CN114151357A

CN114151357A - Electric pump

Info

Publication number: CN114151357A
Application number: CN202111474019.6A
Authority: CN
Inventors: R·奥鲁·奥鲁; J·芭芭拉·冈萨瓦尔
Original assignee: Coprecitec SL
Current assignee: Coprecitec SL
Priority date: 2015-01-14
Filing date: 2016-01-11
Publication date: 2022-03-08
Also published as: ES2870801T3; EP3045735A1; EP3045735B1; ES1135742Y; CN105782064A; ES1135742U

Abstract

The present invention relates to an electric pump. The electric pump comprises a pump body (2) and a motor body (3), the motor body (3) comprising a rotor housing (4), an impeller (5) arranged rotatably on one side of the rotor housing (4) and an electric motor arranged on the other side of the rotor housing (4) and comprising a stator (6), at least one stator coil (6a), a terminal (12) connected to the stator coil (6a) and a rotor (7), the motor body (3) being coupled to the pump body (2) by means of the rotor housing (4), the rotor (7) comprising a shaft (7a) cooperating with the impeller (5), the motor body (3) further comprising a cover (8) attached to the rotor housing (4) such that a leak-proof chamber (9) is formed in the cover (8), wherein the leak-proof chamber (9) is filled with oil as a heat-conducting material, a leak-proof chamber (9) is provided in which no oxygen is present.

Description

Electric pump

This application is a divisional application of patent applications filed on 2016, 11/1, with application number 201610015163.6 and entitled "electric pump".

Technical Field

The present invention relates to electric pumps, and more particularly to pumps including a motor having at least one coil.

Background

It is known to use an electric pump to drive a fluid, typically water. Such pumps are used, for example, in washing machines or dishwashers to discharge the water contained in the washing drum or tub at the end of the washing cycle, away from or towards a circulation duct which re-introduces said water, for which purpose the treatment is carried out again. In such pumps, there are obviously two functional parts, the first part referring to the part that prepares the fluid to be discharged through the discharge element or impeller, and the second part referring to the part that rotates the element in order to allow the fluid to be driven.

Synchronous (preferably brushless) motors are commonly used in such pumps, but synchronous motors may also be used. The type of synchronous motor is an AC (alternating current) motor in which the rotation of the rotor shaft moving the impeller is synchronized with the frequency of the power supply current. The magnetic field required to rotate the rotor shaft is generated by circulating an electric current through coils arranged around the stator.

CN101871459A describes an electric pump having a drive section and a pump section. The driving part comprises a permanent magnet rotor and a wound stator. The stator includes a stator core and a winding wound on the stator core. The drive section includes a housing that is connected to the pump section by a mounting plate. The housing defines a cavity and includes a recess for positioning the stator core and windings outside the cavity. Since the heat conductive material does not contact the stator, heat dissipation cannot be improved (i.e., faster cooling), noise reduction cannot be achieved, and galvanic corrosion of the winding cannot be avoided. Also, in the case of motors that are overheated due to the absence of oxygen in the housing in which the stator is located, possible flame propagation cannot be avoided.

ES 1101080U discloses a discharge pump comprising: a pump body connected to the hydraulic section; and a motor body connected to the electric portion of the pump. The motor main body includes: a rotor housing coupled to the pump body to close the pump at one end; an impeller disposed at one side of the rotor housing; and a synchronous motor disposed at the other side of the rotor housing. The synchronous motor includes a stator having windings and a rotor having a shaft coupled to an impeller.

Disclosure of Invention

It is an object of the present invention to provide an electric pump as described below.

The electric pump of the present invention includes a pump body and a motor body, the motor body including a rotor case, an impeller arranged on one side of the rotor case to be rotatable, and an electric motor arranged on the other side of the rotor case and including a stator, at least one stator coil, a terminal connected to the stator coil, and a rotor, the motor body being coupled to the pump body by the rotor case, the rotor including a shaft cooperating with the impeller, the motor body further including a cover attached to the rotor case such that a leak-proof chamber is formed in the cover. The leak-proof chamber is filled with oil as a heat conductive material, providing a leak-proof chamber free of oxygen, at least a portion of the terminal, the stator, and the coil being arranged inside the leak-proof chamber and in contact with the heat conductive material.

The pump of the invention contributes to improving the heat dissipation of the heat losses of the electric motor, so that the performance of the motor itself is improved, since the temperature reduction of the windings and other parts of the motor is optimized, so that the size of the electric motor can be reduced, enabling material savings.

The pump of the present invention is also quieter. This is advantageous because the thermally conductive material dampens vibrations, thus reducing noise levels.

These and other advantages and features of the invention will become apparent in view of the drawings and detailed description of the invention.

Drawings

Fig. 1 shows a perspective view of a first embodiment of an electric pump according to the present invention, in which a pump body and a motor main body are detached from each other.

Fig. 2 shows a perspective view of the motor body of the pump of fig. 1.

Fig. 3 shows a perspective view of a rotor housing of the motor body of fig. 2.

Fig. 4 is a cross-sectional view of the motor body of fig. 2.

Fig. 5 is a detail of the motor body of fig. 2.

Fig. 6A is another cross-sectional view of the motor body of fig. 2 including a first embodiment of a connection region.

Fig. 6B is another cross-sectional view of the motor body of the present invention including another embodiment of the connection region.

Fig. 7 shows a perspective view of a second embodiment of the motor body.

Detailed Description

The electric pump 1 according to the first embodiment of the present invention includes: a pump body 2 connected to the hydraulic part of the pump 1; and a motor body 3 connected to an electric portion of the pump 1. The motor body 3 includes a rotor housing 4, by means of which rotor housing 4 the motor body 3 is coupled at one end of the pump body 2, enabling the end thereof to be closed. As seen in fig. 1, the other end of the pump body 2 is closed with a filter 2a arranged inside the pump body 2. The pump 1 further comprises an impeller 5 and an electric motor (preferably a synchronous motor). As shown in fig. 1 and 2, the impeller 5 is disposed on one side of the rotor housing 4, and the electric motor is disposed on the other side. The motor of the invention, either single-phase or multi-phase, comprises at least one assembly formed by a stator 6 and at least one stator coil 6a and a rotor 7 comprising a shaft 7a cooperating with the impeller 5.

The pump 1 further comprises a cover 8, which cover 8 is attached to the rotor housing 4 in a leak-proof manner, such that a leak-proof chamber 9 is formed therein. The stator 6 and the stator coils 6a are arranged inside a leak-proof chamber 9, and said chamber 9 is filled with a heat-conducting material, so that the heat generated in the motor (usually due to the passage of electric current) is then rapidly dissipated, mainly by conduction to another point (usually in the atmosphere), thus preventing the motor from overheating. This allows the stator coils 6a of the motor to operate in a smaller temperature range, sufficiently ensuring compliance with the corresponding safety regulations.

On the other hand, however, if it is desired to operate within the same temperature range, the pump 1 according to this first embodiment allows reducing the volume of the conductors of the stator coils 6a, i.e., the material in the stator coils 6a is less, and also the material of the stator 6 can be reduced (e.g., by designing the stator 6 so as to be less thick, etc.), so that a significant saving in material costs and weight reduction can be achieved.

The current circulating through the stator coil 6a is inversely proportional to the impedance opposed by the stator coil 6a itself (i.e., the lead wire of the stator coil 6a), and the longer the length of the winding, the greater the impedance opposed to the passage of the current, and therefore the lower the current intensity. Also, the shorter the length of the winding, the less resistance against the passage of current, and therefore the higher the current intensity, but because the pump 1 of the present invention dissipates heat loss quickly and efficiently, preventing overheating of the motor, allowing the stator coils 6a to continue to operate in the same temperature range.

The pump 1 according to the first embodiment of the present invention includes a single coil 6 a. Optionally, the pump 1 may also comprise several coils.

The pump 1 of the invention is more silent, which is very advantageous. Since the thermally conductive material dampens vibrations, the noise level is reduced.

The heat conducting material arranged in the leak-proof chamber 9 may be a fluid, preferably a liquid, a gel or a solid. The use of air is not recommended beyond all fluids used, since the heat transfer is slow due to the convection provided by the air.

In a preferred embodiment of the invention, the heat conducting material is oil, which provides faster cooling (by convection and conduction) than the cooling produced by convection alone.

The stator coil 6a is arranged inside the leak-proof chamber 9 filled with oil, providing a chamber 9 in which no oxygen is present. Due to the absence of oxygen, galvanic corrosion of the wires of the stator coil 6a is thereby avoided, as well as corrosion of any components arranged inside the leakage-proof chamber 9.

In fact, in the hypothetical case of overheating of the motor, a possible flame propagation is avoided due to this lack of oxygen.

Further, in the preferred embodiment of the present invention, the heat conductive material is a dielectric material, which avoids isolating elements such as the stator coil 6a, the stator 6, and the like.

The pump 1 of the invention further comprises a thermal protector 17, for example a bimetallic switch, connected in series with the coil 6a of the electric motor and the power supply in a known manner. The thermal protector 17 will interrupt the current circulating through the coil 6a in case of overheating.

In a preferred embodiment, the thermal protector 17 is arranged inside the leak-proof chamber 9, as shown in fig. 4, and it is therefore in contact with the heat-conducting material. Advantageously, since the thermal protector 17 is in contact with the heat conducting material, it is more sensitive to temperature variations of the coil 6a, so that it can react more quickly in case of emergency.

In order to ensure a leak-proof closure between the rotor housing 4 and the cover 8, the rotor housing 4 comprises a closure profile 4a such as shown in fig. 3, the closure profile 4a projecting axially from the side where the electric motor is arranged, and the cover 8 comprises, in the profile of the free end, an engagement profile 8a cooperating with the closure profile 4a of the rotor housing 4, as shown in detail in fig. 5.

In this embodiment of the invention, said engagement profile 8a comprises a U-shape so that the closed profile 4a of the rotor housing 4 is introduced by means of form fit so as to be accommodated therein. However, once the closing profile 4a has been fixed in the joining profile 8a, in order to ensure the leak-tightness of the entire attachment joint, in this first embodiment a sealing operation is carried out, for example by means of laser, welding, ultrasound, hot ironing, gluing, siliconizing, etc. Thereby ensuring a leak-proof attachment without the use of elastic joints.

Alternatively, in a variant of this embodiment, not shown in the figures, there is an arrangement between the closing profile 4a of the rotor casing 4 and the engagement profile 8a of the cover 8: an elastic joint ensures a leak-proof attachment between the closing profile 4a and the joining profile 8 a. Thereby avoiding the sealing process described in the previous paragraph.

As is known, an electric motor comprises terminals 12, the terminals 12 being able to connect the motor to an external power source. However, the terminal 12 of the pump 1 of the present invention is arranged at least partially inside the leak-proof chamber 9, preferably at least in the portion connected to the coil 6a and therefore in contact with the heat-conducting material. In this way, in the event of a short circuit, in which local overheating occurs in the vicinity of the connection region of the terminal 12 and the coil 6a, possible flame propagation and deformation in the surrounding elastic member due to the heat generated are avoided, since the heat-conducting material disperses the heat rapidly.

The rotor housing 4 preferably comprises an opening 11 in the front or rear lower part allowing said terminal 12 to pass through. However, in this embodiment of the invention, it is also necessary to seal said opening 11 so that the chamber 9 is practically leak-proof.

To this end, as shown in fig. 4, the pump 1 of the first embodiment of the invention comprises a connecting zone 13 arranged in a leakproof manner in said opening 11. Said connection area 13 is made of plastic, preferably rigid, and is attached to the rotor housing 4 by a subsequent sealing operation around the periphery of the opening 11, for example by welding or gluing, as shown in more detail in fig. 6A.

In order to seal the terminals 12, after the connection region 13 and the opening 11 of the rotor case 4 are sealed in a leak-proof manner, the terminals 12 are assembled and then a resin is applied on the connection region 13 and the terminals 12, thereby forming the elastic seal 16 and thus sealing the terminals 12 in a leak-proof manner.

Alternatively, in another embodiment of the invention (in which no subsequent sealing operation is required), the connection zone 13, also arranged in a leaktight manner in said opening 11, comprises an elastic portion, called sealing connection zone 13', arranged at the end of the connection zone 13, arranged close to the electric motor, as shown in the detail of fig. 6B. Said sealing connection area 13' comprises an elastic area cooperating with the opening 11. In this embodiment of the invention, as seen in fig. 6B, the elastic region is in contact with the inner face of the opening 11. In order to ensure a leak-proof closure with the opening 11 of the rotor housing 4, the elastic region cooperating with the edge of the opening 11 of the connection region 13 comprises an elastic profile 15 near the end, which has a larger cross-section in the entire region in contact with the opening 11. When the elastic region 13 is introduced into the opening 11, the elastic contour 15 is deformed and exerts a pressure on the inner face of the opening 11. For the sake of clarity, the resilient profile 15 is shown arranged in the opening 11 of the rotor housing 4, but is not deformed, so that the original shape of said resilient profile 15 can be better seen. Alternatively, an elastic joint may also be arranged between the connection region 13 and the opening 11.

The sealed connection region 13' of this alternative embodiment also comprises a contracted elastic region 14 (depicted in fig. 6B) for each terminal 12, the region 14 cooperating with the respective terminal 12. The side through which the corresponding terminal 12 must be introduced is a wider side to guide the terminal 12 more easily. The opposite sides (i.e., the sides through which the terminals 12 exit) tend to close, i.e., come together. In a non-limiting example of the invention, the opposite sides come together forming a film that breaks when the respective terminal 12 is introduced, so that when the terminal 12 is introduced, the narrowest region of the constricted region 14 comes into contact with the terminal 12, also exerting pressure on the terminal 12.

In any embodiment, bushing 13 is interchangeable, so it can accommodate different types and positions of terminal 12, allowing greater flexibility of pump 1 as it can accommodate different types of electrical connections.

In a preferred embodiment of the invention, the cover 8 is formed by a single part, but it cannot be excluded that the cover 8 may comprise several parts attached to each other in a leak-proof manner to form the cover 8, or even comprise a single part, but of different materials. This latter variant may be useful, for example, in obtaining a cap 8 with different materials and geometries, which help to guide and optimize the external heat transfer.

In a non-limiting example of embodiment of the invention, the cover 8 of the pump 1 of the invention is preferably made of the same material as the casing 4, made of plastic, preferably polypropylene. As already mentioned in the preceding paragraph, it is not excluded that the cover 8 may comprise more than one material.

In another embodiment of the invention, which differs from the first embodiment only with respect to the external configuration of the enclosure 8, said enclosure 8 comprises in its outer profile a plurality of fins 10 (shown in fig. 7) projecting vertically, so that the contact surface with the atmosphere in general is increased. This configuration allows to further accelerate the cooling, i.e. the heat transfer, of the electric motor of the pump 1 of the invention, since on the one hand the heat is rapidly evacuated from the motor by conduction due to the conductive material arranged in the leak-proof chamber 9, and on the other hand the evacuation of said heat is optimized by convection to the atmosphere.

Pumps such as those described herein are used to move or drive a fluid, preferably water, and are often used in dry environments. An application of this type may be, for example, a drain pump or a circulation pump in an appliance such as a washing machine or a dishwasher or in a dryer.

However, since in the pump 1 of the present invention the chamber 9 containing the stator 6 and the stator coils 6a is leak-proof, the pump 1 can be used in another type of environment (such as an environment with a high humidity level), and the pump 1 of the present invention can also be operated immersed in a liquid. The pump 1 of the invention is therefore also suitable for use in fish tanks, aquariums or similar devices.

Claims

1. An electric pump comprising a pump body (2) and a motor body (3), the motor body (3) comprising a rotor housing (4), an impeller (5) rotatable arranged on one side of the rotor housing (4) and an electric motor arranged on the other side of the rotor housing (4) and comprising a stator (6), at least one stator coil (6a), a rotor (7) and terminals (12) connected to the stator coil (6a), the motor body (3) being coupled to the pump body (2) by means of the rotor housing (4), the rotor (7) comprising a shaft (7a) cooperating with the impeller (5), the motor body (3) further comprising a cover (8) attached to the rotor housing (4) such that a leak-proof chamber (9) is formed in the cover (8), characterized in that, the leak-proof chamber (9) is filled with oil as a heat-conducting material, thereby providing a leak-proof chamber (9) free of oxygen, at least a portion of the terminal (12), the stator (6) and the coil (6a) being arranged inside the leak-proof chamber (9) and in contact with the heat-conducting material.

2. The electric pump of claim 1, wherein the oil is a vegetable oil.

3. An electric pump according to claim 1 or 2, wherein the material is a dielectric material.

4. An electric pump according to claim 1 or 2, wherein the rotor housing (4) comprises a closed contour (4a) projecting axially from the side where the electric motor is arranged.

5. An electric pump according to claim 4, wherein the cover (8) comprises, in the profile of the free end, an engagement profile (8a) cooperating with the closed profile (4a) of the rotor housing (4).

6. Electric pump according to claim 5, wherein the closing profile (4a) of the rotor housing (4) and the engagement profile (8a) of the cover (8) are fixed by means of pressure and are attached to each other in a leaktight manner after the subsequent sealing operation is performed.

7. Electric pump according to claim 5, wherein an elastic joint is arranged between the closing profile (4a) of the rotor housing (4) and the engaging profile (8a) of the cover (8), ensuring a leak-proof attachment between the closing profile (4a) and the engaging profile (8 a).

8. An electric pump according to claim 1 or 2, wherein the rotor housing (4) comprises an opening (11) to allow the terminal (12) of the electric motor to pass through.

9. An electric pump according to claim 8, wherein a connecting region (13) is accommodated in the opening (11) in a leak-proof manner, so that the terminal (12) is also sealed in a leak-proof manner.

10. Electric pump according to claim 9, wherein the elastic region of the connection region (13) cooperating with the edge of the opening (11) comprises, near the end, an elastic profile (15), the elastic profile (15) having a larger cross section in the whole contact region with the opening (11) for sealing the opening (11) in a leak-proof manner.

11. An electric pump according to claim 8, wherein a connecting region (13) is received in the opening (11) in a leaktight manner after a subsequent sealing operation by welding or gluing, the connecting region (13) comprising an elastic seal (16) formed by applying a resin on the connecting region (13) and the terminal (12), wherein the elastic seal (16) cooperates with the terminal (12) so as to seal the terminal (12) in a leaktight manner.

12. An electric pump according to claim 1 or 2, wherein the cover (8) comprises in its outer profile a plurality of fins (10) projecting vertically.

13. An electric pump according to claim 1 or 2, wherein the cover (8) is made of polypropylene or of the same material as the rotor housing (4).

14. An electric pump according to claim 1 or 2, further comprising a thermal protector (17) connected to said coil (6a), said thermal protector (17) being arranged inside said leak-proof chamber (9) and thus being in contact with said heat-conducting material.

15. An electric pump according to claim 1 or 2, wherein the electric motor is a synchronous motor.

16. Electric pump according to claim 5, wherein the engagement profile (8a) of the cover (8) comprises a U-shape for housing the closing profile (4a) therein.

17. The electric pump according to claim 8, wherein the opening (11) is located in a front lower portion or a rear lower portion.

18. An electric pump according to claim 9, wherein the connection region (13) comprises a sealed connection region (13'), the sealed connection region (13') comprising an elastic region cooperating with an edge of the opening (11) and a contracted elastic region (14) for each terminal (12) and cooperating with the respective terminal (12).

19. An electric pump according to claim 1 or 2, wherein at least the portion of each terminal (12) in contact with the heat conducting material is connected with the coil (6a) of the stator (6).

20. An electric pump according to claim 1 or 2, wherein the material of the cover (8) is plastic.