【０００１】
【発明の属する技術分野】
この発明は、工作機械主軸用の転がり軸受のうち、特にエアオイル潤滑やオイルミスト潤滑が適用される軸受の組込み構造に関する。
【０００２】
【従来の技術】
一般的な工作機械においては、加工能率向上のため、主軸の回転速度がより高速になっていく傾向にある。これに対応して、主軸用軸受の潤滑には、搬送エアに潤滑油を混合して軸受軌道面に直接噴射するエアオイル潤滑や、オイルミスト潤滑が多く適用されるようになってきている。図５は、このような方式で潤滑される軸受を組み込んだ工作機械主軸の一例を示す（非特許文献１参照。）。
【０００３】
【非特許文献１】
ＮＴＮ株式会社、カタログ、ＣＡＴ．Ｎｏ．８４０１−ＶＩ／Ｊ、２００１年３月３日
【０００４】
図５に示した主軸における軸受組込み構造は、内部に給油路５１ａを有する筒状の軸受箱５１の側端部内周に、給油用間座５２とアンギュラ玉軸受５３とを箱中央側から順に組み込み、軸受箱５１の側端面に軸受箱蓋５４をボルト止めして、この蓋５４の内側面に形成した環状突部５５と軸受箱５１内周の段差面５１ｂとで軸受５３の外輪５６および間座５２を挟み付けて固定している。このとき、軸受箱５１の給油路５１ａの入口に軸受箱蓋５４の給油口５４ａを、給油路５１ａの出口に間座５２の給油ノズル５２ａ入口をそれぞれ接続し、外部から給油口５４ａに供給されたエアオイルやオイルミストが、給油路５１ａを通って間座５２に導かれ、給油ノズル５２ａ先端から軸受５３に向けて噴射されるようにしている。また、軸受５３の内輪５７は、内輪位置決め間座５８、５９を用いて、軸受箱５１に挿入された回転軸６０に固定している。
【０００５】
【発明が解決しようとする課題】
上述した軸受組込み構造では、通常、軸受の組込み精度を向上させるために、軸受箱蓋を軸受箱に固定するボルトの締付けトルクを管理して、蓋の内側面の環状突部を全周にわたって均等に軸受外輪に押し付けるようにしている。しかし、各部材の寸法の公差内のばらつきにより、蓋と軸受箱の側端面との間に隙間が生じ、蓋の給油口と軸受箱の給油路との接続部からエアオイル等の潤滑油が漏れることがある。
【０００６】
上記の潤滑油漏れをなくすには、軸受箱蓋をその環状突部と軸受箱内周の段差面とで軸受外輪および給油用間座を隙間なく挟む込む位置にセットしたときに、蓋と軸受箱側端面との間に軸受外輪および間座の締め代に相当する３０μｍ程度の所定幅の微小隙間が形成されるようにして、この微小隙間がなくなるまで蓋固定ボルトを締め付ければよい。しかしながら、この方法を採用すると、軸受組込み時に、各部材の寸法測定と、蓋の環状突部の幅を調整する加工が必要となるため、組込み作業が非常に煩雑になり、コストも高くなってしまう。
【０００７】
また、この軸受組込み構造では、組込み時や運転中に給油用間座の給油ノズル入口位置が軸受箱の給油路出口の位置から周方向にずれ、潤滑油が十分に軸受に供給されなくなって、潤滑不良によるトラブルが発生する場合がある。
【０００８】
上記の給油用間座の周方向位置ずれへの対策としては、軸受箱の外周側から差し込んだ止めピンで間座を軸受箱に連結して回り止めする方法がある。しかし、この方法では、軸受を軸受箱に組み込む前に、間座と軸受箱のピン穴の位置を合わせて止めピンを差し込む必要があり、これに手間がかかるため、軸受組込み作業全体の能率が低くなる。また、ノズル詰まり等により間座を交換するときのピン抜き取り作業も面倒である。
【０００９】
そこで、この発明の課題は、軸受組込み時の作業性が確保され、かつ潤滑油を漏れなく確実に軸受に供給できる軸受組込み構造を提供することである。
【００１０】
【課題を解決するための手段】
上記の課題を解決するため、この発明は、筒状の軸受箱が、その側端面から内周面に通じる給油路を有し、内周面には給油路出口よりも中央側で内径が小さくなるように段差が形成されたものであり、この軸受箱の側端部内周に給油ノズルを備えた間座と軸受とを箱中央側から順に組み込み、前記軸受箱の側端面に給油口を有する軸受箱蓋を取り付けて、この蓋の給油口を軸受箱の給油路入口に接続するとともに、この蓋の内側面に形成した環状突部と軸受箱内周の段差面とで前記軸受の外輪および間座を挟み付けて固定し、間座の給油ノズル入口を軸受箱の給油路出口に接続した軸受組込み構造において、前記軸受箱蓋の環状突部を蓋と別体の外輪押えリングとし、この押えリングの幅を、前記軸受外輪の幅および前記間座の幅との合計が、前記軸受箱の側端面に隙間なく取り付けた軸受箱蓋の内側面と軸受箱内周の段差面との間の距離よりも小さくなるように設定し、前記軸受箱蓋に押えねじをねじ込んで、この押えねじにより前記押えリングを軸受外輪に押し付けるようにしたのである。
【００１１】
すなわち、軸受箱の側端部内周に軸受箱蓋と別体の外輪押えリングを軸受外輪および間座とともに組み込んで、軸受箱に蓋を取り付けたときに、蓋の内側面と軸受箱内周の段差面との間に少なくとも１箇所の軸方向隙間ができて、蓋と押えリングとが干渉しないようにし、蓋にねじ込んだ押えねじで押えリングを軸受外輪に押し付けて軸受外輪および間座を固定する構造とすることにより、軸受組込み時の作業性を大きく低下させることなく、蓋を軸受箱の側端面に確実に隙間なく取り付けられるようにして、蓋の給油口と軸受箱の給油路との接続部からの潤滑油の漏れを防止したのである。
【００１２】
また、この発明は、筒状の軸受箱が、その側端面から内周面に通じる給油路を有し、内周面には給油路出口よりも中央側で内径が小さくなるように段差が形成されたものであり、この軸受箱の側端部内周に給油ノズルを備えた間座と軸受とを箱中央側から順に組み込み、前記軸受箱の側端面に給油口を有する軸受箱蓋を取り付けて、この蓋の給油口を軸受箱の給油路入口に接続するとともに、この蓋の内側面に形成した環状突部と軸受箱内周の段差面とで前記軸受の外輪および間座を挟み付けて固定し、間座の給油ノズル入口を軸受箱の給油路出口に接続した軸受組込み構造において、前記間座を前記軸受箱蓋に連結して回り止めすることにより、間座の組み込みに手間をかけずに、間座の給油ノズル入口の位置が軸受箱の給油路出口位置からずれないようにして、潤滑油が確実に軸受に供給されるようにしたのである。
【００１３】
前記間座を軸受箱蓋に連結する手段としては、前記軸受箱蓋の環状突部と前記軸受外輪との対向面および軸受外輪と間座との対向面に、互いに対向するピン穴を少なくとも一組ずつ設け、各組のピン穴に止めピンを挿入して、前記軸受箱蓋に軸受外輪を、軸受外輪に間座をそれぞれ連結するものを採用することができる。
【００１４】
【発明の実施の形態】
以下、図１乃至図４に基づき、この発明の実施形態を説明する。図１および図２は、第１の実施形態の軸受組込み構造を適用して、エアオイルまたはオイルミストで潤滑される軸受を組み込んだ工作機械主軸を示す。図１に示すように、この主軸の軸受箱１は、筒状で、その側端面から内周面に通じる給油路１ａを有しており、内周面には給油路１ａ出口よりも中央側で内径が小さくなるように段差が形成されている。なお、軸受箱１中央の段差部は、この例のように軸受箱１と一体に形成してもよいし、軸受箱１と別体の外輪位置決め間座を組み込むようにしてもよい。
【００１５】
この主軸の軸受組込み構造は、前記軸受箱１の側端部内周に、給油用間座２とアンギュラ玉軸受３とを箱中央側から順に組み込み、さらに軸受箱蓋４と別体に形成した外輪押えリング５を組み込んで、軸受箱蓋４を軸受箱１の側端面に蓋固定ボルト６で固定し、軸受箱蓋４にねじ込んだ押えねじ７により押えリング５を軸受３の外輪８に押し付け、押えリング５と軸受箱１内周の段差面１ｂとで軸受外輪８および間座２を挟み付けて固定している。
【００１６】
このとき、軸受箱１の給油路１ａの入口に軸受箱蓋４の給油口４ａを、給油路１ａの出口に間座２の給油ノズル２ａ入口をそれぞれ接続し、外部から給油口４ａに供給されたエアオイルまたはオイルミストが、給油路１ａを通って間座２に導かれ、給油ノズル２ａ先端から軸受３に向けて噴射されるようにしている。
【００１７】
また、軸受３の内輪９は、内輪位置決め間座１０、１１とともに、軸受箱１に挿入された回転軸１２の一端側の鍔部１３と回転軸１２他端側にねじ結合したナット１４とで挟み付けて固定している。
【００１８】
図２に示すように、前記押えリング５は、その幅Ｗ１ と軸受外輪８の幅Ｗ２ および間座２の幅Ｗ３ との合計が、軸受箱１の側端面に隙間なく取り付けた軸受箱蓋４の内側突出面４ｂと軸受箱１内周の段差面１ｂとの間の距離Ｌよりも小さくなるように形成されている。すなわち、軸受箱１の側端部内周に間座２および軸受３とともに押えリング５を組み込んで、軸受箱１の側端面に軸受箱蓋４をボルト止めした状態では、蓋４の内側突出面４ｂと軸受箱１の段差面１ｂとの間に少なくとも１箇所の軸方向隙間ができ、蓋４と押えリング５とが干渉しないようになっている。そして、この状態で押えねじ７をトルク管理しながら締め込むことにより、軸受外輪８および間座２が押えリング５と軸受箱１の段差面１ｂとで挟み付けられて固定される。
【００１９】
また、軸受箱蓋４をボルト止めするときには、蓋４の給油口４ａと軸受箱１の給油路１ａ入口との接続部にＯリング１５が組み込まれ、押さえねじ７締め込み後には、押さえねじ７用の緩み止めねじ１６が蓋４に取り付けられる。
【００２０】
この軸受組込み構造は、上記の構成であり、軸受箱１に軸受箱蓋４をボルト止めするときに蓋４と押えリング５とが干渉しないので、蓋４を軸受箱１の側端面に確実に隙間なく取り付けられるとともに、蓋４の給油口４ａと軸受箱１の給油路１ａ入口との接続部ではＯリング１５を確実に圧縮でき、この接続部からの潤滑油の漏れを防止することができる。
【００２１】
また、押えねじ７をトルク管理しながら締め込んでいくので、軸受外輪８を周方向にほぼ均等に締め付けることができ、軸受３の組立精度の向上が図れる。なお、押えねじ７の本数を多くするほど、より均等な締め付けができ、軸受３の組立精度を向上させることができる。
【００２２】
さらに、押えリング５の組み込み、押えねじ７の締め込みおよび緩み止めねじ１６の取り付けの各作業は簡単であり、前述した軸受箱蓋の調整加工のような手間がかからないので、軸受組込み時や軸受交換時には、潤滑油漏れ対策を行わない場合とほぼ同程度の作業性が確保される。
【００２３】
図３は、第２の実施形態を示す。この実施形態では、軸受箱蓋４に図１および図２に示した外輪押えリング５を環状突部１７として一体に形成し、この環状突部１７と軸受外輪８との対向面および軸受外輪８と間座２との対向面に、互いに対向するピン穴１８、１８を一組ずつ設け、各組のピン穴１８、１８にそれぞれ止めピン１９を挿入して、軸受箱蓋４に軸受外輪８を、軸受外輪８に間座２をそれぞれ連結することにより、間座２を軸受外輪８を介して蓋４に連結している。その他の部分の構成は、第１の実施形態と同じである。
【００２４】
従って、間座２は軸受箱１に固定した軸受箱蓋４で回り止めされ、その給油ノズル２ａ入口の位置が軸受箱１の給油路１ａ出口位置から周方向にずれることがなく、潤滑油を確実に軸受３に供給することができる。
【００２５】
しかも、前述した軸受箱の外周側から止めピンを差し込む方法に比べて、止めピン１９の差し込みや抜き取りにも手間がかからない。また、間座２と軸受３と軸受箱蓋４とを２本の止めピン１９、１９で一体に連結した状態で軸受箱１に組み込むようにすれば、軸受組込み時の作業性を向上させることができる。
【００２６】
図４は、第２の実施形態における給油用間座の軸受箱蓋への連結方法の変形例を示す。この変形例では、軸受外輪８のピン穴２０を軸方向に貫通させて設け、軸受箱蓋４と軸受外輪８と間座２の各ピン穴１８、２０、１８に１本の長尺の止めピン２１を挿入することにより、間座２の回り止めを行っている。この方法によれば、止めピン２１が１本ですむため、図３の例よりも軸受組込み作業が簡単である。
【００２７】
なお、第２の実施形態では、間座を軸受箱蓋へ連結するのに止めピンを用いたが、軸受箱蓋の環状突部と軸受外輪との対向面および軸受外輪と間座との対向面に、互いに係合する凹凸を少なくとも一組ずつ設けるようにしてもよい。
【００２８】
また、この発明は、上述した各実施形態のようなアンギュラ玉軸受の組込み構造に限らず、円筒ころ軸受等、エアオイルまたはオイルミストで潤滑される各種の軸受の組込み構造に適用が可能である。
【００２９】
【発明の効果】
以上のように、この発明は、軸受箱に間座と軸受と外輪押えリングとを箱中央側から順に組み込んで軸受箱蓋を取り付けたときに、蓋と押えリングとが干渉しないようにし、蓋にねじ込んだ押えねじで押えリングを軸受外輪に押し付けて、軸受外輪および間座を固定する構造としたので、軸受組込み時の作業性を大きく低下させることなく、蓋を軸受箱の側端面に確実に隙間なく取り付けることができ、蓋の給油口と軸受箱の給油路との接続部からの潤滑油の漏れを防止することができる。
【００３０】
また、この発明は、間座を軸受箱蓋に連結して回り止めすることにより、間座の給油ノズル入口位置が軸受箱の給油路出口位置からずれないようにしたので、間座の組み込みに手間がかからず、運転中には潤滑油を確実に軸受に供給でき、潤滑不良によるトラブルを防止することができる。
【図面の簡単な説明】
【図１】第１の実施形態の軸受組込み構造を適用した工作機械主軸の正面断面図
【図２】図１の要部拡大断面図
【図３】第２の実施形態の軸受組込み構造を適用した工作機械主軸の要部の正面断面図
【図４】図３の軸受組込み構造の間座を軸受箱蓋に連結する方法の変形例を示す断面図
【図５】従来の軸受組込み構造を適用した工作機械主軸の正面断面図
【符号の説明】
１ 軸受箱
１ａ 給油路
１ｂ 段差面
２ 給油用間座
２ａ ノズル
３ 軸受
４ 軸受箱蓋
４ａ 給油口
４ｂ 突出面
５ 押えリング
６ ボルト
７ 押えねじ
８ 外輪
９ 内輪
１２ 回転軸
１５ Ｏリング
１６ 緩み止めねじ
１７ 環状突部
１８ ピン穴
１９ 止めピン
２０ ピン穴
２１ 止めピン[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a built-in structure of a rolling bearing for a machine tool main spindle to which air oil lubrication or oil mist lubrication is applied.
[0002]
[Prior art]
In general machine tools, the rotational speed of the spindle tends to be higher in order to improve machining efficiency. Correspondingly, air-oil lubrication, in which lubricating oil is mixed with carrier air and directly injected onto the bearing raceway surface, or oil mist lubrication, has been increasingly used for lubrication of the main shaft bearing. FIG. 5 shows an example of a machine tool spindle incorporating a bearing lubricated in such a manner (see Non-Patent Document 1).
[0003]
[Non-patent document 1]
NTN Corporation, catalog, CAT. No. 8401-VI / J, March 3, 2001
The bearing assembly structure of the main shaft shown in FIG. 5 is such that a lubrication spacer 52 and an angular ball bearing 53 are sequentially assembled from the center of the box on the inner periphery of a side end of a cylindrical bearing box 51 having an oil supply passage 51a therein. The bearing box cover 54 is bolted to the side end surface of the bearing box 51, and the annular projection 55 formed on the inner surface of the cover 54 and the stepped surface 51 b of the inner periphery of the bearing box 51 form a gap between the outer ring 56 of the bearing 53 and The seat 52 is sandwiched and fixed. At this time, the oil supply opening 54a of the bearing box cover 54 is connected to the inlet of the oil supply passage 51a of the bearing box 51, and the inlet of the oil supply nozzle 52a of the spacer 52 is connected to the outlet of the oil supply passage 51a. The air oil or oil mist is guided to the spacer 52 through the oil supply passage 51a, and is injected toward the bearing 53 from the tip of the oil supply nozzle 52a. The inner ring 57 of the bearing 53 is fixed to the rotating shaft 60 inserted into the bearing box 51 by using inner ring positioning spacers 58 and 59.
[0005]
[Problems to be solved by the invention]
In the above-described bearing assembly structure, the tightening torque of the bolts for fixing the bearing box lid to the bearing box is usually managed to improve the accuracy of the bearing installation, and the annular protrusion on the inner surface of the lid is evenly distributed over the entire circumference. To the outer ring of the bearing. However, due to variations in the dimensional tolerance of each member, a gap is generated between the lid and the side end surface of the bearing box, and lubricating oil such as air oil leaks from a connection portion between the oil supply port of the lid and the oil supply passage of the bearing box. Sometimes.
[0006]
In order to eliminate the above-mentioned lubricating oil leakage, when the bearing box lid is set at a position where the bearing outer ring and the lubrication spacer are sandwiched between the annular projection and the stepped surface of the inner periphery of the bearing box without any gap, A minute gap having a predetermined width of about 30 μm corresponding to the interference of the bearing outer ring and the spacer is formed between the box-side end face and the lid fixing bolt until the minute gap disappears. However, if this method is adopted, when assembling the bearing, it is necessary to measure the dimensions of each member and adjust the width of the annular projection of the lid, so that the assembling work becomes very complicated and the cost increases. I will.
[0007]
In addition, with this bearing assembly structure, the lubrication oil is not sufficiently supplied to the bearing when the oil supply nozzle inlet position of the oil supply spacer is displaced in the circumferential direction from the oil supply passage outlet position of the bearing box during installation or during operation. Troubles may occur due to poor lubrication.
[0008]
As a countermeasure against the circumferential displacement of the lubricating spacer, there is a method in which the spacer is connected to the bearing box with a stopper pin inserted from the outer peripheral side of the bearing box to prevent rotation. However, in this method, before mounting the bearing in the bearing housing, it is necessary to align the position of the spacer and the pin hole of the bearing housing and insert the set pin, which is troublesome. Lower. Further, it is troublesome to remove the pin when exchanging the spacer due to nozzle clogging or the like.
[0009]
Accordingly, an object of the present invention is to provide a bearing assembly structure that ensures workability when assembling a bearing and that can reliably supply lubricating oil to a bearing without leakage.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a cylindrical bearing housing, which has an oil supply passage extending from the side end surface to the inner peripheral surface, and the inner peripheral surface has a smaller inner diameter at the center side than the oil supply passage outlet. The bearing is provided with a spacer and a bearing provided with a refueling nozzle on the inner periphery of the side end of the bearing box in order from the center of the box, and has a refueling port on a side end surface of the bearing box. Attach the bearing box lid, connect the oil port of this lid to the oil supply path inlet of the bearing box, and the outer ring of the bearing with the annular projection formed on the inner surface of this lid and the step surface of the inner circumference of the bearing box In a bearing assembly structure in which the spacer is sandwiched and fixed and the filler nozzle inlet of the spacer is connected to the oil supply passage outlet of the bearing box, the annular protrusion of the bearing box cover is formed as an outer ring holding ring separate from the cover. The width of the presser ring is the sum of the width of the bearing outer ring and the width of the spacer. It is set to be smaller than the distance between the inner surface of the bearing box cover attached to the side end surface of the bearing box without any gap and the step surface of the inner periphery of the bearing box, and a cap screw is screwed into the bearing box cover, The presser screw presses the presser ring against the bearing outer ring.
[0011]
In other words, a bearing box cover and a separate outer ring holding ring are incorporated together with the bearing outer ring and spacer on the inner periphery of the side end of the bearing box, and when the cover is attached to the bearing box, the inner surface of the lid and the inner periphery of the bearing box are attached. At least one axial gap is created between the step surface and the lid so that the lid and the holding ring do not interfere with each other. The holding ring screwed into the lid presses the holding ring against the bearing outer ring to fix the bearing outer ring and spacer. With this structure, the lid can be securely attached to the side end surface of the bearing box without any gap without greatly reducing the workability when assembling the bearing. This prevented leakage of lubricating oil from the connection.
[0012]
Further, according to the present invention, the cylindrical bearing housing has an oil supply passage extending from the side end surface to the inner peripheral surface, and a step is formed on the inner peripheral surface so that the inner diameter is smaller at the center side than the oil supply passage outlet. A bearing and a bearing provided with a refueling nozzle on the inner periphery of the side end of the bearing box are sequentially incorporated from the center of the box, and a bearing box lid having a refueling port is mounted on a side end surface of the bearing box. By connecting the filler port of the lid to the filler passage inlet of the bearing box, the outer ring and the spacer of the bearing are sandwiched between the annular projection formed on the inner surface of the lid and the step surface of the inner periphery of the bearing box. In the bearing assembly structure in which the inlet of the oil nozzle of the spacer is connected to the outlet of the oil supply passage of the bearing box, the spacer is connected to the cover of the bearing box to prevent rotation, so that it takes time to incorporate the spacer. If the position of the oiling nozzle inlet of the spacer is the oiling channel outlet position of the bearing housing, As not to shift, it did so the lubricating oil is reliably supplied to the bearing.
[0013]
As means for connecting the spacer to the bearing box cover, at least one pin hole facing each other is provided on a surface facing the annular protrusion of the bearing box cover and the bearing outer ring and a surface facing the bearing outer ring and the spacer. It is possible to adopt a structure in which a set is provided, a stop pin is inserted into a pin hole of each set, and a bearing outer ring is connected to the bearing box cover, and a spacer is connected to the bearing outer ring.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS. FIGS. 1 and 2 show a machine tool main spindle incorporating a bearing lubricated with air oil or oil mist by applying the bearing incorporating structure of the first embodiment. As shown in FIG. 1, the bearing housing 1 of the main shaft has a cylindrical shape, and has a lubrication passage 1a extending from a side end surface to an inner peripheral surface. The inner peripheral surface is closer to the center than the outlet of the lubrication passage 1a. , A step is formed so that the inner diameter becomes smaller. Note that the step portion at the center of the bearing housing 1 may be formed integrally with the bearing housing 1 as in this example, or an outer ring positioning spacer separate from the bearing housing 1 may be incorporated.
[0015]
In the bearing assembly structure of the main shaft, a lubricating spacer 2 and an angular ball bearing 3 are sequentially incorporated into the inner periphery of a side end of the bearing box 1 from the center of the box, and further, an outer ring formed separately from the bearing box lid 4. The holding ring 5 is incorporated, the bearing box cover 4 is fixed to the side end surface of the bearing box 1 with a cover fixing bolt 6, and the holding ring 5 is pressed against the outer ring 8 of the bearing 3 by a holding screw 7 screwed into the bearing box cover 4. The bearing outer ring 8 and the spacer 2 are sandwiched and fixed between the presser ring 5 and the step surface 1b on the inner periphery of the bearing housing 1.
[0016]
At this time, the oil supply opening 4a of the bearing box cover 4 is connected to the inlet of the oil supply passage 1a of the bearing housing 1, and the inlet of the oil supply nozzle 2a of the spacer 2 is connected to the outlet of the oil supply passage 1a. The air oil or oil mist is guided to the spacer 2 through the oil supply passage 1a and is injected toward the bearing 3 from the tip of the oil supply nozzle 2a.
[0017]
In addition, the inner ring 9 of the bearing 3 includes a flange 13 at one end of the rotating shaft 12 inserted into the bearing housing 1 and a nut 14 screwed to the other end of the rotating shaft 12 together with the inner ring positioning spacers 10 and 11. It is pinched and fixed.
[0018]
As shown in FIG. 2, the press ring 5 has a width W 1 , a width W 2 of the bearing outer ring 8, and a width W 3 of the spacer 2, the sum of which is fixed to the side end surface of the bearing box 1 without any gap. It is formed to be smaller than the distance L between the inner protruding surface 4b of the box cover 4 and the step surface 1b on the inner periphery of the bearing box 1. That is, when the holding ring 5 is incorporated together with the spacer 2 and the bearing 3 on the inner periphery of the side end of the bearing box 1 and the bearing box cover 4 is bolted to the side end surface of the bearing box 1, the inner projecting surface 4b of the cover 4 At least one axial gap is formed between the bearing 4 and the step surface 1b of the bearing housing 1 so that the lid 4 and the press ring 5 do not interfere with each other. Then, by tightening the holding screw 7 while controlling the torque in this state, the bearing outer ring 8 and the spacer 2 are sandwiched and fixed between the holding ring 5 and the step surface 1 b of the bearing box 1.
[0019]
When the bearing box cover 4 is bolted, an O-ring 15 is incorporated in a connection portion between the oil supply port 4a of the cover 4 and the inlet of the oil supply passage 1a of the bearing box 1. Locking screw 16 is attached to the lid 4.
[0020]
This bearing assembly structure has the above configuration, and when the bearing box cover 4 is bolted to the bearing box 1, the cover 4 does not interfere with the press ring 5, so that the cover 4 is securely attached to the side end surface of the bearing box 1. The O-ring 15 can be reliably compressed at the connection between the oil supply port 4a of the lid 4 and the inlet of the oil supply passage 1a of the bearing box 1, and the leakage of the lubricating oil from this connection can be prevented. .
[0021]
Further, since the presser screw 7 is tightened while controlling the torque, the bearing outer ring 8 can be tightened substantially uniformly in the circumferential direction, and the assembling accuracy of the bearing 3 can be improved. It should be noted that as the number of the holding screws 7 increases, more uniform tightening can be performed, and the assembling accuracy of the bearing 3 can be improved.
[0022]
Further, the work of assembling the holding ring 5, tightening the holding screw 7 and attaching the locking screw 16 is simple, and does not require the trouble of adjusting the bearing box cover described above. At the time of replacement, almost the same workability as when no measures are taken against lubricating oil leakage is secured.
[0023]
FIG. 3 shows a second embodiment. In this embodiment, the outer ring pressing ring 5 shown in FIGS. 1 and 2 is formed integrally with the bearing box cover 4 as an annular projection 17, and the opposing surface of the annular projection 17 and the bearing outer ring 8 and the bearing outer ring 8 are formed. A pair of pin holes 18, 18 facing each other is provided on the surface facing the spacer 2 and the spacer 2, and a set pin 19 is inserted into each of the pin holes 18, 18 of each set. By connecting the spacer 2 to the bearing outer ring 8, the spacer 2 is connected to the lid 4 via the bearing outer ring 8. The configuration of other parts is the same as that of the first embodiment.
[0024]
Therefore, the spacer 2 is prevented from rotating by the bearing box lid 4 fixed to the bearing box 1, and the position of the inlet of the oil supply nozzle 2a does not shift in the circumferential direction from the position of the oil supply passage 1a of the bearing box 1 in the circumferential direction. It can be reliably supplied to the bearing 3.
[0025]
In addition, as compared with the above-described method of inserting the stopper pin from the outer peripheral side of the bearing housing, the insertion and removal of the stopper pin 19 does not require much trouble. In addition, if the spacer 2, the bearing 3, and the bearing box cover 4 are integrated into the bearing box 1 in a state of being integrally connected by the two fixing pins 19, 19, the workability at the time of assembling the bearing is improved. Can be.
[0026]
FIG. 4 shows a modification of the method of connecting the refueling spacer to the bearing box cover in the second embodiment. In this modification, a pin hole 20 of the bearing outer ring 8 is provided so as to penetrate in the axial direction, and one long stopper is provided in each of the pin holes 18, 20, 18 of the bearing box cover 4, the bearing outer ring 8, and the spacer 2. By inserting the pin 21, the spacer 2 is prevented from rotating. According to this method, since only one stopper pin 21 is required, the work of assembling the bearing is easier than the example of FIG.
[0027]
In the second embodiment, the stop pin is used to connect the spacer to the bearing box cover. However, the facing surface between the annular protrusion of the bearing box cover and the bearing outer ring, and the opposing surface between the bearing outer ring and the spacer are used. The surface may be provided with at least one set of projections and depressions that engage with each other.
[0028]
The present invention is not limited to the built-in structure of the angular ball bearing as in each of the above-described embodiments, but can be applied to the built-in structure of various types of bearings lubricated with air oil or oil mist, such as a cylindrical roller bearing.
[0029]
【The invention's effect】
As described above, the present invention provides a bearing box in which a spacer, a bearing, and an outer ring retainer ring are assembled in order from the center of the box and the bearing box lid is mounted so that the lid and the retainer ring do not interfere with each other. The holding ring is pressed against the bearing outer ring with a holding screw that is screwed into the bearing to fix the bearing outer ring and the spacer, so that the lid can be securely attached to the side end face of the bearing box without greatly reducing the workability when installing the bearing. The lubricating oil can be prevented from leaking from the connection between the oil supply port of the lid and the oil supply passage of the bearing box.
[0030]
In addition, in the present invention, the spacer is connected to the bearing box lid to prevent rotation, so that the fuel nozzle inlet position of the spacer does not deviate from the oil supply path outlet position of the bearing box. Since no trouble is required, lubricating oil can be reliably supplied to the bearing during operation, and trouble due to poor lubrication can be prevented.
[Brief description of the drawings]
FIG. 1 is a front sectional view of a machine tool main spindle to which a bearing built-in structure of a first embodiment is applied. FIG. 2 is an enlarged sectional view of a main part of FIG. 1. FIG. FIG. 4 is a cross-sectional view showing a modified example of a method of connecting the spacer of the bearing-incorporated structure of FIG. 3 to a bearing box cover. Front sectional view of machine tool spindle
REFERENCE SIGNS LIST 1 bearing box 1 a oil supply path 1 b step surface 2 oiling spacer 2 a nozzle 3 bearing 4 bearing box cover 4 a oil supply port 4 b projecting surface 5 presser ring 6 bolt 7 presser screw 8 outer ring 9 inner ring 12 rotating shaft 15 O-ring 16 locking screw 17 annular projection 18 pin hole 19 stop pin 20 pin hole 21 stop pin
