Composite throttling gas static pressure thrust bearing

Abstract

The utility model provides a composite throttling gas static pressure thrust bearing (hereinafter referred to as a bearing) aiming at the problems of low bearing capacity and low stability of a small hole throttling gas static pressure thrust bearing. The bearing is composed of a thrust plate, a bearing base body and an air inlet end cover. The thrust plate is located above the bearing base body. A central blind hole and a surface throttling groove are formed in the upper end face of the bearing base body, a vent hole communicated with the blind hole is formed in the side edge of the bearing base body, a small-hole throttler communicated with the surface throttling groove is installed in the bearing base body, and a counter bore communicated with the small-hole throttler is formed in the lower end face of the bearing base body and attached to the upper end face of the air inlet end cover. A blind hole communicated with the counter bore in the lower end face of the bearing base body is formed in the center of the air inlet end cover, an air inlet communicated with the blind hole is formed in the side edge of the air inlet end cover, and the air inlet end cover and the bearing base body are fixedly connected and sealed through an O-shaped sealing ring.

Description

Technical Field

[0001] This invention relates to a gas hydrostatic thrust bearing, and proposes a composite throttling gas hydrostatic thrust bearing (hereinafter referred to as the bearing) combining orifice throttling and surface throttling. In particular, it relates to a high-rigidity, high-load-bearing composite throttling hydrostatic gas-lubricated thrust bearing combining orifice throttling and surface throttling. Background Technology

[0002] With the development of high technologies such as microelectronics, aerospace, and biomedicine, the demand for ultra-high precision and ultra-high speed machining equipment is increasing. In machine tools, bearings, as the spindle support components, have the most direct impact on machining accuracy. In recent decades, with the rapid development of fluid lubrication technology, traditional rolling bearings have gradually been replaced by fluid-lubricated bearings with higher precision and speeds in many precision and ultra-precision machining equipment. Compared to traditional rolling bearings, gas and liquid bearings enable spindles to achieve higher speeds, higher machining accuracy, improved transmission efficiency, and reduced energy consumption. Furthermore, compared to general liquid bearings, air static pressure bearings have lower gas viscosity and lower frictional resistance, achieving almost zero spindle temperature rise, and offering advantages such as high precision, long lifespan, no pollution, and good vibration resistance. Therefore, air static pressure bearings have wide applications in cutting-edge fields.

[0003] Currently, gas hydrostatic bearings mainly employ single throttling methods such as orifice throttling, slit throttling, surface throttling, and porous throttling. Among these, orifice throttling structures offer high stiffness but suffer from low load-bearing capacity and poor stability; surface throttling structures also exhibit insufficient stability. Therefore, all existing single throttling methods have varying degrees of performance bottlenecks, making it difficult to simultaneously achieve good load-bearing performance and operational stability.

[0004] To address the aforementioned issues, a gas hydrostatic thrust bearing with a composite throttling structure is proposed. This structure combines the advantages of orifice throttling and surface throttling, thereby enhancing static load-bearing capacity and improving operational stability through synergistic throttling. Summary of the Invention

[0005] This invention proposes a composite throttling gas static pressure thrust bearing, comprising a thrust plate, a bearing base, and an inlet end cap. Its key features are: the thrust plate is located above the bearing base; the upper surface of the bearing base has a central blind hole, six rectangular surface throttling grooves evenly distributed along the circumference, and one annular surface throttling groove. The rectangular surface throttling grooves have a length of 6 mm, a width of 0.06 mm, and a depth of 0.04 mm, with their long sides aligned with the radial direction and communicating with the annular surface throttling groove; the side of the bearing base has a vent hole communicating with the central blind hole, inside which is installed a small-hole throttling device, composed of a copper cap and a mounting hole, communicating with the surface throttling grooves; the number of small-hole throttling devices is six, with a diameter of 0.2 mm; the lower surface of the bearing base has a countersunk hole communicating with the small-hole throttling devices and fitting against the upper surface of the inlet end cap. The air intake end cover has a blind hole at the center that communicates with the countersunk hole on the lower end face of the bearing base, and an air intake hole on the side that communicates with the blind hole; the air intake end cover is fixedly connected to the bearing base, and the two are sealed with an O-ring.

[0006] Compared with traditional surface-throttling gas hydrostatic bearings, the bearing proposed in this invention increases the surface throttling area by connecting the area between the throttling orifices through the surface throttling grooves, thus forming a larger high-pressure area and increasing the load-bearing capacity and stiffness of the gas hydrostatic thrust bearing. Compared with traditional small-hole throttling gas hydrostatic bearings, this invention reduces the magnitude of sudden pressure changes around the small orifices, allowing the area connecting the throttling orifices and the surface throttling grooves to be filled with gas at a stable pressure, thereby improving the gas film pressure bearing capacity and resulting in better load-bearing capacity and stiffness. Attached Figure Description

[0007] Figure 1 This is the overall assembly drawing of the composite throttling gas hydrostatic thrust bearing described in this specification.

[0008] Figure 2 This is a structural diagram of the main body of the composite throttling gas hydrostatic thrust bearing described in this specification (excluding the thrust plate).

[0009] Figure 3 Assembly drawing for small orifice throttle Detailed Implementation

[0010] The embodiments of the present invention will be further described below with reference to the accompanying drawings and the usage of the gas static pressure thrust bearing:

[0011] First, clean the parts. Since the orifice throttle (24) is a precision part, it is necessary to ensure that no dirt remains in the orifice during use, and at the same time, the cleaning process should not cause damage to the parts. Therefore, the orifice throttle (24) should be cleaned with an ultrasonic cleaner before assembly.

[0012] Next, the thrust bearing is assembled. The copper cap (241) is bonded to the mounting hole (242) using epoxy resin adhesive to complete the assembly of the orifice throttle. Then, the bearing base (2) is fastened to the intake end cover (3) using fastening screws, and an O-ring is used for sealing.

[0013] The upper surface of the bearing base (2) is machined with six rectangular surface throttling grooves (22) evenly distributed along the circumference and one annular surface throttling groove (23). The rectangular surface throttling grooves (22) are 6 mm long, 0.06 mm wide, and 0.04 mm deep, with their long sides aligned with the radial direction. All rectangular surface throttling grooves (22) are connected to the annular surface throttling groove (23). Six small-hole throttling devices (24), each consisting of a copper cap (241) and a mounting hole (242), are installed inside the bearing base (2) and are connected to the corresponding rectangular surface throttling grooves (22) and annular surface throttling grooves (23). During operation, an adjustable pressure air source is provided to the thrust bearing via an air pump and a pressure reducing valve. The high-pressure gas first enters the air inlet end cover (3) through the air inlet (31), then enters the bearing base (2) through the countersunk hole, and further passes through the six 0.2mm orifice throttling devices (24) to reach the rectangular surface throttling groove (22) and diffuses along the annular surface throttling groove (23), finally overflowing from the upper end of the bearing base (2) to the surrounding area. During operation, the air film gap exists between the thrust plate (1) and the bearing base (2).

Claims

1. A composite throttling aerostatic thrust bearing, characterized in that: it comprises a thrust plate (1), a bearing base (2), and an air inlet end cover (3); the thrust plate (1) is located above the bearing base (2); the upper end surface of the bearing base (2) is provided with a central blind hole, six rectangular surface throttle grooves (22) uniformly distributed in the circumferential direction, and one annular surface throttle groove (23); the long side of the rectangular surface throttle groove (22) is consistent with the radial direction and communicates with the annular surface throttle groove (23); the side edge of the bearing base (2) is provided with an air hole (21) communicating with the central blind hole, and a small hole throttle (24) composed of a copper cap (241) and a mounting hole (242) is installed inside; the small hole throttle (24) communicates with the annular surface throttle groove (23); the lower end surface of the bearing base is provided with a counterbore, and the upper end surface of the air inlet end cover (3) is attached; the center of the air inlet end cover (3) is provided with a blind hole communicating with the counterbore of the lower end surface of the bearing base (2), and the side edge has an air inlet hole (31) communicating with the blind hole; the air inlet end cover (3) is fixedly connected with the bearing base (2) and is sealed and connected by an O-shaped sealing ring.

2. The composite throttling aerostatic thrust bearing according to claim 1, characterized in that: the slot length of the rectangular surface throttle groove (22) is 6 mm, the slot width is 0.06 mm, the slot depth is 0.04 mm, and the long side is consistent with the radial direction; the number of small hole throttles (24) is 6, and the hole diameter is 0.2 mm; the rectangular surface throttle groove (22) and the small hole throttle (24) both communicate with the annular surface throttle groove (23).

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