Porous medium static pressure air floatation spline

Abstract

The invention discloses a porous medium static pressure air floatation spline which comprises a spline shaft, a spline sleeve outer sleeve, an air bearing, a spline sleeve, a flange sleeve, a valve plate and a porous medium. The air floating spline is cylindrical, a plurality of air paths and static pressure cavities are formed in the air floating spline, porous media are mounted in trapezoidal grooves of the spline housing, and the internal static pressure cavities enable circumferential torsional moment applied to the spline shaft to be borne by the porous media and static pressure supports between trapezoidal tooth slopes on the spline shaft when the spline works; radial force applied to the spline shaft is borne by a static pressure support between the porous medium and the inclined plane of the trapezoidal teeth and a static pressure support on the inner ring of the air bearing; the axial load applied to the outer sleeve of the spline housing is borne by the annular static pressure cavity and the annular static pressure cavity; according to the porous medium static pressure air floatation spline, abrasion of the spline in the working process is reduced, and the problem that the spline precision is affected due to abrasion after a traditional ball spline works for a period of time is solved.

Description

Technical Field

[0001] The present invention relates to the field of hydrostatic air bearings, and particularly to a porous medium hydrostatic air spline. Background Art

[0002] With the rapid development of the manufacturing industry, the production efficiency and output of the manufacturing industry are increasing, and the requirements for the service life of mechanical parts in production machines are also getting higher and higher. In order to improve the service life of traditional mechanical parts, rolling contact is generally used to reduce part wear. However, to meet the development of the manufacturing industry, mechanical parts require a higher service life, which means that the part life needs to be improved by changing the contact method. With the discovery of new materials and the research of new technologies, this provides sufficient theoretical support for improving the service life of mechanical parts. Nowadays, the development of hydrostatic lubrication technology is becoming increasingly mature, and many experimental research results have proved its superiority in reducing wear. The application of porous graphite materials in air bearing technology has also achieved practical breakthroughs.

[0003] Hydrostatic lubrication is a lubrication technology that injects gas or liquid externally to form a lubricating oil film or gas film on the lubricating surface, thereby completely separating the two moving surfaces to achieve the effect of reducing friction.

[0004] Air bearing technology has become a hot topic in modern research. For high-speed applications, air bearing technology has shown its great superiority. In a CNC machining center, the use of an air bearing spindle technology for the tool spindle can minimize wear during long-term high-speed operation of the spindle. The air suspension fan that provides power in an aircraft also uses air bearing technology, and the application of air bearing technology in other fields has also attracted more and more attention.

[0005] A spline is a mechanical part that can transmit torque. Because it can transmit high torque, and at the same time has high precision, reliability, good centering and wear resistance, it is widely used in transmission structures. With the continuous improvement of industrial automation, new types of splines such as ball splines have emerged. These new types of splines are no longer restricted to traditional splines. They can complete axial displacement while transmitting torque, which is of great significance for improving the production efficiency of the manufacturing industry. However, ball splines still use the traditional rolling friction method, using the way of balls rolling in grooves to reduce the contact area and thus reduce wear. This method has limitations in improving the part life.

[0006] Traditional hydraulic lubrication technology has now become increasingly mature. The hydraulic oil film can withstand large working loads, and the oily working environment can effectively prevent metal parts from rusting. However, the manufacturing cost of hydraulic lubrication is high. In modern manufacturing production lines, using hydraulic lubrication technology for occasions with small working loads will increase production costs, and liquid leakage will pollute the production environment, making it unsuitable for workplaces with hygiene and safety requirements. This has also drawn more and more extensive attention to the research of new splines with better performance.

[0007] It can be seen that there is sufficient theoretical basis and an obvious development trend to use new technologies to improve ball splines and make them have a longer working life. This is of great significance for improving the production efficiency of the manufacturing industry and meeting the requirements of the production development of the times. Summary of the Invention

[0008] The purpose of the present invention is to provide a porous media hydrostatic air bearing spline, which improves the structure of the traditional ball spline, making it easy to realize the hydrostatic air bearing structure of the spline, reducing the wear during the working process of the spline, increasing the service life of the spline by using air bearing technology, and avoiding the problem that the traditional ball spline is worn during long-term and high-intensity work, affecting the accuracy of the spline.

[0009] To achieve the above object, the technical solution of the present invention is a porous media hydrostatic air bearing spline, including a spline shaft, a spline sleeve outer cylinder, an air bearing, a spline sleeve, a flange sleeve, a flow distribution plate, and a porous media; wherein, the cross-section of the spline shaft is composed of at least three trapezoidal teeth, the spline sleeve is cylindrical, and its internal spline cooperates with the trapezoidal teeth of the spline shaft to form at least three trapezoidal grooves. A gap of 20 - 60 microns is left between the side surfaces of the trapezoidal grooves and the trapezoidal teeth to form an air bearing gap. At least two rectangular mounting grooves are opened on the side surface of each trapezoidal groove, and a porous media is installed in each mounting groove. The porous media forms a hydrostatic pressure gap with the side surface of the trapezoidal teeth of the spline shaft.

[0010] The outer circumference of the spline sleeve is in the shape of a stepped shaft. A plurality of third radial air inlet holes evenly distributed in the circumferential direction are opened on the outer wall of the large cylinder. The third radial air inlet holes are further respectively connected to the third axial air inlet holes, and the third axial air inlet holes are further connected to the mounting grooves through inclined air inlet holes; the spline sleeve outer cylinder is cylindrical, and the outer circumference includes an annular step; the spline sleeve can be installed in the inner hole A of the spline sleeve outer cylinder. A plurality of countersunk through holes evenly distributed in the circumferential direction are opened on the end surface of the large cylinder of the spline sleeve and are fixedly connected by screws with a plurality of threaded holes evenly distributed in the circumferential direction on the spline sleeve outer cylinder.

[0011] The distribution disk is disk-shaped, with a stepped inner hole in the middle, forming an inner hole surface and an inner end surface; distribution grooves are opened on the inner hole surface, and the distribution grooves are a full-circle groove; after assembly, they correspond to at least three third radial air inlet holes of the spline sleeve, and an assembly gap of 10 - 30 micrometers is reserved between the inner hole surface and the outer circular surface of the large cylinder of the spline sleeve to form an air flow resistance; a second annular static pressure cavity is opened on the inner end surface, and a fit gap of 20 - 60 micrometers is reserved between the second annular static pressure cavity and the end surface of the annular step on the outer sleeve of the spline sleeve after assembly to form a static pressure support; a fourth axial air inlet is opened on the end surface of the distribution disk, the fourth axial air inlet communicates with the fourth radial air inlet, the fourth radial air inlet further communicates with the distribution groove and communicates with the second annular static pressure cavity through a branch hole.

[0012] The air bearing includes an air bearing inner ring and an air bearing outer ring. The air bearing inner ring is cylindrical, with an outer circular surface and an annular end surface A. At least three flow splitting grooves are evenly distributed on its outer circular surface, and there is a first annular static pressure cavity on the annular end surface A. The outer sleeve of the spline sleeve can be inserted into the inner hole B of the air bearing inner ring. At least three radial air inlet holes are evenly distributed on each flow splitting groove. A static pressure cavity corresponding to the position of the first radial air inlet hole is provided on the inner hole B of the air bearing inner ring, and the static pressure cavities are respectively communicated with the first radial air inlet holes. A gap of 20 - 60 micrometers is left between the inner hole B of the air bearing inner ring and the outer circular surface of the outer sleeve of the spline sleeve to form a static pressure support; there are first axial air inlet holes on the air bearing inner ring that are respectively communicated with the first radial air inlet holes, and at least three first axial air inlet holes are communicated with the first annular static pressure cavity. After assembly, a fit gap of 20 - 60 micrometers is reserved between the first annular static pressure cavity and the surface of the annular step on the outer sleeve of the spline sleeve to form a static pressure support. The air bearing outer ring is cylindrical, and the air bearing inner ring can be inserted into the inner hole of the air bearing outer ring. Its end surface has a second axial air inlet hole, and the second axial air inlet hole communicates with a plurality of second radial air inlet holes evenly distributed axially. After assembly, the second radial air inlet holes correspond to the positions of the flow splitting grooves of the air bearing inner ring; the flange sleeve is cylindrical, the air bearing outer ring can be inserted into the inner hole C of the flange sleeve, and the flange sleeve is provided with an annular end surface B. At least three evenly distributed axial through holes are further opened on the annular end surface B, and are fixedly connected with at least three evenly distributed bolt holes on the distribution disk through bolts.

[0013] The porous medium of the hydrostatic air floating spline is completely fixed in the installation groove by interference fit; or the porous medium is completely fixed in the installation groove by welding technology in the installation groove.

[0014] The air bearing inner ring of the hydrostatic air floating spline is completely fixed in the air bearing outer ring by interference fit, and the air bearing outer ring is completely fixed in the flange sleeve by interference fit.

[0015] When the hydrostatic air-bearing spline works, the inner ring of the air bearing, the outer ring of the air bearing, the flange sleeve and the flow distribution plate are fixed, the outer sleeve of the spline sleeve and the spline sleeve have rotational freedom, and the spline shaft has both rotational freedom and axial movement freedom.

[0016] The fluid medium of the hydrostatic air-bearing spline is gas. After the gas is introduced from the air inlet, the gas is divided into two paths: Path 1 passes through the second radial air inlet hole of the outer ring of the air bearing, the flow dividing groove of the inner ring of the air bearing and enters the first radial air inlet hole. Here, the gas is divided into two paths. One path passes through the first radial air inlet hole to reach the hydrostatic support gap between the hydrostatic cavity and the small cylinder of the outer sleeve of the spline sleeve; the other path passes through the first radial air inlet hole, the first axial air inlet hole and the first annular hydrostatic cavity of the inner ring of the air bearing in sequence to reach the hydrostatic support gap; another path passes through the second axial air inlet of the outer ring of the air bearing and the fourth axial air inlet hole of the flow distribution plate to reach the fourth radial air inlet hole. Here, the gas is divided into two paths. One path passes through the branch hole and the second annular hydrostatic cavity to reach the hydrostatic support gap; Path 2 passes through the flow distribution groove, the third radial air inlet hole, the third axial air inlet hole, the inclined air inlet hole and the porous medium of the spline sleeve to reach the aerostatic hydrostatic support between the porous medium and the trapezoidal tooth inclined surface on the spline shaft.

[0017] When the hydrostatic air-bearing spline is working, for the circumferential torsional moment applied to the spline shaft, it is borne by the aerostatic hydrostatic support between the porous medium and the trapezoidal tooth inclined surface on the spline shaft; for the radial force applied to the spline shaft, it is borne by the hydrostatic support between the porous medium and the trapezoidal tooth inclined surface on the spline shaft and the hydrostatic support between the hydrostatic cavity on the inner ring of the air bearing and the outer circle of the outer sleeve of the spline sleeve; for the axial load applied to the outer sleeve of the spline sleeve, it is borne by the first annular hydrostatic cavity and the second annular hydrostatic cavity.

[0018] A porous medium hydrostatic gas bearing spline manufactured using the technical solution of the present invention has the following beneficial effects: (1) By adopting hydrostatic gas bearing support, the problem of reduced spline accuracy caused by long-term wear of traditional ball splines is avoided, the service life of the spline is increased, and a porous medium with certain permeability is installed in the installation groove, ensuring that after the gas passes through the porous medium, a stable hydrostatic support is formed on the trapezoidal tooth inclined surface of the spline shaft, which can reduce vibration, impact and noise, and improve the stability of the hydrostatic gas bearing spline during operation; (2) By using gas as the fluid medium, problems such as high manufacturing cost of traditional liquid hydrostatic bearings and liquid leakage polluting the working environment are avoided. The structure of the present invention is small in size and applicable to many occasions, and has good application value and popularization potential; (3) Since the present invention adopts gas bearing support, the outer sleeve of the spline sleeve and the spline sleeve have rotational freedom, and the spline shaft has both rotational freedom and axial movement freedom. Compared with traditional ball splines, the surfaces of the parts in relative motion do not come into contact, and it can be applied to high-speed rotation occasions, avoiding the problem of wear failure of traditional ball splines in high-speed rotation occasions; (4) The gas path configuration method of the present invention realizes the gas distribution of the outer sleeve of the spline sleeve and the spline sleeve with rotational freedom, ensures continuous high-pressure gas supply to the rotating components, solves the problem of winding when the external gas pipe is connected to the air inlet of the rotating component, and provides gas supply guarantee for the realization of the hydrostatic gas bearing spline. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the porous medium hydrostatic gas bearing spline of the present invention;

[0020] Figure 2 It is a cross-sectional view of the porous medium hydrostatic gas bearing spline of the present invention;

[0021] Figure 3 It is a partial enlarged view of the gas bearing support of the outer sleeve of the spline sleeve of the present invention;

[0022] Figure 4 It is a schematic structural diagram of the spline sleeve of the present invention;

[0023] Figure 5 It is a cross-sectional view of the air inlet of the spline sleeve of the present invention;

[0024] Figure 6 It is a cross-sectional view of the air outlet of the spline sleeve of the present invention;

[0025] Figure 7 It is a schematic structural diagram of the outer sleeve of the spline sleeve of the present invention;

[0026] Figure 8 It is a schematic structural diagram of the flow distribution plate of the present invention;

[0027] Figure 9 It is a cross-sectional view of the flow distribution plate of the present invention;

[0028] Figure 10 Schematic diagram of the air bearing structure of the present invention;

[0029] Figure 11 Cross-sectional view of the air bearing of the present invention;

[0030] Figure 12 Axial sectional view of the air bearing of the present invention;

[0031] Figure 13 Schematic diagram of the flange sleeve structure of the present invention.

[0032] In the above figures,

[0033] 1. Spline shaft; 101. Trapezoidal teeth;

[0034] 2. Outer sleeve of spline sleeve; 201. Annular step; 202. Threaded hole; 203. Inner hole A; 204. Outer circle;

[0035] 3. Air bearing; 31. Inner ring of air bearing; 311. Outer cylindrical surface; 312. Shunt groove; 313. Inner hole B; 314. First radial air inlet hole; 315. First axial air inlet hole; 316. First annular static pressure cavity; 317. Annular end face A; 318. Static pressure cavity; 32. Outer ring of air bearing; 321. Second axial air inlet hole; 322. Second radial air inlet hole;

[0036] 4. Spline sleeve; 401. Trapezoidal groove; 402. Side face of trapezoidal groove; 403. Installation groove; 404. Small cylinder; 405. Large cylinder; 406. Third radial air inlet hole; 407. Third axial air inlet hole; 408. Oblique air inlet hole; 409. Countersunk through hole;

[0037] 5. Flange sleeve; 501. Inner hole C; 502. Annular end face B; 503. Through hole;

[0038] 6. Flow distribution plate; 601. Inner hole surface; 602. Inner end face; 603. Flow distribution groove; 604. Second annular static pressure cavity; 605. Fourth axial air inlet hole; 606. Fourth radial air inlet hole; 607. Branch hole; 608. Bolt hole;

[0039] 7. Porous medium. Specific embodiments

[0040] To further illustrate the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific embodiments, structures, features and their effects of the present invention as follows:

[0041] A porous medium hydrostatic air float spline, as Figure 1-2As shown, it includes a spline shaft 1, a spline sleeve outer cylinder 2, an air bearing 3, a spline sleeve 4, a flange sleeve 5, a flow distribution plate 6, and a porous medium 7. Among them, the cross-section of the spline shaft 1 is as Figure 5 shown, and it is composed of 6 trapezoidal teeth 101. The spline sleeve 4 is cylindrical, and its structure is as Figures 4 to 6 shown. An internal spline is provided on it, and the internal spline cooperates with the 6 trapezoidal teeth 101 of the spline shaft 1 to form 6 trapezoidal grooves 401. A gap of 20 - 60 microns is left between the side surface of the trapezoidal groove 401 and the side surface of the trapezoidal tooth 101 to form an air floating gap 14 - 1. Three mounting grooves 403 are opened on the side surface 402 of each trapezoidal groove 401. The mounting grooves 403 are rectangular, and a porous medium 7 is installed in each mounting groove 403. The porous medium 7 forms a hydrostatic gap with the side surface of the trapezoidal tooth 101 of the spline shaft 1.

[0042] Furthermore, as Figures 4-6 shown, the outer circumference of the spline sleeve 4 is in the shape of a stepped shaft, including a small cylinder 404 and a large cylinder 405. Six evenly distributed third radial air inlet holes 406 are radially opened on the outer wall of the large cylinder 405. The third radial air inlet holes 406 are further respectively connected to the third axial air inlet holes 407, and the third axial air inlet holes 407 are further connected to the mounting grooves 403 through inclined air inlet holes 408.

[0043] Furthermore, as Figure 7 shown, the spline sleeve outer cylinder 2 is cylindrical, and its outer circumference includes an annular step 201. The spline sleeve 4 can be inserted into the inner hole A203 of the spline sleeve outer cylinder 2. Six circumferentially evenly distributed counterbore through holes 409 are opened on the end face of the large cylinder 405 of the spline sleeve 4, and are fixedly connected to the six circumferentially evenly distributed threaded holes 202 on the spline sleeve outer cylinder 2 through screws.

[0044] Furthermore, as Figures 8-9 shown, the flow distribution plate 6 is disc-shaped, with a stepped inner hole in the middle, forming an inner hole surface 601 and an inner end face 602. Flow distribution grooves 603 are opened on the inner hole surface 601, and the flow distribution grooves 603 are integral circular grooves. After assembly, they correspond to the positions of the six third radial air inlet holes 406 of the spline sleeve 4. A mounting gap of 10 - 30 microns is reserved between the inner hole surface 601 and the outer circular surface of the large cylinder 405 of the spline sleeve 4 to form an air flow resistance. A second annular hydrostatic cavity 604 is opened on the inner end face 602. After assembly, a fitting gap of 20 - 60 microns is reserved between the second annular hydrostatic cavity 604 and the end face of the annular step 201 on the spline sleeve outer cylinder 2 to form a hydrostatic support. A fourth axial air inlet 605 is opened on the end face of the flow distribution plate 6. The fourth axial air inlet 605 is connected to the fourth radial air inlet 606, and the fourth radial air inlet 606 is further connected to the flow distribution grooves 603 and is connected to the second annular hydrostatic cavity 604 through branch holes 607.

[0045] Furthermore, asFigures 10-12 As shown in the figure, the air bearing 3 includes an inner air bearing ring 31 and an outer air bearing ring 32. The inner air bearing ring 31 is cylindrical, and there is a first annular static pressure chamber 316 on its annular end face A317. The spline sleeve outer sleeve 2 can be inserted into the inner hole B313 of the inner air bearing ring 31. There are 3 equally distributed flow dividing grooves 312 on the outer cylindrical surface 311, and 6 first radial air inlet holes 314 are equally distributed on each flow dividing groove 312. There are multiple static pressure chambers 318 on the inner hole B313, and the static pressure chambers 318 are respectively communicated with the first radial air inlet holes 314. There is a gap of 20 - 60 microns between the inner hole B313 of the inner air bearing ring 31 and the outer cylindrical surface 204 of the spline sleeve outer sleeve 2, forming an air floating gap 23 - 1 to form a static pressure support; there are 6 first axial air inlet holes 315 on the inner air bearing ring 31 that are respectively communicated with the 6 first radial air inlet holes 314, and the 6 first axial air inlet holes 315 are communicated with the first annular static pressure chamber 316. After assembly, a mating gap 23 - 2 of 20 - 60 microns is reserved between the annular end face A317 and the surface 205 of the annular step 201 on the spline sleeve outer sleeve 2 to form a static pressure support. The outer air bearing ring 32 is cylindrical, and the inner air bearing ring 31 can be inserted into the inner hole of the outer air bearing ring 32. There is a second axial air inlet hole 321 on its end face, and the second axial air inlet hole 321 is communicated to 3 axially equally distributed second radial air inlet holes 322. After assembly, the positions of the second radial air inlet holes 322 correspond to the flow dividing grooves 312 of the inner air bearing ring 31.

[0046] Furthermore, as Figure 13 shown, the flange sleeve 5 is cylindrical, the outer air bearing ring 32 can be inserted into the inner hole C501 of the flange sleeve 5, and there is an annular end face B502 on the outer circumference of the flange sleeve 5. Further, 6 equally distributed axial through holes 503 are opened on the annular end face B502 and are fixedly connected by bolts to the 6 equally distributed bolt holes 608 on the flow distribution disk 6.

[0047] In the porous - medium static - pressure air - floating spline of the present invention, when working, the inner air bearing ring 31, the outer air bearing ring 32, the flange sleeve 5, and the flow distribution disk 6 are fixed, the spline sleeve outer sleeve 2 and the spline sleeve 4 have rotational freedom, and the spline shaft 1 has both rotational freedom and axial movement freedom. When working, the gas - flow path is as follows: gas enters from the second axial air inlet 321 of the outer air bearing ring 32, and the gas is divided into two paths:

[0048] One path passes through the second radial air inlet holes 322 of the outer air bearing ring 32, the flow dividing grooves 312 of the inner air bearing ring 31, and enters the first radial air inlet holes 314. Here, the gas is divided into two paths. One path reaches the air - floating gap 23 - 1 through the first radial air inlet holes 314; the other path sequentially passes through the first radial air inlet holes 314, the first axial air inlet holes 315, and the first annular static pressure chamber 316 of the inner air bearing ring 31 to reach the static - pressure support gap 23 - 2.

[0049] The other path passes through the second axial air inlet 321 of the outer ring 32 of the air bearing, the fourth axial air inlet hole 605 of the flow distribution disk 6 to reach the fourth radial air inlet hole 606. Here, the gas is divided into two paths. One path passes through the branch hole 607 and the second annular static pressure cavity 604 to reach the static pressure bearing clearance 26-1. The other path passes through the flow distribution groove 603, the third radial air inlet hole 406, the third axial air inlet hole 407, the inclined air inlet hole 408 of the spline sleeve 4, and the porous medium 7 to reach the aerostatic bearing between the porous medium 7 and the inclined surface of the trapezoidal tooth 101 on the spline shaft 1.

[0050] Such an air path configuration realizes the gas flow distribution of the outer sleeve 2 of the spline sleeve and the spline sleeve 4 with rotational freedom, ensures the continuous high-pressure gas supply to the rotating components, solves the problem of winding when the external air pipe is connected to the air inlet of the rotating component, and provides an air supply guarantee for the realization of the aerostatic spline.

[0051] During operation, the aerostatic spline with porous medium of the present invention can drive the rotation of the outer sleeve 2 of the spline sleeve through transmission by a motor or a hydraulic motor, etc. Through the reciprocating movement of a cylinder or a hydraulic cylinder, or by means of a lead screw-nut transmission, etc., the rotation is converted into a reciprocating movement to drive the spline shaft 1 to achieve axial movement. For the circumferential torque applied to the spline shaft 1, it is borne by the static pressure bearing between the porous medium 7 and the inclined surface of the trapezoidal tooth 101 on the spline shaft 1. For the radial force applied to the spline shaft 1, it is borne by the static pressure bearing between the porous medium 7 and the inclined surface of the trapezoidal tooth 101 on the spline shaft 1 and the static pressure bearing between the static pressure cavity 318 on the inner ring 31 of the air bearing and the outer circle 204 of the outer sleeve 2 of the spline sleeve. For the axial load applied to the outer sleeve 2 of the spline sleeve, it is borne by the first annular static pressure cavity 316 and the second annular static pressure cavity 604. During the rotation process of the outer sleeve 2 of the spline sleeve and the spline sleeve 4, and during the rotation or axial movement process of the spline shaft 1, full static pressure air floating support is achieved on each movement mating interface, which has the advantages of no contact, no friction, high service life, can be applied to occasions requiring high-speed rotation and axial movement, low cost, no pollution, small structural size, and simple installation.

[0052] The porous medium static pressure air floating spline of the present embodiment adopts static pressure air floating support, which avoids the problem of reduced spline precision caused by long-term wear of traditional ball splines and improves the service life of the splines. A porous medium with a certain permeability is installed in the installation groove to ensure that after the gas passes through the porous medium, a stable static pressure support is formed on the trapezoidal tooth slope of the spline shaft, which can reduce vibration impact and noise and improve the stability of the static pressure air floating spline during operation; using gas as the fluid medium avoids the high manufacturing cost of traditional liquid static pressure supports, liquid leakage and environmental pollution and other problems. The present invention has a small structural size, is applicable to many occasions, and can be better promoted and applied; Because the invention adopts air floating support, the outer sleeve of the spline sleeve and the spline sleeve have rotational freedom, and the spline shaft has both rotational freedom and axial movement freedom. Compared with the traditional ball spline, the surfaces of parts that undergo relative motion will not contact each other, and it can be used in high-speed rotation occasions; the air path configuration method of the present invention realizes the gas distribution of the outer sleeve of the spline sleeve and the spline sleeve with rotational freedom, ensures the continuous high-pressure gas supply of the rotating parts, solves the entanglement problem when the external air pipe is connected to the air inlet of the rotating parts, and provides air supply guarantee for the realization of static pressure air floating splines, which is of great significance for improving the service life of the splines and improving the production efficiency of the manufacturing production line.

[0053] The present invention is described above with reference to the preferred embodiments, but the protection scope of the present invention is not limited thereto. Various improvements can be made to the embodiments and parts thereof can be replaced with equivalents without departing from the scope of the present invention. As long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way, and any figure mark in the claims should not be regarded as limiting the claims involved. No matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. Therefore, all technical solutions falling within the scope of the claims are within the protection scope of the present invention.

Claims

1. A porous medium hydrostatic gas-lubricated spline, characterized in that It includes a spline shaft (1), a spline sleeve outer cylinder (2), an air bearing (3), a spline sleeve (4), a flange sleeve (5), a flow distribution plate (6) and a porous medium (7); wherein: The cross-section of the spline shaft (1) is composed of at least three trapezoidal teeth (101). The spline sleeve (4) is cylindrical, and its internal spline cooperates with at least three trapezoidal teeth (101) of the spline shaft (1) to form at least three trapezoidal grooves (401). A gap of 20 - 60 microns is left between the side surface of the trapezoidal groove (401) and the side surface of the trapezoidal tooth (101) to form an air floating gap (14 - 1). At least two rectangular mounting grooves (403) are opened on the side surface (402) of each trapezoidal groove (401), and a porous medium (7) is installed in each mounting groove (403). The porous medium (7) and the side surface of the trapezoidal tooth (101) of the spline shaft (1) form a hydrostatic pressure gap; The outer circumference of the spline sleeve (4) is in the shape of a stepped shaft. A plurality of third radial air inlet holes (406) evenly distributed in the circumferential direction are opened on the outer wall of the large cylinder (405). The third radial air inlet holes (406) are further respectively connected to the third axial air inlet holes (407), and the third axial air inlet holes (407) are further connected to the mounting groove (403) through the inclined air inlet holes (408); The spline sleeve outer cylinder (2) is cylindrical, and its outer circumference includes an annular step (201); the spline sleeve (4) can be inserted into the inner hole A (203) of the spline sleeve outer cylinder (2). At least three counterbore through holes (409) evenly distributed in the circumferential direction are opened on the end surface of the large cylinder (405) of the spline sleeve (4), and are fixedly connected by screws to at least three threaded holes (202) evenly distributed in the circumferential direction on the spline sleeve outer cylinder (2); The flow distribution plate (6) is disc-shaped, with a stepped inner hole in the middle, forming an inner hole surface (601) and an inner end surface (602); a flow distribution groove (603) is opened on the inner hole surface (601), and the flow distribution groove (603) is a whole - circle groove; after assembly, it corresponds to the positions of at least three third radial air inlet holes (406) of the spline sleeve (4). An assembly gap of 10 - 30 microns is reserved between the inner hole surface (601) and the outer circular surface of the large cylinder (405) of the spline sleeve (4) to form an air flow resistance; a second annular hydrostatic pressure cavity (604) is opened on the inner end surface (602). After assembly, a fitting gap of 20 - 60 microns is reserved between the second annular hydrostatic pressure cavity (604) and the end surface of the annular step (201) on the spline sleeve outer cylinder (2) to form a hydrostatic support; a fourth axial air inlet (605) is opened on the end surface of the flow distribution plate (6). The fourth axial air inlet (605) is connected to the fourth radial air inlet (606), and the fourth radial air inlet (606) is further connected to the flow distribution groove (603) and is connected to the second annular hydrostatic pressure cavity (604) through a branch hole (607).

2. The porous media hydrostatic gas bearing spline according to claim 1, wherein The air bearing (3) includes an inner air bearing ring (31) and an outer air bearing ring (32). The inner air bearing ring (31) is cylindrical, and is provided with an outer cylindrical surface (311) and an annular end face A (317). A plurality of flow dividing grooves (312) are evenly distributed on its outer cylindrical surface (311), and a first annular hydrostatic chamber (316) is provided on the annular end face (317). The spline sleeve outer cylinder (2) can be inserted into the inner hole B (313) of the inner air bearing ring (31). At least three first radial air inlet holes (314) are evenly distributed on each flow dividing groove (312). A plurality of hydrostatic chambers (318) are formed on the inner hole B (313). The hydrostatic chambers (318) are respectively communicated with the first radial air inlet holes (314). A gap of 20-60 microns is left between the inner hole B (313) of the inner air bearing ring (31) and the outer cylinder (204) of the spline sleeve outer cylinder (2) to form an air floating gap (23-1). At least three first axial air inlet holes (315) are provided on the inner air bearing ring (31) and are respectively communicated with at least three first radial air inlet holes (314). At least three first axial air inlet holes (315) are communicated with the first annular hydrostatic chamber (316). After assembly, a fitting gap (23-2) of 20-60 microns is reserved between the first annular hydrostatic chamber (316) and the surface (205) of the annular step (201) on the spline sleeve outer cylinder (2) to form a hydrostatic support. The outer air bearing ring (32) is cylindrical, and the inner air bearing ring (31) can be inserted into the inner hole of the outer air bearing ring (32). Its end face is provided with a second axial air inlet hole (321), and the second axial air inlet hole (321) is communicated with a plurality of second radial air inlet holes (322) evenly distributed axially. After assembly, the positions of the second radial air inlet holes (322) correspond to those of the flow dividing grooves (312) of the inner air bearing ring (31).

3. A porous medium hydrostatic gas-lubricated spline according to claim 1, characterized in that, The flange sleeve (5) is cylindrical, and the outer air bearing ring (32) can be inserted into the inner hole C (501) of the flange sleeve (5). An annular end face B (502) is provided on the circumference outside the flange sleeve (5). At least three evenly distributed axial through holes (503) are further formed on the annular end face B (502), and are fixedly connected by bolts with at least three evenly distributed bolt holes (608) on the flow distribution disk (6).

4. A porous medium hydrostatic air bearing spline according to claim 1, wherein, The porous medium (7) is completely fixed in the installation groove (403) by interference fit; or the porous medium (7) is completely fixed in the installation groove (403) by welding technology in the installation groove (403).

5. A porous medium hydrostatic gas-lubricated spline according to claim 1, characterized in that, The inner air bearing ring (31) is completely fixed in the outer air bearing ring (32) by interference fit, and the outer air bearing ring (32) is completely fixed in the flange sleeve (5) by interference fit.

6. A porous medium hydrostatic gas-lubricated spline according to claim 1, wherein The spline sleeve (4) is completely fixed in the spline sleeve outer cylinder (2) by screw connection, and the flange sleeve (5) and the flow distribution disk (6) are completely fixed by bolt connection.

7. A porous medium hydrostatic gas-lubricated spline according to claim 1, wherein The fluid medium of the porous medium hydrostatic air floating spline is gas.

8. A porous medium hydrostatic gas-lubricated spline according to claim 1, wherein When the porous media hydrostatic gas-lubricated spline works, the inner ring (31) of the air bearing, the outer ring (32) of the air bearing, the flange sleeve (5) and the flow distribution plate (6) are fixed, the outer sleeve (2) of the spline sleeve and the spline sleeve (4) have rotational freedom, and the spline shaft (1) has both rotational freedom and axial movement freedom.

9. A porous medium hydrostatic gas-lubricated spline according to claim 1, characterized in that, After the gas is introduced into the porous media hydrostatic gas-lubricated spline through the second axial air inlet (321), the gas is divided into two paths: Path 1 passes through the second radial air inlet hole (322) of the outer ring (32) of the air bearing, the flow dividing groove (312) of the inner ring (31) of the air bearing and enters the first radial air inlet hole (314). Here, the gas is divided into two paths. One path passes through the first radial air inlet hole (314) to reach the air-lubricated clearance (23-1); the other path passes through the first radial air inlet hole (314), the first axial air inlet hole (315) and the first annular hydrostatic cavity (316) of the inner ring (31) of the air bearing in sequence to reach the hydrostatic bearing clearance (23-2); Path 2 passes through the second axial air inlet (321) of the outer ring (32) of the air bearing and the fourth axial air inlet hole (605) of the flow distribution plate (6) to reach the fourth radial air inlet hole (606). Here, the gas is divided into two paths. One path passes through the branch hole (607) and the second annular hydrostatic cavity (604) to reach the hydrostatic bearing clearance (26-1); the other path passes through the flow distribution groove (603), the third radial air inlet hole (406), the third axial air inlet hole (407), the inclined air inlet hole (408) and the porous media (7) to reach the hydrostatic air-lubricated bearing between the porous media (7) and the inclined surface of the trapezoidal tooth (101) on the spline shaft (1).

10. A porous medium hydrostatic gas-lubricated spline according to claim 1, characterized in that, For the circumferential torque applied to the spline shaft (1), it is borne by the hydrostatic air-lubricated bearing between the porous media (7) and the inclined surface of the trapezoidal tooth (101) on the spline shaft (1); for the radial force applied to the spline shaft (1), it is borne by the hydrostatic bearing between the porous media (7) and the inclined surface of the trapezoidal tooth (101) on the spline shaft (1) and the hydrostatic bearing between the hydrostatic cavity (318) on the inner ring (31) of the air bearing and the outer circle (204) of the outer sleeve (2) of the spline sleeve; for the axial load applied to the outer sleeve (2) of the spline sleeve, it is borne by the first annular hydrostatic cavity (316) and the second annular hydrostatic cavity (604).

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