JP2020128760A - Cooling structure of bearing device and main shaft device of machine tool - Google Patents

Cooling structure of bearing device and main shaft device of machine tool Download PDF

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JP2020128760A
JP2020128760A JP2019020645A JP2019020645A JP2020128760A JP 2020128760 A JP2020128760 A JP 2020128760A JP 2019020645 A JP2019020645 A JP 2019020645A JP 2019020645 A JP2019020645 A JP 2019020645A JP 2020128760 A JP2020128760 A JP 2020128760A
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bearing
ring spacer
inner ring
outer ring
nozzle
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JP7185546B2 (en
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惠介 那須
Keisuke NASU
惠介 那須
深田　貴久夫
Kikuo Fukada
貴久夫 深田
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NTN Corp
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NTN Corp
NTN Toyo Bearing Co Ltd
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Priority to JP2019020645A priority Critical patent/JP7185546B2/en
Priority to PCT/JP2019/035365 priority patent/WO2020054661A1/en
Priority to KR1020217007456A priority patent/KR20210057733A/en
Priority to CN201980059203.9A priority patent/CN112673186A/en
Priority to EP19860198.1A priority patent/EP3851692B1/en
Priority to TW108132949A priority patent/TWI821394B/en
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  • Mounting Of Bearings Or Others (AREA)
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Abstract

To provide a cooling structure of an air-cooling bearing device capable of securing a cooling effect of a bearing even in a case where a width dimension of a spacer is large.SOLUTION: An outer ring spacer 4 is provided with a nozzle 10 that discharges compressed air toward the outer peripheral surface of an inner ring spacer 5. The nozzle 10 inclines forward in a rotation direction. This is applied when a width W of the outer ring spacer 4 and the inner ring spacer 5 is 2.5 times or more a bearing width X. A distance Y from the center of the nozzle 10 to the side surface of a bearing 10 is less than or equal to the bearing width X, and more than or equal to 1/2 of the bearing width X.SELECTED DRAWING: Figure 1

Description

この発明は、軸受装置の冷却構造に関し、例えば工作機械の主軸および主軸に組み込まれる軸受の冷却構造に関する。 The present invention relates to a cooling structure for a bearing device, for example, a cooling structure for a main shaft of a machine tool and a bearing incorporated in the main shaft.

工作機械の主軸装置では、加工精度を確保するために、装置の温度上昇は小さく抑える必要がある。しかしながら最近の工作機械では、加工能率を向上させるため高速化の傾向にあり、主軸を支持する軸受からの発熱も高速化と共に大きくなってきている。また、装置内部に駆動用のモータを組込んだいわゆるモータビルトインタイプが多くなってきており、装置の発熱要因ともなってきている。
発熱による軸受の温度上昇は、軸受の予圧の増加をもたらす結果となり、主軸の高速化、加工の高精度化を考えると極力抑えたい。 In the spindle device of a machine tool, it is necessary to keep the temperature rise of the device small in order to ensure machining accuracy. However, in recent machine tools, there is a tendency toward higher speeds in order to improve the machining efficiency, and the heat generated from the bearings that support the spindle is also increasing along with the higher speeds. In addition, the number of so-called motor built-in types in which a driving motor is incorporated inside the device is increasing, which is also a cause of heat generation of the device.
The rise in bearing temperature due to heat generation results in an increase in bearing preload, and we want to suppress it as much as possible in view of higher spindle speed and higher machining accuracy.

主軸装置の温度上昇を抑えるための手段の一つとして、図９に示すように、運転中の軸受１０１を、外輪間座１０４の軸方向中央に設けられたノズル１１０から内輪間座１０５に向けて圧縮エアを吐出させることで冷却する方法が、特許文献１等で提案されている。 As one means for suppressing the temperature rise of the main spindle device, as shown in FIG. 9, the operating bearing 101 is directed from the nozzle 110 provided at the axial center of the outer ring spacer 104 to the inner ring spacer 105. A method of cooling by ejecting compressed air by using compressed air is proposed in Patent Document 1 and the like.

特許６１４４０２４号公報Japanese Patent No. 6144024

特許文献１の構成の場合、間座幅Ｗが軸受幅Ｘと同等のため、外輪間座１０４の軸方向中央に圧縮エアを吐出するノズル１１０が設けられていても、吐出口と軸受の距離が短いため、十分冷却効果を得ることができている。 In the case of the configuration of Patent Document 1, since the spacer width W is equal to the bearing width X, even if the nozzle 110 that discharges compressed air is provided at the axial center of the outer ring spacer 104, the distance between the discharge port and the bearing is large. Since it is short, a sufficient cooling effect can be obtained.

しかし、間座幅Ｗが大きい場合、例えば図１０に示すように軸受幅Ｘに対し、間座幅Ｗが２．５倍以上の場合、外輪間座１０４の軸方向中央に圧縮エアを吐出するノズル１１０を設け、圧縮エアの効果により、内輪間座１０５を冷却させたとしても、積極的に冷却されている箇所Ｓから軸受１までの距離が長いため、冷却効果が下がる。 However, when the spacer width W is large, for example, when the spacer width W is 2.5 times or more the bearing width X as shown in FIG. 10, compressed air is discharged to the axial center of the outer ring spacer 104. Even if the nozzle 110 is provided and the inner ring spacer 105 is cooled by the effect of compressed air, the cooling effect is reduced because the distance from the point S that is actively cooled to the bearing 1 is long.

この発明の目的は、間座の幅寸法が大きい場合でも、軸受の冷却効果が確保できる空冷の軸受装置の冷却構造、および工作機械の主軸装置を提供することである。 An object of the present invention is to provide a cooling structure for an air-cooled bearing device and a spindle device for a machine tool, which can ensure a bearing cooling effect even when the width of the spacer is large.

この発明の軸受装置の冷却構造は、軸受の外輪および内輪にそれぞれ隣接する外輪間座および内輪間座を備え、前記外輪間座に前記内輪間座の外周面に向けて圧縮エアを吐出するノズルが設けられた軸受装置の冷却構造であって、
前記ノズルは前記内輪間座の回転方向の前方へ傾斜し、かつ前記外輪間座の軸心に垂直な断面における任意の半径方向の直線から、この直線と直交する方向にオフセットした位置にあり、
前記外輪間座および内輪間座の幅が軸受幅の２．５倍以上であって、前記ノズルの中心から前記軸受の側面までの距離が、前記軸受幅以下であり、かつ前記軸受幅の１／２以上である。 A cooling structure for a bearing device according to the present invention includes an outer ring spacer and an inner ring spacer that are respectively adjacent to an outer ring and an inner ring of the bearing, and a nozzle that discharges compressed air to the outer ring spacer toward an outer peripheral surface of the inner ring spacer. Is a cooling structure of the bearing device provided with,
The nozzle is inclined forward in the rotation direction of the inner ring spacer, and from a straight line in any radial direction in a cross section perpendicular to the axial center of the outer ring spacer, the nozzle is at a position offset in a direction orthogonal to this straight line,
The width of the outer ring spacer and the inner ring spacer is 2.5 times or more the bearing width, the distance from the center of the nozzle to the side surface of the bearing is the bearing width or less, and 1 of the bearing width. /2 or more.

この構成によると、ノズルを回転方向の前方へ傾斜させたので、冷却用の圧縮エアがノズルから内輪間座の外周面に噴き付けられる。これにより圧縮エアは、内輪間座の外周面と外輪間座の内周面との間の環状のすきま部で、旋回流となって内輪間座を冷却する。結果、内輪間座の端面と接触固定されている軸受内輪が、熱伝導により冷却される。 With this configuration, since the nozzle is inclined forward in the rotational direction, the compressed air for cooling is jetted from the nozzle to the outer peripheral surface of the inner ring spacer. As a result, the compressed air becomes a swirling flow in the annular clearance between the outer peripheral surface of the inner ring spacer and the inner peripheral surface of the outer ring spacer to cool the inner ring spacer. As a result, the bearing inner ring, which is in contact with and fixed to the end surface of the inner ring spacer, is cooled by heat conduction.

前記ノズルは、軸受から遠い位置に配置させると、課題で述べている通り、冷却効果が下がる。一方、軸受から近い位置に配置させると、圧縮エアが内輪回転方向に旋回せず、早々に軸方向に拡散してしまう。そのため、内輪間座の表面に長く留まることができず、冷却効果は下がる。グリース潤滑の場合は、軸受内に封入しているグリースが軸受外に排出されてしまい、潤滑信頼性が下がるという課題がある。
そのため、図８に示すように、内輪間座端面に障害壁１０５ａを設けることで圧縮エアの流入を低減させている。更にノズルの中心から軸受の側面までの距離Ｙを、軸受幅Ｘ以下で、かつ軸受幅Ｘの１／２以上としている。この範囲であると、ノズルから吐出された圧縮エアで内輪間座が冷却される位置から軸受までの距離が遠すぎず、かつノズル位置が近すぎて圧縮エアが旋回せずに拡散してしまうことがなく、間座の幅寸法が大きい場合でも軸受の冷却効果が確保できることが確認できた。間座幅が狭い場合は前記のノズル位置が遠すぎて冷却効果が低下すると言う問題は生じず、間座幅が軸受幅の２．５倍以上と長い場合に、前記のノズルの中心から軸受側面までの距離Ｙを規制したことによる効果が発揮される。 If the nozzle is arranged at a position far from the bearing, the cooling effect is lowered as described in the problem. On the other hand, if the compressed air is arranged at a position close to the bearing, the compressed air will not swirl in the rotation direction of the inner ring, and will quickly diffuse in the axial direction. Therefore, it cannot stay on the surface of the inner ring spacer for a long time, and the cooling effect decreases. In the case of grease lubrication, there is a problem that the grease filled in the bearing is discharged to the outside of the bearing, which lowers the lubrication reliability.
Therefore, as shown in FIG. 8, the inflow of compressed air is reduced by providing the obstacle wall 105a on the inner ring spacer end surface. Further, the distance Y from the center of the nozzle to the side surface of the bearing is set to be the bearing width X or less and 1/2 or more of the bearing width X. Within this range, the distance from the position where the inner ring spacer is cooled by the compressed air discharged from the nozzle to the bearing is not too long, and the nozzle position is too close so that the compressed air diffuses without swirling. It was confirmed that the bearing cooling effect can be secured even when the width of the spacer is large. When the spacer width is narrow, there is no problem that the nozzle position is too far and the cooling effect deteriorates. When the spacer width is as long as 2.5 times the bearing width or more, the bearing is moved from the center of the nozzle to the bearing. The effect of regulating the distance Y to the side surface is exhibited.

この発明の軸受装置の冷却構造において、前記外輪間座に、前記ノズルに対して前記軸受側および反軸受側に、前記外輪間座と内輪間座の間の空間から外部に排気する排気路が設けられていてもよい。 In the cooling structure for a bearing device of the present invention, an exhaust passage for exhausting to the outside from the space between the outer ring spacer and the inner ring spacer is provided on the outer ring spacer, on the bearing side and the opposite bearing side with respect to the nozzle. It may be provided.

軸受近傍に圧縮エアを吐出するノズルを設けた場合、軸受側に流れる圧縮エアは外輪間座と軸受間に設けている排気路、および軸受の内部を通り排出される。一方、反軸受側に流れる圧縮エアは、排気される箇所が無い場合、内輪間座から熱を奪った後に内輪間座と外輪間座間の空間に留まりやすくなり、冷却効果が下がる。このため、反軸受側にも排気を設ける必要がある。 When a nozzle for discharging compressed air is provided in the vicinity of the bearing, the compressed air flowing to the bearing is discharged through the exhaust passage provided between the outer ring spacer and the bearing and the inside of the bearing. On the other hand, the compressed air flowing on the side opposite to the bearing tends to stay in the space between the inner ring spacer and the outer ring spacer after absorbing heat from the inner ring spacer when there is no place to be exhausted, and the cooling effect decreases. Therefore, it is necessary to provide exhaust gas also on the side opposite to the bearing.

前記各排気路を設ける場合、前記反軸受側の排気路が、前記内輪間座の回転方向の前方に排気口が向くように傾斜していてもよい。
前記排気路は径方向に設けても良いが、内輪間座の回転方向の前方へ傾斜させて設けることで、排気性が向上する。 When each of the exhaust passages is provided, the exhaust passage on the side opposite to the bearing may be inclined so that the exhaust port faces forward in the rotation direction of the inner ring spacer.
Although the exhaust passage may be provided in the radial direction, the exhaust performance is improved by inclining the exhaust passage forward in the rotational direction of the inner ring spacer.

また、前記各排気路を設ける場合、前記軸受側の排気路の容積と前記反軸受側の排気路の容積との差が、前記軸受側の排気路の容積の１０％以内であることが好ましい。
反軸受側に設ける排気は、軸受側に設けた排気溝の体積と同等にすることで、圧縮エアが軸受側または、反軸受側のどちらか一方へ偏って流れるのを防ぐことができる。 When the exhaust passages are provided, it is preferable that the difference between the volume of the exhaust passage on the bearing side and the volume of the exhaust passage on the opposite bearing side is within 10% of the volume of the exhaust passage on the bearing side. ..
Exhaust gas provided on the non-bearing side is made equal to the volume of the exhaust groove provided on the bearing side, so that compressed air can be prevented from being biased to either the bearing side or the anti-bearing side.

この発明の軸受装置の冷却構造において、前記外輪間座および前記内輪間座は、隣合う２つの軸受間に介在し、前記外輪間座の間座幅の中心位置に対する両側に前記ノズルが設けられていてもよい。
このように外輪間座および内輪間座が軸受間に配置され、両側の軸受に対して前記ノズルが設けられている場合に、前記ノズルと軸受間の距離や間座幅を規制したことによる冷却効果の確保が、より効果的に発揮される。 In the cooling structure for a bearing device according to the present invention, the outer ring spacer and the inner ring spacer are interposed between two adjacent bearings, and the nozzles are provided on both sides of the center position of the spacer width of the outer ring spacer. May be.
In this way, when the outer ring spacer and the inner ring spacer are arranged between the bearings and the nozzles are provided for the bearings on both sides, cooling by regulating the distance between the nozzle and the bearing and the spacer width is performed. Ensuring the effect is more effectively exerted.

この発明の工作機械の主軸装置は、この発明の前記いずれかの構成の軸受装置の冷却構造を備えていてもよい。
工作機械の主軸装置では、加工精度を確保するために、装置の温度上昇は小さく抑える必要があり、この発明の軸受装置の冷却構造を適用することによる効果が、より効果的に発揮される。 The spindle device for a machine tool according to the present invention may include the cooling structure for a bearing device having any one of the above configurations according to the present invention.
In the spindle device of a machine tool, it is necessary to suppress the temperature rise of the device in order to secure the processing accuracy, and the effect of applying the cooling structure of the bearing device of the present invention is more effectively exhibited.

この発明の軸受装置の冷却構造は、軸受の外輪および内輪にそれぞれ隣接する外輪間座および内輪間座を備え、前記外輪間座に前記内輪間座の外周面に向けて圧縮エアを吐出するノズルが設けられた軸受装置の冷却構造であって、前記ノズルは前記内輪間座の回転方向の前方へ傾斜し、かつ前記外輪間座の軸心に垂直な断面における任意の半径方向の直線から、この直線と直交する方向にオフセットした位置にあり、前記外輪間座および内輪間座の幅が軸受幅の２．５倍以上であって、前記ノズルの中心から前記軸受の側面までの距離が、前記軸受幅以下であり、かつ前記軸受幅の１／２以上であるため、間座の幅寸法が大きい場合でも、軸受の冷却効果を確保することができる。 A cooling structure for a bearing device according to the present invention includes an outer ring spacer and an inner ring spacer that are respectively adjacent to an outer ring and an inner ring of the bearing, and a nozzle that discharges compressed air to the outer ring spacer toward an outer peripheral surface of the inner ring spacer. In the cooling structure of the bearing device provided with, the nozzle is inclined forward in the rotational direction of the inner ring spacer, and from any radial straight line in a cross section perpendicular to the axial center of the outer ring spacer, At a position offset in a direction orthogonal to this straight line, the width of the outer ring spacer and the inner ring spacer is 2.5 times or more the bearing width, and the distance from the center of the nozzle to the side surface of the bearing is Since the bearing width is equal to or less than the bearing width and equal to or more than ½ of the bearing width, the bearing cooling effect can be secured even when the width dimension of the spacer is large.

この発明の工作機械の主軸装置は、この発明の前記いずれかの構成の軸受装置の冷却構造を備えるため、間座の幅寸法が大きい場合でも、軸受の冷却効果が確保することができる。 The spindle device for a machine tool according to the present invention includes the cooling structure for a bearing device having any one of the above configurations according to the present invention. Therefore, even if the width dimension of the spacer is large, the bearing cooling effect can be ensured.

この発明の第１の実施形態に係る軸受装置の冷却構造の断面図である。It is sectional drawing of the cooling structure of the bearing apparatus which concerns on the 1st Embodiment of this invention. その軸受と間座の寸法関係の説明図である。It is explanatory drawing of the dimensional relationship of the bearing and the spacer. 同軸受装置の冷却構造における外輪間座と内輪間座をノズル位置で断面した横断面図である。FIG. 6 is a transverse cross-sectional view of the outer ring spacer and the inner ring spacer in the cooling structure of the bearing device, taken along the nozzle position. この発明の他の実施形態に係る軸受装置の冷却構造の断面図である。It is sectional drawing of the cooling structure of the bearing device which concerns on other embodiment of this invention. 同軸受装置の冷却構造における反軸受側の排気路の一例を示す外輪間座の横断面図である。It is a cross-sectional view of an outer ring spacer showing an example of an exhaust path on the side opposite to the bearing in the cooling structure of the bearing device. 同軸受装置の冷却構造における反軸受側の排気路の他の例を示す外輪間座の横断面図である。FIG. 7 is a cross-sectional view of an outer ring spacer showing another example of the exhaust passage on the side opposite to the bearing in the cooling structure of the bearing device. 同軸受装置の冷却構造を備える工作機械の主軸装置の断面図である。It is a sectional view of a spindle device of a machine tool provided with the cooling structure of the bearing device. 従来例の断面図である。It is sectional drawing of a prior art example. 提案例に係る軸受装置の冷却構造の断面図である。It is sectional drawing of the cooling structure of the bearing apparatus which concerns on a proposal example.

この発明の第１の実施形態に係る軸受装置の冷却構造を、図１ないし図３と共に説明する。この例の軸受装置の冷却構造は、例えば、図７と共に後述する工作機械の主軸装置等に適用される。ただし、工作機械の主軸装置だけに限定されるものではない。
図１に示すように、この軸受装置は、軸方向に並ぶ複数の軸受１、１の外輪２、２間および内輪３、３間に、外輪間座４および内輪間座５がそれぞれ介在している。外輪２および外輪間座４はハウジング６の内周面に設置され、内輪３および内輪間座５は回転軸７の外周面に嵌合する。回転軸７は、例えば工作機械の主軸である。各軸受１には、転がり軸受、具体的にはアンギュラ玉軸受が用いられ、両側の軸受１，１は、背面組合せで設置されている。両側の軸受１，１は、内輪２の外径面および外輪３内径面における接触角の反偏り側に、それぞれカウンタボアが設けられている。内外輪３，２の軌道面間に複数の転動体８が介在し、これら転動体８が保持器９により円周方向に等間隔で保持される。保持器９は、リング形状であり外輪案内形式とされる。 A cooling structure for a bearing device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. The cooling structure of the bearing device of this example is applied to, for example, a spindle device of a machine tool described later with reference to FIG. 7. However, it is not limited to the spindle device of the machine tool.
As shown in FIG. 1, in this bearing device, an outer ring spacer 4 and an inner ring spacer 5 are respectively interposed between outer rings 2 and 2 and inner rings 3 and 3 of a plurality of bearings 1 and 1 arranged in the axial direction. There is. The outer ring 2 and the outer ring spacer 4 are installed on the inner peripheral surface of the housing 6, and the inner ring 3 and the inner ring spacer 5 are fitted on the outer peripheral surface of the rotating shaft 7. The rotary shaft 7 is, for example, a main shaft of a machine tool. A rolling bearing, specifically, an angular contact ball bearing is used as each bearing 1, and the bearings 1 and 1 on both sides are installed in a back surface combination. The bearings 1 and 1 on both sides are provided with counter bores respectively on the outer diameter surface of the inner ring 2 and the inner diameter surface of the outer ring 3 on the opposite side of the contact angle. A plurality of rolling elements 8 are interposed between the raceways of the inner and outer rings 3 and 2, and these rolling elements 8 are held by a cage 9 at equal intervals in the circumferential direction. The cage 9 has a ring shape and is of an outer ring guide type.

冷却構造について説明する。外輪間座４の両端付近に、内輪間座５の外周面に向けて圧縮エアを吐出するノズル１０が、１個または円周方向に複数個（この例では３個）並んで設けられている。ノズル１０は、流入側が太く吐出側が細くなる段付き形状の丸孔とされている。 The cooling structure will be described. In the vicinity of both ends of the outer ring spacer 4, one nozzle 10 for ejecting compressed air toward the outer peripheral surface of the inner ring spacer 5 or a plurality of nozzles 10 (three nozzles in this example) are arranged in the circumferential direction. .. The nozzle 10 is a round hole having a stepped shape in which the inflow side is thick and the discharge side is thin.

外輪間座４には、ノズル１０に対する軸受側に、外輪間座４と内輪間座５の間の空間から外部に排気する排気路１５が、円周方向の１箇所または複数箇所に設けられている。この排気路１５は、外輪間座４の端面に形成された径方向の溝と、軸受１の外輪２の側面とで径方向の貫通孔として構成されている。 On the bearing side with respect to the nozzle 10, the outer ring spacer 4 is provided with exhaust passages 15 for exhausting the space from the space between the outer ring spacer 4 and the inner ring spacer 5 to the outside at one or more positions in the circumferential direction. There is. The exhaust passage 15 is formed as a radial through hole by the radial groove formed on the end surface of the outer ring spacer 4 and the side surface of the outer ring 2 of the bearing 1.

外輪間座４のノズル１０が設けられた軸方向位置の内周面部分は、環状の凸部４ａが形成されて内輪間座５の外周面に近接している。また、内輪間座５の両端の外周面には、突出端が外輪間座４の外周面に近づく環状の障害壁５ａが設けられている。この障害壁５ａは、前記ノズル１０から外輪間座４と内輪間座５の間に吐出された圧縮エアが転がり軸受１側に流れることを邪魔し、排気路１４に流れるように案内する。 An inner peripheral surface portion of the outer ring spacer 4 at the axial position where the nozzle 10 is provided is formed with an annular convex portion 4 a and is close to the outer peripheral surface of the inner ring spacer 5. Further, on the outer peripheral surfaces of both ends of the inner ring spacer 5, annular obstacle walls 5 a whose protruding ends approach the outer peripheral surface of the outer ring spacer 4 are provided. The obstacle wall 5 a hinders the compressed air discharged from the nozzle 10 between the outer ring spacer 4 and the inner ring spacer 5 from flowing to the rolling bearing 1 side and guides the compressed air to the exhaust passage 14.

なお、内輪間座５は、この内輪間座５の両端の障害壁５ａと外輪間座４の両端の前記凸部４ａとが干渉することによりこれら内輪間座５と外輪間座４との組み付けが不可となることを回避するために、軸方向に並ぶ２つの内輪間座分割体５Ａ，５Ａに分割されている。分割位置は軸方向の中央とされているが、いずれかに偏った位置であってもよい。この明細書において、内輪間座５の幅Ｗは、両内輪間座分割体５Ａ，５Ａを合わせた幅を言う。 The inner ring spacer 5 is assembled with the inner ring spacer 5 and the outer ring spacer 4 by interference between the obstacle walls 5a at both ends of the inner ring spacer 5 and the convex portions 4a at both ends of the outer ring spacer 4. In order to avoid that it becomes impossible, it is divided into two inner ring spacer divided bodies 5A, 5A arranged in the axial direction. The division position is the center in the axial direction, but it may be a position deviated to either side. In this specification, the width W of the inner ring spacer 5 refers to the total width of the inner ring spacer divided bodies 5A and 5A.

前記ノズル１０の軸方向位置は、次のように規制されている。すなわち、ノズル１０の中心から前記軸受の側面までの距離Ｙ（図２）が、軸受幅Ｘ以下であり、かつ軸受幅Ｘの１／２以上とされている。式で示すと、
（１／２）Ｘ≧Ｙ≧Ｘである。
ただし、前記距離Ｙの前記の規制は、外輪間座４および内輪間座５の幅Ｗが軸受幅Ｘの２．５倍以上である場合に適用される。 The axial position of the nozzle 10 is regulated as follows. That is, the distance Y (FIG. 2) from the center of the nozzle 10 to the side surface of the bearing is not more than the bearing width X and not less than 1/2 of the bearing width X. In the formula,
(1/2) X≧Y≧X.
However, the restriction of the distance Y is applied when the width W of the outer ring spacer 4 and the inner ring spacer 5 is 2.5 times or more the bearing width X.

図３に示すように、複数設けられる各ノズル１０は円周等配に配設される。各ノズル１０のエア吐出方向は、それぞれ主軸７の回転方向Ａの前方へ傾斜している。各ノズル１０は、それぞれ直線状であって、外輪間座４の軸心に垂直な断面における任意の半径方向の直線Ｌから、この直線Ｌと直交する方向にオフセット量ＯＦＦだけオフセットした位置にある。ノズル１０をオフセットさせる理由は、吐出エアを主軸７の回転方向に旋回流として作用させて、冷却効果を向上させることである。ノズル１０のオフセット量ＯＦＦは、内輪間座５の外径寸法（Ｄ）に対して、０．８Ｄ／２以上、Ｄ／２以下の範囲にする。この範囲は、試験の結果によるもので、冷却効果が最も大きくなる。 As shown in FIG. 3, the plurality of nozzles 10 provided are arranged at equal intervals around the circumference. The air ejection direction of each nozzle 10 is inclined forward of the rotation direction A of the main shaft 7. Each nozzle 10 is linear and is located at a position offset from an arbitrary radial straight line L in a cross section perpendicular to the axis of the outer ring spacer 4 by an offset amount OFF in a direction orthogonal to the straight line L. .. The reason for offsetting the nozzles 10 is to make the discharge air act as a swirl flow in the rotation direction of the main shaft 7 to improve the cooling effect. The offset amount OFF of the nozzle 10 is within a range of 0.8 D/2 or more and D/2 or less with respect to the outer diameter dimension (D) of the inner ring spacer 5. This range is based on the result of the test, and the cooling effect is maximized.

外輪間座４の外周面には、冷却エアである圧縮エアを導入する導入溝１１が設けられている。この導入溝１１に連通するように、ハウジング６に冷却エア用供給孔１３（図１）が設けられ、この冷却エア用供給孔１３は、ハウジング６の外部のブロワー等の圧縮エア供給源（図示せず）に接続されている。 An introduction groove 11 for introducing compressed air that is cooling air is provided on the outer peripheral surface of the outer ring spacer 4. A cooling air supply hole 13 (FIG. 1) is provided in the housing 6 so as to communicate with the introduction groove 11, and the cooling air supply hole 13 is a compressed air supply source such as a blower outside the housing 6 (see FIG. Connected (not shown).

作用効果について説明する。
内輪間座５と外輪間座４とを使用して、内輪間座５の外周面に、外輪間座４に設けたノズル１０より圧縮エアを吐出することで、間接的に軸受１の冷却を行うことができる。外輪間座４の圧縮エアのノズル１０を、回転方向Ａの前方へ傾斜させたので、冷却用の圧縮エアは、ハウジング６に設けた冷却エア用供給孔１３より、ノズル１０を介して内輪間座５の外周面に吹き付けられる。これにより圧縮エアは、内輪間座５の外周面と外輪間座４の内周面との間の環状のすきま部で、旋回流となって内輪間座５を冷却する。結果、内輪間座５の端面と接触固定されている軸受内輪３が、熱伝導により冷却されることになる。 The effects will be described.
The inner ring spacer 5 and the outer ring spacer 4 are used to discharge compressed air from the nozzle 10 provided in the outer ring spacer 4 to the outer peripheral surface of the inner ring spacer 5, thereby indirectly cooling the bearing 1. It can be carried out. Since the compressed air nozzle 10 of the outer ring spacer 4 is inclined forward in the rotational direction A, the compressed air for cooling is supplied from the cooling air supply hole 13 provided in the housing 6 to the inner ring space via the nozzle 10. It is sprayed on the outer peripheral surface of the seat 5. As a result, the compressed air becomes a swirling flow in the annular clearance between the outer peripheral surface of the inner ring spacer 5 and the inner peripheral surface of the outer ring spacer 4 to cool the inner ring spacer 5. As a result, the bearing inner ring 3 fixed in contact with the end surface of the inner ring spacer 5 is cooled by heat conduction.

この場合に、前記ノズル１０は、軸受１から遠すぎると冷却効果が下がる。一方、軸受１から近すぎても圧縮エアが内輪回転方向に旋回せず、早々に軸方向に拡散してしまう。そのため、内輪間座５の表面に長く留まることができないため、冷却効果は下がる。グリース潤滑の場合、軸受１内に封入しているグリースが軸受外に排出されてしまい、潤滑信頼性が下がる。
そのため、ノズル１０の中心から軸受１の側面までの距離Ｙを、軸受幅Ｘ以下で、かつ軸受幅Ｘの１／２以上としている。この範囲であると、ノズル１０から吐出された圧縮エアで内輪間座５が冷却される位置から軸受１までの距離が遠すぎず、かつノズル位置が近すぎて圧縮エアが旋回せずに拡散してしまうことがなく、間座４，５の幅Ｗが大きい場合でも軸受１の冷却効果が確保できる。間座幅Ｗが狭い場合は前記のノズル位置が遠すぎて冷却効果が低下すると言う問題は生じず、間座幅が軸受幅の２．５倍以上と長い場合に、前記のノズル１０の中心から軸受側面までの距離Ｙを規制したことによる効果が発揮される。 In this case, if the nozzle 10 is too far from the bearing 1, the cooling effect is reduced. On the other hand, even if the compressed air is too close to the bearing 1, the compressed air does not swirl in the rotation direction of the inner ring and diffuses quickly in the axial direction. Therefore, the cooling effect is reduced because the inner ring spacer 5 cannot stay on the surface for a long time. In the case of grease lubrication, the grease filled in the bearing 1 is discharged to the outside of the bearing, which lowers the lubrication reliability.
Therefore, the distance Y from the center of the nozzle 10 to the side surface of the bearing 1 is set to be the bearing width X or less and 1/2 or more of the bearing width X. Within this range, the distance from the position where the inner ring spacer 5 is cooled by the compressed air discharged from the nozzle 10 to the bearing 1 is not too long, and the nozzle position is too close to spread the compressed air without swirling. Even if the width W of the spacers 4 and 5 is large, the cooling effect of the bearing 1 can be secured. When the spacer width W is narrow, there is no problem that the nozzle position is too far and the cooling effect deteriorates. When the spacer width is as long as 2.5 times the bearing width or more, the center of the nozzle 10 is The effect is obtained by restricting the distance Y from the bearing to the side surface of the bearing.

図４は、この発明の他の実施形態を示す。この実施形態は、図１〜図３と共に説明した第１の実施形態において、外輪間座４に、前記ノズル１０に対して軸受側に設けられた前記排気路１５の他に、ノズル１０に対して反軸受側となる排気路１６が設けられている。
反軸受側の排気路１６は、外輪間座４の内外の周面間に貫通する孔であり、外輪間座４の軸方向の中央に位置して、円周方向の１箇所または複数箇所に設けられている。また、この例では、反軸受側の排気路１６は、外輪間座４の半径方向に延びている。
前記軸受側の排気路１５と反軸受側の排気路１６とは、その容積との差が、軸受側の排気路１５の容積の１０％以内とされている。
この実施形態において、その他の構成は第１の実施形態と同様である。 FIG. 4 shows another embodiment of the present invention. In this embodiment, in addition to the exhaust passage 15 provided on the bearing side of the nozzle 10 in the outer ring spacer 4 in the first embodiment described with reference to FIGS. An exhaust passage 16 is provided on the side opposite to the bearing.
The exhaust passage 16 on the opposite bearing side is a hole that penetrates between the inner and outer peripheral surfaces of the outer ring spacer 4, is located at the axial center of the outer ring spacer 4, and is located at one or more locations in the circumferential direction. It is provided. Further, in this example, the exhaust passage 16 on the side opposite to the bearing extends in the radial direction of the outer ring spacer 4.
The difference between the volumes of the bearing-side exhaust passage 15 and the non-bearing-side exhaust passage 16 is within 10% of the volume of the bearing-side exhaust passage 15.
In this embodiment, other configurations are the same as those in the first embodiment.

反軸受側に排気路１６を設けたのは、次の理由による。軸受近傍に圧縮エアを吐出するノズル１０を設けた場合、軸受側に流れる圧縮エアは外輪間座４と軸受１の間に設けられている排気路１５、および軸受１の内部を通り排出される。一方、反軸受側に流れる圧縮エアは、排気される箇所が無い場合、内輪間座５から熱を奪った後に、内輪間座１０と外輪間座４の間の空間に留まりやすくなり、冷却効果が下がる。反軸受側に排気路１６を設けることで、上記の内輪間座１０から熱を奪った空気が外部に排出され、冷却効果が高められる。 The exhaust passage 16 is provided on the side opposite to the bearing for the following reason. When the nozzle 10 that discharges the compressed air is provided in the vicinity of the bearing, the compressed air flowing toward the bearing is discharged through the exhaust passage 15 provided between the outer ring spacer 4 and the bearing 1 and the inside of the bearing 1. .. On the other hand, if there is no place to be exhausted, the compressed air flowing on the side opposite to the bearing tends to stay in the space between the inner ring spacer 10 and the outer ring spacer 4 after absorbing heat from the inner ring spacer 5 and the cooling effect. Goes down. By providing the exhaust passage 16 on the side opposite to the bearing, the air deprived of heat from the inner ring spacer 10 is discharged to the outside, and the cooling effect is enhanced.

反軸受側の排気路１６を設ける場合、軸受側の排気路１５の容積と反軸受側の排気路１６の容積との差が、前記軸受側の排気路１５の容積の１０％以内であることが好ましい。
反軸受側に設ける排気路１６は、軸受側に設けた排気路１５の容積と同等にすることで、圧縮エアが軸受側または、反軸受側のどちらか一方へ偏って流れるのを防ぐことができる。 When the exhaust passage 16 on the opposite bearing side is provided, the difference between the volume of the exhaust passage 15 on the bearing side and the volume of the exhaust passage 16 on the opposite bearing side is within 10% of the volume of the exhaust passage 15 on the bearing side. Is preferred.
The exhaust passage 16 provided on the non-bearing side is made to have the same volume as the exhaust passage 15 provided on the bearing side, so that compressed air can be prevented from unevenly flowing to either the bearing side or the anti-bearing side. it can.

外輪間座４の反軸受側の排気路１６は、図６に示すように、内輪間座５の回転方向Ａの前方に排気口１６ａが向くように傾斜していてもよい。
前記排気路１６は、図５のように径方向に設けてもよいが、内輪間座５の回転方向Ａの前方へ傾斜させて設けることで、排気能力がより向上する。 As shown in FIG. 6, the exhaust passage 16 on the side opposite to the bearing of the outer ring spacer 4 may be inclined so that the exhaust port 16a faces forward in the rotation direction A of the inner ring spacer 5.
The exhaust passage 16 may be provided in the radial direction as shown in FIG. 5, but by providing the exhaust passage 16 so as to be inclined forward in the rotation direction A of the inner ring spacer 5, the exhaust capacity is further improved.

図７は、工作機械の主軸装置の一例を示し、図１または図４と共に説明した実施形態の軸受装置の冷却構造が適用されている。
図１の前記回転軸７である主軸７Ａは、ハウジング６にフロント側およびリア側となる前後一対の軸受１，１を介して回転自在に支持されている。前記主軸７Ａは、先端に工具またはワークを把持するチャック１７が設けられ、後端が駆動モータ１８に接続されている。駆動モータ１８は、この例ではハウジング６の外部に設けられているが、ハウジング６内に設けたビルトインタイプとしてもよい。軸受１，１の間には前記構成、例えば図４の例の外輪間座４および内輪間座５が設けられている。ハウジング６には、外輪間座４の各ノズル１０に前記導入溝１１を介して連通する冷却エア用供給孔１３と、前記各排気路１５，１６に連通するハウジング内排気経路２０が設けられている。また、ハウジング６には冷却液を循環させる冷却液流路２１が設けられている。 FIG. 7 shows an example of a spindle device of a machine tool, to which the cooling structure of the bearing device of the embodiment described with reference to FIG. 1 or 4 is applied.
The main shaft 7A, which is the rotary shaft 7 in FIG. 1, is rotatably supported by the housing 6 via a pair of front and rear bearings 1 and 1 on the front side and the rear side. The main shaft 7A is provided with a chuck 17 for holding a tool or a work piece at its front end and is connected to a drive motor 18 at its rear end. The drive motor 18 is provided outside the housing 6 in this example, but may be a built-in type provided inside the housing 6. The above-described configuration, for example, the outer ring spacer 4 and the inner ring spacer 5 in the example of FIG. 4 is provided between the bearings 1 and 1. The housing 6 is provided with a cooling air supply hole 13 that communicates with each nozzle 10 of the outer ring spacer 4 through the introduction groove 11, and an in-housing exhaust passage 20 that communicates with the exhaust passages 15 and 16. There is. Further, the housing 6 is provided with a cooling liquid passage 21 for circulating the cooling liquid.

この構成の工作機械の主軸装置によると、前記軸受装置の冷却構造を適用することによる冷却の効果が発揮され、主軸７Ａの回転の高速化、および加工の高精度化が得られる。 According to the spindle device of the machine tool having this configuration, the cooling effect is exerted by applying the cooling structure of the bearing device, and the rotation speed of the spindle 7A can be increased and the machining accuracy can be improved.

なお、前記各実施形態では、軸受１が２列に設けられてその間に配置された外輪間座４にノズル１０を設けた場合につき説明したが、軸受１は３列または４列以上であってもよく、または１列であってもよい。また、前記ノズル１０を設ける外輪間座４は、軸受間に設けなくても良い。さらに潤滑は、油(エアオイル、オイルミスト)でもグリースでも適用可能であり、潤滑仕様により制限されることはない。 In each of the above-described embodiments, the case where the bearings 1 are provided in two rows and the nozzles 10 are provided in the outer ring spacers 4 arranged therebetween are described, but the bearings 1 have three rows or four rows or more. Or in one row. Further, the outer ring spacer 4 provided with the nozzle 10 may not be provided between the bearings. Further, lubrication can be applied with oil (air oil, oil mist) or grease, and is not limited by lubrication specifications.

以上、実施形態に基づいて本発明を実施するための形態を説明したが、ここで開示した実施の形態はすべての点で例示であって制限的なものではない。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiments for carrying out the present invention have been described above based on the embodiments. However, the embodiments disclosed herein are exemplifications in all respects and are not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

１…軸受
２…外輪
３…内輪
４…外輪間座
５…内輪間座
６…ハウジング
７…回転軸
１０…ノズル
１５…軸受側の排気路
１６…反軸受側の排気路
DESCRIPTION OF SYMBOLS 1... Bearing 2... Outer ring 3... Inner ring 4... Outer ring spacer 5... Inner ring spacer 6... Housing 7... Rotating shaft 10... Nozzle 15... Bearing side exhaust passage 16... Anti-bearing side exhaust passage

Claims (6)

軸受の外輪および内輪にそれぞれ隣接する外輪間座および内輪間座を備え、前記外輪間座に前記内輪間座の外周面に向けて圧縮エアを吐出するノズルが設けられた軸受装置の冷却構造であって、
前記ノズルは前記内輪間座の回転方向の前方へ傾斜し、かつ前記外輪間座の軸心に垂直な断面における任意の半径方向の直線から、この直線と直交する方向にオフセットした位置にあり、
前記外輪間座および内輪間座の幅が軸受幅の２．５倍以上であって、前記ノズルの中心から前記軸受の側面までの距離が、前記軸受幅以下であり、かつ前記軸受幅の１／２以上である軸受装置の冷却構造。 A cooling structure for a bearing device, comprising an outer ring spacer and an inner ring spacer respectively adjacent to an outer ring and an inner ring of the bearing, wherein the outer ring spacer is provided with a nozzle for discharging compressed air toward the outer peripheral surface of the inner ring spacer. There
The nozzle is inclined forward in the rotation direction of the inner ring spacer, and from a straight line in any radial direction in a cross section perpendicular to the axial center of the outer ring spacer, the nozzle is at a position offset in a direction orthogonal to this straight line,
The width of the outer ring spacer and the inner ring spacer is 2.5 times or more the bearing width, the distance from the center of the nozzle to the side surface of the bearing is the bearing width or less, and 1 of the bearing width. /2 or more bearing device cooling structure. 請求項１に記載の軸受装置の冷却構造において、前記外輪間座に、前記ノズルに対して前記軸受側および反軸受側に、前記外輪間座と内輪間座の間の空間から外部に排気する排気路が設けられた軸受装置の冷却構造。 2. The cooling structure for a bearing device according to claim 1, wherein the outer ring spacer is exhausted to the outside from the space between the outer ring spacer and the inner ring spacer to the bearing side and the counter bearing side with respect to the nozzle. Cooling structure for bearing device with exhaust passage. 請求項２に記載の軸受装置の冷却構造において、前記反軸受側の排気路が、前記内輪間座の回転方向の前方に排気口が向くように傾斜した軸受装置の冷却構造。 The cooling structure for a bearing device according to claim 2, wherein the exhaust passage on the side opposite to the bearing is inclined so that the exhaust port faces forward in the rotation direction of the inner ring spacer. 請求項２または請求項３に記載の軸受装置の冷却構造において、前記軸受側の排気路の容積と前記反軸受側の排気路の容積との差が、前記軸受側の排気路の容積の１０％以内である軸受装置の冷却構造。 In the cooling structure for the bearing device according to claim 2 or 3, the difference between the volume of the exhaust passage on the bearing side and the volume of the exhaust passage on the opposite bearing side is 10 times the volume of the exhaust passage on the bearing side. % Cooling structure of bearing device. 請求項１ないし請求項４のいずれか１項に記載の軸受装置の冷却構造において、前記外輪間座および前記内輪間座は、隣合う２つの軸受間に介在し、前記外輪間座の間座幅の中心位置に対する両側に前記ノズルが設けられた軸受装置の冷却構造。 The cooling structure for a bearing device according to any one of claims 1 to 4, wherein the outer ring spacer and the inner ring spacer are interposed between two adjacent bearings, and the outer ring spacer is a spacer. A cooling structure for a bearing device, wherein the nozzles are provided on both sides of the center position of the width. 請求項１ないし請求項５のいずれか１項に記載の軸受装置の冷却構造を備える工作機械の主軸装置。 A spindle device for a machine tool, comprising the cooling structure for a bearing device according to any one of claims 1 to 5.
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JP2019020645A JP7185546B2 (en) 2019-02-07 2019-02-07 Cooling structure of bearing unit and spindle unit of machine tool
PCT/JP2019/035365 WO2020054661A1 (en) 2018-09-13 2019-09-09 Bearing device cooling structure, and main spindle device of machine tool
KR1020217007456A KR20210057733A (en) 2018-09-13 2019-09-09 The cooling structure of the bearing unit and the spindle unit of the machine tool
CN201980059203.9A CN112673186A (en) 2018-09-13 2019-09-09 Cooling structure for bearing device and spindle device for machine tool
EP19860198.1A EP3851692B1 (en) 2018-09-13 2019-09-09 Bearing device cooling structure, and main spindle device of machine tool
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