A foil gas dynamic pressure bearing and motor with protective structure

Abstract

The present invention relates to the technical field of motor bearings, and specifically to a foil gas dynamic pressure bearing and a motor with a protective structure, wherein the foil gas dynamic pressure bearing comprises a bearing seat, an arch foil arranged on the inner side of the bearing seat, a top foil arranged on the inner side of the arch foil, a plurality of protective structures arranged axially on the inner wall of the bearing seat, a plurality of protective structures evenly arranged on the inner wall of the bearing seat, and a mounting groove for accommodating the arch foil is formed between adjacent protective structures; the number of arch foils corresponds to the mounting groove, the distance between the top of the arch foil and the axis of the bearing seat is smaller than the distance between the protective structure and the axis of the bearing seat, and the bottom width of the mounting groove is larger than the width of the arch foil. When the rotor suddenly loses stability and hits the top foil due to power failure or external impact, the deformation degree of the arch foil is within the design range, and irreversible damage will not occur, thereby improving the reliability of the bearing and extending the service life of the bearing. The present invention has a simple structure and does not increase the original size of the bearing.

Description

Technical Field

[0001] The invention relates to the technical field of motor bearings, and in particular to a foil gas dynamic pressure bearing with a protection structure and a motor. Background Art

[0002] Bearings are an important component in contemporary mechanical equipment. Its main function is to support the mechanical rotating body, reduce the friction coefficient during its movement, and ensure its rotation accuracy. In the application of motors, bearings are often used to connect with the rotating shaft of the motor. Common bearings include cylindrical roller bearings, tapered roller bearings, deep groove ball bearings, angular contact ball bearings, thrust roller bearings, spherical roller bearings, gas hydrodynamic bearings, etc. Gas hydrodynamic bearings are a type of sliding bearing. Its structure and working principle are similar to those of liquid sliding bearings. The difference is that it uses gas (mostly air) as a lubricating medium. It has the advantages of extremely low friction, a wide range of operating speeds, and a wide range of applicable temperatures. Elastic foil gas hydrodynamic bearings are a type of gas hydrodynamic bearing. It is a high-speed, low-power, high-precision support technical special bearing. The bearing has the characteristics of no lubricating fluid, no pollution, no contact with the bearing, low loss, high operating speed, low maintenance cost, and long life. The existing elastic foil pneumatic bearing generally sets a circle of arch foil on the inner side of the bearing seat, and sets a top foil on the inner side of the arch foil. The front edges of the arch foil and the top foil are spot welded or clamped on the bearing seat as fixed ends, and the rear edges are free ends. However, when the rotor loses stability due to sudden power failure or strong external impact, the rotor hits the top foil, forcing the top foil to deform outward and squeeze the arch foil. The arch foil may be greatly deformed or even collapsed due to the impact of the rotor, causing overall damage to the bearing. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a foil gas dynamic pressure bearing with a protection structure, and a motor including the foil gas dynamic pressure bearing with a protection structure.

[0004] The present invention is implemented by the following scheme:

[0005] A foil gas dynamic pressure bearing with a protective structure includes a bearing seat, an arch foil arranged on the inner side of the bearing seat, and a top foil arranged on the inner side of the arch foil. The foil gas dynamic pressure bearing with a protective structure also includes a plurality of protective structures arranged axially on the inner wall of the bearing seat, wherein the plurality of protective structures are evenly arranged on the inner wall of the bearing seat, and mounting grooves for accommodating the arch foils are formed between adjacent protective structures; there are a plurality of arch foils, and the number of the arch foils corresponds to the mounting grooves; the distance between the top of the arch foil and the axis of the bearing seat is smaller than the distance between the protective structure and the axis of the bearing seat, and the width of the bottom of the mounting groove is larger than the width of the arch foil.

[0006] Furthermore, the protection structure includes a support portion connected to the bearing seat, a protection portion arranged on the top of the support portion, and a width of the protection portion is greater than that of the support portion.

[0007] Furthermore, the arch foil includes an arch section, and two supporting feet are arranged at two ends of the arch section, and the two supporting feet extend toward the protection structures on both sides of the arch section respectively.

[0008] Furthermore, the bottom of the mounting groove is an arc-shaped surface, and the bottom shape of the support foot matches the bottom shape of the mounting groove.

[0009] Furthermore, the bottom of the mounting groove is a flat surface, and the bottom shape of the support foot matches the bottom shape of the mounting groove.

[0010] Furthermore, both side ends of the bearing seat are recessed inward to form a concave platform, and an end ring for axially limiting the arch foil is installed on the concave platform. The top of the protective structure is at the same height as or higher than the inner wall of the end ring.

[0011] Furthermore, one end portion of the bearing seat is recessed inward to form a recessed platform, and an end ring for axially limiting the arch foil is installed on the recessed platform, and the top of the protective structure is higher than the inner wall of the end ring; a boss is provided at the other end of the bearing seat, and the height of the boss is less than or equal to the height of the protective structure.

[0012] Furthermore, the inner wall of the bearing seat is provided with a connecting groove, and one end of the top foil is inserted into the connecting groove and fixedly connected to the connecting groove.

[0013] Furthermore, one end of the top foil is fixedly connected to the bearing seat by welding or fasteners.

[0014] A motor comprises the aforementioned foil gas dynamic pressure bearing with a protection structure.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention evenly arranges a plurality of protective structures and a plurality of arch foils on the inner wall of the bearing seat, and an installation groove for installing the arch foil is formed between adjacent protective structures. The height of the arch foil is higher than the protective structure and the width of the installation groove is greater than the width of the arch foil. When the rotor suddenly loses stability due to power failure or external impact and hits the top foil, the deformation degree of the arch foil is within the design range, and irreversible damage will not occur due to excessive deformation, which greatly improves the reliability of the bearing and extends the service life of the bearing. At the same time, the structure of the present invention is simple and does not increase the original size of the bearing. On the other hand, the structural design of the present invention is easy to adjust the stiffness of the bearing during processing, and different stiffness of the bearing in the circumferential direction can be achieved through a single arch of different thicknesses. A thicker arch foil is used in an area with high rotor pressure to provide greater support stiffness, and a thinner arch foil is used in a position with less rotor pressure, so as to better consume the energy of the vibration generated by the interference force of the running rotor through the deformation of the arch foil. This structure can make the rotor more stable during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a foil gas dynamic pressure bearing with a protective structure provided by the present invention.

[0018] Figure 2 for Figure 1 Enlarged view of part A in the middle.

[0019] Figure 3 It is a three-dimensional angle schematic diagram of the present invention.

[0020] Included in the picture are:

[0021] Bearing seat 1, end ring 11, connecting groove 12, arch foil 2, arch segment 21, support foot 22, top foil 3, protection structure 4, support part 41, protection part 42, installation groove 5. DETAILED DESCRIPTION

[0022] To facilitate those skilled in the art to understand the present invention, the present invention will be further described in detail below in conjunction with specific embodiments and drawings.

[0023] Example 1

[0024] Reference Figures 1 to 3The present invention provides a foil gas dynamic pressure bearing with a protective structure, comprising a bearing seat 1, an arch foil 2 arranged on the inner side of the bearing seat 1, and a top foil 3 arranged on the inner side of the arch foil 2. The foil gas dynamic pressure bearing with a protective structure 4 also includes a plurality of protective structures 4 arranged axially on the inner wall of the bearing seat 1, and the plurality of protective structures 4 are evenly arranged on the inner wall of the bearing seat 1, and mounting grooves 5 for accommodating the arch foils 2 are formed between adjacent protective structures 4; there are a plurality of arch foils 2, and the number of the arch foils 2 corresponds to the mounting grooves 5; the distance between the top of the arch foil 2 and the axis of the bearing seat 1 is smaller than the distance between the protective structure 4 and the axis of the bearing seat 1, and the width of the bottom of the mounting groove 5 is greater than the width of the arch foil 2.

[0025] The material of the bearing seat 1 can be stainless steel, aluminum, etc., but is not limited to these two materials, as long as the material is soft and convenient for machining, to prevent the bearing protection structure 4 from being too hard and damaging the top foil 3 when the bearing collides with the rotor.

[0026] The protection structure 4 includes a support portion 41 connected to the bearing seat 1, and a protection portion 42 arranged on the top of the support portion 41, and the width of the protection portion 42 is greater than that of the support portion 41. That is, from the axial view, the support portion 41 is arranged along the radial direction, and the cross section of the entire protection structure 4 is generally T-shaped.

[0027] The arch foil 2 includes an arch section 21, two legs 22 arranged at both ends of the arch section 21, and the two legs 22 extend toward the protective structure 4 on both sides of the arch section 21. When the rotor collides with the bearing, the arch foil 2 is subjected to pressure from the top foil 3. When the top of the arch foil 2 is pressed to the lowest point, it does not exceed the yield strength allowed by the material of the arch foil 2. When the bearing is operating normally or stopping, the arch foil 2 can return to its original position, and will not be deformed by the collision, causing the arch foil 2 to deform and unable to return to its original shape. Therefore, it is required that the height of the arch foil 2 is designed to meet the requirement that the top of the arch foil 2 will not exceed the yield strength of the arch foil 2 when it is deformed from the original position (highest point) to the same height as the bearing protection structure 4 (lowest point). Therefore, when the bearing collides, the arch foil 2 will not be irreversibly damaged due to excessive deformation. The arch foil 2 can also be processed into different thicknesses, using a thicker arch foil 2 at a position where the bearing load is large, and using a thinner arch foil 2 at a position where the bearing load is small, so as to improve the stability of the bearing during operation.

[0028] The bottom of the mounting groove 5 is an arc-shaped surface, and the bottom shape of the support leg 22 matches the bottom shape of the mounting groove 5 .

[0029] The two side ends of the bearing seat 1 are both recessed inward to form a concave platform (i.e., a stepped structure, not shown in the drawings), and the concave platform is equipped with an end ring 11 for axially limiting the arch foil 2. The top of the protection structure 4 is at the same height as or higher than the inner wall of the end ring 11. During specific assembly, the arch foil 2 is installed from both sides of the bearing seat 1, and then the end ring 11 is welded or cold-installed on the bearing seat. The top foil and the end ring 11 both limit the arch foil.

[0030] The inner wall of the bearing seat 1 is provided with a connecting groove 12, and one end of the top foil 3 is inserted into the connecting groove 12 and fixedly connected to the connecting groove 12. The top foil 3 is processed by pressing, heat treatment and other processes, and has an open circular ring structure at one end, and is fixed to the connecting groove 12 of the bearing seat 1 by welding or fasteners such as pins and screws, and the other end is free.

[0031] Example 2

[0032] One end portion of the bearing seat 1 is recessed inward to form a concave platform (that is, a stepped structure, not shown in the drawings), and an end ring 11 for axially limiting the arch foil 2 is installed on the concave platform, and the top of the protective structure 4 is higher than the inner wall of the end ring 11; the other end portion of the bearing seat 1 is provided with a boss (not shown in the drawings, which plays the same limiting role as the end ring 11), and the height of the boss is less than or equal to the height of the protective structure 4.

[0033] Example 3

[0034] In this embodiment, the bottom of the mounting groove 5 is a flat surface, and the bottom shape of the support leg 22 matches the bottom shape of the mounting groove 5. The rest of the structure is the same as that of Embodiment 1 or Embodiment 2, and will not be described here.

[0035] Example 4

[0036] The present invention also provides a motor, comprising the aforementioned foil gas dynamic pressure bearing with a protective structure.

[0037] The present invention evenly arranges a plurality of protective structures and a plurality of arch foils on the inner wall of the bearing seat, and an installation groove for installing the arch foil is formed between adjacent protective structures. The height of the arch foil is higher than the protective structure and the width of the installation groove is greater than the width of the arch foil. When the rotor suddenly loses stability due to power failure or external impact and hits the top foil, the deformation degree of the arch foil is within the design range, and irreversible damage will not occur due to excessive deformation, which greatly improves the reliability of the bearing and extends the service life of the bearing. At the same time, the structure of the present invention is simple and does not increase the original size of the bearing. On the other hand, the structural design of the present invention is easy to adjust the stiffness of the bearing during processing, and different stiffness of the bearing in the circumferential direction can be achieved through a single arch of different thicknesses. A thicker arch foil is used in an area with high rotor pressure to provide greater support stiffness, and a thinner arch foil is used in a position with less rotor pressure, so as to better consume the energy of the vibration generated by the interference force of the running rotor through the deformation of the arch foil. This structure can make the rotor more stable during operation.

[0038] In the description of the present invention, it is necessary to understand that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Although the present invention is described in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and changes according to the above content. Therefore, all such substitutions, improvements and changes are included in the scope of the appended claims.

Claims

1. A foil gas dynamic pressure bearing with a protective structure, comprising a bearing seat, an arch foil arranged inside the bearing seat, and a top foil arranged inside the arch foil, characterized in that: The foil gas dynamic pressure bearing with a protective structure also includes a plurality of protective structures axially arranged on the inner wall of the bearing seat, and the plurality of protective structures are evenly arranged on the inner wall of the bearing seat, and an installation groove for accommodating the arch foil is formed between adjacent protective structures; there are a plurality of arch foils, and the number of the arch foils corresponds to the installation grooves; the distance between the top of the arch foil and the axis of the bearing seat is smaller than the distance between the protective structure and the axis of the bearing seat, and the width of the bottom of the installation groove is greater than the width of the arch foil.

2. The foil gas dynamic pressure bearing with a protective structure according to claim 1, characterized in that: The protection structure includes a support portion connected to the bearing seat, and a protection portion arranged on the top of the support portion, and the width of the protection portion is greater than that of the support portion.

3. The foil gas dynamic pressure bearing with a protective structure according to claim 1, characterized in that: The arch foil comprises an arch section and two supporting feet arranged at two ends of the arch section, and the two supporting feet extend toward the protection structures at two sides of the arch section respectively.

4. The foil gas dynamic pressure bearing with a protective structure according to claim 3, characterized in that: The bottom of the mounting groove is an arc-shaped surface, and the bottom shape of the support foot matches the bottom shape of the mounting groove.

5. The foil gas dynamic pressure bearing with a protective structure according to claim 3, characterized in that: The bottom of the mounting groove is a flat surface, and the bottom shape of the supporting foot matches the bottom shape of the mounting groove.

6. The foil gas dynamic pressure bearing with a protective structure according to claim 1, characterized in that: Both side ends of the bearing seat are recessed inward to form a concave platform, and an end ring for axially limiting the arch foil is installed on the concave platform. The top of the protection structure is at the same height as or higher than the inner wall of the end ring.

7. The foil gas dynamic pressure bearing with a protective structure according to claim 1, characterized in that: One end of the bearing seat is recessed inward to form a concave platform, and an end ring for axially limiting the arch foil is installed on the concave platform. The top of the protective structure is higher than the inner wall of the end ring; a boss is arranged at the other end of the bearing seat, and the height of the boss is less than or equal to the height of the protective structure.

8. The foil gas dynamic pressure bearing with a protective structure according to claim 1, characterized in that: The inner wall of the bearing seat is provided with a connecting groove, and one end of the top foil is inserted into the connecting groove and fixedly connected with the connecting groove.

9. The foil gas dynamic pressure bearing with a protective structure according to claim 1, characterized in that: One end of the top foil is fixedly connected to the bearing seat by welding or fasteners.

10. A motor, characterized in that: A foil gas dynamic pressure bearing with a protective structure comprising any one of claims 1-9.

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