A rotary shaft system with floating sleeve

Abstract

The present invention provides a rotary shaft system with a floating sleeve, comprising a rotating shaft, a thrust plate arranged at one end of the rotating shaft, a floating sleeve sleeved outside the rotating shaft, a pad arranged axially outside the floating sleeve and surrounding the floating sleeve, a thrust washer, and a fixed shaft. The rotary shaft system with a floating sleeve of the present invention can increase the axial stiffness without increasing the size, thereby overcoming the disadvantage of low stiffness of air bearings, expanding the application scenarios of air bearings, and has a simple structure, is easy to assemble, and is low in cost.

Description

Technical Field

[0001] The invention relates to a rotary shaft system with a floating shaft sleeve. Background Art

[0002] Air static pressure bearings are widely used in precision machining equipment and testing occasions because of their friction-free, pollution-free and high-speed motion. However, due to the compressibility of gas, air bearings have low stiffness and weak resistance to external disturbances, which in turn affects their performance in ultra-high precision occasions.

[0003] Existing air bearings have low stiffness and limited application scenarios. In order to improve the axial stiffness, the solution of increasing the size of the axial thrust plate is often adopted, which leads to problems such as large rotational inertia, difficult control and difficulty in achieving high speed.

[0004] In view of this, it is necessary to improve the existing rotary shaft system to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a rotary shaft system with a floating sleeve to solve the problem.

[0006] To achieve the above-mentioned purpose, the present invention provides a rotating shaft system with a floating sleeve, the rotating shaft system with a floating sleeve comprising a rotating shaft, a thrust plate arranged at one end of the rotating shaft, a floating sleeve sleeved outside the rotating shaft, a pad and a thrust washer arranged axially outside the floating sleeve and surrounding the floating sleeve, the rotating shaft comprising a shaft body and a base arranged on a side of the shaft body away from the thrust plate, the floating sleeve sleeved on the shaft body, the floating sleeve comprising a first floating portion close to the shaft body, a second floating portion extending from the first floating portion toward the radial direction of the shaft body, the first floating portion and the thrust plate, the base and the shaft The body is arranged at intervals, the cushion block is arranged at intervals with the second floating part, the thrust washer is two in number and is respectively arranged at the upper part and the lower part of the second floating part, the thrust washer includes a first part that abuts against the cushion block, and a second part that is arranged between the second floating part and the thrust plate or the base, the second part and the second floating part, the thrust plate and the base are all arranged at intervals, the cushion block is provided with an air inlet arranged along the radial direction, the thrust washer is provided with an air outlet arranged along the radial direction, the air inlet and the air outlet are communicated, the floating sleeve is provided with an air vent, and the air vent passes through the first floating part and the second floating part.

[0007] As a further improvement of the present invention, the second floating portion and the center of the cushion block are at the same height.

[0008] As a further improvement of the present invention, the second portion includes a throttling portion extending from a side close to the first floating portion toward the second floating portion, and the throttling portion is spaced apart from the second floating portion to form a first throttling gap.

[0009] As a further improvement of the present invention, the second portion is spaced apart from the thrust plate and the base, and the spacing distance is smaller than the gap between the first floating portion and the thrust plate and the base to form a second throttling gap.

[0010] As a further improvement of the present invention, the air inlet is communicated with the air outlet through a second throttling gap.

[0011] As a further improvement of the present invention, a sealing ring is provided between the thrust washer and the first floating part, and the sealing ring is arranged on a side of the air outlet away from the second floating part.

[0012] As a further improvement of the present invention, a processing chamfer is provided at the connection between the first floating part and the second floating part.

[0013] As a further improvement of the present invention, the diameters of the base and the thrust plate are the same.

[0014] As a further improvement of the present invention, the rotary shaft system with the floating sleeve includes a fixed shaft arranged in the middle, and the rotating shaft rotates around the fixed shaft.

[0015] As a further improvement of the present invention, the thrust plate is fixedly connected to the shaft body by screws.

[0016] The beneficial effects of the present invention are as follows: the rotary shaft system with a floating sleeve of the present invention can increase the axial stiffness without increasing the size, thereby overcoming the disadvantage of low stiffness of air bearings, expanding the application scenarios of air bearings, and has a simple structure, is easy to assemble, and has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view of a rotary shaft system with a floating sleeve of the present invention;

[0018] Figure 2 It is a schematic cross-sectional structure diagram of a rotary shaft system with a floating sleeve of the present invention;

[0019] Figure 3 yes Figure 2 A schematic diagram of the enlarged structure of the middle area A;

[0020] Figure 4 yes Figure 2 Schematic diagram of the enlarged structure of area B in the middle. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figures 1 to 4 As shown, the rotary shaft system 100 with a floating sleeve of the present invention includes a rotating shaft 1, a thrust plate 2 arranged at one end of the rotating shaft 1, a floating sleeve 3 sleeved on the outside of the rotating shaft 1, a cushion block 4 axially arranged on the outside of the floating sleeve 3 and arranged around the floating sleeve 3, a thrust washer 5, and a fixed shaft 6.

[0023] The rotating shaft 1 includes a shaft body 11 and a base 12 disposed on a side of the shaft body 11 away from the thrust plate 2 .

[0024] The thrust plate 2 is fixedly connected to the shaft body 11 by screws 7 . The base 12 and the thrust plate 2 have the same diameter, while the shaft body 11 has a smaller diameter than the thrust plate 2 and the base 12 .

[0025] In other embodiments, the diameter of the thrust plate 2 may also be smaller than the diameter of the base 12 , but the diameters of the thrust plate 2 and the base 12 should be larger than the diameter of the shaft body 11 to facilitate installation of the floating sleeve 3 .

[0026] The rotating shaft 1 rotates around the fixed shaft 6 . Specifically, the fixed shaft 6 penetrates the rotating shaft 1 and the thrust plate 2 along the axial direction, so that the rotating shaft 1 can rotate around the fixed shaft 6 .

[0027] The floating sleeve 3 is sleeved on the shaft body 11. The floating sleeve 3 includes a first floating portion 31 close to the shaft body 11, and a second floating portion 32 extending from the first floating portion 31 toward the radial direction of the shaft body 11. The second floating portion 32 is arranged in the middle of the first floating portion 31. The first floating portion 31 is spaced apart from the thrust plate 2, the base 12 and the shaft body 11. A vent 33 is provided on the floating sleeve 3, and the vent 33 passes through the first floating portion 31 and the second floating portion 32. A processing chamfer 34 is provided at the connection between the first floating portion 31 and the second floating portion 32 to make the floating sleeve 3 easier to process.

[0028] The spacing distance between the first floating portion 31 and the thrust plate 2 is set to h0, and the distance between the first floating portion 31 and the base 12 is set to h3.

[0029] The height of the cushion block 4 in the axial direction is higher than the second floating portion 32 and is spaced apart from the second floating portion 32. The second floating portion 32 and the center of the cushion block 4 are at the same height, so that the upper end of the cushion block 4 is higher than the second floating portion 32 and the lower end is lower than the second floating portion 32.

[0030] The cushion block 4 is provided with an air inlet 41 arranged in a radial direction. The air inlet 41 penetrates the cushion block 4 in a radial direction to allow air to enter.

[0031] There are two thrust washers 5, which are respectively arranged at the upper and lower parts of the second floating part 32. The thrust washers 5 include a first portion 51 that abuts against the cushion block 4, and a second portion 52 that is arranged between the second floating part 32 and the thrust plate 2 or the base 12. The second portion 52 is spaced apart from the second floating part 32, the thrust plate 2, and the base 12. The thrust washers 5 are provided with radially arranged air outlets 53.

[0032] The second portion 52 includes a throttle portion 54 extending from the side close to the first floating portion 31 toward the second floating portion 32, and the throttle portion 54 is spaced from the second floating portion 32 to form a first throttle gap. The distance between the second portion 52 from the side away from the first floating portion 31 and the upper side of the second floating portion 32 is set to h1, and the first throttle gap at the upper side is set to h11. The distance between the second portion 52 from the side away from the first floating portion 31 and the lower side of the second floating portion 32 is set to h2, and the first throttle gap at the lower side is set to h21.

[0033] The second portion 52 is spaced from the thrust plate 2 and the base 12, and the spacing distance is smaller than the gap between the first floating portion 31 and the thrust plate 2 and the base 12 to form a second throttling gap. The upper second throttling gap is set as h01, and the lower second throttling gap is set as h31.

[0034] The air inlet 41 is connected to the air outlet 53. Further, the air inlet 41 is connected to the air outlet 53 through a second throttling gap.

[0035] By setting the first throttling gap and the second throttling gap, the rotary shaft system 100 with the floating sleeve is easy to process and has better stability.

[0036] A sealing ring 8 is provided between the thrust washer 5 and the first floating portion 31 . The sealing ring 8 is disposed on a side of the air outlet 53 away from the second floating portion 32 .

[0037] The air flows as follows: the air enters from the air inlet 41, a part of it passes through the gap between the cushion block 4 and the second floating part 32, passes through h1 and h11 at the top, passes through h2 and h21 at the bottom, and then passes through the gap between the second part 52 and the first floating part 31, enters the air outlet 53, and is finally discharged; another part of the air enters the vent 33, and then passes through the gap between the first floating part 31 and the shaft body 11. The air above passes through h0 and h01 in turn and is then discharged, and the air below passes through h3 and h31 in turn and is then discharged.

[0038] The effects that can be achieved are as follows: when the rotary shaft system 100 with a floating sleeve receives a downward load, the thrust plate 2 and the rotating shaft 1 move downward a certain distance, at which time h01 and h0 become smaller, and the corresponding air film forces, F01 and F0, become larger; because F0 becomes larger, the floating sleeve 3 will move downward, causing h1 and h11 to become larger, and h2, h22, h3 and h33 to become smaller; because h33 becomes smaller, the force F33 received by the floating sleeve 3 will increase, causing the floating sleeve 3 to move upward, causing h0 to further decrease and F0 to further increase, until F0 can balance the external load. Through reasonable design, the movement of the floating sleeve 3 can completely balance the external load. At this time, h01 hardly changes, which means that the main shaft has infinite rigidity in the axial direction.

[0039] In addition, the rotary shaft system 100 with a floating sleeve of the present invention is easy to install. A rotating shaft 1 with a fixed shaft 6 is provided, and the thrust plate 2 below, the floating sleeve 3, the cushion block 4, and the thrust plate 2 above are lowered in sequence. Then, the thrust plate 2 and the rotating shaft 1 are fixed with screws 7. The processing is completed and the installation is very convenient.

[0040] The rotary shaft system 100 with a floating sleeve of the present invention can increase the axial stiffness without increasing the size, thereby overcoming the shortcoming of low stiffness of air bearings, expanding the application scenarios of air bearings, and has a simple structure, is easy to assemble, and is low in cost.

[0041] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A rotary shaft system with a floating sleeve, characterized in that: The rotating shaft system with a floating sleeve comprises a rotating shaft, a thrust plate arranged at one end of the rotating shaft, a floating sleeve sleeved on the outside of the rotating shaft, a pad and a thrust washer arranged axially on the outside of the floating sleeve and surrounding the floating sleeve. The rotating shaft comprises a shaft body and a base arranged on the side of the shaft body away from the thrust plate. The floating sleeve is sleeved on the shaft body. The floating sleeve comprises a first floating portion close to the shaft body and a second floating portion extending from the first floating portion toward the radial direction of the shaft body. The first floating portion is spaced apart from the thrust plate, the base and the shaft body. The pad and the first floating portion are spaced apart from each other. The two floating parts are arranged at intervals, the number of the thrust washer is two, which are respectively arranged at the upper and lower parts of the second floating part, the thrust washer includes a first part that abuts against the cushion block, and a second part that is arranged between the second floating part and the thrust plate or the base, the second part and the second floating part, the thrust plate and the base are all arranged at intervals, the cushion block is provided with an air inlet arranged in the radial direction, the thrust washer is provided with an air outlet arranged in the radial direction, the air inlet and the air outlet are communicated, the floating sleeve is provided with an air vent, and the air vent passes through the first floating part and the second floating part.

2. The rotary shaft system with floating sleeve according to claim 1, characterized in that: The second floating portion and the center of the spacer block have the same height.

3. The rotary shaft system with floating sleeve according to claim 1, characterized in that: The second portion includes a throttling portion extending from a side close to the first floating portion toward the second floating portion, and the throttling portion is spaced apart from the second floating portion to form a first throttling gap.

4. The rotary shaft system with floating sleeve according to claim 1, characterized in that: The second portion is spaced apart from the thrust plate and the base, and the spacing distance is smaller than the gap between the first floating portion and the thrust plate and the base to form a second throttling gap.

5. The rotary shaft system with floating sleeve according to claim 1, characterized in that: The air inlet is communicated with the air outlet through a second throttle gap.

6. The rotary shaft system with floating sleeve according to claim 1, characterized in that: A sealing ring is provided between the thrust washer and the first floating part, and the sealing ring is arranged on a side of the air outlet away from the second floating part.

7. The rotary shaft system with floating sleeve according to claim 1, characterized in that: A processing chamfer is arranged at the connection between the first floating part and the second floating part.

8. The rotary shaft system with floating sleeve according to claim 1, characterized in that: The base and the thrust plate have the same diameter.

9. The rotary shaft system with floating sleeve according to claim 1, characterized in that: The rotary shaft system with a floating sleeve comprises a fixed shaft arranged in the middle, and the rotating shaft rotates around the fixed shaft.

10. The rotary shaft system with floating sleeve according to claim 1, characterized in that: The thrust plate is fixedly connected to the shaft body by screws.

Images