A radial magnetic bearing support characteristics testing device

Abstract

The present invention relates to the field of bearing testing technology, and discloses a radial magnetic suspension bearing support characteristic test device, comprising a base, a loading measurement mechanism is arranged on both sides of the top of the base, a height adjustment mechanism is arranged on the top of the base, a bearing to be tested is arranged inside the height adjustment mechanism, and a rotor limit mechanism is arranged on the top of the base; the loading measurement mechanism comprises a connecting frame, iron core supports are arranged on the inner walls around the connecting frame, and a tension sensor is threadedly fixedly installed between the iron core supports and the connecting frame, loading coils are wound on the outer walls of both sides of the four iron core supports, and displacement sensors are threadedly fixedly installed on the inner walls of the four iron core supports. The radial magnetic suspension bearing support characteristic test device can meet a variety of test requirements and loading scenarios, accurately measure the static support characteristics of the magnetic suspension bearing at any radial position, and lay an experimental foundation for the analysis of rotor dynamics system characteristics and control system design.

Description

Technical Field

[0001] The invention relates to the technical field of bearing testing, and in particular to a radial magnetic suspension bearing support characteristic testing device. Background Art

[0002] Magnetic bearings use magnetic field force to suspend the rotor. There is no mechanical contact between the rotor and the stator. They have a series of advantages such as no friction, high speed, no need for lubrication system, low noise, and low vibration. They have broad development prospects in the fields of high-speed rotating machinery, medical equipment, transportation and rail systems, and precision instruments. In the magnetic bearing system, external disturbances will have a great impact on the system's operating stability, dynamic response, and rotor suspension accuracy. The system needs to provide appropriate current stiffness and displacement stiffness to resist external disturbances. Therefore, a reasonable design of a magnetic bearing support characteristic test device to accurately obtain its support characteristics such as current stiffness and displacement stiffness is crucial for conducting dynamic characteristic analysis and control system design of the magnetic suspension rotor system.

[0003] At present, most devices for testing the support characteristics of magnetic bearings use mechanical loading methods to control the rotor displacement. For example, the invention patent No. 201410497868.7 uses a loading rotary twist cover in conjunction with a loading screw to load the magnetic bearing under test and adjust the rotor displacement; the invention patent No. 201811308305.3 controls the rotor displacement by loading the rotor by rotating the radial / axial threaded push rod. However, these devices have the following problems when measuring the static support characteristics of magnetic bearings: First, it is difficult to achieve precise loading, which affects the accuracy of the experimental results. Secondly, it is impossible to comprehensively test the support characteristics of the magnetic bearing at any radial position, and therefore it is impossible to systematically reflect the static support characteristics of the magnetic bearing. These problems are mainly caused by mechanical loading methods.

[0004] In order to overcome the above problems, it is very necessary to design an experimental device for the static support characteristics of radial magnetic bearings using electromagnetic loading to systematically reflect the static support characteristics of magnetic bearings. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the shortcomings of the prior art, the present invention provides a radial magnetic bearing support characteristics testing device, which can accurately measure the static support characteristics of the magnetic bearing at any radial position under different air gap lengths, lay an experimental foundation for the rotor dynamics system characteristics analysis and control system design, and solve the problems raised by the background technology.

[0007] (II) Technical solution

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a radial magnetic bearing support characteristic testing device, comprising a base, loading and measuring mechanisms are provided on both sides of the top of the base, a height adjustment mechanism is provided on the top of the base and between the two loading and measuring mechanisms, a bearing to be tested is provided inside the height adjustment mechanism, and a rotor limiting mechanism is provided on the top of the base and between the loading and measuring mechanism and the height adjustment mechanism; the loading and measuring mechanism comprises a connecting frame, the connecting frame adopts an annular frame, and the bottom two sides of the connecting frame are fixedly installed between the base, iron core supports are provided on the inner walls around the connecting frame, and a tension sensor is threadedly fixedly installed between the iron core support and the connecting frame, loading coils are wound on the outer walls of both sides of the four iron core supports, displacement sensors are threadedly fixedly installed on the inner walls of the four iron core supports, and a rotating shaft is provided between the four iron core supports, and the shaft wall of the rotating shaft passes through the interior of the side bearing and the interior of the rotor limiting mechanism.

[0009] Preferably, L-shaped supports are provided on both sides of the bottom of the connecting frame, one end of the L-shaped support is fixedly connected to the connecting frame, and the other end of the L-shaped support is fixedly connected to the base.

[0010] Preferably, the height adjustment mechanism includes a base, an upper V-shaped pressure block and a lower V-shaped pressure block, the base is fixedly installed on the top of the base, positioning screws are fixedly provided on both sides of the top of the base, the lower V-shaped pressure block is located above the base, and the two ends of the lower V-shaped pressure block are movably inserted on the rod wall of the positioning screw and positioned by two positioning nuts, locking screws are fixedly provided on both sides of the top of the lower V-shaped pressure block, the upper V-shaped pressure block is located above the lower V-shaped pressure block, and the two ends of the upper V-shaped pressure block are movably inserted on the rod wall of the locking screw and fixedly connected by locking nuts.

[0011] Preferably, the upper V-shaped pressing block and the lower V-shaped pressing block are provided with bearing pressing grooves on opposite sides thereof, and the bearing to be tested is located in the bearing pressing groove between the upper V-shaped pressing block and the lower V-shaped pressing block.

[0012] Preferably, the rotor limiting mechanism includes a bearing protection plate and a limiting sleeve, the bearing protection plate is fixedly mounted on the side wall of the limiting sleeve, the side wall of the limiting sleeve is provided with a limiting claw inserted through an opening, the bottom of the limiting sleeve is fixedly mounted with a guide rail seat by a hexagon socket positioning screw, the bottom of the guide rail seat is fixedly provided with a support seat, and the support seat is fixedly connected to the base.

[0013] Preferably, the limiting sleeve includes a left half limiting sleeve and a right half limiting sleeve, the left half limiting sleeve and the right half limiting sleeve are fixedly connected by a first bolt, the bottom of the left half limiting sleeve and the bottom of the right half limiting sleeve are both provided with a curved structure inserted into the guide rail seat, the bearing protection plate includes a plate body, and the plate body is fixedly mounted on the side wall of the limiting sleeve by a second bolt.

[0014] Preferably, the limiting claw includes an arc claw, a positioning pin, a locking pin and a claw cap. The arc claw and the claw cap are movably plugged together, and the arc claw and the claw cap are fixedly connected by the locking pin. The positioning pin is fixedly arranged on the side wall of the arc claw, and the positioning pin is positioned and matched with the semicircular positioning groove on the limiting sleeve.

[0015] (III) Beneficial effects

[0016] Compared with the prior art, the present invention provides a radial magnetic bearing support characteristic testing device, which has the following beneficial effects:

[0017] The radial magnetic bearing support characteristic test device fixes the magnetic bearing and limits the radial displacement of the rotor through a height adjustment mechanism and a rotor limit mechanism, then uses a loading and measuring mechanism to apply electromagnetic force to deflect the rotor, measures the electromagnetic force, rotor displacement and current value, and finally processes the data to obtain the current stiffness and displacement stiffness of the magnetic bearing. Compared with the device using mechanical loading, the device uses electromagnetic loading technology to avoid friction and wear caused by loading errors and mechanical contact, thereby improving the reliability of the experiment and the stability of the experimental results. In addition, the loading path and angle of the device are not restricted, and the support characteristics of the bearing at any radial position can be tested, thereby systematically reflecting the static support characteristics of the magnetic bearing. Therefore, the device uses an electromagnetic loading method, which can meet a variety of test requirements and loading scenarios, accurately measure the static support characteristics of the magnetic bearing at any radial position, and lay an experimental foundation for rotor dynamics system characteristic analysis and control system design. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a radial magnetic bearing support characteristic testing device proposed by the present invention;

[0019] Figure 2 for Figure 1 Schematic diagram of the structure of the loading measurement mechanism;

[0020] Figure 3 for Figure 1 A schematic diagram of the structure of the mid-height adjustment mechanism;

[0021] Figure 4 for Figure 1 The structural diagram of the middle rotor limiting mechanism;

[0022] Figure 5 for Figure 4 Schematic diagram of the structure of the middle limit sleeve and the bearing protection plate;

[0023] Figure 6 for Figure 4 Schematic diagram of the structure of the middle limit claw;

[0024] Figure 7 This is a flow chart for testing the static support characteristics of the radial magnetic bearing proposed in the present invention.

[0025] 1. Base; 2. L-shaped support; 3. Connecting frame; 4. Core support; 5. Displacement sensor; 6. Rotating shaft; 7. Loading coil; 8. Tension sensor; 9. Upper V-shaped pressure block; 10. Locking nut; 11. Locking screw; 12. Bearing protection plate; 12a. Plate body; 12b. Second bolt; 13. Limit sleeve; 13a. Left half limit sleeve; 13b. Right half limit sleeve; 13c. First bolt; 14. Limit claw; 14a. Arc claw; 14b. Positioning pin; 14c. Locking pin; 14d. Claw cap; 15. Hexagon socket positioning screw; 16. Guide rail seat; 17. Support seat; 18. Positioning nut; 19. Positioning screw; 20. Base; 21. Lower V-shaped pressure block. DETAILED DESCRIPTION

[0026] 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 described embodiments 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 creative work are within the scope of protection of the present invention.

[0027] See also Figure 1-7A radial magnetic bearing support characteristic testing device comprises a base 1, wherein both sides of the top of the base 1 are provided with a loading and measuring mechanism, a height adjustment mechanism is provided at the top of the base 1 and between the two loading and measuring mechanisms, a bearing to be tested is provided inside the height adjustment mechanism, and a rotor limiting mechanism is provided at the top of the base 1 and between the loading and measuring mechanism and the height adjustment mechanism. First, the bearing to be tested is fixed by the height adjustment mechanism and the bearing height is adjusted so that its center is aligned with the center of the rotor limiting mechanism. Then, a claw with a suitable inner diameter size is selected and fixed in the rotor limiting mechanism to limit the radial displacement of the rotor and protect the bearing to be tested. Subsequently, an electromagnetic force is applied to the rotor in the loading and measuring mechanism to cause the rotor to deflect. When the rotor moves to a preset position, the electromagnetic force and the rotor displacement are measured by the loading and measuring mechanism. Finally, the measured electromagnetic force, the rotor displacement and the current value collected by the bearing control end are processed, and a current-electromagnetic force curve and an electromagnetic force-rotor displacement curve are drawn to obtain the current stiffness and displacement stiffness of the magnetic bearing.

[0028] The loading measurement mechanism includes a connecting frame 3, which is an annular frame, and the two sides of the bottom of the connecting frame 3 are fixedly installed between the base 1, and L-shaped supports 2 are provided on both sides of the bottom of the connecting frame 3, one end of the L-shaped support 2 is fixedly connected to the connecting frame 3, and the other end of the L-shaped support 2 is fixedly connected to the base 1, and the inner walls of the four surrounding walls of the connecting frame 3 are provided with iron core supports 4, and a tension sensor 8 is threadedly fixedly installed between the iron core supports 4 and the connecting frame 3, and the outer walls of the two sides of the four iron core supports 4 are wound with loading coils 7, and the inner walls of the four iron core supports 4 are threadedly fixedly installed with displacement sensors 5, and a rotating shaft 6 is provided between the four iron core supports 4, and the rotating shaft 6 The shaft wall passes through the inside of the side bearing and the inside of the rotor limiting mechanism; the front end of the rotating shaft 6 cooperates with the rotor of the test magnetic suspension bearing, and the rear end is suspended in the center of the connecting frame 3 under the action of electromagnetic force. When an appropriate current is passed through the loading coil 7, the two ends of the core support 4 will apply electromagnetic force to the rotating shaft 6, so that the rotating shaft 6 drives the rotor to move along the direction of the resultant electromagnetic force. By adjusting the current in the four loading coils 7, the direction of the resultant electromagnetic force can be changed, thereby adjusting the offset angle of the rotor; when the rotor moves to the preset position of the rotor limiting mechanism, the electromagnetic force exerted on the rotor and the displacement of the rotor can be measured by the tension pressure sensor 8 and the displacement sensor 5.

[0029] The height adjustment mechanism comprises a base 20, an upper V-shaped pressing block 9 and a lower V-shaped pressing block 21. The base 20 is fixedly installed on the top of the base 1. Positioning screws 19 are fixedly arranged on both sides of the top of the base 20. The lower V-shaped pressing block 21 is located above the base 20, and the two ends of the lower V-shaped pressing block 21 are movably inserted on the rod wall of the positioning screw 19 and are positioned by two positioning nuts 18. Locking screws 11 are fixedly arranged on both sides of the top of the lower V-shaped pressing block 21. The upper V-shaped pressing block 9 is located above the lower V-shaped pressing block 21, and the two ends of the upper V-shaped pressing block 9 are movably inserted on the rod wall of the locking screw 11 and are fixedly connected by locking nuts 10. The upper V-shaped pressing block 9 and the lower V-shaped pressing block 21 are provided with bearing grooves on the opposite sides. The measured bearing is located in the bearing groove between the upper V-shaped pressing block 9 and the lower V-shaped pressing block 21. By screwing the positioning nuts 18 and the locking nuts 10, not only the height of the measured bearing can be adjusted, but also the measured bearing can be clamped and fixed.

[0030] The rotor limiting mechanism includes a bearing protection plate 12 and a limiting sleeve 13. The bearing protection plate 12 is fixedly mounted on the side wall of the limiting sleeve 13. A limiting claw 14 is inserted through an opening in the side wall of the limiting sleeve 13. A guide rail seat 16 is fixedly mounted on the bottom of the limiting sleeve 13 through a hexagon socket positioning screw 15. A support seat 17 is fixedly mounted on the bottom of the guide rail seat 16. The support seat 17 is fixedly connected to the base 1. The rotor can be installed in a limited position inside the bearing protection plate 12 and the limiting sleeve 13.

[0031] The limiting sleeve 13 includes a left half limiting sleeve 13a and a right half limiting sleeve 13b, which are fixedly connected by a first bolt 13c. The bottom of the left half limiting sleeve 13a and the bottom of the right half limiting sleeve 13b are both provided with a curved structure inserted into the guide rail seat 16. During the installation process, the left half limiting sleeve 13a and the right half limiting sleeve 13b can be opened and wrapped on the outer wall of the rotor, and then fixedly connected by the first bolt 13c; the bearing protection plate 12 includes a plate body 12a, and the plate body 12a is fixedly installed on the side wall of the limiting sleeve 13 by a second bolt 12b. The gap between the bearing protection plate 12 and the rotating shaft 6 is slightly smaller than the air gap spacing of the measured bearing, and can be selected according to different air gap spacings. The bearing protection plate 12 can also be used as a limiting claw 14 with a maximum gap. At this time, no other claws need to be inserted into the limiting sleeve 13.

[0032] The limiting claw 14 includes an arc claw 14a, a positioning pin 14b, a locking pin 14c and a claw cap 14d. The arc claw 14a and the claw cap 14d are movably plugged together, and the arc claw 14a and the claw cap 14d are fixedly connected by the locking pin 14c. The positioning pin 14b is fixedly arranged on the side wall of the arc claw 14a, and the positioning pin 14b is positioned and matched with the semicircular positioning groove on the limiting sleeve 13. By turning the locking pin 14c, the position between the arc claw 14a and the claw cap 14d can be adjusted, and the position can be fixed by the locking pin 14c.

[0033] In summary, the radial magnetic bearing support characteristic test device, the specific test process is as follows:

[0034] 1. After starting the test, select a limit claw 14 with a suitable inner diameter according to the test requirements and install it into the limit sleeve 12.

[0035] 2. Appropriate current is passed through the loading coil 7 to generate corresponding electromagnetic force, causing the rotor to shift to a predetermined position. The rotor offset angle and offset amount can be adjusted by adjusting the current in the four loading coils 7.

[0036] 3. After the rotor reaches the predetermined position, the electromagnetic force and rotor displacement are measured by the sensor on the device, and the current value of the magnetic bearing is collected at the control end of the measured bearing.

[0037] 4. Repeat the above steps until the measurement is completed, process the collected electromagnetic force, shaft 6 displacement and current value, draw the current-electromagnetic force curve and the electromagnetic force-rotor displacement curve, and obtain the current stiffness and displacement stiffness of the magnetic suspension bearing.

[0038] It should be noted that the term "comprises" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article, or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A radial magnetic bearing support characteristic testing device, comprising a base (1), characterized in that: Loading and measuring mechanisms are provided on both sides of the top of the base (1); a height adjustment mechanism is provided on the top of the base (1) and located between the two loading and measuring mechanisms; a bearing to be measured is provided inside the height adjustment mechanism; and a rotor limiting mechanism is provided on the top of the base (1) and located between the loading and measuring mechanism and the height adjustment mechanism; The loading and measuring mechanism comprises a connecting frame (3), the connecting frame (3) is an annular frame, and the two sides of the bottom of the connecting frame (3) are fixedly installed between the base (1), the inner walls around the connecting frame (3) are provided with iron core supports (4), and a tension sensor (8) is threadedly fixedly installed between the iron core supports (4) and the connecting frame (3), the outer walls of the two sides of the four iron core supports (4) are wound with loading coils (7), the inner walls of the four iron core supports (4) are threadedly fixedly installed with displacement sensors (5), and a rotating shaft (6) is provided between the four iron core supports (4), and the shaft wall of the rotating shaft (6) passes through the interior of the measured bearing and the interior of the rotor limit mechanism; The rotor limiting mechanism comprises a bearing protection plate (12) and a limiting sleeve (13); the bearing protection plate (12) is fixedly mounted on the side wall of the limiting sleeve (13); a limiting claw (14) is inserted through an opening in the side wall of the limiting sleeve (13); a guide rail seat (16) is fixedly mounted on the bottom of the limiting sleeve (13) via a hexagon socket set screw (15); a support seat (17) is fixedly mounted on the bottom of the guide rail seat (16); and the support seat (17) is fixedly connected to the base (1); The positioning claw (14) comprises an arc claw (14a), a positioning pin (14b), a locking pin (14c) and a claw cap (14d); the arc claw (14a) and the claw cap (14d) are movably plugged together, and the arc claw (14a) and the claw cap (14d) are fixedly connected via the locking pin (14c); the positioning pin (14b) is fixedly arranged on the side wall of the arc claw (14a), and the positioning pin (14b) is positioned and matched with a semicircular positioning groove on the limiting sleeve (13).

2. A radial magnetic bearing support characteristic testing device according to claim 1, characterized in that: L-shaped supports (2) are provided on both sides of the bottom of the connecting frame (3); one end of the L-shaped support (2) is fixedly connected to the connecting frame (3), and the other end of the L-shaped support (2) is fixedly connected to the base (1).

3. A radial magnetic bearing support characteristic testing device according to claim 1, characterized in that: The height adjustment mechanism comprises a base (20), an upper V-shaped pressing block (9) and a lower V-shaped pressing block (21); the base (20) is fixedly mounted on the top of the pedestal (1); positioning screws (19) are fixedly arranged on both sides of the top of the base (20); the lower V-shaped pressing block (21) is located above the base (20); and both ends of the lower V-shaped pressing block (21) are movably inserted on the rod wall of the positioning screw (19) and are positioned by two positioning nuts (18); locking screws (11) are fixedly arranged on both sides of the top of the lower V-shaped pressing block (21); the upper V-shaped pressing block (9) is located above the lower V-shaped pressing block (21); and both ends of the upper V-shaped pressing block (9) are movably inserted on the rod wall of the locking screw (11) and are fixedly connected by locking nuts (10).

4. A radial magnetic bearing support characteristic testing device according to claim 3, characterized in that: The upper V-shaped pressing block (9) and the lower V-shaped pressing block (21) are both provided with bearing pressing grooves on opposite sides thereof, and the bearing to be tested is located in the bearing pressing groove between the upper V-shaped pressing block (9) and the lower V-shaped pressing block (21).

5. A radial magnetic bearing support characteristic testing device according to claim 4, characterized in that: The limiting sleeve (13) comprises a left half limiting sleeve (13a) and a right half limiting sleeve (13b), the left half limiting sleeve (13a) and the right half limiting sleeve (13b) are fixedly connected by a first bolt (13c), the bottom of the left half limiting sleeve (13a) and the bottom of the right half limiting sleeve (13b) are both provided with a curved structure inserted into the guide rail seat (16), and the bearing protection plate (12) comprises a plate body (12a), and the plate body (12a) is fixedly mounted on the side wall of the limiting sleeve (13) by a second bolt (12b).

Images