JP2019173840A - Vibration damping device for bearing - Google Patents

Abstract

To achieve effective damping effect corresponding to use place and state, in a vibration damping device for a bearing applying spherical particles as a damper element.SOLUTION: A vibration damping device for a bearing includes a device housing 3 disposed on an outer surface of the bearing 5 supporting a rotating shaft 2 in a rotary machine at an interval, an inner cylinder 4 disposed between an inner peripheral face of the device housing 3 and an outer surface of the bearing 5 at an interval and radially displaceable to the device housing 3, a housing space 7 disposed between an outer peripheral face of the inner cylinder 4 and an inner peripheral face of the device housing 3 and filled with spherical particles 6 generating damping action by vibrational friction, a precompression member 13 disposed at a side part in an axial direction of the housing space 7, and applying an axial preload to the spherical particles 6 charged in the housing space 7, and an actuator 14 applying a load to the precompression member 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vibration damping device for a bearing that suppresses vibration of a bearing that supports a high-speed rotating shaft such as a rocket engine turbo pump.

  In high-speed rotating shafts such as rocket engine turbo pumps, shaft vibrations such as forced vibrations and self-excited vibrations at dangerous speeds are often problematic.

  In a jet engine or the like, a squeeze film damper that obtains a vibration damping effect using the viscosity of a lubricating oil is employed as a vibration damping device for a rotating shaft.

  However, lubricating oil cannot be used in oilless equipment, rocket engine turbo pumps operated at extremely low temperatures, and the like.

  For this reason, conventionally, as a vibration damping device for a high-speed rotation shaft such as a rocket engine turbo pump, a ring-shaped wire mesh is disposed between the rotation shaft and the equipment housing, and the force generated by the vibration of the rotation shaft Patent Document 1 discloses a vibration damping device called a wire mesh damper that deforms a ring-shaped wire mesh and dissipates vibration energy by friction generated between the wires to attenuate vibration of the rotating shaft. ing.

  Although the wire mesh damper disclosed in this Patent Document 1 can directly apply a damping force to the rotating shaft, the wire mesh is compressed in a ring shape to obtain a damping action. There is a problem that the shape is easily different and the attenuation performance varies.

  In addition, Non-Patent Document 1 introduces the use of spherical particles as a damper element as a vibration damping device for devices operating at extremely low temperatures and oil-free devices, similar to wire mesh dampers.

  The vibration damping device using spherical particles as a damper element introduced in Non-Patent Document 1 has a structure as shown in FIG.

  A vibration damping device 21 using spherical particles 20 as a damper element shown in FIG. 12 includes a device housing 24 of a rotating machine arranged on the outer surface of a bearing 23 that supports a rotating shaft 22 in the rotating machine, and the device. An inner cylinder 25 that is disposed between the inner peripheral surface of the housing 24 and the outer surface of the bearing 23 and can be displaced in the radial direction with respect to the device housing 24, and the outer peripheral surface of the inner tube 25 and the inner periphery of the device housing 24 A storage space 26 provided between the surface and filled with the spherical particles 20 that generate a damping action by vibration friction, and the storage space 26 disposed at the end in the axial direction of the storage space 26 is filled. Further, a preload ring 27 for applying an axial preload to the spherical particles 20 and a preload spring 28 for applying a preload to the preload ring 27 are provided.

  In the vibration damping device 21 using the spherical particles 20 as a damper element, when radial axial vibration is generated on the rotary shaft 22 of the rotary machine, a radial displacement is generated in the inner cylinder 25 via the bearing 23, and the displacement is caused by the displacement. The spherical particles 20 in the housing space 26 flow, and this flow causes friction between the spherical particles 20, between the spherical particles 20 and the inner cylinder 25, and between the spherical particles 20 and the equipment housing 24. Vibration energy is dissipated by this, and it acts as a damper.

  When the spherical particle 20 is used as a damper element, the parameters that are considered to affect the characteristics are the particle diameter of the spherical particle 20, the outer diameter of the inner cylinder 25, the inner diameter of the equipment housing 24, the length of the receiving space 26, The preload by the load spring 28, the particle material of the spherical particles 20, the spherical particles 20 and the friction coefficient (managed by the surface material) with the equipment, these can be industrially managed, and the wire mesh damper Compared to this, improvement in quality stability can be expected.

  In the vibration damping device having the structure disclosed in Non-Patent Document 1 described above, it is considered necessary to increase the preload in order to effectively obtain a high damping performance. This is because, when the preload applied to the spherical particles 20 in the axial direction is increased in the accommodating space containing the spherical particles, pressure is applied in close contact with the spherical particles, and the frictional force between the spherical particles increases. This is because the attenuation effect can be increased.

JP-A-3-41211

Paper titled “Development of Particle Damper for Turbopump” of the Lecture Meeting of the Space Science and Technology Union at the Japan Aerospace Society held on October 07, 2015

  By the way, in the vibration damping device 21 using the spherical particle 20 introduced in Non-Patent Document 1 as a damper element, a preload is applied to the preload ring 27 by using the biasing force of the preload spring 28. The biasing force of the preload spring 28 is determined by the material, size, and the like.

  Although the required damping performance varies depending on the place and state of use, in the case of using the preload spring 28 described above, the preload is determined by the biasing force of the preload spring 28. For this reason, when changing the preload, it is necessary to replace the preload spring 28 and there is a problem that it takes time to adjust the damping performance.

  Accordingly, an object of the present invention is to provide an effective damping effect in a vibration damping device using spherical particles as a damper element in accordance with the place and state of use.

  In order to solve the above-described problems, the present invention provides a device housing disposed at an interval on an outer surface of a bearing that supports a rotating shaft in a rotating machine, an inner peripheral surface of the device housing, and an outer surface of the bearing. An inner cylinder that is disposed with a gap therebetween and is radially displaceable with respect to the device housing, and vibration friction that is provided between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the device housing. A storage space that fills the spherical particles that generate vibration, and a preload member that is disposed laterally in the axial direction of the storage space and applies an axial preload to the spherical particles filled in the storage space; And an actuator for applying a load to the preload member.

  The present invention adjusts the load applied to the preload member by controlling the operation of the actuator. By adjusting the load, the preload of the spherical particles filled in the accommodation space is adjusted, and the damping force as a damper can be adjusted

  Further, the storage space filled with the spherical particles is a plurality of arc-shaped recesses provided at equal intervals in the circumferential direction, and each of the storage spaces is arranged corresponding to each of the recesses. It may be configured to have an arc-shaped preload member that gives a preload in a direction and an actuator provided corresponding to each preload member, and to apply a load to each preload member by the actuator,

  By changing the magnitude of the load applied to the preload member of each actuator correspondingly, even when the vibration of the rotating shaft has anisotropy in the circumferential direction, a damping force suitable for the vibration can be given. .

  Further, the storage space for filling the spherical particles is an annular recess, and a ring-shaped preload member for preloading the spherical particles filled in the storage space in the axial direction is arranged, and the ring-shaped preload member On the other hand, a load may be applied to the ring-shaped preload member by a plurality of actuators provided at equal intervals in the circumferential direction.

  Further, the actuator can be constituted by either a laminated piezoelectric actuator, a solenoid, or a gas pressure cylinder.

The spherical particles may be made of SUS440C or Si ₃ N _4, and may be of the same size or a combination of different sizes.

  As described above, in the vibration damping device for a bearing according to the present invention, an appropriate preload is given by the actuator, so that it can be set for each operating condition. The attenuation effect can be controlled appropriately.

1 is a schematic cross-sectional view showing a first embodiment of a vibration damping device using spherical particles as damper elements according to the present invention. It is an enlarged view of the accommodation space part with which the spherical particle | grains of FIG. 1 were filled. It is a perspective view which shows the relationship between the apparatus housing and inner cylinder of the vibration damping apparatus of FIG. FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. 1. It is a perspective view which shows the preload member used for the vibration damping apparatus of 1st Embodiment of this invention. It is the schematic explanatory drawing which looked at the vibration damping device of 1st Embodiment of this invention from the direction of the actuator. It is an expansion explanatory view showing the composition at the time of using a lamination piezoelectric actuator as an actuator used for a vibration damping device of a 1st embodiment of this invention. It is an expansion explanatory view showing the composition at the time of using a solenoid as an actuator used for a vibration damping device of a 1st embodiment of this invention. It is an expansion explanatory view showing the composition at the time of using a gas pressure cylinder as an actuator used for a vibration damping device of a 1st embodiment of this invention. It is a schematic explanatory drawing which shows the storage recess of the vibration damping device of 2nd Embodiment of this invention. It is the schematic explanatory drawing which looked at the vibration damping device of 2nd Embodiment of this invention from the direction of the actuator. It is the schematic of the vibration damping device which made the spherical particle introduced into the nonpatent literature 1 the damper element.

  Hereinafter, a first embodiment of a vibration damping device 1 using spherical particles as damper elements according to the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the rotary shaft 2 in the rotary machine of this embodiment is rotatably supported on the inner peripheral surface of a cylindrical device housing 3 via an inner cylinder 4 and a bearing 5. In this embodiment, as the bearing 5, a rolling bearing including an inner ring 5a, an outer ring 5b, and a rolling element 5c accommodated between the inner ring 5a and the outer ring 5b is used.

  Between the inner peripheral surface of the device housing 3 and the outer peripheral surface of the inner cylinder 4, an accommodation space 7 for accommodating spherical particles 6 that are damper elements is provided.

  As a material for forming the device housing 3 and the inner cylinder 4, nickel alloy, SUS304, SUS304L, SUS316, SUS16L, SUS316LN, or the like can be used.

  At one end in the axial direction of the inner cylinder 4, the inner cylinder 4 is supported so as to be displaceable in the radial direction with respect to the equipment housing 3, and the inner cylinder is supported elastically so that the inner cylinder 4 coincides with the axis of the equipment housing 3. The springs 8 are provided at equal intervals in the circumferential direction.

  As shown in FIGS. 1 and 3, the inner cylinder supporting spring 8 includes a protruding piece 8a extending outward in the axial direction of the device housing 3, and a radially outer diameter side from the outer end of the protruding piece 8a. The bent piece 8b is formed into a U-shape consisting of a bent piece 8b and a folded piece 8c folded in the axial direction from the outer diameter end of the bent piece 8b, and the end of the folded piece 8c is formed on the outer diameter portion of the device housing 3. Is engaged.

  An inward flange 3 a that forms one end surface of the accommodation space 7 is formed at one end of the inner peripheral surface of the device housing 3. Between the inner peripheral surface of the inward flange 3 a and the outer peripheral surface of the inner cylinder 4. Is provided with a gap a that allows the inner cylinder 4 to be displaced in the radial direction. The gap a is set to a size that prevents the spherical particles 6 that are damper elements from leaking out.

  A fixing flange 3b protruding toward the outer diameter in the radial direction is formed on the outer peripheral surface opposite to the outer peripheral surface of the device housing 3 with which the inner cylinder supporting spring 8 is engaged. A ring plate 9 forming the other end face of the accommodation space 7 is fixed by a bolt 10.

  The ring plate 9 is provided with an engaging portion 9 a that fits between the inner peripheral surface of the device housing 3 and the inner cylinder 4.

  As shown in FIGS. 1 and 2, a preload member 13 that applies a preload in the axial direction between an end of the engaging portion 9 a on the side of the storage space 7 and the storage space 7, and an actuator that applies a load to the preload member 13 14 is arranged.

  Between the inner peripheral surface of the preload member 13 and the outer peripheral surface of the inner cylinder 4, and between the inner peripheral side of the actuator 14 and the outer peripheral surface of the inner cylinder 4, a gap b that allows displacement of the inner cylinder 4 in the radial direction is provided. The gap b is set to a size that prevents the spherical particles 6 as the damper element from leaking out.

The accommodation space 7 is filled with spherical particles 6. As the spherical particles 6, for example, steel balls (SUS440C) or ceramic balls (Si ₃ N ₄ ) having a particle diameter of about 1 mm can be used. The spherical particles 6 may all be the same size or may be a combination of different sizes.

  By the way, the rocket engine turbo pump is a rotary machine that pumps a propellant to the combustor, and mainly uses liquid oxygen and liquid hydrogen as the propellant, so that the vicinity of the bearing 5 of the rotating shaft 2 is in a cryogenic environment. . In the case of such a device used at a very low temperature, the air in the accommodation space 7 is prevented from freezing before the water is contained in the accommodation space 7 filled with the spherical particles 6 before the cryogenic environment. Is preferably replaced with a propellant gas (for example, hydrogen gas or oxygen gas).

  For this reason, in the form shown in FIG. 1, an air vent channel 15 that connects the inside of the accommodation space 7 and the external environment is provided between the device housing 3 and the ring plate 9.

  Moreover, it is preferable to install a dust-proof filter at the outlet of the air vent flow path 15.

  Next, the operation of the vibration damping device using the spherical particles 6 as damper elements will be described.

  As shown by an arrow X1 in FIG. 1, when an axial displacement occurs due to vibration, the excitation force causes the inner cylinder 4 to change in the radial direction through the bearing 5 as shown by an arrow X2. Due to the fluctuation of the inner cylinder 4, the spherical particles 6 filled in the accommodation space 7 between the inner cylinder 4 and the device housing 3 flow, and the spherical particles 6, the spherical particles 6 and the inner cylinder 4, and the spherical particles 6. And the device housing 3, friction is generated, and the frictional energy is dissipated by the friction to attenuate the vibration.

  The present invention controls the operation of the actuator 14 and adjusts the load applied to the preload member 13. By adjusting the load, the preload of the spherical particles 6 filled in the accommodation space 7 is adjusted, and the damping force as a damper can be adjusted. When the preload applied to the spherical particles 6 in the axial direction is increased in the housing space 7 in which the spherical particles 6 are accommodated, the spherical particles 6 are in close contact with each other and pressure is applied, and the frictional force between the spherical particles 6 increases. Thus, the damping effect (damping force) is increased.

  In this invention, the magnitude | size of the load which the actuator 14 gives to the preload member 13 is controlled so that the preload which obtains the suitable damping effect for every operating condition may be given.

As shown in FIG. 4, the accommodation space 7 of the first embodiment is comprised of a plurality of arcuate recesses 7 _{1-7 4} provided in equal intervals in the circumferential direction. In this embodiment, there are four recesses 7 ₁ , 7 ₂ , 7 ₃ , 7 ₄ . The recesses 7 ₁ , 7 ₂ , 7 ₃ and 7 ₄ are filled with spherical particles 6, respectively.

In the first embodiment, an arc-shaped preload member 13 matching the shape of each of the recesses 7 ₁ , 7 ₂ , 7 ₃ , 7 ₄ as shown in FIG. 5 is used. Then, arc-shaped preloading members 13 that apply axial preloads are disposed in the respective recesses 7 ₁ , 7 ₂ , 7 ₃ , and 7 ₄ .

  As shown in FIG. 6, an actuator 14 is connected to each preload member 13. Each actuator 14 is controlled by a drive control device 14 a and can apply a load to each preload member 13 independently.

The recess 7 preload member 13 spherical particles 6 filled in ₁ and the actuator 14, by applying a predetermined preload, the damping force F ₁ is obtained. Similarly, the spherical particles 6 filled in the recesses 7 ₂ are given a predetermined preload by the preloading member 13 and the actuator 14, so that the damping force F ₂ is applied to the spherical particles 6 filled in the recesses 7 _3. the preload member 13 and the actuator 14, by applying a predetermined preload, the damping force F _3, the spherical particles 6 filled in the recess 7 ₄ by the preload member 13 and the actuator 14, to provide a predetermined preload Thus, the damping force F ₄ is obtained.

  By the way, the vibration of the rotating shaft 2 may be anisotropic in the circumferential direction. In such a case, a damping force suitable for vibration can be applied by changing the magnitude of the load applied to the preload member 13 of each actuator 14 by the drive control device 140.

  An example of the actuator 14 used in this embodiment will be described with reference to FIGS. In FIG. 7, a laminated piezoelectric actuator 141 in which a plurality of piezoelectric elements is laminated is used as the actuator 14. The drive control device 140 controls the current applied to the laminated piezoelectric actuator 141 and controls the magnitude of the preload.

  In FIG. 8, a solenoid 142 is used as the actuator 14. The drive control device 140 controls the current applied to the solenoid 142 and controls the magnitude of the preload.

  In FIG. 9, a gas pressure cylinder 143 is used as the actuator 14. The drive control device 140 controls the gas pressure of the gas pressure cylinder 143 to control the magnitude of the preload.

  As described above, in this embodiment, the actuator 14 is either a laminated piezoelectric actuator, a solenoid, or a gas pressure cylinder. If these devices are used, they can be driven without problems even in applications such as oilless devices and rocket engine turbo pumps operated at extremely low temperatures.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the accommodation space 7 is formed in an annular recess 70. The spherical recesses 6 are filled with the spherical particles 6.

  A ring-shaped preload member 13b for applying a preload in the axial direction is disposed at one end of the annular recess 70.

  In the circumferential direction of the ring-shaped preload member 13b, a plurality of actuators 14, in this embodiment, four actuators 14 are arranged every 90 degrees. The four actuators 14 are controlled by the drive control device 140. That is, the magnitude of the preload applied to each actuator 14 is controlled so as to give a preload that obtains a suitable damping effect for each operating condition.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

1: Vibration damping device 2: Rotating shaft 3: Equipment housing 3a: Inward flange 4: Inner cylinder 5: Bearing 6: Spherical particles 7: Accommodating spaces 7 ₁ , 7 ₂ , 7 ₃ and 7 ₄ : Recesses 13 and 13b : Preload member 14: Actuator 14a: Drive control device

Claims (4)

  A device housing that is arranged at an interval on the outer surface of a bearing that supports a rotating shaft in a rotating machine, and a device housing that is arranged with a gap between the inner peripheral surface of the device housing and the outer surface of the bearing. An inner cylinder that is displaceable in the radial direction, and a housing space that is provided between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the equipment housing, and that is filled with spherical particles that generate vibration damping action by vibration friction; A preloading member that is disposed on the side of the housing space in the axial direction and that applies a preload in the axial direction to the spherical particles filled in the housing space, and an actuator that applies a load to the preloading member. A vibration damping device for bearings.   The storage spaces filled with the spherical particles are a plurality of arc-shaped recesses provided at equal intervals in the circumferential direction, and are arranged corresponding to the respective recesses, and are axially arranged with respect to the spherical particles in each recess. The bearing according to claim 1, further comprising: an arc-shaped preload member for applying a preload; and an actuator provided corresponding to each preload member, wherein each preload member is loaded with an actuator. Vibration damping device.   The storage space for filling the spherical particles is an annular recess, and a ring-shaped preload member for preloading the spherical particles filled in the storage space in the axial direction is arranged, and the ring-shaped preload member The bearing vibration damping device according to claim 1, wherein a load is applied by a plurality of actuators provided at equal intervals in the circumferential direction.   3. The vibration damping device for a bearing according to claim 1, wherein the actuator is composed of a laminated piezoelectric actuator, a solenoid, or a gas pressure cylinder.