High-speed permanent magnet motor rotor and design method

Abstract

The invention discloses a high-speed permanent magnet motor rotor and a design method, the high-speed permanent magnet motor rotor comprises a rotor rotating shaft and a plurality of groups of magnetic steels uniformly distributed on the outer surface of the rotor rotating shaft along the circumference, and the outer surfaces of the plurality of groups of magnetic steels and magnetic isolation strips are provided with carbon fiber sheaths. And one or more groups of rotor axial ventilation holes are arranged along the axial direction. According to the high-speed permanent magnet motor rotor, the rotor axial ventilation holes and the rotor radial air ducts are formed in the rotor shaft, the closed structure of an original high-speed permanent magnet motor rotor is broken, and the efficient heat dissipation effect of heat convection is achieved.

Description

Technical Field

[0001] The present invention relates to the field of high-power high-speed permanent magnet motor design, and in particular to a high-speed permanent magnet motor rotor and a design method thereof. Background Art

[0002] In the field of high-power and high-speed permanent magnet motor design, the concept of high speed is generally defined by the tangential speed of the rotor surface in the circumferential direction (hereinafter referred to as the rotor linear speed). The high-power and high-speed permanent magnet motor defined in this invention refers to a rotor linear speed of not less than 100m / s and a power corresponding range of not more than 60MW (hereinafter referred to as the high-power and high-speed permanent magnet motor).

[0003] For high-speed permanent magnet motors (hereinafter referred to as high-speed permanent magnet motors) with a rotor linear speed of not less than 100m / s, the conventional magnetic steel embedded silicon steel sheet laminated iron core rotor structure or the magnetic steel built-in bolt-fixed solid pole permanent magnet rotor structure will not be applicable; because the internal stress generated by centrifugal force will exceed the material strength limit of the silicon steel sheet or the pole fixing bolts themselves and cause damage; and under high-speed conditions, it is not suitable to use a built-in fan to enhance cooling according to the conventional rotor structure, because it will generate huge mechanical losses, seriously affecting the motor efficiency.

[0004] At present, the rotor of a high-speed permanent magnet motor generally adopts a solid shaft, with rotor magnets pasted on the surface and the magnets are circumferentially fixed using a carbon fiber non-metallic sheath or a high-strength metal sheath. The existing structure is a closed structure formed by a solid shaft and a sheath. For the carbon fiber non-metallic sheath, due to its extremely low thermal conductivity, the electromagnetic loss heat generated by the sheath itself, the magnets, and the solid shaft under the action of the air gap magnetic field cannot be effectively dissipated, resulting in heat accumulation. For the metal sheath, a large amount of eddy current loss heat will be generated due to the air gap magnetic field, and the strength of the metal sheath is relatively low. Such heat accumulation has an adverse effect on the demagnetization of the magnets, the strength of the rotor sheath, the motor performance, temperature rise and capacity. Summary of the invention

[0005] The purpose of the present invention is to provide a high-speed permanent magnet motor rotor and a design method, which can break the closed structure of the original high-speed permanent magnet motor rotor by opening rotor axial ventilation holes and rotor radial air ducts on the rotor shaft to achieve efficient heat dissipation effect by thermal convection.

[0006] The present invention adopts the following technical solutions: A high-speed permanent magnet motor rotor comprises a rotor shaft and a plurality of groups of magnetic steels uniformly distributed on the outer surface of the rotor shaft along the circumference, the plurality of groups of magnetic steels and the outer surfaces of magnetic isolation strips are provided with carbon fiber sheaths, and one or more groups of rotor axial ventilation holes are axially provided on the high-speed permanent magnet motor rotor below the plurality of groups of magnetic steels.

[0007] The rotor shaft is a solid shaft, and the rotor axial ventilation hole is axially opened on the solid shaft below the magnetic steel.

[0008] The rotor shaft adopts a ribbed shaft, and a magnetic steel sleeve is provided on the outer circumference of the ribbed shaft; the space between the ribs of two adjacent ribbed shafts forms a rotor axial ventilation hole, and the opening at the outer end of the rotor axial ventilation hole is closed by the magnetic steel sleeve.

[0009] The rotor shaft is a solid shaft, and a magnetic steel sleeve is provided on the outer circumference of the solid shaft; the rotor axial ventilation hole is axially opened on the magnetic steel sleeve.

[0010] A rotor radial air duct connected to the rotor axial ventilation hole is arranged along the radial direction of the solid shaft; the magnetic steel and carbon fiber sheaths on both sides above the rotor radial air duct are both provided with ventilation gaps adapted to the rotor radial air duct.

[0011] The outer circumferential sleeve of the rotor shaft is provided with a plurality of groups of magnetic steel sleeves spaced apart in the axial direction, the interval between two adjacent groups of magnetic steel sleeves forms a rotor radial air duct, and the magnetic steel and carbon fiber sleeves on both sides above the rotor radial air duct are provided with ventilation gaps adapted to the rotor radial air duct.

[0012] A high-speed permanent magnet motor rotor design method is disclosed. According to the rotor shaft structure of the high-speed permanent magnet motor rotor, one or more groups of rotor axial ventilation holes are opened along the axial direction on the high-speed permanent magnet motor rotor below a plurality of groups of magnetic steels.

[0013] One or more groups of rotor radial air ducts are radially arranged on the rotor of the high-speed permanent magnet motor and are interconnected with the rotor axial ventilation holes, and cooperate with the rotor axial ventilation holes to form an axial-radial mixed ventilation air path.

[0014] When opening the rotor axial ventilation hole, the rotor shaft using a solid shaft can be performed according to any of the following methods: a: On the solid shaft below the magnetic steel, a rotor axial ventilation hole is directly opened along the axial direction; b: Process the solid shaft to form a planed shaft, or directly use the planed shaft; then add a magnetic steel sleeve between the planed shaft and a plurality of sets of magnetic steels, use the space between the axial ribs of two adjacent planed shafts to form a rotor axial ventilation hole, and close the opening of the outer end of the rotor axial ventilation hole with the magnetic steel sleeve; c: A magnetic steel sleeve is added between the solid shaft and a plurality of groups of magnetic steels, and a rotor axial ventilation hole is directly opened on the magnetic steel sleeve along the axial direction.

[0015] When opening the rotor radial air duct, one of the following methods shall be selected for the rotor shaft using a solid shaft: d: A rotor radial air duct connected to the rotor axial ventilation hole is directly opened along the radial direction of the solid shaft; and ventilation gaps matching the rotor radial air duct are set at the magnetic steel and carbon fiber sheaths on both sides above the rotor radial air duct; e: Several groups of magnetic steel sleeves are sleeved on the outer circumference of the planing shaft and spaced apart in the axial direction, and the interval between two adjacent groups of magnetic steel sleeves is used to form a rotor radial air duct; and ventilation gaps matching the rotor radial air duct are set at the magnetic steel and carbon fiber sleeves on both sides above the rotor radial air duct; f: A plurality of groups of magnetic steel sleeves are sleeved on the outer circumference of the solid shaft and are spaced apart in the axial direction; a rotor radial air duct is formed by utilizing the interval between two adjacent groups of magnetic steel sleeves; and ventilation gaps matching the rotor radial air duct are arranged at the magnetic steel and carbon fiber sleeves on both sides above the rotor radial air duct.

[0016] The present invention is suitable for high-speed permanent magnet motor rotors without internal fans and using surface-mounted magnetic steel. The ribbed shaft structure and the magnetic sleeve structure are suitable for rotor linear speeds not less than 100 m / s; the solid shaft structure is suitable for rotor linear speeds not exceeding 300 m / s, and has good speed overlap complementarity.

[0017] The present invention can realize radial ventilation segmentation of the rotor, which can generally be divided into two to three sections; in the case of ultra-high power and ultra-long iron core, it can be divided into four to five sections, and has better process and economy.

[0018] The rotor magnetic poles in the present invention can be 4 poles, which can be expanded to 6 poles for high-speed permanent magnet motors, and has good applicability to variable frequency power supply systems.

[0019] Based on the closed structure formed by the existing solid shaft and the sleeve, the present invention respectively arranges rotor axial ventilation holes and rotor radial air ducts in the axial and radial directions of the rotor, which can break the original closed structure and change the existing permanent magnet surface-mounted solid rotor that mainly relies on low-efficiency heat exchange by conduction and radiation to efficient heat dissipation by heat convection through mixed ventilation holes formed by the combination of the rotor radial air duct and the rotor axial ventilation holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of a ventilated solid rotor provided with rotor axial ventilation holes in the present invention; Figure 2 for Figure 1 A schematic cross-sectional structure diagram of; Figure 3 It is a schematic structural diagram of a ventilated solid rotor when a solid shaft is used in the present invention; Figure 4 is a schematic diagram of the cross-sectional structure of a ventilated solid rotor when the cross section of the rotor axial ventilation hole is rectangular; Figure 5 A schematic diagram of the structure of a rectangular rotor axial ventilation hole cross section; Figure 6 It is a schematic diagram of the cross-sectional structure of a ventilated solid rotor when the cross section of the rotor axial ventilation hole is an oblong; Figure 7 A schematic diagram of the structure of the cross section of the rotor axial ventilation hole is an oblong shape; Figure 8 It is a structural schematic diagram of a ventilated solid rotor when a planing shaft and a magnetic steel sleeve are used in cooperation with each other in the present invention; Fig. 9 for Figure 8 A schematic cross-sectional structure diagram of ; Fig.10 It is a structural schematic diagram of a ventilated solid rotor when a solid shaft and a magnetic steel sleeve are used in combination in the present invention; Fig.11 for Fig.10 A schematic cross-sectional structure diagram of ; Fig.12 It is a structural schematic diagram of a ventilated solid rotor provided with a rotor radial air duct in the present invention; Fig.13 for Fig.12 A schematic cross-sectional structure diagram of ; Fig.14 It is a schematic structural diagram of a ventilated solid rotor using a solid shaft and having a set of rotor radial air ducts in the present invention; Fig.15 It is a structural schematic diagram of a ventilated solid rotor using a solid shaft and having two sets of rotor radial air ducts in the present invention; Fig.16 It is a structural schematic diagram of a ventilated solid rotor in the present invention that uses a planing shaft and a magnetic steel sleeve to cooperate and has a set of rotor radial air ducts; Fig.17 It is a structural schematic diagram of a ventilated solid rotor in the present invention that uses a planing shaft and a magnetic steel sleeve to cooperate and has two sets of rotor radial air ducts; Fig.18 It is a structural schematic diagram of a ventilated solid rotor in the present invention, which adopts a solid shaft and a magnetic steel sleeve and has a set of rotor radial air ducts; Fig.19 It is a structural schematic diagram of a ventilated solid rotor in the present invention that uses a solid shaft and a magnetic steel sleeve and has two sets of rotor radial air ducts. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] like Figures 1 to 19 As shown, the high-speed permanent magnet motor rotor of the present invention comprises a rotor shaft 1 and a plurality of groups of magnetic steels 2 evenly distributed on the outer surface of the rotor shaft 1 along the circumference, a plurality of magnetic isolation strips 3 are evenly inserted between the plurality of groups of magnetic steels 2, and the magnetic isolation strips 3 are connected to the rotor shaft 1 by fastening screws; a carbon fiber sheath 4 is provided on the outer surface of the plurality of groups of magnetic steels 2 and the magnetic isolation strips 3; baffles 5 are also provided on the outer surface of the magnetic steels 2 at the front and rear ends. The above structure belongs to the conventional mechanism of the existing motor rotor and will not be described in detail here.

[0023] like Figure 1 and Figure 2 As shown, in the present invention, one or more groups of rotor axial ventilation holes 6 are axially arranged on the high-speed permanent magnet motor rotor below the plurality of groups of magnetic steels 2. The rotor axial ventilation holes 6 can be arranged on the rotor shaft 1, or on the magnetic conductive steel sleeve 8 additionally arranged between the rotor shaft 1 and the plurality of groups of magnetic steels 2.

[0024] In the present invention, the rotor axial ventilation holes 6 provided on the high-speed permanent magnet motor rotor can be realized in the following different ways: Embodiment 1: like Figure 3 , Figure 4 and Figure 6 As shown, the rotor shaft 1 is a solid shaft, and the rotor axial ventilation holes 6 are axially opened on the solid shaft below the magnetic steel 2; the number of the rotor axial ventilation holes 6 can be determined according to actual use requirements. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the solid shaft along the circumference; the cross-sectional midlines of the rotor axial ventilation holes 6 all point to the axis of the solid shaft.

[0025] In Embodiment 1, the cross section of the rotor axial ventilation hole 6 may be rectangular, such as Figure 4 and Figure 5 As shown; it can also be a rectangular top and an arc (approximately an oblong) protruding toward the center of the solid shaft at the bottom, such as Figure 6 and Figure 7 The rotor axial ventilation hole 6 can be milled by a flat-bottom, round-bottom or other-shaped milling cutter, and then closed by a wedge-shaped magnetic conductive slot wedge 7 after milling, so as to finally obtain a rotor axial ventilation hole 6 that meets the set requirements.

[0026] Embodiment 2: like Figure 8 and Fig. 9 As shown, the rotor shaft 1 adopts a ribbed shaft, and a magnetic steel sleeve 8 is provided on the outer circumference of the ribbed shaft; the space between the axial ribs 9 of two adjacent ribbed shafts forms a rotor axial ventilation hole 6, and the opening at the outer end of the rotor axial ventilation hole 6 is closed by the magnetic steel sleeve 8.

[0027] Among them, the planed rib shaft refers to a solid shaft with a plurality of grooves uniformly processed along the axial direction on the circumferential surface by a planer, and the protrusions formed between two adjacent grooves serve as shaft ribs 9, which belongs to the existing technology in this field and will not be described here.

[0028] In Example 2, the number of axial ribs 9 in the planing shaft can be determined according to actual use requirements, thereby determining the number of rotor axial ventilation holes 6. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the planing shaft along the circumference. The cross-section of the rotor axial ventilation hole 6 can be trapezoidal or arc-shaped; the center line of the cross-section of the rotor axial ventilation hole 6 points to the axis of the planing shaft. The magnetic steel sleeve 8 can be made of alloy steel or carbon steel, or can be formed by laminating silicon steel sheets.

[0029] Embodiment 3: like Fig.10 and Fig.11 As shown, the rotor shaft 1 is a solid shaft, and a magnetic steel sleeve 8 is provided on the outer circumference of the solid shaft; the rotor axial ventilation holes 6 are axially opened on the magnetic steel sleeve 8.

[0030] In Embodiment 3, the number of rotor axial ventilation holes 6 can be determined according to actual use requirements. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the magnetic steel sleeve 8 along the circumference. The cross-section of the rotor axial ventilation holes 6 can be trapezoidal or circular; the midlines of the cross-sections of the rotor axial ventilation holes 6 all point to the axis of the solid shaft. The magnetic steel sleeve 8 can be formed by laminating silicon steel sheets.

[0031] In order to cooperate with the rotor axial ventilation holes 6 set on the high-speed permanent magnet motor rotor, the convection heat dissipation effect of the high-speed permanent magnet motor rotor can be further improved. Fig.12 and Fig.13 As shown, in the present invention, a rotor radial air duct 10 which is in communication with the rotor axial ventilation hole 6 is also radially arranged on the rotor of the high-speed permanent magnet motor.

[0032] In the present invention, the rotor radial air duct 10 that is in communication with the rotor axial ventilation hole 6 can be realized in the following different ways: Embodiment 4: like Fig.14 , Fig.15 and Figure 6As shown, the rotor shaft 1 adopts a solid shaft, and the rotor axial ventilation hole 6 is axially opened on the solid shaft below the magnetic steel 2; a rotor radial air duct 10 communicating with the rotor axial ventilation hole 6 is also arranged along the radial direction of the solid shaft; the rotor radial air duct 10 can be one group or multiple groups, and when multiple groups of rotor radial air ducts 10 are arranged, the multiple groups of rotor radial air ducts 10 are evenly arranged along the axial direction of the solid shaft; the magnetic steel 2 and the carbon fiber sheath 4 on both sides above the rotor radial air duct 10 are provided with ventilation gaps 11 adapted to the rotor radial air duct 10, so as to ensure that the rotor axial ventilation hole 6 is communicated with the outside of the rotor through the rotor radial air duct 10 and the ventilation gap 11; In Embodiment 4, the number of the rotor axial ventilation holes 6 can be determined according to actual use requirements. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the solid shaft along the circumference. The cross section of the rotor axial ventilation holes 6 can be rectangular, such as Figure 4 and Figure 5 As shown; it can also be a rectangular top and an arc-shaped bottom protruding toward the axis of the solid shaft (approximately oblong), such as Figure 6 and Figure 7 The rotor axial ventilation hole 6 can be milled by a flat-bottom, round-bottom or other-shaped milling cutter, and then closed by a wedge-shaped magnetic conductive slot wedge 7 after milling, so as to finally obtain a rotor axial ventilation hole 6 that meets the set requirements.

[0033] The number of rotor radial air ducts 10 can be determined according to actual use requirements, such as 1 group (such as Fig.14 as shown) or 2 groups (as Fig.15 As shown). The outer surfaces of the magnetic steel 2 on both sides of the ventilation gap 11 are also provided with magnetic shielding plates 12. The rotor radial air duct 10 can be milled by a milling cutter during processing, so as to finally obtain a rotor radial air duct 10 that meets the set requirements, and cooperate with the rotor axial ventilation hole 6 to form a mixed ventilation air path.

[0034] Embodiment 5: like Fig.16 , Fig.17 and Fig. 9 As shown, the rotor shaft 1 adopts a ribbed shaft, and the space between the ribs 9 of two adjacent ribbed shafts forms a rotor axial ventilation hole 6, and the outer end of the rotor axial ventilation hole 6 is closed by a magnetic steel sleeve 8; a plurality of groups of magnetic steel sleeves 8 are arranged axially at intervals on the outer circumference of the ribbed shaft, and the interval between two adjacent groups of magnetic steel sleeves 8 forms a rotor radial air duct 10, and the magnetic steel 2 and the carbon fiber sheath 4 on both sides above the rotor radial air duct 10 are provided with ventilation gaps 11 adapted to the rotor radial air duct 10, so as to ensure that the rotor axial ventilation hole 6 is connected to the outside of the rotor through the rotor radial air duct 10 and the ventilation gaps 11.

[0035] In Embodiment 5, the number of axial ribs 9 in the planing shaft can be determined according to actual use requirements, thereby determining the number of rotor axial ventilation holes 6. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the planing shaft along the circumference. The cross-section of the rotor axial ventilation hole 6 can be trapezoidal or arc-shaped; the center lines of the cross-sections of the rotor axial ventilation holes 6 all point to the axis of the planing shaft. The magnetic steel sleeve 8 can be made of alloy steel or carbon steel, or can be formed by laminating silicon steel sheets.

[0036] The number of rotor radial air ducts 10 can be determined according to actual use requirements, such as 1 group (such as Fig.16 as shown) or 2 groups (as Fig.17 The rotor radial air duct 10 cooperates with the rotor axial ventilation hole 6 to form a mixed ventilation air path. Magnetic shielding plates 12 are also provided on the outer surfaces of the magnetic steel 2 and the carbon fiber sheath 4 on both sides of the ventilation gap 11.

[0037] Embodiment 6: like Fig.18 , Fig.19 and Fig.11 As shown, the rotor shaft 1 is a solid shaft, and the outer circumference of the solid shaft is sleeved with a plurality of groups of magnetic steel sleeves 8 arranged at intervals in the axial direction; the rotor axial ventilation holes 6 are opened in the plurality of groups of magnetic steel sleeves 8 in the axial direction. The interval between two adjacent groups of magnetic steel sleeves 8 forms a rotor radial air duct 10, and the magnetic steel 2 and the carbon fiber sheath 4 on both sides above the rotor radial air duct 10 are provided with ventilation gaps 11 adapted to the rotor radial air duct 10, so as to ensure that the rotor axial ventilation holes 6 are connected to the outside of the rotor through the rotor radial air duct 10 and the ventilation gaps 11; In Embodiment 6, the number of the rotor axial ventilation holes 6 can be determined according to actual use requirements. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the magnetic steel sleeve 8 along the circumference. The cross-section of the rotor axial ventilation holes 6 can be trapezoidal or circular; the midlines of the cross-sections of the rotor axial ventilation holes 6 all point to the axis of the solid shaft. The magnetic steel sleeve 8 can be formed by laminating silicon steel sheets.

[0038] The number of rotor radial air ducts 10 can be determined according to actual use requirements, such as 1 group (such as Fig.18 as shown) or 2 groups (as Fig.19 Magnetic shielding plates 12 are also provided on the outer surfaces of the magnetic steel 2 and the carbon fiber sheath 4 on both sides of the ventilation gap 11. The rotor radial air duct 10 cooperates with the rotor axial ventilation hole 6 to form a mixed ventilation air path.

[0039] As shown in the above embodiments, the ventilated solid rotor described in the present invention is suitable for a high-speed permanent magnet motor rotor without an internal fan and using a surface-mounted magnetic steel 2. It can break the original closed structure by setting a number of rotor axial ventilation holes 6 and rotor radial air ducts 10 that are interconnected on the basis of the existing closed structure formed by the solid shaft and the sleeve, and change the existing permanent magnet surface-mounted solid rotor that mainly relies on conduction and radiation for low-efficiency heat exchange to a mixed ventilation air path formed by a combination of the rotor radial air duct 10 and the rotor axial ventilation holes 6 for efficient heat dissipation by heat convection.

[0040] like Figure 1 and Figure 2 As shown, the design method of the high-speed permanent magnet motor rotor described in the present invention is to open one or more groups of rotor axial ventilation holes 6 along the axial direction on the high-speed permanent magnet motor rotor below several groups of magnetic steels 2 according to the rotor shaft 1 structure of the high-speed permanent magnet motor rotor.

[0041] When opening the rotor axial ventilation hole 6, the solid shaft is subjected to any of the following methods: a: A rotor axial ventilation hole 6 is directly opened along the axial direction on the solid shaft below the magnetic steel 2; b: Process the solid shaft to form a planed shaft, or directly use the planed shaft; then add a magnetic steel sleeve 8 between the planed shaft and a plurality of groups of magnetic steels 2, use the space between the axial ribs 9 of two adjacent planed shafts to form a rotor axial ventilation hole 6, and close the opening of the outer end of the rotor axial ventilation hole 6 by the magnetic steel sleeve 8; c: A magnetic steel sleeve 8 is added between the solid shaft and the plurality of groups of magnetic steels 2, and a rotor axial ventilation hole 6 is directly opened on the magnetic steel sleeve 8 along the axial direction.

[0042] In method a, Figure 3 , Figure 4 and Figure 6 As shown, the number of rotor axial ventilation holes 6 can be determined according to actual use requirements. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the solid shaft along the circumference; the cross-sectional midlines of the rotor axial ventilation holes 6 all point to the axis of the solid shaft.

[0043] The cross section of the rotor axial ventilation hole 6 may be rectangular, such as Figure 4 and Figure 5 As shown; it can also be a rectangular top and an arc (approximately an oblong) protruding toward the center of the solid shaft at the bottom, such as Figure 6 and Figure 7 The rotor axial ventilation hole 6 can be milled by a flat-bottom, round-bottom or other-shaped milling cutter, and then closed by a wedge-shaped magnetic conductive slot wedge 7 after milling, so as to finally obtain a rotor axial ventilation hole 6 that meets the set requirements.

[0044] In method b, Figure 8and Fig. 9 As shown, a planed rib shaft refers to a solid shaft that is uniformly machined with a plurality of grooves along the axial direction on the circumference of the shaft by a planer, and the protrusions formed between two adjacent grooves serve as shaft ribs 9, which belongs to the prior art in this field and will not be described in detail here.

[0045] The number of axial ribs 9 in the planing shaft can be determined according to actual use requirements, thereby determining the number of rotor axial ventilation holes 6. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the planing shaft along the circumference. The cross-section of the rotor axial ventilation hole 6 can be trapezoidal or arc-shaped; the center line of the cross-section of the rotor axial ventilation hole 6 points to the axis of the planing shaft. The magnetic steel sleeve 8 can be made of alloy steel or carbon steel, or can be formed by laminating silicon steel sheets.

[0046] In method c, Fig.10 and Fig.11 As shown, the number of rotor axial ventilation holes 6 can be determined according to actual use requirements. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the magnetic steel sleeve 8 along the circumference. The cross-section of the rotor axial ventilation holes 6 can be trapezoidal or circular; the midlines of the cross-sections of the rotor axial ventilation holes 6 all point to the axis of the solid shaft. The magnetic steel sleeve 8 can be formed by laminating silicon steel sheets.

[0047] The design method of the high-speed permanent magnet motor rotor of the present invention is based on the provision of the rotor axial ventilation holes 6. Fig.12 and Fig.13 As shown, a rotor radial air duct 10 which is in communication with the rotor axial ventilation hole 6 is further radially arranged on the high-speed permanent magnet motor rotor to cooperate with the rotor axial ventilation hole 6 to form an axial-radial mixed ventilation air path to further improve the convection heat dissipation effect of the high-speed permanent magnet motor rotor.

[0048] When the rotor radial air duct 10 is opened, the solid shaft is subjected to any of the following methods: d: Corresponding to method a, a rotor radial air duct 10 connected to the rotor axial ventilation hole 6 is directly opened along the radial direction of the solid shaft; and ventilation gaps 11 adapted to the rotor radial air duct 10 are provided at the magnetic steel 2 and the carbon fiber sheath 4 on both sides above the rotor radial air duct 10; to ensure that the rotor axial ventilation hole 6 is connected to the outside of the rotor through the rotor radial air duct 10 and the ventilation gaps 11; e: Corresponding to method b, a plurality of groups of magnetic steel sleeves 8 are sleeved on the outer circumference of the planing shaft at intervals in the axial direction, and the interval between two adjacent groups of magnetic steel sleeves 8 is used to form a rotor radial air duct 10; and ventilation gaps 11 adapted to the rotor radial air duct 10 are provided at the magnetic steels 2 and the carbon fiber sleeves 4 on both sides above the rotor radial air duct 10; so as to ensure that the rotor axial ventilation holes 6 are connected to the outside of the rotor through the rotor radial air duct 10 and the ventilation gaps 11; f: Corresponding to method e, a plurality of groups of magnetic steel sleeves 8 are sleeved on the outer circumference of the solid shaft and are spaced apart along the axial direction; a rotor radial air duct 10 is formed by utilizing the interval between two adjacent groups of magnetic steel sleeves 8; and ventilation gaps 11 adapted to the rotor radial air duct 10 are arranged at the magnetic steels 2 and the carbon fiber sleeves 4 on both sides above the rotor radial air duct 10; so as to ensure that the rotor axial ventilation holes 6 are connected to the outside of the rotor through the rotor radial air duct 10 and the ventilation gaps 11.

[0049] In method d, Fig.14 , Fig.15 and Figure 6 As shown, the rotor shaft 1 adopts a solid shaft, and the rotor axial ventilation hole 6 is axially opened on the solid shaft below the magnetic steel 2; the rotor radial air duct 10 connected with the rotor axial ventilation hole 6 is radially arranged on the solid shaft; the rotor radial air duct 10 can be one group or multiple groups, and when multiple groups of rotor radial air ducts 10 are provided, the multiple groups of rotor radial air ducts 10 are evenly arranged along the axial direction of the solid shaft; the magnetic steel 2 and the carbon fiber sheath 4 on both sides above the rotor radial air duct 10 are provided with ventilation gaps 11 adapted to the rotor radial air duct 10, so as to ensure that the rotor axial ventilation hole 6 is connected with the outside of the rotor through the rotor radial air duct 10 and the ventilation gap 11; The number of the rotor axial ventilation holes 6 can be determined according to actual use requirements. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the solid shaft along the circumference. The cross section of the rotor axial ventilation holes 6 can be rectangular, such as Figure 4 and Figure 5 As shown; it can also be a rectangular top and an arc-shaped bottom protruding toward the axis of the solid shaft (approximately oblong), such as Figure 6 and Figure 7 The rotor axial ventilation hole 6 can be milled by a flat-bottom, round-bottom or other-shaped milling cutter, and then closed by a wedge-shaped magnetic conductive slot wedge 7 after milling, so as to finally obtain a rotor axial ventilation hole 6 that meets the set requirements.

[0050] The number of rotor radial air ducts 10 can be determined according to actual use requirements, such as 1 group (such as Fig.14 as shown) or 2 groups (as Fig.15 As shown). The outer surfaces of the magnetic steel 2 on both sides of the ventilation gap 11 are also provided with magnetic shielding plates 12. The rotor radial air duct 10 can be milled by a milling cutter during processing, so as to finally obtain a rotor radial air duct 10 that meets the set requirements, and cooperate with the rotor axial ventilation hole 6 to form a mixed ventilation air path.

[0051] In method e, Fig.16 , Fig.17 and Fig. 9As shown, the rotor shaft 1 is a ribbed shaft, and the space between the ribs 9 of two adjacent ribbed shafts forms a rotor axial ventilation hole 6, and the outer end of the rotor axial ventilation hole 6 is closed by a magnetic steel sleeve 8; a plurality of groups of magnetic steel sleeves 8 are axially spaced apart on the outer circumference of the ribbed shaft, and the interval between two adjacent groups of magnetic steel sleeves 8 forms a rotor radial air duct 10, and the magnetic steel 2 and the carbon fiber sheath 4 on both sides above the rotor radial air duct 10 are provided with ventilation gaps 11 adapted to the rotor radial air duct 10, so as to ensure that the rotor axial ventilation hole 6 is connected to the outside of the rotor through the rotor radial air duct 10 and the ventilation gaps 11.

[0052] In method e, the number of axial ribs 9 in the planing shaft can be determined according to actual use requirements, thereby determining the number of rotor axial ventilation holes 6. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the planing shaft along the circumference. The cross-section of the rotor axial ventilation hole 6 can be trapezoidal or arc-shaped; the center line of the cross-section of the rotor axial ventilation hole 6 points to the axis of the planing shaft. The magnetic steel sleeve 8 can be made of alloy steel or carbon steel, or can be formed by laminating silicon steel sheets.

[0053] The number of rotor radial air ducts 10 can be determined according to actual use requirements, such as 1 group (such as Fig.16 as shown) or 2 groups (as Fig.17 Magnetic shielding plates 12 are also provided on the outer surfaces of the magnetic steel 2 and the carbon fiber sheath 4 on both sides of the ventilation gap 11. The rotor radial air duct 10 cooperates with the rotor axial ventilation hole 6 to form a mixed ventilation air path.

[0054] In method f, Fig.18 , Fig.19 and Fig.11 As shown, the rotor shaft 1 is a solid shaft, and the outer circumference of the solid shaft is sleeved with a plurality of groups of magnetic steel sleeves 8 spaced in the axial direction; the rotor axial ventilation holes 6 are axially opened on the plurality of groups of magnetic steel sleeves 8. The interval between two adjacent groups of magnetic steel sleeves 8 forms a rotor radial air duct 10, and the magnetic steel 2 and the carbon fiber sheath 4 on both sides above the rotor radial air duct 10 are provided with ventilation gaps 11 adapted to the rotor radial air duct 10, so as to ensure that the rotor axial ventilation holes 6 are connected to the outside of the rotor through the rotor radial air duct 10 and the ventilation gaps 11; In method f, the number of rotor axial ventilation holes 6 can be determined according to actual use requirements. When a plurality of groups of rotor axial ventilation holes 6 are provided, the plurality of groups of rotor axial ventilation holes 6 are evenly distributed on the magnetic steel sleeve 8 along the circumference. The cross-section of the rotor axial ventilation holes 6 can be trapezoidal or circular; the midlines of the cross-sections of the rotor axial ventilation holes 6 all point to the axis of the solid shaft. The magnetic steel sleeve 8 can be formed by laminating silicon steel sheets.

[0055] The number of rotor radial air ducts 10 can be determined according to actual use requirements, such as 1 group (such as Fig.18 as shown) or 2 groups (as Fig.19 Magnetic shielding plates 12 are also provided on the outer surfaces of the magnetic steel 2 and the carbon fiber sheath 4 on both sides of the ventilation gap 11. The rotor radial air duct 10 cooperates with the rotor axial ventilation hole 6 to form a mixed ventilation air path.

[0056] The rotor magnetic poles in the present invention can be 4 poles, which can be expanded to 6 poles for high-speed permanent magnet motors, and has good applicability to variable frequency power supply systems.

[0057] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-speed permanent magnet motor rotor, comprising a rotor shaft and a plurality of groups of magnetic steels uniformly distributed on the outer surface of the rotor shaft along the circumference, wherein the plurality of groups of magnetic steels and the outer surfaces of the magnetic isolation strips are provided with carbon fiber sheaths, characterized in that: One or more groups of rotor axial ventilation holes are arranged along the axial direction on the high-speed permanent magnet motor rotor below the groups of magnetic steels.

2. The high-speed permanent magnet motor rotor according to claim 1, characterized in that: The rotor shaft is a solid shaft, and the rotor axial ventilation hole is axially opened on the solid shaft below the magnetic steel.

3. The high-speed permanent magnet motor rotor according to claim 1, characterized in that: The rotor shaft adopts a ribbed shaft, and a magnetic steel sleeve is provided on the outer circumference of the ribbed shaft; the space between the ribs of two adjacent ribbed shafts forms a rotor axial ventilation hole, and the opening at the outer end of the rotor axial ventilation hole is closed by the magnetic steel sleeve.

4. The high-speed permanent magnet motor rotor according to claim 1, characterized in that: The rotor shaft is a solid shaft, and a magnetic steel sleeve is provided on the outer circumference of the solid shaft; the rotor axial ventilation hole is axially opened on the magnetic steel sleeve.

5. The high-speed permanent magnet motor rotor according to claim 2, characterized in that: A rotor radial air duct connected to the rotor axial ventilation hole is arranged along the radial direction of the solid shaft; the magnetic steel and carbon fiber sheaths on both sides above the rotor radial air duct are both provided with ventilation gaps adapted to the rotor radial air duct.

6. The high-speed permanent magnet motor rotor according to claim 3 or 4, characterized in that: The outer circumferential sleeve of the rotor shaft is provided with a plurality of groups of magnetic steel sleeves spaced apart in the axial direction, the interval between two adjacent groups of magnetic steel sleeves forms a rotor radial air duct, and the magnetic steel and carbon fiber sleeves on both sides above the rotor radial air duct are provided with ventilation gaps adapted to the rotor radial air duct.

7. A high-speed permanent magnet motor rotor design method, characterized in that: According to the rotor shaft structure of the high-speed permanent magnet motor rotor, one or more groups of rotor axial ventilation holes are opened along the axial direction on the high-speed permanent magnet motor rotor below a plurality of groups of magnetic steels.

8. The high-speed permanent magnet motor rotor design method according to claim 8, characterized in that: One or more groups of rotor radial air ducts are radially arranged on the rotor of the high-speed permanent magnet motor and are interconnected with the rotor axial ventilation holes, and cooperate with the rotor axial ventilation holes to form an axial-radial mixed ventilation air path.

9. The high-speed permanent magnet motor rotor design method according to claim 7 or 8, characterized in that: When opening the rotor axial ventilation hole, the rotor shaft using a solid shaft can be performed according to any of the following methods: a: On the solid shaft below the magnetic steel, a rotor axial ventilation hole is directly opened along the axial direction; b: Process the solid shaft to form a planed shaft, or directly use the planed shaft; then add a magnetic steel sleeve between the planed shaft and a plurality of sets of magnetic steels, use the space between the axial ribs of two adjacent planed shafts to form a rotor axial ventilation hole, and close the opening of the outer end of the rotor axial ventilation hole with the magnetic steel sleeve; c: A magnetic steel sleeve is added between the solid shaft and a plurality of groups of magnetic steels, and a rotor axial ventilation hole is directly opened on the magnetic steel sleeve along the axial direction.

10. The high-speed permanent magnet motor rotor design method according to claim 9, characterized in that: When opening the rotor radial air duct, one of the following methods shall be selected for the rotor shaft using a solid shaft: d: A rotor radial air duct connected to the rotor axial ventilation hole is directly opened along the radial direction of the solid shaft; and ventilation gaps matching the rotor radial air duct are set at the magnetic steel and carbon fiber sheaths on both sides above the rotor radial air duct; e: Several groups of magnetic steel sleeves are sleeved on the outer circumference of the planing shaft and spaced apart in the axial direction, and the interval between two adjacent groups of magnetic steel sleeves is used to form a rotor radial air duct; and ventilation gaps matching the rotor radial air duct are set at the magnetic steel and carbon fiber sleeves on both sides above the rotor radial air duct; f: A plurality of groups of magnetic steel sleeves are sleeved on the outer circumference of the solid shaft and are spaced apart in the axial direction; a rotor radial air duct is formed by utilizing the interval between two adjacent groups of magnetic steel sleeves; and ventilation gaps matching the rotor radial air duct are arranged at the magnetic steel and carbon fiber sleeves on both sides above the rotor radial air duct.

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