Oil-immersed motor cooling structure

Abstract

The invention discloses an oil-immersed motor cooling structure which is characterized in that an isolating ring cylinder is arranged between air gaps of a rotor core and a stator core, the outer side surface of the isolating ring cylinder is tightly attached to the inner circular surface of the stator core, and an air gap is reserved between the inner side surface of the isolating ring cylinder and the outer circular surface of the rotor core; one side of the isolating ring cylinder is in sealed connection with the non-transmission end cover, and the other side of the isolating ring cylinder is in sealed connection with the transmission end cover; the internal fluid space of the motor is divided into a stator area and a rotor area which are isolated from each other by the isolation ring cylinder. According to the hybrid cooling structure, the problems of high temperature rise due to large stator heating and low temperature rise due to small rotor heating are solved, and the balance of heating and cooling of the whole motor is ensured. On one hand, the heat dissipation capability of the motor can be enhanced, the temperature rise in the motor operation process is effectively reduced, the motor operation safety is improved, and the motor performance is improved; and on the other hand, the insulation effect of the mineral oil can effectively prevent aging of motor parts, and the service life of the motor is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of motor design, and relates to a motor cooling and heat dissipation structure, in particular to an oil-immersed motor cooling structure. Background Art

[0002] During the operation of the motor, various losses will cause the temperature of the motor components to rise rapidly. Excessive temperature will seriously affect the performance of the motor, age the insulation material, increase the risk of leakage, and even cause the motor to malfunction in severe cases. Traditional motor cooling structures usually use air cooling, including self-ventilation and forced ventilation. For some motors, self-ventilation and forced ventilation with low wind speed cannot meet the motor's heat dissipation requirements, and increased wind speed will cause the pressure at the motor inlet to rise, threatening the safety of the motor structure. Therefore, other cooling methods are needed to deal with this technical problem.

[0003] Compared with air, mineral oil has good thermal conductivity, which can improve the efficiency of heat exchange and quickly take away a lot of heat. Without affecting the normal operation of the motor, cooling and dissipating part of the motor structure by oil immersion can effectively reduce the temperature rise of the motor, improve safety, and increase the service life of the motor.

[0004] Normally, the stator core and windings have large heat losses and high temperature rise, while the rotor core has much lower losses and lower temperature rise than the stator. Based on the above problems, in order to solve the problem that the motor cannot work normally due to excessive temperature rise, from the perspective of improving the heat dissipation capacity of the motor, the present invention proposes a new oil-immersed motor cooling structure, which uses a partition to completely separate the motor into a stator area and a rotor area from the stator-rotor air gap, and adopts a mixed cooling method of stator oil immersion cooling and rotor air cooling, thereby ensuring the balance of the overall heat and cooling of the motor.

[0005] The prior art related to the present invention is as follows: Prior art 1: An oil-cooled motor adopts a closed cooling pipeline, the cooling pipeline includes a cooling pipe, the cooling pipe includes a plurality of straight pipe sections which are connected in sequence and arranged at intervals along the circumference of the stator, each straight pipe section is embedded in a corresponding cooling groove, and by embedding the straight pipe section in the cooling groove, when the cooling oil in the cooling pipe flows from the liquid inlet to the liquid outlet, the heat on the stator can be transferred to the winding through the inner wall surface of the cooling groove, and then transferred to the cooling pipe, and the cooling pipe transfers the heat to the cooling oil through its pipe wall to achieve the purpose of heat dissipation, so as to provide an oil-cooled motor with high overload capacity and significant cooling effect.

[0006] Prior art 2: A slot is provided on the stator core, and the slot is connected to the stator slot on the stator core; a winding is provided in the stator slot and is away from one end of the slot; a packaging device is provided to wrap the winding, and the packaging device is used to block the stator slot, and the inner surface of the packaging device and the slot and the stator slot together form a cooling channel; the return oil groove is connected to the cooling channel. The cooling structure of the oil-cooled motor forms a cooling channel through the inner surface of the packaging device and the slot and the stator slot together, and the cooling oil can fully, comprehensively and evenly flow through the winding and the end of the winding, and fully cool the winding and the end of the winding, thereby achieving heat dissipation uniformity and increasing the utilization rate of the cooling oil.

[0007] Prior art three: A motor shaft for an oil-cooled motor, comprising a shaft body, a cooling oil channel for cooling oil circulation formed in the shaft body, the cooling oil channel having an oil inlet port, the shaft body being provided with a first oil guide hole and a second oil guide hole along its own radial direction for connecting the cooling oil channel with the outside, the first oil guide hole and the second oil guide hole being distributed on the shaft body at intervals along the axial direction of the shaft body, and the first oil guide hole being located between the oil inlet port and the second oil guide hole; the cooling oil channel being provided with an oil blocking step between the first oil guide hole and the second oil guide hole, the oil blocking step being used to block the cooling oil flowing to the second oil guide hole from flowing back to the first oil guide hole, and a first set spacing being provided between the oil blocking step and the first oil guide hole. The application of the present invention can balance the amount of oil flowing into the first oil guide hole and the second oil guide hole, and improve the overall cooling effect of the oil-cooled motor.

[0008] Disadvantages of the prior art: the structure is relatively complex and requires cooling pipes or slots, which brings great difficulties to the production and manufacturing of the motor; at the same time, due to the limited internal space of the motor, the additional pipes and slots greatly increase the design and manufacturing costs. Summary of the invention

[0009] The purpose of the present invention is to provide a novel oil-immersed motor cooling structure, in which the stator part is cooled by oil immersion and the rotor is cooled by air.

[0010] The present invention is achieved by adopting the following technical solutions: An oil-immersed motor cooling structure includes a motor body, the motor body includes a base, a non-drive end cover and a drive end cover are mounted on both sides of the base, a rotating shaft is mounted between the non-drive end cover and the drive end cover, and a rotor core is mounted on the rotating shaft; a stator core is mounted in the base, and a stator winding is mounted in the stator core; an air inlet for cooling the inside of the rotor is provided on the non-drive end cover, and an air outlet for cooling the inside of the rotor is provided on the drive end cover. An isolating ring cylinder is provided between the air gaps of the rotor core and the stator core, the outer side surface of the isolating ring cylinder is tightly fitted with the inner circumference of the stator core, and an air gap is left between the inner side surface and the outer circumference of the rotor core; one side of the isolating ring cylinder is sealed to the non-drive end cover, and the other side is sealed to the drive end cover; the isolating ring cylinder divides the internal fluid space of the motor into a stator area and a rotor area that are isolated from each other.

[0011] Further preferably, a cooling oil inlet for cooling the inside of the stator is provided on one side of the base or the end cover at the non-transmission end, and a cooling oil outlet for cooling the inside of the stator is provided on the other side of the base or the end cover at the transmission end; after the cooling oil enters one side of the stator area from the cooling oil inlet, it first fills the fluid area on the inlet side, then flows along the oil holes inside the stator core, the gap between the stator core and the base, the isolation ring tube and the slot wedge top channel of the stator core to the other side of the stator area, and finally flows out along the cooling oil outlet. The stator core adopts a continuous integral core structure.

[0012] Further preferably, the cooling oil outlet is connected to the oil storage tank inlet through an oil pipeline, the cooling oil inlet is connected to the oil pump through the oil pipeline, and the oil pump is connected to the oil storage tank outlet through the oil pipeline.

[0013] Further preferably, cooling oil inlets for cooling the inside of the stator are provided on both sides of the base or on the non-drive end cover and the drive end cover, and a cooling oil outlet for cooling the inside of the stator is provided in the middle of the base; after the cooling oil enters both sides of the stator region from the cooling oil inlets, it flows into the inside of the stator core from the isolation ring tube and the slot wedge top channel of the stator core, then flows from multiple radial channels in the middle of the stator core to the gap between the stator core and the base, and finally flows out from the cooling oil outlet in the middle of the base. The stator core adopts a segmented core structure.

[0014] Further preferably, the cooling oil is mineral oil.

[0015] Further preferably, the thickness of the isolation ring tube is half of the air gap between the rotor core and the stator core.

[0016] Further preferably, the material of the isolation ring tube is consistent with the material of the non-transmission end cover and the transmission end cover.

[0017] Further preferably, the outer side surface of the isolation ring cylinder and the inner circular surface of the stator core are fixed by welding.

[0018] The hybrid cooling structure of the present invention solves the problem of high temperature rise of the stator and low temperature rise of the rotor, ensuring the balance of heating and cooling of the motor as a whole. On the one hand, it can enhance the heat dissipation capacity of the motor, effectively reduce the temperature rise during the operation of the motor, improve the safety of the motor operation, and improve the performance of the motor; on the other hand, the insulation effect of mineral oil can effectively prevent the aging of motor parts and increase the service life of the motor.

[0019] The invention has reasonable design and good practical application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 The schematic diagram of the overall structure of the present invention is shown.

[0023] Figure 2 A schematic diagram showing the internal ventilation air path of the motor rotor area in the present invention.

[0024] Figure 3 A schematic diagram of a cooling structure in which oil is inlet at one end and outlet at the other end of the stator region of a motor in the present invention is shown.

[0025] Figure 4 express Figure 3 Schematic diagram of the cross section of the cooling structure.

[0026] Figure 5 A schematic diagram of the oil cooling structure of the oil inlet and oil outlet in the middle radial channel of the stator area of ​​the motor of the present invention is shown.

[0027] Figure 6 express Figure 5 Schematic diagram of the cross section of the cooling structure.

[0028] In the figure: 1-base, 2-non-drive end cover, 3-drive end cover, 4-rotating shaft, 5-rotor core, 6-stator core, 7-stator winding, 8-oil storage tank, 9-oil pump, 10-oil pipeline, 11-isolating ring cylinder, 12-air inlet, 13-air outlet, 14-cooling oil inlet, 15-cooling oil outlet, 16-oil hole, 17-slot wedge top channel, 18-radial channel. DETAILED DESCRIPTION

[0029] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0030] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0032] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] An oil-immersed motor cooling structure, such as Figure 1 As shown, it includes a motor body, which includes a base 1. Non-drive end cover 2 and drive end cover 3 are installed on both sides of the base 1. A rotating shaft 4 is installed between the non-drive end cover 2 and the drive end cover 3. A rotor core 5 is installed on the rotating shaft 4. A stator core 6 is installed in the base 1, and a stator winding 7 is installed in the stator core 6.

[0034] The novel oil-immersed motor cooling structure proposed in the present invention adopts oil immersion for cooling the stator part and air cooling for cooling the rotor. This hybrid cooling structure solves the problem of large temperature rise of the stator and small temperature rise of the rotor, and ensures the balance of heating and cooling of the motor as a whole. On the one hand, it can enhance the heat dissipation capacity of the motor, effectively reduce the temperature rise during the operation of the motor, improve the safety of the motor operation, and improve the performance of the motor; on the other hand, the insulating effect of mineral oil can effectively prevent the aging of motor parts and increase the service life of the motor.

[0035] like Figure 1 As shown, the non-drive end cover 2 is provided with an air inlet 12 for cooling the inside of the rotor, and the drive end cover 3 is provided with an air outlet 13 for cooling the inside of the rotor.

[0036] The motor cooling system involved in the present invention mainly includes an external oil pump, an oil tank, an oil pipeline, a pressure gauge, a valve, an isolation ring tube, a transmission end cover, a non-transmission end cover and a machine base. The cooling oil is mineral oil. The mineral oil inlet and outlet on the motor are connected to the oil pipeline, and the oil pipeline is externally connected to the oil pump and the oil tank to form a closed passage. The pipeline is equipped with a pressure gauge and a valve. The pressure gauge is used to monitor the oil pressure to avoid excessive oil pressure, and the valve is used to adjust the flow and pressure of the oil. The internal fluid space of the motor is divided into two parts, the stator area and the rotor area, by an isolation ring tube inside the motor. The material of the isolation ring tube 11 is consistent with that of the non-transmission end cover 2 and the transmission end cover 3, and it is ensured that no gap is left during welding. At the same time, the material is not affected by the mineral oil and does not react chemically with it. The thickness of the isolation ring tube 11 is half of the air gap between the rotor core 5 and the stator core 6, and it fits tightly with the inner circular surface of the stator (for example, the outer side surface of the isolation ring tube 11 is fixed to the inner circular surface of the stator core 6 by welding). Firstly, it ensures that the stator and the isolation ring tube are well connected, and secondly, it ensures that the rotation of the rotor is not affected.

[0037] like Figure 1 As shown, an isolation ring cylinder 11 is provided between the air gaps of the rotor core 5 and the stator core 6, the outer side surface of the isolation ring cylinder 11 is tightly fitted with the inner circular surface of the stator core 6, and an air gap is left between the inner side surface and the outer circular surface of the rotor core 5; one side of the isolation ring cylinder 11 is sealedly connected to the non-transmission end cover 2, and the other side thereof is sealedly connected to the transmission end cover 3; the isolation ring cylinder 11 divides the internal fluid space of the motor into a stator area and a rotor area which are isolated from each other.

[0038] The rotor area wind path design is as follows Figure 2As shown, the fluid in the rotor area separated by the isolation ring tube 11 is air. During the operation of the motor, the cooling method of this area is air cooling. The air enters the motor through the air inlet 12 on the non-drive end of the motor, directly cools the rotor core, rotor bars, drive end and non-drive end bearings of the motor, and then flows through the air gap between the stator core and the rotor core and the rotor ventilation holes, and flows out from the air outlet 13 at the drive end.

[0039] The stator area oil circuit heat dissipation has the following two design structures.

[0040] The first type is a motor structure with oil inlet at one end and oil outlet at the other end. Figure 3 , 4 As shown, a cooling oil inlet 14 for cooling the inside of the stator is provided on one side of the base 1 or the non-drive end cover 2, and a cooling oil outlet 15 for cooling the inside of the stator is provided on the other side of the base 1 or the drive end cover 3; after the cooling oil enters one side of the stator area from the cooling oil inlet 14, it first fills the fluid area on the inlet side, and then flows along the oil through hole 16 (the original ventilation hole, used for cooling oil to pass in this scheme) inside the stator core 6, the gap between the stator core 6 and the base 1, and the slot wedge top channel 17 between the isolation ring tube 11 and the stator core 6 to the other side of the stator area, and finally flows out along the cooling oil outlet 15. The cooling oil outlet 15 is connected to the inlet of the oil storage tank 8 through the oil pipeline 10, the cooling oil inlet 14 is connected to the oil pump 9 through the oil pipeline 10, and the oil pump 9 is connected to the outlet of the oil storage tank 8 through the oil pipeline 10. The stator core 6 adopts a continuous integral core structure.

[0041] During operation, the inlet and outlet of the mineral oil can be set on the base or end cover, and the specific structure can be combined with the actual situation. After the oil enters the motor from the inlet, it first fills the fluid area on one side of the inlet, then flows to the other side along the oil holes inside the stator, the gap between the stator and the base, the channel between the isolation ring and the top of the stator core slot wedge, and finally flows out along the outlet and returns to the inside of the oil tank to complete the cycle.

[0042] The second type is a motor cooling structure with oil inlet on both sides and oil outlet in the middle. Figure 5 As shown, cooling oil inlets 14 for cooling the inside of the stator are provided on both sides of the base 1 or on the non-drive end cover 2 and the drive end cover 3, and a cooling oil outlet 15 for cooling the inside of the stator is provided in the middle of the base 1; after the cooling oil enters the two sides of the stator area from the cooling oil inlet 14, it flows into the inside of the stator core 6 from the isolation ring 11 and the slot wedge top channel 17 of the stator core 6, and then flows from the multiple radial channels 18 in the middle of the stator core 6 to the gap between the stator core 6 and the base 1, and finally flows out from the cooling oil outlet 15 in the middle of the base 1. The stator core 6 adopts a segmented core structure.

[0043] During operation, mineral oil enters the motor from the refueling holes on both sides of the motor, flows into the stator core from the air gap channel formed by the top of the winding slot wedge and the isolation ring tube, flows to the machine base from the multiple radial channels in the middle, and finally flows out from the oil outlet hole in the middle, ultimately achieving the purpose of cooling the core and winding and reducing the temperature rise of the motor.

[0044] The key technical points of the solution of the present invention are as follows: 1) The oil-immersed motor cooling structure described in the present invention adopts a mixed cooling structure of stator oil cooling and rotor air cooling, and uses an isolation ring cylinder to completely isolate the stator and rotor from the stator and rotor air gap into a stator area and a rotor area. The stator is cooled by oil immersion and the rotor is cooled by air.

[0045] 2) The motor stator core of the present invention adopts an oil-immersion cooling structure. Mineral oil enters the stator area from an inlet on one side of the motor, passes through the stator core oil hole, the gap between the stator and the base, and the channel between the isolation ring tube and the top of the stator core slot wedge, and flows out from the outlet on the other side to circulate and cool the stator.

[0046] 3) The stator core of the present invention adopts an oil-immersion cooling structure. Mineral oil enters the motor from the oil filling holes on both sides of the motor, flows into the stator core from the air gap channel formed by the top of the winding slot wedge and the isolation ring tube, flows to the machine base from multiple radial channels in the middle of the stator core, and finally flows out from the oil outlet hole in the middle to circulate and cool the stator.

[0047] 4) The rotor structure of the present invention adopts air cooling, and air flows from the inlet through the rotor core ventilation holes and the air gap channel between the rotor core and the isolation ring tube to cool the rotor, and then flows out from the outlet at the other end.

[0048] 5) The mineral oil of the present invention can flow through the slot wedge top channel between the isolating ring cylinder and the slot top to directly cool the stator winding and the core.

[0049] 6) The stator core of the present invention can adopt a continuous integral core structure or a segmented core structure.

[0050] 7) The isolation ring tube used in the present invention needs to be tightly welded to the end covers on both sides to ensure that the stator area and the rotor area are completely isolated and closed. The isolation ring tube and the end covers at both ends are fixed by welding to ensure that the isolation ring tube does not break during the operation of the motor.

[0051] 8) The stator cooling medium of the present invention adopts mineral oil with a larger heat transfer coefficient and thermal conductivity, which greatly reduces the temperature rise of the stator core and winding in contact with it, solves the problem that the stator core and winding have high heat and high temperature, while the rotor has low heat and low temperature, and ensures the balance of heating and cooling of the whole motor.

[0052] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. An oil-immersed motor cooling structure, comprising a motor body, the motor body comprising a base (1), a non-drive end cover (2) and a drive end cover (3) being mounted on both sides of the base (1), a rotating shaft (4) being mounted between the non-drive end cover (2) and the drive end cover (3), a rotor core (5) being mounted on the rotating shaft (4); a stator core (6) being mounted inside the base (1), and a stator winding (7) being mounted inside the stator core (6); The non-drive end cover (2) is provided with an air inlet (12) for cooling the interior of the rotor, and the drive end cover (3) is provided with an air outlet (13) for cooling the interior of the rotor; Features: An isolating ring cylinder (11) is provided between the air gaps of the rotor core (5) and the stator core (6); the outer side surface of the isolating ring cylinder (11) is tightly fitted with the inner circumferential surface of the stator core (6), and an air gap is left between the inner side surface and the outer circumferential surface of the rotor core (5); one side of the isolating ring cylinder (11) is sealedly connected to the non-transmission end cover (2), and the other side of the isolating ring cylinder (11) is sealedly connected to the transmission end cover (3); the isolating ring cylinder (11) divides the internal fluid space of the motor into a stator area and a rotor area that are isolated from each other.

2. The oil-immersed motor cooling structure according to claim 1, characterized in that: A cooling oil inlet (14) for cooling the inside of the stator is provided on one side of the base (1) or the non-drive end cover (2), and a cooling oil outlet (15) for cooling the inside of the stator is provided on the other side of the base (1) or the drive end cover (3); after the cooling oil enters one side of the stator region from the cooling oil inlet (14), it first fills the fluid region on the inlet side, then flows along the oil through hole (16) inside the stator core (6), the gap between the stator core (6) and the base (1), the isolation ring cylinder (11) and the slot wedge top channel (17) of the stator core (6) to the other side of the stator region, and finally flows out along the cooling oil outlet (15).

3. The oil-immersed motor cooling structure according to claim 2, characterized in that: The cooling oil outlet (15) is connected to the inlet of the oil storage tank (8) via an oil pipeline (10), the cooling oil inlet (14) is connected to the oil pump (9) via an oil pipeline (10), and the oil pump (9) is connected to the outlet of the oil storage tank (8) via an oil pipeline (10).

4. The oil-immersed motor cooling structure according to claim 3 is characterized in that: The stator core (6) adopts a continuous integral core structure.

5. The oil-immersed motor cooling structure according to claim 3, characterized in that: Cooling oil inlets (14) for cooling the inside of the stator are provided on both sides of the base (1) or on the non-drive end cover (2) and the drive end cover (3), and a cooling oil outlet (15) for cooling the inside of the stator is provided in the middle of the base (1); after the cooling oil enters the two sides of the stator region from the cooling oil inlets (14), it flows into the inside of the stator core (6) from the isolation ring cylinder (11) and the slot wedge top channel (17) of the stator core (6), then flows from a plurality of radial channels (18) in the middle of the stator core (6) to the gap between the stator core (6) and the base (1), and finally flows out from the cooling oil outlet (15) in the middle of the base (1).

6. The oil-immersed motor cooling structure according to claim 5, characterized in that: The stator core (6) adopts a segmented core structure.

7. An oil-immersed motor cooling structure according to claim 2 or 5, characterized in that: The cooling oil is mineral oil.

8. The oil-immersed motor cooling structure according to claim 1, characterized in that: The thickness of the isolation ring cylinder (11) is half of the air gap between the rotor core (5) and the stator core (6).

9. An oil-immersed motor cooling structure according to claim 1 or 8, characterized in that: The material of the isolation ring cylinder (11) is consistent with that of the non-transmission end cover (2) and the transmission end cover (3).

10. An oil-immersed motor cooling structure according to claim 1 or 8, characterized in that: The outer side surface of the isolation ring cylinder (11) and the inner circular surface of the stator core (6) are fixed by welding.

Images