Electric machine assembly having internal lubricating oil
By designing internal lubricating oil channels in the motor, using the gearbox oil agitation mechanism to bring the lubricating oil out and transport it to the motor assembly, the problem of insufficient lubrication of motor bearings in low temperature environments is solved, and the motor efficiency is improved and potential risks are reduced.
Patent Information
- Application Number
- CN202311799103.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-25
- Publication Date
- 2025-06-27
AI Technical Summary
Under low temperature environments, the bearings in the motor cavity cannot be lubricated, resulting in an increased risk of bearing failure.
Lubrication of the motor bearings is achieved by designing an internal lubricating oil passage in the motor, and the lubricating oil is carried out using the gearbox oil agitation mechanism and transported to the motor assembly.
In the low temperature state, the risk of failure caused by insufficient bearing lubrication is avoided, the motor efficiency is improved, and the oil pump pressure and the risk of leakage on the sealing surface are reduced.
Smart Images
Figure CN120212223A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of motors, and particularly to a motor assembly having an internal lubricating oil passage and a motor including the motor assembly. Background Art
[0002] In a bridge system, a motor assembly and a reduction gearbox assembly are included. The motor stator and rotor are cooled by active oil, and the motor bearings are lubricated by the active oil in the motor cavity. Generally, the flow of the active oil starts from the bottom oil sump, is sucked in by an oil pump, then enters a heat exchanger, and finally enters the motor cavity for oil cooling of the stator / rotor and oil lubrication of the bearings. The end windings of the motor stator are sprayed with cooling oil, and the sprayed cooling oil drips onto the motor bearings by gravity for bearing lubrication. In addition, the rotor is cooled by oil throwing, so a small amount of oil is also thrown onto the bearings for bearing lubrication. The reduction gearbox is passively lubricated by gear oil agitation, and thus the gear shaft system and the reduction gearbox bearings in the reduction gearbox cavity are simultaneously lubricated by the passive oil.
[0003] In a low-temperature environment, both the motor stator and rotor are at a low temperature, so additional oil cooling is not required, and in this case, the oil pump is selected to be turned off to improve the system efficiency. On the other hand, in a low-temperature environment, the viscosity of the oil is high, and the oil pump requires a greater pressure to push the oil, and the sealing surface also needs to withstand a greater pressure. Therefore, based on the pressure selection of the oil pump and the leakage problem of the sealing surface, it is also considered to turn off the oil pump in the low-temperature state. However, when the oil pump is turned off, the flow of the active oil in the motor cavity will pause, which will cause the bearings in the motor cavity to not be lubricated. Summary of the Invention
[0004] In order to overcome the above defects and deficiencies, the present disclosure provides a motor bearing lubrication mechanism realized by using the oil agitation of the reduction gearbox.
[0005] According to one aspect of the present disclosure, there is provided a motor assembly having an internal lubricating oil passage, the motor assembly including:
[0006] Bearing cover plate and motor end cover. Among them, in the direction of lubricating oil transmission, the bearing cover plate is axially installed downstream of the gearbox, and the motor end cover is axially installed downstream of the bearing cover plate. The bearing cover plate is provided with an oil collecting groove, which extends circumferentially along the bearing cover plate and has an opening pointing radially outward. The opening is used to receive the lubricating oil brought out by the gear oil stirring operation from the gearbox. The oil collecting groove has at least one oil outlet on the groove wall adjacent to the motor end cover axially. The oil outlet is used to lead out the collected lubricating oil from the oil collecting groove. The motor end cover is provided with at least one through oil guiding channel, which is arranged corresponding to the oil outlet and is used to transport a part of the lubricating oil led out from the oil outlet to the balance plate arranged at the axial end of the rotor, and the other part to the drive end bearing.
[0007] With the above structure, when the gears stir the oil, the lubricating oil is brought out (or thrown out) from the gearbox and thrown into the downstream oil collecting groove. The lubricating oil in the oil collecting groove then enters the oil guiding channel along the oil outlet under the action of gravity. A part of the lubricating oil is transported to the drive end bearing, and the other part of the lubricating oil enters the rotor through the balance plate. This part of the lubricating oil entering the rotor is further transported to the non-drive end of the motor by the centrifugal force generated by the rotation of the rotor, thus realizing the lubrication of the non-drive end bearing.
[0008] According to an embodiment of the present disclosure, each of the at least one oil guiding channel has a first end opening and a second end opening opposite to the first end opening. The first end opening is docked with the oil outlet, and the second end opening points to the balance plate of the rotor of the motor and is used to transport a part of the lubricating oil led out from the oil outlet to the balance plate of the rotor.
[0009] According to an embodiment of the present disclosure, the oil guiding channel further includes a bearing hole arranged below the second end opening and extending radially to the drive end bearing. The bearing hole is used to transport the other part of the led-out lubricating oil to the drive end bearing.
[0010] According to an embodiment of the present disclosure, the oil collecting groove has one oil outlet on the groove wall adjacent to the motor end cover axially, and the one oil outlet is arranged at the lowest point close to the bottom of the oil collecting groove.
[0011] According to an embodiment of the present disclosure, the oil collecting groove has two oil outlets on the groove wall adjacent to the motor end cover axially, and the two oil outlets are symmetrically arranged at the two lowest points close to the bottom of the oil collecting groove.
[0012] According to an embodiment of the present disclosure, the bearing cover plate is provided with a plurality of oil collecting grooves, and the circumferential positions of the plurality of oil collecting grooves are determined based on the oil amounts of the lubricating oil brought out by the oil stirring operation at different positions.
[0013] According to an embodiment of the present disclosure, the oil collecting groove is configured to have a fan-shaped cross-sectional shape that tapers inwards radially.
[0014] According to an embodiment of the present disclosure, the included angle of the fan-shaped cross-sectional shape is 10-15 degrees.
[0015] According to an embodiment of the present disclosure, the position where the first end opening of the oil guiding channel is located is higher than the position where the second end opening is located.
[0016] According to an embodiment of the present disclosure, the bearing cover plate is made of metal, and the oil collecting groove and the oil outlet are made by die-casting process; and / or the motor end cover is made of metal, and the oil guiding channel is made by die-casting process and drilling process.
[0017] According to another aspect of the present disclosure, a motor is provided, and the motor includes the above-mentioned motor assembly.
[0018] Compared with the prior art, by using the above-mentioned motor assembly with an internal lubricating oil channel in the motor, the following beneficial technical effects can be achieved:
[0019] First, the motor efficiency is improved. This is because in the low-temperature state, the oil pump is closed, and the supply of active oil in the motor cavity is suspended, thereby improving the motor efficiency.
[0020] Second, because the pressure of the oil pump is reduced, an oil pump with a smaller pressure can be selected, thereby reducing the cost of the oil pump.
[0021] Third, the leakage risk of the sealing surface is reduced, thereby reducing the design difficulty of the sealing surface.
[0022] Fourth, the lubrication of the motor bearing is achieved under the condition that the supply of active oil in the motor cavity is suspended, avoiding the risk of bearing failure caused by insufficient bearing lubrication.
[0023] According to the embodiments described below, these and other aspects of the present disclosure will be clear and will be elucidated with reference to the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In the following description of exemplary embodiments with reference to the accompanying drawings, more details, features and advantages of the present disclosure are disclosed. In the drawings:
[0025] Figure 1 is a side cross-sectional view of a motor equipped with a motor assembly having an internal lubricating oil channel according to an embodiment of the present disclosure;
[0026] Figure 2 is a perspective view showing a bearing cover plate according to an embodiment of the present disclosure;
[0027] Figure 3 is another perspective view showing the bearing cover plate according to an embodiment of the present disclosure;
[0028] Figure 4 FIG. 2 shows a perspective view of a motor end cover according to an embodiment of the present disclosure;
[0029] Figure 5 FIG. 3 shows another perspective view of a motor end cover according to an embodiment of the present disclosure;
[0030] Figure 6 FIG. 4 shows a side cross-sectional view of a motor end cover according to an embodiment of the present disclosure;
[0031] Figure 7 FIG. 5 shows a schematic view of a bearing cover plate having an oil outlet according to an embodiment of the present disclosure;
[0032] Figure 8 FIG. 6 shows a schematic view of a bearing cover plate having an oil outlet according to another embodiment of the present disclosure. DETAILED DESCRIPTION
[0033] Exemplary embodiments of the present disclosure will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art. Like reference numerals in the figures denote the same or similar elements, components, or portions, and thus their repeated description will be omitted.
[0034] It should be understood that the directional terms referred to in the present invention, such as "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "diagonally up", "diagonally down", etc., are only used to illustrate and understand the present invention, and are not used to limit the present invention. In addition, the embodiments described in the specific embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. On the premise of conforming to the technical concept of the embodiments of the present disclosure, the features, structures, characteristics, or other details described in a specific embodiment may be combined in a suitable manner in one or more other embodiments.
[0035] Figure 1 FIG. 7 shows a side view of a motor 100 equipped with a motor assembly having an internal lubricating oil passage according to an embodiment of the present disclosure.
[0036] As Figure 1 shown, the motor 100 generally includes a rotor 1, a stator 6, a drive end bearing 2, a non-drive end bearing 7, and a gearbox 5. In addition, the motor 100 further includes a motor assembly that defines an internal lubricating oil passage, and the motor assembly includes a bearing cover plate 3 and a motor end cover 4.
[0037] When the gears in the gearbox 5 stir the lubricating oil, the motor assembly can transfer a part of the lubricating oil carried out (or thrown out) from the gearbox 5 to the balance plate of the rotor 1 at the downstream through the internal lubricating oil channel defined by it, and transfer another part to the drive end bearing 2. Among them, the balance plate is arranged at the axial end of the rotor 1, and the lubricating oil transferred to the balance plate of the rotor 1 enters the inside of the rotor 1 through the balance plate, and then is further conveyed to the non-drive end of the motor 100 by the centrifugal force generated by the rotation of the rotor 1, so as to realize the lubrication of the non-drive end bearing 7.
[0038] The above internal lubrication channel is generally composed of an oil collecting groove 31 and an oil guiding channel 41 which are butted with each other. The oil collecting groove 31 and the oil guiding channel 41 are respectively arranged on the bearing cover plate 3 and the motor end cover 4. According to Figure 1 the indicated lubricating oil transfer / flow direction (indicated by the dotted arrow F), the bearing cover plate 3 is axially installed downstream of the gearbox 5 along the axial direction Y, and the motor end cover 4 is axially installed downstream of the bearing cover plate 3 along the axial direction Y. The oil collecting groove 31 is used to receive the lubricating oil carried out (or thrown out) by the gear stirring operation from the upstream gearbox 5. The oil guiding channel 41 is used to further guide the lubricating oil collected in the oil collecting groove 31 to the rotor 1 and the non-drive end bearing 2 at the downstream.
[0039] The specific structures of the internal lubrication channel and its components will be further described below.
[0040] Figure 2 and Figure 3 show the perspective views of the bearing cover plate 3 observed from two different front and rear angles. As shown in the figure, the oil collecting groove 31 is arranged on the bearing cover plate 3. The oil collecting groove 31 extends along the circumferential direction C of the bearing cover plate 3 and has an opening 33 pointing radially R outwards. The opening 33 is used to receive the lubricating oil carried out (or thrown out) by the gear stirring operation from the gearbox 5. The oil collecting groove 31 has at least one oil outlet 32 on the groove wall 34 on the side adjacent to the motor end cover 4 in the axial direction Y. The oil outlet 32 is used to lead out the collected lubricating oil from the oil collecting groove 31.
[0041] Figure 4 and Figure 5 show the perspective views of the motor end cover 4 observed from two different front and rear angles. As shown in the figure, at least one oil guiding channel 41 penetrates through the motor end cover 4 and is used to further convey the lubricating oil led out from the oil outlet 32 to the rotor 1 and the drive end bearing 2. Combining Figure 2 and Figure 3 , the oil guiding channel 41 and the oil outlet 32 of the oil collecting groove 31 are arranged corresponding to each other in terms of position and quantity. For example, in the Figure 4 and Figure 5 shown example, two oil guiding channels 41 are provided on the motor end cover 4. Correspondingly, as Figure 2 andFigure 3 As shown, two oil outlets 32 need to be provided on the oil sump 31.
[0042] According to some embodiments of the present disclosure, with reference to Figure 2 and Figure 3 , the oil sump 31 has two oil outlets 32, which are provided on the tank wall 34 adjacent to the motor end cover 4 side in the axial direction Y. The two oil outlets are symmetrically arranged at the two lowest points on the left and right sides near the bottom 35 of the oil sump 31.
[0043] As shown in Figure 2 , the oil sump 31 is arranged directly above the bearing cover plate 3, and the contour of the bottom 35 follows the arc shape of the bearing cover plate 3. At this time, the two oil outlets are respectively arranged at the two lowest points near the bottom 35, that is, the positions of the two lowest points on the left and right sides are the same in height. In this way, the lubricating oil collected in the oil sump 31 can slide along the arc-shaped bottom contour by gravity to the two oil outlets 32, and then be discharged from the oil sump 31 through the oil outlets 32 without other additional power sources.
[0044] According to some embodiments of the present disclosure, only one oil outlet 32 can also be provided on the oil sump 31, and one oil outlet 32 is provided at the lowest point near the bottom 35 of the oil sump 31.
[0045] It should be noted that when there is only one oil outlet 32, the bottom 35 of the oil sump 31 must be designed in an "asymmetric" form in height, so as to realize guiding all the collected lubricating oil to the oil outlet 32 at the lowest point only by gravity.
[0046] For example, with reference to Figure 7 , the oil sump 31 can be constructed obliquely above at a certain angle from directly above. At this time, the bottom 35 of the oil sump 31 can still follow the arc-shaped contour, but it is necessary to ensure that the end with the oil outlet 32 is the lowest point of the entire bottom 35 (i.e., the "global lowest point"), and the other end of the bottom 35 opposite thereto is the highest point of the entire bottom (i.e., the "global highest point"), and the bottom contour between the two points is smoothly transitioned. In other words, in the case of an "asymmetric" bottom 35, there cannot be other local lowest points except the global lowest point, otherwise, it will not be possible to ensure that all the collected lubricating oil is discharged by gravity.
[0047] Also, for example, with reference to Figure 8 , the oil sump 31 can still be constructed directly above the bearing cover plate 3, but at this time, the bottom 35 also needs to be constructed with a certain slope so that the lubricating oil can flow freely to the oil outlet 32 by gravity.
[0048] In some embodiments, a plurality of oil collecting grooves may be provided on the bearing cover plate 3 along the circumferential direction C. The number of the oil collecting grooves 31 and their setting positions may be determined as follows: the specific positions of the plurality of oil collecting grooves in the circumferential direction C may be determined at least in part based on the amount of lubricating oil (brought out by the oil stirring operation) at different circumferential positions C. The amount of oil at different positions may be determined based on the measurement data obtained from the experiment and / or based on the results of computer simulation. For example, according to the different amounts of oil at different positions, a plurality of oil collecting grooves may be provided at several positions with larger amounts of oil. In this way, the thrown-out lubricating oil may be more specifically and fully received, thereby improving the lubrication effect.
[0049] Return to reference Figure 2 and Figure 3 According to some embodiments of the present disclosure, the oil collecting groove 31 may be configured to have a fan-shaped cross-sectional shape (or a ring-shaped segment shape) that tapers inwardly along the radial direction R. In some examples, the included angle of the fan-shaped cross-sectional shape is 5-90 degrees, preferably 10-45 degrees, and further preferably 10-15 degrees.
[0050] Return to reference Figure 4 and Figure 5 According to some embodiments of the present disclosure, each of the at least one oil guide channel 41 has a first end opening 411 and a second end opening 412 opposite to the first end opening. The first end opening 411 is connected to the oil outlet 32, and the second end opening 412 points to the balance plate 8 of the rotor 1, so as to transport a part of the lubricating oil guided from the oil outlet 32 to the balance plate 8 of the rotor 1.
[0051] Return to reference Figure 1 In some embodiments, the direction of the second end opening 412 can be designed to be obliquely downward toward the balance plate 8 of the rotor at a certain incident angle, and the lower surface of the opening 81 on the balance plate 8 is used for reflection to reflect the lubricating oil into the rotor 1. In this way, the oil guide channel 41 can be relatively simple in design structure.
[0052] In some other embodiments, the direction of the second end opening 412 may be substantially consistent with the direction of the opening 81 on the balancing plate 8. In this way, the lubricating oil can be directly introduced into the interior of the rotor 1. In this way, more lubricating oil can be introduced into the rotor with less loss, thereby improving the lubrication efficiency.
[0053] Continue to refer Figure 4, according to some embodiments of the present disclosure, the oil guiding channel 41 further includes a bearing hole 42 disposed below the second end opening 142 and extending radially R to the drive end bearing 2. The bearing hole 42 is used to convey another part of the derived lubricating oil to the drive end bearing 2. The bearing hole 42 is in fluid communication with the second end opening 412. The bearing hole 42 provides additional directional guidance for another part of the lubricating oil, thereby ensuring that this another part of the lubricating oil can accurately reach the drive end bearing 2.
[0054] Figure 6 Fig. shows a side cross-sectional view of the motor end cover 4 according to an embodiment of the present disclosure. As Figure 6 shown, the position of the first end opening 411 of the oil guiding channel 41 is higher than the position of the second end opening 412. Designing a certain height difference between the first end opening 411 and the second end opening 412 is also to achieve the transfer of the collected lubricating oil to the rotor balance plate 8 and the drive end bearing 2 only by gravity. At the same time, it should be understood that the greater the height difference between the first end opening 411 and the second end opening 412, the higher the ejection speed of the lubricating oil from the second end opening 412, so that the amount of lubricating oil that can be introduced into the rotor and then transferred to the non-drive end bearing is greater.
[0055] According to some embodiments of the present disclosure, the bearing cover plate 3 is made of metal, and the oil collecting groove 31 and the oil outlet 32 can be realized by die-casting process. Therefore, the structure and manufacturing process are simple.
[0056] According to some embodiments of the present disclosure, the motor end cover 4 is made of metal, and the oil guiding channel 41 can be realized by pre-die-casting process and drilling process. Therefore, the structure and manufacturing process are simple.
[0057] In summary, compared with the prior art, by using the above-mentioned motor assembly with an internal lubricating oil channel in the motor 100, the following beneficial technical effects can be achieved:
[0058] First, the motor efficiency is improved. This is because at low temperatures, the oil pump is turned off, and the active oil supply in the motor cavity is suspended, thereby improving the motor efficiency.
[0059] Second, because the pressure of the oil pump is reduced, an oil pump with a smaller pressure can be selected, thereby reducing the cost of the oil pump.
[0060] Third, the leakage risk of the sealing surface is reduced, thereby reducing the design difficulty of the sealing surface.
[0061] Fourth, the lubrication of the motor bearings is achieved under the condition of suspending the active oil supply in the motor cavity, avoiding the risk of bearing failure caused by insufficient bearing lubrication.
[0062] List of Reference Signs
[0063] 1. Rotor
[0064] 2. Drive-end bearing
[0065] 3. Bearing cover plate
[0066] 31. Oil sump
[0067] 32. Oil outlet
[0068] 33. Open end
[0069] 34. Tank wall
[0070] 35. Bottom
[0071] 4. Motor end cover
[0072] 41. Oil guiding channel
[0073] 411. First-end opening
[0074] 412. Second-end opening
[0075] 42. Bearing hole
[0076] 5. Gearbox
[0077] 6. Stator
[0078] 7. Non-drive-end bearing
[0079] 8. Balance plate
[0080] 81. Opening
[0081] 100. Motor
Claims
1. A motor assembly having an internal lubricating oil passage, the motor assembly comprising: A bearing cover plate (3) and a motor end cover (4), wherein, in the direction of lubricating oil transfer, the bearing cover plate (3) is axially (Y) installed downstream of the gearbox (5), and the motor end cover (4) is axially (Y) installed downstream of the bearing cover plate (3); Characterized in that, The bearing cover plate (3) is provided with an oil collecting groove (31), the oil collecting groove (31) extends along the circumferential direction (C) of the bearing cover plate (3) and has an opening (33) pointing radially (R) outwards, the opening (33) is used to receive the lubricating oil brought out by the gear oil stirring operation from the gearbox (5), and the oil collecting groove (31) has at least one oil outlet (32) on the groove wall (34) on the side adjacent to the motor end cover (4) in the axial direction (Y), and the oil outlet is used to lead out the collected lubricating oil from the oil collecting groove (31); and The motor end cover (4) is provided with at least one through oil guiding channel (41), the oil guiding channel (41) is arranged corresponding to the oil outlet (32), and is used to convey a part of the lubricating oil led out from the oil outlet (32) to the balance plate (8) arranged at the axial end of the rotor (1), and the other part to the drive end bearing (2).
2. The motor assembly according to claim 1, wherein, Each of the at least one oil guiding channel (41) has a first end opening (411) and a second end opening (412) opposite to the first end opening, the first end opening (411) is docked with the oil outlet (32), and the second end opening (412) points to the balance plate (8) of the rotor of the motor, and is used to convey a part of the lubricating oil led out from the oil outlet (32) to the balance plate (8) of the rotor (1).
3. The motor assembly according to claim 2, wherein, The oil guiding channel (41) further includes a bearing hole (42) arranged below the second end opening (142) and extending radially (R) to the drive end bearing (2), and the bearing hole (42) is used to convey the other part of the led-out lubricating oil to the drive end bearing (2).
4. The motor assembly according to claim 1, wherein, The oil collecting groove (31) has an oil outlet (32) on the groove wall (34) on the side adjacent to the motor end cover (2) in the axial direction (Y), and the oil outlet (32) is arranged at the lowest point near the bottom (35) of the oil collecting groove (31).
5. The motor assembly according to claim 1, wherein, The oil collecting groove (31) has two oil outlets (32) on the groove wall (34) on the side adjacent to the motor end cover (2) in the axial direction (Y), and the two oil outlets are symmetrically arranged at the two lowest points near the bottom (35) of the oil collecting groove (31).
6. The motor assembly according to claim 1, wherein, The bearing cover plate (3) is provided with a plurality of oil collecting grooves (31), and the positions of the plurality of oil collecting grooves (31) in the circumferential direction (C) are determined based on the oil amounts of the lubricating oil brought out by the oil stirring operation at different positions.
7. The motor assembly according to claim 1, wherein the oil sump (31) is configured to have a sector cross-sectional shape that tapers inwardly along the radial direction (R).
8. The motor assembly according to claim 1, wherein, The position of the first end opening (411) of the oil guiding channel (41) is higher than the position of the second end opening (412).
9. The motor assembly according to claim 1, wherein the bearing cover plate (3) is made of metal, and the oil sump (31) and the oil outlet (32) are made by die-casting process; and / or the motor end cover (4) is made of metal, and the oil guiding channel (41) is made by die-casting process and punching process.
10. A motor (100) comprising the motor assembly according to any one of claims 1-9.