A flow guiding structure for lubricating oil in steam turbine bearings and the bearing itself.

Abstract

This invention discloses a flow guiding structure for lubricating oil in turbine bearings and a bearing thereof. The flow guiding structure for lubricating oil in turbine bearings includes a housing with a rotating hole inside. An annular cavity is provided outside the rotating hole. Several guide vanes are arranged circumferentially within the annular cavity, dividing the annular cavity into multiple flow channels. A bearing includes a bearing bush and the housing described above, with the bearing bush disposed within the housing. The structure is simple, easy to install and process, and has good practicality. It can ensure that the lubricating oil in the thrust bearing housing has good lubricity and flow characteristics, and can cool the rotor in a timely manner, thereby further ensuring the safety of the unit.

Description

Technical Field

[0001] This invention relates to the field of rotating machinery technology for steam turbines in thermal power and nuclear power plants, and in particular to a guide structure and bearing suitable for the flow of lubricating oil inside steam turbine bearings. Background Technology

[0002] With the continuous increase in the capacity of power units in thermal power and nuclear power industries, higher requirements are being placed on the safety and economy of steam turbines. As one of the key components of a steam turbine, the losses caused by friction during operation directly affect the turbine's power output. Simultaneously, friction-induced losses cause localized temperature rises on the rotor surface, further impacting the stability and safety of the high-speed rotating rotor. As the capacity of steam turbine units increases, the journal diameter also increases, leading to a higher linear velocity of the rotor's outer diameter and consequently, greater losses due to friction between the rotor and bearings. To reduce frictional losses between the high-speed rotating rotor and the relatively stationary bearings, lubricating oil is injected into the gap between the rotor and bearings. This serves to seal and cool the rotor surface temperature rise, reducing turbine bearing power losses and protecting the rotor and system safety. The high-speed rotating rotor and bearings form an oil film at the gap due to the lubricating oil, directly affecting the rotor surface temperature rise and the lubrication between moving and stationary components. The thickness and pressure of the oil film are influenced by various factors, including rotor speed, lubricating oil viscosity, bearing clearance, bearing load, and bearing structure.

[0003] The relatively high viscosity of lubricating oil leads to uneven distribution within the bearing housing. Friction causes the bearing shell temperature to rise, resulting in localized high temperatures on the bearing surface, significantly increasing power consumption, reducing unit efficiency, and even affecting the safe and stable operation of the unit. Therefore, frictional power consumption caused by oil film viscosity loss is a significant factor in turbine bearing losses. For large-capacity, high-parameter turbine units, ensuring the safe and economical operation of bearings is becoming increasingly important. While ensuring unit safety, there is an urgent need to find a suitable flow guiding structure for the lubricating oil within turbine bearings to further reduce bearing power consumption and improve the economic efficiency of the turbine unit. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems by providing a flow guiding structure and bearing suitable for lubricating oil in turbine bearings. This structure is simple, easy to install and process, and has good practicality. It can ensure that the lubricating oil in the thrust bearing housing has good lubricity and flow characteristics, and can cool the rotor in a timely manner, thereby further ensuring the safety of the unit.

[0005] The technical solution adopted in this invention is as follows:

[0006] A flow guiding structure for lubricating oil in turbine bearings includes a housing, a rotating hole inside the housing, an annular cavity outside the rotating hole, and a plurality of flow guiding blades arranged circumferentially inside the annular cavity, the flow guiding blades dividing the annular cavity into multiple flow channels.

[0007] Alternatively, the guide vanes are arranged to be radially outward along the direction of rotor rotation.

[0008] Optionally, an oil return port is provided on the outer side of the annular cavity.

[0009] Alternatively, the axis of the oil return port may be inclined radially outward along the direction of rotor rotation.

[0010] Alternatively, the extension axis of the oil return port may be parallel to the direction of the lubricating oil velocity within the housing.

[0011] Alternatively, the housing may be provided with an oil inlet.

[0012] Alternatively, the rotary hole can be a stepped hole, which includes a large diameter portion and a small diameter portion, and the annular cavity is located on the outside of the large diameter portion.

[0013] Alternatively, the outer end of the small-diameter portion may also be provided with an oil baffle.

[0014] Alternatively, the radial width of the plurality of guide vanes is smaller than the radial width of the annular cavity.

[0015] A bearing includes a bearing bush and a housing as described above, wherein the bearing bush is disposed within the housing.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0017] 1. The present invention discloses a flow guiding structure and bearing suitable for lubricating oil in turbine bearings. Through the flow guiding blades, the temperature field in the bearing housing cavity can be improved, thereby increasing the service life of the unit; the flow of lubricating oil in the cavity can be accelerated, thereby improving the cooling performance of the lubricating oil on the rotor and improving the safety of the unit; the temperature rise of the lubricating oil can be effectively controlled, the bearing friction loss can be reduced, and the economic efficiency of the unit can be improved.

[0018] 2. The present invention discloses a flow guiding structure and bearing suitable for lubricating oil in turbine bearings. Through the return oil pipe structure that matches the speed direction of the lubricating oil, the flow efficiency is further improved, the local temperature rise caused by the local stagnation of lubricating oil at the return oil port is reduced, and the safety and economy of the bearing structure are improved. Attached Figure Description

[0019] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0020] Figure 1 This is a schematic diagram of the physical model of the bearing.

[0021] Figure 2 This is a schematic diagram of the physical model flow of the bearing.

[0022] Figure 3 This is a cross-sectional schematic diagram of the flow guiding structure of the present invention.

[0023] Figure 4 This is a partial cross-sectional view of the lower half of the flow guiding structure of the present invention.

[0024] Figure 5 This is a partial cross-sectional view of the upper half of the flow guiding structure of the present invention.

[0025] The markings in the diagram are: 1-oil return port, 2-bearing clearance, 3-housing, 4-guide vane, 5-bearing, 6-oil inlet, 7-rotor. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings.

[0027] All features disclosed in this specification, or steps in all methods or processes disclosed herein, may be combined in any way, except for mutually exclusive features and / or steps.

[0028] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is merely one example of a series of equivalent or similar features.

[0029] A flow guiding structure and bearing suitable for lubricating oil in steam turbine bearings, such as... Figure 1-5 As shown, it includes a housing 3, which has a rotating hole inside. An annular cavity is provided outside the rotating hole. Several guide vanes 4 are arranged circumferentially inside the annular cavity, and the guide vanes 4 divide the annular cavity into multiple flow channels.

[0030] Specifically, the guide vanes 4 guide the flow of lubricating oil, improving its flow characteristics within the cavity of the housing 3. This makes the flow field of the lubricating oil within the annular cavity more stable, ensuring stable temperature distribution and thermal stress, and extending the service life of the unit. It also increases the heat exchange area between the lubricating oil and the bearing housing 3, thereby increasing the heat exchange capacity, improving lubricating oil performance, and enhancing the economic efficiency of unit operation. Furthermore, it accelerates the flow of lubricating oil within the cavity, enhancing its cooling effect and improving unit safety. In addition, it changes the velocity direction of the lubricating oil, effectively discharging it from the housing 3 to the oil return system, controlling the lubricating oil temperature rise, reducing bearing friction loss, and improving unit economy.

[0031] In another specific embodiment, the guide vanes 4 are arranged radially outward along the rotation direction of the rotor 7. See also Figure 3 As shown, there is a large annular cavity between the housing 3 and the rotor 7. The lubricating oil has a high viscosity and a low flow velocity within this cavity, resulting in an uneven temperature distribution. The guide vanes 4 are installed in the direction of rotor 7 rotation, dividing the cavity of the housing 3 into multiple flow channels. This reduces the flow area and increases the lubricating oil flow velocity. At the same time, the guide vanes 4 have a certain installation angle, which can change the velocity direction of the lubricating oil, facilitating the discharge of lubricating oil from the return port 1. This effectively controls the lubricating oil temperature and reduces bearing wear.

[0032] In another specific implementation, an oil return port 1 is provided on the outer side of the annular cavity. When the lubricating oil flows unevenly within the housing 3, it is difficult to discharge smoothly, leading to an increase in oil temperature. Through the oil return port 1 located on the outer side of the annular cavity, the lubricating oil passes through the flow channels divided by the guide vanes 4 and is discharged from the oil return port 1, which can effectively optimize the flow path of the lubricating oil.

[0033] In another specific implementation, the axis of the oil return port 1 is inclined radially outward along the rotation direction of the rotor 7. The impact of bearing power consumption is due not only to the high viscosity of the lubricating oil, resulting in uneven distribution of the lubricating oil inside the bearing housing 3 and thus increased oil temperature, but also to the fact that the traditional design of opening radial or tangential outlets on the side of the housing 3 is not conducive to the discharge of lubricating oil from the housing 3, and the unsmooth flow within the flow field further leads to increased oil temperature. By opening the oil return port 1, which matches the direction of the lubricating oil flow velocity, the localized temperature rise caused by localized stagnation of lubricating oil in the oil return port 1 is reduced.

[0034] In another specific implementation, the extension axis of the oil return port 1 is parallel to the velocity direction of the lubricating oil inside the housing 3. When the fluid changes its flow direction, it will deform, generating local resistance that hinders the fluid's movement. By using the oil return port 1, which matches the velocity direction of the lubricating oil inside the housing 3, local resistance can be reduced, making the lubricating oil return smoother.

[0035] In another specific embodiment, the housing 3 is provided with an oil inlet 6. The oil inlet 6 allows lubricating oil to enter the gap between the rotor 7 and the bearing, thereby reducing the frictional loss between the high-speed rotating rotor 7 and the relatively stationary bearing. At the same time, it also seals and cools the surface temperature rise of the rotor 7, reducing the bearing power loss of the turbine and protecting the rotor 7 and the safety of the system.

[0036] In another specific embodiment, the rotary hole is a stepped hole, comprising a large-diameter portion and a small-diameter portion, with the annular cavity located on the outer side of the large-diameter portion. Since the turbine's thrust bearing primarily bears the axial thrust of the rotor 7, determining the axial position of the rotor 7 within the cylinder requires a stepped hole for axial positioning. Specifically, the stepped hole matches the shoulder on the rotor 7, and the oil inlet 6 is located connected to the small-diameter portion. It is worth noting that this embodiment is merely an illustration of a thrust bearing; when the bearing is another type, such as a support bearing, other structures are also possible, requiring only the provision of an annular cavity, without specific structural limitations.

[0037] In another specific embodiment, the outer end of the small-diameter portion is also provided with an oil-blocking portion. Since there is a gap between the housing 3 and the rotor 7 for lubricating oil to pass through, particularly a flow gap between the small-diameter portion and the rotor 7, this gap can lead to lubricating oil leakage. Therefore, the oil-blocking portion can block the lubricating oil, reducing the amount flowing outward from the flow gap. See also Figure 4 and Figure 5 As shown, there is an annular gap a between the end of the large diameter section and the rotor 7, and an annular gap b between the end of the small diameter section and the rotor 7. The lubricating oil enters from the oil inlet 6, and most of it flows out from the lubricating oil return port 1. A small amount of lubricating oil leaks out from the annular gaps a and b.

[0038] In another specific implementation, the radial width of the plurality of guide vanes 4 is smaller than the radial width of the annular cavity. Specifically, the radial inner and outer sides of the guide vanes 4 have gaps with the radial inner and outer sides of the annular cavity. When the guide vanes 4 completely separate the flow channels of the annular cavity, the lubricating oil cannot flow through the channels, resulting in poor flow and difficulty in carrying away local heat, causing a temperature rise. Therefore, the structure with open ends facilitates the flow of lubricating oil and ensures a more uniform temperature field distribution.

[0039] As another specific embodiment, a bearing includes a bearing shell 5 and a housing 3 as described above, wherein the bearing shell 5 is disposed within the housing 3.

[0040] The present invention provides a flow guiding structure and bearing suitable for lubricating oil in steam turbine bearings, the working principle of which is as follows:

[0041] Rotor 7 rotates counterclockwise at high speed, driving the lubricating oil to flow and lubricate it, reducing friction between moving and stationary parts and cooling the rotor 7, thus raising the temperature of the lubricating oil itself. Due to the pressure difference, a small amount of lubricating oil flows out from the gap between the bearing and rotor 7, while most of the lubricating oil flows into the housing 3 and out through the oil return port 1 on the housing 3 to the oil return system. Because the annular area of ​​the cavity of housing 3 is large and the viscosity of the lubricating oil is high, the flow resistance of the lubricating oil in the housing 3 is very large, and the high-speed rotation of rotor 7 increases the stirring power consumption. To address this problem, a certain number of guide vanes 4 are installed circumferentially in the annular cavity of housing 3. The installation direction of the guide vanes 4 is consistent with the rotation direction of rotor 7. On the one hand, this increases the contact area between the lubricating oil and housing 3, increases the heat exchange between the lubricating oil and housing 3, reduces the lubricating oil temperature, and ensures the safe operation of the unit. On the other hand, the guide vanes 4 divide the cavity of housing 3 into multiple flow channels, and the lubricating oil flows in the direction of the guide vanes 4, resulting in better flow conditions and less flow loss. Because the guide vane 4 has a certain installation angle, the speed direction of the lubricating oil changes when it flows through the guide vane 4, which is more conducive to the energy exchange of the lubricating oil and ensures a more uniform temperature field distribution. In addition, an oil return port 1 is opened on one side of the housing 3 to match the flow speed direction of the lubricating oil, so as to reduce the local temperature rise caused by the local retention of lubricating oil in the oil return port 1, and improve the safety and economy of the bearing structure.

[0042] Figure 1 , Figure 2 This is a schematic diagram of the physical model of the present invention, where the arrow points to the rotation direction of the rotor 7. As can be seen from the figure, a lubricating oil inlet 6 is provided on the housing 3. The lubricating oil enters through the inlet 6 and forms an oil film with a certain pressure in the annular gap of the bearing. The oil film flows through the gap between two adjacent bearing shells 5 into the housing 3. A certain number of guide vanes 4 are arranged inside the housing 3. A lubricating oil return port 1 is provided on the outer side of the housing 3, which matches the velocity direction of the lubricating oil in the housing 3. The flow trajectory of the lubricating oil in the bearing housing 3 is shown by a curve.

[0043] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0044] The present invention discloses a flow guiding structure and bearing suitable for lubricating oil in turbine bearings. When applied to turbine bearings, it can improve the flow characteristics of lubricating oil in the annular cavity. Specifically, it can stabilize the flow of lubricating oil in the bearing housing 3, make the temperature field distribution more uniform, and change the velocity direction of lubricating oil in the housing 3, thereby improving the flow field distribution of lubricating oil inside the housing 3. This facilitates the timely discharge of lubricating oil from the oil return port 1 on the side of the housing 3, thereby reducing the risk of bearing failure caused by excessive local temperature rise, reducing bearing friction loss, and improving the safety and economy of turbine unit operation.

[0045] The above specific technical solutions are only used to illustrate the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the above specific technical solutions, those skilled in the art should understand that the present invention can still be modified to the above specific technical solutions, or some of the technical features can be equivalently replaced, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention. The present invention extends to any new feature or any new combination disclosed in this specification, as well as any new method or process step or any new combination disclosed.

Claims

1. A flow guiding structure for lubricating oil in a bearing of a steam turbine, characterized in that: The application relates to a flow guide structure, which comprises a shell (3) provided with a rotating hole, an annular cavity arranged outside the rotating hole, a plurality of flow guide vanes (4) arranged in the circumferential direction of the annular cavity, the flow guide vanes (4) dividing the annular cavity into a plurality of flow channels, the flow guide vanes (4) being arranged in a radial direction from the outside to the inside, the width of the flow guide vanes (4) in the radial direction being smaller than the width of the annular cavity in the radial direction, and the inner and outer sides of the flow guide vanes (4) in the radial direction having gaps with the inner and outer sides of the annular cavity in the radial direction; an oil return port (1) is arranged on the outer side of the annular cavity, the axis of the oil return port (1) being arranged in a radial direction from the outside to the inside in the rotating direction of a rotor (7), and lubricating oil being discharged from the oil return port (1) after passing through the flow channels divided by the flow guide vanes (4).

2. The flow guiding structure for use in the lubricating oil in a bearing of a steam turbine according to claim 1, characterized in that: The extension axis of the oil return port (1) is parallel to the direction of the lubricating oil in the shell (3).

3. The flow guiding structure for use in the lubricating oil in a bearing of a steam turbine according to claim 1, characterized in that: An oil inlet (6) is arranged on the shell (3).

4. The flow guiding structure for use in a turbine bearing lubricating oil as claimed in claim 1, wherein: The rotating hole is a stepped hole, the stepped hole comprises a large-diameter part and a small-diameter part, and the annular cavity is arranged outside the large-diameter part.

5. The flow guiding structure for use in the lubricating oil in a bearing of a steam turbine according to claim 4, characterized in that: The outer end of the small-diameter part is further provided with an oil blocking part.

6. A bearing characterized by: The application further relates to a bearing bush (5) and the flow guide structure as claimed in any one of claims 1-5, the bearing bush (5) being arranged in the shell (3) of the flow guide structure as claimed in any one of claims 1-5.

Images