JP2019190591A - Porous static pressure air bearing and its process of manufacture - Google Patents
Porous static pressure air bearing and its process of manufacture Download PDFInfo
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本発明は、多孔質静圧空気軸受及びその製造方法に関する。 The present invention relates to a porous hydrostatic air bearing and a method for manufacturing the same.
下記特許文献１には、静圧軸受として用いられるハニカムサンドイッチ構造体が開示されている。このハニカムサンドイッチ構造体は、平均粒径１００マイクロメートルのＳｉＣ粉末１００重量部とアクリルバインダー１００質量部及びエタノール２０質量部を混練した接合材を、静圧軸受け形状に切り出した２枚の多孔質カーボン平板のハニカム構造体との接合面に塗布し、その２枚の塗布面の間にＳｉＣハニカム構造体を配置することで構成されている。 Patent Document 1 listed below discloses a honeycomb sandwich structure used as a hydrostatic bearing. This honeycomb sandwich structure has two porous carbons obtained by cutting a bonding material obtained by kneading 100 parts by weight of SiC powder having an average particle diameter of 100 micrometers, 100 parts by weight of an acrylic binder, and 20 parts by weight of ethanol into a static pressure bearing shape. It is configured by applying to the joint surface with the flat honeycomb structure and disposing the SiC honeycomb structure between the two coated surfaces.
ところで、多孔質カーボン平板等の多孔質層とハニカム構造体とを接合材を介して接合する構成や、多孔質層からの空気の流出量を調節するために多孔質層の表面に目詰まり処理を行う構成では、製造コストが増加する。 By the way, the porous layer such as a porous carbon plate and the honeycomb structure are bonded to each other through a bonding material, and the surface of the porous layer is clogged to adjust the outflow amount of air from the porous layer. In the configuration for performing the above, the manufacturing cost increases.
本発明は上記事実を考慮し、製造コストが増加することを抑制できる多孔質静圧空気軸受及びその製造方法を得ること目的とする。 In view of the above facts, an object of the present invention is to obtain a porous hydrostatic air bearing capable of suppressing an increase in manufacturing cost and a manufacturing method thereof.
請求項１記載の多孔質静圧空気軸受は、金属材料を用いて形成され、一方側から他方側へ向けて空気が流れる複数の第１流通部を有する支持部と、金属材料を用いて形成され、前記支持部の他方側の面に沿って前記支持部と一体に形成され、前記第１流通部からの空気が導入されると共にこの空気が前記支持部とは反対側の面から流出する複数の第２流通部を有し、この第２流通部から流出した空気によって軸部材が支持される多孔質層と、を備えている。 The porous hydrostatic air bearing according to claim 1 is formed using a metal material, and a support portion having a plurality of first flow portions through which air flows from one side to the other side, and a metal material. And is formed integrally with the support portion along the other surface of the support portion, and air from the first circulation portion is introduced and the air flows out from the surface opposite to the support portion. A porous layer having a plurality of second circulation portions, and a shaft member supported by the air flowing out from the second circulation portions.
請求項１記載の多孔質静圧空気軸受によれば、第１流通部を有する支持部を形成した後に、この支持部の他方側の面に沿って第２流通部を有する多孔質層を形成する。これにより、製造コストが増加することを抑制することができる。 According to the porous hydrostatic air bearing of claim 1, after forming the support portion having the first flow portion, the porous layer having the second flow portion is formed along the other surface of the support portion. To do. Thereby, it can suppress that manufacturing cost increases.
請求項２記載の多孔質静圧空気軸受は、請求項１記載の多孔質静圧空気軸受において、前記多孔質層をその厚み方向から見て、前記多孔質層の中心部側の前記第２流通部を介した空気の通り易さと外周部側の前記第２流通部を介した空気の通り易さとが異なっている。 The porous hydrostatic air bearing according to claim 2 is the porous hydrostatic air bearing according to claim 1, wherein the second layer on the center side of the porous layer is viewed from the thickness direction of the porous layer. The ease of air passage through the circulation portion is different from the ease of air passage through the second circulation portion on the outer peripheral side.
請求項２記載の多孔質静圧空気軸受によれば、多孔質層の中心部側の第２流通部を介した空気の通り易さと外周部側の第２流通部を介した空気の通り易さとが異なっている。これにより、軸部材と多孔質層との間の空気の繰り返しの圧縮に起因する不安定な振動を抑制することができることがわかっている。なお、以下においてはこの不安定な振動を「ニューマティックハンマ」と呼ぶ。 According to the porous hydrostatic air bearing according to claim 2, the air easily passes through the second circulation part on the center side of the porous layer and the air easily passes through the second circulation part on the outer peripheral part side. Is different. It has been found that this can suppress unstable vibration caused by repeated compression of air between the shaft member and the porous layer. In the following, this unstable vibration is referred to as “pneumatic hammer”.
請求項３記載の多孔質静圧空気軸受は、請求項２記載の多孔質静圧空気軸受において、前記多孔質層の外周部側の前記第２流通部を介した空気の通り易さが、中心部側よりも通り易くなっている。 The porous hydrostatic air bearing according to claim 3 is the porous hydrostatic air bearing according to claim 2, wherein the ease of passing air through the second flow part on the outer peripheral side of the porous layer is as follows. It is easier to pass than the center side.
請求項３記載の多孔質静圧空気軸受によれば、多孔質層の外周部側の第２流通部を介した空気の通り易さが、中心部側よりも通り易くなっている。これにより、ニューマティックハンマが生じることを抑制することができることがわかっている。 According to the porous hydrostatic air bearing of the third aspect, it is easier for air to pass through the second flow part on the outer peripheral side of the porous layer than on the central part side. It has been found that this can suppress the occurrence of a pneumatic hammer.
請求項４記載の多孔質静圧空気軸受は、請求項２記載の多孔質静圧空気軸受において、前記多孔質層の中心部側の前記第２流通部を介した空気の通り易さが、外周部側よりも通り易くなっている。 The porous hydrostatic air bearing according to claim 4 is the porous hydrostatic air bearing according to claim 2, wherein the ease of air passage through the second flow portion on the center side of the porous layer is as follows. It is easier to pass than the outer peripheral side.
請求項４記載の多孔質静圧空気軸受によれば、多孔質層の中心部側の第２流通部を介した空気の通り易さが、外周部側よりも通り易くなっている。これにより、ニューマティックハンマが生じることを抑制することができることがわかっている。 According to the porous hydrostatic air bearing of the fourth aspect, it is easier for air to pass through the second flow part on the central part side of the porous layer than on the outer peripheral part side. It has been found that this can suppress the occurrence of a pneumatic hammer.
請求項５記載の多孔質静圧空気軸受は、請求項１〜請求項４のいずれか１項に記載の多孔質静圧空気軸受において、前記支持部と前記多孔質層とが、同じ金属材料を用いて形成されている。 The porous hydrostatic air bearing according to claim 5 is the porous hydrostatic air bearing according to any one of claims 1 to 4, wherein the support portion and the porous layer are the same metal material. It is formed using.
請求項５記載の多孔質静圧空気軸受によれば、支持部と多孔質層とが、同じ金属材料を用いて形成されている。これにより、第１流通部を有する支持部を形成した後に、材料の変更を行うことなく、この支持部の他方側の面に沿って第２流通部を有する多孔質層を形成することができる。これにより、製造コストが増加することをより一層抑制することができる。 According to the porous hydrostatic air bearing of claim 5, the support portion and the porous layer are formed using the same metal material. Thereby, after forming the support part which has a 1st flow part, the porous layer which has a 2nd flow part can be formed along the surface of the other side of this support part, without changing a material. . Thereby, it can suppress further that a manufacturing cost increases.
請求項６記載の多孔質静圧空気軸受の製造方法は、金属材料を用いて形成され、一方側から他方側へ向けて空気が流れる複数の第１流通部を有する支持部と、金属材料を用いて形成され、前記支持部の他方側の面に沿って前記支持部と一体に形成され、前記第１流通部からの空気が導入されると共にこの空気が前記支持部とは反対側の面から流出する複数の第２流通部を有し、この第２流通部から流出した空気によって軸部材が支持される多孔質層と、を備えた多孔質静圧空気軸受の製造方法に適用され、金属粉末にレーザを照射することで、前記支持部を形成する支持部形成工程と、金属粉末にレーザを照射することで、前記支持部の他方側の面に沿って前記多孔質層を形成する多孔質層形成工程と、を有する。 A method for manufacturing a porous hydrostatic air bearing according to claim 6 is formed using a metal material, and a support portion having a plurality of first flow portions through which air flows from one side to the other side, and a metal material. And is formed integrally with the support portion along the other surface of the support portion, and air from the first circulation portion is introduced and the air is on the opposite surface to the support portion. A porous layer having a plurality of second flow portions flowing out from the second flow portion, and a shaft member supported by the air flowing out from the second flow portions, and applied to a method for producing a porous hydrostatic air bearing, By irradiating the metal powder with a laser, the support part forming step for forming the support part, and by irradiating the metal powder with a laser, the porous layer is formed along the other surface of the support part. And a porous layer forming step.
請求項６記載の多孔質静圧空気軸受の製造方法によれば、金属粉末にレーザを照射することで、支持部を形成する（支持部形成工程）。次いで、金属粉末にレーザを照射することで、支持部の他方側の面に沿って多孔質層を形成する（多孔質層形成工程）。この製造方法では、支持部と多孔質層とを一体に形成でき、製造コストが増加することを抑制することができる。なお、支持部を形成する金属粉末と多孔質層を形成する金属粉末とは、同じ種類の金属粉末であってもよいし異なる種類の金属粉末であってもよい。 According to the method for manufacturing a porous hydrostatic air bearing according to claim 6, the support part is formed by irradiating the metal powder with a laser (support part forming step). Next, the metal powder is irradiated with a laser to form a porous layer along the other surface of the support portion (porous layer forming step). In this manufacturing method, the support portion and the porous layer can be integrally formed, and an increase in manufacturing cost can be suppressed. The metal powder that forms the support portion and the metal powder that forms the porous layer may be the same type of metal powder or different types of metal powder.
請求項７記載の多孔質静圧空気軸受の製造方法は、請求項６記載の多孔質静圧空気軸受の製造方法において、単位体積当たりの前記金属粉末に投入される前記レーザのエネルギをエネルギ密度Ｅ（Ｊ／ｍｍ２）とし、前記多孔質層形成工程においてエネルギ密度Ｅを調節することで、前記多孔質層の前記第２流通部を介した空気の通り易さを調節する。 The method of manufacturing a porous hydrostatic air bearing according to claim 7 is the method of manufacturing a porous hydrostatic air bearing according to claim 6, wherein the energy of the laser supplied to the metal powder per unit volume is energy density. E (J / mm 2 ), and by adjusting the energy density E in the porous layer forming step, the ease of passing air through the second flow part of the porous layer is adjusted.
請求項７記載の多孔質静圧空気軸受の製造方法によれば、エネルギ密度Ｅを調節することにより、多孔質層の第２流通部を介した空気の通り易さを調節することができる。 According to the manufacturing method of the porous hydrostatic air bearing of the seventh aspect, by adjusting the energy density E, it is possible to adjust the ease of passing air through the second flow part of the porous layer.
請求項８記載の多孔質静圧空気軸受の製造方法は、請求項７記載の多孔質静圧空気軸受の製造方法において、ステンレス鋼の前記金属粉末を用い、前記多孔質層形成工程において前記エネルギ密度Ｅを２８．１２５Ｊ／ｍｍ２以下に設定する。 The method for producing a porous hydrostatic air bearing according to claim 8 is the method for producing a porous hydrostatic air bearing according to claim 7, wherein the metal powder of stainless steel is used, and the energy is formed in the porous layer forming step. setting the density E in 28.125J / mm 2 or less.
請求項８記載の多孔質静圧空気軸受の製造方法によれば、ステンレス鋼の金属粉末を用いると共にエネルギ密度Ｅを２８．１２５Ｊ／ｍｍ２以下に設定することにより、多孔質静圧空気軸受として機能する多孔質層を得ることができる。 According to the method for producing a porous hydrostatic air bearing according to claim 8, by using stainless steel metal powder and setting the energy density E to 28.125 J / mm 2 or less, A functioning porous layer can be obtained.
本発明に係る多孔質静圧空気軸受及びその製造方法は、製造コストが増加することを抑制できる、という優れた効果を有する。 The porous hydrostatic air bearing and the manufacturing method thereof according to the present invention have an excellent effect that an increase in manufacturing cost can be suppressed.
（はじめに）
多孔質静圧空気軸受は、高い負荷容量や剛性が得られることから、超精密加工機や測定器などに広く使用されている。さて、現在市販されている多孔質空気軸受は、厚さ数ｍｍの多孔質材（グラファイト，セラミックス，金属粉末焼結体）をハニカム構造の部材や、給気溝を設けた部材に接着等することにより製作している。また、ニューマティックハンマを防止するため、表面目詰まり（多孔質表層部の通気率を母材通気率よりも低くする処理）を施している。そのため、量産製造に際しては、接着や多孔質層の表面の目詰まり度の管理が必要となり、コストの増加の原因となっている。
(Introduction)
Porous hydrostatic air bearings are widely used in ultra-precision processing machines and measuring instruments because of their high load capacity and rigidity. Well-known porous air bearings are bonded with a porous material (graphite, ceramics, metal powder sintered body) having a thickness of several millimeters to a honeycomb structure member or a member provided with an air supply groove. It is produced by. In order to prevent pneumatic hammer, clogging of the surface (treatment for making the air permeability of the porous surface layer portion lower than the base material air permeability) is performed. Therefore, in mass production, it is necessary to manage adhesion and the degree of clogging of the surface of the porous layer, which causes an increase in cost.
そこで、本発明では、従来の多孔質静圧空気軸受の表面目詰まり層と同等の通気率を持つ多孔質層（厚さ：数十μｍ〜数百μｍ）と、ハニカム形状の支持部材が一体となった構造を提案し、金属粉末積層焼結３Ｄプリンタ（３Ｄ Ｓｙｓｔｅｍｓ，ＰｒｏＸ（登録商標）ＤＭＰ３００）を用いて多孔質静圧空気軸受を製作した。この構造を採用することにより、表面の多孔質層は強度を維持しつつ、簡易的な多孔質静圧空気軸受の作製が期待できる。本発明では、試作した軸受の静特性に関して、実験的検討を行い、提案する多孔質静圧空気軸受の構造の有用性を以下に示す。 Therefore, in the present invention, a porous layer (thickness: several tens of μm to several hundreds of μm) having the same air permeability as the surface clogging layer of a conventional porous hydrostatic air bearing and a honeycomb-shaped support member are integrated. The proposed structure was proposed, and a porous hydrostatic air bearing was manufactured using a metal powder laminated sintered 3D printer (3D Systems, ProX (registered trademark) DMP300). By adopting this structure, a simple porous hydrostatic air bearing can be expected while maintaining the strength of the porous layer on the surface. In the present invention, an experimental study is performed on the static characteristics of the prototype bearing, and the usefulness of the proposed structure of the porous hydrostatic air bearing is shown below.
（第１実施形態に係る多孔質静圧空気軸受１０の構成）
先ず、本発明の第１実施形態に係る多孔質静圧空気軸受１０の構成について説明する。
(Configuration of the porous hydrostatic air bearing 10 according to the first embodiment)
First, the configuration of the porous hydrostatic air bearing 10 according to the first embodiment of the present invention will be described.
図１〜図３に示されるように、本実施形態の多孔質静圧空気軸受１０は、金属材料を用いて一体に形成された支持部としての多孔質層支持部１２及び多孔質層１４を備えている。 As shown in FIG. 1 to FIG. 3, the porous hydrostatic air bearing 10 of the present embodiment includes a porous layer support 12 and a porous layer 14 that are integrally formed using a metal material. I have.
多孔質層支持部１２は、円板状に形成されている。この多孔質層支持部１２の外周部は、固定フランジ部１６とされており、この固定フランジ部１６には、周方向に間隔をあけて配置された複数のボルト挿通孔１８が形成されている。そして、図４に示されるように、ボルト挿通孔１８に挿通されたボルト２０がバックメタル２２等の被取付部に螺合されることで、多孔質静圧空気軸受１０がバックメタル２２等の被取付部に取付けられるようになっている。なお、本実施形態では固定フランジ部１６を設けた例について説明したが、多孔質層支持部１２がハウジング等と一体化された構成では、固定フランジ部１６を設けなくてもよい。 The porous layer support 12 is formed in a disk shape. The outer peripheral portion of the porous layer support portion 12 is a fixed flange portion 16, and a plurality of bolt insertion holes 18 arranged at intervals in the circumferential direction are formed in the fixed flange portion 16. . And as FIG. 4 shows, the volt | bolt 20 penetrated by the bolt insertion hole 18 is screwed by to-be-attached parts, such as the back metal 22, etc., and thereby the porous hydrostatic air bearing 10 is made of the back metal 22, etc. It can be attached to the mounted part. In the present embodiment, the example in which the fixing flange portion 16 is provided has been described. However, in the configuration in which the porous layer support portion 12 is integrated with a housing or the like, the fixing flange portion 16 may not be provided.
また、多孔質層支持部１２において固定フランジ部１６よりも内側の部分には、軸方向に貫通された第１流通部としての複数の第１流通孔２４が形成されている。なお、軸方向一方側を矢印Ｚで示している。図３に示されるように、この第１流通孔２４は、軸方向から見て内周面が正六角形状に形成されている。また、複数の第１流通孔２４は、軸方向から見て略蜂の巣状に規則的に並んでいる。ここで、本実施形態では、第１流通孔２４の内周面の１片（正六角形の１片）の長さが０．５ｍｍに設定されている。また、隣り合う第１流通孔２４の間の間隔は、０．２５ｍｍに設定されている。なお、多孔質層支持部１２において複数の第１流通孔２４が形成されている部分をハニカム部２６と呼ぶ。ここで、第１流通孔２４の内周面の１片（正六角形の１片）の長さは、後述する多孔質層１４の変形（多孔質層支持部１２側からの空気の圧力ｐｓｇによる変形）を考慮して、０．５ｍｍ以下に設定するとよい。換言すると、第１流通孔２４の半径を０．５ｍｍ以下に設定するとよい。これにより、後述する多孔質層１４の変形が抑制され、多孔質層１４の変形によって当該多孔質層１４と後述するシャフト３４とが接触することを効果的に抑制することができる。 In the porous layer support portion 12, a plurality of first flow holes 24 as first flow portions penetrating in the axial direction are formed in a portion inside the fixed flange portion 16. One side in the axial direction is indicated by an arrow Z. As shown in FIG. 3, the first circulation hole 24 has an inner peripheral surface formed in a regular hexagonal shape as viewed from the axial direction. The plurality of first flow holes 24 are regularly arranged in a substantially honeycomb shape when viewed from the axial direction. Here, in this embodiment, the length of one piece (one piece of regular hexagon) of the inner peripheral surface of the first flow hole 24 is set to 0.5 mm. Moreover, the space | interval between the adjacent 1st circulation holes 24 is set to 0.25 mm. A portion where the plurality of first flow holes 24 are formed in the porous layer support portion 12 is referred to as a honeycomb portion 26. Here, the length of one piece (one piece of regular hexagon) on the inner peripheral surface of the first flow hole 24 is the deformation of the porous layer 14 described later (the pressure of air p sg from the porous layer support 12 side). In consideration of deformation due to the In other words, the radius of the first flow hole 24 may be set to 0.5 mm or less. Thereby, the deformation | transformation of the porous layer 14 mentioned later is suppressed, and it can suppress effectively that the said porous layer 14 and the shaft 34 mentioned later by a deformation | transformation of the porous layer 14 contact.
また、多孔質層支持部１２は、ハニカム部２６の外周部から軸方向他方側（矢印Ｚ方向とは反対側）へ向けて突出する環状の外壁部２８を備えている。この外壁部２８の内周側に多孔質層１４が形成されている。 Further, the porous layer support portion 12 includes an annular outer wall portion 28 that protrudes from the outer peripheral portion of the honeycomb portion 26 toward the other side in the axial direction (the side opposite to the arrow Z direction). The porous layer 14 is formed on the inner peripheral side of the outer wall portion 28.
図１及び図２に示されるように、多孔質層１４は、多孔質層支持部１２の外壁部２８の内周側においてハニカム部２６と一体に形成されている。この多孔質層１４には、多孔質層支持部１２のハニカム部２６に形成された複数の第１流通孔２４からからの空気が導入されると共にこの空気がハニカム部２６とは反対側の面３０から流出する第２流通部としての複数の第２流通孔３２が形成されている。なお、複数の第２流通孔３２は、後述するように第１流通孔２４と比べて極めて小さな孔である。 As shown in FIGS. 1 and 2, the porous layer 14 is formed integrally with the honeycomb portion 26 on the inner peripheral side of the outer wall portion 28 of the porous layer support portion 12. Air from the plurality of first flow holes 24 formed in the honeycomb portion 26 of the porous layer support portion 12 is introduced into the porous layer 14 and the air is on the surface opposite to the honeycomb portion 26. A plurality of second circulation holes 32 are formed as second circulation portions that flow out from 30. The plurality of second flow holes 32 are extremely small holes as compared with the first flow holes 24 as will be described later.
図４に示されるように、以上説明した本実施形態の多孔質静圧空気軸受１０では、多孔質層支持部１２のハニカム部２６の軸方向一方側（矢印Ｚ方向側）の空気の圧力が所定の圧力に設定されている。その結果、多孔質層支持部１２のハニカム部２６の軸方向一方側の空気は、ハニカム部２６に形成された複数の第１流通孔２４の内部に導入される。複数の第１流通孔２４内に導入された空気は、軸方向他方側（矢印Ｚ方向とは反対側）へ向けて流れる。また、複数の第１流通孔２４内を軸方向他方側へ向けて流れた空気は、多孔質層１４に形成された複数の第２流通孔３２内に導入される。そして、複数の第２流通孔３２内に導入された空気は、多孔質層１４においてハニカム部２６とは反対側の面３０から流出する。この多孔質層１４においてハニカム部２６とは反対側の面３０から流出する空気によって、軸部材としてのシャフト３４が支持されるようになっている。 As shown in FIG. 4, in the porous hydrostatic air bearing 10 of the present embodiment described above, the pressure of the air on one axial side (arrow Z direction side) of the honeycomb portion 26 of the porous layer support portion 12 is low. It is set to a predetermined pressure. As a result, the air on one axial side of the honeycomb portion 26 of the porous layer support portion 12 is introduced into the plurality of first flow holes 24 formed in the honeycomb portion 26. The air introduced into the plurality of first circulation holes 24 flows toward the other side in the axial direction (the side opposite to the arrow Z direction). Further, the air that has flowed in the plurality of first flow holes 24 toward the other side in the axial direction is introduced into the plurality of second flow holes 32 formed in the porous layer 14. The air introduced into the plurality of second circulation holes 32 flows out from the surface 30 on the opposite side of the honeycomb portion 26 in the porous layer 14. A shaft 34 as a shaft member is supported by the air flowing out from the surface 30 opposite to the honeycomb portion 26 in the porous layer 14.
（多孔質静圧空気軸受１０の製造方法）
次に、多孔質静圧空気軸受１０の製造方法について説明する。
(Manufacturing method of porous hydrostatic air bearing 10)
Next, a method for manufacturing the porous hydrostatic air bearing 10 will be described.
本実施形態の多孔質静圧空気軸受１０は、多孔質層１４（厚さ数百μｍ）と、多孔質層支持部１２が一体となっており、金属粉末焼結３Ｄプリンタを用いて製作した。これにより、多孔質静圧空気軸受１０の製造コストが増加することが抑制されている。 The porous hydrostatic air bearing 10 of the present embodiment has a porous layer 14 (thickness of several hundreds μm) and a porous layer support 12 integrated with each other, and is manufactured using a metal powder sintered 3D printer. . Thereby, it is suppressed that the manufacturing cost of the porous hydrostatic air bearing 10 increases.
本実施形態で用いた金属３Ｄプリンタは、金属粉末を半導体レーザ（スポット径約８０μｍ、最大出力５００Ｗ）により溶融させて焼結を行うが、多孔質静圧空気軸受１０の製作に使用した金属粉末はステンレス鋼の金属粉末である１７−４ＰＨ（ＳＵＳ６３０相当）、平均粒径は２０μｍである。３Ｄプリンタによる積層焼結のピッチは４０μｍとした。 In the metal 3D printer used in this embodiment, the metal powder is melted and sintered by a semiconductor laser (spot diameter: about 80 μm, maximum output: 500 W), but the metal powder used for manufacturing the porous hydrostatic air bearing 10 is used. Is a stainless steel metal powder, 17-4PH (equivalent to SUS630), and the average particle size is 20 μm. The pitch of lamination sintering by a 3D printer was 40 μm.
今回使用した３Ｄプリンタによる多孔質静圧空気軸受１０の製造においては、同時に複数個の多孔質静圧空気軸受１０を製造可能である。製造時間は、多孔質静圧空気軸受１０を４個同時製造の場合は約８時間、８個同時製造の場合は約１０時間である。 In the production of the porous hydrostatic air bearing 10 by the 3D printer used this time, a plurality of porous hydrostatic air bearings 10 can be produced at the same time. The manufacturing time is about 8 hours in the case of simultaneously manufacturing four porous hydrostatic air bearings 10 and about 10 hours in the case of simultaneous manufacturing of eight.
本実施形態では、金属粉末にレーザを照射することで、多孔質層支持部１２を形成し（支持部形成工程）、多孔質層支持部１２上の金属粉末にレーザを照射することで、多孔質層支持部１２の軸方向他方側の面に沿って多孔質層１４を形成する（多孔質層形成工程）。金属３Ｄプリンタにより多孔質静圧空気軸受１０を製作した後、軸受下面（多孔質層支持部１２における多孔質層１４とは反対側の面）を研削加工し、その後、ワイヤ放電加工機を用いて多孔質層１４の表面をカットし、多孔質層１４を初期厚さの１０００μｍから任意の厚さｔｐに加工した。 In the present embodiment, the porous layer support portion 12 is formed by irradiating the metal powder with a laser (support portion forming step), and the metal powder on the porous layer support portion 12 is irradiated with the laser so as to be porous. The porous layer 14 is formed along the other surface in the axial direction of the porous layer support 12 (porous layer forming step). After the porous hydrostatic air bearing 10 is manufactured by the metal 3D printer, the lower surface of the bearing (the surface opposite to the porous layer 14 in the porous layer support portion 12) is ground, and then a wire electric discharge machine is used. Then, the surface of the porous layer 14 was cut, and the porous layer 14 was processed from an initial thickness of 1000 μm to an arbitrary thickness tp.
本実施形態で用いた金属３Ｄプリンタは、金属粉末を半導体レーザにより溶融させて造形を行うが、レーザ強度を調整することで、多孔質層１４と緻密部をそれぞれ製作することが可能である。多孔質静圧空気軸受１０の試作に際しては、多孔質層１４を製作するための最適レーザ強度を選定するため、レーザ強度を、２００Ｗから３００Ｗまで２５Ｗずつ変化させて造形を行い、比較を行った。レーザ走査速度は何れも２５００ｍｍ／ｓとした。以下の表１（Ｔａｂｌｅ１）にレーザの照射条件の一覧を、図５〜図９に、造形後の多孔質層１４の断面の顕微鏡写真を示す。 The metal 3D printer used in the present embodiment performs modeling by melting metal powder with a semiconductor laser, and the porous layer 14 and the dense portion can be manufactured by adjusting the laser intensity. In the trial production of the porous hydrostatic air bearing 10, in order to select the optimum laser intensity for producing the porous layer 14, the laser intensity was changed from 200 W to 300 W in increments of 25 W, and the comparison was performed. . The laser scanning speed was all 2500 mm / s. Table 1 (Table 1) below shows a list of laser irradiation conditions, and FIGS. 5 to 9 show micrographs of cross sections of the porous layer 14 after modeling.
図５に示すように、レーザ密度２５Ｊ／ｍｍ３（２００Ｗ）や、図６に示すように、レーザ密度２８．１２５Ｊ／ｍｍ３（２２５Ｗ）では、断面に数十μｍの空孔（第２流通孔３２）が多く確認された。図５や図６に示すものは、多孔質層１４の断面写真であるため、空孔同士はつながっていないように見えるが、３次元的には空孔同士がつながっていると考えられ、多孔質層１４は通気性を有する。 As shown in FIG. 5, at a laser density of 25 J / mm 3 (200 W) or a laser density of 28.125 J / mm 3 (225 W) as shown in FIG. Many holes 32) were observed. FIG. 5 and FIG. 6 are cross-sectional photographs of the porous layer 14, so that it seems that the pores are not connected to each other, but it is considered that the pores are connected in three dimensions. The quality layer 14 has air permeability.
一方、図７に示すレーザ密度３１．２５Ｊ／ｍｍ３（２５０Ｗ）、図８に示すレーザ密度３４．３７５Ｊ／ｍｍ３（２７５Ｗ）、図９に示すレーザ密度３７．５Ｊ／ｍｍ３（３００Ｗ）では断面に存在する空孔（第２流通孔３２）はわずかであり，通気性はほぼ無い。このことから、金属粉末として１７−４ＰＨ（ＳＵＳ６３０相当）を用いて多孔質層１４を製作するには、レーザ密度２８．１２５Ｊ／ｍｍ３（２２５Ｗ）以下とする必要があることがわかった。 On the other hand, the laser density 31.25J / mm 3 shown in FIG. 7 (250 W), the laser density 34.375J / mm 3 shown in FIG. 8 (275W), the laser density 37.5J / mm 3 shown in FIG. 9 (300 W) There are few holes (second flow holes 32) present in the cross section, and there is almost no air permeability. From this, it was found that in order to produce the porous layer 14 using 17-4PH (equivalent to SUS630) as the metal powder, it is necessary to make the laser density 28.125 J / mm 3 (225 W) or less.
以上の結果により、多孔質層１４を製作する際のレーザ密度を、２５Ｊ／ｍｍ３（２００Ｗ）および２８．１２５Ｊ／ｍｍ３（２２５Ｗ）として多孔質静圧空気軸受１０を製作し、３Ｄプリンタで製造後、多孔質層１４を初期の約１０００μｍから２００μｍカットして（多孔質層１４の厚さｔｐ＝約８００μｍ）、多孔質静圧空気軸受１０の開放流量を測定した。 Based on the above results, the porous hydrostatic air bearing 10 was manufactured with a laser density of 25 J / mm 3 (200 W) and 28.125 J / mm 3 (225 W) when the porous layer 14 was manufactured. After production, the porous layer 14 was cut from the initial about 1000 μm to 200 μm (thickness tp of the porous layer 14 = about 800 μm), and the open flow rate of the porous hydrostatic air bearing 10 was measured.
測定の結果、レーザ密度２５Ｊ／ｍｍ３（２００Ｗ）では流量が５．８５ｌ／ｍｉｎ（ｐｓｇ＝０．５ＭＰａ）であった。ここで、ｐｓｇとは、多孔質層支持部１２のハニカム部２６の軸方向一方側（矢印Ｚ方向側）の空気の圧力（図４参照）のことである。また、レーザ密度２８．１２５Ｊ／ｍｍ３（２２５Ｗ）では流量が０．５５ｌ／ｍｉｎ（ｐｓｇ＝０．５ＭＰａ）であった。今回試作した多孔質静圧空気軸受１０の外径（多孔質層１４の外径）は４０ｍｍであるが、外径４０ｍｍの市販品の多孔質静圧空気軸受の開放流量は１〜２ｌ／ｍｉｎ 程度であることから、レーザ密度２５Ｊ／ｍｍ３（２００Ｗ）では流量が過大となる。以上の結果により、本実施形態では，多孔質層１４を製作するためのレーザ密度を２８．１２５Ｊ／ｍｍ３（２２５Ｗ）に決定した。なお、多孔質層１４を支持する多孔質層支持部１２については、1 辺０．５ｍｍの六角形の穴（第１流通孔２４）から多孔質層１４に給気する。多孔質層支持部１２は通気性を持たない緻密構造とするため、レーザ密度は４０．６２５Ｊ／ｍｍ３（３２５Ｗ）とて製作した。 As a result of the measurement, the flow rate in the laser density 25J / mm 3 (200W) was 5.85l / min (p sg = 0.5MPa ). Here, p sg is the air pressure (see FIG. 4) on one axial side (arrow Z direction side) of the honeycomb portion 26 of the porous layer support portion 12. The flow rate was 0.55 l / min (p sg = 0.5 MPa) at a laser density of 28.125 J / mm 3 (225 W). The outer diameter of the experimentally produced porous hydrostatic air bearing 10 (the outer diameter of the porous layer 14) is 40 mm, but the open flow rate of a commercially available porous hydrostatic air bearing having an outer diameter of 40 mm is 1 to 2 l / min. Therefore, the flow rate becomes excessive at a laser density of 25 J / mm 3 (200 W). Based on the above results, in this embodiment, the laser density for manufacturing the porous layer 14 was determined to be 28.125 J / mm 3 (225 W). In addition, about the porous layer support part 12 which supports the porous layer 14, it supplies to the porous layer 14 from the hexagonal hole (1st through-hole 24) of 0.5 mm of 1 side. Since the porous layer support 12 has a dense structure without air permeability, the laser density was 40.625 J / mm 3 (325 W).
ところで、多孔質静圧空気軸受１０の特性は、軸受開放流量により大きく変化する。本実施形態で取り扱う多孔質静圧空気軸受１０では、多孔質層１４を通過する気体の流速が遅く粘性が支配的であるため、多孔質層１４を通過する気体の流れはＤａｒｃｙの法則に従うとすると、開放流量は多孔質層１４の厚さｔｐに反比例する。そのため、多孔質層１４の厚さｔｐを変化させることで、流量を調整することが可能となる。本実施形態では、多孔質層１４の厚さｔｐを、初期厚さである１０００μｍからワイヤ放電加工機によりカットして、市販品と同等の１〜２ｌ／ｍｉｎ程度の流量が得られるように調整した。そして、試験軸受（多孔質層厚さｔｐ＝約３００μｍ、軸受開放流量１．１４ｌ／ｍｉｎ：ｐｓｇ＝０．６ＭＰａ）を製作した。なお、この試験軸受けの多孔質層１４は、レーザ密度２７．５Ｊ／ｍｍ３（２２０Ｗ）で製作している。 By the way, the characteristics of the porous hydrostatic air bearing 10 vary greatly depending on the bearing opening flow rate. In the porous hydrostatic air bearing 10 handled in the present embodiment, the flow rate of the gas passing through the porous layer 14 is slow and the viscosity is dominant. Therefore, the flow of the gas passing through the porous layer 14 follows Darcy's law. Then, the open flow rate is inversely proportional to the thickness tp of the porous layer 14. Therefore, the flow rate can be adjusted by changing the thickness tp of the porous layer 14. In this embodiment, the thickness tp of the porous layer 14 is cut from the initial thickness of 1000 μm with a wire electric discharge machine so that a flow rate of about 1 to 2 l / min equivalent to a commercially available product is obtained. did. Then, a test bearing (porous layer thickness tp = about 300 μm, bearing opening flow rate 1.14 l / min: p sg = 0.6 MPa) was manufactured. The porous layer 14 of this test bearing is manufactured at a laser density of 27.5 J / mm 3 (220 W).
（多孔質静圧空気軸受１０の特性の評価）
次に、本実施形態の多孔質静圧空気軸受１０の特性の評価について説明する。
(Evaluation of characteristics of porous hydrostatic air bearing 10)
Next, evaluation of the characteristics of the porous hydrostatic air bearing 10 of the present embodiment will be described.
図１０には、実験装置３６の概略図が示されている。この図に示されるように、試験軸受である多孔質静圧空気軸受１０は、軸受面を下向きとされた状態で天蓋部３８の一部を構成するバックメタル２２にボルト２０で固定されている。 FIG. 10 shows a schematic diagram of the experimental apparatus 36. As shown in this figure, a porous hydrostatic air bearing 10 as a test bearing is fixed with a bolt 20 to a back metal 22 constituting a part of the canopy 38 with the bearing surface facing downward. .
質量ｍ＝３．５ｋｇのシャフト３４は鉛直に置かれ、静圧空気ジャーナル軸受４０により非接触支持されている。このシャフト３４の下部はエアシリンダ４２となっており、エアシリンダ４２への給気圧力ｐｆを変化させることで試験軸受である多孔質静圧空気軸受１０に任意の負荷ｗを与えることができる。実験に際しては、軸受負荷ｗ［Ｎ］を変化させた際の軸受すきまｈ［μｍ］の変化量を静電容量型非接触変位計により測定した。軸受無次元負荷容量Ｗおよび無次元静剛性ＫＳは、以下の式１、式２により求めた。Ａは軸受面積である。 A shaft 34 having a mass m = 3.5 kg is placed vertically and supported by a hydrostatic air journal bearing 40 in a non-contact manner. The lower portion of the shaft 34 is an air cylinder 42. By changing the supply pressure pf to the air cylinder 42, an arbitrary load w can be applied to the porous hydrostatic air bearing 10 that is a test bearing. In the experiment, the amount of change in the bearing clearance h [μm] when the bearing load w [N] was changed was measured with a capacitance type non-contact displacement meter. Bearing dimensionless load capacity W and the dimensionless static stiffness K S of the formula 1 below, was determined by equation 2. A is a bearing area.
図１１にｐｓｇ＝０．４ＭＰａの場合の無次元軸受負荷容量Ｗおよび無次元静剛性ＫＳの測定結果を示し、図１２にｐｓｇ＝０．６ＭＰａの場合の無次元軸受負荷容量Ｗおよび無次元静剛性ＫＳの測定結果を示す。これらの図に示すように、無次元軸受負荷容量Ｗはすきまｈの減少にともない増加し、無次元静剛性ＫＳの値が最大となる最適軸受すきまは、ｈ＝３〜５μｍ程度、無次元静剛性ＫＳの最大値は０．４程度であった。これらの軸受静特性は、市販されている多孔質静圧空気軸受とおおむね同程度の値であり、本実施形態で提案する軸受構造と金属３Ｄプリンタを用いた製造方法により、通常の製作方法より簡便に多孔質静圧空気軸受１０を製作できることが確認された。なお、ｐｓｇ＝０．６ＭＰａの場合、軸受すきまｈ＝６．５〜１４μｍにおいて実験データが無いが、これはニューマティックハンマによりデータの取得が困難であったためである。 Figure 11 shows the measurement results of p sg = dimensionless bearing load capacity W and the dimensionless static stiffness K S in the case of 0.4 MPa, dimensionless bearing load capacity W and in the case of p sg = 0.6 MPa in Figure 12 the measurement results of the dimensionless static stiffness K S. As shown in these figures, the dimensionless bearing load capacity W increases with the decrease of the gap h, the optimum bearing clearance values of dimensionless static rigidity K S is maximized, h = 3 to 5 [mu] m approximately, dimensionless the maximum value of the static rigidity K S was about 0.4. The static characteristics of these bearings are almost the same values as those of commercially available porous hydrostatic air bearings. The bearing structure proposed in this embodiment and the manufacturing method using a metal 3D printer are more effective than the normal manufacturing method. It was confirmed that the porous hydrostatic air bearing 10 can be easily manufactured. In the case of p sg = 0.6 MPa, there is no experimental data when the bearing clearance h is 6.5 to 14 μm. This is because it is difficult to acquire data by a pneumatic hammer.
（第２実施形態及び第３実施形態に係る多孔質静圧空気軸受）
以上説明したように、第１実施形態に係る多孔質静圧空気軸受１０においても、一般的な多孔質静圧空気軸受と同じく、給気圧や軸受すきまによっては、ニューマティックハンマが生じることが明らかとなった。以下、このニューマティックハンマが生じることを抑制した第２実施形態及び第３実施形態に係る多孔質静圧空気軸受について説明する。なお、第２実施形態及び第３実施形態に係る多孔質静圧空気軸受において、前述の多孔質静圧空気軸受１０と対応する部分には、当該多孔質静圧空気軸受１０と対応する部分と同一の符号を付して、その説明を省略することがある。
(Porous Hydrostatic Air Bearing According to Second and Third Embodiments)
As described above, in the porous hydrostatic air bearing 10 according to the first embodiment, it is clear that a pneumatic hammer is generated depending on the supply air pressure and the bearing clearance, as in the case of a general porous hydrostatic air bearing. It became. Hereinafter, porous hydrostatic air bearings according to the second and third embodiments in which the occurrence of the pneumatic hammer is suppressed will be described. In the porous hydrostatic air bearings according to the second and third embodiments, the portion corresponding to the porous hydrostatic air bearing 10 described above includes a portion corresponding to the porous hydrostatic air bearing 10 and The same reference numerals may be attached and the description thereof may be omitted.
図１３及び図１４に示されるように、第２実施形態に係る多孔質静圧空気軸受４４及び第３実施形態に係る多孔質静圧空気軸受４６は、多孔質層１４の内径部４８を焼結する際のレーザ強度と多孔質層１４の外径部５０を焼結する際のレーザ強度を変化させることで、多孔質層１４の通気率を内径部４８と外径部５０で変化させている。 As shown in FIGS. 13 and 14, the porous hydrostatic air bearing 44 according to the second embodiment and the porous hydrostatic air bearing 46 according to the third embodiment baked the inner diameter portion 48 of the porous layer 14. By changing the laser intensity when sintering and the laser intensity when sintering the outer diameter part 50 of the porous layer 14, the air permeability of the porous layer 14 is changed between the inner diameter part 48 and the outer diameter part 50. Yes.
図１３に示された第２実施形態に係る多孔質静圧空気軸受４４では、多孔質層１４の内径部４８（直径２４．５ｍｍより内径側）の通気率（空気の通り易さ）が外径部５０より大きく（空気が通り易く）なるように焼結している。具体的には、多孔質層１４の内径部４８をレーザ密度２６．８７５Ｊ／ｍｍ３（２１５Ｗ）で焼結し、多孔質層１４の外径部５０をレーザ密度２８．７５Ｊ／ｍｍ３（２３０Ｗ）で焼結している。 In the porous hydrostatic air bearing 44 according to the second embodiment shown in FIG. 13, the air permeability (ease of air passage) of the inner diameter portion 48 (the inner diameter side of the diameter 24.5 mm) of the porous layer 14 is outside. Sintering is performed so as to be larger than the diameter portion 50 (air easily passes through). Specifically, the inner diameter portion 48 of the porous layer 14 is sintered at a laser density of 26.875 J / mm 3 (215 W), and the outer diameter portion 50 of the porous layer 14 is sintered at a laser density of 28.75 J / mm 3 (230 W). ).
図１４に示された第３実施形態に係る多孔質静圧空気軸受４６では、多孔質層１４の外径部５０（直径２４．５ｍｍより外径側）の通気率（空気の通り易さ）が内径部４８より大きく（空気が通り易く）なるように焼結している。具体的には、多孔質層１４の内径部４８をレーザ密度２８．７５Ｊ／ｍｍ３（２３０Ｗ）で焼結し、多孔質層１４の外径部５０をレーザ密度で２６．８７５Ｊ／ｍｍ３（２１５Ｗ）焼結している。 In the porous hydrostatic air bearing 46 according to the third embodiment shown in FIG. 14, the air permeability (ease of air passage) of the outer diameter portion 50 (the outer diameter side of the diameter 24.5 mm) of the porous layer 14. Is sintered to be larger than the inner diameter portion 48 (air can easily pass through). Specifically, the inner diameter portion 48 of the porous layer 14 is sintered at a laser density of 28.75 J / mm 3 (230 W), and the outer diameter portion 50 of the porous layer 14 is sintered at a laser density of 26.875 J / mm 3 ( 215W) Sintering.
なお、多孔質静圧空気軸受４４、４６の試作においては、何れの軸受においても、軸受開放流量が０．８〜１．２ｌ／ｍｉｎ（吸気圧ｐｓｇ＝０．６ＭＰａ）となるよう多孔質層１４の厚みをワイヤ放電加工機により加工して調節した。 In the trial production of the porous hydrostatic air bearings 44 and 46, the porous flow rate is 0.8 to 1.2 l / min (intake pressure p sg = 0.6 MPa) in any bearing. The thickness of the layer 14 was adjusted by processing with a wire electric discharge machine.
以上説明した多孔質静圧空気軸受４４、４６について、図１０に示された実験装置３６を用いて、前述と同様に無次元軸受負荷容量Ｗおよび無次元静剛性ＫＳを測定した。 Above for the porous static pressure air bearings 44 and 46 as described, using the experimental apparatus 36 shown in FIG. 10 was measured dimensionless bearing load capacity W and the dimensionless static stiffness K S in the same manner as described above.
また、多孔質静圧空気軸受４４、４６の動特性の実験においては、実験装置３６のシャフト３４の下部にインパルス荷重を与え、その際の自由振動波形を非接触変位計に接続したデジタルオシロスコープにより記録する。その自由振動波形により、振動周波数ｆ、対数減衰率δを求める。得られた値を以下の式３に代入し無次元減衰係数Ｂを、また以下の式４から無次元動剛性Ｋｄを求める。 In the experiment of the dynamic characteristics of the porous hydrostatic air bearings 44 and 46, an impulse load is applied to the lower part of the shaft 34 of the experimental device 36, and the free vibration waveform at that time is measured by a digital oscilloscope connected to a non-contact displacement meter. Record. From the free vibration waveform, the vibration frequency f and the logarithmic attenuation rate δ are obtained. By substituting the obtained value into the following formula 3, the dimensionless damping coefficient B is obtained, and from the following formula 4, the dimensionless dynamic stiffness Kd is obtained.
軸受静特性については、図１５に無次元軸受負荷容量Ｗおよび無次元静剛性ＫＳの測定結果を示す。この図に示すように、前述の第１実施形態に係る多孔質静圧空気軸受１０（ＴｙｐｅＡ）については、軸受すきまｈ＝６．５〜１４μｍにおいてニューマティックハンマが生じたが、第２実施形態に係る多孔質静圧空気軸受４４（ＴｙｐｅＢ）および第３実施形態に係る多孔質静圧空気軸受４６（ＴｙｐｅＣ）においては、ニューマティックハンマは生じなかった。軸受静特性を比較すると、第１実施形態に係る多孔質静圧空気軸受１０に関しては、静剛性の値が最大となる最適軸受すきまはｈ＝３〜５μｍ、第２実施形態に係る多孔質静圧空気軸受４４および第３実施形態に係る多孔質静圧空気軸受４６はｈ＝５〜７μｍであり、第２実施形態に係る多孔質静圧空気軸受４４と第３実施形態に係る多孔質静圧空気軸受４６については、ほぼ同等の性能であった。なお、第１実施形態に係る多孔質静圧空気軸受１０については、軸受開放流量を多くすることで、無次元軸受負荷容量Ｗが増加し、最適軸受すきまｈを第２実施形態に係る多孔質静圧空気軸受４４および第３実施形態に係る多孔質静圧空気軸受４６と同等にすることは可能であるが、軸受開放流量を多くするとニューマティックハンマ発生すきま領域がさらに増加する可能性が高くなる。 The bearing static characteristics, showing a measurement result of the dimensionless bearing load capacity W and the dimensionless static stiffness K S in Figure 15. As shown in this figure, with respect to the porous hydrostatic air bearing 10 (Type A) according to the first embodiment described above, a pneumatic hammer occurs in the bearing clearance h = 6.5 to 14 μm. In the porous hydrostatic air bearing 44 (Type B) and the porous hydrostatic air bearing 46 (Type C) according to the third embodiment, no pneumatic hammer occurred. Comparing the bearing static characteristics, in the porous hydrostatic air bearing 10 according to the first embodiment, the optimum bearing clearance at which the static stiffness value is maximized is h = 3 to 5 μm, and the porous static air bearing according to the second embodiment. The compressed air bearing 44 and the porous hydrostatic air bearing 46 according to the third embodiment have h = 5 to 7 μm, and the porous hydrostatic air bearing 44 according to the second embodiment and the porous static air bearing 44 according to the third embodiment. The compressed air bearing 46 had almost the same performance. For the porous hydrostatic air bearing 10 according to the first embodiment, the dimensionless bearing load capacity W is increased by increasing the bearing opening flow rate, and the optimum bearing clearance h is set to the porous according to the second embodiment. Although it is possible to make it equivalent to the hydrostatic air bearing 44 and the porous hydrostatic air bearing 46 according to the third embodiment, if the bearing opening flow rate is increased, there is a high possibility that the pneumatic hammer generating clearance region is further increased. Become.
軸受動特性については、図１６に動特性の試験結果を示す。この図に示すように、無次元減衰係数Ｂの値を見ると、第１実施形態に係る多孔質静圧空気軸受１０においては、ｈ＝６．５〜１４μｍにおいてニューマティックハンマにより測定結果が得られていないが、ｈ＝６．５〜１４μｍにおいて無次元減衰係数Ｂが負の値になっていると考えらえられる。 一方、静特性試験においてニューマティックハンマは生じなかった第２実施形態に係る多孔質静圧空気軸受４４および第３実施形態に係る多孔質静圧空気軸受４６においては、すべての軸受すきまｈにおいて、無次元減衰係数Ｂが正の値であることがわかる。第２実施形態に係る多孔質静圧空気軸受４４および第３実施形態に係る多孔質静圧空気軸受４６を比較すると、両者の静特性は同等であったが、無次元動剛性Ｋｄや無次元減衰係数Ｂについては、第３実施形態に係る多孔質静圧空気軸受４６の方が高い値であり、第３実施形態に係る多孔質静圧空気軸受４６のほうが軸受動特性に優れるという結果となった。第３実施形態に係る多孔質静圧空気軸受４６は，多孔質層１４の内径部４８の通気率を外径部５０の通気率よりも低くしているが、軸受すきまの変動により生じる軸受すきまから多孔質層１４の内部への流入・流出流量が少なくなることで、高いスクイーズ効果が得られたものと考えられる。 As for the bearing dynamic characteristics, FIG. 16 shows the dynamic characteristic test results. As shown in this figure, when the value of the dimensionless damping coefficient B is seen, in the porous hydrostatic air bearing 10 according to the first embodiment, a measurement result is obtained by a pneumatic hammer at h = 6.5 to 14 μm. Although not shown, it can be considered that the dimensionless attenuation coefficient B is a negative value at h = 6.5 to 14 μm. On the other hand, in the porous hydrostatic air bearing 44 according to the second embodiment and the porous hydrostatic air bearing 46 according to the third embodiment in which no pneumatic hammer has occurred in the static characteristic test, in all the bearing clearances h, It can be seen that the dimensionless attenuation coefficient B is a positive value. Comparing the porous hydrostatic air bearing 44 according to the second embodiment and the porous hydrostatic air bearing 46 according to the third embodiment, the static characteristics of both were the same, but the dimensionless dynamic rigidity Kd and no Regarding the dimensional damping coefficient B, the porous hydrostatic air bearing 46 according to the third embodiment has a higher value, and the porous hydrostatic air bearing 46 according to the third embodiment is superior in bearing dynamic characteristics. It became. In the porous hydrostatic air bearing 46 according to the third embodiment, the air permeability of the inner diameter portion 48 of the porous layer 14 is lower than the air permeability of the outer diameter portion 50, but the bearing clearance generated due to the variation of the bearing clearance. It is considered that a high squeeze effect was obtained by reducing the inflow / outflow flow rate from the inside to the inside of the porous layer 14.
なお、以上説明した多孔質静圧空気軸受１０、４４、４６では、多孔質層支持部１２と多孔質層１４とを同じ金属粉末によって形成した例について説明したが、本発明はこれに限定されない。例えば、多孔質層支持部１２と多孔質層１４とを互いに異なる金属粉末によって形成してもよい。 In the above-described porous hydrostatic air bearings 10, 44, and 46, an example in which the porous layer support 12 and the porous layer 14 are formed of the same metal powder has been described. However, the present invention is not limited to this. . For example, the porous layer support 12 and the porous layer 14 may be formed of different metal powders.
また、以上説明した多孔質静圧空気軸受１０、４４、４６は、シャフト３４の軸方向の端部を支持するが、本発明は他のタイプの多孔質静圧空気軸受に適用することもできる。例えば、図１７及び図１８に示されるように、シャフト３４を径方向に支持する多孔質静圧空気軸受５２に本発明を適用することもできる。なお、多孔質静圧空気軸受５２において、前述の多孔質静圧空気軸受１０、４４、４６と対応する部分には、当該多孔質静圧空気軸受１０、４４、４６と対応する部分と同一の符号を付している。 The porous hydrostatic air bearings 10, 44, and 46 described above support the axial end of the shaft 34, but the present invention can also be applied to other types of porous hydrostatic air bearings. . For example, as shown in FIGS. 17 and 18, the present invention can be applied to a porous hydrostatic air bearing 52 that supports the shaft 34 in the radial direction. In the porous hydrostatic air bearing 52, the portion corresponding to the porous hydrostatic air bearing 10, 44, 46 is the same as the portion corresponding to the porous hydrostatic air bearing 10, 44, 46. The code is attached.
以上、本発明の一実施形態について説明したが、本発明は、上記に限定されるものでなく、その主旨を逸脱しない範囲内において上記以外にも種々変形して実施することが可能であることは勿論である。 Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications other than the above can be implemented without departing from the spirit of the present invention. Of course.
１０ 多孔質静圧空気軸受
１２ 多孔質層支持部（支持部）
１４ 多孔質層
２４ 第１流通孔（第１流通部）
３２ 第２流通孔（第２流通部）
４４ 多孔質静圧空気軸受
４６ 多孔質静圧空気軸受
５２ 多孔質静圧空気軸受
10 Porous static pressure air bearing 12 Porous layer support part (support part)
14 Porous layer 24 1st flow hole (1st flow part)
32 2nd flow hole (2nd flow part)
44 Porous Hydrostatic Air Bearing 46 Porous Hydrostatic Air Bearing 52 Porous Hydrostatic Air Bearing
Claims (8)
金属材料を用いて形成され、前記支持部の他方側の面に沿って前記支持部と一体に形成され、前記第１流通部からの空気が導入されると共にこの空気が前記支持部とは反対側の面から流出する複数の第２流通部を有し、この第２流通部から流出した空気によって軸部材が支持される多孔質層と、
を備えた多孔質静圧空気軸受。 A support part that is formed using a metal material and has a plurality of first flow parts through which air flows from one side to the other side;
It is formed using a metal material, is formed integrally with the support portion along the other surface of the support portion, and air from the first circulation portion is introduced and the air is opposite to the support portion. A porous layer having a plurality of second flow portions flowing out from the side surface, and the shaft member supported by the air flowing out from the second flow portions;
Porous hydrostatic air bearing with
金属材料を用いて形成され、前記支持部の他方側の面に沿って前記支持部と一体に形成され、前記第１流通部からの空気が導入されると共にこの空気が前記支持部とは反対側の面から流出する複数の第２流通部を有し、この第２流通部から流出した空気によって軸部材が支持される多孔質層と、
を備えた多孔質静圧空気軸受の製造方法に適用され、
金属粉末にレーザを照射することで、前記支持部を形成する支持部形成工程と、
金属粉末にレーザを照射することで、前記支持部の他方側の面に沿って前記多孔質層を形成する多孔質層形成工程と、
を有する多孔質静圧空気軸受の製造方法。 A support part that is formed using a metal material and has a plurality of first flow parts through which air flows from one side to the other side;
It is formed using a metal material, is formed integrally with the support portion along the other surface of the support portion, and air from the first circulation portion is introduced and the air is opposite to the support portion. A porous layer having a plurality of second flow portions flowing out from the side surface, and the shaft member supported by the air flowing out from the second flow portions;
Applied to a method of manufacturing a porous hydrostatic air bearing with
By irradiating the metal powder with a laser, a supporting part forming step for forming the supporting part,
A porous layer forming step of forming the porous layer along the other surface of the support portion by irradiating the metal powder with a laser;
A method for producing a porous hydrostatic air bearing.
前記多孔質層形成工程においてエネルギ密度Ｅを調節することで、前記多孔質層の前記第２流通部を介した空気の通り易さを調節する請求項６記載の多孔質静圧空気軸受の製造方法。 The energy of the laser input to the metal powder per unit volume is defined as energy density E (J / mm 2 ),
The manufacture of a porous hydrostatic air bearing according to claim 6, wherein the ease of passing air through the second flow part of the porous layer is adjusted by adjusting the energy density E in the porous layer forming step. Method.
前記多孔質層形成工程において前記エネルギ密度Ｅを２８．１２５Ｊ／ｍｍ２以下に設定する請求項７記載の多孔質静圧空気軸受の製造方法。 Using the metal powder of stainless steel,
The method for manufacturing a porous hydrostatic air bearing according to claim 7, wherein the energy density E is set to 28.125 J / mm 2 or less in the porous layer forming step.
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| Application Number | Title | Priority Date | Filing Date |
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| JP2018085277A Pending JP2019190591A (en) | 2018-04-26 | 2018-04-26 | Porous static pressure air bearing and its process of manufacture |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112922961A (en) * | 2021-03-23 | 2021-06-08 | 哈尔滨工业大学 | Static pressure air flotation unit based on porous throttling unit and processing method |
| CN114810821A (en) * | 2021-01-21 | 2022-07-29 | 厦门市奥正智能科技有限公司 | 3D printing air hydrostatic bearing structure and machining process thereof |
| WO2022209685A1 (en) * | 2021-03-31 | 2022-10-06 | 日本精工株式会社 | Gas bearing pad |
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| JP2001027240A (en) * | 1999-07-12 | 2001-01-30 | Hideo Nakajima | Static pressure porous bearing and manufacture thereof |
| US20040071374A1 (en) * | 2002-08-28 | 2004-04-15 | Hirotsugu Tomita | Bearing material for porous hydrostatic gas bearing and porous hydrostatic gas bearing using the same |
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| CN86106556A (en) * | 1985-09-27 | 1987-05-27 | 佩尔特荷派卡斯公司 | Gas bearing and the bearing member and the bearing material that are fit to do gas bearing |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114810821A (en) * | 2021-01-21 | 2022-07-29 | 厦门市奥正智能科技有限公司 | 3D printing air hydrostatic bearing structure and machining process thereof |
| CN112922961A (en) * | 2021-03-23 | 2021-06-08 | 哈尔滨工业大学 | Static pressure air flotation unit based on porous throttling unit and processing method |
| CN112922961B (en) * | 2021-03-23 | 2022-06-24 | 哈尔滨工业大学 | Static pressure air flotation unit based on porous throttling unit and processing method |
| WO2022209685A1 (en) * | 2021-03-31 | 2022-10-06 | 日本精工株式会社 | Gas bearing pad |
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