Motor rotor cooling structure and bridge driving system

Abstract

The utility model provides a motor rotor cooling structure and a bridge driving system, the motor rotor cooling structure comprises a rotor shaft (3), the rotor shaft (3) is a hollow shaft provided with a center hole, and the peripheral wall of the rotor shaft (3) is provided with an oil inlet hole (34); the rotor core (2) is arranged on the rotor shaft (3) in a sleeving mode, the rotor core (2) is provided with a radial oil channel (22) extending in the radial direction (R) of the rotor core (2), and the radial oil channel (22) is communicated with the oil inlet hole (34); the mandrel (7) is arranged in a center hole of the rotor shaft (3), and an oil inlet channel (S) is formed on the radial outer side of the mandrel (7) and the radial inner side of the rotor shaft (3); and the rotor sealing assembly (5) is arranged between the core shaft (7) and the rotor shaft (3), and the rotor sealing assembly (5) is located on the downstream side of the oil inlet hole (34) in the oil inlet direction in which oil enters the oil inlet channel (S) in the axial direction (A) of the rotor shaft (3).

Description

Technical Field

[0001] This application relates to a motor rotor cooling structure and an electric bridge drive system. Background Technology

[0002] Patent application CN115864747A discloses an oil-cooled motor, powertrain, and vehicle, which delivers oil to a cooling channel inside the rotor core through a hollow rotor shaft, thereby reducing the temperature of the motor rotor.

[0003] However, in some electric bridge drive systems, a spindle is coaxially arranged inside the hollow rotor shaft, making it difficult to guide the oil in the narrow gap between the rotor shaft and the spindle into the interior of the rotor core. Utility Model Content

[0004] This application aims to propose a motor rotor cooling structure to solve the problem of guiding oil in a narrow gap into the interior of the rotor core.

[0005] This application proposes a motor rotor cooling structure, including:

[0006] The rotor shaft is a hollow shaft with a central hole, and the peripheral wall of the rotor shaft is provided with an oil inlet hole;

[0007] A rotor core, which is sleeved on the rotor shaft, is provided with a radial oil passage extending radially therefrom, and the radial oil passage is connected to the oil inlet hole;

[0008] A mandrel, wherein the mandrel is disposed in the central hole of the rotor shaft, and an oil inlet channel is formed on the radially outer side of the mandrel and the radially inner side of the rotor shaft; and

[0009] A rotor sealing assembly is disposed between the mandrel and the rotor shaft, and in the oil inlet direction where oil enters the oil inlet channel along the axial direction of the rotor shaft, the rotor sealing assembly is located downstream of the oil inlet hole.

[0010] In at least one possible implementation, the inner wall surface of the rotor shaft includes a tapered portion, a large-diameter portion, and a small-diameter portion.

[0011] The inner diameter of the larger diameter portion is larger than the inner diameter of the smaller diameter portion. The larger diameter portion and the smaller diameter portion are smoothly connected by a tapered section. The tapered section extends radially outward towards the opening side of the oil inlet channel. The opening of the oil inlet channel is located on one axial side of the rotor shaft, allowing oil to enter the oil inlet channel.

[0012] In the axial direction, the rotor sealing assembly is located on the small diameter side of the conical section, and the oil inlet is located on the large diameter side of the conical section.

[0013] In at least one possible implementation, the rotor sealing assembly includes an outer lip, a skeleton, and an inner lip, the skeleton and the inner lip being connected to the outer lip, and the inner lip being located radially inside the skeleton.

[0014] In at least one possible implementation, the inner lip is provided with a plurality of centrifugal blades, which are disposed on the outer peripheral surface of the inner lip and protrude radially outward, and the centrifugal blades are in the same axial position as the conical surface and / or the oil inlet.

[0015] In at least one possible implementation, the rotor core is provided with an axial oil passage extending along the axial direction, the axial oil passage communicating with the radial oil passage, and the axial oil passage being located at the radially outer end of the radial oil passage.

[0016] In at least one possible implementation, the motor rotor cooling structure further includes a balance disc, which is sleeved on the rotor shaft and disposed at both axial ends of the rotor core. The balance disc is provided with an oil drain hole, which is aligned with the axial oil passage.

[0017] In at least one possible implementation, the rotor core is provided with a plurality of sets of magnet mounting slots along its circumference, and the axial oil passages are provided with a plurality of sets along the circumference of the rotor core, each of the axial oil passages being located between two adjacent sets of magnet mounting slots of the rotor core.

[0018] In at least one possible implementation, the inner wall surface of the rotor shaft and / or the outer wall surface of the mandrel are provided with a shoulder, the shoulder being located on the other side of the axial direction of the rotor sealing assembly, and the mandrel is fitted with a retaining ring, the retaining ring being located on one side of the axial direction of the rotor sealing assembly, the axial installation position of the rotor sealing assembly being positioned by the shoulder and the retaining ring.

[0019] This application also proposes an electric bridge drive system, including a motor rotor cooling structure and a gear assembly as described in any of the above technical solutions, wherein the rotor shaft and the spindle are connected through the gear assembly.

[0020] In at least one possible implementation, the opening of the oil inlet channel faces the side where the gear assembly is located, for receiving oil that lubricates the gear assembly.

[0021] By adopting the above technical solution, the use of rotor sealing components can form a seal between the rotor shaft and the power output shaft, preventing oil from leaking from the oil inlet channel to the other side of the axial direction of the oil inlet channel. This helps to utilize the oil to cool the rotor as much as possible. Attached Figure Description

[0022] Figure 1A schematic diagram of the structure of an electric bridge drive system according to an embodiment of this application is shown.

[0023] Figure 2 It shows Figure 1 A magnified view of a portion of the image.

[0024] Figure 3 A partial structural schematic diagram of an electric bridge drive system according to an embodiment of this application is shown.

[0025] Figure 4 A schematic diagram of the rotor sealing assembly of an electric bridge drive system according to an embodiment of this application is shown.

[0026] Explanation of reference numerals in the attached figures

[0027] 100 motor 200 gearbox

[0028] 1 stator

[0029] 2 rotor core 21 axial oil passage 22 radial oil passage

[0030] 3. Rotor shaft; 31. Conical section; 32. Large diameter section; 33. Small diameter section; 34. Oil inlet.

[0031] 4 balance discs, 41 oil drain holes

[0032] 5 Rotor sealing assembly 51 Outer lip 52 Frame 53 Inner lip 531 Centrifugal blade

[0033] 6-ring

[0034] 7 Power Take-Off Shaft

[0035] S oil inlet channel

[0036] Axial direction C circumferential direction R radial direction Detailed Implementation

[0037] To more clearly illustrate the above-mentioned objectives, features, and advantages of this application, specific embodiments of this application are described in detail in this section with reference to the accompanying drawings. Besides the embodiments described in this section, this application can also be implemented in other different ways. Those skilled in the art can make corresponding improvements, modifications, and substitutions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed in this section. The scope of protection of this application should be determined by the claims.

[0038] It is understandable that the axial, circumferential, and radial directions of the electric bridge drive system are consistent with those of the motor 100, transmission 200, rotor core 2, rotor shaft 3, and balance disc 4, and are therefore sometimes simply referred to as axial, circumferential, and radial directions.

[0039] like Figures 1 to 4As shown, embodiments of this application propose an electric axle drive system that can be used to drive electric vehicles or hybrid vehicles.

[0040] The electric axle drive system may include a motor 100 and a transmission 200. The motor 100 and transmission 200 may be separate units or integrated into one unit. When the motor 100 is used as an electric motor to output power, the transmission 200 can receive the power output from the motor 100 and transmit it to the wheels, driving them to rotate. When the motor 100 is used as a generator to recover kinetic energy, the power from the rotating wheels is transmitted to the transmission 200, and the motor 100 can receive the power output from the transmission 200.

[0041] The motor 100 includes a stator 1, a rotor core 2, a rotor shaft 3, and a balance disc 4. The stator 1 may include windings, and the rotor core 2 may have multiple sets of magnet mounting slots along its circumference to accommodate magnets. The rotor core 2 and the balance disc 4 are both sleeved on the rotor shaft 3, and the balance disc 4 is located at both axial ends of the rotor core 2. The rotor core 2 and the balance disc 4 can rotate synchronously with the rotor shaft 3. The rotor shaft 3 is rotatably mounted relative to the stator 1, and the stator 1 can be sleeved on the radially outer side of the rotor core 2.

[0042] like Figure 1 As shown, the transmission 200 includes a power output shaft 7 (spindle) and a gear assembly. The rotor shaft 3 of the motor 100 and the power output shaft 7 of the transmission 200 can be connected through the gear assembly. The power output shaft 7 and the rotor shaft 3 have different rotational speeds.

[0043] like Figures 1 to 3 As shown, the power output shaft 7 can be inserted into the center hole of the rotor shaft 3. The power output shaft 7 and the rotor shaft 3 are coaxially arranged, and an oil inlet channel S is formed on the radially outer side of the power output shaft 7 and the radially inner side of the rotor shaft 3. The opening of the oil inlet channel S faces the side where the gear assembly is located. Figures 1 to 3 The right side of the rotor shaft 3 is used to receive oil for lubricating the gear assembly. In other words, the opening of the oil inlet channel S is located on the axial side of the rotor shaft 3, allowing oil to enter the oil inlet channel S.

[0044] like Figure 2As shown, the rotor core 2 is provided with axial oil passages 21 and radial oil passages 22. The axial oil passage 21 extends along the axial direction A of the rotor core 2 and penetrates the rotor core 2. The radial oil passage 22 extends along the radial direction R of the rotor core 2 and forms an opening on the inner circumferential surface of the rotor core 2. The axial oil passage 21 can be located at the radially outer end of the radial oil passage 22, and the axial oil passage 21 and the radial oil passage 22 are connected. Multiple axial oil passages 21 and multiple radial oil passages 22 can be evenly arranged along the circumference of the rotor core 2. For example, eight axial oil passages 21 and eight radial oil passages 22 can be provided, with multiple axial oil passages 21 and multiple radial oil passages 22 corresponding to each other in the circumferential direction of the rotor core 2. The radial oil passage 22 can be located at the middle position in the axial direction of the axial oil passage 21, so that the oil in the axial oil passage 21 can flow to both sides of the axial direction.

[0045] Furthermore, each axial oil passage 21 can be located between two adjacent sets of magnet mounting slots of the rotor core 2, so that the oil flowing through the axial oil passage 21 can cool the rotor core 2 more fully.

[0046] The balance disc 4 is provided with an oil drain hole 41, which extends through the balance disc 4 along the axial direction A. The oil drain hole 41 is aligned with the axial oil passage 21, and the oil that has entered the rotor core 2 can be discharged through the oil drain hole 41.

[0047] The rotor shaft 3 is a hollow shaft, meaning it has a central hole. The inner wall of the rotor shaft 3 may include a tapered portion 31, a large-diameter portion 32, and a small-diameter portion 33. The inner diameter of the large-diameter portion 32 is larger than the inner diameter of the small-diameter portion 33. The large-diameter portion 32 and the small-diameter portion 33 are smoothly connected via the tapered portion 31, which extends towards the opening side of the oil inlet channel S. Figures 1 to 3 (On the right side) it extends further outward radially.

[0048] The rotor shaft 3 has oil inlet holes 34 on its peripheral wall. Multiple oil inlet holes 34 can be provided along the circumference of the rotor shaft 3, for example, there can be 8 oil inlet holes 34. The oil inlet holes 34 are connected to the radial oil passages 22 in a one-to-one correspondence.

[0049] like Figure 2 As shown, the rotor seal assembly 5 can be disposed between the inner wall surface of the rotor shaft 3 and the outer wall surface of the power output shaft 7. In the axial direction A, the rotor seal assembly 5 is located on the small diameter side of the conical section 31. Figure 2 (Left side of the middle), the oil inlet 34 is located on the large diameter side of the conical section 31 ( Figure 2 (Right side of the image). When the electric bridge drive system is working, the oil in the oil inlet channel S can flow smoothly along the conical section 31 and lead to the oil inlet hole 34. Optionally, the oil inlet hole 34 can be located at the large-diameter end of the conical section 31 or at the junction of the conical section 31 and the large-diameter section 32.

[0050] When the electric bridge drive system is working, the rotor seal assembly 5 will increasingly press the inner circumferential surface of the rotor shaft 3 under centrifugal force. That is, the rotor seal assembly 5 and the rotor shaft 3 can rotate together. The oil enters the oil inlet channel S along the axial direction A of the rotor shaft 3 (in the oil inlet direction). Figure 2 (From right to left) The rotor seal assembly 5 is located downstream of the oil inlet 34, allowing it to block the oil from continuing to flow axially along A and instead directing the oil into the rotor core 2 radially along R. The rotor seal assembly 5 also prevents oil from flowing into the housing of the motor 100.

[0051] like Figure 2 and Figure 3 As shown, the inner wall surface of the rotor shaft 3 and / or the outer wall surface of the power output shaft 7 may be provided with a shoulder, which is located on the other side of the axial direction of the rotor sealing assembly 5. Figure 2 and Figure 3 (Left side of the image). The power output shaft 7 may be fitted with a retaining ring 6, which is located on one axial side of the rotor sealing assembly 5. Figure 2 and Figure 3 (Right side). The axial mounting position of the rotor seal assembly 5 is located by the shaft shoulder and retaining ring 6.

[0052] Figure 2 The unidirectional arrows indicate the direction of oil flow. The oil between the inner wall of the rotor shaft 3 and the outer wall of the power output shaft 7 can enter the radial oil passage 22 through the oil inlet 34, then flow to the axial oil passage 21, and exit the rotor core 2 through the oil outlet 41. The oil flowing through the radial oil passage 22 and the axial oil passage 21 can cool the rotor core 2.

[0053] The rotor sealing assembly 5 can form a seal between the rotor shaft 3 and the power output shaft 7, preventing oil from leaking from the oil inlet channel S to the other side of the axial direction of the oil inlet channel S. Figure 2 and Figure 3 (on the left side of the image), which helps to utilize the oil to cool the rotor as much as possible.

[0054] like Figure 4 As shown, the rotor sealing assembly 5 may include an outer lip 51, a skeleton 52 and an inner lip 53. The skeleton 52 and the inner lip 53 may be connected to the outer lip 51, and the inner lip 53 may be located radially inside the skeleton 52.

[0055] The outer peripheral surface of the outer lip 51 can be a straight annular surface extending along the axial direction A; the axial cross-sectional shape of the skeleton 52 can be L-shaped; the inner peripheral surface of the inner lip 53 can include a conical surface inclined relative to the axial direction A; the inner peripheral surface of the inner lip 53 extends towards the opening side of the oil inlet channel S. Figure 2The smaller the radial dimension extending from the right side (in the diagram), the smaller the radial dimension. Correspondingly, the portion of the power output shaft 7 that mates with the rotor seal assembly 5 can also be a conical surface, which similarly extends towards the opening side of the oil inlet passage S (…). Figure 2 The smaller the radial dimension (on the right side of the image), the better.

[0056] The inner lip 53 may be provided with multiple centrifugal blades 531, which may be disposed on the outer peripheral surface of the inner lip 53 and protrude radially outward. The radially outer surface of the centrifugal blades 531 may be inclined relative to the axial direction of the rotor seal assembly 5, with the centrifugal blades 531 moving towards the side where the motor 100 is located. Figure 1 and Figure 2 (On the left side) it extends further inward and outward in a radial direction.

[0057] Multiple centrifugal blades 531 can be arranged circumferentially along the rotor sealing assembly 5, for example, eight centrifugal blades 531 can be arranged. The centrifugal blades 531 and the conical surface 31 and / or the oil inlet 34 can be in the same axial position. When the electric bridge drive system is working, under the centrifugal action, the oil in the oil inlet channel S can be stirred and guided by the centrifugal blades 531 to flow to the conical surface 31 and / or the oil inlet 34, so that the oil flow rate is large and the cooling effect is better.

[0058] The centrifugal blade 531 can support the inner lip 53. When the electric bridge drive system is working, the support of the frame 52 can prevent the inner lip 52 from being affected by centrifugal force and the power output shaft 7 from forming gaps, so that the inner lip 53 and the power output shaft 7 are tightly fitted, thereby preventing oil leakage.

[0059] The outer lip 51 and inner lip 53 can be made of rubber materials; for example, the outer lip 51 can be made of ethylene acrylate rubber (AEM), and the inner lip 53 can be made of polytetrafluoroethylene (PTFE). The skeleton 52 can be made of metal; for example, the skeleton 52 can be made of steel. The three parts, outer lip 51, skeleton 52, and inner lip 53, can be joined together by vulcanization.

[0060] This application is not limited to the above embodiments. Those skilled in the art can make various modifications to the above embodiments of this application under the guidance of this application, without departing from the scope of this application. In addition, the following description is provided.

[0061] (1) In the above embodiments, the outer lip and the inner lip are made of different materials. However, this application is not limited to this. In at least one possible embodiment, the outer lip and the inner lip can be made of the same material. For example, the outer lip and the inner lip can be integrally formed.

[0062] (2) The skeleton may be enclosed within the outer or inner lip. In at least one possible implementation, the skeleton may be omitted.

[0063] (3) Centrifugal blades may be formed wholly or partially from a skeleton or the material of the skeleton.

[0064] It should be understood that at least some aspects or features of the above-described implementation methods, embodiments, or examples can be appropriately combined.

[0065] It is understood that, in this application, when the number of parts or components is not specifically limited, the number can be one or more, where multiple refers to two or more. For cases where the number of parts or components shown in the drawings and / or described in the specification is, for example, two, three, four, etc., this specific number is generally exemplary and not restrictive, and can be understood as multiple, i.e., two or more; however, this does not mean that this application excludes the case of one.

[0066] In this application, unless otherwise expressly stated or limited, terms such as "installation," "assembly," "connection," "linking," "joining," "linking," "abutment," "communication," "connection," "conduction," "fixing," and "fastening" should be interpreted broadly, for example, they can be direct or indirect. For instance, regarding connection, 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 an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly stated or limited. For instance, regarding communication / conduction, it can be direct communication / conduction or indirect communication / conduction through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0067] In this application, unless otherwise expressly stated or limited, a component being disposed / installed / located / enclosed / placed within, inside, or incorporated in another component can be either of the following two situations: a portion or a majority of the one component is located within the other component; or the one component is completely enclosed within the other component.

[0068] Although the present application has been described in detail using the above embodiments, it will be apparent to those skilled in the art that the present application is not limited to the embodiments described herein. The present application can be modified and implemented as alternative embodiments without departing from the spirit and scope of the present application as defined by the claims. Therefore, the description in this specification is for illustrative purposes only and does not have any limiting meaning for the present application.

Claims

1. An electric machine rotor cooling structure, characterized by, The motor rotor cooling structure comprises: a rotor shaft, which is a hollow shaft provided with a central hole, a circumferential wall of the rotor shaft being provided with an oil inlet hole; a rotor core, which is sleeved on the rotor shaft, the rotor core being provided with a radial oil passage extending in a radial direction thereof, the radial oil passage and the oil inlet hole being in communication; a mandrel, which is arranged in the central hole of the rotor shaft, an oil inlet passage being formed between a radially outer side of the mandrel and a radially inner side of the rotor shaft; and a rotor seal assembly, which is arranged between the mandrel and the rotor shaft, the rotor seal assembly being located on a downstream side of the oil inlet hole in an oil inlet direction in which oil enters the oil inlet passage along an axial direction of the rotor shaft.

2. The motor rotor cooling structure of claim 1, wherein An inner wall surface of the rotor shaft comprises a conical surface portion, a large-diameter portion and a small-diameter portion, an inner diameter of the large-diameter portion is larger than an inner diameter of the small-diameter portion, the large-diameter portion and the small-diameter portion are connected smoothly through the conical surface portion, the conical surface portion extends to a radially outer side as it extends to an opening side of the oil inlet passage, the opening of the oil inlet passage is located on one side of the axial direction of the rotor shaft for oil to enter the oil inlet passage, in the axial direction, the rotor seal assembly is located on a small-diameter side of the conical surface portion, and the oil inlet hole is located on a large-diameter side of the conical surface portion.

3. The motor rotor cooling structure of claim 2, wherein The rotor seal assembly comprises an outer lip, a skeleton and an inner lip, the skeleton and the inner lip being connected to the outer lip, and the inner lip being located on a radially inner side of the skeleton.

4. The motor rotor cooling structure of claim 3, wherein The inner lip is provided with a plurality of centrifugal blades, the centrifugal blades being arranged on an outer peripheral surface of the inner lip and protruding to a radially outer side, and the centrifugal blades being located at the same axial position as the conical surface portion and / or the oil inlet hole.

5. The motor rotor cooling structure of claim 1, wherein The rotor core is provided with an axial oil passage extending in the axial direction, the axial oil passage and the radial oil passage being in communication, and the axial oil passage being located at a radially outer side end of the radial oil passage.

6. The motor rotor cooling structure of claim 5, wherein The motor rotor cooling structure further comprises a balance disc, which is sleeved on the rotor shaft, the balance disc being arranged at both axial ends of the rotor core, the balance disc being provided with an oil discharge hole, and the oil discharge hole being aligned with the axial oil passage.

7. The motor rotor cooling structure of claim 5, wherein The rotor core is provided with a plurality of groups of magnet mounting grooves for accommodating magnets along a circumferential direction thereof, and the axial oil passage is arranged in a plurality of groups along the circumferential direction of the rotor core, each of the axial oil passages being located between two adjacent groups of the magnet mounting grooves of the rotor core.

8. The motor rotor cooling structure of claim 1, wherein An inner wall surface of the rotor shaft and / or an outer wall surface of the mandrel is provided with a shaft shoulder, the shaft shoulder being located on an axial other side of the rotor seal assembly, the mandrel is sleeved with a retainer ring, the retainer ring being located on an axial one side of the rotor seal assembly, and the axial installation position of the rotor seal assembly is positioned by the shaft shoulder and the retainer ring.

9. A bridge drive system, characterized by The motor rotor cooling structure and a gear assembly are comprised, the rotor shaft and the mandrel are connected through the gear assembly.

10. The bridge drive system of claim 9, wherein, The opening of the oil inlet passage is directed to a side where the gear assembly is located, for receiving oil for lubricating the gear assembly.

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