Oil-gas separation labyrinth device of liquid cooling motor

Abstract

The invention discloses an oil-gas separation labyrinth device of a liquid-cooled motor. The oil-gas separation labyrinth device is detachably and fixedly arranged in an end cover, provided with a ventilation valve, of the liquid-cooled motor. The oil-gas separation device comprises an upper cover and a bottom cover which are buckled with each other, the bottom cover is provided with at least two circles of lower oil retaining rings, the upper cover is provided with at least two circles of upper oil retaining rings, and when the upper cover and the bottom cover are buckled with each other, the upper oil retaining rings are inserted into gaps of the lower oil retaining rings to form a labyrinth inner cavity with multiple circles of oil-gas separation channels; and the labyrinth device formed by buckling the upper cover and the bottom cover is detachably and fixedly connected with the end cover through the bottom cover. The oil-gas separator overcomes the defects that in the prior art, an oil-gas separation path is too short, the replacement cost is too high when the oil-gas separator is arranged on an end cover, and the like, the multi-stage S-shaped roundabout air duct is formed by the upper oil deflector ring and the lower oil deflector ring, the collision frequency is increased while the oil mist path is prolonged, and the condensation separation efficiency is improved to 95% or above.

Description

Technical Field

[0001] This invention relates to the field of hub motor technology, specifically to an oil-gas separation labyrinth device for a liquid-cooled motor. Background Technology

[0002] Inside a hub motor, 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 experience oil leakage. Therefore, it is necessary to depressurize the inside of the oil-cooled motor housing. Current technology commonly uses a vent valve on the motor housing, utilizing a vent membrane for gas exchange between the inside and outside of the motor. However, the high temperature of the motor operation causes the coolant to atomize, and the resulting gaseous liquid-gas mixture also 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 membrane to lose its gas permeability. Therefore, preventing the liquid-gas mixture from diffusing to the vent valve is a key problem that current liquid-cooled motor technology needs to solve.

[0003] 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.

[0004] 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.

[0005] 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. The labyrinth structure, with only one vent channel, provides too short a path for the liquid-gas mixture. 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, impairing its permeability and affecting the balance of air pressure inside and outside the motor. Furthermore, the labyrinth is located on the end cap, and replacing it would require replacing the entire end cap, which is too costly. Moreover, the existing end cap material has a strong adhesion to oil mist, which is also a reason why oil mist can reach the vent valve. Of course, the entire labyrinth liquid-blocking structure is complex, and the mold manufacturing cost is high. Summary of the Invention

[0006] The purpose of this invention is to provide an oil-gas separation labyrinth device for a liquid-cooled motor, which overcomes the shortcomings of the prior art, such as the oil-gas separation path being too short and the oil-gas separation device being too costly to replace on the end cover.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] An oil-gas separation labyrinth device for a liquid-cooled motor is detachably fixed inside an end cover of the liquid-cooled motor equipped with a vent valve. It includes an upper cover and a bottom cover, with the upper cover fastened onto the bottom cover. The bottom cover includes an annular lower base plate, at least two raised lower oil baffle rings disposed on the lower base plate, and at least three mounting posts disposed on the lower base plate. The upper cover includes an annular upper base plate, at least two raised upper oil baffle rings disposed on the upper base plate, and mounting holes disposed on the upper base plate in the same number as the mounting posts.

[0009] The upper and lower base plates are circular structures based on the same center. The upper and lower oil baffle rings are multi-ring structures with different radii based on the same center of the upper and lower base plates. The radii of the upper and lower oil baffle rings are spaced apart from the inside out. When the upper cover and the lower cover are fastened together, the upper oil baffle ring is inserted into the gap of the lower oil baffle ring, forming a labyrinthine cavity with multiple oil-gas separation channels. The diameter of the central hole of the lower base plate is larger than the diameter of the central hole of the upper base plate. The labyrinth device formed by the fastening of the upper cover and the lower cover is detachably fixedly connected by the lower cover and the end cover.

[0010] The bottom plate has at least two protrusions extending outwards at intervals along its outer edge, and the end cap has a slot. The labyrinth device is engaged with the end cap slot by the protrusions of the bottom cap.

[0011] One end of the boss is a tapered insertion part, and the other end is a circumferential stop part. The boss enters the slot through the insertion part and is limited by the stop part.

[0012] The height of the mounting post is greater than the height of the lower oil baffle ring.

[0013] At least three support pillars are spaced apart at the top of the lower oil baffle ring.

[0014] The support column is located at the top of the lower oil baffle ring of the inner ring.

[0015] Both the top and bottom covers are made of grease-free plastic.

[0016] In view of the above technical features, the present invention has the following beneficial effects: 1. The labyrinth of the present invention is composed of a symmetrically arranged upper cover and a lower cover. At least two concentric raised circular oil-blocking rings are provided on their opposite surfaces. After the upper and lower covers are fastened together, the upper and lower oil-blocking rings are radially staggered, forming a multi-stage S-shaped meandering ventilation channel. This extends the oil mist path and increases the number of collisions, improving the condensation and separation efficiency to over 95%. The path of oil mist entering the labyrinth from the high-pressure zone inside the motor cavity is forcibly extended. Each time it passes through a staggered oil-blocking ring, a directional change is completed, providing a structural basis for subsequent collision condensation and centrifugal separation; 2. The present invention is independently molded as a separate component, installed on the motor end cover near the shaft center, and rotates synchronously at high speed with the motor hub. Through "structural guidance + mechanical drive + multi-effect separation", it achieves this effect. The synergistic effect of the components achieves oil mist interception, condensation separation, and protection of the vent valve; 3. The invention is molded as a separate component, which is convenient for installation, maintenance, and replacement, and is compatible with oil-cooled motors of different specifications; no additional power is required, and the oil and oil mist are thrown off by the rotation of the motor, which is energy-saving and efficient; 4. The invention ensures the cleanliness of the vented air through the dual action of "physical blocking + condensation separation", avoids clogging of the vent valve, and maintains a long-term stable air permeability; 5. The top and bottom covers are made of plastic that is not wetted by oil, which not only solves the problem of oil adhesion, but also reduces the weight of the labyrinth device and reduces costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is an exploded view of the structure of the present invention;

[0019] Figure 3 This is an overall longitudinal sectional view of the present invention;

[0020] Figure 4 This is a schematic diagram of the structure of the upper cover of the present invention;

[0021] Figure 5 This is a schematic diagram of the bottom cover of the present invention;

[0022] Figure 6 This is an exploded view of the connection relationship between the maze device and the end cap of the present invention;

[0023] Figure 7 This is a longitudinal sectional view of the labyrinth device of the present invention disposed on the end cap and a schematic diagram of the oil mist diffusion path;

[0024] In the diagram: 1-Top cover; 11-Top base plate; 12-Top oil baffle ring; 13-Mounting hole; 2-Bottom cover; 21-Lower base plate; 22-Lower oil baffle ring; 23-Mounting post; 24-Support post; 3-Boss; 31-Insertion part; 32-Stop part; 4-End cover; 5-Ventilator; 6-Slot; 7-Top oil seal. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that some components well-known to those skilled in the art but not related to the main content of the present invention may be omitted in the drawings or description. Additionally, for ease of description, some components in the drawings may be omitted, enlarged, or reduced, but this does not represent the actual size or complete structure of the product.

[0026] An oil-gas separation labyrinth device for a liquid-cooled motor, such as Figure 1-7 As shown, it is detachably fixed inside the end cover 4 of the liquid-cooled motor, which is equipped with the vent valve 5; as Figure 1-5 As shown, it includes an upper cover 1 and a bottom cover 2, with the upper cover 1 fastened onto the bottom cover 2.

[0027] like Figure 2 , 5 As shown, the bottom cover 2 includes an annular lower base plate 21, at least two raised lower oil baffle rings 22 disposed on the lower base plate 21, and at least three mounting posts 23 disposed on the lower base plate 21. Figure 2 , 4 As shown, the upper cover 1 includes an annular upper base plate 11, at least two raised upper oil baffle rings 12 disposed on the upper base plate 11, and mounting holes 13 disposed on the upper base plate 11 in the same number as the mounting posts 23; as Figure 1 As shown, the upper cover 1 is fastened to the lower cover 2, and the mounting hole 13 corresponds to the mounting post 23. Preferably, the upper cover 1 is fixed to the lower cover 2 by bolts through the mounting hole 13 and the mounting post 23. Of course, other connectors can also be used to fix the upper cover 1 and the lower cover 2 through the mounting hole 13 and the mounting post 23.

[0028] like Figure 1-5As shown, the upper base plate 11 and the lower base plate 21 are circular structures based on the same center, and the upper oil baffle ring 12 and the lower oil baffle ring 22 are multi-ring structures with different radii based on the same center of the upper base plate 11 and the lower base plate 21. The radii of the upper oil baffle ring 12 and the lower oil baffle ring 22 are set alternately from the inside to the outside. That is, when the upper cover 1 and the bottom cover 2 are fastened together, there is an alternating arrangement of one lower oil baffle ring 22 and one upper oil baffle ring 12 from the inside to the outside. In other words, when the upper cover 1 and the bottom cover 2 are fastened together, the upper oil baffle ring 12 is inserted into the gap of the lower oil baffle ring 22, forming a labyrinthine cavity with multiple oil-gas separation channels.

[0029] Furthermore, the height of the mounting post 23 is greater than the height of the lower oil baffle ring 22. When the upper cover 1 and the bottom cover 2 are fastened together, there is a gap between the upper oil baffle ring 12 and the lower base plate 21, and there is also a gap between the lower oil baffle ring 22 and the upper base plate 11. Figure 3 , Figure 7 As shown, after the upper cover 1 and the bottom cover 2 are fastened together, the upper oil baffle ring 12 and the lower oil baffle ring 22 form a multi-stage S-shaped meandering ventilation channel. The path of the oil mist from the high-pressure area of ​​the motor cavity into the labyrinthine cavity formed by the upper cover 1 and the bottom cover 2 is forcibly extended. Each time it passes through a circle of intersecting oil baffle rings, it completes a directional change, providing a structural basis for subsequent collision condensation and centrifugal separation.

[0030] To prevent collapse caused by the high voltage inside the motor acting on the upper cover 1 and the bottom cover 2, at least three support pillars 24 are spaced apart at the top of the lower oil baffle ring 22. Preferably, the support pillars 24 are located at the top of the lower oil baffle ring 22 of the inner ring. In this way, the support pillars 24 and the mounting pillars 23 form a support surface for the upper cover 1.

[0031] Due to the design of the end cover 4 to match the motor, such as Figure 2 , 6 As shown, the diameter of the annular central hole of the lower base plate 21 is larger than the diameter of the annular central hole of the upper base plate 11; the annular central hole of the lower base plate 21 matches the central hole of the end cap 4, and the annular central hole of the upper base plate 11 matches the size of the upper oil seal 7. The labyrinth device formed by the upper cover 1 and the bottom cover 2 is detachably fixedly connected to the end cap 4 through the bottom cover 2.

[0032] like Figure 5 , 6 As shown, at least two protrusions 3 extending outwards are provided at intervals on the outer edge of the bottom plate 21, and a slot 6 is provided inside the end cover 4. The labyrinth device is engaged with the slot 6 of the end cover 4 through the protrusions 3 of the bottom cover 2.

[0033] Furthermore, one end of the boss 3 is a tapered insertion part 31, and the other end of the boss 3 is a circumferential stop part 32. The boss 3 enters the slot 6 through the insertion part 31 and is limited by the stop part 32. This design makes the labyrinth device a convenient and replaceable independent component, enabling adaptation to various motors without changing the original internal structure of the motor.

[0034] To achieve better oil mist separation, both the top cover 1 and the bottom cover 2 are made of grease-free plastic. This reduces the amount of oil droplets adhering to the labyrinth device and makes it easier for the oil droplets to be ejected under centrifugal force.

[0035] like Figure 6 , 7 As shown, the maze device is secured to the center hole of the end cap 4 by the bottom cover 2, and the upper oil seal 7 fixes the maze device in place.

[0036] When the motor rotates at high speed, the labyrinth device synchronously acquires angular velocity, forming a radially outward force field gradient under the action of centrifugal force. The liquid oil entering the labyrinth channel, due to its high density and strong inertia, is directly thrown to the outside of the channel by centrifugal force, that is, the side wall of the raised oil baffle ring, and flows back quickly to the inner cavity of the motor along the side wall, preventing the liquid oil from migrating towards the breather valve 5. The high-temperature small molecule oil mist—with a particle size of 0.1~2μm, although it is diffused in a gaseous state, is still enriched to the outside of the channel under the action of centrifugal force, creating concentration conditions for subsequent collision and agglomeration.

[0037] like Figure 7 The extended S-shaped flow channel and staggered oil-blocking rings shown exert multiple forces on the oil mist, pushing small molecule oil mist to condense into large molecule oil droplets. Due to the extended path and directional changes, the oil mist needs to pass through the gaps of the staggered oil-blocking rings multiple times. Each turn requires a change in flow direction. Because the inertia of oil mist particles is greater than that of air molecules, they cannot turn synchronously with the airflow and will inevitably collide with the side walls of the raised oil-blocking rings and the inner walls of the channel. During the collision process, the particles agglomerate.

[0038] The staggered raised oil-blocking rings form a multi-stage throttling structure, creating localized eddies and low-velocity zones within the channel, extending the residence time of the oil mist and increasing the probability of particle collisions. Simultaneously, a thin oil film gradually forms on the inner wall of the channel due to oil mist collisions, capturing submicron-sized oil mist through surface tension and van der Waals forces, further promoting agglomeration. During the flow of the oil-gas mixture within the oil-gas separation channel, oil mist particles undergo inertial collisions with and adhere to the inner wall of the channel, gradually forming a continuous and stable thin oil film. This thin oil film, through surface tension, generates liquid-phase affinity adsorption on oil mist particles near the wall surface. Simultaneously, when the interface between submicron-sized oil mist particles and the oil film approaches the molecular scale, van der Waals forces provide continuous intermolecular adsorption, achieving highly efficient capture of submicron-sized oil mist that is difficult to capture using traditional separation methods. The captured tiny oil droplets continuously coalesce and merge on the surface of the oil film, forming larger oil droplets. Under the combined action of gravity, airflow shear, and centrifugal force, the large oil droplets flow along the wall, converge, and flow back to the oil pan, completing the oil mist condensation, separation, and recovery.

[0039] The motor's internal cavity is a relatively high-pressure area, while the labyrinth channel near the vent valve 5 is a relatively low-pressure area. Oil mist flows through this area under the pressure difference. Figure 7 The S-shaped labyrinth channel is shown. As the airflow decreases in pressure along the path, it undergoes near-adiabatic expansion, causing the airflow temperature to drop accordingly. This results in the oil vapor and tiny oil mist particles being in a supersaturated state, promoting the condensation of oil molecules from the gas phase to the liquid phase and accelerating the collision, aggregation, and growth of submicron-sized oil mist particles, thus improving the oil-gas separation effect.

[0040] The condensed large molecular oil droplets—with a particle size of 5~50μm—are completely thrown away from the core area of ​​the labyrinth channel under the action of centrifugal force due to their increased mass. They flow back into the motor cavity along the return groove on the outside of the channel and re-participate in the heat absorption and heat dissipation cycle, thus realizing oil recovery.

[0041] After multi-stage separation, clean air containing only trace amounts of uncondensed oil mist, insufficient to cause blockage or pollution, gathers in the negative pressure zone at the center of the maze and connects to the outside atmosphere through the vent valve 5. In this way, the internal and external pressure of the motor is balanced, preventing the intrusion of external dust and moisture, and ensuring that the vent valve 5 is always in a clean working environment, extending its service life and maintaining a stable air permeability.

[0042] 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 oil-gas separation labyrinth device for a liquid-cooled motor, detachably and fixedly installed inside the end cap (4) of the liquid-cooled motor equipped with a vent valve (5); characterized in that: It includes an upper cover (1) and a bottom cover (2), with the upper cover (1) fastened to the bottom cover (2); wherein, the bottom cover (2) includes an annular lower base plate (21), at least two raised lower oil baffle rings (22) disposed on the lower base plate (21), and at least three mounting posts (23) disposed on the lower base plate (21); the upper cover (1) includes an annular upper base plate (11), at least two raised upper oil baffle rings (12) disposed on the upper base plate (11), and mounting holes (13) on the upper base plate (11) in the same number as the mounting posts (23). The upper base plate (11) and the lower base plate (21) are circular ring structures based on the same center. The upper oil baffle ring (12) and the lower oil baffle ring (22) are multi-ring structures with different radii based on the same center of the upper base plate (11) and the lower base plate (21). The radii of the upper oil baffle ring (12) and the lower oil baffle ring (22) are spaced apart from the inside to the outside. When the upper cover (1) and the lower cover (2) are fastened together, the upper oil baffle ring (12) is inserted into the gap of the lower oil baffle ring (22) to form a labyrinth cavity with multiple oil-gas separation channels. The diameter of the central hole of the ring of the lower base plate (21) is larger than the diameter of the central hole of the ring of the upper base plate (11). The labyrinth device formed by the fastening of the upper cover (1) and the lower cover (2) is detachably fixedly connected to the end cover (4) through the lower cover (2).

2. The oil-gas separation labyrinth device according to claim 1, characterized in that: At least two protrusions (3) extending outward from the outer edge of the bottom plate (21) are provided at intervals, and a slot (6) is provided inside the end cover (4). The maze device is engaged with the slot (6) of the end cover (4) through the protrusions (3) of the bottom cover (2).

3. The oil-gas separation labyrinth device according to claim 2, characterized in that: One end of the boss (3) is a conical insertion part (31), and the other end of the boss (3) is a circumferential stop part (32). The boss (3) enters the slot (6) through the insertion part (31) and is limited by the stop part (32).

4. The oil-gas separation labyrinth device according to claim 1, characterized in that: The height of the mounting post (23) is greater than the height of the lower oil ring (22).

5. The oil-gas separation labyrinth device according to claim 4, characterized in that: At least three support pillars (24) are provided at intervals on the top of the lower oil baffle ring (22).

6. The oil-gas separation labyrinth device according to claim 5, characterized in that: The support column (24) is located on top of the lower oil baffle ring (22) of the inner ring.

7. The oil-gas separation labyrinth device according to claim 1, characterized in that: Both the top cover (1) and the bottom cover (2) are made of grease-free plastic.

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