GB2496014A

GB2496014A - Canned motor pump with power circuit cooling

Info

Publication number: GB2496014A
Application number: GB201215058A
Authority: GB
Inventors: Noriaki Matsunaga; Hiroki Aso
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2011-10-28
Filing date: 2012-08-23
Publication date: 2013-05-01
Anticipated expiration: 2032-08-23
Also published as: CN103089711A; GB2496014B; JP2013099021A; GB201215058D0; CN103089711B

Abstract

A canned motor pump with an electric circuit 30 that supplies power to the stator 17a, a heat dissipation plate 31 that dissipates the heat generated by the electric circuit, and a heat transfer plate 32 that transfers the heat of the electric circuit from the heat dissipation plate to part of the lower casing 15 which separates the stator and rotor. Preferably the electric circuit, heat dissipation plate and heat transfer plate are joined by resin, spot welding or by screws. A spacer may be included which controls the separation between the electric circuit and the lower casing. Also claimed is a heat pump comprising, a water circuit including the aforementioned pump, a refrigerant circuit and a heat exchanger between the water and refrigerant circuits.

Description

N.1 17694

PUMP AND HEAT PUMP DEVICE

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to a pump and a heat pump device that uses this pump, and more particularly, to a canned pump and a heat pump device that uses this canned pump.

Description of the Related Art

[00021 Conventional pumps include, for example, a pump including "a molded electric motor having a molded stator in which the stator unit is integrally formed by means of molded resin, a rotor assembly, and a bracket, wherein the stator unit has a stator that is composed of laminated electromagnetic steel plates and formed by mounting an insulating member to a stator iron core having a plurality of slots and by providing wiring in the slots, a driving element that is mounted on a surface opposite to the stator and drives the molded electric motor, and a temperature sensing resistor element that monitors the temperatures of the molded electric motor, and also including a circuit substrate fixed to one end portion in one axial direction of the insulating member, and a heat dissipation plate mounted to the driving element and disposed substantially parallel to the circuit substrate, and also disposed so as to face the temperature sensing resistor element in the axial direction, and dissipate the heat generated by the driving element." The pump as described above includes "a configuration in which "the heat dissipation plate 21 (for example, an aluminum plate) is separately attached to the driving element 12, so that temperature rise in the driving element 12 is avoided by the heat dissipation plate 21" (see Patent Literature 1).

[0003] Conventional pumps include, for example, a pump that "consists of a stator 3 having a coil 31, a control circuit substrate 4 that performs energization control for the coil 31, a rotor 2 that is rotated by means of the energization control of the control circuit substrate 4, a frame 12 having a reception chamber 16 for receiving the stator 3 and the control circuit substrate 4, a protrusion unit 5 that is mounted to the frame 12 and projects into the reception chamber 16, and a heat transfer member filled as a filling material 6 in the reception chamber 16, and the control circuit substrate 4 is provided with a semiconductor device 41 that converts electric power supplied from outside to driving power for a motor, and the heat dissipation surface of the semiconductor device 41 faces the heat receiving surface of the protrusion unitS, and the filling material 6 is filled in an area between the heat dissipation surface of the semiconductor device 41 and the heat receiving surface of the protrusion unit 5 that faces the heat dissipation surface." The pump as described above includes a configuration in which "since the filling material 6 is filled between the two surfaces, facing each other, of the semiconductor device 41 and the protrusion unit 5, the semiconductor device 41 will not directly come in contact with the protrusion unit 5 or frame 12, and the heat generated in the semiconductor device 41 is transmitted from the heat transfer member which is the filling material 6 through the protrusion unit 5 to the frame 12 and then discharged to the outside (see Patent Literature 2).

[0004] [Patent Literature 1] Japanese Patent Application Laid-Open (JP-A) No. 2010- 93962 (Paragraphs [0007] and [0016]) [Patent Literature 21 Japanese Patent Application Laid-Open (JP-A) No. 2010- 273443 (Paragraph [0010])

SUMMARY OF THE INVENTION

[0005] However, in the conventional pump (Patent Literature 1), the heat dissipation plate for the driving element for driving the molded electric motor was formed by being molded integrally into resin together with the substrate for mounting the stator and the driving element. For this reason, the heat generated by the driving element was not sufficiently thermally transferred to the outside. Accordingly, efficient heat dissipation was not certainly carried out.

[0006] Also, in the conventional pump (Patent Literature 2), the protrusion unit provided inside an external metal frame was, by way of filling material, in contact with a semiconductor device that converts electric power supplied to the control substrate into the driving power for the motor. For this reason, the heat generated by the semiconductor device was thermally transferred by way of the filling material, and the heat thus transferred was further thermally transferred to the external metal frame by way of the protrusion unit, and then dissipated to the outside. For this reason, efficient heat dissipation was not certainly carried out.

[0007] As a result, the heat generated by the driving element for driving the pump was not dissipated sufficiently. For this reason, it ended up in temperature rise in the driving element for the pump and in the part constituting the stator. Consequently, there was a problem of decreased pump reliability contrarily to one's intention [0008] The present invention has been made to solve the problems mentioned above, and an object thereof is to provide a pump and a heat pump device, each capable of efficiently performing heat dissipation in the parts constituting the driving element and the stator of the pump.

[00091 A pump according to the prevent invention includes a rotor, a stator that rotates the rotor by electromagnetic interaction with the rotor, a pump unit including an upper casing in which a suction inlet and a discharge cutlet are formed, and a vane wheel contained in the upper casing and mounted to the rotor, the pump unit taking in a liquid through the suction inlet by rotation of the vane wheel, supplying the liquid to the rotor, and at the same time discharging the liquid taken in through the suction inlet by way of the vane wheel from the discharge outlet, a lower casing that is substantially in the form of an iron pot and separates the pump unit from the stator with the rotor being contained in the inner side of the area having the form of an iron pot, a circuit element that supplies electric power to the stator, a heat dissipation plate that is mounted to the circuit element and dissipates the heat generated by the circuit element, and a heat transfer plate that comes in contact with both part of the lower casing and the heat dissipation plate and transfers the heat generated by the circuit element to pad of the lower casing, wherein the heat generated by the circuit element is dissipated by being transferred through the heat dissipation plate, the heat transfer plate, part of the lower casing and the liquid that exists inside of the lower casing, in the order named.

[0010] The present invention has an effect that the reliability of a pump can be improved as a result that heat dissipation in the pads of a pump that constitute a driving element and a stator can be efficiently carried out.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Fig. lisa block diagram illustrating a heat pump device in Embodiment 1 of the prevent invention.

Fig. 2 is a cross section of a pump in Embodiment 1 of the prevent invention.

Fig. 3 is a cross section of a pump in Embodiment 2 of the prevent invention.

DESCRIPTION OF EMBODIMENTS

[0012] The present invention is explained below in detail by reference to the attached drawings.

[0013] Embodiment 1.

Embodiment 1 of the prevent invention is explained below by reference to Figs. 1 and 2.

[0014] In Embodiment 1 of the prevent invention, the pump 2 that causes water to circulate is used in the heat pump device 100.

[0015] (Heat pump device 100) Fig. Us a block diagram of the heat pump device in Embodiment 1 of the prevent invention. As shown in Fig. 1, the heat pump device 100 includes a compressor (not illustrated), a heat exchanger 3, etc. In the heat pump device 100, heat exchange is performed by a refrigerant circuit 5 and a water circuit 4 by way of the heat exchanger 3.

To put it specifically, the heat pump device 100 includes the refrigerant circuit S through which refrigerant 9 flows, and the heat exchanger 3. Also, the heat pump device 100 includes a tank 1, the pump 2, the water circuit 4 through which the water 8 flows, water temperature detection means 6 that detects water temperature in the water circuit 4, and a water amount control unit 7. The water amount control unit 7 inputs a water temperature setting command signal 7a and water temperature information 6a coming from the water temperature detection means 6, and outputs a speed command signal 2a to the pump 2. And through control of the pump 2 by the water amount control unit 7, the amount of water 8 that circulates through the water circuit 4 is adjusted, and accompanied by such adjustment, the amount of heat exchanged at the heat exchanger 3 between the refrigerant circuit 5 and the water circuit 4 is adjusted.

[0016] It should be noted that the configuration of the heat pump device 100 as explained above is an example, and the present invention is not limited to the same.

[0017] (Configuration of pump 2) Fig. 2 shows a cross section of the pump in Embodiment 1 of the prevent invention.

Using Fig. 2, the configuration of the pump 2 is explained here. As shown in Fig. 2, the pump 2 includes a stator unit 17, a rotor unit 21, a pump unit 26, and a shaft 27. The shaft 27 is fixed, around which the rotor unit 21 rotates.

[0018] It should be noted that the configuration of the pump 2 as explained above is an example, and the present invention is not limited to the same.

[0019] (Stator unit 17) The configuration of the stator unit 17 is explained below.

[0020] The stator unit 17 includes, for example, substantially doughnut-shaped iron core 10 that is formed by laminating a plurality of electromagnetic steel plates that are punched in a specified shape, wiring 11 that is inserted into the slot (not illustrated) of this iron core 10 by way of an insulator 12 (an insulation member), a circuit substrate 13 to which a lead wire 14 is connected, and a lower casing 15 substantially in the form of an iron pot.

[0021] The iron core 10 and the wiring 11 that is inserted into the slat (not illustrated) of this iron core 10 by way of the insulator 12 (an insulation member) form a stator 1 7a that makes the rotor unit 21 (rotor) rotate by generating a moment of rotation therein by electromagnetic interaction with the rotor unit 21.

[0022] The circuit substrate 13 is disposed in the vicinity of one end in the axial direction of the stator unit 17, namely, in the direction opposite to the pump unit 26 in relation to the lower casing 15. Also, with regard to the circuit substrate 13, the phase in the direction of rotation and height in the axial direction of the rotor unit 21 are positioned automatically by inserting a projection in the form of a pin of insulator 12 into a hole that has been made beforehand on the circuit substrate 13 itself.

[0023] The rotor unit 2lis contained in the space inside the lower casing 15 that is substantially in the form of an iron pot. As shown in Fig. 2, the lower casing 15 has a shape consisting of a lower casing bottom 15b, a lower casing hollow cylinder 15c that stands upright from the lower casing bottom 1 5b, and a lower casing side plate unit 1 Sd which is a doughnut-like plate that is formed along the edge of a lower casing hollow cylinder 15c while intersecting at right angles with the external side of the lower casing hollow cylinder 15c. Namely, the lower casing 15 is substantially in the form of an iron pot, consisting of the lower casing bottom 1 Sb, the lower casing hollow cylinder 1 5c, and the lower casing side plate unit 15d. In the inner side of this lower casing hollow cylinder 15c, the shaft 27 and the rotor unit 21 are contained. Also, the lower casing 15 forms an interface between the external side of the lower casing hollow cylinder 15c and the molded resin that confines the stator ha. Namely, the lower casing 15 separates the pump unit 26 and the stator 17a from each other. Also, the area substantially at the center of the lower casing bottom 15b receives the end of the shaft 27 while restraining the rotation of the shaft 27. The shaft 27 is inserted into the lower casing shaft hole 1 5a so as to prevent the rotation of the shaft 27 itself. For this reason, part of the circular area of shaft 27 to be inserted into the lower casing shaft hole 1 5a has the shape of a notch. Likewise, at the end of the shaft 27 at the side of the pump unit 26 as well, part of the circular area of the shaft 27 at the side of insertion has the shape of a notch. The lower casing shaft hole 1 5a also has nearly the same shape as shaft 27, and is one size larger in diameter than shaft 27. An upper casing shaft hole 24a also has the same shape as that of the lower casing shaft hole 1 5a.

[0024] Also, the "lower casing bottom 1 5b" corresponds to the "bottom" in the present invention.

Also, the "lower casing hollow cylinder 1 5c" corresponds to the "hollow cylinder unit" in the present invention.

[0025] The stator unit 17 is formed integrally with the stator 1 7a having the iron core 10 around which the wiring 11 is wound and the circuit substrate 13 by using the molded resin 16. The external area of the stator 17 is formed by the molded resin 16. A bearing 18, a wheel 19, and a magnet unit 20 integrally form the rotor unit 21.

[0026] Also, the space surrounded by the lower casing 15 and the upper casing 24 is filled with the water 8 in the water circuit 4 or hot water. For this reason, the rotor unit 21, a vane wheel 25, the shaft 27, and a washer 28 have a construction such that they touch the water 8 or hot water that flows through the pump 2. As can be seen clearly from this fact as well, the pump 2 is of the canned type in which the water 8 or hot water flowing through the inside of the pump 2 is in contact with the rotor unit 21 of a brushless DC motor. Note that explanations will be given below in the case of using the water 8 only, and explanations in the case of using hot water will be omitted.

[0027] Also, the "water 8 or hot water" corresponds to the "liquid" in the present invention.

[0028] It should be noted that the shape, etc. of stator unit 17 as explained above is an example, and the present invention is not limited to the same.

[0029] (Rotor unit 21) The rotor unit 21 has the bearing 18 substantially at its center. The rotor unit 21 is mounted rotatably onto the shaft 27. Outside of the bearing 18, a resin-made wheel 19 is disposed. Moreover, outside of the wheel 19, the magnet unit 20 is provided. The magnet unit 20 is formed, for example, by mixing magnetic powder such as ferrite and resin, thereby being subjected to a process of magnetization. Also, the rotor unit 21 has a somewhat longitudinal shape in relation to the direction of the shaft 27, i.e. the direction of the rotational axis, and has a somewhat transversal shape in relation to the direction intersecting the direction of the rotational axis substantially at right angles.

[0030] It should be noted that the shape, etc. of the rotor unit 21 as explained above is an example, and the present invention is not limited to the same.

[0031] Also, the "rotor unit 21" corresponds to the "rotor" in the present invention.

[0032] (Brushless DC motor) The stator unit 17 and the rotor unit 21 form, for example, a brushless DC motor.

[0033] (Pump unit 26) The pump unit 26 includes the upper casing 24 provided with a suction inlet 22 and a discharge outlet 23, and the vane wheel 25. On the upper casing 24, an upper casing shaft hole 24a is formed which restraints the rotation of the shaft 27 and receives the end of the shaft 27. The vane wheel 25 is fixedly installed to the rotor unit 21 and rotates with the rotor unit 21. The water circuit 4 communicates with the suction inlet 22 and the discharge outlet 23. To put it specifically, the vane wheel 25 is mounted to the part of the wheel 19 at one end of the rotor unit 21. Also, the other end of the rotor unit 21 is in close proximity to the lower casing bottom 1 Sb. To put it more specifically, the vane wheel 25 and the rotor unit 21 always continue to rotate around the fixed shaft 27 as the rotational axis when moment of rotation is generated due to electromagnetic interaction between the stator 17a and the rotor unit 21. At this time, the pump unit 26 sucks the water 8 through the suction inlet 22 and discharge the water 8 whose pressure has been altered, from the discharge outlet 23 by way of the vane wheel 25.

Also, the vane wheel 25 has a cross-sectional shape having a contour like that of a yukata (an informal cotton kimono for summer wear) spread for display. In the cross-sectional shape of the vane wheel, portions corresponding to the sleeves of the yukata are tapered, being made narrower toward the tip of each sleeve. Also, in the cross-sectional shape of the vane wheel, the passage inside the discharge outlet 23 through which the water 8 passes is tapered, in such a manner as to become narrower as the position in the passage moves from the outside toward the inside. Also, in the cross-sectional shape of the internal spaces of the upper casing 24, the space in close proximity to the vane wheel 25 is formed such that the space is in close proximity to the taper shape on either side of the two sleeves of the vane wheel.

[0034] It should be noted that the shape, etc. of the pump unit 26 as explained above is an example, and the present invention is not limited to the same.

[0035] Next, on condition that the above configuration is provided, configuration concerning heat dissipation which forms the principal part of the prevent invention is explained below.

[0036] A driving element 30 supplies electric power to the stator 17a in the stator unit 17.

Specifically, the driving element 30 converts electric power supplied through a power supply unit (not illustrated) from an external electric power supply source (not illustrated) to electric power for driving the brushless DC motor. To put it more specifically, the driving element 30 is a power semiconductor device that has rectification functions for converting alternating current supplied externally to direct current, frequency conversion functions for converting alternating current frequency, and regulator functions for stepping up or stepping down direct current voltage. The driving element 30 may be, for example, a rectifier diode, a power MOSFET, IGBT, a thyristor, GTO, TRIAC, or the like.

[0037] Namely, the driving element 30 makes the brushless DC motor rotate by supplying electric power to the brushless DC motor. When the brushless DC motor rotates, the pump 2 starts to operate, and the water 8 circulates through the water circuit 4.

Specifically, the driving element 30 supplies electric power to the stator 17a. Then, the stator 17a rotates the rotor unit 21, when electric power is supplied, due to electromagnetic interaction with the rotor unit 21. When the rotor unit 21 rotates, the vane wheel 25 that is fixed to the rotor unit 21 rotates with the rotor unit. When the vane wheel 25 rotates, the pump 2 starts suction of water through the suction inlet 22, and starts discharging through the discharge outlet 23. Then, the pump 2 causes the water 8 to circulate through the water circuit 4. Thus, the driving element 30 has functions for driving the pump 2.

[0038] It should be noted that the driving element 30 is not limited to a power semiconductor device. For example, it may be FPGA or the like in which the functions of a power semiconductor device are made into a package, or an integrated circuit such as a micro-controller. Specifically, the driving element 30 may be a power module in which a plurality of elements are contained in a package, or an intelligent power module or the like that includes a control circuit, a driving circuit, and a protection circuit, etc. as modules.

[0039] In other words, the driving element 30 should have functions for supplying electric power to the stator 17a.

[0040] Also, the "driving element 30" corresponds to the "circuit element" in the present invention.

[0041] Like this, when the pump 2 is driven, heat is generated in the driving element 30. For this reason, heat is dissipated by using the heat dissipation plate 31 and the heat transfer plate 32.

[0042] The heat dissipation plate 31 is formed, for example, by aluminum, etc. having high thermal conductivity. The heat dissipation plate 31 is mounted to the driving element 30.

Consequently, the heat that raises the internal temperature of the driving element 30 is dissipated to the area surrounding the driving element by way of the heat dissipation plate 31. Namely, the heat dissipation plate 31 is a heating medium that transfers the heat generated by driving device 30 to others. Also, the area surrounding the driving element itself is also a heating medium, but the use of the heat dissipation plate 31 having high thermal conductivity enables heat to be thermally transferred to others with higher efficiency. For example, if the surrounding heating medium is air, the heat dissipation plate 31 has higher thermal conductivity than air. Hence, it is possible to dissipate heat more efficiently.

[0043] It should be noted that the present invention does not impose any limitations to the area of installation, method of installation, material, shape, etc. of heat dissipation plate 31, and the requirement for the heat dissipation plate 31 is that it should be able to dissipate heat by making in contact with the driving element 30.

[0044] The heat transfer plate 32 is formed, for example, by aluminum, etc. having high thermal conductivity. The heat transfer plate 32 is partially in contact with the heat dissipation plate 31. The heat transfer plate 32 is also partially in contact with the lower casing bottom 15b. Namely, the heat transfer plate 32 is in contact with both the lower casing bottom 15b which is part of the lower casing 15 and the heat dissipation plate 31.

[00451 Specifically, the heat transfer plate 32 is formed, for example, to have a cross-sectional shape that is substantially in the form of a trapezoidal wave, as shown in Fig. 2. When the cross-sectional shape of the heat transfer plate 32 is made to be substantially in the form of a trapezoidal wave, the portion corresponding to the peak of the substantially trapezoidal wave is in contact with the heat dissipation plate 31. Also, when the cross-sectional shape of the heat transfer plate 32 is made to be substantially in the form of a trapezoidal wave, each of the two portions that correspond to the states where there is no change in amplitude before and after pulse input is in contact with the lower casing bottom 1 5b. Namely, the heat transfer plate 32 is formed to have a shape in which the substantially trapezoidal wave is reversed in the negative direction in relation to the amplitude.

[0046] Note that the heat transfer plate 32 may be joined to the heat dissipation plate 31 so that these contact each other by means of fixation with screws or joining by fusion such as spot welding. By joining them like this, the degree of contact between the heat transfer plate 32 and the heat dissipation plate 31 is increased, so that heat can be transferred from the heat dissipation plate 3lto the heat transfer plate 32 with high efficiency.

[0047] Also, the heat transfer plate 32 may be joined with the lower casing bottom 1 5b so that they partially make in contact with each other by means of joining by fusion such as spot welding. By joining them like this, the degree of contact between the heat transfer plate 32 and the lower casing bottom 1 5b is increased, so that heat can be transferred from the heat transfer plate 32 to the lower casing bottom 1 5b with high efficiency.

[0048] It should be noted that the present invention does not impose any limitations to the area of installation, method of installation, material, shape, etc. of the heat transfer plate 32, and the requirement for the heat transfer plate 32 is that it should be in contact with both the heat dissipation plate 31 and the lower casing bottom 1 5b to perform heat conduction.

[0049] Thus, as a result of being intermediated by the heat transfer plate 32, the heat dissipation plate 31 provided at the driving element 30 and the lower casing bottom 1 Sb form a so-called heat bridge. Namely, the heat transfer plate 32, the lower casing bottom 1 5b which is pad of the lower casing 15, and the heat dissipation plate 31 form a heat bridge.

[0050] By means of a heat bridge such as this, a heating medium having high efficiency is formed, and therefore the heat generated at the driving element 30 can be dissipated to the lower casing 15 with high efficiency.

[0051] Since the heat generated at the driving element 30 can be dissipated at the lower casing 15, it becomes possible to exchange heat between the driving device 30 and the water 8 that is located inside the lower casing hollow cylinder 1 Sc. This enables the heat generated at the driving element 30 to be dissipated to the water 8 that is located inside the lower casing hollow cylinder 1 Sc.

[0052] And the heat generated at the driving element 30 is transferred one by one from the heat dissipation plate 31, through the heat transfer plate 32 and the lower casing bottom 1 Sb to the water 8 inside the lower casing hollow cylinder 1 Sc. Thus, the medium transferring heat is not air, and therefore it is possible to improve thermal conversion efficiency.

[0053] Also, since the stator 1 7a is configured to be in contact with the lower casing hollow cylinder 15c, it is possible to dissipate the heat generated at the stator 17a in the stator unit 17 to the water 8 inside the lower casing hollow cylinder 1 Sc by way of the lower casing hollow cylinder lSc. Namely, heat can be exchanged between the stator 17a and the water 8 inside the lower casing hollow cylinder 1 Sc.

[0054] By making arrangements such as the above, heat dissipation can be performed with high efficiency because the heat generated at stator 17a can also be subjected to heat exchange with high efficiency.

10055] Note that the stator unit 17 is molded with resin as explained above. Namely, the lower casing 15, the stator 17a, the driving device 30, the heat dissipation plate 31 and the heat transfer plate 32 are adhered integrally by means of resin.

[0056] And both the resin and heat bridge are heating mediums. Also, the heat bridge has better heat conduction performance. For this reason, it is possible to improve heat exchange efficiency between the driving device 30 and the water 8 inside the lower casing 15 by way of the heat bridge due to the molding with resin as explained above.

[0057] Next, on the basis of the above configuration, an explanation is given about heat dissipation of the driving device 30 when the pump 2 is put into actual operation.

[0058] In the first place, the driving element 30 supplies electric power to the stator 17a. The stator 17a generates a rotating magnetic field according to the electric power supplied.

Next, the rotor unit 21 rotates according to the rotating magnetic field generated. When the rotor unit 21 rotates, the vane wheel 25 that is mounted rigidly to the rotor unit 21 rotates. When the vane wheel 25 rotates, the liquid sucked through the suction inlet 22 (for example, water 8) is pressurized. Next, the liquid thus pressurized is discharged from the discharge outlet 23.

[0059] In such a state as above, the temperature of the driving element 30 keeps on rising.

Also, at this time the inside of the lower casing hollow cylinder 1 Sc is filled with the water 8. The rotor unit 21 keeps on rotating in the space inside of the lower casing hollow cylinder 15c that is filled with the water 8. The rotational speed of the rotor unit 21 at this time is controlled due to a speed command signal 2a being transmitted from the water amount control unit 7 shown in Fig. 1.

[0060] At the same time, in such a state as above, the heat generated at the driving element is always transmitted one by one from the driving device 30 through the heat dissipation plate 31, the heat transfer plate 32, the lower casing bottom 1 5b, and the water 8 located inside the lower casing hollow cylinder 15c. Consequently, heat exchange is performed between the driving element 30 and the water 8 that is located inside the lower casing hollow cylinder 15c.

[0061] Also, the heat generated at the stator 1 7a is transferred to the water 8 that is filled inside the lower casing hollow cylinder 1 5c by way of the lower casing hollow cylinder 1 Sc. Consequently, heat exchange is performed between the stator 1 7a and the water 8 that is located inside the lower casing hollow cylinder 15c.

[0062] Therefore, since heat dissipation for the driving element 30 and the stator 1 7a can be performed efficiently, it is possible to improve reliability of the pump.

[0063] Also, an explanation has been given of an example of the pump 2 to be used when conveying or circulating the water 8 in heat pump device 100, but it goes without saying that any other type of pump may be used in place of the type of pump explained above.

For example, the system can be used with a pump for home use, or the like as well.

[0064] As described above, in this Embodiment 1, the equipment has the rotor unit 21, the stator 1 7a that rotates the rotor unit 21 by electromagnetic interaction with the rotor unit 21, and the upper casing 24 in which the vane wheel 25 mounted to the rotor unit 21, the suction inlet 22, and the discharge outlet 23 are formed, and has the pump unit 26 that takes in the water 8 or hot water from the suction unit 2 by rotation of the vane wheel 25, supplies the water 8 or not water to the rotor unit, and discharges the water 8 or hot water taken in through the suction inlet 22 by way of the vane wheel 25 through the discharge outlet 23, the lower casing 15 that is substantially in the form of an iron pot and separates the pump unit 26 from the stator ha with the rotor unit being contained inside of the area having the shape of an iron pot, the driving element 30 that supplied electric power to the stator 17a, the heat dissipation plate 31 that is mounted to the driving element 30 and dissipates the heat generated by the driving element 30, and a heat transfer plate that comes in contact with both part of the lower casing 15 and the heat dissipation plate 31 and transfers the heat generated by the driving element 30 to pad of the lower casing 15, wherein the heat generated by the driving element 30 is dissipated by being transferred through the heat dissipation plate 31, the heat transfer plate 32, part of the lower casing 15 and the water 8 or hot water that exists inside of the lower casing 15, in the order named. Therefore, heat dissipation can be performed with high efficiency in the portions that constitute the driving element 30 of the pump and the stator 17a, whereby reliability of the pump 2 can be improved.

[0065] Also, in Embodiment 1 of the present invention, the transfer plate 32, pad of the lower casing 15, and the heat dissipation plate 31 form a heat bridge, and the heat bridge is designed to be a heating medium having higher thermal conductivity than the heating mediums around driving elements 30, so that the heat generated at the driving element can be dissipated efficiently to the lower casing 15.

[0066] Also, in Embodiment 1 of the present invention, the lower casing 15, the stator 17a, the driving element 30, and the heat bridge have been designed to be adhered integrally by means of resin, so that it is possible to improve the efficiency of heat exchange between the driving element 30 and the water 8 inside the lower casing 15 by way of the heat bridge.

[0067] Also, in Embodiment 1 of the present invention, the heat transfer plate 32 is designed to come in contact with both part of the lower casing 15 and the heat dissipation plate 31 by means of spot welding, whereby the degree of contact between the heat transfer plate 32 and the heat dissipation plate 31 is increased, so that heat can be transferred from the heat dissipation plate 31 to the heat transfer plate 32 with high efficiency.

[0068] Also, in Embodiment 1 of the present invention, the heat transfer plate 32 is designed to come in contact with both part of the lower casing 15 and the heat dissipation plate 31 by means ot tastening with screws, whereby the degree of contact between the heat transfer plate 32 and the heat dissipation plate 31 is increased, so that heat can be transferred from the heat dissipation plate 31 to the heat transfer plate 32 with high efficiency.

[0069] Embodiment 2.

Fig. 3 is a cross section of the pump in Embodiment 2 of the present invention.

[0070] Note that with regard to this Embodiment 2, the matters which are not specifically described will be the same as those in Embodiment 1, and the same functions and configuration will be described by using the same symbols.

[0071] The difference from Embodiment 1 lies in the provision of a spacer 33 in the circuit substrate 13. Specifically, the spacer 33 is provided so that the distance between the circuit substrate 13 and the lower casing bottom 1 5b is kept constant. To put it more specifically, the spacer 33 is formed, for example, into a substantially cylindrical shape having its longitudinal direction in the axial direction. One end of such cylindrical shape is mounted onto the circuit substrate 13, and the other end of such cylindrical shape is mounted onto the outer side of the lower casing bottom 1 5b. As a result, the distance between the circuit substrate 13 and the lower casing bottom 15b is kept constant at a value that equals to the length of the spacer 33 in the longitudinal direction.

[0072] During molding, there was the danger that the circuit substrate 13 might be distorted by the pressure of the resin to be molded, but by means of the spacer 33 as described above, distortion of the circuit substrate 13 can be prevented even in such a case.

Since this enables distortion of the circuit substrate 13 to be prevented, it is possible to avoid damage occurring in the heat dissipation plate 31 that is provided on the driving element 30 as caused by stress associated with the distortion of the circuit substrate 13.

[0073] Therefore, since damage to heat dissipation plate 31 can be prevented, it is possible to perform heat dissipation with high efficiency by means of the heat dissipation plate 31.

This enables reliability of the pump to be improved.

[0074] Note that the spacer 33 such as the above further enables distortion of the circuit substrate 13 to be prevented by providing a plurality of such spacers in an area between the circuit substrate 13 and the lower casing bottom 15.

[0075] It should be noted that the material and shape of the spacer 33 are not particularly limited.

[0076] Also, an explanation has been given of an example of the pump 2 to be used when conveying or circulating the water 8 in the heat pump device 100, but it goes without saying that any other type of pump may be used in place of the type of pump explained above. For example, the system can be used with a pump for home use, or the like as well.

[00771 As described above, in this Embodiment 2, the equipment has the spacer 33 that separates the lower casing 15 from the driving element 30 at a specified distance between them, and in the state in which the above-mentioned members are separated at a specified distance, it has been designed to make the lower casing 15, the stator 17a, the driving element 30, and the heat bridge be adhered integrally by means of resin, so that distortion of the circuit substrate 13 can be prevented. As a result, it is possible to prevent distortion of the circuit substrate 13, and consequently it is possible to avoid damage caused in the heat dissipation plate 31 that is provided on the driving element 30 as caused by stress associated with the distortion of the circuit substrate 13.

Therefore, since damage caused in the heat dissipation plate 31 can be prevented, it is possible to perform heat dissipation with high efficiency by means of the heat dissipation plate 31. This enables reliability of the pump to be improved.

[0078] Embodiment 3.

In Embodiments 1 and 2, the material of the lower casing 15 was not explained, but in Embodiment 3 the material of the lower casing 15 is explained below.

[0079] Note that with regard to this Embodiment 3, the matters which are not specifically described will be the same as those in Embodiment 1, and the same functions and configuration will be described by using the same symbols.

[0080] Also, it goes without saying that the material of the lower casing 15 to be explained in this Embodiment 3 may also be applicable to Embodiments 1 and 2 that have been explained above.

[0081] As for the material of the lower casing 15, if it is made of a metal having high heat conduction performance, then the effect of heat dissipation by means of the heat dissipation plate 31 is further increased. Specifically, in the lower casing 15, if the lower casing hollow cylinder 15 c, in particular, is made of a non-magnetic metal (for example, stainless steel represented by the symbol SUS in JIS standards), then the material is a metal with high heat conduction performance and at the same time it is a non-magnetic metal that can suppress an influence on the magnetic characteristics of the lower casing hollow cylinder 1 5c, so that heat exchange can be performed efficiently when performing heat exchange between the atmosphere around the stator unit 17 and the water 8 inside the lower casing 15. Therefore, the heat generated at the stator unit 17 is dissipated efficiently, with the result that the effect of heat dissipation is further increased.

[0082] Note that the use of a non-magnetic metal is intended to prevent hindrance to the lines of magnetic force between the stator unit 17 and the rotor unit 21. For this reason, it is preferable to select the material of the lower casing 15 in consideration of the properties such as magnetic hysteresis, etc. as well.

[0083] Also, when farming the lower casing 15 with a non-magnetic metal, the lower casing may be farmed, for example, by means of plastic forming.

[0084] Also, when forming the lower casing 15, the materials used for the lower casing bottom 15b and the lower casing hollow cylinder 15c may be different from each other.

For example, the material of lower casing bottom 1 Sb may be a metal, and the material of lower casing hollow cylinder 15c may be a resin.

[0085] Also, after having inserted an insert part (for example, a metal part) to be embedded into a specified mold, the metal part may be formed integrally with resin by injecting a resin that can be melted into a molding machine.

[0086] At this time, the resin to be used may be heat resistant thermoplastic resin such as PPS (polyphenylene sulfide resin), SPS (syndiotactic polystyrene resin), m-PPE (denaturatedpolyphenylene ether resin), or the like.

[0087] Also, as an example of resin material to be used, that which is made by adding to unsaturated polyester thermosetting resin a filler such as calcium carbonate and glass fiber, various types of fillers, as well as heat-dissipating fillers such as alumina and boron nitride and has a thermal conductivity of 01 (WImk) is preferable, and more preferably that which has a thermal conductivity of 1.0 (W/mk) or more should be used.

For example, CE 2840 (thermal conductivity: 1.0 -1.5) and CE 2890 (thermal conductivity: 2.0 -2.2) of Panasonic Electric Works Co., Ltd., HTC-250 (thermal conductivity: 2.5) and HTC-500 (thermal conductivity: 5.0) of Showa Denko K.K., and others are preferable. As an example of substrate material to be used, a composite copper-lined laminated board (thermal conductivity: 0.4 (W/mk)) such as CEM-3 (Composite Epoxy Material Grade-3) is preferable which is made by pasting a copper plate onto a composite of epoxy resin using glass fiber as a base material, and more preferably the 1787 having a thermal conductivity of 1.0 (W/mk) as manufactured by Panasonic Electric Works Co., Ltd. should be used.

[0088] Also, the lower casing bottom 1 5b is less affected by magnetism than the lower casing hollow cylinder 1 5c. Hence, there are more choices of metal material to be used for the lower casing bottom 1 5b.

Aside from stainless steel, for example, iron, copper, aluminum, or the like, may also be used.

[00891 Note that when forming the lower casing 15, in order to join the lower casing bottom 1 5b with the lower casing hollow cylinder 1 5c using different materials (for example, a resin and a metal), very small holes should be made at the metal side beforehand by means of etching or the like. By employing a method such as this, it is possible to increase joining strength during molding as a result of an anchor effect in which molten resin gets into the holes on the metal. The use of such method is preferable from the viewpoint of prevention of leakage of liquid from joint interface as well. Or, blast treatment may be done in place of etching or the like.

[0090] By employing a method such as this, it is possible to use different materials for the lower casing bottom 1 5b and the lower casing hollow cylinder 1 5c, as necessary in terms of design, with regard to heat dissipation for the stator unit 17 and heat dissipation for driving element 30. As a result, selection can be made as to which should be given preference in cooling, heat dissipation for the stator unit 17 or the heat dissipation for the driving element 30.

[0091] Also, by employing a method such as this, it is possible to use a different material for lower casing hollow cylinder 1 Sc that partially constitutes the lower casing 15, as necessary in terms of design, with regard to heat dissipation for the stator unit 17. As a result, selection can be made as to which should be given preference, the efficiency of magnetic characteristics or cooling performance for the stator unit 17, when the pump is viewed in terms of an electric motor.

10092J Also, an explanation has been given of an example of the pump 2 to be used when conveying or circulating the water 8 in the heat pump device 100, but it goes without saying that any other type of pump may be used in place of the type of pump explained above. For example, the system can be used with a pump for home use, or the like as well.

[0093] As described above, in this Embodiment 3, the lower casing 15 consists, at least, of the lower casing bottom 15b and the lower casing hollow cylinder 15c that stands upright from the lower casing bottom 1 5b, and the lower casing bottom 1 5b and the lower casing hollow cylinder 15c are designed to be made of different materials, and so it is possible to use different materials as necessary in terms of design. As a result, selection can be made as to which should be given preference in cooling, heat dissipation for the stator unit 17 or the heat dissipation for the driving element 30. Also, it is possible to use a different material for the lower casing hollow cylinder 15c that partially constitutes the lower casing 15, as necessary in terms of design, and so selection can be made as to which should be given preference, the efficiency of magnetic characteristics or cooling performance for the stator unit 17, when the pump is viewed in terms of an electric motor.

[0094] Also, in this Embodiment 3, as the heating mediums around the driving element 30, resins of which thermal conductivity of 0.5 (W/mk) or more have been used, and so heat dissipation for the parts of the pump that constitute the driving device and stator can be performed efficiently.

[0095] Also, in this Embodiment 3, a composite-based material consisting of glass fiber and resin has been used for the circuit substrate 13 on which the driving element 30 is mounted, and its thermal conductivity has been set to 0.4 (W/mk) or above, and so heat dissipation for the parts of the pump that constitute the driving element and the stator can be performed efficiently.

[0096] As described above, in these Embodiments 1 through 3, the equipment is designed to comprise the pump 2, the water circuit 4 through which the water 8 or hot water is circulated by the pump 2, the refrigerant circuit 5 through which the refrigerant 9 circulates, and the heat exchanger 3 where heat is exchanged between the water 8 or hot water in the water circuit 4 and the refrigerant 9 in the refrigerant circuit 5, so that heat dissipation for the parts of the pump that constitute the driving element and the stator can be performed efficiently, whereby the reliability of the pump can be improved.

Hence, itis possible to improve the reliability of the heat pump device 100.

Reference Signs List 10097J 1: Tank, 2: Pump, 2a: Speed command signal, 3: Heat exchanger, 4: Water circuit, 5: Refrigerant circuit, 6: Water temperature detection means, 6a: Water temperature information, 7: Water amount control unit, 7a: Water temperature setting command signal, 8: Water, 9: Refrigerant, 10: Iron core, 11: Wiring, 12: Insulator, 13: Circuit substrate, 14: Lead wire, 15: Lower casing, 15a: Lower casing shaft hole, 15b: Lower casing bottom, 15c; Lower casing hollow cylinder, 15d: Lower casing side plate unit, 16: Molded resin, 17: Stator unit, 17a: Stator, 18: Bearing, 19: Wheel, 20: Magnet unit, 21: Rotor unit, 22: Suction inlet, 23: Discharge outlet, 24: Upper casing, 24a: Upper casing shaft hole, 25: Vane wheel, 26: Pump unit, 27: Shaft, 28: Washer, 30: Driving element, 31: Heat dissipation plate, 32: Heat transfer plate, 33: Spacer, 100: Heat pump device.