A shaft end damping structure, a compressor rotor with a damping structure, and a compressor

Abstract

The present invention discloses a shaft end damping structure, a compressor rotor having a damping structure, and a compressor, which are intended to solve the dynamic problems of the slender shaft rotor of a high-speed multi-stage compressor. The shaft end damping structure includes a damping ring and a damping ring housing. The damping ring is arranged on the outside of the bearing body at the end of the rotor through an annular bushing. The damping ring housing is arranged outside the damping ring. The damping ring housing, the blind hole on the rotor end face, and the damping ring form a transition cavity. A first oil circuit is provided in the bearing body, a second oil circuit is provided in the damping ring, and a third oil circuit is provided on the side wall of the blind hole on the rotor end face. The first oil circuit, the second oil circuit, and the third oil circuit are connected, and the outlet of the second oil circuit is located at the annular bushing. The shaft end of the compressor rotor is provided with the shaft end damping structure, and the rotor of the compressor adopts the rotor provided with the shaft end damping structure.

Description

Technical Field

[0001] The present invention belongs to a high-speed rotor damping structure, and in particular relates to a shaft end damping structure, a compressor rotor with the damping structure, and a compressor. Background Art

[0002] With the high-end development of centrifugal compressors, the rotor speed is getting higher and higher. In many application scenarios, compressors with large-span rotors are often required. Their rotors are multi-stage slender shaft structures. This type of rotor has high requirements for dynamic design.

[0003] Currently, this is typically achieved by changing the model and reducing the speed. This involves increasing the diameter of the impeller at the inlet, thickening the main shaft, and increasing the impeller diameter to meet the dynamic design requirements of this type of multi-stage slender shaft. However, this design approach often results in heavier rotors, increasing costs, and poor aerodynamic performance, making the unit less competitive in the market. Therefore, a new structure is needed to address the dynamic challenges of high-speed, multi-stage slender shaft compressors. Summary of the Invention

[0004] The present invention provides a shaft end damping structure, a compressor rotor having the damping structure, and a compressor, aiming to solve the rotor dynamics problems of current high-speed multi-stage slender shaft compressors.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A shaft end damping structure is used for a rotor with a blind hole in the middle of the end face. The rotor is located in a bearing body, and the end protrudes from the bearing body, leaving a gap between the rotor and the bearing body.

[0007] The special feature of the device is that it includes a damping ring and a damping ring housing;

[0008] The damping ring is arranged on the outer side of the rotor end through the ring bushing, and a gap is left between the ring bushing and the rotor;

[0009] The damping ring housing is arranged outside the damping ring, and is fixedly connected to the bearing body, and is used to press the damping ring onto the end face of the bearing body; the damping ring housing, the blind hole on the rotor end face and the damping ring form a transition cavity;

[0010] A first oil circuit is defined in the bearing body, a second oil circuit is defined in the damping ring, and a third oil circuit is defined in the sidewall of the blind hole on the rotor end face. The first oil circuit, the second oil circuit, and the third oil circuit are interconnected. The inlet of the first oil circuit is for lubricating oil to enter, and the outlet of the third oil circuit is connected to the gap between the rotor and the bearing body.

[0011] The outlet of the second oil passage is located at the ring liner.

[0012] Furthermore, an annular cavity is provided inside the damping ring housing;

[0013] A fourth oil circuit is provided in the damping ring housing located on the side of the annular cavity close to the rotor. The first oil circuit, the annular cavity, the fourth oil circuit and the second oil circuit are connected in sequence.

[0014] Furthermore, the inner diameters of the first oil passage, the fourth oil passage, and the second oil passage are gradually reduced;

[0015] There are multiple second oil passages and multiple third oil passages;

[0016] The total cross-sectional area of ​​the plurality of third oil passages is greater than or equal to the total cross-sectional area of ​​the plurality of second oil passages.

[0017] Furthermore, the ratio of the number of the third oil passages to the number of the second oil passages is 1.2-2;

[0018] The ring liner is welded inside the damping ring.

[0019] Furthermore, two O-rings are provided between the damping ring housing and the damping ring. The two O-rings are respectively located at two ends of the damping ring, and the second oil circuit inlet is located between the two O-rings.

[0020] Furthermore, the first oil circuit includes a radial first oil circuit and an axial first oil circuit;

[0021] The inlet of the radial first oil passage is located on the outer wall of the bearing body;

[0022] The inlet of the first axial oil passage intersects with the outlet of the first radial oil passage. The outlet of the first axial oil passage is located on the end surface of the bearing body and in the annular cavity.

[0023] Furthermore, the end surface of the bearing body is in a step shape, and the step surface close to the rotor is lower than the step surface away from the rotor, and the two step surfaces are connected by a transition surface;

[0024] The damping ring is pressed against the step surface of the bearing end face close to the rotor, and the damping ring housing located on the side of the annular cavity close to the rotor is located between the transition surface between the two step surfaces of the bearing end face and the damping ring;

[0025] The fourth oil circuit is arranged to be inclined relative to the radial direction of the rotor, and the inlet of the fourth oil circuit faces the outlet of the first oil circuit in the axial direction;

[0026] The second oil circuit is arranged along the radial direction of the rotor, and the inlet of the second oil circuit corresponds to the outlet of the fourth oil circuit.

[0027] Furthermore, the third oil circuit is arranged at an inclination relative to the radial direction of the rotor, and is arranged closer to the bottom of the blind hole on the rotor end face relative to the second oil circuit;

[0028] The gap widths between the two ends of the ring liner and the rotor are equal, and the gap widths between the two ends of the ring liner and the rotor are smaller than the gap width between the middle part of the ring liner and the rotor.

[0029] The present invention also provides a compressor rotor with a damping structure, the special feature of which is that the shaft end damping structure is provided at one end or both ends of the compressor rotor.

[0030] In addition, the present invention also provides a compressor with a damping structure, the special feature of which is that the rotor of the compressor adopts the above-mentioned compressor rotor with a damping structure.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The shaft end damping structure of the present invention is designed for a rotor with a blind hole on the end face of the shaft end. Lubricating oil enters from the inlet of the first oil circuit under a certain pressure, and reaches the ring liner of the damping ring through the first oil circuit and the second oil circuit in sequence. During the high-speed rotation of the rotor, an oil film is formed between the ring liner of the damping ring and the rotor shaft end, which can play a role similar to that of a supporting bearing and provide a certain support for the rotor shaft end. This auxiliary support structure can effectively limit the amplitude of the radial vibration of the rotor and has a damping and vibration reduction function. Afterwards, the lubricating oil is discharged from both ends of the ring liner, a part of which is discharged directly from the rear end of the ring liner to the gap between the rotor and the bearing body, and the other part flows from the front end of the ring liner into the transition cavity where the blind hole on the rotor end face is located, and then flows out through the third oil circuit to the gap between the rotor and the bearing body. The opening of the third oil circuit can avoid the accumulation of lubricating oil at the ring liner.

[0033] 2. In the present invention, the structural shape design of the damping ring housing ensures the connectivity of the entire oil circuit while also ensuring the installation stability of the damping ring.

[0034] 3. In order to effectively discharge the lubricating oil in the transition cavity where the blind hole on the rotor end face is located, the present invention designs an oil drainage pipeline from the transition cavity to the outside, that is, the sum of the cross-sectional areas of multiple third oil passages is greater than or equal to the sum of the cross-sectional areas of multiple second oil passages.

[0035] 4. In the present invention, the inner diameters of the first oil circuit, the fourth oil circuit and the second oil circuit are gradually reduced, so that the lubricating oil with a certain pressure entering from the inlet of the first oil circuit has a certain flow rate when it reaches the ring liner and the rotor, thereby being conducive to the formation of an oil film at the ring liner. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of an embodiment of a compressor rotor with a damping structure according to the present invention;

[0037] Figure 2 For the present invention Figure 1A local enlargement of point A in the middle.

[0038] Among them: 1-rotor, 2-damping ring, 3-damping ring housing, 4-O-ring, 5-bearing body, 6-oil inlet, 7-oil outlet, 801-first oil circuit, 8011-radial first oil circuit, 8012-axial first oil circuit, 802-second oil circuit, 803-third oil circuit, 804-fourth oil circuit, 9-ring liner, 10-annular cavity, 11-transition cavity. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0040] This invention addresses the rotor dynamics issues of high-speed, multi-stage centrifugal compressors. By adding a damping structure to the rotor and configuring corresponding oil circuits, an oil film is formed on the ring liner to suppress rotor vibration, increase the rotor's critical speed, or reduce the corresponding amplification factor, thereby meeting rotor dynamics design requirements.

[0041] The present invention is described in further detail below with reference to the accompanying drawings:

[0042] See also Figure 1 , is an embodiment of a compressor rotor with a damping structure of the present invention. The compressor rotor involved in the present invention is mainly aimed at a rotor 1 with a blind hole in the middle of the end face. The rotor 1 is located in the same position as the rotor 1 in a general compressor. The rotor 1 is located in the bearing body 5, and the end extends out of the bearing body 5. A gap is left between the rotor 1 and the bearing body 5. In order to solve the above-mentioned problem, an axial end damping structure is provided at both ends of the rotor 1, including a damping ring 2 and a damping ring housing 3. The damping ring 2 is sleeved on the end of the rotor 1 extending out of the bearing body 5 through the annular liner 9. A gap is left between the annular liner 9 and the rotor 1, which enables the lubricating oil to flow out from both ends of the gap. The damping ring housing 3 is provided on the outside of the damping ring 2. The damping ring housing 3 is fixedly connected to the bearing body 5 and is used to press the damping ring 2 against the end face of the bearing body 5. The damping ring housing 3, the blind hole on the end face of the rotor 1 and the damping ring 2 can form a transition cavity 11. The specific shape and structure of the damping ring 2 and the damping ring housing 3 can be set in a variety of ways. Figure 1In a preferred method, an annular cavity 10 is defined within the damping ring housing 3. The end face of the bearing body 5 is stepped, with the step surface closer to the rotor 1 being axially lower than the step surface farther from the rotor 1. The two step surfaces are connected by a transition surface, forming a single step. The damping ring 2 is pressed against the step surface of the bearing body 5 end face closer to the rotor 1. The damping ring housing 3, located on the side of the annular cavity 10 closer to the rotor 1, is positioned between the transition surface between the two step surfaces of the bearing body 5 end face and the damping ring 2. This structural form ensures a more stable installation of the damping ring 2.

[0043] A first oil circuit 801 is provided in the bearing body 5, a second oil circuit 802 is provided in the damping ring 2, a third oil circuit 803 is provided on the side wall of the blind hole on the end face of the rotor 1, and a fourth oil circuit 804 is provided in the damping ring housing 3 located on the side of the annular cavity 10 close to the rotor 1. The first oil circuit 801, the annular cavity 10, the fourth oil circuit 804 and the second oil circuit 802 are connected in sequence. The entrance of the first oil circuit 801 is the oil inlet 6 for the entry of lubricating oil. The outlet of the third oil circuit 803 is the oil drain 7, which is connected to the gap between the rotor 1 and the bearing body 5 for the discharge of lubricating oil. The outlet of the second oil circuit 802 is located at the ring liner 9, which is used to guide the lubricating oil between the rotor 1 and the damping ring 2 when the lubricating oil flows out of the second oil circuit 802, so that an oil film is formed at the shaft end of the rotor 1 when the rotor 1 runs at high speed.

[0044] The following is a preferred arrangement for the entire oil circuit: the first oil circuit 801 comprises a radial first oil circuit 8011 and an axial first oil circuit 8012. The radial first oil circuit 8011 is arranged radially along the rotor 1, with its inlet located on the outer wall of the bearing body 5 (i.e., the oil inlet 6 is located on the sidewall of the bearing body 5). The axial first oil circuit 8012 is arranged axially along the rotor 1, with its inlet intersecting with the outlet of the radial first oil circuit 8011 to form a continuous oil circuit. The outlet of the axial first oil circuit 8012 is located on the end face of the bearing body 5 and within the annular cavity 10, allowing lubricating oil to flow directly from the axial first oil circuit 8012 into the annular cavity 10. The fourth oil circuit 804 is arranged radially obliquely with respect to the rotor 1, with its inlet facing the outlet of the axial first oil circuit 8012. The second oil circuit 802 is arranged radially along the rotor 1, with its inlet corresponding to the outlet of the fourth oil circuit 804. The outlet of the second oil passage 802 is located at the center of the ring liner 9. After being discharged from the outlet of the second oil passage 802, the lubricating oil flows toward the ends of the ring liner 9. The lubricating oil flowing toward the front end of the ring liner 9 enters the transition cavity 11 formed by the damping ring housing 3, the blind hole on the end face of the rotor 1, and the damping ring 2. The lubricating oil then flows out through the third oil passage 803 into the gap between the rotor 1 and the bearing body 5. The lubricating oil flowing toward the rear end of the ring liner 9 directly enters the gap between the rotor 1 and the bearing body 5. The third oil passage 803 is radially inclined relative to the rotor 1 and is located closer to the bottom of the blind hole on the end face of the rotor 1 than the second oil passage 802. The gap widths between the ends of the ring liner 9 and the rotor 1 are equal, and the gap widths between the ends of the ring liner 9 and the rotor 1 are smaller than the gap width between the middle portion of the ring liner 9 and the rotor 1. The cross-section of the ring liner 9 is gate-shaped. In other embodiments of the present invention, the specific arrangement of each oil circuit, such as shape, path, etc., can be adjusted as needed, as long as it is ensured that the lubricating oil can reach the ring liner 9, and when the rotor 1 rotates at high speed, an oil film is formed on the shaft end of the rotor 1 to provide certain support for the rotor and reduce the vibration of the rotor 1.

[0045] In addition, two O-rings 4 are provided between the damping ring housing 3 and the damping ring 2. The two O-rings 4 are respectively located at the two ends of the damping ring 2, and the second oil passage 802 is located between the two O-rings 4 to prevent the lubricating oil from flowing out from the bypass. The number and specific shape of the O-rings 4 can be adjusted according to actual conditions. Only one preferred solution is shown in this embodiment.

[0046] To effectively drain the lubricating oil from the transition cavity 11 formed by the damping ring housing 3, the blind hole on the end face of the rotor 1, and the damping ring 2, allowing the lubricating oil to fully function, the cross-sectional diameter of the oil passages gradually decreases from the inlet to the outlet to facilitate the formation of an oil film on the ring liner. Specifically, the inner diameters of the first oil passage 801, the fourth oil passage 804, and the second oil passage 802 gradually decrease. Furthermore, the diameter of the oil drain pipe from the transition cavity 11 outward is required to be no less than the diameter of the oil pipe within the damping ring 2, and the number of oil drain pipes from the transition cavity 11 outward is required to be greater than the number of oil pipes within the damping ring 2. Specifically, multiple second oil passages 802 and third oil passages 803 are provided, and the combined cross-sectional area of ​​the multiple third oil passages 803 is greater than or equal to the combined cross-sectional area of ​​the multiple second oil passages 802. The number of third oil passages 803 can be set to 1.2-2 times the number of second oil passages 802. The number of each oil passage can be one or more, both of which are reasonable adjustments made in accordance with the present invention.

[0047] In addition, the above-mentioned shaft end damping structure of the present invention can be applied to any other high-speed rotating shaft in addition to being used for compressor rotors. In other application environments, the shaft can be replaced with the aforementioned rotor 1 for application, and the vibration of the high-speed rotating shaft can be effectively reduced. Accordingly, the bearing body 5 can be replaced with other structures corresponding to the shaft, and the opening position and path of the corresponding oil circuit can be adaptively adjusted.

[0048] The compressor rotor with a damping structure of the present invention can be directly installed in a compressor and can be used to manufacture new compressors or to retrofit existing compressors to adapt to high-speed development. During high-speed rotation of the rotor 1, an oil film forms on the ring liner 9 of the damping ring 2, providing auxiliary support, increasing structural constraints, and limiting vibration amplitude, thereby achieving higher requirements for the dynamic design of the rotor 1.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A shaft end damping structure for a rotor (1) having a blind hole in the middle of its end face, wherein the rotor (1) is located in a bearing body (5) and its end extends out of the bearing body (5), with a gap between the rotor (1) and the bearing body (5); It is characterized by: It comprises a damping ring (2) and a damping ring housing (3); The damping ring (2) is sleeved on the outer side of the rotor end through the ring liner (9), and a gap is left between the ring liner (9) and the rotor (1); The damping ring housing (3) is arranged outside the damping ring (2), and the damping ring housing (3) is fixedly connected to the bearing body (5) and is used to press the damping ring (2) onto the end face of the bearing body (5); the damping ring housing (3), the blind hole on the end face of the rotor (1) and the damping ring (2) form a transition cavity (11); A first oil passage (801) is provided in the bearing body (5), a second oil passage (802) is provided in the damping ring (2), and a third oil passage (803) is provided on the side wall of the blind hole on the end face of the rotor (1); the first oil passage (801), the second oil passage (802), and the third oil passage (803) are connected; the inlet of the first oil passage (801) is used for lubricating oil to enter, and the outlet of the third oil passage (803) is connected to the gap between the rotor (1) and the bearing body (5); The outlet of the second oil passage (802) is located at the ring liner (9); An annular cavity (10) is provided inside the damping ring housing (3); A fourth oil circuit (804) is provided in the damping ring housing (3) located on the side of the annular cavity (10) close to the rotor (1), and the first oil circuit (801), the annular cavity (10), the fourth oil circuit (804) and the second oil circuit (802) are connected in sequence.

2. The shaft end damping structure according to claim 1, characterized in that: The inner diameters of the first oil passage (801), the fourth oil passage (804) and the second oil passage (802) gradually decrease; The second oil passage (802) and the third oil passage (803) are both provided with a plurality of them; The sum of the cross-sectional areas of the plurality of third oil passages (803) is greater than or equal to the sum of the cross-sectional areas of the plurality of second oil passages (802).

3. The shaft end damping structure according to claim 2, characterized in that: The ratio of the number of the third oil passages (803) to the number of the second oil passages (802) is 1.2-2; The ring liner (9) is welded inside the damping ring (2).

4. The shaft end damping structure according to any one of claims 1 to 3, characterized in that: Two O-rings (4) are provided between the damping ring housing (3) and the damping ring (2), the two O-rings (4) are respectively located at two ends of the damping ring (2), and the inlet of the second oil circuit (802) is located between the two O-rings (4).

5. The shaft end damping structure according to claim 4, characterized in that: The first oil passage (801) includes a radial first oil passage (8011) and an axial first oil passage (8012); The inlet of the radial first oil passage (8011) is located on the outer wall of the bearing body (5); The inlet of the first axial oil circuit (8012) intersects with the outlet of the first radial oil circuit (8011), and the outlet of the first axial oil circuit (8012) is located on the end surface of the bearing body (5) and in the annular cavity (10).

6. The shaft end damping structure according to claim 5, characterized in that: The end surface of the bearing body (5) is in a step-like shape, and the step surface close to the rotor (1) is lower than the step surface away from the rotor (1), and the two step surfaces are connected by a transition surface; The damping ring (2) is pressed against the step surface of the end face of the bearing body (5) close to the rotor (1), and the damping ring housing (3) located on the side of the annular cavity (10) close to the rotor (1) is located between the transition surface between the two step surfaces of the end face of the bearing body (5) and the damping ring (2); The fourth oil passage (804) is arranged radially and tilted relative to the rotor (1), and the inlet of the fourth oil passage (804) faces the outlet of the axial first oil passage (8012); The second oil passage (802) is arranged along the radial direction of the rotor (1), and the inlet of the second oil passage (802) corresponds to the outlet of the fourth oil passage (804).

7. The shaft end damping structure according to claim 6, characterized in that: The third oil passage (803) is arranged radially inclined relative to the rotor (1), and is arranged near the bottom of the blind hole on the end face of the rotor (1) relative to the second oil passage (802); The gap widths between the two ends of the ring liner (9) and the rotor (1) are equal, and the gap widths between the two ends of the ring liner (9) and the rotor (1) are smaller than the gap width between the middle of the ring liner (9) and the rotor (1).

8. A compressor rotor with a damping structure, characterized in that: One end or both ends of the compressor rotor are provided with the shaft end damping structure according to any one of claims 1 to 7.

9. A compressor with a damping structure, characterized in that: The rotor of the compressor adopts the compressor rotor with a damping structure as claimed in claim 8.

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