JPH0749040Y2 - Impeller mounting structure - Google Patents
Impeller mounting structureInfo
- Publication number
- JPH0749040Y2 JPH0749040Y2 JP1989116413U JP11641389U JPH0749040Y2 JP H0749040 Y2 JPH0749040 Y2 JP H0749040Y2 JP 1989116413 U JP1989116413 U JP 1989116413U JP 11641389 U JP11641389 U JP 11641389U JP H0749040 Y2 JPH0749040 Y2 JP H0749040Y2
- Authority
- JP
- Japan
- Prior art keywords
- impeller
- main shaft
- rotor main
- stepped portion
- rotor
- 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.)
- Expired - Lifetime
Links
Landscapes
- Non-Positive Displacement Air Blowers (AREA)
Description
【考案の詳細な説明】 〔産業上の利用分野〕 本考案はターボ分子ポンプ等の高速回転体における固有
振動数の安定化に好適な羽根車取付構造に関するもので
ある。DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an impeller mounting structure suitable for stabilizing the natural frequency of a high-speed rotating body such as a turbo molecular pump.
軸受に磁気浮上方式の軸受、即ち磁気軸受を用いたター
ボ分子ポンプとしては、第６図に示す断面構造示すもの
がある。同図において、１はロータ主軸であり、該ロー
タ主軸１には羽根車２を位置決めするための位置決用段
付部３が設けられており、該ロータ主軸１に羽根車２が
そのボス部が位置決用段付部３の密接するように、焼嵌
め固着され、回転ロータが構成されている。該回転体ロ
ータのロータ主軸１はラジアル磁気軸受4,5及びスラス
ト磁気軸受６で時期的に浮上支持されている。なお、同
図において、７は羽根車２に固定されロータブレード、
９はポンプケーシングに固定されステータブレード、1
0,11は緊急時の機械式軸受（ベアリング）、12はスラス
トギャップセンサ、13,14はラジアルギャップセンサ、1
5はモータである。As a bearing of a magnetic levitation type, that is, a turbo molecular pump using a magnetic bearing, there is one having a sectional structure shown in FIG. In the figure, reference numeral 1 is a rotor main shaft, and a positioning stepped portion 3 for positioning an impeller 2 is provided on the rotor main shaft 1, and the impeller 2 is attached to the rotor main shaft 1. Is shrink-fitted and fixed so that the positioning stepped portion 3 comes into close contact with each other to form a rotating rotor. The rotor main shaft 1 of the rotor is temporally levitationally supported by radial magnetic bearings 4 and 5 and thrust magnetic bearings 6. In the figure, 7 is a rotor blade fixed to the impeller 2,
9 is a stator blade fixed to the pump casing, 1
0,11 are mechanical bearings in an emergency, 12 is a thrust gap sensor, 13 and 14 are radial gap sensors, 1
5 is a motor.
上記構造のターボ分子ポンプにおいては、回転体の固有
振動数特性に応じて磁気軸受系の制御安定性を確保する
ためバンドパスフィルタを利用して特定の周波数帯域
（回転体の固有振動数に対応する周波数）で位相進みを
増進させて、固有振動値の発信を防止している。一方、
図示するようなロータ主軸１と羽根車２の固着方法で
は、回転体の温度上昇（ラジアル磁気軸受4,5やスラス
ト磁気軸受６の渦電流損、モータ15の銅損や鉄損、気体
の圧縮熱等が原因）に伴ってロータ系の固有振動が高い
値と変化するという問題があった。第４図はその例を示
す図であり、同図（Ａ）は温度20℃の時の１次曲げ固有
値を示し、同図（Ｂ）は温度90℃の時の１次曲げ固有値
を示している。図示するように、温度20℃では775Hzで
あった１次曲げ固有値が温度90℃では925Hzと高くなる
ことが分かる。In the turbo molecular pump with the above structure, a bandpass filter is used to ensure control stability of the magnetic bearing system according to the natural frequency characteristics of the rotating body, and a specific frequency band (corresponding to the natural frequency of the rotating body is supported). Frequency) to increase the phase advance to prevent the transmission of natural vibration values. on the other hand,
In the fixing method of the rotor main shaft 1 and the impeller 2 as shown in the figure, the temperature rise of the rotating body (eddy current loss of the radial magnetic bearings 4,5 and the thrust magnetic bearing 6, copper loss and iron loss of the motor 15, compression of gas) There is a problem that the natural vibration of the rotor system changes to a high value due to heat (or the like). FIG. 4 is a diagram showing an example thereof. FIG. 4A shows the primary bending characteristic value at a temperature of 20 ° C., and FIG. 4B shows the primary bending characteristic value at a temperature of 90 ° C. There is. As shown in the figure, it can be seen that the primary bending eigenvalue, which was 775 Hz at a temperature of 20 ° C, becomes as high as 925 Hz at a temperature of 90 ° C.
この原因は、回転体の温度上昇に伴って羽根車２（アル
ミニウム材からなる）とロータ主軸１（ステンレススチ
ール材からなる）の熱膨張の差により、羽根車２が軸方
向に大きく伸び、ロータ主軸１の位置決用段付部３と羽
根車２のボス部の間の面圧が上昇することに発生してい
る。This is because the difference in thermal expansion between the impeller 2 (made of an aluminum material) and the rotor main shaft 1 (made of a stainless steel material) greatly expands in the axial direction as the temperature of the rotor increases, and It occurs because the surface pressure between the positioning stepped portion 3 of the main shaft 1 and the boss portion of the impeller 2 increases.
磁気軸受位相補償回路のバンドパスフィルタの帯域は一
定の幅で設定されているため、固有振動数の変化が大き
いと、この固有振動数は該バンドパスフィルタの有効帯
域を外れ、位相進せることによる固有振動数の減衰効果
が作用しなくなり、不都合があった。Since the band of the band-pass filter of the magnetic bearing phase compensation circuit is set with a constant width, if the change in the natural frequency is large, the natural frequency may go out of the effective band of the band-pass filter and advance in phase. There was a problem that the effect of damping the natural frequency due to did not work.
本考案は上述の点に鑑みてなされたもので、回転体の温
度が上昇しても固有振動数が変化しないか或いは変化が
極めて小さい、固有振動数の安定化に好適な羽根車取付
構造を提供することにある。The present invention has been made in view of the above points, and provides an impeller mounting structure suitable for stabilizing the natural frequency, in which the natural frequency does not change or changes very little even when the temperature of the rotating body rises. To provide.
上記課題を解決するため本考案は、互いに熱膨張率の異
なる材料から羽根車とロータ主軸とを具備し、該ロータ
主軸の軸方向所定位置には径の大きい位置決用段付部が
形成されており、前記羽根車を該ロータ主軸に位置決用
段付部の端面に羽根車のボス部片面を当接させ且つ焼嵌
して固着した構成の羽根車取付構造において、ロータ主
軸の位置決用段付部の外周で且つ前記羽根車が当接する
端面の近傍に軸中心に向かう細溝を設けたことを特徴と
する。In order to solve the above problems, the present invention comprises an impeller and a rotor main shaft made of materials having different thermal expansion coefficients, and a positioning stepped portion having a large diameter is formed at a predetermined axial position of the rotor main shaft. In the impeller mounting structure having a structure in which one side of the boss portion of the impeller is brought into contact with the end surface of the stepped portion for positioning on the rotor main shaft and the boss part is shrink-fitted and fixed, the position of the rotor main shaft is determined. It is characterized in that a thin groove extending toward the axial center is provided on the outer periphery of the stepped portion and in the vicinity of the end face with which the impeller abuts.
本考案は上記のようにロータ主軸の位置決用段付部の外
周で且つ羽根車を当接する端面の近傍に軸中心に向かう
細溝を設けたので、回転ロータの温度上昇により、羽根
車のボス部が回転ロータ主軸の軸方向に膨張し、該ボス
部と位置決用段付部の間に加わる面圧が上昇しても、こ
の細溝の変形により、固有振動数の変動となるこの面圧
上昇を吸収するから、回転ロータの固有振動数が安定す
る。According to the present invention, as described above, the thin groove extending toward the shaft center is provided on the outer periphery of the positioning stepped portion of the rotor main shaft and in the vicinity of the end face contacting the impeller. Even if the boss portion expands in the axial direction of the rotary rotor main shaft and the surface pressure applied between the boss portion and the positioning stepped portion rises, the deformation of the narrow groove causes a change in the natural frequency. Since the increase in the surface pressure is absorbed, the natural frequency of the rotating rotor becomes stable.
〔実施例〕 以下、考案の一実施例を図面に基づいて説明する。[Embodiment] An embodiment of the invention will be described below with reference to the drawings.
第１図乃至第３図は考案に係る羽根車取付構造を示す図
で、図において、第６図と同一符号を付した部分は同一
部分を示す。1 to 3 are views showing an impeller mounting structure according to the invention. In the drawings, the same reference numerals as those in FIG. 6 denote the same parts.
図示するように、ロータ主軸１には羽根車２を位置決め
するための位置決用段付部３が設けられており、ロータ
主軸１に羽根車２がそのボス部が位置決用段付部３に密
接するように、焼嵌めで固着され、更に押圧部材21をボ
ルト22でロータ主軸１の端部に締め付けことにより、該
押圧部材21の先端が羽根車２を位置決用段付部３方向に
押圧し、羽根車２はロータ主軸１に強固に着される。な
お、羽根車２は、例えばアルミニウム製で、ロータ主軸
１はステンレススチール製というように、羽根車２とロ
ータ主軸１はそれぞれ熱膨張率の異なる材料からなる。As shown in the figure, the rotor spindle 1 is provided with a positioning stepped portion 3 for positioning the impeller 2. The rotor spindle 1 has an impeller 2 whose boss portion is a positioning stepped portion 3. Is fixed by shrink fitting so as to be in close contact with the end of the rotor main shaft 1 with a bolt 22 so that the tip of the pressing member 21 moves the impeller 2 toward the positioning stepped portion 3 direction. The impeller 2 is firmly attached to the rotor main shaft 1. The impeller 2 is made of, for example, aluminum, and the rotor main shaft 1 is made of stainless steel. The impeller 2 and the rotor main shaft 1 are made of materials having different coefficients of thermal expansion.
ロータ主軸１の位置決用段付部３の周囲には羽根車２の
取付位置近傍には第３図に示すように、細溝20が設けら
れておいる。回転ロータが温度上昇し、ロータ主軸１と
羽根車２の熱膨張率の差により羽根車２のボスブが位置
決用段付部３を押圧し、更に、第２図に示すように羽根
車２の高速回転による遠心力の作用により、位置決用段
付部３に近い部分において、羽根車２とロータ主軸１と
の間に焼嵌め解放部24が形成され、その反対側に焼嵌め
維持部23が形成される。これにより羽根車２のボス部の
伸びが位置決用段付部３方向に集中するが、前述のよう
に位置決用段付部３の周囲には羽根車２の取付位置近傍
に細溝20が設けられているので、該細溝20が変形して羽
根車２のボス部と位置決用段付部３の間の面圧上昇を吸
収するから、この面圧上昇による固有振動数の上昇がな
くなる。As shown in FIG. 3, a narrow groove 20 is provided in the vicinity of the mounting position of the impeller 2 around the positioning stepped portion 3 of the rotor main shaft 1. The temperature of the rotating rotor rises, the boss of the impeller 2 presses the positioning stepped portion 3 due to the difference in the coefficient of thermal expansion between the rotor main shaft 1 and the impeller 2, and as shown in FIG. Due to the action of the centrifugal force due to the high speed rotation, the shrink fitting release portion 24 is formed between the impeller 2 and the rotor main shaft 1 in the portion close to the positioning step portion 3, and the shrink fitting maintaining portion is provided on the opposite side thereof. 23 is formed. As a result, the expansion of the boss portion of the impeller 2 is concentrated in the direction of the positioning stepped portion 3, but as described above, the narrow groove 20 is formed around the positioning stepped portion 3 in the vicinity of the mounting position of the impeller 2. Since the narrow groove 20 is deformed to absorb the increase in the surface pressure between the boss portion of the impeller 2 and the positioning stepped portion 3, the increase in the natural frequency due to the increase in the surface pressure. Disappears.
第５図は位置決段付部３に細溝20を設けた場合の１次曲
げ固有値の測定結果を示す図、同図（Ａ）は温度20℃に
おける測定結果を、同図（Ｂ）は温度90℃における測定
結果をそれぞれ示す。図示するによに、温度20℃で825H
zであった１次曲げ固有値が、温度90℃でも825Hzと全く
変化しないことが実験的にも確認できる。FIG. 5 is a diagram showing the measurement result of the primary bending eigenvalue when the fine groove 20 is provided in the positioning stepped portion 3, FIG. 5A shows the measurement result at a temperature of 20 ° C., and FIG. The measurement results at a temperature of 90 ° C are shown below. As shown in the figure, 825H at a temperature of 20 ℃
It can be confirmed experimentally that the primary bending eigenvalue, which was z, does not change at all to 825 Hz even at a temperature of 90 ° C.
なお、第５図における測定は、位置決用段付部３の外径
φ１＝60mm、細溝20の底部外径φ２＝42mm、ロータ主軸
１の羽根車２の取り付け部外径φ３＝35mm、細溝20の幅
寸法S1＝2mm、細溝20と羽根車２の圧接面の幅寸法S2＝4
mmとした場合（第３図参照）の測定結果である。The measurement in the fifth diagram, an outer diameter phi 1 = 60 mm of the positioning knob stepped portion 3, bottom outer diameter phi 2 = 42mm narrow grooves 20, mounting the outer diameter phi 3 of the impeller 2 of the rotor spindle 1 = 35 mm, width of narrow groove 20 S 1 = 2 mm, width of narrow groove 20 and pressure contact surface of impeller 2 S 2 = 4
The measurement results are shown in mm (see FIG. 3).
以上説明したように本考案によれば、ロータ主軸の位置
決用段付部の外周で且つ羽根車を当接する端面の近傍に
軸中心に向かう細溝を設けたので、回転ロータの温度上
昇により、羽根車のボス部が回転ロータ主軸の軸方向に
膨張し、該ボス部と位置決用段付部の間に加わる面圧が
上昇しても、この細溝の変形により、固有振動数の変動
となるこの面圧上昇を吸収するから、回転ロータの固有
振動数が安定するという優れた効果が得られる。As described above, according to the present invention, since the fine groove extending toward the shaft center is provided on the outer periphery of the positioning stepped portion of the rotor main shaft and near the end face that contacts the impeller, the temperature rise of the rotating rotor Even if the boss portion of the impeller expands in the axial direction of the rotary rotor main shaft and the surface pressure applied between the boss portion and the positioning stepped portion increases, the deformation of the narrow groove causes the natural frequency Since this increase in the surface pressure, which is a fluctuation, is absorbed, an excellent effect that the natural frequency of the rotating rotor is stabilized can be obtained.
【図面の簡単な説明】 第１図は本考案に係る羽根車取付構造を示す部分断面
図、第２図はその羽根車取付構造の作用を説明するため
の図、第３図はロータ主軸の形状を示す図、第４図
（Ａ），（Ｂ）はそれぞれ従来の羽根車取付構造におけ
る１次曲げ固有値の測定結果を示す図、第５図（Ａ），
（Ｂ）はそれぞれ本考案の羽根車取付構造における１次
曲げ固有値の測定結果を示す図、第６図は磁気軸受を用
いたターボ分子ポンプの構造を示す図である。 図中、１……ロータ主軸、２……羽根車、３……位置決
用段付部、20……細溝、21……押圧部材、22……ボル
ト、23……焼嵌め維持部、24……焼嵌め解放部。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional view showing an impeller mounting structure according to the present invention, FIG. 2 is a diagram for explaining the operation of the impeller mounting structure, and FIG. 3 is a rotor spindle. The figure showing the shape, FIGS. 4 (A) and 4 (B) are diagrams showing the measurement results of the primary bending eigenvalue in the conventional impeller mounting structure, FIG. 5 (A),
(B) is a diagram showing a measurement result of the primary bending eigenvalue in the impeller mounting structure of the present invention, and FIG. 6 is a diagram showing a structure of a turbo molecular pump using a magnetic bearing. In the figure, 1 ... Rotor spindle, 2 ... Impeller, 3 ... Positioning stepped portion, 20 ... Fine groove, 21 ... Pressing member, 22 ... Bolt, 23 ... Shrink-fitting maintenance portion, 24 ... Shrink fitting release section.
Claims (1)
車とロータ主軸とを具備し、該ロータ主軸の軸方向所定
位置には径の大きい位置決用段付部が形成されており、
前記羽根車を該ロータ主軸に位置決用段付部の端面に羽
根車のボス部片面を当接させ且つ焼嵌して固着した構成
の羽根車取付構造において、 前記ロータ主軸の位置決用段付部の外周で且つ前記羽根
車が当接する端面の近傍に軸中心に向かう細溝を設けた
ことを特徴とする羽根車取付構造。1. An impeller made of materials having different coefficients of thermal expansion and a rotor main shaft, and a positioning stepped portion having a large diameter is formed at a predetermined axial position of the rotor main shaft.
In the impeller mounting structure of the rotor main shaft, wherein the one end surface of the positioning stepped portion is in contact with one side of the boss portion of the impeller, and is fixed by shrink fitting, the rotor main shaft positioning step An impeller mounting structure, characterized in that a thin groove extending toward the axial center is provided on the outer periphery of the attached portion and in the vicinity of the end face with which the impeller abuts.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989116413U JPH0749040Y2 (en) | 1989-10-03 | 1989-10-03 | Impeller mounting structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1989116413U JPH0749040Y2 (en) | 1989-10-03 | 1989-10-03 | Impeller mounting structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0356896U JPH0356896U (en) | 1991-05-31 |
| JPH0749040Y2 true JPH0749040Y2 (en) | 1995-11-13 |
Family
ID=31664691
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1989116413U Expired - Lifetime JPH0749040Y2 (en) | 1989-10-03 | 1989-10-03 | Impeller mounting structure |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0749040Y2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2722528B1 (en) * | 2011-06-16 | 2018-05-30 | Edwards Japan Limited | Rotor assembly and vacuum pump there with |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0613889B2 (en) * | 1986-10-15 | 1994-02-23 | 三菱重工業株式会社 | Bolt fastening structure for disc-shaped body of high-speed rotating body of 10,000 rpm or more and shaft |
-
1989
- 1989-10-03 JP JP1989116413U patent/JPH0749040Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0356896U (en) | 1991-05-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |