Pump device

Abstract

This pump device (1) comprises: a shaft (46); a rotor (8) rotatably supported by the shaft (46); a housing (2) that accommodates the rotor (8); a stator (9) fixed to the housing (2); a base (6) that supports the shaft (46); and a plate (7) disposed side by side with the base (6) in the rotation axis direction. The housing (2) is provided with an opening (45) penetrating in the rotation axis direction, the base (6) covers one side of the opening (45) in the rotation axis direction, the plate (7) covers the other side of the opening (45) in the rotation axis direction, and an elastic member (10) is sandwiched and fixed between the base (6) and the plate (7).

Description

Pump device

[0001] The present invention relates to a pump device.

[0002] For example, Patent Document 1 discloses a water pump that pumps coolant. This pump has a housing that houses a shaft and a rotor rotatably supported by the shaft. The shaft is formed of a metal material, and the housing is formed of a resin material.

[0003] Japanese Patent Application Laid-Open No. 2023-11432

[0004] Due to the difference in materials, the linear expansion coefficients between the shaft and the housing are different. As a result, a gap may occur between the shaft and the housing due to a change in the temperature of the coolant. It is necessary to prevent leakage of the coolant through such a gap.

[0005] The present invention has been made in view of the above problems, and one of the problems is to provide a pump device capable of improving the sealing performance of the opening of the housing.

[0006] A pump device according to an aspect of the present invention includes a shaft, a rotor rotatably supported by the shaft, a housing that houses the rotor, a stator fixed to the housing, a base that supports the shaft, and a plate arranged side by side with the base in the rotational axis direction. The housing has an opening penetrating in the rotational axis direction. In the rotational axis direction, the base covers one side of the opening, and in the rotational axis direction, the plate covers the other side of the opening. An elastic member is sandwiched and fixed between the base and the plate.

[0007] This is a schematic perspective view showing the structure of a pump device 1 according to one embodiment of the present invention. This is a schematic perspective view showing the structure of a pump device 1 according to one embodiment of the present invention. This is a cross-sectional view along line 3-3 in Figure 1. This is a cross-sectional view along line 4-4 in Figure 3. This is a partially enlarged perspective cross-sectional view showing a schematic part of the structure of a pump device 1. This is an exploded perspective view showing a schematic of the structure of the base 6, plate 7 and elastic member 10. This is a partially enlarged cross-sectional view along line 7-7 in Figure 5. This is a partially enlarged cross-sectional view showing a schematic of the structure of a pump device 1A according to one modified example. This is a partially enlarged cross-sectional view showing a schematic of the structure of a pump device 1 corresponding to Figure 8. This is a partially enlarged cross-sectional view showing a schematic of the structure of a pump device 1B according to another modified example. This is an exploded perspective view showing a schematic of the structure of the base 6A, shaft 46 and circuit board 96. This is an exploded perspective view showing a schematic of the structure of the base 6A, shaft 46 and circuit board 96.

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Figures 1 and 2 are schematic perspective views showing the structure of a pump device 1 according to an embodiment of the present invention. This pump device 1 is, for example, a water pump. A water pump is a centrifugal pump for transferring (pressurizing) a fluid, i.e., a coolant. The pump device 1 is installed, for example, in the engine room or motor room of a vehicle. The pump device 1 is used, for example, to cool a drive source such as the engine or motor of a vehicle by transferring coolant to the drive source.

[0009] In pump device 1, the direction along axis x is defined as the rotation axis direction. In this rotation axis direction, one side is defined as the upper side and the other side as the lower side. The upper and lower sides do not necessarily coincide with the upper and lower sides in the direction of gravity. Furthermore, the direction perpendicular to axis x is defined as the radial direction. In the radial direction, the direction approaching axis x is defined as the inner circumference side and the direction moving away from axis x is defined as the outer circumference side. In addition, a circumferential direction is defined around axis x. The clockwise and counterclockwise directions in the circumferential direction are defined as the direction when viewed from above in the rotation axis direction.

[0010] Figure 1 is a perspective view of the pump device 1 as seen from above in the direction of rotation axis, and Figure 2 is a perspective view of the pump device 1 as seen from below in the direction of rotation axis. Referring to both Figures 1 and 2, the pump device 1 includes a housing 2 that is formed in a generally cylindrical shape with axis x as the center. The housing 2 has a case 3, a can portion 4, and a cover 5 arranged in order from top to bottom along axis x. The case 3 and the can portion 4 are formed by injection molding from a thermoplastic resin material, such as PPS (polyphenylene sulfide). The cover 5 is formed from a metal material, such as aluminum. The internal space of the housing 2 is defined by the case 3 and the can portion 4.

[0011] Case 3 comprises a main body 31 and an inlet 32 ​​and an outlet 33 integrally formed on the main body 31. The main body 31 is formed, for example, as a flat cylindrical shape with the top closed. The inlet 32 ​​protrudes upward from the upper surface of the main body 31 along the axis x. The inlet 32 ​​is formed, for example, as a cylindrical shape centered on the axis x. The inlet 32 ​​allows fluid to flow into the internal space of the housing 2. The outlet 33 is formed on the main body 31 along the tangent to a virtual circle centered on the axis x. In this example, the outlet 33 extends from an inner circumferential end defined within the main body 31 to an outer circumferential end defined by an opening provided on the outer circumferential surface of the main body 31. That is, the outlet 33 does not protrude outward from the outer circumferential surface of the main body 31. The outlet 33 allows fluid to flow out from the internal space of the housing 2. However, the outlet 33 may be extended by a cylinder (not shown) attached, for example, by adhesive or welding, to the opening at the outer circumferential end.

[0012] The can portion 4 is formed as a whole, for example, in a cylindrical shape. A case 3 is attached to the upper end of the can portion 4, while a cover 5 is attached to the lower end of the can portion 4. The cover 5 has a main body 51 and a connector housing 52. The main body 51 is formed, for example, in a flat cylindrical shape with the lower side closed. The main body 51 is attached to the can portion 4 by one or more engaging portions 51a formed on the cylindrical portion engaging with projections 40 that protrude outward from the outer circumferential surface of the can portion 4.

[0013] The connector housing 52 is formed in a cylindrical shape that protrudes downward from the lower surface 51b of the main body 51. One or more connector pins 53 are housed inside the connector housing 52. The connector pins 53 protrude downward from the main body 51. Connectors (not shown) of external devices are connected to the connector pins 53. In this way, power and signals are supplied from the external device to the pump device 1 via the connector pins 53. The main body 51 and the connector housing 52 are integrally formed from a thermally conductive metal material such as aluminum. However, the connector housing 52 may be formed from a resin material as a separate component from the main body 51.

[0014] Figure 3 is a cross-sectional view along line 3-3 in Figure 1. As shown in Figure 3, the can portion 4 has a bottom wall 41, an inner wall 42, a top wall 43, and an outer wall 44. The bottom wall 41 is formed, for example, in the shape of a flat disc perpendicular to the axis x. The inner wall 42 extends upward from the outer edge of the bottom wall 41. The inner wall 42 is formed in the shape of a cylinder centered on the axis x. The top wall 43 extends outward from the upper edge of the inner wall 42. The top wall 43 is formed in the shape of an annular ring centered on the axis x. The outer wall 44 extends downward from the outer edge of the top wall 43. The outer wall 44 is formed in the shape of a cylinder centered on the axis x.

[0015] An internal space S is formed within the housing 2 by the case 3 and the can section 4. The internal space S has a first space S1 formed by the main body 31 of the case 3 and the top wall 43 of the can section 4, and a second space S2 formed by the bottom wall 41 and the inner wall 42 of the can section 4. In this example, both the first space S1 and the second space S2 are generally cylindrical spaces centered on axis x. The first space S1 and the second space S2 are in communication with each other. In the radial direction, the diameter of the first space S1 is larger than the diameter of the second space S2. On the other hand, in the direction of rotation, the height of the first space S1 is smaller than the height of the second space S2.

[0016] Case 3 includes a support portion 34 located within the main body 31 below the lower base end of the inlet portion 32, and a plurality of spokes 35 supporting the support portion 34. In this example, the support portion 34 is positioned to enter the first space S1 from the lower end of the inlet portion 32 along the axis x. The support portion 34 as a whole is formed in a generally cylindrical shape centered on the axis x. The plurality of spokes 35 connect the outer surface of the support portion 34 and the inner surface of the inlet portion 32 to each other. In this example, three spokes 35 are arranged at predetermined intervals in the circumferential direction. Each spoke 35 is formed in a flat plate shape extending, for example, along a virtual plane containing the axis x.

[0017] An opening 45 is formed in the bottom wall 41 of the can section 4, penetrating the bottom wall 41 along the axis of rotation. The pump device 1 includes a base 6 and a plate 7 arranged to cover this opening 45. In this example, the base 6 covers one side, i.e., the upper side, of the opening 45. The plate 7 covers the other side, i.e., the lower side, of the opening 45. A shaft 46 is arranged in the internal space S of the housing 2. The shaft 46 is formed in a cylindrical shape, for example, with an axis x as its center. The upper end of the shaft 46 is fixed to a recess 34a formed in the lower surface of the support section 34 of the case 3. On the other hand, the lower end of the shaft 46 is supported by the base 6 and the plate 7. That is, the base 6 and the plate 7 constitute the support section of the shaft 46.

[0018] The pump device 1 includes a rotor 8 supported by a shaft 46 around an axis x. The rotor 8 is housed in a housing 2. The rotor 8 has a bearing 81 rotatably supported by the shaft 46, a rotor body 82 fixed to the bearing 81, and a magnet 83 fixed to the rotor body 82. The bearing 81 is formed in a cylindrical shape along the axis x. The inner circumferential surface of the bearing 81 faces the outer circumferential surface of the shaft 46 with a predetermined gap between them. Thus, the bearing 81, and thus the rotor 8, is configured to be rotatable around the axis x and movable in the vertical direction along the axis x. The bearing 81 is a so-called sliding bearing.

[0019] The rotor body 82 includes an inner cylinder 84, a flange 85, an upper cover 86, a plurality of blades 87, and an outer cylinder 88. The rotor body 82 is integrally formed by injection molding from a thermoplastic resin material, such as PPS (polyphenylene sulfide). The inner cylinder 84 is formed in a cylindrical shape with axis x as the center. The flange 85 extends radially in an annular shape from the upper end of the inner cylinder 84 in the direction of rotation axis. That is, the flange 85 is formed in a disc shape with axis x as the center. The plurality of blades 87 rise upward from the upper surface of the flange 85. The plurality of blades 87 are arranged in the circumferential direction.

[0020] In this example, all blades 87 have the same shape and dimensions. Each blade 87 extends in a curved manner from the inner end to the outer end of the flange 85. In this example, when viewed from above, each blade 87 extends diagonally in a counterclockwise direction with respect to the radial direction from the inner end to the outer end. The height of each blade 87 from the upper surface of the flange 85 decreases, for example, from the inner end to the outer end of the blade 87. In other words, the height of each blade 87 may differ between the inner and outer ends, and more preferably, the height of the inner end of each blade 87 may be greater than the height of the outer end.

[0021] The upper cover 86 is formed, for example, in a disc shape around an axis x. The upper cover 86 covers the flange 85 from above. The lower end of the blade 87 is integrally connected to the flange 85, and the upper end of the blade 87 is integrally connected to the upper cover 86. An opening 86a is formed in the upper cover 86 that penetrates the upper cover 86 in the direction of the rotation axis. In this way, a swirling fluid flow path is formed between the flange 85 and the upper cover 86, from the opening 86a of the upper cover 86, passing between the circumferentially adjacent blades 87, 87, and moving from the inner circumferential end to the outer circumferential end of the blade 87, around an axis x.

[0022] The outer cylinder 88 is integrally coupled to the inner cylinder 84 at its lower end. In this example, the upper end of the outer cylinder 88 is integrally coupled to the outer circumferential surface of the inner cylinder 84. The outer cylinder 88 has a larger outer diameter than the inner cylinder 84. In this example, an annular gap is formed between the outer circumferential surface of the inner cylinder 84 and the inner circumferential surface of the outer cylinder 88. A magnet 83 is fixed to the outer circumferential surface of the outer cylinder 88. In this example, the magnet 83 is formed in a cylindrical shape centered on axis x. This magnet 83 is, for example, a permanent magnet. The magnet 83 has, for example, alternating regions magnetized as south poles and regions magnetized as north poles in the circumferential direction.

[0023] In the direction of rotation, a predetermined gap is secured between the upper end of the bearing 81 and the lower surface of the support portion 34, and between the lower ends of the bearing 81 and the rotor body 82 and the base 6. The flange 85 and blades 87 of the rotor body 82 are housed in the first space S1, while the magnet 83 is housed in the second space S2. In the radial direction, the blades 87 face the inner surface of the body 31 of the case 3 with a predetermined gap between them. In the radial direction, the outer circumferential surface of the magnet 83 faces the inner circumferential surface of the inner wall 42 with a predetermined gap between them. Also, in the direction of rotation, the lower surface of the magnet 83 faces the bottom wall 41 of the can portion 4 and the base 6 with a predetermined gap between them.

[0024] Figure 4 is a cross-sectional view along line 4-4 in Figure 3. Referring to Figures 3 and 4 together, the pump device 1 includes a stator 9 incorporated into the can section 4. The stator 9 is positioned in an annular space between the inner wall 42 and the outer wall 44 and is fixed to the inner circumferential surface of the outer wall 44, i.e., the housing 2. The stator 9 includes a stator core 91, a plurality of coils 92, and an insulator 93. The stator core 91 is formed from a laminate of a plurality of thin plates stacked in the direction of the rotation axis. The laminate is made of a magnetic material. The coils 92 have windings, for example, made of copper wire. The insulator 93 electrically insulates the stator core 91 from the plurality of coils 92. The insulator 93 is made of an insulating material, for example, a resin material.

[0025] The stator core 91 comprises an annular portion 94 and a plurality of teeth 95. The annular portion 94 is fixed to the inner circumferential surface of the outer wall 44 of the can portion 4. The annular portion 94 is defined in an annular shape around the axis x. Each tooth 95 protrudes inward from the inner circumferential surface of the annular portion 94. Each tooth 95 faces the outer circumferential surface of the magnet 83 of the rotor body 82 with a predetermined magnetic gap, with the inner wall 42 of the can portion 4 in between. The insulator 93 covering each tooth 95 is wound with the windings of the coil 92. In this example, there are six teeth 95, but the number of teeth 95 can be any number, such as 12 or 18. The number of poles of the rotor body 82 can also be changed in accordance with the change in the number of teeth 95.

[0026] In the pump device 1, when current is supplied to the coil 92, the magnetic interaction between the coil 92 and the magnet 83 causes the rotor body 82 to rotate counterclockwise around the axis x. This rotation generates a flow of coolant from the inlet 32 ​​into the first space S1 via multiple blades 87. The coolant flows outwards through the multiple blades 87 and then flows out from the outlet 33. In this way, the coolant is pumped to, for example, a drive source. The coolant may include, for example, water. Other liquids may be included in the water. Other liquids may include, for example, antifreeze such as propylene glycol or ethylene glycol, or rust inhibitors.

[0027] Returning to Figure 3, the pump device 1 includes a circuit board 96 incorporated within the cover 5. In this example, the circuit board 96 is formed in a disc shape along a plane perpendicular to the axis x. One or more electronic components 97 are provided on the front and back surfaces of the circuit board 96. These electronic components 97 include, for example, field-effect transistors (FETs) and capacitors. Wiring, i.e., connector pins 53, are also mounted on the circuit board 96. In this example, the upper surface 51c of the main body 51 of the cover 5 faces the back surface of the circuit board 96. The connector pins 53 protrude downward from the back surface of the circuit board 96 and extend into the connector housing 52.

[0028] Some of the coils 92 are electrically connected to the circuit board 96 by terminals 98. Meanwhile, connector pins 53 mounted on the circuit board 96 are electrically connected to connectors (not shown) of external devices. Power and signals are supplied from the external device to the electronic components 97 and coils 92 on the circuit board 96 via these connector pins 53 and terminals 98. For example, the supply of power causes the electronic components 97 and coils 92 on the circuit board 96 to generate heat. In one example, the temperature due to the heat generated by the electronic components 97 tends to be higher than the temperature due to the heat generated by the coils 92.

[0029] Figure 5 is a partially enlarged perspective cross-sectional view schematically showing the structure of a part of the pump device 1. The cross-section in Figure 5 corresponds to the cross-section in Figure 3. Referring to Figure 5, as described above, an opening 45 is formed in the bottom wall 41 of the can section 4, penetrating the bottom wall 41 along the rotation axis direction. The opening 45 has a first portion 47 that is recessed from the upper surface 41a toward the lower surface 41b of the bottom wall 41, a second portion 48 that is recessed from the lower surface 41b toward the upper surface 41a of the bottom wall 41, and a third portion 49 that is positioned between the first portion 47 and the second portion 48 in the rotation axis direction. The first portion 47, the second portion 48, and the third portion 49 each define, for example, a flat cylindrical space with different diameters. In this example, in the radial direction, the dimension of the first portion 47 is larger than the dimension of the second portion 48, and the dimension of the second portion 48 is larger than the dimension of the third portion 49.

[0030] A base 6 is positioned in the first part 47. Meanwhile, a portion of a plate 7 is positioned in the second part 48. In this example, the plate 7 is positioned adjacent to the lower surface 41b of the bottom wall 41. Thus, the base 6 and the plate 7 are positioned side by side in the direction of rotation. In the direction of rotation, the base 6 covers the upper side of the opening 45, and the plate 7 covers the lower side of the opening 45. An annular elastic member 10 is housed in the opening 45. The elastic member 10 is a gasket, such as an O-ring, formed from an elastic material. Elastic materials include, for example, fluororubber (FKM), ethylene propylene diene rubber (EPDM), and silicone rubber (VMQ).

[0031] Figure 6 is an exploded perspective view schematically showing the structure of the base 6, plate 7, and elastic member 10. In one specific example, the base 6 has a disc-shaped base body 61 centered on axis x, and a projection 62 projecting upward from the upper surface 61a of the base body 61. The projection 62 is formed, for example, in the shape of a frustocone centered on axis x. Through holes 63 are formed in the base body 61 and the projection 62, penetrating the base body 61 and the projection 62 in the direction of rotation axis. The shaft 46 is supported in the through holes 63. The base body 61 is further formed with one or more holes 64 that penetrate from the upper surface 61a to the lower surface 61b in the direction of rotation axis. In this example, four holes 64 are arranged at predetermined intervals around axis x. The upper surface 61a and the lower surface 61b of the base body 61 are defined, for example, along a plane perpendicular to axis x.

[0032] On the other hand, in one specific example, the plate 7 has a disc-shaped plate body 71 centered on an axis x, and a cylinder 72 projecting upward from the upper surface 71a of the plate body 71. The cylinder 72 is formed, for example, in a cylindrical shape centered on an axis x. The upper surface 72a of the cylinder 72 is defined along a plane perpendicular to the axis x. Holes 73 are formed in the plate body 71 and the cylinder 72, penetrating them in the direction of the rotation axis. That is, the holes 73 extend from the upper surface of the cylinder 72 to the lower surface 71b of the plate body 71. In this example, the upper surface 71a and the lower surface 71b of the plate body 71 are defined, for example, along a plane perpendicular to the axis x. The base 6 and the plate 7 are formed from a metal material having high thermal conductivity, such as aluminum.

[0033] Figure 7 is a partially enlarged cross-sectional view along the line 7-7 in Figure 5. Referring to both Figures 5 and 7, the base body 61 of the base 6 is positioned within the first portion 47 of the bottom wall 41. The bottom wall 41 has one or more bosses 41c extending in the direction of the rotation axis from the bottom surface of the first portion 47 within the first portion 47. In this example, four bosses 41c are formed corresponding to holes 64 formed in the base body 61. Each boss 41c is inserted into the hole 64. The upper ends of the four bosses 41c are connected to each other by a connecting portion 41d that is formed annularly around the axis x in this example (see Figure 5). The connecting portion 41d extends annularly along the upper surface 61a of the base body 61, on the outer circumference side of the projection 62 on the upper surface 61a of the base body 61. The connecting portion 41d may be divided into multiple parts arranged in the circumferential direction. A shaft 46 is supported and fixed in the through hole 63 of the base body 61, for example by press-fitting.

[0034] The base 6 is integrated with the can portion 4 by insert molding. Specifically, when the can portion 4 is molded from resin material, the base 6, with the shaft 46 press-fitted into the through hole 63, is pre-positioned in the mold. When resin material is injected into the mold in this state, the base 6 is positioned in the first recess 48 of the bottom wall 41 of the can portion 4. At this time, the flow of resin material into the hole 64 of the base body 61 forms bosses 41c, and simultaneously forms annular connecting portions 41d that connect the upper ends of the four bosses 41c to each other. In this way, the base 6 that supports the shaft 46 is fixed to the bottom wall 41. The insertion of the bosses 41c into the hole 64 and the connecting portions 41d that connect the bosses 41c prevent relative rotation of the base 6 with respect to the bottom wall 41 around the axis x.

[0035] As shown in Figure 5, the plate 7 is positioned adjacent to the lower surface 41b of the bottom wall 41. The cylinder 72 of the plate body 71 is positioned within the second portion 48 of the opening 45. In this example, in the radial direction, the dimensions of the plate body 71 are larger than those of the bottom wall 41 and the base body 61. The upper surface 71a of the plate body 71 is in contact with the entire lower surface 41b of the bottom wall 41. The shaft 46 is supported and fixed in the holes 73 of the plate body 71 and the cylinder 72, for example, by press-fitting. The elastic member 10 is housed within the opening 45 and is sandwiched and fixed between the lower surface 61b of the base body 61 of the base 6 and the upper surface 72a of the cylinder 72 of the plate 7. Specifically, the elastic member 10 is compressed between the lower surface 61b and the upper surface 72a. In the radial direction, the elastic member 10 is in contact with the inner circumferential surface 49a of the third portion 49 of the opening 45 and the outer circumferential surface of the shaft 46.

[0036] In the pump device 1 described above, as mentioned earlier, when the rotor 8 rotates around the axis x due to the supply of current to the coil 92, the coolant flowing in from the inlet 32 ​​flows to the outer circumference through the multiple blades 87 and then flows out from the outlet 33. At this time, the coolant also flows into the second space S2 which is in communication with the first space S1. However, the elastic member 10 is sandwiched and fixed between the base 6 and the plate 7 within the opening 45 of the bottom wall 41, thereby sealing the space between the base 6 and the bottom wall 41. Therefore, even if a minute gap is formed between the bottom wall 41 and the base 6, which have different coefficients of thermal expansion, it is possible to prevent the coolant from leaking out of the internal space S to the outside of the can section 4. In this way, the sealing performance of the can section 4, i.e., the housing 2, can be improved.

[0037] Figure 8 is a partially enlarged cross-sectional view schematically showing the structure of a modified pump device 1A. Figure 8 is a partially enlarged cross-sectional view along the line 8-8 in Figure 3. In this example, the second portion 48 is in direct communication with the first portion 47 at the opening 45 of the bottom wall 41. That is, the formation of the third portion 49 is omitted at the opening 45. A cylinder 72 made of plate 7 is housed inside the second portion 48. Thus, the upper surface 72a of the cylinder 72 is in contact with the lower surface 61b of the base body 61 inside the opening 45. An annular groove 72b is formed on the upper surface 72a of the cylinder 72. The groove 72b is formed along the outer circumferential surface of the cylinder 72. The bottom surface 72c of the groove 72b extends along a plane perpendicular to the axis x, for example. The bottom surface 72c is a plane that is one step lower than the upper surface 72a of the cylinder 72 in the direction of the rotation axis.

[0038] The elastic member 10 is sandwiched and fixed between the bottom surface 72c of the groove 72b and the lower surface 61b of the base body 61. Specifically, the elastic member 10 is compressed between the bottom surface 72c and the lower surface 61b. In the radial direction, the elastic member 10 is in contact with the outer circumferential surface of the groove 72b and the inner circumferential surface 48a of the second portion 48 of the opening 45. Other components similar to those in the previously described embodiment are given the same reference numerals, and redundant explanations are omitted here. In this pump device 1, the elastic member 10 is sandwiched and fixed between the base 6 and the plate 7 within the opening 45, thereby sealing the space between the base 6 and the bottom wall 41. As a result, leakage of coolant from the internal space S to the outside of the can portion 4 can be prevented.

[0039] Figure 9 corresponds to Figure 8 and is a partially enlarged cross-sectional view schematically showing the structure of the pump device 1. As shown in Figure 9, in the aforementioned pump device 1, the plate body 71 of the plate 7 and the electronic component 97 are in contact with each other via a member having high thermal conductivity (hereinafter referred to as "thermal conductive member") 11. Specifically, the thermal conductive member 11 is sandwiched, for example, between the lower surface 71b of the plate body 71 of the plate 7 and the upper surface of the circuit board 96. In this example, the thermal conductive member 11 is formed, for example, in the shape of a flat disc centered on axis x. The thermal conductive member 11 has dimensions in the radial direction that are approximately the same as the dimensions of the lower surface 71b of the plate body 71. That is, the thermal conductive member 11 is in contact with the entire surface of the lower surface 71b.

[0040] In this example, all electronic components 97 mounted on the surface of the circuit board 96 are in contact with the heat conductive member 11. Even if the height of each electronic component 97 from the surface of the circuit board 96 differs, this height can be absorbed, for example, by adjusting the thickness of the heat conductive member 11. In this way, all electronic components 97 on the surface of the circuit board 96 can be in contact with the heat conductive member 11. In this example, the heat conductive member 11 is a heat conductive sheet, but as an alternative, it may be a paste-like fluid having a predetermined viscosity, such as thermally conductive silicone.

[0041] In this pump device 1, heat is generated in the electronic components 97 when power is supplied from an external device to the circuit board 96 and coil 92. This heat is conducted via the heat conductive member 11 to the can portion 4, as well as to the plate body 71 of the plate 7, the base body 61 of the base 6, and the shaft 46, which are made of a metal material with high thermal conductivity. As a result, heat is transferred to the coolant from the upper surface 61a of the base body 61, the outer surface, bottom wall 41, and inner wall 42 of the shaft 46, which are in contact with the coolant in the internal space S, i.e., the second space S2. Since the coolant circulates within the internal space S, the heat is released from the pump device 1 along with the coolant. As a result, the electronic components 97 can be cooled efficiently.

[0042] In the pump devices 1 and 1A described above, the base 6 may be fixed within the opening 45 of the bottom wall 41 after injection molding of the can portion 4. In the bottom wall 41 after injection molding, only the boss 41c corresponding to the hole 64 of the base 6 is formed from the bottom surface of the first portion 47. That is, the formation of the connecting portion 41d that connects the upper ends of the bosses 41c to each other is omitted. By inserting the boss 41c into the hole 64 of the base body 61, the base body 61 is positioned within the first portion 47 of the opening 45. The portion of the base body 61 that protrudes upward from the hole 64 is deformed toward the upper surface 61a of the base body 61, for example by heat scribing. As a result, the base 6 is fixed within the opening 45.

[0043] Further, for example, in the pump devices 1 and 1A, the upper surface 71a of the plate body 71 of the plate 7 may not be in contact with the lower surface 41b of the bottom wall 41. Also, in the pump device 1A, as long as the elastic member 10 is sufficiently crushed between the base 6 and the plate 7, the upper surface 72a of the cylinder 72 of the plate body 71 does not necessarily have to be in contact with the lower surface 61b of the base body 61. Further, the elastic member 10 disposed between the base 6 and the plate 7 may be formed by applying an elastic material containing, for example, a liquid adhesive or the like. Also, instead of press-fitting the plate 7 onto the shaft 46, the plate 7 may be fixed to the shaft 46 by screwing, adhesion, or the like.

[0044] FIG. 10 is a partially enlarged cross-sectional view schematically showing the structure of a pump device 1B according to another modified example. In this pump device 1B, a base 6A is incorporated instead of the aforementioned base 6. FIGS. 11 and 12 are exploded perspective views schematically showing the structures of the base 6A, the shaft 46, and the circuit board 96. FIG. 11 is a perspective view seen from above in the rotational axis direction, and FIG. 12 is a perspective view seen from below in the rotational axis direction. Referring to FIGS. 10 to 12 together, the base 6A has a disk-shaped base body 61 centered on the axis x, a support portion 65 protruding upward from the upper surface 61a of the base body 61, and a convex portion 66 protruding upward from the upper surface 61a on the outer peripheral side of the support portion 65.

[0045] In this example, the base body 61 is formed in a flat plate shape of a flat cylinder extending along a plane orthogonal to the axis x. The support portion 65 is formed, for example, in a cylindrical shape centered on the axis x. A cylindrical space having a bottom surface is formed inside the support portion 65. The lower end of the shaft 46 is press-fitted into this space, for example, so that the shaft 46 is supported by the support portion 65 in the radial direction. The convex portion 66 is disposed on the outer peripheral side of the support portion 65 and is formed concentrically with the support portion 65. The convex portion 66 is formed, for example, in a cylindrical shape centered on the axis x. In this example, in the rotational axis direction, the height of the support portion 65 from the upper surface 61a of the base body 61 is set to be greater than the height of the convex portion 66 from the upper surface 61a.

[0046] On the outer periphery of the protrusion 66, one or more holes 67 are formed in the base body 61, penetrating from the upper surface 61a to the lower surface 61b. In this example, six holes 67 are arranged at predetermined intervals in the circumferential direction. Fixing members 68 for fixing the base 6A to the bottom wall 41 pass through the holes 67. The fixing members 68 are, for example, screws or bolts. In one example, the fixing member 68 is a low-profile countersunk screw, and the head of the fixing member 68 is completely housed within the hole 67. However, regarding the method of fixing the base 6A to the bottom wall 41, the base 6A may be fixed to the bottom wall 41 by other methods such as adhesive or press-fitting instead of the fixing members 68. The base 6A is formed of a metal material with high thermal conductivity, such as aluminum.

[0047] As shown in Figure 10, the aforementioned opening 45 is formed in the bottom wall 41 of the can portion 4. In addition, an annular recess 41e is formed in the lower surface 41b of the bottom wall 41. Furthermore, a plurality of screw holes 41f are formed in the lower surface 41b of the bottom wall 41. The base 6A is fixed to the bottom wall 41. Specifically, the support portion 65 of the base 6A is inserted into the opening 45 until the upper surface 61a of the base body 61 of the base 6A contacts the lower surface 41b of the bottom wall 41. In this state, the fixing member 68 is screwed into the screw holes 41f of the bottom wall 41 through the hole 67. In this way, the base body 61 is fixed to the bottom wall 41. The protrusion 66 is received in the annular recess 41e of the bottom wall 41. Since the fixing member 68 is housed in the hole 67 up to its head, the head of the fixing member 68 does not protrude below the hole 67.

[0048] An annular recess 45a is formed on the inner peripheral surface of the opening 45 of the bottom wall 41 by a step. In this example, the recess 45a is formed adjacent to the lower surface 41b of the bottom wall 41. An annular elastic member 12 is disposed in the recess 45a around the axis x. The elastic member 12 is a gasket such as an O-ring formed of an elastic material, similar to the elastic member 10. In this example, when the support portion 65 of the base 6 is fixed in the opening 45 of the bottom wall 41 by, for example, press-fitting, the elastic member 12 is elastically crushed between the outer peripheral surface of the support portion 65 and the inner peripheral surface of the opening 45 of the bottom wall 41 in the radial direction. That is, the elastic member 12 is disposed between the support portion 65 and the convex portion 66 in the radial direction. Thus, the sealing performance between the shaft 46 and the bottom wall 41 is ensured.

[0049] An electronic component 97 mounted on the circuit board 96 is in contact with the base 6A via a member having high thermal conductivity (hereinafter referred to as a "thermal conductive member") 13. Specifically, the thermal conductive member 13 is sandwiched, for example, between the lower surface 61b of the base body 61 and the upper surface of the circuit board 96. In this example, the thermal conductive member 13 is formed, for example, in a flat disk shape centered on the axis x. As shown in FIGS. 10 and 12, the electronic component 97 may be embedded in the thermal conductive member 13. Note that the thermal conductive member 13 is a thermal conductive sheet in this example, but alternatively, it may be a paste-like fluid having a predetermined viscosity such as silicone having thermal conductivity.

[0050] According to the pump device 1C as described above, the base 6A fixed to the bottom wall 41 of the can portion 4 supports the shaft 46 by the support portion 65. An elastic member 12 is sandwiched and fixed between the support portion 65 and the opening 45 of the bottom wall 41. The elastic member 12 can seal between the base 6A and the bottom wall 41. As a result, leakage of the coolant from the internal space S to the outside of the can portion 4 can be prevented. Moreover, since the convex portion 66 is formed on the outer peripheral side of the support portion 65, the elastic member 12 is disposed between the support portion 65 and the convex portion 66. Even when stress is generated by crushing of the elastic member 12, the convex portion 66 can suppress deformation of the bottom wall 41, for example.

[0051] Furthermore, the heat generated by the electronic component 97 is conducted to the can portion 4 and shaft 46 via the heat conductive member 13 and base 6A, which are made of a metal material with high thermal conductivity. As a result, heat is transferred to the coolant from the support portion 65 of the base body 61, the outer surface, bottom wall 41, and inner wall 42 of the shaft 46, which are in contact with the coolant in the internal space S, i.e., the second space S2. Since the coolant circulates within the internal space S, the heat is released from the pump device 1 along with the coolant. As a result, the electronic component 97 can be cooled efficiently.

[0052] Although the present invention has been described above through the embodiments described above, the technical scope of the present invention is not limited to the scope described in the embodiments above. It will be obvious to those skilled in the art that various modifications or improvements can be made to the embodiments described above. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0053] The embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit its interpretation. Furthermore, the embodiments described above do not limit the scope of application of the present invention, and the present invention may encompass anything as its target application. The components of the above embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified and can be modified as appropriate.

[0054] For example, the present invention includes differences that arise in the implementation of manufacturing tolerances, etc. Furthermore, components shown in different embodiments can be partially substituted or combined to the extent that they do not conflict with the technical requirements. In addition, each component can be selectively combined as appropriate to achieve at least some of the above-mentioned problems and effects.

[0055] 1, 1A, 1B, 1C Pump device, 2 Housing, 3 Case, 31 Main body, 32 Inlet, 33 Outlet, 34 Support part, 34a Recess, 35 Spoke, 4 Can part, 40 Projection, 41 Bottom wall, 41a Top surface, 41b Bottom surface, 41c Boss, 41d Connection part, 41e Recess, 41f Screw hole, 42 Inner wall, 43 Top wall, 44 Outer wall, 45 Opening, 45a, 46 Shaft, 47 First part, 48 Second part, 48a Inner circumferential surface, 49 Third part, 49a Inner circumferential surface, 5 Cover, 51 Main body, 51a Engaging part, 51b Bottom surface, 51c Top surface, 52 Connector housing, 53 Connector pin, 6, 6A Base, 61 Base body, 61a Top surface, 61b 91, 12, 13, 14, 15, 16, 17, 18, 19, 10, 12, 11, 13, 11, 12, 12, 13, 14, 15, 16, 17, 18, 19, 10, 12, 11, 13, 12, 13, 14, 15, 16, 17, 18, 19, 10, 12, 11, 13, 14, 15, 16, 17, 18, 19, 10, 12, 11, 13, 14, 15, 16, 17, 18, 19, 10, 12, 11, 13, 15, 16, 17, 18, 19, 18, 19, 19, 10, 12, 11, 139, 11 2nd space, x axis

Claims

1. A pump device comprising: a shaft; a rotor rotatably supported on the shaft; a housing for housing the rotor; a stator fixed to the housing; a base for supporting the shaft; and a plate positioned alongside the base in the direction of rotation axis, wherein the housing has an opening that penetrates in the direction of rotation axis; the base covers one side of the opening in the direction of rotation axis; the plate covers the other side of the opening in the direction of rotation axis; and an elastic member is sandwiched and fixed between the base and the plate.

2. The pump device according to claim 1, wherein the base and the plate are in contact inside the opening.

3. The pump device according to claim 1 or 2, wherein the plate comprises a cylinder extending in the direction of the rotation axis, the elastic member is fixed between the cylinder and the base, and the elastic member is housed in the opening.

4. In the radial direction, the elastic member is in contact with the inner circumferential surface of the opening, the pump device according to any one of claims 1 to 3.

5. The pump device according to any one of claims 1 to 4, wherein the base has a hole that penetrates in the direction of the rotation axis, the housing has a boss that extends in the direction of the rotation axis, and the base is fixed to the housing by the boss being inserted into the hole.

6. A pump device according to any one of claims 1 to 5, comprising an electronic component that generates heat, wherein the plate and the electronic component are in contact with each other via a thermally conductive member.

7. The pump device according to any one of claims 1 to 6, wherein the base comprises a support portion for supporting the shaft in the radial direction and a protrusion, and an elastic member is provided between the support portion and the protrusion.

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