A new type of oil recessed hydrostatic and hydrodynamic thrust bearing

Abstract

A new type of oil cavity recess type static and dynamic pressure thrust bearing, with the development of high speed heavy load cutting technology, heavy equipment gradually to high speed heavy load development, we are more and more high performance requirements of static pressure thrust bearing, but with the increase of speed and load, the lubricating oil film because of the action of shear force and extrusion force, shear heat increases, oil film thin, even in local tribology failure phenomenon, and bearing because of local overheating deformation, resulting in lubricating oil leakage, and lubricating oil viscosity decreases, will produce static pressure loss, therefore, the patent puts forward a new type of oil cavity recess type static and dynamic pressure thrust bearing, so that the static pressure thrust bearing work, oil cavity and rotary workbench guide surface between the total wedge gap, under the condition of rotary workbench high speed rotation, meet the conditions of dynamic pressure effect, use dynamic pressure effect, through the dynamic pressure to make up for the lack of static pressure bearing capacity, in order to achieve the purpose of improving the bearing capacity and stability.

Description

Technical Field

[0001] This invention relates to a novel type of oil-cavity concave static and dynamic pressure thrust bearing. Background Technology

[0002] Hydrostatic thrust bearings, due to their high precision, long service life, and good stability, have become core components of large-scale CNC equipment in key national industries such as aerospace, heavy machinery, shipbuilding, and national defense. With the development of high-speed, heavy-load cutting technology, heavy equipment is increasingly moving towards high-speed, heavy-load operation, leading to higher performance requirements for hydrostatic thrust bearings. However, with increasing speed and load, the lubricating oil film experiences increased shear heat due to shear and extrusion forces, causing changes in lubricating oil viscosity. Uneven temperature distribution further contributes to localized bearing deformation, thinning of the oil film in certain areas, and even tribological failure, resulting in severe lubricating oil leakage and significant hydrostatic pressure loss. Therefore, this patent proposes a novel concave-cavity hydrostatic-dynamic thrust bearing. During operation, a wedge-shaped gap is created between the oil cavity and the rotary table guide surface, satisfying the conditions for generating a hydrodynamic pressure effect. This hydrodynamic pressure effect compensates for the lack of hydrostatic load-bearing capacity, thereby improving the bearing's load-bearing capacity and stability. Summary of the Invention

[0003] The present invention focuses on solving the problem of friction failure caused by insufficient hydrostatic bearing capacity in high-speed heavy-duty hydrostatic thrust bearings, which in turn affects the bearing's accuracy and lifespan. A novel type of oil-cavity concave hydrostatic thrust bearing is proposed to solve this problem.

[0004] The technical solution is as follows: A novel oil-cavity concave static and dynamic pressure thrust bearing, the main body of which is the bearing body, characterized in that the oil pad body is fan-shaped, the oil cavity is racetrack-shaped, and the inside of the oil cavity is concave. When the bearing is working, a wedge-shaped gap can always be generated at any position between the bottom guide rail surface of the rotating worktable and the oil cavity, which satisfies the conditions for dynamic pressure generation.

[0005] In Scheme 1, the total thickness of the oil pad is 50mm. The oil sealing edge (9) of the oil pad is racetrack shaped. The inside of the oil pad consists of a 3mm thick racetrack-shaped cavity and a racetrack-shaped bottom and a 5mm high concave arched shape forming an oil cavity (8), with an oil inlet hole (7).

[0006] In Scheme 2, the total thickness of the oil pad is 50mm, the oil sealing edge (12) on the oil pad is racetrack shaped, the inside of the oil pad is a concave arched oil cavity (11) with a racetrack-shaped oil sealing edge at the bottom and a height of 8mm, and a cylindrical oil inlet hole (10) to form an oil cavity. Compared with Scheme 1, Scheme 2 has a larger wedge gap, a larger bearing area, and can provide greater dynamic pressure compensation.

[0007] Compared to existing hydrostatic thrust bearings, conventional hydrostatic thrust bearings cannot generate dynamic pressure, and are prone to hydrostatic pressure loss due to severe lubricant leakage and changes in lubricant viscosity, thus affecting bearing operation, accuracy, and lifespan. This patent, however, uses wedge-shaped grooves in the oil cavity to generate dynamic pressure and increase the oil pad bearing area. Furthermore, this invention simultaneously possesses the characteristics of both hydrostatic and dynamic bearings. During bearing operation, hydrostatic pressure dominates at low speeds, while dynamic pressure is generated at high speeds, compensating for the loss of hydrostatic pressure. This invention provides two wedge-shaped groove structures, such as... Figure 1 This is a 1 / 12 exploded view of a new type of oil-cavity concave static and dynamic pressure thrust bearing. Figure 2 This is the side view of Option 1. Figure 3 This is a cross-sectional view of Scheme 1. Figure 4 This is a sectional view of Scheme 1, such as... Figure 5 This is a side view of Scheme 2 for a novel oil-cavity concave static and dynamic pressure thrust bearing. Figure 6 This is a cross-sectional view of Scheme 2. Figure 7 This is a sectional view of Scheme 2. Figure 11 It is the pressure field of the oil film in a conventional hydrostatic thrust bearing under given operating conditions, while Figure 12 This invention relates to the novel oil-cavity concave static and dynamic pressure thrust bearing scheme 1, under the same working conditions, and the oil film pressure field. Figure 11 and Figure 12 The comparison shows that compared to conventional hydrostatic thrust bearings, the new type of oil-cavity concave hydrostatic thrust bearing significantly increases the maximum pressure of the pressure field. Furthermore, conventional hydrostatic thrust bearings exhibit uneven pressure distribution, with a certain pressure gradient within the oil cavity. In contrast, the oil cavity pressure distribution of the oil-cavity concave hydrostatic thrust bearing is uniform, with both high-pressure and low-pressure zones located at the oil sealing edge, thus fulfilling the original purpose of this invention: improving load-bearing capacity. Advantages of this invention:

[0008] 1. The oil cavity is concave in shape. When the bearing is working, regardless of the bearing rotation direction, a wedge-shaped gap can always be generated at any position between the guide rail surface of the rotating worktable and the oil cavity. When the bearing is working, the hydraulic oil in the oil cavity can meet the conditions for the formation of hydrodynamic effect regardless of the outflow direction.

[0009] 2. The oil cavity of this bearing is inclined, and the oil pad has a shallow depth. The height of the concave plane is close to the height of the oil sealing edge. Because the inside of the oil cavity is concave, the concave surface area is larger than that of the flat surface inside the oil cavity of a conventional hydrostatic bearing. Therefore, the bearing oil pad has a larger bearing area, stronger bearing capacity, and better stability than conventional hydrostatic bearing oil pads. It can compensate for the lack of hydrostatic pressure through the dynamic pressure effect. At low speeds, the oil pad is mainly based on hydrostatic pressure, while at high speeds, it can generate dynamic pressure through the dynamic pressure effect to compensate for the loss of hydrostatic pressure caused by lubricating oil leakage and viscosity changes, thereby improving the bearing's bearing capacity. It has all the advantages of hydrostatic and dynamic pressure bearings. Moreover, the pressure distribution of both types of oil pads is more uniform and more precise than that of conventional hydrostatic and hydrostatic thrust bearings.

[0010] 3. From Figure 11 and Figure 12 The comparison shows that, compared with conventional hydrostatic thrust bearings, the pressure field of the new type of oil-cavity concave hydrostatic thrust bearing is significantly improved, with a much higher maximum pressure. Furthermore, the pressure distribution of conventional hydrostatic thrust bearings is uneven, with a certain pressure gradient in the oil cavity. In contrast, the oil cavity pressure distribution of the oil-cavity concave hydrostatic thrust bearing is uniform, with both high-pressure and low-pressure areas located at the oil sealing edge, thus fulfilling the original intention of this invention to improve load-bearing capacity. Attached Figure Description

[0011] Figure 1 This is an exploded view of a 1 / 12th part of a concave static and dynamic pressure thrust bearing. Figure 2 This is a perspective view of the oil pad in Scheme 1. Figure 3 This is a cross-sectional view of the oil pad in Scheme 1. Figure 4 This is a sectional view of the oil pad in Scheme 1. Figure 5 This is a perspective view of the oil pad in Scheme 2. Figure 6 This is a cross-sectional view of the oil pad in Scheme 2. Figure 7 This is a sectional view of the oil pad in Scheme 2. Figure 8 This is the assembly diagram for the oil pad and base. Figure 9 This is a 1 / 12 assembly drawing of a hydrostatic thrust bearing. Figure 10 A complete layout diagram of the static and dynamic pressure bearing oil pad. Figure 11 This refers to the oil chamber pressure of a conventional hydrostatic thrust bearing under extreme operating conditions. Figure 12 It is the oil chamber pressure of a new type of oil chamber concave static and dynamic pressure thrust bearing under the same working conditions. Detailed Implementation

[0012] The technical solution of the present invention will be described below with reference to the accompanying drawings. Of course, this is only a part of the present invention and not all of it. In the first solution, the total thickness of the oil pad (4) is 50mm, the oil sealing edge (9) on the oil pad is racetrack shaped, and the inside of the oil pad is a 3mm thick racetrack-shaped cavity and an oil cavity (8) composed of a racetrack-shaped bottom and a 5mm high concave arch, and has an oil inlet hole (7). Figure 10 It is a complete hydrostatic bearing assembly Figure 10 Half of the bearing oil pads are identical in all parts, so they can be analyzed separately. The working principle is as follows: when working, after assembling the oil pad and the base, the rotating worktable is placed on the oil pad, the load is placed on the worktable, and oil is supplied by the oil pump. The lubricating oil enters the oil chamber (8) from the oil inlet (7). Due to the action of hydraulic resistance, the rotating worktable is lifted, and a lubricating oil film (2) is formed between the guide rail surface (6) of the rotating worktable and the oil chamber (3). As the speed and load increase, the oil film temperature gradually rises. When the bearing is working, the hydraulic oil in the oil chamber can meet the conditions for the formation of dynamic pressure effect regardless of the direction of outflow. The oil pad is mainly static pressure at low speed. At high speed, the lubricating oil temperature rises and the lubricating oil viscosity decreases due to the shearing action, which causes the local temperature of the oil film to overheat, thereby causing the bearing to deform, causing the lubricating oil to leak, and generating static pressure loss. However, because the conditions for dynamic pressure effect are met, dynamic pressure is generated to make up for the lack of static pressure, and a reasonable matching effect of dynamic and static pressure is achieved, thereby achieving the purpose of improving the bearing load capacity. In Scheme 2, the total thickness of the oil pad is 50mm, the oil sealing edge (12) on the oil pad is racetrack-shaped, and the inside of the oil pad is a concave arched oil cavity (11) with a racetrack-shaped oil sealing edge at the bottom and a height of 8mm, which together with the cylindrical oil inlet hole (10) form the oil cavity. Scheme 1 and Scheme 2 work on the same principle, but compared with Scheme 1, Scheme 2 has a larger wedge gap, and because the oil cavity depth is shallower than that of Scheme 1, the bearing area is larger, so the dynamic pressure compensation that can be provided is also greater. The above are just specific embodiments of the present invention. Within the scope of the present invention, any easy modifications or substitutions made based on the present invention should be protected in the present invention.

Claims

1. A type of oil-cavity concave static and dynamic pressure thrust bearing, characterized in that: The oil cavity concave static and dynamic pressure thrust bearing consists of a rotating worktable (1), an oil cavity (3), an oil pad (4), a base (5), and an oil film (2) formed between the oil cavity (3) and the guide rail surface (6) of the worktable. The oil cavity (3) is concave in shape. The total thickness of the oil pad (4) is 50mm. The oil sealing edge (9) on the oil pad (4) is racetrack-shaped. The inside of the oil pad (4) consists of an oil cavity with a racetrack-shaped cavity on the upper side and a racetrack-shaped bottom on the lower side. The bottom height is 5mm. The oil cavity is concave and has an oil inlet hole (7). The oil cavity of this bearing is inclined. The oil pad oil cavity is shallow. The height of the concave plane is close to the height of the oil sealing edge. The inside of the oil cavity is concave. Compared with the plane inside the oil cavity of ordinary static pressure bearings, the concave surface area is larger.

2. A type of oil-cavity concave static and dynamic pressure thrust bearing, characterized in that: The oil-cavity concave static and dynamic thrust bearing consists of a rotating worktable (1), an oil cavity (3), an oil pad (4), a base (5), and an oil film (2) formed between the oil cavity (3) and the guide rail surface (6) of the worktable. The oil cavity (3) is concave in shape, and the total thickness of the oil pad (4) is 50mm. The oil sealing edge (12) on the oil pad (4) is racetrack-shaped, and the inside of the oil pad (4) is a racetrack-shaped bottom with a concave arch 8mm high and a cylindrical oil inlet hole (10). When working, after assembling the oil pad (4) and the base (5), the rotating worktable is placed on the oil pad, the load is placed on the worktable, and oil is supplied by the oil pump. The lubricating oil enters the oil cavity (3) from the oil inlet. Due to the action of the hydraulic resistance, the rotating worktable (1) is lifted, and a lubricating oil film (2) is formed between the guide rail surface (6) of the worktable and the oil cavity (3).

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