Centrifugal permanent magnet cooling structure for maglev high-speed permanent magnet motor

Abstract

The present invention provides a centrifugal magnet cooling structure for a maglev high-speed permanent magnet motor, which includes a machine base, a rotating shaft and a stator. A ventilation hole in the form of a blind hole is axially formed at the tail end of the rotating shaft, and the inner end of the ventilation hole is communicated with the surface of the rotating shaft through a plurality of obliquely blowing air holes. There is a gap between the stator and the rotating shaft, and the outlet of the obliquely blowing air hole is located on one side of the gap. When the rotating shaft rotates, the air in the obliquely ventilated hole is thrown out from the outlet under the action of rotational centrifugal force, resulting in negative pressure in the ventilation hole, so that cold air is sucked in from the outer end of the ventilation hole to absorb the heat inside the device. At the same time, the air thrown out from the outlet of the obliquely ventilated hole flows outward, and after heat exchange and cooling, it flows back to the fan position, and so on in a cycle to ensure that the temperature of the rotating shaft and the magnets on its surface is within a safe range.

Description

Technical Field

[0001] The present invention relates to a high-power and ultra-high-speed permanent magnet motor, and particularly to a magnetic steel cooling structure inside the high-power and ultra-high-speed permanent magnet motor. Background Art

[0002] As Figure 1 shown, it is a structural schematic diagram of an existing high-power and ultra-high-speed permanent magnet motor. The rotating shaft 1 is rotatably connected to the machine base 5 through a thrust bearing 2, a magnetic suspension bearing 3, and an auxiliary bearing 4. A stator 6 is also fixed on the machine base 5 at the outer peripheral side position of the rotating shaft 1. When the winding on the stator 6 is energized, it can drive the rotating shaft 1 to rotate and output torque.

[0003] As Figure 2 、 Figure 3 shown, a plurality of magnetic steels 11 are sleeved on the rotating shaft 1. The magnetic steels 11 are separated by a magnetic isolation bridge 12, and the outer sides of the magnetic steels 11 are fixed by a carbon fiber sleeve or a non-magnetic metal sleeve 13.

[0004] As the power of the permanent magnet motor increases, the radius of the rotating shaft 1 also increases accordingly. Therefore, the centrifugal force received by the magnetic steels 11 increases geometrically. In order to prevent the magnetic steels 11 from being thrown out, the thickness of the carbon fiber sleeve or the non-magnetic metal sleeve 13 must also increase, but the heat dissipation capacity decreases. Even more seriously, the harmonic magnetic field generated by the stator 6 can pass through the carbon fiber sleeve or the non-magnetic metal sleeve 13, causing the magnetic steels 11 to heat up, resulting in a decrease in the performance of the magnetic steels 11 or even demagnetization due to too high temperature. This is more obvious in motors with larger power.

[0005] Existing high-power and ultra-high-speed permanent magnet motors are generally equipped with an external fan 7 for cooling the motor. However, since the magnetic steels 11 are located inside the rotating shaft 1, the external fan 7 cannot blow the air flow to the rotating shaft 1, and in fact, the magnetic steels 11 cannot be cooled at all. Utility Model Content

[0006] The purpose of the present invention is to provide a centrifugal magnetic steel cooling structure for a magnetic suspension high-speed permanent magnet motor, so as to solve the technical problem that the existing technology cannot effectively cool the magnetic steels.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A centrifugal magnetic steel cooling structure for a magnetic suspension high-speed permanent magnet motor, including a machine base, a rotating shaft, and a stator, characterized in that:

[0009] A blind-hole form ventilation hole is axially formed at the tail end of the rotating shaft, and the inner end of the ventilation hole is communicated to the surface of the rotating shaft through a plurality of air outlet holes;

[0010] There is a gap between the stator and the rotating shaft, and the outlet of the air outlet hole is located on one side of the gap.

[0011] The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor, wherein: a ventilation slot is further reserved between the stator and the machine base; a return air channel from the inside of the motor cavity to the ventilation hole of the rotating shaft is provided on the bearing seat at the tail end of the rotating shaft.

[0012] The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor, wherein: a fan blade integrally formed with the rotating shaft is formed on the outer surface of the rotating shaft, the fan blade protrudes from the cylindrical surface of the rotating shaft, and the fan blade is located on the other side of the gap and can send air to the gap.

[0013] The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor, wherein: the fan blade protrudes from the cylindrical surface of the rotating shaft by 3-6 mm.

[0014] The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor, wherein: the fan blade protrudes from the cylindrical surface of the rotating shaft by 4-5 mm.

[0015] The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor, wherein: the fan blade is arranged obliquely at a certain angle with respect to the axial direction of the rotating shaft in the length direction.

[0016] The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor, wherein: the angle is between 23-30 degrees.

[0017] The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor, wherein: a water cooling system is provided on the machine base outside the stator and in thermal contact with the stator.

[0018] The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor, wherein: the air outlet hole is an inclined air outlet hole.

[0019] Compared with the prior art, the advantages of the present invention adopting the above technical solution are as follows: when the rotating shaft rotates, the air in the inclined ventilation hole is thrown out from the outlet under the action of the rotating centrifugal force, resulting in negative pressure in the ventilation hole, so that cold air is sucked in from the outer end of the ventilation hole to absorb the heat inside the device. At the same time, the air thrown out from the outlet of the inclined ventilation hole flows outward, and after heat exchange and cooling, it flows back to the fan position, and so on in a cycle, ensuring that the temperature of the rotating shaft and the magnets on its surface is within a safe range. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the structural schematic diagram of the existing high-power ultra-high-speed permanent magnet motor;

[0021] Figure 2 、 Figure 3They are respectively a schematic diagram of the shaft plane and a transverse cross-sectional view of an existing high-power super-high-speed permanent magnet motor;

[0022] Figure 4 It is a structural schematic diagram of the magnetic levitation high-speed permanent magnet motor provided by the present invention;

[0023] Figure 5 、 Figure 6 They are respectively a schematic diagram of the shaft plane and a longitudinal cross-sectional view of the shaft of the magnetic levitation high-speed permanent magnet motor provided by the present invention.

[0024] Explanation of reference numerals: shafts 1, 1'; permanent magnets 11; magnetic isolation bridges 12; carbon fiber sleeves or non-magnetic metal sleeves 13; fan blades 15; thrust bearings 2, magnetic levitation bearings 3; auxiliary bearings 4; machine base 5; stator 6; external fan 7; ventilation holes 8; oblique air outlet holes 81; ventilation grooves 91; return air channels 92; gap h; angle k. Detailed implementation manners

[0025] As Figure 4 shown, the present invention provides a centrifugal permanent magnet cooling structure for a magnetic levitation high-speed permanent magnet motor, including a machine base 5, a shaft 1' and a stator 6, wherein:

[0026] As Figure 5 、 Figure 6 shown, a fan blade 15 integrally formed with the shaft 1' is formed on the outer surface of the shaft 1', the fan blade 15 protrudes 3-6 mm (preferably 4-5 mm) from the cylindrical surface of the shaft 1', and the fan blade 15 is arranged obliquely at a certain angle k with respect to the axial direction of the shaft 1', and the angle k is between 23-30 degrees.

[0027] As Figure 4 shown, since there must be a gap h between the permanent magnet installation section of the shaft 1' and the stator 6, when the shaft 1' rotates, the fan blade 15 on one side of the gap h will send air to the gap h, so that the hot air at the gap h is blown to the other side of the gap h, thereby taking away the heat generated by the permanent magnet 11 in time and playing a role in cooling the permanent magnet 11.

[0028] As Figure 5 、 Figure 6 shown, a ventilation hole 8 in the form of a blind hole is further formed axially at the tail end of the shaft 1', and the inner end of the ventilation hole 8 is communicated to the surface of the shaft 1' through 3-6 oblique air outlet holes 81. In this embodiment, the outlets of the oblique air outlet holes 81 and the fan blade 15 are respectively located on both sides of the gap h (also on both sides of the permanent magnet installation section); in order to form a better heat exchange cycle, a ventilation groove 91 is reserved between the stator 6 and the machine base 5, and a return air channel 92 from the inside of the motor cavity to the ventilation hole 8 of the shaft is provided on the bearing seat at the tail end of the shaft 1'.

[0029] As Figure 4 shown, when the rotating shaft 1' rotates, the air in the diagonal ventilation hole 8 is thrown out from the outlet under the action of rotational centrifugal force, resulting in a negative pressure inside the ventilation hole 8, thereby sucking cold air from the outer end of the ventilation hole 8 to absorb the heat inside the absorption device. At the same time, the air thrown out from the outlet of the diagonal ventilation hole 8 flows outward, and after heat exchange and cooling through the ventilation groove 91, a part of it flows back to the fan position and continues to pass through the gap h to take away the heat outside the rotating shaft 1', and the other part flows back to the ventilation hole 8 through the air return channel 92 on the end bearing seat of the rotating shaft 1'. This cycle repeats to ensure that the temperature of the rotating shaft 1' and the magnetic steel 11 on its surface is within a safe range.

[0030] To further improve the cooling effect of the motor, a water cooling system 61 is provided on the machine base 5 outside the stator 6 and in thermal contact with the stator 6. When the air flow circulates between the rotating shaft 1' and the stator 6, the heat can be taken away more quickly through the water cooling system 61.

[0031] The above embodiments are only illustrative of the present invention and do not limit the protection scope of this application. Those skilled in the art can make routine modifications or substitutions based on the above embodiments, but these modifications or substitutions should still fall within the protection scope of this application.

Claims

1. A centrifugal magnet cooling structure for a maglev high-speed permanent magnet motor, comprising a frame, a rotating shaft and a stator, characterized in that: A number of magnets are embedded in the middle of the rotating shaft, with magnetic bridges between the magnets, and the outer side of the magnets is fixed with a carbon fiber sleeve or a non-magnetic metal sleeve to form a magnet installation section; A blind hole-shaped ventilation hole is formed at the rear end of the rotating shaft along the axial direction, and the inner end of the ventilation hole is connected to the surface of the rotating shaft through a plurality of air outlet holes; There is a gap between the stator and the rotating shaft, and the outlet of the air outlet is located on one side of the gap; the air outlet is an oblique air outlet; A ventilation slot is also reserved between the stator and the base; a return air channel from the motor cavity to the ventilation hole of the shaft is provided on the bearing seat at the rear end of the shaft; a fan blade is formed on the outer surface of the shaft in an integrated structure with the shaft, the fan blade protrudes from the cylindrical surface of the shaft, and the fan blade is located on the other side of the gap and can supply air to the gap; A water cooling system is provided on the machine base and is located outside the stator and forms thermal contact with the stator; The fan blades protrude from the cylindrical surface of the rotating shaft by 3-6 mm.

2. The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor according to claim 1, wherein: The fan blades protrude from the cylindrical surface of the rotating shaft by 4-5 mm.

3. The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor according to claim 1, characterized in that: The length direction of the fan blades is arranged to be inclined at a certain angle to the axial direction of the rotating shaft.

4. The centrifugal magnet cooling structure of the magnetic levitation high-speed permanent magnet motor according to claim 3, wherein: The angle is between 23-30 degrees.

Images