CN113422472A

CN113422472A - Oil-cooled motor cooling system

Info

Publication number: CN113422472A
Application number: CN202110094746.3A
Authority: CN
Inventors: 魏颖颖; 于拓舟; 高一; 王金昊; 郭守仑; 赵慧超; 王宇; 孙明冲; 林展汐; 尹相睿
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2021-09-21
Also published as: WO2022156546A1

Abstract

The invention relates to an oil-cooled motor cooling system, which comprises a cooling pipe, a machine shell, a balance end plate, a bearing, an oil return groove, a rotor, a stator core and a shaft, wherein a tubular cavity is arranged in the machine shell, three groups of spray holes are formed in the cooling pipe, cooling oil is introduced into the cooling pipe from the tubular cavity, and part of the cooling oil is sprayed out from the three groups of spray holes of the cooling pipe in sequence to perform direct heat convection with the stator core and the end part of a coil; the remaining cooling oil flows out of the cooling tube outlet, along the tubular cavity to the bearings, and is sprayed onto the shaft, balance end plate and coil ends. The invention indirectly cools the iron core of the rotor, the heating elements such as the magnetic steel and the like in a way of cooling the shaft and balancing the end plate, and the cooling effect is better; the arrangement of the cooling pipes and the arrangement of the spray holes on the cooling pipes are optimized, so that cooling oil is sprayed to the end parts of the stator core and the coil more uniformly, and the cooling uniformity is improved; surface groove treatment is adopted on the outer side of the balance end plate, the splashing range of cooling oil is increased, the end part of the stator coil is cooled again, and the cooling efficiency is higher.

Description

Oil-cooled motor cooling system

Technical Field

The invention belongs to the technical field of motors, and particularly relates to an oil-cooled motor cooling system.

Background

In recent years, hybrid vehicles have been widely used, and the demand for driving motors in hybrid vehicles has been increasing. The demands for low cost, miniaturization and high power density of the motor have increased the heat dissipation requirements for the motor. The existing common water cooling and air cooling technology has low heat dissipation efficiency, large occupied space and difficult meeting the requirements. In order to overcome the problems, the motor can be radiated by adopting an oil cooling spraying radiating technology.

The motor generates a large amount of heat during operation, which needs to be dissipated through a motor cooling system. The motor cooling system has the main effects of preventing the motor from generating heat damage caused by heat accumulation, heat inertia and the like in the running process of the vehicle, ensuring the performance output and stable work of the motor and having longer service life. The stator core, the coil winding and the rotor are of a motor structure which is easy to generate local hot spots and high in temperature rise, and the requirement on heat dissipation is also strict. The existing oil cooling spraying design can not meet the heat dissipation requirements of a stator core, a coil winding and a rotor, and the heat uniformity is not high.

The prior art discloses an oil-cooled motor structure, main drive motor and motor cooling system, oil-cooled motor structure includes the casing, set up the stator in the casing inside, set up the rotor in the stator inside, the pivot of being connected with the rotor, set up the winding solenoid at the stator both ends, the oil duct ring subassembly of setting in the casing, the oil duct ring is connected in the inner wall of casing, the stator sets up inside the oil duct ring subassembly, oil duct ring subassembly and stator, the casing constitutes annular oil duct, the oil duct ring subassembly constitutes a plurality of axial oil ducts with the casing, and annular oil duct and axial oil duct intercommunication. The cooling oil in the technology can directly cool the heating parts such as the winding, the rotor, the bearing and the like of the motor, and the heat dissipation effect is obvious. However, the cooling system does not perform direct convection heat transfer of the sprayed cooling oil on the stator core, which easily causes local hot spots of the stator.

The prior art also discloses a motor/generator cooling system of a hybrid vehicle having first and second motor/generators arranged in an axial direction in a transmission, which may include: a cooling duct that may be arranged in the transmission in an axial direction along upper outer sides of the first and second motor/generators; a rear cover connectable to a downstream side of the cooling duct so that the cooling duct can be fixed thereto; an input support that may be connected to an upstream side of the cooling pipe, forms a cooling oil passage, and rotatably supports a rotor of the first motor/generator; and a case on which the rear cover and the input support may be mounted, in which an oil filter connected to a hydraulic pump may be mounted, and in which a through-hole may be formed, through which the cooling pipe penetrates to be fixed in the case. However, the cooling pipe fixed to the cooling system box cannot cool the bearing and the rotor, which easily causes the rotor to have an excessively high temperature and generate local hot spots.

The prior art also discloses a rotating electrical machine comprising a housing, a cover and a cooling pipe. The housing houses the rotor and the stator, and has an opening at one end thereof in the axial direction of the rotor. The cover is fixed to the periphery of the opening of the housing. The cover is configured to cover the opening. The cooling tube is disposed adjacent to the stator inside the housing. The cooling pipe extends in the axial direction. One end of the cooling pipe is configured to abut on the back face of the cover via an elastic member, and the other end of the cooling pipe is fastened and fixed to the housing. However, the cooling pipe only cools the stator portion, which easily causes a large temperature rise of the rotor and generates a local hot spot.

In conclusion, the conventional cooling oil path structure cannot cool the stator core, the coil end part, the bearing and the shaft at the same time, and is poor in cooling heat uniformity and easy to generate local hot spots.

Disclosure of Invention

The invention provides an oil-cooled motor cooling system, which aims to solve the problems that an existing cooling oil path structure cannot cool a stator core, a coil end part, a bearing and a shaft at the same time, and the cooling effect is poor.

The purpose of the invention is realized by the following technical scheme:

an oil-cooled motor cooling system comprises a cooling pipe 1, a machine shell 2, a balance end plate 7, a bearing 8, an oil return groove 9, a rotor 11, a stator core 12 and a shaft 13;

two sections of tubular cavities 4 for guiding the flow direction of cooling oil are arranged in the shell 2, the shell 2 supports and fixes two ends of the cooling pipe 1, two ends of the cooling pipe 1 are respectively communicated with the tubular cavities 4, and the cooling pipe 1 is provided with three groups of spray holes, namely a spray hole I3, a spray hole II 5 and a spray hole III 6;

the stator core 12 is arranged in the casing 2, the coil end parts 10 are arranged at two ends of the stator core 12, the rotor 11 connected with the shaft 13 is arranged in the stator core 12, and the balance end plates 7 used for keeping the dynamic balance of the rotor 11 are arranged at two sides of the rotor 11;

the oil return groove 9 is connected with an opening of the machine shell 2 at the bottom end of the motor;

cooling oil is introduced into an inlet of the cooling pipe 1 from the section of tubular cavity 4, part of the cooling oil is sprayed out from three groups of spray holes of the cooling pipe 1 in sequence, and direct convection heat exchange is carried out between the cooling oil and the stator iron core 12 and the coil end part 10 under the dual action of pressure and gravity; the remaining cooling oil flows out from the outlet of the cooling pipe 1, flows to the bearing 8 along the other section of the tubular cavity 4, and is sprayed to the shaft 13, the balance end plate 7 and the coil end 10 from the axial oil passage formed by the casing 2 and the bearing 8.

Further, the balance end plate 7 is columnar, and the grooves 14 in the circular array are arranged along the outer side of the axial direction of the balance end plate 7, so that the cooling oil falling to the balance end plate 7 is stored in the grooves 14, and the stored cooling oil is thrown away by the centrifugal force generated by rotation to cool the end part 10 of the stator coil again.

Furthermore, the cooling pipes 1 are two cooling pipes 1, the two cooling pipes 1 are symmetrically distributed by taking the shaft 13 as a symmetry axis and are distributed on the oblique side of the top of the motor, and the normal direction of the cooling pipes 1 and the shaft 13 and the gravity direction of the cooling pipes 1 form a certain angle theta.

Still further, the optimal angle θ ranges from 30 to 50 °.

Further, the ratio of the distance from the outer diameter of the cooling pipe 1 to the outer diameter of the stator is 1:12, and the distribution center of each group of spray holes is in the normal direction of the surface of the stator.

Furthermore, the group of spray holes, the spray hole I3, is located at the L/2 position of the stator core 12, and the other two groups of spray holes, the spray hole II 5 and the spray hole III 6, are respectively located at the L/2 position of the coil end 10, so as to respectively cool the stator core 12 and the coil winding 10.

Furthermore, two groups of

spray holes

5 and 6 of the cooling coil end part 10 on the cooling pipe 1 respectively comprise four spray holes which are distributed in a non-collinear way, and two groups of spray holes I3 of the cooling stator core 12 form a certain included angle alpha with the axis in the circumferential direction.

Furthermore, α is 90 ° and is symmetrically distributed with the axis 13 as a symmetry axis.

Further, after cooling the coil end 10, a part of the cooling oil sprayed from the spray holes of the cooling pipe 1 flows onto the balance end plate 7, and the part of the cooling oil is thrown away by the centrifugal force generated by the rotating balance end plate 7 and exchanges heat with the end of the stator coil again for cooling; the cooling oil after heat exchange falls back to the oil return tank 9 under the action of gravity.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention relates to an oil-cooled motor cooling system, which is designed for cooling a stator core, a coil winding, a bearing and a shaft. The cooling design includes: cooling pipes of the stator core and the coil winding are cooled, and spray holes in the cooling pipes are reasonably arranged, so that the spraying cooling uniformity is improved; still include and carry out structure processing at the balanced end plate surface of fixed rotor, can with the cooling oil storage that drops on balanced end plate and get rid of the coil tip again, increased the scope that splashes of cooling oil, make the cooling oil cool off stator coil tip once more, improved cooling efficiency.

2. The cooling design enables the cooling oil to directly cool heating parts such as a stator core, a coil end part, a bearing, a shaft and a balance end plate of the motor, the shaft has an indirect cooling effect on the rotor, the heat dissipation effect is obvious, the peak output power duration of the motor is prolonged, the weakening of the magnetic performance of a permanent magnet of the rotor is inhibited, and the output performance of the motor is ensured.

3. The invention also realizes forced oil lubrication by guiding the cooling oil to the bearing, thereby eliminating the risk of carbonization after long-term operation of bearing grease and oil seal.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic structural diagram of an oil-cooled motor cooling system according to the present invention;

FIG. 2 is a schematic structural view of a rotor balancing end plate;

FIG. 3 is a schematic view of a cooling tube arrangement;

fig. 4 is a schematic structural view of a cooling pipe portion.

In the figure, 1, a cooling pipe 2, a machine shell 3, a spray hole I4, a tubular cavity 5, a spray hole II 6, a spray hole III 7, a balance end plate 8, a bearing 9, an oil return groove 10, a coil end 11, a rotor 12, a stator iron core 13, a shaft 14 and a groove.

Detailed Description

The invention is further illustrated by the following examples:

the present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.

As shown in fig. 1, the oil-cooled motor cooling system of the present invention is mainly composed of a cooling pipe 1, a casing 2, a tubular cavity 4, a balance end plate 7, a bearing 8, an oil return groove 9, a rotor 11, a stator core 12, and a shaft 13.

The inside of the machine shell 2 is provided with a tubular cavity 4 for guiding the flowing direction of cooling oil, guiding the cooling oil to the ends of the cooling pipe 1 and the bearing 8 and spraying the cooling oil to the stator core 12, the coil end part 10, the shaft 13 and the balance end plate 7. The machine shell 2 supports and fixes two ends of the cooling pipe 1.

And two ends of the cooling pipe 1 are respectively communicated with the tubular cavity 4. The cooling oil is introduced into the cooling pipe 1 from the tubular cavity 4, the cooling oil flowing out from the outlet of the cooling pipe 1 is guided to the bearing 8 again through the tubular cavity 4, and then is sprayed to the shaft 13, the balance end plate 7 and the coil end part 10 from the axial oil passage formed by the casing 2 and the bearing 8. The cooling oil guide bearing plays a role in lubricating the bearing while radiating heat for the bearing.

Stator core 12 is installed in casing 2, and its both ends are equipped with coil end portion 10, and stator core 12 is inside to be equipped with rotor 11, and rotor 11 links to each other with axle 13, and rotor 11 both sides are equipped with balanced end plate 7.

The oil return groove 9 is connected with the hole of the motor bottom end casing 2.

As shown in fig. 2, the balance end plate 7 is in a cylindrical shape and located on both sides of the rotor 11 for keeping the rotor 11 dynamically balanced. The concave surfaces such as the grooves 14 or the pits are arranged in a circular array along the axial outer side of the balance end plate 7, so that the cooling oil falling to the balance end plate 7 is stored in the grooves 14 or the pits, and the stored cooling oil is thrown away by the centrifugal force generated by rotation to cool the end part 10 of the stator coil again. The arrangement of the concave surfaces such as the groove 14 or the pit also increases the splashing angle and the splashing range of the cooling oil, the cooling oil is repeatedly utilized for multiple times, and the cooling efficiency is improved.

As shown in figure 3, the invention is provided with two cooling pipes 1, the two cooling pipes 1 are symmetrically distributed by taking a shaft 13 as a symmetry axis and are distributed on the oblique side of the top of the motor, the normal direction of the cooling pipes 1 and the shaft 13 and the gravity direction of the cooling pipes 1 form a certain angle theta, and the optimal angle range of the theta is 30-50 degrees. The ratio of the distance from the outer diameter of the cooling pipe 1 to the outer diameter of the stator is 1:12, the distribution center of each group of spray holes is in the normal direction of the surface of the stator, the arrangement mode enables the surfaces on the two sides of the stator to be in more uniform contact with cooling oil, the spray range of the spray holes is fully utilized to dissipate heat at the top of the stator, and the thermal uniformity and the heat dissipation efficiency of the stator are improved.

The cooling pipe 1 is provided with three groups of spray holes, one group of spray holes, the spray hole I3 is positioned at the L/2 position of the stator iron core 12, the other two groups of spray holes, the spray hole II 5 and the spray hole III 6 are respectively positioned at the L/2 position of the coil end part 10, the stator iron core 12 and the coil winding 10 are respectively cooled, and the generation probability of stator local hot spots is reduced. The reason why the three parts of the stator are respectively provided with one group of spray holes is that under the condition that the total flow is the same, the unit flow of one group of spray holes is larger than that of a plurality of groups of spray holes, so that the spraying range of the stator in the circumferential direction is wider, and the stator is cooled more uniformly.

The spray holes II 5 and III 6 at the end part of the cooling coil on the cooling pipe 1 respectively comprise four spray holes which are distributed in a non-collinear way, the number of the spray holes I3 of the cooling stator core 12 is two, and the two spray holes form a certain included angle alpha with the axis in the circumferential direction, wherein the alpha is 90 degrees in the embodiment of the invention and is symmetrically distributed by taking the axis 13 as a symmetric axis. The arrangement mode enables the spraying range to be larger, the distribution of the cooling oil on the stator to be relatively more uniform, and the thermal uniformity is improved.

When the cooling device works, under the driving of the power device, cooling oil firstly enters from an oil inlet of the tubular cavity 4 in the shell 2, flows to an inlet of the cooling pipe 1 and enters the cooling pipe 1, part of the cooling oil is sprayed out from three groups of spray holes of the cooling pipe 1 in sequence, and direct convection heat exchange is carried out between the cooling oil and the stator core 12 and the coil end part 10 under the dual effects of pressure and gravity. A part of the cooling oil is left to flow out of the cooling pipe 1, enter the tubular cavity 4 inside the casing 2, flow along the tubular cavity 4 to the bearings, and spray from the tubular cavity 4 to the shaft 13, the rotor balance end plate 7 and the coil end plate 10, and the part of the oil directly cools the casing 2, the bearings 8, the shaft 13, the coil end plate 10 and the balance end plate 7 by convective heat exchange at the same time. After cooling the coil end 10, the cooling oil sprayed through the spray holes of the cooling pipe 1 flows onto the balance end plate 7 from a part, and the part of the cooling oil is thrown away by the centrifugal force generated by the rotating balance end plate 7 and exchanges heat with the stator coil end 10 again for cooling. The cooling oil after heat exchange falls back to the oil return tank 9 under the action of gravity, so that the next cooling circulation is performed.

The invention carries out direct cooling treatment on the stator iron core 12, the coil end part 10, the bearing 8 and the shaft 13, and indirectly cools the iron core of the rotor 11, the heating bodies such as magnetic steel and the like in a mode of cooling the shaft 13 and the balance end plate 7, thereby having better cooling effect. The arrangement of the cooling pipes and the arrangement of the spray holes on the cooling pipes are optimized, so that cooling oil is sprayed to the stator core 12 and the coil end 10 more uniformly, the cooling uniformity is improved, and local high temperature is avoided. Meanwhile, the outer side of the balance end plate 7 is subjected to concave treatment of a surface groove or a round pit, the splashing range of cooling oil is increased, the end part of the stator coil is cooled again, and the cooling efficiency is higher. In this embodiment, the cooling oil can also lubricate the internal components.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. The utility model provides an oil-cooled motor cooling system which characterized in that: the device comprises a cooling pipe (1), a machine shell (2), a balance end plate (7), a bearing (8), an oil return groove (9), a rotor (11), a stator core (12) and a shaft (13);

two sections of tubular cavities (4) for guiding the flow direction of cooling oil are arranged in the shell (2), the shell (2) supports and fixes two ends of the cooling pipe (1), two ends of the cooling pipe (1) are respectively communicated with one section of tubular cavities (4), and three groups of spray holes, namely a spray hole I (3), a spray hole II (5) and a spray hole III (6), are formed in the cooling pipe (1);

the stator iron core (12) is arranged in the shell (2), coil end parts (10) are arranged at two ends of the stator iron core, a rotor (11) connected with a shaft (13) is arranged in the stator iron core (12), and balance end plates (7) used for keeping the rotor (11) in dynamic balance are arranged at two sides of the rotor (11);

the oil return groove (9) is connected with an opening of the machine shell (2) at the bottom end of the motor;

cooling oil is introduced into an inlet of the cooling pipe (1) from the section of tubular cavity (4), part of the cooling oil is sprayed out from three groups of spray holes of the cooling pipe (1) in sequence, and direct convection heat exchange is carried out on the cooling oil, the stator iron core (12) and the coil end (10) under the dual action of pressure and gravity; the rest cooling oil flows out from the outlet of the cooling pipe (1), flows to the bearing (8) along the other section of the tubular cavity (4), and is sprayed to the shaft (13), the balance end plate (7) and the coil end part (10) from an axial oil passage formed by the casing (2) and the bearing (8).

2. The oil-cooled motor cooling system of claim 1, wherein: the balance end plate (7) is columnar, the grooves (14) in a circular array are arranged along the outer side of the axial direction of the balance end plate (7), cooling oil falling to the balance end plate (7) is stored in the grooves (14), the stored cooling oil is thrown away through centrifugal force generated by rotation, and the end part (10) of the stator coil is cooled again.

3. The oil-cooled motor cooling system of claim 1, wherein: the two cooling pipes (1) are symmetrically distributed by taking the shaft (13) as a symmetry axis and distributed on the inclined side of the top of the motor, and the normal direction of the cooling pipes (1) and the shaft (13) and the gravity direction of the cooling pipes (1) form a certain angle theta.

4. The oil-cooled motor cooling system of claim 3, wherein: the theta angle ranges from 30 to 50 deg..

5. The oil-cooled motor cooling system of claim 1, wherein: the ratio of the distance from the outer diameter of the cooling pipe (1) to the outer diameter of the stator is 1:12, and the distribution center of each group of spray holes is in the normal direction of the surface of the stator.

6. The oil-cooled motor cooling system of claim 1, wherein: one group of spray holes, namely the spray hole I (3), are positioned at the L/2 position of the stator core (12), and the other two groups of spray holes, namely the spray hole II (5) and the spray hole III (6), are respectively positioned at the L/2 position of the coil end part (10) to respectively cool the stator core (12) and the coil winding (10).

7. The oil-cooled motor cooling system of claim 1, wherein: the cooling structure is characterized in that the spray holes II (5) and the spray holes III (6) of the cooling coil end part (10) on the cooling pipe (1) respectively comprise four spray holes which are distributed in a non-collinear manner, the spray holes I (3) of the cooling stator core (12) are two, and the two spray holes form a certain included angle alpha with an axis in the circumferential direction.

8. The oil-cooled machine cooling system of claim 7, wherein: the alpha is 90 degrees and is symmetrically distributed by taking the shaft (13) as a symmetry axis.

9. The oil-cooled motor cooling system of claim 1, wherein: cooling oil sprayed out through the spray holes of the cooling pipe (1) flows onto the balance end plate (7) from one part after cooling the end part (10) of the coil, and the part of the cooling oil is thrown away by the centrifugal force generated by the rotating balance end plate (7) and exchanges heat with the end part of the stator coil for cooling again; the cooling oil after heat exchange falls back to the oil return tank (9) under the action of gravity.