A rotor cooling structure for a drive motor

Abstract

A rotor cooling structure for a drive motor includes a rotor core with a central shaft hole. Several magnetic slots are arranged around the central shaft hole, each containing a magnet. Oil channels are formed in the sides of the magnetic slots, with the length of the oil channels inclined to the length of the magnetic slots. Two oil channels are provided in each magnetic slot, located on opposite sides. The end openings of the two oil channels are positioned opposite each other in the magnetic slots, and the two oil channels are parallel; alternatively, the end openings are positioned diagonally opposite each other in the magnetic slots, and the two oil channels are staggered. This invention provides cooling oil channels in the sides of the magnetic slots. Cooling oil enters the oil channels and contacts the magnets, increasing the heat dissipation area of ​​the magnets and effectively cooling both the magnets and the rotor core simultaneously, significantly improving the cooling efficiency of the magnets.

Description

Technical Field

[0001] This invention relates to the field of machinery, and more particularly to electric motors, especially a rotor cooling structure for a drive motor. Background Technology

[0002] Currently, electric motors are developing towards miniaturization and high speed. Motor speed is directly proportional to frequency; as motor speed increases, frequency gradually increases. High frequencies increase magnetic field harmonics, which in turn increase eddy current losses in the rotor magnets, leading to increased motor temperature and reduced efficiency. In severe cases, it can cause demagnetization of the permanent magnets, significantly impacting the stable operation of the motor. Therefore, rotor cooling technology is crucial. For permanent magnet synchronous motors, in existing technology, dynamic balance plates are installed on the rotor shaft at both ends of the rotor core. Oil inlets are located inside the rotor shaft, through which cooling oil enters the oil reservoir of the dynamic balance plate and then flows through the reservoir into the weight-reducing holes of the rotor core for cooling. However, this cooling structure only cools the rotor core and cannot effectively cool the magnets within it. Summary of the Invention

[0003] The purpose of this invention is to provide a cooling structure for the rotor of a drive motor, which solves the technical problem of inadequate cooling of magnets in the prior art.

[0004] The present invention provides a rotor cooling structure for a drive motor, including a rotor core, a central shaft hole on the rotor core, a plurality of magnetic steel slots arranged around the central shaft hole on the rotor core, the length direction of the magnetic steel slots being parallel to the axial direction of the rotor core, each magnetic steel slot containing a magnet, and an oil passage provided in the side of the magnetic steel slot.

[0005] Preferably, the length direction of the oil passage is inclined to the length direction of the magnet groove.

[0006] Preferably, each magnet groove contains two oil channels, which are respectively located on two opposite sides of the magnet groove.

[0007] Preferably, the end openings of the two oil passages are located at opposite positions in the magnet groove, and the two oil passages are parallel to each other;

[0008] Alternatively, the end openings of the two oil passages are located at opposite corners of the magnet slot, and the two oil passages intersect each other.

[0009] Preferably, the rotor core is formed by stacking multiple core laminations, each stack of core laminations is formed by stacking multiple silicon steel sheets, and each stack of core laminations is provided with an oil groove, with the oil grooves of adjacent core laminations being staggered and connected to form an oil channel.

[0010] Preferably, the oil passage is in a straight line or in a V-shape.

[0011] Preferably, an insert mounting hole is provided between adjacent magnet slots, an insert is provided in the insert mounting hole, an oil inlet is provided in the insert, and an oil passage is provided on the side of the oil passage of adjacent magnet slots. The oil inlet includes a main oil passage and two branch oil passages. The main oil passage is connected to the two oil passages through the two branch oil passages, and the two oil passages are connected to the oil passages of the two magnet slots.

[0012] Preferably, adjacent magnetic grooves form a first positioning groove, and a second positioning groove is provided on the iron core between the first positioning groove and the outer circle of the iron core, with an oil passage provided on the side of the second positioning groove.

[0013] Preferably, the cross-sectional shape of the oil passage is rectangular, trapezoidal, semi-circular, rhomboid, or elliptical.

[0014] Compared with existing technologies, the effects of this invention are positive and significant. This invention incorporates cooling oil channels in the side of the magnet slot. The cooling oil enters these channels and comes into contact with the magnet, thereby increasing the magnet's heat dissipation area. This allows for effective simultaneous cooling of both the magnet and the rotor core, greatly improving the cooling efficiency and effect of the magnet, enhancing the motor's peak and rated performance, reducing the risk of permanent magnet demagnetization, and improving the motor's durability and reliability. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the rotor of Embodiment 1 of a drive motor rotor cooling structure of the present invention.

[0016] Figure 2 This is a three-dimensional schematic diagram of the rotor of Embodiment 1 of a drive motor rotor cooling structure of the present invention.

[0017] Figure 3 This is a schematic diagram of the first oil passage in Embodiment 1 of a drive motor rotor cooling structure of the present invention.

[0018] Figure 4 This is a schematic diagram of the rotor of a second embodiment of a drive motor rotor cooling structure according to the present invention.

[0019] Figure 5 This is a schematic diagram of the first oil passage in Embodiment 2 of a drive motor rotor cooling structure of the present invention.

[0020] Figure 6 This is a schematic diagram of the second oil passage in Embodiment 2 of a drive motor rotor cooling structure of the present invention.

[0021] Figure 7 This is a schematic diagram of the rotor in Embodiment 3 of a drive motor rotor cooling structure of the present invention.

[0022] Figure 8 This is a schematic diagram of the first oil passage in Embodiment 3 of a drive motor rotor cooling structure of the present invention.

[0023] Figure 9 This is a schematic diagram of the second oil passage in Embodiment 3 of a drive motor rotor cooling structure of the present invention.

[0024] Figure 10 This is a schematic diagram of the rotor in Embodiment 4 of a drive motor rotor cooling structure according to the present invention.

[0025] Figure 11 This is a schematic diagram of the first oil passage in Embodiment 4 of a drive motor rotor cooling structure of the present invention.

[0026] Figure 12 This is a schematic diagram of the second oil passage in Embodiment 4 of a drive motor rotor cooling structure of the present invention.

[0027] Figure 13 This is a schematic diagram of an oil passage in Embodiment 5 of a drive motor rotor cooling structure of the present invention.

[0028] Figure 14 This is a schematic diagram of two oil passages in Embodiment 5 of a drive motor rotor cooling structure of the present invention.

[0029] Figure 15 This is a first schematic diagram of the oil passage and insert of an embodiment 5 of a drive motor rotor cooling structure of the present invention.

[0030] Figure 16 This is a second schematic diagram of the oil passage and insert of an embodiment 5 of a drive motor rotor cooling structure of the present invention.

[0031] Figure 17 This is a schematic diagram of an insert in Embodiment 5 of a drive motor rotor cooling structure of the present invention.

[0032] Figure 18 This is a third schematic diagram of the oil passages and inserts in Embodiment 5 of a drive motor rotor cooling structure of the present invention. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings. Any similar variations of the present invention should be included within the scope of protection of the present invention. The directional terms such as "upper," "lower," "front," and "rear" in the present invention are defined based on the orientation shown in the accompanying drawings. The use of directional terms is solely for clarity and convenience of description, and does not indicate or imply that the referred technical features must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the present invention.

[0034] like Figures 1-18As shown, the present invention provides a rotor cooling structure for a drive motor, including a rotor core, a central shaft hole 2 on the rotor core, a plurality of magnetic steel grooves 3 arranged around the central shaft hole on the rotor core, the length direction of the magnetic steel grooves 3 being parallel to the axial direction of the rotor core, each magnetic steel groove 3 being provided with a magnet 4, and an oil passage being provided in the side of the magnetic steel groove 3.

[0035] The present invention provides an oil channel for cooling in the side of the magnet slot 3. After the cooling oil enters the oil channel, it comes into contact with the magnet 4, thereby increasing the heat dissipation area of ​​the magnet 4 and effectively cooling the magnet 4 and the rotor core at the same time. This greatly improves the cooling efficiency and cooling effect of the magnet 4, enhances the peak and rated performance of the motor, reduces the risk of permanent magnet demagnetization, and improves the durability and reliability of the motor.

[0036] Preferred, such as Figure 3 As shown, the length direction of the oil passage is inclined to the length direction of the magnet groove 3.

[0037] This approach increases the contact area between the oil passage and the magnet 4, thereby improving the cooling effect of the magnet 4.

[0038] Preferably, the number of oil channels in any one of the magnet slots 3 is two, such as Figure 1 As shown, the two oil passages are respectively located on the two opposite sides of the magnet groove 3.

[0039] Preferred, such as Figures 1-3 , Figures 10-12 As shown, the end openings of the two oil passages are located at opposite positions (i.e., on the same side) of the magnetic steel groove 3, and the two oil passages are parallel to each other.

[0040] Or, such as Figures 4-9 As shown, the end openings of the two oil passages are located at opposite corners (i.e., on opposite sides) of the magnet groove 3, and the two oil passages are intersected.

[0041] Preferred, such as Figure 2 , Figure 3 As shown, the rotor core is formed by stacking multiple core laminations 1. Each stack of core laminations 1 is formed by stacking multiple silicon steel sheets. Each stack of core laminations 1 has a slot, and the slots of adjacent core laminations 1 are staggered and connected to form an oil passage.

[0042] Preferred, such as Figure 3 , Figure 5 , Figure 6 As shown, the oil passage is in a straight line, or, as... Figure 8 , Figure 9 , Figure 11 , Figure 12 As shown, the oil passage is V-shaped.

[0043] Preferred, such as Figures 13-18As shown, an insert mounting hole 40 is provided between adjacent magnet grooves 3, an insert 41 is provided in the insert mounting hole 40, and an oil inlet passage 31 is provided in the insert 41. An oil passage 7 is provided on the side of the oil passage of adjacent magnet grooves 3. The oil inlet passage 31 includes a main oil passage and two branch oil passages. The main oil passage is connected to the two oil passages 7 through the two branch oil passages respectively. The two oil passages 7 are connected to the oil passages of the two magnet grooves 3 respectively.

[0044] Using this scheme, the cooling oil is diverted through the oil inlet 31 of the insert 41, so that the cooling oil can precisely cool the rotor core and magnets.

[0045] Preferred, such as Figure 1 As shown, adjacent magnet slots 3 form a first positioning slot, and a second positioning slot is provided on the rotor core between the first positioning slot and the outer circle of the core. An oil passage is provided on the side of the second positioning slot.

[0046] The oil passages on the second positioning groove have the same structure as those on the first positioning groove. The number of oil passages on the second positioning groove can be one or more. The two oil passages can be set to extend forward in parallel or in an alternating manner, thereby improving the cooling effect on the magnets in the second positioning groove.

[0047] Preferably, the cross-sectional shape of the oil passage is rectangular, trapezoidal, semi-circular, rhomboid, or elliptical.

[0048] Example 1

[0049] like Figures 1 to 3 As shown, a permanent magnet synchronous rotor core includes multiple stacked core laminations 1, which are stacked to form the rotor core. A central shaft hole 2 is provided on the rotor core for the rotating shaft to pass through. Multiple first positioning slots for fixing magnets are provided around the central shaft hole 2, and the first positioning slots are connected by a magnetic bridge. Magnets 4 are placed in the magnet slots 3 of the first positioning slots. First oil passages 5 and second oil passages 6 are formed on opposite sides of the first positioning slots. Figure 3 As shown, the end openings of the first oil passage 5 and the second oil passage 6 are located on the same side of the magnetic steel groove 3. Figure 3 As shown, two slots are formed in the first stack of iron core laminations 1. Two oil grooves are also formed on the first positioning slot in the second stack of iron core laminations 1. These grooves have the same size and shape as the first stack of iron core laminations 1 and are connected to and offset from the two oil grooves in the first stack of iron core laminations 1. The oil grooves of adjacent stacks of iron core laminations 1 are interconnected and inclined axially, forming a parallel, straight first oil passage 5 and a second oil passage 6. In practical applications, only the first oil passage 5 or only the second oil passage 6 can be provided.

[0050] The working principle of this embodiment is as follows: During operation, cooling oil enters the oil reservoir of the dynamic balance plate from the oil inlet hole on the rotor shaft. Then, the cooling oil in the oil reservoir of the dynamic balance plate enters the first oil passage 5 and the second oil passage 6. It flows through the entire rotor core through the oil passage and finally flows out through the dynamic balance plate, thereby precisely cooling the rotor core and magnets, greatly improving the cooling efficiency and cooling effect of the magnets, improving the peak and rated performance of the motor, reducing the risk of permanent magnet demagnetization, and improving the durability and reliability of the motor.

[0051] Example 2

[0052] like Figures 4-6 As shown, the difference between Embodiment 2 and Embodiment 1 is that the end openings of the first oil channel 5 and the second oil channel 6 are located on opposite sides of the magnetic steel groove 3, in a diagonal configuration. The first oil channel 5 and the second oil channel 6 are each in a straight line and intersect each other.

[0053] Example 3

[0054] like Figures 7-9 As shown, the difference between Example 3 and Example 2 is that in a stack of iron core laminations 1, the first oil channel 5 and the second oil channel 6 are each V-shaped and interlaced with each other.

[0055] Example 4

[0056] like Figures 10-12 As shown, the difference between Embodiment 4 and Embodiment 3 is that the end openings of the first oil passage 5 and the second oil passage 6 are located on the same side of the magnetic steel groove 3. The first oil passage 5 and the second oil passage 6 are each V-shaped and parallel to each other.

[0057] Example 5

[0058] See Figures 13 to 18 A permanent magnet synchronous rotor core includes multiple stacked core laminations 1, which are stacked to form the rotor core. A central shaft hole 2 is provided on the rotor core for a rotating shaft to pass through. Multiple first positioning slots for fixing magnets are provided around the central shaft hole 2. Magnets 4 are placed in the magnet slots 3 of the first positioning slots. An insert mounting hole 40 is provided in the middle of the opening of each first positioning slot, and an insert 41 is placed in the insert mounting hole 40. The insert 41 is made of a low-permeability 6061 type aluminum alloy. The low permeability material can reduce motor leakage flux and improve motor performance. An oil inlet passage 31 is provided in the insert 41, and cooling oil flows through the oil inlet passage 31 and oil passage 7 into the oil passages of adjacent magnet slots 3. The oil passages can be... Figure 16 The diagram shows an inclined straight line shape, but it can also be a V-shape. If an oil inlet 31 is provided in the insert 41, then the first oil channel 5 does not need to be provided in the first iron core lamination 1. The first oil channel 5 is opened in the second and subsequent iron core laminations 1. The oil flows into the oil channel 7 through the oil inlet 31 of the insert 41, and then into the first oil channel 5 of the magnet groove 3.

[0059] The working principle of this embodiment is as follows: During operation, cooling oil enters the oil reservoir of the dynamic balance plate from the oil inlet hole on the rotor shaft, then enters the oil inlet passage 31 of the insert 41, then flows into the first oil passage 5 through the oil passage 7, flows through the entire rotor core, and finally flows out through the dynamic balance plate. The oil inlet passage 31 of the insert 41 diverts the cooling oil, allowing for precise cooling of the rotor core and magnets 4. This greatly improves cooling efficiency and effect, enhances the peak and rated performance of the motor, reduces the risk of permanent magnet demagnetization, and improves the durability and reliability of the motor.

[0060] In this invention, all parts not described in detail adopt well-known solutions from the prior art.

Claims

1. A rotor cooling structure for a drive motor, characterized in that, It includes a rotor core, a central shaft hole on the rotor core, and several magnetic slots arranged around the central shaft hole on the rotor core. The length direction of the magnetic slots is parallel to the axial direction of the rotor core. Each magnetic slot contains a magnet, and oil passages are provided on the side of the magnetic slots. The length direction of the oil passage is inclined to the length direction of the magnetic groove; Each magnet trough contains two oil passages, which are located on two opposite sides of the magnet trough. The end openings of the two oil passages are set at opposite positions in the magnetic steel groove, and the two oil passages are parallel to each other; Alternatively, the end openings of the two oil passages are located at opposite corners of the magnet slot, and the two oil passages are staggered. The rotor core is formed by stacking multiple core laminations. Each stack of core laminations is formed by stacking multiple silicon steel sheets. Each stack of core laminations has an oil groove, and the oil grooves of adjacent core laminations are staggered and connected to form an oil channel. The oil passage is either straight or V-shaped; An insert mounting hole is provided between adjacent magnet slots, and an insert is provided in the insert mounting hole. An oil inlet is provided in the insert. An oil passage is provided on the side of the oil passage of adjacent magnet slots. The oil inlet includes a main oil passage and two branch oil passages. The main oil passage is connected to the two oil passages through the two branch oil passages. The two oil passages are connected to the oil passages of the two magnet slots.

2. The drive motor rotor cooling structure according to claim 1, characterized in that, Adjacent magnetic steel slots form a first positioning slot, and a second positioning slot is provided on the iron core between the first positioning slot and the outer circle of the iron core. An oil passage is provided on the side of the second positioning slot.

3. The drive motor rotor cooling structure according to claim 1, characterized in that, The cross-sectional shape of the oil passage is rectangular, trapezoidal, semi-circular, rhomboid, or elliptical.

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