End cover for a liquid-cooled electric machine

Abstract

The application relates to an end cover of a liquid-cooled motor, which is provided with a center hole, a liquid injection hole and a gas valve mounting hole arranged around the center hole, a liquid-gas separation ring groove arranged around the center hole, the liquid-gas separation ring groove being provided with an air exchange opening, and a liquid blocking cover plate arranged on the liquid-gas separation ring groove to form a liquid-gas separation channel. A liquid blocking plate is arranged at the air exchange opening. The liquid-gas separation ring groove and the multiple liquid-gas separation ring grooves are arranged to separate the gaseous cooling liquid generated by the high temperature of the motor from the air mixture, thereby solving the problem that the cooling liquid damages the air permeability of the gas valve.

Description

Technical Field

[0001] This invention relates to the field of hub motor technology, specifically to an end cap for a liquid-cooled motor. Background Technology

[0002] Motors generate heat during operation. To quickly dissipate heat from the motor core and maintain high efficiency within a suitable temperature range, insulating liquid is injected inside the motor to achieve rapid heat dissipation. In oil-cooled motors, the high temperature and high-speed rotation of the rotor cause some of the coolant inside the motor housing to atomize, forming a gaseous liquid-gas mixture. This results in excessively high pressure inside the motor housing, posing a significant challenge to the motor's seal. Motors with poor sealing will then leak oil. Therefore, it is necessary to depressurize the inside of the oil-cooled motor housing.

[0003] The commonly used method in current technology is to install a vent valve on the motor housing, utilizing the vent membrane on the vent valve for gas exchange between the inside and outside of the motor. However, the high temperature of the motor during operation causes the coolant to atomize, and the resulting gaseous liquid-gas mixture diffuses to the vent valve. When the atomized coolant in the liquid-gas mixture cools and condenses into droplets, it adheres to the vent membrane, ultimately causing the vent membrane to lose its gas permeability. Therefore, preventing the liquid-gas mixture from diffusing to the vent valve is a problem that current liquid-cooled motors need to solve.

[0004] Chinese invention application CN117639352A discloses a liquid-cooled motor liquid-blocking labyrinth structure, including a mounting plate with a central hole, and a labyrinth liquid-blocking component mounted on the mounting plate. The labyrinth liquid-blocking component has a ring structure and is distributed around the central hole. The labyrinth liquid-blocking component has a venting channel, and the labyrinth liquid-blocking component has a first vent and a second vent communicating with the venting channel. Each vent is provided with a main liquid-blocking plate. The labyrinth liquid-blocking component and / or the mounting plate are provided with a vent valve mounting hole for installing a vent valve. Gas entering the venting channel through the vent can be discharged through the vent valve installed in the vent valve mounting hole.

[0005] The aforementioned labyrinth structure aims to block coolant from entering the vent. However, some coolant may still enter the venting channel through the vent. Since the labyrinth baffle is a ring structure distributed around the central hole, the centrifugal force generated by the rotor rotation will throw this portion of coolant out of the vent, minimizing the possibility of coolant contacting the vent valve. The vent valve can maintain stable operation for a long time, ensuring the balance of air pressure inside and outside the motor at all times.

[0006] The above technical solution can theoretically avoid contact between the coolant and the vent valve. However, the main factor affecting air exchange in liquid-cooled motors is the liquid-gas mixture generated by the high temperature of the motor. Because the above labyrinth structure has only one vent channel, the path for the liquid-gas mixture is too short. The liquid coolant may be centrifugally ejected, but a certain amount of uncondensed liquid-gas mixture will still reach the vent valve. When the liquid-gas mixture condenses, the coolant will still adhere to the vent membrane, damaging the permeability of the vent membrane and thus affecting the balance of air pressure inside and outside the motor. In addition, the entire labyrinth liquid-blocking component structure is complex and the mold manufacturing cost is high. Summary of the Invention

[0007] The purpose of this invention is to provide an end cap for a liquid-cooled motor. By setting up a liquid-gas separation annular groove and multiple rings of liquid-gas separation annular grooves, the gaseous coolant and air mixture generated by the high temperature of the motor operation can be fully separated, thus solving the problem of coolant damaging the permeability of the vent valve in the prior art.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] An end cap for a liquid-cooled motor has a central hole, and around the central hole are a liquid injection hole and a vent valve mounting hole.

[0010] A liquid-gas separation annular groove is provided around the central hole, and the liquid-gas separation annular groove is provided with an air exchange port; a liquid-blocking cover plate is also provided to cover the liquid-gas separation annular groove, and the liquid-blocking cover plate closes on the liquid-gas separation annular groove to form a liquid-gas separation channel.

[0011] A liquid-gas separation annular groove is set around the central hole, and a liquid-blocking plate is set at the air exchange port.

[0012] At least two rings of liquid-gas separation annular grooves are arranged around the central hole from the outside to the inside. Each ring of liquid-gas separation annular groove is equipped with an air exchange port, and the air exchange ports of the multiple liquid-gas separation annular grooves are staggered.

[0013] The liquid-gas separation annular groove is designed as an elliptical annular groove, and the air exchange port is located at the intersection of the major axis of the ellipse and the ellipse.

[0014] The major axes of the ellipses of two adjacent rings of liquid-gas separation grooves do not coincide. Each ring of liquid-gas separation grooves has two air exchange ports at the two intersections of its ellipse and major axis. The outermost ring of liquid-gas separation grooves has two first air exchange ports.

[0015] The liquid blocking plate is located at the first air exchange port.

[0016] The liquid-gas separation annular groove is arranged around the central hole, and the height of the groove wall decreases sequentially from the outside to the inside.

[0017] The liquid baffle plate is provided with recessed steps from the outside to the inside, corresponding to the height of the tank wall of each liquid-gas separation ring tank. Each recessed step and the corresponding liquid-gas separation ring tank are covered to form a liquid-gas separation channel. The diameter of each air exchange port decreases from the outside to the inside.

[0018] Centrifugal blades are installed on the outer surface of the liquid-blocking cover.

[0019] A filtration device is installed in the liquid-gas separation annular tank.

[0020] The advantages of this invention are: 1. The liquid-gas separation annular groove surrounding the central hole can use centrifugal force to throw out the coolant entering the liquid-gas separation annular groove; 2. The multiple rings of liquid-gas separation annular grooves surrounding the central hole can extend the running path of the liquid-gas mixture generated by the high temperature of the motor and the air, allowing the atomized coolant in the liquid-gas mixture sufficient condensation time to achieve the effect of complete liquid-gas separation; 3. The liquid baffle can prevent coolant dripping from above the air exchange port into the liquid-gas separation annular groove; 4. The liquid-gas separation annular groove is elliptical, and the air exchange port is located on the major axis of the ellipse, which can maximize the centrifugal effect; 5. A filter device is installed in the liquid-gas separation annular groove to retain the liquid-gas mixture. 6. Coolant condensed during the operation of the mixture is then thrown out of the liquid-gas separation ring groove by centrifugal force, further improving the liquid-gas separation effect and ensuring that coolant does not enter the location of the vent valve; 7. The height of the multi-ring liquid-gas separation groove decreases from the outside to the inside, and the liquid baffle plate is set with corresponding recessed steps to ensure that the gaseous liquid-gas mixture diffuses to the vent valve along the designed route to achieve the best liquid-gas separation effect; 8. The air exchange port of each liquid-gas separation ring groove has a continuously decreasing diameter from the outside to the inside, which continuously reduces the possibility of coolant entering the innermost liquid-gas separation ring groove, further enhancing the liquid-gas separation effect; 9. The centrifugal blades on the outer surface of the liquid baffle plate reduce the amount of coolant entering the liquid-gas separation ring groove. Attached Figure Description

[0021] Figure 1 This is an exploded view of the structure of the present invention, which includes two rings of liquid-gas separation grooves.

[0022] Figure 2 This is a longitudinal structural view of the liquid-retaining cover plate corresponding to the two rings of liquid-gas separation grooves in this invention.

[0023] Figure 3 This is a cross-sectional view of the structure of the present invention, which includes two rings of liquid-gas separation grooves.

[0024] Figure 4 This is a schematic diagram of the structure of the present invention, which includes multiple rings of liquid-gas separation grooves.

[0025] Figure 5 This is a cross-sectional view of the structure of the present invention, which includes multiple rings of liquid-gas separation grooves.

[0026] In the figure: 1-Central hole; 2-Injection hole; 3-Ventilator mounting hole; 4-Liquid-gas separation ring groove; 41-Gate wall; 5-Air exchange port; 51-First air exchange port; 6-Liquid baffle plate; 61-Recessed step; 62-Centrifugal blade; 7-Liquid baffle plate; 8-Filter device. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings. The drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0028] To simplify the description of this embodiment, some components that are well-known to those skilled in the art but are not related to the main content of this invention may be omitted in the accompanying drawings or description. Additionally, for ease of description, some components in the drawings may be omitted, enlarged, or reduced, but these do not represent the actual product dimensions or the complete structure.

[0029] An end cap for a liquid-cooled motor according to the present invention, such as Figure 1-5 As shown, it is provided with a central hole 1, and around the central hole 1 are a liquid injection hole 2 for injecting coolant, and a vent valve mounting hole 3 for installing the vent valve.

[0030] A liquid-gas separation annular groove 4 is arranged around the central hole 1, with multiple rings radiating outwards from the central hole 1. The liquid-gas separation annular groove 4 is equipped with an air exchange port 5. When the motor is running, coolant enters the liquid-gas separation annular groove 4, and the centrifugal force of the motor rotation throws the coolant out through the air exchange port 5. To achieve the best centrifugal effect, the liquid-gas separation annular groove 4 is designed as an elliptical groove, which maximizes the centrifugal force on the coolant. The air exchange port 5 is located at the intersection of the major axis of the ellipse and the ellipse itself, so that under the same centrifugal force, the amount of coolant thrown out is maximized.

[0031] like Figure 1 As shown, a liquid-retaining cover plate 6 is also provided, which covers the liquid-gas separation annular groove 4. The liquid-retaining cover plate 6 covers the liquid-gas separation annular groove 4 to form a liquid-gas separation channel. The liquid-gas separation channel is the place where the gaseous liquid-gas mixture generated at high temperature during motor operation is separated. The liquid-retaining cover plate 6 that constitutes the liquid-gas separation channel and the liquid-gas separation annular groove 4 can be formed by fixing the two together by bolts, riveting or even welding, or they can be integrally formed.

[0032] One approach is to set a liquid-gas separation annular groove 4 around the central hole 1. Since the rotor rotation will drive the coolant into the entire internal cavity of the motor when the motor is running, in order to prevent the coolant above the air exchange port 5 from dripping directly into the air exchange port 5, a liquid blocking plate 7 is set at the air exchange port 5 to prevent the coolant from directly entering the liquid-gas separation annular groove 4 through the air exchange port 5.

[0033] To achieve better liquid-gas separation, the liquid-gas separation channel formed by the liquid baffle 6 covering the liquid-gas separation annular groove 4 should be as long as possible. This extends the liquid-gas separation channel within the confined motor space, allowing the liquid-gas mixture to travel a longer path, ensuring that the gas reaching the vent valve contains little or no coolant, thus extending the vent valve's service life.

[0034] Another option is, such as Figure 1 , Figure 4 As shown, at least two rings of multi-ring liquid-gas separation grooves 4 are arranged around the central hole 1 from the outside to the inside. Each ring of liquid-gas separation grooves 4 is provided with an air exchange port 5, and the air exchange ports 5 of the multiple liquid-gas separation grooves 4 are staggered.

[0035] like Figure 1 , Figure 4 As shown, when the liquid-gas separation annular groove 4 is set as an elliptical annular groove, the major axes of the ellipses of two adjacent liquid-gas separation annular grooves 4 do not coincide. This ensures that the air exchange ports 5 of the inner and outer rings of the liquid-gas separation annular groove 4 are staggered. In particular, the air exchange ports 5 of two adjacent liquid-gas separation annular grooves 4 must be staggered.

[0036] To increase gas exchange efficiency, each ring of the liquid-gas separation annulus 4 has two air exchange ports 5 at the two intersections of its ellipse and major axis. The air exchange ports 5 of each ring do not overlap, which can lengthen the diffusion path of the liquid-gas mixture. The outermost ring of the liquid-gas separation annulus 4 has two first air exchange ports 51, and the liquid blocking plate 7 is set at the first air exchange ports 51.

[0037] In order to ensure that the liquid-gas mixture enters the innermost liquid-gas separation annular groove 4 sequentially from the outside to the inside, the height of the groove wall 41 of the liquid-gas separation annular groove 4, which is set around the central hole 1, decreases sequentially from the outside to the inside.

[0038] At the same time, such as Figure 2 , Figure 3 , Figure 5 As shown, the liquid-blocking cover plate 6 is provided with recessed steps 61 from the outside to the inside, corresponding to the height of the tank wall 41 of each liquid-gas separation annular tank. Each recessed step 61 and the corresponding liquid-gas separation annular tank 4 cover each other to form a liquid-gas separation channel. In this way, not only is the running path of the liquid-gas mixture extended, so that the coolant in the liquid-gas mixture is liquefied as much as possible in the outer ring, but the atomized coolant condenses in the liquid-gas separation annular tank 4 and is centrifugally thrown out during the process of entering sequentially from the outside to the inside, but also the diameter of each air exchange port 5 decreases from the outside to the inside, making it increasingly difficult for the liquefied coolant to enter the inner ring.

[0039] Of course, the coolant cannot be completely ejected by centrifugation. To ensure that the liquid-gas mixture is fully separated, only air remains when it reaches the vent valve. Figure 1 As shown, a filter device 8 is installed inside the liquid-gas separation annular tank 4. Since the motor coolant is usually cooling oil, the filter device 8 can be made of materials with oil-repellent properties, such as stainless steel mesh, glass fiber, or polyurethane. The small holes on the filter screen condense the blocked oil mist into oil droplets, which are then retained in the filter device 8. Under the action of centrifugal force, the droplets are thrown out of the filter screen and flow out along the elliptical liquid-gas separation annular tank 4.

[0040] To increase the centrifugal effect on the coolant and minimize the amount of coolant entering the liquid-gas separation annular tank 4, centrifugal blades 62 are provided on the outer surface of the liquid baffle 6.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. All equivalent changes and modifications made within the scope of the claims of this invention should be considered within the technical scope of this invention.

Claims

1. An end cap for a liquid-cooled motor, having a central hole (1), and an injection hole (2) and a vent valve mounting hole (3) arranged around the central hole (1). characterized in that A liquid-gas separation annular groove (4) is provided around the central hole (1), and an air exchange port (5) is provided in the liquid-gas separation annular groove (4); a liquid-blocking cover plate (6) is also provided covering the liquid-gas separation annular groove (4), and the liquid-blocking cover plate (6) covers the liquid-gas separation annular groove (4) to form a liquid-gas separation channel. The liquid-gas separation annular groove (4) is set as an elliptical annular groove, and the air exchange port (5) is set at the intersection of the major axis of the ellipse and the ellipse; At least two rings of multi-ring liquid-gas separation grooves (4) are arranged around the central hole (1) from the outside to the inside. Each ring of liquid-gas separation grooves (4) is provided with an air exchange port (5). The air exchange ports (5) of the multiple liquid-gas separation grooves (4) are staggered. The major axes of the ellipses of two adjacent rings of liquid-gas separation grooves (4) do not coincide. Each ring of liquid-gas separation grooves (4) is provided with two air exchange ports (5) at the two intersections of its ellipse and major axis. The outermost ring of liquid-gas separation grooves (4) is provided with two first air exchange ports (51). The liquid blocking plate (7) is located at the first air exchange port (51).

2. The end cover of the liquid-cooled motor according to claim 1, characterized in that: The height of the wall (41) of the liquid-gas separation annular groove (4) surrounding the central hole (1) decreases sequentially from the outside to the inside.

3. The end cover of the liquid-cooled motor according to claim 2, characterized in that: The liquid baffle (6) is provided with recessed steps (61) from the outside to the inside, corresponding to the height of the tank wall (41) of each liquid-gas separation ring tank. Each recessed step (61) and the corresponding liquid-gas separation ring tank (4) are covered to form a liquid-gas separation channel. The diameter of each air exchange port (5) decreases from the outside to the inside.

4. The liquid-cooled motor endshield of claim 1, wherein: Centrifugal blades (62) are provided on the outer surface of the liquid-blocking cover plate (6).

5. The liquid-cooled motor endshield of claim 1, wherein: A filter device (8) is installed in the liquid-gas separation annular tank (4).

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