Large-flow-channel fluid dynamic pressure bearing

Abstract

The utility model discloses a large flow channel fluid dynamic pressure bearing which comprises a bearing body, an inner cavity used for installing a fluid dynamic pressure rotating shaft is formed in the bearing body, a plurality of dynamic pressure grooves which are arranged at intervals in the axial direction are concavely formed in the inner circumferential face of the inner cavity, a protruding strip is formed between every two adjacent dynamic pressure grooves, and the width of each dynamic pressure groove is larger than that of each protruding strip. And the shape of the dynamic pressure groove is designed to be gradually contracted towards the groove opening. Thus, the oil storage amount is large, oil throwing is prevented, pressure buildup is fast, and the lubricating effect is good, specifically, compared with the inherent scheme that in the prior art, the dynamic pressure grooves are obviously smaller than protruding strips between the adjacent dynamic pressure grooves, the dynamic pressure grooves are obviously widened to contain more lubricating oil, particularly, the requirement for the large oil amount under the high-speed heavy-load working condition can be better met, and meanwhile the lubricating effect is good. And the lubricating oil is effectively prevented from being thrown out during high-speed rotation, so that the oil throwing phenomenon is obviously reduced on the premise of ensuring sufficient lubrication, the stability and reliability of bearing operation are improved, and the oil consumption and the maintenance cost are reduced.

Description

Technical Field

[0001] This utility model relates to the field of hydrodynamic bearings, and in particular to a large-channel fluid hydrodynamic bearing. Background Technology

[0002] Hydrodynamic sliding bearings are widely used in various rotating machinery (such as turbines, compressors, motors, gearboxes, etc.). They generate hydrodynamic pressure in the bearing clearance by filling the hydrodynamic grooves with dynamic lubricating fluid, thereby supporting the hydrodynamic shaft in a non-contact manner. They are suitable for high-speed rotation and have advantages such as high rotational accuracy, low noise and long service life.

[0003] In traditional technology, the dynamic pressure grooves are significantly smaller than the ridges between adjacent dynamic pressure grooves. Under high-speed, heavy-load, or conditions requiring strong cooling, ensuring or further improving rapid pressure build-up and lubrication during operation necessitates an increased demand for bearing lubricant. While widening the dynamic pressure grooves can increase oil storage capacity, this also leads to oil being more easily thrown out of the bearing end by centrifugal force during high-speed rotation (the "oil slinging" phenomenon). This not only wastes lubricant and pollutes the environment but, more importantly, results in insufficient oil volume inside the bearing, inadequate oil film formation, and consequently, poor lubrication, excessive temperature rise, and accelerated wear. Alternatively, reinforcing the bearing end with an oil retainer ring and designing complex return channels can be considered, but these structures often increase bearing complexity and manufacturing costs, and are difficult to implement in space-constrained applications.

[0004] Therefore, a new technical solution needs to be researched to address the above problems. Utility Model Content

[0005] In view of this, the present invention addresses the deficiencies of the existing technology and its main purpose is to provide a large-channel hydrodynamic bearing that can meet the demand for large oil supply and effectively suppress oil slinging. It has advantages such as simple structure, large oil storage capacity, anti-slinging, fast pressure build-up, and good lubrication effect, and is suitable for widespread application.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A large-channel hydrodynamic bearing includes a bearing body. The bearing body has an axially penetrating inner cavity for mounting a hydrodynamic shaft. The inner circumferential surface of the inner cavity is recessed with a plurality of hydrodynamic grooves arranged at axial intervals. A ridge is formed between adjacent hydrodynamic grooves. The width of the hydrodynamic groove is greater than the width of the ridge, and the shape of the hydrodynamic groove is a gradually tapering design towards the groove opening.

[0008] As a preferred embodiment, the cross-sectional shape of the dynamic pressure groove is a trapezoid that gradually decreases towards the groove opening.

[0009] As a preferred embodiment, the trapezoidal cross-section of the dynamic pressure groove has two oblique lines on both sides, resulting in two base angles of 45-80°.

[0010] As a preferred embodiment, the trapezoidal cross-section of the dynamic pressure groove is an isosceles trapezoid or a non-isosceles trapezoid.

[0011] As a preferred embodiment, the ratio of the width of the dynamic pressure groove to the width of the convex strip is 3:2 to 2.5:1.

[0012] As a preferred embodiment, the ratio of the width of the dynamic pressure groove to the width of the convex strip is 2:1.

[0013] As a preferred embodiment, the inner wall of the dynamic pressure groove is either straight or curved.

[0014] As a preferred embodiment, the dynamic pressure groove is V-shaped, and a pressure-building point is formed at the protruding part of the V-shaped bend.

[0015] As a preferred embodiment, the inner cavity is divided into a first groove segment, a smooth segment, and a second groove segment along the axial direction. The dynamic pressure grooves are respectively arranged in the first groove segment and the second groove segment. The inner diameters of the first groove segment and the second groove segment are the same and are both smaller than the inner diameter of the smooth segment. The axial length of the first groove segment is equal to the axial length of the smooth segment and is both greater than the axial length of the second groove segment.

[0016] As a preferred embodiment, the bearing body is made of powder metallurgy material or ceramic material.

[0017] Compared with existing technologies, this utility model has significant advantages and beneficial effects. Specifically, as can be seen from the above technical solution, it mainly achieves this by making the width of the dynamic pressure groove greater than the width of the convex strip, and designing the shape of the dynamic pressure groove to gradually taper towards the groove opening. This design offers advantages such as simple structure, large oil storage capacity, prevention of oil splashing, rapid pressure build-up, and good lubrication effect, making it suitable for widespread application. Specifically, compared with the traditional technology where the dynamic pressure groove is significantly smaller than the convex strip between adjacent dynamic pressure grooves, this design significantly widens the dynamic pressure groove to accommodate more lubricating oil, especially better meeting the large oil volume requirements under high-speed and heavy-load conditions. At the same time, it effectively prevents lubricating oil from being splashed out during high-speed rotation, thereby significantly reducing oil splashing while ensuring sufficient lubrication, improving the stability and reliability of bearing operation, and reducing oil consumption and maintenance costs.

[0018] To more clearly illustrate the structural features and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0019] Figure 1 This is an end view of a large-channel hydrodynamic bearing according to an embodiment of the present invention;

[0020] Figure 2 This is another end view of the large-channel hydrodynamic bearing according to an embodiment of the present invention;

[0021] Figure 3 This is a cross-sectional view of a large-channel hydrodynamic bearing according to an embodiment of the present invention;

[0022] Figure 4 This is a texture development diagram of the first groove segment and the second groove segment of the inner cavity of the large flow channel hydrodynamic bearing according to an embodiment of this utility model;

[0023] Figure 5 This is a partial cross-sectional view of the hydrodynamic groove of the large flow channel hydrodynamic bearing according to an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached drawings: bearing body 10, inner cavity 101, dynamic pressure groove 11, convex strip 12, width W1 of dynamic pressure groove, width W2 of convex strip, first groove segment 1021, second groove segment 1022, inner diameter D1 of first groove segment, inner diameter D2 of smooth segment, axial length L1 of first groove segment, axial length L3 of smooth segment, axial length L2 of second groove segment, upper base width W11 of trapezoid, lower base width W12 of trapezoid. Detailed Implementation

[0025] Please refer to Figures 1 to 5 As shown, it illustrates the specific structure of an embodiment of the present invention.

[0026] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", 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 utility model 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, they should not be construed as limitations on this utility model.

[0027] A large-channel hydrodynamic bearing includes a bearing body 10, which is cylindrical or substantially cylindrical, and the bearing body 10 is made of powder metallurgy material or ceramic material, etc. The bearing body 10 has an axially penetrating inner cavity 101 for mounting a hydrodynamic shaft.

[0028] The inner circumferential surface of the inner cavity 101 is recessed with a plurality of dynamic pressure grooves 11 arranged at axial intervals. The dynamic pressure grooves 11 are V-shaped bends, and pressure build-up points are formed at the protruding parts of the V-shape bends. Typically, the bending angle is 30° to 60°. A ridge 12 is formed between adjacent dynamic pressure grooves 11. The width of the dynamic pressure groove 11 is greater than the width of the ridge 12, and the shape of the dynamic pressure groove 11 is a gradually tapering design towards the groove opening. Thus, in this utility model, by changing the ratio of dynamic pressure grooves 11 to ridges 12 to increase the oil supply, and combined with the special structural design of the dynamic pressure grooves 11, oil slingshot is prevented. This overcomes the defect that oil slingshot easily occurs when technicians simply use dynamic pressure bearings to widen the grooves to meet large oil demand. It provides a large flow channel fluid dynamic pressure bearing with simple structure, low manufacturing cost, and the ability to simultaneously achieve large oil supply and effective oil slingshot prevention.

[0029] Compared to the traditional design where the dynamic pressure groove is significantly smaller than the ridge between adjacent dynamic pressure grooves, this design significantly widens the dynamic pressure groove 11 to accommodate more lubricating oil, meeting the high oil volume requirements under high-speed, heavy-load conditions. Simultaneously, to effectively prevent lubricating oil from being thrown out during high-speed rotation, the dynamic pressure groove 11 has a tapering shape towards the groove opening. When the bearing rotates at high speed, centripetal hydrodynamic pressure is generated. As the lubricating oil flows from the bottom of the dynamic pressure groove 11 towards the groove opening (i.e., the bearing working surface), the flow cross-sectional area gradually decreases. According to fluid mechanics principles, this accelerates the oil flow. More importantly, this tapering structure forms a converging wedge-shaped gap in the oil flow direction, which generates a hydrodynamic pressure component pointing inwards towards the bearing. Simultaneously, the generated centripetal hydrodynamic pressure effectively resists centrifugal force, constraining the lubricating oil within the groove to flow primarily axially and radially inwards (towards the center of the bearing's load-bearing area), rather than being radially thrown outwards from the bearing end. Because only widening the dynamic pressure groove 11 and changing its geometry are required, without the need for additional oil retaining rings or more complex return grooves, the original bearing design remains simple, making it easy to manufacture, cost-effective, and highly reliable. By ensuring sufficient lubricating oil volume while reducing oil spillage, more lubricating oil can effectively participate in the formation of the bearing oil film, significantly improving lubrication efficiency, reducing frictional power consumption and operating temperature, and extending bearing life. Furthermore, the significantly reduced amount of lubricating oil spillage lowers operating oil consumption and environmental pollution, while also reducing the frequency and cost of lubricating oil replenishment.

[0030] In this embodiment, the cross-sectional shape of the dynamic pressure groove 11 is a trapezoid that gradually decreases towards the groove opening, such as... Figure 5As shown, the width of the upper base W11 of the trapezoid is smaller than the width of the lower base W12. Both sides of the trapezoidal cross-section of the dynamic pressure groove 11 are oblique lines, resulting in two base angles of 45-80°. The trapezoidal cross-section of the dynamic pressure groove 11 can be an isosceles trapezoid or a non-isosceles trapezoid. Furthermore, the inner sidewall of the dynamic pressure groove 11 can be straight or curved.

[0031] Furthermore, the ratio of the width W1 of the dynamic pressure groove to the width W2 of the protrusion is 3:2 to 2.5:1. Preferably, the ratio of the width of the dynamic pressure groove 11 to the width of the protrusion 12 is 2:1.

[0032] like Figure 3 and Figure 4 As shown, the inner cavity 101 is divided into a first groove segment 1021, a smooth section, and a second groove segment 1022 along the axial direction. The dynamic pressure grooves 11 are respectively arranged in the first groove segment 1021 and the second groove segment 1022. The inner diameter D1 of the first groove segment is the same as the inner diameter of the second groove segment, and both are smaller than the inner diameter D2 of the smooth section. The axial length L1 of the first groove segment is equal to the axial length L3 of the smooth section, and both are greater than the axial length L2 of the second groove segment.

[0033] It should also be noted that, as mentioned above, the bearing body 10 is made of powder metallurgy materials or ceramic materials, etc. The aforementioned powder metallurgy materials also refer to porous metallic materials. These materials are made by pressing and sintering (same or different) metal powders, resulting in a porous structure with pores accounting for approximately 10%-35% of the volume. Before use, the bearing shell is immersed in hot oil for several hours to fill the pores with lubricating oil. The resulting bearing is called an oil-impregnated bearing, which has self-lubricating properties. In practical applications, the materials are not limited to powder metallurgy materials or ceramic materials. Non-metallic materials, such as plastics, rubber, and nylon, can also be used in hydrodynamic bearings under specific operating conditions, such as when there are special requirements for noise reduction and corrosion resistance. It can also be metallic materials, such as: 1. Bearing alloys, also known as Babbitt metal, which contain tin and lead matrix, have good comprehensive performance but low mechanical strength, and can be cast onto steel or cast iron bearing bases; 2. Copper alloys, mainly tin bronze, aluminum bronze and lead bronze. Tin bronze is suitable for medium speed, medium load or heavy load conditions, aluminum bronze is suitable for low speed and heavy load conditions, and lead bronze is suitable for high speed and heavy load conditions; 3. Cast iron, which is a light load and low speed bearing material, is often used in hydrodynamic bearings in corresponding working environments.

[0034] Furthermore, the machining of the dynamic pressure groove can be carried out using different machining methods, such as: a CNC cutter extending into the inner cavity to machine, with its cutting tip carving out the dynamic pressure groove on the inner circumferential surface of the inner cavity; or, obtaining the dynamic pressure bearing blank with the dynamic pressure groove first by injection molding, and then removing the filler; or other suitable machining methods. In this utility model, the specific machining method for this type of large-channel fluid dynamic pressure bearing is not limited.

[0035] The key design feature of this invention lies in the fact that the width of the dynamic pressure groove 11 is greater than the width of the ridge 12, and the shape of the dynamic pressure groove 11 is a gradually tapering design towards the groove opening. This design offers advantages such as simple structure, large oil storage capacity, prevention of oil splashing, rapid pressure build-up, and good lubrication effect, making it suitable for widespread application. Specifically, compared to the traditional design where the dynamic pressure groove 11 is significantly smaller than the ridge 12 between adjacent dynamic pressure grooves 11, this design significantly widens the dynamic pressure groove 11 to accommodate more lubricating oil. In particular, it better meets the large oil volume requirements under high-speed, heavy-load conditions. At the same time, it effectively prevents lubricating oil from being splashed out during high-speed rotation, thereby significantly reducing oil splashing while ensuring sufficient lubrication. This improves the stability and reliability of bearing operation and reduces oil consumption and maintenance costs.

[0036] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A large-channel hydrodynamic bearing, comprising a bearing body, wherein the bearing body has an axially penetrating inner cavity for mounting a hydrodynamic shaft, characterized in that: The inner circumferential surface of the inner cavity is provided with a plurality of dynamic pressure grooves arranged at axial intervals. A ridge is formed between adjacent dynamic pressure grooves. The width of the dynamic pressure groove is greater than the width of the ridge, and the shape of the dynamic pressure groove is a gradually tapering design towards the groove opening.

2. A hydrodynamic fluid film bearing of claim 1, wherein: The cross-sectional shape of the dynamic pressure groove is a trapezoid that gradually decreases towards the groove opening.

3. A hydrodynamic bearing of the type defined in claim 2, characterised in that: The trapezoidal cross-section of the dynamic pressure groove has two oblique lines on both sides, making the two base angles 45-80°.

4. A hydrodynamic bearing of the type defined by claim 2, characterised in that: The trapezoidal cross-section of the dynamic pressure groove is either an isosceles trapezoid or a non-isosceles trapezoid.

5. A large flow passage hydrodynamic bearing according to claim 1, wherein: The ratio of the width of the dynamic pressure groove to the width of the convex strip is 3:2 to 2.5:

1.

6. A large flow channel hydrodynamic bearing according to claim 5, wherein: The ratio of the width of the dynamic pressure groove to the width of the convex strip is 2:

1.

7. A hydrodynamic bearing of the type defined in claim 1, characterised in that: The inner wall of the dynamic pressure groove is either straight or curved.

8. A hydrodynamic bearing of the type defined by claim 1, characterised in that: The dynamic pressure groove is V-shaped, and pressure build-up points are formed at the protruding parts of the V-shaped bend.

9. A hydrodynamic bearing of the type defined by claim 1, characterised in that: The inner cavity is divided into a first groove section, a smooth section and a second groove section along the axial direction. The dynamic pressure grooves are respectively arranged in the first groove section and the second groove section. The inner diameters of the first groove section and the second groove section are the same and are both smaller than the inner diameter of the smooth section. The axial length of the first groove section is equal to the axial length of the smooth section and is both greater than the axial length of the second groove section.

10. A large flow passage hydrodynamic bearing as in claim 1 wherein: The bearing body is made of powder metallurgy material or ceramic material.

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