A differential screw precision adjustment mechanism applied to motor magnetic bearings

Abstract

This invention belongs to the technical field of high-speed dual-winding generators, specifically a differential screw precision adjustment mechanism applied to a motor magnetic bearing. Addressing the problems raised in the background technology regarding the difficulty of machining smaller screw pitches and the use of traditional shims or single threads for adjustment, the present invention proposes the following solution: A differential adjustment bolt is mounted on the outer wall of one side of the left stator of the magnetic bearing, and a BS end cap is connected to one end of the differential adjustment bolt's outer wall. This invention achieves high-precision adjustment through the relative movement between two threaded pairs in the differential adjustment bolt. This structure avoids the problem of difficult machining. Furthermore, a small screw pitch reduces thread strength; using a differential structure allows for a smaller screw pitch with a larger thread profile. The differential screw adjustment structure not only facilitates installation but also reduces the difficulty of bolt machining, providing a simplified installation reference for other generators using magnetic bearings.

Description

Technical Field

[0001] This invention relates to the field of high-speed dual-winding generator technology, and in particular to a differential screw precision adjustment mechanism applied to a motor magnetic bearing. Background Technology

[0002] Existing magnetic levitation bearing structures typically control the gap between the stator and rotor by adjusting shims. Because magnetic levitation bearings require high precision, installation errors are also relatively large. It is necessary not only to control the cumulative error and axial movement of the base and shaft as a whole, but also to ensure the minute gap between the magnetic bearing stator and rotor.

[0003] For example, to ensure a 0.8mm gap, the shim thickness must be 0.1mm, and the diameter must be 500mm. During adjustment and disassembly, shims that are too thin are not only difficult to remove but also easily deformed. This also makes installation time-consuming and labor-intensive for workers.

[0004] Existing clearance adjustment methods rely on a single thread, adjusting the axial clearance by rotating a standard bolt one revolution. Therefore, to achieve higher adjustment precision, the bolt pitch must be shortened, resulting in a minimum adjustment accuracy of only 0.2mm for M1 bolts. This does not meet the required rigidity or adjustment precision. In practice, machining small-pitch threads on M12 bolts is not only difficult, but even if possible, the small thread height cannot withstand heavy loads, easily leading to stripping. Therefore, adjustment using a single thread is difficult to achieve. How to adjust the magnetic bearing installation precision becomes a challenging problem to overcome on-site. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a differential screw precision adjustment mechanism for use in motor magnetic bearings. This mechanism overcomes the deficiencies of existing technologies and effectively solves the problems of the difficulty in machining smaller screw pitches and the need for adjustment using traditional shims or single threads.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A differential screw precision adjustment mechanism for use in a motor magnetic bearing includes a left stator of the magnetic bearing, a differential adjustment bolt is installed on the outer wall of one side of the left stator of the magnetic bearing, and a BS end cap is connected to the outer wall of one end of the differential adjustment bolt. A movable end face is provided on the outer wall of one side of the left stator of the magnetic bearing, and one end of the differential adjustment bolt is connected to the inner wall of the movable end face.

[0008] A magnetic bearing right stator is provided on one side of the left stator of the magnetic bearing, and a magnetic bearing rotor disk is installed between the left stator and the right stator of the magnetic bearing. A rotor is installed on the inner wall of the magnetic bearing rotor disk, and a shaft is provided on one side of the outer wall of the bottom of the rotor.

[0009] Preferably, the differential adjusting bolt is provided with an outer tube, an inner tube, and a screw rod screwed to the inner wall of the outer tube and the inner tube, and the outer tube and the inner tube are respectively installed on the inner wall of the stator and the moving end face on the left side of the magnetic bearing.

[0010] Preferably, the screw includes a first threaded pair and a second threaded pair, wherein the pitch of the first threaded pair is 1.5 mm and the pitch of the second threaded pair is 1.4 mm.

[0011] Preferably, an observation hole is provided on the outer wall of the top of the right stator of the magnetic bearing.

[0012] Preferably, a mating plate is fixedly connected to the outer wall of the bottom of the right stator of the magnetic bearing by bolts, and a housing is fixedly connected to the outer wall of one side of the mating plate by bolts.

[0013] Preferably, the inner wall of the outer casing is fixedly connected to the bearing seat by bolts.

[0014] The beneficial effects of this invention are as follows:

[0015] 1. The differential screw precision adjustment mechanism of the present invention applied to the magnetic bearing of the motor achieves high-precision adjustment through the relative movement between two threaded pairs in the differential adjustment bolt. For each rotation, the actual distance moved between the stator on the left side of the magnetic bearing and the BS end cover is the difference in pitch between the two threads. This structure has two advantages: the smaller the pitch, the more difficult it is to process. This structure can avoid the problem of processing difficulties. Secondly, the strength of the thread will be reduced if the pitch is too small. Using a differential structure, a small pitch can be obtained with a larger tooth profile.

[0016] 2. The differential screw precision adjustment mechanism of the present invention applied to the magnetic bearing of the motor realizes adjustment without the need for traditional shims or single threads. The differential screw adjustment structure is not only easy to install, but also reduces the difficulty of bolt processing. It has reference significance for the simplified installation of other generators using magnetic bearings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the differential structure of a differential screw precision adjustment mechanism for motor magnetic bearings proposed in this invention, mounted on the magnetic bearing.

[0018] Figure 2 This is a schematic diagram of the differential screw structure of a differential screw precision adjustment mechanism applied to a motor magnetic bearing, as proposed in this invention.

[0019] Figure 3 This is a three-dimensional schematic diagram of the differential screw of a differential screw precision adjustment mechanism applied to a motor magnetic bearing, as proposed in this invention.

[0020] In the diagram: 1. Left stator of magnetic bearing; 2. Differential adjusting bolt; 3. BS end cover; 4. Moving end face; 5. Right stator of magnetic bearing; 6. Magnetic bearing rotor disk; 7. Rotor; 8. Shaft; 9. Outer tube; 10. Inner tube; 11. Screw; 12. First threaded pair; 13. Second threaded pair; 14. Observation hole; 15. Connecting plate; 16. Outer shell; 17. Shaft seat. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] Example 1, refer to Figure 1-2 A differential screw precision adjustment mechanism applied to a magnetic bearing of an electric motor includes a left stator 1 of the magnetic bearing, a differential adjustment bolt 2 installed on the outer wall of one side of the left stator 1 of the magnetic bearing, and a BS end cap 3 connected to the outer wall of one end of the differential adjustment bolt 2. A movable end face 4 is provided on the outer wall of one side of the left stator 1 of the magnetic bearing, and one end of the differential adjustment bolt 2 is connected to the inner wall of the movable end face 4.

[0023] In this embodiment, high-precision adjustment is achieved in the differential adjusting bolt 2 through the relative movement between the two threaded pairs. Each rotation of the bolt results in the actual distance moved between the stator 1 on the left side of the magnetic bearing and the BS end cover 3, which is the difference in the pitch of the two threads. This structure has two advantages: the smaller the pitch, the more difficult it is to process, and this structure can avoid the problem of processing difficulties. Secondly, if the pitch is too small, the strength of the thread will be reduced, and the differential structure can use a larger tooth profile to obtain a small pitch.

[0024] Example 2, refer to Figure 1 A differential screw precision adjustment mechanism applied to a motor magnetic bearing, wherein a magnetic bearing right stator 5 is provided on one side of the magnetic bearing left stator 1, and a magnetic bearing rotor disk 6 is installed between the magnetic bearing left stator 1 and the magnetic bearing right stator 5. A rotor 7 is installed on the inner wall of the magnetic bearing rotor disk 6, and a shaft 8 is provided on one side of the bottom outer wall of the rotor 7.

[0025] In this embodiment, adjustment is achieved without the need for traditional shims or single threads. The differential screw adjustment structure is not only easy to install but also reduces the difficulty of bolt processing, which has reference value for simplifying the installation of other generators using magnetic bearings.

[0026] Reference Figure 3 The differential adjusting bolt 2 is equipped with an outer tube 9, an inner tube 10, and a screw 11 screwed to the inner wall of the outer tube 9 and the inner tube 10, respectively. The outer tube 9 and the inner tube 10 are respectively installed on the inner wall of the stator 1 on the left side of the magnetic bearing and the moving end face 4.

[0027] Reference Figure 3 The screw 11 includes a first threaded pair 12 and a second threaded pair 13, with the first threaded pair 12 having a pitch of 1.5 mm and the second threaded pair 13 having a pitch of 1.4 mm.

[0028] Reference Figure 1 An observation hole 14 is provided on the outer wall of the top of the stator 5 on the right side of the magnetic bearing.

[0029] Reference Figure 1 A mating plate 15 is bolted to the bottom outer wall of the stator 5 on the right side of the magnetic bearing, and a housing 16 is bolted to one side of the outer wall of the mating plate 15.

[0030] Reference Figure 1 The inner wall of the outer casing 16 is fixedly connected to the bearing 17 by bolts.

[0031] Working principle: First, a threaded hole with an M8 pitch of 1.4mm is drilled on the moving end face 4. Then, a threaded hole with an M12 pitch of 1.5mm is drilled on the left stator 1 of the magnetic bearing. During installation, the M8 screw 11 at the front end of the differential adjustment bolt 2 passes through the M12 hole of the left stator 1 of the magnetic bearing. At this time, the M8 screw 11 is equivalent to a through hole. When the front end of the differential adjustment bolt 2 is screwed into the hole of the moving end face 4, the differential adjustment begins to play a role. Tightening it one turn reduces the gap between the differential adjustment bolt 2 and the moving end face 4 by 1.4mm and the gap between the differential adjustment bolt 2 and the left stator 1 of the magnetic bearing by 1.5mm. At this time, the distance between the moving end face 4 and the left stator 1 of the magnetic bearing increases by 0.1mm.

[0032] During installation, first install the BS end cover 3 on the base, then install the rotor 7, and then heat-fit the magnetic bearing rotor disc 6 onto the shaft 8. Then press the rotor 7 and the magnetic bearing rotor disc 6 together until their end faces are in contact. At this point, screw in the differential adjustment bolt 2 to adjust the gap between the moving end face 4 and the left stator 1 of the magnetic bearing. Each turn of the bolt separates the gap by 0.1 mm. You can measure whether the adjustment is in place by inserting a feeler gauge through the observation hole 14.

[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A differential screw precision adjustment mechanism applied to a magnetic bearing of an electric motor, comprising a stator (1) on the left side of the magnetic bearing, characterized in that, A differential adjustment bolt (2) is installed on the outer wall of the left stator (1) of the magnetic bearing, and a BS end cap (3) is connected to the outer wall of one end of the differential adjustment bolt (2). A movable end face (4) is provided on the outer wall of the left stator (1) of the magnetic bearing, and one end of the differential adjustment bolt (2) is connected to the inner wall of the movable end face (4). A magnetic bearing right stator (5) is provided on one side of the magnetic bearing left stator (1), and a magnetic bearing rotor disk (6) is installed between the magnetic bearing left stator (1) and the magnetic bearing right stator (5). A rotor (7) is installed on the inner wall of the magnetic bearing rotor disk (6), and a shaft (8) is provided on one side of the bottom outer wall of the rotor (7).

2. The differential screw precision adjustment mechanism applied to a motor magnetic bearing according to claim 1, characterized in that, The differential adjusting bolt (2) is provided with an outer tube (9), an inner tube (10) and a screw (11) screwed to the inner wall of the outer tube (9) and the inner tube (10), and the outer tube (9) and the inner tube (10) are respectively installed on the inner wall of the stator (1) on the left side of the magnetic bearing and the moving end face (4).

3. The differential screw precision adjustment mechanism applied to a motor magnetic bearing according to claim 2, characterized in that, The screw (11) includes a first threaded pair (12) and a second threaded pair (13), and the pitch of the first threaded pair (12) is 1.5 mm, and the pitch of the second threaded pair (13) is 1.4 mm.

4. The differential screw precision adjustment mechanism applied to a motor magnetic bearing according to claim 1, characterized in that, An observation hole (14) is provided on the top outer wall of the stator (5) on the right side of the magnetic bearing.

5. A differential screw precision adjustment mechanism applied to a motor magnetic bearing according to claim 1, characterized in that, The bottom outer wall of the stator (5) on the right side of the magnetic bearing is fixedly connected to a mating plate (15) by bolts, and the outer wall of one side of the mating plate (15) is fixedly connected to a shell (16) by bolts.

6. A differential screw precision adjustment mechanism applied to a motor magnetic bearing according to claim 5, characterized in that, The inner wall of the outer casing (16) is fixedly connected to the bearing seat (17) by bolts.

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