JP2016136047A - Static pressure fluid bearing device, and spindle device for machine tool using static pressure fluid bearing device - Google Patents

Static pressure fluid bearing device, and spindle device for machine tool using static pressure fluid bearing device Download PDF

Info

Publication number
JP2016136047A
JP2016136047A JP2015011583A JP2015011583A JP2016136047A JP 2016136047 A JP2016136047 A JP 2016136047A JP 2015011583 A JP2015011583 A JP 2015011583A JP 2015011583 A JP2015011583 A JP 2015011583A JP 2016136047 A JP2016136047 A JP 2016136047A
Authority
JP
Japan
Prior art keywords
bearing
rotating shaft
lubricant
bearing gap
static pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2015011583A
Other languages
Japanese (ja)
Other versions
JP6455177B2 (en
Inventor
大和　宏樹
Hiroki Yamato
宏樹 大和
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JTEKT Corp
Original Assignee
JTEKT Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by JTEKT Corp filed Critical JTEKT Corp
Priority to JP2015011583A priority Critical patent/JP6455177B2/en
Priority to DE102016100995.4A priority patent/DE102016100995A1/en
Priority to CN201610040469.7A priority patent/CN105817650A/en
Publication of JP2016136047A publication Critical patent/JP2016136047A/en
Application granted granted Critical
Publication of JP6455177B2 publication Critical patent/JP6455177B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q1/00—Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
    • B23Q1/25—Movable or adjustable work or tool supports
    • B23Q1/26—Movable or adjustable work or tool supports characterised by constructional features relating to the co-operation of relatively movable members; Means for preventing relative movement of such members
    • B23Q1/38—Movable or adjustable work or tool supports characterised by constructional features relating to the co-operation of relatively movable members; Means for preventing relative movement of such members using fluid bearings or fluid cushion supports
    • B23Q1/385—Movable or adjustable work or tool supports characterised by constructional features relating to the co-operation of relatively movable members; Means for preventing relative movement of such members using fluid bearings or fluid cushion supports in which the thickness of the fluid-layer is adjustable
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q1/00—Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
    • B23Q1/70—Stationary or movable members for carrying working-spindles for attachment of tools or work
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B41/00—Component parts such as frames, beds, carriages, headstocks
    • B24B41/04—Headstocks; Working-spindles; Features relating thereto
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B5/00—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor
    • B24B5/02—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centres or chucks for holding work
    • B24B5/04—Machines or devices designed for grinding surfaces of revolution on work, including those which also grind adjacent plane surfaces; Accessories therefor involving centres or chucks for holding work for grinding cylindrical surfaces externally
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C32/00—Bearings not otherwise provided for
    • F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
    • F16C32/0629—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion
    • F16C32/064—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion the liquid being supplied under pressure
    • F16C32/0651—Details of the bearing area per se
    • F16C32/0659—Details of the bearing area per se of pockets or grooves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2322/00—Apparatus used in shaping articles
    • F16C2322/39—General buildup of machine tools, e.g. spindles, slides, actuators

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Magnetic Bearings And Hydrostatic Bearings (AREA)
  • Turning (AREA)
  • Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)

Abstract

PROBLEM TO BE SOLVED: To reduce power loss by suppressing an increase in speed gradient of a fluid in a pocket of a static pressure fluid bearing device.SOLUTION: The present invention relates to a static pressure fluid bearing device. A static pressure part 18 has a bearing gap 20, a bearing plane part 22, a plurality of pockets 24, and a land part 30, and a groove part 40 has a side groove part, an upstream groove part 44 and a downstream groove part 46; and the upstream groove part 44 has a flow passage 16 (supply path), and the bearing gap 20 has a first bearing gap C and a second bearing gap H. The second bearing gap H is larger than a first bearing gap C, and has a Reynolds number Re=ρUH/μ, where ρ is a density of a lubricating agent R, μ is a viscosity coefficient of the lubricating agent R, U is a peripheral speed of a rotating shaft, and H is the second bearing gap H. A flow of the lubricating agent R in the second bearing gap H in a state in which the rotating shaft is supported and rotated is represented as Re<2,000.SELECTED DRAWING: Figure 6

Description

この発明は静圧流体軸受装置、静圧流体軸受装置を用いた工作機械用主軸装置に関する。   The present invention relates to a hydrostatic bearing device and a spindle device for a machine tool using the hydrostatic bearing device.

従来、工作機械の主軸などの高速回転する回転軸を潤滑液剤等の加圧流体の静圧によって支持する静圧流体軸受装置が知られている（特許文献１参照）。例えば、特許文献１には、回転軸を回転支持するための静圧部を有する軸受メタルを備える静圧流体軸受装置の技術が開示されている。係る静圧部は、回転軸の表面との間に軸受隙間を有する軸受面部と、軸受面部の周方向に隣接して凹設される複数のポケットとを有し、係るポケットに潤滑液剤などの流体を供給することで、回転軸を流体圧（静圧）によって支持する技術である。   2. Description of the Related Art Conventionally, a hydrostatic bearing device that supports a rotating shaft that rotates at high speed, such as a main shaft of a machine tool, by static pressure of a pressurized fluid such as a lubricant (see Patent Document 1). For example, Patent Document 1 discloses a technique of a hydrostatic fluid bearing device including a bearing metal having a hydrostatic portion for rotating and supporting a rotating shaft. The static pressure part has a bearing surface part having a bearing gap with the surface of the rotating shaft and a plurality of pockets recessed adjacent to the circumferential direction of the bearing surface part, and a lubricant or the like is provided in the pocket. This is a technique for supporting the rotating shaft by fluid pressure (static pressure) by supplying fluid.

特開２００１−３０４２６０号公報JP 2001-304260 A

しかしながら、静圧流体軸受装置に使用される潤滑液剤は、図９、１０に示すように回転軸の回転によってポケット内において所謂つれ回りによる流れを引き起こし、回転軸の回転方向の流れと、ポケットの底部における回転軸の回転と逆方向の流れと、が生じる。これに伴い静圧流体軸受装置は、回転軸の表面近傍に大きな速度勾配が発生し、大きな流体せん断抵抗による動力損失が懸念される。また、ポケット内部は、レイノルズ数が２００００〜３００００の強い乱流となっており、回転軸の表面近傍の大きな速度勾配の発生、大きな流体せん断抵抗による動力損失が懸念される。この傾向は、回転軸が高速回転するにつれて一層顕著となる。   However, as shown in FIGS. 9 and 10, the lubricant used in the hydrostatic bearing device causes a so-called swirling flow in the pocket due to the rotation of the rotation shaft, and the flow in the rotation direction of the rotation shaft and the pocket A flow in the direction opposite to the rotation of the rotation shaft at the bottom occurs. Along with this, a large velocity gradient is generated in the vicinity of the surface of the rotating shaft in the hydrostatic bearing device, and there is a concern about power loss due to a large fluid shear resistance. Further, the inside of the pocket is a strong turbulent flow with a Reynolds number of 20000 to 30000, and there is a concern about the generation of a large velocity gradient near the surface of the rotating shaft and the power loss due to the large fluid shear resistance. This tendency becomes more remarkable as the rotating shaft rotates at a high speed.

そこで本発明は、このような点に鑑みて創案されたものであり、本発明が解決しようとする課題は、静圧流体軸受装置のポケットにおける流体の速度勾配の上昇を抑制し動力損失の低減を図ることにある。   Therefore, the present invention has been made in view of the above points, and the problem to be solved by the present invention is to suppress an increase in the velocity gradient of the fluid in the pocket of the hydrostatic bearing device and reduce power loss. Is to plan.

上記課題を解決するために、本発明の静圧流体軸受装置は次の手段をとる。先ず、第１の発明に係る静圧流体軸受装置は、静圧流体軸受装置であって、回転軸を回転支持するための静圧部を有する軸受メタルを備え、前記静圧部は、前記回転軸の表面との間に潤滑液剤が充填される軸受隙間と、前記回転軸の表面と並行する軸受面部と、該軸受面部の周方向に隣接して凹設される複数のポケットと、該ポケットの底部から前記回転軸の表面に向かって突出し前記回転軸の表面と並行する対向面と前記ポケットの縁部との間に溝部を有するランド部と、を有し、前記溝部は、前記ランド部の両側部に円周方向に配設された側溝部と、前記回転軸の回転方向の上流側に位置する上流溝部と下流側に位置する下流溝部とを有し、前記上流溝部に連通し前記静圧部に潤滑液剤を供給する供給路を有し、前記軸受隙間は、前記回転軸の表面と前記軸受面部との間の第１軸受隙間と、前記回転軸の表面と前記対向面との間の第２軸受隙間と、を有し、前記第２軸受隙間は、前記第１軸受隙間より大きい関係であり、前記潤滑液剤の密度をρ、前記潤滑液剤の粘性係数をμ、前記回転軸の周速をＵ、前記第２軸受隙間をＨである場合に、前記第２軸受隙間におけるレイノルズ数Ｒｅは、Ｒｅ＝ρＵＨ／μで表され、前記回転軸が回転支持される状態の第２軸受隙間における潤滑液剤の流れはＲｅ＜２０００である。   In order to solve the above problems, the hydrostatic bearing device of the present invention takes the following means. First, the hydrostatic bearing device according to the first aspect of the present invention is a hydrostatic bearing device, comprising a bearing metal having a hydrostatic portion for rotating and supporting a rotating shaft, and the hydrostatic portion is configured to rotate the rotating shaft. A bearing gap filled with a lubricant between the surface of the shaft, a bearing surface portion parallel to the surface of the rotary shaft, a plurality of pockets recessed adjacent to the circumferential direction of the bearing surface portion, and the pocket A land portion that protrudes from the bottom of the rotary shaft toward the surface of the rotating shaft and has a groove portion between an opposing surface parallel to the surface of the rotating shaft and an edge of the pocket, and the groove portion is the land portion. Side groove portions disposed on both sides of the rotating shaft, an upstream groove portion located on the upstream side in the rotational direction of the rotating shaft, and a downstream groove portion located on the downstream side, and communicated with the upstream groove portion. A supply path for supplying a lubricant to the static pressure part, and the bearing gap is A first bearing gap between the surface of the shaft and the bearing surface portion, and a second bearing gap between the surface of the rotary shaft and the facing surface, wherein the second bearing gap is the first bearing gap. When the density of the lubricant is ρ, the viscosity coefficient of the lubricant is μ, the peripheral speed of the rotating shaft is U, and the second bearing gap is H, the second bearing is larger than the bearing gap. The Reynolds number Re in the gap is represented by Re = ρUH / μ, and the flow of the lubricant in the second bearing gap in a state where the rotating shaft is rotationally supported is Re <2000.

この第１の発明によれば、静圧部には、ポケットの底部から回転軸の表面に向かって突出し回転軸の表面と並行する対向面とポケットの縁部との間に溝部を有するランド部を有している。溝部は、ランド部の両側部に円周方向に配設された側溝部と、回転軸の回転方向の上流側に位置する上流溝部と下流側に位置する下流溝部とを有し、上流溝部に連通し静圧部に潤滑液剤を供給する供給路を有する。これにより、潤滑液剤の流れは、対向面上が回転軸の回転方向の流れとなり、側溝部が回転軸の回転と逆方向の流れとなるため、相互の影響を及ぼし難くなる。これにより、静圧流体軸受装置のポケットにおける流体の速度勾配の上昇を抑制し動力損失の低減を図ることができる。また、潤滑液剤の密度をρ、潤滑液剤の粘性係数をμ、回転軸の周速をＵ、第２軸受隙間をＨである場合に、第２軸受隙間におけるレイノルズ数ＲｅはＲｅ＝ρＵＨ／μで表される。そして、回転軸が回転支持される状態の第２軸受隙間における潤滑液剤の流れはＲｅ＜２０００である。すなわち、第２軸受隙間における潤滑液剤の流れにともなう大きな流体せん断抵抗が生じ難くなり、動力損失が抑制され得る。   According to the first aspect of the present invention, the static pressure portion includes a land portion that protrudes from the bottom of the pocket toward the surface of the rotating shaft and has a groove portion between the facing surface parallel to the surface of the rotating shaft and the edge of the pocket. have. The groove portion includes a side groove portion disposed circumferentially on both sides of the land portion, an upstream groove portion located on the upstream side in the rotation direction of the rotating shaft, and a downstream groove portion located on the downstream side. A supply path for supplying a lubricant to the communicating static pressure part is provided. As a result, the flow of the lubricating liquid becomes a flow in the rotation direction of the rotation shaft on the opposite surface, and the side groove portion flows in a direction opposite to the rotation of the rotation shaft, so that it is difficult to exert mutual influence. Thereby, it is possible to suppress an increase in the velocity gradient of the fluid in the pocket of the hydrostatic bearing device and to reduce power loss. Further, when the density of the lubricant is ρ, the viscosity coefficient of the lubricant is μ, the peripheral speed of the rotating shaft is U, and the second bearing gap is H, the Reynolds number Re in the second bearing gap is Re = ρUH / μ. It is represented by The flow of the lubricant in the second bearing gap in a state where the rotation shaft is rotationally supported is Re <2000. In other words, a large fluid shear resistance due to the flow of the lubricant in the second bearing gap is less likely to occur, and power loss can be suppressed.

次に、第２の発明に係る静圧流体軸受装置は、上述した第１の発明に係る静圧流体軸受装置であって、前記潤滑液剤は、水または組成に占める水の割合が９０％以上の水溶液または、低粘度鉱油である。   Next, the hydrostatic bearing device according to the second aspect of the invention is the hydrostatic bearing device according to the first aspect of the invention described above, wherein the lubricating liquid agent has a ratio of water or water in the composition of 90% or more. Or a low viscosity mineral oil.

この第２の発明によれば、潤滑液剤は、水または組成に占める水の割合が９０％以上の水溶液または、低粘度鉱油であると好適である。   According to the second aspect of the present invention, the lubricating liquid is preferably water or an aqueous solution having a ratio of water to the composition of 90% or more, or a low viscosity mineral oil.

次に、第３の発明に係る静圧流体軸受装置は、上述した第１の発明または第２の発明に係る静圧流体軸受装置であって、前記回転軸が回転支持される状態の前記第２軸受隙間における前記潤滑液剤は前記回転軸の回転方向に沿って流れる層流であり、前記層流の潤滑液剤の一部は前記側溝部を経由して前記供給路を有する前記上流溝部への流れとなる。   Next, a hydrostatic bearing device according to a third invention is the hydrostatic bearing device according to the first invention or the second invention described above, wherein the rotating shaft is rotatably supported. The lubricating liquid agent in the two bearing gaps is a laminar flow flowing along the rotation direction of the rotating shaft, and a part of the laminar lubricating liquid agent passes through the side groove portion to the upstream groove portion having the supply path. It becomes a flow.

この第３の発明によれば、第２軸受隙間における潤滑液剤は回転軸の回転方向に沿って流れる層流であり、層流の潤滑液剤の一部は側溝部を経由して供給路を有する前記上流溝部への流れとなる。これにより、ランド部は、第２軸受隙間における層流と、側溝部における反回転方向の流れを分ける。そのため相互の影響を及ぼし難くなる。よってポケットにおける流体の速度勾配の上昇を抑制し動力損失の低減をより一層図ることができ得る。   According to the third aspect of the invention, the lubricant in the second bearing gap is a laminar flow that flows along the rotation direction of the rotating shaft, and a part of the laminar lubricant has a supply path via the side groove. The flow is to the upstream groove. Thereby, the land portion separates the laminar flow in the second bearing gap and the flow in the counter-rotating direction in the side groove portion. Therefore, it becomes difficult to have mutual influence. Therefore, the increase in the velocity gradient of the fluid in the pocket can be suppressed, and the power loss can be further reduced.

次に、第４の発明は、上述した第１の発明から第３の発明のいずれかに係る静圧流体軸受装置を用いて工作機械における工作機械用主軸を回転支持する工作機械用主軸装置とする。このように、工作機械用主軸装置に上記静圧流体軸受装置を用いると好適である。   Next, a fourth invention relates to a machine tool spindle device that rotatably supports a machine tool spindle in a machine tool using the hydrostatic fluid bearing device according to any one of the first to third inventions described above. To do. Thus, it is preferable to use the hydrostatic bearing device for the spindle device for machine tools.

本発明は上記各発明の手段をとることにより、静圧流体軸受装置のポケットにおける流体の速度勾配の上昇を抑制し動力損失の低減を図ることができる。   According to the present invention, by taking the measures of the respective inventions described above, an increase in the velocity gradient of the fluid in the pocket of the hydrostatic bearing device can be suppressed and power loss can be reduced.

実施形態に係る静圧流体軸受装置を用いた工作機械用主軸装置の一例として研削盤の全体構成を示す平面図である。It is a top view showing the whole grinding machine composition as an example of the spindle device for machine tools using the hydrostatic bearing device concerning an embodiment. 図１に示す研削盤の右側面図である。It is a right view of the grinding machine shown in FIG. 図１のＩＩＩ部の拡大断面図である。It is an expanded sectional view of the III section of FIG. 図３のＩＶ−ＩＶ線断面図である。It is the IV-IV sectional view taken on the line of FIG. 軸受メタルを一部割断して内部形状を示した斜視図である。It is the perspective view which partially cut off the bearing metal and showed the internal shape. 図３のＩＶ−ＩＶ線の拡大断面図でありポケット内の潤滑液剤の流れを示した図である。FIG. 4 is an enlarged cross-sectional view taken along the line IV-IV in FIG. 3, illustrating a flow of a lubricant in a pocket. ポケット内の潤滑液剤の流れの速度分布図である。FIG. 6 is a velocity distribution diagram of the flow of the lubricant in the pocket. 静圧流体軸受装置の消費電力を示した図である。It is the figure which showed the power consumption of a hydrostatic bearing device. 従来のポケット内の潤滑液剤の流れの速度分布図である。It is a velocity distribution diagram of the flow of the lubricant in the conventional pocket. 従来のポケット内の潤滑液剤の流れを示した図である。It is the figure which showed the flow of the lubricating liquid agent in the conventional pocket.

以下に本発明を実施するための一形態として静圧流体軸受装置、静圧流体軸受装置を用いた工作機械用主軸装置を図面を用いて説明する。   Hereinafter, a hydrostatic bearing device and a spindle device for a machine tool using the hydrostatic fluid bearing device will be described with reference to the drawings as an embodiment for carrying out the present invention.

図１は、実施形態に係る静圧流体軸受装置を用いた工作機械用主軸装置の一例として研削盤１０の全体構成を示す平面図である。図２は、研削盤１０の右側面図である。なお、図２では保持台１５１を備えたワーク保持装置１５０の図示を省略している。ここで、Ｘ軸、Ｙ軸、Ｚ軸が記載されているすべての図面において、Ｘ軸とＹ軸とＺ軸は互いに直交しており、Ｙ軸は鉛直上向きを示しており、Ｚ軸とＸ軸は水平方向を示している。そして、Ｚ軸方向は砥石回転軸Ｌ１と平行な方向（換言すれば、ワーク回転軸方向）を示しており、Ｘ軸方向は砥石回転軸Ｌ１に直交する方向であり、砥石１３２がワークＷに切り込む方向を示している。また、砥石回転軸Ｌ１とワーク回転軸Ｌ２とツルア回転軸Ｌ３は、いずれもＺ軸方向と平行である。   FIG. 1 is a plan view showing an overall configuration of a grinding machine 10 as an example of a spindle device for a machine tool using a hydrostatic bearing device according to an embodiment. FIG. 2 is a right side view of the grinding machine 10. In FIG. 2, the work holding device 150 including the holding table 151 is not shown. Here, in all drawings in which the X axis, the Y axis, and the Z axis are described, the X axis, the Y axis, and the Z axis are orthogonal to each other, the Y axis indicates a vertically upward direction, and the Z axis and the X axis The axis indicates the horizontal direction. The Z-axis direction indicates a direction parallel to the grindstone rotation axis L1 (in other words, the workpiece rotation axis direction), the X-axis direction is a direction orthogonal to the grindstone rotation axis L1, and the grindstone 132 is placed on the workpiece W. The direction of cutting is shown. The grindstone rotation axis L1, the workpiece rotation axis L2, and the truer rotation axis L3 are all parallel to the Z-axis direction.

図１、２に示される研削盤１０は、ワークＷに対して砥石１３２をＸ軸方向及びＺ軸方向へ相対的に移動制御してワークＷを研削するようになっている。平面形状で矩形に形成された基台１１０上の略中央部には、Ｚ軸方向に延びる一対のＺ軸方向ガイドレール１１１にスライド案内されるＺ軸方向スライドテーブル１１２が配設されている。Ｚ軸方向スライドテーブル１１２は、制御手段１８０（ＮＣ制御装置等）によって作動制御されるＺ軸方向駆動モータ１１４を駆動源とするＺ軸方向送りねじ１１３の回転動作によってＺ軸方向へスライドされる。また、Ｚ軸方向駆動モータ１１４には、Ｚ軸方向スライドテーブル１１２のＺ軸方向の位置を確認するために、Ｚ軸駆動モータ１１４の出力軸の回転角度を検出してその検出信号を制御手段１８０に送るエンコーダ等のＺ軸方向位置検出手段１１５が設けられている。制御手段１８０は、Ｚ軸方向駆動モータ１１４を用いて、ツルア１７７又はワークＷに対して砥石１３２を相対的にＺ軸方向へ移動させ、Ｚ軸方向位置検出手段１１５からの検出信号に基づいて、ツルア１７７又はワークＷに対する砥石１３２のＺ軸方向への相対的な移動量を検出可能である。   The grinding machine 10 shown in FIGS. 1 and 2 grinds the workpiece W by controlling the movement of the grindstone 132 relative to the workpiece W in the X-axis direction and the Z-axis direction. A Z-axis direction slide table 112 that is slidably guided by a pair of Z-axis direction guide rails 111 extending in the Z-axis direction is disposed at a substantially central portion on the base 110 that is formed in a rectangular shape in a planar shape. The Z-axis direction slide table 112 is slid in the Z-axis direction by the rotation operation of the Z-axis direction feed screw 113 using the Z-axis direction drive motor 114 controlled by the control means 180 (NC control device or the like) as a drive source. . Further, the Z-axis direction drive motor 114 detects the rotation angle of the output shaft of the Z-axis drive motor 114 and controls the detection signal in order to confirm the position of the Z-axis direction slide table 112 in the Z-axis direction. Z-axis direction position detecting means 115 such as an encoder for sending to 180 is provided. The control means 180 uses the Z-axis direction drive motor 114 to move the grindstone 132 relative to the truer 177 or the workpiece W in the Z-axis direction, and based on the detection signal from the Z-axis direction position detection means 115. The relative movement amount of the grindstone 132 in the Z-axis direction with respect to the truer 177 or the workpiece W can be detected.

Ｚ軸方向スライドテーブル１１２上には、Ｘ軸方向に延びる一対のＸ軸方向ガイドレール１２１にスライド案内されるＸ軸方向スライドテーブル１２２が配設されている。Ｘ軸方向スライドテーブル１２２は、制御手段１８０によって作動制御されるＸ軸方向駆動モータ１２４を駆動源とするＸ軸方向送りねじ１２３の回転動作によってＸ軸方向へスライドされる。また、Ｘ軸方向駆動モータ１２４には、Ｘ軸方向スライドテーブル１２２のＸ軸方向の位置を確認するために、Ｘ軸方向駆動モータ１２４の出力軸の回転角度を検出してその検出信号を制御手段１８０に送るエンコーダ等のＸ軸方向位置検出手段１２５が設けられている。制御手段１８０は、Ｘ軸方向駆動モータ１２４を用いて、ツルア１７７又はワークＷに対して砥石１３２を相対的にＸ軸方向へ移動させ、Ｘ軸方向位置検出手段１２５からの検出信号に基づいて、ツルア１７７又はワークＷに対する砥石１３２のＸ軸方向への相対的な移動量を検出可能である。   On the Z-axis direction slide table 112, an X-axis direction slide table 122 that is slidably guided by a pair of X-axis direction guide rails 121 extending in the X-axis direction is disposed. The X-axis direction slide table 122 is slid in the X-axis direction by the rotation operation of the X-axis direction feed screw 123 using the X-axis direction drive motor 124 controlled by the control means 180 as a drive source. The X-axis direction drive motor 124 detects the rotation angle of the output shaft of the X-axis direction drive motor 124 and controls the detection signal in order to confirm the position of the X-axis direction slide table 122 in the X-axis direction. An X-axis direction position detecting means 125 such as an encoder for sending to the means 180 is provided. The control means 180 uses the X-axis direction drive motor 124 to move the grindstone 132 relative to the truer 177 or the workpiece W in the X-axis direction, and based on the detection signal from the X-axis direction position detection means 125. The relative movement amount of the grindstone 132 in the X-axis direction with respect to the truer 177 or the workpiece W can be detected.

Ｘ軸方向スライドテーブル１２２上には、砥石駆動モータ１２６と砥石軸ホルダ１３０とがそれぞれ配設されており、砥石駆動モータ１２６の出力軸には駆動プーリ１２７が設けられる。一方、砥石軸ホルダ１３０に回転可能に支持されかつ一端部に略円筒状の砥石１３２が設けられる砥石軸１３１（Ｚ軸方向に平行な砥石回転軸Ｌ１回りに回転する砥石軸）の他端には、従動プーリ１２８が設けられている。そして、駆動プーリ１２７と従動プーリ１２８との間にはベルト１２９が張設され、これによって、砥石駆動モータ１２６の出力軸のトルクがベルト１２９を介して砥石軸１３１に伝達される。   A grindstone drive motor 126 and a grindstone shaft holder 130 are provided on the X-axis direction slide table 122, and a drive pulley 127 is provided on the output shaft of the grindstone drive motor 126. On the other hand, at the other end of the grindstone shaft 131 (the grindstone shaft rotating around the grindstone rotation axis L1 parallel to the Z-axis direction), which is rotatably supported by the grindstone shaft holder 130 and provided with a substantially cylindrical grindstone 132 at one end. Is provided with a driven pulley 128. A belt 129 is stretched between the driving pulley 127 and the driven pulley 128, whereby the torque of the output shaft of the grindstone driving motor 126 is transmitted to the grindstone shaft 131 via the belt 129.

基台１１０上には、軸状のワークＷをＺ軸方向のワーク回転軸Ｌ２回りに回転させながら設定位置に保持するワーク保持装置１４０とワーク保持装置１５０とが、Ｚ軸方向に平行なワーク回転軸Ｌ２上に配設されている。ワーク保持装置１４０は、基台１１０上に固定された保持台１４１と、保持台１４１に対しワーク回転軸Ｌ２上に往復動可能な保持軸ハウジング１４２と、この保持軸ハウジング１４２内でワーク回転軸Ｌ２回りに回転可能に支持された保持軸部材１４３とを備え、保持軸部材１４３の先端にはワークＷの一方の端面の中心部を支持するセンタ部材１４４が設けられている。また、保持軸部材１４３は、制御手段１８０によって作動制御される保持軸モータ（図示省略）を駆動源として任意の角速度で任意の角度まで回転制御される。また、ワーク保持装置１５０においても、ワーク保持装置１４０と同様にして保持台１５１、保持軸ハウジング１５２、保持軸部材１５３及びセンタ部材１５４を備えて構成されている。また、保持軸ハウジング１４２にはツルア回転軸Ｌ３回りに回転可能に支持されたツルア１７７を備えたツルーイング装置１６０が設けられている。なお、図２に示すように、砥石回転軸Ｌ１と、ワーク回転軸Ｌ２と、ツルア回転軸Ｌ３は、いずれもＸ軸方向及びＺ軸方向に平行な平面である仮想平面ＶＭ上にある。   On the base 110, there are a workpiece holding device 140 and a workpiece holding device 150 that hold the shaft-like workpiece W around the workpiece rotation axis L2 in the Z-axis direction at a set position, and the workpiece parallel to the Z-axis direction. It is arrange | positioned on the rotating shaft L2. The workpiece holding device 140 includes a holding table 141 fixed on the base 110, a holding shaft housing 142 that can reciprocate on the workpiece rotation axis L <b> 2 with respect to the holding table 141, and a workpiece rotation axis within the holding shaft housing 142. A holding shaft member 143 supported rotatably around L2 is provided, and a center member 144 that supports the center of one end surface of the workpiece W is provided at the tip of the holding shaft member 143. The holding shaft member 143 is rotationally controlled to an arbitrary angle at an arbitrary angular velocity by using a holding shaft motor (not shown) that is controlled by the control unit 180 as a drive source. In addition, the work holding device 150 is configured to include a holding base 151, a holding shaft housing 152, a holding shaft member 153, and a center member 154, similarly to the work holding device 140. Further, the holding shaft housing 142 is provided with a truing device 160 including a truer 177 that is rotatably supported around the truer rotation axis L3. As shown in FIG. 2, the grindstone rotation axis L1, the workpiece rotation axis L2, and the truer rotation axis L3 are all on a virtual plane VM that is a plane parallel to the X-axis direction and the Z-axis direction.

このように、研削盤１０は、ワークＷまたはツルア１７７に対して砥石１３２をＺ軸方向及びＸ軸方向に相対移動させることで、ワークＷの研削を施し、またはツルア１７７によって砥石１３２の外形形状を適宜型直しを施す。   In this way, the grinding machine 10 performs grinding of the workpiece W by moving the grindstone 132 relative to the workpiece W or the truer 177 in the Z-axis direction and the X-axis direction, or the outer shape of the grindstone 132 by the truer 177. Reshape as appropriate.

図３は、砥石軸ホルダ１３０の拡大断面図（図１のＩＩＩ部の箇所）である。図４は、図３のＩＶ−ＩＶ線断面図である。図５は、軸受メタルを一部割断して内部形状を示した斜視図である。図６は、図３のＩＶ−ＩＶ線の拡大断面図でありポケット内の潤滑液剤の流れを示した図である。砥石軸ホルダ１３０は、図３に示すように砥石軸ハウジング１２と、砥石軸ハウジング１２内に固定される軸受メタル１４を有する。砥石軸１３１（回転軸）は軸受メタル１４に回転支持されている。図４に示すように、軸受メタル１４は、軸受メタル１４内にポンプＰ（図４参照）等から流路１６を介して潤滑液剤Ｒなどの流体を供給することで砥石軸１３１を流体圧（静圧）によって回転支持するための静圧部１８を有する。軸受メタル１４は、図５に示すように鉄鋼製の筒状に構成されている。静圧部１８は、図６に示すように軸受メタル１４の内周面において、軸受隙間２０と、軸受面部２２と、複数のポケット２４と、ランド部３０と、が構成される。なお、潤滑液剤Ｒは、水または組成に占める水の割合が９０％以上の水溶液または、低粘度鉱油であることが望ましい。   FIG. 3 is an enlarged cross-sectional view of the grindstone shaft holder 130 (part III in FIG. 1). 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a perspective view showing the internal shape by partially cutting the bearing metal. FIG. 6 is an enlarged cross-sectional view taken along the line IV-IV in FIG. 3 and shows the flow of the lubricant in the pocket. As shown in FIG. 3, the grindstone shaft holder 130 includes a grindstone shaft housing 12 and a bearing metal 14 fixed in the grindstone shaft housing 12. The grindstone shaft 131 (rotary shaft) is rotatably supported by the bearing metal 14. As shown in FIG. 4, the bearing metal 14 supplies fluid such as a lubricant R through the flow path 16 from the pump P (see FIG. 4) or the like into the bearing metal 14 to cause the grinding wheel shaft 131 to be fluid pressure ( It has a static pressure part 18 for rotational support by static pressure). As shown in FIG. 5, the bearing metal 14 is formed in a steel cylinder shape. As shown in FIG. 6, the static pressure portion 18 includes a bearing gap 20, a bearing surface portion 22, a plurality of pockets 24, and a land portion 30 on the inner peripheral surface of the bearing metal 14. The lubricating liquid R is preferably water or an aqueous solution having a ratio of water of 90% or more to the composition or a low-viscosity mineral oil.

軸受面部２２は、図５、６に示すように砥石軸１３１の表面と並行する面である。ポケット２４は、ポンプＰ等から流路１６（供給路）を介して供給される潤滑液剤Ｒを溜める部位である。ポケット２４は、軸受メタル１４の軸受面部２２に凹設され、周方向に複数個が分割されて隣接している。本実施形態では、４個のポケット２４にそれぞれ潤滑液剤Ｒが流路１６を介して供給される。なお、ポケット２４の個数は、４個に限定されるものではない。なお、ポケット２４、軸方向ポケット（図示省略）にて砥石軸１３１の静圧支持に使用されて流出した流体は、ドレイン（図示省略）を経由して回収され、オイルクーラ等にて冷却されてタンクＴ（図４参照）に戻される。   The bearing surface portion 22 is a surface parallel to the surface of the grindstone shaft 131 as shown in FIGS. The pocket 24 is a part for storing the lubricant R supplied from the pump P or the like via the flow path 16 (supply path). The pockets 24 are recessed in the bearing surface portion 22 of the bearing metal 14, and a plurality of pockets 24 are adjacent to each other in the circumferential direction. In the present embodiment, the lubricant R is supplied to each of the four pockets 24 via the flow path 16. The number of pockets 24 is not limited to four. In addition, the fluid that is used for static pressure support of the grindstone shaft 131 in the pocket 24 and the axial pocket (not shown) is recovered via a drain (not shown) and cooled by an oil cooler or the like. It is returned to the tank T (see FIG. 4).

ランド部３０は、ポケット２４の底部２６から砥石軸１３１の表面に向かって突出し砥石軸１３１の表面と並行する対向面３２とポケット２４の縁部２８との間に溝部４０を有する。溝部４０は、ランド部３０の両側部に円周方向に配設された側溝部４２と、回転軸の回転方向の上流側に位置する上流溝部４４と下流側に位置する下流溝部４６とを有する。また、上流溝部４４に連通し静圧部１８に潤滑液剤Ｒを供給する流路１６（供給路）を有する。   The land portion 30 has a groove portion 40 between the facing surface 32 that protrudes from the bottom portion 26 of the pocket 24 toward the surface of the grindstone shaft 131 and is parallel to the surface of the grindstone shaft 131 and the edge portion 28 of the pocket 24. The groove portion 40 includes a side groove portion 42 disposed in the circumferential direction on both sides of the land portion 30, an upstream groove portion 44 located on the upstream side in the rotation direction of the rotation shaft, and a downstream groove portion 46 located on the downstream side. . Further, the flow path 16 (supply path) that communicates with the upstream groove portion 44 and supplies the lubricant R to the static pressure portion 18 is provided.

軸受隙間２０は、砥石軸１３１の表面との間に潤滑液剤Ｒが充填される空間である。軸受隙間２０は、砥石軸１３１の表面と軸受面部２２との間の第１軸受隙間Ｃと、砥石軸１３１の表面と対向面３２との間の第２軸受隙間Ｈを有する。第２軸受隙間Ｈは、第１軸受隙間Ｃより大きい関係で設定される。軸受メタル１４は、内周面を切削加工を施して複数のポケット２４と、ポケット２４内にランド部３０とを形成する。これにより、軸受メタル１４は、砥石軸１３１の表面との間に潤滑液剤Ｒが充填される軸受隙間２０と、砥石軸１３１の表面と並行する軸受面部２２と、軸受面部２２の周方向に隣接して凹設される複数のポケット２４と、ポケット２４の底部２６から砥石軸１３１の表面に向かって突出し砥石軸１３１の表面と並行する対向面３２とポケット２４の縁部２８との間に溝部４０を有するランド部３０と、を有する静圧部１８となる。   The bearing gap 20 is a space filled with the lubricant R between the surface of the grindstone shaft 131. The bearing gap 20 has a first bearing gap C between the surface of the grindstone shaft 131 and the bearing surface portion 22, and a second bearing gap H between the surface of the grindstone shaft 131 and the facing surface 32. The second bearing gap H is set so as to be larger than the first bearing gap C. The bearing metal 14 cuts the inner peripheral surface to form a plurality of pockets 24 and land portions 30 in the pockets 24. Thereby, the bearing metal 14 is adjacent to the surface of the grindstone shaft 131 with the bearing gap 20 filled with the lubricant R, the bearing surface portion 22 parallel to the surface of the grindstone shaft 131, and the circumferential direction of the bearing surface portion 22. A plurality of pockets 24 that are recessed, and a groove portion between the edge 28 of the pocket 24 and a facing surface 32 that protrudes from the bottom 26 of the pocket 24 toward the surface of the grindstone shaft 131 and is parallel to the surface of the grindstone shaft 131. The static pressure part 18 having the land part 30 having 40.

砥石軸１３１は、係るポケット２４に潤滑液剤Ｒなどの流体を供給することで流体圧（静圧）によって支持される。ここで、潤滑液剤Ｒの密度ρ、潤滑液剤Ｒの粘性係数μ、砥石軸１３１の周速Ｕ、第２軸受隙間Ｈである場合に、第２軸受隙間Ｈにおけるレイノルズ数ＲｅはＲｅ＝ρＵＨ／μで表される。ここで、砥石軸１３１の周速Ｕの設定は、砥石軸１３１の設計標準仕様速度、想定する使用頻度の高い回転速度や平均速度、などをもとに適宜設定することが例示される。砥石軸１３１が回転支持される状態の潤滑液剤Ｒの流れはＲｅ＜２０００で設定されるように第２軸受隙間Ｈの間隔を設定する。砥石軸１３１が回転支持される状態の第２軸受隙間Ｈにおける潤滑液剤Ｒは砥石軸１３１の回転方向に沿って流れる層流となり、層流の潤滑液剤Ｒの一部は、ポケット２４の縁部２８に遮られ下流溝部４６、側溝部４２を経由して流路１６を有する上流溝部４４への流れとなる。そのため側溝部４２を流れる潤滑液剤Ｒは砥石軸１３１の反回転方向の流れとなる。   The grindstone shaft 131 is supported by fluid pressure (static pressure) by supplying a fluid such as the lubricant R to the pocket 24. Here, when the density ρ of the lubricant R, the viscosity coefficient μ of the lubricant R, the peripheral speed U of the grindstone shaft 131, and the second bearing gap H, the Reynolds number Re in the second bearing gap H is Re = ρUH / It is expressed in μ. Here, the setting of the peripheral speed U of the grindstone shaft 131 is exemplified by setting as appropriate based on the design standard specification speed of the grindstone shaft 131, the rotation speed and the average speed that are assumed to be frequently used, and the like. The interval of the second bearing gap H is set so that the flow of the lubricant R in a state where the grindstone shaft 131 is rotationally supported is set to Re <2000. The lubricant R in the second bearing gap H in a state where the grindstone shaft 131 is rotationally supported becomes a laminar flow flowing along the rotation direction of the grindstone shaft 131, and a part of the laminar lubricant R is an edge of the pocket 24. The flow flows to the upstream groove 44 having the flow path 16 via the downstream groove 46 and the side groove 42. Therefore, the lubricant R flowing through the side groove portion 42 flows in the counter-rotating direction of the grindstone shaft 131.

ここで、従来におけるランド部３０を有さないポケット２２４内の潤滑液剤Ｒは、図９、１０に示すように砥石軸２３１の回転によってポケット２２４内において所謂つれ回りによる流れを引き起こし、砥石軸２３１回転方向の流れと、ポケット２２４の底部２２６における砥石軸２３１の回転と逆方向の流れと、が生じる。これに伴い静圧流体軸受装置は、砥石軸２３１の表面近傍に大きな速度勾配が発生し、大きな流体せん断抵抗による動力損失が懸念される。軸受内の潤滑液剤Ｒの流れがレイノルズ数２００００〜３００００の強い乱流の状況下では、ポケット深さＫ、砥石軸２３１の周速Ｓとしたときの潤滑液剤Ｒの流れの速度勾配が∂Ｓ／∂Ｋと表される。ここで、潤滑液剤Ｒの粘性係数μの場合、砥石軸２３１に係るせん断力τ１は、τ１＝μ×（∂Ｓ／∂Ｋ）と表される。そして、ポケット２２４内の潤滑液剤Ｒが砥石軸２３１に及ぼす動力損失Ｐ１は、ポケット２２４の開口面積Ａとすると、Ｐ１＝Ｓ×τ１×Ａと表される。してみると、砥石軸２３１の周速Ｓ及びポケット２２４の開口面積Ａが固定の値であると仮定した場合、動力損失Ｐ１に影響を及ぼすのは、せん断力τ１となる。さらには、潤滑液剤Ｒの温度変化が一定であれば粘性係数μは一定である。そのため、τ１における速度勾配の∂Ｓ／∂Ｋが動力損失Ｐ１に影響を及ぼす要因となる。   Here, as shown in FIGS. 9 and 10, the lubricant R in the pocket 224 having no conventional land portion 30 causes a so-called whirling flow in the pocket 224 due to the rotation of the grindstone shaft 231, and the grindstone shaft 231. A flow in the rotation direction and a flow in the direction opposite to the rotation of the grindstone shaft 231 at the bottom 226 of the pocket 224 are generated. Accordingly, in the hydrostatic bearing device, a large velocity gradient is generated in the vicinity of the surface of the grindstone shaft 231, and there is a concern about power loss due to a large fluid shear resistance. Under a strong turbulent flow condition in which the flow of the lubricant R in the bearing has a Reynolds number of 20000 to 30000, the velocity gradient of the flow of the lubricant R when the pocket depth K and the peripheral speed S of the grinding wheel shaft 231 are ∂S. / Represented as ∂K. Here, in the case of the viscosity coefficient μ of the lubricant R, the shearing force τ1 applied to the grindstone shaft 231 is expressed as τ1 = μ × (∂S / ∂K). The power loss P1 that the lubricant R in the pocket 224 exerts on the grindstone shaft 231 is expressed as P1 = S × τ1 × A where the opening area A of the pocket 224 is assumed. Assuming that the peripheral speed S of the grinding wheel shaft 231 and the opening area A of the pocket 224 are fixed values, it is the shearing force τ1 that affects the power loss P1. Further, if the temperature change of the lubricant R is constant, the viscosity coefficient μ is constant. Therefore, the speed gradient ∂S / ∂K at τ1 is a factor affecting the power loss P1.

一方、図６に示すように軸受内の潤滑液剤Ｒの流れが層流状況下においては、速度勾配をＵ／Ｈと近似することができる。砥石軸１３１に係るせん断力τ２は、τ２＝μ×（Ｕ／Ｈ）と表される。そして、ポケット２４内の潤滑液剤Ｒが砥石軸１３１に及ぼす動力損失Ｐ２は、ポケット２４の開口面積Ａとすると、Ｐ２＝Ｕ×τ２×Ａと表される。してみると、砥石軸１３１の周速Ｕ及びポケット２４の開口面積Ａが固定の値であると仮定した場合、動力損失Ｐ２に影響を及ぼすのは、せん断力τ２となる。さらには、潤滑液剤Ｒの温度変化が一定であれば粘性係数μは一定である。そのため、τ２は、速度勾配のＵ／Ｈの内、Ｈが動力損失Ｐ２に影響を及ぼす要因となる。   On the other hand, as shown in FIG. 6, when the flow of the lubricant R in the bearing is in a laminar flow state, the velocity gradient can be approximated to U / H. The shearing force τ2 related to the grindstone shaft 131 is expressed as τ2 = μ × (U / H). The power loss P2 that the lubricant R in the pocket 24 exerts on the grindstone shaft 131 is expressed as P2 = U × τ2 × A where the opening area A of the pocket 24 is assumed. Assuming that the peripheral speed U of the grindstone shaft 131 and the opening area A of the pocket 24 are fixed values, it is the shearing force τ2 that affects the power loss P2. Further, if the temperature change of the lubricant R is constant, the viscosity coefficient μ is constant. Therefore, τ2 is a factor in which H affects the power loss P2 in the U / H of the velocity gradient.

そのため、本実施形態の静圧部１８は、図６、７に示すように砥石軸１３１の表面近傍を層流状況下としつつ、砥石軸１３１の回転方向の流れと、ポケット２４の側溝部４２における砥石軸１３１の回転と逆方向の流れを分けて相互に影響を及ぼさないようにするために、ランド部３０を採用した。このランド部３０の対向面３２と砥石軸１３１の表面との間の第２軸受隙間Ｈを層流が維持できる範囲内で最大に設定する。このランド部３０の構成により、静圧部１８の軸受隙間２０は、砥石軸１３１の表面と軸受面部２２との間の第１軸受隙間Ｃと、砥石軸１３１の表面とランド部３０との間の第２軸受隙間Ｈを有する。ここで、第２軸受隙間Ｈは、第１軸受隙間Ｃより大きい関係で設定される。以上より、砥石軸１３１が回転支持される状態の第２軸受隙間Ｈにおける潤滑液剤Ｒは砥石軸１３１の回転方向に沿って流れる層流となる。また、ポケット２４の側溝部４２における潤滑液剤Ｒは、上記第２軸受隙間Ｈの層流の流れへの影響を抑制しつつ砥石軸１３１の反回転方向の流れとなって流路１６に戻る。これにより、図８に示すように、潤滑液剤Ｒを水、水溶液、低粘度鉱油いずれを用いても、消費電力を低減する結果が得られた。   Therefore, as shown in FIGS. 6 and 7, the static pressure unit 18 of the present embodiment has a laminar flow in the vicinity of the surface of the grindstone shaft 131, and the flow in the rotational direction of the grindstone shaft 131 and the side groove 42 of the pocket 24. In order to separate the flow in the direction opposite to the rotation of the grindstone shaft 131 in order not to affect each other, the land portion 30 was employed. The second bearing gap H between the facing surface 32 of the land portion 30 and the surface of the grindstone shaft 131 is set to the maximum within a range where laminar flow can be maintained. With the configuration of the land portion 30, the bearing gap 20 of the static pressure portion 18 is between the first bearing gap C between the surface of the grindstone shaft 131 and the bearing surface portion 22, and between the surface of the grindstone shaft 131 and the land portion 30. Second bearing gap H. Here, the second bearing gap H is set to be larger than the first bearing gap C. As described above, the lubricant R in the second bearing gap H in a state where the grindstone shaft 131 is rotatably supported becomes a laminar flow that flows along the rotation direction of the grindstone shaft 131. Further, the lubricant R in the side groove portion 42 of the pocket 24 returns to the flow path 16 as a flow in the counter-rotating direction of the grindstone shaft 131 while suppressing the influence of the second bearing gap H on the laminar flow. As a result, as shown in FIG. 8, the result of reducing the power consumption was obtained regardless of whether the lubricant R was water, an aqueous solution, or a low-viscosity mineral oil.

このように、実施形態の静圧流体軸受装置によれば、静圧部１８には、ポケット２４の底部から砥石軸１３１の表面に向かって突出し砥石軸１３１の表面と並行する対向面３２とポケット２４の縁部２８との間に溝部４０を有するランド部３０を有している。溝部４０は、ランド部３０の両側部に円周方向に配設された側溝部４２と、砥石軸１３１の回転方向の上流側に位置する上流溝部４４と下流側に位置する下流溝部４６とを有し、上流溝部４４に連通し静圧部１８に潤滑液剤Ｒを供給する流路１６（供給路）を有する。これにより、潤滑液剤Ｒの流れは、対向面３２上が砥石軸１３１の回転方向の流れとなり、側溝部４２が砥石軸１３１の回転と逆方向の流れとなるため、相互の影響を及ぼし難くなる。これにより、静圧流体軸受装置のポケット２４における流体の速度勾配の上昇を抑制し動力損失の低減を図ることができる。また、潤滑液剤Ｒの密度をρ、潤滑液剤Ｒの粘性係数をμ、砥石軸１３１の周速をＵ、第２軸受隙間Ｈである場合に、第２軸受隙間Ｈにおけるレイノルズ数ＲｅはＲｅ＝ρＵＨ／μで表される。そして、砥石軸１３１が回転支持される状態の第２軸受隙間Ｈにおける潤滑液剤Ｒの流れはＲｅ＜２０００である。すなわち、第２軸受隙間Ｈにおける潤滑液剤Ｒの流れにともなう大きな流体せん断抵抗が生じ難くなり、動力損失が抑制され得る。   As described above, according to the hydrostatic bearing device of the embodiment, the hydrostatic portion 18 includes the opposing surface 32 that protrudes from the bottom of the pocket 24 toward the surface of the grindstone shaft 131 and the pocket parallel to the surface of the grindstone shaft 131. A land portion 30 having a groove portion 40 is provided between 24 edge portions 28. The groove portion 40 includes a side groove portion 42 disposed circumferentially on both sides of the land portion 30, an upstream groove portion 44 positioned on the upstream side in the rotational direction of the grindstone shaft 131, and a downstream groove portion 46 positioned on the downstream side. And a flow path 16 (supply path) that communicates with the upstream groove portion 44 and supplies the lubricant R to the static pressure portion 18. Thereby, the flow of the lubricant R is a flow in the rotation direction of the grindstone shaft 131 on the opposing surface 32 and the side groove portion 42 is a flow in a direction opposite to the rotation of the grindstone shaft 131, so that it is difficult to influence each other. . Thereby, it is possible to suppress an increase in the velocity gradient of the fluid in the pocket 24 of the hydrostatic bearing device and to reduce power loss. Further, when the density of the lubricant R is ρ, the viscosity coefficient of the lubricant R is μ, the peripheral speed of the grindstone shaft 131 is U, and the second bearing gap H is Reynolds number Re in the second bearing gap H is Re = It is represented by ρUH / μ. The flow of the lubricant R in the second bearing gap H in a state where the grindstone shaft 131 is rotationally supported is Re <2000. That is, a large fluid shear resistance due to the flow of the lubricant R in the second bearing gap H is less likely to occur, and power loss can be suppressed.

また、潤滑液剤Ｒは、水または組成に占める水の割合が９０％以上の水溶液または、低粘度鉱油であると好適である。   In addition, the lubricant R is preferably water or an aqueous solution having a ratio of water to the composition of 90% or more, or a low viscosity mineral oil.

また、第２軸受隙間Ｈにおける潤滑液剤Ｒは砥石軸１３１の回転方向に沿って流れる層流であり、層流の潤滑液剤Ｒの一部は上流溝部４４、側溝部４２を経由して供給路を有する上流溝部４４への流れとなる。これにより、ランド部３０は、第２軸受隙間Ｈにおける層流と、側溝部４２における反回転方向の流れを分ける。そのため相互の影響を及ぼし難くなる。よって、ポケット２４における流体の速度勾配の上昇を抑制し動力損失の低減をより一層図ることができ得る。   The lubricant R in the second bearing gap H is a laminar flow that flows along the rotation direction of the grindstone shaft 131, and a part of the laminar lubricant R is supplied through the upstream groove 44 and the side groove 42. It becomes the flow to the upstream groove part 44 which has. Thereby, the land portion 30 separates the laminar flow in the second bearing gap H and the flow in the counter-rotating direction in the side groove portion 42. Therefore, it becomes difficult to have mutual influence. Therefore, an increase in the fluid velocity gradient in the pocket 24 can be suppressed, and the power loss can be further reduced.

また、上記構成の静圧流体軸受装置を用いて工作機械における工作機械用主軸を回転支持する工作機械用主軸装置とすると好適である。   In addition, it is preferable to use a hydrostatic bearing device having the above-described configuration as a machine tool spindle device that rotatably supports a machine tool spindle in a machine tool.

以上、本発明の実施形態について説明したが、本発明の静圧流体軸受装置、静圧流体軸受装置を用いた工作機械用主軸装置及び静圧流体軸受装置の製造方法は、実施形態に限定されず、その他各種の形態で実施することができるものである。   Although the embodiments of the present invention have been described above, the hydrostatic bearing device of the present invention, the spindle device for machine tools using the hydrostatic bearing device, and the manufacturing method of the hydrostatic bearing device are limited to the embodiments. It can be implemented in various other forms.

１０ 研削盤
１２ 砥石軸ハウジング
１４ 軸受メタル
１６ 流路（供給路）
１８ 静圧部
２０ 軸受隙間
２２ 軸受面部
２４ ポケット
２６ ポケットの底部
２８ ポケットの縁部
３０ ランド部
３２ 対向面
４０ 溝部
４２ 側溝部
４４ 上流溝部
４６ 下流溝部
１１０ 基台
１１１ Ｚ軸方向ガイドレール
１１２ Ｚ軸方向スライドテーブル
１１３ Ｚ軸方向送りねじ
１１４ Ｚ軸方向駆動モータ
１１５ Ｚ軸方向位置検出手段
１２１ Ｘ軸方向ガイドレール
１２２ Ｘ軸方向スライドテーブル
１２３ Ｘ軸方向送りねじ
１２４ Ｘ軸方向駆動モータ
１２５ Ｘ軸方向位置検出手段
１２６ 砥石駆動モータ
１２７ 駆動プーリ
１２８ 従動プーリ
１２９ ベルト
１３０ 砥石軸ホルダ
１３１ 砥石軸（回転軸）
１３２ 砥石
１４０ ワーク保持装置
１４１ 保持台
１４２ 保持軸ハウジング
１４３ 保持軸部材
１４４ センタ部材
１５０ ワーク保持装置
１５１ 保持台
１５２ 保持軸ハウジング
１５３ 保持軸部材
１５４ センタ部材
１６０ ツルーイング装置
１７７ ツルア
１８０ 制御手段
Ｃ 第１軸受隙間
Ｈ 第２軸受隙間
Ｌ１ 砥石回転軸
Ｌ２ ワーク回転軸
Ｌ３ ツルア回転軸
Ｐ ポンプ
Ｒ 潤滑液剤
Ｕ 砥石軸の周速
ＶＭ 仮想平面
Ｗ ワーク
DESCRIPTION OF SYMBOLS 10 Grinding machine 12 Grinding wheel shaft housing 14 Bearing metal 16 Flow path (supply path)
18 Hydrostatic part 20 Bearing gap 22 Bearing surface part 24 Pocket 26 Pocket bottom part 28 Pocket edge part 30 Land part 32 Opposing surface 40 Groove part 42 Side groove part 44 Upstream groove part 46 Downstream groove part 110 Base 111 Z-axis direction guide rail 112 Z axis Direction slide table 113 Z-axis direction feed screw 114 Z-axis direction drive motor 115 Z-axis direction position detecting means 121 X-axis direction guide rail 122 X-axis direction slide table 123 X-axis direction feed screw 124 X-axis direction drive motor 125 X-axis direction Position detection means 126 Grinding wheel drive motor 127 Drive pulley 128 Driven pulley 129 Belt 130 Grinding wheel shaft holder 131 Grinding wheel shaft (rotating shaft)
132 Grinding wheel 140 Work holding device 141 Holding stand 142 Holding shaft housing 143 Holding shaft member 144 Center member 150 Work holding device 151 Holding stand 152 Holding shaft housing 153 Holding shaft member 154 Center member 160 Truing device 177 Truer 180 Control means C First bearing Clearance H Second bearing clearance L1 Grinding wheel rotation axis L2 Work rotation axis L3 Truer rotation axis P Pump R Lubricant U Peripheral speed VM of grinding wheel axis Virtual plane W Workpiece

Claims (4)

静圧流体軸受装置であって、
回転軸を回転支持するための静圧部を有する軸受メタルを備え、
前記静圧部は、前記回転軸の表面との間に潤滑液剤が充填される軸受隙間と、前記回転軸の表面と並行する軸受面部と、該軸受面部の周方向に隣接して凹設される複数のポケットと、該ポケットの底部から前記回転軸の表面に向かって突出し前記回転軸の表面と並行する対向面と前記ポケットの縁部との間に溝部を有するランド部と、を有し、
前記溝部は、前記ランド部の両側部に円周方向に配設された側溝部と、前記回転軸の回転方向の上流側に位置する上流溝部と下流側に位置する下流溝部とを有し、
前記上流溝部に連通し前記静圧部に潤滑液剤を供給する供給路を有し、
前記軸受隙間は、前記回転軸の表面と前記軸受面部との間の第１軸受隙間と、前記回転軸の表面と前記対向面との間の第２軸受隙間と、を有し、
前記第２軸受隙間は、前記第１軸受隙間より大きい関係であり、
前記潤滑液剤の密度をρ、
前記潤滑液剤の粘性係数をμ、
前記回転軸の周速をＵ、
前記第２軸受隙間をＨである場合に、
前記第２軸受隙間におけるレイノルズ数Ｒｅは、Ｒｅ＝ρＵＨ／μで表され、
前記回転軸が回転支持される状態の第２軸受隙間における潤滑液剤の流れはＲｅ＜２０００である静圧流体軸受装置。 A hydrostatic bearing device,
A bearing metal having a static pressure part for rotating and supporting the rotating shaft,
The static pressure portion is recessedly formed adjacent to the bearing clearance filled with a lubricant between the surface of the rotating shaft, a bearing surface portion parallel to the surface of the rotating shaft, and the circumferential direction of the bearing surface portion. A plurality of pockets, and a land portion that protrudes from the bottom of the pocket toward the surface of the rotating shaft and has a groove portion between an opposing surface parallel to the surface of the rotating shaft and an edge of the pocket. ,
The groove portion includes a side groove portion disposed circumferentially on both sides of the land portion, an upstream groove portion located on the upstream side in the rotation direction of the rotating shaft, and a downstream groove portion located on the downstream side,
A supply path that communicates with the upstream groove and supplies the lubricant to the static pressure section;
The bearing gap has a first bearing gap between the surface of the rotating shaft and the bearing surface portion, and a second bearing gap between the surface of the rotating shaft and the facing surface,
The second bearing gap is larger than the first bearing gap,
The density of the lubricant is ρ,
The viscosity coefficient of the lubricant is μ,
The peripheral speed of the rotating shaft is U,
When the second bearing gap is H,
The Reynolds number Re in the second bearing gap is represented by Re = ρUH / μ,
The hydrostatic bearing device in which the flow of the lubricant in the second bearing gap in a state where the rotating shaft is rotatably supported is Re <2000. 請求項１に記載の静圧流体軸受装置であって、
前記潤滑液剤は、水または組成に占める水の割合が９０％以上の水溶液または、低粘度鉱油である静圧流体軸受装置。 The hydrostatic bearing device according to claim 1,
The lubricating fluid is a hydrostatic bearing device, wherein the lubricant is water or an aqueous solution having a ratio of water to 90% or more, or low-viscosity mineral oil. 請求項１または請求項２のいずれかに記載の静圧流体軸受装置であって、
前記回転軸が回転支持される状態の前記第２軸受隙間における前記潤滑液剤は前記回転軸の回転方向に沿って流れる層流であり、
前記層流の潤滑液剤の一部は前記側溝部を経由して前記供給路を有する前記上流溝部への流れとなる静圧流体軸受装置。 The hydrostatic bearing device according to claim 1 or 2,
The lubricant in the second bearing gap in a state where the rotating shaft is rotatably supported is a laminar flow that flows along the rotation direction of the rotating shaft;
A hydrostatic bearing device in which a part of the laminar flow lubricant flows through the side groove to the upstream groove having the supply path. 請求項１から請求項３のいずれかに記載の静圧流体軸受装置を用いて工作機械における工作機械用主軸を回転支持する工作機械用主軸装置。
A spindle device for a machine tool that rotatably supports a spindle for a machine tool in a machine tool using the hydrostatic bearing device according to any one of claims 1 to 3.
JP2015011583A 2015-01-23 2015-01-23 Hydrostatic bearing device, spindle device for machine tool using hydrostatic bearing device Active JP6455177B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2015011583A JP6455177B2 (en) 2015-01-23 2015-01-23 Hydrostatic bearing device, spindle device for machine tool using hydrostatic bearing device
DE102016100995.4A DE102016100995A1 (en) 2015-01-23 2016-01-21 Hydrostatic bearing device and machine tool main spindle device with hydrostatic bearing device
CN201610040469.7A CN105817650A (en) 2015-01-23 2016-01-21 Hydrostatic bearing apparatus and machine-tool main-spindle apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2015011583A JP6455177B2 (en) 2015-01-23 2015-01-23 Hydrostatic bearing device, spindle device for machine tool using hydrostatic bearing device

Publications (2)

Publication Number Publication Date
JP2016136047A true JP2016136047A (en) 2016-07-28
JP6455177B2 JP6455177B2 (en) 2019-01-23

Family

ID=56364677

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2015011583A Active JP6455177B2 (en) 2015-01-23 2015-01-23 Hydrostatic bearing device, spindle device for machine tool using hydrostatic bearing device

Country Status (3)

Country Link
JP (1) JP6455177B2 (en)
CN (1) CN105817650A (en)
DE (1) DE102016100995A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112405219A (en) * 2020-10-20 2021-02-26 南京合信自动化有限公司 Environment-friendly polishing robot with quick positioning mechanism for machining mechanical parts

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04249614A (en) * 1991-01-07 1992-09-04 Toyoda Mach Works Ltd Fluid bearing
JPH10500194A (en) * 1994-03-10 1998-01-06 アドバンス・エンジニアリング・システムズ，オペレイションズ・アンド・プロダクツ・インコーポレイテッド High speed hydrostatic spindle design
JP2001304260A (en) * 2000-04-27 2001-10-31 Toyoda Mach Works Ltd Fluid bearing device and grinding wheel spindle device for grinder using fluid bearing device
JP2011149500A (en) * 2010-01-22 2011-08-04 Sintokogio Ltd Hydrostatic bearing device and stage provided with the hydrostatic bearing device

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3903993A (en) * 1973-03-26 1975-09-09 Minster Machine Co Hydrostatic bearing arrangement for press slide
US4307918A (en) * 1978-05-17 1981-12-29 National Research Development Corporation Bearings
EP0051944B1 (en) * 1980-11-07 1985-12-18 National Research Development Corporation Improvements in or relating to fluid bearings
JPH0953640A (en) * 1995-08-18 1997-02-25 Mitsutoyo Corp Static pressure bearing device
CN203051487U (en) * 2012-11-30 2013-07-10 綦江齿轮传动有限公司 Lubricating oil path structure of hybrid bearing of grinding machine
CN203176167U (en) * 2013-04-12 2013-09-04 胡惜时 Hybrid bearing
CN103230824B (en) * 2013-04-28 2016-02-10 昆明学院 A kind of energy-conservation mixer-mill
CN203730559U (en) * 2014-02-19 2014-07-23 日本精工株式会社 Aerostatic bearing

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04249614A (en) * 1991-01-07 1992-09-04 Toyoda Mach Works Ltd Fluid bearing
JPH10500194A (en) * 1994-03-10 1998-01-06 アドバンス・エンジニアリング・システムズ，オペレイションズ・アンド・プロダクツ・インコーポレイテッド High speed hydrostatic spindle design
JP2001304260A (en) * 2000-04-27 2001-10-31 Toyoda Mach Works Ltd Fluid bearing device and grinding wheel spindle device for grinder using fluid bearing device
JP2011149500A (en) * 2010-01-22 2011-08-04 Sintokogio Ltd Hydrostatic bearing device and stage provided with the hydrostatic bearing device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112405219A (en) * 2020-10-20 2021-02-26 南京合信自动化有限公司 Environment-friendly polishing robot with quick positioning mechanism for machining mechanical parts
CN112405219B (en) * 2020-10-20 2022-09-23 南京合信自动化有限公司 Machine parts machining is with machine people of polishing with quick positioning mechanism

Also Published As

Publication number Publication date
DE102016100995A1 (en) 2016-07-28
CN105817650A (en) 2016-08-03
JP6455177B2 (en) 2019-01-23

Similar Documents

Publication Publication Date Title
CN106001611B (en) A kind of interrupted UVC method of high speed and precision
US9731360B2 (en) End milling apparatus, CAM apparatus, and NC program
JP6297627B2 (en) Liquid discharge pipe structure
CN104741986A (en) Buoyancy type inner bore processing device and method
CN102658507A (en) Flexible passivating processing method for superhard cutting tool and flexible passivating processing device thereof
JP6476910B2 (en) Hydrostatic bearing device, spindle device for machine tool using hydrostatic bearing device, and manufacturing method of hydrostatic bearing device
TWI481459B (en) Workpiece having a non-revolution curved surface
KR102673212B1 (en) Honing tools and honing processing methods
JP2011240432A (en) Compound machine tool
JP6455177B2 (en) Hydrostatic bearing device, spindle device for machine tool using hydrostatic bearing device
CN103551955A (en) Honing floating installing and clamping device
US20160184908A1 (en) Wire sawing machine
JP6464775B2 (en) Air seal structure and spindle device to which air seal structure is applied
JP6440872B2 (en) Grinding equipment
CN203679950U (en) Buoyancy inner hole machining device
EP3999274B1 (en) Method for suppressing the phenomenon of chatter in a machine tool
JP2017015218A (en) Static pressure fluid bearing, its manufacturing method and machine tool using the same
JP2007301705A (en) Saddle guide chiller of precision roll lathe
CN103978412A (en) Spherical surface finishing machine
JP2015213993A (en) Lubrication or cooling flow passage forming method in machine tool, and flow passage structure
JP6145384B2 (en) Dicing machine
JP2023057601A (en) Machine tool and manufacturing method of workpiece
CN103394713B (en) The main shaft device of machining tool
JP2011156644A (en) Cutting method
JP2020020348A (en) Rotary shaft member supporting device and grinder

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20171208

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20180816

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20180816

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20181015

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20181120

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20181203

R150 Certificate of patent or registration of utility model

Ref document number: 6455177

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150