Motor rotor sheath and motor rotor

Abstract

The application relates to a motor rotor sheath and a motor rotor, an inner peripheral wall of the rotor sheath and / or an interior of the rotor sheath is provided with a spiral cooling groove through which a cooling medium can flow; the spiral cooling groove penetrates the rotor sheath along an axial direction, and both ends of the rotor sheath are respectively provided with a flow guide opening through which the cooling medium can flow into and out of the spiral cooling groove. The motor rotor comprises a permanent magnet, a rotating shaft and the above rotor sheath, the rotor sheath is sleeved outside the permanent magnet and is connected with the rotating shaft. When the motor operates, the cooling medium in the motor can enter the spiral cooling groove of the sheath through the flow guide opening, so that the cooling medium can take away the heat of the rotor from both sides of the sheath, not only the heat dissipation efficiency can be improved, the demagnetization phenomenon of the permanent magnet caused by high temperature can be avoided, but also the eddy current loss can be effectively reduced, and the reliable operation of the motor can be ensured.

Description

Technical Field

[0001] This invention relates to the field of motor rotor technology, specifically to a motor rotor sheath and a motor rotor. Background Technology

[0002] High-speed motors face challenges in heat dissipation due to their small size, high power density, and high loss density. Surface-mounted internal rotor motors typically use solid or toroidal permanent magnets. Since permanent magnets are brittle materials and cannot withstand significant centrifugal tensile stress, they are usually encased in a protective sleeve to ensure their safety during high-speed operation. During high-frequency, high-speed operation, the rotor's induced eddy current losses increase rapidly, causing a sharp rise in rotor temperature. If heat dissipation is insufficient, irreversible demagnetization of the permanent magnets due to overheating can occur, leading to decreased motor accuracy or reduced motor efficiency.

[0003] For inner rotors with alloy sheaths, a common heat dissipation method is to create radial or helical grooves on the outer surface of the sheath. This method increases heat dissipation capacity by improving the flow rate of the cooling medium passing through the rotor surface, but the heat dissipation effect is relatively limited. Therefore, while ensuring stable high-speed operation of the motor, it is particularly important to reduce eddy current losses and increase rotor heat dissipation capacity to lower its operating temperature. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art in reducing the generation of high-frequency eddy current loss of rotor and the difficulty of rotor heat dissipation, thereby providing a motor rotor sheath and motor rotor that can effectively reduce eddy current loss and improve rotor heat dissipation.

[0005] To address the aforementioned problems, in a first aspect, the present invention provides a motor rotor sleeve, wherein the inner peripheral wall of the rotor sleeve and / or the interior of the rotor sleeve are provided with spiral cooling grooves for the flow of cooling medium.

[0006] The spiral cooling groove extends axially through the rotor sleeve, and the rotor sleeve has flow guide openings at both ends for the cooling medium to flow into and out of the spiral cooling groove.

[0007] Optionally, the inner circumferential wall of the rotor sheath is provided with multiple sets of spiral cooling grooves, and the multiple sets of spiral cooling grooves are arranged at intervals along the circumference of the rotor sheath; the guide openings are multiple sets, and each set corresponds to one of the multiple sets of spiral cooling grooves.

[0008] Optionally, each group of spiral cooling grooves includes a first spiral cooling groove and a second spiral cooling groove with opposite directions of rotation;

[0009] The first and second spiral cooling grooves of the multiple sets of spiral cooling grooves intersect each other on the inner peripheral wall of the rotor sheath to form a mesh-like cooling channel and cover the inner surface of the rotor sheath.

[0010] Optionally, the first spiral cooling groove is left-handed, and the width of the first spiral cooling groove is greater than the width of the second spiral cooling groove.

[0011] Optionally, the rotor sheath includes:

[0012] A hollow section is provided on the rotor sheath, and the hollow section is spiral-shaped;

[0013] The main body of the sheath is a hollow tubular structure with a spiral hollow channel inside, which constitutes the spiral cooling groove.

[0014] Optionally, the sheath body includes:

[0015] The spiral section is composed of multiple hollow spiral coils;

[0016] The connecting end includes a first connecting end and a second connecting end located at both ends of the spiral part, and the first connecting end and the second connecting end are respectively provided with the flow guide opening.

[0017] Optionally, the sheath body further includes a reinforcing portion connected between two adjacent spiral coils;

[0018] And / or, the wall thickness of the hollow spiral ring is not less than 1 / 4 of the thickness of the sheath body.

[0019] In a second aspect, the present invention provides an electric motor rotor, comprising a permanent magnet, a rotating shaft, and the aforementioned rotor sheath, wherein the rotor sheath is sleeved on the permanent magnet and connected to the rotating shaft.

[0020] Optionally, the rotating shaft includes a first short shaft and a second short shaft disposed on both sides of the permanent magnet, and the flow guide openings are formed on both end faces of the rotor sheath;

[0021] The first short shaft and the second short shaft are respectively provided with annular positioning steps suitable for limiting and abutting against the two ends of the rotor sheath, and the two annular positioning steps are respectively provided with communicating grooves suitable for communicating with the flow guide opening.

[0022] Optionally, the connecting groove includes a plurality of inclined grooves spaced circumferentially on the annular positioning step, and the plurality of inclined grooves correspond one-to-one with a plurality of the flow guiding openings;

[0023] When the rotor sheath draws in the cooling medium, the inclination direction of the plurality of inclined slots located on the medium drawing side is in line with the rotation direction of the motor.

[0024] The present invention has the following advantages:

[0025] 1. Using the technical solution of the present invention, when the motor is running, the cooling medium inside the motor can be drawn into the spiral cooling groove of the sheath through the guide opening, so that the cooling medium can carry away the heat accumulated by the rotor from both the inner and outer sides of the sheath. This not only accelerates the reduction of rotor temperature and ensures that the permanent magnet will not be demagnetized due to high temperature, but also effectively reduces eddy current loss and ensures reliable operation of the motor.

[0026] 2. In this invention, a spiral cooling groove is formed on the inner surface of the rotor sleeve. The spiral cooling groove extends through both ends of the sleeve, and corresponding guide openings communicating with the spiral cooling groove are formed on both ends of the sleeve, allowing the interior of the spiral cooling groove to communicate with the exterior of the sleeve. Due to the spiral cooling groove, during rotor operation, the cooling medium inside the motor flows into the sleeve through the guide openings, directly carrying away the heat accumulated inside the sleeve. At this time, the cooling medium can directly contact the permanent magnet, carrying away the large amount of heat generated by the magnet at high frequency in the most direct way. In addition, the cooling medium inside the motor can also directly flow through the outer surface of the sleeve, carrying away the heat transferred to the outer surface of the sleeve. The motor cooling medium flows through the inside and outside of the rotor, achieving efficient heat dissipation through both internal and external channels. This not only accelerates the reduction of rotor temperature but also effectively ensures that the permanent magnet will not demagnetize due to high temperature.

[0027] 3. By opening spiral cooling grooves on the inner circumferential wall of the sheath, the present invention can not only effectively remove heat from the inside and outside of the rotor, but also reduce the weight of the rotor itself. The sheath is made of non-magnetic material, which will generate eddy current losses when the motor is running. Opening cooling grooves on the inner circumferential wall of the rotor sheath can effectively prevent the formation of eddy current loops, thereby reducing rotor eddy current losses, reducing motor heat generation and improving energy efficiency.

[0028] 4. The spiral cooling groove described in this invention includes a first spiral cooling groove and a second spiral cooling groove with opposite directions of rotation. The first spiral cooling groove is left-handed, and its width is greater than that of the second spiral cooling groove. By adopting the above design, the first spiral cooling groove serves as the main groove for coolant flow, providing a wide and unobstructed main flow path for the cooling fluid. This allows the cooling medium to quickly pass through the sheath under centrifugal force, carrying away the heat accumulated inside the sheath. The second spiral cooling groove, as a secondary groove, serves to reduce load and divert flow. The combined effect of the first and second spiral cooling grooves greatly improves the rotor's heat dissipation.

[0029] 5. In this invention, the sheath body has a spiral hollow channel inside, through which the cooling medium can pass to accelerate the removal of heat from the inside of the sheath and improve heat dissipation efficiency. Furthermore, the rotor sheath has a spiral hollow part, which makes the sheath body form a hollow structure. The cooling medium can also directly remove heat from the permanent magnet through the hollow part. At the same time, the hollow design greatly reduces the overall eddy current loss of the sheath, reduces the weight of the rotor itself, improves the running accuracy, and makes the rotor dynamic response better and the motor run more smoothly.

[0030] 6. In this invention, a connecting groove is provided on the rotating shaft. The connecting groove corresponds to and communicates with the flow guide opening at the end of the sheath, so that the cooling medium inside the motor can enter the spiral cooling groove of the rotor sheath through the connecting groove. It is more convenient to open or process the connecting groove on the rotating shaft, and the effect is better.

[0031] 7. In this invention, the connecting groove includes multiple inclined grooves spaced circumferentially on the annular positioning step. Each inclined groove corresponds one-to-one with a set of guide openings. Furthermore, when the rotor sheath draws in the cooling medium, the inclination direction of the multiple inclined grooves on the medium intake side aligns with the rotation direction of the motor. By adopting this design, the multiple inclined grooves function similarly to centrifugal fan blades, allowing the rotor to better draw in the cooling medium during high-speed operation. This accelerates the entry of the cooling medium into the sheath's cooling grooves, allowing the high-speed flowing cooling medium to pass through the spiral cooling grooves inside the sheath, carrying away the heat accumulated inside the sheath and further improving the heat dissipation effect. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 A partial cross-sectional view of the motor rotor in the embodiment is shown;

[0034] Figure 2 A cross-sectional view of the rotor sheath in the embodiment is shown;

[0035] Figure 3 A schematic diagram of spiral cooling grooves formed on the inner peripheral wall of the sheath in the embodiment is shown;

[0036] Figure 4 A schematic diagram of the motor rotor cross-section is shown in the embodiment;

[0037] Figure 5 A schematic diagram of the rotor short shaft in the embodiment is shown;

[0038] Figure 6 A cross-sectional schematic diagram of the rotor short shaft with a connecting slot is shown in the embodiment;

[0039] Figure 7 A schematic diagram of the rotor sheath in the second embodiment is shown;

[0040] Figure 8 It shows Figure 7 Another structural diagram from a different perspective;

[0041] Figure 9 It shows Figure 7 A cross-sectional view;

[0042] Figure 10 A schematic diagram of the rotor sheath according to the third embodiment is shown;

[0043] Figure 11 It shows Figure 10 Another structural diagram from a different perspective;

[0044] Figure 12 A cross-sectional view of the motor rotor in the embodiment is shown;

[0045] Explanation of reference numerals in the attached figures:

[0046] 10. Rotor sleeve; 11. Spiral cooling groove; 111. First spiral cooling groove; 112. Second spiral cooling groove; 12. Guide opening;

[0047] 101. Hollowed-out section; 102. Sheath body; 1021. Spiral section; 1022. Connecting end; 1023. Reinforcing section;

[0048] 20. Rotating shaft; 21. Annular positioning step; 211. Communicating groove; 22. Axial connection section;

[0049] 30. Permanent magnet. Detailed Implementation

[0050] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0054] Example 1

[0055] like Figures 1 to 12 As shown, this embodiment provides a motor rotor sleeve 10, wherein the inner peripheral wall of the rotor sleeve 10 and / or the interior of the rotor sleeve 10 are provided with a spiral cooling groove 11 for the flow of cooling medium; the spiral cooling groove 11 extends through the rotor sleeve 10 along the axial direction, and the two ends of the rotor sleeve 10 are respectively provided with guide openings 12 for the flow of cooling medium into and out of the spiral cooling groove 11.

[0056] Using the above technical solution, when the rotor is running, the cooling medium inside the motor can enter the spiral cooling groove 11 of the sheath through the guide opening 12, so that the cooling medium can carry away the heat accumulated by the rotor from both the inside and outside of the sheath. This not only speeds up the reduction of rotor temperature and ensures that the permanent magnet 30 will not be demagnetized due to high temperature, but also effectively reduces eddy current losses and ensures reliable operation of the motor.

[0057] In this embodiment, the flow guiding opening 12 is adapted to connect the interior of the spiral cooling groove 11 and the exterior of the sheath, so that the cooling medium can enter the spiral cooling groove 11. Optionally, the flow guiding opening 12 can be disposed on the end face of the rotor sheath 10, with both ends of the spiral cooling groove 11 extending to both end faces of the sheath to form the flow guiding opening 12. Alternatively, a notch or through hole can be formed on the end peripheral wall of the rotor sheath 10 to form the flow guiding opening 12.

[0058] In this embodiment, when the motor rotates, the guide opening 12 at the first end of the rotor sleeve 10 serves as an inlet to draw the cooling medium inside the motor into the spiral cooling groove 11; the guide opening 12 at the second end of the rotor sleeve 10 serves as an outlet for the cooling medium to flow out. When the motor rotates in the reverse direction, the guide opening 12 at the second end of the rotor sleeve 10 serves as an inlet to draw the cooling medium inside the motor into the spiral cooling groove 11; the guide opening 12 at the first end of the rotor sleeve 10 serves as an outlet for the cooling medium to flow out.

[0059] In this embodiment, the rotor sheath 10 is made of a high-temperature resistant, high-strength, non-magnetic alloy material.

[0060] like Figures 1 to 6 and Figure 12 As shown, in the first embodiment of this example, the spiral cooling groove 11 is formed on the inner peripheral wall of the rotor sleeve 10, that is, the spiral cooling groove 11 is a groove structure formed on the inner peripheral surface of the rotor sleeve 10. By forming the spiral cooling groove 11 on the inner surface of the rotor sleeve 10, the spiral cooling groove 11 penetrates through both ends of the sleeve, and the two ends of the sleeve are correspondingly provided with guide openings 12 communicating with the spiral cooling groove 11, so that the inside of the cooling groove is connected to the outside of the sleeve.

[0061] Due to the spiral cooling groove 11, during rotor operation, the cooling medium inside the motor flows into the sheath through the guide opening 12, directly carrying away the heat accumulated inside the sheath. At this time, the cooling medium can directly contact the permanent magnet 30, carrying away the large amount of heat generated by the magnet at high frequency in the most direct way. In addition, the cooling medium inside the motor can also flow directly across the outer surface of the sheath, carrying away the heat transferred to the outer surface of the sheath. The motor cooling medium flows through the inside and outside of the rotor, realizing efficient heat dissipation through both internal and external channels. This not only accelerates the reduction of rotor temperature but also effectively ensures that the permanent magnet 30 will not demagnetize due to high temperature.

[0062] Optionally, the inner peripheral wall of the rotor sleeve 10 is provided with multiple sets of spiral cooling grooves 11, and the multiple sets of spiral cooling grooves 11 are arranged at intervals along the circumference of the rotor sleeve 10; the guide openings 12 are multiple sets, and correspond one-to-one with the multiple sets of spiral cooling grooves 11.

[0063] In the above scheme, by setting multiple sets of spiral cooling grooves 11, the number of channels for the cooling medium to circulate can be increased, thereby improving the heat dissipation effect.

[0064] This embodiment uses spiral cooling grooves 11 on the inner circumferential wall of the sheath to effectively remove heat from the inside and outside of the rotor, and also to reduce the weight of the rotor itself. The sheath is made of non-magnetic material, which will generate eddy current losses when the motor is running. The cooling grooves on the inner circumferential wall of the rotor sheath 10 can effectively prevent the formation of eddy current loops, thereby reducing rotor eddy current losses, reducing motor heat generation and improving energy efficiency.

[0065] Optionally, in this embodiment, each set of spiral cooling grooves 11 includes a first spiral cooling groove 111 and a second spiral cooling groove 112 with opposite directions of rotation; the first spiral cooling grooves 111 and the second spiral cooling grooves 112 of the multiple sets of spiral cooling grooves 11 intersect each other to form a mesh-like cooling channel on the inner peripheral wall of the rotor sleeve 10, and cover the inner surface of the rotor sleeve 10.

[0066] In the above scheme, the first spiral cooling groove 111 is left-handed and serves as the main groove for the flow of coolant, which is the main flow path of the cooling fluid. This allows the cooling medium to quickly pass through the sheath under the action of centrifugal force and carry away the heat accumulated inside the sheath. The second spiral cooling groove 112 is right-handed and serves as the secondary groove to reduce load and divert flow. With the cooperation of the first spiral cooling groove 111 and the second spiral cooling groove 112, the heat dissipation effect of the rotor can be greatly improved.

[0067] Of course, in other variations, the first spiral cooling groove 111 can also rotate clockwise and serve as the main groove for coolant flow.

[0068] Specifically, in this embodiment, the first spiral cooling groove 111 spirals counterclockwise from the first end of the rotor sleeve 10 to the second end, and the second spiral cooling groove 112 spirals clockwise from the first end of the rotor sleeve 10 to the second end. When the motor rotates clockwise, the cooling medium enters through the guide opening 12 at the first end of the rotor sleeve 10 and flows along the first end of the first spiral cooling groove 111 towards the second end, and then flows out from the guide opening 12 at the second end; when the motor rotates counterclockwise, the cooling medium enters through the guide opening 12 at the second end of the rotor sleeve 10 and flows along the second end of the first spiral cooling groove 111 towards the first end, and then flows out from the guide opening 12 at the first end.

[0069] Optionally, in this embodiment, the first spiral cooling groove 111 is left-handed, and the width of the first spiral cooling groove 111 is greater than the width of the second spiral cooling groove 112. This design allows the first spiral cooling groove 111 to provide a wide and unobstructed flow path for the cooling fluid, increasing the flow rate of the coolant and increasing the contact area between the coolant and the permanent magnet 30, thereby improving the cooling effect.

[0070] Preferably, the width of the first spiral cooling groove 111 is 10% to 40% larger than the width of the second spiral cooling groove 112.

[0071] In this embodiment, a grid-like cooling channel is formed on the inner surface of the sheath and covers and penetrates the inner surface of the sheath. The spiral cooling groove 11 can be rectangular or semi-circular, and the groove depth and groove spacing are designed according to the actual strength requirements. The first spiral cooling groove 111 and the second spiral cooling groove 112 are intertwined and connected.

[0072] In this embodiment, the first spiral cooling groove 111 serves as the main groove. Viewed from the medium intake side, the first spiral cooling groove 111 aligns with the motor's rotation direction. For example, if the motor rotates clockwise, the first spiral cooling groove 111 should rotate approximately counter-clockwise or approximately counter-clockwise. The cooling medium flows from the first end of the first spiral cooling groove 111 into the second end and out. Conversely, if the motor rotates counter-clockwise, the medium flows from the second end of the first spiral cooling groove 111 into the first end and out. The second spiral cooling groove 112 serves as the secondary groove, intersecting with the main groove in the opposite direction to form a grid pattern. The openings of the main groove and the secondary groove converge and overlap at both ends of the sheath, forming multiple guide openings 12 evenly distributed circumferentially along the rotor sheath 10. When the cooling medium flows through the inside of the sheath, the main groove provides a wide and unobstructed main flow path for the cooling fluid. Under centrifugal force, the cooling medium quickly passes through the cooling grooves inside the sheath, while the secondary grooves act as diversion and load reduction channels. Both contribute to the heat dissipation inside the sheath.

[0073] Combination Figures 7 to 9 As shown, in the second embodiment of this example, the spiral cooling groove 11 is disposed inside the rotor sheath 10.

[0074] Optionally, the rotor sheath 10 includes a hollow portion 101 and a sheath body 102. The hollow portion 101 is disposed on the rotor sheath 10 and is spiral in shape. The sheath body 102 is a hollow tubular structure with a spiral hollow channel inside, and the hollow channel constitutes the spiral cooling groove 11.

[0075] In the above scheme, the sheath body 102 has a spiral hollow channel inside, and the cooling medium can enter the hollow channel to accelerate the removal of heat from the inside of the sheath and improve the heat dissipation efficiency. In addition, the rotor sheath 10 has a spiral hollow part 101, which makes the sheath body 102 form a hollow structure. The cooling medium can also directly remove the heat of the permanent magnet 30 through the hollow part 101. At the same time, the hollow design greatly reduces the overall eddy current loss of the sheath, reduces the weight of the rotor itself, improves the running accuracy, and makes the rotor dynamic response better and the motor run more smoothly.

[0076] Optionally, the sheath body 102 includes a spiral portion 1021 and a connecting end 1022. The spiral portion 1021 is composed of a plurality of hollow spiral coils. The connecting end 1022 includes a first connecting end and a second connecting end located at both ends of the spiral portion 1021. The first connecting end and the second connecting end are respectively provided with the flow guide opening 12.

[0077] In the above scheme, the rotor sleeve 10 is a hollow spiral tube structure, and the hollow channel inside the hollow spiral tube forms the spiral cooling groove 11. The middle of the sleeve is spiral tube-shaped, and the spiral ring can be a single spiral tube or a multi-spiral tube structure. The two ends of the sleeve are short cylindrical structures forming the first connecting end and the second connecting end. The first connecting end and the second connecting end are respectively provided with guide openings 12 that connect to the spiral cooling groove 11. The motor cooling medium can be drawn in through the guide opening 12 on one side, then enter the hollow spiral tube-shaped sleeve and flow out of the sleeve through the guide opening 12 on the other end, or flow out directly through the hollow part 101, thereby directly carrying away the heat generated by the rotor sleeve 10 and the permanent magnet 30 and reducing the rotor temperature.

[0078] Optionally, the sheath body 102 further includes a reinforcing portion 1023 connected between two adjacent spiral coils, wherein the reinforcing portion 1023 is a reinforcing rib connected between two adjacent spiral coils. The reinforcing ribs further improve the overall structural strength of the rotor sheath 10. Optionally, multiple reinforcing ribs are provided between two adjacent spiral coils along the circumferential direction of the sheath body 102.

[0079] Optionally, the wall thickness of the hollow spiral ring is not less than 1 / 4 of the thickness of the sheath body 102. By adopting the above design, it is possible to effectively avoid the hollow channel diameter inside the spiral ring being too large, which would result in the spiral ring having too small a wall thickness and thus too low structural strength.

[0080] like Figure 10 and Figure 11 As shown, this embodiment also provides a third implementation of the rotor sheath 10, which is a variation of the second implementation described above:

[0081] The main difference between this modified embodiment and the second embodiment is that the sheath body 102 is a solid spiral tubular structure, that is, there is no longer a spiral hollow channel inside it, and there is no need to introduce cooling medium inside the sheath. The cooling medium can directly enter the sheath through the spiral hollow part 101, and the heat dissipation effect is also quite considerable. Although it adopts a solid structure and eliminates the internal hollow channel, the overall structural strength of the rotor sheath 10 will be improved.

[0082] Compared to the existing solution of setting cooling grooves on the outer surface of the sheath, the sheath structure provided in this embodiment allows some of the magnets to be directly exposed. This allows the cooling medium to cool the outer surface of the rotor and also directly cool the magnets inside the rotor. In addition, the spiral structure of the sheath itself can also generate high-speed spiral fluid and air pressure, which is more conducive to heat dissipation and has a better heat dissipation effect.

[0083] Example 2

[0084] like Figures 1 to 12 As shown, this embodiment provides a motor rotor, including a permanent magnet 30, a rotating shaft 20, and the aforementioned rotor sleeve 10. The rotor sleeve 10 is sleeved outside the permanent magnet 30 and connected to the rotating shaft 20.

[0085] In this embodiment, the motor rotor is a surface-mounted rotor, and the permanent magnet 30, the rotating shaft 20, and the rotor sleeve 10 are connected by an interference fit. The spiral cooling grooves 11 inside the rotor sleeve 10 independently form a cooling space inside the rotor sleeve 10, or the fitting clearance between the spiral cooling grooves 11 on the inner circumferential wall of the rotor sleeve 10 and the permanent magnet 30 and the short shaft forms a cooling space inside the rotor sleeve 10. The permanent magnet 30 is a magnetic steel.

[0086] Optionally, such as Figure 1 , Figure 5 , Figure 6 , Figure 12 As shown, the rotating shaft 20 includes a first short shaft and a second short shaft disposed on both sides of the permanent magnet 30, and the flow guide opening 12 is formed on both end faces of the rotor sleeve 10; the first short shaft and the second short shaft are respectively provided with annular positioning steps 21 suitable for limiting and abutting against the two ends of the rotor sleeve 10, and the two annular positioning steps 21 are respectively provided with communicating grooves 211 suitable for communicating with the flow guide opening 12.

[0087] The short shaft has a corresponding connecting groove 211 at the end that connects with the sheath to provide a cooling medium inlet and outlet, so that the inner surface of the rotor sheath 10 and the contact surface of the permanent magnet 30 and the short shaft form an internal cooling space for the rotor. When the rotor dissipates heat, the cooling medium can carry away the heat on the rotor surface or enter the sheath to carry away the heat generated by the magnet, thus achieving efficient heat dissipation through both internal and external channels.

[0088] Specifically, in this embodiment, the motor rotor is a three-section type. The rotating shaft 20 includes a first short shaft and a second short shaft. The motor rotor includes a first short shaft, a second short shaft, a permanent magnet 30 located in the middle section, and a rotor sleeve 10. The first short shaft and the second short shaft are located on both sides of the permanent magnet 30. The rotor sleeve 10 is sleeved on the outside of the permanent magnet 30 and the first and second short shafts to connect the two short shafts with the permanent magnet 30. The short shafts and the permanent magnet 30 are in axial surface contact. The rotor sleeve 10 is connected to the short shafts and the magnets by a circumferential interference fit, thereby realizing the connection of the entire motor rotor.

[0089] In this embodiment, both the first short shaft and the second short shaft are stepped, which facilitates the assembly of components.

[0090] In this embodiment, the rotating shaft 20 is a solid structure. The rotating shaft 20 includes an axial connecting section 22 extending into the rotor sleeve 10. The outer diameter of the axial connecting section 22 is the same as the outer diameter of the permanent magnet 30. The end face of the axial connecting section 22 is in contact with the surface of the permanent magnet 30. The rotor sleeve 10 then provides an interference fit between the axial connecting section 22 of the first and second short shafts and the permanent magnet 30, achieving a stable and reliable connection between the permanent magnet 30 and the rotating shaft 20. The outer diameter of the annular positioning step 21 is the same as the outer diameter of the rotor sleeve 10. The flow-guiding opening 12 at the end of the sleeve is aligned with the connecting groove 211 on the annular positioning step 21. Optionally, the cooling medium can enter the spiral cooling groove 11 through the connecting groove 211 and the flow-guiding opening 12 of the first short shaft, and then flow out through the connecting groove 211 of the second short shaft at the other end.

[0091] In this embodiment, the connecting groove 211 is provided on the outer periphery of the end face of the annular positioning step 21 and the rotor sleeve 10, and the groove structure of the first short shaft and the second short shaft is the same.

[0092] The motor cooling medium can be introduced into the sheath with a hollow spiral channel under the action of the short shaft connecting groove 211 and flow out after spiral motion, or enter the sheath through the spiral cooling groove 11 on the inner peripheral wall of the sheath, or directly enter the sheath through the hollow part 101, directly taking away the heat generated by the sheath and permanent magnet 30 and reducing the rotor temperature.

[0093] In this embodiment, a connecting groove 211 is provided on the rotating shaft 20. The connecting groove 211 corresponds to and is connected to the flow guide opening 12 at the end of the sheath, so that the cooling medium inside the motor can enter the spiral cooling groove 11 of the rotor sheath 10 through the connecting groove 211. It is more convenient to open or process the connecting groove 211 on the rotating shaft 20, and the effect is better.

[0094] Optionally, the connecting groove 211 includes a plurality of inclined grooves spaced circumferentially on the annular positioning step 21, with each inclined groove corresponding to a plurality of sets of flow guide openings 12; when the rotor sleeve 10 draws in the cooling medium, the inclination direction of the plurality of inclined grooves on the medium intake side follows the rotation direction of the motor. Here, "follows" is interpreted as: if the motor rotates clockwise, the inclination direction of the openings of the plurality of inclined grooves on the medium intake side should be clockwise, and vice versa.

[0095] In the above scheme, the connecting groove 211 is formed at the peripheral edge of the annular positioning step 21, and the inclined groove is an inclined notch formed on the circumferential edge of the annular positioning step 21. The opening of the inclined groove corresponds to and communicates with the guide opening 12 of the sheath. The connecting groove 211 is formed on the outer peripheral wall or end wall of the annular positioning step 21. Figure 6 As shown, the tangential angle of the inclined groove is set to... α The tangential angles of the multiple inclined slots are inclined in the direction of the motor's rotation. Optionally, α Between 30 and 60°.

[0096] In this embodiment, as Figure 5 and Figure 6 As shown, the connecting groove 211 includes multiple inclined grooves spaced circumferentially on the annular positioning step 21. Each inclined groove corresponds to one of the multiple sets of flow-guiding openings 12. When the rotor sleeve 10 draws in the cooling medium, the inclination direction of the multiple inclined grooves on the medium-drawing side follows the rotation direction of the motor. By adopting this design, the multiple inclined grooves can function similarly to centrifugal fan blades, allowing the rotor to better draw in the cooling medium during high-speed operation, accelerating the entry of the cooling medium into the cooling grooves of the sleeve. This allows the high-speed flowing cooling medium to pass through the spiral cooling grooves 11 inside the sleeve, carrying away the heat accumulated inside the sleeve, thereby further improving the heat dissipation effect.

[0097] In this embodiment, the rotor sleeve 10 has a grid-like spiral cooling groove 11 inside, with the main and auxiliary grooves interlacing to guide the cooling medium, which can directly cool the permanent magnet 30; alternatively, the sleeve is a hollow spiral tube, with the cooling medium flowing through it, and the sleeve has a hollow design, so the cooling medium can cool both the sleeve and the permanent magnet 30. Both of these design methods effectively increase heat dissipation channels, improve heat dissipation efficiency, reduce rotor temperature, and simultaneously reduce eddy current losses, resulting in better heat dissipation.

[0098] In this embodiment, when the inner surface of the sheath has spiral cooling grooves 11 or a spiral structure, the cooling medium inside the motor can flow not only across the rotor surface but also into the sheath during operation, directly and efficiently removing the heat generated by the permanent magnet 30, achieving multi-area and multi-path heat dissipation of the rotor. Furthermore, the staggered mesh cooling channels, hollow sheath, or spiral sheath structure can also reduce the generation of eddy currents in the rotor sheath 10 to a certain extent, thus reducing the heat loss due to eddy currents. In summary, this embodiment efficiently reduces the rotor temperature by increasing the rotor's heat dissipation capacity and reducing heat generation in the sheath. This lowers the risk of demagnetization of the rotor permanent magnet 30, allowing the motor to operate more reliably, efficiently, and stably.

[0099] It should be noted that the outer surface of the rotor sheath 10 also refers to the outer surface of the rotor, which is located inside the motor. The motor requires a cooling medium (such as refrigerant) to cool the rotor and stator. Since the motor's internal space is sealed, the internal cooling space of the rotor is increased by the internal mesh cooling channels or spiral structure of the rotor sheath 10, which optimizes the rotor's heat dissipation effect and reduces eddy current losses, thereby enabling the motor to operate more efficiently and stably at high frequencies and high speeds.

[0100] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A motor rotor, characterized in that, It includes a permanent magnet (30), a rotating shaft (20) and a rotor sleeve (10), wherein the rotor sleeve (10) is fitted over the permanent magnet (30) and connected to the rotating shaft (20); The inner peripheral wall of the rotor sleeve (10) and / or the interior of the rotor sleeve (10) are provided with spiral cooling grooves (11) for the flow of cooling medium; The spiral cooling groove (11) extends through the rotor sleeve (10) along the axial direction. Both ends of the rotor sleeve (10) are respectively provided with guide openings (12) for the cooling medium to flow into and out of the spiral cooling groove (11). The rotating shaft (20) includes a first short shaft and a second short shaft disposed on both sides of the permanent magnet (30), and the flow guide opening (12) is formed on both end faces of the rotor sheath (10); The first short shaft and the second short shaft are respectively provided with annular positioning steps (21) suitable for limiting and abutting against the two ends of the rotor sleeve (10), and the two annular positioning steps (21) are respectively provided with communicating grooves (211) suitable for communicating with the flow guide opening (12); The connecting groove (211) includes a plurality of inclined grooves spaced circumferentially on the annular positioning step (21), and the plurality of inclined grooves correspond one-to-one with the plurality of the flow guiding openings (12); The inclined groove is a notch groove that is inclinedly arranged on the circumferential edge of the annular positioning step (21); When the rotor sleeve (10) draws in the cooling medium, the inclination direction of the plurality of grooves located on the medium drawing side is in line with the rotation direction of the motor.

2. The motor rotor according to claim 1, characterized in that, The inner circumferential wall of the rotor sleeve (10) is provided with multiple sets of spiral cooling grooves (11), and the multiple sets of spiral cooling grooves (11) are arranged at intervals along the circumference of the rotor sleeve (10); the guide openings (12) are multiple sets, and correspond one-to-one with the multiple sets of spiral cooling grooves (11).

3. The motor rotor according to claim 2, characterized in that, Each set of spiral cooling grooves (11) includes a first spiral cooling groove (111) and a second spiral cooling groove (112) with opposite directions of rotation; The first spiral cooling groove (111) and the second spiral cooling groove (112) of the multiple sets of spiral cooling grooves (11) intersect each other to form a mesh-like cooling channel on the inner peripheral wall of the rotor sleeve (10) and cover the inner surface of the rotor sleeve (10).

4. The motor rotor according to claim 3, characterized in that, The first spiral cooling groove (111) is left-handed, and the width of the first spiral cooling groove (111) is greater than the width of the second spiral cooling groove (112).

5. The motor rotor according to claim 1, characterized in that, The rotor sheath (10) includes: A hollow section (101) is provided on the rotor sheath, and the hollow section (101) is spiral in shape; The sheath body (102) is a hollow tubular structure with a spiral hollow channel inside, which constitutes the spiral cooling groove (11).

6. The motor rotor according to claim 5, characterized in that, The sheath body (102) includes: The spiral section (1021) is composed of multiple hollow spiral coils; The connecting end (1022) includes a first connecting end and a second connecting end located at both ends of the spiral part (1021), and the first connecting end and the second connecting end are respectively provided with the flow guide opening (12).

7. The motor rotor according to claim 6, characterized in that, The sheath body (102) also includes a reinforcing part (1023) connected between two adjacent spiral coils; And / or, the wall thickness of the hollow spiral ring is not less than 1 / 4 of the thickness of the sheath body (102).

Images