A dynamic balancing testing device and method for a turboexpander rotor system

Abstract

The application relates to a dynamic balance testing device and testing method of a turboexpander rotor system, which comprises a shell, a gas bearing arranged in the shell and scale cover plates arranged on both sides of the shell, wherein the gas bearing is provided with a central through slot, the scale cover plates are provided with central holes corresponding to the central through slot, a rotating shaft of the turboexpander rotor system is rotatably arranged in the central through slot and protrudes from the corresponding scale cover plate through the corresponding central hole at both ends, scales are arranged on the scale cover plates, and the end of the rotating shaft protruding from the scale cover plate is provided with a zero scale mark; the dynamic balance testing device can expose the position for eliminating unbalanced mass to the outside and intuitively indicate the data of the unbalanced mass, and the angle position of the unbalanced mass of the rotor system of different sizes can be quickly marked by the scales on the dynamic balance testing device.

Description

Technical Field

[0001] This invention relates to the field of rotor dynamic balancing testing technology, and in particular to a dynamic balancing testing device and method for a turbine expander rotor system. Background Technology

[0002] Small-scale turboexpanders are key components in large-scale cryogenic refrigeration systems, crucial for achieving cryogenic environments. The bearing-rotor system is a vital subsystem of these small-scale turboexpanders; the high-speed, stable rotation of the rotor within the bearings is essential for achieving expansion and cooling. The rotor system in a small-scale turboexpander mainly consists of a drive wheel, a shaft, and a brake wheel. Imbalance in the rotor system is a significant factor contributing to rotor instability at high speeds. Due to uneven material density distribution and machining processes, the rotor's center of mass is not at its geometric center. When the rotor rotates at high speed around this geometric center, the imbalance generates centrifugal force, which increases rapidly with rotational speed. When this centrifugal force exceeds the film force provided by the bearings, the rotor system becomes unstable within the gas bearings. Therefore, eliminating the imbalance in the rotor system is crucial for ensuring good rotor dynamics and achieving high-speed, stable rotation within the small-scale turboexpander.

[0003] Currently, in prototype small-scale turbo expanders, the space exposed outside the rotor system that can be used to eliminate unbalanced mass is extremely small. Therefore, during the process of eliminating unbalanced mass in the rotor system of a small-scale turbo expander, it is impossible to quickly and accurately locate the unbalanced mass. Summary of the Invention

[0004] One objective of this invention is to provide a dynamic balancing test device and method for a turbine expander rotor system. This dynamic balancing test device can quickly and intuitively mark the unbalanced mass of the turbine expander rotor system, providing support for the dynamic balancing test and adjustment of the turbine expander rotor system.

[0005] The present invention provides a dynamic balancing test device for a turbine expander rotor system, comprising a housing, a gas bearing disposed within the housing, and scale covers respectively mounted on both sides of the housing. The gas bearing has a central through-groove, and the scale covers have central holes corresponding to the central through-groove. The rotor shaft of the turbine expander rotor system is rotatably disposed within the central through-groove, with both ends passing through the corresponding central holes and protruding from the corresponding scale covers. The scale covers have graduations, and the end of the rotor shaft protruding from the scale covers has a zero-gradient mark. The dynamic balancing test device is used to mark the unbalanced mass of the turbine expander rotor system by the position indicated by the zero-gradient mark on the scale covers when the rotor shaft rotates.

[0006] In one embodiment of the present invention, the gas bearing has radial and axial air supply holes that are both connected to an external high-pressure gas source, so that the rotating shaft is suspended in the radial and axial directions.

[0007] In one embodiment of the present invention, there are two gas bearings, which are pressed and fixed by two scale plates on both sides of the housing.

[0008] In one embodiment of the present invention, the zero marks of the two scale covers are kept parallel and in the same direction, and the scale values ​​of the two scale covers increase in opposite directions. The zero mark of the rotating shaft is in the same direction as the zero marks of the two scale covers.

[0009] In one embodiment of the present invention, the two scale plates are respectively fixed to both ends of the outer casing by a plurality of first fasteners.

[0010] In one embodiment of the present invention, the turbine expander rotor system further includes a drive wheel and a brake wheel respectively disposed at both ends of the rotating shaft, wherein the brake wheel is fixed on the rotating shaft by a second fixing member, and the second fixing member is provided with the zero scale mark.

[0011] In one embodiment of the present invention, the scale of the scale cover plate of the dynamic balancing testing device located on the side near the brake wheel increases in a counterclockwise direction, and the scale of the scale cover plate located on the side near the drive wheel increases in a clockwise direction.

[0012] In one embodiment of the present invention, the first fixing member and the second fixing member are bolts or screws.

[0013] In another aspect, the present invention also provides a method for dynamic balancing testing of a small turbine expander, comprising the following method performed using a dynamic balancing testing device for the turbine expander rotor system:

[0014] The drive shaft rotates, and the zero mark on the scale cover plate marks the unbalanced mass of the turbine expander rotor system on the drive wheel side.

[0015] The unbalanced mass displayed by the dynamic balancing test device is balanced by either the weight removal method or the weight addition method.

[0016] The shaft is driven to rotate again, and the zero mark on the shaft is used to determine whether the unbalanced mass of the turbine expander rotor system on the drive wheel side meets the requirements.

[0017] Following the same procedure described above, test whether the unbalanced mass of the turbine expander rotor system on the brake wheel side meets the requirements.

[0018] Finally, it is checked whether the unbalanced mass of the turbine expander rotor system meets the requirements on both the drive wheel side and the brake wheel side.

[0019] In one embodiment of the present invention, the unbalanced mass of the turbine expander rotor system is determined to meet the requirements when the angles of the unbalanced mass indicated by the zero-scale marks on the drive wheel side and the brake wheel side of the turbine expander rotor system are consistent.

[0020] The dynamic balancing testing device of this invention can suspend the turbine expander rotor system in both radial and axial directions. Under high rotational speeds, the rotor system's shaft transmits centrifugal force to the dynamic balancing testing device. This device exposes the locations used to eliminate imbalance mass on the outside and visually indicates the imbalance mass data. The scale on the device allows for rapid marking of the angular positions of imbalance masses in rotor systems of different sizes, facilitating support for the dynamic balancing testing and adjustment of the turbine expander rotor system.

[0021] The further objects and advantages of the invention will become fully apparent from the following description and accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a cross-sectional schematic diagram of the dynamic balancing test device for the turbine expander rotor system according to a preferred embodiment of the present invention.

[0023] Figure 2 This is a top view of the brake wheel side of the dynamic balancing test device for the turbine expander rotor system of the present invention.

[0024] Figure 3 This is a top view of the drive wheel side of the dynamic balancing test device for the turbine expander rotor system of the present invention.

[0025] Figure 4 This is a three-dimensional structural diagram of the rotor system of a turbine expander.

[0026] Figure 5 This is a cross-sectional schematic diagram of the gas bearing in the dynamic balancing test device for the turbine expander rotor system of the present invention.

[0027] Reference numerals: 1. Housing; 2. Gas bearing; 21. Center slot; 3. Scale cover; 31. Zero scale; 32. Center hole; 4. First fixing component; 5. Turbine expander rotor system; 51. Shaft; 52. Drive wheel; 53. Brake wheel; 54. Second fixing component. Detailed Implementation

[0028] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0029] Those skilled in the art should understand that, in the disclosure of this invention, the terms "vertical," "horizontal," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0030] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] This invention aims to provide a device that, during the testing of the unbalance mass of a rotor system on a dynamic balancing testing device for a small turbine expander, can establish a connection between the rotor system and the dynamic balancing testing device, and quickly mark the location of the unbalance amount for rotor systems of various sizes. For example... Figures 1 to 5 As shown, the specific structure of a dynamic balancing test device for a turbine expander rotor system according to a preferred embodiment of the present invention is illustrated.

[0033] Specifically, such as Figure 1As shown, the dynamic balancing test device for the turbine expander rotor system includes a housing 1, a gas bearing 2 disposed inside the housing 1, and scale cover plates 3 respectively installed on both sides of the housing 1. The gas bearing 2 is provided with a central through groove 21, and the scale cover plate 3 is provided with a central hole 32 corresponding to the central through groove 21. The rotating shaft 51 of the turbine expander rotor system 5 is rotatably disposed in the central through groove 21, and both ends pass through the corresponding central holes 32 and protrude from the corresponding scale cover plates 3. The scale cover plate 3 is provided with a scale, and the end of the rotating shaft 51 protruding from the scale cover plate 3 is provided with a zero scale mark. The zero scale mark is used to indicate the angle of unbalanced mass of the turbine expander rotor system 5 when the rotating shaft 51 rotates.

[0034] Specifically, the gas bearing 2 has radial and axial air supply holes that are both connected to an external high-pressure gas source, so that the rotating shaft 51 is suspended in the radial and axial directions.

[0035] In other words, by introducing gas through the radial and axial air supply holes of the gas bearing 2, the dynamic balancing test device of the present invention can suspend the turbine expander rotor system 5 in both radial and axial directions. Under high rotational speed conditions, the rotor shaft 51 of the rotor system transmits centrifugal force to the dynamic balancing test device. The dynamic balancing test device marks the unbalanced mass of the turbine expander rotor system 5 by indicating the position of the zero mark on the scale cover plate 3 when the shaft 51 rotates.

[0036] It is worth mentioning that the zero marks 31 of the two scale covers 3 of the dynamic balancing test device are kept parallel and in the same direction, for example, pointing to the 12 o'clock direction at the same time, and the scale values ​​of the two scale covers 3 increase in opposite directions. The zero mark of the rotating shaft 51 is in the same direction as the zero marks 31 of the two scale covers 3.

[0037] It is also worth mentioning that the two scale plates are respectively fixed to both ends of the outer casing 1 by a plurality of first fixing members 4. In this specific embodiment of the present invention, there are two gas bearings 2, which are pressed and fixed by the two scale plates on both sides of the outer casing 1. The specific structure of the gas bearings 2 is as follows: Figure 1 and Figure 5 As shown.

[0038] Specifically, the length of the rotating shaft 51 is greater than that of the gas bearing 2 and the housing 1, thereby enabling it to extend beyond the corresponding scale cover plates 3 at both ends. It is understood that by replacing the gas bearing 2 with different sizes (including inner diameter and length), the dynamic balancing test requirements for rotor systems of different sizes can be met.

[0039] Furthermore, such as Figures 2 to 4 As shown, the turbine expander rotor system 5 also includes a drive wheel 52 and a brake wheel 53 respectively disposed at both ends of the rotating shaft 51, wherein the brake wheel 53 is fixed on the rotating shaft 51 by a second fixing member 54, and the second fixing member 54 is provided with the zero scale mark.

[0040] It should be understood that the zero mark on the rotating shaft 51 can be set on any component at the end of the rotating shaft 51, such as the drive wheel 52, brake wheel 53, fixing bolt, etc., as long as it can indicate the corresponding angle when the rotating shaft 51 rotates. The present invention does not limit this.

[0041] In this specific embodiment, the zero mark is set on the second fixing member 54, and the zero mark of the second fixing member 54 is in the same direction as the zero mark 31 of the two scale covers 3, so as to serve as the initial position for dynamic balance testing.

[0042] Optionally, the first fixing member 4 and the second fixing member 54 are bolts or screws. In this specific embodiment, both the first fixing member 4 and the second fixing member 54 are bolts.

[0043] It is worth mentioning that, in this specific embodiment of the present invention, the scale of the scale cover plate 3 of the dynamic balance testing device located on the side near the brake wheel 53 increases in a counterclockwise direction, and the scale of the scale cover plate 3 located on the side near the drive wheel 52 increases in a clockwise direction.

[0044] It is understood that by observing the angle indicated by the zero mark when the shaft 51 rotates, the angle corresponding to the unbalanced mass of the turbine expander rotor system 5 can be read intuitively. In this way, the unbalanced mass of the turbine expander rotor system 5 can be balanced by the weight removal method or the weight addition method, thereby eliminating the unbalanced mass of the turbine expander rotor system 5. This is beneficial to ensuring that the rotor system has good rotor dynamic characteristics and realizing high-speed and stable rotation of the rotor in the small turbine expander.

[0045] It is worth mentioning that in this invention, the dynamic balancing weight removal method can be carried out by boring, drilling, chiseling, milling, grinding and other methods; the dynamic balancing weight addition method can be carried out by welding, soldering, riveting, screwing, adding weight blocks and other methods.

[0046] The method of using the dynamic balancing test device for the turbine expander rotor system is as follows:

[0047] All parts according to Figure 1After installation, the two scale covers 3 are fixed to the outer casing 1 under the action of the first fixing member 4. At the same time, the two scale covers 3 press the two gas bearings 2 together, allowing the rotating shaft 51 to move slightly within the gap reserved between the two gas bearings 2. The rotating shaft 51 can be suspended radially and axially under the gas film lubrication effect generated by the two gas bearings 2. After suspension, there is almost no friction between the rotating shaft 51 and the gas bearings 2. When the drive wheel 52 is driven to rotate at high speed, the drive wheel 52 can drive the rotating shaft 51 and the brake wheel 53 to rotate at high speed together, which can fully meet the speed required for the dynamic balancing test device.

[0048] It is understood that the rotor system composed of the drive wheel 52, the shaft 51, and the brake wheel 53, due to imbalance caused by machining or uneven material density, will generate centrifugal force during high-speed rotation. The dynamic balancing test device can measure the magnitude and angle of the imbalance on the drive wheel 52 side and the brake wheel 53 side of the rotor system, respectively. The test method is as follows:

[0049] The dynamic balancing test device measures the magnitude and angle of the unbalanced mass of the rotor system on the drive wheel 52 side. Based on the angle position indicated by the dynamic balancing test device, the angle position of the unbalanced mass on the drive wheel 52 side can be quickly marked on the dial. The unbalanced mass displayed by the dynamic balancing test device is balanced by the weight removal method or the weight addition method. The unbalanced mass of the rotor system on the brake wheel 53 side is then measured again by the dynamic balancing test device to see if it meets the requirements. The same operation is performed to test whether the unbalanced mass of the rotor system on the brake wheel 53 side meets the requirements. Finally, it is checked whether the unbalanced mass of the rotor system on both the drive wheel 52 side and the brake wheel 53 side meets the requirements simultaneously.

[0050] In other words, the present invention also provides a method for dynamic balancing testing of a small turbine expander, comprising the following method performed using the dynamic balancing testing device for the turbine expander rotor system:

[0051] The drive shaft 51 is rotated, and the zero mark on the scale cover plate 3 marks the unbalanced mass of the turbine expander rotor system 5 on the drive wheel 52 side.

[0052] The unbalanced mass displayed by the dynamic balancing test device is balanced by either the weight removal method or the weight addition method.

[0053] The rotating shaft 51 is driven to rotate again, and the zero mark on the rotating shaft 51 is used to determine whether the unbalanced mass of the turbine expander rotor system 5 on the drive wheel 52 side meets the requirements.

[0054] Following the same procedure described above, test whether the unbalanced mass of the turbine expander rotor system 5 on the brake wheel 53 side meets the requirements.

[0055] Finally, it is checked whether the unbalanced mass of the turbine expander rotor system 5 meets the requirements on both the drive wheel 52 side and the brake wheel 53 side.

[0056] It should be understood that when the angles of the unbalanced mass indicated by the zero-scale marks on the drive wheel 52 side and the brake wheel 53 side of the turbine expander rotor system 5 are consistent, it is determined that the unbalanced mass of the turbine expander rotor system 5 meets the requirements, and at this time the unbalanced mass of the turbine expander rotor system 5 is completely eliminated.

[0057] In summary, the dynamic balancing testing device of the present invention can suspend the turbine expander rotor system 5 in both radial and axial directions. Under high rotational speeds, the rotor shaft 51 of the rotor system transmits centrifugal force to the dynamic balancing testing device. The dynamic balancing testing device exposes the locations used to eliminate unbalanced masses and visually indicates the unbalanced mass data. The scale on the dynamic balancing testing device allows for quick marking of the angular positions of unbalanced masses in rotor systems of different sizes, which is beneficial for supporting the dynamic balancing testing and adjustment of the turbine expander rotor system 5. Furthermore, by replacing the gas bearings 2 of different sizes, the dynamic balancing testing device can meet the dynamic balancing testing requirements of rotor systems of different sizes.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above embodiments merely illustrate preferred implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention should be determined by the appended claims.

Claims

1. A dynamic balancing test device for a turbexpander rotor system, characterized by, The system includes a housing, a gas bearing housed within the housing, and graduated cover plates mounted on both sides of the housing. The gas bearing has a central through-groove, and the graduated cover plates have central holes corresponding to the central through-groove. The rotor shaft of the turbine expander rotor system is rotatably mounted within the central through-groove, with both ends passing through corresponding central holes and protruding from corresponding graduated cover plates. The graduated cover plates have graduations, and the ends of the rotor shaft protruding from the graduated cover plates have zero-gradient marks. The dynamic balancing testing device is used to mark the unbalanced mass of the turbine expander rotor system by the position indicated by the zero-gradient mark on the graduated cover plates when the rotor shaft rotates. The zero marks of the scale covers are kept parallel and aligned, and the scale values ​​of the two scale covers increase in opposite directions. The zero mark of the rotating shaft is aligned with the zero marks of the two scale covers. The length of the rotating shaft is greater than that of the gas bearing and the housing, thus forming a state where both ends protrude from the corresponding scale covers. The dynamic balancing test device can meet the dynamic balancing test requirements of rotor systems of different sizes by replacing gas bearings of different sizes. When the angles of the unbalanced mass indicated by the zero marks on the drive wheel side and the brake wheel side of the turbine expander rotor system are consistent, the unbalanced mass of the turbine expander rotor system is determined to meet the requirements.

2. The dynamic balancing test device for a turboexpander rotor system according to claim 1, wherein, The gas bearing has radial and axial air supply holes, both connected to an external high-pressure gas source, so that the shaft can be suspended in the radial and axial directions.

3. The apparatus for dynamic balancing of a turboexpander rotor system according to claim 2, wherein, There are two gas bearings, which are pressed and fixed by two scale cover plates on both sides of the housing.

4. The apparatus for dynamic balancing test of a turboexpander rotor system according to claim 1, wherein, The two scale covers are respectively fixed to both ends of the outer casing by a plurality of first fasteners.

5. The dynamic balancing test device for a turbine expander rotor system according to claim 4, characterized in that, The turbine expander rotor system also includes a drive wheel and a brake wheel respectively disposed at both ends of the rotating shaft, wherein the brake wheel is fixed to the rotating shaft by a second fixing member, and the second fixing member is provided with the zero scale mark.

6. The dynamic balancing test device for a turbine expander rotor system according to claim 5, characterized in that, The scale of the dynamic balancing test device is arranged on the scale cover plate near the brake wheel, with the scale increasing counterclockwise, and the scale of the scale cover plate near the drive wheel, with the scale increasing clockwise.

7. The dynamic balancing test device for a turbine expander rotor system according to claim 6, characterized in that, The first and second fasteners are bolts or screws.

8. A method for testing the expansion and dynamic balance of a small turbine, characterized in that, The following methods are included, performed using the dynamic balancing test apparatus for a turbine expander rotor system according to any one of claims 1 to 7: The drive shaft rotates, and the zero mark on the scale cover plate marks the unbalanced mass of the turbine expander rotor system on the drive wheel side. The unbalanced mass displayed by the dynamic balancing test device is balanced by either the weight removal method or the weight addition method. The shaft is driven to rotate again, and the zero mark on the shaft is used to determine whether the unbalanced mass of the turbine expander rotor system on the drive wheel side meets the requirements. Following the same procedure described above, test whether the unbalanced mass of the turbine expander rotor system on the brake wheel side meets the requirements. Finally, it is checked whether the unbalanced mass of the turbine expander rotor system meets the requirements on both the drive wheel side and the brake wheel side.

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