CN209469912U - A kind of air bearing rotary joint - Google Patents

Abstract

The utility model discloses a kind of air bearing rotary joints, including outer barrel, the bracket being connected on outer barrel and it is mounted on the intracorporal mandrel of outer cylinder, the mandrel is the hollow structure for being provided with fluid flow passageway, the first pipe passage and the second pipe passage are provided on the outer barrel, both first pipe passage and the second pipe passage are mutually independent fluid flow passageway, and wherein one end of the two is respectively positioned on the outside of outer barrel；The mandrel and outer barrel clearance fit, in described the two, the other end of one of them is communicated with the gap between mandrel and outer barrel, and the other end of another one is communicated with the fluid flow passageway on mandrel.This rotary joint overcomes the deficiency that kinematic accuracy existing for conventional rotation joints is poor, abrasion is larger, vibration is stronger etc., can effectively improve the kinematic accuracy and service life of rotary joint.

Description

A kind of air bearing rotary joint

Technical field

The utility model relates to precision component processing technique fields, more particularly to a kind of air bearing rotary joint.

Background technique

In precision and ultra-precision machining lathe, in order to reduce influence of the chucking power to processing element precision, it is often used clamping Power is small and uniform vacuum attracting instrument is as fixture.In order to form vacuum, generally require to be applied to rotary joint as component.

Rotary joint is that the connection for making fluid media (medium) (liquid, gas etc.) circulate in static duct and slewing seals Part has a wide range of applications in the precision machinery process unit of such as numerical control machining center one kind.With manufacturing development, Industry also continue to optimize rotary joint structure design, as Chinese patent (103047501 B of CN) discloses one kind can be same When connection inflator and vacuum pump, inflation path it is parallel with evacuated path and evenly around rotation axis, with compared with high sealing The gas rotary joint of property.

The structure for advanced optimizing rotary joint is designed so that it can preferably serve part processing, is this field Technical staff's technical problem urgently to be resolved.

The rotary joint does not consider the problems of kinematic accuracy using mechanical rolling bearing,

The attainable requirement on machining accuracy of above-mentioned machining device institute is higher and higher, the required precision to all parts It is promoted therewith.The revolute of conventional rotation joints is mostly using mechanical bearing as bearing, and contact is rigid mostly, no Avoidable ground can generate friction and fever, and rigid structure can not effectively obstruct the vibration of mechanical structure, constrain rotation and connect The kinematic accuracy and service life of head generate large effect for the rotating accuracy of main shaft.

Chinese patent (103047501 B of CN) discloses one kind can connect inflator and vacuum pump, inflation path simultaneously It is parallel with evacuated path and evenly around rotation axis, with the gas rotary joint compared with high leakproofness.The rotary joint is adopted With mechanical rolling bearing, kinematic accuracy is not considered the problems of.

Utility model content

It is designed so that it can preferably serve zero for the structure for advanced optimizing rotary joint set forth above The problem of part processing is those skilled in the art's technical problem urgently to be resolved, the utility model provide a kind of air bearing rotation Adapter.This rotary joint overcomes that kinematic accuracy existing for conventional rotation joints is poor, abrasion is larger, vibration is stronger etc. no Foot, can effectively improve the kinematic accuracy and service life of rotary joint.

In view of the above-mentioned problems, a kind of air bearing rotary joint provided by the utility model solves to ask by following technical essential Topic: a kind of air bearing rotary joint including outer barrel, the bracket being connected on outer barrel and is mounted on the intracorporal mandrel of outer cylinder, The mandrel is the hollow structure for being provided with fluid flow passageway, and the first pipe passage and are provided on the outer barrel Two pipe passages, both first pipe passage and the second pipe passage are mutually independent fluid flow passageway, and the two Wherein one end be respectively positioned on the outside of outer barrel；

The mandrel and outer barrel clearance fit, in described the two, the other end of one of them be located at mandrel and outer cylinder Gap between body communicates, and the other end of another one is communicated with the fluid flow passageway on mandrel.

Specifically, arrangement above are as follows: both first pipe passage and the second pipe passage are mutually independent fluid Circulation passage, i.e., above first pipe passage and the second pipe passage are the pipeline being arranged on outer barrel, and two pipelines Middle fluid is not interfere with each other.

When specifically used, the end of the mandrel is connected with lathe spindle, bracket and lathe outer end cap or outer housing phase Even, and the nozzle negative pressure extracting channel corresponding on lathe spindle of mandrel upper fluid circulation passage connects, the first pipe passage With in both the second pipe passages, one of them connects pressure source, such as compresses gas bottle, compressor, another one connection vacuum Pump, and one of be connected with pressure source and to be communicated with the gap, the fluid flow passageway one of being connected with vacuum pump with mandrel It communicates, so that corresponding vacuum attracting instrument obtains the adsorption capacity of constraint parts to be processed on lathe spindle.Using the above connection scheme, In lathe spindle rotation, mandrel is as the rotary part on this rotary joint, and outer barrel is as static on this rotary joint Component.Therefore for the corresponding fluids adapter tube outside outer barrel, this programme is easy to connect with adapter tube, corresponding connection structure is simple, And adapter tube connects reliable feature.In the prior art, the revolute of conventional rotation joints is mostly using mechanical bearing as branch It holds, contact is rigid mostly, inevitably results from friction and fever, while rigid structure can not effectively obstruct machinery The vibration of structure constrains the kinematic accuracy and service life of rotary joint, therefore conventional rotation joints are when in use, for master The rotating accuracy of axis is with centainly influencing, in this way, it is excellent to be unfavorable for that accurate, super-precision machine tools embody its machining accuracy Gesture.In the present solution, pressure medium, such as compressed gas are introduced into the gap by the correspondence one in both of the above, due to Outer barrel is set in the outside of mandrel by centre bore thereon, therefore the above gap is actually the ring between mandrel and outer barrel Shape gap, in this way, the medium in the above gap can be traditional to replace with contactless hydrostatic support by pneumatically supported mode Bearing based on mechanical contact can effectively avoid because by Mechanical Contact in traditional rotary joint in this way, using this programme The problems such as introducing frictional dissipation, fever deformation and vibration, thus reach improve the kinematic accuracy of rotary joint, service life and The purpose of spindle rotation accuracy；Meanwhile higher feature is supported compared to contact based on air bearing support accuracy itself, it can also protect Demonstrate,prove the rotating accuracy of main shaft.

As those skilled in the art, due to realizing that the above pneumatically supported air gap is located at the outside of mandrel, therefore prolonged by outer barrel One of fluid flow passageway in mandrel is extended to need across air gap, it, can be by outside when realizing both described mutually indepedent Ring type seal is set between on the inside of cylinder and on the outside of mandrel, the gap is isolated into positioned at mandrel not by the above ring type seal The region of coaxial position, part of the partial region therein as one of them in described the two, other regions are as institute The region of another one in the two is stated, i.e., the above ring type seal is for realizing the isolation of both of the above or as both of the above Boundary.

Further technical solution are as follows:

As the specific implementation of outer barrel, the outer barrel includes tubular current divider and throttle sleeve, institute The outside that current divider is set in throttle sleeve is stated, mandrel clearance fit is in the inner hole of throttle sleeve, and current divider and throat bushing There is first annular chamber annular in shape between cylinder, the first annular chamber as the part one of communicated with the gap, and The through-hole in its interior outside of multiple perforations, connection of each through-hole as the gap and first annular chamber are additionally provided on throttle sleeve Channel.Using this programme, mandrel in the radial direction, respectively mandrel, throttle sleeve and current divider, are set as from the inside to the outside Including the first annular chamber, the above first annular chamber is being uniformly distributed for realizing pressure medium: realizing that the air bearing needs It wants the gap to have multiple entrances, while there is outlet, and consider the volume of outer barrel, should not only be set on the outside of outer barrel Multiple pipe fittings are set, while being such as set as including multiple pipe fittings, different through-holes are identical as different pipe fittings, are also possible to out in this way Existing through-hole respectively in the excessive situation of pressure difference between pressure medium, and this situation be detrimental to generate it is stable pneumatically supported, therefore Based on this, using above scheme, as first annular cavity pressure medium introducing port only one to facilitate setting pipe fitting In the case of, by the first annular chamber, aloows multiple through-holes to obtain pressure difference pressure as small as possible between each other and be situated between Matter is realized such as compressed gas and reliable contactless presses bearing.

The flow of pressure medium, setting are as follows: section is mounted in each through-hole are introduced into the gap for accurate each through-hole Stream plug, the fluid negotiability of through-hole where the orifice plug is used to control.

For the pressure difference for further decreasing pressure medium obtained in multiple through-holes, setting are as follows: also set up on the current divider There are axial hole, radial hole and the first nipple orifice, one end of first nipple orifice is located at the outside of current divider, first connector The other side in hole is communicated with axial hole, intercommunicating pore of the radial hole as axial hole and first annular chamber, and radial hole is more It is a.Using this programme, radial hole can be drilled along the radial direction of current divider by drilling axial hole by the end of current divider, The axial hole can be the through-hole of perforation flow diverter side wall, and radial hole for the through-hole at perforation current divider both ends, the radial hole Intersect with axial hole, after completion radial hole drills, aperture of the radial hole on the outside of current divider blocked using such as end socket, The aperture of axial hole is blocked using such as end socket simultaneously, in this way, introducing pressure in through the first nipple orifice in the axial direction hole After medium, it can make first annular chamber that there are multiple pressure medium introduction points by axial hole, above multiple pressure mediums introduce Point may make first annular intracavitary each point pressure difference smaller, in the multiple through-holes being directed on throttle sleeve, may make by each logical There is smaller pressure difference between the pressure medium that hole is introduced into the gap.

Pressure medium is introduced into the first nipple orifice for convenience, and guarantees the reliability of the first connector hole location sealing, Setting are as follows: the first pipe fitting is also connected in first nipple orifice, and the first nipple orifice and the first pipe fitting pass through pipe screw thread Connection.

As noted previously, as needing duct to be arranged on the side wall of mandrel to realize to be the fluid flow passageway of mandrel Negative pressure is vacuumized or extracted, therefore is actually to need to open up corresponding duct on the side wall of mandrel, institute can be optimized as one kind The fluid negotiability in duct is stated, while the above duct being made to generate the technical side that less force performance influences on mandrel as far as possible Case, setting are as follows: also there is the second annular chamber, second annular chamber is made between the inner wall of the throttle sleeve and the outer wall of mandrel For the part one of communicated with the fluid flow passageway on mandrel；

The duct in its interior outside of multiple perforations is additionally provided on the side wall of mandrel, each duct is as the fluid flow passageway With the communicating passage of the second annular chamber.This programme in the specific implementation, more than second annular chamber and the gap can pass through The ring type seal of offer is as boundary, it may be assumed that projection of second annular chamber on mandrel axis covers all ducts in mandrel axis Projection on line, in this way, setting duct can be reduced by multiple ducts on influence caused by mandrel mechanical property, while multiple Duct collective effect realizes the vacuum drawn of mandrel upper fluid circulation passage to facilitate.

To avoid duct from causing mandrel centre-of gravity shift, and mandrel is made to generate bigger amplitude, the duct in rotation Axis annular around mandrel is uniformly distributed, and duct is located at the same axial location of mandrel.

It is reliable for convenience of connecting negative pressure equipment and the negative pressure equipment tie point position on current divider being made to be easier to acquisition Sealing effect, setting are as follows: further include the second pipe fitting being connected to by pipe screw thread on current divider, the second pipe fitting conduct The pipe fitting one of communicated with the fluid flow passageway on mandrel.

To make this rotary joint, structure is more compact at work, to improve the rotating accuracy of mandrel, setting are as follows: described Bracket is in the form of annular discs, and bracket, current divider, throttle sleeve three are coaxial, and one end of current divider is fixed on bracket, further includes setting In the end casing of the current divider other end, the end casing is as the connecting plate between current divider and throttle sleeve.

As noted previously, as required gap needs to be vented in the work of this connector, it is easily fabricated as one kind, and It can intuitively reflect the implementation of pressure medium working condition in the gap, be arranged are as follows: the end casing is in the form of annular discs, and holds Cover board is connect with current divider and the equal screw of throttle sleeve.

The utility model has the following beneficial effects:

When specifically used, the end of the mandrel is connected with lathe spindle, bracket and lathe outer end cap or outer housing phase Even, and the nozzle negative pressure extracting channel corresponding on lathe spindle of mandrel upper fluid circulation passage connects, the first pipe passage With in both the second pipe passages, one of them connects pressure source, such as compresses gas bottle, compressor, another one connection vacuum Pump, and one of be connected with pressure source and to be communicated with the gap, the fluid flow passageway one of being connected with vacuum pump with mandrel It communicates, so that corresponding vacuum attracting instrument obtains the adsorption capacity of constraint parts to be processed on lathe spindle.Using the above connection scheme, In lathe spindle rotation, mandrel is as the rotary part on this rotary joint, and outer barrel is as static on this rotary joint Component.Therefore for the corresponding fluids adapter tube outside outer barrel, this programme is easy to connect with adapter tube, corresponding connection structure is simple, And adapter tube connects reliable feature.In the prior art, the revolute of conventional rotation joints is mostly using mechanical bearing as branch It holds, contact is rigid mostly, inevitably results from friction and fever, while rigid structure can not effectively obstruct machinery The vibration of structure constrains the kinematic accuracy and service life of rotary joint, therefore conventional rotation joints are when in use, for master The rotating accuracy of axis is with centainly influencing, in this way, it is excellent to be unfavorable for that accurate, super-precision machine tools embody its machining accuracy Gesture.In the present solution, pressure medium, such as compressed gas are introduced into the gap by the correspondence one in both of the above, due to Outer barrel is set in the outside of mandrel by centre bore thereon, therefore the above gap is actually the ring between mandrel and outer barrel Shape gap, in this way, the medium in the above gap can be traditional to replace with contactless hydrostatic support by pneumatically supported mode Bearing based on mechanical contact can effectively avoid because by Mechanical Contact in traditional rotary joint in this way, using this programme The problems such as introducing frictional dissipation, fever deformation and vibration, thus reach improve the kinematic accuracy of rotary joint, service life and The purpose of spindle rotation accuracy；Meanwhile higher feature is supported compared to contact based on air bearing support accuracy itself, it can also protect Demonstrate,prove the rotating accuracy of main shaft.

Detailed description of the invention

Fig. 1 is a kind of structural upright schematic diagram of one specific embodiment of air bearing rotary joint described in the utility model；

Fig. 2 is a kind of structure sectional view of one specific embodiment of air bearing rotary joint described in the utility model, and edge The direction A-A shown in Fig. 3 carry out section view；

Fig. 3 is a kind of top view or side view of one specific embodiment of air bearing rotary joint described in the utility model.

Figure acceptance of the bid, which is remembered, is respectively as follows: 1, end casing, 2, current divider, 3, throttle sleeve, 4, bracket, 5, mandrel, 6, orifice plug, 7, First pipe fitting, the 8, second pipe fitting.

Specific embodiment

Below with reference to embodiment, the utility model is described in further detail, but the utility model be not limited only to Lower embodiment:

Embodiment 1:

As shown in Figure 1 to Figure 3, a kind of air bearing rotary joint, including outer barrel, the bracket being connected on outer barrel 4 and It is mounted on the intracorporal mandrel 5 of outer cylinder, the mandrel 5 is the hollow structure for being provided with fluid flow passageway, the outer barrel On be provided with the first pipe passage and the second pipe passage, both first pipe passage and the second pipe passage are mutually solely Vertical fluid flow passageway, and wherein one end of the two is respectively positioned on the outside of outer barrel；

The mandrel 5 and outer barrel clearance fit, in described the two, the other end of one of them be located at mandrel 5 and outer Gap between cylinder communicates, and the other end of another one is communicated with the fluid flow passageway on mandrel 5.

Specifically, arrangement above are as follows: both first pipe passage and the second pipe passage are mutually independent fluid Circulation passage, i.e., above first pipe passage and the second pipe passage are the pipeline being arranged on outer barrel, and two pipelines Middle fluid is not interfere with each other.

When specifically used, the end of the mandrel 5 is connected with lathe spindle, bracket 4 and lathe outer end cap or outer housing It is connected, and the nozzle negative pressure extracting channel corresponding on lathe spindle of 5 upper fluid circulation passage of mandrel connects, the first pipeline is logical In both road and the second pipe passage, one of them connects pressure source, such as compression gas bottle, compressor, and another one connection is true Sky pump, and one of be connected with pressure source and to communicate with the gap one of is connected to circulate with the fluid of mandrel 5 with vacuum pump and lead to Road communicates, so that corresponding vacuum attracting instrument obtains the adsorption capacity of constraint parts to be processed on lathe spindle.Using the above connection side Case, in lathe spindle rotation, mandrel 5 is as the rotary part on this rotary joint, and outer barrel is as on this rotary joint Stationary parts.Therefore for the corresponding fluids adapter tube outside outer barrel, this programme, which has, takes over easy to connect, corresponding connection structure letter Single and adapter tube connects reliable feature.In the prior art, the revolute of conventional rotation joints mostly uses mechanical bearing conduct Bearing, contact are rigid mostly, inevitably result from friction and fever, while rigid structure can not effectively obstruct machine The vibration of tool structure constrains the kinematic accuracy and service life of rotary joint, therefore conventional rotation joints are when in use, for The rotating accuracy of main shaft is with centainly influencing, in this way, it is excellent to be unfavorable for that accurate, super-precision machine tools embody its machining accuracy Gesture.In the present solution, pressure medium, such as compressed gas are introduced into the gap by the correspondence one in both of the above, due to Outer barrel is set in the outside of mandrel 5 by centre bore thereon, therefore the above gap is actually between mandrel 5 and outer barrel Annular gap, in this way, medium in the above gap can replace tradition with contactless hydrostatic support by pneumatically supported mode The bearing based on mechanical contact can effectively avoid because being connect in traditional rotary joint by machinery in this way, using this programme Touching introduces the problems such as frictional dissipation, fever deformation and vibration, thus reach improve the kinematic accuracy of rotary joint, service life with And the purpose of spindle rotation accuracy；Meanwhile higher feature is supported compared to contact based on air bearing support accuracy itself, also may be used Guarantee the rotating accuracy of main shaft.

As those skilled in the art, due to realizing that the above pneumatically supported air gap is located at the outside of mandrel 5, therefore prolonged by outer barrel One of fluid flow passageway in mandrel 5 is extended to need across air gap, it, can be by outside when realizing both described mutually indepedent Ring type seal is set between 5 outside of mandrel on the inside of cylinder, the gap is isolated into positioned at mandrel 5 by the above ring type seal The not region of coaxial position, part of the partial region therein as one of them in described the two, other region conducts The region of another one in described the two, i.e., the above ring type seal is for realizing the isolation of both of the above or as above two The boundary of person.

Embodiment 2:

The present embodiment is further qualified on the basis of embodiment 1, as shown in Figure 1 to Figure 3, as the specific of outer barrel Implementation, the outer barrel include tubular current divider 2 and throttle sleeve 3, and the current divider 2 is set in throttle sleeve 3 outside, 5 clearance fit of mandrel have annular in shape in the inner hole of throttle sleeve 3, and between current divider 2 and throttle sleeve 3 First annular chamber, the first annular chamber are additionally provided on throttle sleeve 3 as the part one of communicated with the gap The through-hole in its interior outside of multiple perforations, communicating passage of each through-hole as the gap and first annular chamber.Using this programme, In the radial direction, respectively mandrel 5, throttle sleeve 3 and current divider 2, are set as including first ring mandrel 5 from the inside to the outside Shape chamber, the above first annular chamber are being uniformly distributed for realizing pressure medium: it is more to realize that the air bearing needs the gap to have A entrance, while there is outlet, and consider the volume of outer barrel, multiple pipe fittings should not be not only set on the outside of outer barrel, It is such as set as including multiple pipe fittings simultaneously, different through-holes are identical as different pipe fittings, in this way it is also possible that through-hole is respectively interior The excessive situation of pressure difference between pressure medium, and this situation is detrimental to generate stable pneumatically supported, therefore is based on this, use with Upper scheme passes through institute in the case where pipe fitting is arranged to facilitate in only one as first annular cavity pressure medium introducing port First annular chamber is stated, multiple through-holes is aloowed to obtain pressure difference pressure medium as small as possible, such as compressed gas between each other Press bearing so that realization is reliably contactless.

The flow of pressure medium, setting are as follows: section is mounted in each through-hole are introduced into the gap for accurate each through-hole Stream plug 6, the fluid negotiability of through-hole where the orifice plug 6 is used to control.

For the pressure difference for further decreasing pressure medium obtained in multiple through-holes, setting are as follows: also set up on the current divider 2 There are axial hole, radial hole and the first nipple orifice, one end of first nipple orifice is located at the outside of current divider 2, and described first connects The other side of head bore is communicated with axial hole, intercommunicating pore of the radial hole as axial hole and first annular chamber, and radial hole is It is multiple.Using this programme, axial hole can be drilled by the end by current divider 2, drill radial direction along the radial direction of current divider 2 Hole, the axial hole can be the through-hole of perforation 2 side wall of current divider, and diameter for the through-hole at perforation 2 both ends of current divider, the radial hole Radial hole after completion radial hole drills, is utilized such as end socket to carry out by the intersection of Xiang Kongyu axial hole close to the aperture in 2 outside of current divider It blocks, while the aperture of axial hole being blocked using such as end socket, in this way, being introduced in through the first nipple orifice in the axial direction hole After pressure medium, it can make first annular chamber that there are multiple pressure medium introduction points, above multiple pressure mediums by axial hole Introduction point may make first annular intracavitary each point pressure difference smaller, in the multiple through-holes being directed on throttle sleeve 3, may make and passes through There is smaller pressure difference between the pressure medium that each through-hole is introduced into the gap.

Pressure medium is introduced into the first nipple orifice for convenience, and guarantees the reliability of the first connector hole location sealing, Setting are as follows: the first pipe fitting 7 is also connected in first nipple orifice, and the first nipple orifice and the first pipe fitting 7 pass through pipe spiral shell Line connection.

As noted previously, as needing to be arranged on the side wall of mandrel 5 duct to realize and can lead to for the fluid circulation of mandrel 5 Road vacuumizes or extracts negative pressure, therefore is actually to need to open up corresponding duct on the side wall of mandrel 5, can optimize as one kind The fluid negotiability in the duct, while the above duct being made to generate the skill that less force performance influences on mandrel 5 as far as possible Art scheme, setting are as follows: also there is the second annular chamber, second ring between the inner wall of the throttle sleeve 3 and the outer wall of mandrel 5 Shape chamber is as the part one of communicated with the fluid flow passageway on mandrel 5；

The duct in its interior outside of multiple perforations is additionally provided on the side wall of mandrel 5, each duct is logical as fluid circulation The communicating passage in road and the second annular chamber.This programme in the specific implementation, second annular chamber and the gap can by with The ring type seal of upper offer is as boundary, it may be assumed that projection of second annular chamber on 5 axis of mandrel covers all ducts in mandrel Projection on 5 axis, in this way, setting duct can be reduced by multiple ducts on influence caused by 5 mechanical property of mandrel, simultaneously Multiple duct collective effects realize the vacuum drawn of 5 upper fluid circulation passage of mandrel to facilitate.

To avoid duct from causing 5 centre-of gravity shift of mandrel, and mandrel 5 is made to generate bigger amplitude, the hole in rotation Road is uniformly distributed around the axis annular of mandrel 5, and duct is located at the same axial location of mandrel 5.

It is reliable for convenience of connecting negative pressure equipment and the negative pressure equipment tie point position on current divider 2 being made to be easier to acquisition Sealing effect, setting are as follows: further include the second pipe fitting 8 being connected to by pipe screw thread on current divider 2, second pipe fitting 8 As the pipe fitting one of communicated with the fluid flow passageway on mandrel 5.

To make this rotary joint, structure is more compact at work, to improve the rotating accuracy of mandrel 5, setting are as follows: institute It is in the form of annular discs to state bracket 4, bracket 4, current divider 2,3 three of throttle sleeve are coaxial, and one end of current divider 2 is fixed on bracket 4, also End casing 1 including 2 other end of current divider is arranged in, the end casing 1 is as the connection between current divider 2 and throttle sleeve 3 Plate.

As noted previously, as required gap needs to be vented in the work of this connector, it is easily fabricated as one kind, and It can intuitively reflect the implementation of pressure medium working condition in the gap, be arranged are as follows: the end casing 1 is in the form of annular discs, and End casing 1 is connect with current divider 2 and the equal screw of throttle sleeve 3.

The above content is the further descriptions made in conjunction with specific preferred embodiment to the utility model, cannot recognize Determine specific embodiment of the present utility model to be only limited to these instructions.For the common skill of the utility model technical field For art personnel, the other embodiments obtained in the case where not departing from the technical solution of the utility model be should be included in practical In novel protection scope.

Claims (10)

1. a kind of air bearing rotary joint, including outer barrel, the bracket being connected on outer barrel (4) and to be mounted on outer cylinder intracorporal Mandrel (5), the mandrel (5) are the hollow structure for being provided with fluid flow passageway, which is characterized in that on the outer barrel It is provided with the first pipe passage and the second pipe passage, both first pipe passage and the second pipe passage are mutually indepedent Fluid flow passageway, and wherein one end of the two is respectively positioned on the outside of outer barrel；

The mandrel (5) and outer barrel clearance fit, in described the two, the other end of one of them be located at it is mandrel (5) and outer Gap between cylinder communicates, and the other end of another one is communicated with the fluid flow passageway on mandrel (5).

2. a kind of air bearing rotary joint according to claim 1, which is characterized in that the outer barrel includes tubular Current divider (2) and throttle sleeve (3), the current divider (2) are set in the outside of throttle sleeve (3), and mandrel (5) clearance fit exists In the inner hole of throttle sleeve (3),

And there is first annular chamber annular in shape between current divider (2) and throttle sleeve (3), the first annular chamber as with institute The part that gap one of communicates is stated, and is additionally provided with the through-holes in multiple perforations outside in it on throttle sleeve (3), each through-hole is made For the communicating passage in the gap and first annular chamber.

3. a kind of air bearing rotary joint according to claim 2, which is characterized in that be mounted on orifice plug in each through-hole (6), the fluid negotiability of through-hole where the orifice plug (6) is used to control.

4. a kind of air bearing rotary joint according to claim 2, which is characterized in that be additionally provided on the current divider (2) Axial hole, radial hole and the first nipple orifice, one end of first nipple orifice are located at the outside of current divider (2), and described first connects The other side of head bore is communicated with axial hole, intercommunicating pore of the radial hole as axial hole and first annular chamber, and radial hole is It is multiple.

5. a kind of air bearing rotary joint according to claim 4, which is characterized in that be also connected in first nipple orifice First pipe fitting (7), and the first nipple orifice is connect with the first pipe fitting (7) by pipe screw thread.

6. a kind of air bearing rotary joint according to claim 2, which is characterized in that the inner wall of the throttle sleeve (3) with Between the outer wall of mandrel (5) also have the second annular chamber, second annular chamber as with the fluid flow passageway on mandrel (5) The part one of communicated；

The duct in its interior outside of multiple perforations is additionally provided on the side wall of mandrel (5), each duct is as the fluid flow passageway With the communicating passage of the second annular chamber.

7. a kind of air bearing rotary joint according to claim 6, which is characterized in that axis of the duct around mandrel (5) Annular is uniformly distributed, and duct is located at the same axial location of mandrel (5).

8. a kind of air bearing rotary joint according to claim 6, which is characterized in that further include being connected to by pipe screw thread point Flow the second pipe fitting (8) on device (2), second pipe fitting (8) is as communicating with the fluid flow passageway on mandrel (5) The pipe fitting of one.

9. a kind of air bearing rotary joint as claimed in any of claims 2 to 8, which is characterized in that the bracket (4) In the form of annular discs, bracket (4), current divider (2), throttle sleeve (3) three are coaxial, and bracket (4) are fixed in one end of current divider (2) On, it further include end casing (1) of the setting in current divider (2) other end, the end casing (1) is used as current divider (2) and throat bushing Connecting plate between cylinder (3).

10. a kind of air bearing rotary joint according to claim 9, which is characterized in that the end casing (1) is in the form of annular discs, And end casing (1) is connect with current divider (2) and throttle sleeve (3) screw.