CN116136220A - Canned electric pump driven by external rotor motor for conveying coolant - Google Patents

Abstract

A shielded electric pump driven by an external rotor motor for conveying coolant, which includes: a pump cover, a pump body and a volute enclosed by the two; a mandrel supporting the impeller at the center of the pump cover and the pump body; leading to the volute along the axis of the impeller An inlet pipe on the suction side with the opening facing downwards, the inlet pipe passes through the center of the stator of the outer rotor motor; adjacent to the cylindrical stator cavity surrounding the inlet pipe and opening downwards, the stator of the outer rotor motor accommodated in the stator cavity, said The inner and outer peripheries of the stator are in heat conduction contact with the inner and outer walls of the stator cavity; the cylindrical rotor cavity surrounding the stator cavity and opening upwards through the volute is used to accommodate the rotor of the outer rotor motor. In the shielded outer rotor electric pump, except that the rotor is completely surrounded by the pump fluid, the inner and outer circumferences of the inner stator core can conduct heat conduction with the flowing pump fluid, so that the cooling fluid is driven for use, and the heat emitted by the motor is dissipated. This improves pump efficiency and eliminates the need for additional cooling, helping to reduce pump size.

Description

Canned electric pump driven by external rotor motor for conveying coolant

technical field

The invention relates to a shielded electric pump driven by an outer rotor motor for conveying cooling liquid, and the IPC classification may belong to F04D13/06, F04D29/58 or F04D29/40.

Background technique

Canned electric pumps driven by external rotor motors in the prior art can be seen in Chinese patent documents CN2844514Y, CN104179693B and CN109983232A and Chinese Taiwan patent document TW200928117A. Its cooling structure still needs to be further improved to reduce the temperature rise of the motor.

For terms and common knowledge in this manual, refer to the national standard GB/T 33925.1 "General Terms, Definitions, Quantities, Characters and Units for Liquid Pumps and Their Devices Part 1: Liquid Pumps" and GB/T 7021 "Terms and Terms for Centrifugal Pumps", Mechanical Industry standard JB/T 5415 "Miniature Centrifugal Electric Pump", "IEC Electrical and Electronic Standard Terminology Dictionary" published by China Standard Press in 1992, "Mechanical Engineering Handbook" and "Electrical Engineering Handbook" published in 1983 or 1997 edition by Machinery Industry Press, The 2014 edition of "Pump Theory and Technology" by China Machinery Industry Press and the 2011 edition of "Modern Pump Theory and Design" by China Aerospace Press.

Contents of the invention

The purpose of the present invention is to provide a canned electric pump driven by an outer rotor motor for conveying cooling liquid, which can improve heat transfer efficiency and reduce pump size compared with the prior art. The canned electric pump includes:

- pump cover, pump body and the volute enclosed by them;

- the mandrel supporting the impeller along the axis of the volute to the pump cover and pump body;

- an inlet pipe leading to the suction side of the volute along the axis of the volute and opening downwards, the inlet pipe passing through the center of the stator of the external rotor motor;

——A cylindrical stator chamber surrounding the inlet pipe with its opening facing downwards, accommodating the stator of the outer rotor motor in the stator chamber, the inner and outer circumferences of the stator of the outer rotor motor are in thermal contact with the inner and outer walls of the stator chamber respectively;

- a cylindrical rotor cavity surrounding the stator cavity and opening upwards through the volute, for accommodating the rotor of the outer rotor motor.

In this shielded electric pump, except that the rotor is completely surrounded by the pump fluid, the inner and outer circumferences of the inner stator core can conduct heat conduction with the flowing pump fluid (the heat conduction method is not isolated by the air with a very small thermal conductivity), so that the coolant is driven to While being used, the heat emitted by the motor is dissipated, thus improving the pump efficiency and eliminating the need for additional cooling devices, which helps to reduce the size of the pump.

Further, one end of the inlet pipe of the pump body is provided with a suction port for inputting cooling liquid, and the other end connected to the volute is provided with a support seat supporting the mandrel, and the connection between the support seat and the inlet pipe wall is provided with several communication holes. The inlet pipe through hole of the volute. This structure can guide the coolant to the scroll chamber and be driven by the impeller. At the same time, the two ends of the mandrel are fixed to increase the stability of the pump operation.

Furthermore, the inlet pipe, the stator cavity and the rotor cavity are integrally injection-molded into a concave-convex shape when viewed along the axis, and the functional structures are formed in an axially staggered concave-convex manner. The structure is compact and simple, which helps to reduce the size of the pump and facilitate high efficiency. manufacture.

Preferably, the rotor has a cylindrical bracket, one end of the cylinder is provided with a bottom wall, the other end is open, the inner wall of the cylinder is fixed with a permanent magnet, and the center of the bottom wall is provided with a through hole, the through hole The outer edge of the cylinder protrudes outward in the axial direction to form a protrusion defining the mandrel, and an impeller for driving the cooling liquid is fixed on the upper end surface of the bottom wall of the outer periphery of the protrusion, and several Guide the coolant flowing into the through hole to the side through hole of the impeller flow channel. The rotor structure can guide the coolant input from the inlet pipe to the impeller that rotates with it, and the impeller drives the coolant to discharge out of the pump.

Further, the top of the cylindrical wall of the bracket is provided with several return holes, and the centrifugal force of the rotating cylinder is used to guide the internal cooling liquid to the return holes at the top of the inner wall of the cylinder and discharge it back to the volute, so as to realize the circulation of the cooling liquid in the rotor cavity .

Furthermore, the center line of the return hole is set at the interface between the cylinder wall and the bottom wall, and this position allows most of the cooling liquid to flow back to the volute, and can avoid accumulation of residues at the intersection.

Further, it also includes a control board arranged at the opening end of the stator cavity, and a plug connector for detachable electrical connection with an external power supply formed by integral injection molding with the pump body, and the control board is electrically connected with the plug connector. This structure can realize the detachable connection between the motor and the external power supply.

Furthermore, the heat-generating power elements on the control board are in thermal contact with the inlet pipe directly or through heat-conducting parts, so that the heat emitted by the heat-generating power elements can be dissipated by flowing cooling fluid, so as to avoid excessive temperature and affect the performance of the control board Stablize.

Description of drawings

Fig. 1 is the front view of embodiment 1 of the canned electric pump driven by the outer rotor motor for conveying cooling liquid of the present invention;

Fig. 2 is A-A sectional view of Fig. 1;

Fig. 3 is the cooling liquid flow schematic diagram of embodiment 1 of the canned electric pump driven by the outer rotor motor for conveying cooling liquid of the present invention;

Fig. 4 is the sectional view along the axial direction of the pump body of embodiment 1 of the canned electric pump driven by the outer rotor motor for conveying cooling liquid of the present invention;

Fig. 5 is a sectional view along the axial direction of the rotor embodiment 1 of the canned electric pump embodiment 1 driven by the outer rotor motor for conveying cooling liquid of the present invention;

Fig. 6 is an axial cross-sectional view of the second embodiment of the rotor of the canned electric pump embodiment 1 driven by the outer rotor motor for conveying cooling liquid;

Fig. 7 is an axial cross-sectional view of the third embodiment of the rotor of the canned electric pump embodiment 1 driven by the outer rotor motor for conveying cooling liquid;

Fig. 8 is the cross-sectional view along the axial direction of embodiment 2 of the canned electric pump driven by the outer rotor motor for conveying cooling liquid of the present invention;

Fig. 9 is an axial cross-sectional view of the rotor of embodiment 2 of the canned electric pump driven by the outer rotor motor for conveying cooling liquid of the present invention;

Reference signs:

10—pump cover, 101—discharge port, 102—volute, 103—mandrel; 20—rotor, 201—bracket, 202—impeller, 203—drain hole, 204—permanent magnet, 205—bottom wall, 206— Through hole, 207—bearing support seat, 208—bearing, 209—side through hole, 210—mandrel support seat; 30—stator; 40—pump body, 401—inlet pipe, 402—suction port, 403—stator cavity, 404—rotor cavity, 4041—inlet, 405—support seat, 4051—through hole of inlet pipe, second bearing—406; 50—control panel; 60—rear cover.

Detailed ways

The term "thermal contact" used in the description of the present invention specifically refers to the contact without air gap between two parts, including close contact or contact between two parts filled with high thermal conductivity materials such as thermal conductive silicone grease to form good thermal conductivity; above or The upper side refers to the side where the electric pump is close to the volute, and the lower or lower side is the opposite.

In order to facilitate understanding of the present invention, the present invention will be described more fully below in conjunction with examples.

Fig. 1-2 shows the front view and the sectional view of embodiment 1 of the canned electric pump driven by the outer rotor motor for conveying cooling liquid of the present invention, the electric pump comprises a pump cover 10, a pump body 40, and the pump cover 10 and the pump body 40 are in phase The volute chamber 102 is enclosed by a fixed connection. The pump cover 10 is provided with a discharge port 101 connected to the volute chamber 102. One end of the mandrel 103 is fixed in the center of the pump cover 10. The pump body 40 is generally columnar, and the two ends of the column are provided with fixing flanges. As shown in Figure 1, the flange is also provided with screw posts in the circumferential direction, and the pump cover 10 and the pump body 40 of this embodiment are fixedly connected by screws. Connections are also possible. As shown in Figure 4, the inlet pipe 401, the stator chamber 403 and the rotor chamber 404 are made as an integral injection molded pump body 40 that is concave-convex in cross-section along the axis as a whole. The center of the pump body 40 is the inlet pipe 401 that communicates with the external cooling liquid One end is provided with a suction port 402, the other end is connected to the volute chamber 102, and the center of one end of the inlet pipe connected to the volute chamber 102 is provided with a support seat 405 that can support the other end of the mandrel 103, and the connection between the support seat 405 and the inner wall of the inlet pipe is provided with several The inlet pipe through-holes 4051 communicating with the volute 102 are preferably 3 or 4. The outer periphery of the inlet pipe 401 is provided with a cylindrical stator chamber 403 coaxial with it. The stator chamber 403 opens toward the suction port 402 at one end. The outer periphery of the stator chamber 403 is provided with a cylindrical rotor chamber 404 coaxial with it. The rotor chamber 404 faces the volute chamber. The opening at one end of 102 communicates with the volute chamber 102.

The electric pump also includes a stator 30 and a rotor 20 of an outer rotor motor, and the stator 30 is fixedly arranged in the stator cavity 403 of the pump body. The inner wall of the cavity 404) is in close contact with the outer circumference of the iron core of the stator 30 and the outer wall of the stator cavity 403 (that is, the inner wall of the rotor cavity 404) is filled with heat-conducting silicone grease for thermal contact; the iron core of the stator 30 The inner circumference and the inner wall of the stator cavity 403 (that is, the wall of the inlet pipe 401 ) are in close contact with each other or the inner circumference of the iron core of the stator 30 and the inner wall of the stator cavity 403 (that is, the wall of the inlet pipe 401 ) are filled with heat conduction Silicone thermal contact. In this way, the iron core of the stator 30 and the coolant flowing in the inlet pipe are not isolated by the air with low thermal conductivity, good heat conduction can be realized through the inlet pipe wall and the coolant, and the iron core of the stator 30 and the coolant flowing in the rotor cavity 404 pass through the rotor The inner cavity walls of the cavity 404 can also achieve good heat conduction. Further, the upper and lower ends of the stator 30 are filled with thermal conductive resin, which can fix and enhance the heat dissipation capability of the stator 30 . The rotor 20 is accommodated in the rotor cavity 404 of the pump body, surrounded by flowing cooling liquid, and its heat is taken away by the flowing cooling liquid.

The specific structure of the rotor 20 in this embodiment is shown in Figure 5. The main body of the rotor 20 is a cylindrical bracket 201. One end of the cylinder is open towards the suction inlet, and the other end is provided with a bottom wall 205. The inner wall of the cylinder is fixed with a permanent The center of the magnet 204 and the bottom wall 205 is provided with a through hole 206. The outer portion of the through hole 206 protrudes axially outward to form a hollow columnar protrusion. The protrusion forms a bearing support seat 207, and the inner portion of the bearing support seat 207 The cavity is fixed with a bearing 208, and the lower part of the inner cavity wall of the bearing support seat 207 is radially provided with several side through holes 209, which are used to guide the cooling liquid flowing in through the through holes 206 to the impeller area. On the upper end surface of the bottom wall 205, the impeller 202 for driving the coolant is fixed on the outer side of the bearing support seat 207. The impeller 202 is fixedly connected to the bottom wall of the bracket 201 and forms the outer rotor of the motor in this way. The fixed connection method can be ultrasonic welding, Conventional processes such as threaded screw connection. The rotor 20 shown in FIG. 6 is a modified design of the embodiment in FIG. 5. Several side through holes 209 are opened in the connection area between the bottom wall 205 and the bearing support seat 207. This structure increases the axial length of the bearing support seat 207 and the bearing 208. , the stability of the rotation of the rotor 20 can be improved. The rotor 20 shown in FIG. 7 is another modified design of the embodiment in FIG. 5. The bracket 201 is a plastic part, which is integrally injected with the permanent magnet 204 or the bearing 208. This structure simplifies the installation process of the rotor 20. And each part is firmly connected.

After the electric pump is assembled, the rotor 20 is sleeved on the mandrel 103 through the bearing 208 and supported in the rotor chamber 404 of the pump body 40. The rotor 20 and the stator 30 together form a motor, and the rotor 20 is driven by the rotating magnetic field generated by the stator 30 to rotate. The impeller 202 fixed on the upper end of its bottom wall is driven to rotate around the mandrel 103 through the bearing 208, and pressure is formed in the volute 102 of the pump body, so that the cooling liquid can be input through the suction port 402 and passed through the discharge port as shown by the big arrow in Fig. 3 . Exit 101 Export.

Further optimized design is shown in Fig. 2 and Fig. 3, several return holes 203 are provided at the top of the barrel wall of the bracket 201, preferably, the center line of the return holes 203 is set at the interface between the barrel wall and the bottom wall. The annular gap between the outer wall of the rotor chamber 404 of the pump body and the cylindrical support 201 is provided as an inlet 4041 for cooling liquid for cooling the motor part. Therefore, as shown by the small arrow in Figure 3, the coolant circulates from the high-pressure side of the volute of the pump to the gap between the cylindrical support 201 and the inner wall of the rotor cavity 404 through the inlet 4041, and finally flows back through the return hole 203. The volute is driven by the impeller to discharge. The cooling liquid surrounds the flow channel of the rotor 20, and the heat of the rotor 20 is taken away by the flowing cooling liquid, so that the heat dissipation capability is strong.

Further, the electric pump also includes a control board 50 arranged at the open end of the stator cavity 403 and below the stator 30. The control board 50 is electrically connected to the stator 30 to control the operation of the motor. It can be connected to an external power supply through a flexible wire, or can be As shown in FIG. 1 , through the electrical connection with the plug joint formed by integral injection molding with the pump body, the detachable and convenient connection with the external power supply is realized. Preferably, the heating power element on the control board 50 is in close contact with the wall of the inlet pipe 401 directly or through a heat conduction element, or the gap between them is filled with heat-conducting silicone grease for heat conduction contact. To take the heat generated by the power element, the heat conduction part specifically refers to a structural part made of a metal material with high thermal conductivity such as aluminum that can be fitted with the shape of the power element and the inlet pipe 401; the electric pump also includes a stator cavity 403 One side is covered with the flange of the pump body to shield the control panel 50 and the back cover 60 of the stator 30. Preferably, the joint between the back cover 60 and the pump body is sealed with an elastic seal to prevent dust and moisture from entering the inside of the stator 30. .

Fig. 8 shows the cross-sectional view along the axial direction of embodiment 2 of the canned electric pump driven by the outer rotor motor for conveying cooling liquid of the present invention. The difference between embodiment 2 and embodiment 1 is that the mandrel 103 is fixed at the center of the rotor 20; A bearing 208 is fixed in the counterbore at the center of the pump cover 10, and the bearing 208 can be fixed integrally with the pump cover by injection molding, or can be fixed on the pump cover in different ways such as interference compression, hot-melt welding or bonding; The supporting base 405 is fixedly provided with a second bearing 406 . When the electric pump is assembled, the rotor 20 is inserted into the second bearing 406 and the bearing 208 through the mandrel 103 to be supported and limited, and accommodated in the rotor chamber 404 of the pump body 40. The rotor 20 and the stator 30 together form a motor, and the rotor 20 is formed by The magnetic field generated by the stator 30 drives the rotation, drives the impeller 202 fixed on the upper end of the rotor bottom wall to rotate together with the mandrel 103, and creates pressure in the volute 102 of the pump body, so that the coolant can also be sucked in as shown by the big arrow in Figure 3. Port 402 inputs and exits through outlet 101 .

Fig. 9 shows the specific structure of the rotor 20 of this embodiment. The difference from the rotor in Fig. 5 of Embodiment 1 is mainly: the outer edge of the central through hole 206 of the bottom wall 205 protrudes outwards from the cylindrical support to form a cylindrical protrusion. The protrusion becomes the mandrel support seat 210, and the center of the mandrel support seat 210 is fixedly provided with the mandrel 103, and the inner chamber wall lower section of the mandrel support seat 210 is radially provided with several side through holes 209, which are used to guide 206 The coolant that flows into the impeller channel. The mandrel 103 and the mandrel support seat 210 can be fixed by conventional techniques such as hot-melt welding, interference fit or integral injection molding.

The above-mentioned embodiments and design examples only express several implementations of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the protection scope of the present invention. It should be noted that, for those skilled in the art, some deformations and improvements can be made without departing from the concept of the present invention. For example, the mandrel 103 can be fixed on the pump body 40, while the pump cover A support seat is arranged in the center, and when the pump body and the pump cover are closed and fixed, the other end of the mandrel 103 is inserted into the pump cover support seat to be supported. These all belong to the protection scope of the present invention.

Claims (8)

1. A canned motor pump driven by an external rotor motor for delivering a cooling fluid, comprising:

-a pump cover (10), a pump body (40) and a volute (102) enclosed by the two;

-a spindle (103) supporting the impeller along the axis of the volute (102) at the pump cover (10) and the pump body (40);

-an inlet pipe (401) leading along the axis of the volute (102) to the suction side of the volute (102) and opening downwards, said inlet pipe (401) passing through the centre of the stator (30) of the external rotor motor;

-a cylindrical stator chamber (403) surrounding the inlet pipe (401) and opening downwards, a stator (30) of an outer rotor motor accommodated in the stator chamber (403), an inner and an outer circumference of the stator (30) of the outer rotor motor being in heat conducting contact with an inner and an outer chamber wall of the stator chamber (403), respectively;

-a cylindrical rotor chamber (403) surrounding the stator chamber (403) and opening up through the volute (102) for housing the rotor (20) of the external rotor motor.

2. The canned motor pump driven by an external rotor motor for conveying cooling liquid according to claim 1, wherein one end of the pump body inlet pipe (401) is provided with a suction inlet (402) for inputting cooling liquid, the other end of the communicating volute chamber (102) is provided with a supporting seat (405) for supporting the mandrel (103), and a plurality of inlet pipe through holes (4051) for communicating the volute chamber (102) are arranged at the connecting part of the supporting seat (405) and the inlet pipe wall.

3. The canned motor pump driven by an external rotor motor for transporting cooling liquid according to claim 2, wherein the inlet pipe (401), the stator cavity (403) and the rotor cavity (403) are integrally injection-molded to be concave-convex in cross section along the axis.

4. The canned motor pump driven by an external rotor motor for transporting cooling liquid according to claim 1, wherein the rotor (20) has a cylindrical support (201), a bottom wall (205) is provided at one end of the cylinder, the other end is open, a permanent magnet (204) is fixed on the inner cylindrical surface of the cylinder, a through hole (206) is provided at the center of the bottom wall (205), a protrusion defining the spindle (103) protrudes outwards from the outer side of the through hole (206) along the axial direction, an impeller (202) for driving the cooling liquid is fixed on the upper end surface of the bottom wall (205) at the periphery of the protrusion, and a plurality of side through holes (209) for guiding the cooling liquid flowing in through holes (206) to the impeller flow channels are provided at the junction of the protrusion and the bottom wall (205).

5. The canned motor pump driven by an external rotor motor for transporting cooling liquid according to claim 4, wherein the top end of the cylindrical wall of the bracket (201) is provided with a plurality of backflow holes (203).

6. The canned motor pump driven by an external rotor motor for transporting cooling liquid according to claim 5, wherein a center line of the return hole (203) is provided at an interface between the cylindrical wall and the bottom wall.

7. The electric shielding pump driven by an external rotor motor for transporting cooling liquid according to any one of claims 1 to 6, further comprising a control board (50) provided at an opening end of the stator cavity (403), a plug integrally injection-molded with the pump body for detachable electric connection with an external power source, the control board being electrically connected with the plug.

8. The electric canned motor pump driven by an external rotor motor for transporting cooling liquid according to claim 7, wherein the heat-generating power element on the control board (50) is in heat-conducting contact with the inlet pipe (401) directly or through a heat-conducting member.

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