Precise rotor structure for high-speed magnetic suspension motor

Abstract

The utility model discloses a precise rotor structure for a high-speed magnetic suspension motor. The precise rotor structure comprises a protection mechanism and a rotor shaft, the protection mechanism comprises a front protection barrel, a rear protection barrel, an air inlet hole and a spiral guide vane, key grooves are formed in the upper sides and the lower sides, deviating from the outer ends, of the inner arc faces of the front protection barrel and the rear protection barrel, the air inlet hole is formed in the left end of the outer arc face of the front protection barrel, and the spiral guide vane is arranged in the front protection barrel; the rear end of the spiral guide vane extends into the rear protection barrel; flat keys are arranged on the upper side and the lower side of the front end and the rear end of the outer cambered surface of the rotor shaft, and the flat keys and the longitudinally adjacent key grooves are installed in a matched mode. And irreversible damage to a rotor shaft caused by high-temperature welding due to direct contact between the rotor rotating at a high speed and the radial magnetic suspension bearing is avoided, and meanwhile, the uniformity of heat dissipation of the rotor is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a precision rotor structure for a high-speed magnetic levitation motor. Background Art

[0002] High-speed magnetic levitation motors are based on magnetic levitation technology. They use electromagnetic force to suspend the motor's rotor, eliminating mechanical contact between it and the stator. Generally, electromagnetic windings on the stator generate a magnetic field that interacts with permanent magnets or electromagnets on the rotor, generating an upward magnetic force to balance the rotor's gravity, thereby achieving levitation.

[0003] When the magnetic bearings of a magnetic levitation high-speed motor are not started, the motor rotor falls on the front and rear radial bearings. When the motor is started, the motor rotor is suspended in the center of the magnetic bearing and rotates at high speed. When the running motor has a line fault, the motor rotor will fall on the front and rear radial bearings. At this time, the high-speed rotating motor rotor will contact the adjacent radial bearings. At this time, high temperature will be generated under high-speed rotation and friction, resulting in high-temperature welding between the motor rotor and the inner ring of the radial bearing, so that the motor rotor and the inner ring of the radial bearing are welded together, thereby causing irreversible damage to the motor rotor. The heat dissipation method for the high temperature generated by the high-speed rotation of the rotor is still only to use heat dissipation holes. For this reason, we propose a precision rotor structure for high-speed magnetic levitation motors. Utility Model Content

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide a precision rotor structure for a high-speed magnetic levitation motor, so as to avoid the situation in which, after a high-speed magnetic levitation motor fails, the high-speed rotating rotor directly contacts the radial magnetic levitation bearing and causes high-temperature welding, resulting in irreversible damage to the rotor shaft. At the same time, the uniformity of the heat dissipation of the rotor is improved, which can effectively solve the problems in the background technology.

[0005] To achieve the above-mentioned object, the present utility model provides the following technical solutions: a precision rotor structure for a high-speed magnetic levitation motor, comprising a protection mechanism and a rotor shaft;

[0006] The protection mechanism includes a front protection barrel, a rear protection barrel, an air inlet, and a spiral guide vane. The inner arc surfaces of the front and rear protection barrels are provided with key slots on both upper and lower sides facing away from the outer ends. The left end of the outer arc surface of the front protection barrel is provided with an air inlet. The interior of the front protection barrel is provided with a spiral guide vane, the rear end of which extends deep into the interior of the rear protection barrel.

[0007] Rotor shaft: Flat keys are provided on the upper and lower sides of the front and rear ends of its outer arc surface. The flat keys are installed in conjunction with the longitudinally adjacent keyways. The middle part of the rotor shaft is located inside the spiral guide vane. This prevents the high-speed rotating rotor from directly contacting the radial magnetic bearing after a high-speed magnetic levitation motor fails, causing high-temperature welding and irreversible damage to the rotor shaft. At the same time, the uniformity of the rotor heat dissipation is improved.

[0008] Furthermore, the front protection barrel and the rear protection barrel are installed in cooperation with each other through an expansion sleeve, and the central axes of the front protection barrel and the rear protection barrel coincide with each other to protect the rotor.

[0009] Furthermore, the protection mechanism also includes a grille and an exhaust port. The grille is arranged inside the air inlet, and the exhaust port is opened on the rear side of the rear protection barrel to facilitate heat dissipation.

[0010] Furthermore, it also includes a single-chip microcomputer, which is located on the left side of the front protective barrel. The input end of the single-chip microcomputer is electrically connected to an external power supply for stable control.

[0011] Furthermore, it also includes radial magnetic bearings, which are respectively located on the front and rear sides of the rotor shaft, and the front end of the front protective barrel and the rear end of the rear protective barrel are both located inside the inner rings of the front and rear adjacent radial magnetic bearings. The diameters of the front end of the front protective barrel and the rear end of the rear protective barrel are both smaller than the diameters of the inner rings of the adjacent radial magnetic bearings. The central axes of the two radial magnetic bearings coincide, and the input ends of the radial magnetic bearings are electrically connected to the output ends of the single-chip microcomputer. The electromagnetic force suspends the rotor of the motor so that there is no mechanical contact between it and the stator.

[0012] Furthermore, it also includes position sensors, which are symmetrically distributed on the opposite outer sides of the two radial magnetic bearings. The input ends of the position sensors are electrically connected to the output ends of the single-chip microcomputer to facilitate monitoring the position of the rotor.

[0013] Furthermore, it also includes an axial magnetic levitation bearing, which is located in front of the radial magnetic levitation bearing on the front side, and the central axis of the axial magnetic levitation bearing coincides with the central axis of the radial magnetic levitation bearing on the front side. The front end of the front protective barrel passes through the inner ring of the front radial magnetic levitation bearing and extends into the inner ring of the axial magnetic levitation bearing. The input end of the axial magnetic levitation bearing is electrically connected to the output end of the single-chip microcomputer, and the electromagnetic force suspends the rotor of the motor so that there is no mechanical contact between it and the stator.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the high-speed magnetic levitation motor uses a precision rotor structure, which has the following advantages:

[0015] 1. When a high-speed magnetic levitation motor or radial magnetic levitation bearing fails and loses magnetic force, the front end and rear protective barrel of the front protective barrel are in contact with the inner arc surface of the inner ring of the radial magnetic levitation bearing. This avoids the situation where the rotor shaft directly contacts the radial magnetic levitation bearing and high-temperature welding occurs, causing irreversible damage to the rotor shaft.

[0016] 2. With the cooperation of the spiral guide blades, the airflow forms an axial and circumferential composite flow after entering the front end of the front protective barrel and the rear protective barrel, thereby improving the uniformity of heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of the utility model;

[0018] Figure 2 It is a structural diagram of the left side of the utility model;

[0019] Figure 3 This is a schematic diagram of the structure of the utility model in a sectional view from the left side;

[0020] Figure 4 This is a schematic diagram of the partial structure of the rotor shaft of the utility model;

[0021] Figure 5 This is a partial structural diagram of the radial magnetic bearing of the utility model.

[0022] In the figure: 1 radial magnetic bearing, 2 protection mechanism, 21 front protection barrel, 22 rear protection barrel, 23 air inlet, 24 grille, 25 spiral guide vane, 26 air outlet, 3 rotor shaft, 4 position sensor, 5 flat key, 6 axial magnetic bearing, 7 single chip microcomputer. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] See also Figure 1-5 ,This embodiment provides a technical solution: a precision rotor structure for a high-speed magnetic levitation motor, comprising a protection mechanism 2 and a rotor shaft 3;

[0025] Protection mechanism 2: It includes a front protection barrel 21, a rear protection barrel 22, an air inlet 23, and a spiral guide blade 25. The inner arc surface of the front protection barrel 21 and the rear protection barrel 22 are opposite to the outer end and are provided with key slots on both sides. The front protection barrel 21 and the rear protection barrel 22 are installed by an expansion sleeve (the inner ring of the expansion sleeve is sleeved on the end of the front protection barrel 21, and the outer ring of the expansion sleeve is sleeved on the end of the rear protection barrel 22, and then the inner and outer rings of the expansion sleeve are relative to each other by tightening the bolts. , so that the expansion sleeve expands and holds the front protection barrel 21 and the rear protection barrel 22 tightly to achieve connection), the central axes of the front protection barrel 21 and the rear protection barrel 22 coincide, and an air inlet 23 is provided at the left end of the outer arc surface of the front protection barrel 21. The protection mechanism 2 also includes a grille 24 and an air outlet 26. The grille 24 is arranged inside the air inlet 23, and an air outlet 26 is provided on the rear side of the rear protection barrel 22. A spiral guide blade 25 is provided inside the front protection barrel 21, and the rear end of the spiral guide blade 25 is deep. The interior of the rear protection barrel 22 also includes a single-chip microcomputer 7, which is located on the left side of the front protection barrel 21. The input end of the single-chip microcomputer 7 is electrically connected to an external power supply. When the front protection barrel 21 and the rear protection barrel 22 rotate at high speed, the surrounding air will be driven to flow. The air inlet 23 on the front protection barrel 21 (the grille 24 inside the air inlet 23 will block the dust and debris in the air) provides an inlet and outlet channel for the air, so that the cold air can continuously enter the interior of the front protection barrel 21 and the rear protection barrel 22 from the heat dissipation holes, flow through the surface of the rotor shaft 3, absorb heat, and then be discharged from the exhaust port 26 of the rear protection barrel 22, thereby forming effective air convection, accelerating heat dissipation, and improving heat dissipation efficiency. In this process, when the air flow enters the front protection barrel 21 through the air inlet 23, the spiral guide blades 25 can guide the air flow to flow according to a predetermined path, so that the air flow forms a composite flow of axial and circumferential directions after entering, thereby improving the uniformity of heat dissipation;

[0026] Rotor shaft 3: Flat keys 5 are provided on the upper and lower sides of the front and rear ends of its outer arc surface, and the flat keys 5 are installed in conjunction with the longitudinally adjacent keyways. The middle part of the rotor shaft 3 is located inside the spiral guide vane 25. It also includes a radial magnetic bearing 1, which is located on the front and rear sides of the rotor shaft 3 respectively. The front end of the front protective barrel 21 and the rear end of the rear protective barrel 22 are both located inside the inner rings of the front and rear adjacent radial magnetic bearings 1. The diameters of the front end of the front protective barrel 21 and the rear end of the rear protective barrel 22 are both smaller than the diameters of the inner rings of the adjacent radial magnetic bearings 1. The central axes of the two radial magnetic bearings 1 coincide, and the input ends of the radial magnetic bearings 1 are electrically connected to the output ends of the single-chip computer 7. It also includes a position sensor 4, which is symmetrically distributed. It is arranged on the opposite outer sides of the two radial magnetic bearings 1, and the input ends of the position sensor 4 are electrically connected to the output ends of the single-chip computer 7. It also includes an axial magnetic bearing 6. The axial magnetic bearing 6 is located in front of the front radial magnetic bearing 1. The central axis of the axial magnetic bearing 6 coincides with the central axis of the front radial magnetic bearing 1. The front end of the front protective barrel 21 passes through the inner ring of the front radial magnetic bearing 1 and extends into the inner ring of the axial magnetic bearing 6. The input end of the axial magnetic bearing 6 is electrically connected to the output end of the single-chip computer 7. In the initial state, no current is passed through the radial magnetic bearing 1. At this time, the front end of the front protective barrel 21 and the rear end of the rear protective barrel 22 fall on the adjacent radial magnetic bearing 1. The worker manipulates the single-chip computer The machine 7 starts the operation of the radial magnetic bearing 1, the axial magnetic bearing 6 and the position sensor 4. At this time, current is passed through the stator windings of the radial magnetic bearing 1 and the axial magnetic bearing 6 to generate a magnetic field. The permanent magnets or electromagnets on the rotors of the radial magnetic bearing 1 and the axial magnetic bearing 6 will be affected by the electromagnetic force in the magnetic field. By precisely controlling the magnitude, direction and frequency of the current in the stator winding, the magnitude and direction of the electromagnetic force can be adjusted, so that the front protective barrel 21 and the rear protective barrel 22 can carry the rotor shaft 3 and stably suspend in the air in the radial and axial directions, maintaining a certain gap between them and the stator, thereby realizing support without mechanical contact. The position sensor 4 always monitors the position information of the front end of the front protective barrel 21 and the rear protective barrel 22. And feed it back to the single chip microcomputer 7, which compares and calculates the received position feedback signal with the preset target position, and then adjusts the current in the stator winding of the radial magnetic bearing 1 to generate a suitable electromagnetic force, correct the position deviation of the front protection barrel 21 and the rear protection barrel 22, so that it always remains in a stable suspension position. During the high-speed rotation of the rotor shaft 3, if the high-speed magnetic levitation motor or the radial magnetic levitation bearing 1 fails, the magnetic force disappears, but the rotor shaft 3 is still rotating at high speed. At this time, the rotor shaft 3 will fall on the radial magnetic levitation bearing 1 and contact the inner ring, but the radial magnetic levitation bearing 1 does not rotate and is in a relatively static state with the ground. In this way, there is a speed difference between the rotor shaft 3 and the radial magnetic levitation bearing 1. At the moment the two come into contact,Due to the high temperature generated by mutual friction, the outer arc surface of the rotor shaft 3 and the inner arc surface of the inner ring of the adjacent radial magnetic bearing 1 are hot-melted and welded at high temperature. However, due to the presence of the front protective barrel 21 and the rear protective barrel 22, the above situation will not occur. Instead, the rotor shaft 3 drives the front end of the front protective barrel 21 and the rear protective barrel 22 to rotate at high speed through the cooperation of the flat key and the keyway. Even if the high-speed magnetic levitation motor or the radial magnetic bearing 1 fails and loses magnetic force, it is the front end of the front protective barrel 21 and the rear protective barrel 22 that contact the inner arc surface of the inner ring of the radial magnetic bearing 1. This avoids the situation where the rotor shaft 3 directly contacts the radial magnetic bearing 1 and high-temperature welding occurs, causing irreversible damage to the rotor shaft 3.

[0027] The working principle of a precision rotor structure for a high-speed magnetic levitation motor provided by the present invention is as follows: in the initial state, no current is passed through the radial magnetic levitation bearing 1. At this time, the front end of the front protective barrel 21 and the rear end of the rear protective barrel 22 fall on the adjacent radial magnetic levitation bearing 1. The worker controls the single-chip microcomputer 7 to start the operation of the radial magnetic levitation bearing 1, the axial magnetic levitation bearing 6 and the position sensor 4. At this time, current is passed through the stator windings of the radial magnetic levitation bearing 1 and the axial magnetic levitation bearing 6 to generate a magnetic field, and the permanent magnets or electromagnets on the rotors of the radial magnetic levitation bearing 1 and the axial magnetic levitation bearing 6 will be affected by the electromagnetic force in the magnetic field. By accurately controlling the size, direction and frequency of the current in the stator winding, the size and direction of the electromagnetic force can be adjusted. direction, so that the front protection barrel 21 and the rear protection barrel 22 can carry the rotor shaft 3 and be stably suspended in the air in the radial and axial directions, maintaining a certain gap between them and the stator to achieve support without mechanical contact, and the position sensor 4 always monitors the position information of the front end of the front protection barrel 21 and the rear protection barrel 22, and feeds it back to the single-chip microcomputer 7. The single-chip microcomputer 7 compares and calculates the received position feedback signal with the preset target position, and then adjusts the current in the stator winding of the radial magnetic bearing 1 to generate a suitable electromagnetic force, corrects the position deviation of the front protection barrel 21 and the rear protection barrel 22, and keeps it in a stable suspension position at all times. During the high-speed rotation of the rotor shaft 3, if the high-speed magnetic levitation motor or the radial magnetic levitation bearing 1 occurs Fault, at this time the magnetic force disappears, but the rotor shaft 3 is still rotating at high speed, and the rotor shaft 3 will fall on the radial magnetic bearing 1 and contact the inner ring, but the radial magnetic bearing 1 does not rotate and is in a relatively static state with the ground, so there is a speed difference between the rotor shaft 3 and the radial magnetic bearing 1. At the moment the two contact, high temperature is generated due to mutual friction, causing the outer arc surface of the rotor shaft 3 and the inner arc surface of the inner ring of the adjacent radial magnetic bearing 1 to melt and weld at high temperature. However, due to the presence of the front protective barrel 21 and the rear protective barrel 22, the above situation will not happen. Instead, the rotor shaft 3 drives the front end of the front protective barrel 21 and the rear protective barrel 22 to rotate at high speed through the cooperation of the flat key and the keyway, even if the high-speed magnetic levitation motor or radial When the magnetic bearing 1 fails and loses its magnetic force, the front end of the front protective barrel 21 and the rear protective barrel 22 are in contact with the inner arc surface of the inner ring of the radial magnetic bearing 1. This avoids the rotor shaft 3 from directly contacting the radial magnetic bearing 1 and causing high-temperature welding to cause irreversible damage to the rotor shaft 3. When the front protective barrel 21 and the rear protective barrel 22 rotate at high speed, the surrounding air will flow. The air inlet 23 on the front protective barrel 21 (the grille 24 inside the air inlet 23 will block dust and debris in the air) provides an inlet and outlet channel for air, so that cold air can continuously enter the interior of the front protective barrel 21 and the rear protective barrel 22 from the heat dissipation holes and flow through the surface of the rotor shaft 3.After absorbing heat, it is discharged from the exhaust port 26 of the rear protective barrel 22, thereby forming effective air convection, accelerating heat dissipation and improving heat dissipation efficiency. During this process, when the airflow enters the front protective barrel 21 through the air inlet 23, the spiral guide blades 25 can guide the airflow along a predetermined path, so that the airflow forms a composite axial and circumferential flow after entering, thereby improving the uniformity of heat dissipation.

[0028] It is worth noting that the radial magnetic bearing 1 disclosed in the above embodiment can be a radial electromagnetic bearing, the position sensor 4 can be model MSAF070P, the axial magnetic bearing 6 can be a disc-type axial electromagnetic bearing, and the single-chip microcomputer 7 controls the operation of the radial magnetic bearing 1, the position sensor 4 and the axial magnetic bearing 6 using methods commonly used in the prior art.

[0029] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A precision rotor structure for a high-speed magnetic levitation motor, characterized by: It includes a protection mechanism (2) and a rotor shaft (3); The protection mechanism (2) comprises a front protection barrel (21), a rear protection barrel (22), an air inlet (23), and a spiral guide vane (25). The inner arc surfaces of the front protection barrel (21) and the rear protection barrel (22) are provided with key slots on both upper and lower sides facing away from the outer ends. The left end of the outer arc surface of the front protection barrel (21) is provided with an air inlet (23). The interior of the front protection barrel (21) is provided with a spiral guide vane (25), and the rear end of the spiral guide vane (25) extends deep into the interior of the rear protection barrel (22). The rotor shaft (3) is provided with flat keys (5) on both upper and lower sides of the front and rear ends of the outer arc surface, and the flat keys (5) are installed in conjunction with the longitudinally adjacent keyways. The middle part of the rotor shaft (3) is located inside the spiral guide vane (25).

2. The precision rotor structure for a high-speed magnetic levitation motor according to claim 1, characterized in that: The front protection barrel (21) and the rear protection barrel (22) are mounted together via an expansion sleeve, and the central axes of the front protection barrel (21) and the rear protection barrel (22) coincide with each other.

3. The precision rotor structure for a high-speed magnetic levitation motor according to claim 1, characterized in that: The protection mechanism (2) further comprises a grille (24) and an air outlet (26); the grille (24) is arranged inside the air inlet (23); and the air outlet (26) is provided on the rear side of the rear protection barrel (22).

4. The precision rotor structure for a high-speed magnetic levitation motor according to claim 1, characterized in that: It also includes a single chip microcomputer (7), which is located on the left side of the front protection barrel (21), and an input end of the single chip microcomputer (7) is electrically connected to an external power supply.

5. The precision rotor structure for a high-speed magnetic levitation motor according to claim 4, characterized in that: The invention also includes a radial magnetic suspension bearing (1), wherein the radial magnetic suspension bearing (1) is respectively located on the front and rear sides of the rotor shaft (3), the front end of the front protection barrel (21) and the rear end of the rear protection barrel (22) are both located inside the inner rings of the front and rear adjacent radial magnetic suspension bearings (1), the diameters of the front end of the front protection barrel (21) and the rear end of the rear protection barrel (22) are both smaller than the diameters of the inner rings of the adjacent radial magnetic suspension bearings (1), the central axes of the two radial magnetic suspension bearings (1) coincide, and the input ends of the radial magnetic suspension bearings (1) are both electrically connected to the output ends of the single-chip computer (7).

6. The precision rotor structure for a high-speed magnetic levitation motor according to claim 5, characterized in that: It also includes position sensors (4), which are symmetrically distributed and arranged on the opposite outer sides of the two radial magnetic suspension bearings (1), and the input ends of the position sensors (4) are electrically connected to the output ends of the single-chip computer (7).

7. The precision rotor structure for a high-speed magnetic levitation motor according to claim 4, characterized in that: The invention also includes an axial magnetic suspension bearing (6), wherein the axial magnetic suspension bearing (6) is located in front of the radial magnetic suspension bearing (1) on the front side, and the central axis of the axial magnetic suspension bearing (6) coincides with the central axis of the radial magnetic suspension bearing (1) on the front side. The front end of the front protective barrel (21) passes through the inner ring of the radial magnetic suspension bearing (1) on the front side and extends into the inner ring of the axial magnetic suspension bearing (6). The input end of the axial magnetic suspension bearing (6) is electrically connected to the output end of the single-chip computer (7).

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