having a discharge passage communicating with the recess 41.

The recess 41 includes an annular bottom surface 41a and a cylindrical inner peripheral surface 41b extending from the outer peripheral edge of the bottom surface 41a to the other side L2 in the axial direction L. The water supply pipe 43 includes a cylindrical projecting portion 45 projecting from the center of the bottom surface 41a toward the other side L2 in the axial direction L. The protruding portion 45 is disposed coaxially with the inner peripheral surface 41b of the recess 41. A pump chamber side opening 43a of the water supply pipe 43 is provided at the tip of the projection 45. Further, a pump-chamber-side opening 44a of the discharge pipe 44 is provided in a part of the inner circumferential surface 41b in the circumferential direction. The discharge pipe 44 extends in the tangential direction of the inner peripheral surface 41 b.

The housing 15 includes a housing-side rotor support portion 47 extending in the axial direction L at the radial center of the recess 41. The housing-side rotor support portion 47 is disposed on the other side L2 in the axial direction L of the protruding portion 45, and is positioned forward in the inflow direction of the fluid flowing in from the pump chamber side opening 43a of the water supply pipe 43. The housing-side rotor support portion 47 is supported by three leg portions 48 projecting from the inner wall surface of the projecting portion 45 toward the other side L2 in the axial direction L.

As shown in fig. 2, the end portion of one side L1 in the axial direction L of the support shaft 40 protruding from the boss 35 of the rotor 2 toward the housing 15 is inserted into the housing-side rotor support portion 47. A spacer 50 is disposed between the boss 35 and the case-side rotor support portion 47. The sleeve 35 and the case-side rotor support portion 47 abut via the spacer 50 in the axial direction L.

As shown in fig. 2, the partition member 16 forms a concave space for accommodating the shaft portion 12 of the rotor 2 and the magnet 13 on the other side in the axial direction L of the impeller 11, and blocks the fluid from flowing to the stator 17 disposed on the outer peripheral side of the magnet 13. The partition member 16 includes an annular facing portion 51 facing the impeller 11 from the other side L2 in the axial direction L, and a closing portion 53 extending from an inner peripheral end edge of the facing portion 51 to the other side L2 in the axial direction L and surrounding the cylindrical portion 52 of the magnet 13 from the outer peripheral side and closing an end portion of the other side L2 in the axial direction L of the cylindrical portion 52. The opposing portion 51 faces the bottom surface 41a of the recess 41 of the casing body 42 via the impeller 11.

As shown in fig. 2 and 3, the partition member 16 includes an outer tube portion 54 extending from an outer peripheral edge of the facing portion 51 to the other side L2 in the axial direction L, and an annular flange portion 55 extending radially outward from the outer tube portion 54. As shown in fig. 2, the outer tube portion 54 is fitted into the recess 41 of the housing body 42, and the flange portion 55 abuts on the end surface of the other side L2 of the housing body 42 in the axial direction L. An annular step portion 57 recessed radially outward from the inner peripheral surface 41b is provided at the opening edge of the other side L2 of the recess 41 in the axial direction L. An O-ring 58 is disposed on the step portion 57. The O-ring 58 seals between the housing body 42 and the partition member 16 in a radially compressed state between the housing body 42 and the outer cylindrical portion 54.

As shown in fig. 2, the partition member 16 includes a partition member-side rotor support portion 62 protruding from the center of the closing portion 53 to one side L1 in the axial direction L. The partition member-side rotor support portion 62 includes a support shaft fixing recess 63 that opens at an end surface of one side L1 in the axial direction L. The other end L2 of the shaft 40 in the axial direction L is inserted into the shaft fixing recess 63.

The partition member-side rotor supporting portion 62 is inserted into the shaft hole 12a of the shaft portion 12 of the rotor 2 from the other side L2 in the axial direction L. A gap is present between the outer peripheral surface of the partition member-side rotor support portion 62 and the inner wall surface of the shaft hole 12 a. The boss 35 is located on one side L1 in the axial direction L of the partition member-side rotor support portion 62. When the pump device 1 is operated to rotate the impeller 11, the rotor 2 is displaced to the side L1 in the axial direction L, and a gap is formed between the end face of the partition member-side rotor support portion 62 on the side L1 in the axial direction L and the boss 35.

The inner peripheral surface (the bottom surface 41a and the inner peripheral surface 41b) of the recess 41 of the housing body 42, the surface of one side L1 in the axial direction L of the facing portion 51 of the partition member 16, the inner peripheral surface of the tube portion 52, and the end surface of one side L1 in the axial direction L of the closing portion 53 constitute the inner wall surface of the pump chamber 3.

(stator)

As shown in fig. 2, the stator 17 is disposed on the outer peripheral side of the cylindrical portion 52 of the partition member 16. The stator 17 includes a stator core 18 and a plurality of coils 19, the stator core 18 includes a plurality of cores arranged in a ring shape, and the plurality of coils 19 are wound around salient poles 66 provided on the respective cores via insulators 67. The inner peripheral end surface of each salient pole 66 is radially opposed to the magnet 13 of the rotor 2 via the cylindrical portion 52.

In the present embodiment, the motor mechanism 5 is a three-phase brushless motor. That is, in the present embodiment, nine salient poles 66 are provided, and the nine coils 19 wound around each salient pole 66 constitute three U-phase coils 19, three V-phase coils 19, and three W-phase coils 19. The nine coils 19 are arranged such that the U-phase coil 19, the V-phase coil 19, and the W-phase coil 19 are arranged in this order.

As shown in fig. 2, the circuit board 21 is disposed on the other side L2 in the axial direction L of the closing portion 53 of the partition member 16. The end of the winding drawn out from the coil 19 of the stator 17 is electrically connected to the circuit board 21. Further, a connector 68 is mounted on the circuit board 21. The stator 17 and the circuit board 21 are sealed by a resin sealing member 22. The resin sealing member 22 is a Bulk Molding Compound (BMC) which is a thermosetting resin material.

The base member 23 is fixed to the end surface of the other side L2 of the resin seal member 22 in the axial direction L. The base member 23 is a reinforcing member that reinforces the resin sealing member 22. The base member 23 has a disk shape, and has screw holes 23a at four positions around the axis of the outer peripheral edge.

As shown in fig. 1, the resin seal member 22 constitutes a part of the exterior of the pump device 1. As shown in fig. 3 and 4, the housing 15 includes housing-side through holes 15a that penetrate in the axial direction L at four circumferential positions. The partition member 16 includes partition member-side through holes 16a that penetrate in the axial direction L at four circumferential positions. The resin seal member 22 includes resin seal member-side through holes 22a that penetrate in the axial direction L at four circumferential positions. The case 15 is fixed to the partition member 16 by a headed screw 69 (see fig. 1), and the headed screw 69 is screwed into the screw hole 23a of the base member 23 through the case side through hole 15a, the resin seal member 22 side through hole, and the resin seal member side through hole 22a in the axial direction L.

When the pump device 1 is driven, power is supplied to the coils 19 of the stator 17 in a predetermined order to rotate the rotor 2. As a result, the impeller 11 rotates in the predetermined rotation direction R, and the fluid flows in the circumferential direction in the pump chamber 3. Thereby, the fluid is sucked into the pump chamber 3 from the water supply pipe 43, and the fluid is discharged from the discharge pipe 44.

(elastic Member)

Fig. 6 is a perspective view of the housing 15 and the frost damage prevention portion 29 viewed from the other side in the axial direction L. Fig. 7 is a perspective view of the elastic member 25, the partition member 26, the sheet member 27, and the positioning ring 28. Fig. 8 is a partial sectional view of the frost damage prevention portion 29, which is a partial sectional view of the region a of fig. 2. The pump device 1 of this embodiment is provided with a frost damage prevention portion 29. The anti-freezing portion 29 includes an elastic member 25 which is disposed in the pump chamber 3 and is compressed when the fluid freezes. As shown in fig. 2 and 8, the elastic member 25 is disposed on the bottom surface 41a of the recess 41 for accommodating the impeller 11. The bottom surface 41a of the recess 41 is an inner wall surface portion facing the impeller 11 in the axial direction L in the inner wall surface of the pump chamber 3.

As shown in fig. 7, the elastic member 25 has a ring shape. As shown in fig. 2, in this embodiment, the arrangement region of the elastic member 25 extends from the protruding portion 45 arranged at the center of the recessed portion 41 to the entire inner peripheral surface 41b of the recessed portion 41. Therefore, the elastic member 25 is disposed on the entire bottom surface 41a of the recess 41. Since the recess 41 accommodates the impeller 11, the arrangement region of the elastic member 25 is expanded to the outer peripheral side of the impeller 11.

The height (thickness) of the elastic member 25 in the axial direction L is lower than the height of the protruding portion 45 provided at the center of the recess 41 in the axial direction L. Therefore, as shown in fig. 2 and 6, the protruding portion 45 protrudes from the elastic member 25 to the other side L2 in the axial direction L. As shown in fig. 6, the pump chamber side opening 43a of the water supply pipe 43 provided at the tip of the protruding portion 45 and the pump chamber side opening 44a of the discharge pipe 44 opening to the inner peripheral surface 41b of the recessed portion 41 are both positioned on the other side in the axial direction L than the elastic member 25. The pump-chamber-side opening 43a of the water supply pipe 43 and the pump-chamber-side opening 44a of the discharge pipe 44 are easily affected by the external environment and are easily frozen at low temperatures. Therefore, in this embodiment, the elastic member 25 is disposed at a portion of the pump chamber 3 that is likely to freeze.

The resilient member 25 is a closed cell foam. In this embodiment, the elastic member 25 is EPDM (ethylene propylene diene monomer). For example, as the elastic member 25, teflon (registered trademark), nitrile rubber, or the like can be exemplified. The elastic member 25 has a smooth surface on which air bubbles are not exposed at least on a surface facing the impeller 11. The elastic member 25 has a size that can absorb the volume of the fluid increased by freezing by elastic deformation of the elastic member 25 when the fluid remaining in the pump chamber 3 is frozen. In this embodiment, the elastic member 25 is of a size that can be elastically deformed by a volume amount equal to or greater than 10% of the volume of the pump chamber 3 when changing from the natural state to the compressed state.

(partition member)

The partition member 26 is disposed between the elastic member 25 and the impeller, and is fixed to the casing 15. As shown in fig. 6 and 7, the partition member 26 includes an opening 260 that overlaps a part of the elastic member 25 when viewed in the axial direction L. The partition member 26 includes an outer annular portion 261, an inner annular portion 262 disposed on an inner peripheral side of the outer annular portion 261, and a plurality of connecting portions 263 connecting the outer annular portion 261 and the inner annular portion 262. Each of the connection portions 263 extends in the radial direction, and the plurality of connection portions 263 are arranged radially at equal intervals in the circumferential direction. A fan-shaped opening 260 is provided between the circumferentially adjacent connecting portions 263. The outer annular portion 261 is welded to a welding portion 49 provided on the inner peripheral surface of the recess 41. Further, the inner annular portion 262 is fitted into the protruding portion 45. The positioning ring 28 is fitted into the protrusion 45 from the other side L2 in the axial direction L of the inner annular portion 262. The inner annular portion 262 is positioned in the axial direction L by the positioning ring 28.

As shown in fig. 5, the inner peripheral surface 41b of the recess 41 has a protrusion 49a extending from the outer peripheral edge of the bottom surface 41a to the other side L2 in the axial direction L. The welded portion 49 is a convex portion protruding from the end face 49b of the other side L2 in the axial direction L of the protruding portion 49 a. The projection 49a projects radially inward from the inner peripheral surface 41b, and the outer annular portion 261 abuts against an end surface 49b of the projection 49 a. In the present embodiment, the protrusions 49a and the welding portions 49 are formed at five positions and arranged at equal intervals in the circumferential direction. Each welding portion 49 is disposed in a welding notch 264 provided on the outer peripheral edge of the outer annular portion 261. As shown in fig. 7, connecting portions 263 are provided at five positions of the partition member 26, and a welding notch portion 264 is formed on the outer peripheral side of each connecting portion 263. By heating and flattening each welded portion 49, the outer annular portion 261 is heat-welded to the case 15.

(sheet Member)

The sheet member 27 is annular and is disposed between the elastic member 25 and the partition member 26. As described above, the outer peripheral edge of the partition member 26 is welded to the case 15, but the sheet member 27 is not fixed to the case 15, nor to any of the elastic member 25 and the partition member 26. The sheet member 27 is positioned in the axial direction L by being disposed between the elastic member 25 and the partition member 26.

The sheet member 27 overlaps with a part of the opening 260 of the partition member 26 when viewed in the axial direction L. As shown in fig. 8, in the present embodiment, the outer diameter of the sheet member 27 is substantially the same as the inner diameter of the outer annular portion 261 of the partition member 26, and the inner diameter of the sheet member 27 is larger than the outer diameter of the inner annular portion 262. Therefore, in the opening portion 260 of the partition member 26, a first region 260a radially inward of the sheet member 27 and radially outward of the outer peripheral edge of the positioning ring 28 does not overlap the sheet member 27, and a second region 260b radially outward of the inner peripheral edge of the sheet member 27 overlaps the sheet member 27. Therefore, the portion of the elastic member 25 overlapping the first region 260a of the opening 260 is exposed in the pump chamber 3.

The partition member 26 and the sheet member 27 are flexible sheet members such as polyethylene film (PET film). For example, as the partition member 26 and the sheet member 27, a lemiller (registered trademark) manufactured by dongli corporation can be exemplified. Further, the partition member 26 and the sheet member 27 may be made of other materials. The partition member 26 and the sheet member 27 may be different members or may be different members. For example, a polyethylene film may be used as the sheet member 27, while a sheet metal member may be used as the partition member 26.

(positioning ring)

As shown in fig. 6 and 7, the positioning ring 28 is a snap ring including an annular portion 281 and a plurality of tooth portions 282 formed on the inner periphery of the annular portion 281. The positioning ring 28 is made of metal and is fixed to the tip end portion of the projection 45. As shown in fig. 5 and 8, the distal end portion of the protruding portion 45 includes an annular stepped portion 452 and a small diameter portion 453 protruding to the other side L2 in the axial direction L on the inner peripheral side of the stepped portion 452. As shown in fig. 5, a plurality of protruding portions 454 extending in the axial direction L are formed on the outer peripheral surface 451 of the protruding portion 45. In the present embodiment, the protrusions 454 are formed at three positions and arranged at equal intervals in the circumferential direction. When the elastic member 25 is attached to the recess 41, the inner peripheral surface of the elastic member 25 deforms so as to follow the shape of the protruding portion 454. As shown in fig. 8, the stepped portion 452 serves as a position regulating portion for regulating the partition member 26 so as not to move by a certain amount or more toward the bottom surface 41a side of the recess 41 (i.e., the one side L1 in the axial direction L).

The positioning ring 28 is attached to the small diameter portion 453 from the other side in the axial direction L. As shown in fig. 2, the tooth portion 282 of the positioning ring 28 is inclined in the direction toward the other side in the axial direction L as it goes radially inward so as to elastically contact the outer peripheral surface of the small diameter portion 453. Thereby, the positioning ring 28 is fixed so as not to come out from the small diameter portion 453.

The annular portion 281 of the positioning ring 28 overlaps the tip end surface of the protrusion portion 454 as viewed in the axial direction L. Further, the inner annular portion 262 of the partition member 26 overlaps the distal end surface of the protrusion portion 454 as viewed in the axial direction L. Therefore, by fixing the positioning ring 28 to the small-diameter portion 453, the inner annular portion 262 is positioned in the axial direction L, and the elastic member 25 is positioned in the axial direction via the partition member 26.

Fig. 9 is a graph showing the influence of the freeze-damage preventing portion 29 on the pump characteristics. The horizontal axis of fig. 9 is the flow rate per unit time, and the vertical axis is the head. The solid line data represents the pump characteristics of the pump device in which the elastic member 25 is not disposed in the recess 41. ● data is the pump characteristics of the pump device 1 including the anti-freeze portion 29 according to the present embodiment, and is the pump characteristics of the configuration in which the elastic member 25, the partition member 26, and the sheet member 27 are arranged in the recess 41. The data is the pump characteristic of the configuration in which the sheet member 27 is omitted from the anti-freeze portion 29 of the present embodiment, and is the pump characteristic of the configuration in which the elastic member 25 and the partition member 26 are disposed in the concave portion 41. The broken line data is the pump characteristic of the structure in which only the elastic member 25 is disposed in the recess 41.

It was confirmed that the pump device 1 including the freeze-damage preventing portion 29 of the present embodiment and the pump device having the structure in which the sheet member 27 is omitted from the freeze-damage preventing portion 29 of the present embodiment did not cause the casing 4 to crack or the impeller 11 to be damaged in the freeze test. As shown in fig. 9, it was confirmed that, although the pump head is lowered by disposing the elastic member 25 for preventing frost damage, the lowering of the pump head is suppressed by covering a part of the elastic member 25 with the partition member 26 and the sheet member 27, and the lowering of the pump characteristic is suppressed. In addition, it was confirmed that in the configuration in which the sheet member 27 is omitted and only the partition member 26 is disposed, the pump head is reduced as compared with the configuration of the present embodiment, but the reduction in pump head and the reduction in pump characteristics are suppressed as compared with the configuration in which only the elastic member 25 is disposed.

(main action and Effect of the present embodiment)

As described above, the pump device 1 of the present embodiment includes: a rotor 2 including an impeller 11, a shaft portion 12 extending coaxially with the impeller 11, and a magnet 13 fixed to the shaft portion 12 and spaced apart from the impeller 11 in an axial direction L of the shaft portion 12; a casing 4, the casing 4 including a casing 15 and a partition member 16, the casing 15 including a recess 41 for accommodating the impeller 11, the partition member 16 covering the casing 15 in the axial direction L, and defining a pump chamber 3 for accommodating the rotor 2 together with the casing 15; an elastic member 25, the elastic member 25 being disposed on the bottom surface 41a of the recess 41; and a partition member 26, the partition member 26 being disposed between the elastic member 25 and the impeller 11 and fixed to the casing 15. The partition member 26 includes an opening 260 that overlaps a part of the elastic member 25 when viewed in the axial direction L.

According to the present embodiment, the housing 15 that defines the pump chamber 3 includes the recess 41 that accommodates the impeller 11, and the elastic member 25 is disposed on the bottom surface 41a of the recess 41. The partition member 26 disposed between the elastic member 25 and the impeller 11 includes an opening 260 that overlaps a part of the elastic member 25. Therefore, since a part of the elastic member 25 is exposed in the pump chamber 3 through the opening 260, when the volume of the fluid remaining in the pump chamber 3 increases due to freezing, the elastic member 25 is compressed around the impeller 11 having a large space in which the fluid exists in the pump chamber 3, and the capacity of the pump chamber 3 is increased. This can reduce the pressure applied to the inner wall surface of the pump chamber 3 when the fluid freezes, and therefore can suppress damage to the housing 4. In addition, since the elastic member 25 can be positioned by the partition member 26, it is possible to suppress the elastic member 25 from being deformed by the pressure of the fluid when the pump apparatus operates and the gap between the impeller 11 and the elastic member 25 from becoming large. Therefore, since the pump chamber 3 can be prevented from being lowered in lift by disposing the elastic member 25, the casing 4 can be prevented from being damaged when the fluid freezes, and the pump performance can be prevented from being lowered.

In proposing the pump device 1 of the present embodiment, the following considerations are taken into account. When the fluid remaining in the connection pipe connected to the pump chamber, the water supply pipe, and the discharge pipe in the pump device freezes due to cold or the like, the fluid tends to remain in the space near the impeller of the connection pipe in the pump chamber, and therefore, the volume expansion of the fluid due to freezing tends to occur near the impeller. Conventionally, a pump device in which an elastic member is disposed at a position away from an impeller has been proposed. However, in such a configuration, when the freezing of the fluid starts from the periphery of the impeller, the capacity of the pump chamber cannot be increased at the periphery of the impeller to absorb the volume expansion of the fluid, and the casing may be damaged. As described above, in the pump device 1 of the present embodiment, the elastic member 25 is compressed around the impeller 11 to expand the capacity of the pump chamber 3, so that damage to the casing 4 can be suppressed.

The pump device 1 of the present embodiment includes the sheet member 27 disposed between the partition member 26 and the elastic member 25, and the sheet member 27 overlaps a part of the opening 260 as viewed in the axial direction L. As described above, by covering a part of the elastic member 25 disposed in the opening 260 with the sheet member 27, which is a member different from the partition member 26 fixed to the housing 4, the effect of suppressing the damage of the housing 4 when the fluid is frozen is maintained, and the deformation of the elastic member 25 can be appropriately suppressed when the pump device is operated, and the reduction of the lift due to the disposition of the elastic member 25 in the pump chamber 3 can be suppressed. Therefore, a decrease in pump performance can be suppressed. For example, by using a polyethylene film as the sheet member 27, the elastic member 25 can be compressed during freezing, and the elastic member 25 can be appropriately suppressed from being compressed in the axial direction L by the pressure of the fluid during operation of the pump device 1.

In this embodiment, the elastic member 25 is annular, the partition member 26 includes an outer annular portion 261, an inner annular portion 262 disposed on the inner peripheral side of the outer annular portion 261, and a plurality of connecting portions 263 connecting the outer annular portion 261 and the inner annular portion 262, and the opening 260 is provided between the circumferentially adjacent connecting portions 263. Accordingly, since the inner and outer peripheral edges of the elastic member 25 can be positioned by the partition member 26, it is easy to suppress the increase in the distance between the impeller 11 and the elastic member 25 due to the deformation of the elastic member 25.

In the present embodiment, the housing 15 includes a protruding portion 45 protruding from the center of the bottom surface 41a of the recess 41 in the axial direction L toward the impeller 11. In addition. The inner annular portion 262 is positioned in the axial direction L by the metal positioning ring 28 fitted into the protruding portion 45. Thus, by using the positioning ring 28, the partition member 26 can be easily fixed, and the inner annular portion 262 can be easily positioned. Further, by fixing with the positioning ring 28, the positional accuracy of the inner annular portion 262 in the axial direction L can be improved. Therefore, the gap between the impeller 11 and the elastic member 25 can be set to be narrow, and therefore, the elastic member 25 can be disposed in the inner wall surface portion facing the impeller 11 in the axial direction L, and the pump performance can be prevented from being degraded.

In the present embodiment, the housing 15 includes the protruding portion 454 protruding from the outer peripheral surface of the protruding portion 45, and the positioning ring 28 overlaps the protruding portion 454 as viewed in the axial direction L. Accordingly, the inner annular portion 262 can be held between the positioning ring 28 and the distal end surface of the protruding portion 454. Therefore, the positional accuracy of the inner annular portion 262 can be improved. In addition, since the positioning ring 28 and the protruding portion 454 overlap in the axial direction L, the overlapping area of the positioning ring 28 and the elastic member 25 can be reduced. Therefore, deformation of the elastic member 25 can be appropriately suppressed.

Since the positioning ring 28 of the present embodiment is a snap ring having a toothed portion formed on the inner peripheral edge, the positioning ring 28 can be easily fixed. In addition, the retaining ring 28 can be inhibited from falling off after installation.

In this embodiment, since the elastic member 25 is disposed on the entire bottom surface 41a of the recess 41, the elastic member 25 can be prevented from disturbing the water flow generated by the impeller 11.

In this embodiment, the outer annular portion 261 is welded to the welding portion 49 provided on the inner peripheral surface 41b of the recess 41, so that the outer annular portion 261 can be firmly fixed. In addition, since there is no need to use a fixing component such as the positioning ring 28, the increase in the number of components can be suppressed, and the structure of the housing 4 can be simplified.

In this embodiment, the resilient member 25 is a closed cell foam. By using closed cell foam, the resilient member 25 is compressed when frozen, thereby expanding the volume of the pump chamber 3.

In this embodiment, the elastic member 25 is disposed on the entire bottom surface 41a of the recess 41, and the elastic member 25 has a large volume. Therefore, the capacity of the pump chamber 3 can be greatly increased by the compressive deformation of the elastic member 25. In this embodiment, the elastic member 25 is of a size that can be elastically deformed by a volume amount equal to or greater than 10% of the volume of the pump chamber 3 when changing from the natural state to the compressed state. Accordingly, the pressure applied to the inner wall surface of the pump chamber 3 at the time of freezing can be reduced, and damage to the housing 4 can be prevented.

(other embodiments)

In the above-described embodiment, the partition member 26 and the sheet member 27 are disposed between the elastic member 25 and the impeller 11, and the partition member 26 is fixed to the casing 15 by the welding and the positioning ring 28 to form the frost damage preventing portion 29, but as described above, it has been confirmed that the case 4 is not cracked in the freezing test even if the sheet member 27 is omitted. In addition, it has been confirmed that even in the configuration in which the sheet member 27 is omitted, the reduction in the head is suppressed and the reduction in the pump characteristics is suppressed as compared with the configuration in which only the elastic member 25 is disposed in the recess 41. Therefore, the sheet member 27 may be omitted and the elastic member 25 may be positioned only by the partition member 26. In this case, as the partition member 26, a flexible sheet member such as a polyethylene film or a sheet metal member may be used as in the above-described configuration.

Claims (13)

1. A pump device, comprising:

a rotor including an impeller, a shaft portion extending coaxially with the impeller, and a magnet fixed to the shaft portion and separated from the impeller in an axial direction of the shaft portion;

a casing including a housing having a recess for accommodating the impeller, and a partition member that covers the housing from the axial direction and partitions a pump chamber for accommodating the rotor together with the housing;

an elastic member disposed on a bottom surface of the recess; and

a partition member disposed between the elastic member and the impeller and fixed to the housing,

the partition member includes an opening portion that overlaps a part of the elastic member when viewed in the axial direction.

2. Pump apparatus according to claim 1,

a sheet member disposed between the partition member and the elastic member,

the sheet member overlaps with a part of the opening when viewed in the axial direction.

3. Pump arrangement according to claim 1 or 2,

the elastic component is in a ring shape,

the partition member includes: an outer annular portion; an inner annular portion disposed on an inner peripheral side of the outer annular portion; and a plurality of connecting portions connecting the outer annular portion and the inner annular portion,

the opening portion is provided between the circumferentially adjacent connecting portions.

4. Pump apparatus according to claim 3,

the housing includes a protruding portion protruding from the center of the bottom surface of the recess in the axial direction,

the inner annular portion is positioned in the axial direction by a metal positioning ring fitted into the protruding portion.

5. The pump arrangement according to claim 4,

a protrusion portion protruding from an outer peripheral surface of the protrusion portion,

the positioning ring overlaps the protrusion as viewed in the axial direction.

6. Pump arrangement according to claim 4 or 5,

the positioning ring is a snap ring with teeth formed on the inner periphery.

7. Pump arrangement according to any one of claims 3 to 6,

the outer annular portion is welded to a welding portion provided on an inner peripheral surface of the recessed portion.

8. Pump device according to any one of claims 1 to 7,

the resilient member is a closed cell foam.

9. Pump device according to any one of claims 1 to 8,

the elastic member is disposed over the entire bottom surface.

10. The pump arrangement according to claim 7,

the weld is a convex portion protruding from an end surface of a second protruding portion extending in an axial direction from an outer peripheral edge of a bottom surface of the concave portion,

the outer peripheral annular portion abuts against the end surface,

the welding portion is disposed in a welding cutout portion provided in an outer peripheral edge of the outer annular portion,

the outer annular portion is heat welded to the case by heating and flattening the welded portion.

11. The pump arrangement according to claim 10,

the welding notches are formed on the outer peripheral side of each of the plurality of connecting portions.

12. The pump arrangement according to claim 4,

the tip end portion of the protruding portion includes an annular stepped portion and a small diameter portion protruding in the axial direction on the inner peripheral side of the stepped portion,

the stepped portion is a position regulating portion for regulating the movement of the partition member toward the bottom surface side of the recessed portion by a predetermined amount or more.

13. The pump arrangement according to claim 4,

in the opening of the partition member, a first region radially inward of the sheet member and radially outward of an outer peripheral edge of the positioning ring does not overlap the sheet member, and a second region radially outward of an inner peripheral edge of the sheet member overlaps the sheet member,

a portion of the elastic member that overlaps the first region of the opening portion is exposed in the pump chamber.

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