Flexible rotor dynamic balancing auxiliary device and use method thereof

Abstract

The present invention discloses a flexible rotor dynamic balancing auxiliary device and its use method. The device includes a base fixedly installed in a flexible rotor system coaxially with the flexible rotor, a limiting ring sleeved outside the base to limit the amplitude of the flexible rotor, and a pressure cover pressed on the base to limit the axial position of the limiting ring; a boss is provided on the outer wall of the base to limit the axial position of the limiting ring; the limiting ring and the base can be tightened to limit the torque of the limiting ring in the circumferential direction. The device uses the friction between the limiting ring and the annular inner wall of the magnetic bearing position of the hollow cylindrical rotor to limit the amplitude of the test rotor, prevent the amplitude from being too large during the over-critical process, realize auxiliary startup, and can realize the speed increase assistance of the flexible rotor system constrained by the magnetic bearing, which is beneficial to improve the dynamic balancing efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of supercritical rotating machinery, and in particular to a flexible rotor dynamic balancing auxiliary device and a use method thereof. Background Art

[0002] In supercritical rotating machinery, the operating speed of the flexible rotor is higher than the critical frequency. Dynamic balancing is required to achieve supercriticality. Typically, the flexible rotor is dynamically balanced in a range above the critical speed. This condition is easily met for systems with large support stiffness. However, for supercritical rotors with relatively small support system stiffness, it is impossible to increase the speed to the supercritical speed range on its own. Without the use of auxiliary devices, dynamic balancing can only be performed in the subcritical speed range, which affects the balancing efficiency and accuracy. Currently, there are no relevant auxiliary devices. Therefore, it is necessary to develop a device for auxiliary dynamic balancing so that flexible rotors with relatively small support system stiffness can reach the supercritical speed before dynamic balancing. Summary of the Invention

[0003] The purpose of the present invention is to provide a flexible rotor dynamic balancing auxiliary device for a supercritical rotor with a relatively small supporting system stiffness, which cannot be accelerated to a supercritical speed region by itself.

[0004] Another object of the present invention is to provide a method for using the flexible rotor dynamic balancing auxiliary device.

[0005] The technical solution adopted to achieve the purpose of the present invention is:

[0006] A flexible rotor dynamic balancing auxiliary device comprises a base fixedly mounted coaxially with the flexible rotor in a flexible rotor system, a limiting ring sleeved outside the base to limit the amplitude of the flexible rotor, and a pressure cover pressed on the base to limit the axial position of the limiting ring;

[0007] A base boss is provided on the outer side wall of the base to limit the axial position of the limiting ring;

[0008] The limiting ring and the base can be tightened together to limit the torque of the limiting ring rotating along the circumferential direction.

[0009] In the above technical solution, the base is annular.

[0010] In the above technical solution, the base is made of stainless steel.

[0011] In the above technical solution, the inner edge of the limiting ring is circular; the outer edge of the limiting ring is a Lello triangle.

[0012] In the above technical solution, the material of the limiting ring is polytetrafluoroethylene.

[0013] In the above technical solution, an internal thread is provided on the inner edge side wall of the limiting ring; and an external thread matching the internal thread is provided on the outer side wall of the base.

[0014] In the above technical solution, the number of turns of the external thread is smaller than the number of turns of the internal thread.

[0015] In the above technical solution, the pressure cover is annular, and a pressure cover boss is provided on its inner edge to press the pressure cover on the base; the outer edge diameter of the pressure cover is larger than the inner edge diameter of the limiting ring to limit the limiting ring under the pressure cover.

[0016] In the above technical solution, the material of the gland is steel or aluminum.

[0017] In another aspect of the present invention, a method for using the flexible rotor dynamic balancing auxiliary device comprises the following steps:

[0018] Step 1: Fix the base to the flexible rotor system, ensuring that the base and the flexible rotor are coaxial;

[0019] Step 2: Tighten the limiting ring and the base; press the gland onto the base;

[0020] Step 3: Start the motor to make the flexible rotor start to rotate. As the speed increases, the flexible rotor begins to rub against the outer wall of the limit ring, and the rubbing force increases with the increase in speed until the limit ring and the base are released from the tightened state. The limit ring begins to rotate with the flexible rotor to achieve auxiliary starting.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The flexible rotor dynamic balancing auxiliary device provided by the present invention uses the friction force between the limit ring and the inner wall of the magnetic conductive ring in the flexible rotor to limit the amplitude of the test rotor, prevent the amplitude from being too large during the critical process, and achieve auxiliary starting.

[0023] 2. The flexible rotor dynamic balancing auxiliary device provided by the present invention can assist the flexible rotor system constrained by low-rigidity magnetic bearings to increase its speed beyond the critical region and enter the supercritical region, which is beneficial for dynamic balancing measurement, thereby improving the dynamic balancing accuracy and efficiency.

[0024] 3. The flexible rotor dynamic balancing auxiliary device provided by the present invention can assist in increasing the speed of the flexible rotor system constrained by magnetic bearings, which is beneficial to improving the dynamic balancing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Shown is a front view of the flexible rotor dynamic balancing auxiliary device;

[0026] Figure 2The figure shows a top view of the flexible rotor dynamic balancing auxiliary device;

[0027] Figure 3 Shown is a cross-sectional view of a flexible rotor dynamic balancing auxiliary device;

[0028] Figure 4 Shown Figure 3 A partial enlarged view of

[0029] Figure 5 Shown is a schematic structural diagram of the limit ring.

[0030] In the figure: 1-base, 2-limiting ring, 3-pressure cover, 4-base boss, 5-pressure cover boss, 6-external thread, 7-internal thread. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] In the following embodiments, the flexible rotor refers to a hollow cylindrical rotor with one end constrained by a magnetic bearing. Flexible rotor is a rotor dynamics term, and "flexible" refers to the hollow cylindrical rotor operating at a speed above its bending resonance frequency. The magnetic bearing consists of two parts: a magnet and a magnetic ring. The magnet is located at the rotor's axis. The magnetic ring is a fixed structure installed at one end of the rotor.

[0033] Example 1

[0034] A flexible rotor dynamic balancing auxiliary device includes a base 1, a limiting ring 2 and a pressure cover 3;

[0035] The base 1 is used to limit the position of the entire device;

[0036] The outer wall of the limit ring 2 cooperates with the inner wall of the magnetic ring in the flexible rotor to limit the vibration amplitude of the flexible rotor when it passes the critical point;

[0037] The pressure cover 3 is used to limit the axial position of the limiting ring 2 to prevent the limiting ring 2 from moving upward and separating from the base 1 during rotation;

[0038] The base 1 is fixedly installed in the flexible rotor system and is arranged coaxially with the flexible rotor; the machine where the flexible rotor is located has a threaded cylinder coaxial with the magnetic steel in the flexible rotor. The base 1 is mounted on the cylinder to achieve horizontal XY direction limitation, and then the height direction limitation is achieved by tightening the locking nut matching the cylinder.

[0039] A base boss 4 is provided on the outer side wall of the base 1 for limiting the axial position of the limiting ring 2;

[0040] like Figure 4 As shown, an external thread 6 is provided on the outer side wall of the lower end portion of the base 1; the inner edge of the cross-section of the limiting ring 2 is circular, and an internal thread 7 matching the external thread 6 is provided on the side wall of the inner edge; the limiting ring 2 is sleeved on the outside of the base 1, and the two can be tightened by cooperating with the internal thread 7 and the external thread 6 to limit the torque of the limiting ring 2 rotating along the circumferential direction of the base 1; the number of turns of the external thread 6 is smaller than the number of turns of the internal thread 7, and when the threads between the limiting ring 2 and the base 1 are tightened, the lower surface of the limiting ring 2 is in close contact with the upper surface of the base boss 4, and the limiting ring 2 cannot rotate relative to the base 1; when the limiting ring 2 is upward, so that its internal thread 7 is disengaged from the external thread 6, the limiting ring 2 can rotate relative to the base 1;

[0041] The gland 3 is pressed on the base 1. The gland 3 is annular, and a gland boss 5 is provided on its inner edge to press the gland 3 on the base 1. The outer diameter of the gland 3 is larger than the inner diameter of the limiting ring 2 to limit the limiting ring 2 below the gland 3.

[0042] Example 2

[0043] This embodiment introduces its use method based on embodiment 1, including the following steps:

[0044] Step 1: Fix the base 1 at a reserved position in the magnetic bearing system, ensuring that the axis of the base 1 is coaxial with the axis of the flexible rotor;

[0045] Step 2: Select a limit ring 2 of appropriate size based on the size of the flexible rotor, the estimated unbalanced mass, and the amplitude control requirements; rotate the limit ring 2 and insert it into the base 1 so that the internal and external threads fit together. Tighten it with a torque wrench and adjust it to the appropriate torque. Then press the gland 3 to fix the axial position of the base 1 and limit the axial movement range of the limit ring 2.

[0046] Step 3: Start the motor to make the flexible rotor start to rotate. The amplitude of the flexible rotor will gradually increase as the speed increases. As the speed increases, the flexible rotor begins to rub against the outer wall of the limit ring 2. The rubbing force becomes increasingly intense as the speed continues to increase, and enters the full-circle rubbing stage.

[0047] Step 4: The contact force between the limit ring 2 and the flexible rotor and the torque between the limit ring 2 and the base 1 continue to increase until the limit ring 2 is screwed upward and exits the cooperation with the base 1, and the limit ring 2 begins to rotate with the flexible rotor; since the outer edge of the limit ring 2 is a Lélau triangle that has been dimensionally verified, the radial restraint force on the flexible rotor suddenly weakens, and the limit ring 2 and the flexible rotor are out of the friction state, achieving auxiliary starting.

[0048] In summary, the flexible rotor dynamic balancing auxiliary device described in Example 1 is used to complete the auxiliary start-up of a single needle-type lower support constrained flexible rotor, shortening the test preparation time, reducing the operational difficulty, and improving the safety of testing this type of rotor.

[0049] Example 3

[0050] This embodiment introduces the material information based on the first and second embodiments.

[0051] The base 1 is made of stainless steel, which has high strength and is conducive to the stability of the entire system.

[0052] The material of the limiting ring 2 is polytetrafluoroethylene, mainly because polytetrafluoroethylene has a small friction coefficient and a low Young's modulus, and the friction force and collision stiffness generated after collision are low, and it is corrosion-resistant.

[0053] The material of the pressure cover 3 is steel or aluminum, which has high strength and can form a strong limiting effect, which is beneficial to the stability of the entire system.

[0054] For ease of explanation, spatial relative terms such as "upper", "lower", "left", and "right" are used in the embodiments to illustrate the relationship between one element or feature shown in the figures and another element or feature. It should be understood that, in addition to the orientation shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "above" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0055] Moreover, relational terms such as “first” and “second” are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any actual relationship or order between these components.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A flexible rotor dynamic balancing auxiliary device, characterized in that: It includes a base fixedly installed in the flexible rotor system coaxially with the flexible rotor, a limiting ring sleeved outside the base to limit the amplitude of the flexible rotor, and a pressure cover pressed on the base to limit the axial position of the limiting ring; A base boss is provided on the outer side wall of the base to limit the axial position of the limiting ring; The limiting ring and the base can be tightened together to limit the torque of the limiting ring rotating in the circumferential direction; The base is annular; The inner edge of the limiting ring is circular; the outer edge of the limiting ring is a Lello triangle; An internal thread is provided on the inner edge side wall of the limiting ring; an external thread matching the internal thread is provided on the outer side wall of the base; The pressure cover is annular, and a pressure cover boss is provided on its inner edge so that the pressure cover is pressed on the base; the outer edge diameter of the pressure cover is larger than the inner edge diameter of the limiting ring so as to limit the limiting ring below the pressure cover.

2. The flexible rotor dynamic balancing auxiliary device according to claim 1, characterized in that: The base is made of stainless steel.

3. The flexible rotor dynamic balancing auxiliary device according to claim 1, characterized in that: The material of the limiting ring is polytetrafluoroethylene.

4. The flexible rotor dynamic balancing auxiliary device according to claim 1, characterized in that: The number of turns of the external thread is smaller than the number of turns of the internal thread.

5. The flexible rotor dynamic balancing auxiliary device according to claim 1, characterized in that: The material of the gland is steel or aluminum.

6. The method for using the flexible rotor dynamic balancing auxiliary device according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Fix the base to the flexible rotor system, ensuring that the base and the flexible rotor are coaxial; Step 2: Tighten the limiting ring and the base; press the gland onto the base; Step 3: Start the motor to make the flexible rotor start to rotate. As the speed increases, the flexible rotor begins to rub against the outer wall of the limit ring, and the rubbing force increases with the increase in speed until the limit ring and the base are released from the tightened state. The limit ring begins to rotate with the flexible rotor to achieve auxiliary starting.

Images