Conical structure of protection bearing of magnetic suspension bearing and magnetic suspension mechanism

Abstract

The invention relates to the technical field of protective bearings of magnetic suspension bearings, and provides a conical structure of a protective bearing of a magnetic suspension bearing and a magnetic suspension mechanism, the conical structure of the protective bearing of the magnetic suspension bearing comprises a main shaft, and a first protective bearing, a second protective bearing and an axial unit which are sequentially arranged along the main shaft, the first protection bearing and the second protection bearing are respectively sleeved on the first part and the second part; the surfaces of the first part and the second part are respectively a first conical outer surface and a second conical outer surface, and the inner surface of the first protective bearing inner ring and the inner surface of the second protective bearing inner ring are respectively a first conical inner surface and a second conical inner surface which are matched with the first conical outer surface and the second conical outer surface. On the premise that the traditional layout of the protective bearing is not changed, only the cylindrical structures of the journal and the bearing inner ring are changed into matched conical structures, adverse effects caused by impact and vibration are greatly reduced, and the protective bearing has the advantages of being simple in structure, low in cost and high in practicability.

Description

Technical Field

[0001] The present invention relates to the technical field of bearing protection, and in particular, to a conical structure of a protection bearing of a magnetic levitation bearing and a magnetic levitation mechanism, and more particularly, to a conical structure of a protection bearing of a magnetic levitation bearing and a magnetic levitation mechanism for automatically eliminating a protection gap. Background Art

[0002] In a magnetic levitation mechanism, a scenario where a main shaft and a protection bearing are used in cooperation is often required. When the main shaft rotates at a high speed (up to tens of thousands of revolutions per minute), it has a clearance fit with the protection bearing to achieve the effect of levitation operation. However, when the magnetic levitation mechanism fails, malfunctions, or is subjected to external interference and impacts, the main shaft will drop into the protection bearing. However, due to the previous cylindrical design, the clearance cannot be eliminated when the journal of the main shaft drops into the inner ring of the protection bearing, which is likely to cause a strong impact, resulting in easy impact damage to the protection bearing, magnetic coils, sensors, the main shaft, and even the working wheel and stationary vane, resulting in great losses.

[0003] Currently, commonly used protection bearings either cannot eliminate the protection gap, or have a complex structure, are difficult to implement, or have a very high cost, are extremely impractical, have an unsatisfactory buffering effect on impact forces, and have a poor protection effect. Summary of the Invention

[0004] Aiming at the defects in the prior art, the purpose of the present invention is to provide a conical structure of a protection bearing of a magnetic levitation bearing and a magnetic levitation mechanism.

[0005] According to a conical structure of a protection bearing of a magnetic levitation bearing provided by the present invention, it includes a main shaft and a first protection bearing, a second protection bearing, and an axial unit arranged in sequence along the main shaft. The main shaft has a first part and a second part. The first protection bearing is sleeved on the first part, and the second protection bearing is sleeved on the second part; The surface of the first part is a first conical outer surface, the surface of the second part is a second conical outer surface, the inner surface of the inner ring of the first protection bearing is a first conical inner surface matching the first conical outer surface, and the inner surface of the inner ring of the second protection bearing is a second conical inner surface matching the second conical outer surface. The main shaft has a levitation state and a dropping state, and the direction of movement from the dropping state to the levitation state is the first direction. When the main shaft is in the levitation state, there are protection gaps between the main shaft and the first protection bearing and the second protection bearing respectively. When the main shaft switches from the levitation state to the dropping state, the main shaft relies on the axial unit to apply force to the main shaft and / or its own gravity to move in the second direction, so that the conical outer surface moves towards the conical inner surface, and finally the two conical outer surfaces are closely attached to the two conical inner surfaces and drive the inner rings of the two bearings to rotate synchronously, where the second direction is opposite to the first direction.

[0006] Preferably, the axial unit is arranged at the end of the main shaft.

[0007] Preferably, the axial unit includes a thrust disk and a force applying body. The thrust disk is arranged at the end of the main shaft. The force applying body can apply a force to the thrust disk, so as to drive the main shaft to move in the second direction and / or make the main shaft have a tendency to move in the second direction.

[0008] Preferably, the force applying body includes a first force applying member and a second force applying member. The first force applying member and the second force applying member are respectively arranged on both sides of the thrust disk with a gap and are both electromagnets. The thrust disk is made of a magnetic material, and the electromagnets apply a force to the thrust disk through magnetic force.

[0009] Preferably, the timing of the axial unit applying a force to the main shaft is triggered by the position change of the main shaft and can output different forces according to different rotational speeds, weights, inclination angles, and positions of the main shaft.

[0010] Preferably, when the first conical outer surface is in close fit with the first conical inner surface, the second conical outer surface is also exactly in close fit with the second conical inner surface.

[0011] Preferably, the main shaft is configured to be vertically arranged, horizontally arranged, inversely arranged, or inclinedly arranged.

[0012] Preferably, it further includes a first elastic damping element, a second elastic damping element, a third elastic damping element, and a fourth elastic damping element. The second elastic damping element and the fourth elastic damping element are respectively arranged along the circumferences of the first protective bearing and the second protective bearing. The first elastic damping element is arranged at the bottom of the first protective bearing, and the third elastic damping element is arranged at the bottom of the second protective bearing.

[0013] Preferably, an axial position sensor is further provided. The axial position sensor is arranged at the end of the main shaft and has an axial gap with the end of the main shaft.

[0014] A magnetic levitation mechanism provided by the present invention includes the conical structure of the protective bearing of the magnetic levitation bearing.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. Without changing the traditional layout of the protective bearing, the present invention only changes the cylindrical structure of the journal and the inner ring of the bearing into a matching conical structure. During the rotor drop process, through the combined force of the axial magnetic force of the axial unit and / or the self-weight load of the rotor, the protective gap between the conical surface of the journal of the main shaft and the conical surface of the inner ring of the protective bearing is eliminated, and the two are closely matched and rotate synchronously, greatly reducing the adverse effects brought by impact and vibration. By designing the journal of the rotor main shaft and the inner ring of the protective bearing into a matching conical structure, the problem of difficult elimination of the protective gap is solved, and it has the characteristics of simple structure, low cost and strong practicability.

[0016] 2. When using the electromagnetic attraction force of the force application body on the thrust disc in the present invention, only the control program needs to be modified and the magnetic force of the output force application body needs to be increased, without making other adjustments to the hardware, and the operation is simple, convenient and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments read in conjunction with the accompanying drawings: Figure 1 It is a schematic structural diagram of the main shaft in a suspended state in the present invention, in which the machine base is not fully drawn; Figure 2 is Figure 1 a schematic enlarged view of the structure of part A in Figure 3 is Figure 1 a schematic enlarged view of the structure of part B in Figure 4 It is a schematic structural diagram of the main shaft in a dropped state in the present invention, in which the machine base is not fully drawn; Figure 5 is Figure 4 a schematic enlarged view of the structure of part C in Figure 6 is Figure 4 a schematic enlarged view of the structure of part D in

[0018] As shown in the figure: Main shaft 1; First conical outer surface 11; Second conical outer surface 12; Axial position sensor 13; Axial target head 14; First gasket 15; Second gasket 16; First protective bearing 2; First conical inner surface 21; First elastic damping element 22; Second elastic damping element 23; The first protective bearing cover 24; The second protective bearing 3; The second conical inner surface 31; The third elastic damping element 32; The fourth elastic damping element 33; The second protective bearing cover 34; The axial unit 4; The thrust disk 41; The first force-applying member 42; The second force-applying member 43; The first protective bearing seat 5; The first radial position sensor 51; The machine base 6; The second radial position sensor 61; The motor 7; The first radial magnetic coil 71; The second radial magnetic coil 72. Detailed implementation mode

[0019] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all belong to the protection scope of the present invention.

[0020] The present invention provides a conical structure of a protective bearing for a magnetic levitation bearing, which includes a main shaft 1, a first protective bearing 2, a second protective bearing 3, and an axial unit 4 arranged in sequence along the main shaft 1. The main shaft 1 has a first part and a second part. The first protective bearing 2 is sleeved on the first part, and the second protective bearing 3 is sleeved on the second part. The outer surface of the first part is a first conical outer surface 11, and the outer surface of the second part is a second conical outer surface 12. The inner surface of the inner ring of the first protective bearing 2 is a first conical inner surface 21 that matches the first conical outer surface 11, and the inner surface of the inner ring of the second protective bearing 3 is a second conical inner surface 31 that matches the second conical outer surface 12. The main shaft 1 has a suspended state and a falling state. The direction of movement from the falling state to the suspended state is the first direction, and the direction opposite to the first direction is the second direction. When the main shaft 1 is in the suspended state, the main shaft 1 has a clearance fit with the first protective bearing 2 and the second protective bearing 3 respectively. When the main shaft 1 is in a high-speed rotation state, the first protective bearing 2 and the second protective bearing 3 are relatively stationary; when the main shaft 1 converts from the suspended state to the falling state, the main shaft 1 relies on the axial unit 4 to apply force to the main shaft 1 and / or its own gravity load, so that the main shaft 1 moves towards the second direction, causing both conical outer surfaces to move towards the conical inner surfaces, and finally the conical outer surfaces are closely attached to the conical inner surfaces, that is, the first conical inner surface 21 is closely attached to the first conical outer surface 11, and the second conical inner surface 31 is closely attached to the second conical outer surface 12, eliminating the protective clearance between the conical surface of the rotor main shaft journal and the conical surface of the inner ring of the protective bearing. After the conical outer surface is closely attached to the conical inner surface, the high-speed rotating main shaft 1 can drive the inner rings of the two bearings to rotate smoothly, automatically eliminating the protective clearance, greatly reducing the impact and vibration between the main shaft 1 and the inner ring of the bearing, not only avoiding various adverse effects and hazards brought to the magnetic levitation bearing system, but also greatly improving the service life of the protective bearing.

[0021] Specifically, the axial unit 4 is preferably arranged at the end of the main shaft 1, at one end towards the small end of the inner rings of the two bearings. The axial unit 4 includes a thrust disc 41 and a force-applying body. The thrust disc 41 is sleeved on the main shaft 1, and the force-applying body can apply force to the thrust disc 41, so as to enable the main shaft 1 to move towards the second direction and / or make the main shaft 1 have a tendency to move towards the second direction.

[0022] The force-applying body includes a first force-applying member 42 and a second force-applying member 43. The first force-applying member 42 and the second force-applying member 43 are respectively arranged at both sides of the thrust disc 41 with a clearance and are both electromagnets. The thrust disc 41 is made of a magnetic material. After the electromagnets are energized, they have an electromagnetic field, and the thrust disc 41 is applied with force through the magnetic force of the electromagnetic field.

[0023] It should be noted that the timing of the axial unit 4 applying force to the main shaft 1 is triggered by the vibration and impact conditions of the main shaft 1. The controller controls the axial unit 4 to apply force to the thrust disk 41, and can output different forces according to different rotational speeds, weights, tilt angles, and positions of the main shaft 1 to meet the requirement of the main shaft 1 quickly entering the falling state, eliminate the gap between the main shaft 1 and the inner ring of the bearing, and reduce the impact and vibration between the main shaft 1 and the inner ring of the bearing.

[0024] The main shaft 1 in the present invention can be configured in various postures, and can be configured to be vertically arranged, horizontally arranged, inverted arranged, or inclined arranged, etc. When the main shaft 1 is configured to be vertically arranged or inclined arranged, when the main shaft 1 is converted from the suspended state to the falling state, the state conversion is completed by relying on the combined force of gravity and the force applied by the axial unit 4. When the main shaft 1 is in the horizontally arranged state, when the main shaft 1 is converted from the suspended state to the falling state, the state conversion is completed by relying on the force applied by the axial unit 4. Among them, the vertical state includes the upright state and the inverted state. When in the upright state, when the main shaft 1 is converted from the suspended state to the falling state, the state conversion is completed by relying on the combined force formed by the force applied by the axial unit 4 and its own gravity. When in the inverted state, when the main shaft 1 is converted from the suspended state to the falling state, the state conversion is completed by relying on the combined force obtained by subtracting the force applied by the axial unit 4 from its own gravity.

[0025] In the present invention, the journal part of the main shaft 1 of the magnetic levitation bearing and the inner ring of the protective bearing are designed into a conical fit structure. During the falling process of the rotor, through the axial magnetic force of the axial unit 4 or the combined force of the axial magnetic force of the axial unit 4 and the self-weight load of the rotor, the protective gap between the conical surface of the journal of the main shaft 1 and the conical surface of the inner ring of the protective bearing is eliminated, and the two are closely matched and rotate synchronously, greatly reducing the adverse effects brought by impact and vibration. By designing the journal of the rotor main shaft and the inner ring of the protective bearing into a matching conical structure, the problem of difficult elimination of the protective gap is solved.

[0026] It should be pointed out that in the initial stage when the main shaft 1 falls into the first protective bearing 2 and the second protective bearing 3, the protective gap has not been eliminated. At this time, a strong impact force will be generated between the journal of the main shaft 1 and the inner rings of the first protective bearing 2 and the second protective bearing 3, and there will be an axial component force in the axial direction, causing the main shaft 1 to axially move. To avoid this phenomenon, at this time, it is necessary to rely on the electromagnetic attraction force of the force application body in the axial unit 4 on the thrust disk 41 to overcome the axial component force generated by the impact, and make the journal of the main shaft 1 closely adhere to the inner rings of the first protective bearing 2 and the second protective bearing 3. Of course, in the upright state, if the self-weight of the rotor or the load it bears has satisfied that the journal of the main shaft 1 closely adheres to the inner rings of the first protective bearing 2 and the second protective bearing 3, then there is no need to use the axial magnetic force of the axial unit 4. That is to say, the axial magnetic force of this axial unit 4 is designed according to actual needs.

[0027] Regardless of whether the magnetic suspension bearing is installed upright, horizontally or inverted, when the rotor deadweight or load conditions are not met, it is necessary to overcome the axial force generated by the impact by adjusting the electromagnetic attraction of the force-applying body in the axial unit 4 to the thrust plate 41, so that the shaft neck of the main shaft 1 is tightly fitted with the inner rings of the first protection bearing 2 and the second protection bearing 3, eliminate the protection gap, maintain concentricity, reduce vibration and impact, and brake the magnetic suspension bearing to stop. At the same time, in order to make the first protection bearing 2 and the second protection bearing 3 evenly stressed, the present invention also provides a first elastic damping element 22 and a third elastic damping element 32, and is equipped with a second elastic damping element 23 and a fourth elastic damping element 33 to provide damping, wherein the second elastic damping element 23 and the fourth elastic damping element 33 are arranged along the circumference of the first protection bearing 2 and the second protection bearing 3, respectively, the first elastic damping element 22 is arranged at the bottom of the first protection bearing 2, and the third elastic damping element 32 is arranged at the bottom of the second protection bearing 3. The design of the elastic damping element can be reasonably set according to the actual application scenario, or it can be omitted.

[0028] It should be pointed out that the first protective bearing 2 and the second protective bearing 3 can be double-row bearings or single-row bearings, angular contact bearings or deep groove ball bearings. The bearing type is selected according to actual needs and should not be understood as a limitation on the present application.

[0029] The present invention adopts a conical design of the journal and the inner ring of the protective bearing. When the magnetic bearing falls due to a fault or abnormal out-of-control, the journal falls into the inner ring of the bearing, thereby eliminating the protective gap and solving the vibration and impact problems of the traditional protective bearing caused by the existence of the protective gap. The above design in the present invention does not need to change the traditional layout of the protective bearing, but only changes the cylindrical structure of the journal and the inner ring of the bearing to a conical structure. When the electromagnetic attraction of the force-applying body to the thrust plate 41 is used, only the control program needs to be modified to increase the magnetic force of the output force-applying body, and no other adjustments need to be made to the hardware.

[0030] The present invention also provides a magnetic levitation bearing mechanism, which includes a conical structure of the protective bearing of the magnetic levitation bearing. It also includes a first radial position sensor 51, a first radial magnetic coil 71, a motor 7, a second radial magnetic coil 72, a second radial position sensor 61, and an axial position sensor 13. The first radial position sensor 51, the first radial magnetic coil 71, the motor 7, the second radial magnetic coil 72, the second radial position sensor 61, and the axial position sensor 13 are all fixed on the machine base 6. During normal operation, the main shaft 1 will levitate to the correct position and is driven by the motor 7 to operate. It should be noted that an axial target head 14 is arranged between the axial position sensor 13 and the thrust disk 41. The axial target head 14 is used to lock the thrust disk 41 and provide a relative position reference for the axial position sensor 13. The axial target head 14 is detachably arranged at the end of the main shaft 1. A first gasket 15 and a second gasket 16 are also arranged between the thrust disk 41 and the main shaft 1.

[0031] In addition, the first protective bearing seat 5, the first protective bearing cover 24, the first protective bearing 2, the first elastic damping element 22, and the second elastic damping element 23 form a relatively complete first protective bearing system. Similar to the first protective bearing system, the first force-applying member 42, the second protective bearing cover 34, the second protective bearing 3, the third elastic damping element 32, and the fourth elastic damping element 33 form a relatively complete second protective bearing system. Among them, the first force-applying member 42 also serves as the second protective bearing seat at the same time.

[0032] The working principle of the present invention is as follows: The journal of the rotor main shaft 1 of the magnetic levitation bearing and the inner rings of the first protective bearing 2 and the second protective bearing 3 are both designed as conical. When the main shaft 1 is in the levitation state, as Figure 1 、 Figure 2 、 Figure 3 shown, the main shaft 1 is in a disengaged state from the inner rings of the first protective bearing 2 and the second protective bearing 3. There is a gap between the main shaft 1 and the first protective bearing 2 and the second protective bearing 3. This gap is also called the protection gap or protection air gap. When the magnetic levitation mechanism drops due to factors such as faults, abnormalities, power outages, etc., through the self-weight of the rotor and / or axial magnetic force, the conical surface of the journal of the rotor main shaft 1 is embedded into the conical surface of the inner ring of the protective bearing, eliminating the protection gap, as Figure 4 、 Figure 5 、 Figure 6 shown, realizing synchronous operation of the two, reducing impact and vibration. Specifically: In the levitation state, as Figure 1 、 Figure 2 、 Figure 3As shown, the main shaft 1 is disengaged from the first protective bearing 2 and the second protective bearing 3 respectively, and there is an obvious protective gap in the middle. At this time, the main shaft 1 is generally in a high-speed running state (it can also be in a hovering state or a low-speed running state). Since the main shaft 1 is disengaged from the first protective bearing 2 and the second protective bearing 3, the first protective bearing 2 and the second protective bearing 3 do not rotate but are in a static state.

[0033] When a fault, abnormality, or external interference and impact occur in the magnetic levitation mechanism, the main shaft 1 will drop and be embedded in the first protective bearing 2 and the second protective bearing 3. The protective gap in the middle is eliminated, and the three are concentric. The main shaft 1 impacts the first protective bearing 2 and the second protective bearing 3, and the first protective bearing 2 and the second protective bearing 3 accelerate sharply. In a short time, the three reach synchronous operation, forming a state as shown in Figure 4 , Figure 5 , Figure 6 to reduce the adverse effects and hazards of the impact and vibration caused by the protective gap.

[0034] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it should not be construed as a limitation to the present application.

[0035] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments. Those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A tapered structure for protecting a magnetic bearing, characterized in that: The invention comprises a main shaft (1), and a first protective bearing (2), a second protective bearing (3), and an axial unit (4) arranged in sequence along the main shaft (1), wherein the main shaft (1) has a first portion and a second portion, the first protective bearing (2) is sleeved on the first portion, and the second protective bearing (3) is sleeved on the second portion; The surface of the first portion is a first conical outer surface (11), the surface of the second portion is a second conical outer surface (12), the inner surface of the inner ring of the first protective bearing (2) is a first conical inner surface (21) matching the first conical outer surface (11), and the inner surface of the inner ring of the second protective bearing (3) is a second conical inner surface (31) matching the second conical outer surface (12). The main shaft (1) has a suspended state and a falling state, and the direction of movement from the falling state to the suspended state is a first direction. When the main shaft (1) is in the suspended state, the main shaft (1) is clearance-matched with the first protective bearing (2) and the second protective bearing (3) respectively. When the main shaft (1) is converted from the suspended state to the falling state, the main shaft (1) relies on the axial unit (4) to apply force to the main shaft (1) and / or its own gravity to move in the second direction, thereby causing the conical outer surface to move toward the conical inner surface, and finally the two conical outer surfaces are tightly attached to the two conical inner surfaces and drive the inner rings of the two bearings to rotate synchronously, wherein the second direction is opposite to the first direction.

2. The tapered structure of the protective bearing of the magnetic bearing according to claim 1 is characterized in that: The axial unit (4) is arranged at the end of the main shaft (1).

3. The tapered structure of the protective bearing of the magnetic bearing according to claim 2 is characterized in that: The axial unit (4) comprises a thrust disk (41) and a force-applying body, wherein the thrust disk (41) is arranged at the end of the main shaft (1), and the force-applying body can apply force to the thrust disk (41) so that the thrust disk (41) drives the main shaft (1) to move in a second direction and / or causes the main shaft (1) to have a tendency to move in the second direction.

4. The tapered structure of the protective bearing of the magnetic bearing according to claim 3 is characterized in that: The force-applying body comprises a first force-applying member (42) and a second force-applying member (43); the first force-applying member (42) and the second force-applying member (43) are respectively arranged at intervals on both sides of the thrust disk (41) and are both electromagnets; the thrust disk (41) is made of magnetic material; and the electromagnet applies force to the thrust disk (41) through magnetic force.

5. The tapered structure of the protective bearing of the magnetic bearing according to claim 1 is characterized in that: The timing at which the axial unit (4) applies force to the main shaft (1) is triggered by a change in the position of the main shaft (1), and can output different forces according to different rotation speeds, weights, tilt angles, and positions of the main shaft (1).

6. The tapered structure of the protective bearing of the magnetic bearing according to claim 1 is characterized in that: When the first conical outer surface (11) is tightly fitted with the first conical inner surface (21), the second conical outer surface (12) is also tightly fitted with the second conical inner surface (31).

7. The tapered structure for protecting the bearing of the magnetic bearing according to claim 1, characterized in that: The main shaft (1) is configured to be arranged vertically, horizontally or inclined.

8. The tapered structure for protecting the bearing of the magnetic bearing according to claim 1, characterized in that: The invention also comprises a first elastic damping element (22), a second elastic damping element (23), a third elastic damping element (32) and a fourth elastic damping element (33); the second elastic damping element (23) and the fourth elastic damping element (33) are arranged along the circumference of the first protection bearing (2) and the second protection bearing (3), respectively; the first elastic damping element (22) is arranged at the end of the first protection bearing (2), and the third elastic damping element (32) is arranged at the end of the second protection bearing (3).

9. The tapered structure for protecting the bearing of the magnetic bearing according to claim 1, characterized in that: An axial position sensor (13) is also provided, and the axial position sensor (13) is arranged at the end of the main shaft (1) and is spaced apart from the main shaft (1).

10. A magnetic suspension mechanism, characterized in that: A tapered structure for protecting a magnetic bearing comprising any one of claims 1 to 9.

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